ABSTRACT
SUMMARY OBJECTIVE: To analyze the association between patients with diabetes mellitus and the increased severity and its complications that arise with a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. METHODS: This is a complementary review of literature in which 14 articles published in 2020 were selected. These reviewed articles were written in both Portuguese and English available in the SciELO and PubMed databases. This review also involved searching on websites of international and national organizations in order to gather information published by these bodies about diabetic population and coronavirus disease (COVID-19)-infected individuals. DISCUSSION: The presence of comorbidities in SARS-CoV-2-infected individuals causes an increase in the expression level of angiotensin-converting enzyme 2, facilitating the entry of the virus into the cell. Diabetes causes metabolic and vascular changes, thus weakening the immune system through the inhibition of the innate immune system and the secretion of various inflammatory cytokines. This hyperinflammation can lead to multiple organ failure. The interaction between this comorbidity and COVID-19 can worsen pre-existing diabetes or predispose the onset of diabetes in non-diabetic individuals. CONCLUSIONS: Diabetes mellitus is related to the increased severity and complications of COVID-19. The association between diabetes and COVID-19 creates a devastating double pandemic, as it worsens the prognosis of COVID-19.