Association between six-minute walk test parameters and the health-related quality of life in patients with pulmonary Mycobacterium avium complex disease

Background Pulmonary Mycobacterium avium complex (pMAC) disease is a chronic, slowly progressive disease. The aim of the present study was to determine the association of six-minute walk test (6MWT) parameters with pulmonary function and the health-related quality of life (HRQL) in patients with pMAC disease. Methods This cross-sectional study included adult patients with pMAC and was conducted at Keio University Hospital. We investigated the relationship of 6MWT parameters with clinical parameters, including pulmonary function, and HRQL, which was assessed using the 36-Item Short Form Health Survey (SF-36) and St. George’s Respiratory Questionnaire (SGRQ). Results In total, 103 consecutive patients with pMAC participated in 6MWT (median age, 64 years; 80 women) and completed SF-36 and SGRQ. The six-minute walk distance (6MWD) showed significant negative and positive correlations with all SGRQ domain scores [ρ = (− 0.54)–(− 0.32)] and the physical component summary (PCS) score (ρ = 0.39) in SF-36, respectively; the opposite was observed for the final Borg scale (FBS) score (all SGRQ scores, ρ = 0.34–0.58; PCS score, ρ = − 0.50). The distance-saturation product showed significant negative and positive correlations with all SGRQ scores [ρ = (− 0.29)–(− 0.55)] and the PCS score (ρ = 0.40), respectively. Multivariate analysis revealed that 6MWD and the FBS score were significant predictors of HRQL. Conclusions Our findings suggest that 6MWD and the FBS score are useful parameters for evaluating HRQL in patients with pMAC. Further studies should investigate the impact of 6WMT parameters on disease progression, treatment responses, and prognosis. Electronic supplementary material The online version of this article (10.1186/s12890-018-0686-5) contains supplementary material, which is available to authorized users.