COPD assessment test and FEV₁: do they predict oxygen uptake in COPD?

Abstract

BackgroundChronic obstructive pulmonary disease (COPD) manifests itself in complex ways, with local and systemic effects; because of this, a multifactorial approach is needed for disease evaluation, in order to understand its severity and impact on each individual. Thus, our objective was to study the correlation between easily accessible variables, usually available in clinical practice, and maximum aerobic capacity, and to determine models for peak oxygen uptake (VO2peak) estimation in COPD patients.Subjects and methodsIndividuals with COPD were selected for the study. At the first visit, clinical evaluation was performed. During the second visit, the volunteers were subjected to the cardiopulmonary exercise test. To determine the correlation coefficient of VO2peak with forced expiratory volume in 1 second (FEV1) (% pred.) and the COPD Assessment Test score (CATs), Pearson or Spearman tests were performed. VO2 at the peak of the exercise was estimated from the clinical variables by simple and multiple linear regression analyses.ResultsA total of 249 subjects were selected, 27 of whom were included after screening (gender: 21M/5F; age: 65.0±7.3 years; body mass index: 26.6±5.0 kg/m2; FEV1 (% pred.): 56.4±15.7, CAT: 12.4±7.4). Mean VO2 peak was 12.8±3.0 mL⋅kg−1⋅min−1 and VO2peak (% pred.) was 62.1%±14.9%. VO2peak presented a strong positive correlation with FEV1 (% pred.), r: 0.70, and a moderate negative correlation with the CATs, r: -0.54. In the VO2peak estimation model based on the CAT (estimated VO2peak =15.148− [0.185× CATs]), the index explained 20% of the variance, with estimated error of 2.826 mL⋅kg−1⋅min−1. In the VO2peak estimation model based on FEV1 (estimated VO2peak =6.490+ [0.113× FEV1]), the variable explained 50% of the variance, with an estimated error of 2.231 mL⋅kg−1⋅min−1. In the VO2peak estimation model based on CATs and FEV1 (estimated VO2peak =8.441− [0.0999× CAT] + [0.1000× FEV1]), the variables explained 55% of the variance, with an estimated error of 2.156 mL⋅kg−1⋅min−1.ConclusionCOPD patients’ maximum aerobic capacity has a significant correlation with easily accessible and widely used clinical variables, such as the CATs and FEV1, which can be used to estimate peak VO2.

Handgrip strength measurement in patients with chronic obstructive pulmonary disease: Possible predictor of exercise capacity

“…Thus, the 6MWD seems to be more closely correlated with the %FEV1, rather than the %FVC. Our findings concerning the relationship between the 6MWD and age or CAT score were also consistent with those of previous reports [21,22].…”

Severe loss of mechanical efficiency in COVID‐19 patients

“…As expected, functional capacity was significantly reduced in patients with diseases compared with the control group. Similar values of VO 2 peak have been observed in other studies in patients with COPD (12.8 mL·kg −1 ·min −1 , 42 heart diseases (16–18 mL·kg −1 ·min −1 ) 43 and COVID‐19 (17.2 mL·kg −1 ·min −1 ) 44 . Interestingly, Carvalho‐Jr et al .…”

“…Interestingly, Carvalho‐Jr et al . found that patients with COPD who had lower FEV1 had lower VO 2 peak 42 . They concluded that FEV1 was a predictor of VO 2 peak to determine risk and severity in patients with COPD.…”

<p>Association Between the Predictors of Functional Capacity and Heart Rate Off-Kinetics in Patients with Chronic Obstructive Pulmonary Disease</p>

“…28,29 The CAT is composed of eight items (cough, phlegm, chest tightness, breathlessness, limited activities, confidence leaving home, sleeplessness and energy) purposed to evaluate and quantify the impact of symptoms in patients with COPD. The patients with COPD are classified into mild (6-10), moderate (11)(12)(13)(14)(15)(16)(17)(18)(19)(20), severe (21)(22)(23)(24)(25)(26)(27)(28)(29)(30) and very severe (31)(32)(33)(34)(35)(36)(37)(38)(39)(40). 1 Regarding the DASI, the higher the scoring (maximal score: 58.2), the higher the estimated V O 2 , which represents a better physical fitness.…”

“…Additionally, the CAT is useful to evaluate the individuals' health status, as well as the impact of exercise intolerance in daily routine, well-being and general health of these patients 1 and described an appliance that can be estimating the V O 2 peak. 15 Besides the high correlation with mortality predictors in patients with COPD such as the BODE, 16 the 6MWT also enables the evaluation of functional capacity, symptoms, as well as, cardiovascular variables that are also considered to be important to predict functional capacity. [16][17][18][19] The post-exercise heart rate (HR) recovery (off-kinetics) has been recognized as a predictor factor for exacerbation and mortality in multiple respiratory diseases (ie, COPD), and it is straightly related to functional capacity and quality of life.…”