Examining the effects of shear rate on flow mediated dilation in children and adults
department or school: Health and Social Development, Faculty of (Okanagan)
department or school: Health and Exercise Sciences, School of (Okanagan)
data provider: DSpace
degree campus: UBCO
creator: Shabir, Nadhiyya
issued: 2024-05-13T16:46:28Z
issued: 2024
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Purpose: Variations in shear stimulus has been shown to impact endothelial function. Studies have shown that increases in shear improves endothelial function and overall vascular health while decreases in shear leads to impairments in endothelial function and develops risk of cardiovascular diseases. Although this pattern is noticed in adult studies, there are limited studies that investigate this relationship in children. Therefore, the aim of this study was to examine the relationship between shear rate and flow mediated dilation (FMD) in children and adults. Methods: Nine adults and seven children completed two protocols: passive heat and low-pressure cuff. Superficial femoral artery diameter, flow, shear rate, FMD were measured pre and post condition. Results: Mean shear rate increased significantly post passive heat condition in children (103.1 ± 41.5 s⁻¹ to 230.4 ± 79.1 s⁻¹) and adults (29.9 ± 12.1 s⁻¹ to 140.3 ± 36.0 s⁻¹) with a greater increase in adults than children. Despite the increases in mean shear rate and antegrade shear rate, FMD did not significantly improve post heat. There were no age-related differences in FMD responses post passive heat condition. Mean shear rate decreased significantly following low cuff condition in children (142.4 ± 67.4 s⁻¹ to 101.1 ± 22.1 s⁻¹) and adults (38.7 ± 19.5 s⁻¹ to 23.8 ± 15.4 s⁻¹). The significant increases in retrograde shear rate post low pressure cuff was followed by a significant decline in FMD in children (4.3 ± 1.8% to 2.6 ± 1.4%) and adults (4.1 ± 1.2% to 2.9 ± 0.78%). Conclusions: Passive heat can increase shear rates and flow in both children and adults but may not be enough to stimulate positive endothelial function. Low pressure cuff can impair endothelial function through decreases in shear, flow and FMD in children and adults. These findings have implications for understanding vascular function in different age groups and for developing interventions to enhance vascular health.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/88283
note: EXAMINING THE EFFECTS OF SHEAR RATE ON FLOW MEDIATED DILATION IN CHILDREN AND ADULTS by Nadhiyya Shabir B.S.c, McMaster University, 2021 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE COLLEGE OF GRADUATE STUDIES (Health and Exercise Sciences) THE UNIVERSITY OF BRITISH COLUMBIA Okanagan April 2024 © Nadhiyya Shabir, 2024 ii The following individuals certify that they have read, and recommend to the College of Graduate Studies for acceptance, a thesis entitled: EXAMINING THE EFFECTS OF SHEAR RATE ON FLOW MEDIATED DILATION IN CHILDREN AND ADULTS submitted by Nadhiyya Shabir in partial fulfillment of the requirements for the degree of Master of Science in Health and Exercise Sciences Examining Committee: Dr. Alison McManus, Faculty of Health and Social Development Supervisor Dr. Glen Foster, Faculty of Health and Social Development Supervisory Committee Member Dr. Kurt Smith, Faculty of Education Supervisory Committee Member Dr. Brian Timmons, Faculty of Health Sciences University Examiner iii Abstract Purpose: Variations in shear stimulus has been shown to impact endothelial function. Studies have shown that increases in shear improves endothelial function and overall vascular health while decreases in shear leads to impairments in endothelial function and develops risk of cardiovascular diseases. Although this pattern is noticed in adult studies, there are limited studies that investigate this relationship in children. Therefore, the aim of this study was to examine the relationship between shear rate and flow mediated dilation (FMD) in children and adults. Methods: Nine adults and seven children completed two protocols: passive heat and low-pressure cuff. Superficial femoral artery diameter, flow, shear rate, FMD were measured pre and post condition. Results: Mean shear rate increased significantly post passive heat condition in children (103.1 ± 41.5 s-1 to 230.4 ± 79.1 s-1) and adults (29.9 ± 12.1 s-1 to 140…
has type: Thesis/Dissertation
date issued: 2024-09
is shown at: 10.14288/1.0443082
language: eng
degree discipline: Health and Exercise Sciences
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: McManus, A. M. (Alison M.)
type: Text
identifier URI: http://hdl.handle.net/2429/88283