A new German study, published last month in the journal Diabetologia, has found that diabetes and COVID-19 could be a deadly mix, and the risk is particularly high in people with uncontrolled or poorly controlled diabetes.

The new study analyzed data from 22 studies that included more than 18,000 people, but researchers discovered that simply having diabetes did not raise a COVID-19 patient’s risk for death.

The researchers found that COVID-19 death rates among diabetics were similar to those who are non-diabetic. It was the severity of diabetes, which seemed to increase the risk of poor prognosis among patients with diabetes and COVID-19.

The team wrote, “Being male, older and having other chronic health conditions, as well as being treated with insulin rather than the diabetes drug metformin, were risk factors for worse outcomes,” according to Medicine Net.

Lead researcher Dr. Sabrina Schlesinger of the Leibniz Center for Diabetes Research at Heinrich Heine University in Düsseldorf said the use of insulin as treatment indicates “a more progressive course of diabetes.”

The team found that patients taking insulin were 75% more likely to die from COVID-19. And patients taking metformin, an oral drug used in most cases of type 2 diabetes, were 50% less likely to die from COVID-19.

The study also found that men with diabetes were 28% more likely to die with COVID-19 than women with diabetes. Furthermore, older people with diabetes were more than three times more likely to die than younger people with diabetes.

Uncontrolled diabetes upon hospitalization was one of the greatest death risks in people with diabetes and COVID-19.

Some experts in the United States were not surprised by the findings.

Dr. Minisha Sood of Lenox Hill Hospital in New York City said, “The takeaway is that people with diabetes should focus on what has always been the priority: A healthy lifestyle to control inflammation from chronically elevated glucose [blood sugar], which would lessen the risk of chronic diseases and organ damage.”

“Metformin [Glucophage]appears to have a protective role, which is not surprising,” she added.

Dr. Barbara Keber of Glen Cove Hospital, New York, said she believes that the length of time a patient has lived with diabetes maybe even more important to COVID-19 outcomes than its current severity, according to Medicine Net. And she also believes that more research is needed to understand the key risk factors for diabetic patients.

Meanwhile, “all these types of patients have increased risk for death,” Dr. Keber cautioned. “These groups of patients should therefore receive earlier interventions, such as the use of monoclonal antibodies [combination casrivimab and imdevimab shown to be the current best combination] as soon as they are diagnosed to prevent severe disease or death.” The article was published online on Medicine Net.