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William T. Cefalu

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DOI: 10.2337/dci19-0028
2019
Cited 2,219 times
Clinical Targets for Continuous Glucose Monitoring Data Interpretation: Recommendations From the International Consensus on Time in Range
Improvements in sensor accuracy, greater convenience and ease of use, and expanding reimbursement have led to growing adoption of continuous glucose monitoring (CGM). However, successful utilization of CGM technology in routine clinical practice remains relatively low. This may be due in part to the lack of clear and agreed-upon glycemic targets that both diabetes teams and people with diabetes can work toward. Although unified recommendations for use of key CGM metrics have been established in three separate peer-reviewed articles, formal adoption by diabetes professional organizations and guidance in the practical application of these metrics in clinical practice have been lacking. In February 2019, the Advanced Technologies & Treatments for Diabetes (ATTD) Congress convened an international panel of physicians, researchers, and individuals with diabetes who are expert in CGM technologies to address this issue. This article summarizes the ATTD consensus recommendations for relevant aspects of CGM data utilization and reporting among the various diabetes populations.
DOI: 10.2337/db08-1637
2009
Cited 1,661 times
Butyrate Improves Insulin Sensitivity and Increases Energy Expenditure in Mice
We examined the role of butyric acid, a short-chain fatty acid formed by fermentation in the large intestine, in the regulation of insulin sensitivity in mice fed a high-fat diet.In dietary-obese C57BL/6J mice, sodium butyrate was administrated through diet supplementation at 5% wt/wt in the high-fat diet. Insulin sensitivity was examined with insulin tolerance testing and homeostasis model assessment for insulin resistance. Energy metabolism was monitored in a metabolic chamber. Mitochondrial function was investigated in brown adipocytes and skeletal muscle in the mice.On the high-fat diet, supplementation of butyrate prevented development of insulin resistance and obesity in C57BL/6 mice. Fasting blood glucose, fasting insulin, and insulin tolerance were all preserved in the treated mice. Body fat content was maintained at 10% without a reduction in food intake. Adaptive thermogenesis and fatty acid oxidation were enhanced. An increase in mitochondrial function and biogenesis was observed in skeletal muscle and brown fat. The type I fiber was enriched in skeletal muscle. Peroxisome proliferator-activated receptor-gamma coactivator-1alpha expression was elevated at mRNA and protein levels. AMP kinase and p38 activities were elevated. In the obese mice, supplementation of butyrate led to an increase in insulin sensitivity and a reduction in adiposity.Dietary supplementation of butyrate can prevent and treat diet-induced insulin resistance in mouse. The mechanism of butyrate action is related to promotion of energy expenditure and induction of mitochondria function.
DOI: 10.1016/j.cmet.2018.04.010
2018
Cited 895 times
Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes
Intermittent fasting (IF) improves cardiometabolic health; however, it is unknown whether these effects are due solely to weight loss. We conducted the first supervised controlled feeding trial to test whether IF has benefits independent of weight loss by feeding participants enough food to maintain their weight. Our proof-of-concept study also constitutes the first trial of early time-restricted feeding (eTRF), a form of IF that involves eating early in the day to be in alignment with circadian rhythms in metabolism. Men with prediabetes were randomized to eTRF (6-hr feeding period, with dinner before 3 p.m.) or a control schedule (12-hr feeding period) for 5 weeks and later crossed over to the other schedule. eTRF improved insulin sensitivity, β cell responsiveness, blood pressure, oxidative stress, and appetite. We demonstrate for the first time in humans that eTRF improves some aspects of cardiometabolic health and that IF's effects are not solely due to weight loss.
DOI: 10.2337/dc09-9036
2009
Cited 857 times
How Do We Define Cure of Diabetes?
The mission of the American Diabetes Association is “to prevent and cure diabetes and to improve the lives of all people affected by diabetes.” Increasingly, scientific and medical articles (1) and commentaries (2) about diabetes interventions use the terms “remission” and “cure” as possible outcomes. Several approved or experimental treatments for type 1 and type 2 diabetes (e.g., pancreas or islet transplants, immunomodulation, bariatric/metabolic surgery) are of curative intent or have been portrayed in the media as a possible cure. However, defining remission or cure of diabetes is not as straightforward as it may seem. Unlike “dichotomous” diseases such as many malignancies, diabetes is defined by hyperglycemia, which exists on a continuum and may be impacted over a short time frame by everyday treatment or events (medications, diet, activity, intercurrent illness). The distinction between successful treatment and cure is blurred in the case of diabetes. Presumably improved or normalized glycemia must be part of the definition of remission or cure. Glycemic measures below diagnostic cut points for diabetes can occur with ongoing medications (e.g., antihyperglycemic drugs, immunosuppressive medications after a transplant), major efforts at lifestyle change, a history of bariatric/metabolic surgery, or ongoing procedures (such as repeated replacements of endoluminal devices). Do we use the terms remission or cure for all patients with normal glycemic measures, regardless of how this is achieved? A consensus group comprised of experts in pediatric and adult endocrinology, diabetes education, transplantation, metabolism, bariatric/metabolic surgery, and (for another perspective) hematology-oncology met in June 2009 to discuss these issues. The group considered a wide variety of questions, including whether it is ever accurate to say that a chronic illness is cured; what the definitions of management, remission, or cure might be; whether goals of managing comorbid conditions revert to those of patients without diabetes if someone is …
DOI: 10.2337/dc16-0236
2016
Cited 723 times
Metabolic Surgery in the Treatment Algorithm for Type 2 Diabetes: A Joint Statement by International Diabetes Organizations
Despite growing evidence that bariatric/metabolic surgery powerfully improves type 2 diabetes (T2D), existing diabetes treatment algorithms do not include surgical options.The 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference, was convened in collaboration with leading diabetes organizations to develop global guidelines to inform clinicians and policymakers about benefits and limitations of metabolic surgery for T2D.A multidisciplinary group of 48 international clinicians/scholars (75% nonsurgeons), including representatives of leading diabetes organizations, participated in DSS-II. After evidence appraisal (MEDLINE [1 January 2005-30 September 2015]), three rounds of Delphi-like questionnaires were used to measure consensus for 32 data-based conclusions. These drafts were presented at the combined DSS-II and 3rd World Congress on Interventional Therapies for Type 2 Diabetes (London, U.K., 28-30 September 2015), where they were open to public comment by other professionals and amended face-to-face by the Expert Committee.Given its role in metabolic regulation, the gastrointestinal tract constitutes a meaningful target to manage T2D. Numerous randomized clinical trials, albeit mostly short/midterm, demonstrate that metabolic surgery achieves excellent glycemic control and reduces cardiovascular risk factors. On the basis of such evidence, metabolic surgery should be recommended to treat T2D in patients with class III obesity (BMI ≥40 kg/m(2)) and in those with class II obesity (BMI 35.0-39.9 kg/m(2)) when hyperglycemia is inadequately controlled by lifestyle and optimal medical therapy. Surgery should also be considered for patients with T2D and BMI 30.0-34.9 kg/m(2) if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications. These BMI thresholds should be reduced by 2.5 kg/m(2) for Asian patients.Although additional studies are needed to further demonstrate long-term benefits, there is sufficient clinical and mechanistic evidence to support inclusion of metabolic surgery among antidiabetes interventions for people with T2D and obesity. To date, the DSS-II guidelines have been formally endorsed by 45 worldwide medical and scientific societies. Health care regulators should introduce appropriate reimbursement policies.
DOI: 10.1016/s0140-6736(13)60683-2
2013
Cited 632 times
Efficacy and safety of canagliflozin versus glimepiride in patients with type 2 diabetes inadequately controlled with metformin (CANTATA-SU): 52 week results from a randomised, double-blind, phase 3 non-inferiority trial
Background Sodium–glucose cotransporter 2 (SGLT2) inhibitors improve glycaemia in patients with type 2 diabetes by enhancing urinary glucose excretion. We compared the efficacy and safety of canagliflozin, an SGLT2 inhibitor, with glimepiride in patients with type 2 diabetes inadequately controlled with metformin. Methods We undertook this 52 week, randomised, double-blind, active-controlled, phase 3 non-inferiority trial at 157 centres in 19 countries between Aug 28, 2009, and Dec 21, 2011. Patients aged 18–80 years with type 2 diabetes and glycated haemoglobin A1c (HbA1c) of 7·0–9·5% on stable metformin were randomly assigned (1:1:1) by computer-generated random sequence via an interactive voice or web response system to receive canagliflozin 100 mg or 300 mg, or glimepiride (up-titrated to 6 mg or 8 mg per day) orally once daily. Patients, study investigators, and local sponsor personnel were masked to treatment. The primary endpoint was change in HbA1c from baseline to week 52, with a non-inferiority margin of 0·3% for the comparison of each canagliflozin dose with glimepiride. If non-inferiority was shown, we assessed superiority on the basis of an upper bound of the 95% CI for the difference of each canagliflozin dose versus glimepiride of less than 0·0%. Analysis was done in a modified intention-to-treat population, including all randomised patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT00968812. Findings 1450 of 1452 randomised patients received at least one dose of glimepiride (n=482), canagliflozin 100 mg (n=483), or canagliflozin 300 mg (n=485). For lowering of HbA1c at 52 weeks, canagliflozin 100 mg was non-inferior to glimepiride (least-squares mean difference −0·01% [95% CI −0·11 to 0·09]), and canagliflozin 300 mg was superior to glimepiride (–0·12% [–0·22 to −0·02]). 39 (8%) patients had serious adverse events in the glimepiride group versus 24 (5%) in the canagliflozin 100 mg group and 26 (5%) in the 300 mg group. In the canagliflozin 100 mg and 300 mg groups versus the glimepiride group, we recorded a greater number of genital mycotic infections (women: 26 [11%] and 34 [14%] vs five [2%]; men: 17 [7%] and 20 [8%] vs three [1%]), urinary tract infections (31 [6%] for both canagliflozin doses vs 22 [5%]), and osmotic diuresis-related events (pollakiuria: 12 [3%] for both doses vs one [<1%]; polyuria: four [<1%] for both doses vs two [<1%]). Interpretation Canagliflozin provides greater HbA1c reduction than does glimepiride, and is well tolerated in patients with type 2 diabetes receiving metformin. These findings support the use of canagliflozin as a viable treatment option for patients who do not achieve sufficient glycaemic control with metformin therapy. Funding Janssen Research & Development, LLC.
DOI: 10.1111/dom.12054
2013
Cited 539 times
Efficacy and safety of canagliflozin monotherapy in subjects with type 2 diabetes mellitus inadequately controlled with diet and exercise
Canagliflozin is a sodium glucose co-transporter 2 inhibitor in development for type 2 diabetes mellitus (T2DM). The efficacy and safety of canagliflozin were evaluated in subjects with T2DM inadequately controlled with diet and exercise.In this 26-week, randomized, double-blind, placebo-controlled, phase 3 trial, subjects (N = 584) received canagliflozin 100 or 300 mg or placebo once daily. Primary endpoint was the change from baseline in haemoglobin A1c (HbA1c) at week 26. Secondary endpoints included the proportion of subjects achieving HbA1c < 7.0%; change from baseline in fasting plasma glucose (FPG), 2-h postprandial glucose (PPG) and systolic blood pressure (BP); and percent change in body weight, high-density lipoprotein cholesterol (HDL-C) and triglycerides. Adverse events (AEs) were recorded throughout the study.At week 26, HbA1c was significantly reduced from baseline with canagliflozin 100 and 300 mg compared with placebo (-0.77, -1.03 and 0.14%, respectively; p < 0.001 for both). Both canagliflozin doses significantly decreased FPG, 2-h PPG, body weight and systolic BP (p < 0.001 for all), and increased HDL-C compared with placebo (p < 0.01 for both). Overall incidences of AEs were modestly higher with canagliflozin versus placebo; rates of serious AEs and AE-related discontinuations were low and similar across groups. Incidences of genital mycotic infections, urinary tract infections and osmotic diuresis-related AEs were higher with canagliflozin; these led to few discontinuations. The incidence of hypoglycaemia was low across groups.Canagliflozin treatment improved glycaemic control, reduced body weight and was generally well tolerated in subjects with T2DM inadequately controlled with diet and exercise.
DOI: 10.2337/diacare.27.11.2741
2004
Cited 501 times
Role of Chromium in Human Health and in Diabetes
Despite widespread use by patients with diabetes and anecdotal reports in the past regarding its efficacy, until recently, data in humans concerning chromium’s effects on insulin action in vivo or on cellular aspects of insulin action were scarce. Consequently, significant controversy still exists regarding the effect of chromium supplementation on parameters assessing human health. Furthermore, elucidating the cellular and molecular mechanisms by which chromium supplements affect carbohydrate metabolism in vivo is necessary before specific recommendations can be made regarding its routine use in the management of diabetes. This review focuses on providing current information about this trace mineral’s specific mechanisms of action and clinical trials in patients with diabetes. Chromium, one of the most common elements in the earth’s crust and seawater, exists in our environment in several oxidation states, principally as metallic (Cr), trivalent (+3), and hexavalent (+6) chromium. The latter is largely synthesized by the oxidation of the more common and naturally occurring trivalent chromium and is highly toxic. Trivalent chromium, found in most foods and nutrient supplements, is an essential nutrient with very low toxicity. The interest in chromium as a nutritional enhancement to glucose metabolism can be traced back to the 1950s, when it was suggested that brewer’s yeast contained a glucose tolerance factor (GTF) that prevented diabetes in experimental animals (1). This factor was eventually suggested to be a biologically active form of trivalent chromium that could substantially lower plasma glucose levels in diabetic mice (2). Interest regarding chromium administration in patients with diabetes was kindled by the observation in the 1970s that it truly was an essential nutrient required for normal carbohydrate metabolism. A patient receiving total parenteral nutrition (TPN) developed severe signs of diabetes, including weight loss and hyperglycemia that was refractory to increasing insulin dosing (3). Based on previous animal studies …
DOI: 10.2337/dc18-1581
2018
Cited 413 times
Glucose Management Indicator (GMI): A New Term for Estimating A1C From Continuous Glucose Monitoring
While A1C is well established as an important risk marker for diabetes complications, with the increasing use of continuous glucose monitoring (CGM) to help facilitate safe and effective diabetes management, it is important to understand how CGM metrics, such as mean glucose, and A1C correlate. Estimated A1C (eA1C) is a measure converting the mean glucose from CGM or self-monitored blood glucose readings, using a formula derived from glucose readings from a population of individuals, into an estimate of a simultaneously measured laboratory A1C. Many patients and clinicians find the eA1C to be a helpful educational tool, but others are often confused or even frustrated if the eA1C and laboratory-measured A1C do not agree. In the U.S., the Food and Drug Administration determined that the nomenclature of eA1C needed to change. This led the authors to work toward a multipart solution to facilitate the retention of such a metric, which includes renaming the eA1C the glucose management indicator (GMI) and generating a new formula for converting CGM-derived mean glucose to GMI based on recent clinical trials using the most accurate CGM systems available. The final aspect of ensuring a smooth transition from the old eA1C to the new GMI is providing new CGM analyses and explanations to further understand how to interpret GMI and use it most effectively in clinical practice. This Perspective will address why a new name for eA1C was needed, why GMI was selected as the new name, how GMI is calculated, and how to understand and explain GMI if one chooses to use GMI as a tool in diabetes education or management.
DOI: 10.1016/j.appet.2010.03.009
2010
Cited 342 times
Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels
Consumption of sugar-sweetened beverages may be one of the dietary causes of metabolic disorders, such as obesity. Therefore, substituting sugar with low calorie sweeteners may be an efficacious weight management strategy. We tested the effect of preloads containing stevia, aspartame, or sucrose on food intake, satiety, and postprandial glucose and insulin levels.19 healthy lean (BMI=20.0-24.9) and 12 obese (BMI=30.0-39.9) individuals 18-50 years old completed three separate food test days during which they received preloads containing stevia (290kcal), aspartame (290kcal), or sucrose (493kcal) before the lunch and dinner meal. The preload order was balanced, and food intake (kcal) was directly calculated. Hunger and satiety levels were reported before and after meals, and every hour throughout the afternoon. Participants provided blood samples immediately before and 20min after the lunch preload. Despite the caloric difference in preloads (290kcal vs. 493kcal), participants did not compensate by eating more at their lunch and dinner meals when they consumed stevia and aspartame versus sucrose in preloads (mean differences in food intake over entire day between sucrose and stevia=301kcal, p<.01; aspartame=330kcal, p<.01). Self-reported hunger and satiety levels did not differ by condition. Stevia preloads significantly reduced postprandial glucose levels compared to sucrose preloads (p<.01), and postprandial insulin levels compared to both aspartame and sucrose preloads (p<.05). When consuming stevia and aspartame preloads, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety compared to when they consumed the higher calorie sucrose preload.
DOI: 10.3945/jn.110.125336
2010
Cited 341 times
Bioactives in Blueberries Improve Insulin Sensitivity in Obese, Insulin-Resistant Men and Women1–4
Dietary supplementation with whole blueberries in a preclinical study resulted in a reduction in glucose concentrations over time. We sought to evaluate the effect of daily dietary supplementation with bioactives from blueberries on whole-body insulin sensitivity in men and women. A double-blinded, randomized, and placebo-controlled clinical study design was used. After screening to resolve study eligibility, baseline (wk 0) insulin sensitivity was measured on 32 obese, nondiabetic, and insulin-resistant subjects using a high-dose hyperinsulinemic-euglycemic clamp (insulin infusion of 120 mU(861 pmol)⋅m(-2)⋅min(-1)). Serum inflammatory biomarkers and adiposity were measured at baseline. At the end of the study, insulin sensitivity, inflammatory biomarkers, and adiposity were reassessed. Participants were randomized to consume either a smoothie containing 22.5 g blueberry bioactives (blueberry group, n = 15) or a smoothie of equal nutritional value without added blueberry bioactives (placebo group, n = 17) twice daily for 6 wk. Both groups were instructed to maintain their body weight by reducing ad libitum intake by an amount equal to the energy intake of the smoothies. Participants' body weights were evaluated weekly and 3-d food records were collected at baseline, the middle, and end of the study. The mean change in insulin sensitivity improved more in the blueberry group (1.7 ± 0.5 mg⋅kg FFM(-1)⋅min(-1)) than in the placebo group (0.4 ± 0.4 mg⋅kg FFM(-1)⋅min(-1)) (P = 0.04). Insulin sensitivity was enhanced in the blueberry group at the end of the study without significant changes in adiposity, energy intake, and inflammatory biomarkers. In conclusion, daily dietary supplementation with bioactives from whole blueberries improved insulin sensitivity in obese, nondiabetic, and insulin-resistant participants.
DOI: 10.2337/dci17-0057
2017
Cited 327 times
Cardiovascular Outcomes Trials in Type 2 Diabetes: Where Do We Go From Here? Reflections From a<i>Diabetes Care</i>Editors’ Expert Forum
In December 2008, the U.S. Food and Drug Administration issued guidance to the pharmaceutical industry setting new expectations for the development of antidiabetes drugs for type 2 diabetes. This guidance expanded the scope and cost of research necessary for approval of such drugs by mandating long-term cardiovascular outcomes trials (CVOTs) for safety. Since 2008, 9 CVOTs have been reported, 13 are under way, and 4 have been terminated. Reassuringly, each of the completed trials demonstrated the noninferiority of their respective drugs to placebo for their primary cardiovascular (CV) composite end point. Notably, four additionally provided evidence of CV benefit in the form of significant decreases in the primary CV composite end point, two suggested reductions in CV death, and three suggested reductions in all-cause mortality. Although these trials have yielded much valuable information, whether that information justifies the investment of time and resources is controversial. In June 2016, a Diabetes Care Editors' Expert Forum convened to review the processes and challenges of CVOTs, discuss the benefits and limitations of their current designs, and weigh the merits of modifications that might improve the efficiency and clinical value of future trials. Discussion and analysis continued with the CVOT trial results released in June 2017 at the American Diabetes Association's Scientific Sessions and in September 2017 at the European Association for the Study of Diabetes scientific meeting. This article summarizes the discussion and findings to date.
