Association between diabetic retinopathy and hemoglobin level

Anemia maybe considered to be an independent risk factor for the development of diabetic retinopathy (DR) in patients with renal failure. The purpose of this study was to investigate the association between blood hemoglobin level and retinopathy in diabetic patients with normal renal function tests. From 2009 to 2011, 1100 diabetic patients were anderwent for retinal examination. Among them, 159 subjects were diagnosed to have DR and were compared with 318 diabetic subjects with normal retinal examination as control. Level of hemoglobin (Hb), Hb A1C, serum iron, ferritin, and total iron binding capacity (TIBC) were compared between these two groups. Among the 159 patients with DR, 112 (70.4%) had mild to moderate nonproliferative retinopathy (NPDR) and 47 (29.6%) had advanced retinopathy (severe NPDR or proliferative). Mean hemoglobin level in case and control group was 12.15±1.50 and 12.73±1.38 g/dl, respectively (p<0.001). The prevalence of anemia was 45.9% and 26.1% in the case and control groups, respectively (p<0.001). The prevalence of iron deficiency anemia (ferritin<15ng/ml) in DM patients with DR was not significantly different compared to DM patients without DR (7.4% versus 6.1%, respectively). The results show that diabetic patients with retinopathy have lower level of hemoglobin and higher prevalence of anemia. It is suggested that the level of hemoglobin should be evaluated periodically in diabetic patients.