title: Oxidative stress in patients treated with continuous ambulatory peritoneal dialysis (CAPD) and the significant role of vitamin C and E supplementation.
abstract: OBJECTIVE
  Chronic renal failure patients undergoing peritoneal dialysis (PD) are characterized by increased oxidative stress (OS), which is associated with enhanced cardiovascular risk. Moreover, oxidative stress also contributes to peritoneal membrane changes and ultrafiltration failure. The aim of this study was to evaluate OS in PD patients and the effect of treatment with ascorbic acid and α-tocopherol.
  
  
  METHODS
  Plasma, erythrocyte, urine, and peritoneal effluent samples from 20 patients on PD were evaluated for glutathione peroxidase and superoxide dismutase activity, total antioxidant capacity (TAC) and malondialdehyde (MDA) levels, as well as protein carbonyl formation, before and after administration of vitamin C, alone or in combination with vitamin E, in comparison with 10 apparently healthy control individuals.
  
  
  RESULTS
  All studied markers showed enhanced OS in the PD group, compared to controls. The supplementation of vitamin C and E resulted in improvements of all the OS markers, as indicated by increased erythrocyte antioxidant enzymes activity and TAC levels, as well as decreased MDA concentration and carbonyl compound formation.
  
  
  CONCLUSIONS
  The oral supplementation of antioxidant vitamins C and E, in combination, can lead to decreased OS, thus providing a useful and cost-effective therapeutic option in PD patients.
authors.affiliation: Laboratory of Physiology, Faculty of Medicine, University of Ioannina, 45110, Ioannina, Greece. georgios.bountouris@gmail.com
authors.forename: Georgios
authors.initials: G
authors.lastname: Boudouris
authors.forename: Ioannis I
authors.initials: II
authors.lastname: Verginadis
authors.forename: Yannis V
authors.initials: YV
authors.lastname: Simos
authors.forename: Andreas
authors.initials: A
authors.lastname: Zouridakis
authors.forename: Vasilios
authors.initials: V
authors.lastname: Ragos
authors.forename: Spyridon Ch
authors.initials: SCh
authors.lastname: Karkabounas
authors.forename: Angelos M
authors.initials: AM
authors.lastname: Evangelou
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D001205:Ascorbic Acid / Q000627:therapeutic use*; D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control*; D016022:Case-Control Studies; D019587:Dietary Supplements; D005260:Female; D005500:Follow-Up Studies; D005979:Glutathione Peroxidase / Q000032:analysis / Q000378:metabolism; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000628:therapy*; D008297:Male; D008315:Malondialdehyde / Q000032:analysis / Q000378:metabolism; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects*; D010531:Peritoneal Dialysis, Continuous Ambulatory / Q000009:adverse effects* / Q000379:methods; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D013482:Superoxide Dismutase / Q000032:analysis / Q000378:metabolism; D016896:Treatment Outcome; D014810:Vitamin E / Q000627:therapeutic use*
chemical_list: D014810:Vitamin E; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001205:Ascorbic Acid