[Angiotensin-converting enzyme and diabetes mellitus]

Elevation of serum angiotensin-converting enzyme (ACE) has been reported to occur in 25 p. 100 of diabetic patients. This finding would decrease the specificity of increased ACE level in sarcoidosis. We measured serum ACE in 90 diabetic patients with simultaneous analysis of various parameters including those appreciating the degree of metabolic control. Serum ACE values, observed in diabetics are not different from values measured in controls, respectively 22,3 +/- 6,4 and 21,1 +/- 6,7 U/ml (means +/- SD). Only 5,5 p. 100 of diabetic patients had (slightly) increased serum ACE levels, i.e.: levels above mean +/- 2 SD of values observed in controls. Serum ACE levels were higher in insulin-dependent diabetics: 24,7 +/- 6,7 (n = 34) than in non insulin-dependent diabetics: 20,8 +/- 5,9 (n = 56) (p = 0,01). In the diabetic group, there is a positive linear correlation between serum ACE level and 24h-glycosuria or glycosylated A1c hemoglobin. These are parameters appreciating middle or long-term metabolic control. In the other hand, no correlation was observed between serum ACE and glycemia, triglyceridemia, serum creatinin, blood pressure or the presence of diabetic retinopathy. These findings do not show an elevation of serum ACE in diabetic patients. However, they suggest that long-term metabolic control of diabetes influence serum ACE level.