Ongoing Increase in Incidence of Diabetes in Austrian Children and Adolescents (1989-2021): Results from a Nationwide Registry

Introduction. Since there is no uniform global diabetes trend in childhood and adolescence, regional epidemiological surveys of diabetes incidences are important. In Austria, the incidences of type 1 diabetes (T1D), type 2 diabetes (T2D), and other forms of diabetes have been recorded for decades. Methods. To analyze recent developments of diabetes incidence within the decades long-standing Austrian nationwide prospective population-based incidence study for diabetes in children aged <15 years. We estimated time trends of age-standardized rates from 1989 to 2021 for T1D and T2D by joinpoint analysis. Annual percent changes (APCs) were calculated. Case ascertainment was 97%. Results. We observed an unusual increase of T1D incidence in the year 2021, reaching a peak of 28.7/100,000/PY (person years). From 2011 to 2020, there had been a constant plateau phase in the total cohort (APC 0.78, 95% CI [-0.99, 2.58], p=0.379), which had followed a steep increase of T1D incidence (APC 4.6, 95% CI [3.94, 5.19], p<0.001) from 1989 to 2011. Age-specific differences in T1D incidence development were observed. For the first time, we observed a statistically significant constant increase in T2D during the observation period (APC 3.47, 95% CI [0.76, 6.26], p=0.014). Other forms of diabetes are two times more common than T2D in this age group. Conclusion. The incidence of T1D in Austrian children <15 years is still increasing and showed a peak in 2021. For the first time, a significant increase in pediatric T2D was observed in Austria.