Skeletal effects of erythropoietin in hemodialysis patients

To assess the effects of erythropoietin (EPO) on bone metabolism in patients receiving chronic hemodialysis (HD).

Forty one patients were divided into two groups whether they required the administration of EPO to treat renal anemia or not. Serial measurements of predialysis blood samples and bone mineral density were performed prospectively over a year.

The administration of EPO was associated with an increased serum creatinine (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 micrograms/ml, p < 0.05) as well as decreased iron level (112 +/- 7 to 88 +/- 7 micrograms/dl, p < 0.005). Furthermore, in EPO-treated group, exogenous EPO doses correlated with the increments in 1,25-dihydroxy-vitamin D (r = 0.38, p < 0.05), intact osteocalcin (r = 0.42, p < 0.05) and bone alkali-phosphatase (r = 0.53, p < 0.005), but not intact parathyroid hormone (r = 0.09). Both metacarpal index (0.47 +/- 0.02 to 0.47 +/- 0.02) and the summation of gray scale/diameter (2.68 +/- 0.06 to 2.61 +/- 0.07 mmAl), bone mineral density parameters, remained unchanged.

The present data provide evidence that 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 in HD patients, possibly through its actions on metabolism.