RETINOPATHY IN TYPE-II DIABETES-MELLITUS ASSOCIATED WITH ABOVE-NORMALURINARY-EXCRETION OF RBP

We performed a cross-sectional study on the urinary excretion profiles of albumin (a marker of glomerular dysfunction) and retinol-binding p rotein (a low molecular mass protein marker of renal proximal tubular dysfunction) in non-insulin dependent (Type II) diabetics, with or wit hout retinopathy. The urinary excretion of both proteins, in particula r retinol-binding protein, was significantly higher in patients with b ackground/proliferative retinopathy compared to patients without retin opathy. The degree of retinopathy correlated to the urinary excretion of albumin (P < 0.005) and retinol-binding protein (P < 0.0001). Retin opathy occurred at a higher frequency in patients with above-normal ur inary excretion of retinol-binding protein, both in the absence or pre sence of micro/macroalbuminuria. The frequency of retinopathy among mi cro/ macroalbuminuric patients with a normal urinary excretion of reti nol-binding protein did not differ significantly from that observed in patients with a normal urinary excretion of both proteins. We cannot explain the association between retinopathy and proximal tubular dysfu nction in Type II diabetes. However, it is possible that both phenomen a are related to a common pathogenetic factor.