Trends in the incidence of type 1 diabetes and type 2 diabetes in children and adolescents in North Rhine-Westphalia, Germany, from 2002 to 2022

Abstract

Aims

The objective of this study was to assess overall and segmented trends in the incidence of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) in children and adolescents younger than 20 years, from 2002 to 2022.

Methods

This study used registry data on physician-diagnosed T1DM or T2DM from primary and secondary sources, covering the German federal state of North Rhine-Westphalia with 18 million inhabitants. The ages at T1DM and T2DM onset ranged from 0 to 19 and 10–19 years, respectively. The main outcomes were direct age- and/or sex-standardized incidence rates per 100,000 person-years (PYs) and trends estimated as annual percentage changes (APCs), both with 95 % confidence intervals. The segmented trends for subperiods were based on joinpoint regression models.

Results

From 2002–2022, 17,470 and 819 persons had incident T1DM and T2DM, respectively. The total number of PYs was 73,743,982 for T1DM and 39,210,453 for T2DM, with a mean coverage rate of 98 % for T1DM and 90 % for T2DM. The standardized T1DM incidence increased from 17.6 [16.3;18.9} in 2002 to 33.2 [31.3;35.1] in 2022, with an APC of 2.7 % [2.3 %;3.1 %]. The standardized T2DM incidence increased from 1.3 [0.8;1.7] in 2002 to 2.8 [2.0;3.6] in 2022, with an APC of 6.4 % [4.9 %;8.0 %]. There were four different segmented trends for T1DM and T2DM, with the incidence peaking in 2021 and subsequently declining.

Conclusions

The incidence rates of T1DM and T2DM have increased over the past 20 years, with a wave-like pattern during the Covid-19 pandemic.