COPD, Smoking
Conditions
Keywords
smoking, small airway dysfunction, mild COPD, dyspnea, exercise, clinical outcomes
Brief summary
The Canadian Respiratory Research Network (CRRN) has recently been established to study the origins and evolution of airways disease in the population. The CRRN is funded by the Institute of Cardio-respiratory Health (ICRH), an institute of the CIHR. The Physiology platform will support the other CRRN platforms (biology, imaging, population health, knowledge transfer) by providing a comprehensive characterization of the nature and extent of physiological impairment of respiratory function in smokers at risk for airways disease and in those with early or mild airway obstruction. The planned studies of the physiology group (core sites located at Queen's University, University of British Columbia and McGill University) will initially focus on smoking-related lung injury in those at risk for COPD and in those meeting spirometric criteria for mild airway obstruction, with or without respiratory symptoms. The primary aim of this initial study is to identify and validate sensitive test(s) of peripheral airway dysfunction that may qualify as physiological biomarkers for use in future CRRN studies.
Interventions
None listed
Sponsors
Canadian Institutes of Health Research (CIHR)
Ottawa Hospital Research Institute
University of British Columbia
McGill University
Dr. Denis O'Donnell
Study design
Observational model
CASE_CONTROL
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
40 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Stable patients with GOLD grade 1 mild COPD will be included in the study if they have: a post-bronchodilator FEV1≥80 %predicted and an FEV1/FVC ratio \<0.7 and \<LLN; ≥40 years of age; and a cigarette smoking history ≥10 pack-years or ≥10 years of exposure to other inhaled substances (i.e., second hand smoke and/or biomass). Symptomatic (category B) subjects will have a Baseline Dyspnea Index (BDI) total score ≤9, a modified Medical Research Council (MRC) dyspnea score ≥2, or a COPD Assessment Test (CAT) score ≥10. Asymptomatic (category A) subjects will have a BDI\>9, modified MRC\<2 or CAT\<10, no history of seeking medical care for respiratory symptoms, and no history of using respiratory medications. Symptomatic current or ex-smokers (\>10 pack-year history) who do not meet criteria for COPD (e.g., post-bronchodilator FEV1\<80%predicted and FEV1/FVC\<0.7, with both measurements also \<LLN) and who are on no respiratory medication will be included. Symptomatic will be defined as: BDI≤9, modified MRC≥2 or CAT\>10. Healthy, age- and sex-matched, non-smoking (\<2 pack-year history) participants with normal spirometry will be used for comparison purposes.
Exclusion criteria
* presence of clinically significant comorbidities that could contribute to dyspnea or exercise limitation (i.e., unstable heart disease, a pulmonary disease other than COPD, uncontrolled diabetes, neuromuscular or orthopedic impairment); * history/clinical evidence of asthma; * contraindications to exercise testing; * \<40 years of age; * body mass index \<18.5 or \>=35 kg/m2.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Small airway function | 1 day (Time of visit) | There is no single measurement of small airway function since this study is evaluating which measurements, among a list of conventional and experimental physiological parameters, best characterize the nature and extent of impairment of respiratory function in the smoking study groups and which of these parameters best predict clinical outcome (i.e., dyspnea, exercise capacity, ventilatory capacity, health status). Assessments will include: spirometry, closing volume, impulse oscillometry, frequency dependence of dynamic lung compliance, plethysmographic lung volumes and metronome-paced dynamic hyperinflation. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cardiopulmonary exercise test | 1 day (Time of visit) | Includes measurements of exertional dyspnea (intensity and quality), peak exercise capacity (peak oxygen uptake \[VO2\]) and ventilatory responses (ventilation, pulmonary gas exchange, breathing pattern, operating lung volumes and tidal flow-volume loops) during symptom-limited incremental cardiopulmonary cycle exercise testing. |
| Clinical outcome | 1 day (Time of visit) | Includes questionnaires regarding chronic activity-related dyspnea, respiratory symptoms, health status and physical activity. |
Countries
Canada
Outcome results
None listed