Ignite Creation Date:
2024-10-26 @ 3:35 PM
Last Modification Date:
2024-10-26 @ 3:35 PM
Study NCT ID:
NCT06505902
Status:
RECRUITING
Last Update Posted:
None
First Post:
2024-07-08
Brief Title:
Pulmonary Diffusing Capacity During Incremental Exercise in COPD
Sponsor:
None
Organization:
None
Study Overview
Official Title:
Pulmonary Diffusing Capacity During Incremental Exercise in COPD A Case-Control Study
Status:
RECRUITING
Status Verified Date:
2024-07
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
No
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
DiffLung3
Brief Summary:
Background
The combined measurement of pulmonary diffusing capacity for carbon monoxide CO and nitric oxide NO DLCONO 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 DLCONO and arterial blood gases will be measured during exercise at a bicycle ergometer at 0 20 40 60 and 80 of the individuals maximal workload
Sample size To detect a 15 mmol min-1 kPa-1 difference in DLNO between groups at 60 of maximal workload with a power of 90 and a significance level of 005 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
The combined measurement of pulmonary diffusing capacity for carbon monoxide CO and nitric oxide NO DLCONO 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 DLCONO and arterial blood gases will be measured during exercise at a bicycle ergometer at 0 20 40 60 and 80 of the individuals maximal workload
Sample size To detect a 15 mmol min-1 kPa-1 difference in DLNO between groups at 60 of maximal workload with a power of 90 and a significance level of 005 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
Detailed Description:
Introduction and background A pattern that applies to the majority of the more than 250 million people who suffer from chronic obstructive pulmonary disease COPD worldwide is a downward spiral of exertional dyspnoea to poor quality of life invalidity and early death A critical mechanism of exertional dyspnoea in these patients is thought to be reduced alveolar-capillary reserve that is a reduced ability to recruit and distend the pulmonary capillary bed to increase diffusing capacity upon an increase in cardiac output which may be assessed by measuring the dual test pulmonary diffusing capacity DLCONO during exercise This technique permits up to 12 repeated manoeuvres within a session without affecting measurements and it is thus ideal for assessing acute changes in pulmonary diffusing capacity and its components during various physiological manoeuvres With this technique the investigators have recently documented that alveolar-capillary recruitment assessed by the change in the pulmonary diffusing capacity for nitric oxide DLNO at a fixed workload of 60 of maximum is blunted in COPD seemingly in a severity-dependent fashion unpublished observations However it is unknown whether this is already evident at low workloads andor whether it persists at near-maximal workloads and it remains to be established to which extent this has an impact on pulmonary gas exchange conventionally measured by the alveolar-arterial oxygen difference
Aim The overall aim is to determine whether and how alveolar-capillary recruitment during incremental exercise differs between patients with mild-to-moderate COPD and healthy individuals
Study design and recruitment 12 patients with mild-to-moderate COPD and 12 healthy age- and sex-matched controls will be included in the study where DLCONO will be measured at rest and during incremental workloads Visit 0 consist of medical health interview and brief examination including blood pressure heart rate and ECG measurement to investigate inclusion and exclusion criteria Baseline measurements Visit 1 will be performed to assess fitness and cardiopulmonary health status for the included patients and participants The baseline measurements include cardiopulmonary exercise testing lung function testing dynamic spirometry whole-body plethysmography and 10-second single-breath diffusing capacity for carbon monoxide and an assessment of body composition On Visit 2 which is at least two days later an arterial catheter is inserted after which DLCONO and arterial blood gases are measured at rest and at 20 40 60 and 80 of maximal workload on a bicycle ergometer as determined during the cardiopulmonary exercise text on Visit 1
Sample size Based on unpublished data in which a difference in DLNO mmol min-1 kPa-1 between COPD and control at 60 of maximal workload during cycling exercise the power calculation was based on a two-sided independent samples t-test with a power of 90 and a significance level alpha of 005 To detect a 15 mmol min-1 kPa-1 difference in DLNO between groups at 60 of maximal workload with a power of 90 and a significance level of 005 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 procedure The investigators will perform a linear mixed effect model with group and time as factors with participant as random effect accounting for repeated measures The investigators will then perform pairwise testing of estimated marginal means from our mixed effect model to test for between group differences and within group differences The investigators will perform Holm correction due to multiple testing
General information This study is novel as it investigates pulmonary capillary recruitment in COPD which is thought to be an important mechanism of exertional dyspnoea which have primarily only been discussed in theoretical terms in previous studies This study will be conducted in accordance with the regional ethical committee and the Declaration of Helsinki Informed consent will be obtained from all study participants before enrolment and baseline testing
Significance novelty and expected impact The physiological assessments that are evaluated in the present study have the potential to be used provide information on the cause of dyspnoea in the individual COPD patient This is relevant for the understanding of basic respiratory physiology and for designing future studies with interventions that aim to affect pulmonary capillary recruitment in COPD
Aim The overall aim is to determine whether and how alveolar-capillary recruitment during incremental exercise differs between patients with mild-to-moderate COPD and healthy individuals
Study design and recruitment 12 patients with mild-to-moderate COPD and 12 healthy age- and sex-matched controls will be included in the study where DLCONO will be measured at rest and during incremental workloads Visit 0 consist of medical health interview and brief examination including blood pressure heart rate and ECG measurement to investigate inclusion and exclusion criteria Baseline measurements Visit 1 will be performed to assess fitness and cardiopulmonary health status for the included patients and participants The baseline measurements include cardiopulmonary exercise testing lung function testing dynamic spirometry whole-body plethysmography and 10-second single-breath diffusing capacity for carbon monoxide and an assessment of body composition On Visit 2 which is at least two days later an arterial catheter is inserted after which DLCONO and arterial blood gases are measured at rest and at 20 40 60 and 80 of maximal workload on a bicycle ergometer as determined during the cardiopulmonary exercise text on Visit 1
Sample size Based on unpublished data in which a difference in DLNO mmol min-1 kPa-1 between COPD and control at 60 of maximal workload during cycling exercise the power calculation was based on a two-sided independent samples t-test with a power of 90 and a significance level alpha of 005 To detect a 15 mmol min-1 kPa-1 difference in DLNO between groups at 60 of maximal workload with a power of 90 and a significance level of 005 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 procedure The investigators will perform a linear mixed effect model with group and time as factors with participant as random effect accounting for repeated measures The investigators will then perform pairwise testing of estimated marginal means from our mixed effect model to test for between group differences and within group differences The investigators will perform Holm correction due to multiple testing
General information This study is novel as it investigates pulmonary capillary recruitment in COPD which is thought to be an important mechanism of exertional dyspnoea which have primarily only been discussed in theoretical terms in previous studies This study will be conducted in accordance with the regional ethical committee and the Declaration of Helsinki Informed consent will be obtained from all study participants before enrolment and baseline testing
Significance novelty and expected impact The physiological assessments that are evaluated in the present study have the potential to be used provide information on the cause of dyspnoea in the individual COPD patient This is relevant for the understanding of basic respiratory physiology and for designing future studies with interventions that aim to affect pulmonary capillary recruitment in COPD
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None