Long-Term Effects of the Angiotensin Converting Enzyme Inhibitor Captopril on Metabolic Control in Non – Insulin-Dependent Diabetes Mellitus

Abstract

The role of angiotensin converting enzyme (ACE) inhibitors in improving insulin-mediated glucose uptake has been described. However, their effects on long-term glucose control in diabetes mellitus are less well established. This study examines the effect of 4 months of captopril treatment on blood pressure (BP) and glucose control in 130 subjects with non-insulin-dependent diabetes mellitus (NIDDM) and hypertension. Therapy for glycemic control was adjusted during a 3 month period prior to entry into active BP treatment and was not changed during 4 months of captopril administration. Fasting blood glucose and sitting BP were measured before and at 1, 2, 3, and 4 months of captopril monotherapy. Hemoglobin (Hb) A1c, serum electrolytes, creatinine, total cholesterol, and triglycerides were measured before and at 4 months. There were significant reductions in fasting blood glucose from baseline at 1 month (P < .01) and further stepwise decreases in values at 2, 3, and 4 months. Differences in glucose from month to month were highly significant. HbA1c was stable over a 3-month pretrial period, then decreased (P < .001) from baseline at 4 months of active treatment. Mean serum potassium increased from 4.4 to 4.7 (P < .001) at month 4 and there was an inverse correlation (r = -0.2, P < .025) between changes in potassium and HbA1c. Total serum cholesterol fell (P < .01) at month 4 of treatment. Serum creatinine and blood urea were unchanged, but of 18 patients with mild proteinuria pretrial, 12 of 18 were negative for protein at 4 months.(ABSTRACT TRUNCATED AT 250 WORDS)