Short-term Cardiovascular Benefits of Wearing Particulate-filtering Respirators

Study Overview
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Brief Summary
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An intervention study to assess the short-term cardiovascular effects of reducing personal air pollution exposure by wearing particulate filtering respirators.

Detailed Description
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A group of healthy adult college students fulfilling the recruitment criteria were randomly divided into two sub-groups. One sub-group weared the particulate filtering respirators for 2 continuous days during which the respirator was required to wear as much as possible both indoor and outdoor. The other group acted as normal at the same time. The measurements on health effects including heart rate varibility, blood pressure, circulating biomarkers as well as the ambient air pollution were performed in both groups during the intervention period. After a 3-week rest period,the two groups interchanged their roles of wearing the respirator or not. The same measurements of both health effects indicators and ambient air pollution were repeated.

Official Title
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Short-term Cardiovascular Benefits of Wearing Particulate-filtering Respirators: a Randomized Controlled Crossover Trial Among Healthy Young Adults

Conditions
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Autonomic Nervous System Imbalance, Blood Pressure, Inflammation, Vasoconstriction, Blood Coagulation Disorders

Intervention / Treatment
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* Behavioral: Wear respirator


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Equal to or older than 18 years old, No history of smoking and alcohol addiction. No chronic diseases,such as hypertension,diabetes,chronic obstructive pulmonary disease or other respiratory/cardiovascular diseases reported by volunteers. No respiratory or allergic diseases, like asthma, rhinitis,or other allergic diseases. Exclusion Criteria: Current smokers Chronic drug use due on cardiovascular or respiratory diseases

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Wear respirator<br>The recruited healthy subjects were randomly allocated into two groups.In each intervention, one group wore the high-efficiency respirator as much as possible for continuous 48hr and the other group behaved as usual. After a three-week interval, the two groups exchanged their roles in wearing the respirator or not. The same protocol on the measurements of health indicators and ambient air pollution was applied in the 1st intervention and 2nd intervention period. | Behavioral: Wear respirator<br>* Healthy adult subjects wore the particulate filtering respirators for continuous 48 hours as much as possible both indoor and outdoor.<br>* Other names: particulate filtering respirator;|
| No Intervention: Not wear respirator<br>The recruited healthy subjects were randomly allocated into two groups.In each intervention, one group wore the high-efficiency respirator as much as possible for continuous 48hr and the other group behaved as usual. After a three-week interval, the two groups exchanged their roles in wearing the respirator or not. The same protocol on the measurements of health indicators and ambient air pollution was applied in the 1st intervention and 2nd intervention period. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Heart Rate Variability-LF Power,HF Power,VLF Power | HRV is a quantitative health marker reflecting how the autonomic nervous system modulates the sinoatrial node in the heart and HRV has therefore been widely used to estimate cardiac autonomic function and control. Subjects were attached with Holter monitor on the 2nd day in each of the 48-hr intervention period.A total of 8 parameters of HRV were analyzed including 4 time-domain indices and 4 frequency-domain indices. Frequency domain methods assign bands of frequency and then count the number of NN intervals that match each band. The bands are typically high frequency (HF) from 0.15 to 0.4 Hz, low frequency (LF) from 0.04 to 0.15 Hz, and the very low frequency (VLF) from 0.0033 to 0.04 Hz. Parasympathetic activity is a major contributor to the HF component. More problematic is the interpretation of the LF component, which was considered by some as a marker of sympathetic modulation but is now known to include both sympathetic and vagal influences. | up to 24 hours | 
| Blood Pressure | The blood pressure were measured by automatic blood pressure monitor during the intervention study. | up to 24 hours | 
| Heart Rate Variability-SDNN,SDANN, rMSSD | HRV is a quantitative health marker reflecting how the autonomic nervous system modulates the sinoatrial node in the heart and HRV has therefore been widely used to estimate cardiac autonomic function and control.A total of 8 parameters of HRV were analyzed including 4 time-domain indices and 4 frequency-domain indices. Subjects were attached with Holter monitor on the 2nd day in each of the 48-hr intervention period. Heart rate and heart automatic function indices including the standard deviation of the normal-to-normal interval(SDNN),the standard deviation of the average NN intervals calculated over short periods(SDANN), the root mean square of the successive differences(rMSSD) were automatically recorded during the intervention. | Up to 24 hours | 
| Heart Rate Variability-LF/HF | HRV is a quantitative health marker reflecting how the autonomic nervous system modulates the sinoatrial node in the heart and HRV has therefore been widely used to estimate cardiac autonomic function and control. Subjects were attached with Holter monitor on the 2nd day in each of the 48-hr intervention period.A total of 8 parameters of HRV were analyzed including 4 time-domain indices and 4 frequency-domain indices. Frequency domain methods assign bands of frequency and then count the number of NN intervals that match each band. The bands are typically high frequency (HF) from 0.15 to 0.4 Hz, low frequency (LF) from 0.04 to 0.15 Hz. Parasympathetic activity is a major contributor to the HF component. More problematic is the interpretation of the LF component, which was considered by some as a marker of sympathetic modulation but is now known to include both sympathetic and vagal influences. | Up to 24 hours | 
| Heart Rate Variability-pNN50 | HRV is a quantitative health marker reflecting how the autonomic nervous system modulates the sinoatrial node in the heart and HRV has therefore been widely used to estimate cardiac autonomic function and control.A total of 8 parameters of HRV were analyzed including 4 time-domain indices and 4 frequency-domain indices. Subjects were attached with Holter monitor on the 2nd day in each of the 48-hr intervention period. Heart rate and heart automatic function indices including the proportion of successive normal NN intervals differing by more than 50 ms in the total number of NNs（pNN50） were automatically recorded during the intervention. | Up to 24 hours | 
| Circulating Biomarkers--Fibrinogen，vWF | At the end of each intervention, participants were asked to rest in a quiet room for half an hour. Peripheral venous blood samples were collected and centrifuged immediately. The serum were collected and stored at -80℃ within 30 minutes to minimize the in-vitro changes in biomarker proteins. Fibrinogen and von Willebrand factor(vWF) were measured by using the Millipore MILLIPLEX MAP human cytokine/chemokine kit (Millipore Corp., Billerica, Massachusetts) | Up to 24 hours | 
| Circulating Biomarkers--P- Selectin,VCAM-1 | At the end of each intervention, participants were asked to rest in a quiet room for half an hour. Peripheral venous blood samples were collected and centrifuged immediately. The serum were collected and stored at -80℃ within 30 minutes to minimize the in-vitro changes in biomarker proteins. P- selectin,VCAM-1(vascular cell adhesion molecule-1) were measured by using the Millipore MILLIPLEX MAP human cytokine/chemokine kit (Millipore Corp., Billerica, Massachusetts) | Up to 24 hours | 
| Circulating Biomarkers--ET-1 | At the end of each intervention, participants were asked to rest in a quiet room for half an hour. Peripheral venous blood samples were collected and centrifuged immediately. The serum were collected and stored at -80℃ within 30 minutes to minimize the in-vitro changes in biomarker proteins. Endothelin-1(ET-1) was using enzyme-linked immunosorbent assays. | Up to 24 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Heart rate variability, Blood pressure, Circulating biomarkers, Respirator, Fine particulate matter