The 58-year-old patient has a fasting blood glucose of 6.6 mmol/L, which, in the case of undiagnosed diabetes mellitus, indicates elevated blood glucose and possible prediabetes. If the diabetic patient, blood sugar in the normal glycemic control standard target range. 1. Undiagnosed diabetic patients: healthy people in general fasting blood glucose standard 3.9 ~ 6.1 mmol / L, patients with fasting blood glucose 6.6 mmol / L is greater than the normal blood glucose standard, and less than 7.0 mmol / L, if at the same time sugar load 2 hours after the glucose is less than 7.8 mmol / L, it is suggestive of impaired fasting blood glucose. It is recommended that patients under the guidance of a doctor combined with diet, exercise, medication and other methods, it is possible to normalize blood sugar. 2. Diabetic patients: diabetic patients comply with medical advice to standardize the use of hypoglycemic drugs, fasting blood glucose control target of 4.4 ~ 7.0 mmol / L, the patient’s fasting blood glucose 6.6 mmol / L, indicating that the patient is well-treated, blood glucose in the normal control of sugar within the range of standards. It is recommended that undiagnosed diabetic patients with fasting blood glucose 6.6 mmol/L go to the hospital in time.