Impact of supplementary air-stacking (AS) on the effect of inspiratory muscle training (IMT) in patients with Late Onset Pompe Disease (LOPD): preliminary results from a multicenter cross-over randomized Trial.

<bold>Background:</bold> In neuromuscular diseases inspiratory muscle weakness, lower chest-wall and lung compliance are associated with a reduction in vital capacity. IMT and AS may improve inspiratory muscle strength and lung and chest wall mechanics. <bold>Aim:</bold> to evaluate the effects of IMT+AS vs IMT alone on respiratory and pulmonary function in patients with LOPD pharmacologically treated with enzyme replacement therapy (ERT). <bold>Methods:</bold> LOPD patients under ERT performed IMT+AS (n=6, 67%male, age 60 SD9) or IMT (n=8, 38%male, age 46 SD 9), 6d/week, for 8 weeks. External IMT load was set at 30%MIP at baseline and increased according to patient tolerance. Training characteristics were recorded with the training device (PowerBreathe KH2). Differences in MIP and forced vital capacity (FVC) were recorded. <bold>Results:</bold> <fig><object-id>erj;64/suppl_68/PA4123/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Conclusion:</bold> Respiratory muscle strength was preserved in both groups. Providing IMT alone without combining it with AS may be more efficient in improving FVC in patients with LOPD. AS may have reduced the total training load in IMT+AS due to possible chest and lung mechanics improvements.