Captopril does not alter metabolic control in elderly hypertensive diabetics during secondary failure.

In elderly patients diabetes and hypertension play an important and synergistic role in the development of cardiovascular complications. For this reason therapy must reduce blood pressure without compromising blood glucose control. We investigated the question of whether captopril, an angiotensin converting enzyme inhibitor, can be used without interference to glucose metabolism in diabetics with secondary failure. Ten elderly hypertensive diabetics (diastolic blood pressure greater than 95 mmHg), maintained in good metabolic control using oral hypoglycaemic agents and insulin, were studied before and after 30 days of captopril at 100 mg/day. We measured the following parameters: blood pressure, heart rate, fructosamine and a daily profile for blood glucose and c-peptide. There was a statistically significant reduction in systolic and diastolic blood pressure. No difference was observed in the levels of blood glucose and fructosamine. Insulin secretion as determined by c-peptide levels was not modified, in contrast with findings reported for the use of beta-blockers, diuretics or nifedipine. It seems that captopril is useful and without side effects, even in secondary-failure diabetic patients characterized by unstable metabolic control.