Risk factors for the development of diabetic retinopathy in Japanese type 2 diabetic patients

This study investigated the risk factors for development uf diabetic retinopathy (DR) in 787 type 2 diabetic patients with no retinopathy at the first visit. The subjects were followed up fur at least 3 years (mean. 6.7 years). Among the baseline factors, significant correlations were observed between the development of DR and HbA(1c) (P < 0.0001), the method of therapy (P < 0.005), the duration of diabetes at the first visit (P < 0.005) and the past maximal body mass index (BMI) (P < 0.01). No significant correlation was found with the blood pressure, age, gender, TC or BMI. Among the follow-up variables, the mean HbA(1c) (P < 0.0001) and duration of diabetes (P < 0.001) correlated significantly with DR development, whereas the blued pressure and age did nut. We found that a 1% decrease in HbA(1c) led to a 35% reduction in the risk of development of DR during the follow-up. The patients whose HbA(1c) at the first visit was higher than the median value of 8.2% showed a higher probability of development of DR during the next 3 years even when the same blood glucose control was maintained during the follow-up. In conclusion, our study demonstrated that the most important risk factor influencing the development of DR was the blood glucose control. Moreover, we found that the glycemic level;rt the first visit also influenced the development of DR. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.