Respiratory muscle training with enzyme replacement therapy improves muscle strength in late - onset Pompe disease

Abstract

BackgroundPompe disease is an autosomal recessive metabolic disorder caused by the deficiency of the lysosomal enzyme acid α-glucosidase. This deficiency leads to glycogen accumulation in the lysosomes of muscle tissue causing progressive muscular weakness particularly of the respiratory system. Enzyme replacement therapy (ERT) has demonstrated efficacy in slowing down disease progression in infants. Despite the large number of studies describing the effects of physical training in juvenile and adult late onset Pompe disease (LOPD). There are very few reports that analyze the benefits of respiratory muscle rehabilitation or training. MethodsThe effectiveness of respiratory muscle training was investigated using a specific appliance with adjustable resistance (Threshold). The primary endpoint was effect on respiratory muscular strength by measurements of MIP and MEP. Eight late-onset Pompe patients (aged 13 to 58years; 4 female, 4 male) with respiratory muscle deficiency on functional respiratory tests were studied. All patients received ERT at the dosage of 20mg/kg/every 2weeks and underwent training with Threshold at specified pressures for 24months. ResultsA significant increase in MIP was observed during the follow-up of 24month: 39.6cm H2O (+25.0%) at month 3; 39.5cm H2O (+24.9%) at month 6; 39.1cm H2O (+23.7%) at month 9; 37.3cm H2O (+18.2%) at month 12; and 37.3cm H2O (+17.8%) at month 24. Median MEP values also showed a significant increase during the first 9months: 29.8cm H2O, (+14.3%) at month 3; 31.0cm H2O (+18.6) at month 6; and 29.5cm H2O (+12.9) at month 9. MEP was then shown to be decreased at months 12 and 24; median MEP was 27.2cm H2O (+4.3%) at 12months and 26.6cm H2O (+1.9%) at 24months. The FVC remain stable throughout the study. ConclusionAn increase in respiratory muscular strength was demonstrated with Threshold training when used in combination with ERT.