Growth differentiation factor GDF-15 does not influence iron metabolism in stable chronic haemodialysis patients.

Background Growth differentiation factor-15 (GDF-15) is a divergent member of transforming growth factor-beta super family. Under physiological states, it is weakly expressed in most tissues, but it is elevated in impaired kidney function. High concentrations of GDF-15 have been found in some haemoglobinopathies associated with suppressed concentration of hepcidin and iron overload. It is not clear whether the increased concentration of GDF-15 in chronic kidney disease influences iron metabolism. Methods The serum concentrations of GDF-15 and hepcidin, iron (Fe), ferritin, transferrin (Tf), total iron binding capacity, transferrin saturation, soluble transferrin receptor1 (sTfR1), erythropoietin and Hb were measured in 32 stable chronic kidney disease stage 5-dialysis (CKD5-D) patients and 24 healthy adults (controls) to investigate any relationship between GDF-15 and iron indices. Results GDF-15 was significantly elevated in the haemodialysis group (4840.61520.5ng/L) compared to control (472.8 +/- 148.1ng/L). There was a positive correlation between GDF-15 concentration and age in both groups. In the haemodialysis group, hepcidin was increased and correlated with serum ferritin, Tf, total iron binding capacity and sTfR1. There was no correlation between GDF-15 and hepcidin or other iron indices. Conclusions GDF-15 was significantly elevated in our haemodialysis patients but there was no correlation between GDF-15, hepcidin and various iron indices. In this small observational study, GDF-15 would not appear to be associated with iron metabolism in stable CKD5-D patients.