Artery Function Responses to Changes in Blood Flow

NCT02982044 | Completed

• 1 other identifier: ASPEN
• Study Type: interventional
• Target: 10
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to determine if different blood flow patterns change artery function. We hypothesize that the temporary induction of an oscillatory blood flow pattern will result in an immediate improvement in artery function. Participants will be asked to come to the Vascular Dynamics Lab (IWC E102) at McMaster University for a total of 3 visits. The first visit will allow the participant to get comfortable with the lab and the upcoming tests; and the next 2 visits will be scheduled at the same time of day to collect data. For visits 2 and 3, participants will be asked to arrive after a 4 hour fast. At these visits, ultrasound imaging will be used to examine the arteries and how they may change when blood flow patterns through an artery in the arm are changed. To change blood flow in the arm, heat, rhythmic squeezing of the forearm with a cuff, or handgrip exercise will be used. These interventions will be applied to the left forearm, from the elbow to the fingertips. A trained technician will also draw a blood sample during both data collection visits. A total of 10 participants will be recruited for the entire study.

Conditions

Endothelial Dysfunction

Keywords

blood flow; endothelial function; shear stress

Outcome Measures

Primary Outcomes (1)

• Brachial artery flow-mediated dilation

  Collected using vascular ultrasound and analyzed using semi-automated edge-tracking software

  Up to 2 weeks

Secondary Outcomes (5)

• Mean blood velocity magnitude and direction

  Up to 2 weeks

• Reynolds number (blood flow turbulence)

  Up to 2 weeks

• Endothelial shear stress

  Up to 2 weeks

• Oscillatory shear index

  Up to 2 weeks

• Endothelial shear rate

  Up to 2 weeks

Study Arms (1)

Experimental-Control

EXPERIMENTAL

Participants will undergo all interventions, while simultaneously serving as their own within-subject control. The left side of the body will be designated "experimental", and all interventions will be applied to the left arm. The right side of the body will be designated as "control", and will not receive any interventions.

Other: Suprasystolic (300 mmHg) cuff compressions; Other: Handgrip exercise; Other: Passive heat stress

Interventions

Suprasystolic (300 mmHg) cuff compressions OTHER

10 minutes of ECG-gated repeated suprasystolic (300 mmHg) cuff compressions, with inflation occurring every other heart cycle. These cuff compressions may be triggered 0 seconds, 0.2 seconds, or 0.4 seconds from the R spike (systole) on the ECG signal.

Experimental-Control

Handgrip exercise OTHER

10 minutes of ECG-gated rhythmic handgrip exercise at 30% maximal voluntary contraction, with contraction occurring every other heart cycle

Experimental-Control

Passive heat stress OTHER

10 minutes of passive heat stress at 42 degrees Celsius with a commercially available heating blanket

Experimental-Control

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy (no cardiovascular, musculoskeletal, or metabolic disease)
• Male
• years old
• Recreationally active (exercising 2-3 times per week)

You may not qualify if:

• Cardiovascular, musculoskeletal, or metabolic disease

Sponsors & Collaborators

• McMaster University: lead
• Natural Sciences and Engineering Research Council, Canada: collaborator

Study Sites (1)

McMaster University Vascular Dynamics Lab

Hamilton, Ontario, L8S 4L8, Canada

Location

Related Publications (6)

• Wang C, Baker BM, Chen CS, Schwartz MA. Endothelial cell sensing of flow direction. Arterioscler Thromb Vasc Biol. 2013 Sep;33(9):2130-6. doi: 10.1161/ATVBAHA.113.301826. Epub 2013 Jun 27.

  PMID: 23814115 BACKGROUND

• Tinken TM, Thijssen DH, Hopkins N, Dawson EA, Cable NT, Green DJ. Shear stress mediates endothelial adaptations to exercise training in humans. Hypertension. 2010 Feb;55(2):312-8. doi: 10.1161/HYPERTENSIONAHA.109.146282. Epub 2010 Jan 4.

  PMID: 20048193 BACKGROUND

• Thijssen DH, Dawson EA, Black MA, Hopman MT, Cable NT, Green DJ. Brachial artery blood flow responses to different modalities of lower limb exercise. Med Sci Sports Exerc. 2009 May;41(5):1072-9. doi: 10.1249/MSS.0b013e3181923957.

  PMID: 19346980 BACKGROUND

• Gurovich AN, Braith RW. Enhanced external counterpulsation creates acute blood flow patterns responsible for improved flow-mediated dilation in humans. Hypertens Res. 2013 Apr;36(4):297-305. doi: 10.1038/hr.2012.169. Epub 2012 Oct 18.

  PMID: 23076403 BACKGROUND

• Reneman RS, Arts T, Hoeks AP. Wall shear stress--an important determinant of endothelial cell function and structure--in the arterial system in vivo. Discrepancies with theory. J Vasc Res. 2006;43(3):251-69. doi: 10.1159/000091648. Epub 2006 Feb 20.

  PMID: 16491020 BACKGROUND

• Totosy de Zepetnek JO, Ditor DS, Au JS, MacDonald MJ. Impact of shear rate pattern on upper and lower limb conduit artery endothelial function in both spinal cord-injured and able-bodied men. Exp Physiol. 2015 Oct;100(10):1107-17. doi: 10.1113/EP085056. Epub 2015 Aug 18.

  PMID: 26206681 BACKGROUND

Study Officials

• Maureen J MacDonald, PhD

  McMaster University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 24, 2016
• First Posted: December 5, 2016
• Study Start: January 1, 2017
• Primary Completion: March 1, 2017
• Study Completion: March 1, 2017
• Last Updated: January 18, 2018

Record last verified: 2018-01

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)