COVID-19 and Diabetes Mellitus: Mutual Interplay of Two Diseases.

Currently, when the world is fighting against the rapidly spreading pandemic of COVID-19, the silent epidemic of diabetes should not be set aside. In comparison, while COVID- 19 led to about 6 million deaths in 2021, diabetes caused 6.7 million deaths in the same year. Diabetes mellitus is a serious risk factor for worse outcomes in COVID-19 patients. Moreover, it seems that there is a bidirectional relationship between pre-existing diabetes pandemic and the rapidly spreading COVID-19 pandemic. In this article, we summarize mechanisms by which SARS-CoV-2 infects the host cell and discuss the bidirectional relationship between diabetes and COVID-19. We also focus on clinical variables in which diabetic patients differ from non-diabetic patients and which could have promising predictive value for the course and outcome of diabetic COVID-19 patients' therapy management.