Differences in brachial and femoral artery responses to prolonged sitting.

Saurabh S Thosar,Sylvanna L Bielko,Janet P Wallace,Chad C Wiggins

doi:10.1186/1476-7120-12-50

Abstract

IntroductionIt is unknown if there are limb differences in vascular function during prolonged sitting.PurposeThis study was designed to test whether the effects of prolonged sitting on brachial artery (BA) and the superficial femoral artery (SFA) are similar.MethodsTwelve men (24.2 ± 4 yrs.) participated in a 3 hr prolonged sitting trial (SIT). SFA and BA flow mediated dilation (FMD) and respective flow patterns were measured at baseline, 1 hr, 2 hr and 3 hr.ResultsBy a one-way ANOVA there was a significant decline in SFA FMD during 3 hrs of SIT (p < 0.001). Simultaneously, there was a significant decline in antegrade (p = 0.04) and mean (0.037) shear rates. By a one way ANOVA there were no significant differences in BA FMD during 3 hrs of sitting. There were no changes in the shear rates in the BA except for a significant decrease in antegrade shear rate (p = 0.029) and a significant increase in oscillatory shear index (p = 0.034) during 3 hrs of sitting. Furthermore, there was no correlation between BA and SFA FMD measurements.ConclusionThree hours of sitting resulted in impaired SFA FMD but not BA FMD. Although 3 hours of sitting did not impair BA FMD, it impaired shear patterns in the BA.

Highlights

It is unknown if there are limb differences in vascular function during prolonged sitting
By a one way ANOVA there were no significant differences in brachial artery (BA) flow mediated dilation (FMD) during 3 hrs of sitting
Prolonged sitting decreased mean and antegrade shear rates in the superficial femoral artery (SFA) and impaired endothelial function measured by flow mediated dilation (FMD) [5]

Summary

Introduction

It is unknown if there are limb differences in vascular function during prolonged sitting. Because of the increased presence of sitting, we recently studied the effects of 3 hours of sitting on lower extremity (superficial femoral artery [SFA]) endothelial function and discovered that 3 hrs of prolonged sitting decreased mean and antegrade shear rates in the SFA and impaired endothelial function measured by flow mediated dilation (FMD) [5]. Low shear stresses during prolonged sitting [5] decrease the expression of nitric oxide synthase [11] and this may lead to impairment in endothelial function, putting the vasculature at risk of atherosclerosis. In the presence of our recent findings on the impairment of endothelial function on sitting [5], it is interesting to study whether upper extremity (brachial artery [BA]) endothelial function is affected on prolonged sitting. The purpose of this study was to investigate if the effects of prolonged sitting on BA and SFA are similar

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