EFFECT OF DOXAZOSIN THERAPY ON GLUCOSE-TOLERANCE AND LIPID-METABOLISMIN HYPERTENSIVE PATIENTS WITH IMPAIRED GLUCOSE-TOLERANCE

The effects of long-term monotherapy with doxazosin, an alpha(1)-block er, or placebo on blood pressure (BP), glucose tolerance, and serum li pid levels were investigated prospectively in 43 hypertensive patients with impaired glucose tolerance. The levels of plasma glucose, serum lipids, fructosamine, and glycated hemoglobin A(1c) (Hb A(1c)) were de termined before and during long-term (mean treatment period, 6.7 month s) therapy with doxazosin (n = 23) or placebo (n = 20). A 75-g oral gl ucose tolerance test was performed before and during therapy. Signific ant decreases in both systolic and diastolic BP were maintained during doxazosin therapy; BP did not change in the placebo group. Neither fa sting nor post-glucose-load venous plasma glucose levels were altered, and there was no significant change in the insulinogenic index in eit her group. Glucose intolerance was slightly improved with significant reductions in Hb Al, and fructosamine levels during doxazosin therapy. Serum total cholesterol (TC) and low-density lipoprotein (LDL) choles terol levels were significantly decreased, and high-density lipoprotei n cholesterol levels were significantly increased in patients treated with doxazosin. Moreover, TC, LDL cholesterol, and apolipoprotein B le vels were significantly decreased in patients with hypercholesterolemi a (TC greater than or equal to 5.69 mmol/L). In contrast, there were n o significant changes in Hb A(1c), fructosamine, and lipid levels in t he placebo group. These results suggest that long-term doxazosin thera py may improve glucose and lipid metabolism in hypertensive patients. Doxazosin appears useful as an antihypertensive agent for hypertensive patients with either impaired glucose metabolism or dyslipidemia.