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Researchers find no difference in rate of childhood diabetes in Ontario during COVID-19 pandemic


A new study from ICES and The Hospital for Sick Children (SickKids) finds no overall difference in the relative rate of childhood diabetes in Ontario during the first 18 months of the COVID-19 pandemic.

Recent studies have raised concerns that COVID-19 infection may increase the risk of diabetes in children. However, the methods and findings of these studies have been called into question, as there is no clear or proven biological explanation for why a COVID-19 infection might cause the onset of diabetes.

To examine the changes in the incidence of diabetes in children during the pandemic, a large population-based study was undertaken in Ontario, Canada. Published in JAMA Network Open, the study included 2.7 million children between one and 18-years of age in 2021 and compared this group to pre-pandemic and early pandemic cohorts. The outcome of interest was a new diabetes diagnosis (type 1 and type 2) between March 2020 and September 2021.

“We found no overall increase in new diabetes diagnoses, but did show that there were fewer cases documented early on in the pandemic,” says Dr. Astrid Guttmann, senior author of the study, chief science officer at ICES, and staff paediatrician and senior scientist in the Child Health Evaluative Sciences program at SickKids. “This was followed by an increase later in the pandemic, suggesting possible delays in the diagnosis of diabetes and a catch-up effect.”

Specific findings include:

  • No overall difference in the observed vs. expected rates of new cases of diabetes (relative rate of 1.09, 95% CI 0.91-1.30)
  • A decrease in the rate of new-onset diabetes in the first 3 months (March to May 2020) of the pandemic (15-32% lower)
  • An increase in the rate of diabetes diagnoses from February to July 2021 (33-50% higher)

Although the researchers could not differentiate between type 1 and 2 diabetes, 95% of Ontario children and youth with diabetes are diagnosed with type 1 diabetes. Further, the data were collected prior to the emergence of the Omicron variant and do not cover the time during which there were high rates of infection in children with variants of concern. Estimates have shown that 3.3% of Ontario children were infected with COVID-19 between November 2020 and April 2021.

Given these limitations, additional long-term, population-based studies are needed to examine any potential direct or indirect association between COVID-19 infection and diabetes.

“Our study is definitely not the final word on this,” says Dr. Rayzel Shulman, adjunct scientist at ICES, staff physician in the Division of Endocrinology and scientist in the Child Health Evaluative Sciences program at SickKids. ”However, our findings call into question whether a direct association between COVID-19 and new-onset diabetes in children exists.”

The study, “Trends in incidence of diabetes in children during the COVID-19 pandemic in Ontario, Canada, March 2020 to September 2021,” was published in JAMA Network Open.

Author block: Shulman R, Cohen E, Stukel TA, Diong C, Guttmann A.

ICES is an independent, non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. In October 2018, the institute formerly known as the Institute for Clinical Evaluative Sciences formally adopted the initialism ICES as its official name. For the latest ICES news, follow us on Twitter: @ICESOntario

The Hospital for Sick Children (SickKids) is recognized as one of the world’s foremost paediatric health-care institutions and is Canada’s leading centre dedicated to advancing children’s health through the integration of patient care, research and education. Founded in 1875 and affiliated with the University of Toronto, SickKids is one of Canada’s most research-intensive hospitals and has generated discoveries that have helped children globally. Its mission is to provide the best in complex and specialized family-centred care; pioneer scientific and clinical advancements; share expertise; foster an academic environment that nurtures health-care professionals; and champion an accessible, comprehensive and sustainable child health system. SickKids is a founding member of Kids Health Alliance, a network of partners working to create a high quality, consistent and coordinated approach to paediatric healthcare that is centred around children, youth and their families. SickKids is proud of its vision for “Healthier Children. A Better World.”


Misty Pratt
Senior Communications Officer, ICES
[email protected]

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