Passive Heat Therapy for People With COPD

Official title

The Acute and Chronic Benefits of Passive Heat Therapy for People With COPD

Overview

People with Chronic Obstructive Pulmonary Disease (COPD) often develop high blood pressure and heart disease due to their sedentary lifestyle and difficulty exercising. The investigators will test if heating can mimic the health benefits of exercise by monitoring the increase in leg blood-flow using ultrasound during a 45-minute hot-water footbath. The patients will then undergo 6-weeks of hot-water footbaths to examine whether the changes to blood-flow lead to improvements in blood pressure and other indicators of heart disease risk.

Detailed description

People with COPD are at higher risk of developing cardiovascular disease (CVD). While exercise training is a potent therapy for CVD, people with COPD have a low tolerance for exercise due to dyspnea and premature muscle fatigue. Thus, there is a need to develop more effective strategies to improve CVD risk in people with COPD. A novel way to reduce blood pressure and enhance arterial health is with passive heat therapy (PHT). An acute 45-min bout of lower limb hot-water immersion has been shown to increase leg blood flow and reduce blood pressure in healthy older adults, suggesting that PHT could have similar hypotensive and anti-atherosclerotic effects as exercise. Augmenting leg blood flow with PHT may also have functional benefits by reducing peripheral muscle fatigue and improving exercise tolerance. No study to date has looked at the acute and chronic hemodynamic and vascular responses to PHT in people with COPD, nor whether it can acutely or chronically improve exercise tolerance.

Interventions

• Behavioral Passive Heat Therapy
  The intervention will consist of 6 weeks of repeated (3x/week) 45-min lower-leg immersions.
• Behavioral Sham Immersion
  The sham intervention will consist of 6 weeks of repeated (3x/week) 45-min lower-leg immersions.

Primary outcome measures

• Mean 24-hour ambulatory blood pressure following chronic passive heat therapy [Time frame: 6 weeks]

Secondary outcome measures (5)

• Flow mediated dilation of the superficial femoral artery following chronic passive heat therapy. [Time frame: 6 weeks]
• Arterial stiffness following chronic passive heat therapy [Time frame: 6 weeks]
• Exercise tolerance following chronic passive heat therapy [Time frame: 6 weeks]
• The acute changes in leg blood flow from a single bout of passive heat therapy [Time frame: During procedure: 60-minutes]
• The acute changes in superficial femoral artery shear stress from a single bout of passive heat therapy [Time frame: During procedure: 60-minutes]

Eligibility criteria

Inclusion criteria

• Non-smoking individuals
• >40 years of age
• Stable (exacerbation free for >6 weeks), moderate-to-severe COPD (post bronchodilator FEV1/FVC <lower limit of normal and FEV1 z-score <2.51)

Exclusion criteria

• Performing structured exercise training (i.e. pulmonary rehabilitation)
• Have advanced cardiac or cerebrovascular disease (i.e. a history of heart failure, previous stroke or myocardial infarction)
• Have uncontrolled hypertension (>160/95 mmHg at rest)
• Have hypotension (<110/60 mmHg)
• Are taking Beta Blockers
• Regularly (>1/week) have hot baths (>30 min) or use a hot tub or sauna.

Exclusion Criteria for exercise outcomes:

• Have resting blood pressure > 150/95 mmHg
• On supplemental oxygen for hypoxemia.
• Musculoskeletal pain that limits their ability to perform stationary cycling.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Canada · 1 center

• University of British Columbia — Kelowna

Identifiers

NCT: NCT05962164 · H21-01868

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