• Last updated: Wed, Dec 10, 2025 Status: Published   Read paper
• Diabetologia, September 2025
• Annelie Carlsson, Dominik Dietler, Elsa Palmqvist, Louise Bennet, and Magnus Jöud

Trends in type 1 diabetes incidence between 2007 and 2023 and their association with SARS-CoV-2 infection in a population-based matched cohort study among individuals under 30 years old in Sweden

Type 1 diabetes is one of the most common chronic diseases in children. Sweden has the second-highest incidence in the world, after Finland. The etiology of the disease is mostly unknown, but type 1 diabetes is considered an autoimmune disease. Triggers for developing the disease include viral infections, increased growth, inactivity and obesity. A series of epidemiological studies have reported that the number of people with newly diagnosed type 1 diabetes increased during the COVID-19 epidemic. Some support the SARS-CoV-2 infection as such is behind the disease while other studies that also show an increase do not support any connections to an infection with SARS-CoV-2.

The overarching goal of the study is to assess the potential associations between SARS-CoV-2 infection and onset of type 1 diabetes (T1D) among children in Sweden. In a first step, the overall trends in T1D over time among the total population under 18 years will be compared before (2006-2019), and during (2020-2023) the pandemic. In a second step, the potential association between SARS-CoV-2 infection and onset of T1D in different age groups will be studied and contributing factors, such as socioeconomic factors, vaccination status, or different restrictions explored.