MILAN — Rates of both type 1 diabetes (T1D) and type 2 diabetes (T2D) are rising among youth in the United States, while the global T1D burden is expected to skyrocket in the coming years, data from two epidemiologic studies suggest. 

Results of both studies are being presented separately here at the European Association for the Study of Diabetes (EASD) 2026 Annual Meeting.

T2D Outpacing T1D in American Youth 

The incidence of T1D in those younger than 20 years has been rising since 2014, while T2D in that age group has been increasing steadily — and at a higher rate than T1D, since 2003 — said epidemiologist Tessa Crume, PhD, of the Colorado School of Public Health, Aurora.

"What's going on in Colorado is not unique to Colorado," she told Medscape Medical News. "This has been happening at a larger scale throughout the United States…It points to the importance of screening teens for metabolic health." 

The data come from the Colorado Youth Diabetes Registry, which since 2002 has conducted annual ascertainment of diabetes incidence among youth younger than 20 years across health systems in the state, from electronic health records. Incidence rates are presented per 100,000 youth aged less than 20 years for T1D and per 100,000 youth aged 10-19 years for T2D. 

Overall, from 2002 through 2023, the annual percentage change (APC) in T1D was 1.49% (P < .001). But, during 2002-2014, the APC of 0.66% was not significant, while there was a sharp increase in APC to 2.62% during 2015-2023 (P < .001). 

Comparing the years 2002-2003 with 2022-2023, the steepest incidence increases were seen among youth aged 15-19 and in Black and Hispanic youth. 

For T2D, the overall increase from 2002 to 2023 was greater than for T1D, 3.79% APC overall (P < .001). Here, the rise was significant going back to 2002, but there was a spike from 2.92% (P < .001) during 2002-2013 to 4.72% in 2014-2023 (P < .001). Here, the steepest rises were among males and again in Black and Hispanic youth.

"Type 2 diabetes is rising faster than type 1 and, by 2002 to 2023, exceeded type 1 incidence among 15- to 19-year-olds," Crume noted, adding that the pace of change over two decades is too fast to reflect shifts in genetic susceptibility, implicating environmental and social drivers. The COVID pandemic likely played a role in the latter-year spikes, she told Medscape. 

Global T1D Rising Burden Projected 

Worldwide, the number of children and adults living with T1D is projected to increase from 9.4 million in 2025 to 12.2 million by 2049, according to Morten Bjerregaard-Andersen, MD, PhD, of the Department of Endocrinology and Nephrology at the University Hospital of Southern Denmark, Esbjerg, who will present on Wednesday. 

"Clinicians should prepare for more T1D patients in the future, both in hospital wards and outpatient clinics," Bjerregaard-Andersen told Medscape Medical News.

The data were derived from the DIAMOND-T1D model, which provides global, regional, and country-specific estimates of T1D incidence, prevalence, and mortality going back to 1900, projecting through to 2050. The model incorporates available data on T1D incidence, country demographics, population survival, and the date of introduction of insulin in each country, combined with assumptions regarding age-specific T1D incidence and mortality rates. It has been validated against population-based register data in Denmark and Scotland. 

Globally, the model estimates that T1D incidence will rise from 532,970 cases in 2025 to 608,638 by 2049, with the largest increase expected in low-income countries. Youth aged 0-19 years are expected to account for 42% of the incident cases in 2025, ranging from 37% in high-income countries to 49% in low-income countries. Thus, "the vast majority of people living with T1D are adults, and will be so also in the future," said Bjerregaard-Andersen.

Mortality related to T1D is estimated to increase from 353,449 in 2025 to 531,095 in 2049. Youth aged 0-19 years were estimated to account for 15% of T1D global deaths in 2025, ranging from 4% of T1D deaths in high-income countries to 34% in low-income countries. 

The reason for the increasing T1D prevalence "mainly relates to improved survival in persons with T1D, due to better treatments such as continuous glucose monitors, insulin pumps, and modern insulin analogues, and also combined with better treatments for diabetic complications," he said.  

However, the reason for the increased incidence is less certain, "but it likely has to do with a complex interplay between environmental and genetic factors. It is a trend observed in other data." 

The authors report no disclosures. 

Miriam E. Tucker is a freelance journalist based in the Washington DC area. She is a regular contributor to Medscape, with other work appearing in the Washington Post, NPR's Shots blog, and Diatribe. She is on X (formerly Twitter) @MiriamETucker and BlueSky @miriametucker.bsky.social