Effects of smoking on serum lipid and lipoprotein concentrations and lecithin: cholesterol acyltransferase activity

Cigarette smoking is one of the major risk factors for cardiovascular disease. The mechanism responsible for this association is still unknown. We measured the activity of lecithin: cholesterol acyltransferase (LCAT), a key factor in the esterification of plasma cholesterol and reverse cholesterol transport, and the levels of lipids and apolipoproteins in the serum of 27 cigarette smoking and 31 non-smoking (control) men. We could not find any significant difference among these parameters between the groups. Serum LCAT activity was lower in smokers, but the difference was statistically nonsignificant. We also classified the two groups in respect to their serum lipid levels as hyper- and normolipidemic, we observed that normolipidemic-smokers had lower (p < 0.05) high density lipoprotein-cholesterol (HDL-C) and HDL-ester cholesterol levels compared to the normolipidemic-nonsmokers. While there were no any significant differences between hyperlipidemic-smokers and nonsmokers with respect to any of the parameters. In the end we have got the idea that smoking seems to affect HDL-C and HDL-ester cholesterol levels in the normolipidemic-smokers group, only, Also, LCAT activity tended to be lower in smokers compared to nonsmokers.