Patients of both genders aged more than 18 years will be considered eligible for the study if they had been receiving bicarbonate hemodialysis treatment for at least six months and stable ESA therapy for at least three months, and had adequate iron stores (ferritin levels >200 ng/ml and transferrin saturation >20%). Patients with haemoglobinopathies, sickle cell anemia, thalassemia or malignancies will be excluded, as were those who had experienced infection, vascular access thrombosis, stroke, myocardial infarction, heavy blood loss, major surgery or blood transfusion in the previous three months.