Clinicians and researchers continue to search for some of the long-term effects and risks patients face after having COVID-19. Three newly published studies are exploring whether infection increases the risk of developing type-1 diabetes, or T1D. Previously called juvenile diabetes, T1D is typically diagnosed in children and occurs when the pancreas fails to produce a hormone called insulin. The body uses insulin to allow sugar (glucose) to enter the cells and produce energy. According to the Centers for Disease Control and Prevention (CDC), roughly 187,000 children and adolescents under the age of 20 have T1D in the United States.
In a study published last week in JAMA Network Open, researchers analyzed the electronic health records of 571,256 international patients aged zero to 18 who tested positive for COVID-19 or other respiratory infections from March 2020 to December 2021.
Of the total participants who received a positive COVID test, 123 (0.04 percent) were newly diagnosed with T1D. Only 72 (0.03 percent) with a confirmed respiratory infection that wasn’t COVID-19 ended up with a T1D diagnosis. This represents a 72 percent increase in new diagnoses just based on COVID-19 status.
The risk of T1D was substantially higher for the COVID-19 survivors after one, three, and six months of infection when compared to those with other respiratory infections.
Despite the high numbers, the scientists still don’t know whether COVID-19 triggers the development of T1D.
“Type 1 diabetes is considered an autoimmune disease,” corresponding author Pamela Davis, professor of medicine at Case Western University, said in a news release. “It occurs mostly because the body’s immune defenses attack the cells that produce insulin, thereby stopping insulin production and causing the disease. COVID has been suggested to increase autoimmune responses, and our present finding reinforces that suggestion.”
Going forward, the team behind the study advises families with a high risk of T1D to look for diabetes symptoms after COVID-19 infection. Pediatricians also must be vigilant and prepared for a surge of new T1D cases. “We may see a substantial increase in this disease in the coming months to years,” Davis added. “Type 1 diabetes is a lifelong challenge for those who have it, and increased incidence represents substantial numbers of children afflicted.”
Additionally, a study presented at the European Association for the Study of Diabetes (EASD) Annual Meeting in Stockholm, Sweden, used the national health registers of 1.2 million Norwegian children between March 1, 2020 (when COVID-19 was beginning to spread throughout Europe)and March 1, 2022. The study finds that 0.13 percent of children and teens were diagnosed with T1D one month or more after COVID-19 infection versus 0.08 percent in uninfected children. This is a 62 percent increase in relative risk.
The research was conducted by Norwegian Institute of Public Health investigators and colleagues and found that out of 424,354 children who tested positive for COVID-19, 990 were diagnosed with T1D during the period of study.
“The absolute risk of developing type 1 diabetes increased from 0.08 percent to 0.13 percent, and is still low,” lead author Hanne Løvdal Gulseth, a diabetes expert at the Norwegian Institute of Public Health, said in a press release. “The vast majority of young people who get COVID-19 will not go on to develop type 1 diabetes, but it is important that clinicians and parents are aware of the signs and symptoms of type 1 diabetes. Constant thirst, frequent urination, extreme fatigue and unexpected weight loss are tell-tale symptoms.”
The team noted that T1D is suspected of being an outsized immune response by the body. Some suspect viral infections like COVID-19 could create a similar reaction, but a link between the two hasn’t been established. Gulseth also speculated delays in seeking medical care because of the pandemic may explain some of the increase in cases. “However, several studies have shown that SARS-CoV-2 can attack the beta cells in the pancreas that produce insulin, which could lead to development of type 1 diabetes,” he explained in the release. “It’s also possible that inflammation caused by the virus may lead to exacerbation of already existing autoimmunity,”
Finally, a study published this summer in Diabetes Care that was presented at this year’s EASD meeting finds the risk of developing T1D after being infected with COVID-19 only exists for a short period of time. The team evaluated Scottish diabetes registry data on 1.8 million people under the age of 35 from March 2020 to November 2021. In that time, 365,080 children and young adults tested positive for COVID-19 at least once, and 1,074 were diagnosed with T1D. COVID-19 was associated with a rate of new-onset T1D over twice as many times compared to uninfected participants and three times as high in children younger than 16 years, but this association only lasted for one month.
The researchers speculate that the increase in T1D diagnosis after infection is possibly related to increased testing for COVID-19 at the time of the T1D diagnosis rather than from COVID itself. Also, because the average time from onset of T1D symptoms to diagnosis is about 25 days in patients younger than 16 in England, many of those who tested positive for COVID-19 within 30 days of a diabetes diagnosis probably already had T1D, they said in a release.
“Our findings call into question whether a direct association between COVID-19 and new-onset type 1 diabetes in adults and children exists,” corresponding author Helen Colhoun, an epidemiologist at Public Health Scotland and the University of Edinburgh, said in a news release. However, Calhoun reiterated that if scientists replicate these findings, “this is going to create a large number of people with newly diagnosed diabetes and might also alter the risk–benefit balance for COVID-19 vaccination in young children.”
While the picture on whether or not COVID-19 causes type-1 diabetes is still not fully clear, they point to the need for more vigilance and research into what long-term affects the novel virus may cause. According to the Mayo Clinic, some of the major symptoms of type-1 diabetes to look for in children are frequent thirst and urination, extreme hunger, unintentional weight loss, and a change in behavior or increase irritability.