title: Temporal variation of oxidant stress in critically ill patients.
abstract: OBJECTIVE
  Our aim was to investigate indicators of lipid peroxidation via observing temporal changes or daily fluctuations in cytoprotective enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), and serum components possessing antioxidant activity against free radicals and malondialdehyde (MDA) such as uric acid. This study was conducted in a small number of critically ill patients versus healthy volunteers in order to design an effective antioxidant therapy regimen under oxidative stress.
  
  
  METHODS
  Six critically ill patients and 6 young healthy volunteers were recruited. Blood samples were collected 6 times a day with 4 h intervals starting from 8 a.m. From the blood samples, SOD and GSH-PX activities and uric acid and MDA levels were determined. One-way ANOVA and unpaired t-test were used to assess differences within and between the groups, respectively. A two dimensional table curve cosine formulation was performed to elucidate rhythmycity.
  
  
  RESULTS
  No significant differences were found in SOD and GSH-PX activities or uric acid levels within the 24 h period or between the groups. MDA levels were significantly higher in the study group at 8 p.m. than that of control group (P<0.05), but no significant difference was found within the 24 h period. We showed that GSH-PX activities in control and study groups revealed temporal variation, whereas uric acid levels varied temporally only in the study group.
  
  
  CONCLUSIONS
  We concluded that there are signs of oxidative stress in ICU patients that vary in time but further studies are required in order to design appropriate antioxidant treatments.
authors.affiliation: Department of Anesthesiology and Reanimation, Faculty of Medicine, Gazi University, Ankara, Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Gunaydin
authors.forename: B
authors.initials: B
authors.lastname: Sancak
authors.forename: S
authors.initials: S
authors.lastname: Candan
authors.forename: M
authors.initials: M
authors.lastname: Sariahmetoğlu
authors.forename: G
authors.initials: G
authors.lastname: Ozçağli
authors.forename: B
authors.initials: B
authors.lastname: Tunçtan
authors.forename: I
authors.initials: I
authors.lastname: Cakici
authors.forename: M
authors.initials: M
authors.lastname: Akçabay
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism / Q000627:therapeutic use*; D016638:Critical Illness; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D018384:Oxidative Stress / Q000502:physiology*; D013482:Superoxide Dismutase / Q000097:blood; D013997:Time Factors; D016896:Treatment Outcome; D014527:Uric Acid / Q000097:blood
chemical_list: D000975:Antioxidants; D014527:Uric Acid; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase