Effect of low-dose ramipril on microalbuminuria in normotensive or mild hypertensive non-insulin-dependent diabetic patients

Microalbuminuria predicts early mortality and renal disease in non-insulin-dependent diabetic patients. In insulin-dependent diabetic patients, angiotensin converting enzyme inhibition decreases microalbuminuria and retards the progression of renal disease. The aim of this study was to evaluate the effect of low dose ramipril on albumin excretion rate (AER) and blood pressure in non-insulin-dependent diabetic patients with persistent microalbuminuria (AER > 20 < 200 μg/min) and normal blood pressure or mild hypertension. The study was a randomized, double-blind, placebo-controlled clinical trial of 6 months duration at 14 hospital-based diabetes centers in northeastern Italy. Blood pressure, plasma glucose, and body weight were determined every month; AER, serum creatinine, glycosylated hemoglobin, and plasma lipids at baseline, after 1 month, and at the end of the study. Of 122 non-insulin-dependent diabetic patients randomly allocated in blocks of four to receive either ramipril (1.25 mg/day) or placebo, 108 (54 in the ramipril group and 54 in the placebo group) completed the study. At baseline, age, duration of diabetes, body mass index, and glycosylated hemoglobin were similar in the two groups and remained unchanged throughout the study. In the placebo group, AER rose from a baseline median of 65 μg/min (range 53 to 76, 95% confidence Interval) to 72 μg/min (57 to 87) and to 83 μg/min (62 to 104) after 1 and 6 months, respectively, but fell from 62 μg/min (48 to 76) to 45 μg/min (33 to 57) and to 53 μg/min (38 to 69), respectively, in the ramipril group, a significant difference between the groups (P< .01). Blood pressure was similar in the two groups at baseline and only systolic blood pressure was lower in the ramipril group at several time points during the study. In conclusion, low-dose angiotensin converting enzyme inhibition with ramipril can arrest the progressive rise in albuminuria in non-insulin-dependent diabetic patients with persistent microalbuminuria.