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.