Our results showed that the mean scores of neutrophil counts, monocyte count, Basophil count, ESR, PTT, CRP, platelets, white blood cells, and MCHC differed significantly between those with and those without diabetes However, the inflammatory markers that significantly affected the severity of COVID-19 among patients with diabetes were not the same ones that affected the severity in patients without diabetes. Here, CRP is linked to COVID-19.