Blood lipid effects of antihypertensive therapy: a double-blind comparison of the effects of methyldopa and propranolol.

Thirty-two middle-aged men with essential hypertension completed a double-blind randomly allocated comparison of the effects of methyldopa versus propranolol on blood lipid levels. After a four-week period on a placebo for each drug, subjects were titrated for the next six weeks with either methyldopa from 500 to 2000 mg/day or propranolol from 80 to 320 mg/day plus a placebo for the other drug until supine diastolic blood pressure was below 90 mm Hg or the ceiling dose was reached. Subjects were then maintained on the achieved drug dose for an additional six weeks and finally switched back to a placebo for each drug for four more weeks. Blood lipid levels were measured twice during each study period and the values averaged and compared. Neither drug significantly affected levels of total plasma cholesterol. However, both drugs reduced high-density lipoprotein (HDL) cholesterol levels about 10 per cent and increased the total cholesterol to HDL cholesterol ratio. In addition, propranolol significantly increased plasma triglyceride levels (28.3 per cent). The changes in lipid levels were not dose related. Whether or not these blood lipid changes persist and their possible clinical implication during prolonged therapy remain to be elucidated.