Effect of 1-year treatment with nitrendipine versus enalapril on urinary albumin and alpha 1-microglobulin excretion in microalbuminuric patients with type 1 diabetes mellitus. A randomized, single-blind comparative study.

In order to compare the long-term effects of nitrendipine (CAS 39562-70-4) and enalapril (CAS 75847-73-3) on variables of glomerular and tubular function in type 1 diabetes mellitus, a single-blind, randomised comparative 1-year study was carried out in microalbuminuric patients (6 women, 14 men, age, 30-58 years, duration of diabetes, 3-41 years, HbA1 sigma 5.5-10%). 10 patients were treated with 20 mg/d nitrendipine, 10 patients were treated with 10 mg/d enalapril. On the average, urinary albumin excretion was decreased by 38 +/- 4% by nitrendipine (p < 0.01 vs. before treatment) and by 21 +/- 8% by enalapril (p < 0.05 vs. before treatment). The excretion of alpha 1-microglobulin decreased by 35 +/- 10% and by 39 +/- 9%, respectively (p < 0.05 vs. before treatment). Creatine clearance rose by 20 +/- 30% during nitrendipine treatment (p < 0.05 vs. before treatment) but was unchanged during enalapril treatment. Total kidney volume decreased by 23 +/- 4% (p < 0.01) and by 14 +/- 6% (p < 0.05), respectively. Blood pressure fell by 8 +/- 1% systolic and by 13 +/- 1% (diastolic) in nitrendipine-treated patients (both p < 0.01) and by 10 +/- 1% and 13 +/- 1% in enalapril-treated patients (both p < 0.01). Thus, nitrendipine long-term treatment of microalbuminuric type 1 diabetic appeared to be as effective as the treatment with enalapril in preventing or postponing the progression of diabetic nephropathy.