Physical Activity, Air Pollution, and High Blood Pressure

Study Overview
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Brief Summary
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The investigators are investigating the effects of traffic-related air pollution (TRAP) on the cardiovascular and pulmonary response to exercise in patients with hypertension using a real world randomized, crossover study design. Participants will be exposed to 2 conditions: a low TRAP environment and a high TRAP environment. Each exposure will consist of 30 min of moderate-intensity exercise. Cardiovascular and pulmonary health outcomes will be measured before, during, and up to 24 hours following exposures. A minimum washout period of 1 week will be used to minimize carryover effects.

Official Title
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Impact of Traffic-related Air Pollution on the Cardiovascular and Pulmonary Response to Physical Activity in Patients With Hypertension

Conditions
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Essential Hypertension

Intervention / Treatment
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* Behavioral: Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age between 40-70 years of age Previously diagnosed with elevated blood pressure or hypertension by a physician Exclusion Criteria: Current or ex-smokers (abstinent for less than one year) Lives with an individual who currently smokes cigarettes, e-cigarettes (i.e., vaping), or cannabis Hormone replacement therapy use Currently on beta-blocker or angiotensin receptor blocker (ARB) therapy Currently using over the counter drugs or supplements that may alter cardiovascular measures (as per the principal investigator's discretion) Prior diagnosis of any other existing cardiovascular or pulmonary diseases and/or conditions (other than hypertension) Musculoskeletal injury or lower limb limitation preventing safe engagement in moderate-intensity exercise

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High traffic-related air pollution first<br>Participants will exercise in an environment with high levels of traffic-related air pollution first. Afterwards, participants will complete the same exercise in an environment with low levels of traffic-related air pollution. | Behavioral: Exercise<br>* Participants will engage in moderate-intensity (40-59% HRR) exercise for 30 min<br>|
| Experimental: Low traffic-related air pollution<br>Participants will exercise in an environment with low levels of traffic-related air pollution first. Afterwards, participants will complete the same exercise in an environment with high levels of traffic-related air pollution. | Behavioral: Exercise<br>* Participants will engage in moderate-intensity (40-59% HRR) exercise for 30 min<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from Baseline Blood Pressure at 2 Hours Post-Exposure | MAP, SBP, and DBP | Baseline and 2 hours post-exposure | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24-Hour Blood Pressure | MAP, SBP, and DBP | 24 hours post-exposure | 
| Heart Rate Variability | Indices of heart rate variability | Baseline and up to 24 hours post-exposure | 
| Change from Baseline Arterial Stiffness at 2 Hours Post-Exposure | Pulse wave velocity and augmentation index | Baseline and 2 hours post-exposure | 
| Change from Baseline Microvascular Responsiveness at 2 Hours Post-Exposure | Microvascular responsiveness (measured by near-infrared spectroscopy) | Baseline and 2 hours post-exposure | 
| Muscle Oxygen Saturation | Muscle oxygen saturation (measured by near-infrared spectroscopy) | Continuously throughout the 30 minute exercise bouts (during exposure) | 
| Change from Baseline FEV1 and FVC at 2 Hours Post-Exposure | Forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) measured by spirometry (in L) | Baseline and 2 hours post-exposure | 
| Change from Baseline FEV1/FVC at 2 Hours Post-Exposure | FEV1/FVC ratio measured by spirometry | Baseline and 2 hours post-exposure | 
| Change from Baseline FEF25-75 and PEFR at 2 Hours Post-Exposure | Forced expiratory flow at 25-75% of forced vital capacity (FEF25-75) and peak expiratory flow rate (PEFR) measured by spirometry (in L/s) | Baseline and 2 hours post-exposure | 
| Severity of Symptoms | Severity of respiratory symptoms (e.g., dyspnea, cough, wheeze, chest tightness) and headache on a 0-5 scale | Baseline and 2 hours post-exposure | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Traffic-related air pollution, Physical activity, Exercise, Blood pressure, Heart rate variability, Arterial stiffness, Microvascular responsiveness, Muscle oxygen saturation, Lung function