Among adults without diabetes, quitting smoking was associated with a lower risk of cardiovascular disease, even after taking into account subsequent weight gain, when compared with continuing smoking, according to a study.

In background information for the study, which appears in the March 13 issue of the Journal of the American Medical Association, researchers noted that "quitting smoking is associated with a small number of adverse health consequences, weight gain being one of smokers’ major concerns." The average post-cessation weight gain among North American smokers is between 6.6 and 13.2 pounds, happens within six months of cessation and persists over time.

Given that obesity also is a risk factor for cardiovascular disease, weight gain following smoking cessation might lessen the benefits of quitting on CVD outcomes, the authors noted. Among those with type 2 diabetes, weight gain following smoking cessation could be of greater concern because it is a risk factor for poor diabetes control and increased risk of illness and death.

Overall, "the effect on CVD of potential weight gain following smoking cessation is not well understood," the authors wrote.

Carole Clair, MD, MSc, of the University of Lausanne (Switzerland) and colleagues conducted a study to assess the association between four-year weight gain following smoking cessation and CVD event rate among adults with and without diabetes. The study included data from the Framingham Offspring Study, collected from 1984 through 2011. The primary outcome measure was the incidence over six years of total CVD events, comprising coronary heart disease, cerebrovascular events, peripheral artery disease and heart failure.

After an average follow-up of 25 years, 631 CVD events occurred among 3,251 participants. The researchers found 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.

After adjustment for CVD risk factors, compared with smokers, recent quitters had a 53% lower risk for CVD and long-term quitters had a 54% lower risk for CVD; these associations changed only minimally after further adjustment for weight change.

Among participants with diabetes, the researchers found similar point estimates, but those did not reach statistical significance.

The researchers observed similar benefits associated with smoking cessation for total CVD and for fatal and nonfatal coronary heart disease, with the cessation benefits not offset by weight gain.

"Among adults without diabetes, quitting smoking was associated with a lower risk of CVD compared with continuing smoking," the authors concluded. "There were qualitatively similar lower risks among participants with diabetes that did not reach statistical significance, possibly because of limited study power.

"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."

In an accompanying editorial, Michael C. Fiore, MD, MPH, MBA and Timothy B. Baker, PhD, of the University of Wisconsin School of Medicine and Public Health in Madison, suggested ways in which the findings of this study can be used by clinicians.

The data "can be used to reassure patients concerned with the health effects of cessation-related weight gain," they wrote. "About 50% of female smokers and about 25% of male smokers are 'weight concerned,’ which may discourage quit attempts and quitting success. Although such reassurance may not assuage concerns about the effects of weight gain on appearance, it may nevertheless be helpful."

In addition, they wrote, clinicians "should use this information to reinforce their commitment to provide or arrange evidence-based treatment for all patients who smoke."

The full study is available at http://jama.jamanetwork.com/article.aspx?articleid=1667090.