Researchers found that of more than 285,000 children with COVID, 0.04% were diagnosed with type 1 diabetes over the next six months. While that's a small percentage, it was 72% higher than the rate in a comparison group of kids with no history of COVID.
Type 1 diabetes is far less common than type 2 diabetes, which typically arises in adulthood and is often associated with obesity. In contrast, type 1 is an autoimmune disease where the immune system mistakenly attacks cells in the pancreas that produce insulin -- a hormone that helps move sugars from food into body cells to be used for fuel.
People can develop type 1 diabetes at any age, but it usually strikes in childhood.
A number of studies have tied COVID to an increased risk of adults developing type 2 diabetes, but less has been known about whether kids with the infection might have a heightened risk of type 1.
"It's a tiny portion of children with COVID who get type 1 diabetes," said Rong Xu, one of the researchers on the new study.
So for any one child, the risk would be quite small, according to Xu, a professor at Case Western Reserve School of Medicine in Cleveland.
But, she added, since a huge swath of the world's population has been or will be exposed to COVID, even a small increase in the risk of type 1 diabetes could translate into a large number of cases.
There is no cure for type 1 diabetes, and people with the disease need to take synthetic insulin every day for life.
An infectious disease expert stressed, however, that the findings do not prove that COVID directly raises the risk of type 1.
The autoimmune reaction that leads to the disease develops over time. And one possibility is that kids with such autoimmunity were more likely to contract COVID, said Dr. Aaron Glatt, chief of infectious diseases at Mount Sinai South Nassau in Oceanside, N.Y.
Still, the notion that a viral infection could trigger type 1 diabetes is not new, said Glatt, who is also a spokesman for the Infectious Diseases Society of America. He was not involved with the study.
Glatt noted that researchers have long theorized that certain viruses might set off the autoimmune reaction that causes type 1 diabetes -- in people with a genetic susceptibility, for example.
"But that's not proven," Glatt stressed.
There is other evidence, from lab research, supporting the idea that COVID infection can lead to diabetes, including type 1.
Shuibing Chen, an associate professor at Weill Cornell Medicine in New York City, is among the researchers doing that work.
She said that SARS-CoV-2, the virus that causes COVID, has been detected in pancreatic beta cells from patients who died of the infection; beta cells are responsible for producing insulin. And in the lab, Chen's team has found that SARS-CoV-2 infection seems to change beta cells in a way that decreases insulin expression and boosts expression of glucagon -- a hormone that raises blood sugar.
It's possible, Chen said, that SARS-CoV-2 could lead to diabetes by directly damaging pancreatic cells, and -- particularly in the case of type 1 -- by spurring an immune response in the pancreas that furthers the damage.
The new findings -- recently published in JAMA Network Open -- are based on health records from more than 570,000 pediatric patients from 15 countries. Half had been diagnosed with COVID at some point between March 2020 and December 2021. The other half had contracted a different type of respiratory infection during the same period.
In the COVID group, just over 0.04% were diagnosed with type 1 diabetes within six months of infection. That rate was 72% higher versus the comparison group, where 0.025% of kids developed diabetes.
After researchers weighed certain other factors, including family history of diabetes, COVID infection was still linked to an 83% higher risk of diabetes at the six-month mark.
Clearly, the experts said, the vast majority of kids with COVID do not develop type 1 diabetes. So if the virus does trigger the disease in some, other factors -- like genetic susceptibility -- would have to be at play, too.
At this point, Xu said, it's unclear how long the diabetes risk remains elevated post-COVID, or how COVID severity fits in.
While questions remain, Glatt said the message for parents is straightforward: "This is yet another reason to protect your kids from COVID."
The American Academy of Pediatrics has more on post-COVID conditions.
SOURCES: Rong Xu, PhD, professor, biomedical informatics, Case Western Reserve School of Medicine, Cleveland; Aaron Glatt, MD, chief, infectious diseases and hospital epidemiologist, Mount Sinai South Nassau, Oceanside, N.Y., and professor, medicine, Icahn School of Medicine at Mount Sinai, New York City; Shuibing Chen, PhD, associate professor, chemical biology in surgery, and chemical biology in biochemistry, Weill Cornell Medicine, New York City; JAMA Network Open, Sept. 23, 2022, online