Femoral Artery Blood Flow During Rest and One-leg Knee Extensor Exercise in Patients With COPD (COPD-DOPPLER)

Rigshospitalet

Status: Completed

Conditions: Healthy; Chronic Obstructive Pulmonary Disease; COPD

Treatments: Diagnostic Test: One-legged knee-extensor exercise with Doppler measurements

Study type: Interventional

Funder types: Other

Identifiers

NCT06135701

H-23049997

Details and patient eligibility

About

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.

Full 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.

Enrollment: 32 patients

Sex: All

Ages: 45 to 80 years old

Volunteers: Accepts Healthy Volunteers

Inclusion and exclusion criteria

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

Exclusion Criteria for healthy matched controls:

• Known chronic lung disease
• Known ischaemic heart disease
• Known heart failure
• Symptoms of disease within 2 weeks prior to the study
• Known malignant disease
• Claudication
• Pregnancy
• Unstable cardiac arrhythmic disease
• Renal or liver dysfunction

Trial design

Primary purpose: Diagnostic

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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32 participants in 2 patient groups

COPD-patients

Experimental group

Description:

The participants will be instructed to abstain from caffeine, nicotine, alcohol, and strenuous exercise all known to affect blood flow to the limb for 12 hours prior to the study day. After being placed on the one-leg kicking chair, baseline measurements will be performed, followed by passive leg movement for 2 minutes. Then participants will perform one-legged knee-extension exercise at submaximal intensity, first at 10% and then at 20% of the previously measured WLpeak, remaining 3.5 minutes at each level, while femoral blood flow is measured. This study day will be repeated within 2-10 days.

Treatment:

Diagnostic Test: One-legged knee-extensor exercise with Doppler measurements

Matched healthy volunteers

Experimental group

Description:

The participants will be instructed to abstain from caffeine, nicotine, alcohol, and strenuous exercise all known to affect blood flow to the limb for 12 hours prior to the study day. After being placed on the one-leg kicking chair, baseline measurements will be performed, followed by passive leg movement for 2 minutes. Then participants will perform one-legged knee-extension exercise at submaximal intensity, first at 10% and then at 20% of the previously measured WLpeak, remaining 3.5 minutes at each level, while femoral blood flow is measured. This study day will be repeated within 2-10 days.

Treatment:

Diagnostic Test: One-legged knee-extensor exercise with Doppler measurements