Pulmonary Diffusing Capacity During Incremental Exercise in COPD
NCT Number: NCT06505902
Acronym: DiffLung3
Status: RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: COPD|Healthy|Lung Diseases
Interventions: OTHER: Exercise
Sponsor: Rigshospitalet, Denmark
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 24
Study Design: Allocation: NON_RANDOMIZED|Intervention Model: PARALLEL|Masking: NONE|Primary Purpose: BASIC_SCIENCE
Start Date: 2024-07-15
Completion Date: 2024-11-01
Locations: Center for Aktiv Sundhed (CFAS), Rigshospitalet, Copenhagen, Denmark., Copenhagen, København Ø, 2100, Denmark

Summary:
Background:

The combined measurement of pulmonary diffusing capacity for carbon monoxide (CO) and nitric oxide (NO) (DL,CO,NO) has recently been standardized and validated for clinical use. It involves a noticeably short breath-hold time (≤5 seconds), making it feasible to perform on patients with chronic obstructive pulmonary disease (COPD). These patients have lower diffusing capacity and are unable to increase it during exercise, which is thought to be caused by changes in pulmonary perfusion potentially leading to exertional dyspnea. The aim of the present study is to examine whether pulmonary diffusing capacity for incremental exercise differs between patients with COPD and matched healthy controls.

Methods:

Inclusion of 12 individuals with mild-to-severe COPD and 12 healthy age- and sex-matched controls.

Design: Case-control study

Intervention: DL,CO,NO and arterial blood gases will be measured during exercise at a bicycle ergometer at 0, 20, 40, 60 and 80% of the individual's maximal workload.

Sample size: To detect a 15 mmol min-1 kPa-1 difference in DL,NO between groups at 60% of maximal workload, with a power of 90% and a significance level of 0.05, at least 12 subjects are required in each group. To account for potential dropouts, power will be permitted to decrease to 80%, corresponding to a total of 10 subjects in each group.

Statistical design: Linear mixed effect model and pairwise testing of estimated marginal means.

Perspective: This study will add to the understanding exertional dyspnoea in patients with COPD.

Primary Outcome Measures: Primary outcome, Between-group difference in the change in DL,NO from rest to exercise as a function of workload, Measured at day 2
Secondary Outcome Measures: Key secondary outcome, Between-group difference in the change of the alveolar-arterial oxygen difference from rest to exercise as a function of workload, Measured at day 2|Other secondary outcome, Between-group difference in the change in DL,NO from rest to exercise as a function of VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change of the alveolar-arterial oxygen difference from rest to exercise as a function of VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in cardiac output from rest to exercise as a function of workload, Measured at day 2|Other secondary outcome, Between-group difference in the change in stroke volume from rest to exercise as a function of workload, Measured at day 2|Other secondary outcome, Between-group difference in the change in heart rate from rest to exercise as a function of workload, Measured at day 2|Other secondary outcome, Between-group difference in the change in mean arterial blood pressure from rest to exercise as a function of workload, Measured at day 2|Other secondary outcome, Between-group difference in the change in cardiac output from rest to exercise as a function of VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in stroke volume from rest to exercise as a function of VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in heart rate from rest to exercise as a function of VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in mean arterial blood pressure from rest to exercise as a function of VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in PaO2 from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in SaO2 from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in PaCO2 from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in pH from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in base excess from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in lactate from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in respiratory rate from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in DL,CO,5s from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in DM from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in VC from rest to exercise as a function of workload and VO2, Measured at day 2|Other secondary outcome, Between-group difference in the change in VA from rest to exercise as a function of workload and VO2, Measured at day 2
Other Outcome Measures: Exploratory outcomes, Between-group difference in time constant (phase 2) (s) from VO2kinetics, Measured at day 2|Exploratory outcomes, Between-group difference in mean response time (s) from VO2kinetics, Measured at day 2|Exploratory outcomes, Between-group difference in amplitude (mLO2/min) from VO2kinetics, Measured at day 2|Exploratory outcomes, Between-group difference in steady state gain (mLO2•min-1•watt-1) from VO2kinetics, Measured at day 2|Exploratory outcomes, Between-group difference in time delay (phase 1) (s) from VO2kinetics, Measured at day 2|Exploratory outcomes, Between-group difference in relative (mL/kg/min) VO2peak, Measured at day 2|Exploratory outcomes, Between-group difference in absolute (mL/min) VO2peak, Measured at day 2|Exploratory outcomes, Between-group difference in ventilatory threshold (%), Measured at day 2|Exploratory outcomes, Between-group difference in ventilatory reserve (%), Measured at day 2|Exploratory outcomes, Between-group difference in resistance (Rrs, R5-R20) measured by IOS, Measured at day 2|Exploratory outcomes, Between-group difference in reactance (Xrs, X5) measured by IOS, Measured at day 2|Exploratory outcomes, Between group difference in mean arterial pressure (MAP) as a function of workload., Measured at day 2|Exploratory outcomes, Between group difference in systolic blood pressure (SBP) as a function of workload., Measured at day 2