Effect of antituberculosis treatment on cardiopulmonary responses to exercise in miliary tuberculosis.

BACKGROUND & OBJECTIVES Tuberculosis (TB) is a major health problem in the developing world. In this preliminary study, we report the effect of antituberculosis treatment (ATT) on cardiopulmonary responses to exercise in patients with miliary tuberculosis (MTB). METHODS The prospective study of cardiopulmonary responses to exercise in patients with MTB within one month of starting (n=14), on completion of ATT (n=7) and in 15 healthy subjects using the incremental exercise test was performed on a bicycle ergometer. RESULTS In MTB patients, mean body mass index (BMI), exercise duration (3.1 vs 4.6 min), work load (63 vs 91.4 watts), resting tachycardia, tachypnoea and the mean oxygen saturation improved significantly (P<0.05) with ATT. Mean oxygen consumption (V . O(2)) at anaerobic threshold (546.7 vs 580.9 ml/min) and maximum exercise (1008.1 vs 1022 ml/min) were similar before and after ATT. In MTB patients, post-treatment mean body weight, BMI, resting heart rate, respiratory rate and oxygen saturation during maximum exercise were similar, but exercise duration (4.6 vs 6.2 min, P<0.05), work load (91.4 vs 145.5 watts, P<0.05), V . O(2) and oxygen pulse were significantly lower as compared to healthy subjects. INTERPRETATION & CONCLUSION In MTB patients, though there was significant improvement in clinical parameters, functional abnormalities persisted on exercise testing after completion of ATT. As most patients with MTB are young and economically active, these observations obviously have long-term implications for these individuals.