Effect of mepindolol on serum lipids.

In view of the postulated association between plasma lipids and the development of atherosclerosis, there is growing interest in the effects of beta blockers on plasma lipids. This study was undertaken to investigate whether a nonselective beta blocker, such as mepindolol, which possesses intrinsic sympathomimetic activity, causes significant changes in serum lipids, particularly in their ditribution among the different lipoproteins. Eighteen healthy subjects, twelve males and six females, were given mepindolol orally, daily doses of 0.2 mg/kg averaging 10-15 mg. Pre- and post-treatment fasting total serum cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides were evaulated; the ratio LDL cholesterol/HDL cholesterol was also calculated. Total cholesterol did not change significantly after treatment with mepindolol (- 1.9 mg%), whereas a small and nonsignificant decrease was observed in LDL cholesterol (- 6 mg%); no change was found in HDL cholesterol (- 0. mg%). Serum triglycerides showed a significant increase (+ 20.9 mg%, p less than 0.01). Thus, the most prominent effect of even a short period of treatment with mepindolol is a net increase in serum triglyceride levels. It must be remembered that high triglyceride levels do not constitute a cardiovascular risk factor. On the other hand, no significant changes in total cholesterol, HDL and LDL cholesterol, and in LDL cholesterol/HDL cholesterol ratio were observed. The results of this study show that mepindolol, unlike other beta-blocking agents, does not affect cholesterol concentration and distribution among the lipoproteins. In particular it does not reduce HDL cholesterol, which is currently assumed to be inversely related to the development of atherosclerosis.