Abstract: Objective The aim of study was to investigate gender differences in the burden of non-alcoholic fatty liver disease (NAFLD among the BRICS countries, e.g., Brazil, Russia, India, China and South Africa, and to analyze the epidemiologic trends in disease burden from 1990 to 2023. Methods Data on the incidence and disability adjusted life years (DALYs) of NAFLD in the BRICS countries were extracted from the Global Burden of Disease Study 2023 (GBD 2023). Age-standardized rates were applied for cross-country comparisons, and long-term trends were analyzed by using linear mixed-effects models. Factors influencing gender differences were assessed with generalized linear models. Future burden was predicted by using Bayesian age-period-cohort model (BAPC). Results In 2023, the incidence of NAFLD in BRICS countries exhibited a progressive decline in the male-to-female ratio with elderly age, culminated in a gender reversal within specific age groups, notably, earliest onset of this reversal (30 to 34 year-old) in China, whereas in India demonstrated the most delayed occurrence (60 to 64 year-old); from 1990 to 2023, both the incidence and mortality rates associated with NAFLD across BRICS nations demonstrated a sustained upward trends, and the highest increase in NAFLD incidence [42.4% (95% CI: 42.1-43.3) and average annual percent change (AAPC)=1.16 in India, while the most obvious rise in mortality [431.5% (95% CI: 409.6-456.2) and AAPC=6.18] in Russia; disability-adjusted life year trends analysis and prediction based on the Bayesian age-period-cohort model from 1990 to 2023 revealed different trends among BRICS countries, e.g., a progressive decline in disease burdens in China and India, a continuous increase in Russia and South Africa, and a relatively stable disease burden in Brazil throughout the study period. Conclusion Prevalence of NAFLD in BRICS countries is common in middle-aged and young male adults and elderly female, with a significant differencewith countries, ages and gender.

Key words: Non-alcoholic fatty liver disease, Global burden of disease, Gender, Epidemiology, BRICS countries