DOI: 10.1097/med.0000000000000311
2017
Cited 302 times
An update on sodium-glucose co-transporter-2 inhibitors for the treatment of diabetes mellitus
Purpose of review Sodium-glucose co-transporter-2 (SGLT2) inhibitors are the newest class of oral antihyperglycemic agents that have been approved for the treatment of diabetes mellitus. Over the past year, there have been significant developments in both the safety and efficacy of this class of medications that are presented in this review. Recent findings Apart from data on the glucose-lowering effect of SGLT2 inhibitors, other metabolic benefits have been demonstrated for this class of medications. Moreover, there have been three Food and Drug Administration Drug Safety Communications issued in 2015 that have led to additional drug labeling. The basic mechanism of action, indications, glucose-lowering benefits, other metabolic benefits, and adverse side-effects of SGLT2 inhibitors are presented in this review. Summary SGLT2 inhibitors are medications that have a unique mechanism of action and that lower glucose independent of insulin. Given the recent findings on efficacy and benefits, these agents are rapidly establishing their role in the treatment of diabetes. Especially in patients with type 2 diabetes not willing or not ready to start insulin, SGLT2 inhibitors may be another option in those patients requiring additional glucose lowering and in those with acceptable risk factor profiles. Although there appears to be some positive benefits in cardiovascular endpoints, more research on the long-term outcomes in people taking SGLT2 inhibitors is warranted.
DOI: 10.1111/j.1463-1326.2009.01173.x
2009
Cited 287 times
Efficacy and safety of sitagliptin when added to insulin therapy in patients with type 2 diabetes
To evaluate the efficacy and tolerability of sitagliptin when added to insulin therapy alone or in combination with metformin in patients with type 2 diabetes.After a 2 week placebo run-in period, eligible patients inadequately controlled on long-acting, intermediate-acting or premixed insulin (HbA1c > or = 7.5% and < or = 11%), were randomised 1:1 to the addition of once-daily sitagliptin 100 mg or matching placebo over a 24-week study period. The study capped the proportion of randomised patients on insulin plus metformin at 75%. Further, the study capped the proportion of randomised patients on premixed insulin at 25%. The metformin dose and the insulin dose were to remain stable throughout the study. The primary endpoint was HbA1c change from baseline at week 24.Mean baseline characteristics were similar between the sitagliptin (n = 322) and placebo (n = 319) groups, including HbA1c (8.7 vs. 8.6%), diabetes duration (13 vs. 12 years), body mass index (31.4 vs. 31.4 kg/m(2)), and total daily insulin dose (51 vs. 52 IU), respectively. At 24 weeks, the addition of sitagliptin significantly (p < 0.001) reduced HbA1c by 0.6% compared with placebo (0.0%). A greater proportion of patients achieved an HbA1c level < 7% while randomised to sitagliptin as compared with placebo (13 vs. 5% respectively; p < 0.001). Similar HbA1c reductions were observed in the patient strata defined by insulin type (long-acting and intermediate-acting insulins or premixed insulins) and by baseline metformin treatment. The addition of sitagliptin significantly (p < 0.001) reduced fasting plasma glucose by 15.0 mg/dl (0.8 mmol/l) and 2-h postmeal glucose by 36.1 mg/dl (2.0 mmol/l) relative to placebo. A higher incidence of adverse experiences was reported with sitagliptin (52%) compared with placebo (43%), due mainly to the increased incidence of hypoglycaemia (sitagliptin, 16% vs. placebo, 8%). The number of hypoglycaemic events meeting the protocol-specified criteria for severity was low with sitagliptin (n = 2) and placebo (n = 1). No significant change from baseline in body weight was observed in either group.In this 24-week study, the addition of sitagliptin to ongoing, stable-dose insulin therapy with or without concomitant metformin improved glycaemic control and was generally well tolerated in patients with type 2 diabetes.
DOI: 10.1172/jci44421
2012
Cited 273 times
Adipocyte iron regulates adiponectin and insulin sensitivity
Iron overload is associated with increased diabetes risk. We therefore investigated the effect of iron on adiponectin, an insulin-sensitizing adipokine that is decreased in diabetic patients. In humans, normal-range serum ferritin levels were inversely associated with adiponectin, independent of inflammation. Ferritin was increased and adiponectin was decreased in type 2 diabetic and in obese diabetic subjects compared with those in equally obese individuals without metabolic syndrome. Mice fed a high-iron diet and cultured adipocytes treated with iron exhibited decreased adiponectin mRNA and protein. We found that iron negatively regulated adiponectin transcription via FOXO1-mediated repression. Further, loss of the adipocyte iron export channel, ferroportin, in mice resulted in adipocyte iron loading, decreased adiponectin, and insulin resistance. Conversely, organismal iron overload and increased adipocyte ferroportin expression because of hemochromatosis are associated with decreased adipocyte iron, increased adiponectin, improved glucose tolerance, and increased insulin sensitivity. Phlebotomy of humans with impaired glucose tolerance and ferritin values in the highest quartile of normal increased adiponectin and improved glucose tolerance. These findings demonstrate a causal role for iron as a risk factor for metabolic syndrome and a role for adipocytes in modulating metabolism through adiponectin in response to iron stores.
DOI: 10.1016/j.jacc.2018.09.020
2018
Cited 252 times
2018 ACC Expert Consensus Decision Pathway on Novel Therapies for Cardiovascular Risk Reduction in Patients With Type 2 Diabetes and Atherosclerotic Cardiovascular Disease
James L. Januzzi, Jr, MD, FACC, Chair Tariq Ahmad, MD, MPH, FACC Brendan Everett, MD, FACC William Hucker, MD, PHD Dharam J. Kumbhani, MD, SM, FACC Joseph E. Marine, MD, FACC Pamela B. Morris, MD, FACC Robert N. Piana, MD, FACC Sunil V. Rao, MD, FACC Marielle Scherrer-Crosbie, MD, PhD
DOI: 10.1016/j.metabol.2008.03.001
2008
Cited 242 times
A natural history of botanical therapeutics
Plants have been used as a source of medicine throughout history and continue to serve as the basis for many pharmaceuticals used today. Although the modern pharmaceutical industry was born from botanical medicine, synthetic approaches to drug discovery have become standard. However, this modern approach has led to a decline in new drug development in recent years and a growing market for botanical therapeutics that are currently available as dietary supplements, drugs, or botanical drugs. Most botanical therapeutics are derived from medicinal plants that have been cultivated for increased yields of bioactive components. The phytochemical composition of many plants has changed over time, with domestication of agricultural crops resulting in the enhanced content of some bioactive compounds and diminished content of others. Plants continue to serve as a valuable source of therapeutic compounds because of their vast biosynthetic capacity. A primary advantage of botanicals is their complex composition consisting of collections of related compounds having multiple activities that interact for a greater total activity.
DOI: 10.2337/dc11-2339
2012
Cited 227 times
Defining Insulin Resistance From Hyperinsulinemic-Euglycemic Clamps
OBJECTIVE This study was designed to determine a cutoff point for identifying insulin resistance from hyperinsulinemic-euglycemic clamp studies performed at 120 mU/m2 ⋅ min in a white population and to generate equations from routinely measured clinic and blood variables for predicting clamp-derived glucose disposal rate (GDR), i.e., insulin sensitivity. RESEARCH DESIGN AND METHODS We assembled data from hyperinsulinemic-euglycemic clamps (120 mU/m2 ⋅ min insulin dose) performed at the Pennington Biomedical Research Center between 2001 and 2011. Subjects were divided into subjects with diabetes (n = 51) and subjects without diabetes (n = 116) by self-report and/or fasting glucose ≥126 mg/dL. RESULTS We found that 75% of individuals with a GDR &amp;lt;5.6 mg/kg fat-free mass (FFM) + 17.7 ⋅ min were truly insulin resistant. Cutoff values for GDRs normalized for body weight, body surface area, or FFM were 4.9 mg/kg ⋅ min, 212.2 mg/m2 ⋅ min, and 7.3 mg/kgFFM ⋅ min, respectively. Next, we used classification tree models to predict GDR from routinely measured clinical and biochemical variables. We found that individual insulin resistance could be estimated with good sensitivity (89%) and specificity (67%) from the homeostasis model assessment of insulin resistance (HOMA-IR) &amp;gt;5.9 or 2.8&amp;lt; HOMA-IR &amp;lt;5.9 with HDL &amp;lt;51 mg/dL. CONCLUSIONS We developed a cutoff for defining insulin resistance from hyperinsulinemic-euglycemic clamps. Moreover, we now provide classification trees for predicting insulin resistance from routinely measured clinical and biochemical markers. These findings extend the clamp from a research tool to providing a clinically meaningful message for participants in research studies, potentially providing greater opportunity for earlier recognition of insulin resistance.
DOI: 10.2337/dci18-0019
2018
Cited 212 times
Insulin Access and Affordability Working Group: Conclusions and Recommendations
There are more than 30 million Americans with diabetes, a disease that costs the U.S. more than $327 billion per year (1,2). Achieving glycemic control and controlling cardiovascular risk factors have been conclusively shown to reduce diabetes complications, comorbidities, and mortality. To achieve these desired outcomes, the medical community now has available many classes of medications and many formulations of insulin to effectively manage the metabolic abnormalities for people with diabetes. However, the affordability of medications in general, and for insulin specifically, is currently of great concern to people with diabetes, their families, health care providers, insurers, and employers. For millions of people living with diabetes, including all individuals with type 1 diabetes, access to insulin is literally a matter of life and death. The average list price of insulin has skyrocketed in recent years, nearly tripling between 2002 and 2013 (3). The reasons for this increase are not entirely clear but are due in part to the complexity of drug pricing in general and of insulin pricing in particular. As the price of insulin continues to rise, individuals with diabetes are often forced to choose between purchasing their medications or paying for other necessities, exposing them to serious short- and long-term health consequences (4–9). To find solutions to the issue of insulin affordability, there must be a better understanding of the transactions throughout the insulin supply chain, the impact each stakeholder has on what people with diabetes pay for insulin, and the relative efficacy of therapeutic options. Thus, as the nation’s leading voluntary health organization whose mission is “to prevent and cure diabetes and to improve the lives of all people affected by diabetes,” the American Diabetes Association (ADA) is committed to finding ways to provide relief for individuals and families who lack affordable access …
DOI: 10.2337/dci20-0022
2020
Cited 211 times
Precision Medicine in Diabetes: A Consensus Report From the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)
The convergence of advances in medical science, human biology, data science, and technology has enabled the generation of new insights into the phenotype known as "diabetes." Increased knowledge of this condition has emerged from populations around the world, illuminating the differences in how diabetes presents, its variable prevalence, and how best practice in treatment varies between populations. In parallel, focus has been placed on the development of tools for the application of precision medicine to numerous conditions. This Consensus Report presents the American Diabetes Association (ADA) Precision Medicine in Diabetes Initiative in partnership with the European Association for the Study of Diabetes (EASD), including its mission, the current state of the field, and prospects for the future. Expert opinions are presented on areas of precision diagnostics and precision therapeutics (including prevention and treatment), and key barriers to and opportunities for implementation of precision diabetes medicine, with better care and outcomes around the globe, are highlighted. Cases where precision diagnosis is already feasible and effective (i.e., monogenic forms of diabetes) are presented, while the major hurdles to the global implementation of precision diagnosis of complex forms of diabetes are discussed. The situation is similar for precision therapeutics, in which the appropriate therapy will often change over time owing to the manner in which diabetes evolves within individual patients. This Consensus Report describes a foundation for precision diabetes medicine, while highlighting what remains to be done to realize its potential. This, combined with a subsequent, detailed evidence-based review (due 2022), will provide a roadmap for precision medicine in diabetes that helps improve the quality of life for all those with diabetes.
DOI: 10.2337/dc15-1081
2015
Cited 187 times
Advances in the Science, Treatment, and Prevention of the Disease of Obesity: Reflections From a <i>Diabetes Care</i> Editors’ Expert Forum
As obesity rates increase, so too do the risks of type 2 diabetes, cardiovascular disease, and numerous other detrimental conditions. The prevalence of obesity in U.S. adults more than doubled between 1980 and 2010, from 15.0 to 36.1%. Although this trend may be leveling off, obesity and its individual, societal, and economic costs remain of grave concern. In June 2014, a Diabetes Care Editors' Expert Forum convened to review the state of obesity research and discuss the latest prevention initiatives and behavioral, medical, and surgical therapies. This article, an outgrowth of the forum, offers an expansive view of the obesity epidemic, beginning with a discussion of its root causes. Recent insights into the genetic and physiological factors that influence body weight are reviewed, as are the pathophysiology of obesity-related metabolic dysfunction and the concept of metabolically healthy obesity. The authors address the crucial question of how much weight loss is necessary to yield meaningful benefits. They describe the challenges of behavioral modification and predictors of its success. The effects of diabetes pharmacotherapies on body weight are reviewed, including potential weight-neutral combination therapies. The authors also summarize the evidence for safety and efficacy of pharmacotherapeutic and surgical obesity treatments. The article concludes with an impassioned call for researchers, clinicians, governmental agencies, health policymakers, and health-related industries to collectively embrace the urgent mandate to improve prevention and treatment and for society at large to acknowledge and manage obesity as a serious disease.
DOI: 10.2337/dc14-2806
2015
Cited 185 times
Sotagliflozin, a Dual SGLT1 and SGLT2 Inhibitor, as Adjunct Therapy to Insulin in Type 1 Diabetes
OBJECTIVE To assess the safety and efficacy of dual sodium–glucose cotransporter (SGLT) 1 and SGLT2 inhibition with sotagliflozin as adjunct therapy to insulin in type 1 diabetes. RESEARCH DESIGN AND METHODS We treated 33 patients with sotagliflozin, an oral dual SGLT1 and SGLT2 inhibitor, or placebo in a randomized, double-blind trial assessing safety, insulin dose, glycemic control, and other metabolic parameters over 29 days of treatment. RESULTS In the sotagliflozin-treated group, the percent reduction from baseline in the primary end point of bolus insulin dose was 32.1% (P = 0.007), accompanied by lower mean daily glucose measured by continuous glucose monitoring (CGM) of 148.8 mg/dL (8.3 mmol/L) (P = 0.010) and a reduction of 0.55% (5.9 mmol/mol) (P = 0.002) in HbA1c compared with the placebo group that showed 6.4% reduction in bolus insulin dose, a mean daily glucose of 170.3 mg/dL (9.5 mmol/L), and a decrease of 0.06% (0.65 mmol/mol) in HbA1c. The percentage of time in target glucose range 70–180 mg/dL (3.9–10.0 mmol/L) increased from baseline with sotagliflozin compared with placebo, to 68.2% vs. 54.0% (P = 0.003), while the percentage of time in hyperglycemic range &amp;gt;180 mg/dL (10.0 mmol/L) decreased from baseline, to 25.0% vs. 40.2% (P = 0.002), for sotagliflozin and placebo, respectively. Body weight decreased (1.7 kg) with sotagliflozin compared with a 0.5 kg gain (P = 0.005) in the placebo group. CONCLUSIONS As adjunct to insulin, dual SGLT1 and SGLT2 inhibition with sotagliflozin improved glycemic control and the CGM profile with bolus insulin dose reduction, weight loss, and no increased hypoglycemia in type 1 diabetes.
DOI: 10.2337/dci21-0034
2021
Cited 163 times
Consensus Report: Definition and Interpretation of Remission in Type 2 Diabetes
Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks versus benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed "remission" as the most appropriate descriptive term, and HbA1c <6.5% (48 mmol/mol) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.
DOI: 10.2337/dci17-0005
2017
Cited 150 times
Diabetes and Aging: Unique Considerations and Goals of Care
Diabetes in older adults is a growing public health burden. The unprecedented aging of the world's population is a major contributor to the diabetes epidemic, and older adults represent one of the fastest growing segments of the diabetes population. Of impending concern is that these numbers are projected to grow dramatically over the next few decades (1,2). Almost one-third of U.S. adults over the age of 65 years have diabetes. Approximately half of those are undiagnosed, and an additional one-third of older adults have prediabetes (3). Persons with diabetes today are living much longer compared with those in the past. We also recognize that management of older adults with diabetes is clearly more complicated given the observation that they commonly have multiple coexisting medical conditions that can impact clinical management. While rates of diabetes-related complications have declined overall in the general population, the incidence rates of macrovascular complications such as acute myocardial infarction and stroke continue to be the highest in older age-groups. These individuals also have the highest rate of diabetes-related end-stage renal disease (4). Heterogeneity in the health status of older adults (ranging from robust and otherwise healthy individuals to those with frailty and multiple comorbid conditions) and the paucity of evidence from clinical trials represent a challenge to making generalized treatment recommendations for older adults. Although many more individuals with type 1 diabetes are living longer (5), type 2 diabetes remains the most common type in older age-groups. Furthermore, older adults with diabetes may either have elderly onset disease (diagnosed at age 65 years or older) or long-standing diabetes with onset in middle age or earlier years (6), adding to the complexity of managing diabetes in older adults. Consequently, the American Diabetes Association (ADA) organized a Consensus Development Conference on Diabetes and Older Adults …
DOI: 10.1007/s00125-020-05181-w
2020
Cited 110 times
Precision medicine in diabetes: a Consensus Report from the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD)
The convergence of advances in medical science, human biology, data science and technology has enabled the generation of new insights into the phenotype known as 'diabetes'. Increased knowledge of this condition has emerged from populations around the world, illuminating the differences in how diabetes presents, its variable prevalence and how best practice in treatment varies between populations. In parallel, focus has been placed on the development of tools for the application of precision medicine to numerous conditions. This Consensus Report presents the American Diabetes Association (ADA) Precision Medicine in Diabetes Initiative in partnership with the European Association for the Study of Diabetes (EASD), including its mission, the current state of the field and prospects for the future. Expert opinions are presented on areas of precision diagnostics and precision therapeutics (including prevention and treatment) and key barriers to and opportunities for implementation of precision diabetes medicine, with better care and outcomes around the globe, are highlighted. Cases where precision diagnosis is already feasible and effective (i.e. monogenic forms of diabetes) are presented, while the major hurdles to the global implementation of precision diagnosis of complex forms of diabetes are discussed. The situation is similar for precision therapeutics, in which the appropriate therapy will often change over time owing to the manner in which diabetes evolves within individual patients. This Consensus Report describes a foundation for precision diabetes medicine, while highlighting what remains to be done to realise its potential. This, combined with a subsequent, detailed evidence-based review (due 2022), will provide a roadmap for precision medicine in diabetes that helps improve the quality of life for all those with diabetes.
DOI: 10.1016/s0140-6736(00)03638-2
2001
Cited 294 times
Efficacy of inhaled human insulin in type 1 diabetes mellitus: a randomised proof-of-concept study
Effective glycaemic control in type 1 diabetes mellitus usually requires two or more insulin injections daily. Inhaled intrapulmonary delivery of insulin offers a potential new way to deliver meal-related insulin, eliminating the need for preprandial injections.73 patients with type 1 diabetes mellitus were studied in an open-label, proof-of-concept, parallel-group randomised trial. Patients in the experimental group received preprandial inhaled insulin plus a bedtime subcutaneous ultralente insulin injection. Patients in the control group received their usual insulin regimen of two to three injections per day. Participants monitored their blood glucose four times daily, and adjusted insulin doses weekly to achieve preprandial glucose targets of 5.6-8.9 mmol/L. The primary outcome measure was change in glycosylated haemoglobin (HbA1c) after 12 weeks. Secondary outcomes were fasting and postprandial glucose response to a mixed meal; hypoglycaemia frequency and severity; pulmonary function; and patients' satisfaction.Changes in HbA1c were indistinguishable between groups (difference 0.2% [95% CI -0.2 to 0.5]). Changes in fasting and postprandial glucose concentrations, and occurrence and severity of hypoglycaemia were also similar between groups. Inhaled insulin was well tolerated and had no effect on pulmonary function (ie, spirometry, lung volumes, diffusion capacity, and oxygen saturation).This proof-of-concept study shows that preprandial insulin can be given by inhalation in individuals with insulin-deficient type 1 diabetes as a less invasive alternative to conventional preprandial insulin injections.
