Short-term Cardiovascular Benefits of Wearing Particulate-filtering Respirators

Not Applicable

Completed

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

Interventions: Behavioral: Wear respirator

Registration Number: NCT02238028

Lead Sponsor: Fudan University

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

Detailed Description: 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.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 28

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Wear respirator	Wear respirator	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.

Primary Outcome Measures

Name	Time	Method
Heart Rate Variability-LF Power,HF Power,VLF Power	up to 24 hours	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.
Blood Pressure	up to 24 hours	The blood pressure were measured by automatic blood pressure monitor during the intervention study.
Circulating Biomarkers--ET-1	Up to 24 hours	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.
Heart Rate Variability-LF/HF	Up to 24 hours	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.
Heart Rate Variability-SDNN,SDANN, rMSSD	Up to 24 hours	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.
Circulating Biomarkers--Fibrinogen，vWF	Up to 24 hours	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)
Circulating Biomarkers--P- Selectin,VCAM-1	Up to 24 hours	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)
Heart Rate Variability-pNN50	Up to 24 hours	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.