The purpose of this study is to determine whether exercise can be prolonged in COPD can by the inhaled bronchodilator Stiolto Respimat. The study will identify whether any endurance benefit is due to reduction in fatigue that originates within the skeletal muscles and/or from effects on neural activation of the skeletal muscles.
Patients with chronic obstructive pulmonary disease (COPD) have reduced exercise tolerance. One mechanism for this is thought to be due to dynamic hyperinflation during exercise (an increase in the end-expiratory lung volume) that contributes to the sensation of breathlessness. Whether this also contributes to inhibiting motor recruitment, and reduces the available power output (termed performance fatigue; PF), is not well understood. Preliminary data suggests that many COPD patients, unlike healthy subjects, stop exercise with a 'skeletal muscle power reserve' i.e. the ability to acutely increase muscle power output. This suggests that they are limited in the exercise task by mechanisms other than acute intramuscular limitations to power production (termed muscle fatigue; MF). Exercise tolerance is increased by treatment with the fixed-dose combination bronchodilator, STIOLTO™ RESPIMAT®. We hypothesize that increased exercise tolerance with STIOLTO™ RESPIMAT® (reduced performance fatigue; PF) will be mediated by a combination of: 1) reduced inhibition of muscle activation (termed activation fatigue; AF) allowing patients to drive their leg muscles harder, and thus; 2) increased muscle fatigue (MF).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
QUADRUPLE
Enrollment
14
Oral inhalation spray
Oral inhalation spray
Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
Torrance, California, United States
The Magnitude of Change in Isokinetic Power (Performance Fatigue, PF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)
Constant work rate (CWR) exercise causes fatigue. Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The magnitude of fatigue is measured in watts at the time of the shortest exercise duration in either study arm, which is termed "isotime". A smaller value (in watts) of performance fatigue means that the intervention was associated with less fatigue after a given CWR exercise duration (i.e. at isotime).
Time frame: Baseline and day 7 of each treatment period
The Magnitude of Change Electromyographic (EMG) Muscle Activity (Activation Fatigue, AF) Associated With Stiolto Respimat Compared With Placebo Respimat at Isotime During Constant Work Rate Exercise (CWR)
Constant work rate (CWR) exercise causes fatigue and reduces muscle activation. The relationship between muscle activation and power is measured at baseline (unfatigued condition). Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The fraction of fatigue that is ascribed to reduced muscle activity is then calculated. The magnitude of activation fatigue is measured in EMG activity and expressed in watts at the time of the shortest exercise duration in either study arm, which is termed "isotime". A smaller value (in watts) of activation fatigue means that the intervention was associated with a less reduction in EMG activity after a given CWR exercise duration (i.e. at isotime).
Time frame: Baseline and day 7 of each treatment period
Exercise Endurance Time During CWR Cycling Exercise
The duration in seconds for which constant work rate (CWR) cycling exercise could be tolerated prior to voluntary termination of exercise.
Time frame: Baseline and day 7 of each treatment period
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Change From Period Baseline in the Exercise-isotime Inspiratory Reserve Volume During CWR
Inspiratory reserve volume (IRV) measured during CWR cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater IRV would reflect a beneficial response to intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Exercise-isotime Inspiratory Capacity During CWR
Inspiratory capacity (IC) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater IC would reflect a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Forced Expiratory Volume in 1 Second (FEV1)
This outcome describes the the effect of the intervention on forced expiratory volume in 1 second (FEV1) during resting spirometry. A greater FEV1 would reflect a positive benefit of the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Exercise-isotime in Pulse Oximeter Oxygen Saturation During CWR
Percentage of arterial hemoglobin that is saturated with oxygen, measured using pulse oximetry during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater pulse oximeter oxygen saturation would reflect a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Exercise-isotime Ventilation During CWR
Minute ventilation (VE) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lesser VE would reflect a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Exercise-isotime Oxygen Uptake (VO2) During CWR
Pulmonary oxygen uptake (VO2) measured during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lesser VO2 would reflect a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Exercise-isotime Frontal Lobe Oxygen Saturation During CWR
Tissue saturation of hemoglobin with oxygen is measured by spatially resolved near-infrared spectroscopy from the frontal lobe during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater frontal lobe oxygen saturation at isotime would reflect a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Exercise-isotime Muscle Oxygen Saturation During CWR
Tissue saturation of hemoglobin plus myoglobin with oxygen is measured by spatially resolved near-infrared spectroscopy from the vastus lateralis muscle during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A greater muscle oxygen saturation at isotime would reflect a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Dyspnea During CWR
Borg rating of perceived shortness of breath (dyspnea) were measured on a category-ratio scale from 0 to 10 (CR-10) during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lower CR-10 score for dyspnea at isotime would reflect a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Exercise-isotime Borg CR-10 Rating of Perceived Leg Fatigue During CWR
Borg rating of perceived tiredness on the legs (leg fatigue) were measured on a category-ratio scale from 0 to 10 (CR-10) during constant work rate (CWR) cycling exercise at the time of the shortest duration of each intervention arm (isotime). A lower CR-10 score for leg fatigue at isotime would reflect a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period
Change From Period Baseline in the Pre/Post Exercise-induced Decline in Peak Isokinetic Power Normalized to the Measured Muscle Activity (Muscle Fatigue, MF) During CWR
Constant work rate (CWR) exercise causes muscle fatigue (MF) and reduces muscle activation (activation fatigue; AF). The relationship between muscle activity (using EMG) and power is measured at baseline (unfatigued condition). Fatigue is measured by the difference between pre-CWR and post-CWR maximal voluntary isokinetic power i.e. how much maximal voluntary isokinetic power declines during CWR. The fraction of the total fall in voluntary isokinetic power (total fatigue) that is ascribed to reduced muscle activity is then calculated from the reduction in EMG activity. The remainder is ascribed to muscle fatigue (MF) and expressed as a percentage of total fatigue. This measurement was made at peak exercise. A smaller value (%) of MF would be associated with a beneficial response to the intervention.
Time frame: Baseline and day 7 of each treatment period