Emerging data from US cohort studies imply that the costs of gout and hyperuricemia are disproportionately greater for adults claiming Black race, and for Black women in particular than for those reporting White race. These racial variances may stem from differences in non-genetic, primarily changeable gout risk factors such as body mass index (BMI), diet, and chronic kidney disease (CKD). However, there is a lack of population-level information on racial disparities in the burden of gout and possible mediators at the national level, broken down by sex. In this study, researchers used a nationally representative sample of US adults of both sexes to identify and quantify sex-specific mediators of racial disparities in gout prevalence. With the most recent 10 years’ worth of data (2007-2016) on physician-diagnosed gout and hyperuricemia from the National Health and Nutrition Examination Survey, investigators compared current sex- and race-specific prevalences and performed sequential causal mediation analysis (adjusting for upstream mediators following causal pathways) to determine what percentage of the racial differences can be attributed to 7 potentially mediating social and clinical factors: low education, low education, poverty, BMI, alcohol, poor quality diet, diuretic use, and CKD (eGFR < 60 mL/min, using latest equations that do not include a coefficient for the Black race, per National Kidney Foundation and American Society of Nephrology recommendations.) Black women (3.5%) were more likely to get gout than White women (2%) were (age-adjusted OR =1.8 [95% CI: 1.3 to 2.5]), while the corresponding figures for Black and White males were 7.0% and 5.4% (age-adjusted OR =1.3 [1.0 to 1.6]). About 6 of the 7 risk factors were more common or higher in black adults than whites, while blacks consumed less alcohol overall (both sexes). Black women had a higher BMI and poverty rate than White women, while White males had similar rates. Variations in gout prevalence by race were canceled out after accounting for the 6 risk variables. The most moderating factor of the racial difference in gout cases among Black women was body mass index (BMI) excess, which accounted for 56% of the phenomenon (independent of education, poverty, food, and alcohol), followed by CKD (24%), poverty (17%), and poor-quality diet (12%). The prevalence of CKD (46%), dietary quality (20%), and diuretic use (14%) were the most common mediators among males. The percentage of the racial difference that was mediated by BMI (12%) and poverty (0.5%) was higher among women than males. Differences in hyperuricemia by race and its mediators correlated strongly with gout incidence. Among adult U.S. blacks, gout is more common than among whites, especially among women (2-times greater in Black women vs. White). About 6 primarily modifiable clinical and social/environmental factors, including CKD, diuretics, and nutrition quality, account for these ethnic variations. Weight-related issues and economic hardship were far more significant for females. Gout inequalities may be mitigated if more attention is paid to these cultural elements.
