For a diabetic patient, with smooth blood sugar control and no serious complications, his life expectancy is the same as that of a normal person, that is, if the diabetic’s blood sugar is well controlled, it does not affect the person’s life expectancy. However, if the blood sugar is not well controlled, after 5-8 years of diabetes, various complications may occur successively, such as diabetic peripheral neuropathy, diabetic nephropathy, diabetic eye disease, diabetic macrovascular as well as microvascular lesions. With the occurrence and development of various complications, there will be a serious impact on the life expectancy of people, especially for type 1 diabetics, whose life expectancy may be shortened by 30-40 years if their blood sugar is not well controlled, and at least 10-20 years for type 2 diabetics.