# Age‐specific incidence and prevalence of childhood type 1 diabetes: Development over four decades in Southwest Germany

## TL;DR

This study tracks the rise and stabilization of type 1 diabetes in children in Germany over 38 years, noting a peak during the pandemic.

## Contribution

The paper provides a detailed age- and sex-specific analysis of type 1 diabetes trends in Southwest Germany over four decades.

## Key findings

- The incidence of type 1 diabetes doubled from 10.1 to 20.2 per 100,000 children per year between 1987 and 2024.
- The highest incidence was observed in boys aged 10–14 years at 25.4 per 100,000 children per year.
- A marked increase during the pandemic was seen mainly in children under 10 years.

## Abstract

This study evaluated the incidence and prevalence of type 1 diabetes in children and adolescents in Baden–Wuerttemberg over 38 years considering various subgroups.

Data were drawn from the German Diabetes Registry (DIARY) for 11,797 children aged <15 years with clinically diagnosed type 1 diabetes. Incidence rates were calculated per 100,000 person‐years and presented as crude, age‐ and sex‐specific rates, including annual percent changes (APC) from 1987 to 2024.

In 1987, the crude incidence was 10.1 per 100,000 children per year, rising to 20.2 per 100,000 children per year in 2024. Between 1987 and 2008, the incidence increased steadily at 4.0% annually, followed by a plateau through 2024 despite demographic shifts including declining birth rates and increased immigration. The peak incidence occurred during the COVID‐19 pandemic, reaching 31.1 per 100,000 children per year in 2021, before returning to 20.2 per 100,000 children per year by 2024. The highest subgroup incidence was found in boys aged 10–14 years at 25.4 per 100,000 children per year. A marked increase during the pandemic was seen mainly in children under 10 years. The estimated prevalence as of 31 December 2024 was 0.154%.

Incidence rates have doubled since the first documentation in 1987. Since 2008, the rates have remained stable at a high level without further increase. The long‐term trend suggests a levelling off in incidence, with pandemic‐related increases limited primarily to younger children.