DOI: 10.1210/jcem-61-4-705
1985
Cited 256 times
Bioavailability of Albumin-Bound Testosterone†
The unbound fraction of plasma testosterone (T) can freely enter tissues, whereas the bioavailability of the albumin-bound T is controversial. A clinical observation in hirsute women receiving spironolactone suggested an experimental paradigm to test the effect of albumin binding on T bioavailability. We found an increase in the non-T-estrogen-binding globulin-bound fraction of plasma T in women from 24.1 +/- 3.9% to 42.0 +/- 8.1% (+/-SEM) while they received spironolactone. Computer modeling indicated that the absolute increase in the albumin-bound T concentration would be about 22.4-fold greater than that in the unbound T concentration (the ratio of albumin-bound to free T remaining virtually constant) because of the binding of T to albumin. We reasoned that the addition of graded amounts of spironolactone and its metabolites to plasma would provide a means to increase the albumin-bound T concentration appreciably. We evaluated the biological effects of this perturbation of T transport by spironolactone and its metabolites in a bioassay system using the Oldendorf technique. Bioavailable T increased proportionately with increments in free and albumin-bound T (r = 0.85; P less than 0.01). A major portion of the albumin-bound T (i.e. 55%) entered tissues under all conditions; the amount that was bioavailable vastly exceeded the amount of T that was unbound in the injected samples. An index of the amount of bioavailable T can be determined using the ammonium sulfate precipitation technique, as the percentage of non-T-estrogen-binding globulin-bound T in vitro correlated well with T bioavailability in vitro (r = 0.86; P less than 0.01). These studies support the conclusion that albumin-bound T is biologically important.
DOI: 10.1093/jn/132.6.1107
2002
Cited 210 times
Oral Chromium Picolinate Improves Carbohydrate and Lipid Metabolism and Enhances Skeletal Muscle Glut-4 Translocation in Obese, Hyperinsulinemic (JCR-LA Corpulent) Rats
Human studies suggest that chromium picolinate (CrPic) decreases insulin levels and improves glucose disposal in obese and type 2 diabetic populations. To evaluate whether CrPic may aid in treatment of the insulin resistance syndrome, we assessed its effects in JCR:LA-corpulent rats, a model of this syndrome. Male lean and obese hyperinsulinemic rats were randomly assigned to receive oral CrPic [80 microg/(kg. d); n = 5 or 6, respectively) in water or to control conditions (water, n = 5). After 3 mo, a 120-min intraperitoneal glucose tolerance test (IPGTT) and a 30-min insulin tolerance test were performed. Obese rats administered CrPic had significantly lower fasting insulin levels (1848 +/- 102 vs. 2688 +/- 234 pmol/L; P < 0.001; mean +/- SEM) and significantly improved glucose disappearance (P < 0.001) compared with obese controls. Glucose and insulin areas under the curve for IPGTT were significantly less for obese CrPic-treated rats than in obese controls (P < 0.001). Obese CrPic-treated rats had lower plasma total cholesterol (3.57 +/- 0.28 vs. 4.11 +/- 0.47 mmol/L, P < 0.05) and higher HDL cholesterol levels (1.92 +/- 0.09 vs. 1.37 +/- 0.36 mmol/L, P < 0.01) than obese controls. CrPic did not alter plasma glucose or cholesterol levels in lean rats. Total skeletal muscle glucose transporter (Glut)-4 did not differ among groups; however, CrPic significantly enhanced membrane-associated Glut-4 in obese rats after insulin stimulation. Thus, CrPic supplementation enhances insulin sensitivity and glucose disappearance, and improves lipids in male obese hyperinsulinemic JCR:LA-corpulent rats.
DOI: 10.1016/0026-0495(95)90251-1
1995
Cited 204 times
Contribution of visceral fat mass to the insulin resistance of aging
Recent studies have shown that central obesity (increased waist to hip ratio [WHR]) is related to insulin resistance and aging. Furthermore, in central-obesity states, the intraabdominal fat (IAF) depot has been postulated to contribute most to the development of insulin resistance. Therefore, the observed insulin resistance of aging may be related more to changes in body composition than to aging per se. The purpose of this study was to explore the association of IAF with age and insulin sensitivity (SI) after controlling for obesity. We examined 60 healthy nondiabetic subjects (normal 75-g oral glucose tolerance test, aged 23 to 83, 15 men and 45 women). We chose subjects so that those < or = 125% and greater than 125% of ideal body weight were equally represented in each age decade. We quantified total and subcutaneous abdominal fat and IAF at the umbilicus using a validated magnetic resonance imaging (MRI) scanning technique and determined SI using a modified minimal model. IAF correlated significantly with age (r = .49, P = .0001) in the group as a whole, as well as in men (r = .58, P = .022) and women (r = .48, P = .0008) separately. In all subjects, SI was significantly related to IAF (r = -.50, P < .0001) but was not related to age (r = .00, P = .98). In multivariate analysis for various combinations of age, sex, and measures of fat distribution, WHR accounted for 28% and IAF for 51% of the variance in SI, whereas age, sex, and interactions of age and sex accounted for only 1%.(ABSTRACT TRUNCATED AT 250 WORDS)
DOI: 10.1093/gerona/54.12.b521
1999
Cited 199 times
Pleiotropic Effects of Growth Hormone and Insulin-like Growth Factor (IGF)-1 on Biological Aging: Inferences From Moderate Caloric-Restricted Animals
Moderate caloric restriction (60% of ad libitum intake) is an important model to investigate potential mechanisms of biological aging. This regimen has been reported to decrease the number of pathologies and increase life span in all species tested to date. Although moderate caloric restriction induces a wide range of physiological changes within the organism, adaptive changes within the endocrine system are evident and serve to maintain blood levels of glucose. These alterations include an increase in growth hormone secretory dynamics and a decline in plasma levels ofIGF-1. These endocrine compensatory mechanisms can be induced at any age, and we have proposed that these alterations mediate some of the beneficial aspects of moderate caloric restriction. Numerous studies indicate that growth hormone and IGF-1 decrease with age and that administration of these hormones ameliorates the deterioration of tissue function evident in aged ad libitum-fed animals, suggesting that the absence of these hormones contributes to thephenotype of aging. Nevertheless, IGF-1 is an important risk factor in age-related pathologies including lung, breast, and prostate cancer. From these studies, we propose that endocrine compensatory mechanisms induced by moderate caloric restriction (including increased growth hormone and decreased IGF-1) decrease the stimulus for cellular replication, resulting in a decline in pathologies and increased life span observed in these animals. These findings have important implications f or potential mechanisms of moderate caloric restriction and suggest that neuroendocrine compensatory mechanisms exert a key role on the actions of moderate caloric restriction on life span.
DOI: 10.1016/j.metabol.2008.03.003
2008
Cited 198 times
Quercetin transiently increases energy expenditure but persistently decreases circulating markers of inflammation in C57BL/6J mice fed a high-fat diet
Quercetin, a polyphenolic compound and a major bioflavonoid in the human diet, has anti-inflammatory properties and has been postulated to enhance energy expenditure (EE). We sought to determine whether quercetin alters body weight, body composition, EE, and circulating markers of inflammation. At 6 weeks (W) of age, 2 cohorts of C57BL/6J mice (N = 80) were placed on one of 2 diets for 3W or 8W: (1) high fat (HF) (45% kcal fat) or (2) high fat + quercetin (HF + Q) (45% kcal fat + 0.8% quercetin). Quercetin concentrations in the diet and plasma were evaluated using mass spectrometry. Body weight, composition (nuclear magnetic resonance), and food consumption were measured weekly. Energy expenditure was measured by indirect calorimetry at 3 and 8W, and inflammatory markers were measured in plasma obtained at 8W. The presence of quercetin in the HF diet did not alter food consumption over time in the HF + Q group and did not differ from the HF group at any time point. However, circulating plasma quercetin concentrations declined between 3 and 8W. At 3W, EE was higher during both day and night phases (P < .0001) in the HF + Q group compared with the HF group; but this difference was not detected at 8W and did not translate into significant differences between the HF + Q and HF groups with respect to body weight or body composition. During the night phase, concentrations of the inflammatory markers (interferon-gamma, interleukin-1alpha, and interleukin-4) were significantly lower when compared with HF treatment group (P < .05). Dietary supplementation with quercetin produces transient (3W) increases in EE that are not detected after 8W on the diet. A corresponding decrease in circulating quercetin between 3 and 8W suggests that metabolic adaptation may have diminished the impact of quercetin's early effect on EE and diminished its overall effect on nutrient partitioning and adiposity. However, quercetin at the levels provided was effective in reducing circulating markers of inflammation observed in animals on an HF diet at 8W.
DOI: 10.7326/0003-4819-134-3-200102060-00011
2001
Cited 193 times
Inhaled Human Insulin Treatment in Patients with Type 2 Diabetes Mellitus
Background: Despite demonstrated benefits, intensive insulin therapy has not gained widespread clinical acceptance for several reasons: Multiple daily injections are inconvenient, adherence is a concern, and the time-activity profile may not mimic normal insulin secretion. As such, alternate means of administering insulin are being evaluated. Objective: To assess the efficacy and safety of pulmonary delivery of insulin in type 2 diabetic patients who require insulin. Design: Randomized, open-label, 3-month study consisting of a screening visit, a 4-week baseline lead-in phase, and a 12-week treatment phase. Setting: General clinical research center and outpatient research clinics. Patients: 26 patients (16 men, 10 women) with type 2 diabetes (average age, 51.1 years; average duration of diabetes, 11.2 years). Intervention: Patients received inhaled insulin before each meal plus a bedtime injection of ultralente insulin, performed home glucose monitoring, and had weekly adjustment of insulin dose; target level for preprandial plasma glucose was 5.55 to 8.88 mmol/L (100 to 160 mg/dL). Measurements: Glycemic control (hemoglobin A1c level) obtained at baseline and monthly for 3 months. Pulmonary function tests were done at baseline and at the end of the study. Results: Inhaled insulin treatment for 3 months significantly improved glycemic control compared with baseline: Mean hemoglobin A1c levels decreased by 0.0071 ± 0.0072 (0.71% ± 0.72%). Patients experienced an average of 0.83 mild to moderate hypoglycemic event per month; no severe events were recorded. Patients showed no significant weight gain or change in pulmonary function compared with baseline. Conclusions: Pulmonary delivery of insulin in type 2 diabetic patients who require insulin improved glycemic control, was well tolerated, and demonstrated no adverse pulmonary effects. Larger-scale studies are ongoing to provide long-term efficacy and safety data. *For members of the Inhaled Insulin Study Group, see Appendix.
DOI: 10.1177/153537020122600103
2001
Cited 192 times
Insulin Resistance: Cellular and Clinical Concepts
Insulin resistance is defined as a clinical state in which a normal or elevated insulin level produces an attenuated biologic response. Specifically, the biologic response most studied is insulin-stimulated glucose disposal, yet the precise cellular mechanism responsible is not yet known. However, the presence of insulin resistance is observed many years before the onset of clinical hyperglycemia and the diagnosis of Type 2 diabetes. Insulin resistance at this stage appears to be significantly associated with a clustering of cardiovascular risk factors predisposing the individual to accelerated cardiovascular disease. An overview of insulin resistance and the associated clinical insulin resistant state will be discussed.
DOI: 10.2337/dc06-0254
2006
Cited 191 times
Chromium Picolinate Supplementation Attenuates Body Weight Gain and Increases Insulin Sensitivity in Subjects With Type 2 Diabetes
Chromium picolinate (CrPic) supplementation has been suggested to improve glycemia, but there are conflicting reports on efficacy. We sought to determine the effect of CrPic on insulin sensitivity, glycemic control, and body composition in subjects with type 2 diabetes.Thirty-seven subjects with type 2 diabetes were evaluated. After baseline, subjects were placed on a sulfonylurea (glipizide gastrointestinal therapeutic system 5 mg/day) with placebo for 3 months. Subjects were then randomized in a double-blind fashion to receive either the sulfonylurea plus placebo (n = 12) or the sulfonylurea plus 1,000 microg Cr as CrPic (n = 17) for 6 months. Body composition, insulin sensitivity, and glycemic control were determined at baseline, end of the 3-month single-blind placebo phase, and end of study.Subjects randomized to sulfonylurea/placebo, as opposed to those randomized to sulfonylurea/CrPic, had a significant increase in body weight (2.2 kg, P < 0.001 vs. 0.9 kg, P = 0.11), percent body fat (1.17%, P < 0.001 vs. 0.12%, P = 0.7), and total abdominal fat (32.5 cm(2), P < 0.05 vs. 12.2 cm(2), P < 0.10) from baseline. Subjects randomized to sulfonylurea/CrPic had significant improvements in insulin sensitivity corrected for fat-free mass (28.8, P < 0.05 vs. 15.9, P = 0.4), GHb (-1.16%, P < 0.005 vs. -0.4%, P = 0.3), and free fatty acids (-0.2 mmol/l, P < 0.001 vs. -0.12 mmol/l, P < 0.03) as opposed to sulfonylurea/placebo.This study demonstrates that CrPic supplementation in subjects with type 2 diabetes who are taking sulfonylurea agents significantly improves insulin sensitivity and glucose control. Further, CrPic supplementation significantly attenuated body weight gain and visceral fat accumulation compared with the placebo group.
DOI: 10.1093/ilar.47.3.186
2006
Cited 163 times
Animal Models of Type 2 Diabetes: Clinical Presentation and Pathophysiological Relevance to the Human Condition
The prevalence of diabetes throughout the world has increased dramatically over the recent past, and the trend will continue for the foreseeable future. One of the major concerns associated with diabetes relates to the development of micro- and macrovascular complications, which contribute greatly to the morbidity and mortality associated with the disease. Progression of the disease from prediabetic state to overt diabetes and the development of complications occur over many years. Assessment of interventions designed to delay or prevent disease progression or complications in humans also takes years and requires tremendous resources. To better study both the pathogenesis and potential therapeutic agents, appropriate animal models of type 2 diabetes (T2D) mellitus are needed. However, for an animal model to have relevance to the study of diabetes, either the characteristics of the animal model should mirror the pathophysiology and natural history of diabetes or the model should develop complications of diabetes with an etiology similar to that of the human condition. There appears to be no single animal model that encompasses all of these characteristics, but there are many that provide very similar characteristics in one or more aspects of T2D in humans. Use of the appropriate animal model based on these similarities can provide much needed data on pathophysiological mechanisms operative in human T2D.
DOI: 10.2337/diacare.27.1.239
2004
Cited 162 times
Concept, Strategies, and Feasibility of Noninvasive Insulin Delivery
To comprehensively review the progress to date on the development of alternative routes for insulin delivery.Study data were collected through a Medline review.Proof of principle has been established for many routes of administration including dermal, nasal, oral, buccal, and pulmonary insulin delivery.Of all the approaches to date, pulmonary delivery appears to be most feasible. Ongoing phase III studies will ultimately determine safety, tolerability, and efficacy before approval for clinical use.
DOI: 10.1016/j.ecl.2010.05.009
2010
Cited 157 times
Complications of Type 1 Diabetes
The prevalence of diabetes is increasing worldwide and the concern regarding the number of new cases of diabetes relates to the development of chronic complications. It has been recognized for years that the complications are a cause of considerable morbidity and mortality worldwide and as such, negatively affect the quality of life in individuals with diabetes with an increase in disability and death. Specifically, the complications of diabetes have been classified as either microvascular (ie, retinopathy, nephropathy, and neuropathy) or macrovascular (ie, cardiovascular disease, cerebrovascular accidents, and peripheral vascular disease). For purposes of this article, the authors focus on a brief review of the major complications.
DOI: 10.7326/0003-4819-143-8-200510180-00005
2005
Cited 154 times
Inhaled Insulin Improves Glycemic Control When Substituted for or Added to Oral Combination Therapy in Type 2 Diabetes
Patients with type 2 diabetes who do not achieve glycemic control with oral agent therapy eventually require insulin.To determine the effect on glycemic control of inhaled insulin alone or added to dual oral therapy (insulin secretagogue and sensitizer) after failure of dual oral therapy.Open-label, randomized, controlled trial.48 outpatient centers in the United States and Canada.309 patients with type 2 diabetes, no clinically significant respiratory disease, and hemoglobin A(1c) level of 8% to 11% who were receiving dual oral therapy.Primary end point was change in hemoglobin A(1c) level from baseline to 12 weeks. Secondary outcomes included hemoglobin A(1c) level less than 8% and less than 7%, hypoglycemia, weight, lipid levels, pulmonary function, insulin antibody binding, and adverse events.Inhaled insulin (Exubera; Pfizer Inc. [New York, New York], sanofi-aventis Group [Paris, France], and Nektar Therapeutics [San Carlos, California]), titrated to blood glucose, administered alone (n = 104) or added to dual oral agents (n = 103) versus oral therapy alone (n = 99).Reductions in hemoglobin A(1c) level were greater with inhaled insulin. Adjusted treatment group differences for inhaled insulin plus oral agents and inhaled insulin alone compared with continued oral agent therapy were -1.67 percentage points (95% CI, -1.90 to -1.44 percentage points; P < 0.001) and -1.18 percentage points (CI, -1.41 to -0.95 percentage point; P < 0.001), respectively. Hemoglobin A(1c) level less than 7% was achieved by 32% (inhaled insulin plus oral agents) and by 1% (oral agent therapy) of patients (adjusted odds ratio, 44.7 [CI, 6.0 to 335.2]). Hypoglycemia, mild weight gain, mild cough, and insulin antibodies were more frequent with inhaled insulin than with oral agent therapy alone. Pulmonary function was similar in all groups.This study evaluated only patients with hemoglobin A1c levels of 8% to 11%, did not compare inhaled insulin with other insulins or oral therapy except a dual regimen of secretagogue and sensitizer, and lasted only 12 weeks.Inhaled insulin improved overall glycemic control and hemoglobin A1c level when added to or substituted for dual oral agent therapy with an insulin secretagogue and sensitizer. Consistent with other insulin therapies, hypoglycemia and mild weight gain occurred. Pulmonary function showed no between-group differences.
DOI: 10.1111/jgs.12881
2014
Cited 142 times
Dapagliflozin Added to Usual Care in Individuals with Type 2 Diabetes Mellitus with Preexisting Cardiovascular Disease: A 24‐Week, Multicenter, Randomized, Double‐Blind, Placebo‐Controlled Study with a 28‐Week Extension
Objectives To assess the efficacy of dapagliflozin, a sodium–glucose cotransporter 2 inhibitor, for the treatment of individuals with type 2 diabetes mellitus (T2 DM ) and preexisting cardiovascular disease ( CVD ). Design Randomized, double‐blind, age‐stratified (&lt;65 and ≥65), 24‐week clinical trial with a 28‐week extension. Setting One hundred seventy‐three centers in 10 countries. Participants Individuals (N = 964) with T2 DM , glycosylated hemoglobin (HbA1c) of 7.0% to 10.0%, and documented CVD . Intervention Dapagliflozin 10 mg/d or placebo was added to usual care. Participants receiving insulin had their total daily insulin dose reduced by 25% at randomization. Measurements Two equal primary end points: change from baseline in HbA1c and proportion of participants achieving a three‐item end point (reduction of ≥0.5% in HbA1c, ≥3% in body weight, and ≥3 mmHg in systolic blood pressure) at 24 weeks. Results Forty‐seven percent were aged 65 and older, 7.7% were aged 75 and older, mean duration of T2 DM was 13 years, mean baseline HbA1c was 8.1%, and approximately 60% were taking insulin. The placebo‐corrected change in HbA1c with dapagliflozin was −0.4% at 24 weeks. Significantly more participants achieved the three‐item end point with dapagliflozin (10.0%) than with placebo (1.9%). The placebo‐corrected percentage change in body weight for dapagliflozin was −1.9% (−1.8 kg). Similar results were observed in both age strata, and changes were maintained over 52 weeks. More than one‐quarter (28.2%) of participants receiving dapagliflozin and 25.3% of those receiving placebo experienced hypoglycemia. More participants receiving dapagliflozin had vulvovaginitis, balanitis, or urinary tract infection. Conclusion When added to a usual background regimen in an older population with advanced T2 DM and preexisting comorbid CVD , dapagliflozin improved glycemic control without an increase in hypoglycemic risk, promoted weight loss, and was well tolerated.
DOI: 10.1185/03007995.2013.850066
2013
Cited 141 times
Long-term efficacy and safety of canagliflozin monotherapy in patients with type 2 diabetes inadequately controlled with diet and exercise: findings from the 52-week CANTATA-M study
Canagliflozin is a sodium glucose co-transporter 2 inhibitor developed for treatment of type 2 diabetes mellitus (T2DM). The long-term efficacy and safety of canagliflozin monotherapy were evaluated over 52 weeks in patients with T2DM inadequately controlled with diet and exercise.This randomized, double-blind, Phase 3 study included a placebo-controlled, 26-week core period (canagliflozin 100 or 300 mg vs placebo) and an active-controlled, 26-week extension (blinded switch of placebo-treated patients to sitagliptin 100 mg [placebo/sitagliptin]).ClinicalTrials.gov, NCT01081834.Efficacy endpoints assessed at 52 weeks included changes in hemoglobin A1c (HbA1c), fasting plasma glucose (FPG), and systolic blood pressure (BP); and percentage changes in body weight and fasting plasma lipids. Adverse events (AEs) were recorded throughout the study. Efficacy data are reported for canagliflozin 100 and 300 mg (placebo/sitagliptin group was used to maintain the double-blind and to serve as a control group for safety purposes; not as an efficacy comparator); safety data are reported for canagliflozin 100 and 300 mg and placebo/sitagliptin.Efficacy analyses included 451 patients who were randomized and dosed, entered the extension, and did not receive rescue therapy during the core period. Safety analyses included 584 patients who were randomized and dosed. At Week 52, canagliflozin 100 and 300 mg provided dose-related decreases from baseline in HbA1c of -0.81% and -1.11%. Canagliflozin 100 and 300 mg decreased FPG (-1.5 and -2.2 mmol/L [-27.4 and -39.1 mg/dL]), body weight (-3.3% and -4.4%), and systolic BP (-1.4 and -3.9 mmHg); decreased triglycerides and increased HDL-C and LDL-C were also seen. Over 52 weeks, overall AE rates were 67.2%, 66.0%, and 64.1% with canagliflozin 100 and 300 mg and placebo/sitagliptin; rates of serious AEs and AE-related discontinuations were low across groups. Compared with placebo/sitagliptin, canagliflozin was associated with higher rates of genital mycotic infections and AEs related to osmotic diuresis; these led to few discontinuations. Rates of volume depletion AEs and documented hypoglycemia were low across groups.Canagliflozin monotherapy provided sustained improvement in glycemic control and body weight reduction, and was generally well tolerated in patients with T2DM over 52 weeks.
DOI: 10.1152/japplphysiol.00045.2014
2014
Cited 141 times
Total body skeletal muscle mass: estimation by creatine (<i>methyl</i>-d<sub>3</sub>) dilution in humans
Current methods for clinical estimation of total body skeletal muscle mass have significant limitations. We tested the hypothesis that creatine ( methyl-d 3 ) dilution (D 3 -creatine) measured by enrichment of urine D 3 -creatinine reveals total body creatine pool size, providing an accurate estimate of total body skeletal muscle mass. Healthy subjects with different muscle masses [ n = 35: 20 men (19–30 yr, 70–84 yr), 15 postmenopausal women (51–62 yr, 70–84 yr)] were housed for 5 days. Optimal tracer dose was explored with single oral doses of 30, 60, or 100 mg D 3 -creatine given on day 1. Serial plasma samples were collected for D 3 -creatine pharmacokinetics. All urine was collected through day 5. Creatine and creatinine (deuterated and unlabeled) were measured by liquid chromatography mass spectrometry. Total body creatine pool size and muscle mass were calculated from D 3 -creatinine enrichment in urine. Muscle mass was also measured by magnetic resonance imaging (MRI), dual-energy x-ray absorptiometry (DXA), and traditional 24-h urine creatinine. D 3 -creatine was rapidly absorbed and cleared with variable urinary excretion. Isotopic steady-state of D 3 -creatinine enrichment in the urine was achieved by 30.7 ± 11.2 h. Mean steady-state enrichment in urine provided muscle mass estimates that correlated well with MRI estimates for all subjects ( r = 0.868, P &lt; 0.0001), with less bias compared with lean body mass assessment by DXA, which overestimated muscle mass compared with MRI. The dilution of an oral D 3 -creatine dose determined by urine D 3 -creatinine enrichment provides an estimate of total body muscle mass strongly correlated with estimates from serial MRI with less bias than total lean body mass assessment by DXA.
DOI: 10.1016/j.phymed.2005.09.007
2006
Cited 139 times
Antihyperglycemic activity of Tarralin™, an ethanolic extract of Artemisia dracunculus L.
The studies reported here were undertaken to examine the antihyperglycemic activity of an ethanolic extract of Artemisia dracunculus L., called Tarralin™ in diabetic and non-diabetic animals. In genetically diabetic KK-Aγ mice, Tarralin™ treatment by gavage (500 mg/kg body wt./day for 7 days) lowered elevated blood glucose levels by 24% from 479±25 to 352±16 mg/dl relative to control animals. In comparison, treatment with the known antidiabetic drugs, troglitazone (30 mg/kg body wt./day) and metformin (300 mg/kg body wt./day), decreased blood glucose concentrations by 28% and 41%, respectively. Blood insulin concentrations were reduced in the KK-Aγ mice by 33% with Tarralin™, 48% with troglitazone and 52% with metformin. In (STZ)-induced diabetic mice, Tarralin™ treatment, (500 mg/kg body wt./day for 7 days), also significantly lowered blood glucose concentrations, by 20%, from 429±41 to 376±58 mg/dl relative to control. As a possible mechanism, Tarralin™ was shown to significantly decrease phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression by 28% in STZ-induced diabetic rats. In non-diabetic animals, treatment with Tarralin™ did not significantly alter PEPCK expression, blood glucose or insulin concentrations. The extract was also shown to increase the binding of glucagon-like peptide (GLP-1) to its receptor in vitro. These results indicate that Tarralin™ has antihyperglycemic activity and a potential role in the management of diabetic states.
DOI: 10.1210/jc.2010-2493
2011
Cited 135 times
Dietary Methionine Restriction Increases Fat Oxidation in Obese Adults with Metabolic Syndrome
Objective:In preclinical reports, restriction of dietary methionine intake was shown to enhance metabolic flexibility, improve lipid profiles, and reduce fat deposition. The present report is the outcome of a "proof of concept" study to evaluate the efficacy of dietary methionine restriction (MR) in humans with metabolic syndrome.
DOI: 10.2337/dc13-0512
2013
Cited 132 times
Personalized Management of Hyperglycemia in Type 2 Diabetes
In June 2012, 13 thought leaders convened in a Diabetes Care Editors' Expert Forum to discuss the concept of personalized medicine in the wake of a recently published American Diabetes Association/European Association for the Study of Diabetes position statement calling for a patient-centered approach to hyperglycemia management in type 2 diabetes. This article, an outgrowth of that forum, offers a clinical translation of the underlying issues that need to be considered for effectively personalizing diabetes care. The medical management of type 2 diabetes has become increasingly complex, and its complications remain a great burden to individual patients and the larger society. The burgeoning armamentarium of pharmacological agents for hyperglycemia management should aid clinicians in providing early treatment to delay or prevent these complications. However, trial evidence is limited for the optimal use of these agents, especially in dual or triple combinations. In the distant future, genotyping and testing for metabolomic markers may help us to better phenotype patients and predict their responses to antihyperglycemic drugs. For now, a personalized ("n of 1") approach in which drugs are tested in a trial-and-error manner in each patient may be the most practical strategy for achieving therapeutic targets. Patient-centered care and standardized algorithmic management are conflicting approaches, but they can be made more compatible by recognizing instances in which personalized A1C targets are warranted and clinical circumstances that may call for comanagement by primary care and specialty clinicians.
DOI: 10.2337/dc14-0315
2015
Cited 128 times
Dapagliflozin’s Effects on Glycemia and Cardiovascular Risk Factors in High-Risk Patients With Type 2 Diabetes: A 24-Week, Multicenter, Randomized, Double-Blind, Placebo-Controlled Study With a 28-Week Extension
OBJECTIVE To assess the efficacy and safety of dapagliflozin, a selective sodium-glucose cotransporter 2 inhibitor, compared with placebo in patients with type 2 diabetes (T2D), documented pre-existing cardiovascular disease (CVD), and a history of hypertension. RESEARCH DESIGN AND METHODS Patients (N = 922) were randomized to receive 10 mg dapagliflozin or placebo in a double-blind trial for 24 weeks, followed by a 28-week extension period. In patients receiving insulin, the insulin dose was reduced by 25% at randomization. Patients were stratified by age, insulin use, and time from the most recent qualifying cardiovascular (CV) event. Co-primary end points were a change from baseline in hemoglobin A1c (HbA1c) and the proportion of patients achieving a combined reduction in HbA1c of ≥0.5% (5.5 mmol/mol), body weight (BW) of ≥3%, and systolic blood pressure (SBP) of ≥3 mmHg. RESULTS At 24 weeks, dapagliflozin significantly reduced HbA1c (−0.38% [−4.2 mmol/mol]) from baseline (8.18%) compared with a slight increase with placebo from baseline (8.08%) (0.08% [0.9 mmol/mol]). Significantly more patients met the three-item end point with treatment with dapagliflozin than with placebo (11.7% vs. 0.9%, respectively). Changes were maintained over 52 weeks. Although ∼42% of patients were ≥65 years old, similar results were observed in both age-stratified groups. Serious adverse events, hypoglycemia, urinary tract infections, and cardiac disorders were similar between groups. Adverse events of hypotension, dehydration, hypovolemia, genital infection, and renal failure or impairment occurred more often with dapagliflozin treatment. CONCLUSIONS In this study that evaluated T2D patients who were at high risk for future CVD events, dapagliflozin administration had significantly greater effects in reducing HbA1c, BW, and SBP, without adversely impacting CV safety when compared with placebo treatment.
DOI: 10.1002/mnfr.201400679
2015
Cited 127 times
Isothiocyanate‐rich <i>Moringa oleifera</i> extract reduces weight gain, insulin resistance, and hepatic gluconeogenesis in mice
Scope Moringa oleifera (moringa) is tropical plant traditionally used as an antidiabetic food. It produces structurally unique and chemically stable moringa isothiocyanates (MICs) that were evaluated for their therapeutic use in vivo. Methods and results C57BL/6L mice fed very high fat diet (VHFD) supplemented with 5% moringa concentrate (MC, delivering 66 mg/kg/d of MICs) accumulated fat mass, had improved glucose tolerance and insulin signaling, and did not develop fatty liver disease compared to VHFD‐fed mice. MC‐fed group also had reduced plasma insulin, leptin, resistin, cholesterol, IL‐1β, TNFα, and lower hepatic glucose‐6‐phosphatase (G6P) expression. In hepatoma cells, MC and MICs at low micromolar concentrations inhibited gluconeogenesis and G6P expression. MICs and MC effects on lipolysis in vitro and on thermogenic and lipolytic genes in adipose tissue in vivo argued these are not likely primary targets for the anti‐obesity and anti‐diabetic effects observed. Conclusion Data suggest that MICs are the main anti‐obesity and anti‐diabetic bioactives of MC, and that they exert their effects by inhibiting rate‐limiting steps in liver gluconeogenesis resulting in direct or indirect increase in insulin signaling and sensitivity. These conclusions suggest that MC may be an effective dietary food for the prevention and treatment of obesity and type 2 diabetes.
DOI: 10.2337/dc13-2743
2014
Cited 123 times
Insulin Therapy in People With Type 2 Diabetes: Opportunities and Challenges?
Given the continued interest in defining the optimal management of individuals with type 2 diabetes, the Editor of Diabetes Care convened a working party of diabetes specialists to examine this topic in the context of insulin therapy. This was prompted by recent new evidence on the use of insulin in such people. The group was aware of evidence that the benefits of insulin therapy are still usually offered late, and thus the aim of the discussion was how to define the optimal timing and basis for decisions regarding insulin and to apply these concepts in practice. It was noted that recent evidence had built upon that of the previous decades, together confirming the benefits and safety of insulin therapy, albeit with concerns about the potential for hypoglycemia and gain in body weight. Insulin offers a unique ability to control hyperglycemia, being used from the time of diagnosis in some circumstances, when metabolic control is disturbed by medical illness, procedures, or therapy, as well as in the longer term in ambulatory care. For those previously starting insulin, various other forms of therapy can be added later, which offer complementary effects appropriate to individual needs. Here we review current evidence and circumstances in which insulin can be used, consider individualized choices of alternatives and combination regimens, and offer some guidance on personalized targets and tactics for glycemic control in type 2 diabetes.
DOI: 10.1007/s00125-015-3547-2
2015
Cited 121 times
Effects of canagliflozin on body weight and relationship to HbA1c and blood pressure changes in patients with type 2 diabetes
Canagliflozin, a sodium glucose co-transporter 2 inhibitor, reduces HbA1c, body weight and systolic BP (SBP) in patients with type 2 diabetes. As weight loss is known to reduce both HbA1c and SBP, these analyses were performed to evaluate the contribution of weight loss resulting from treatment with canagliflozin to HbA1c and SBP reductions in patients with type 2 diabetes. Pooled data from four placebo-controlled Phase 3 studies (N = 2,250) in patients with type 2 diabetes were used in the analyses. In each study, patients were treated with placebo, canagliflozin 100 mg or canagliflozin 300 mg, once daily for 26 weeks. Changes from baseline in body weight, HbA1c and SBP were measured at week 26, and the contribution of weight loss to the lowering of HbA1c and SBP was obtained using ANCOVA. Canagliflozin 100 and 300 mg reduced mean body weight, HbA1c and SBP compared with placebo (p < 0.001 for each), and more patients had body-weight reductions >0%, ≥5% and ≥10% with canagliflozin treatment than with placebo. Weight-loss-independent and weight-loss-associated mechanisms contributed to HbA1c and SBP lowering with canagliflozin: ~85% of HbA1c lowering and ~60% of SBP lowering was independent of weight loss. In patients with type 2 diabetes, canagliflozin provided clinically meaningful body-weight reductions, and the weight loss contributed to reductions in HbA1c and SBP. Trial registration: ClinicalTrials.gov NCT01081834; NCT01106625; NCT01106677; and NCT01106690
DOI: 10.3390/nu7064107
2015
Cited 118 times
Blueberries Improve Endothelial Function, but Not Blood Pressure, in Adults with Metabolic Syndrome: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial
Blueberry consumption has been shown to have various health benefits in humans. However, little is known about the effect of blueberry consumption on blood pressure, endothelial function and insulin sensitivity in humans. The present study investigated the role of blueberry consumption on modifying blood pressure in subjects with metabolic syndrome. In addition, endothelial function and insulin sensitivity (secondary measurements) were also assessed. A double-blind and placebo-controlled study was conducted in 44 adults (blueberry, n = 23; and placebo, n = 21). They were randomized to receive a blueberry or placebo smoothie twice daily for six weeks. Twenty-four-hour ambulatory blood pressure, endothelial function and insulin sensitivity were assessed pre- and post-intervention. The blood pressure and insulin sensitivity did not differ between the blueberry and placebo groups. However, the mean change in resting endothelial function, expressed as reactive hyperemia index (RHI), was improved significantly more in the group consuming the blueberries versus the placebo group (p = 0.024). Even after adjusting for confounding factors, i.e., the percent body fat and gender, the blueberry group still had a greater improvement in endothelial function when compared to their counterpart (RHI; 0.32 ± 0.13 versus -0.33 ± 0.14; p = 0.0023). In conclusion, daily dietary consumption of blueberries did not improve blood pressure, but improved (i.e., increased) endothelial function over six weeks in subjects with metabolic syndrome.
DOI: 10.2337/dc16-0873
2016
Cited 113 times
Update and Next Steps for Real-World Translation of Interventions for Type 2 Diabetes Prevention: Reflections From a Diabetes Care Editors’ Expert Forum
The International Diabetes Federation estimates that 415 million adults worldwide now have diabetes and 318 million have impaired glucose tolerance. These numbers are expected to increase to 642 million and 482 million, respectively, by 2040. This burgeoning pandemic places an enormous burden on countries worldwide, particularly resource-poor regions. Numerous landmark trials evaluating both intensive lifestyle modification and pharmacological interventions have persuasively demonstrated that type 2 diabetes can be prevented or its onset can be delayed in high-risk individuals with impaired glucose tolerance. However, key challenges remain, including how to scale up such approaches for widespread translation and implementation, how to select appropriately from various interventions and tailor them for different populations and settings, and how to ensure that preventive interventions yield clinically meaningful, cost-effective outcomes. In June 2015, a Diabetes Care Editors' Expert Forum convened to discuss these issues. This article, an outgrowth of the forum, begins with a summary of seminal prevention trials, followed by a discussion of considerations for selecting appropriate populations for intervention and the clinical implications of the various diagnostic criteria for prediabetes. The authors outline knowledge gaps in need of elucidation and explore a possible new avenue for securing regulatory approval of a prevention-related indication for metformin, as well as specific considerations for future pharmacological interventions to delay the onset of type 2 diabetes. They conclude with descriptions of some innovative, pragmatic translational initiatives already under way around the world.
DOI: 10.1001/jama.2012.185445
2013
Cited 110 times
Does Body Mass Index Adequately Convey a Patient's Mortality Risk?
Our website uses cookies to enhance your experience. By continuing to use our site, or clicking "Continue," you are agreeing to our Cookie Policy | Continue JAMA HomeNew OnlineCurrent IssueFor Authors Publications JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry (1919-1959) Podcasts Clinical Reviews Editors' Summary Medical News Author Interviews More JN Learning / CMESubscribeJobsInstitutions / LibrariansReprints & Permissions Terms of Use | Privacy Policy | Accessibility Statement 2023 American Medical Association. All Rights Reserved Search All JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Forum Archive JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry Input Search Term Sign In Individual Sign In Sign inCreate an Account Access through your institution Sign In Purchase Options: Buy this article Rent this article Subscribe to the JAMA journal
DOI: 10.1172/jci81860
2015
Cited 94 times
Adipocyte iron regulates leptin and food intake
Dietary iron supplementation is associated with increased appetite. Here, we investigated the effect of iron on the hormone leptin, which regulates food intake and energy homeostasis. Serum ferritin was negatively associated with serum leptin in a cohort of patients with metabolic syndrome. Moreover, the same inverse correlation was observed in mice fed a high-iron diet. Adipocyte-specific loss of the iron exporter ferroportin resulted in iron loading and decreased leptin, while decreased levels of hepcidin in a murine hereditary hemochromatosis (HH) model increased adipocyte ferroportin expression, decreased adipocyte iron, and increased leptin. Treatment of 3T3-L1 adipocytes with iron decreased leptin mRNA in a dose-dependent manner. We found that iron negatively regulates leptin transcription via cAMP-responsive element binding protein activation (CREB activation) and identified 2 potential CREB-binding sites in the mouse leptin promoter region. Mutation of both sites completely blocked the effect of iron on promoter activity. ChIP analysis revealed that binding of phosphorylated CREB is enriched at these two sites in iron-treated 3T3-L1 adipocytes compared with untreated cells. Consistent with the changes in leptin, dietary iron content was also directly related to food intake, independently of weight. These findings indicate that levels of dietary iron play an important role in regulation of appetite and metabolism through CREB-dependent modulation of leptin expression.
