Differences in brachial and femoral artery responses to prolonged sitting

INTRODUCTION It is unknown if there are limb differences in vascular function during prolonged sitting. PURPOSE This study was designed to test whether the effects of prolonged sitting on brachial artery (BA) and the superficial femoral artery (SFA) are similar. METHODS Twelve 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. RESULTS By 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. CONCLUSION Three 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.