Acute Effects of Autoregulated and Non-autoregulated Blood Flow Restrictive Exercise on Indices of Arterial Stiffness

To investigate the acute effects of autoregulated (AR) and non-autoregulated (NAR) BFR exercise on indices of arterial stiffness. AR BFR training devices adjust pressure in the cuff ensuring similar pressure throughout the range of motion when the muscles are contracted (dilatated) and relaxed. NAR BFR training devices do not adjust pressure in the cuff throughout the range of motion when the muscles are contracted and relaxed which cause greater pressures at different points in the range of motion. METHODS: Following a randomized AR or NAR familiarization training session, 20 adults (23±5 years; 7 female) participated in 3 randomized treatment-order sessions with AR-BFR, NAR-BFR, and no- BFR separated by 1-week washout periods. Participants performed 4 sets of dumbbell wall squats to failure using 20% of 1 repetition maximum (1-RM) at 2-second concentric/eccentric cadence. Training limb occlusion pressure (LOP) was set at 60% of supine LOP for both the AT and NAR sessions. Testing before and immediately following the training session included ultrasonography of the carotid artery, applanation tonometry, and blood pressure acquisition. Two-way ANOVAs were used to examine the effects of treatment and the treatment-order interaction on pulse wave velocity (PWV), beta-stiffness index (β-stiff), and arterial compliance (AC). RESULTS: There were no baseline differences in CF- (carotid-femoral) PWV, CR- (carotid-radial) PWV, β-stiff, and AC (all p > 0.05). CF-PWV increased in the NAR-BFR (mean difference = 0.57±1.12 m/s, p = 0.02) and no-BFR (mean difference = 0.63±1.42 m/s, p = 0.03) groups following the exercise session. CR-PWV increased in the no-BFR (mean difference = 0.82±1.5 m/s, p = 0.03) group. And there was an interaction effect in CFPWV between AR-BFR and NAR-BFR (mean difference = 0.70±1.6 m/s, p = 0.03). CONCLUSION: These findings show acute AR-BFR training does not influence indices of arterial stiffness while acute NAR-BRF training increases central stiffness.

Study Overview

• Status: Completed
• Conditions: Healthy Lifestyle; Arterial Stiffness
• Intervention / Treatment: Device: Delfi Personal Tourniquet Systems

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Salisbury, Maryland, United States, 21801
      • Salisbury University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Age 18-40 years old
2. Physically active (> 6 months of consistent exercise training)
3. Weight stable for previous 6 months (+/-2.5 kg)
4. Female subjects only- reported regular menstrual cycles for the last 2 years

Exclusion Criteria:

1. BP>140/90 mmHg
2. BMI>40 kg/m2
3. Diabetes
4. Familial hypercholesterolemia
5. Past or current history of CHD, stroke or major CVD events. Respiratory diseases (not including asthma), endocrine or metabolic, neurological, or hematological disorders that would compromise the study or the health of the subject.
6. Women must not be pregnant, plan to become pregnant during the study, or be nursing
7. Active renal or liver disease
8. All medications and supplements that influence dependent variables
9. Recent surgery < 2 months
10. Alcohol abuse
11. Sleep apnea
12. Claustrophobia

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: NONE

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Autoregulated blood flow restriction; Autoregulated BFR expands as the muscle progresses into the stretch-shortening cycle.	Device: Delfi Personal Tourniquet Systems; Measure within & between differences in acute vascular compliance from pre- to post-training with autoregulated BFR, nonautoregulated BFR and no BFR conditions.
ACTIVE_COMPARATOR: Non-autoregulated blood flow restriction; Non-autoregulated BFR does not expand as the muscle progresses into the stretch-shortening cycle.	Device: Delfi Personal Tourniquet Systems; Measure within & between differences in acute vascular compliance from pre- to post-training with autoregulated BFR, nonautoregulated BFR and no BFR conditions.
ACTIVE_COMPARATOR: No blood flow restriction; This group serves as the control group for this study	Device: Delfi Personal Tourniquet Systems; Measure within & between differences in acute vascular compliance from pre- to post-training with autoregulated BFR, nonautoregulated BFR and no BFR conditions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Beta-Stiffness Index	A measurement that compares carotid SBP and DBP with carotid systolic and diastole diameters.	Baseline and 10 minutes after exercise on day 1
Carotid-femoral pulse wave velocity	A measurement that records the time difference between the foot of the systolic wave form as it arrives at the carotid and femoral arterial sites. It is measured with an arterial tonometer.	Baseline and 10 minutes after exercise on day 1

Collaborators and Investigators

• Sponsor: Salisbury University

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 1, 2022
• Primary Completion (ACTUAL): December 10, 2022
• Study Completion (ACTUAL): January 10, 2023

Study Registration Dates

• First Submitted: January 12, 2023
• First Submitted That Met QC Criteria: January 31, 2023
• First Posted (ACTUAL): February 8, 2023

Study Record Updates

• Last Update Posted (ACTUAL): February 8, 2023
• Last Update Submitted That Met QC Criteria: January 31, 2023
• Last Verified: January 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: #7

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes