Small Airways DiseasesCLOUDNCT06819969
The Canadian Lung Outcomes in Users of Vaping Devices Study
An observational study of Small Airways Diseases and Vaping, run by University of British Columbia at 8 sites in Canada.
Trial summary
Vaping is increasingly popular with both adolescent and adult Canadians, but the long-term health impacts remain unknown. We believe that the tools we currently have to detect lung disease in people who vape may be insufficient and propose new ways to find lung injuries that may impact them over the course of their… Read more about this study
- Who is it for?
- Ages 12 years and olderHealthy volunteers can take part
- Conditions the study is for
- Small Airways Diseases, Vaping, Vaping Related Disorder
- How many people
- 500 participants
- Where
- 8 sitesCanada
- Study dates
- 25 Jul 2025to 31 Dec 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 12 years and older
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Study population: This study will enroll both adolescent (ages ≥12 and <19 years) and adult (≥19 years) e-cigarette and non-e-cigarette users in six academic hospital centres across Canada.
Who may be able to join
- Adolescent arm:
- Aged ≥12 and <19 years old
- Either 1) use neither combustible cigarettes nor e-cigarettes or 2) use e-cigarettes exclusively
- Adult arm:
- Aged ≥19 years old
- Fall into one of the following categories: 1) use neither combustible cigarettes nor e-cigarettes; 2) use combustible cigarettes exclusively, never using e-cigarettes; 3) use e-cigarettes exclusively, never using combustible cigarettes; or 4) use both combustible cigarettes and e-cigarettes currently
Who cannot join
- Adolescent arm:
- Contraindication to pulmonary function testing and cardiopulmonary exercise testing
- Have smoked combustible cannabis within the last month and/or have a combustible cannabis smoking history of >1 joint-year
- Have smoked combustible cigarettes within the last 6 months
- Have a physician-diagnosed chronic lung disease (such as asthma, cystic fibrosis, or bronchopulmonary dysplasia)
- Inability to provide written informed consent
Show all 12Show fewer
- Adult arm:
- Contraindication to pulmonary function testing and cardiopulmonary exercise testing
- Have smoked combustible cannabis within the last month and/or have a combustible cannabis smoking history of >1 joint-year
- Currently undergoing treatment for lung cancer
- Inability to provide written informed consent
- No limitations will be placed on the type of e-liquids used by participants; e.g., e-cigarette users of nicotine, tetrahydrocannabinol, and cannabidiol will be all enrolled.
Trial locations and contacts
8 sites in 1 country. Contact the study team or a site near you to ask about taking part.
8 sites in 1 country
Canada8 sites, 8 recruiting
- Recruiting
University of Alberta (Clinical Sciences Building)
Edmonton, Alberta, T6G 2B7
Michael Stickland, (780) 492-1657, mks2@ualberta.ca
Desi Fuhr, fuhr@ualberta.ca
- Not yet recruiting
McMaster University (Research Institute of St. Joe's Hamilton)
Hamilton, Ontario, L8N 4A6
Terence Ho, Unavailable, hot4@mcmaster.ca
Sarah Svenningsen, 905-522-1155, svennins@mcmaster.ca
- Recruiting
University of Ottawa (The Ottawa Hospital General Campus)
Ottawa, Ontario, K1H 8L6
Shawn Aaron, 613-737-8899 ext. 74729, saaron@ohri.ca
Kathy Vandemheen, kvandemheen@toh.ca
- Not yet recruiting
Université de Sherbrooke
Sherbrooke, Quebec, J1N 3C6
Simon Couillard, Unavailable, simon.couillard2@usherbrooke.ca
Martine Duval, martine.duval@usherbrooke.ca
- Not yet recruiting
University of Toronto (The Hospital for Sick Children)
Toronto, Ontario, M5G 1E8
Trisha Tulloch, Unavailable, trisha.tulloch@sickkids.ca
Brandon Zanette, brandon.zanette@sickkids.ca
- Recruiting
BC Cancer Agency
Vancouver, British Columbia, V5Z 4E6
Stephen Lam, 604-675-8094, slam2@bccancer.bc.ca
Sukhinder Khattra, skhattra@bccancer.bc.ca
- Recruiting
BC Children's Hospital Research Institute
Vancouver, British Columbia, V6H 3N1
Jonathan Rayment, 604-875-2345 ext. 7606, jonathan.rayment@bcchr.ca
Alireza Mojibian, alireza.mojibian@bcchr.ca
- Recruiting
St. Paul's Hospital
Vancouver, British Columbia, V6Z 1Y6
Janice Leung, 604-836-0423, janice.leung@hli.ubc.ca
Paloma Burns, 604-442-7021, pburns@providencehealth.bc.ca
About this study
Official title: The Canadian Lung Outcomes in Users of Vaping Devices (CLOUD) Study
Vaping is increasingly popular with both adolescent and adult Canadians, but the long-term health impacts remain unknown. We believe that the tools we currently have to detect lung disease in people who vape may be insufficient and propose new ways to find lung injuries that may impact them over the course of their lives. These include exercise testing, new imaging techniques, and new breathing tests that will demonstrate how vaping may harm their lungs. We will use these tools in both adolescent and adult Canadians to give Canadians who vape important information on the consequences of vaping.
Read the detailed description
Promoted as a safer method of inhaling nicotine compared to cigarettes and as smoking cessation tools, e-cigarettes have substantially grown in popularity with rates of uptake now exceeding those of cigarette smoking. In Canada, 6% of Canadians aged 15 years and older have vaped in the past 30 days. Younger Canadians appear to be the most susceptible to these habits, with 14% of those aged 15-19 years and 18% of those aged 20-24 years reporting past 30 day use. Indigenous populations are also disproportionately affected by the spread of vaping which may place them at higher risk for potential downstream respiratory complications. As Canadians increasingly reach for e-cigarettes, especially at younger ages and not just for the purposes of smoking cessation, greater clarity into the pulmonary toxicities vaping is urgently needed.
The Canadian Lung Outcomes in Users of Vaping Devices (CLOUD) Study is a pan-Canadian, multicentre, multidisciplinary, and longitudinal approach to studying vaping from cell to society. The characterization of e-cigarettes' respiratory effects remains superficial and a more comprehensive phenotyping of vaping-exposed lungs across the lifespan using novel imaging and pulmonary function techniques, dynamic exercise testing, and airway cell sequencing would significantly enhance our understanding of the potential harms. As with combustible cigarette smoking, the small airways (characterized by a diameter <2mm) may be particularly vulnerable during vaping given their high degree of exposure to particulate matter. These regions of the lung may harbour the earliest signs of injury, ultimately setting the stage for future obstructive airways disease.
Objectives
The objective of the CLOUD Study is to characterize small airway injury in adolescent and adult Canadians who use e-cigarettes. Specifically, our goals are to:
- Characterize the structural and functional disruptions associated with e-cigarette use using oscillometry, multiple breath washout, chest computed tomography, hyperpolarized 129-xenon magnetic resonance imaging, cardiopulmonary exercise testing, and bronchoscopy.
- Determine the association between e-cigarette use and respiratory outcomes, including symptom burdens, exacerbation-like respiratory events, and school and work absences.
- Characterize the epigenetic and transcriptomic disruptions associated with e-cigarette use in blood, sputum, airway epithelium, and lung immune cells.
Methods Our observational, longitudinal cohort study encompasses six academic hospital centres across Canada (the University of British Columbia, the University of Alberta, McMaster University, the University of Ottawa, the University of Toronto, and the Université de Sherbrooke). Participants (n=100 ages >12 and <19 years and n=400 ages ≥19 years) will be followed over 3 years, undergoing repeat demographic and respiratory symptom questionnaires, oscillometry, pulmonary function testing, and exercise testing. Adolescent participants will additionally undergo multiple breath washout and induced sputum collection and adult participants will undergo chest CT imaging and bronchoscopy. A substudy of adolescent and adult participants undergoing pulmonary hyperpolarized 129-xenon gas magnetic resonance imaging will also be performed. Induced sputum and bronchoscopy-derived airway epithelial and bronchoalveolar lavage samples will be sequenced for methylation and transcriptomics.
- Keywords
- CLOUD, small airway injury, vaping, vape, e-cigarette, oscillometry, multiple breath washout, chest computed tomography, chest CT, hyperpolarized 129-xenon, MRI, CPET, bronchoscopy, transcriptomics, epigenetics
- Medical subject headings
- Vaping
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Adults | Canadian adults aged 19 years or older. We will be enrolling e-cigarette-only users, non-e-cigarette and non-combustible cigarette users, combustible cigarette-only users, and dual combustible cigarette-e-cigarette users. | |
| Adolescents | Canadian adolescents aged between 12 and <19 years, inclusive. We will be enrolling e-cigarette-only users, as well as non-e-cigarette and non-combustible cigarette users. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Composite Measure of Small Airways Dysfunction
Participants meeting at least one of the following criteria will be considered to have small airways dysfunction:
For adolescent participants, these measures will include 1) a change in resistance from 5-20 Hz (R5-R20) >upper limit of normal (ULN) on oscillometry or 2) peak oxygen consumption (VO2)<lower limit of normal (LLN) plus a ventilatory response or minute ventilation/carbon dioxide production (VE/VCO2) nadir >ULN. For adult participants, these measures will include 1) R5-R20 >ULN, 2) disease probability measure functional small airways disease >10% on chest CT, or 3) peak VO2<84% predicted plus a VE/VCO2 nadir >ULN. The proportion of participants meeting at least one of the criteria for small airways dysfunction at any time point will be compared between the vaping and control groups using Chi-square tests. Multivariable logistic regressions will be used to adjust for possible covariates, such as age, sex, and their interaction with vaping/smoking groups.
Measured: From enrollment (Baseline) to the end of study participation (36 Months).
Secondary outcomes (30)
FEV1
Outcome measured in units of Liters (L) for all study participants.
Measured: 36 Months
FVC
Outcome measured in units of Liters (L) for all study participants.
Measured: 36 Months
FEV1/FVC
Outcome measured in units of 0-100% for all study participants.
Measured: 36 Months
FEV3/FEV6
Outcome measured in units of 0-100% for all study participants.
Measured: 36 Months
Total Lung Capacity
Outcome measured in units of Liters (L) for all study participants.
Measured: 36 Months
Diffusion Capacity
Outcome measured in units of mL/min/mmHg for all study participants.
Measured: 36 Months
Small Airways Resistance R5-R20
Outcome measured in units of kPa/l/s for all study participants.
Measured: 36 Months
Ventilation Defect Percent
Outcomes measured in units of 0-100% for study participants in the following sites: St. Paul's Hospital (University of British Columbia), BC Children's Hospital (University of British Columbia), the Hospital for Sick Children (University of Toronto), St. Joseph's Healthcare Hamilton (McMaster University).
Measured: 36 Months
RBC to Membrane Ratio
Outcomes measured in units of a ratio for study participants in the following sites: St. Paul's Hospital (University of British Columbia), BC Children's Hospital (University of British Columbia), the Hospital for Sick Children (University of Toronto), St. Joseph's Healthcare Hamilton (McMaster University).
Measured: 36 Months
Membrane to Gas Ratio
Outcomes measured in units of a ratio for study participants in the following sites: St. Paul's Hospital (University of British Columbia), BC Children's Hospital (University of British Columbia), the Hospital for Sick Children (University of Toronto), St. Joseph's Healthcare Hamilton (McMaster University).
Measured: 36 Months
Apparent Diffusion Coefficient
Outcomes measured in units of cm2/s for study participants in the following sites: St. Paul's Hospital (University of British Columbia), BC Children's Hospital (University of British Columbia), the Hospital for Sick Children (University of Toronto), St. Joseph's Healthcare Hamilton (McMaster University).
Measured: 36 Months
Peak VO2 %predicted
Outcomes measured in units of 0-100% for all study participants.
Measured: 36 Months
VE/VCO2 nadir
Outcomes measured in units of a ratio for all study participants.
Measured: 36 Months
Epigenetic Age (Blood Methylation)
Outcomes measured in units of age acceleration residual for all study participants.
Measured: 36 Months
Differentially Methylated Genes (Blood Methylation)
Outcomes measured in units of beta-values for all study participants.
Measured: 36 Months
Differentially Expressed Genes (Blood Transcriptome)
Outcomes measured in units of transcripts per million for all study participants.
Measured: 36 Months
Epigenetic Age (Induced Sputum Methylation)
Outcomes measured in units of age acceleration residual for adolescent study participants in the following sites: BC Children's Hospital (University of British Columbia), the Hospital for Sick Children (University of Toronto), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke).
Measured: 36 Months
Differentially Methylated Genes (Induced Sputum Methylation)
Outcomes measured in units of beta-values for adolescent study participants in the following sites: BC Children's Hospital (University of British Columbia), the Hospital for Sick Children (University of Toronto), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke).
Measured: 36 Months
Differentially Expressed Genes (Induced Sputum Transcriptome)
Outcomes measured in units of transcripts per million for adolescent study participants in the following sites: BC Children's Hospital (University of British Columbia), the Hospital for Sick Children (University of Toronto), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke).
Measured: 36 Months
Epigenetic Age (Bronchial Epithelial Cell and Bronchoalveolar Lavage Methylation)
Outcomes measured in units of age acceleration residual for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke).
Measured: 36 Months
Differentially Methylated Genes (Bronchial Epithelial Cell and Bronchoalveolar Lavage Methylation)
Outcomes measured in units of beta-values for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke).
Measured: 36 Months
Differentially Expressed Genes (Bronchial Epithelial Cell and Bronchoalveolar Lavage Transcriptome)
Outcomes measured in units of transcripts per million for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke).
Measured: 36 Months
Lung Clearance Index
Outcomes measured in counts for adolescent study participants in the following sites: BC Children's Hospital (University of British Columbia), the Hospital for Sick Children (University of Toronto).
Measured: 36 Months
DPM fSAD
Outcomes measured in units of 0-100% for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke), Clinical Sciences Building (University of Alberta), Ottawa Hospital General Campus (University of Ottawa).
Measured: 36 Months
LAA856
Outcomes measured in units of 0-100% for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke), Clinical Sciences Building (University of Alberta), Ottawa Hospital General Campus (University of Ottawa).
Measured: 36 Months
LAA950 (Quantitative Emphysema)
Outcomes measured in units of 0-100% for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke), Clinical Sciences Building (University of Alberta), Ottawa Hospital General Campus (University of Ottawa).
Measured: 36 Months
Qualitative Emphysema
Outcomes measured in units of 0-100% for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke), Clinical Sciences Building (University of Alberta), Ottawa Hospital General Campus (University of Ottawa).
Measured: 36 Months
Pulmonary Vascular Volume
Outcomes measured in units of milliliters (mL) for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke), Clinical Sciences Building (University of Alberta), Ottawa Hospital General Campus (University of Ottawa).
Measured: 36 Months
Mucus Score
Outcomes measured in counts for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke), Clinical Sciences Building (University of Alberta), Ottawa Hospital General Campus (University of Ottawa).
Measured: 36 Months
Total Airway Counts
Outcomes measured in counts for adult study participants in the following sites: St. Paul's Hospital (University of British Columbia), St. Joseph's Healthcare Hamilton (McMaster University), Centre Hospitalier Universitaire de Sherbrooke (Universite de Sherbrooke), Clinical Sciences Building (University of Alberta), Ottawa Hospital General Campus (University of Ottawa).
Measured: 36 Months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Feb 2025
- Study start25 Jul 2025
- Primary completion31 Dec 2029 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Small Airways DiseasesStudies of the same condition, open and under way.
- More trials run by University of British ColumbiaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 500 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of British Columbia
- Sponsor type
- University, hospital or other
- Collaborators
- BC Children's Hospital Research Institute, Providence Healthcare, British Columbia Cancer Agency, University of Alberta, McMaster University, University of Ottawa, Université de Sherbrooke, University of Toronto
- Responsible party
- Principal investigator, Janice Leung, University of British Columbia
- Investigators
- Janice Leung, MD, Principal investigator, University of British Columbia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06819969
- Sponsor's protocol ID
- H24-00374
- Other IDs
- FRN-193735, FRN-193735, FRN-193735
- Acronym
- CLOUD
- Status last verified
- Mar 2026
- First submitted
- 27 Jan 2025
- Last updated
- 30 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Burns P, Eddy RL, Li X, Yang J, Dhillon SS, Couillard S, Stickland MK, Guenette J, Svenningsen S, Tulloch T, Samji H, Meza R, Struik LL, Aaron S, Ho T, Lam S, Leipsic J, Maclean J, Afshar T, Moraes TJ, Zanette B, Santyr G, Counil FP, Hernandez Cordero AI, Matano S, de Arruda Maluf G, Leung C, Feng C, Bal L, Dhaliwal H, Mumuni A, Lui C, Drew H, Sin DD, Rayment JH, Leung JM. The Canadian Lung Outcomes in Users of Vaping Devices (CLOUD) Study: protocol for a prospective, observational cohort study. BMJ Open. 2025 Mar 6;15(3):e100568. doi: 10.1136/bmjopen-2025-100568.
PubMed 40050062
Study at a glance
From the registry record, last updated by the sponsor on 30 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Canadian Lung Outcomes in Users of Vaping Devices (CLOUD) Study
- ClinicalTrials.gov ID
- NCT06819969
- Acronym / sponsor ID
- CLOUD / H24-00374
- Keywords
- CLOUD, small airway injury, vaping, vape, e-cigarette, oscillometry, multiple breath washout, chest computed tomography
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 500 participants (estimated)
- Lead sponsor
- University of British ColumbiaUniversity, hospital or other
- Collaborators
- BC Children's Hospital Research Institute, Providence Healthcare, British Columbia Cancer Agency, University of Alberta, McMaster University, University of Ottawa, Université de Sherbrooke, University of Toronto
- Study start
- 25 Jul 2025 (actual)
- Primary completion
- 31 Dec 2029 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 11 Feb 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Vaping is increasingly popular with both adolescent and adult Canadians, but the long-term health impacts remain unknown. We believe that the tools we currently have to detect lung disease in people who vape may be insufficient and propose new ways to find lung injuries that may impact them over the course of their lives. These include exercise testing, new imaging techniques, and new breathing tests that will demonstrate how vaping may harm their lungs. We will use these tools in both adolescent and adult Canadians to give Canadians who vape important information on the consequences of vaping.
Detailed description
Promoted as a safer method of inhaling nicotine compared to cigarettes and as smoking cessation tools, e-cigarettes have substantially grown in popularity with rates of uptake now exceeding those of cigarette smoking. In Canada, 6% of Canadians aged 15 years and older have vaped in the past 30 days. Younger Canadians appear to be the most susceptible to these habits, with 14% of those aged 15-19 years and 18% of those aged 20-24 years reporting past 30 day use. Indigenous populations are also disproportionately affected by the spread of vaping which may place them at higher risk for potential downstream respiratory complications. As Canadians increasingly reach for e-cigarettes, especially at younger ages and not just for the purposes of smoking cessation, greater clarity into the pulmonary toxicities vaping is urgently needed.
The Canadian Lung Outcomes in Users of Vaping Devices (CLOUD) Study is a pan-Canadian, multicentre, multidisciplinary, and longitudinal approach to studying vaping from cell to society. The characterization of e-cigarettes' respiratory effects remains superficial and a more comprehensive phenotyping of vaping-exposed lungs across the lifespan using novel imaging and pulmonary function techniques, dynamic exercise testing, and airway cell sequencing would significantly enhance our understanding of the potential harms. As with combustible cigarette smoking, the small airways (characterized by a diameter <2mm) may be particularly vulnerable during vaping given their high degree of exposure to particulate matter. These regions of the lung may harbour the earliest signs of injury, ultimately setting the stage for future obstructive airways disease.
Objectives
The objective of the CLOUD Study is to characterize small airway injury in adolescent and adult Canadians who use e-cigarettes. Specifically, our goals are to:
- Characterize the structural and functional disruptions associated with e-cigarette use using oscillometry, multiple breath washout, chest computed tomography, hyperpolarized 129-xenon magnetic resonance imaging, cardiopulmonary exercise testing, and bronchoscopy.
- Determine the association between e-cigarette use and respiratory outcomes, including symptom burdens, exacerbation-like respiratory events, and school and work absences.
- Characterize the epigenetic and transcriptomic disruptions associated with e-cigarette use in blood, sputum, airway epithelium, and lung immune cells.
Methods Our observational, longitudinal cohort study encompasses six academic hospital centres across Canada (the University of British Columbia, the University of Alberta, McMaster University, the University of Ottawa, the University of Toronto, and the Université de Sherbrooke). Participants (n=100 ages >12 and <19 years and n=400 ages ≥19 years) will be followed over 3 years, undergoing repeat demographic and respiratory symptom questionnaires, oscillometry, pulmonary function testing, and exercise testing. Adolescent participants will additionally undergo multiple breath washout and induced sputum collection and adult participants will undergo chest CT imaging and bronchoscopy. A substudy of adolescent and adult participants undergoing pulmonary hyperpolarized 129-xenon gas magnetic resonance imaging will also be performed. Induced sputum and bronchoscopy-derived airway epithelial and bronchoalveolar lavage samples will be sequenced for methylation and transcriptomics.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Adults | – | –Canadian adults aged 19 years or older. We will be enrolling e-cigarette-only users, non-e-cigarette and non-combustible cigarette users, combustible cigarette-only users, and dual combustible cigarette-e-cigarette users. |
| Adolescents | – | –Canadian adolescents aged between 12 and <19 years, inclusive. We will be enrolling e-cigarette-only users, as well as non-e-cigarette and non-combustible cigarette users. |
Who may qualify
- Ages
- 12 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
- Study population
- This study will enroll both adolescent (ages ≥12 and <19 years) and adult (≥19 years) e-cigarette and non-e-cigarette users in six academic hospital centres across Canada.
Key inclusion criteria (6 listed)
- Aged ≥12 and <19 years old
- Either 1) use neither combustible cigarettes nor e-cigarettes or 2) use e-cigarettes exclusively
- Aged ≥19 years old
- Fall into one of the following categories: 1) use neither combustible cigarettes nor e-cigarettes; 2) use combustible cigarettes exclusively, never using e-cigarettes; 3) use e-cigarettes exclusively, never using combustible cigarettes; or 4) use both combustible cigarettes and e-cigarettes currently
Key exclusion criteria (12 listed)
- Contraindication to pulmonary function testing and cardiopulmonary exercise testing
- Have smoked combustible cannabis within the last month and/or have a combustible cannabis smoking history of >1 joint-year
- Have smoked combustible cigarettes within the last 6 months
- Have a physician-diagnosed chronic lung disease (such as asthma, cystic fibrosis, or bronchopulmonary dysplasia)
- Inability to provide written informed consent
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Composite Measure of Small Airways Dysfunction
Time frame: From enrollment (Baseline) to the end of study participation (36 Months).
Participants meeting at least one of the following criteria will be considered to have small airways dysfunction: For adolescent participants, these measures will include 1) a change in resistance from 5-20 Hz (R5-R20) >upper limit of normal (ULN) on oscillometry or 2) peak oxygen consumption (VO2)<lower limit of normal (LLN) plus a ventilatory response or minute ventilation/carbon dioxide production (VE/VCO2) nadir >ULN. For adult participants, these measures will include 1) R5-R20 >ULN, 2) disease probability measure functional small airways disease >10% on chest CT, or 3) peak VO2<84% predicted plus a VE/VCO2 nadir >ULN. The proportion of participants meeting at least one of the criteria for small airways dysfunction at any time point will be compared between the vaping and control groups using Chi-square tests. Multivariable logistic regressions will be used to adjust for possible covariates, such as age, sex, and their interaction with vaping/smoking groups.
30 secondary outcomes
FEV1
Time frame: 36 Months
FVC
Time frame: 36 Months
FEV1/FVC
Time frame: 36 Months
FEV3/FEV6
Time frame: 36 Months
Total Lung Capacity
Time frame: 36 Months
Diffusion Capacity
Time frame: 36 Months
Small Airways Resistance R5-R20
Time frame: 36 Months
Ventilation Defect Percent
Time frame: 36 Months
RBC to Membrane Ratio
Time frame: 36 Months
Membrane to Gas Ratio
Time frame: 36 Months
Apparent Diffusion Coefficient
Time frame: 36 Months
Peak VO2 %predicted
Time frame: 36 Months
VE/VCO2 nadir
Time frame: 36 Months
Epigenetic Age (Blood Methylation)
Time frame: 36 Months
Differentially Methylated Genes (Blood Methylation)
Time frame: 36 Months
Differentially Expressed Genes (Blood Transcriptome)
Time frame: 36 Months
Epigenetic Age (Induced Sputum Methylation)
Time frame: 36 Months
Differentially Methylated Genes (Induced Sputum Methylation)
Time frame: 36 Months
Differentially Expressed Genes (Induced Sputum Transcriptome)
Time frame: 36 Months
Epigenetic Age (Bronchial Epithelial Cell and Bronchoalveolar Lavage Methylation)
Time frame: 36 Months
Differentially Methylated Genes (Bronchial Epithelial Cell and Bronchoalveolar Lavage Methylation)
Time frame: 36 Months
Differentially Expressed Genes (Bronchial Epithelial Cell and Bronchoalveolar Lavage Transcriptome)
Time frame: 36 Months
Lung Clearance Index
Time frame: 36 Months
DPM fSAD
Time frame: 36 Months
LAA856
Time frame: 36 Months
LAA950 (Quantitative Emphysema)
Time frame: 36 Months
Qualitative Emphysema
Time frame: 36 Months
Pulmonary Vascular Volume
Time frame: 36 Months
Mucus Score
Time frame: 36 Months
Total Airway Counts
Time frame: 36 Months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Mar 2026.
- Derived from this study: PubMed 40050062Burns P, Eddy RL, Li X, Yang J, Dhillon SS, Couillard S, Stickland MK, Guenette J, Svenningsen S, Tulloch T, Samji H, Meza R, Struik LL, Aaron S, Ho T, Lam S, Leipsic J, Maclean J, Afshar T, Moraes TJ, Zanette B, Santyr G, Counil FP, Hernandez Cordero AI, Matano S, de Arruda Maluf G, Leung C, Feng C, Bal L, Dhaliwal H, Mumuni A, Lui C, Drew H, Sin DD, Rayment JH, Leung JM. The Canadian Lung Outcomes in Users of Vaping Devices (CLOUD) Study: protocol for a prospective, observational cohort study. BMJ Open. 2025 Mar 6;15(3):e100568. doi: 10.1136/bmjopen-2025-100568.
- CLOUD Study website containing all details and contact information related to the study.Link provided by the sponsor.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Janice Leung, MD principal investigator
University of British Columbia
8 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Small Airways Diseases and Vaping, run by University of British Columbia at 8 sites in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 30 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 8 sites in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Janice Leung, MD (604-836-0423, janice.leung@hli.ubc.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Composite Measure of Small Airways Dysfunction (time frame: From enrollment (Baseline) to the end of study participation (36 Months).). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06819969, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Mar 2026; AzTrials last refreshed its copy on 7 Nov 2026.