Experts Explain How COVID-19 May Be Causing New Cases of Diabetes

New research finds that 14% of people who have been hospitalized due to COVID-19 have developed severe diabetes, according to an article published in December in the journal Diabetes, Obesity and Metabolism. But researchers have not yet pinpointed why that might be and whether COVID-19 is the culprit.

Existing research suggests that those who are newly diagnosed with diabetes may be at a greater risk for severe COVID-19 compared to individuals with no diabetes or pre-existing conditions. Spencer Kroll, MD, PhD, FNLA, a board-certified internal medicine specialist and cholesterol and lipid disease expert based in New Jersey, tells Verywell that there are several hypotheses as to why there has been an increased incidence of new-onset diabetes in COVID-19 patients.

“The novel coronavirus enters respiratory cells through ACE2 receptor," Kroll says. "These receptors are also present on pancreatic beta cells where insulin is produced. The entry of viral particles into beta cells may impair their function or even destroy them.” 

COVID-19 May Be Exacerbating Diabetes

Diabetes occurs when there’s a problem with the body’s blood glucose levels. Insulin helps control blood glucose levels, and in cases of type 1 diabetes, the body produces little to none of it. Experts hypothesize COVID-19 may be destroying the cells that help to produce insulin. 

Camilo Ricordi, MD, FNAI, director of the Diabetes Research Institute, tells Verywell that inflammation plays a role. "COVID-19 can trigger type 1 diabetes in subjects at risk that would modulate inflammation," Ricordi says. "The inflammatory response can arrive very close to the insulin-producing cells."

Because the body is responding to infection, this may cause beta-cell destruction which is often associated with type 1 diabetes. “Beta-cell destruction has been demonstrated with other infections including other coronavirus strains and viral hepatitis,” Krolls says. “It is also possible that the stress of hospitalization is exacerbating pre-existing mild diabetes that has been previously undiagnosed in the patient.” 

Ricordi says that severe COVID-19 could trigger type 1 diabetes and autoimmunity—when the immune system mistakes the body’s own tissues and organs as foreign and attacks its own healthy cells. In type 1 diabetes, autoimmunity means that the immune system will destroy cells in the pancreas that produce insulin. “The insulin resistance associated with inflammation can precipitate type 2 diabetes progression,” Ricordi says. 

Although there is insufficient data on whether people with diabetes would be more likely to get COVID-19, people with diabetes are more likely to experience worse complications if they are infected. The research shows that COVID-19 patients with diabetes frequently experience uncontrolled hyperglycemia—high levels of glucose in the body—requiring high doses of insulin.

Kroll says there is a two-way interaction between COVID-19 and diabetes. “People with diabetes are more likely to be infected with COVID-19 and have complications from viral infection and people without diabetes who are infected with coronavirus seem to be at a statistically significant higher risk for developing diabetes,” Kroll explains. 

Research is still underway about whether family history plays a role. However, people with no family history of diabetes who contracted COVID-19 have shown an increased incidence of new-onset diabetes, according to Krolls.

Treatment Options for COVID-19 and Diabetes 

Treatment efforts for COVID-19 and diabetes patients have been directed toward the new onset of diabetes, according to Kroll. Any shifts in the body’s metabolism such as diabetic ketoacidosis and hyperosmolar states, the two most serious complications from diabetes, can be life-threatening. These disorders can occur in type 1 and type 2 diabetes.

Because diabetic ketoacidosis is accompanied by dehydration, Krolls says that “IV fluid and electrolyte repletion, as well as intravenous insulin”, are needed. 

Steroid treatment could be another treatment option, but Kroll cautions people on its usage. “Treatment may be complicated with concurrent steroid treatment, which has been shown to mitigate the respiratory complication of COVID-19 infection but raises blood sugar and insulin,” Kroll says. 

On the other hand, Ricordi suggests lifestyle changes to prevent the progression of both autoimmune disease conditions and severe cases of COVID-19. These lifestyle changes include improving diet and exercising. “These strategies will also be important to prevent recurrence of disease after a successful intervention,” Ricordi explains. 

Recovery After COVID-19

Those that recover from COVID-19 should be on the lookout for any long-term symptoms, Ricordi says. “There are increased reports on long COVID-19, indicating that there are long sequelae of the disease, especially in subjects exposed to the most severe cases,” Ricordi states. 

Kroll explains that there are still unknowns about COVID-19 and diabetes recovery. “It is possible that insulin requirements may decrease during that time and the patient may be able to be discharged with close follow-up and dietary modification including strict carbohydrate reduction,” Krolls says. “Patients will have to be monitored closely for future post-infection diabetes.” 

“The consequences of viral infection with COVID-19 are new and the data is still being accumulated," Kroll adds. "The full extent of the problem will take years to evaluate and it is possible that we could see a massive surge in diabetic prevalence cropping up months and years after COVID-19 infection."