Trends and projected inequalities in type 2 diabetes mellitus mortality in the United States, 1999–2025, with projections to 2035: A CDC WONDER multiple cause of death analysis

Type 2 diabetes mellitus (T2DM) is a major contributor to premature illness and death in the United States. Prevalence is well tracked, but demographically detailed mortality projections are limited. This study describes mortality trends and projects age-adjusted mortality rates (AAMRs) through 2035 across demographic and geographic groups. We conducted an ecological time-series analysis using the CDC WONDER Multiple Cause of Death database to identify deaths with T2DM (ICD-10: E11) recorded on death certificates between 1999 and 2025; data for 2025 are provisional. Annual AAMRs per 100,000 were calculated overall and by sex, age group, race and ethnicity, census region, urbanization, state, and place of death. Trends were assessed with Joinpoint regression. Forecasts to 2035 used an ensemble of two Holt exponential-smoothing specifications fitted to the pre-pandemic window 2008–2019, with race and census-region projections constrained to be coherent with the national forecast (product-ratio method). We identified 2,334,931 deaths. The overall AAMR rose from 21.51 in 1999 to 56.27 in 2025, an average annual percent change (AAPC) of 3.44 (95% CI: 2.11–4.78; p < 0.001). Rates increased from 1999 to 2005, were stable to 2015, rose sharply to 2021, and declined modestly through 2025. AAMRs were higher in men, highest at 65–85+, and greatest among non-Hispanic American Indian/Alaska Native adults, with Hispanic/Latino and non-Hispanic Black adults elevated at similar levels. The West and non-metropolitan areas had the highest mean AAMRs. The overall AAMR is projected to reach 67.03 per 100,000 by 2035 (95% model-based prediction interval 57.57 to 76.48; empirically calibrated 95% upper bound 148.17), approximately 19% above the 2025 rate, with the highest projected rates among non-Hispanic American Indian/Alaska Native adults (115.94) and in the West (88.79); the projection resumes below the 2025 observation. Urbanization projections, resting on data ending in 2020, are a sensitivity analysis. T2DM-related mortality increased substantially from 1999 to 2025 and is projected to keep rising through 2035, with persistent demographic and geographic disparities. These patterns identify populations carrying a disproportionate and growing burden, for whom earlier prevention, stronger risk-factor control, and more equitable access to reno-protective and cardio-protective therapies are priorities.