Patients with diabetes have an increased risk of infection due to lowered immunity[24]; besides, they may also have a worse prognosis due to alveolar–capillary barrier dysfunction brought on by elevated angiotensin converting enzyme 2 expression in lung tissues.[25,26] These findings suggest that diabetes and cardio-cerebrovascular disease may be indicators of severe disease in COVID-19 patients. This evidence concerns the gene ACE2 and diabetes mellitus.