Safety and effectiveness of resistance training in patients with late onset Pompe disease - a pilot study

Pompe disease is a progressive myopathy resulting from deficiency in lysosomal enzyme acid α-glucosidase (GAA), which leads to glycogen accumulation in lysosomes primarily in skeletal and cardiac muscle. Enzyme replacement therapy (ERT) with recombinant human (rh) GAA works well in alleviating the cardiomyopathy; however, many patients continue to have progressive muscle weakness. The purpose of this study was to evaluate the effectiveness of a respiratory training combined with 24-week supervised resistance training program on muscle strength (measured by Biodex)), and respiratory function including maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP) in subjects with late onset Pompe disease receiving ERT. Ten subjects participated in a 24-week resistance exercise program, three times per week, in addition to respiratory muscle exercise training six days per week. Overall, at the end of the resistance training program, as measured by Biodex dynamometry, the leg extensor strength improved by 10.5 ± 3.2Nm. (<p 0.01), leg flexors improved by 12.1 ± 4.1Nm (p < 0.01), the elbow flexors improved by 5.1 ± 2.3Nm (p = 0.03), and the elbow extensor strength improved by a mean of 4.5 ± 1.9Nm. (p = 0.02). MIP improved by 8.5 ± 3.7 cm H₂O (p = 0.03) and the MEP by 6.4 ± 4.4 (p = 0.16). The exercise training significantly improved the trajectories of MIP and 6 MWT outcomes but not FVC when compared with the natural history data available in 6 individuals. These pilot results indicate that resistance training combined with respiratory training and ERT had a positive effect on muscular strength, functional capacity, and respiratory function in patients with late-onset Pompe disease and might be considered as a potential adjunct therapy in this population.