Is Prevalence of Retinopathy Related to the Age of Onset of Diabetes? Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetic Report No. 5

Abstract

Aim: To compare the prevalence of diabetic retinopathy (DR) and risk factors in patients with a known onset of diabetes before 40 years and after 40 years of age. Methods: This is a population-based study for which 1,414 diabetics were recruited. The fundi were photographed using 45-degree 4-field stereoscopic digital photography. The diagnosis of DR was based on Klein’s classification of the Early Treatment Diabetic Retinopathy Study scales. Results: The prevalence of DR was 33.3% (95% confidence interval, CI: 26.6–39.9) in known onset of diabetes (≤40 years) compared to 15.6% (95% CI: 13.6–17.6) in those with late onset (>40 years; p < 0.0001). In the group with age of known onset of diabetes ≤40 years, the risk factors, associated with any DR, were poor glycemic control (odds ratio, OR: 1.36 for every g% increase in glycosylated hemoglobin), insulin use (OR: 4.21), increasing known duration of diabetes (OR: 1.10 for increase of every year in known duration of diabetes) and presence of macroalbuminuria (OR: 13.39). In the late onset of diabetes group, besides the above-mentioned risk factors, the presence of microalbuminuria (OR: 2.08), male gender (OR: 1.67), presence of anemia (OR: 1.89) and increased systolic blood pressure (OR: 1.01) were the risk factors for DR. Conclusion: The prevalence of DR was almost twice more in those subjects who developed diabetes before the age of 40 years than those who developed it later.