Oral vitamin C prevents the attenuation in flow mediated dilation during prolonged sitting (546.3)

Abstract

Prolonged sitting has been hypothesized to impair endothelial function via mechanisms involving oxidative stress. This study was designed to determine if Vitamin C prevents the decline in flow mediated dilation (FMD) during 3hr of sitting.Methods: Eleven inactive, non‐obese, healthy men (24.2±4.4 yrs) participated in two randomized 3 hr sitting trials, performed fasting in the morning on both occasions. In the prolonged sitting (SIT) trial, subjects were seated for 3 hours without moving their lower extremities. In the vitamin C trial (VIT) subjects sat similar to the SIT trial, but were asked to swallow two vitamin C tablets (1000 mg and 500 mg) at 0:30 and 1:30 hr respectively. Superficial femoral artery (SFA) FMD was measured every hour for 3 hrs. Paired sample t‐tests were performed to examine the differences at each time point between SIT and VIT trial. Significance was set at p蠄0.05.Results: Baseline SFA FMD% did not differ between the study conditions (SIT 5.05±3.77; VIT 2.74±2.32). However, FMD% was significantly different between conditions at 1hr (SIT 0.56±0.88; VIT 4.54±3.96) 2hr (SIT 1.76±1.10; VIT 5.28± 3.32) and 3hr (SIT 2.35±2.19; VIT 6.45±4.03).Conclusion: Our data demonstrate that acute oral vitamin C supplementation prevents the acute decline in SFA FMD with prolonged sitting, suggesting that oxidative stress may contribute to the associated impairment in endothelial function.Grant Funding Source: Supported by American College of Sports Medicine Foundation grant