The burden of functional impairment after tuberculosis (TB) treatment is a global health issue, now referred to as post-tuberculosis lung disease (PTLD). These patients often suffer not only from persistent respiratory symptoms but also from exercise intolerance as a result of the pulmonary sequelae.

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) using a small sample of the expired volume through a miniaturized chamber. Additionally, the following assessments were performed: pulmonary function through spirometry and impulse oscillometry (IOS), chest X-ray (CXR), and QoL using the WHOQOL-BREF.

Of the participants included in the study, 34 (56.7%) were women. The mean age was 55.1 ± 14.1 years, while the median time since the end of TB treatment was 24 months (range, 20–27 months). A history of smoking was reported by 29 (48.3%) participants, with a median smoking load of 25 (9–39) pack-years. While 46 (76.7%) participants had an mMRC score of 0–1, only 14 (23.3%) had an mMRC score of 2–4. Regarding QoL as assessed by the WHOQOL-BREF questionnaire, the worst-performing domains were physical and environment. The mean peak oxygen uptake (VO2peak) was 16.1 ± 6.8 ml/kg/min. There were positive correlations between VO2peak and several parameters, including height (rs = 0.343, P = 0.007), physical–WHOQOL-BREF (rs = 0.275, P = 0.033), and forced vital capacity (FVC, rs = 0.603, P < 0.0001). There were negative correlations between VO2peak and several parameters, including age (rs = -0.452, P = 0.0002), heterogeneity of resistance between 5-20 Hz (rs = -0.466, P = 0.0001), frequency response (Fres, rs = -0.675, P < 0.0001), and reactance-area (rs = -0.647, P < 0.0001). In IOS, patients with small airway disease had a lower VO2peak. Regarding CXR, only pulmonary cavitation and nodular opacities were associated with a lower VO2peak. In multivariate analysis, FVC, age, male sex, and Fres explained 65.2% of the variability in VO2peak.

Patients with PTLD present low VO2peak. There is a relationship between VO2peak and lung mechanics. In these patients, IOS is able to detect more pulmonary mechanical alterations than spirometry, including those reflecting small airway disease (SAD). There is a relationship between VO2peak and radiographic abnormalities, particularly pulmonary cavitation and nodular opacities. However, the relationship between VO2peak and QoL is virtually nonexistent. Thus, the use of both CPET and IOS may aid in the monitoring of patients with PTLD.

There is still much to be discovered, as PTLD, a post-PTB disease, is a developing field, with few studies. This study highlights the impact of VO2peak on individuals with PTLD. Tools such as CPET, IOS, spirometry, CXR, and QoL assist in guiding and managing treatment. Personalized and patient-centered care is important to improve limitations in this population, with early interventions to improve functional capacity, minimizing the impact of the disease, and improving QoL.