Type 2 diabetes burden, inequalities, and epidemiological patterns among postmenopausal women, 1990–2021: a global ecological modelling study

Background Type 2 diabetes mellitus (T2DM) is a major global cause of mortality and morbidity globally. Postmenopausal women bear a disproportionately high burden due to the intertwined effects of aging, biological changes, and structural disadvantages. This study aims to assess the global burden, temporal trends, health inequalities, associated risks and divergent epidemiological patterns of T2DM among this population. Methods Data regarding the incidence and mortality rate of T2DM in postmenopausal women were obtained from the Global Burden of Disease Study 2021. Women aged ≥ 55 years were used as an age-based operational proxy for postmenopausal status. Temporal trends were assessed using estimated annual percent changes (EAPC). We applied several machine learning methods, including K-means and hierarchical clustering, ensemble tree-based models (Random Forest and XG Boost) with SHAP analysis to assess the divergent burden and risk profiles and among postmenopausal women globally. Results Globally, the incidence rate of T2DM among postmenopausal women increased by 1.40% per year (95% CI 1.35–1.44) since 1990, reaching nearly 600 cases per 100,000 population in 2021. Marked health inequalities persisted, with substantially higher mortality burdens observed in lower-SDI (Sociodemographic index) countries. Three distinct disease patterns were identified: 83 countries, primarily in the Middle East, Southeast Asia, the USA, and Russia, showed a high and rapidly increasing pattern, whereas 33 countries, mainly small island developing states, had the highest incidence rates but relatively stable trends. Three risk profiles were also observed, with Western dietary risks and high LDL cholesterol more prevalent in higher-SDI countries, while high sodium intake and low fruit consumption predominated in Asian and African countries. Trend-based projections suggested continued increases in T2DM incidence rates globally, with persistent inequalities. Conclusions Postmenopausal women face a substantial and growing T2DM burden, marked by pronounced geographic and socioeconomic inequities and heterogeneous risk patterns. These findings underscore the need to move beyond one-size-fits-all strategies toward tailored prevention and healthcare strategies.