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.
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
32
The intervention will consist of 6 weeks of repeated (3x/week) 45-min lower-leg immersions.
The sham intervention will consist of 6 weeks of repeated (3x/week) 45-min lower-leg immersions.
University of British Columbia
Kelowna, British Columbia, Canada
RECRUITINGMean 24-hour ambulatory blood pressure following chronic passive heat therapy
The change in 24-hour ambulatory systolic, diastolic and mean arterial blood pressure from baseline to post intervention.
Time frame: 6 weeks
Flow mediated dilation of the superficial femoral artery following chronic passive heat therapy.
The change in the percent dilation of the superficial femoral artery (measured using ultrasound) in response to reactive hyperemia (from a 5-min supra-systolic occlusion) from baseline to post intervention.
Time frame: 6 weeks
Arterial stiffness following chronic passive heat therapy
The change in pulse wave velocity (m/s) measured by applanation tonometry from baseline to post intervention.
Time frame: 6 weeks
Exercise tolerance following chronic passive heat therapy
The change in constant load exercise time (seconds) at 75% of peak power from baseline to post intervention.
Time frame: 6 weeks
The acute changes in leg blood flow from a single bout of passive heat therapy
Superficial femoral artery blood flow (mL/min) will be measured by duplex ultrasound. Measurements will be taken every 15-min throughout immersion until 15-min following the first session of passive heat therapy or Sham treatment.
Time frame: During procedure: 60-minutes
The acute changes in superficial femoral artery shear stress from a single bout of passive heat therapy
Superficial femoral artery shear stress (1/s) patterns will be measured by duplex ultrasound. Measurements will be taken every 15-min throughout immersion until 15-min following the first session of passive heat therapy or Sham treatment.
Time frame: During procedure: 60-minutes
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.