Two new studies from different parts of the world have identified an increase in the incidence of type 1 diabetes in children since the COVID-19 pandemic began, but the reasons still aren’t clear.
The findings from the two studies, in Germany and the United States, align closely, endocrinologist Jane J. Kim, MD, professor of pediatrics and principal investigator of the U.S. study, told this news organization. “I think that the general conclusion based on their data and our data is that there appears to be an increased rate of new type 1 diabetes diagnoses in children since the onset of the pandemic.”
Dr. Kim noted that because her group’s data pertain to just a single center, she is “heartened to see that the [German team’s] general conclusions are the same as ours.” Moreover, she pointed out that other studies examining this question came from Europe early in the pandemic, whereas “now both they [the German group] and we have had the opportunity to look at what’s happening over a longer period of time.”
But the reason for the association remains unclear. Some answers may be forthcoming from a database designed in mid-2020 specifically to examine the relationship between COVID-19 and new-onset diabetes. Called CoviDiab, the registry aims “to establish the extent and characteristics of new-onset, COVID-19–related diabetes and to investigate its pathogenesis, management, and outcomes,” according to the website.
The first new study, a multicenter German diabetes registry study, was published online Jan. 17 in Diabetes Care by Clemens Kamrath, MD, of Justus Liebig University, Giessen, Germany, and colleagues.
The other, from Rady Children’s Hospital of San Diego, was published online Jan. 24 in JAMA Pediatrics by Bethany L. Gottesman, MD, and colleagues, all with the University of California, San Diego.
Mechanisms likely to differ for type 1 versus type 2 diabetes
Neither the German nor the U.S. investigators were able to directly correlate current or prior SARS-CoV-2 infection in children with the subsequent development of type 1 diabetes.
Earlier this month, a study from the U.S. Centers for Disease Control and Prevention did examine that issue, but it also included youth with type 2 diabetes and did not separate out the two groups.
Dr. Kim said her institution has also seen an increase in type 2 diabetes among youth since the COVID-19 pandemic began but did not include that in their current article.
“When we started looking at our data, diabetes and COVID-19 in adults had been relatively well established. To see an increase in type 2 [diabetes] was not so surprising to our group. But we had the sense we were seeing more patients with type 1, and when we looked at our hospital that was very much the case. I think that was a surprise to people,” said Dr. Kim.
Although a direct effect of SARS-CoV-2 on pancreatic beta cells has been proposed, in both the German and San Diego datasets the diagnosis of type 1 diabetes was confirmed with autoantibodies that are typically present years prior to the onset of clinical symptoms.
The German group suggests possible other explanations for the link, including the lack of immune system exposure to other common pediatric infections during pandemic-necessitated social distancing – the so-called hygiene hypothesis – as well as the possible role of psychological stress, which several studies have linked to type 1 diabetes.
But as of now, Dr. Kim said, “Nobody really knows.”