compared with the pre-pandemic rate, in new research.
This contrasts with findings from a U.S. study and a German study, but this is “not the final word” about this possible association, lead author Rayzel Shulman, MD, admits, since the study may have been underpowered.
The population-based, cross-sectional study was published recently as a research letter in JAMA Open.
The researchers found a nonsignificant increase in the monthly rate of new diabetes during the first 18 months of the COVID-19 pandemic, compared with the 3 prior years (relative risk 1.09, 95% confidence interval).
New study contrasts with previous reports
This differs from a Morbidity and Mortality Weekly Report from the U.S. Centers for Disease Control and Prevention, in which COVID-19 infection was associated with a significant increase in new onset of diabetes in children during March 2020 through June 2021, “although some experts have criticized the study methods and conclusion validity,” Dr. Shulman and colleagues write.
Another study, from Germany, reported a significant 1.15-fold increase in type 1 diabetes in children during the pandemic, they note.
The current study may have been underpowered and too small to show a significant association between COVID-19 and new diabetes, the researchers acknowledge.
And the 1.30 upper limit of the confidence interval shows that it “cannot rule out a possible 1.3-fold increase” in relative risk of a diagnosis of diabetes related to COVID, Dr. Shulman explained to this news organization.
It will be important to see how the rates have changed since September 2021 (the end of the current study), added Dr. Shulman, an adjunct scientist at the Institute for Clinical Evaluative Sciences (ICES) and a physician and scientist at the Hospital for Sick Children, Toronto.
The current study did find a decreased (delayed) rate of diagnosis of new diabetes during the first months of the pandemic when there were lockdowns, followed by a “catch-up” increase in rates later on, as has beenearlier.
“Our study is definitely not the final word on this,” Dr. Shulman summarized in a statement from ICES. “However, our findings call into question whether a direct association between COVID-19 and new-onset diabetes in children exists.”
The researchers analyzed health administrative data from January 2017 to September 2021.
They identified 2,700,178 children and youth in Ontario who were under age 18 in 2021, who had a mean age of 9.2, and about half were girls.
Between November 2020 and April 2021, an estimated 3.3% of children in Ontario had a SARS-COV-2 infection.
New diagnoses of diabetes in this age group are mostly type 1 diabetes, based on previous studies.
The rate of incident diabetes was 15%-32% lower during the first 3 months of the pandemic, March-May 2020 (1.67-2.34 cases per 100,000), compared with the pre-pandemic monthly rate during 2017, 2018, and 2019 (2.54-2.59 cases per 100,000).
The rate of incident diabetes was 33%-50% higher during February to July 2021 (3.48-4.18 cases per 100,000), compared with the pre-pandemic rate.
The pre-pandemic and pandemic monthly rates of incident diabetes were similar during the other months.
The group concludes: “The lack of both an observable increase in overall diabetes incidence among children during the 18-month pandemic restrictions [in this Ontario study] and a plausible biological mechanism call into question an association between COVID-19 and new-onset diabetes.”
More research is needed. “Given the variability in monthly [relative risks], additional population-based, longer-term data are needed to examine the direct and indirect effects of COVID-19 and diabetes risk among children,” the authors write.
This study was supported by ICES (which is funded by the Ontario Ministry of Health) and by a grant from the Canadian Institutes of Health Research. Dr. Shulman reported receiving fees from Dexcom outside the submitted work, and she and three other authors reported receiving grants from the Canadian Institutes of Health Research outside the submitted work.
A version of this article first appeared on.