Comparison of effects on lipid metabolism of antihypertensive drugs with alpha- and beta-adrenergic antagonist properties.

Elevated blood cholesterol levels are a major cause of coronary heart disease. High-density lipoprotein cholesterol is regarded as a protective cholesterol fraction that is negatively associated with the incidence of coronary heart disease. Thus, the ratio of high-density lipoprotein to total cholesterol levels is an expression of the total atherogenicity--the higher the ratio, the lower the risk of coronary heart disease. There is a sharp contrast between alpha- and beta-adrenergic blockers with regard to their effect on the profile of blood lipids. In most studies, alpha blockers increased high-density lipoprotein cholesterol levels and decreased serum triglyceride levels. In addition, alpha blockers generally reduce total serum cholesterol levels. On the other hand, most beta blockers reduce serum levels of high-density lipoprotein cholesterol and increase serum triglyceride levels. European clinical trials recently investigated the effects of alpha blockers and beta blockers on blood lipids in a total of 104 and 281 patients with hypertension, respectively. On the average, selective alpha blockade increased the high-density lipoprotein cholesterol:total cholesterol ratio by 11.3 percent and reduced serum triglyceride levels by 11.4 percent. In contrast, the selective and nonselective beta-adrenergic blockers atenolol, metoprolol, and propranolol reduced that ratio by 11.7 percent and increased serum triglyceride levels by 25.8 percent. This difference between alpha and beta blockers may significantly influence the risk profile of coronary heart disease and should be given strong consideration when choosing drug therapy for hypertensive patients.