The global burden of early‐onset type 2 diabetes (1990–2050): An age–period–cohort analysis of incidence, disparities, and projections

Abstract Background Early‐onset type 2 diabetes mellitus ( T2DM ), diagnosed between 15 and 39 years of age, poses a major public health challenge worldwide. Using data from the Global Burden of Disease Study ( GBD ) 2021, this study aimed to comprehensively assess its global burden, trends, and inequalities from 1990 to 2021, and to project the future burden to 2050. Methods We analysed age‐standardised incidence ( ASIR ), prevalence ( ASPR ), mortality ( ASMR ), and disability‐adjusted life years ( ASDR ) rates across 204 countries. Analyses included trend analysis, socioeconomic inequality assessment, decomposition, frontier analysis, risk factor analysis, and Bayesian modelling for projections. Results Between 1990 and 2021, global prevalent cases increased by 222.32%. ASIR , ASPR , and ASDR all rose significantly, with estimated annual percentage changes ( EAPCs ) of 2.45, 2.85, and 2.10, respectively. The burden peaked in middle‐sociodemographic index ( SDI ) regions and South/East Asia, while Oceania had the highest ASRs . The 35–39‐year age group and males bore the highest burden. Socioeconomic inequalities widened, with a 35% increase in mortality disparity affecting low‐income populations. Epidemiological changes were the primary driver of increased incidence and DALYs . High BMI accounted for 44.7%–69.2% of attributable DALYs . We project ASIR will rise to 529.52 per 100 000 by 2050, with 17.14 million new cases. Conclusions The global burden of early‐onset T2DM rose markedly over the past three decades, with distinct disparities. Persistent inequalities, the dominant role of high BMI , and projected increases highlight an urgent need for targeted prevention in younger populations and high‐risk groups.