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Fluctuation in shear rate, with unaltered mean shear rate, improves brachial artery flow-mediated dilation in healthy, young men
- Source :
- Journal of Applied Physiology, 126, 6, pp. 1687-1693, Journal of Applied Physiology, 126, 1687-1693
- Publication Year :
- 2019
-
Abstract
- Increase in mean shear stress represents an important and potent hemodynamic stimulus to improve conduit artery endothelial function in humans. No previous study has examined whether fluctuations in shear rate patterns, without altering mean shear stress, impacts conduit artery endothelial function. This study examined the hypothesis that 30-min exposure to fluctuations in shear rate patterns, in the presence of unaltered mean shear rate, improves brachial artery flow-mediated dilation. Fifteen healthy men (27.3 ± 5.0 yr) completed the study. Bilateral brachial artery flow-mediated dilation was assessed before and after unilateral exposure to 30 min of intermittent negative pressure (10 s, −40mmHg; 7 s, 0 mmHg) to induce fluctuation in shear rate, while the contralateral arm was exposed to a resting period. Negative pressure significantly increased shear rate, followed by a decrease in shear rate upon pressure release (both P < 0.001). Across the 30-min intervention, mean shear rate was not different compared with baseline ( P = 0.458). A linear mixed model revealed a significant effect of time observed for flow-mediated dilation ( P = 0.029), with exploratory post hoc analysis showing an increase in the intervention arm (∆FMD +2.0%, P = 0.008), but not in the contralateral control arm (∆FMD +0.5%, P = 0.664). However, there was no effect for arm ( P = 0.619) or interaction effect ( P = 0.096). In conclusion, we found that fluctuations in shear patterns, with unaltered mean shear, improves brachial artery flow-mediated dilation. These novel data suggest that fluctuations in shear pattern, even in the absence of altered mean shear, represent a stimulus to acute change in endothelial function in healthy individuals. NEW & NOTEWORTHY Intermittent negative pressure applied to the forearm induced significant fluctuations in antegrade and retrograde shear rate, while mean shear was preserved relative to baseline. Our exploratory study revealed that brachial artery flow-mediated dilation was significantly improved following 30-min exposure to intermittent negative pressure. Fluctuations in blood flow or shear rate, with unaltered mean shear, may have important implications for vascular health; however, further research is required to identify the underlying mechanisms and potential long-term health benefits.
- Subjects :
- Adult
Male
medicine.medical_specialty
Brachial Artery
Physiology
Vascular damage Radboud Institute for Health Sciences [Radboudumc 16]
Flow mediated dilation
030204 cardiovascular system & hematology
Q1
Lower limb
RC1200
03 medical and health sciences
0302 clinical medicine
All institutes and research themes of the Radboud University Medical Center
Forearm
Physiology (medical)
Internal medicine
medicine.artery
Medicine
Humans
Brachial artery
Exercise
business.industry
Hemodynamics
030229 sport sciences
Blood flow
QP
Dilatation
Shear rate
Vasodilation
medicine.anatomical_structure
Shear (geology)
Regional Blood Flow
Cardiology
Endothelium, Vascular
Stress, Mechanical
business
Subjects
Details
- ISSN :
- 87507587 and 16871693
- Database :
- OpenAIRE
- Journal :
- Journal of Applied Physiology, 126, 6, pp. 1687-1693, Journal of Applied Physiology, 126, 1687-1693
- Accession number :
- edsair.doi.dedup.....8d995f6f0a645fdce960a19483936358