Trends in global risk factors for the development of type 2 diabetes mellitus: Evidence from the global burden of disease study, 1990–2021

AIMS: To explore the geographical and risk factor trends associated with type 2 diabetes mellitus using Global Burden of Disease (GBD) data (1990-2021). METHODS: Age-standardized T2DM incidence, prevalence, mortality and disability-adjusted life years (DALYs) were extracted from the GBD for 204 countries stratified by sociodemographic index (SDI). Trends were analysed using joinpoint regression to compute average annual percentage changes (AAPCs) and mapping. Age-standardized burden estimates were calculated across 5-year age groups. Risk factor attribution was performed using Bayesian meta-regression and spatiotemporal analysis, illustrating the relative importance of each risk factor by bubble plots. RESULTS: From 1990 to 2021, the global age-standardized incidence rate of T2DM increased (AAPC = 1.83%), with the most pronounced rises in low-middle SDI regions. Mortality slightly increased globally (AAPC = 0.30%) but declined in high-SDI regions. The burden was highest in middle-aged and elderly populations, with a concerning increase in adolescent cases. High body mass index (BMI) was the leading risk factor, estimated to account for 44.5% (95% UI: 19.0%-65.2%) of deaths and 51.9% (95% UI: 24.7%-71.5%) of DALYs in 2021, followed by ambient particulate matter pollution and physical inactivity. The contribution of dietary risks and air pollution varied significantly across SDI regions. CONCLUSIONS: Our analysis identifies high BMI, ambient air pollution and physical inactivity as the primary risk drivers of the global T2DM burden. All indicators increased most markedly in low-middle SDI regions, with substantial disparities across age and sex groups. These findings underscore the need for risk-specific and region-tailored preventive strategies.