Type 2 diabetes in teens rises nearly 10-fold

Clinical takeaway: A high-BMI teen with high blood sugar could have either type of diabetes, making autoantibody and metabolic testing the deciding step. 

For most of the modern era, type 2 diabetes surfaced during middle age. A teenager presenting with hyperglycemia could be assumed to have type 1 diabetes, until proven otherwise. But that assumption is eroding as obesity rates climb. As type 2 diabetes has moved into adolescence, the two conditions have come to look increasingly alike at diagnosis even though they demand different treatment. 

Two decades of continuous, population-level surveillance from the Colorado Diabetes Registry quantified the shift. Between 2002 and 2023, new-onset type 2 diabetes among youth aged 10 to 19 climbed to 22.30 cases per 100,000, up from 2.37. The pace picked up as well: annual growth from 2014 on ran half again faster than in the years before. Type 1 diabetes barely moved by comparison. 

Type 1 diabetes had its own inflection: incidence held flat from 2002 through 2014, then began rising 2.62% annually. By 2023 its rate stood at 27.39 per 100,000. Why type 1 incidence also rose remains unknown, leading explanations involve potential environmental triggers acting on genetically susceptible children. Better detection contributes to, but does not entirely account for, the rise.

Ascertainment ran across Colorado's health systems from 2002 through 2023, identifying new diagnoses through diagnosis codes, laboratory results, and medication data, with census data supplying population denominators. Eligible youth were non-military, non-institutionalized Colorado residents at diagnosis. Rates were calculated per 100,000 youth under 20 for type 1 diabetes and per 100,000 ages 10 to 19 for type 2, since type 2 diabetes under age 10 is extremely rare. 

The authors say the overlap with type 1 is now the clinical reality: a teenager's presentation no longer reveals the diabetes type. And the urgency, they argue, comes from the disease course itself. Youth-onset type 2 diabetes runs more aggressive than the adult form: insulin-producing cells decline faster, glucose is harder to control, and kidney, eye, nerve, and heart complications can arrive within years rather than decades, with an associated shortening of life expectancy. A child diagnosed as a young teen faces those potential complications in early adulthood, which is why recognition and correct classification cannot wait. 

"The services needed, then, are not only about capacity to treat a growing number of young people; they are about ensuring that every child with new-onset diabetes receives proper autoantibody and metabolic testing rather than being classified on impression," said Tessa Crume of the Colorado School of Public Health. 

Source: Crume TL, et al. (2026 Sep 28) EASD Annual Meeting. Trends in type 1 and type 2 diabetes incidence in youth over a 21-year period in Colorado, USA