ANTIHYPERTENSIVE THERAPY WITH ENALAPRIL IMPROVES GLUCOSE STORAGE AND INSULIN SENSITIVITY IN HYPERTENSIVE PATIENTS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS

A double-blind, placebo-controlled, 4-week trial was performed to dete rmine the antihypertensive and metabolic effects of enalapril (20 to 4 0 mg/d) in 16 hypertensive patients with non-insulin-dependent diabete s mellitus (NIDDM) aged 55 +/- 2 years and with a body mass index of 2 9 +/- 1 kg/m(2). Glucose utilization was determined after an overnight fast and during insulin stimulation at 0 and 4 weeks (methods: euglyc emic clamp, [3-H-3]glucose infusion, indirect calorimetry). Enalapril decreased systolic (166 +/- 4 v 152 +/- 5 mm Hg, P < .05) and diastoli c (102 +/- 2 v 95 +/- 2 mm Hg, P < .05) blood pressure. Peripheral ins ulin sensitivity, ie, insulin stimulation of glucose utilization, incr eased approximately 30%, or by 4.3 +/- 1.7 mu mol/kg.min (13.1 +/- 2.0 v 17.4 +/- 3.5 mu mol/kg.min, P < .05, 0 v 4 weeks) during enalapril treatment, but remained unchanged during placebo treatment (15.4 +/- 2 .8 v 15.3 +/- 2.7 mu mol/kg.min, respectively). The increase in glucos e utilization during enalapril treatment was fully explained by an inc rease of 4.1 +/- 1.7 mu mol/kg.min in glucose storage (4.1 +/- 1.2 v 8 .1 +/- 2.9 mu mol/kg.min, P < .05) while glucose oxidation remained un changed. High-density lipoprotein (HDL) cholesterol increased by 8% (P < .05) and hemoglobin A(1c) (HbA(1c)) improved slightly (7.7% +/- 0.7 % v 7.3% +/- 0.7%, P < .05) in the enalapril group, but not in the pla cebo group. We conclude that enalapril improves insulin sensitivity by increasing glucose storage in hypertensive patients with NIDDM. These data indicate that the beneficial metabolic effects of angiotensin-co nverting enzyme (ACE) inhibitors are not restricted to nondiabetic pat ients, and that insulin resistance is partially reversible in hyperten sive NIDDM patients. Copyright (C) 1995 by W.B. Saunders Company