Do β-blockers alter lipids and what are the consequences?

The unpredictable effect of antihypertensive therapy on coronary risk resulting from changes in lipid levels is an increasingly recognized problem. Different drugs have been shown to exert varying effects on lipids. This problem is particularly evident in young hypertensive patients who may be candidates for lifelong therapy. The effects of chlorthalidone and metoprolol on fasting plasma lipids and lipoprotein levels were compared in two similar nonrandomized groups of patients with mild hypertension. Chlorthalidone therapy was associated with an increase in serum cholesterol of 8.1% (17 mg/dl), mainly reflecting an increase in low-density lipoprotein (LDL) cholesterol. Serum triglycerides increased by 16% (20 mg/dl) and high-density lipoprotein (HDL) cholesterol levels decreased by 10% (3 mg/dl, not significant). Metoprolol therapy induced no changes in total, low, very low, or high-density lipoprotein. Serum triglyceride concentration increased by 22% (28 mg/dl). Application of the Israel Ischemic Heart Disease Study data to these findings indicates a slight decrease at most in the 5-year estimated probability of myocardial infarction in the chlorthalidone-treated group, whereas a clearly favorable influence on the calculated risk of coronary heart disease was observed for those treated with metoprolol. These data suggest that the different forms of therapy for mild hypertension carry varying degrees of significance in terms of risk of coronary heart disease, which should be considered when choosing medication.