High-density lipoprotein concentrations increase after stopping smoking

Abstract

Concentrations of plasma lipoproteins in 10 men who were habitual smokers were monitored for six weeks after they stopped smoking and related to changes in diet and body weight. The energy intake increased by 10% (p < 0.05) owing to a higher consumption of carbohydrate and fat, and body weight increased by 2% (p < 0.01). Plasma triglyceride, cholesterol, and low-density lipoprotein cholesterol concentrations did not change significantly. The most prominent finding was a rapid and pronounced increase in high-density lipoprotein concentrations. From comparatively low values (mean 0.82 mmol/l) they rose by 20% (p < 0.01) within two weeks and remained at this value throughout the observation period. In three subjects who resumed smoking after the end of the study they again fell to initial values six weeks later. The initial increase in concentration could be accounted for mainly by an increase in the esterified fraction and only to a lesser extent in the free cholesterol fraction. The changes in concentration were accompanied by similar but less pronounced rises in high-density lipoprotein phospholipid and in apolipoprotein AI concentrations (p < 0.01), whereas high-density lipoprotein triglyceride concentrations did not change significantly. These findings confirm and extend those of earlier cross-sectional studies which showed low concentrations of high-density lipoproteins in cigarette smokers. A significant correlation between the rise in high-density lipoprotein cholesterol concentrations and the increase in fat consumption after stopping smoking indicate that the changes in high-density lipoprotein concentrations may be partly due to nutritional factors.