EFFECTS OF ANGIOTENSIN-CONVERTING ENZYME-INHIBITORS, CA2-ADRENERGIC BLOCKERS ON GLUCOSE AND LIPID-METABOLISM IN NIDDM PATIENTS WITH HYPERTENSION( CHANNEL ANTAGONISTS, AND ALPHA)

We compared the effects of captopril, nifedipine, and doxazosin on glu cose and Lipid metabolism in 30 hypertensive non-insulin-dependent dia betes mellitus (NIDDM) patients (age = 50 +/- 3 years; body mass index = 30 +/- 1 kg/m(2)). Of these patients, 9 were treated with captopril , 11 with nifedipine, and 10 with doxazosin for 12 weeks, Blood pressu re, fasting plasma glucose (FPG) concentration, HbA(1c), oral glucose tolerance test (OGTT), euglycemic insulin clamp, and plasma lipids wer e measured before and after a 3-month period, Mean arterial blood pres sure (114 +/- 2 mmHg) was similar in ad groups before initiating antih ypertensive therapy and declined to 102 +/- 2 (captopril), 103 +/- 1 ( nifedipine), and 103 +/- 2 (doxazosin) mmHg (P < 0.001), Baseline FPG (148 +/- 11 mg/dl) and HbA(1c) (6.3 +/- 1%) were similar in all groups and did not change significantly with treatment, Plasma glucose, insu lin, and free fatty acid (FFA) concentrations during the OGTT mere sim ilar in all groups before antihypertensive treatment and did not chang e with captopril and nifedipine; after doxazosin, plasma glucose and F FA concentrations during the OGTT decreased (both P < 0.05) without ch ange in plasma insulin response. Insulin-mediated glucose uptake (144 +/- 11 mg . m(-2). min(-1)), glucose oxidation (76 +/- 4 mg . m(-2). m in(-1)), and nonoxidative glucose disposal (71 +/- 6 mg . m(-2). min(- 1)) were similar in all groups before the start of antihypertensive tr eatment and did not change in captopril and nifedipine groups. After d oxazosin, total glucose uptake (180 +/- 25 mg . m(-2)min(-1)) and gluc ose oxidation (108 +/- 8 mg . m(-2). min(-1)) increased significantly (P < 0.01); nonoxidative glucose disposal did not change, Plasma lipid levels improved after doxazosin therapy: high-density Lipoprotein ros e from 40 +/- 3 to 44 +/- 3 mg/dl (P < 0.01) and triglycerides fell fr om 210 +/- 18 to 178 +/- 17 (P < 0.05). No changes in plasma lipid lev els were observed with captopril or nifedipine. We concluded that in h ypertensive NIDDM subjects, 1) captopril, nifedipine, and doxazosin ar e equally effective in lowering blood pressure; 2) captopril and nifed ipine have no adverse effects on glucose tolerance, insulin sensitivit y, or plasma lipid profile; and 3) doxazosin significantly improves in sulin sensitivity during the euglycemic insulin clamp, enhances OGTT w hile decreasing the plasma insulin response, and improves the plasma l ipid profile.