The Effect of Alacepril on Insulin Sensitivity in Patients with Essential Hypertension

: The aim of this study was to determine the effect of angiotensin-converting-enzyme inhibitor, alacepril, on insulin sensitivity in patients with essential hypertension (EHT). Ten patients (5 men and 5 women) with EHT (3 with mild diabetes and 2 with borderline glucose tolerance) participated. We measured insulin sensitivity using the two-hour euglycemic-hyperinsulinemic clamp technique and plasma glucose and insulin responses to a 75 g oral glucose tolerance test (75 g OGTT) before and after 6-8 weeks of treatment with alacepril (dose, 50 mg/day). Glucose infusion rate (GIR) during the last 30 min of the clamp study increased from 5.83 +/- 0.70 to 6.59 +/- 0.65 mg per kilogram of body weight per minute (P < 0.05) after treatment with alacepril. The insulin-sensitivity index, which was calculated by dividing the GIR by the mean insulin concentration during the same period of the clamp, also increased from 5.91 +/- 0.66 to 7.20 +/- 0.90 (P < 0.05) after treatment with alacepril. Plasma glucose responses to a 75 g OGTT were changed from diabetic pattern to borderline pattern in two patients and from borderline pattern to normal pattern in one patient after treatment with alacepril. Body weight did not significantly change throughout the study in any of the patients studied. Our study demonstrated that alacepril significantly improves insulin sensitivity in patients with EHT.