Intravenous iron supplementation links to inflammation and oxidative stress in hemodialysis patients

Objective To investigate the influence of intravenous iron therapy on oxidalive stress and microinflammation in patients undergoing maintenance hemodialysis (MHD). Methods Seventy-one MHD patients with hematocrit(Hct) less than 0.27 and tranferrin saturation(TAST) less than 0.25 were randomly divided into intravenous iron group (n=24), oral iron group (n=27) and non-iron group (n =20). Patients of intravenous group received 100mg iron dextran by slow IV injection and a total of 1000 mg was administered during ten sequential dialysis sessions. Patients in the oral group took 600 mg ferrous succinate daily gor 8 weeks. Iron was strictly excluded in the non-iron group. Their Hct, hemoglobin (Hb), serum iron (SI), serum ferrin(SF), TAST,redox markers and biomarkers of inflammation were measured at the beginning and the end of the study. These oxidalive stress markers included plasma and erythrocyte malondialdehyde(MDA), superoxide dismutase (SOD), glutathione peroxidase(Gpx), whole blood catalase(CAT). Biomarkers of inflammation include serum C-reactive protein (CRP), interleukin-1β(IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α). Twenty healthy volunteers were as normal controls. Results At baseline, levels of CRP, IL-1β, IL-6, and TNF-α except IL-10 were significantly higher in MHD patients compared with those in healthy subjects (P 0.01 or P 0.05). Plasma and erythrocyte MDA, SOD, Gpx and whole blood CAT were also higher than those ol normal controls before study. After eight-week observation period , Hb and SF levels were significantly higher in intravenous group than those in oral group and non-iron group. At the end of the trial, MDA elevated significantly, whereas SOD, Gpx and whole blood CAT decreased markedly. CRP, IL-1β and TNF-α increased significantly in intravenous group (P 0.01 or P 0.05). The level of plasma MDA was positively correlated to the levels of SF(r=0.7800, P0.01) and TNF-α(r=0.5451 , P0.01) at the end of the trial. Conclusions Erythropoietin and iron administration is important for managing the anemia of MHD patients. Parenteral iron supplementation also aggravates the status of oxidalive stress and microinflammation, and oxidative stress appears to be a key component associated with chronic inflammation in hemodialysis patients.