Improved exercise tolerance after enzyme replacement therapy in pompe disease

Purpose: Enzyme replacement therapy (ERT) has recently became available for Pompe disease. Data on the effects of ERT on physiological variables related to exercise tolerance have never been published. Methods: Pulmonary gas exchange, cardiac output (by impedance cardiography), and vastus lateralis muscle O 2 extraction (by near-infrared spectroscopy) were determined during cycle ergometer exercise in a 50-yr-old patient before and after 1, 12, and 24 months of ERT. Results: At the same constant-workload submaximal exercise, RPE, R, pulmonary ventilation, and HR were lower during ERT versus before, suggesting an increased exercise tolerance. Peak oxygen uptake (V̇O 2peak) increased by ∼35% from before (0.64 L•min -1 or 11.4 mL•kg -1•min -1) to 1 month (0.88 L•min -1 or 15.7 mL•kg -1•min -1) of treatment and did not significantly change thereafter. Also, peak cardiac output significantly increased during ERT, whereas peak skeletal muscle fractional O 2 extraction was unchanged compared with before. Conclusions: Improvements of peak exercise capacity and exercise tolerance at submaximal workloads were observed in a patient with Pompe disease after 1 month of ERT, with no further changes during the ensuing treatment period (up to 24 months). © 2012 by the American College of Sports Medicine