DOI: 10.2337/dc16-0824
2016
Cited 78 times
The Artificial Pancreas in 2016: A Digital Treatment Ecosystem for Diabetes
With the increasing availability of continuous glucose monitoring (CGM) and continuous subcutaneous insulin infusion (CSII), the artificial pancreas (AP) (the commonly accepted term for closed-loop control [CLC] of blood glucose [BG] levels in diabetes) has become a hot area in translational research and industrial development. After a prolonged period of inpatient, clinical research center trials using cumbersome systems, the field has progressed rapidly over the past 2 years to long-term, free-living studies running AP algorithms on smartphones. Although it is still not a cure, the AP is the most promising advance in the treatment of diabetes at this time. This issue of Diabetes Care presents today’s AP state of the art, including reports on multinational home-use AP trials, studies in young children, the use of multihormonal approaches to mitigate meal-related hyperglycemia, and discussions of AP study designs and outcome measures. This collection of articles establishes the AP as a new diabetes treatment paradigm—not a single-function CGM or CSII device but an adaptable wearable network encompassing the patient in a digital treatment ecosystem. In its May 2014 issue, Diabetes Care featured the progress in the AP field in a series of articles labeled “Advances in Artificial Pancreas Development.” In addition to an editorial discussing the state of the art of AP development in 2014 (1), the issue included original articles that covered a broad range of topics including analyses of the possible physiological inputs to CLC (2), real-time estimation of insulin sensitivity from CGM and insulin pump data (3), engineering of the AP algorithms (4), reports of predictive low-glucose suspend (LGS) systems (5), studies of overnight CLC at home (6), feasibility of the AP in type 2 diabetes (7), and the first around-the-clock outpatient CLC running a model predictive control (MPC) algorithm on a portable AP system (8). Since then, …
DOI: 10.2337/dcs15-3007
2016
Cited 77 times
Clinical Considerations for Use of Initial Combination Therapy in Type 2 Diabetes
Type 2 diabetes is a progressive disorder characterized by increasing hyperglycemia and the need to gradually intensify therapy in order to achieve and maintain glycemic control. Early initiation of combination therapy has been proposed as an approach to achieve glycemic goals earlier and delay the deterioration of glycemic control and with possible better preservation of β-cell function. We discuss in this article the pros and cons of this approach, focusing on individuals with HbA1c at diagnosis of 7.5-9.0%, where difference of opinion still exists on management. Initial combination therapy is proposed to lead to better and faster achievement of glycemic targets versus monotherapy and to impede clinical inertia and may possibly slow the deterioration of β-cell function. However, treating patients with sequential therapy is proposed to allow one to fully assess the efficacy and risk-to-benefit ratio of each drug as it is added. Furthermore, there is no evidence to support that rapid addition and titration of medications according to the glycemic profile achieved are inferior to initial combination therapy if glycemic targets are attained in a timely manner. Initial combination therapy is argued to postpone clinical inertia to the next decision point but does not eliminate it. Additionally, it may have been the agents chosen and not the timing of their initiation that led to improved β-cell function in the studies of initial combination therapy, and there are no data currently comparing use of the same drugs initiated simultaneously or sequentially. Heightened awareness of providers, individualization of therapy and setting, and reaching glycemic targets remain the mainstays of care.
DOI: 10.1007/s00125-021-05542-z
2021
Cited 43 times
Consensus report: definition and interpretation of remission in type 2 diabetes
Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks vs benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed 'remission' as the most appropriate descriptive term, and HbA1c <48 mmol/mol (6.5%) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.
DOI: 10.1016/s0026-0495(97)90016-0
1997
Cited 148 times
Dietary soy protein and estrogen replacement therapy improve cardiovascular risk factors and decrease aortic cholesteryl ester content in ovariectomized cynomolgus monkeys
Estrogen replacement therapy (ERT) decreases the progression of coronary artery atherosclerosis in monkeys. Dietary soy protein also retards the progression of atherosclerosis relative to animal proteins such as casein. Soy protein contains weakly estrogenic compounds called isoflavones or phytoestrogens that may be responsible for the cardioprotective effects. This study was designed as a 2 x 2 factorial to determine the magnitude of soy protein's effects on cardiovascular risk factors relative to casein and lactalbumin, with or without estradiol treatment. Ovariectomized female monkeys were randomized to four treatment groups based on past dietary cholesterol consumption, their origin, and past reproductive history, and studied for 7 months. The animals were divided into (1) a group fed casein and lactalbumin as the protein source (n = 14), (2) a group fed casein and lactalbumin as the protein source plus 17 beta-estradiol (E2) (n = 13), (3) a group fed soybean protein isolate as the protein source (n = 11), and (4) a group fed soybean protein isolate as the protein source plus E2 (n = 10). Soy protein compared with casein consumption resulted in a significant improvement in plasma lipid and lipoprotein concentrations, a significant improvement in insulin sensitivity and glucose effectiveness as determined by minimal-model analyses, and a decrease in arterial lipid peroxidation. E2-treated monkeys had a significant reduction in fasting insulin levels and insulin to glucose ratios, total body weight, and amounts of abdominal fat, and had smaller low-density lipoprotein (LDL) particles. In addition, E2 treatment resulted in a significant reduction (P = .001) in aortic cholesteryl ester content. A similar trend (P = .14) was found for soy protein compared with casein. There also was a significant interaction (P = .02) with soy and E2, such that animals consuming soy protein +E2 had the least arterial cholesteryl ester content. These results suggest that both ERT and dietary soybean protein have beneficial effects on cardiovascular risk factors. Interestingly, the two treatments affected different risk factors and together resulted in the greatest reduction in arterial cholesterol content. Further studies are needed to determine the active component of the soy protein and to assess its long-term effects on the cardiovascular system and other organ systems (such as the bones and reproductive system).
DOI: 10.1053/ajkd.2002.30549
2002
Cited 138 times
Long-term glycemic control measurements in diabetic patients receiving hemodialysis
Cardiovascular morbidity is increased in patients with diabetes mellitus and there is a great prevalence of diabetes and cardiovascular disease among patients with end-stage renal disease (ESRD). Control of glycemia can decrease cardiovascular and end-organ damage. Because the validity of glycemic control tests have not been rigorously studied in patients with ESRD, we evaluated the value of various measures in these patients. The overall clinical goal was to investigate whether hemoglobin A1C (A1C) accurately reflects actual glycemic control as compared with other measures in light of the importance of attaining appropriately controlled blood glucose (BG). The commonly used tests of total glycated hemoglobin (GHb) and A1C may be unreliable in patients with ESRD because of the presence of anemia, shortened red blood cell (RBC) survival, and assay interferences from uremia. The primary aim of this study was to assess the relationship of capillary BG measurements to A1C, GHb, total glycated plasma proteins (GPP), and fructosamine (Fr) in diabetic patients receiving hemodialysis. Twenty-three patients were instructed to obtain BG evaluations twice daily for 7 days by using the Elite glucometer (Bayer Corporation, Elkhart, IN). These determinations included 6 fasting, 6 preprandial, and 3 separate 2-hour postprandial levels. Blood was obtained on day 7 for measurement of A1C, GHb, GPP, and Fr. A1C was analyzed by an immunoassay, GPP and GHb were assayed by affinity high-performance liquid chromatography (HPLC), and Fr by automated nitroblue colorimetric assay. Scatter plots were generated by plotting the average BG versus A1C, GHb, GPP, or Fr. Linear regression was performed for each plot showing the following relationships: A1C = 0.0174 (BG) + 4.76 (r = 0.58; P < 0.05): GHb = 0.0371 (BG) + 3.57 (r = 0.584; P < 0.05): GPP = 0.0083 (BG) + 26.13 (r = 0.065; P = 0.77): Fr = 0.6865 (BG) + 250 (r = 0.345; P = 0.11). Despite anemia and shortened RBC lifespan in patients with ESRD, A1C in the range of 6% to 7% estimates glycemic control similarly to patients without severe renal impairment. A1C values above 7.5% may overestimate hyperglycemia in patients with ESRD. Thus, diabetic patients receiving hemodialysis may have long-term BG that are more properly controlled than previously determined, reducing their risks of the macro- and microvascular complications of diabetes mellitus.
DOI: 10.1093/jn/136.2.415
2006
Cited 133 times
Chromium Picolinate Enhances Skeletal Muscle Cellular Insulin Signaling In Vivo in Obese, Insulin-Resistant JCR:LA-cp Rats
Chromium is one of the few trace minerals for which a specific cellular mechanism of action has not been identified. Recent in vitro studies suggest that chromium supplementation may improve insulin sensitivity by enhancing insulin receptor signaling, but this has not been demonstrated in vivo. We investigated the effect of chromium supplementation on insulin receptor signaling in an insulin-resistant rat model, the JCR:LA-corpulent rat. Male JCR:LA-cp rats (4 mo of age) were randomly assigned to receive chromium picolinate (CrPic) (obese n=6, lean n=5) or vehicle (obese n=5, lean n=5) for 3 mo. The CrPic was provided in the water, and based on calculated water intake, rats randomized to CrPic received 80 microg/(kg.d). At the end of the study, skeletal muscle (vastus lateralis) biopsies were obtained at baseline and at 5, 15, and 30 min postinsulin stimulation to assess insulin signaling. Obese rats treated with CrPic had significantly improved glucose disposal rates and demonstrated a significant increase in insulin-stimulated phosphorylation of insulin receptor substrate (IRS)-1 and phosphatidylinositol (PI)-3 kinase activity in skeletal muscle compared with obese controls. The increase in cellular signaling was not associated with increased protein levels of the IRS proteins, PI-3 kinase or Akt. However, protein tyrosine phosphatase 1B (PTP1B) levels were significantly lower in obese rats administered CrPic than obese controls. When corrected for protein content, PTP1B activity was also significantly lower in obese rats administered CrPic than obese controls. Our data suggest that chromium supplementation of obese, insulin-resistant rats may improve insulin action by enhancing intracellular signaling.
DOI: 10.1093/aje/142.7.724
1995
Cited 127 times
A BREIF ORIGINAL CONTRIBUTION
Both abnormal insulin levels and low insulin sensitivity have been implicated as risk factors for Type II diabetes mellitus and cardiovascular disease. While insulin level is relatively simple to assess, direct measurement of insulin sensitivity is much more invasive, costly, and time-consuming. The authors considered eight previously described measures or indices of indices of insulin sensitivity derived from the frequently sampled intravenous glucose tolerance test (FSIGT). Each one was evaluated by strength and consistency of association with insulin sensitivity computed from glucose clamp (SI(clamp)), across three glucose tolerance groups, including participants with normal glucose tolerance (n = 11), impaired glucose tolerance (n = 20), and non-insulin-dependent diabetes mellitus (n = 24). Minimal model analysis (MINMOD SI(22)), based on the 22-sample FSIGT, performed best based on statistical criteria of strong and consistent association with SI(clamp). An insulin sensitivity measure similar to that of Galvin et al. (Diabetic Medicine 1990;9:921-8), defined as glucose disappearance (10-50 minutes) divided by insulin area under the curve above baseline from 0-50 minutes, performed best based on statistical criteria and time-savings. Galvin insulin sensitivity is simple to calculate, requires only a 50-minute FSIGT, and is significantly (p < 0.001) and not inconsistently (p = 0.12 for inconsistent association) associated with SI(clamp) over a wide range of glucose tolerance.
DOI: 10.2337/diacare.28.8.1922
2005
Cited 125 times
Efficacy of Inhaled Insulin in Patients With Type 2 Diabetes not Controlled With Diet and Exercise
Effective type 2 diabetes management requires prompt intervention if glycemic control is not achieved by nonpharmacological means. This study investigates whether inhaled insulin (INH; Exubera) can achieve target glycemic control in patients failing on diet and exercise.Patients with suboptimal control on diet and exercise (HbA(1c) [A1C] 8-11%) were randomized to 3 months' treatment with either INH before meals (n = 76) or rosiglitazone 4 mg twice a day (n = 69), in conjunction with a diet and exercise regimen. The primary end point was percentage of patients achieving A1C <8.0%.The INH and rosiglitazone groups had comparable baseline A1C values (9.5 vs. 9.4%, respectively). Significantly more patients achieved A1C <8.0% (83 vs. 58%, adjusted odds ratio 7.14 [95% CI 2.48-20.58], P = 0.0003), A1C <7.0% (44 vs. 18%, 4.43 [1.94-10.12]), and A1C < or = 6.5% (28 vs. 7.5% 5.34 [1.83-15.57]) with INH. A1C decrease was greater with INH (-2.3% vs. -1.4%, adjusted treatment group difference: -0.89% [95% CI -1.23 to -0.55]) with final mean A1C values of 7.2 and 8.0% for INH and rosiglitazone, respectively. Hypoglycemia (episodes per subject-month) was higher with INH (0.7 vs. 0.05, risk ratio 14.72 [95% CI 7.51-28.83]), with no severe hypoglycemic episodes. Pulmonary function changes were small and comparable between groups.INH could be an effective therapy for people with type 2 diabetes early in the course of their disease.
DOI: 10.1093/gerona/50a.6.b337
1995
Cited 117 times
Caloric Restriction Decreases Age-Dependent Accumulation of the Glycoxidation Products, Nisin-(Carboxymethyl)lysine and Pentosidine, in Rat Skin Collagen
Nonenzymatic glycation of body proteins and subsequent advanced glycation reactions have been implicated in the aging process, while caloric restriction (CR) in rodents results in an increase in both mean and maximum life span. We have evaluated the effect of chronic (25 months) CR on glycation of blood proteins and accumulation of advanced glycation and oxidation (glycoxidation) products, N epsilon-(carboxymethyl)lysine (CML), and pentosidine, in skin collagen. Brown-Norway rats, fed ad libitum (AL) from birth, were divided into two equal groups at 4 months of age and placed on AL or CR diets (CR = 60% of AL diet). Cohorts of animals were sacrificed at 7, 13, and 25 months after the initiation of CR. At necropsy glycated hemoglobin was measured by affinity HPLC and glycated plasma protein by the fructosamine assay; extracts of skin collagen were analyzed by gas chromatography-mass spectrometry for CML and by reversed-phase HPLC for pentosidine. Glycation of hemoglobin, plasma proteins, and skin collagen was decreased significantly (18-33%) by CR. Concentrations of CML and pentosidine increased significantly with age in skin collagen in both AL and CR animals; however, CR significantly reduced levels of CML (25%), pentosidine (50%), and fluorescence (15%) in collagen in the oldest rats. We conclude that CR reduces the extent of glycation of blood and tissue proteins and the age-related accumulation of glycoxidation products in skin collagen.
DOI: 10.1007/s11892-010-0097-3
2010
Cited 106 times
Current Concepts About Chromium Supplementation in Type 2 Diabetes and Insulin Resistance
DOI: 10.2337/diacare.28.5.1113
2005
Cited 105 times
Elevated Pregnancy Losses at High and Low Extremes of Maternal Glucose in Early Normal and Diabetic Pregnancy
Early pregnancy losses increase with marked hyperglycemia in diabetic pregnancy. However, mean loss rates do not differ from those of nondiabetic pregnancy. This observation might be explained by increased fetal losses at the extremes of glycemia in diabetic and nondiabetic pregnancy. To test this hypothesis, we examined relationships of proximate measures of prior glycemia, glycated protein and fructosamine, to pregnancy loss.A total of 389 diabetic and 429 nondiabetic pregnant subjects participated in the Diabetes In Early Pregnancy study. Glycated protein and fructosamine measurements were standardized as multiples of control values for each center (Z score). The logarithm of odds of pregnancy loss were plotted against Z scores and tested by logistic models.Mean pregnancy loss rates were 12% in diabetic and 13% in normal pregnancies. However, over six intervals of glycated protein in diabetic pregnancy, fetal loss rates at the upper and lower extremes (24 and 33%, respectively) were approximately threefold higher than the four intervening rates (8-14%). The odds ratio of pregnancy loss for these extreme intervals to the intervening intervals is 3.0 (P = 0.01). Nondiabetic losses showed a similar pattern. In confirmation, logit pregnancy losses were increased in a J-shaped curve at the glycemic extremes in normal (P < 0.019) and diabetic (P < 0.015) pregnancy. The upper glycemic extreme in diabetic pregnancy was two- to fivefold higher than in control pregnancy.Pregnancy losses are increased at the extremes of glycemia in both normal and diabetic pregnancy but at higher levels in diabetic pregnancy. The data suggest defensive adaptations against hyperglycemia in diabetic pregnancy.
DOI: 10.1016/j.metabol.2009.09.023
2010
Cited 103 times
Characterization of the metabolic and physiologic response to chromium supplementation in subjects with type 2 diabetes mellitus
The objective of the study was to provide a comprehensive evaluation of chromium (Cr) supplementation on metabolic parameters in a cohort of type 2 diabetes mellitus subjects representing a wide phenotype range and to evaluate changes in “responders” and “nonresponders.” After preintervention testing to assess glycemia, insulin sensitivity (assessed by euglycemic clamps), Cr status, and body composition, subjects were randomized in a double-blind fashion to placebo or 1000 μg Cr. A substudy was performed to evaluate 24-hour energy balance/substrate oxidation and myocellular/intrahepatic lipid content. There was not a consistent effect of Cr supplementation to improve insulin action across all phenotypes. Insulin sensitivity was negatively correlated to soleus and tibialis muscle intramyocellular lipids and intrahepatic lipid content. Myocellular lipids were significantly lower in subjects randomized to Cr. At preintervention, responders, defined as insulin sensitivity change from baseline of at least 10% or greater, had significantly lower insulin sensitivity and higher fasting glucose and A1c when compared with placebo and nonresponders, that is, insulin sensitivity change from baseline of less than 10%. Clinical response was significantly correlated (P < .001) to the baseline insulin sensitivity, fasting glucose, and A1c. There was no difference in Cr status between responder and nonresponders. Clinical response to Cr is more likely in insulin-resistant subjects who have more elevated fasting glucose and A1c levels. Chromium may reduce myocellular lipids and enhance insulin sensitivity in subjects with type 2 diabetes mellitus who do respond clinically independent of effects on weight or hepatic glucose production. Thus, modulation of lipid metabolism by Cr in peripheral tissues may represent a novel mechanism of action.
DOI: 10.1210/en.2006-0672
2007
Cited 101 times
Increased Hypothalamic Protein Tyrosine Phosphatase 1B Contributes to Leptin Resistance with Age
Animals at advanced ages exhibit a reduction in central leptin sensitivity. However, changes in growth, metabolism, and obesity risk occur much earlier in life, particularly during the transition from youth to middle age. To determine when initial decreases in central leptin sensitivity occur, leptin-dependent suppression of food intake was tested in 8-, 12-, and 20-wk-old male, chow-fed Sprague Dawley rats. Intracerebroventricular leptin injection (3 microg) suppressed 24-h food intake in 8- and 12-wk-old rats (P < 0.05) but not 20-wk-old rats. To identify potential cellular mediators of this resistance, we focused on protein tyrosine phosphatase 1B (PTP1B), a recently described inhibitor of leptin signaling. PTP1B protein levels, as determined by Western blot, were significantly higher in mediobasal hypothalamic punches collected from 20-wk-old rats, compared with 8-wk-old rats (P < 0.05). When 20-wk-old rats were fasted for 24 h, levels of hypothalamic PTP1B decreased (P < 0.05), coincident with a restoration of leptin sensitivity. To directly test whether inhibition of PTP1B restores leptin sensitivity, 20-wk-old chow-fed rats were pretreated with a pharmacological PTP1B inhibitor 1 h before leptin, and 24-h food intake was recorded. As expected, leptin alone produced a small but nonsignificant reduction in food intake. However, pretreatment with the PTP1B inhibitor resulted in a marked improvement in leptin-dependent suppression of food intake (P < 0.05). These data are consistent with the hypothesis that increases in PTP1B contribute to hypothalamic leptin resistance as rats transition into middle age.
