Femoral Artery Blood Flow During Rest and One-leg Knee Extensor Exercise in Patients With COPD
Condition: COPD; Healthy; Chronic Obstructive Pulmonary Disease
MeSH terms: Lung Diseases, Obstructive; Pulmonary Disease, Chronic Obstructive
Study type: Interventional

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.
    

Intervention name(s): One-legged knee-extensor exercise with Doppler measurements
Intervention type(s): Diagnostic Test
Intervention description(s): Doppler ultrasound is used while participants exercise according to the one-legged knee-extensor exercise model
Allocation: Non-Randomized
Intervention model: Parallel Assignment
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 ̅).
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Ultrasound; COPD; Test-retest