MICROALBUMINURIA IN INSULIN-DEPENDENT DIABETICS - PREVENTION OF DIABETIC NEPHROPATHY BY ANGIOTENSIN CONVERTING ENZYME-INHIBITION

We evaluated the effects of angiotensin converting enzyme inhibition upon the urinary excretion of albumin in 36 insulin dependent normotensive diabetic patients with adequate metabolic control and no evidence of renal failure. 19 subjects had normal levels of albumin excretion (< 30 mg/24 h) and 17 showed microalbuminuria from 30 to 300 mg/24 h. Half of the patients were randomly selected in each group to receive enalapril, 5 mg/day. A progressive decrease in albumin excretion levels was observed for both enalapril treated subgroups, from 18.9 +/- 8.3 to 8.1 +/- 2.7 mg/24 h (normoalbuminurics) and from 73.1 +/- 25.0 to 40.1 +/- 26.3 mg/24 h (microalbuminurics). In contrast, an increase in albumin excretion from 19.4 +/- 6.8 to 29.4 +/- 14.2 mg/24 h was observed in non treated normoalbuminuric patients. Untreated patients with microalbuminuria remained with stable albumin excretion levels (67.4 +/- 39 to 64.8 +/- 23.4 mg/24 h). Enalapril treatment was associated to a significant (p < 0.05) decrease in creatinine clearance which remained within normal limits. Blood pressure, Na and K plasma levels and total proteins remained normal throughout the study. Thus, angiotensin converting enzyme inhibition reduces the urinary excretion of albumin in insulin dependent diabetics with normo or microalbuminuria.