Some people infected with the new coronavirus might find more than COVID-19 on their medical chart: a new diagnosis of diabetes.
It’s early in the research and experts are still looking for definitive answers, but it appears COVID-19 may be triggering diabetes in a portion of patients.
“The data is saying absolutely that seems to be the case, and it's at a higher rate than we first realized,” Dr. Robert Gabbay, chief scientific and medical officer for the American Diabetes Association, told TODAY.
“It’s very, very concerning. We're living in the midst of an epidemic of diabetes and literally the last thing we need is something that's increasing the rates even further.”
Up to 14% of those hospitalized for COVID-19 developed newly-diagnosed diabetes, an analysis of eight studies involving more than 3,700 patients in the U.S., Italy and China found.
More than 370 doctors from around the world have offered to share patient stories for a global registry of COVID-19-related diabetes, said Dr. Francesco Rubino, the registry’s principal investigator and chair of metabolic and bariatric surgery at King’s College London in the U.K.
He and his colleagues first reported about new-onset diabetes in COVID-19 last August in The New England Journal of Medicine.
At least 160 cases have been fully documented, with researchers preparing to analyze them to understand what is going on, he noted.
“Clearly, the vast majority of people who have COVID-19 will not have diabetes,” Rubino said. “(But) I think there is a problem… even a relatively infrequent event might become significant when COVID is so prevalent.”
Some of the new diabetes cases seem to be in people who have no history of the disease and possibly no risk factors — people who “were not expecting to develop diabetes who now have it,” Gabbay noted.
Why it may be happening
The pancreas makes insulin, a hormone that helps control blood sugar levels. But in diabetes, blood sugar levels are too high — either because the body doesn’t make insulin (Type 1 diabetes) or because the body don't respond well to it (Type 2 diabetes).
The new coronavirus can enter cells in not only the pancreas, but also the intestine, the liver and fat tissue — all very important in maintaining normal sugar metabolism — and affect those organs, causing potential dysfunctions, Rubino said.
In some people, “it appears as if the virus is actually attacking the cells that make insulin and damaging them in a way where one is not able to make sufficient insulin,” Gabbay added.
Because multiple organs could be disrupted at the same time, causing complex changes in sugar metabolism, the symptoms doctors see in COVID-19 patients don't look like a typical Type 1 or Type 2 diabetes, but potentially a “mix” of the two — possibly a new type of diabetes, Rubino said.
It may not even require the severe type of COVID-19 to happen: One case study in Germany described a 19-year-old man who had an asymptomatic coronavirus infection last spring, and was diagnosed with diabetes several weeks later. The authors concluded doctors “should be aware of the possibility of insulin-dependent diabetes as an acute complication” of COVID-19.
Looking for answers
There’s already a strong relationship between diabetes and COVID-19: People who have diabetes are more likely to have serious complications from the infection and 40% of people who have died from COVID-19 have had diabetes, Gabbay noted.
But it’s going to be a challenge to scientifically prove COVID-19 causes new onset diabetes, Rubino noted.
“Any inflammatory state can cause insulin resistance,” wrote Dr. Domenico Accili, director of the Columbia University Diabetes and Endocrinology Research Center in New York, in a commentary in Nature Metabolism.
“We should not dismiss the possibility that SARS-CoV-2 can cause diabetes, but we should not contrive it out of thin air if it is not supported by evidence, either.”
Rubino hoped the global registry of COVID-19-related diabetes can provide concrete answers, including whether diabetes associated with the new coronavirus goes away after a patient recovers or if it can persist beyond the infection.
The advice for new or recent COVID-19 patients is to be aware of diabetes symptoms such as excessive urination, excessive thirst, blurry vision, fatigue, unexplained weight loss and, for women, yeast infections.
“There is no reason to panic about diabetes, but there is reason to be alert and pay attention to the connection between COVID and diabetes,” Rubino said.