Factors Leading to High Morbidity and Mortality of COVID‐19 in Patients with Type 2 Diabetes

Rajpal, Aman; Rahimi, Leili; Ismail‐Beigi, Faramarz

COVID‐19 is a recent pandemic caused by SARS‐Cov‐2, a novel coronavirus. Diabetes (mostly type 2 diabetes mellitus, T2DM) and hyperglycemia are among the major comorbidities in patients with COVID‐19 leading to poor outcomes. Reports show that patients with diabetes and COVID‐19 are at an increased risk for developing severe complications including acute respiratory distress syndrome (ARDS), multi‐organ failure and death. Here we explore potential mechanistic links that could explain the observed higher morbidity and mortality in this patient population. Patients with T2DM have an underlying increased level of inflammation associated with obesity and insulin resistance in addition to other comorbidities including HTN, obesity, CVD, dyslipidemia and being older. We review evidence that T2DM with hyperglycemia are among factors that lead to elevated expression of ACE2 in lungs and other tissues; ACE2 is the cellular “receptor” and port of viral entry. The pre‐existing chronic inflammation with augmented inflammatory response to the infection and the increasing viral load leads to extreme systemic immune response (“cytokine storm”) that is strongly associated with increased severity of COVID‐19. Based on the available evidence, it is recommended by a panel of experts that safe but stringent control of blood glucose, blood pressure and lipids be carried out in patients with T2DM, measures that could potentially serve to decrease the severity of COVID‐19 should these patients contract the viral infection. Once the infection occurs, then attention should be directed to proper glycemic control with use of insulin and frequent monitoring of blood glucose levels.