Association of obesity with diabetic retinopathy: Sankara Nethralaya Diabetic Retinopathy Epidemiology and Molecular Genetics Study (SN-DREAMS Report no. 8)

The aim of the study was to report the prevalence of obesity indices in individuals with diabetes and find out their association with diabetic retinopathy in the urban Indian population. Subjects (n = 1,414) were recruited from Sankara Nethralaya Diabetic Retinopathy Epidemiology And Molecular Genetics Study (SN-DREAMS-I), a cross-sectional study between 2003 and 2006. Anthropometric measurements were carried out, and all patients’ fundi were photographed using 45° four-field stereoscopic digital photography. The diagnosis of diabetic retinopathy was based on the modified Klein classification. Generalized obesity and abdominal obesity were defined using WHO Asia Pacific guidelines with the BMI (body mass index) cutoff as ≥23 kg/m², WC (waist circumference) cutoffs as ≥90 cm in men and ≥80 cm in women and WHO guidelines using WHR (waist-to-hip ratio) cutoffs as ≥0.90 for men and ≥0.85 for women. Prevalence of obesity defined by BMI and WC was more in women compared to men, and that defined by WHR was more in men compared to women (P < 0.001). The prevalence of isolated generalized obesity, isolated abdominal obesity and combined obesity were 5.4, 10.1 and 58% in men and 4.5, 10.8 and 74.4% in women, respectively. The prevalence of any diabetic retinopathy and sight-threatening diabetic retinopathy was more in the isolated abdominal obesity group (26.35 and 6.08%, respectively) than in other subgroups. On logistic regression analysis, isolated abdominal obesity (OR 2.02, 95% CI: 1.06–3.86) and increased WHR in women (OR 1.48 95% CI: 1.10–2.38) were associated with diabetic retinopathy; BMI ≥ 23 (OR 0.66, 95% CI: 0.48–0.90) and combined obesity (OR 0.72, 95% CI: 0.53–0.99) had a protective role for any diabetic retinopathy in the overall group. In the urban south Indian population, isolated abdominal obesity and higher WHR in women were associated with diabetic retinopathy, but not with the severity of diabetic retinopathy.