Some COVID-19 survivors are developing diabetes. Experts don't know why.

Some COVID-19 survivors are developing diabetes. Experts don't know why.
A paramedic checking the blood sugar levels of a diabetes patient.Beawiharta Beawiharta/Reuters
  • Experts have found that some COVID-19 patients are developing type 1 or type 2 diabetes.
  • It's not clear whether diabetes could be a permanent side effect of coronavirus infection.
  • People with autoimmune disorders, prediabetes, or obesity have high risks of COVID-19 complications.

Diabetes is known to be a risk factor for severe cases of COVID-19.

But new evidence suggests the inverse might also be true: some patients who've recovered from COVID-19 are developing diabetes, including type 1 and type 2, according to research published November 2020 in Diabetes, Obesity and Metabolism.

More than one in 10 coronavirus patients (14.4%) were newly diagnosed with diabetes after recovering from the disease caused by the novel coronavirus, according to the analysis of 3,711 patients across eight different studies.

New cases of diabetes could be the result of inflammation and insulin problems related to COVID-19, according to the study's authors, researchers from several universities including McMaster University in Canada.

Read more: A 'COVID tongue' that's swollen, bumpy, or patchy may be a sign of virus infection


COVID-19 might worsen existing health issues like prediabetes, causing type 2 diabetes

In at least some of these cases, it could be that some of the patients in the study already had diabetes and were unaware of it until they were hospitalized for COVID-19, according to the study.

But evidence also suggests that COVID-19 might be enough to worsen existing metabolic health issues into full-blown type 2 diabetes, according to Dr. Jose Aleman, assistant professor of endocrinology at NYU Langone Health.

"Stressful conditions lead to elevated levels of regulatory hormones that raise blood sugar to aid the body in fighting whatever insult it's facing, such as illness or injury," Aleman told Insider. "For people with underlying conditions, that can be enough to kick them over the edge."

These conditions include prediabetes, obesity, insulin resistance, or high blood pressure. That may explain how the virus is linked to new cases of type 2 diabetes, which happens when people become less responsive to insulin and have blood sugar control as a result.

Experts are more confused by the new cases of type 1 diabetes

What's less clear is how it might also be linked to new cases of type 1 diabetes. While type 2 diabetes occurs when people become less sensitive to insulin, type 1 happens when people don't produce enough insulin in the first place, due to a lack of specific cells in pancreas called beta cells.


The best theory we currently have, according to Aleman, is that COVID-19 can cause the immune system to overreact and destroy some of the body's own cells while fighting the virus.

Researchers found that the coronavirus, or the body's immune response to it, can disrupt beta cells in the pancreas, potentially triggering the onset of type 1 diabetes.

Patients with existing auto-immune disorders, or older patients with immune system problems, may be particularly at risk of this.

We don't know if COVID-related diabetes is permanent

However, we don't yet know enough about how the two illnesses are related to fully understand patients' long term prognoses. It's likely that at least some patients will have ongoing issues.

"I think this is going to be one of the long-haul complications of COVID," Aleman said.


In the meantime, he recommends that people at risk diabetes start treatment for underlying conditions such as obesity and high blood sugar now as a preventative measure.

"It's hard to treat when you're already sick and in the hospital, and this is a motivation to treat those conditions now," he said.