Impaired Lung Function and Quality of Life Outcomes in Patients with Tuberculosis: A Cross-Sectional Study

Tuberculosis (TB) continues to be the world’s deadliest infectious disease, with an estimated 10.8 million new cases reported in 2023, of which India alone accounted for 28% of the global burden. This study aims to evaluate the impact of tuberculosis on pulmonary function and exercise tolerance, and to examine how these impairments affect health-related quality of life (HRQoL). In a cross-sectional design, 96 bacteriologically confirmed TB patients and 96 age- and sex-matched community controls underwent spirometry, six-minute-walk test (6 MWT), and HRQoL evaluation. DR-TB was detected in 27 patients (28.1%): Isoniazid monoresistance 59.3%, rifampicin monoresistance 11.1%, and XDR-TB 29.6%. Dyspnoea (70.8%) and cough (37.5%) were the most commonly reported symptoms among TB patients. Mean values of FEV1, FVC, and FEV1/FVC were significantly lower in TB patients compared to controls (62.8%, 65.97%, and 70.08% vs. 82.55%, 80.09%, and 78.08%, respectively; p < 0.001). Recurrent or DR-TB was associated with reduced spirometric indices and 6 MWT distances (241 m vs. 358 m in drug-sensitive TB). St. George’s respiratory questionnaire (SGRQ) scores indicated significantly poorer health-related quality of life (HRQoL) in patients compared to controls across all domains—symptoms (23.7 vs. 10.7), activity (33.3 vs. 14.2), and impact (20.6 vs. 9.4; p < 0.05). SGRQ scores were inversely correlated with lung function parameters (r = −0.42 to −0.56). These findings underscore the persistent health burden TB poses post-therapy, highlighting the need for routine post-TB functional screening and robust DR-TB control to achieve End-TB goals.