Even with weight gain, smoking cessation lowers risk of cardiovascular disease

by Bruce Sylvester – taken from JAMA – Among  non-diabetic adults, smoking cessation compared with continued smoking correlates to a reduced risk of cardiovascular disease, even with subsequent weight gain. Researchers reported this finding in the March 13 issue of Journal of the American Medical Association.

Lead author Carole Clair, M.D., M.Sc., of the University of Lausanne, Switzerland, and colleagues wrote, “Weight gain that occurred following smoking cessation was not associated with a reduction in the benefits of quitting smoking on CVD risk among adults without diabetes. This supports a net cardiovascular benefit of smoking cessation, despite subsequent weight gain.”

As background they noted that prior research shows that average post-cessation weight gain varies between 6.6 lbs. and 13.2 lbs. in North America, it occurs within 6 months after cessation, and it persists over time.

Dr, Clair and her team evaluated retrospectively the association between 4-year weight gain following smoking cessation and CVD event rate among adults with and without diabetes. They used data from the Framingham Offspring Study collected from 1984 through 2011.

The subjects were categorized at 4-year intervals as smoker, recent quitter (≤ 4 years), long-term quitter (>4 years), and nonsmoker. The researchers used established models to determine the association between cessation and 6-year CVD events, and to test whether 4-year change in weight following cessation changed the association between smoking cessation and CVD events.

The primary outcome of the study was the incidence in 6 years of total CVD events, including coronary heart disease, cerebrovascular events, peripheral artery disease, and congestive heart failure.

Among subjects without diabetes, recent quitters gained significantly more weight (median 5.9 lbs.) than long-term quitters (1.9 lbs.), smokers (1.9 lbs.), and nonsmokers (3 lbs.). Among diabetic subjects, recent quitters gained significantly more weight (7.9 lbs.) than smokers (1.9 lbs.), long-term quitters (0.0 lbs., and nonsmokers (1.1 lbs.).

After an average follow-up of 25 years, 631 CVD events occurred among 3,251 subjects. The investigators reported that, among participants without diabetes, the age- and sex-adjusted CVD incidence rates were lower for nonsmokers, recent quitters, and long-term quitters, compared with smokers. Following adjustment for CVD risk factors, they found that compared with smokers, recent quitters had a 53 percent lower risk for CVD, and long-term quitters had a 54 percent lower risk for CVD.

Notably, these associations showed non-significant changes after further adjustment for weight change. “Among participants with diabetes, there were similar point estimates that did not reach statistical significance,” the authors said.

The researchers reported similar benefits associated with smoking cessation for total CVD and for fatal and non-fatal coronary heart disease, with these benefits not changed significantly by weight gain.