Oral iron absorption in hemodialysis patients treated with erythropoietin.

The effect of the erythropoietic activity of the bone marrow on oral iron absorption was investigated in hemodialysis patients. The subjects were enrolled in the Canadian Multicentre Erythropoietin (EPO) Trial; four patients were in the placebo group and four were in the EPO group. All patients were maintained iron replete with oral and intravenous iron as required to maintain ferritin greater than 200 micrograms/L. All patients had two oral radio-labelled iron (59Fe) absorption tests. The first took place during the last two months of the EPO trial, and the second within the first three months of the maintenance phase where all patients received EPO. The erythropoietic activity of the bone marrow was changed by administration of EPO to the placebo group. The group with an unchanged EPO prescription served as controls. The placebo group absorbed 4.5% and 3.9% of 59Fe pre- and post-EPO, respectively (delta NS). The control group absorbed 3.2% and 4.4% of 59Fe and thus similarly showed no change in iron absorption. Oral iron absorption is low in hemodialysis patients, and is not augmented by short-term EPO therapy. The high level of iron stores (i.e., ferritin) present in the Canadian EPO study patients may prevent an effect of the erythropoietic stimulation on iron absorption. Although an increase in iron absorption by EPO was not demonstrated, a type II error could not be excluded.