Diabetes mellitus and COVID-19: review of a lethal interaction from the cellular and molecular level to the bedside.

Introduction: While the main mode of transmission of coronavirus disease 2019 (COVID-19) is close contact with other individuals, the presence of chronic underlying diseases such as Diabetes Mellitus (DM) increases the chance of hospitalization and mortality rate due to infection.

Areas Covered: To investigate the effects of COVID-19 infection in DM patients, we reviewed literature from Google Scholar search engine and PubMed database from '2013 to 2020' using the terms "COVID-19; SARS-CoV-2; Diabetes mellitus; obesity; Angiotensin-converting enzyme 2; ACE2; Insulin and Metformin. Evidence suggests that COVID-19 exacerbates the course of diabetes.