The effect of etidronate disodium (EHDP) on retinopathy in insulin-dependent diabetic patients

Abstract

In a randomized double-blind study the effect of etidronate disodium (EHDP) on retinopathy, plasma inorganic phosphate and blood oxygen transport was assessed in 26 insulin-dependent diabetic patients. Following 6 months of EHDP administration, plasma inorganic phosphate had increased significantly (1.48 vs 1.14 mmol/l; P less than 0.01). Red cell, 2,3-diphosphoglycerate concentration (16.9 vs 15.1 mumol/g Hb; P less than 0.01) and the haemoglobin-oxygen affinity measured by pO2 at 50% oxygen saturation (P50) had also increased significantly (27.5 vs 26.3 mmHg; P less than 0.01). No changes had occurred in mean blood glucose and haemoglobin A1c concentrations, indicating a comparable degree of glucose regulation. Following 6 months of EHDP administration an association was found between improvement in retinopathy and the increase in plasma inorganic phosphate.

Disturbance of inorganic phosphate metabolism in diabetes mellitus: temporary therapeutic intervention trials

“…Studies of nonproliferative retinopathy suggested that a 6-month course of EHDP administration may improve retinopathy. 25 EHDP in large doses may also suppress bone turnover, inhibits bone mineralization and affect tooth development, deleterious effects that discourage general use. 38,39 The therapeutic use of fructose-1, 6 diphosphate (FDP) in diabetes is much more attractive since it is a natural intermediate in glycolysis and also acts as human bioenergy, delivering intracellular phosphorus and 4 moles ATP per mole of FDP.…”

“…A subsequent randomized, 6-month, double-blind study of 26 type 1 diabetic patients with nonproliferative retinopathy confirmed the effect of EHDP on Pi, red cell 2, 3-DPG and P 50 of ODC. 25 Furthermore, the lack of changes in mean glucose and HbA 1c indicated an interesting association between improvement in retinopathy as evaluated by retinal fluorescein angiography and increased Pi (P  0.05).…”