Severe COVID cases spurring new diabetes diagnoses

Experts say the escalation of glucose levels caused by COVID-19 may be to blame.

Dave Yasvinski 3 minute read August 27, 2021
COVID diabetes

Some people without a history of the disease are developing diabetes after coming down with a harsh case of COVID-19. Getty

Just over 14 per cent of people admitted to hospital with severe cases of COVID-19 have developed diabetes, a condition that impedes the immune system’s ability to fend off the virus and complicates recovery.

The meta-analysis of eight studies that were conducted during the first five months of the pandemic — and published in the Journal of Diabetes, Obesity and Metabolism — found that 14.4 per cent of 3,700 patients were diagnosed with the metabolic disease during treatment for the virus. While the analysis said the increased stress of hospitalization cannot be discounted as a factor in the phenomenon, the “diabetogenic effect of COVID-19” must be considered, particularly in light of previous research that shows diabetic patients critically ill with the virus have “exceptionally high insulin requirements.”

“There are two populations that are very bad risk in terms of COVID,” said Ralph DeFronzo, the deputy director of University Health’s Texas Diabetes Institute, according to News 4 San Antonio. “One is the diabetic population, the other is people who are overweight.”

But with virus potentially causing diabetes, the stakes have been raised for all patients, even those with no history of the disease. The culprit, according to DeFronzo, lies in the escalation of glucose levels caused by COVID-19. “The higher your glucose level, the more paralyzed so to speak is your immune system and its ability to engulf the bacteria or kill the virus and prevent it from spreading throughout your lungs,” he said.

One in three Canadians are currently living with prediabetes or diabetes, a disease in which one’s body does not produce insulin or does not properly use the insulin it does produce, according to Diabetes Canada. Diabetes has long been thought to increase the risk of infection because the disease weakens the immune system’s ability to stop the spread of problematic pathogens. Previous research has shown people with diabetes have an elevated risk of common and rare infections — a concerning risk factor in the age of COVID-19. “From 2000 to 2015 the overall rate of hospitalization from infections in U.S. adults rose significantly, especially in people with diabetes,” researchers wrote in the separate study.

While it remains unclear why some patients overcome the virus without developing diabetes and others do not, DeFronzo suspects the body’s inflammatory response to the virus plays a role. This inflammation can induce a “thyroid storm” that may make the body resistant to insulin and cause blood sugar levels to spike in the same manner that makes diabetics more vulnerable to the virus. “In diabetics, this is a real problem because their immune system already doesn’t work normally, so now it’s a paralyzed immune system,” DeFronzo said.

It’s also possible that people who process glucose normally have a genetic predisposition to the disease or are not aware they have prediabetes, said DeFronzo, who encourages people unsure of their status to get tested for the disease before a potential COVID diagnosis has a chance to complicate the issue.

“Recent reports have shown that newly diagnosed diabetes may confer a greater risk for poor prognosis of COVID-19 than no diabetes or pre-existing diabetes,” according to the meta-analysis. “Therefore, COVID-19 patients with newly diagnosed diabetes should be managed early and appropriately and closely monitored for the emergence of full-blown diabetes and other cardiometabolic disorders in the long term.”

For more information on diabetes, support or to connect with other patients, visit Diabetes Canada, and the Juvenile Diabetes Research Foundation (JDRF).

Dave Yasvinski is a writer with