Pompe disease is a rare inherited metabolic disorder due to the deficiency of the lysosomal enzyme alfa glucosidase, with consequent abnormal glycogen accumulation in muscle fibres. The late-onset form (LOPD) is characterised by a progressive motor and respiratory impairment. The specific enzyme replacement therapy (ERT), has been proved to stabilise muscle functions, but its effect after many years of treatment seems to be limited, especially for those patients who are already compromised at baseline. Exercise intolerance is one of the first clinical hallmarks affecting LOPD patients' quality of life. Functional evaluation of exercise tolerance is a recently tested method to assess clinical LOPD outcome. Before the introduction of ERT, the positive effects of diet and exercise training had already been demonstrated in LOPD, but the effect of these interventions on patients treated with ERT is still debated and poorly known. This thesis is articulated into 3 studies, the first investigate the long term (more than 5 years) effects of ERT on a cohort of patients with the juvenile form of LOPD. The second investigates the acute effects of ERT on the main variables linked to exercise tolerance, dividing patients by clinical severity and level of habitual physical activity, and comparing results obtained from exercise tolerance test with those from standard six minutes walking test (6MWT). The third study is still ongoing, and investigates if a specific program of exercise training, alone or combined to hyperproteic diet, can ameliorate exercise tolerance in LOPD patients chronically treated with ERT. For patients’ clinical evaluation the following parameters were mainly used: serum muscle enzymes (AST, ALT, CPK, LDH ), muscle strength (by dynamometer), motor function (6MWT, Walton Scale), neurologic functional tests, pulmonary function tests (standard spirometry, Maximal Inspiratory Pressure, Maximal Expiratory Pressure). The functional evaluation of exercise tolerance was conducted on a cycle-ergometer and a specific exercise protocol adapted to patients was developed. The main variable of exercise tolerance assessed were: maximal aerobic power; gas exchange threshold; kinetics of pulmonary gas exchange during constant work-rate exercises; skeletal muscle fractional O2 extraction by near-infrared spectroscopy; heart rate, pulmonary ventilation and gas exchange ratio during constant work-rate exercise; rates of perceived exertion; time to exhaustion. The results of these studies demonstrate: 1. Patients with the juvenile form of Pompe disease show a stabilization of motor and respiratory functions after 5 years of regular treatment with ERT. Patients who started therapy in an asymptomatic phase were still free of symptoms after 6 years of follow up, suggesting that ERT is more efficient if started at early stages of the disease. 2. The exercise tolerance test is not acutely influenced by ERT, its main utility in clinical practice is in the long term follow up of patients, in which it seems to be more sensible than the 6MWT. The habitual physical activity seems to improve the exercise tolerance, regardless the disease severity. 3. Aerobic exercise training may ameliorate skeletal muscle force, maximal aerobic capacity and peripheral oxygen extraction in LOPD patients on chronic ERT treatment

Exercise physiology applied to the evaluation of exercise tolerance in patients with late-onset pompe disease / Annalisa Sechi - Udine. , 2017 Mar 31. 29. ciclo

Exercise physiology applied to the evaluation of exercise tolerance in patients with late-onset pompe disease

SECHI, ANNALISA
2017-03-31

Abstract

Pompe disease is a rare inherited metabolic disorder due to the deficiency of the lysosomal enzyme alfa glucosidase, with consequent abnormal glycogen accumulation in muscle fibres. The late-onset form (LOPD) is characterised by a progressive motor and respiratory impairment. The specific enzyme replacement therapy (ERT), has been proved to stabilise muscle functions, but its effect after many years of treatment seems to be limited, especially for those patients who are already compromised at baseline. Exercise intolerance is one of the first clinical hallmarks affecting LOPD patients' quality of life. Functional evaluation of exercise tolerance is a recently tested method to assess clinical LOPD outcome. Before the introduction of ERT, the positive effects of diet and exercise training had already been demonstrated in LOPD, but the effect of these interventions on patients treated with ERT is still debated and poorly known. This thesis is articulated into 3 studies, the first investigate the long term (more than 5 years) effects of ERT on a cohort of patients with the juvenile form of LOPD. The second investigates the acute effects of ERT on the main variables linked to exercise tolerance, dividing patients by clinical severity and level of habitual physical activity, and comparing results obtained from exercise tolerance test with those from standard six minutes walking test (6MWT). The third study is still ongoing, and investigates if a specific program of exercise training, alone or combined to hyperproteic diet, can ameliorate exercise tolerance in LOPD patients chronically treated with ERT. For patients’ clinical evaluation the following parameters were mainly used: serum muscle enzymes (AST, ALT, CPK, LDH ), muscle strength (by dynamometer), motor function (6MWT, Walton Scale), neurologic functional tests, pulmonary function tests (standard spirometry, Maximal Inspiratory Pressure, Maximal Expiratory Pressure). The functional evaluation of exercise tolerance was conducted on a cycle-ergometer and a specific exercise protocol adapted to patients was developed. The main variable of exercise tolerance assessed were: maximal aerobic power; gas exchange threshold; kinetics of pulmonary gas exchange during constant work-rate exercises; skeletal muscle fractional O2 extraction by near-infrared spectroscopy; heart rate, pulmonary ventilation and gas exchange ratio during constant work-rate exercise; rates of perceived exertion; time to exhaustion. The results of these studies demonstrate: 1. Patients with the juvenile form of Pompe disease show a stabilization of motor and respiratory functions after 5 years of regular treatment with ERT. Patients who started therapy in an asymptomatic phase were still free of symptoms after 6 years of follow up, suggesting that ERT is more efficient if started at early stages of the disease. 2. The exercise tolerance test is not acutely influenced by ERT, its main utility in clinical practice is in the long term follow up of patients, in which it seems to be more sensible than the 6MWT. The habitual physical activity seems to improve the exercise tolerance, regardless the disease severity. 3. Aerobic exercise training may ameliorate skeletal muscle force, maximal aerobic capacity and peripheral oxygen extraction in LOPD patients on chronic ERT treatment
31-mar-2017
Pompe disease; Exercise physiology; Enzyme replacement therapy
Exercise physiology applied to the evaluation of exercise tolerance in patients with late-onset pompe disease / Annalisa Sechi - Udine. , 2017 Mar 31. 29. ciclo
File in questo prodotto:
File Dimensione Formato  
10990_808_Tesi finale_Annalisa Sechi phD.pdf

Open Access dal 01/10/2018

Tipologia: Tesi di dottorato
Licenza: Non specificato
Dimensione 1.55 MB
Formato Adobe PDF
1.55 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11390/1132192
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact