The Prognostic Value of Residual Volume/Total Lung Capacity in Patients with Chronic Obstructive Pulmonary Disease

Abstract

The prognostic role of resting pulmonary hyperinflation as measured by residual volume (RV)/total lung capacity (TLC) in chronic obstructive pulmonary disease (COPD) remains poorly understood. Therefore, this study aimed to identify the factors related to resting pulmonary hyperinflation in COPD and to determine whether resting pulmonary hyperinflation is a prognostic factor in COPD. In total, 353 patients with COPD in the Korean Obstructive Lung Disease cohort recruited from 16 hospitals were enrolled. Resting pulmonary hyperinflation was defined as RV/TLC ≥ 40%. Multivariate logistic regression analysis demonstrated that older age (P = 0.001), lower forced expiratory volume in 1 second (FEV1) (P < 0.001), higher St. George Respiratory Questionnaire (SGRQ) score (P = 0.019), and higher emphysema index (P = 0.010) were associated independently with resting hyperinflation. Multivariate Cox regression model that included age, gender, dyspnea scale, SGRQ, RV/TLC, and 6-min walking distance revealed that an older age (HR = 1.07, P = 0.027), a higher RV/TLC (HR = 1.04, P = 0.025), and a shorter 6-min walking distance (HR = 0.99, P < 0.001) were independent predictors of all-cause mortality. Our data showed that older age, higher emphysema index, higher SGRQ score, and lower FEV1 were associated independently with resting pulmonary hyperinflation in COPD. RV/TLC is an independent risk factor for all-cause mortality in COPD.Graphical Abstract

<p>Mixed Phenotype of Emphysema and Airway Wall Thickening Is Associated with Frequent Exacerbation in Chronic Obstructive Pulmonary Disease Patients</p>

“…Increased RV/TLC is associated with small airway disease, frequent exacerbations of COPD, and increased mortality in patients with COPD. [20][21][22][23] In addition, we assumed that the component of bronchial wall thickening was added to the emphysema component, which eventually contributed to poor outcome. Chronic bronchitis patients with COPD are characterized by airway wall thickening as detected via thoracic CT. 6,14 Such patients are often more symptomatic and show more frequent exacerbations compared to patients without chronic bronchitis.…”

Plasma Inflammatory Cytokine IL-4, IL-8, IL-10, and TNF-α Levels Correlate with Pulmonary Function in Patients with Asthma-Chronic Obstructive Pulmonary Disease (COPD) Overlap Syndrome

“…As a parameter used to define the presence of airflow limitation, FEV1/FVC ratio has been recommended as an index to diagnose patients with COPD and those at risk, and a low FEV1/FVC ratio after bronchodilator use might indicate the need for corticosteroid therapy in mild asthma [ 29 – 31 ]. The differences in pulmonary function index in patients with asthma, AECOPD, and ACOS could help to diagnose these 3 diseases more quickly and accurately, which is of great clinical importance [ 32 ].…”

Chronic Obstructive Pulmonar Disease Mortality. SEPAR COPD-Smoking Year

“…Moreover, hyperinflation predicts exercise capacity 3 and is measured by the 6-minute walk test (6MWT), which has been clearly correlated with mortality in COPD patients. Recently, Rim Shin et al 4 confirmed that, in addition to advanced age, both raised RV/TLC and a short 6-minute walking distance are independent predictors for all-cause mortality. -Multidimensional indices.…”