[Increase of angiotensin converting enzyme activity during oral load of glucose]

Elevated serum angiotensin I-converting enzyme activity may occur in diabetic subjects. This may signal alteration of vascular endothelium. To study the effect of acute glucose change on serum Angiotensin Converting Enzyme (ACE), we performed an oral glucose tolerance test in 17 obese subjects (7M/10F), (Body Mass Index, (BMI): 31 +/- 1 kg/m2), aged 48 +/- 3 years. We measured serum ACE activity (Lieberman's method), active renin (RIA Pasteur kit), and aldosterone (RIA, Cis-International kit), before and 2 hours after oral glucose intake (75 g), and plasma glucose and insulin every 30 min. After oral glucose tolerance test, subjects were classified as 6 Non Insulin-Dependent Diabetic (NIDD), 8 Glucose intolerant (GI), and 3 NormoGlycaemic (NG) subjects. Active renin did not vary after glucose loading (14 +/- 2 vs 15 +/- 2 pg/ml) nor aldosterone (104 +/- 14 vs 133 +/- 18 pg/ml), while ACE activity rose significantly (229 +/- 25 vs 277 +/- 28 IU/l; p = 0.02). Serum ACE activity were different in the 3 groups before glucose loading (NIDD: 266 +/- 37, GI: 252 +/- 32, NG: 90 +/- 21 IU/l; Kruskal-Wallis H = 7.03; p = 0.03), but not after 2 hours (NIDD: 297 +/- 42, GI: 275 +/- 36, NG: 204 +/- 113 IU/l; ns).(ABSTRACT TRUNCATED AT 250 WORDS)