A recent study conducted on the Scottish population has demonstrated that although the incidence of type 1 diabetes increases among children during coronavirus disease 2019 (COVID-19) pandemic, previous infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) does not directly act as a causal factor.
Study: Relation of incident Type 1 diabetes to recent COVID-19 infection: cohort study using e-health record linkage in Scotland. Image Credit: Gecko Studio/Shutterstock
The study is currently available on the medRxiv* preprint server.
This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources
Background
Viral infection in Pancreatic beta cells is known to increase the risk of type 1 diabetes by triggering autoimmune reactions. In normoglycemic people with autoimmune beta cell death, viral infection can also increase the rate of disease progression. Recently, a report published by the Centers of Disease Control and Prevention, USA, has demonstrated that the incidence of type 1 diabetes has increased significantly among children under the age of 18 years who have a history of SARS-CoV-2 infection.
In Scotland, all new cases of type 1 diabetes are recorded in the nationwide diabetes Scottish Care Information-Diabetes (SCI-Diabetes) registry within 24 hours of diagnosis. Similarly. All new cases of laboratory-confirmed COVID-19 are reported in a national database by Public Health Scotland.
Using these two databases, the scientists have investigated whether SARS-CoV-2 infection increases the risk of type 1 diabetes among children and adults. Specifically, they have focused on the time interval between the onset of SARS-CoV-2 infection and the diagnosis of type 1 diabetes. In addition, they have investigated the trajectory of type 1 diabetes incidence between 2015 and 2021.
Study design
The study was conducted on a group of 1849411 individuals aged less than 35 years in Scotland who did not have a history of diabetes. The individuals who subsequently developed SARS-CoV-2 infection were also included in the study group. All individuals were followed between March 1, 2020, and November 22, 2021.
A generalized additive model was used to estimate the trends in type 1 diabetes incidence in the total study population between 2015 and 2021. The correlation between SARS-CoV-2 infection and diagnosis of type 1 diabetes was assessed using specialized statistical analyses.
Relationship between SARS-CoV-2 infection and type 1 diabetes
Among the total study population, 365080 individuals developed SARS-CoV-2 infection, and 1074 developed type 1 diabetes during the follow-up period. Overall, only 2% of type 1 diabetes patients had been detected with SARS-CoV-2 infection during the follow-up period. Among individuals who tested positive for SARS-CoV-2, only two had developed reinfection around 90 days after the first positive test.
Regarding the interval between SARS-CoV-2 first positive test and diagnosis of type 1 diabetes, no significant correlation was observed for infections that occurred more than 30 days earlier. This trend was observed in the total study population, as well as in those under the age of 16 years.
For infections that occurred within the last 30 days, a significant correlation was observed between prior SARS-CoV-2 infection and diagnosis of type 1 diabetes in the total population, as well as in those under the age of 16 years.
Considering the rate of COVID-19 testing around the date of type 1 diabetes diagnosis, the analysis revealed a significantly high number of tests before and after the diagnosis of diabetes. The high testing rate could impact the observed association, as stated by the scientists.
Type 1 diabetes trajectory during COVID-19 pandemic
Regarding the incidence rate of type 1 diabetes in the Scottish population aged below 35 years, a mixed pattern of peaks and troughs was observed during the follow-up period (2015 – 2021). A higher amplitude of variation in the incidence rate was observed in young children (age range: 0 – 14 years) compared to that in adolescents and young adults (age range: 15 – 34 years).
A seasonal effect on the incidence rate was observed, with incidence increasing in February and September and decreasing in July, compared to the average incidence rate.
A linear increase in the incidence rate was observed from 2015 to 2021 in individuals aged 15 – 34 years. However, a 20% induction in the incidence rate was observed from 2020 to 2021 in individuals aged 0 – 14 years.
Study significance
The study highlights that the incidence of type 1 diabetes has increased by 1.2-fold in children during the COVID-19 pandemic. Importantly, the study reveals that SARS-CoV-2 infection does not increase the risk of type 1 diabetes as no correlation has been observed between the disease diagnosis and viral exposure that occurred more than 30 days earlier. The absence of any correlation between COVID-19 vaccination status and diabetes incidence further supports this observation.
This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources
Article Revisions
- May 12 2023 - The preprint preliminary research paper that this article was based upon was accepted for publication in a peer-reviewed Scientific Journal. This article was edited accordingly to include a link to the final peer-reviewed paper, now shown in the sources section.
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