Children who have recovered from Covid-19 appear to be at significantly increased risk of developing Type 1 or Type 2 diabetes, researchers at the Centers for Disease Control and Prevention reported on Friday.
A heightened risk of diabetes has already been seen among adults who recovered from Covid, according to some studies. Researchers in Europe have reported an increase in the number of children being diagnosed with Type 1 diabetes since the pandemic started.
But the C.D.C. study is among the first to examine large insurance claim databases in the United States to estimate the prevalence of new diabetes diagnoses in children under age 18 who had Covid or were known to be infected with the coronavirus.
The study used two claim databases from U.S. health plans to look at diabetes diagnoses made in youngsters under 18 over the course of a year or more, starting in March 1, 2020, comparing those who had Covid with those who did not.
The researchers found increases in diabetes in both data sets, though the relative rates were quite different: they found a 2.6-fold increase in new diabetes cases among children in one, and a smaller 30 percent increase in another.
“Even a 30 percent increase is a big increase in risk,” said Sharon Saydah, a researcher at the C.D.C. and lead author of the study. The differences likely result from different ways of classifying children as having Covid, she added.
Dr. Saydah said it was not yet clear whether post-Covid Type 2 diabetes would be a chronic condition in these children, or a transient condition that resolves. (Type 1 diabetes is not reversible.) Most of the children were only followed about four and a half months.
The finding underscores the importance of vaccinating all eligible children against Covid, she added, and using measures like masking and distancing, especially to protect the youngest, who cannot yet be vaccinated.
“It’s really important for clinicians, pediatricians and parents to be aware of the signs and symptoms of diabetes, so they can get their kids diagnosed,” Dr. Saydah said. Increased thirst, frequent urination, unintentional weight loss and fatigue are among the telltale symptoms.
She noted that weight gain and sedentary behavior, which have increased during the pandemic, are also risk factors for Type 2 diabetes.
Many of the children in the study were only diagnosed after having an episode of diabetic ketoacidosis, a life-threatening complication that occurs when the body doesn’t have enough insulin to allow blood sugar into cells to use for energy.
Dr. Saydah and her colleagues did not distinguish between types of diabetes, including both Type 1 and Type 2 in their analysis. The increases were seen both among those who had been ill with Covid, and those who were asymptomatic but tested positive.
Another study, also released on Friday by the C.D.C., found that two doses of the Pfizer-BioNTech vaccine protected hospitalized youngsters between the ages of 12 and 18 against severe multisystem inflammatory syndrome, or MIS-C, which can develop two to six weeks after infection with the virus.
The study looked at 24 hospitals in 20 states between July and Dec. 9, 2021, during the period when the Delta variant was dominant. It concluded that vaccination had an efficacy rate of 91 percent against MIS-C, and noted that among 38 hospitalized patients aged 12 to 18 who required life support, all were unvaccinated.