Age of Onset of Diabetes and Its Comparison with Prevalence and Risk Factors for Diabetic Retinopathy in a Rural Population of India

Aim: To compare the age of onset of diabetes with the prevalence and risk factors of diabetic retinopathy (DR) in a rural population of India.

Methods: This is a population-based study for which 1,190 people with diabetes were recruited from rural areas of the districts of Kanchipuram and Thiruvallur, Tamil Nadu, India. The fundi of all patients were photographed using a 45°, four-field stereoscopic digital fundus camera. The diagnosis of DR was based on the Klein classification of the Early Treatment Diabetic Retinopathy Study scale.

Results: The prevalence of DR was 11.5% in individuals with known onset of diabetes (aged ≤40 years) compared to 10.0% in those with late onset. The risk factors for any DR in both groups included longer known duration of diabetes, use of insulin, and the presence of high systolic blood pressure and hypertension. In the group with known onset of diabetes at ≤40 years, older age (p < 0.0001) and male gender (p = 0.018) were the significant factors for DR. In the group with age of onset of diabetes at > 40 years, high diastolic pressure (p = 0.001), higher HbA1c (p < 0.0001), high microalbuminuria (p < 0.0001), and high macroalbuminuria (p < 0.008) were the significant risk factors for DR.

Conclusion: Control of risk factors in people with younger age of onset of diabetes may reduce both the prevalence and impact of retinopathy in rural populations.