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Uphill Walking as Exercise for COPD Patients

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT04026529
Recruitment Status : Not yet recruiting
First Posted : July 19, 2019
Last Update Posted : December 9, 2019
University of Nebraska, Omaha
Information provided by (Responsible Party):
VA Office of Research and Development

Brief Summary:
This study is designed to provide preliminary information regarding how to improve pulmonary rehabilitation for persons with chronic obstructive pulmonary disease (COPD). Pulmonary rehabilitation is an exercise program for COPD patients that is recommended and benefits some, but not all, patients. The question being studied in this trial is whether walking on an incline might be better than walking on faster on a flat surface in training muscles so that patients might be less short of breath with exercise.

Condition or disease Intervention/treatment Phase
Chronic Obstructive Pulmonary Disease Other: walking on incline or walking at increasing speed Not Applicable

Detailed Description:
Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality and presents an important healthcare problem, especially for Veterans. Prevalence of COPD in the Veteran population ranges from 33%-43%, a higher prevalence than among the general population of the United States. COPD patients experience diminished exercise capacity. A significant portion of this limitation in exercise capacity is due to dynamic hyperinflation and dyspnea. Humans demonstrate a coupled relationship between walking and breathing. The investigators' preliminary data indicates that patients with COPD demonstrate an abnormal coupling pattern compared to those without COPD, using one stride for one breath, even at speeds outside of their self-selected walking pace. Current pulmonary rehabilitation relies on increasing intensity of exercise through accelerated walking. Based on coupling patterns in patients with COPD, increasing speed leads to an increase in respiratory rate, dynamic hyperinflation, and dyspnea, thus limiting exercise time. The goal of this proposed project is to investigate, in Veteran COPD patients, the effect of walking faster vs. walking on a slope on dynamic hyperinflation and dyspnea, oxygen uptake and dead space, and walking and breathing coupling. The investigators hypothesize that walking on a slope will alter breathing and walking coupling, lower respiratory rates, and reduce dynamic hyperinflation and associated dyspnea. The investigators predict that walking on a slope will permit an increase in oxygen uptake and a decrease in dead space in patients with COPD as compared to accelerated walking speeds. These hypotheses will be tested through three aims: 1) Identify differences in dynamic hyperinflation and dyspnea; 2) Compare differences in respiratory rate, oxygen uptake, and lung dead space; 3) Determine the complexity of walking and breathing coupling ratios. In this cross-sectional study, Veterans with COPD will be recruited and screened using a cardiopulmonary exercise test. A total of 25 eligible Veterans will be enrolled through stratified sampling of disease severity. The time course of work rate will be calculated from the cardiopulmonary exercise test. The speed and slope that corresponds to 70%-80% of peak work rate will be used. An additional constant work rate test will be given using increases in speed with a level treadmill to determine the speed that elicits oxygen uptake comparable to the sloped walking test. Subjects will be asked to perform two experimental trials (walking faster vs. walking on a slope) at 70%-80% peak work rate. Measures of dynamic hyperinflation, dyspnea, oxygen uptake, dead space, and coupling will be recorded during all walking trials. Possible covariates will also be collected. The investigators anticipate that dynamic hyperinflation and dyspnea will be reduced in patients with COPD due to slower walking and slower respiratory rates during sloped walking as compared to faster level walking. It is expected that this will be influenced by the complexity in breathing and walking coupling ratios. The investigators' multidisciplinary team will provide combined expertise from several disciplines and is uniquely qualified to complete the aims proposed. Results from this feasibility and acceptability study will set the stage for a rigorous, well-powered, full Merit award outcome study evaluating the effectiveness of a slope-based training regimen as part of rehabilitation.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 25 participants
Intervention Model: Single Group Assignment
Intervention Model Description: Cross-sectional design
Masking: None (Open Label)
Primary Purpose: Supportive Care
Official Title: Improving Exercise Capacity in Chronic Obstructive Pulmonary Disease Patients Through Uphill Walking
Estimated Study Start Date : January 6, 2020
Estimated Primary Completion Date : September 30, 2021
Estimated Study Completion Date : November 30, 2021

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: walking at incline
Subjects will walk on treadmill at slope and speed to equal 70-80% of their peak work rate as determined on baseline cardiopulmonary exercise test.
Other: walking on incline or walking at increasing speed

Subjects will be prepared for data collection by wearing a form-fitting suit (i.e., wrestling singlet) and obtaining height and body weight. Retro-reflective markers will be placed bilaterally on anatomical locations of the feet, legs, and hips,in addition to 89 markers on the thorax and abdomen.Subjects will

be outfitted with the portable metabolic cart and oximeter as in the previous visit. One of two treadmill trials will be performed: 1) at the speed and 2) at the slope +speed determined in the previous visit. Trial order will be randomized among subjects and across visits 3 & 4. For each trial, subjects will be asked to walk on a treadmill for up to 6 minutes. Speed or slope will be increased every 30 seconds and they will be asked to walk for one minute at that speed or

