Background: Determining which diabetic patients are at risk for complications and targeting these patients for intensive therapy may avoid the unwanted consequences of hypoglycemia in low-risk patients. Since aging is associated with a decrease in the incidence of diabetic retinopathy, we assessed whether long complication-free duration can define elderly patients at lower risk for future development of diabetic retinopathy.
Methods: In a 10-year clinic-based study, we studied 833 type 2 diabetic patients who were free of diabetic retinopathy and older than 50 years, followed up for more than 4 years. Data included demographic and clinical information on arrival, updated every 3 to 6 months, and yearly direct ophthalmoscopic examination after pupillary dilation by experienced ophthalmologists. All the data were prospectively compiled on relational databases. End points studied were presence of retinopathy, nephropathy, peripheral neuropathy, peripheral vascular disease, hyperlipidemia, and hypertension.
Results: Of the patients without retinopathy at the age of 50 years, 10% developed retinopathy during 4 years of follow-up. These patients had longer duration and younger onset of diabetes than the group without retinopathy at the 4-year follow-up. Clustering of microvascular and macrovascular complications was noted. Discriminant analysis showed the following factors to be significant and independent predictors of the development of retinopathy in the elderly: duration of diabetes, body mass index, age, and glucose control.
Conclusions: A long complication-free period does not define elderly patients with type 2 diabetes who are at lower risk for future development of retinopathy. On the contrary, the increase in disease duration is significantly associated with the development of retinopathy in this age group, as described in younger patients.