The effects of inspiratory muscle training on aerobic capacity, pulmonary functions and functional status in patients with ankylosing spondylitis

Abstract

Most of the ankylosing spondylitis (AS) patients have the complaint of reduced exercise capacity. Pulmonary function impairment, chest wall restriction, weak respiratory muscle performance and deconditioning have been reported as the hypotheses for reduced exercise capacity. The aim of this study was to assess the effects of inspiratory muscle training (IMT) on aerobic capacity, pulmonary function and functional status in patients with AS. Thirty-two patients (mean age:37.3±10.4 years) were included in the study. The patients were randomized as two groups: Group I recieved IMT in addition to conventional exercise (CE), Group II recieved only CE. All assessments were done before and after the training (8 weeks). Pulmonary functions, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP) were measured. Six-minute walk test(6MWT) was used for the assessment of aerobic capacity. For the functional status, the Bath Ankylosing Spondylitis Functional Index (BASFI), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Metrology Index (BASMI) were used. There were significant increases in MIP (p=0.000), MEP (p=0.005) and 6MWT (p=0.041) in Group I. Patients in Group II showed a significant increase only in MEP (p=0.020). There were no significant increases of spirometric measurements after training in both groups. Comparison of the groups showed significantly better results for group I in BASDAI (p=0.049) and MIP (p=0.003). AS patients performed IMT in addition to CE, had an increased respiratory muscle strength, a better aerobic capacity and disease activity than those who performed CE only.