Glycemic control and prevention of retinopathy in Japanese NIDDM patients. A 10-year follow-up study

Abstract

Objective: To examine glycemic control for the prevention of retinopathy in early diagnosed Japanese NIDDM patients.

Research design and methods: There were 137 patients with NIDDM but without retinopathy who first visited our facility from 1983-1985. Their age at diagnosis ranged from 30-65 years, with a disease duration of < 3 years. The optic fundi were examined at least annually. The prevalence of retinopathy in the 10th year after registration in the study was compared in four groups stratified by mean HbA1c values for 10 years. Multiple logistic regression analysis was used to assess the relationship between retinopathy and covariates.

Results: None of the patients with a mean HbA1c < 6% had retinopathy. The prevalence of retinopathy was 17.2% in the group with a mean HbA1c of 6-6.9%, 14.3% in the group with a mean HbA1c of 7-7.9%, 41.9% at a mean HbA1c of 8-8.9%, and 54.8% when the mean HbA1c exceeded 9%. The prevalence of retinopathy increased with the increase in the mean HbA1c values over 10 years (trend, P < 0.005). Multiple logistic regression analysis revealed that mean HbA1c was the only significant risk factor for the development of retinopathy.

Conclusions: Our results support the concept that an early diagnosis and better control lessen the risk for the development of retinopathy in Japanese NIDDM patients.