Atenolol and metoprolol: comparison of effects on blood pressure and serum lipoproteins, and side effects.

Several beta-blockers increase VLDL-TG and decrease HDL-cholesterol concentrations. The underlying mechanism is not yet clear. Some studies have suggested that the effect is less pronounced during treatment with selective beta-blockers. The effects of 2 such drugs, metoprolol 200 mg/day and atenolol 50 mg/day, have been compared in 50 hypertensive patients (WHO Stage I-II), mean age 47 years. Serum lipoproteins were determined in 20 patients before treatment and after treatment with either drug for 3 months. Both drugs were equally effective in reducing blood pressure. After atenolol the initial VLDL-cholesterol concentration of 1.04 mmol/l had not changed, but it rose to 1.29 mmol/l after metoprolol (p less than 0.05). The HDL-cholesterol concentration 1.42 mmol/l did not fall during atenolol treatment, but during metoprolol there was a small reduction to 1.31 mmol/l (p less than 0.05). Hyperlipoproteinaemia is common in hypertensive patients, 40% of the present group had hypertriglyceridaemia and 25% had hypercholesterolaemia. Thus, atenolol 50 mg was found not to affect lipoproteins, whereas metoprolol 200 mg increased the VLDL concentration in 75% of the patients.