Abstract 8797: Effects of Smoking and Smoking Cessation on Lipids and Lipoproteins: Outcomes from a Randomized Clinical Trial
Background: Although observational studies and smaller clinical trials, suggest that cigarette smoking is associated with a more atherogenic lipid profile, no studies have prospectively evaluated the effects of smoking cessation and continued smoking on lipids and lipoprotein subfractions in a large, contemporary cohort of current smokers.
Methods: This was a one-year, prospective, double-blind, randomized, placebo-controlled clinical trial of the effects of 5 smoking cessation pharmacotherapies. Fasting nuclear magnetic resonance spectroscopy lipoprotein profiles were obtained before and one year after the target smoking cessation date. The effects of smoking cessation and predictors of changes in lipoproteins after one year were identified by multivariable regression analysis.
Results: The 1,504 current smokers were mean (standard deviation) 45.4 (11.3) years old and smoked 21.4 (8.9) cigarettes/day at baseline. The 923 smokers who returned after one year (a typical return rate in smoking cessation clinical trials) included 334 (36.2%) that had quit smoking. Despite gaining more weight (4.6 kg [5.7] vs. 0.7 kg [5.1], p<0.001], abstainers had increases in high-density lipoprotein (HDL) cholesterol (2.4 [8.3] vs. 0.1 [8.8] mg/dL, p<0.001], total HDL particles [1.0 (4.6) vs. −0.3 mcmol/L (5.0), p<0.001] and large HDL particles (0.6 [2.2] vs. 0.1 [2.1] mcmol/L, p=0.003) compared with continuing smokers. Significant changes in low-density lipoprotein (LDL) cholesterol, LDL particles, LDL size, and HDL size were not observed. After adjustment, abstinence from smoking (p<0.001) was independently associated with increases in HDL-C and total HDL particles. HDL responses to smoking cessation were not affected by baseline smoking intensity or smoking cessation strategy.
Conclusions: Despite weight gain, smoking cessation improved HDL cholesterol, total HDL and large HDL particles. Smoking cessation did not affect LDL or LDL size. Increases in HDL may mediate part of the reduced cardiovascular disease risk observed after smoking cessation.
- © 2010 by American Heart Association, Inc.