Abstract
The first case of pneumonia caused by a SARS-CoV-like coronavirus was diagnosed in December 2019 in Wuhan, in Hubei Province of China. World Health Organization (WHO) declared this pneumonia outbreak as a public health emergency of international concern and officially named it "coronavirus disease 2019 (COVID-19)" on 11th February 2020. COVID-19 has spread unexpectedly and very rapidly around the world, leading to the 2019-2020 pandemic. According to recent data from September 24th, 2021, more than 230 million cases of COVID-19 have been confirmed worldwide and more than 4.72 million deaths reported since December 31st, 2019. Diabetes and COVID-19 have in common acute and chronic inflammation, insulin resistance and kidney damage. Both diseases can influence each other in terms of clinical course and outcome, and a fusion between these inflammatory states can increase the damage induced by the inflammations. Diabetes mellitus, epidemiologically, is the second most common comorbidity of COVID-19. Studies have shown that 12 to 16% of patients with a complication were diabetic, with mortality approximately 3-fold higher in diabetics. The roles of angiotensin-converting-enzyme-2 and dipeptidyl peptidase-4 in COVID-19 infection and diabetes, as well as the side effects of some drugs used in the management of diabetic patients infected by COVID-19, are the major factors of severity in COVID-19 infection, thus increasing mortality in these patients. To date, there is no established treatment regimen for diabetic patients infected with COVID-19. The best alternative for diabetic patients remains prevention and then, in the event of infection, the use of evidence-based therapy.