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Risk Factors for Respiratory and Cardiovascular DiseaseNCT02769208

Influence of Indoor Air Filtration Strategies on Occupant Health Indicators

A study testing Central air handling unit air purification technologies in people with Risk Factors for Respiratory and Cardiovascular Disease, run by Feng Li at 1 site in China.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of this study is to evaluate whether two different central air purification technologies reduce air pollutant exposure and beneficially influence health as evaluated with a suite of biological markers related to cardiovascular and respiratory disease risk. Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
What is being tested?
Central air handling unit air purification technologies
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
89 participants
Where
1 siteChina
Study dates
Nov 2014to Jan 2015
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 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Healthy adults;
  • Live and work at the Broad Town work campus in eastern Changsha, Hunan Province, China

Who cannot join

  • Has any of the following diseases: chronic respiratory, cardiovascular, liver, renal, hematological disease; diabetes mellitus;
  • Has any other diseases that may confound or complicate the effects of the intervention
  • Pregnant females

Trial locations and contacts

1 site in 1 country.

China1 site
  • Shanghai First People's Hospital

    Shanghai, Shanghai Municipality, 201620

Other trials in China

About this study

The purpose of this study is to evaluate whether two different central air purification technologies reduce air pollutant exposure and beneficially influence health as evaluated with a suite of biological markers related to cardiovascular and respiratory disease risk.

Read the detailed description

This study will test two common types of central air handling unit filtration technologies, high-efficiency particulate air (HEPA) filters and electrostatic precipitators (ESPs), to evaluate the impacts of these technologies on personal exposure to air pollutants and the associated cardiovascular and respiratory health outcomes. HEPA filters remove a high percentage of the particulate matter in the air, as do ESPs, but ESPs also generate ozone, which may have its own detrimental health effects. These air purification technologies will be placed in different combinations with a coarse pre-filter to protect the air exchange machinery (combinations: pre-filter only, pre-filter + HEPA, and pre-filter + HEPA + ESP) in both the residences and offices of study participants living on a factory campus in Changsha, Hunan Province, China. Large dormitories and office buildings with central air handling units are common in China and around the world, and so adding air purification into the central ducts represents a practical strategy to reducing personal exposure to air pollution and related health outcomes. The Changsha area commonly suffers from high air pollution, and the dormitories and offices on this workspace are already outfitted with both HEPA filters and ESPs. Therefore, testing these technologies in this environment presents a natural experimental condition to test the benefits of air purification. The study investigators hypothesize that both the pre-filter + HEPA and pre-filter + HEPA + ESP conditions will reduce particulate matter exposure and reduce biological markers of cardiovascular and respiratory disease compared to the pre-filter alone, but that the ESP will generate enough ozone to lead to lower health benefits than HEPA+pre-filter condition.

Being tested
Central air handling unit air purification technologies
Keywords
Air Pollution, Air Filtration, Exposure Assessment, HEPA Filter, Electrostatic Precipitator, Cardiovascular Disease Biomarkers, Respiratory Disease Biomarkers
Medical subject headings
Cardiovascular Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Central air handling unit air purification technologiesDevice

    Also called Pre-filter, HEPA filter, Electrostatic precipitator (ESP)

    As described in the arm descriptions, the interventions involve changing the baseline pre-filter + HEPA + ESP conditions by removing either just the ESP or both the ESP and the HEPA for a five week period.

Study groups in NCT02769208
Study groupRoleWhat they receive
Group A: Pre-Filter Only InterventionActive comparatorSubjects in Group A start with baseline conditions of pre-filter + HEPA + ESP in their offices and dorms. After a baseline biological measurement, they then receive a 5-week intervention in which both the HEPA and ESP are removed, leaving only a pre-filter. This intervention period includes a biological measurement 2 weeks into the intervention and other 4-5 weeks into the intervention. The baseline air purification conditions are then restored, and another biological measurement is taken 2 weeks after that.
Receives: Device: Central air handling unit air purification technologies
Group B: Pre-filter + HEPA InterventionActive comparatorSubjects in Group B start with baseline conditions of pre-filter + HEPA + ESP in their offices and dorms. After a baseline biological measurement, they then receive a 5-week intervention in which the ESP is removed, leaving a pre-filter + HEPA combination. This intervention period includes a biological measurement 2 weeks into the intervention and other 4-5 weeks into the intervention. The baseline air purification conditions are then restored, and another biological measurement is taken 2 weeks after that.
Receives: Device: Central air handling unit air purification technologies

