A placebo-controlled, double-blind clinical trial has been initiated to determine whether angiotensin-converting enzyme inhibitor (ACEI) therapy with captopril (25 mg three times daily) slows the progressive loss of renal function in patients with type 1 diabetes mellitus. Entry criteria include; (1) ages 18 to 50 yr; (2) onset of insulin-dependent diabetes before the age of 30 yr, insulin dependent for at least 7 yr; (3) 24-h urine protein excretion500 mg, plus: (a) diabetic retinopathy or (b) if no retinopathy, a renal biopsy diagnosis of diabetic nephropathy; (4) serum creatinine (SCr)2.5 mg/dL; (5) informed consent. Patients follow strict medical management protocols. Systemic blood pressure is controlled to predefined goals (140-90 mm Hg). The primary outcome of the Study is a doubling of the patients' entry SCr to at least 2 mg/dL confirmed by a50% decrease in GFR by radioactive iothalamate clearance technique. Baseline characteristics of the cohort at entry into the Study are (mean +/- SD): male/female, 52%/48%; age, 35 +/- 8 yr; duration of diabetes, 21 +/- 7 yr; duration of proteinuria, 2.8 +/- 3.3 yr; duration of retinopathy, 4.5 +/- 4.1 yr; 50% of cohort presented with hypertension, duration, 4 +/- 4.7 yr; blood pressure, 139/86 +/- 19/12; SCr, 1.35 +/- 0.44 mg/dL; GFR 78 +/- 32 mL/min; BUN, 24 +/- 11 mg/dL; proteinuria, 3.1 +/- 3.3 g/day; cholesterol, 236 +/- 50 mg/dL; total glycosylated hemoglobin, 11.1 +/- 2.1%.(ABSTRACT TRUNCATED AT 250 WORDS)
