The coefficient variation of home blood pressure is a novel factor associated with macroalbuminuria in type 2 diabetes mellitus

The purpose of this study was to investigate the association between day-by-day variability in home blood pressure (HBP) on 14 consecutive days and macroalbuminuria in patients with type 2 diabetes. We compared the coefficient of variation (CV) of HBP in 858 Japanese patients with and without macroalbuminuria. Next, we analyzed the relationship between the logarithm of urinary albumin excretion (UAE) and the CV of HBP using linear regression analysis. Then, we evaluated the association between the CV of HBP and macroalbuminuria, defined as UAE ≥300 mg g(-1) creatinine, using logistic regression analysis. The CVs of morning and evening systolic blood pressure (SBP) were significantly greater in patients with macroalbuminuria than in those without (8.08±3.35 vs. 7.19±2.25%, P<0.05 and 9.01±3.58 vs. 7.98±2.57%, P<0.05, respectively). Multivariate linear regression analyses indicated that the CVs of morning SBP (P<0.05) and diastolic blood pressure (DBP; P<0.05), and those of evening SBP (P<0.05) were the independent explanatory variables for the logarithm of UAE. Multivariate logistic regression analyses also demonstrated that the odds ratio for the CVs of morning SBP, morning DBP and evening SBP for macroalbuminuria were 1.35 (P<0.05), 1.29 (P<0.05) and 1.44 (P<0.05), respectively. We conclude that the CV of HBP is correlated with macroalbuminuria, independent of the known risk factors, in Japanese patients with type 2 diabetes.