CRP and diabetes mellitus: The risk factors of a poor prognosis in patients with COVID-19 include old age (≥ 50 years); male sex; smoking; chronic kidney disease; chronic obstructive pulmonary disease; cerebrovascular disease; elevated levels of lactate dehydrogenase, CRP, and D-dimer; decreased blood platelet and lymphocyte counts; cardiovascular disease; hypertension; and diabetes mellitus [17].