Development, progression, and regression of microalbuminuria in Japanese patients with type 2 diabetes under tight glycemic and blood pressure control - The Kashiwa study

OBJECTIVE - The goal of this study was to know the fate of albuminuria in Japanese patients with type 2 diabetes under tight blood pressure and glycemic control. RESEARCH DESIGN AND METHODS - Patients having normoalbuminuria (urinary albumin excretion < 30 mg/g creatinine, n = 179) or microalbuminuria (albumin excretion 30-299 mg/g creatinine, n = 94) at baseline have been followed up for 8 years: ratio of men to women was 160/113, the mean age was 58 years, pretreatment HbA(1c) (A1C) was 8.8% and blood pressure was 136/76 mmHg. AIC < 6.5% and blood pressure < 130/80 mmHg were targeted, and the AIC of 6.5 +/- 0.7% (mean +/- SD) and the blood pressure of 127 +/- 11/72 +/- 6 mmHg have been maintained during the 8 years. Development of microalbuminuria or macroalbuminuria (albumin excretion >= 300 mg/g creatinine) in initially normoalbuminuric patients and progression to macroalbuminuria or regression to normoalbuminuria in initially microalbuminuric patients were assessed at year 8. RESULTS - Development occurred in 27 (15%) of the normoalbuminuric patients and progression and regression in 16 (17%) and 20 (21%), respectively, of the microalbummuric patients. Significant independent relationships existed between development and higher achieved mean systolic blood presssure (SBP) and regression and lower achieved mean SBP. In the patients with achieved mean SBP < 120 mmHg, development was 3%, and regression was 44% during 8 years. Prediction for nephropathy by blood pressure and glycemia alone was limited. Nevertheless, albumin excretion at year 8 was positively correlated with achieved mean SBP and baseline albuminuria. CONCLUSIONS - Development and progression were low and regression was high with SBP of 120 mmHg, provided A1C was maintained at 6.5%.