A trio of new studies from the United States and Europe are exploring a possible link between COVID-19 and new-onset type 1 diabetes (T1D) in children.
A US study with data from 14 nations finds that children and adolescents have a 72% increased risk of developing T1D in the first 6 months after a COVID-19 infection. Another study, this one from Norway, came to similar conclusions, while a Scottish study concluded the virus is unlikely to be the cause.
T1D, a failure of the pancreas to produce insulin, is typically diagnosed in children.
Causal relationship not established
In the US study published today in JAMA network opena team led by researchers from Case Western Reserve University analyzed the electronic medical records of 285,628 patients aged 0 to 9 years and an equal number from 10 to 18 years in the United States and 13 other countries who tested positive for COVID-19 or another respiratory infection were tested from March 2020 to December 2021.
Of the 571,256 total participants, 123 (0.04%) were newly diagnosed with T1D compared to 72 (0.03%) who had non-COVID respiratory infections, an increase of 72%. In both age groups 1, 3 and 6 months after infection, the T1D risk for COVID-19 survivors was significantly higher than for those with other respiratory infections.
The researchers said they don’t know if SARS-CoV-2 triggers the development of T1D.
“Type 1 diabetes is considered an autoimmune disease,” said corresponding author Pamela Davis, MD, PhD, in a Case Western press release. “It mainly occurs because the body’s immune defenses attack the cells that produce insulin, stopping insulin production and causing the disease. It has been suggested that COVID enhances autoimmune responses, and our current results reinforce this suggestion.”
Davis advises families at high risk of T1D to check for diabetes symptoms after COVID-19 infection and pediatricians to keep an eye out for a surge in new T1D cases, especially given the prevalence of the highly transmissible Omicron variant.
“We could see a significant increase in this disease over the coming months to years,” she said. “Type 1 diabetes is a lifelong challenge for those who have it, and increased incidence means it affects a significant number of children.”
In the press release, study co-author Rong Xu, PhD, called for future investigations into whether the increased risk of T1D persists, which patients are most at risk, and treatment for COVID-associated T1D. “We are also investigating possible changes in the development of type 2 diabetes in children after SARS-CoV2 infection,” she said.
63% higher relative risk in Norway
A nationwide observational study of 1.2 million Norwegian children during the first two years of the pandemic found that 0.13% of children and adolescents were diagnosed with T1D 1 month or more after COVID-19 infection, versus 0.08% uninfected children, i.e. 63%. increase in relative risk.
The research, conducted by researchers and colleagues at the Norwegian Institute of Public Health, was presented this week at the annual meeting of the European Association for the Study of Diabetes (EASD) in Stockholm, Sweden. The team used national health registries to identify new T1D diagnoses in 1,202,174 children under the age of 18 from March 1, 2020 to the same date in 2022.
During the study period, 424,354 children tested positive for COVID-19 and 990 were diagnosed with T1D.
In a press release from Diabetologia, lead author Hanne Lovdal Gulseth, MD, PhD said the results suggest a link between COVID-19 and T1D, but the risk is small. “The absolute risk of developing type 1 diabetes increased from 0.08% to 0.13% and is still low,” she said.
“The vast majority of young people who get COVID-19 will not develop type 1 diabetes, but it’s important for doctors and parents to be aware of the signs and symptoms of type 1 diabetes,” Gulseth said. “Constant thirst, frequent urination, extreme fatigue, and unexpected weight loss are telltale symptoms.”
Researchers noted that T1D has long been suspected to be an oversized immune response, possibly to viral infection, although a link to SARS-CoV-2 has not been established.
“It’s possible that delays in finding medical care due to the pandemic could explain some of the increases in new cases,” Gulseth said.
“However, several studies have shown that SARS-CoV-2 can attack the beta cells in the pancreas that produce insulin, which could lead to the development of type 1 diabetes. It’s also possible that inflammation caused by the virus may exacerbate already existing autoimmunity.”
Artifact of enhanced COVID testing?
In another study presented at EASD, a team led by the University of Edinburgh and Public Health Scotland investigators analyzed Scottish diabetes registry data on 1.8 million people under the age of 35 from March 2020 to November 2021. The study was published on July 12 diabetes treatment.
During the study period, 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 2.5-fold higher T1D rate than uninfected participants and 3-fold higher in children under 16, but only for 1 month.
The researchers said the increase in T1D diagnoses after COVID-19 infection is likely an artifact of increased COVID-19 testing at the time of T1D diagnoses, and not SARS-CoV-2 itself. Because the median time from onset of T1D symptoms to diagnosis in patients under 16 in England is about 25 days, many of those who tested positive for COVID-19 within 30 days of a diabetes diagnosis likely already had T1D, they said you.
“Our findings question whether there is a direct association between COVID-19 and new-onset type 1 diabetes in adults and children,” said related author Helen Colhoun, MD, MPH, in another Diabetologia press release.
But if the research is replicated, she said, “it will result in large numbers of people being newly diagnosed with diabetes and could also change the risk/benefit ratio for COVID-19 vaccination in young children.”
In the press release, Paul McKeigue, MBBCh, PhD said other possible causes of T1D elevation needed to be investigated. “We need to consider what has happened in terms of the spread of viruses such as enteroviruses during the pandemic and whether there are other environmental factors such as sun exposure and vitamin D levels that may have changed during the lockdown that may also be relevant. ” he said.