 Diabetic complications are very common; the patients of end-stage renal failure with diabetes were 56.7 and patients who begin renal replacement therapy with diabetes were 70.5 in 2003. The prevalence rate of eye problems including cataract, retinopathies and glaucoma in diabetic patients is 1.9 times higher than that in non-diabetic patients. In addition, it is estimated that the incidence rate of acute stroke, which is a complication of the great vessels of diabetic patients, is also 5.2 times higher than that of the general population. As diabetes could cause various complications and be dangerous, the regulation of blood glucose level is essential in order to prevent these complications. 