Diabetic patients generally do not have complications if their blood sugar is well controlled. The occurrence of complications is very closely related to the length of the patient’s diabetes and the control of blood sugar, especially the increase in postprandial blood sugar, and the occurrence and development of microangiopathy and macroangiopathy, so it has been emphasized that diabetic patients should strictly control their blood sugar, which will also significantly reduce the the occurrence of complications. The theory is not absolute, there are also some diabetic patients, although the blood sugar control is relatively good, but easy to occur microvascular or macrovascular disease, may be related to the patient’s high blood pressure and high blood lipids and other factors.