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change from baseline FEV1

    FEV1 (forced expiratory volume in the first second of exhalation, unit: liter) was measured by spirometry in all subjects at four separate time points to compare FEV1 changes at different times before, during, and after the filtration intervention as a marker of lung function.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  2. Change from baseline soluble P-selectin

    Soluble P-selectin (a protein shed by activated platelets in the blood, unit: ng/ml) was measured by ELISA in plasma in all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of platelet activation.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  3. Change from baseline von Willebrand factor (VWF)

    VWF (a glycoprotein released by damaged vascular cells into the blood, unit: ug/ml) was measured by ELISA in plasma in all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of endothelial cell damage.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  4. Change from baseline augmentation index (AI)

    AI (a measure of how much the reflecting pulse wave augments the outgoing systole pulse wave, unit: N/A (index)) was measured by pulse wave analysis in all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of arterial stiffness.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  5. Change from baseline systolic blood pressure (SBP)

    Brachial SBP (unit: mm Hg) was measured by an oscillometric method in all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of vasoconstriction.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  6. Change from baseline fractional exhaled nitric oxide (FeNO)

    FeNO (produced from inflammatory nitric oxide signalling in the lung, unit: ppb) was measured with an ambient NO-scrubbing collection method and chemiluminescence in all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of airway inflammation.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

Secondary outcomes (7)
  1. Change from baseline C-reactive protein (CRP)

    CRP (an inflammatory protein in the blood, unit: ng/ml) was measured with an ELISA in blood samples for all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of systemic inflammation.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  2. Change from baseline 8-hydroxy-2'-deoxyguanosine (8-OHdG)

    8-OHdG (a product of DNA oxidation found in the urine, unit: ng/ml) was measured with LC-MS in urine samples for all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of systemic oxidative stress.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  3. Change from baseline exhaled breath condensate malondialdehyde (EBC MDA)

    EBC MDA (a product of lipid oxidation found in the exhaled breath, unit: nM) was measured with HPLC in exhaled breath condensate samples for all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of airway oxidative stress.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  4. Change from baseline exhaled breath condensate nitrite + nitrate (EBCNN)

    EBCNN (a product of airway inflammatory NO signaling found in the exhaled breath, unit: uM) was measured with HPLC in exhaled breath condensate samples for all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of airway inflammation.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  5. Change from baseline exhaled breath condensate pH (EBC pH)

    EBC pH (a characteristic of exhaled breath associated with inflammation, unit: pH) was measured with a pH meter in exhaled breath condensate samples for all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of airway inflammation.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  6. Change from baseline diastolic blood pressure (DBP)

    DBP (unit: mm Hg) was measured with an oscillometric method for all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of vasoconstriction.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

  7. Change from baseline forced vital capacity (FVC)

    FVC (unit: liter) was measured with spirometry for all subjects at four separate time points to compare levels at different times before, during, and after the filtration intervention as a marker of airway function.

    Measured: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted11 May 2016 (estimated)
  2. Study startNov 2014
  3. Primary completionJan 2015
  4. Study completionJan 2015

Resources

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
Non-randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
89 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02769208
Sponsor's protocol ID
2014KY107
Status last verified
May 2016
First submitted
10 May 2016
Last updated
1 Jun 2016
Results posted
No
Data monitoring committee
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Central air handling unit air purification technologies in people with Risk Factors for Respiratory and Cardiovascular Disease, run by Feng Li at 1 site in China.

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 2 inclusion and 3 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 1 Jun 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 China. 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?

Change from baseline FEV1 (time frame: At baseline, 2 weeks and 4 weeks into the intervention period, and then 2 weeks post-intervention). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 1 Jun 2016.

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