Is the effect direct or indirect?
Using data from the multicenter German Diabetes Prospective Follow-up Registry, Dr. Kamrath and colleagues compared the incidence of type 1 diabetes in children and adolescents from Jan. 1, 2020 through June 30, 2021 with the incidence in 2011-2019.
During the pandemic period, a total of 5,162 youth were newly diagnosed with type 1 diabetes at 236 German centers. That incidence, 24.4 per 100,000 patient-years, was significantly higher than the 21.2 per 100,000 patient-years expected based on the prior decade, with an incidence rate ratio of 1.15 (P < .001). The increase was similar in both males and females.
There was a difference by age, however, as the phenomenon appeared to be limited to the preadolescent age groups. The incidence rate ratios (IRRs) for ages below 6 years and 6-11 years were 1.23 and 1.18 (both P < .001), respectively, compared to a nonsignificant IRR of 1.06 (P = .13) in those aged 12-17 years.
Compared with the expected monthly incidence, the observed incidence was significantly higher in June 2020 (IRR, 1.43; P = .003), July 2020 (IRR, 1.48; P < 0.001), March 2021 (IRR, 1.29; P = .028), and June 2021 (IRR, 1.39; P = .01).
Among the 3,851 patients for whom data on type 1 diabetes-associated autoantibodies were available, the adjusted rates of autoantibody negativity did not differ from 2018-2019 during the entire pandemic period or during the year 2020 or the first half of 2021.
“Therefore, the increase in the incidence of type 1 diabetes in children appears to be due to immune-mediated type 1 diabetes. However, because autoimmunity and progressive beta-cell destruction typically begin long before the clinical diagnosis of type 1 diabetes, we were surprised to see the incidence of type 1 diabetes followed the peak incidence of COVID-19 and also the pandemic containment measures by only approximately 3 months,” Dr. Kamrath and colleagues write.
Taken together, they say, the data suggest that “the impact on type 1 diabetes incidence is not due to infection with SARS-CoV-2 but rather a consequence of environmental changes resulting from the pandemic itself or pandemic containment measures.”
Similar findings at a U.S. children’s hospital
In the cross-sectional study in San Diego, Dr. Gottesman and colleagues looked at the electronic medical records (EMRs) at Rady Children’s Hospital for patients aged younger than 19 years with at least one positive type 1 diabetes antibody titer.
During March 19, 2020 to March 18, 2021, a total of 187 children were admitted for new-onset type 1 diabetes, compared with just 119 the previous year, a 57% increase.
From July 2020 through February 2021, the number of new type 1 diabetes diagnoses significantly exceeded the number expected based on a quarterly moving average of each of the preceding 5 years.
Only four of the 187 patients (2.1%) diagnosed during the pandemic period had a COVID-19 infection at the time of presentation. Antibody testing to assess prior infection wasn’t feasible, and now that children are receiving the vaccine – and therefore most will have antibodies – “we’ve lost our window of opportunity to look at that question,” Dr. Kim noted.
As has been previously shown, there was an increase in the percentage of patients presenting with diabetic ketoacidosis during the pandemic compared with the prior 5 years (49.7% vs. 40.7% requiring insulin infusion). However, there was no difference in mean age at presentation, body mass index, A1c, or percentage requiring admission to intensive care.
Because these data only go through March 2021, Dr. Kim noted, “We need to see what’s happening with these different variants. We’ll have a chance to look in a month or two to see the effects of Omicron on the rates of diabetes in the hospital.”