AHA spokesman Russell Luepker, MD, of the University of Minnesota School of Public Health, tells WebMD that studies have suggested that weight gain may have more of a negative effect on LDL levels than on HDL levels.
"If people hadn't gained weight, there might have been an LDL benefit [associated with quitting smoking] and an even more robust benefit in terms of HDL," says Luepker, who was not involved with the work.
Interestingly, heavy smokers and light smokers gained the same HDL benefit, Gepner says. The type of smoking cessation strategy also did not affect the results.
The study involved 923 men and women enrolled in a study testing various smoking cessation methods, including nicotine lozenges and nicotine patches. When they entered the study, participants smoked an average of about two packs a day. By one year later, about one-third had successfully kicked the habit.
Gepner says exactly how smoking affects cholesterol levels is unknown, although it is believed to have to do with transporting lipid particles.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.