Association of serum and vitreous concentrations of osteoprotegerin with diabetic retinopathy

Background Angiogenesis is involved in the pathogenesis of diabetic retinopathy. Osteoprotegerin, a recently identified glycoprotein belonging to the tumour necrosis factor receptor superfamily, has been implicated to be correlated with angiogenesis. This study aims to determine whether serum and vitreous concentrations of osteoprotegerin are associated with diabetic retinopathy. Methods This study consisted of 254 diabetic patients (100 without diabetic retinopathy, 64 with non-proliferative diabetic retinopathy and 90 with proliferative diabetic retinopathy) and 62 control subjects. Serum and vitreous concentrations of osteoprotegerin were evaluated using enzyme-linked immunosorbent assay method. Results Serum and vitreous osteoprotegerin concentrations in proliferative diabetic retinopathy patients were significantly elevated compared with those of the other three groups. Non-proliferative diabetic retinopathy patients showed elevated concentrations of serum and vitreous osteoprotegerin compared with patients without diabetic retinopathy. In addition, control subjects had significantly lower serum and vitreous osteoprotegerin concentrations compared with diabetic patients without retinopathy, non-proliferative diabetic retinopathy patients and proliferative diabetic retinopathy patients. Conclusions Serum and vitreous osteoprotegerin concentrations are associated with the presence and severity of diabetic retinopathy.