Correlation between CT-determined emphysema and the severity of acute exacerbation of chronic obstructive pulmonary disease: a cross-sectional study
TL;DR
In patients with severe AECOPD, CT-determined emphysema is associated with decreased lung function and poor HRQoL and the stepwise multiple linear regression model showed that FEV1/FVC and age could be predictors of %LAA−950.
Abstract
Background The high prevalence of chronic obstructive pulmonary disease (COPD) poses a significant social burden. Emphysema is a basic pathological change associated with poor lung function in stable COPD. However, few studies have focused on the potential role of emphysema in acute exacerbation of COPD (AECOPD). The current study aimed to explore the correlation between CT-determined emphysema and other main physiological parameters of severe AECOPD. Methods In total 90 hospitalized patients with AECOPD participated in this cross-sectional study. All of them underwent chest CT scans and lung function tests as planned. Emphysema was defined as the percentage of low attenuation areas (LAA) below −950 Hounsfield Units (%LAA−950) on inspiratory CT scans. Health-Related Quality of Life (HRQoL) was assessed using four questionnaires, including the St. George’s Respiratory Questionnaire (SGRQ), modified Medical Research Council dyspnea scale, COPD Assessment Test, and EXAcerbation of Chronic Pulmonary Disease Tool (EXACT). Qualified data from 73 patients were included in the analysis. Results %LAA−950 was significantly correlated with spirometry parameters and HRQoL scores. The SGRQ and EXACT scores were significantly positively correlated with %LAA−950 (ρ = 0.399, p < 0.001; ρ = 0.370, p = 0.001, respectively). The ratio of the forced expiratory volume in the first 1 s to the forced vital capacity of the lungs and the percentage of predicted forced expiratory volume in first 1 s, which are functional indicators of airflow limitation, were significantly negatively correlated with %LAA−950 (ρ = −0.735, p < 0.00; ρ = −0.602, p < 0.001, respectively). Based on the stepwise multiple linear regression model showed that FEV1/FVC and age could be predictors of %LAA−950 (R2 = 0.592, F = 50.762, p < 0.001). Conclusion In patients with severe AECOPD, CT-determined emphysema is associated with decreased lung function and poor HRQoL. Trial registration The study was registered on the Chinese Clinical Trial Registry (registration number: ChiCTR2000033101).