Combined Effect of Smoking and Obesity on Coronary Heart Disease Mortality in Male Veterans: A 30-year Cohort Study

Objective Evidence is lacking regarding the combined effects of smoking and obesity on mortality from coronary heart disease in male veterans. This study aimed to explore the combined effect of smoking and obesity on coronary heart disease mortality in male veterans in China. Methods A cohort of 1,268 male veterans from 22 veteran centers in Xi'an (Shaanxi Province, China) were followed up once every 2 years from February 1, 1987 to October 30, 2016. The endpoint was death from any cause. The hazard ratio (HR) of each risk factor and the 95% confidence interval (CI) were calculated using a multivariate Cox proportional hazard model. Results The total follow-up was 24394.21 person-years; each subject was followed up for a mean duration of 19.24 years. By the end of the study, of the 1,268 veterans, 889 had died, 363 were alive, and 16 were lost to follow-up. Cox regression analysis results revealed that current smoking (HR: 1.552, 95% CI: 1.074-2.243), obesity (HR: 1.625, 95% CI: 1.024-2.581), and the combined effect of the two factors (HR: 2.828, 95% CI: 1.520-5.262) were associated with coronary heart disease mortality. Conclusion Our results suggest that obese veterans who smoke might be an important target population for coronary heart disease mortality control.