Hypoxic Exercise in Lower Extremity Artery Disease

Vaud University Hospital Center

Status: Unknown

Conditions: Peripheral Arterial Disease

Treatments: Other: Exercise in hypoxia 2500m; Other: Exercise in normoxia; Other: Exercise in hypoxia 1500m

Study type: Interventional

Funder types: Other

Identifiers

NCT03506607

2017_00397_Phase1

Details and patient eligibility

About

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).

Full 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.

Enrollment: 20 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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20 participants in 3 patient groups, including a placebo group

Exercise in hypoxia 1500m

Experimental group

Description:

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%.

Treatment:

Other: Exercise in hypoxia 1500m

Exercise in hypoxia 2500m

Experimental group

Description:

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%.

Treatment:

Other: Exercise in hypoxia 2500m

Exercise in normoxia

Placebo Comparator group

Description:

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.

Treatment:

Other: Exercise in normoxia