ABSTRACT
Objective To investigate the association of smoking status with incident cardiovascular disease (CVD) and its subtypes among the middle-aged and older male populations. Methods This study included 13 940 males from Dongfeng-Tongji (DFTJ) cohort who were free of coronary heart disease (CHD), stroke, cancer or severely abnormal electrocardiogram (ECG) at baseline. All participants completed baseline questionnaires, physical examinations, clinical biochemical tests and blood sample collection. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confident intervals (CI) for the association analyses. Results Compared with never smokers, current smokers had significant higher risks of CVD, CHD and stroke, the adjusted HRs of current smokers who smoked for more than 40 pack-years were 1.49 (95% CI: 1.32-1.68, Ptrend=0.001), 1.40 (95% CI: 1.22-1.62, Ptrend=0.026) and 1.59 (95% CI: 1.26-2.00, Ptrend=0.029) for CVD, CHD and stroke, respectively; and the adjusted HRs of current smokers who started smoking before 20 years old were 1.29 (95% CI: 1.06-1.58, Ptrend=0.007) and 1.30 (95% CI: 1.03-1.64, Ptrend=0.010) for CVD and CHD, respectively. Former smokers who had quitted smoking for 10 or more years had significant lower risks of CVD (HR: 0.80, 95% CI: 0.71-0.91, Ptrend=0.017) and stroke (HR: 0.65, 95% CI: 0.50-0.84, Ptrend=0.207) when comparing to current smokers. Conclusions Smoking is significantly associated with higher risks of CVD, CHD and stroke, and greater amount of smoking and earlier age at smoking initiation are associated with a higher risk of CVD. Smoking cessation can reduce the risk of CVD.