Weight gain not linked to CVD in ex-smokers with, without diabetes

Smoking cessation decreases the risk for developing cardiovascular disease, but weight gain has previously been thought to worsen this risk among patients with diabetes. However, recent data indicate subsequent weight gain did not increase the risk for cardiovascular disease among patients with or without diabetes.

“Our findings suggest that a modest weight gain, around 5 to 10 pounds, has a negligible effect on the net benefit of quitting smoking,” researcher Caroline Fox, MD, MPH, of the NIH’s National Heart, Lung, and Blood Institute (NHLBI), said in a press release. “Being able to quantify to some degree the relationship between the benefits and side effects of smoking cessation can help in counseling those who have quit or are thinking about quitting.”

Researchers from the NIH and various institutions conducted a prospective community-based cohort study, utilizing data from the Framingham Offspring Study, collected from 1984 to 2011.

After a 25-year follow-up (standard deviation [SD], 9.5 years) 631 CVD events were found among 3,251 patients. According to data, the median weight gain during 4 years was greater for recent quitters without diabetes (2.7 kg) and with diabetes (3.6 kg) compared with long-term quitters (0.9 kg; P<.001).

After adjustments for age and sex, data indicate patients without diabetes had an incidence rate for CVD of 5.9 per 100 person-examinations (95% CI, 4.9-7.1) in smokers; 3.2 per 100 person-examinations (95% CI, 2.1-4.5) in recent quitters; 3.1 per 100 person-examinations (95% CI, 2.6-3.7) in long-term quitters; and 2.4 per 100 person-examinations (95% CI, 2.0-3.0) in nonsmokers.

The researchers calculated HRs based on adjustments for CVD risk factors, comparing recent quitters (HR=0.47; 95% CI, 0.23-0.94) and long-term quitters (HR=0.46; 95% CI, 0.34-0.63). According to data, these associations had only a minimal difference after further adjustments for weight change. In patients with diabetes, researchers wrote that similar estimates were not considered statistically significant.

In a viewpoint accompanying the study, Dhruv Khullar, BA, of Yale University School of Medicine, and Steven A. Schroeder, MD, and John Maa, MD, of the University of California in San Francisco, wrote that every patient should be encouraged to quit smoking, especially before surgical procedures.

“Collaborations with primary care physicians, anesthesiologists, nurses, and others can facilitate smoking cessation and the delivery of better surgical care,” they wrote.

In an editorial written by Michael C. Fiore, MD, MPH, MBA, and Timothy B. Baker, PhD, of the Center for Tobacco Research and Intervention at the University of Wisconsin School of Medicine and Public Health, the researchers wrote that the effects of weight gain on CVD may be nonlinear.

“However, overall, the study supports the belief that smoking cessation is beneficial for smokers, and no subpopulation has yet been identified that shows significantly reduced benefit from quitting, let alone harm,” Fiore and Baker wrote.

For more information:

Clair C. JAMA. 2013;309:1014-1021.

Fiore MC. JAMA. 2013;309:1032-1033.

Khullar D. JAMA. 2013;309:993-994.

Disclosure: Fiore reports institutional support from Pfizer for a phase 4 study of varenicline. Maa (viewpoint) reports serving as vice chair of the Scientific Advisory Committee of the University of California Office of the President Tobacco-Related Disease Research Program. Study researcher Pencina reported serving as a data and safety monitoring board member for Thoracos. Study researcher Rigotti reported serving as an unpaid consultant to Pfizer and Allere Wellbeing Inc.; conducting research projects sponsored by Pfizer and Nabi Biopharmaceuticals; and receiving royalties from UpToDatefor chapters related to smoking cessation. All other researchers report no relevant financial disclosures.