Correlations between exercise oxygen consumption, lung function, image findings, and quality of life in adults with post-tuberculosis lung disease

The aim of this study is to evaluate the correlations of peak oxygen uptake (VO2peak) with lung mechanics, radiographic abnormalities, and quality of life (QoL) in adults with post-tuberculosis lung disease (PTLD). This is a cross-sectional study in which 60 adults with PTLD underwent a cardiopulmonary exercise test (CPET). Additionally, the following assessments were performed: spirometry, impulse oscillometry (IOS), chest X-ray (CXR), and QoL using the WHOQOL-BREF. The mean peak oxygen uptake (VO_2peak) was 16.1 ± 6.8 ml/kg/min. There were positive correlations between VO_2peak and several parameters, including height, physical-WHOQOL-BREF, and forced vital capacity (FVC). There were negative correlations between VO_2peak and several parameters, including age, heterogeneity of resistance between 5 and 20 Hz, frequency response (Fres), and reactance-area. In IOS, patients with small airway disease (SAD) had a lower VO_2peak. Regarding CXR, only cavitation and nodular opacities were associated with a lower VO_2peak. In multivariate analysis, FVC, age, male sex, and Fres explained 65.2% of the variability in VO_2peak. In conclusion, there is a relationship between VO_2peak and lung mechanics in patients with PTLD. In these patients, IOS is able to detect more pulmonary mechanical alterations than spirometry, including those reflecting SAD. Thus, the use of both CPET and IOS may aid in the monitoring of patients with PTLD.