Health inequalities in gout burden across G20 countries: comparative attribution to high BMI and impaired kidney function, 1990–2050 (GBD 2021)

Gout is a growing global health challenge, yet the relative roles of metabolic/renal risks and burden inequalities across G20 nations remain unclear. This study quantifies gout burden from high BMI and impaired kidney function to inform equity-oriented public health strategies. It is grounded in the GBD comparative risk assessment framework, plus demographic transition, socioeconomic gradient theories, and biological mechanisms linking the two risk factors to hyperuricemia and gout disparities. We analyzed 1990–2021 GBD 2021 data for G20 countries, including disability-adjusted life years (DALYs), years lived with disability (YLDs), and age-standardized rates (ASRs), stratified by sex, age, Socio-Demographic Index (SDI). Temporal trends were quantified via estimated annual percentage change (EAPC), burden drivers decomposed, and 2022–2050 trends projected using multiple models. Gout burden exhibited marked geographic heterogeneity, with higher risks in adults ≥70 years and males. 1990–2021 attributable DALYs/YLDs rose steadily (high BMI as dominant driver), with epidemiological changes and aging as key contributors. 2050 projections show rising cases and persistent male predominance. Disparities stem from socioeconomic, policy, and genetic factors; gout-CVD comorbidities and pediatric cases are critical gaps. We advocate integrated strategies and embedding gout in chronic disease frameworks to reduce inequalities.