Physical Activity, Air Pollution, and High Blood Pressure

Sponsor

University of British Columbia (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT05092672

Collaborator

(none)

Enrollment

Location

Arms

Anticipated Duration (Months)

2.5

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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.

Condition or Disease	Intervention/Treatment	Phase
Essential Hypertension	Behavioral: Exercise	N/A

Study Design

Study Type:

Interventional

Anticipated Enrollment :

30 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Intervention Model Description:

Crossover AssignmentCrossover Assignment

Masking:

None (Open Label)

Primary Purpose:

Treatment

Official Title:

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

Anticipated Study Start Date :

Oct 1, 2021

Anticipated Primary Completion Date :

Aug 1, 2022

Anticipated Study Completion Date :

Oct 1, 2022

Arms and Interventions

Arm	Intervention/Treatment
Experimental: High traffic-related air pollution first 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 Participants will engage in moderate-intensity (40-59% HRR) exercise for 30 min
Experimental: Low traffic-related air pollution 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 Participants will engage in moderate-intensity (40-59% HRR) exercise for 30 min

Arm

Intervention/Treatment

Experimental: High traffic-related air pollution first

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

Participants will engage in moderate-intensity (40-59% HRR) exercise for 30 min

Experimental: Low traffic-related air pollution

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

Participants will engage in moderate-intensity (40-59% HRR) exercise for 30 min

Outcome Measures

Primary Outcome Measures

Change from Baseline Blood Pressure at 2 Hours Post-Exposure [Baseline and 2 hours post-exposure]
MAP, SBP, and DBP

Secondary Outcome Measures

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

Eligibility Criteria

Criteria

Ages Eligible for Study:

40 Years to 70 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

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