Skeletal effects of erythropoietin in hemodialysis patients

Aims: To assess the effects of erythropoietin(EPO) on bone metabolism in patients receivingchronic hemodialysis (HD).Methods: Forty one patients were divided intotwo groups whether they required theadministration of EPO to treat renal anemia ornot. Serial measurements of predialysis bloodsamples and bone mineral density were performedprospectively over a year.Results: The administration of EPO wasassociated with an increased serum creatinirle(11.9 ± 0.4 to 12.5 ± 0.4 mg/dl, p < 0.05),insulin-like growth factor binding protein(3.0 ± 0.2 to 3.4 ± 0.2 µg/ml, p < 0.05) as well as a decreasediron level (112 ± 7 to 88 ± 7 µg/dl, p < 0.005). Furthermore, in EPO-treated group, exogenous EPO doses correlated with the increments in1,25-dihydroxy-vitamin D (r = 0.38, p < 0.05),intact osteocalcin (r = 0.42, p < 0.05) and bonealkali-phosphatase (r = 0.53, p < 0.005), but notintact parathyroid hormone (r = 0.09). Both metacarpal index (0.47 ± 0.02 to 0.47 ± 0.02) andthe summation of gray scale/diameter (2.68 ±0.06 to 2.61 ± 0.07 mmAl), bone mineral densityparameters, remained unchanged. Conclusion: The present data provide evidencethat EPO may modulate the production of 1,25-dihydroxy-vitamin D in HD patients.Furthermore, our findings suggest that EPO therapy activates insulin-like growth factor system inHD patients, possibly through its actions on metabolism.