Increased risk of gout among patients with bipolar disorder: a nationwide population-based study

This study aims to explore the association between bipolar disorder and the risk of gout using a nationwide population-based dataset. We used the 1996-2006 data from the Taiwan National Health Insurance Research Database. The study cohort comprised 24,262 patients who had visited outpatient departments for the treatment of bipolar disorder in the year 2000. A total of 121,310 enrollees matched with the study group in terms of age and gender, and were selected as the comparison cohort. Each patient was tracked 6 years from the index outpatient visit in 2000 until 2006 to identify all who had developed gout. Cox proportional hazard regressions were performed to compute the 6-year gout-free survival rate, adjusting for other variables. We found that gout occurred among 16.4% of the patients with bipolar disorder and 13.6% of the patients in the comparison cohort between 2000 and 2006 (P<0.001). After adjusting for potential confounders, the regression analysis shows that the hazard of developing gout during the 6-year follow-up period was 1.19 greater (95% confidence interval (CI)=1.10-1.24, P<0.001) for patients with bipolar disorder than their counterparts in the comparison cohort. We conclude that patients with bipolar disorder had increased risk of developing gout even after adjusting for possible confounding factors.