Abstract
There is increasing evidence that coronavirus disease 2019 (COVID-19) may lead to new-onset diabetes mellitus (DM). This may occur even in patients without predisposing factors for impaired glucose metabolism. Both impaired pancreatic insulin secretion and insulin resistance have been implicated as underlying mechanisms. Importantly, new-onset hyperglycaemia is associated with worse prognosis in patients with COVID-19. Indeed, its prognosis may be even more sinister than in patients with pre-existing DM. More research data and knowledge are currently being collected to improve our insights into this constellation and to guide therapies in clinical reality.