Weight gain after smoking cessation may ‘dilute’ CV benefit in type 2 diabetes
Adults with type 2 diabetes who gain weight after they quit smoking do not decrease their cardiovascular disease risks as much as those who do not gain weight; however, all-cause and cause-specific mortality are similar among quitters who gain or maintain weight, according to findings published in The Lancet Diabetes & Endocrinology.
“Smoking cessation without subsequent weight gain is associated with a reduced risk of cardiovascular disease and mortality among smokers with type 2 diabetes,” Gang Liu, PhD, professor in the department of nutrition and food hygiene at the School of Public Health, Tongji Medical College, Huazhong University of Science and Technology in Hubei, China, told Healio. “Weight gain after smoking cessation attenuates the reduction in risk for developing cardiovascular disease but does not attenuate the beneficial effect of smoking cessation with respect to mortality. These findings confirm the overall health benefits of quitting smoking among people with type 2 diabetes, but also emphasize the importance of weight management after smoking cessation to maximize its health benefits.”
Liu and colleagues analyzed data from adults with type 2 diabetes participating in two prospective cohorts in the United States: the Nurses’ Health Study (1976-2014; n = 121,700) and the Health Professionals Follow-Up Study (1986-2014; n = 51,529). Participants had prevalent type 2 diabetes or were diagnosed during the study, and were current smokers or never smokers without CVD or cancer at diabetes diagnosis.
Information on demographics, newly diagnosed diseases, medical history and lifestyle factors, including smoking status and weight change, was updated every 2 years through questionnaires. Researchers assessed the incidence of CVD and all-cause and cause-specific mortality among recent quitters (within 2 to 6 consecutive years of stopping) and long-term quitters (> 6 years) associated with weight change within 6 years of smoking cessation among people with type 2 diabetes. Within the cohort, 10,809 people with type 2 diabetes were included in the incident CVD disease analysis (24.4% current smokers at diabetes diagnosis) and 9,688 were included in the mortality analysis. Researchers used Cox proportional hazard models to estimate HRs for associations between smoking cessation and weight change on outcomes.
Researchers observed 2,580 incident cases of CVD during 153,166 person-years of follow-up, and 3,827 deaths during 152,811 person-years of follow-up. Median weight gain among quitters after smoking cessation within 6 years was 3.2 kg.
Recent quitters without weight gain within the first 6 years of quitting were less likely to develop CVD compared with people who continued to smoke among all recent quitters, with an adjusted HR of 0.83 (95% CI, 0.7-0.99). In sensitivity analyses stratifying participants by no weight gain or any weight gain, the adjusted HRs for CVD among quitters were 0.77 among those without weight gain (95% CI, 0.62-0.95) and 0.94 among those who experienced weight gain (95% CI, 0.73-1.2)
Weight gain within 6 years after smoking cessation did not attenuate the inverse relation between long-term cessation and all-cause mortality among long-term quitters without weight gain (aHR = 0.69; 95% CI, 0.58-0.82), among long-term quitters with weight gain of 0.1 kg to 5 kg (aHR = 0.57; 95% CI, 0.45-0.71), and among long-term quitters with weight gain of at least 5 kg (aHR = 0.51; 95% CI, 0.42-0.62). Results were similar for CV and cancer mortality.
“Smoking cessation is particularly important for people with type 2 diabetes because their risk of developing cardiovascular disease or other morbidities is substantially augmented by both smoking and insulin resistance or glycemia,” the researchers wrote. “However, smoking cessation is often accompanied by weight gain (eg, mean weight gain of 4-5 kg after 1 year of abstinence), which is a risk factor for cardiometabolic diseases and might dilute the health benefits of quitting.” – by Regina Schaffer
For more information:
Gang Liu, PhD, can be reached at the Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan 430030, Hubei, China; email: email@example.com.
Disclosures: The authors report no relevant financial disclosures.