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

Rigshospitalet, Denmark32 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

COPD Healthy Chronic Obstructive Pulmonary Disease

Interventions

One-legged knee-extensor exercise with Doppler measurementsDIAGNOSTIC_TEST

Doppler ultrasound is used while participants exercise according to the one-legged knee-extensor exercise model

Eligibility

Sex: ALLMin age: 45 YearsMax age: 80 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Locations (1)

Center for Aktiv Sundhed (CFAS), Rigshospitalet, Copenhagen, Denmark.

Copenhagen, København Ø, Denmark

Outcomes

Primary Outcomes

Between-day smallest real difference (SRD) for femoral blood flow at rest and at each relative exercise intensity in COPD vs. healthy controls

Doppler ultrasound measured blood flow during one leg knee extensor exercise with different intensities.