Hypoxic Exercise in Lower Extremity Artery Disease

Peripheral Arterial Disease Clinical Trial

Official title:

Exercise Training Under Hypoxic Conditions in Lower Extremity Artery Disease

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT03506607
• Other study ID #: 2017_00397_Phase1
• Status: Recruiting
• Phase: N/A
• Start date: January 23, 2020
• Est. completion date: December 2022

Study information

• Verified date: November 2020
• Source: Centre Hospitalier Universitaire Vaudois
• Contact: Lucia Mazzolai, Prof
• Phone: +41 (0)79 556 56 61
• Email: lucia.mazzolai[@]chuv.ch
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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).

Description:

The results of this first phase will then be used to determine the optimal hypoxic level for the exercise training program which will be assessed during the Phase II.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 20
• Est. completion date: December 2022
• Est. primary completion date: December 2022
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• 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

Exclusion Criteria:

• 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

Related Conditions & MeSH terms

• Peripheral Arterial Disease
• Peripheral Vascular Diseases

Intervention

Other:
• 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 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 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). 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 normoxia
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.

Locations

Country	Name	City	State
Switzerland	CHUV	Lausanne	Vaud

Sponsors (1)

Lead Sponsor	Collaborator
Centre Hospitalier Universitaire Vaudois

Country where clinical trial is conducted

Switzerland, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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)
Primary	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)
Primary	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)
Primary	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)
Primary	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)
Primary	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	Ankle-brachial index	Ankle-brachial index 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)
Secondary	Toe-brachial index	Toe-brachial index 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)
Secondary	Rate of perceived exertion	Rate of perceived exertion (RPE) will be assessed using Borg's scale. RPE is a widely used and reliable indicator to monitor and guide exercise intensity. The scale allows individuals to subjectively rate their level of exertion during 6 min treadmill test. Patients will classify their RPE between 6 (light) and 20 (maximal).	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	Leg pain	Leg pain during exercise will be measured with a 10-points (0: "no pain" and 10: "worst imaginable pain") visual analogic scale (VAS).	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)