Retinopathy, glucose, and insulin in an elderly population. The Rotterdam Study

We studied the association between retinopathy and glucose metabolism in a population-based study of elderly men and women. Glucose metabolism was assessed by serum fructosamine and a nonfasting oral glucose tolerance test, and retinopathy was evaluated by fundus photography. Retinopathy was present in 296 of 6,191 subjects examined (4.8%; 120 men and 176 women). Serum glucose and fructosamine levels were higher in subjects with retinopathy compared with those without (8.4 vs. 6.8 mmol/l and 329.8 vs. 308.5 mumol/l, respectively, P < 0.001). Two-hour postload insulin levels and insulin resistance, assessed by the ratio of postload insulin over postload glucose level, did not differ between the two groups. These associations were similar in men and women and in subjects with and without diabetes and did not change after adjustment for body mass index or systolic blood pressure. Within the group of subjects who had retinopathy, serum glucose was significantly associated with the number of hemorrhages. These findings suggest that the presence and severity of retinopathy are associated with higher serum glucose levels, both in subjects with and without diabetes.