[Sex-specific associations between tobacco smoking and risk of cardiovascular diseases in Chinese adults].

Objective: To examine the sex-specific associations between tobacco smoking and risk of cardiovascular diseases in Chinese adults. Methods: The present analysis included 487 373 participants from the China Kadoorie Biobank after excluding those with cancer, heart diseases, stroke at baseline survey. The baseline survey was conducted from June 2004 to July 2008. The number of follow-up years was calculated from the time that the participants completed baseline survey to the time of any event: CVD incidence, death, loss of follow-up, or December 31, 2015, whichever occurred first. We used Cox proportional hazards regression models to estimate the HRs and 95%CI of incident cardiovascular diseases with tobacco smoking. Results: During a median follow-up of 8.9 years(a total of 4.1 million person years), we documented 33 947 cases of ischemic heart diseases, 6 048 cases of major coronary diseases, 7 794 cases of intracerebral hemorrhage, and 31 722 cases of cerebral infarction. The prevalence of smoking was much higher in men (67.9%) than in women (2.7%). Smoking increased risk of all subtypes of cardiovascular diseases. Compared with nonsmokers, the multivariable-adjusted HRs (95% CI) for current smokers were 1.54 (1.43-1.66) for major coronary event, 1.28 (1.24-1.32) for ischemic heart disease, 1.18 (1.14-1.22) for cerebral infarction, and 1.07 (1.00-1.15) for intracerebral hemorrhage, respectively. Female smokers tended to have greater risk of developing major coronary event associated with amount of tobacco smoked daily (interaction P=0.006) and age when smoking started (interaction P=0.011). There was no sex difference in these two effects for ischemic heart diseases, intracerebral hemorrhage and cerebral infarction (all interaction P>0.05). Conclusions: This prospective study confirmed increased risk of all subtypes of cardiovascular diseases in current smokers. Smoking was more harmful to women than to men for major coronary event.