Whether you personally contracted COVID-19 or learned about the disease through an unlucky friend or family member, we are all familiar with its trademark symptoms at this point. Intermittent waves of headaches, persistent fever, overwhelming fatigue, gastrointestinal distress, and a complete loss of taste and smell are the perhaps the most well-known indications of this peculiar illness. While these symptoms are not altogether unusual in the realm of colds and flus, SARS-CoV-2 has been shown to cause strange long-term side effects uncharacteristic of other viruses, from hair loss and "COVID toes" to delirium and brain fog that lasts for months after infection. Even more alarming, scientists have recently uncovered another unexpected consequence of COVID-19 -- an increased risk of developing diabetes.
Early on in the pandemic, we learned that diabetes was one of the leading comorbidities associated with COVID-19, as more than 25% of patients admitted to the hospital for COVID-19 suffered from the metabolic disorder. However, several recent studies have indicated that COVID-19 can actually cause high blood sugar levels during the infection period and even after recovery from the illness. In one study of over 3,800 patients hospitalized with COVID-19 in New York, 49.7% of patients presented with hyperglycemia or developed it during their hospital stays. In another study, researchers found that new diabetes diagnoses were 166% more likely to occur among patients with COVID-19 than among those without COVID-19.
What is the reason behind this odd connection between COVID-19 and high blood sugar? While the science is still emerging, preliminary research suggests that adipose tissue, or body fat, is to blame. Patients with severe cases of COVID-19 have been shown to experience severe declines in blood levels of adiponectin, a hormone produced by fat cells that helps protect against diabetes by enhancing insulin sensitivity. By infecting fat cells and increasing overall inflammation in the body, SARS-CoV-2 disrupts the normal function of adipose tissue both directly and indirectly. This biological mechanism also explains the dangerous link between COVID-19 and obesity.
For this reason, people with insulin resistance or prediabetes must take extreme caution with regard to COVID-19. If you have tested positive for SARS-CoV-2 recently, stay on the lookout for any signs of hyperglycemia and discuss your risk factors with your physician.