The occurrence of diabetes and the level of D‐dimer, white blood cell (WBC), procalcitonin, interleukin‐6 (IL‐6), erythrocyte sedimentation rate (ESR) and C‐reactive protein (CRP) in critical cases were significantly higher than severe cases (P < .01), indicating that patients with diabetes and a higher level of D‐dimer and inflammation are more susceptible to develop critical conditions. Here, CRP is linked to diabetes mellitus.