Abstract: Objective The aim of this study was to investigate global disease burden and epidemic trends and non-alcoholic fatty liver disease (NAFLD) over the past three decades in the world. Methods Based on the global burden of disease (GBD) data in 2021,this study retrieve relevant data of NAFLD all over the world. The analysis was conducted by using annual percentage change (APC), estimated annual percentage change (EAPC) and percentage change to assess epidemic trends of NAFLD burden and employed a Joinpoint regression analysis model to quantitatively describe its significant points of change. Pearson correlation coefficient was applied to evaluate geographical disparities in the NAFLD disease burden. Results From 1990 to 2021, the prevalence of NAFLD worldwide increased significantly; the crude number of cases rose from 564.43 million to 1267.87 million, with an increase rate as high as 125%, and the EAPC was 1.4 (95% confidence interval: -1.33-4.2); the Joinpoint regression analysis showed that the NAFLD prevalence particularly significantly increased during the period from 2008 to 2015; the prevalence and incidence of NAFLD had an inverted U-shaped changes as the sociodemographic index (SDI) varied, e.g., with the increase of SDI, the prevalence and incidence of NAFLD showed a trend of rising first and falling thereafter; in terms of risk factors, the research indicated that metabolic factors, such as high fasting blood glucose was the main drivers of NAFLD, and in the past 30 years, the proportion of metabolic factors in the pathogenesis of NAFLD had significantly increased; furthermore, the incidences of liver cirrhosis, non-alcoholic steatohepatitis (NASH), and even primary liver cancer derived from NAFLD increased in most regions around the world. Conclusion Overall, over the past 30 years, the disease burden of NAFLD has significantly increased globally, and its epidemic characteristics show significant heterogeneity at different regions, countries, ages and genders, indicating the necessity of constructing a multi-dimensional and hierarchical precise prevention and control system. This study might provide a key epidemiological evidence for the precise management and intervention strategies of the entity.

Key words: Non-alcoholic fatty liver disease, Global burden of disease, Metabolic syndrome, Socio-demographic index