Although the literature on childhood diabetes has traditionally focused on Type 1 diabetes (T1D), youth-onset Type 2 diabetes (T2D) and its associated morbidities have become increasingly prevalent. This study reports on the incidence and demographics of a population-based cohort of children diagnosed with diabetes over a 50-year period.AIMSAlthough the literature on childhood diabetes has traditionally focused on Type 1 diabetes (T1D), youth-onset Type 2 diabetes (T2D) and its associated morbidities have become increasingly prevalent. This study reports on the incidence and demographics of a population-based cohort of children diagnosed with diabetes over a 50-year period.Medical records of patients < 22 years diagnosed with diabetes from January 1, 1970, through December 31, 2019, were retrospectively reviewed using the Rochester Epidemiology Project, a database of clinics and hospitals in Olmsted County, Minnesota.METHODSMedical records of patients < 22 years diagnosed with diabetes from January 1, 1970, through December 31, 2019, were retrospectively reviewed using the Rochester Epidemiology Project, a database of clinics and hospitals in Olmsted County, Minnesota.Of 606 children diagnosed with diabetes, 519 (85.6%) were diagnosed with T1D at a mean age of 10.9 ± 5.3 years. 87 (14.4%) were diagnosed with T2D at a mean age of 17.4 ± 3.4 years. The incidence of T2D increased 23-fold (p < 0.001) over the five-decade period (5 per 100,000 children/year) while T1D remained stable (26 per 100,000 children/year; p = 0.08). The mean body mass index at T2D diagnosis (35.5 kg/m2 ± 10.4) was significantly higher than in T1D (18.9 kg/m2 ± 4.6 95% CI for difference 14.2-19.0; p < 0.0001). Sixty-nine percent of children diagnosed with T2D were female, and the hazard ratio of developing diabetic retinopathy in females with T2D compared to males was 6.83 (95% CI 1.53-30.44; p = 0.012).RESULTSOf 606 children diagnosed with diabetes, 519 (85.6%) were diagnosed with T1D at a mean age of 10.9 ± 5.3 years. 87 (14.4%) were diagnosed with T2D at a mean age of 17.4 ± 3.4 years. The incidence of T2D increased 23-fold (p < 0.001) over the five-decade period (5 per 100,000 children/year) while T1D remained stable (26 per 100,000 children/year; p = 0.08). The mean body mass index at T2D diagnosis (35.5 kg/m2 ± 10.4) was significantly higher than in T1D (18.9 kg/m2 ± 4.6 95% CI for difference 14.2-19.0; p < 0.0001). Sixty-nine percent of children diagnosed with T2D were female, and the hazard ratio of developing diabetic retinopathy in females with T2D compared to males was 6.83 (95% CI 1.53-30.44; p = 0.012).The incidence of youth-onset T2D increased significantly over the 50-year period while the incidence of T1D remained stable. A higher proportion of females were diagnosed with youth-onset T2D. Females with T2D were more than six times likelier to develop diabetic retinopathy than males.CONCLUSIONSThe incidence of youth-onset T2D increased significantly over the 50-year period while the incidence of T1D remained stable. A higher proportion of females were diagnosed with youth-onset T2D. Females with T2D were more than six times likelier to develop diabetic retinopathy than males.