Hypoxic Exercise in Lower Extremity Artery Disease
- Conditions
- Peripheral Arterial Disease
- Interventions
- Other: Exercise in hypoxia 1500mOther: Exercise in hypoxia 2500mOther: Exercise in normoxia
- Registration Number
- NCT03506607
- Lead Sponsor
- Centre Hospitalier Universitaire Vaudois
- 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).
- Detailed 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 & Eligibility
- Status
- UNKNOWN
- Sex
- All
- Target Recruitment
- 20
- 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
- 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
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Exercise in hypoxia 1500m Exercise in hypoxia 1500m 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%. Exercise in hypoxia 2500m Exercise in hypoxia 2500m 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%. Exercise in normoxia Exercise in normoxia 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.
- Primary Outcome Measures
Name Time Method Flow-mediated dilation 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 before and after the 6 min treadmill test
Pulse oxygen saturation 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 during the 6 min treadmill test
Walking performance 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) Total walking distance (in meters) during the 6 min treadmill test
Pain free walking time 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 during the 6 min treadmill test
Muscle oxygenation during exercise 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 the 6 min treadmill test (assessed by near-infrared spectroscopy)
Pulse wave velocity 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 wave velocity before and after the 6 min treadmill test
- Secondary Outcome Measures
Name Time Method 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) Ankle-brachial index before and after the 6 min treadmill test
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) 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).
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) Leg pain during exercise will be measured with a 10-points (0: "no pain" and 10: "worst imaginable pain") visual analogic scale (VAS).
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) Toe-brachial index before and after the 6 min treadmill test
Trial Locations
- Locations (1)
CHUV
🇨🇭Lausanne, Vaud, Switzerland