Abstract
AIM: We aimed to investigate if the incidence of type 1 diabetes increased in children during the SARS-CoV-2 pandemic and whether SARS-CoV-2 antibodies were more frequently present at diagnosis compared with healthy individuals. We also examined whether clinical characteristics and coexisting autoimmunity differed between SARS-CoV-2 antibody positive and negative individuals. METHODS: This retrospective, longitudinal observational study included children aged 0-17 years diagnosed with type 1 diabetes between 01 January 2018 and 31 December 2023 at Skåne University Hospital, Sweden. Blood samples were analysed for SARS-CoV-2 antibodies and islet autoantibodies and compared to analyses of healthy children from the same period. Clinical characteristics and thyroid autoimmunity at onset were collected from medical records. RESULTS: The incidence of type 1 diabetes increased from 40/100.000 (pre-pandemic) to 53/100.000 (pandemic). Children diagnosed with type 1 diabetes more likely tested positive for SARS-CoV-2 nucleocapsid protein (NCP) antibodies compared to healthy children. The SARS-CoV-2-NCP positive group had a higher prevalence of thyroid autoimmunity compared to the SARS-CoV-2-NCP negative group. CONCLUSION: The incidence of type 1 diabetes increased during the SARS-CoV-2 pandemic, with a possible connection to COVID-19. Interestingly, children positive for SARS-CoV-2 antibodies at type 1 diabetes diagnosis had a higher likelihood of thyroid autoimmunity compared to children negative for SARS-CoV-2 antibodies.