A Sweet Paradox: Severe Insulin Resistance and Hyperglycemia in Asymptomatic COVID-19 Infection

There is a well-established association between hyperglycemia and severe coronavirus disease 2019 (COVID-19) infection, regardless of the diagnosis of diabetes prior to the infection. However, it is unusual for patients with a mild infection to present with severe hyperglycemia and insulin resistance requiring intravenous insulin therapy. Uncontrolled hyperglycemia is associated with worse outcomes in COVID-19, making it crucial to achieve optimal glycemic control, which occasionally requires IV insulin therapy. We report a patient with type 1 diabetes mellitus (T1DM), on hemodialysis, who presented with diabetic ketoacidosis (DKA) due to non-adherence to insulin. He was found to be incidentally positive for COVID-19 on admission. Although he was asymptomatic and did not require steroids for the treatment of COVID-19, he was noted to have persistent severe hyperglycemia requiring unusually high levels of intravenous insulin. This proposes that even a mild infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can trigger a systemic response that can lead to downstream manifestations including insulin resistance and severe hyperglycemia. Interestingly, our patient had three admissions within the past six months as well as another admission two weeks after the current presentation with DKA secondary to insulin non-compliance, all of which required IV insulin for <24 hours following which he was transitioned to a basal-bolus insulin regimen with well-controlled glucose levels.