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
Dietler, Dominik LU
; Björk, Jonas
LU
; Palmkvist, Elsa
LU
and Carlsson, Annelie
LU
(2025)
In Diabetologia
- Abstract
AIMS/HYPOTHESIS: The incidence of type 1 diabetes increased during the pandemic in various countries. SARS-CoV-2 infections may trigger the development of type 1 diabetes, but the evidence is inconclusive. This study aimed to assess trends in type 1 diabetes incidence between 2007 and 2023, and to quantify the association between SARS-CoV-2 infections and the risk for developing type 1 diabetes.
METHODS: The study included all individuals under 30 years old registered in Sweden. Deviations in type 1 diabetes incidence from pre-pandemic trends (2007-2019) were assessed for each pandemic year (2020-2023) using Poisson regression. The effect of SARS-CoV-2 infections was assessed using Cox proportional hazards models in a cohort of... (More)
AIMS/HYPOTHESIS: The incidence of type 1 diabetes increased during the pandemic in various countries. SARS-CoV-2 infections may trigger the development of type 1 diabetes, but the evidence is inconclusive. This study aimed to assess trends in type 1 diabetes incidence between 2007 and 2023, and to quantify the association between SARS-CoV-2 infections and the risk for developing type 1 diabetes.
METHODS: The study included all individuals under 30 years old registered in Sweden. Deviations in type 1 diabetes incidence from pre-pandemic trends (2007-2019) were assessed for each pandemic year (2020-2023) using Poisson regression. The effect of SARS-CoV-2 infections was assessed using Cox proportional hazards models in a cohort of infected individuals with five control individuals from the infection date of the case, matched by birth year, sex and region.
RESULTS: Compared with the predicted linear trend, type 1 diabetes incidence increased by 12% during 2021 (incidence rate ratio [IRR] 1.12; 95% CI 1.06, 1.19) and 9% during 2022 (IRR 1.09; 95% CI 1.02, 1.16), but reverted to pre-pandemic trends in 2023. Overall, the adjusted HR for developing type 1 diabetes after SARS-CoV-2 infection was 0.96 (95% CI 0.79, 1.16). Children between 5 and 10 years old were more likely to develop type 1 diabetes within the first 28 days after infection (HR 2.68; 95% CI 1.22, 5.89), although their hazard over the whole follow-up period was not increased.
CONCLUSIONS/INTERPRETATION: Sweden, with its non-restrictive pandemic response, saw a transient increase in type 1 diabetes incidence that was only partially associated with SARS-CoV-2 infections. Other explanations should be investigated, including environmental and lifestyle factors.
(Less)
- author
- Dietler, Dominik
LU
; Björk, Jonas
LU
; Palmkvist, Elsa
LU
and Carlsson, Annelie
LU
- organization
- publishing date
- 2025-09-18
- type
- Contribution to journal
- publication status
- epub
- subject
- keywords
- COVID-19, Epidemiology, Type 1 diabetes, Viral disease
- in
- Diabetologia
- publisher
- Springer
- external identifiers
-
- pmid:40968189
- scopus:105016660049
- pmid:40968189
- ISSN
- 1432-0428
- DOI
- 10.1007/s00125-025-06540-1
- language
- English
- LU publication?
- yes
- id
- ab9101b7-283a-4b82-a9c8-0068cfb15b9d
- date added to LUP
- 2025-09-25 10:28:24
- date last changed
- 2025-10-17 09:47:30
@article{ab9101b7-283a-4b82-a9c8-0068cfb15b9d,
abstract = {{<p>AIMS/HYPOTHESIS: The incidence of type 1 diabetes increased during the pandemic in various countries. SARS-CoV-2 infections may trigger the development of type 1 diabetes, but the evidence is inconclusive. This study aimed to assess trends in type 1 diabetes incidence between 2007 and 2023, and to quantify the association between SARS-CoV-2 infections and the risk for developing type 1 diabetes.</p><p>METHODS: The study included all individuals under 30 years old registered in Sweden. Deviations in type 1 diabetes incidence from pre-pandemic trends (2007-2019) were assessed for each pandemic year (2020-2023) using Poisson regression. The effect of SARS-CoV-2 infections was assessed using Cox proportional hazards models in a cohort of infected individuals with five control individuals from the infection date of the case, matched by birth year, sex and region.</p><p>RESULTS: Compared with the predicted linear trend, type 1 diabetes incidence increased by 12% during 2021 (incidence rate ratio [IRR] 1.12; 95% CI 1.06, 1.19) and 9% during 2022 (IRR 1.09; 95% CI 1.02, 1.16), but reverted to pre-pandemic trends in 2023. Overall, the adjusted HR for developing type 1 diabetes after SARS-CoV-2 infection was 0.96 (95% CI 0.79, 1.16). Children between 5 and 10 years old were more likely to develop type 1 diabetes within the first 28 days after infection (HR 2.68; 95% CI 1.22, 5.89), although their hazard over the whole follow-up period was not increased.</p><p>CONCLUSIONS/INTERPRETATION: Sweden, with its non-restrictive pandemic response, saw a transient increase in type 1 diabetes incidence that was only partially associated with SARS-CoV-2 infections. Other explanations should be investigated, including environmental and lifestyle factors.</p>}},
author = {{Dietler, Dominik and Björk, Jonas and Palmkvist, Elsa and Carlsson, Annelie}},
issn = {{1432-0428}},
keywords = {{COVID-19; Epidemiology; Type 1 diabetes; Viral disease}},
language = {{eng}},
month = {{09}},
publisher = {{Springer}},
series = {{Diabetologia}},
title = {{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}},
url = {{http://dx.doi.org/10.1007/s00125-025-06540-1}},
doi = {{10.1007/s00125-025-06540-1}},
year = {{2025}},
}