Hospitals worldwide have been reporting high rates of newly diagnosed diabetes mellitus (NDDM) in patients admitted for COVID. But are these new diabetes cases or previously undiagnosed cases?

Recent research indicates that COVID patients diagnosed with diabetes may actually have a temporary form of diabetes caused by the stress of COVID infection. These patients are more likely to be younger, non-White, and uninsured or on Medicaid compared patients with previously diagnosed diabetes. This suggests that many of these new-onset cases may be preexisting but undiagnosed diabetes in people with little health care access.

In other words, instead of directly causing diabetes, COVID may cause people with preexisting but undiagnosed diabetes to see a doctor for the first time, at which time their diabetes is diagnosed.

Patients with NDDM hospitalized longer with more severe symptoms

The study also found that people diagnosed with diabetes when admitted to the hospital for COVID had lower glucose but more severe COVID symptoms, compared to people with pre-existing diabetes. NDDM was associated with less need for insulin, longer hospital stay, and need for intensive care but not death.

Of 1902 people hospitalized with COVID, 31.2% had diabetes. Of these, 13% had newly diagnosed diabetes. Compared to pre-existing diabetes, NDDM was more common in younger patients and less common in non-Hispanic White patients.

Many patients return to normal glucose levels after being released from the hospital

This diabetes may be transitory, as blood sugar levels may return to normal soon after they are released from the hospital. In this study, almost half of patients with COVID and newly diagnosed diabetes returned to normal blood glucose level, or prediabetes. This suggests that stress hyperglycemia (an excess of glucose in the bloodstream due to stress), and not COVID-caused damage to beta-cells, may explain the COVID-associated newly diagnosed diabetes.

Factors associated with newly diagnosed diabetes and long-term glycemic outcomes are not yet known.


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