DOI: 10.1111/j.1471-4159.1985.tb10557.x
1985
Cited 99 times
Restrictive Transport of a Lipid‐Soluble Peptide (Cyclosporin) Through the Blood–Brain Barrier
Abstract: The blood–brain barrier (BBB) transport of a highly lipid‐soluble peptide, [ 3 H]cyclosporin, was studied in ketamine‐anesthetized rats using the carotid artery injection technique. For comparison, peptide transport into rat liver was also assessed with the portal vein injection technique. Despite the high lipid solubility of this peptide (1‐octanol/Ringer's partition coefficient = 991 ± 55), the extraction by rat brain was only 2.9 ± 0.5% in the presence of 80% human serum, and this value approximated the extraction for a poorly diffusible substance such as [ 3 H]inulin, 2.0 ± 0.1%. In contrast, the hepatic extraction of [ 3 H]cyclosporin was high, 84 ± 2%, in the presence of 80% human serum. The BBB transport of cyclosporin is markedly restricted owing to the combined effects of binding by serum proteins and a paradoxically low permeability of the BBB to the peptide.
DOI: 10.1016/j.cmet.2010.04.004
2010
Cited 86 times
Regulation of Skeletal Muscle Oxidative Capacity and Insulin Signaling by the Mitochondrial Rhomboid Protease PARL
Type 2 diabetes mellitus (T2DM) and aging are characterized by insulin resistance and impaired mitochondrial energetics. In lower organisms, remodeling by the protease pcp1 (PARL ortholog) maintains the function and lifecycle of mitochondria. We examined whether variation in PARL protein content is associated with mitochondrial abnormalities and insulin resistance. PARL mRNA and mitochondrial mass were both reduced in elderly subjects and in subjects with T2DM. Muscle knockdown of PARL in mice resulted in malformed mitochondrial cristae, lower mitochondrial content, decreased PGC1alpha protein levels, and impaired insulin signaling. Suppression of PARL protein in healthy myotubes lowered mitochondrial mass and insulin-stimulated glycogen synthesis and increased reactive oxygen species production. We propose that lower PARL expression may contribute to the mitochondrial abnormalities seen in aging and T2DM.
DOI: 10.1152/ajpendo.90772.2008
2009
Cited 83 times
20-Hydroxyecdysone decreases weight and hyperglycemia in a diet-induced obesity mice model
The steroid hormone 20-hydroxyecdysone (20HE) is an essential signaling molecule that modulates molting response in insects and may function as a putative anabolic factor in vertebrate animals, although no mammalian 20HE receptor has been identified. Here we show that in H4IIE cell culture, 20HE treatment decreased expression of phospho enolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), reduced glucose production, and induced Akt2 phosphorylation sensitive to the phosphoinositide-3 kinase pathway-specific inhibitor LY-294002. Daily oral administration of 20HE (10 mg/kg for 13 wk) ameliorated obesity and insulin resistance in C57BL/6J mice fed a high-fat diet and produced a significant decrease of body weight gain and body fat mass compared with nontreated animals as demonstrated by dual-energy X-ray absorptiometry analysis. In addition, plasma insulin levels and glucose tolerance were significantly lowered by 20HE treatment. These changes were accompanied by the reduced hepatic expression of PEPCK and G6Pase and increased adiponectin production by visceral fat tissue. These studies demonstrate the anti-obesity and anti-diabetic effects of 20HE and begin to elucidate its putative cellular targets both in vitro and in vivo.
DOI: 10.1074/jbc.m110.203000
2011
Cited 80 times
Inactivation of the Mitochondrial Carrier SLC25A25 (ATP-Mg2+/Pi Transporter) Reduces Physical Endurance and Metabolic Efficiency in Mice
An ATP-Mg(2+/)P(i) inner mitochondrial membrane solute transporter (SLC25A25), which is induced during adaptation to cold stress in the skeletal muscle of mice with defective UCP1/brown adipose tissue thermogenesis, has been evaluated for its role in metabolic efficiency. SLC25A25 is thought to control ATP homeostasis by functioning as a Ca(2+)-regulated shuttle of ATP-Mg(2+) and P(i) across the inner mitochondrial membrane. Mice with an inactivated Slc25a25 gene have reduced metabolic efficiency as evidenced by enhanced resistance to diet-induced obesity and impaired exercise performance on a treadmill. Mouse embryo fibroblasts from Slc25a25(-/-) mice have reduced Ca(2+) flux across the endoplasmic reticulum, basal mitochondrial respiration, and ATP content. Although Slc25a25(-/-) mice are metabolically inefficient, the source of the inefficiency is not from a primary function in thermogenesis, because Slc25a25(-/-) mice maintain body temperature upon acute exposure to the cold (4 °C). Rather, the role of SLC25A25 in metabolic efficiency is most likely linked to muscle function as evidenced from the physical endurance test of mutant mice on a treadmill. Consequently, in the absence of SLC25A25 the efficiency of ATP production required for skeletal muscle function is diminished with secondary effects on adiposity. However, in the absence of UCP1-based thermogenesis, induction of Slc25a25 in mice with an intact gene may contribute to an alternative thermogenic pathway for the maintenance of body temperature during cold stress.
DOI: 10.1161/circulationaha.114.009098
2014
Cited 73 times
Body Mass Index and the Risk of All-Cause Mortality Among Patients With Type 2 Diabetes Mellitus
Several prospective studies have evaluated the association between body mass index (BMI) and death risk among patients with diabetes mellitus; however, the results have been inconsistent.We performed a prospective cohort study of 19 478 black and 15 354 white patients with type 2 diabetes mellitus. Cox proportional hazards regression models were used to estimate the association of different levels of BMI stratification with all-cause mortality. During a mean follow-up of 8.7 years, 4042 deaths were identified. The multivariable-adjusted (age, sex, smoking, income, and type of insurance) hazard ratios for all-cause mortality associated with BMI levels (18.5-22.9, 23-24.9, 25-29.9, 30-34.9 [reference group], 35-39.9, and ≥40 kg/m(2)) at baseline were 2.12 (95% confidence interval [CI], 1.80-2.49), 1.74 (95% CI, 1.46-2.07), 1.23 (95% CI, 1.08-1.41), 1.00, 1.19 (95% CI, 1.03-1.39), and 1.23 (95% CI, 1.05-1.43) for blacks and 1.70 (95% CI, 1.42-2.04), 1.51 (95% CI, 1.27-1.80), 1.07 (95% CI, 0.94-1.21), 1.00, 1.07 (95% CI, 0.93-1.23), and 1.20 (95% CI, 1.05-1.38) for whites, respectively. When stratified by age, smoking status, patient type, or the use of antidiabetic drugs, a U-shaped association was still present. When BMI was included in the Cox model as a time-dependent variable, the U-shaped association of BMI with all-cause mortality risk did not change.The present study indicated a U-shaped association of BMI with all-cause mortality risk among black and white patients with type 2 diabetes mellitus. A significantly increased risk of all-cause mortality was observed among blacks with BMI <30 kg/m(2) and ≥35 kg/m(2) and among whites with BMI <25 kg/m(2) and ≥40 kg/m(2) compared with patients with BMI of 30 to 34.9 kg/m(2).
DOI: 10.1007/s12263-014-0451-1
2014
Cited 68 times
In vivo effects of dietary quercetin and quercetin-rich red onion extract on skeletal muscle mitochondria, metabolism, and insulin sensitivity
Red onions and low doses of the flavonoid, quercetin, increase insulin sensitivity and improve glucose tolerance. We hypothesized that dietary supplementation with red onion extract (RO) would attenuate high fat diet (HFD)-induced obesity and insulin resistance similar to quercetin supplementation by increasing energy expenditure through a mechanism involving skeletal muscle mitochondrial adaptations. To test this hypothesis, C57BL/6J mice were randomized into four groups and fed either a low fat diet (LF), HFD (HF), HFD + quercetin (HF + Q), or HFD + RO (HF + RO) for 9 weeks. Food consumption and body weight and composition were measured weekly. Insulin sensitivity was assessed by insulin and glucose tolerance tests. Energy expenditure and physical activity were measured by indirect calorimetry. Skeletal muscle incomplete beta oxidation, mitochondrial number, and mtDNA-encoded gene expression were measured. Quercetin and RO supplementation decreased HFD-induced fat mass accumulation and insulin resistance (measured by insulin tolerance test) and increased energy expenditure; however, only HF + Q showed an increase in physical activity levels. Although quercetin and RO similarly increased skeletal muscle mitochondrial number and decreased incomplete beta oxidation, establishing mitochondrial function similar to that seen in LF, only HF + Q exhibited consistently lower mRNA levels of mtDNA-encoded genes necessary for complexes IV and V compared to LF. Quercetin- and RO-induced improvements in adiposity, insulin resistance, and energy expenditure occur through differential mechanisms, with quercetin—but not RO-induced energy expenditure being related to increases in physical activity. While both treatments improved skeletal muscle mitochondrial number and function, mtDNA-encoded transcript levels suggest that the antiobesogenic, insulin-sensitizing effects of purified quercetin aglycone, and RO may occur through differential mechanisms.
DOI: 10.2337/dc14-0890
2014
Cited 67 times
Greater Dose-Ranging Effects on A1C Levels Than on Glucosuria With LX4211, a Dual Inhibitor of SGLT1 and SGLT2, in Patients With Type 2 Diabetes on Metformin Monotherapy
OBJECTIVE To assess the dose-ranging efficacy and safety of LX4211, a dual inhibitor of sodium–glucose cotransporter (SGLT) 1 and SGLT2, in type 2 diabetes. RESEARCH DESIGN AND METHODS Type 2 diabetic patients inadequately controlled on metformin were randomly assigned to 75 mg once daily, 200 mg once daily, 200 mg twice daily, or 400 mg once daily of LX4211 or placebo. Primary end point was A1C change from baseline to week 12. Secondary end points included changes in blood pressure (BP) and body weight. RESULTS Baseline characteristics in 299 patients randomly assigned to LX4211 or placebo in this 12-week dose-ranging study were similar: mean age 55.9 years, A1C 8.1% (65 mmol/mol), BMI 33.1 kg/m2, and BP 124/79 mmHg. LX4211 significantly reduced A1C to week 12 in a dose-dependent manner by 0.42% (4.6 mmol/mol), 0.52% (5.7 mmol/mol), 0.80% (8.7 mmol/mol), and 0.92% (10.0 mmol/mol), respectively (P &amp;lt; 0.001 each), compared with 0.09% (1.0 mmol/mol) for placebo. Greater A1C reductions were produced by 400 mg once a day than 200 mg once a day LX4211 without higher urinary glucose excretion, suggesting a contribution of SGLT1 inhibition. Significant reductions were seen in body weight (−1.85 kg; P &amp;lt; 0.001) and systolic BP (−5.7 mmHg; P &amp;lt; 0.001), but diastolic BP was unchanged (−1.6; P = 0.164). Adverse events with LX4211 were mild to moderate and similar to placebo, including urinary tract infections and gastrointestinal-related events; genital infections were limited to LX4211 groups (0–5.0%). No hypoglycemia occurred. CONCLUSIONS Dual inhibition of SGLT1/SGLT2 with LX4211 produced significant dose-ranging improvements in glucose control without dose-increasing glucosuria and was associated with reductions in weight and systolic BP in metformin-treated patients with type 2 diabetes.
DOI: 10.2337/dc14-1395
2014
Cited 58 times
Beyond Metformin: Safety Considerations in the Decision-Making Process for Selecting a Second Medication for Type 2 Diabetes Management
The trend toward personalized management of diabetes has focused attention on the differences among available pharmacological agents in terms of mechanisms of action, efficacy, and, most important, safety. Clinicians must select from these features to develop individualized therapy regimens. In June 2013, a nine-member Diabetes Care Editors’ Expert Forum convened to review safety evidence for six major diabetes drug classes: insulin, sulfonylureas (SUs), thiazolidinediones (TZDs), glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, and sodium glucose cotransporter 2 inhibitors. This article, an outgrowth of the forum, summarizes well-delineated and theoretical safety concerns related to these drug classes, as well as the panelists’ opinions regarding their best use in patients with type 2 diabetes. All of the options appear to have reasonably wide safety margins when used appropriately. Those about which we know the most—metformin, SUs, insulin, and perhaps now also TZDs—are efficacious in most patients and can be placed into a basic initial algorithm. However, these agents leave some clinical needs unmet. Selecting next steps is a more formidable process involving newer agents that are understood less well and for which there are unresolved questions regarding risk versus benefit in certain populations. Choosing a specific agent is not as important as implementing some form of early intervention and advancing rapidly to some form of combination therapy as needed. When all options are relatively safe given the benefits they confer, therapeutic decision making must rely on a personalized approach, taking into account patients’ clinical circumstances, phenotype, pathophysiological defects, preferences, abilities, and costs.
DOI: 10.2337/dc16-0686
2016
Cited 54 times
Metabolic Surgery for Type 2 Diabetes: Changing the Landscape of Diabetes Care
The accelerating pandemic of diabetes is recognized as one of the greatest global public health threats of our time (1). When one reviews the latest estimates for diabetes prevalence and projections worldwide, it is easy to appreciate the magnitude of the problem facing us not only today but also for generations to come. Given the microvascular and macrovascular complications associated with this disease, as well as the resulting morbidity and mortality, the personal, medical, and societal costs are enormous (2,3). In addition, despite continuing advances in diabetes pharmacotherapy, fewer than half of adults with type 2 diabetes mellitus (T2D) attain therapeutic goals designed to reduce long-term risks of complications, especially for glycemic control (4–6), and lifestyle interventions are disappointing in the long term (7). In facing these challenges, it is imperative that interventions that may interdict the disease process and complement existing therapies be expeditiously advanced into clinical practice while also balancing the costs attributed to each intervention. This month’s issue of Diabetes Care includes 11 articles that report the latest data supporting bariatric/metabolic surgery as a new treatment option in the management of T2D. In the centerpiece of this collection, Rubino et al. (8) report new evidence-based guidelines for surgical treatment of T2D, writing on behalf of 48 voting delegates (75% are nonsurgeons) of the 2nd Diabetes Surgery Summit (DSS-II), an international consensus conference organized in collaboration with major diabetes organizations. These recommendations, endorsed thus far by 45 international professional societies [see Table 1, Rubino et al. (8)], reflect a large body of evidence demonstrating that several gastrointestinal (GI) operations initially designed to promote weight loss (bariatric surgery) can improve glucose homeostasis more effectively than any known pharmaceutical or behavioral approach (9–24), causing durable remission in many patients with T2D (25,26 …
DOI: 10.1152/japplphysiol.00455.2016
2018
Cited 52 times
Creatine (<i>methyl</i>-d<sub>3</sub>) dilution in urine for estimation of total body skeletal muscle mass: accuracy and variability vs. MRI and DXA
A noninvasive method to estimate muscle mass based on creatine ( methyl-d3) (D3-creatine) dilution using fasting morning urine was evaluated for accuracy and variability over a 3- to 4-mo period. Healthy older (67- to 80-yr-old) subjects ( n = 14) with muscle wasting secondary to aging and four patients with chronic disease (58-76 yr old) fasted overnight and then received an oral 30-mg dose of D3-creatine at 8 AM ( day 1). Urine was collected during 4 h of continued fasting and then at consecutive 4- to 8-h intervals through day 5. Assessment was repeated 3-4 mo later in 13 healthy subjects and 1 patient with congestive heart failure. Deuterated and unlabeled creatine and creatinine were measured using liquid chromatography-tandem mass spectrometry. Total body creatine pool size and muscle mass were calculated from D3-creatinine enrichment in urine. Muscle mass was also measured by whole body MRI and 24-h urine creatinine, and lean body mass (LBM) was measured by dual-energy X-ray absorptiometry (DXA). D3-creatinine urinary enrichment from day 5 provided muscle mass estimates that correlated with MRI for all subjects ( r = 0.88, P < 0.0001), with less bias [difference from MRI = -3.00 ± 2.75 (SD) kg] than total LBM assessment by DXA, which overestimated muscle mass vs. MRI (+22.5 ± 3.7 kg). However, intraindividual variability was high with the D3-creatine dilution method, with intrasubject SD for estimated muscle mass of 2.5 kg vs. MRI (0.5 kg) and DXA (0.8 kg). This study supports further clinical validation of the D3-creatine method for estimating muscle mass. NEW & NOTEWORTHY Measurement of creatine ( methyl-d3) (D3-creatine) and D3-creatinine excretion in fasted morning urine samples may be a simple, less costly alternative to MRI or dual-energy X-ray absorptiometry (DXA) to calculate total body muscle mass. The D3-creatine enrichment method provides estimates of muscle mass that correlate well with MRI, and with less bias than DXA. However, intraindividual variability is high with the D3-creatine method. Studies to refine the spot urine sample method for estimation of muscle mass may be warranted.
DOI: 10.1210/clinem/dgab585
2021
Cited 36 times
Consensus Report: Definition and Interpretation of Remission in Type 2 Diabetes
Improvement of glucose levels into the normal range can occur in some people living with diabetes, either spontaneously or after medical interventions, and in some cases can persist after withdrawal of glucose-lowering pharmacotherapy. Such sustained improvement may now be occurring more often due to newer forms of treatment. However, terminology for describing this process and objective measures for defining it are not well established, and the long-term risks versus benefits of its attainment are not well understood. To update prior discussions of this issue, an international expert group was convened by the American Diabetes Association to propose nomenclature and principles for data collection and analysis, with the goal of establishing a base of information to support future clinical guidance. This group proposed "remission" as the most appropriate descriptive term, and HbA1c < 6.5% (48 mmol/mol) measured at least 3 months after cessation of glucose-lowering pharmacotherapy as the usual diagnostic criterion. The group also made suggestions for active observation of individuals experiencing a remission and discussed further questions and unmet needs regarding predictors and outcomes of remission.
