Maximal Oxygen Uptake (VO2max) in Patients With COPD

Rigshospitalet, Denmark24 enrolled

Overview

Patients with chronic obstructive pulmonary disease (COPD), facing a decline in lung function and compromised quality of life, often benefit from regular exercise (1). Assessing their cardiorespiratory fitness through maximal oxygen uptake (VO2max) is crucial (2), yet research on its validity and reliability in COPD patients remains sparse. This study aims to fill this gap, examining the content validity and test-retest reliability of the VO2-max test in COPD, comparing it with healthy controls.

Introduction and background Patients with COPD face a challenging journey characterized by a progressive loss of lung function, ultimately resulting in a diminished quality of life, exercise limitations and heightened vulnerability to disability and premature mortality. Recognizing the pivotal role of regular exercise in enhancing the well-being of COPD patients, it becomes crucial to evaluate their cardiorespiratory fitness through parameters such as maximal oxygen uptake (VO2max). This metric serves as a cornerstone in assessing the maximal capacity of the cardiovascular system to deliver oxygen to working muscles and the muscles' ability to utilize oxygen during sustained exercise. In broader health contexts high VO2max has been established as a key indicator inversely correlated with the risk of cardiovascular diseases and mortality. However, despite the acknowledged importance of VO2max, there is a notable gap in research focusing specifically on VO2max of COPD patients. The need for a thorough examination of the content validity of the VO2-max test in the context of COPD, along with an assessment of its test-retest reliability (day-to-day variation), has not been adequately addressed, especially in comparison with healthy individuals. While regular exercise has proven to be a transformative factor in improving the quality of life for COPD patients, there remains a critical need to explore the reliability of VO2-max testing within this population. Not only does COPD induce a decline in physical activity, but it can also contribute to a reduction in VO2-max. Consequently, understanding the validity and test-retest reliability of VO2-max testing in COPD becomes paramount. Aim To compare the validity and test-retest reliability of the VO2-max test in COPD patients compared with healthy controls. Perspective The results are relevant for designing future studies of VO2max and VO2kinetics as outcomes in COPD patients.

Study Type

OBSERVATIONAL

Enrollment

Conditions

COPD

Interventions

VO2maxOTHER

Overall design 16 non-smoking individuals with COPD and 16 controls (non-smokers) matched for age and sex on a group level will be included in the study. The study consists of two study days. Separation between the study days are at least 48 hours and maximum 10 days. Before entering the study: Informed written and oral consent. Study day 1: Medical examination, full lung function testing (dynamic spirometry, whole-body plethysmography, diffusion capacity) followed by a maximal oxygen consumption test (VO2peak), VO2-verification bout and VO2kinetic test (duration 3h). Study day 2: Participants will undergo a maximal oxygen consumption test (VO2peak), VO2-verification bout and VO2kinetic test (duration 1,5h).

Eligibility

Sex: ALLMin age: 40 YearsMax age: 80 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion criteria - COPD patients * Men and women * 45-80 years * COPD (GOLD stage I to IIII) * 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% Inclusion criteria - healthy 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 - 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 Exclusion criteria - healthy 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