Cough and sputum symptoms reduce physical activity in patients with NTM pulmonary disease

Although physical activity is an important outcome in patients with chronic respiratory disease, it has not been characterised in those with non-tuberculous mycobacterial pulmonary disease (NTM-PD). This study aimed to evaluate physical activity and its associated factors in patients with NTM-PD.This prospective observational study measured daily step counts using an accelerometer to assess physical activity (steps per day). We investigated serum C-reactive protein (CRP), incremental shuttle walk test distance (ISWD), Leicester Cough Questionnaire (LCQ), modified Medical Research Council (mMRC) dyspnoea scale, and chronic cough and sputum symptoms (CCS). Patients were divided into two groups based on the presence or absence of CCS, and their physical activity were compared. The association between physical activity and these variables was examined using multivariate analysis.We included 131 patients, with a median daily step count of 3,960. Patients with CCS had significantly lower daily step counts than those without CCS (3,426 vs 4,567). Daily step count significantly correlated with age, mMRC dyspnoea grade, CRP level, ISWD, and LCQ. Multiple regression analysis showed that the daily step count was significantly associated with ISWD and CCS.These results suggest that CCS should be considered when assessing physical activity in patients with NTM-PD..