Familial Risk of Gout and Interaction With Obesity and Alcohol Consumption: A Population‐Based Cohort Study in Korea

Objective Population‐based studies of the familial aggregation of gout are scarce, and gene/environment interactions are not well studied. This study was undertaken to evaluate the familial aggregation of gout as well as assess interactions between family history and obesity or alcohol consumption on the development of gout. Methods Using the Korean National Health Insurance database, which includes information regarding familial relationships and risk factor data, we identified 5,524,403 individuals from 2002 to 2018. Familial risk was calculated using hazard ratios (HRs) with 95% confidence intervals (95% CIs) to compare the risk in individuals with and those without affected first‐degree relatives. Interactions between family history and obesity/alcohol consumption were assessed on an additive scale using the relative excess risk due to interaction (RERI). Results Individuals with a gout‐affected first‐degree relative had a 2.42‐fold (95% CI 2.39, 2.46) increased risk of disease compared to those with unaffected first‐degree relatives. Having both a family history of gout and being either overweight or having moderate alcohol consumption was associated with a markedly increased risk of disease, with HRs of 4.39 (95% CI 4.29, 4.49) and 2.28 (95% CI 2.22, 2.35), respectively, which exceeded the sum of their individual risks but was only statistically significant in overweight individuals (RERI 0.96 [95% CI 0.85, 1.06]). Obese individuals (RERI 1.88 [95% CI 1.61, 2.16]) and heavy drinkers (RERI 0.36 [95% CI 0.20, 0.52]) had a more prominent interaction compared to overweight individuals and moderate drinkers, suggesting a dose‐response interaction pattern. Conclusion Our findings indicate the possibility of an interaction between gout‐associated genetic factors and obesity/alcohol consumption.