Primary Outcome Measures :
  1. Dyspnea [ Time Frame: within 6 weeks of enrollment ]
    Perceived dyspnea: Breathlessness will be measured based on a 0 to 10-point Borg scale at the end of the treadmill trials. 0 on scale is no breathlessness and 10 is maximal breathlessness

Other Outcome Measures:
  1. Dynamic hyperinflation [ Time Frame: within 6 weeks of enrollment ]
    Dynamic hyperinflation will be assessed through opto-plethysmography, an established method of computing lung volumes, including dynamic hyperinflation. Opto-plethysmography uses three-dimensional motion capture information to determine lung volumes. The 3-D coordinates of the 89 markers on the abdomen and thorax will be used to create a representation of the surface of the trunk (Motion Analysis Corp., Santa Rosa, CA; 120Hz). The volume of the trunk enclosed by the surface will be obtained through a custom computer code (MathWorks, Inc., Natick, MA). Dynamic hyperinflation will be considered to be present when end-expiratory chest wall volume increased in relation to resting values.

  2. respiratory rate [ Time Frame: 7 days after the initial assessment ]
    Respiratory rate will be analyzed using motion capture markers on the chest. With custom computer code, the markers will be identified to model a sphere. The volume of the sphere will be recorded over time. As the volume increases and decreases, respiratory flow will be identified, and respiratory rate can be calculated.

  3. Coupling [ Time Frame: within 14 days after initial assessment ]

    The laboratory is equipped with a 17-camera, digital motion capture system (Motion Analysis Corp., Santa Rosa, CA; 120Hz) to allow for collection of three-dimensional marker positions in real time. The marker position data will be analyzed using custom MATLAB code. Data will be plotted to detect spikes and outliers. Spikes and data points greater than three standard deviations from the mean will be removed. A cubic spline will be used to interpolate the removed data points. All marker data are then normalized to the unit vector for comparison.

    Coupling is often quantified as frequency coupling. Frequency coupling refers to how many heel strikes occur within a single cycle of respiration (one inhalation to the next); it is usually counted in integer or half-integer ratios, measured using discrete relative phase. The range of ratios and the percentage of time each ratio is utilized will be recorded.

  4. oxygen uptake [ Time Frame: 7days after initial assessment ]
    Heart rate and pulmonary gas exchange analysis will be recorded on a breath-by-breath basis. This will provide an accurate measure of pulmonary gas exchange, including oxygen uptake, i.e. VO2, . Steady-state VO2 while walking will be averaged and normalized to standing metabolic rate.

  5. lung dead space [ Time Frame: within 7 days of initial assessment ]
    Dead space: Tidal volume and expired carbon dioxide will be measured using the same equipment as oxygen uptake above. Partial pressure of arterial carbon dioxide will be measured using a transcutaneous sensor.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   45 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Veterans from all sex/gender, race, and ethnicity will be recruited
  • All subjects will undergo post-bronchodilator spirometry and be clinically stable
  • All subjects must have documented FEV1/FVC ratio of <0.7, and between 30% to 80% FEV1% predicted
  • If subjects have non-qualifying spirometry, they will not be screened further
  • Subjects with qualifying spirometry will be screened further
  • Potential subjects must have a BMI of less than 35 kg/m2 and must be free from co-morbidities that may affect walking patterns

    • e.g., peripheral arterial disease, diabetes, low back pain

Exclusion Criteria:

  • Confounding effects such as neurological, musculoskeletal, or metabolic disease
  • Subjects taking medications that alter mood or metabolic demand will be excluded
  • All potential subjects must be cleared for participation by a physician after undergoing a cardiopulmonary exercise test

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 identifier (NCT number): NCT04026529

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Contact: Debra J Romberger, MD (402) 346-8800 ext 3542

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United States, Nebraska
Omaha VA Nebraska-Western Iowa Health Care System, Omaha, NE
Omaha, Nebraska, United States, 68105-1873
Contact: Frederick G Hamel    402-995-3032   
Contact: Wendy A Inselman    (402) 346-8800 ext 3940   
Principal Investigator: Debra J. Romberger, MD         
Sponsors and Collaborators
VA Office of Research and Development
University of Nebraska, Omaha
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Principal Investigator: Debra J. Romberger, MD Omaha VA Nebraska-Western Iowa Health Care System, Omaha, NE

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Responsible Party: VA Office of Research and Development Identifier: NCT04026529    
Other Study ID Numbers: E3294-P
1I21RX003294-01 ( U.S. NIH Grant/Contract )
First Posted: July 19, 2019    Key Record Dates
Last Update Posted: December 9, 2019
Last Verified: December 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Keywords provided by VA Office of Research and Development:
pulmonary rehabilitation
Additional relevant MeSH terms:
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Lung Diseases
Lung Diseases, Obstructive
Pulmonary Disease, Chronic Obstructive
Respiratory Tract Diseases
Central Nervous System Stimulants
Physiological Effects of Drugs
Autonomic Agents
Peripheral Nervous System Agents
Dopamine Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Adrenergic Agents
Adrenergic Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Membrane Transport Modulators
Dopamine Uptake Inhibitors