You probably know a known link between COVID-19 and diabetes: Diabetes is one of the conditions that puts people at higher risk of complications and death when contracting COVID-19. However, scientists are investigating another, more mysterious link between the two, as CBS News reports: COVID-19 infections could trigger new cases of diabetes.
The evidence for this link comes from a systematic review and meta-analysis published in the November 2020 journal Diabetes, Obesity and Metabolism. The researchers pooled data from eight studies conducted between January and May 2020 in China, Italy, and the United States looked at the prevalence of emerging diabetes in COVID-19 patients. Out of a total of 3,711 COVID-19 patients, 492 (14.4%) developed new cases of diabetes. That doesn’t mean the coronavirus infections definitely caused her diabetes, but it does suggest that the virus may have played a role.
Only one of the previous studies that these researchers included reported whether the patients were diagnosed with type 1 or type 2 diabetes. However, there is evidence of a link between COVID-19 and new cases of both types of disease, reports the Washington Post.
Although the evidence is still preliminary, the possibility that COVID-19 could contribute to type 1 diabetes is “not surprising,” to researchers, pediatrician Dyan Hes, MD, told CBS News on Tuesday. (This is the rarer form of the disease, where the body’s immune system attacks its own insulin-producing pancreatic cells.) In fact, even before the COVID, scientists were studying the link between viral infections in general and the occurrence of type 1 diabetes -19 pandemic, so they have has been investigating the possible connection with coronavirus for some time.
We do not fully understand the complex autoimmune process that leads to type 1 diabetes. However, genetic and environmental triggers, including viruses, may play a role, according to the Centers for Disease Control and Prevention. Experts are now investigating whether SARS-CoV-2, the virus that causes COVID-19, can trigger new cases of diabetes in this way.
How exactly the virus could lead to new cases of diabetes is not yet clear, but experts have some theories. One is that SARS-CoV-2 destroys or alters insulin-producing beta cells in the pancreas, possibly by binding to ACE2 receptors, according to a brief letter published in the New England Journal of Medicine. These receptors are found in the pancreas, intestines, and kidneys. And growing body of evidence suggests that the virus uses them to infect the body, potentially changing the way cells that contain ACE2 receptors work.
This could possibly explain new cases of type 2 diabetes as well. Like Type 1, this form of the disease is caused by a variety of factors, including genes and lifestyle, according to the National Institute of Diabetes and Digestive and Kidney Diseases. The process usually starts with insulin resistance (where the body cannot use insulin efficiently). As a result, the pancreas produces more and more insulin and eventually burns out these insulin-producing beta cells.
“If scientists could figure out how or if viral infection can damage beta cells, or what role viruses play in the development of the disease, it would be a real turning point,” said Katie Colbert Coate, Ph.D., diabetes researcher and educator at Vanderbilt University Medical Center said the Washington Post.
Scientists are currently collecting more evidence and studying these cases in more detail to gain a better understanding of what is going on, explained Dr. Hes. Some of the people in the new study may have developed diabetes even without COVID-19. Others may have had a family history of diabetes or autoimmune disease, which could also have been a contributing factor.
Because COVID-19 is a global disease and the association with new cases of diabetes has been observed in several countries, researchers around the world are pooling data on these patients using a global registry called CoviDIAB. The scientists working on it hope to learn more about how COVID-19-related diabetes is developing and how best to treat these patients.