Effects of cessation of smoking on serum lipids and high density lipoprotein-cholesterol.

This study examined the effect of cessation of smoking on serum lipid and lipoprotein levels. Twenty-six females who smoked a minimum of 20 cigarettes per day for the past 5 years served as volunteers. Twelve subjects abstained from smoking for a period of 60 days (ex-smokers). Six stopped smoking for 30 days then resumed smoking for an additional 30 days (re-smokers). Eight subjects continued to smoke for the entire 60 days (smokers). Additionally, 10 females who had never smoked served as non-smoking controls (non-smokers). Pre-cessation HDL-C levels for all smoker groups were 15-20% (P less than 0.05) below those of non-smokers. By day 30 of cessation HDL-C levels of ex-smokers and re-smokers significantly increased by 5.7 and 10.5 mg/dl, respectively, and were significantly higher than those of smokers. At day 60, HDL-C of ex-smokers increased another 6.8 mg/dl to 63.9 mg/dl while levels of re-smokers returned to pre-cessation levels (50.7 mg/dl). The findings of this study suggest that low levels of HDL-C associated with smoking in females do not appear to be cumulative and can be reversed in as little as 30 days.