title: Antioxidant vitamin C prevents decline in endothelial function during sitting.
abstract: BACKGROUND
  This study was designed to test the hypothesis that antioxidant Vitamin C prevents the impairment of endothelial function during prolonged sitting.
  
  
  METHODS
  Eleven men (24.2 ± 4.4 yrs) participated in 2 randomized 3-h sitting trials. In the sitting without vitamin C (SIT) and the sitting with vitamin C (VIT) trial, participants were seated for 3 h without moving their legs. Additionally, in the VIT trial, participants ingested 2 vitamin C tablets (1 g and 500 mg) at 30 min and 1 h 30 min, respectively. Superficial femoral artery (SFA) flow-mediated dilation (FMD) was measured hourly for 3 h.
  
  
  RESULTS
  By a 1-way ANOVA, there was a significant decline in FMD during 3 h of SIT (p<0.001). Simultaneously, there was a significant decline in antegrade (p=0.04) and mean (0.037) shear rates. For the SIT and VIT trials by a 2-way (trial x time) repeated measures ANOVA, there was a significant interaction (p=0.001). Pairwise testing revealed significant between-SFA FMD in the SIT and VIT trial at each hour after baseline, showing that VIT prevented the decline in FMD 1 h (p=0.009), 2 h (p=0.016), and 3 h (p=0.004). There was no difference in the shear rates between SIT and VIT trials (p>0.05).
  
  
  CONCLUSIONS
  Three hours of sitting resulted in impaired SFA FMD. Antioxidant Vitamin C prevented the decline in SFA FMD, suggesting that oxidative stress may contribute to the impairment in endothelial function during sitting.
authors.affiliation: Department of Kinesiology, Indiana University School of Public Health, Indiana University, Bloomington, IN, USA.
authors.forename: Saurabh S
authors.initials: SS
authors.lastname: Thosar
authors.affiliation: Department of Kinesiology, Indiana University School of Public Health, Indiana University, Bloomington, IN, USA.
authors.forename: Sylvanna L
authors.initials: SL
authors.lastname: Bielko
authors.affiliation: Department of Kinesiology, Indiana University School of Public Health, Indiana University, Bloomington, IN, USA.
authors.forename: Chad C
authors.initials: CC
authors.lastname: Wiggins
authors.affiliation: Department of Environmental Health, Indiana University School of Public Health, Indiana University, Bloomington, IN, USA.
authors.forename: James E
authors.initials: JE
authors.lastname: Klaunig
authors.affiliation: Department of Medicine, Indiana University School of Medicine, Indiana University, Indianapolis, IN, USA.
authors.forename: Kieren J
authors.initials: KJ
authors.lastname: Mather
authors.affiliation: Department of Kinesiology, Indiana University School of Public Health, Indiana University, Bloomington, IN, USA.
authors.forename: Janet P
authors.initials: JP
authors.lastname: Wallace
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D003710:Demography; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000503:physiopathology*; D005263:Femoral Artery / Q000503:physiopathology; D006801:Humans; D008297:Male; D011187:Posture; D012039:Regional Blood Flow / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects
chemical_list: D000975:Antioxidants; D001205:Ascorbic Acid
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