Reduction of serum cholesterol levels and beta-lipoprotein cholesterol levels by nicotinic acid.

Introduction Because of the statistical relationship between hypercholesteremia and atherosclerosis, reduction in serum levels of cholesterol (especially the β-lipoprotein cholesterol fraction) has been the goal of numerous programs of treatment. In evaluating any form of therapy, three main questions must be answered: 1. Will it effectively reduce cholesterol levels? 2. Is it nontoxic and otherwise suitable for long-term use? 3. Does it prevent or retard the development of atherosclerosis? Several groups of investigators have found nicotinic acid in large doses to be effective in reducing serum cholesterol levels in hypercholesteremic and normal persons. 1-13 Nicotinamide in equal dosage failed to produce or maintain reduction in cholesterol levels, 1,3 its action resembling that of a placebo. 7,11 Neither the mechanism of action of nicotinic acid nor the reason for the failure of the amide is yet understood. No group has reported any toxic effects which would make nicotinic acid unsuitable for