Exploring the Implications of New-Onset Diabetes in COVID-19: A Narrative Review

Post-viral new-onset diabetes has been an important feature of the COVID-19 pandemic. It is not always clear if new-onset diabetes is the unmasking of a previously undiagnosed condition, the acceleration of prediabetes, or new-onset diabetes that would not have otherwise occurred. Even asymptomatic cases of COVID-19 have been associated with new-onset diabetes. Diabetes that emerges during acute COVID-19 infection tends to have an atypical presentation, characterized by hyperglycemia and potentially life-threatening diabetic ketoacidosis. It is not always clear if new-onset diabetes is type 1 or type 2 diabetes mellitus. Many cases of COVID-associated diabetes appear to be type 1 diabetes, which is actually an autoimmune disorder. The clinical course varies temporally and with respect to outcomes; in some cases, diabetes resolves completely or improves incrementally after recovery from COVID-19. Disruptions in macrophagy caused by COVID-19 infection along with an exaggerated inflammatory response that can occur in COVID-19 also play a role. Those who survive COVID-19 remain at a 40% elevated risk for diabetes in the first year, even if their case of COVID-19 was not particularly severe. A subsequent post-pandemic wave of new diabetes patients may be expected.