The COVID-19 pandemic affects seasonality with increasing cases of new-onset type 1 diabetes in children from the worldwide SWEET registry
Aims: To analyze whether the COVID-19 pandemic increased the number of cases or impacted seasonality of new-onset type 1 diabetes (T1D) in large pediatric diabetes centers globally.
Methods: 17.280 cases of T1D diagnosed 2018 – 2021 from 92 worldwide centers participating in the SWEET registry were analysed using hierarchic linear regression models.
Results: The average number of new-onset T1D per center adjusted for the total number of patients treated at the center per year and stratified by age groups increased from 11.2 [95%-confidence interval: 10.1-12.2] in 2018 to 21.7 [20.6-22.8] in 2021 in the youngest age group <6 years, from 13.1 [12.2-14.0] in 2018 to 26.7 [25.7-27.7] in 2021 in children 6 to <12 year and from 12.2 [11.5-12.9] to 24.7 [24.0-25.5] in adolescents 12 to 18 years (all p<0.001). These increases remained within the expected increase with the 95%-confidence interval of the regression line. However, in Europe and North America following the lockdown early in 2020, the typical seasonality of more cases during winter season was delayed with a peak during the summer and autumn months. While the seasonal pattern in Europe returned to pre-pandemic times in 2021 this was not the case in North America. Compared to 2018-2019 (HbA1c 7.7%), higher average A1c levels (2020: 8.1%, 2021: 8.6%, p<0.001) were present within the first year of T1D during the pandemic.
Conclusions: The slope of the rise in pediatric new-onset T1D in SWEET centers remained unchanged during the COVID pandemic but a change in the seasonality at onset became apparent.