To determine risk factors for progression of diabetic retinopathy, a study was conducted in 92 patients with diabetes whose HbA1c levels were more than 9.5% when they were admitted to our hospital.
The progression of retinopathy was observed in 50% of the patients during 12 months after admission. Their cases were diagnosed as preproliferative retinopathy. The duration of no-treatment, serum cholesterol level, blood pressure and proteinuria were significantly greater in the deterioration group of retinopathy than in the no-deterioration group. Nerve conduction velocity was significantly lower in the deterioration group of retinopathy than in the no-deterioration group. The reduction of HbA1c level during the period of 3 months after admission was significantly higher in the deterioration group than in the improved group. In the patients whose initial levels of HbA1c were less than 10%, the deterioration of retinopathy was not observed. In conclusion, these findings suggest that the duration of no-treatment, serum cholesterol level, blood pressure, proteinuria, nerve conduction velocity, retinopathy severity, the HbA1c level at admission and the reduction of HbA1c level during the 3-month period are risk factors for the progression of retinopathy.

A 62-year-old woman was adimitted to our hospital because of thirst and a body weight loss of 9kg. She had a history of vasospastic breast pang 5months before. The level of fasting plasma glucose was 320 mg/dl and the level of HbA_1c was 13.0%. The autoantibody to glutamic acid decarboxylase was positive. The level of urine C-peptide was 28.6μg/day. She rejected insulin injections and was treated with glibenclamide. The level of urine C-peptide increased to 70.0μg/day. The disease was controlled with the levels of 6.0% of HbA_1c. But her condition became uncontrollable gradually after 6 months and she was treated by insulin therapy.
Insulin secretion in type 1 diabetes mellitus was transiently improved by sulfony 1 urea. This suggests that not only the insulin secretion but also glucotoxicity plays an important role in early stage of type 1 diabetes mellitus.