Chronic Obstructive Pulmonary Disease, COPD, Healthy
Conditions
Keywords
Ultrasound, COPD, Test-retest
Brief summary
Doppler ultrasound is generally considered to provide reliable femoral blood flow measurements between rest and exercise, and the blood flow response to exercise is widely believed to be reduced in patients with chronic obstructive pulmonary disease (COPD). However, the test-retest reliability of the method during one-leg knee extensor exercise has not previously been compared between matched healthy individuals.
Detailed description
Experimental assessments of changes in skeletal muscle blood flow during exercise in humans are important for elucidating the factors that limit exercise capacity and adaptations, both in healthy humans, including athletes, as well as in various disease states with functional impairment, such as chronic obstructive pulmonary disease COPD). A classical 'gold standard' for measuring blood flow is thermodilution, and this has notably applied to provide data on femoral blood flow during exercise. Because thermodilution required invasive catheterization, many have replaced it with Doppler ultrasound, but the test-retest reliability of Doppler ultrasound in this context is unknown. However, many studies have used Doppler ultrasound to document that the femoral blood flow response to exercise is impaired in COPD, which ultimately affects oxygen uptake and thus exercise capacity, but the interpretation of these findings is currently hampered by the lack of knowledge regarding the test-retest reliability of the method in this patient group. The investigators aim is to compare the femoral blood flow response to one-legged knee extensor exercise in patients with COPD vs. healthy participants, and to provide an estimate of the test-retest reliability the femoral blood flow measurements obtained by Doppler ultrasound.
Interventions
DIAGNOSTIC_TESTOne-legged knee-extensor exercise with Doppler measurements
Doppler ultrasound is used while participants exercise according to the one-legged knee-extensor exercise model
Sponsors
Rigshospitalet, Denmark
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE
Intervention model description
Experimental setup Femoral blood flow will be measured by Doppler ultrasound at rest and during one-knee leg extensor exercise. Preliminary maximal knee extensor test The maximal workload (WLpeak) of the thigh muscles during one-legged knee-extensor exercise on a customized one-leg kicking chair will be determined. One-legged knee-extensor exercise protocol In rest upright and supine 0 watt 20%watt max 10 watt. This study day will be repeated within 2-7 days. Doppler ultrasound Doppler-based blood flow in the common femoral artery (QDop) is obtained using a linear probe (4.3-5.0 MHz) to obtain two-dimensional (2D) femoral arterial cross-sectional area (A) and mean blood velocity (v ̅).
Eligibility
Sex/Gender
ALL
Age
45 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
for COPD patients: * Men and women * 45-80 years * COPD (GOLD stage I to III) * Forced expiratory volume in 1 sec (FEV1)/forced vital capacity ratio (FVC) \< 0.8, FEV1 \< 90% of predicted value * Modified Medical Research Council score (mMRC 0 - 3) Resting arterial oxygenation \> 90%
Exclusion criteria
for COPD patients: * Symptoms of ischaemic heart disease * Known heart failure * Claudication * Symptoms of disease within 2 weeks prior to the study * Participation in pulmonary rehabilitation within 6 months * Known malignant disease * Pregnancy * Unstable cardiac arrhythmic disease * Renal or liver dysfunction Inclusion Criteria for healthy matched controls: * Men and women * 45-80 years * Normal FEV1, FVC, FEV1/FVC, and single-breath diffusion capacity * Same sex, age (± 3 years) as the COPD patients
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Between-day smallest real difference (SRD) for femoral blood flow at rest and at each relative exercise intensity in COPD vs. healthy controls | Measured at day 1 and day 2 | Doppler ultrasound measured blood flow during one leg knee extensor exercise with different intensities. |
| • Between-day coefficient of variance (CV) for femoral blood flow at rest and at each relative exercise intensity in COPD vs. healthy controls (co-primary) | Measured at day 1 and day 2 | Doppler ultrasound measured blood flow during one leg knee extensor exercise with different intensities. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Femoral blood flow response to exercise at each relative exercise intensity in COPD vs. healthy controls (key secondary) | Measured at day 1 and day 2 | Doppler ultrasound measured blood flow during one leg knee extensor exercise with different intensities. |
| Between-day smallest real difference (SRD) for femoral blood flow at rest and at each absolute exercise intensity in COPD vs. healthy controls | Measured at day 1 and day 2 | Doppler ultrasound measured blood flow during one leg knee extensor exercise with different intensities. |
| • Between-day coefficient of variance (CV) for femoral blood flow at rest and at each absolute exercise intensity in COPD vs. healthy controls (co-primary) | Measured at day 1 and day 2 | Doppler ultrasound measured blood flow during one leg knee extensor exercise with different intensities. |
Countries
Denmark
Outcome results
None listed