There is no influence of rHu-EPO therapy on serum concentrations of IGF-I in chronic hemodialysis patients. Furthermore, IGF-I bioavailability (free IGF-I) needed to be estimated through measuring the circulating IGF binding proteins in chronic hemodialysis patients. Also our results suggested that IGF-I might play a role in the regulation of erythropoiesis through its EPO-like action. Moreover, no correlations have been found between total IGF-I and renal functions, or with nutritional status in our patients.