Cigarette Smoking and the Risk of Incident Gout in a Prospective Cohort Study

Objective. Cigarette smoking is shown to reduce serum urate. However, its impact on risk of gout is unknown. We prospectively examined the relationship between cigarette smoking and gout risk in this Asian cohort. Methods. We analyzed the data from the Singapore Chinese Health Study, a cohort of 63,257 Chinese ages 45-74 years at recruitment in 1993-1998. Information on cigarette smoking and other lifestyle factors was collected through in-person interviews at recruitment. This analysis included 53,213 participants who took part in either the first followup (1999-2004) and/or the second followup interviews (2006-2010). Cox proportional hazards models were used to assess the relationship between cigarette smoking and gout risk. Results. A total of 2,244 incident cases of physician-diagnosed gout were identified after a mean followup of 11.1 years. Among men, compared to never smokers, the risk of gout in current smokers was decreased by 27% (hazard ratio [HR] 0.73 [95% confidence interval (95% CI) 0.63-0.84]). This risk reduction was greater in lean male smokers (HR 0.69 [95% CI 0.57-0.83]) than overweight smokers (HR 0.87 [95% CI 0.67-1.13]) (P=0.09 for interaction). This inverse association with smoking was rapidly attenuated to become null even in former smokers who had recently quit smoking. Conversely, there was no association between smoking and gout risk in women. In a companion cross-sectional study, current smokers had significantly lower levels of serum urate than former and never smokers, and this observation was present in men and not women. Conclusion. Current smoking is associated with lower risk of gout in men in this Asian cohort.