Serum angiotensin-converting enzyme in diabetes mellitus: a negative report

Serum angiotensin-converting enzyme (ACE) was measured by a direct photometric method in 78 normotensive diabetic patients and in 34 controls. For comparison, ACE was also assayed in 24 subjects by a radiometric procedure. We found no ACE elevations in diabetics and no significant difference in mean ACE levels between diabetics and normals. Within the diabetic group, enzyme levels were not affected by duration of disease, degree of metabolic control, or presence or not of microangiopathy. Only type I subjects had mean ACE significantly (p less than 0.05) higher than type II, very likely due to their younger age. Serum ACE data from photometric and radiometric methods significantly correlated. ACE measurement seems to be of scarce significance in diabetes mellitus.