Can Micro-doses of Physical Activity Offset the Negative Cardiovascular Consequences of Being Sedentary in Patients With COPD?
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Enrollment
- 20
- Locations
- 1
- Primary Endpoint
- Change in superficial femoral artery endothelial function
Study Overview
Brief Summary
Chronic obstructive pulmonary disease (COPD) is a disease of the lungs that makes it hard for people to breath. Those with COPD spend considerably more time sitting and lying and less time performing physical activity than healthy individuals. Those who are the most sedentary have a greater risk of heart and blood vessel disease, which may lead to an early death. This project will investigate the effect of sitting still for 3 hours on blood vessel health in individuals with COPD. It will also investigate whether breaking up the amount of time patients sit with regular short bouts of walking (5 minutes each hour) at a comfortable pace chosen by the patient can have a positive effect on maintaining the health of their blood vessels. It is hypothesized that blood vessel health will be worse after 3 hours of sitting compared to when the sitting is broken up by short bouts of walking.
Detailed Description
The Purpose of the Study:
The aim of the proposed study is to examine whether regular microdoses of low intensity physical activity (PA) can reduce the vascular dysfunction and adverse cardiovascular consequences associated with being sedentary in patients with COPD.
Hypothesis to be Tested:
Primary Hypothesis: Endothelial function (measured as superficial femoral flow mediated dilation) will be reduced in patients with COPD after 3-hours of prolonged sitting compared to the same duration of sitting interspersed with micro-doses of PA (5 min/hour of walking).
Secondary Hypothesis: Superficial femoral endothelial shear rate and antegrade blood flow will be reduced and retrograde blood flow and arterial stiffness will be increased following prolonged sitting compared to the same duration of sitting interspersed with micro-doses of PA. Mean 24-hour blood pressure will be lower when micro-doses of PA are used to reduce sedentary time.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Prevention
- Masking
- Single (Outcomes Assessor)
Masking Description
The investigator who will analyze the primary outcome data will be blinded to the participant and condition.
Eligibility Criteria
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Non-smoking (\>6 months) patients with stable moderate-to-severe COPD (post bronchodilator forced expired volume in 1 sec/forced vital capacity\<0.7 and \6 weeks) will be recruited for the study.
Exclusion Criteria
- •performing structured exercise training (or pulmonary rehabilitation)
- •have a history of deep vein thrombosis
- •are on anticoagulant medication
- •have advanced cardiac or cerebrovascular disease (i.e. heart failure, previous stroke or myocardial infarction)
- •have diabetes
- •have musculoskeletal contraindications that limit their ability to perform physical activity
- •vascular ultrasound measurements cannot be obtained.
Arms & Interventions
Microdoses of Activity
5-min bouts of walking will break up 3 hours of sitting at minutes 30, 90 and 150.
Intervention: Microdoses of activity (Behavioral)
Control
Prolonged sitting (3 hours)
Outcomes
Primary Outcomes
Change in superficial femoral artery endothelial function
Time Frame: Within 3 hours of sitting (Day1) or within 3 hours of micro-doses of physical activity (Day 2). Days performed in a randomized order.
The change in endothelial function (measured by the flow-mediated dilation response to reactive hyperaemia of the superficial femoral artery using ultrasound) from baseline to 3-hours of prolonged sitting in the control condition compared to performing 3-hours of sitting broken up by micro-doses of physical activity.
Secondary Outcomes
- Change in superficial femoral artery blood flow patterns(Within 3 hours of sitting (Day1) or within 3 hours of micro-doses of physical activity (Day 2). Days performed in a randomized order.)
- Difference in 24-hour ambulatory blood pressure between the two conditions(Within 24 hours of sitting (Day 1) or within 24 hours of micro-doses of physical activity (Day 2). Days performed in a randomized order.)
Investigators
Neil Eves
Professor
University of British Columbia