DOI: 10.1002/(sici)1520-670x(1999)12:2<71::aid-jtra4>3.0.co;2-8
1999
Cited 108 times
Effect of chromium picolinate on insulin sensitivity in vivo
The Journal of Trace Elements in Experimental MedicineVolume 12, Issue 2 p. 71-83 Effect of chromium picolinate on insulin sensitivity in vivo† William T. Cefalu, Corresponding Author William T. Cefalu Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaEndocrine Unit, University of Vermont College of Medicine, Given C331, Burlington, VT 05405Search for more papers by this authorAudrey D. Bell-Farrow, Audrey D. Bell-Farrow Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorJane Stegner, Jane Stegner Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorZhong Q. Wang, Zhong Q. Wang Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorTelle King, Telle King Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorTim Morgan, Tim Morgan Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorJames G. Terry, James G. Terry Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this author William T. Cefalu, Corresponding Author William T. Cefalu Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaEndocrine Unit, University of Vermont College of Medicine, Given C331, Burlington, VT 05405Search for more papers by this authorAudrey D. Bell-Farrow, Audrey D. Bell-Farrow Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorJane Stegner, Jane Stegner Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorZhong Q. Wang, Zhong Q. Wang Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorTelle King, Telle King Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorTim Morgan, Tim Morgan Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this authorJames G. Terry, James G. Terry Department of Medicine and Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North CarolinaSearch for more papers by this author First published: 05 May 1999 https://doi.org/10.1002/(SICI)1520-670X(1999)12:2<71::AID-JTRA4>3.0.CO;2-8Citations: 80 † This work was presented at the International Symposium on the Health Effects of Dietary Chromium, Tufts University School of Medicine, U.S. Department of Agriculture, and Chromium Information Bureau, Dedham, MA, 1 May 1998 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract This study assessed the effect of chromium (Cr) supplementation on insulin sensitivity and body composition in subjects at high risk for Type 2 diabetes because of family history and obesity. Twenty-nine subjects (14 men, 15 women) were evaluated in a double-blind, randomized, placebo-controlled trial using chromium picolinate (CrPic) (1,000 μg/day), or placebo for 8 months of study. Clinical and metabolic evaluations consisted of insulin sensitivity (SI) and glucose effectiveness (Sg); measurement of glucose tolerance and insulin response to an oral glucose tolerance test (75 g OGTT); and 24-hour glucose and insulin profiles. Anthropometric measures and magnetic resonance imaging (MRI) assessed abdominal fat distribution. Fasting plasma glucose and insulin levels and measures of glycemia (glycated hemoglobin and fructosamine) were also assessed. The CrPic group showed a significant increase in insulin sensitivity at midpoint (P < .05) and end of study (P < .005) compared with controls, which had no significant changes. No change in Sg was seen in either group. There was no effect of CrPic on body weight, abdominal fat distribution, or body mass index. However, CrPic significantly improved insulin sensitivity in these obese subjects with a family history of Type 2 diabetes. Improvement in insulin sensitivity without a change in body fat distribution suggests that Cr may alter insulin sensitivity independent of a change in weight or body fat percentage, thereby implying a direct effect on muscle insulin action. Definitive double-blinded, placebo-controlled trials are currently being conducted to confirm this observation in Type 2 diabetic subjects and evaluate the effects of Cr supplementation on insulin action and glycemic control. J. Trace Elem. Exp. Med. 12:71–83, 1999. © 1999 Wiley-Liss, Inc. Citing Literature Volume12, Issue2Special Issue: International Symposium on the Health Effects of Dietary Chromium1999Pages 71-83 RelatedInformation
DOI: 10.1016/s0149-2918(02)85131-1
2002
Cited 97 times
Treatment satisfaction in type 2 diabetes: A comparison between an inhaled insulin regimen and a subcutaneous insulin regimen
In patients with type 2 diabetes, published data suggest that glycemic control can be achieved as effectively with an inhaled insulin regimen (preprandial inhaled intrapulmonary insulin plus a single bedtime Ultralente injection) as with a conventional subcutaneous insulin regimen involving 2 to 3 injections per day. It is unknown whether inhalation delivery of insulin improves patient satisfaction.Our objective was to compare patient satisfaction between an inhaled insulin regimen and a subcutaneous insulin regimen.This was a 12-week randomized, open-label, parallel-group, controlled trial in patients with type 2 diabetes. They were randomized to receive either a subcutaneous insulin regimen (split/mixed insulin with 2 to 3 injections daily) or an inhaled insulin regimen (inhaled insulin before meals and a single Ultralente insulin injection at bedtime). Change in glycosylated hemoglobin (HbA1c) from baseline to week 12 was the study's primary end point. At baseline and week 12, patients completed a questionnaire (Patient Satisfaction with Insulin Therapy Questionnaire) covering attributes of patient satisfaction. Treatment regimens were compared on each item with the Wilcoxon rank sum test and on the overall score with a t test.Fifty-one patients (age range, 35-65 years) participated in the study, 26 receiving inhaled insulin and 25 receiving subcutaneous insulin. Forty-seven patients (22 inhaled insulin, 25 subcutaneous insulin) completed the satisfaction questionnaire. The mean percent improvement in overall satisfaction with an inhaled insulin regimen (31%; 95% CI, 14-50) was significantly greater (P < 0.05) than that with a subcutaneous insulin regimen (13%; 95% CI, 7-19). Increases in overall satisfaction correlated with improvements in glycemic control (r = 0.30; P < 0.05). Both treatment regimens experienced a mean HbA1c reduction of approximately 0.7%. Although patient satisfaction was the chief focus of this article, these results should be considered exploratory, as the trial was powered prospectively for HbA1c values (the primary end point) and not for patient satisfaction.Administration of an inhaled insulin regimen may offer the first practical, noninvasive alternative to insulin injections. In the patients with type 2 diabetes studied, an inhaled insulin regimen with the need for only 1 subcutaneous injection at bedtime appeared to offer more ease of use, comfort, and convenience, as well as greater overall satisfaction, than a subcutaneous insulin regimen of 2 to 3 injections daily.
DOI: 10.1093/clinchem/40.7.1317
1994
Cited 88 times
Glycohemoglobin measured by automated affinity HPLC correlates with both short-term and long-term antecedent glycemia
Abstract We evaluated glycohemoglobin (GHb) and glycated plasma protein (GPP) by automated affinity HPLC for their ability to monitor both short-term and long-term antecedent glycemia in 70 diabetic subjects. We placed 30 subjects on an intervention protocol in which insulin and (or) dietary changes were made twice weekly to acutely decrease glycemia. We monitored 40 subjects at 6-week intervals; changes in the clinical regimen were made at that time only. Despite weekly changes in mean blood glucose in the subjects who received more intensive intervention. GHb concentrations correlated significantly with the weekly (r = 0.66, P &amp;lt; 0.001), 2-week (r = 0.70, P &amp;lt; 0.001), 3-week (r = 0.72, P &amp;lt; 0.001), and 6-week (r = 0.83, P &amp;lt; 0.001) mean glucose concentrations. GPP correlated significantly with measured glycated albumin determined by boronate affinity columns (r = 0.83, P &amp;lt; .001) and correlated best with the 1-week (r = 0.66, P &amp;lt; 0.001), 2-week (r = 0.64, P &amp;lt; .001) and 3-week (r = 0.60, P &amp;lt; 0.001) mean antecedent glucose concentration. Thus, GHb, traditionally considered a marker for only long-term diabetic control, correlated significantly with both short-term and long-term antecedent glycemia.
DOI: 10.1016/j.metabol.2008.04.006
2008
Cited 83 times
Modulation of peroxisome proliferator–activated receptor γ stability and transcriptional activity in adipocytes by resveratrol
The peroxisome proliferator-activated receptor (PPAR) gamma is essential for the formation and function of adipocytes. It is also involved in regulating insulin sensitivity and is the functional target of the thiazolidinedione class of insulin-sensitizing drugs. Whereas thiazolidinediones activate PPARgamma and decrease PPARgamma protein levels, genetic models indicate that decreased expression of PPARgamma is also associated with increased insulin sensitivity. In this study, we show that resveratrol modulates PPARgamma protein levels in 3T3-L1 adipocytes via inhibition of PPARgamma gene expression coupled with increased ubiquitin-proteasome-dependent degradation of PPARgamma proteins. Resveratrol-mediated decreases in PPARgamma expression are associated with repression of PPARgamma transcriptional activity when assayed using a panel of PPARgamma target genes in adipocytes. Finally, we demonstrate that resveratrol inhibits insulin-dependent changes in glucose uptake and glycogen levels and decreases insulin receptor substrate 1 and glucose transporter 4 protein levels, indicating that resveratrol represses insulin sensitivity in adipocytes. These results indicate that the resveratrol-mediated effects in adipocytes involve regulation of PPARgamma expression and transcriptional activity along with decreased responsiveness to insulin.
DOI: 10.2337/db07-1313
2008
Cited 78 times
Human Adenovirus Type 36 Enhances Glucose Uptake in Diabetic and Nondiabetic Human Skeletal Muscle Cells Independent of Insulin Signaling
Human adenovirus type 36 (Ad-36) increases adiposity but improves insulin sensitivity in experimentally infected animals. We determined the ability of Ad-36 to increase glucose uptake by human primary skeletal muscle (HSKM) cells.The effect of Ad-36 on glucose uptake and cell signaling was determined in HSKM cells obtained from type 2 diabetic and healthy lean subjects. Ad-2, another human adenovirus, was used as a negative control. Gene expression and proteins of GLUT1 and GLUT4 were measured by real-time PCR and Western blotting. Role of insulin and Ras signaling pathways was determined in Ad-36-infected HSKM cells.Ad-36 and Ad-2 infections were confirmed by the presence of respective viral mRNA and protein expressions. In a dose-dependent manner, Ad-36 significantly increased glucose uptake in diabetic and nondiabetic HSKM cells. Ad-36 increased gene expression and protein abundance of GLUT1 and GLUT4, GLUT4 translocation to plasma membrane, and phosphatidylinositol 3-kinase (PI 3-kinase) activity in an insulin-independent manner. In fact, Ad-36 decreased insulin receptor substrate-1 (IRS-1) tyrosine phosphorylation and IRS-1-and IRS-2-associated PI 3-kinase activities. On the other hand, Ad-36 increased Ras gene expression and protein abundance, and Ras siRNA abrogated Ad-36-induced PI 3-kinase activation, GLUT4 protein abundance, and glucose uptake. These effects were not observed with Ad-2 infection.Ad-36 infection increases glucose uptake in HSKM cells via Ras-activated PI 3-kinase pathway in an insulin-independent manner. These findings may provide impetus to exploit the role of Ad-36 proteins as novel therapeutic targets for improving glucose handling.
DOI: 10.1152/ajpendo.00420.2007
2007
Cited 76 times
Polyphenolic compounds from<i>Artemisia dracunculus L.</i>inhibit PEPCK gene expression and gluconeogenesis in an H4IIE hepatoma cell line
An ethanolic extract of Russian tarragon, Artemisia dracunculus L., with antihyperglycemic activity in animal models was reported to decrease phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression in STZ-induced diabetic rats. A quantitative polymerase chain reaction (qPCR) assay was developed for the bioactivity-guided purification of the compounds within the extract that decrease PEPCK expression. The assay was based on the inhibition of dexamethasone-stimulated PEPCK upregulation in an H4IIE hepatoma cell line. Two polyphenolic compounds that inhibited PEPCK mRNA levels were isolated and identified as 6-demethoxycapillarisin and 2',4'-dihydroxy-4-methoxydihydrochalcone with IC(50) values of 43 and 61 muM, respectively. The phosphoinositide-3 kinase (PI3K) inhibitor LY-294002 showed that 6-demethoxycapillarisin exerts its effect through the activation of the PI3K pathway, similarly to insulin. The effect of 2',4'-dihydroxy-4-methoxydihydrochalcone is not regulated by PI3K and dependent on activation of AMPK pathway. These results indicate that the isolated compounds may be responsible for much of the glucose-lowering activity of the Artemisia dracunculus extract.
DOI: 10.2337/db07-1311
2008
Cited 74 times
Metabolically Favorable Remodeling of Human Adipose Tissue by Human Adenovirus Type 36
Experimental infection of rats with human adenovirus type 36 (Ad-36) promotes adipogenesis and improves insulin sensitivity in a manner reminiscent of the pharmacologic effect of thiozolinediones. To exploit the potential of the viral proteins as a therapeutic target for treating insulin resistance, this study investigated the ability of Ad-36 to induce metabolically favorable changes in human adipose tissue.We determined whether Ad-36 increases glucose uptake in human adipose tissue explants. Cell-signaling pathways targeted by Ad-36 to increase glucose uptake were determined in the explants and human adipose-derived stem cells. Ad-2, a nonadipogenic human adenovirus, was used as a negative control. As a proof of concept, nondiabetic and diabetic subjects were screened for the presence of Ad-36 antibodies to ascertain if natural Ad-36 infection predicted improved glycemic control.Ad-36 increased glucose uptake by adipose tissue explants obtained from nondiabetic and diabetic subjects. Without insulin stimulation, Ad-36 upregulated expressions of several proadipogenic genes, adiponectin, and fatty acid synthase and reduced the expression of inflammatory cytokine macrophage chemoattractant protein-1 in a phosphotidylinositol 3-kinase (PI3K)-dependent manner. In turn, the activation of PI3K by Ad-36 was independent of insulin receptor signaling but dependent on Ras signaling recruited by Ad-36. Ad-2 was nonadipogenic and did not increase glucose uptake. Natural Ad-36 infection in nondiabetic and diabetic subjects was associated with significantly lower fasting glucose levels and A1C, respectively.Ad-36 proteins may provide novel therapeutic targets that remodel human adipose tissue to a more metabolically favorable profile.
DOI: 10.1056/nejme0803831
2008
Cited 72 times
Glycemic Targets and Cardiovascular Disease
Cardiovascular disease in patients with diabetes is clearly associated with the degree of hyperglycemia, as measured clinically with the use of glycated hemoglobin.13 However, there remains an unanswered question in diabetes management: Does the targeting of near normal levels of glycated hemoglobin reduce the rate of cardiovascular events? Randomized clinical trials that address this question are ongoing.In this issue of the Journal, results are presented from two recently completed multicenter clinical trials, the ACCORD (Action to Control Cardiovascular Risk in Diabetes) trial (ClinicalTrials.gov number, NCT00000620)4 and the ADVANCE (Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified . . .
DOI: 10.1016/j.metabol.2007.07.004
2007
Cited 70 times
Effects of dietary fibers on weight gain, carbohydrate metabolism, and gastric ghrelin gene expression in mice fed a high-fat diet
Diets that are high in dietary fiber are reported to have substantial health benefits. We sought to compare the metabolic effects of 3 types of dietary fibers -- sugarcane fiber (SCF), psyllium (PSY), and cellulose (CEL) -- on body weight, carbohydrate metabolism, and stomach ghrelin gene expression in a high-fat diet-fed mouse model. Thirty-six male mice (C57BL/6) were randomly divided into 4 groups that consumed high-fat diet alone (HFD) or high-fat diet containing 10% SCF, PSY, and CEL, respectively. After baseline measurements were assessed for body weight, plasma insulin, glucose, leptin, and glucagon-like peptide 1 (GLP-1), animals were treated for 12 weeks. Parameters were reevaluated at the end of study. Whereas there was no difference at the baseline, body weight gains in the PSY and SCF groups were significantly lower than in the CEL group at the end of study. No difference in body weight was observed between the PSY and SCF animals. Body composition analysis demonstrated that fat mass in the SCF group was considerably lower than in the CEL and HFD groups. In addition, fasting plasma glucose and insulin and areas under the curve of intraperitoneal glucose tolerance test were also significantly lower in the SCF and PSY groups than in the CEL and HFD groups. Moreover, fasting plasma concentrations of leptin were significantly lower and GLP-1 level was 2-fold higher in the SCF and PSY mice than in the HFD and CEL mice. Ghrelin messenger RNA levels of stomach in the SCF group were significantly lower than in the CEL and HFD groups as well. These results suggest differences in response to dietary fiber intake in this animal model because high-fat diets incorporating dietary fibers such as SCF and PSY appeared to attenuate weight gain, enhance insulin sensitivity, and modulate leptin and GLP-1 secretion and gastric ghrelin gene expression.
DOI: 10.1021/jf071999d
2008
Cited 70 times
Phytochemical Composition and Metabolic Performance-Enhancing Activity of Dietary Berries Traditionally Used by Native North Americans
Four wild berry species, Amelanchier alnifolia, Viburnum trilobum, Prunus virginiana, and Shepherdia argentea, all integral to the traditional subsistence diet of Native American tribal communities, were evaluated to elucidate phytochemical composition and bioactive properties related to performance and human health. Biological activity was screened using a range of bioassays that assessed the potential for these little-known dietary berries to affect diabetic microvascular complications, hyperglycemia, pro-inflammatory gene expression, and metabolic syndrome symptoms. Nonpolar constituents from berries, including carotenoids, were potent inhibitors of aldose reductase (an enzyme involved in the etiology of diabetic microvascular complications), whereas the polar constituents, mainly phenolic acids, anthocyanins, and proanthocyanidins, were hypoglycemic agents and strong inhibitors of IL-1β and COX-2 gene expression. Berry samples also showed the ability to modulate lipid metabolism and energy expenditure in a manner consistent with improving metabolic syndrome. The results demonstrate that these berries traditionally consumed by tribal cultures contain a rich array of phytochemicals that have the capacity to promote health and protect against chronic diseases, such as diabetes.
DOI: 10.1016/j.jnutbio.2010.09.004
2011
Cited 68 times
Bioactives from bitter melon enhance insulin signaling and modulate acyl carnitine content in skeletal muscle in high-fat diet-fed mice
Bioactive components from bitter melon (BM) have been reported to improve glucose metabolism in vivo, but definitive studies on efficacy and mechanism of action are lacking. We sought to investigate the effects of BM bioactives on body weight, muscle lipid content and insulin signaling in mice fed a high-fat diet and on insulin signaling in L6 myotubes. Male C57BL/6J mice were randomly divided into low-fat diet control (LFD), high-fat diet (HFD) and HFD plus BM (BM) groups. Body weight, body composition, plasma glucose, leptin, insulin and muscle lipid profile were determined over 12 weeks. Insulin signaling was determined in the mouse muscle taken at end of study and in L6 myotubes exposed to the extract. Body weight, plasma glucose, insulin, leptin levels and HOMA-IR values were significantly lower in the BM-fed HFD group when compared to the HFD group. BM supplementation significantly increased IRS-2, IR β, PI 3K and GLUT4 protein abundance in skeletal muscle, as well as phosphorylation of IRS-1, Akt1 and Akt2 when compared with HFD (P<.05 and P<.01). BM also significantly reduced muscle lipid content in the HFD mice. BM extract greatly increased glucose uptake and enhanced insulin signaling in L6 myotubes. This study shows that BM bioactives reduced body weight, improved glucose metabolism and enhanced skeletal muscle insulin signaling. A contributing mechanism to the enhanced insulin signaling may be associated with the reduction in skeletal muscle lipid content. Nutritional supplementation with this extract, if validated for human studies, may offer an adjunctive therapy for diabetes.
DOI: 10.1016/j.ijpharm.2008.11.012
2009
Cited 66 times
Improved absorption and bioactivity of active compounds from an anti-diabetic extract of Artemisia dracunculus L☆
An ethanolic extract of Artemisia dracunculus L. (PMI-5011) was shown to be hypoglycemic in animal models for Type 2 diabetes and contains at least 6 bioactive compounds responsible for its anti-diabetic properties. To evaluate the bioavailability of the active compounds, high fat dietary induced obese C57BL/6J male mice were gavaged with PMI-5011 at 500 mg/kg body weight, after 4 h of food restriction. Blood plasma samples (200 uL) were obtained after ingestion, and the concentrations of the active compound in the blood sera were measured by electrospray LC-MS and determined to be maximal 4–6 h after gavage. Formulations of the extract with bioenhancers/solubilizers were evaluated in vivo for hypoglycemic activity and their effect on the abundance of active compounds in blood sera. At doses of 50–500 mg/kg/day, the hypoglycemic activity of the extract was enhanced 3–5-fold with the bioenhancer Labrasol, making it comparable to the activity of the anti-diabetic drug metformin. When combined with Labrasol, one of the active compounds, 2′, 4′-dihydroxy-4-methoxydihydrochalcone, was at least as effective as metformin at doses of 200–300 mg/kg/day. Therefore, bioenhancing agents like Labrasol can be used with multicomponent botanical therapeutics such as PMI-5011 to increase their efficacy and/or to reduce the effective dose.
DOI: 10.1016/j.metabol.2008.04.003
2008
Cited 66 times
Bioactives of Artemisia dracunculus L enhance cellular insulin signaling in primary human skeletal muscle culture
An alcoholic extract of Artemisia dracunculus L (PMI 5011) has been shown to decrease glucose and improve insulin levels in animal models, suggesting an ability to enhance insulin sensitivity. We sought to assess the cellular mechanism by which this botanical affects carbohydrate metabolism in primary human skeletal muscle culture. We measured basal and insulin-stimulated glucose uptake, glycogen accumulation, phosphoinositide 3 (PI-3) kinase activity, and Akt phosphorylation in primary skeletal muscle culture from subjects with type 2 diabetes mellitus incubated with or without various concentrations of PMI 5011. We also analyzed the abundance of insulin receptor signaling proteins, for example, IRS-1, IRS-2, and PI-3 kinase. Glucose uptake was significantly increased in the presence of increasing concentrations of PMI 5011. In addition, glycogen accumulation, observed to be decreased with increasing free fatty acid levels, was partially restored with PMI 5011. PMI 5011 treatment did not appear to significantly affect protein abundance for IRS-1, IRS-2, PI-3 kinase, Akt, insulin receptor, or Glut-4. However, PMI 5011 significantly decreased levels of a specific protein tyrosine phosphatase, that is, PTP1B. Time course studies confirmed that protein abundance of PTP1B decreases in the presence of PMI 5011. The cellular mechanism of action to explain the effects by which an alcoholic extract of A dracunculus L improves carbohydrate metabolism on a clinical level may be secondary to enhancing insulin receptor signaling and modulating levels of a specific protein tyrosine phosphatase, that is, PTP1B.
