NCT03506607

Brief Summary

The aim of this randomized controlled trial is to: Phase I: To explore, in a first pilot phase, the adequate combination of hypoxia severity and exercise intensity in patients with symptomatic lower extremity artery disease (LEAD). Acute walking performances and physiological responses (vascular and muscular) to a normobaric hypoxic exercise performed will be assessed at two different altitudes (1500 m and 2500 m).

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
20

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Jan 2020

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

March 28, 2018

Completed
27 days until next milestone

First Posted

Study publicly available on registry

April 24, 2018

Completed
1.8 years until next milestone

Study Start

First participant enrolled

January 23, 2020

Completed
2.9 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 1, 2022

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 1, 2022

Completed
Last Updated

November 24, 2020

Status Verified

November 1, 2020

Enrollment Period

2.9 years

First QC Date

March 28, 2018

Last Update Submit

November 23, 2020

Conditions

Keywords

exercisecardiovascularnormobaric hypoxia

Outcome Measures

Primary Outcomes (6)

  • Walking performance

    Total walking distance (in meters) during the 6 min treadmill test

    After each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

  • Pain free walking time

    Pain free walking time during the 6 min treadmill test

    After each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

  • Muscle oxygenation during exercise

    Muscle oxygenation during the 6 min treadmill test (assessed by near-infrared spectroscopy)

    After each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

  • Pulse wave velocity

    Pulse wave velocity before and after the 6 min treadmill test

    Before and after each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

  • Flow-mediated dilation

    Flow-mediated dilation before and after the 6 min treadmill test

    Before and after each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

  • Pulse oxygen saturation

    Pulse oxygen saturation during the 6 min treadmill test

    After each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

Secondary Outcomes (4)

  • Ankle-brachial index

    Before and after each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

  • Toe-brachial index

    Before and after each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

  • Rate of perceived exertion

    After each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

  • Leg pain

    After each 6 min treadmill test performed under hypoxic condition (1500 and 2500 m) and under normoxic condition (i.e., average of 3 weeks; one condition per week)

Study Arms (3)

Exercise in hypoxia 1500m

EXPERIMENTAL

During this visit, subjects will perform a 6-min treadmill exercise wearing an oronasal mask connected (through a hose) with a three-way valve to an altitude simulation device (Altitrainer; SMTech, Nyon, Switzerland). The ambient air will be mixed with nitrogen and inspired oxygen fraction will be reduced to 16%.

Other: Exercise in hypoxia 1500m

Exercise in hypoxia 2500m

EXPERIMENTAL

During this visit, subjects will perform a 6-min treadmill exercise wearing an oronasal mask connected (through a hose) with a three-way valve to an altitude simulation device (Altitrainer; SMTech, Nyon, Switzerland). The ambient air will be mixed with nitrogen and inspired oxygen fraction will be reduced to 14%.

Other: Exercise in hypoxia 2500m

Exercise in normoxia

PLACEBO COMPARATOR

During this visit, subjects will perform a 6-min treadmill exercise wearing an oronasal mask connected (through a hose) with a three-way valve to an altitude simulation device (Altitrainer; SMTech, Nyon, Switzerland). For the exercise performed in normoxia conditions, subjects will breathe room air.

Other: Exercise in normoxia

Interventions

Subjects will perform a 6-min treadmill exercise wearing an oronasal mask connected (through a hose) with a three-way valve to an altitude simulation device (Altitrainer; SMTech, Nyon, Switzerland). The ambient air will be mixed with nitrogen and inspired oxygen fraction will be reduced to 16%. The first 3 min will be performed at 70% of the mean speed calculated during a previous visit, and the last 3 min at an intensity between 12-14 on the Borg's scale.

Exercise in hypoxia 1500m

Subjects will perform a 6-min treadmill exercise wearing an oronasal mask connected (through a hose) with a three-way valve to an altitude simulation device (Altitrainer; SMTech, Nyon, Switzerland). The ambient air will be mixed with nitrogen and inspired oxygen fraction will be reduced to 14%. The first 3 min will be performed at 70% of the mean speed calculated during a previous visit, and the last 3 min at an intensity between 12-14 on the Borg's scale.

Exercise in hypoxia 2500m

Subjects will perform a 6-min treadmill exercise wearing an oronasal mask connected (through a hose) with a three-way valve to an altitude simulation device (Altitrainer; SMTech, Nyon, Switzerland). For the exercise performed in normoxia conditions, subjects will breathe room air. The first 3 min will be performed at 70% of the mean speed calculated during a previous visit, and the last 3 min at an intensity between 12-14 on the Borg's scale.

Exercise in normoxia

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Patients with symptomatic LEAD (Fontaine stage ≥ IIa)
  • ABI ≤ 0.9
  • TBI ≤ 0.6 if incompressible arteries (diabetes and renal insufficiency)
  • Signed written informed consent form

You may not qualify if:

  • Neurological and neuromuscular disorders which can limit balance and walking
  • Any history of altitude-related sickness
  • Any health risks (assessed during clinical history) linked to hypoxia exposure
  • Acclimatization or exposure to hypoxia of more than 2000 m for more than 48 h during a period of 6 months before the study
  • Medication required for the treatment of migraines, claustrophobia that may interfere with the interpretation of the results
  • Obstructive sleep apnea (\> 25 Apnea-Hypopnea Index)
  • Prior leg/foot amputation
  • Pregnant women
  • Cardiac contraindication to exercise

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

CHUV

Lausanne, Canton of Vaud, 1011, Switzerland

RECRUITING

MeSH Terms

Conditions

Peripheral Arterial DiseaseMotor Activity

Interventions

Exercise

Condition Hierarchy (Ancestors)

AtherosclerosisArteriosclerosisArterial Occlusive DiseasesVascular DiseasesCardiovascular DiseasesPeripheral Vascular DiseasesBehavior

Intervention Hierarchy (Ancestors)

Motor ActivityMovementMusculoskeletal Physiological PhenomenaMusculoskeletal and Neural Physiological Phenomena

Study Officials

  • Lucia Mazzolai, Prof

    Division of angiology, Lausanne University Hospital

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
SINGLE
Who Masked
PARTICIPANT
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Principal Investigator

Study Record Dates

First Submitted

March 28, 2018

First Posted

April 24, 2018

Study Start

January 23, 2020

Primary Completion

December 1, 2022

Study Completion

December 1, 2022

Last Updated

November 24, 2020

Record last verified: 2020-11

Data Sharing

IPD Sharing
Will not share

Locations