COVID-19 and diabetes mellitus: a review of the incidence, pathophysiology and management of diabetes during the pandemic

Plain Language SummaryThe COVID-19 pandemic has affected medical care worldwide. Healthcare systems have been overwhelmed during 'surges' of COVID-19 illness, and access to care has been affected during prolonged lockdowns. COVID-19 is caused by the SARS-CoV-2 virus, which is highly contagious. Infection with SARS-CoV-2 can lead to serious illness, primarily in the lungs, but it often affects many other organ systems, leading to disability and death. Recent studies show that persons with diabetes can have a more severe course of illness if infected with SARS-CoV-2. There is also growing evidence that COVID-19 may cause diabetes or worsen preexisting diabetes. In this review, we discuss the findings of studies that show an increase in the frequency of diabetes diagnosed worldwide during the COVID-19 pandemic. We also examine recent data that suggest SARS-CoV-2 can infect and damage the insulin-producing cells in the pancreas. Finally, we provide an overview of the impact of COVID-19 on the management of patients with diabetes, and the emerging use of telemedicine in diabetes care. IntroductionThe COVID-19 pandemic has changed the landscape of modern medicine on a global scale. An emerging concern is the recognition of a bidirectional relationship between COVID-19 and diabetes. Diabetes is a risk factor for severe COVID-19 illness. Intriguingly, recent epidemiological and in vitro studies suggest that infection with SARS-CoV-2, the causative viral agent of COVID-19, is associated with new-onset diabetes and worsening diabetes control. These factors have affected the management of diabetes.Areas coveredThis review provides an overview of our current understanding of the incidence and prevalence of diabetes in relation to the COVID-19 pandemic, highlights studies evaluating SARS-CoV-2's beta cell tropism and its effects on insulin secretion and sensitivity and evaluates the impact of the pandemic on diabetes management and metabolic control.Expert opinionEpidemiological studies have noted an increase in the incidence of new-onset diabetes associated with COVID-19 in patients with phenotypes of type 1 diabetes, type 2 diabetes and Ketosis-Prone Diabetes. Prospective studies are needed to fully elucidate the association between COVID-19 and diabetes and to characterize persons at risk of developing diabetes after SARS-CoV-2 infection, identify those who should be screened for diabetes, and determine the natural histories of different forms of diabetes associated with COVID-19.