Objective To analyze the spatiotemporal trends in hepatitis B-related mortality and disability-adjusted life years (DALYs) attributable to high BMI at the global, regional, and national levels. Methods We extracted data on hepatitis B-related mortality numbers, DALYs, age-standardised mortality rates (ASMR), and age-standardised DALY rates (ASDR) attributed to high BMI from the GBD 2021 database for the period 1990-2021, stratified by gender, age, country, and social demographic index (SDI). Time trends were assessed using estimated annual percentage change (EAPC), and decomposition analysis and frontier analysis were employed to identify the drivers of burden changes and leading countries. Inequality indicators (inequality slope index SII and concentration index CI) were used to measure health disparities across SDI levels, and the Bayesian Age Period Cohort Model (BAPC) was applied to predict disease trends up to 2050. Results The global burden of hepatitis B disease attributable to high BMI continues to rise. In 2021, the number of DALYs reached 499 900 (four times that of 1990), and the number of deaths was five times that of 1990. The burden and rate of increase were most pronounced in Asia: in 2021, East Asia recorded 7 919.70 deaths (95%UI 2 984.05 to 14 386.39) and 257 954.31 DALYs (95%UI 97 807.17 to 482 232.54), ranked highest among the 21 GBD regions; From 1990 to 2021, South Asia recorded the fastest increase in ASMR (EAPC=4.99, 95%CI 4.83 to 5.16) and the highest growth rate in ASDR (EAPC=4.92, 95%CI 4.74 to 5.10); at the national level, China and the United States had the heaviest burden. Countries with medium SDI had the highest burden, peaking at an SDI of 0.65. Global and regional decomposition analyses indicate that epidemiological changes are the primary drivers of the increased burden. The CI and SII values derived from inequality analyses of ASDR and ASMR have both increased, indicating worsening health inequalities. Frontier analysis further confirmed that certain countries, such as Tonga and Mongolia, bear a significantly higher burden than expected for their developmental level, demonstrating marked disparities in disease burden across nations. The BAPC model predicts that the burden attributable to high BMI will continue to rise in the absence of interventions. Conclusion High BMI has become an important risk factor for hepatitis B-related diseases globally, with the burden particularly pronounced in Asian regions and middle-income countries. Health inequalities must not be overlooked. Precise interventions should be implemented based on regional, gender, and age differences.
