Body mass index and the risk of gout: a systematic review and dose-response meta-analysis of prospective studies

Greater body fatness has been associated with increased risk of gout in several studies; however, the strength of the association has differed between studies, and it is not clear whether the association differs by gender. We conducted a systematic review and meta-analysis of prospective studies to clarify the association between adiposity and risk of gout. PubMed and Embase were searched up to August 30, 2013. Summary relative risks (RRs) were calculated using a random effects model. Ten prospective studies of body mass index (BMI) and gout risk with 27,944 cases and 215,739 participants were included (median follow-up 10.5 years). The summary RR for a 5 unit increment was 1.55 [95 % confidence interval (95 % CI) 1.44-1.66, I (2) = 67 %] for all studies combined. The heterogeneity was explained by one study, which appeared to be an outlier. The summary RR per 5 BMI units was 1.62 (95 % CI 1.33-1.98, I (2) = 79 %) for men and 1.49 (95 % CI 1.32-1.68, I (2) = 30 %) for women, p (heterogeneity) = 0.72. The relative risks were 1.78, 2.67, 3.62, and 4.64 for persons with BMI 25, 30, 35, and 40 compared with persons with a BMI of 20. BMI in young adulthood, waist-to-hip ratio, and weight gain from age 21-25 to midlife were also associated with increased risk, but few studies were included in these analyses. Greater body mass index increases risk of gout. Further studies are needed on adiposity throughout the life course, waist-to-hip ratio, and weight changes in relation to gout as there were few studies that had published on these exposures.