Anemia as a Risk Factor for Diabetic Retinopathy (DR) with Special Reference to Nutritional Etiology

Background: Anemia is increasingly recognized as a risk factor for DR. Nutritional anemia is a major cause of anemia in India. This study was undertaken to explore anemia as a risk factor for DR. Methodology: Patients with type 2 diabetes admitted to the medical wards of a tertiary care hospital were enrolled into the study, in the absence of renal failure, pregnancy and ocular disorders unrelated to diabetes. Retinopathy was classified as per ETDRS classification. Anemia was defined and graded based on WHO guidelines. In patients with anemia, serum B 12 , serum iron, total iron binding capacity (TIBC) and percent saturation were assayed. Results: A total of 170 patients were enrolled into the study (males 93, females 77). The mean age of the study group was 59 ± 12.30 (SD) years. Patients with DR (n=85) were classified as Group 1 and those without DR (n=85) as Group 2. The mean age of patients in Group 1 was 60.74 ± 13.00 (SD) years and that in Group 2 was 57.26 ± 11.39 (SD) years. The mean duration of diabetes was 12.40 ± 7.60 (SD) years for Group 1 and 6.64 ± 4.48 (SD) years for Group 2. The mean Hb of patients in Group 1 was 10.40 ± 0.25 (SD) gm% and in Group 2 was 12.70 ± 0.18 (SD) gm% (p=0.001). Within these groupings, 67 patients had anemia (56 in Group 1, 11 in Group 2). There was a significant association between anemia and DR (p=0.001) and a trend towards association between increasing grades of anemia and severity of DR (p=0.06). In Group 1, among patients with anemia, 28 (50%) patients had nutritional anemia (iron: 24, B 12 : 3 and dual: 1). On logistic regression analysis, anemia and duration of diabetes emerged as predictors of DR. Discussion: Anemia in patients with diabetes may be multifactorial in etiology. While metformin therapy, albuminuria and reduced renal function are implicated, vegetarian diet is a major contributor for nutritional anemia. Regular monitoring of Hb and treatment with supplements or dietary modifications may reduce occurrence and arrest progression of DR. Disclosure J. Idiculla: None. S. Nithyanandam: None. M. Joseph: None. C. J.: None.