COVID-19 is not the cause of long-term type 1 diabetes?
COVID-19 is not the cause of long-term type 1 diabetes?

COVID-19 is not the cause of long-term type 1 diabetes?

This study was published on as a pre-print and has not yet been peer reviewed.

Key takeaways

  • A survey of around 1.8 million people living in Scotland in 2020-2021 showed no link between a SARS-CoV-2 infection that occurred more than 30 days earlier with the incident type 1 diabetesboth overall (whole age surveys) as well as specifically in children under 16 years of age.

  • The estimated incidence of type 1 diabetes in children 0-14 years in Scotland increased during the 2020-2021 (during the COVID-19 pandemic) to about 1.2 times the average over the study period. In this age group, however, the incidence of type 1 diabetes varies greatly from year to year. For example, the incidence in 2019 was 10% below the long-term average incidence. The study found no evidence among individuals aged 15-34 years for increased type 1 diabetes incidence in 2020-2021 other than the long-term upward trend in the incidence of type 1 diabetes.

  • The absence of any protection against COVID-19 vaccination against type 1 diabetes is further evidence of a causal effect of COVID-19 on type 1 diabetes.

Why this matters

  • The results do not confirm an association between the occurrence of type 1 diabetes before the age of 18 with SARS-CoV-2 infection more than 30 days before, as previously reported by the U.S. Centers for Disease Control and Prevention.

  • The authors say they are not aware of any other reports that directly tested the association at the individual-patient level between SARS-CoV-2 infection with accidental type 1 diabetes.

Study design

  • The survey included all 1.8 million Scottish people in Scotland REACT-SCOT study that at baseline was less than 35 years old and had not been diagnosed with diabetes. REACT-SCOT is a potential database of almost 4 million Scottish residents enrolled shortly after the start of the COVID-19 pandemic by November 2021, which includes all Scottish residents diagnosed with COVID-19.

  • The researchers found incidental cases of type 1 diabetes in Scotland from 2015-2021 based on the date of diagnosis and type of diabetes as recorded by clinicians in Scottish Care Information-Diabetes the registry.

Key results

  • The study included 365,080 individuals with a first detected SARS-CoV-2 infection between March 1, 2020 and November 22, 2021, which included 1,074 individuals who developed accidental type 1 diabetes during follow-up.

  • Hazard ratios for type 1 diabetes associated with previous SARS-CoV-2 infection were significant 2.62 for infection in the previous 30 days and negligible 0.88 for individuals infected more than 30 days previously. Among the subgroup of persons under 16 years of age, the corresponding ratios were significant 3.15 when the infection had occurred during the previous 30 days, and a negligible 0.81 when the infection had occurred earlier than the previous 30 days.

  • A person’s vaccination status against SARS-CoV-2 was not associated with the occurrence of type 1 diabetes


  • The number of cases of type 1 diabetes in people exposed to SARS-CoV-2 infection was relatively small, so the researchers modeled the hazard ratio using the relatively broad categories of 0-30 and more than 30 days for the exposure period. However, the grouping of negative and positive tests around the time of diagnosis is evident in the data.

  • Until mass testing for SARS-CoV-2 began in late 2020, most infections in younger people remained undetected. However, estimates place the cumulative incidence of infection in UK children aged 5-14 years at around 15% until the end of 2020, so misclassification of exposed individuals as unexposed would only reduce the rate ratio of type 1 diabetes associated with detected infection. in this age group a bit.


This is a summary of one preprint research study, “Relationship of incident Type 1 diabetes to recent COVID-19 infection: cohort study using e-health journal link in Scotland “written by researchers from Edinburgh and Glasgow, UK, on ​​medRxiv provided to you by Medscape. This study has not yet been peer reviewed. The full text of the study can be found at

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