Increased angiotensin-converting enzyme activities in diabetes mellitus: Analysis of diabetes type, state of metabolic control and occurrence of diabetic vascular disease

Abstract

Serum angiotensin-converting enzyme activities were measured in 41 type 1 diabetics (16.4 ± 4.0 U/ml), in 40 type 2 diabetics (15.0 ± 5.2 U/ml) and in 52 controls (13.0 ± 2.7 U/ml, mean ± SD). Twenty six (32%) of 81 patients presented with serum angiotensin-converting enzyme activities above the normal range. No relation between serum angiotensin-converting enzyme activities and the presence or lack of diabetic vascular diseases in type 1 and type 2 diabetics could be detected. No significant differences in serum angiotensin-converting enzyme activities were found when comparing various types of diabetic vascular disease (retinopathy, neuropathy, renal failure, arterial vascular disease, diabetic vascular disease, coronary artery disease). However, mean serum angiotensin-converting enzyme activities were significantly increased in diabetics with retinopathy when compared with controls (p < 0.0005). Correlation between metabolic long term control as determined by measuring glycohaemoglobin (HbA1) concentrations and serum angiotensin-converting enzyme activities could not be established. Serum angiotensin-converting enzyme activities did not show any correlations with duration of diabetes, age or sex of patients. A representative number of diabetics (32%) showed elevated serum angiotensin-converting enzyme activities, but a correlation with diabetic vascular disease, metabolic control or type of disease could not be established.