Inspiratory muscle strength training improves lung function in patients with the hypermobile Ehlers-Danlos syndrome: A randomized controlled trial.

As exertional inspiratory dyspnea is a common disabling complaint in hypermobile Ehlers-Danlos syndrome (hEDS) often also known as joint hypermobility syndrome (JHS), we investigated inspiratory muscle (IM) strength in patients with hEDS, and we assessed the effects of IM training (IMT) on IM strength, lung function, and exercise capacity. A prospective evaluation of IM strength followed by a randomized controlled trial of IMT was performed in women with hEDS. Sniff nasal inspiratory pressure (SNIP) was used to routinely measure IM strength and IMT was carried out using a pressure threshold device. IM strength (main outcome), cardiopulmonary function, exercise capacity, and emotional distress of both the treated and control groups were evaluated at the start and at the end of the 6-week training period. IM strength was reduced (<80% of predicted) in 77% of patients (80/104). Lung function was normal, although 24% of patients had a higher forced expiratory vital capacity (FVC) than normal and 12% of patients had a higher total lung capacity (TLC) than normal. Both the IMT and control groups (n = 20) had similar baseline characteristics. Significant changes were noted only in the IMT group after IMT. At the end of the program, IMT improved SNIP (20%) (before: 41 +/- 17 cm H2O [28, 53] vs. after: 49 +/- 18 cm H2O [34;65]), six-minute walking distance (6MWD) (60 m) (455 +/- 107 m [379,532] vs. 515 +/- 127 m [408, 621]), and forced expiratory volume in one second (FEV1) (285 mL) (94 +/- 14% pred [84,104] vs. 103 +/- 11% pred [94, 112]). IM strength is significantly reduced in patients with hEDS. IMT improved IM strength, lung function, and exercise capacity. Our findings suggest that IMT should be added to usual care.