Cigarette Smoking and Risk of Stroke in the Chinese Adult Population

BACKGROUND AND PURPOSE: We studied the relationship between cigarette smoking and stroke incidence and mortality in the Chinese adult population. METHODS: We conducted a prospective cohort study in a nationally representative sample of 169 871 Chinese men and women aged 40 years and older. Data on cigarette smoking and other covariables were collected at a baseline examination in 1991 using a standard protocol. Follow-up evaluation was conducted in 1999 to 2000, with a response rate of 93.4%. RESULTS: During an average of 8.3 years follow-up, a total of 6780 stroke events (3979 fatal strokes) were observed. The multivariate-adjusted relative risks (95% confidence interval) of stroke incidence and mortality associated with present cigarette smoking were 1.28 (1.19 to 1.37) and 1.13 (1.03 to 1.25) in men and 1.25 (1.13 to 1.37) and 1.19 (1.04 to 1.36) in women, respectively. The corresponding population attributable risks were 14.2% and 7.1% in men and 3.1% and 2.4% in women. Compared to never-smokers, the multivariate-adjusted relative risks of stroke incidence (95% confidence interval) were 1.21 (1.12 to 1.31), 1.21 (1.11 to 1.32), and 1.36 (1.25 to 1.47) for those who smoked 1 to 9, 10 to 19, and >/=20 cigarettes per day; and 1.18 (1.09 to 1.28), 1.25 (1.15 to 1.35), and 1.34 (1.24 to 1.44) for those who smoked 1 to 11, 12 to 26, and >26 pack-years, respectively (both P<0.0001 for linear trends). CONCLUSIONS: Our study identified a positive and dose-response relationship between cigarette smoking and risk of stroke. Smoking prevention and cessation programs should be an important strategy for reducing the burden of stroke in Chinese adults.