Impact of Prolonged Sitting on Peripheral and Central Vascular Health
Prolonged, uninterrupted sitting negatively impacts markers of peripheral vascular health, particularly, vasodilatory function of leg arteries. Whether sitting can similarly impact measures of central vascular health, as well as overall leg vasoreactivity (i.e., vasodilatory and vasoconstrictor function) remains unknown. To address this, measurements were made in relatively healthy participants (i.e., free of overt disease; N=20, age=26±7; BMI=30±7 kg/m2; 7 female) pre, during and post 3 hours of uninterrupted sitting. Measures of central vascular health included arterial wave reflection (augmentation index—AIx, and Reflection Magnitude—RM%) and aortic vascular stiffness (aortic pulse wave velocity—aPWV). Local vasoreactivity of the distal, posterior tibial artery was measured using flow-mediated dilation—FMD, coupled with low-flow mediated constriction, and microvascular function was assessed via the total hyperemic blood velocity (AUC) response during FMD. Following sitting, there was a significant increase in aPWV (pre sit=5.7±0.3 vs. post sit=6.1±0.3 m/sec; p=0.009, d=0.36), whereas, AIx decreased (pre sit=13±3 vs. post sit=3±1 %; p<0.001, d=0.71). Albeit a moderate effect for decrease, RM% was not significantly altered during sitting (p=0.13, d=0.3). Vasodilatory (i.e., FMD pre sit=0.5±0.04 vs. post sit=0.3±0.04 mm; p=0.014, d=0.29) and microvascular function (i.e., Microvascular AUC: pre sit=2,196±333 vs. 1,157±172 AU; p=0.003, d=0.31) decreased, but vasoconstrictor function (low-flow mediated constriction; p=0.85, d=0.005) was unaffected by sitting. In conclusion, these data demonstrate that a prolonged bout of uninterrupted sitting negatively impacts markers of peripheral and central vascular health in relatively healthy adults.
The American Journal of Cardiology
Dolbow, D. R.,
McCoy, S. M.
(2018). Impact of Prolonged Sitting on Peripheral and Central Vascular Health. The American Journal of Cardiology.
Available at: https://aquila.usm.edu/fac_pubs/15623