Vitamins E and C in patients with end-stage renal disease undergoing hemodialysis

Graduation date: 2003Patients with end-stage renal disease undergoing hemodialysis have a high\ud incidence of oxidative stress-related diseases. This study evaluated oxidative stress\ud and inflammatory markers in patients undergoing hemodialysis before and during\ud vitamin E supplementation. Blood samples were obtained before and after dialysis\ud during two separate dialysis sessions to establish baseline measurements. For the\ud next two months, subjects consumed 400 IU RRR-α-tocopherol daily. At one\ud month and two months of supplementation, blood samples were also obtained\ud before and after dialysis. Circulating concentrations of α- and γ-tocopherols and\ud their metabolites (carboxyethyl-hydroxychromans, α- and γ-CEHCs), vitamin C,\ud and uric acid were determined by HPLC with electrochemical detection. C-reactive\ud protein (CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were\ud measured using standard clinical assays. F₂-isoprostanes were evaluated using an\ud enzyme immunoassay. Dietary vitamins E and C were assessed using two 24-hour\ud recalls. In response to vitamin E supplementation, plasma α-tocopherol\ud concentrations increased from 18 ± 1.7 μM to 31 ± 5.4 μM (p<0.0001), while γ-tocopherol\ud concentrations decreased from 2.8 ±1.0 μM to 1.7 ± 0.6 μM (p=0.001). Additionally, serum vitamin E metabolites increased, α-CEHCs from 68 ± 20\ud pmol/ml to 771 ± 161 (p<0.0001) and γ-CEHC from 837 ± 161.8 pmol/ml to 1136\ud ± 225.9 (p=0.0083). Both CEHCs are well above reported normal values\ud (p