Global type 1 diabetes prevalence, incidence, and mortality estimates 2025: Results from the International diabetes Federation Atlas, 11th Edition, and the T1D Index Version 3.0

AIMS: Globally, symptomatic type 1 diabetes (T1D) prevalence varies markedly. The International Diabetes Federation 11thEdition Atlas/T1D Index Version 3.0 estimated 2025 numbers for 202 countries/territories ("countries"), and projected to2040.

METHODS: The T1D Index model, a Markov model with sub-models for incidence-over-time, adult incidence, and mortality-over-time, was updated with recent population-based T1D incidence, mortality and prevalence studies. For countries without studies, data were extrapolated from countries with similarsettings.

RESULTS: There are estimated 9.5 million people living with T1D globally (compared to 8.4 million in 2021, a 13 % increase), with 1.0 million of these aged 0-14, and 0.8 million aged 15-19 years. In lower-income countries, prevalent cases increased by 20 % from 1.8 million in 2021 to 2.1 million in 2025. Incident cases in 2025 are an estimated 513,000 (164,000 aged 0-14 and 58,000 aged 15-19 years), with incidence increasing by 2.4 % in the last year. Premature deaths are estimated at 174,000, with 17.2 % of these due to non-diagnosis soon after clinical onset. The estimated remaining life expectancy of a 10-year-old child diagnosed with T1D in 2025 varies between countries from 6 to 66 years. There are still no data available for 119 countries. The projectedT1D population for 2040 is estimated to be14.7 million.

CONCLUSIONS: The number of global T1D cases is rising quickly, especially in lower-income settings, due to increasing diagnosed incidence, falling mortality and ageing, and population growth. Contemporary data are unavailable for over 50% of all countries, highlighting need for epidemiological studies.