Muscle Metabolism and Oxygenation During Localized Fatigue-exercise in COPD

Not Applicable

• Conditions: Pulmonary Disease, Chronic Obstructive
• Interventions: Other: Fatiguing exercise

• Registration Number: NCT01909544
• Lead Sponsor: Laval University

Brief Summary

The purpose of this study is to investigate whether a localized exercise, in which cardiorespiratory demand is reduced, will result in greater limb muscle fatigue in patients with COPD as a consequence of muscle oxygenation and muscle metabolism disturbances.

Detailed Description

Not available

Study Timeline

• Study Start: 2011-09
• Study First Submitted: 2013-07-16
• Study First Submitted QC: 2013-07-23
• Study First Posted: 2013-07-26
• Status Verified: 2014-02
• Last Update Submitted: 2014-02-06
• Last Update Posted: 2014-02-07
• Primary Completion: 2014-07

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• COPD (FEV1/FVC < 0.70 and FEV1 < 0.80 predicted
• Healthy subjects: no evidence of airways obstruction (FEV1/FVC > 0.70 and FEV1 > 0.80 predicted)
• Smoking history > 15 pack-years

Exclusion Criteria

• Chronic hypoxemia and/or hypercapnia (PaO2 < 60 mmHg or SpO2 < 88% at rest and/or PaCO2 > 45 mmHg)
• Recent exacerbation (< 3 months)
• Recent cancer (< 3 years)
• Diabetes
• Myopathy, neuromuscular or articular disease
• Unstable cardiac disease
• Absolute contraindications to exercise testing
• Regular physical activity or exercise training program in the last 2 months
• Physical activity score > 9 in the Voorips questionnaire
• Thigh skinfold thickness > 15 mm
• BMI > 30

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Oxygen	Fatiguing exercise	-
Room air	Fatiguing exercise	-

Primary Outcome Measures

Name	Time	Method
Muscle deoxygenation	45 seconds post-exercise (knee-extension repetitions)	Changes of deoxyhemoglobin/myoglobin concentrations measured by near-infrared spectroscopy of vastus lateralis muscle.
Muscle metabolism	45 seconds post-exercise (knee extension repetitions)	Changes in glycolytic and oxidative metabolism pathway markers, energy substrates (glycogen and glucose), end-products of glycolysis (pyruvate, and lactate), intermediate markers of glycolysis and high-energy phosphate compounds obtained from muscle biopsies

Secondary Outcome Measures

Name	Time	Method
Ventilatory response	Baseline, beginning and end of each serie of knee extensions (fatiguing exercise)	Minute ventilation will be monitored during the fatigue-inducing exercise and it will be compared between subjects and conditions (FiO2 = 21% vs. FiO2 = 100%)
total muscle work	end of fatiguing exercise	Total muscle work performed during fatigue-inducing exercise that will be composed by subsequent isokinetic knee-extensions repetitions at 40% of maximal peak torque
Quadriceps muscle fatigue	baseline, 15 min and 40 min after the fatigue-inducing exercise	Quadriceps muscle fatigue will be determined by loss of quadriceps strength measured by magnetic stimulation after the fatigue-inducing exercise.; Surface electromyography will also be measured to characterize muscle fatigue.

Trial Locations

Locations (1)

Institut universitaire de cardiologie et de pneumologie de Québec; 🇨🇦 Québec, Quebec, Canada