Antioxidant vitamin C prevents decline in endothelial function during sitting

• Published in: Medical science monitor Vol. 21; pp. 1015 - 1021
• Main Authors: Thosar, Saurabh S, Bielko, Sylvanna L, Wiggins, Chad C, Klaunig, James E, Mather, Kieren J, Wallace, Janet P
• Format: Journal Article
• Language: English
• Published: United States International Scientific Literature, Inc 07.04.2015
• Subjects: Adult; Antioxidants - pharmacology; Ascorbic Acid - pharmacology; Clinical Research; Demography; Endothelium, Vascular - drug effects; Endothelium, Vascular - physiopathology; Femoral Artery - physiopathology; Humans; Male; Posture; Regional Blood Flow - drug effects; Vasodilation - drug effects
• ISSN: 1643-3750; 1234-1010; 1643-3750
• DOI: 10.12659/msm.893192

This study was designed to test the hypothesis that antioxidant Vitamin C prevents the impairment of endothelial function during prolonged sitting. 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. 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). 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.