Plasma lipid and lipoprotein profiles of cigarette smokers from randomly selected families: Enhancement of hyperlipidemia and depression of high-density lipoprotein

Cigarette smoking is an important risk factor for coronary heart disease. However, its mechanisms of action remain to be fully explored. The hypothesis of the present study is that 1 mechanism whereby cigarette smoking enhances coronary disease might result from its effects upon the plasma lipids. Accordingly, we measured the plasma lipids and lipoproteins in cigarette smokers, exsmokers and nonsmokers from 233 randomly selected American families. Cigarette smokers (male and female) had significantly lower high-density lipoprotein levels and higher very low density lipoprotein and plasma triglyceride levels than the exsmokers and nonsmokers. The plasma levels of lipids and lipoproteins were related to the number of cigarettes smoked per day. Heavier cigarette smokers (> 25 cigarettes/ day) had significantly lower high-density lipoprotein levels and significantly higher very low density lipoprotein total cholesterol and plasma triglyceride levels than those who smoked < 25 cigarettes/day, nonsmokers and exsmokers. The lipid and lipoprotein values of those who smoked < 15 cigarettes/ day were similar to those of exsmokers and nonsmokers. Inasmuch as exsmokers had levels of plasma lipids and lipoproteins similar to those of nonsmokers, these findings add another healthenhancing benefit to the cessation of smoking.