This study is to evaluate the glycemic variation using Continuous Glucose Monitoring System in patients in the intensive care unit, find out the occult hypoglycemia, and investigate the relationship between glycemic variation, especially the incidence of hypoglycemia and prognosis of patients. Meanwhile, the inflammatory factors were measured and the relationship between inflammatory factors and glycemic variation.

Inclusion Criteria:

1. Patients with history of diabetes;
2. Patients without history of diabetes, but their random blood glucose≧7.8mmol/L or fast blood glucose≧5 mmol/L;
3. The patients hospitalized in care unit (ICU or CCU) for more than 48 hours.

Exclusion Criteria:

1. Patient had history of mental illness;
2. Patient was not suitable for using the CGMS;
3. blood glucose > 22.2 mmol/L at admission.

Patients admitted into care unit of Nanjing First Hospital.