Spotlight on COVID-19 and new type 1 diabetes

A few case reports suggested a link between SARS-CoV-2 and development of insulin-dependent diabetes, but recent analyses of type 1 diabetes incidence during the pandemic have shown mixed results.

Several recent studies looked at onset of type 1 diabetes during the pandemic.

A letter, published by Nature Metabolism on Sept. 2, described the development of insulin-dependent diabetes five to seven weeks after probable SARS-CoV-2 infection in a 19-year-old man. The patient presented with diabetic ketoacidosis and an HbA1c of 16.8% and positive antibodies to SARS-CoV-2. He did not have any of the autoantibodies typical for type 1 diabetes, leading the authors to speculate that direct beta-cell damage from the virus may have led to the diabetes, without the classical autoimmune pathology. They concluded that “diabetologists should be aware of the possibility of insulin-dependent diabetes as an acute complication in patients infected with SARS-CoV-2.”

Another report of a single patient with new insulin-dependent diabetes after SARS-CoV-2 infection was published by Acta Diabetologia on July 11. The 29-year-old woman, with a medical history of gastric bypass and a family history of diabetes, presented a month after treatment for COVID-19 with acute polyuria-polydipsia syndrome and an HbA1c of 11.8%. Testing for glutamic acid decarboxylase-65 autoantibodies was positive, as was SARS-CoV-2 serology. “It remains to determine if the hyperinflammation/cytokine storm described with this infection could accelerate the onset of type 1 diabetes in genetically susceptible individuals,” the authors said.

An analysis from multiple hospitals in North West London, published in the August Diabetes Care, reported on 30 children who presented with new-onset type 1 diabetes in April and May. This represented an apparent increase in two of the studied hospitals, with 10 cases each, compared to two and four, respectively, in the previous five years. The study also observed a high proportion (70%) presenting with diabetic ketoacidosis. Two of 21 children who met local testing criteria had positive SARS-CoV-2 polymerase chain reaction tests, and three of 16 tested for antibodies were positive. “While our data does not prove a link, we postulate that SARS-CoV-2 exposure contributed to the observed increase in cases by precipitating or accelerating type 1 diabetes onset,” they said.

In contrast, a report from 53 Italian pediatric diabetes centers, published online by Diabetes Care on Aug. 11, found a 23% reduction in new diabetes cases in 2020 compared with 2019. Of those who presented with diabetic ketoacidosis, the proportion in which it was severe was higher in 2020 (44.3% vs. 36.1% in 2019; P<0.03). The authors theorized that there might have been fewer cases presenting due to either fear of SARS-CoV-2 exposure or lower exposure to seasonal viruses.

An analysis from 216 diabetes centers in Germany, published by Diabetes Care on Aug. 21, found that the rate of type 1 diabetes incidence in 2020 was similar to what was predicted, since the disease had been on the rise, from 16.4 per 100,000 patient-years in 2011 to 22.2 in 2019 and 23.4 in 2020. “Thus, strong direct diabetogenic effects seem very unlikely, but weak effects cannot be excluded given the relatively low COVID-19 infection rate in Germany,” the authors said.

An editorial, published by Diabetes Care on Sept. 4, offered an overview of the three European reports. “Taken in sum, these three articles do not provide compelling evidence that the pandemic is leading to dramatic short-term adverse changes in incidence of pediatric type 1 diabetes,” it said. The editorial did note a number of ways the pandemic could negatively affect diabetes incidence and outcomes, including increased stress and reductions in activity, access to care, and funding for patient programs. “We must continue to be humble and patient about what we know and advocate strenuously for coordinated, expanded, and responsive public health systems to support youth with both type 1 and type 2 diabetes,” the editorial concluded.