Effect of chronic treatment with enalapril on glucose tolerance and serum insulin in non-insulin-resistant Japanese patients with essential hypertension

The effect of enalapril, an angiotensin converting enzyme inhibitor, on glucose tolerance and serum insulin response to a glucose load has been evaluated in 8 non-obese patients (3 women and 5 men) with untreated essential hypertension (WHO Stage I or II) and without insulin resistance. Following a 2-month run-in control period, each patient received oral enalapril 10 mg once daily for 6 months, and an intravenous glucose tolerance test (IVGTT) was performed at the end of the run-in control and active treatment periods. Treatment with enalapril significantly lowered both the systolic and diastolic blood pressures. The response of plasma glucose to the IVGTT, glucose disappearance rate (k-value) and area under the serum insulin concentration time curve were comparable between the two phases. The results suggest that long-term treatment with enalapril has no effect on glucose tolerance in non-obese, non-insulin-resistant patients with mild-to-moderate essential hypertension.