Angiotensin converting enzyme (ACE) activity levels in insulin-independentdiabetes mellitus and effect of ACE levels on diabetic patients with nephropathy

Involvement of complications is considered to be one of the major factors i n the prognosis of diabetes mellitus (DM). Recent studies indicate that mos t diabetic complications such as nephropathy and hypertension are vascular- originated, Renin-angiotensin involvement, especially changes in ACE activi ty level, is considered to be a key factor since ACE converts angiotensin I to angiotensin II which is a potent vasoconstrictor and plays a vital role in the regulation of blood pressure. Our present study focused on ACE acti vity levels along with blood glucose and HbA(1c) levels in diabetic patient s with (n = 18) or without (ii = 25) nephropathy as compared to control sub jects (n = 25), Blood glucose levels were significantly higher in both diab etic groups compared to controls (p < 0.001). On the other hand. compared t o controls, blood HbA(1c) levels were slightly higher in DM patients withou t complications whereas they were significantly increased in nephropatic DM patients (p < 0.001). There was a very strong increase (p < 0.001) at the level of ACE activity in both of the diabetic groups (with nephropathy: 47. 11 +/- 3.70 U l(-1); without complications: 43.72 +/- 2.93 U l(-1): control s: 25.15 +/- 2.30 U l(-1)). ACE activity levels were also significantly hig her in diabetic patients with nephropathy than in type II DM patients witho ut complication (p < 0.01). Our results demonstrate that ACE activity level s are increased in diabetic patients. Additional significant increase in AC E activity levels in diabetic patients with complications such as nephropat hy supports the hypothesis that ACE activity has an essential role in the d evelopment of complications in diabetes, Copyright (C) 2000 John Wiley &: S ons, Ltd.