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Exercise in Health and Chronic Obstructive Pulmonary Disease

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ClinicalTrials.gov Identifier: NCT02300064
Recruitment Status : Completed
First Posted : November 24, 2014
Last Update Posted : June 1, 2016
Sponsor:
Information provided by (Responsible Party):
Russell Richardson, University of Utah

Brief Summary:
The purpose of this study is to find out more about the effects of chronic obstructive pulmonary disease (COPD) on the function of blood vessels, the heart, and muscle at rest and during exercise.

Condition or disease Intervention/treatment Phase
Chronic Obstructive Pulmonary Disease Other: Knee-extensor exercise test Other: Exercise test with restricting/releasing blood flow Other: Exercise test with variable oxygen concentration and MRI Other: Exercise test with oral antioxidant or placebo cocktail Not Applicable

Detailed Description:
Oxidative stress, defined as an imbalance between pro and antioxidant molecular species in favor of the former, has recently been recognized as a potential mechanism in the peripheral muscle dysfunction associated with COPD. a series of studies are proposed to better understand the role and source of oxidative stress in the skeletal muscle of patients with COPD. Specifically, three main aims will address the following questions regarding COPD, skeletal muscle, and oxidative stress: where is oxidative stress most prevalent, why does oxidative stress occur, and what are the consequences of oxidative stress in COPD? the overall hypothesis to be tested is that COPD results in a shift toward greater intramuscular oxidative stress and this is, at least in part, responsible for the diminished mechanical efficiency and greater peripheral muscle fatiguability during muscular work often associated with this disease. The vascular consequence of this augmented free radical load is altered vascular function and a disruption of the local matching of perfusion and metabolism in skeletal muscle during exercise. These crucial changes result in a cascade of factors such as local hypoxia and elevated vascular shear stress, entering a vicious cycle that leads to the generation of more free radicals, especially during physical work. It is proposed that this imbalance between pro and antioxidant potential, toward oxidative stress, plays a significant role in the attenuated exercise capacity and reduced muscle fatigue resistance associated with COPD.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 185 participants
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Mechanisms of Adaptation to Exercise in Health and Chronic Obstructive Pulmonary Disease (COPD); Oxidative Stress Links Aging, Activity and Mobility
Study Start Date : January 2009
Actual Primary Completion Date : May 2016
Actual Study Completion Date : May 2016

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Experimental: Healthy volunteers
Healthy volunteers will undergo one or more exercise interventions: knee-extensor exercise test; exercise test with restricting/releasing blood flow; exercise test with variable oxygen concentration and MRI; or exercise test with oral antioxidant or placebo cocktail.
Other: Knee-extensor exercise test
Steady-state, single leg knee-extensor exercise at 20 Watts for 10 minutes

Other: Exercise test with restricting/releasing blood flow
10 minute submaximal (20 Watts) single leg knee-extensor exercise with blood flow clamped 10-15% lower by arterial infustion of phenylephrine; 10 minute passive single leg knee-extensor exercise with blood flow matched to the 20 Watt work rate level by arterial adenosine infusion; 10 minute seated rest with blood flow matched to the 20 Watt work rate level by adenosine infusion. Each test separated by at least 30 minutes rest.

Other: Exercise test with variable oxygen concentration and MRI
Two bouts of single leg knee-extensor exercise to maximal effort breathing regular air (21% oxygen) or 100% oxygen through a mouthpiece, with a 90 minute rest period between each bout. The same experiment performed again on a separate day in an magnetic resonance imaging (MRI) machine

Other: Exercise test with oral antioxidant or placebo cocktail
Antioxidants (Vitamin E - 400 international units, Vitamin C - 1000 milligrams and Alpha lipoic acid - 600 milligrams) or matching placebo capsules administered orally followed by femoral nerve stimulation and single leg knee-extensor exercise for 30 minutes at 50% maximum effort

Experimental: COPD patients
Patients with Chronic Obstructive Pulmonary Disease (COPD) will undergo one or more exercise interventions: knee-extensor exercise test; exercise test with restricting/releasing blood flow; exercise test with variable oxygen concentration and MRI; or exercise test with oral antioxidant or placebo cocktail.
Other: Knee-extensor exercise test
Steady-state, single leg knee-extensor exercise at 20 Watts for 10 minutes

Other: Exercise test with restricting/releasing blood flow
10 minute submaximal (20 Watts) single leg knee-extensor exercise with blood flow clamped 10-15% lower by arterial infustion of phenylephrine; 10 minute passive single leg knee-extensor exercise with blood flow matched to the 20 Watt work rate level by arterial adenosine infusion; 10 minute seated rest with blood flow matched to the 20 Watt work rate level by adenosine infusion. Each test separated by at least 30 minutes rest.

Other: Exercise test with variable oxygen concentration and MRI
Two bouts of single leg knee-extensor exercise to maximal effort breathing regular air (21% oxygen) or 100% oxygen through a mouthpiece, with a 90 minute rest period between each bout. The same experiment performed again on a separate day in an magnetic resonance imaging (MRI) machine

Other: Exercise test with oral antioxidant or placebo cocktail
Antioxidants (Vitamin E - 400 international units, Vitamin C - 1000 milligrams and Alpha lipoic acid - 600 milligrams) or matching placebo capsules administered orally followed by femoral nerve stimulation and single leg knee-extensor exercise for 30 minutes at 50% maximum effort




Primary Outcome Measures :
  1. Change in Free Radical Concentration in Muscle Tissue Following Exercise [ Time Frame: Baseline to two hours ]

Secondary Outcome Measures :
  1. Change in Free Radical Concentration in Muscle Venous Outflow following Exercise [ Time Frame: Baseline to two hours ]


Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Chronic Obstructive Pulmonary Disease (COPD) patients (over 18 years old) and
  • age-matched healthy controls (over 18 years old)

Exclusion Criteria:

  • Severe Chronic Obstructive Pulmonary Disease (volume exhaled at the end of the first section of forced expiration is predicted to be under 30 percent),
  • Severe Heart Failure

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02300064


Locations
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United States, Utah
Veterans Affairs Salt Lake City Heath Care System
Salt Lake City, Utah, United States, 84148
Sponsors and Collaborators
University of Utah
Investigators
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Principal Investigator: Russell Richardson, Ph.D. US Department of Veterans Affairs

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Responsible Party: Russell Richardson, Ph.D., University of Utah
ClinicalTrials.gov Identifier: NCT02300064     History of Changes
Other Study ID Numbers: 32404
First Posted: November 24, 2014    Key Record Dates
Last Update Posted: June 1, 2016
Last Verified: May 2016

Additional relevant MeSH terms:
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Lung Diseases
Lung Diseases, Obstructive
Pulmonary Disease, Chronic Obstructive
Respiratory Tract Diseases
Antioxidants
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs