Background: The aims of this study were to estimate the risk for diabetic retinopathy (DR) and to identify risk factors. We investigated a nationwide population-based cohort with diabetes diagnosed at age 15-34 years.
Patients and methods: Of 794 patients registered 1987-1988 in the Diabetes Incidence Study in Sweden (DISS) 444 (56%) patients with retinal photos available for classification of retinopathy participated in a follow-up study 15-19 (median 17) years after diagnosis. Mean age was 42.3 +/- 5.7 years, BMI 26.1 +/- 4.1 kg/m(2), 62% were male and 91% had type 1 diabetes. A sub-study was performed in 367 patients with retinal photos from both the 9 and 17 year follow up and the risk for development of retinopathy between 9 and 17 years of follow up was calculated.
Results: After median 17 years 324/444 (73%, 67% of T1D and 71% of T2D), had developed any DR but only 5.4% proliferative DR. Male sex increased the risk of developing retinopathy (OR 1.9, 95% CI 1.2-2.9). In the sub-study obesity (OR 1.2, 95% CI 1.04-1.4), hyperglycemia (OR 2.5, 95% CI 1.6-3.8) and tobacco use (OR 2.9, 95% CI 1.1-7.3) predicted onset of retinopathy between 9 and 17 years after diagnosis of diabetes.
Conclusion: The number of patients with severe retinopathy after 17 years of diabetes disease was small. The risk of developing retinopathy with onset between 9 and 17 years after diagnosis of diabetes was strongly associated to modifiable risk factors such as glycemic control, obesity and tobacco use.