Relationship of diabetic retinopathy with coronary artery disease in Asian Indians with type 2 diabetes: the Chennai Urban Rural Epidemiology Study (CURES) Eye Study--3.

Objectives: This study assessed the relationship between diabetic retinopathy (DR) and coronary artery diseases (CAD) in Asian Indians, who are known to be at high risk of CAD and diabetes but have lower prevalence of DR. Subjects and Methods: Type 2 diabetes subjects (n=1,736) were selected from the urban component of the population-based Chennai Urban Rural Epidemiology Study Eye Study. Four-field stereo retinal color photography was done, and DR when present was classified according to the Early Treatment Diabetic Retinopathy Study grading system. Among the 1,723 subjects with gradable fundus photographs, 12-lead electrocardiogram (ECG) was performed in 1,602 individuals, and analysis was restricted to this group. CAD was diagnosed based on documented medical history of CAD or Minnesota coding of ECGs. Results: The prevalence of CAD was significantly higher among subjects with DR compared with those without (11.3% vs. 6.7%; P=0.007). A significant association was observed between DR and CAD in subjects with glycated hemoglobin (HbA1c) levels >7% (P=0.002). After controlling for age and gender, only hard exudates were associated with CAD (P=0.032). Logistic regression analysis revealed that even after adjusting for age, gender, HbA1c, mean arterial blood pressure, smoking, serum cholesterol, triglyceride, and low-density lipoprotein cholesterol levels, DR was significantly associated with CAD among the study subjects (odds ratio [OR]=1.58; 95% confidence interval [CI], 1.00-2.49; P=0.049) and those subjects with duration of diabetes >10 years (OR=4.06; 95% CI, 1.55-10.60; P=0.004). Conclusions: This cross-sectional study shows a significant association between DR and CAD in South Indian subjects with type 2 diabetes.