title: Baseline oxysterols and other markers of oxidative stress, inflammation and malnutrition in the vitamin e and intima media thickness progression in end-stage renal disease (VIPER) cohort.
abstract: OBJECTIVE
  Oxysterols are markers of oxidative stress, levels of which have not yet been reported in hemodialysis (HD) patients. This study was designed to compare levels of the oxysterols 7-ketocholesterol (7KC) and 7beta-hydroxycholesterol (7betaOH) between a cohort of HD patients and healthy controls.
  
  
  METHODS
  This nested cross-sectional study reflects baseline (pre-intervention) values for markers of oxidative stress, inflammation and nutrition status in the 160-member vitamin E and carotid intima media thickness progression in end-stage renal disease (VIPER) cohort (age 64.1 +/- 8.8, 33.5% female). Age- and sex-matched healthy volunteers served as controls. Plasma oxysterols 7KC and 7betaOH were determined by isotope dilution gas chromatography/mass spectrometry.
  
  
  RESULTS
  Despite higher plasma alpha-tocopherol levels in HD patients than controls (36.0 +/- 9.3 vs. 31.8 +/- 8.4 micromol/l, p = 0.007), 7KC levels (9.8 +/- 6.9 vs. 5.9 +/- 2.8 nmol/mmol cholesterol, p < 0.0001) and 7betaOH levels (8.7 +/- 4.3 vs. 2.7 +/- 1.6 nmol/mmol cholesterol, p < 0.0001) were higher in HD patients. The oxysterol 7betaOH was significantly, inversely associated with prealbumin (r = -0.18, p = 0.03), though neither oxysterol was significantly associated with any other marker of oxidative stress, inflammation or nutrition status and did not discriminate for CVD in HD patients.
  
  
  CONCLUSIONS
  Elevated levels of the oxysterols 7KC and 7betaOH indicate that HD patients are in a state of oxidative stress compared to healthy controls. However, oxysterols 7KC and 7betaOH did not appear to contribute additional information about oxidative stress among HD patients.
authors.affiliation: Epidemiology Unit, E. Wolfson Medical Center, Holon, Israel. mboaz8@yahoo.com
authors.forename: Mona
authors.initials: M
authors.lastname: Boaz
authors.forename: Luigi
authors.initials: L
authors.lastname: Iuliano
authors.forename: Jonathan
authors.initials: J
authors.lastname: Himmelfarb
authors.forename: Zipora
authors.initials: Z
authors.lastname: Matas
authors.forename: Fausta
authors.initials: F
authors.lastname: Micheletta
authors.forename: Ellen
authors.initials: E
authors.lastname: McMonagle
authors.forename: Victoria
authors.initials: V
authors.lastname: Friedman
authors.forename: Silvia
authors.initials: S
authors.lastname: Natoli
authors.forename: Gabriella
authors.initials: G
authors.lastname: Gvirtz
authors.forename: Alexander
authors.initials: A
authors.lastname: Biro
authors.forename: Shmuel
authors.initials: S
authors.lastname: Smetana
authors.forename: Gideon
authors.initials: G
authors.lastname: Sabo
authors.forename: Uzi
authors.initials: U
authors.lastname: Gafter
authors.forename: Talia
authors.initials: T
authors.lastname: Weinstein
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers; D002318:Cardiovascular Diseases / Q000209:etiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006888:Hydroxycholesterols / Q000097:blood*; D007249:Inflammation / Q000209:etiology*; D007653:Ketocholesterols / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D008297:Male; D044342:Malnutrition / Q000209:etiology*; D008875:Middle Aged; D018384:Oxidative Stress; D006435:Renal Dialysis; D017540:Tunica Media / Q000473:pathology*; D014810:Vitamin E / Q000097:blood*
chemical_list: D015415:Biomarkers; D006888:Hydroxycholesterols; D007653:Ketocholesterols; D014810:Vitamin E; C011724:cholest-5-en-3 beta,7 alpha-diol; C003001:7-ketocholesterol