Endothelial FunctionWESTNCT01256957
Effect of HEPA Air Filters on Subclinical Markers of Cardiovascular Health
A study testing HEPA filter in people with Endothelial Function and Oxidative Stress, run by Simon Fraser University at 1 site in Canada.
Trial summary
The purpose of this study is to evaluate the ability of portable high efficiency particle air (HEPA) filters to reduce exposures to PM2.5 and woodsmoke air pollution indoors and to improve subclinical indicators of microvascular function, systemic inflammation, and oxidative stress among healthy adult participants. Read more about this study
- Who is it for?
- Ages 19 years and olderHealthy volunteers can take part
- Conditions the study is for
- Endothelial Function, Oxidative Stress, Systemic Inflammation
- What is being tested?
- HEPA filter
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 56 participants
- Where
- 1 siteCanada
- Study dates
- Nov 2008to Apr 2009
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 19 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 19 years or older
- Non-smoking household
- Lives in study region (Smithers or Telkwa British Columbia)
Who cannot join
- -
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Assessing the Impact of Wood Stove Interventions on Air Quality
The purpose of this study is to evaluate the ability of portable high efficiency particle air (HEPA) filters to reduce exposures to PM2.5 and woodsmoke air pollution indoors and to improve subclinical indicators of microvascular function, systemic inflammation, and oxidative stress among healthy adult participants.
Read the detailed description
The investigators will use portable HEPA filters in a single-blind randomized crossover design. Each participant's home will be monitored for two consecutive seven-day periods, during which time two HEPA units (one in the bedroom and one in the main living room) will be operated indoors. During one 7-day period the HEPA filters will be operated normally, and during the other period the HEPA unit will be operated without the internal filter in place (i.e., "placebo filtration"), thus blinding participants to the filters' status. The order of filtration or non-filtration will be random. At the end of each 7-day period microvascular function will be assessed, blood will be collected for assessment of systemic inflammatory markers, and urine will be collected for assessment of oxidative stress markers.
- Being tested
- HEPA filter
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
HEPA filterDevice
Also called Honeywell model 50300, Honeywell model 18150
| Study group | Role | What they receive |
|---|---|---|
| Indoor air HEPA filtration | Active comparator | HEPA filters operating in the participant's bedroom and living room. Receives: Device: HEPA filter |
| Control | No intervention | Control |
What is being measured
The primary outcome is the main question the study is designed to answer.
Reactive hyperemia index
Measured: After 1 week of air filtration
Secondary outcomes (1)
C-reactive protein
Measured: After 1 week of filtration
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Dec 2010 (estimated)
- Study startNov 2008
- Primary completionApr 2009
- Study completionApr 2009
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 Endothelial FunctionStudies of the same condition, open and under way.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 56 participants (actual)
Sponsor and investigators
- Lead sponsor
- Simon Fraser University
- Sponsor type
- University, hospital or other
- Collaborators
- University of British Columbia, Health Canada, Ministry of Environment, British Columbia
- Responsible party
- Principal investigator, Ryan Allen, Simon Fraser University
- Investigators
- Ryan Allen, PhD, Principal investigator, Simon Fraser University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01256957
- Sponsor's protocol ID
- 869329
- Acronym
- WEST
- Status last verified
- Dec 2010
- First submitted
- 8 Dec 2010
- Last updated
- 5 Dec 2016
- Results posted
- No
- Data monitoring committee
- No
Publications
Allen RW, Carlsten C, Karlen B, Leckie S, van Eeden S, Vedal S, Wong I, Brauer M. An air filter intervention study of endothelial function among healthy adults in a woodsmoke-impacted community. Am J Respir Crit Care Med. 2011 May 1;183(9):1222-30. doi: 10.1164/rccm.201010-1572OC. Epub 2011 Jan 21.
PubMed 21257787
Study at a glance
From the registry record, last updated by the sponsor on 5 Dec 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessing the Impact of Wood Stove Interventions on Air Quality
- ClinicalTrials.gov ID
- NCT01256957
- Acronym / sponsor ID
- WEST / 869329
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 56 participants (actual)
- Lead sponsor
- Simon Fraser UniversityUniversity, hospital or other
- Collaborators
- University of British Columbia, Health Canada, Ministry of Environment, British Columbia
- Study start
- Nov 2008
- Primary completion
- Apr 2009 (actual)
- Study completion
- Apr 2009 (actual)
- First posted
- 9 Dec 2010 (estimated)
- 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.
The purpose of this study is to evaluate the ability of portable high efficiency particle air (HEPA) filters to reduce exposures to PM2.5 and woodsmoke air pollution indoors and to improve subclinical indicators of microvascular function, systemic inflammation, and oxidative stress among healthy adult participants.
Detailed description
The investigators will use portable HEPA filters in a single-blind randomized crossover design. Each participant's home will be monitored for two consecutive seven-day periods, during which time two HEPA units (one in the bedroom and one in the main living room) will be operated indoors. During one 7-day period the HEPA filters will be operated normally, and during the other period the HEPA unit will be operated without the internal filter in place (i.e., "placebo filtration"), thus blinding participants to the filters' status. The order of filtration or non-filtration will be random. At the end of each 7-day period microvascular function will be assessed, blood will be collected for assessment of systemic inflammatory markers, and urine will be collected for assessment of oxidative stress markers.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Indoor air HEPA filtration | Active comparator | Device: HEPA filterHEPA filters operating in the participant's bedroom and living room. |
| Control | No intervention | –Control |
Who may qualify
- Ages
- 19 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- 19 years or older
- Non-smoking household
- Lives in study region (Smithers or Telkwa British Columbia)
Key exclusion criteria (1 listed)
- -
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| HEPA filterAlso: Honeywell model 50300, Honeywell model 18150 | Device | Indoor air HEPA filtration |
Primary outcome
Reactive hyperemia index
Time frame: After 1 week of air filtration
1 secondary outcome
C-reactive protein
Time frame: After 1 week of filtration
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Dec 2016.
- Derived from this study: PubMed 21257787Allen RW, Carlsten C, Karlen B, Leckie S, van Eeden S, Vedal S, Wong I, Brauer M. An air filter intervention study of endothelial function among healthy adults in a woodsmoke-impacted community. Am J Respir Crit Care Med. 2011 May 1;183(9):1222-30. doi: 10.1164/rccm.201010-1572OC. Epub 2011 Jan 21.
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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. This study is not recruiting at the moment.
Ryan Allen, PhD principal investigator
Simon Fraser University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing HEPA filter in people with Endothelial Function and Oxidative Stress, run by Simon Fraser University at 1 site 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 3 inclusion and 1 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: finished, as of the sponsor's last update on 5 Dec 2016. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Reactive hyperemia index (time frame: After 1 week of air filtration). 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 NCT01256957, 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 5 Dec 2016.