DOI: 10.1038/oby.2011.264
2012
Cited 61 times
Impaired Insulin Sensitivity and Elevated Ectopic Fat in Healthy Obese vs. Nonobese Prepubertal Children
Insulin sensitivity is impaired and ectopic fat (accretion of lipids outside of typical adipose tissue depots) increased in obese adults and adolescents. It is unknown how early in life this occurs; thus, it is important to evaluate young children to identify potential factors leading to the development of metabolic syndrome. We examined an ethnically diverse cohort of healthy, exclusively prepubertal children (N = 123; F = 57, M = 66; age 8.04 ± 0.77 years) to examine differences in insulin sensitivity and ectopic and visceral fat deposition between obese and nonobese youth. Obesity was categorized by age- and sex-adjusted BMI z-scores (nonobese = z-score <2 (N = 94) and obese = z-score ≥2 (N = 29)). Insulin sensitivity was assessed by both a frequently sampled intravenous glucose tolerance test (S(i)) and the homeostatic model assessment of insulin resistance (HOMA(IR)). Intramyocellular lipids (IMCLs) from soleus and intrahepatic lipids (IHLs) were assessed by magnetic resonance spectroscopy, visceral adipose tissue (VAT) by magnetic resonance imaging, and total body fat by dual-energy X-ray absorptiometry. We also examined serum lipids (total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol) and blood pressure (diastolic and systolic). Obese children exhibited significantly lower S(i) (5.9 ± 5.98 vs. 13.43 ± 8.18 (mµ/l)(-1)·min(-1), P = 0.01) and HDL-C and higher HOMA(IR) (1.68 ± 1.49 vs. 0.63 ± 0.47, P < 0.0001), IMCL (0.74 ± 0.39 vs. 0.44 ± 0.21% water peak, P < 0.0001), IHL (1.49 ± 1.13 vs. 0.54 ± 0.42% water peak, P < 0.0001), VAT (20.16 ± 8.01 vs. 10.62 ± 5.44 cm(2), P < 0.0001), total cholesterol, triglycerides, low-density lipoprotein cholesterol, and systolic blood pressure relative to nonobese children. These results confirm significantly increased ectopic fat and insulin resistance in healthy obese vs. nonobese children prior to puberty. Excessive adiposity during early development appears concomitant with precursors of type 2 diabetes and the metabolic syndrome.
DOI: 10.1016/j.metabol.2013.03.004
2013
Cited 50 times
Artemisia scoparia extract attenuates non-alcoholic fatty liver disease in diet-induced obesity mice by enhancing hepatic insulin and AMPK signaling independently of FGF21 pathway
Nonalcoholic fatty liver disease (NAFLD) is a common liver disease which has no standard treatment. In this regard, we sought to evaluate the effects of extracts of Artemisia santolinaefolia (SANT) and Artemisia scoparia (SCO) on hepatic lipid deposition and cellular signaling in a diet-induced obesity (DIO) animal model.DIO C57/B6J mice were randomly divided into three groups, i.e. HFD, SANT and SCO. Both extracts were incorporated into HFD at a concentration of 0.5% (w/w). Fasting plasma glucose, insulin, adiponectin, and FGF21 concentrations were measured.At the end of the 4-week intervention, liver tissues were collected for analysis of insulin, AMPK, and FGF21 signaling. SANT and SCO supplementation significantly increased plasma adiponectin levels when compared with the HFD mice (P<0.001). Fasting insulin levels were significantly lower in the SCO than HFD mice, but not in SANT group. Hepatic H&E staining showed fewer lipid droplets in the SCO group than in the other two groups. Cellular signaling data demonstrated that SCO significantly increased liver IRS-2 content, phosphorylation of IRS-1, IR β, Akt1 and Akt2, AMPK α1 and AMPK activity and significantly reduced PTP 1B abundance when compared with the HFD group. SCO also significantly decreased fatty acid synthase (FAS), HMG-CoA Reductase (HMGR), and Sterol regulatory element-binding protein 1c (SREBP1c), but not Carnitine palmitoyltransferase I (CPT-1) when compared with HFD group. Neither SANT nor SCO significantly altered plasma FGF21 concentrations and liver FGF21 signaling.This study suggests that SCO may attenuate liver lipid accumulation in DIO mice. Contributing mechanisms were postulated to include promotion of adiponectin expression, inhibition of hepatic lipogenesis, and/or enhanced insulin and AMPK signaling independent of FGF21 pathway.
DOI: 10.2337/dci18-0018
2018
Cited 45 times
A1C Targets Should Be Personalized to Maximize Benefits While Limiting Risks
A set of guidance statements recently published by the American College of Physicians (ACP) advocates relaxation of goals for control of glycated hemoglobin (A1C) by people with type 2 diabetes (T2D) (1). This publication advises that “clinicians should reevaluate HbA1c levels and revise treatment strategies on the basis of changes in the balance of benefits and harms.” Specifically, it proposes reducing pharmacotherapy for any person when A1C is <6.5%, seeking a level between 7 and 8% for “most patients,” and aiming only to minimize symptoms without any specific A1C goal for those over age 80 years or with chronic medical conditions likely to limit life expectancy. These recommendations are at odds with those of other professional organizations, including the American Diabetes Association (ADA) (2–5). We believe the ACP recommendations fail to consider several important bodies of scientific evidence, and if they are widely adopted in clinical practice, the recent progress in management of diabetes may be threatened. Each of the ACP’s recommendations requires specific comments. These will be followed by a more general discussion of our concerns. The ACP’s main justification for decreasing therapy whenever A1C is <6.5% is the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial’s finding of ∼20% increased mortality—mostly from cardiovascular (CV) events—when the median A1C attained by intensive treatment was 6.4% (6). However, this generalized advice does not acknowledge experience in other trials. In contrast to ACCORD, the Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) trial (7) and the Veterans Affairs Diabetes Trial (VADT) (8), which similarly enrolled high-risk patients and sought A1C levels <7%, did not show increased short-term CV risk or mortality. Importantly, the newly diagnosed, low-risk participants in the UK Prospective Diabetes Study (UKPDS) also showed no tendency toward increased early mortality …
DOI: 10.1016/j.nut.2014.03.009
2014
Cited 44 times
Artemisia dracunculus L. polyphenols complexed to soy protein show enhanced bioavailability and hypoglycemic activity in C57BL/6 mice
Scientifically validated food-based interventions are a practical means of addressing the epidemic of metabolic syndrome. An ethanolic extract of Artemisia dracunculus L. (PMI-5011) containing bioactive polyphenols, such as 2′, 4′–dihydroxy-4-methoxydihydrochalcone (DMC-2), improved insulin resistance in vitro and in vivo. Plant polyphenols are concentrated and stabilized when complexed to protein-rich matrices, such as soy protein isolate (SPI), which act as effective food-based delivery vehicles. The aim of this study was to compare the bioaccessibility, bioavailability, and efficacy of polyphenols extracted from A. dracunculus and delivered as PMI-5011 (ethanolic extract alone), formulated with the non-food excipient Gelucire®, (5011- Gelucire), or sorbed to SPI (5011-Nutrasorb®). PMI-5011, 5011-Gelucire or 5011-Nutrasorb each containing 162 μg of DMC-2 was delivered to the TNO intestinal model-1 of the human upper gastrointestinal tract to compare the effect of delivery vehicle on DMC-2 bioaccessibility. C57BL6/J mice were orally administered 5011-Nutrasorb or PMI-5011 to compare effects of polyphenol–protein complexation on acute hypoglycemic activity and bioavailability of DMC-2 in serum. At 500 mg/kg, 5011-Nutrasorb and PMI-5011 had similar hypoglycemic activity in a high-fat diet-induced diabetes mouse model despite the fact that 5011-Nutrasorb delivered 15 times less DMC-2 (40 versus 600 μg/kg). This can be partially explained by eight times greater DMC-2 absorption into serum from 5011-Nutrasorb than from PMI-5011. TNO intestinal model-1 experiments confirmed higher total bioaccessibility of DMC-2 in vitro when delivered in 5011-Nutrasorb (50.2%) or Gelucire-5011 (44.4%) compared with PMI-5011 (27.1%; P = 0.08). Complexation with soy protein makes antidiabetic A. dracunculus polyphenols more bioavailable and bioaccessible.
DOI: 10.2337/dc15-0187
2015
Cited 44 times
Clinical Assessment of Individualized Glycemic Goals in Patients With Type 2 Diabetes: Formulation of an Algorithm Based on a Survey Among Leading Worldwide Diabetologists
Observations over the past few years have demonstrated the need to adjust glycemic targets based on parameters pertaining to individual patient characteristics and comorbidities. However, the weight and value given to each parameter will clearly vary depending on the experience of the provider, the characteristics of the patient, and the specific clinical situation.To determine if there is current consensus on a global level with regard to identifying these parameters and their relative importance, we conducted a survey among 244 key worldwide opinion-leading diabetologists. Initially, the physicians were to rank the factors they take into consideration when setting their patients' glycemic target according to their relative importance. Subsequently, six clinical vignettes were presented, and the experts were requested to suggest an appropriate glycemic target. The survey results were used to formulate an algorithm according to which an estimate of the patient's glycemic target based on individualized parameters can be computed. Three additional clinical cases were submitted to a new set of experts for validation of the algorithm.A total of 151 (61.9%) experts responded to the survey. The parameters "life expectancy" and "risk of hypoglycemia from treatment" were considered to be the most important. "Resources" and "disease duration" ranked the lowest. An algorithm was constructed based on survey results. It was validated by presenting three new cases to 57 leading diabetologists who suggested glycemic targets that were similar to those calculated by the algorithm.The resultant suggested algorithm is an additional decision-making tool offered to the clinician to supplement clinical decision making when considering a glycemic target for the individual patient with diabetes.
DOI: 10.2337/dc14-3048
2015
Cited 42 times
SGLT2 Inhibitors: The Latest “New Kids on the Block”!
Everything in the world of diabetes is moving fast these days. Over the last few months, we have received extensive new information regarding the burden of diabetes and suggested changes in treatment strategies. Specifically, in the December 2014 issue of Diabetes Care , we reported startling new statistics about the rising costs associated with diabetes and prediabetes (1). The economic burden associated with diagnosed and undiagnosed diabetes, gestational diabetes mellitus, and prediabetes was estimated to be 48% higher than that reported in 2007. For 2012, the estimated total burden exceeded $322 billion, comprising $244 billion in excess medical costs and $78 billion in reduced productivity (1). Following the release of these economic statistics there came further proposals regarding strategies for managing diabetes. In the January 2015 issue of Diabetes Care , and coordinated with a release in Diabetologia , there was an update to the 2012 position statement of the American Diabetes Association (ADA) and the European Association for the Study of Diabetes (EASD) on the management of hyperglycemia (2). A prominent change with respect to treatment options since publication of the 2012 statement concerned the sodium–glucose cotransporter (SGLT) 2 inhibitors. Metformin remains the preferred drug for monotherapy, but based on a rapid accumulation of new information about SGLT2 inhibitors, this new class of agents is included as a reasonable choice for second-line or third-line therapy in the updated statement. Because Diabetes Care has recently received many submissions reporting new data and evolving clinical strategies for SGLT2 blockers, our editorial team has elected to feature this class of agents in this issue of Diabetes Care . The articles presented in this issue describe research related to novel combinations with a dipeptidyl peptidase-4 inhibitor or with insulin, favorable effects on blood pressure and weight as well as glycemic control, and …
DOI: 10.1093/gerona/52a.1.b10
1997
Cited 79 times
A Study of Caloric Restriction and Cardiovascular Aging in Cynomolgus Monkeys (Macacafascicularis): A Potential Model for Aging Research
Caloric restriction has been demonstrated to retard aging processes and extend maximal life span in rodents, and is currently being evaluated in several nonhuman primate trials. We initiated a study in 32 adult cynomolgus monkeys to evaluate the effect of caloric restriction on parameters contributing to atherosclerosis extent. Following pretrial determinations, at which time a baseline measure of ad libitum (ad lib) dietary intake was assessed, animals were randomized to an ad lib fed group (control) or a caloric restriction group (30% reduction from baseline intake). The animals are being evaluated for glycated proteins, insulin, glucose, insulin sensitivity measures, and specific measures of body fat composition by CT scans (e.g., intra-abdominal fat) over specified intervals. The results from the first year of observation demonstrate a significant diet effect on body weight, and specifically intra-abdominal fat. Further, insulin sensitivity has been significantly increased after 1 year of caloric restriction compared to the ad lib fed group. These studies indicate that caloric restriction has a marked effect on a pathologic fat depot, and this change is associated significantly with an improvement in peripheral tissue insulin sensitivity.
DOI: 10.1080/019262301301418955
2001
Cited 72 times
Naturally Occurring and Experimental Diabetes in Cynomolgus Monkeys: A Comparison of Carbohydrate and Lipid Metabolism and Islet Pathology
Diabetes is a major health problem of increasing incidence in the United States. Diabetes research has been limited by lack of availability of good animal models, particularly for the study of comorbidities associated with diabetes. We investigated the use of cynomolgus monkeys as an animal model of both type 1 and type 2 diabetes and compared these naturally occurring diseases with streptozotocin-induced diabetes. Both type 1 diabetics and streptozotocin-induced diabetics present with sudden onset of hyperglycemia and are ketosis prone without exogenous insulin. Type 2 diabetics can have a very long period of moderate hyperglycemia and hypertriglyceridemia and only require exogenous insulin therapy if pancreatic islet reserves are depleted. Type 2 diabetes is preceded by a relatively long period of insulin resistance that is associated with obesity and dyslipidemia. As insulin resistance progresses, islet size and insulin content increases initially. However, with sustained periods of insulin resistance, islet amyloid polypeptide (IAPP) is deposited in islets and can replace normal islet architecture, resulting in an insulin-deficient state. Appearance of IAPP also occurs in human type 2 diabetics but not in conventional rodent models. Unlike type 2 diabetes, neither type 1 nor streptozotocin-induced diabetes is associated with IAPP. Rather, islets can appear normal histologically, but have decreased insulin secretion and immunostaining. Further, the amount of insulin present in the islet is correlated with plasma insulin levels following glucose challenge. Studies are ongoing to determine the pathogenic changes associated with the progression of diabetes and to find novel drug treatments for diabetics.
DOI: 10.1016/j.metabol.2007.07.007
2007
Cited 64 times
Phenotype of subjects with type 2 diabetes mellitus may determine clinical response to chromium supplementation
Considerable controversy exists regarding the use of chromium (Cr) supplementation to modulate carbohydrate metabolism in subjects with diabetes. Recently, we reported that Cr supplementation, provided as 1000 microg/d as Cr picolinate, enhanced insulin sensitivity in subjects with type 2 diabetes mellitus. Our data agreed with some, but not all, studies that evaluated a similar dose and formulation in type 2 diabetes mellitus and suggested that subject selection and characteristics may be important considerations when assessing the clinical response. Thus, the goal of this study was to assess which metabolic or clinical characteristics, when obtained at baseline, best determine a clinical response to Cr when assessing changes in insulin sensitivity. Seventy-three subjects with type 2 diabetes mellitus were assessed in a double-blinded, randomized, placebo-controlled study. Subjects were assessed at baseline for glycemic control with glycated hemoglobin measures, oral glucose tolerance tests, and body weight and body fat measures (dual-energy x-ray absorptiometry). After baseline, insulin sensitivity in vivo was assessed with the use of hyperinsulinemic-euglycemic clamps. After the baseline clamp, subjects were randomized to receive Cr supplementation (1000 microg Cr/d provided as Cr picolinate) or placebo daily for 6 months. All study parameters were repeated after 6 months. The relationship of the baseline characteristics of the study subjects to the change in insulin sensitivity was determined. Sixty-three percent of the subjects with type 2 diabetes mellitus responded to the Cr treatment as compared with 30% with placebo. The only subject variable significantly associated with the clinical response to Cr was the baseline insulin sensitivity, as assessed with the hyperinsulinemic-euglycemic clamp (partial R(2) = .4038) (P = .0004). Subject phenotype appears to be very important when assessing the clinical response to Cr because baseline insulin sensitivity was found to account for nearly 40% of the variance in the clinical response to Cr.
DOI: 10.1210/jcem-62-4-761
1986
Cited 64 times
Enhanced Hepatic Extraction of Estrogens Used for Replacement Therapy*
Oral estrogen administration elicits greater effects on hepatic than on nonhepatic markers of estrogen action. This has important clinical implications, since the hepatic actions of estrogens are believed to account for several complications of this form of therapy. To date, the mechanism responsible has been attributed to the so-called first pass effect of the orally administered hormones. The present study was undertaken to examine the in vivo extraction from the circulation of all commercially available classes of estrogens used for replacement therapy. Influxes from the microcirculation into three important target organs of estrogen action, i.e. the brain, uterus, and liver, were assessed. This was accomplished by the use of previously described double isotope, single injection, timed tissue-sampling techniques. For the brain, two patterns of influx were found using different injection vehicles. The first was characterized by high extraction (80-100%) in the absence of plasma proteins. The only inhibitory effects on influx were exerted by plasma proteins. Estrogens displaying this pattern were estradiol, estrone, and ethinyl estradiol. The second pattern was characterized by very restricted influx in the absence of plasma proteins, and plasma protein binding had little or no additional effect. In the absence of plasma proteins, the percentages extracted of estrone sulfate (E1S) and diethylstilbestrol were 6.5% and 38.5%, respectively. For the uterus, the patterns of extraction of all five estrogens were similar to those found for the brain. In contrast, the hepatic microvasculature was freely permeable to all estrogens including E1S and diethylstilbestrol. Albumin binding had little or no effect on hepatic uptake. Significant reductions in the influx of estradiol and E1S were found only when the injection vehicle was human pregnancy serum (high sex hormone-binding globulin concentration). In the presence of plasma proteins, the hepatic extraction of all of the estrogens studied significantly exceeded that in the brain and uterus. We conclude that enhanced delivery of circulating estrogens to the liver compared to that to the brain and uterus provides a further explanation for the enhanced hepatic actions of these preparations when used for oral replacement therapy.
DOI: 10.2174/187153008784534376
2008
Cited 64 times
Efficacy of Dietary Supplementation with Botanicals on Carbohydrate Metabolism in Humans
Botanical products are widely used in nutritional supplementation for promotion of health or prevention of diseases. With the high prevalence of obesity and type 2 diabetes, abnormalities in carbohydrate metabolism are common in the general population and obtaining glycemic control is important in reducing the complications of diabetes. If shown to be effective, botanical products have a unique position in potentially aiding the general public in regard to obesity and diabetes. They can be obtained "over-the-counter" and may have less side effects compared to many synthetic drugs. Although most of the popular botanicals have a long history in folk medicine, there is paucity of data regarding their efficacy and safety, particularly as it relates to human studies. In this review, we discuss the data that was available in the literature for nine botanicals that are frequently promoted to help manage blood glucose. They are Bitter Melon (Momordica charantia), Fenugreek (trigonella foenum graecum), Gymnema Sylvestre, Ivy Gourd (Coccinia indica), Nopal or Prickly Pear Cactus (Opuntia streptacantha), Ginseng, Aloe Vera, Russian Tarragon (Artemisia dracunculus), and Garlic (Allium sativum). The discussion is emphasized on the clinical aspect of these botanicals. Due to the lack of sufficient evidence from clinical studies for any of the botanicals reviewed, it is premature to actively recommend use of any particular herb to treat either glucose or other risk factors. Thus, well defined randomized clinical trials are warranted in this area.