During the pandemic of coronavirus infection, medical staff around the world has faced the problem of a significant deterioration in the health conditions of patients, who have a history of type 2 diabetes mellitus and who have infected with COVID-19. The problem of the combination of the coronavirus infection and diabetes mellitus is urgent and requires an in-depth study in this context. This article presents and reviews some results of an experiment during which the clinical indicators of 15 patients with type 2 diabetes mellitus, with elevated glycated hemoglobin, infected with coronavirus infection, aged 45 to 65, were taken on the 14th day of observation.