Abnormal plasma cholesterol metabolism in cigarette smokers.

Plasma cholesterol metabolism was studied in young, nonobese, normolipidemic men with a moderate level of cigarette smoking (24 +/- 5d-1) and in a comparable nonsmoking normal control group. The smokers showed a decreased cholesterol net transport from cell membranes into plasma (P less than 0.001) and a decreased ratio of cholesteryl ester transfer to low and very low density lipoprotein, relative to lecithin:cholesterol acyltransferase (P less than 0.05). Apoprotein E was increased in smokers' plasma (P less than 0.05) whereas apoprotein A-I, the major apoprotein of HDL, was decreased (P less than 0.05). This pattern of abnormalities has been previously observed in several other groups of subjects at increased risk for atherosclerotic vascular disease (diabetics, dysbetalipoproteinemics, and hyperbetalipoproteinemics). These data suggest a deleterious effect of smoking on plasma lipoprotein metabolism significant even in young smokers, which could partly explain the later incidence of atherosclerotic vascular disease in this group.