The efficiency of inspiratory muscle training in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is an inflammatory rheumatic disease affecting mainly the axial skeleton and sacroiliac joints. The aim of the current study was to investigate the effects of inspiratory muscle training (IMT) on respiratory muscles and functional exercise capacity, as well as on the specific outcomes of the disease in AS patients. A total of 32 AS patients (mean age 37.37 ± 10.41 years) were randomly assigned as the Training Group (TG) (n = 16, mean age = 35.62 ± 8.18 years) who received IMT + conventional exercise, and the Control Group (CG) (n = 16, mean age = 39.12 ± 12.26 years) who only performed the conventional exercise program. All the subjects were evaluated at baseline and at the end of the 8th week. Respiratory muscle strength was assessed by measuring the maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax). Functional exercise capacity was measured using the 6-min walk test (6MWT). The Bath AS Disease Activity Index (BASDAI), Bath AS Disease Function Index and Bath AS Metrology Index were used for activity, function and basic measurements of the disease. A statistically significant improvement was determined in the PImax (p = 0.000), PEmax (p = 0.002), 6MWT (p = 0.041) and BASDAI (p = 0.049) values in the TG after training. There was a significant difference between baseline and after conventional exercise in terms of PEmax (p = 0.017) in the CG. The PEmax (p = 0.001) and the 6MWT (p = 0.053) values were significantly better in the TG. The results of this study demonstrated that IMT in addition to conventional exercises increased inspiratory muscle strength, functional exercise capacity and positively affected the disease activity in AS.