Clinical trial NCT03500614: The Use of Air Cleaners to Mitigate Cardiopulmonary Health Impact of Indoor Exposure to Particles and Phthalates
Official title: An Interventional Study on the Use of Air Cleaners to Mitigate Cardiopulmonary Health Impact of Indoor Exposure to Particles and Phthalates in Healthy Adults: a Randomized Double-blinded Crossover Trial.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Blood Pressure
Lung Function
Inflammation
Oxidative Stress
Keywords: particulate matter
phthalates
cytokines
chemokines
epigenetics
DNA methylation
peripheral blood mononuclear cells
immune function
Lead sponsor: Peking University
Sponsor class: OTHER
First posted: 2018-04-18
Enrollment: 57
Sex: ALL
Minimum age (years): 18
Maximum age (years): 30
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: PREVENTION

Brief summary: This study aims to evaluate whether a short-term intervention strategy using air cleaner reduces indoor exposure to airborne particles (particulate matter with an aerodynamic diameter ≤2.5μm, PM2.5) and phthalates and improves cardiopulmonary health among Chinese healthy adults based on a randomized double-blinded crossover trial.

Detailed description: The randomized double-blind crossover trial includes two cohorts with different intervention and health examination settings and will be conducted in Beijing, China between November 2017-May 2018.

The first cohort plans to include 70 healthy college students who live in school dormitories, which were randomized into two dormitory groups to receive either true or sham air cleaner treatment for 1 week and then alternate the treatment after a wash out interval of at least 2 weeks (But in the enrollment, only 57 students were recruited actually). All participants and research staff are blinded to the group assignment. All participants are encouraged to stay in the dormitory with windows/doors tightly closed throughout the 1-week treatment period as far as possible, whereas necessary outdoor activities such as attending classes and dining in school canteens are allowed. All interventions will start at noon on Tuesday or Thursday and continue to the next morning of Tuesday or Thursday to avoid issues related to diurnal variation. Real-time PM2.5 concentrations will be measured using portable monitors and airborne PM2.5 mass samples will be collected in air filters throughout the treatment period. Air and fine particle phase phthalates samples will be collected using glass sampling tube filled with XAD2 macroporous resin and PM2.5 air filters respectively during the last day (24 hours) of the treatment period. Health variables, including blood pressure, lung function, fractional exhaled nitric oxide (FeNO), will be evaluated and biological samples including morning urine and fasting blood will be collected immediately after the completion of each treatment period. Efficacy of air cleaner treatment to reduce indoor exposure to particles and phthalates and related improvements in cardiopulmonary health variables will be evaluated using professional statistical methods.

The second cohort plans to include 30 healthy college students who will undergo extended treatment period covering the start, peak and end phases of smog episodes occurring in Beijing (To avoid dropout, 32 students were initially recruited). All interventions will start from the beginning to the end of typical smog episodes. PM2.5 exposure monitoring as detailed above will be performed throughout the treatment period and repeated health examinations will be conducted at time points corresponding to the start, peak and end phases of the smog episodes. Efficacy of air cleaner treatment to reduce indoor exposure to PM2.5 and related improvements in cardiopulmonary health variables throughout the smog episodes will be evaluated using professional statistical methods.

Eligibility criteria: Inclusion Criteria:

* Healthy college students aged between 18 and 30 years old;
* Will stay within the central urban area of Beijing over the entire study including the wash-out period;
* BMI \<30 kg/m3.

Exclusion Criteria:

* Current or ever smokers;
* A history of chronic respiratory diseases;
* A history of chronic cardiovascular diseases;
* Acute infections;
* Medication use in recent one month;
* Leave Beijing during the intervention.

Primary outcomes:
measure: Blood pressure (BP) (cohort 1)
timeFrame: through the study completion, an average of 1-week
measure: Lung function (cohort 1)
timeFrame: through the study completion, an average of 1-week
measure: Fractional exhaled nitric oxide (FeNO) (cohort 1)
timeFrame: through the study completion, an average of 1-week
measure: Urinary oxidative biomarkers (cohort 1)
timeFrame: through the study completion, an average of 1-week
measure: Circulating cytokine and chemokine biomarkers (cohort 1)
timeFrame: through the study completion, an average of 1-week
measure: Inflammatory and immune markers for peripheral blood mononuclear cell (PBMC) (cohort 1)
timeFrame: through the study completion, an average of 1-week
measure: Change in blood pressure from baseline to during and after the intervention (cohort 2)
timeFrame: before, during and after the smog episodes (up to 10 days)
measure: Change in lung function from baseline to during and after the intervention (cohort 2)
timeFrame: before, during and after the smog episodes (up to 10 days)
measure: Change in fractional exhaled nitric oxide (FeNO) from baseline to during and after the intervention (cohort 2)
timeFrame: before, during and after the smog episodes (up to 10 days)
measure: Change in urinary oxidative biomarkers from baseline to during and after the intervention (cohort 2)
timeFrame: before, during and after the smog episodes (up to 10 days)
measure: Change in circulating cytokine and chemokine biomarkers from baseline to during and after the intervention (cohort 2)
timeFrame: before, during and after the smog episodes (up to 10 days)
Secondary outcomes:
measure: DNA methylation (cohort 1)
timeFrame: through the study completion, an average of 1-week
measure: Concentrations of urinary phthalate metabolites (cohort 1）
timeFrame: through the study completion, an average of 1-week
measure: Change in DNA methylation from baseline to during and after the intervention (cohort 2)
timeFrame: before, during and after the smog episodes (up to 10 days)
Other outcomes:
Locations:
city: Beijing
country: China
facility: Department of Occupational & Environmental Health Sciences, School of Public Health, Peking University
Study officials:
affiliation: Peking University
name: Jing Huang, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: Peking University
name: Shaowei Wu, PhD
role: PRINCIPAL_INVESTIGATOR
References: