Among Covid-19's many ripple effects, the worsening of the global diabetes burden could carry a heavy public-health toll. The underlying mechanisms stoking new-onset diabetes aren't clear, though some doctors suspect the SARS-CoV-2 virus may damage the pancreas, the gland that makes insulin which is needed to convert blood-sugar into energy. Sedentary lifestyles brought on by lockdowns could also be playing a role, as might late diagnoses after people avoided doctors' offices. Even some children's mild coronavirus cases can be followed by the swift onset of diabetes, scientists found.

Considered exclusively a lung disease in the early days of the pandemic, Covid-19 is increasingly recognized for its ability to ravage multiple organs and bodily systems, causing persistent and sometimes debilitating symptoms in 1 in 10 sufferers months after their apparent recovery.

Lingering metabolic complications, sometimes requiring high doses of insulin, suggest a subset of survivors are developing diabetes - swelling the ranks of the more than the 463 million people living with the chronic condition.

The disease, in which the body fails to produce enough or properly use insulin, cost an estimated $760 billion in the year before Covid struck, driven by life-shortening complications spanning stroke and kidney failure to foot ulcers and blindness.

“We have a risk of seeing a clash of two pandemics,” said Francesco Rubino, chair of metabolic and bariatric surgery at King's College London, who set up a global registry of Covid-related diabetes cases with Paul Zimmet, a professor of diabetes at Melbourne's Monash University.

Researchers have hypothesized pathways in which Covid might increase the likelihood of a diabetes diagnosis, including the possibility that the pancreas's insulin-excreting beta cells are destroyed either by the virus or by the body's response to the infection.

Other explanations may include an acute stress response to the infection, the use of steroid treatments that help survival but increase blood-sugar, or just the unmasking of diabetes cases that had previously escaped diagnosis, according to John Nicholls, a clinical professor of pathology at the University of Hong Kong.

Almost 500 doctors from around the world have agreed to share data via Rubino's diabetes registry. They will upload patients' known risk factors, lab results, clinical features, treatment, and disease course - information that will help identify the most prevalent form of the disease, possible causes, and likely prognoses.

So far, close to 350 cases have been documented through the registry and descriptive anecdotes are flowing in almost every day through emails from concerned patients and parents.

In Los Angeles, meantime, doctors report a worrying pattern among children with new cases of type-2 diabetes - the chronic form linked to obesity and sedentary lifestyles that's mainly seen in adults.

They found one in five new pediatric type-2 cases last year required hospitalization for diabetic ketoacidosis, a dangerous buildup of acid in the blood due to inadequate insulin supply. By contrast, only 3% of new patients faced this life-threatening problem in 2019. While none of the children in 2020 had active Covid-19, doctors weren't systematically testing for a prior SARS-CoV-2 infection. Of those who were tested, a third were positive.

Doctors in Canada suggest a drop in utilization of medical services during the pandemic might have delayed care for children with new-onset type 1 diabetes - the rarer form caused by an autoimmune reaction that destroys insulin-producing cells in the pancreas. A study from Alberta province found the incidence of severe diabetic ketoacidosis in these patients more than doubled to 27% in 2020.

Rubino aims to publish initial findings from the diabetes registry data mid-year, and offers a word of early caution already: there's enough evidence of Covid-19's long-term consequences that it should be avoided at any age.

“This is not just a flu that, OK, you've got it and you're done with it,” he said. “You might not be done. It's a serious thing.”

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