ABSTRACT
The COVID-19 pandemic, caused by the novel coronavirus, SARS-CoV-2, is threating our health systems and daily lives and is responsible for causing substantial morbidity and mortality. In particular, aged individuals and individuals with comorbidities, including obesity, diabetes mellitus, and hypertension, have significantly higher risks of hospitalization and death than normal individuals. The renin-angiotensin system (RAS) plays a pivotal role in the pathogenesis of diabetes mellitus, obesity, and hypertension. Angiotensin-converting enzyme 2 (ACE2), belonging to the RAS family, has received much attention during this COVID-19 pandemic, owing to the fact that SARS-CoV-2 uses ACE2 as a receptor for cellular entry. Additionally, the RAS greatly affects energy metabolism in certain pathological conditions, including cardiac failure, diabetes mellitus, and viral infections. This article discusses the potential mechanisms by which SARS-CoV-2 modulates the RAS and energy metabolism in individuals with obesity and diabetes mellitus. The article aims to highlight the appropriate strategies for combating the COVID-19 pandemic in the clinical setting and emphasize on the areas that require further investigation in relation to COVID-19 infections in patients with obesity and diabetes mellitus from the viewpoint of endocrinology and metabolism.