Postprandial blood glucose is most commonly used clinically as 2 hours postprandial blood glucose. If the postprandial blood glucose is around 8.0mmol/L for a long time, if it is a general population, it needs to be noticed and may develop into diabetes; if it is a diabetic patient, it means that the blood glucose control basically reaches the standard. Therefore, the consequences related to different groups of people should be analyzed, and there are several cases as follows: 1. General population: under normal circumstances, the blood sugar of 2 hours after meal is <7.8mmol/L. If it is >7.8mmol/L and <11.1mmol/L, it is called impaired glucose tolerance. Patients without a diagnosis of diabetes often have a postprandial 2-hour blood glucose of around 8.0 mmol/L, suggesting that the patient has an abnormal glucose metabolism and may have hypoglycemia. Such patients need to pay high attention if they are over 40 years old, obese, have hyperlipidemia, hyperuricemia or combined with hypertension and atherosclerosis, etc., and may turn into diabetes the following year. 2. Diabetic patients: diabetic patients with 2-hour postprandial blood glucose control at 8.0mmol/L indicates that blood glucose control is basically up to standard. Patients in a state of good blood glucose control rarely have acute complications of diabetes, and the progress of chronic complications will be delayed. Because blood sugar fluctuates back and forth or runs at high level, it can easily lead to all kinds of acute complications and accelerate the occurrence and development of chronic complications of diabetes. Therefore, it is best for diabetic patients to control their blood glucose at about 8.0 mmol/L 2 hours after meal, but it can be relaxed for elderly patients. If elderly people have diabetes and also have cardiovascular disease, they can limit the value of postprandial blood glucose to 10.0mmol/L or less.