An interventional study of 12-week Physiotherapy Intervention and 13C-Glucose Breath Test in Metabolic Myopathies, sponsored by University of British Columbia. Completed at 1 site in Canada. Open to participants aged 10 Years to 18 Years. Per ClinicalTrials.gov, last updated 2025-12-05.
Sponsored by University of British Columbia · Not applicable, Interventional, and Basic science
Patients with metabolic myopathies suffer from exercise intolerance due to impaired ability to produce energy and secondary de-conditioning. There is a lack of methods enabling a non-invasive assessment of muscle energy production and studies regarding the benefits of therapeutic interventions are lacking as well. In this pilot study, the main aim is to assess the benefit of an intervention: a regular at home physiotherapy program for metabolic myopathies by measuring different outcomes pre and post therapeutic intervention using minimally invasive tests. The secondary aim of this study: investigators plan to describe the results of established non-invasive stable isotope tracer tests, namely, "glucose breath test" and "doubly labelled water \& urine test" in patients pre and post 12 weeks at-home physiotherapy exercise program. The results of this study will be used for a larger scale study to assess energy metabolism in patients in patients with metabolic myopathies using non-invasive tests like breath and urine tests.
Metabolic myopathies are a group of genetic conditions which affect the production of energy in the muscle and are caused by muscle adenosine triphosphate (ATP) depletion. This group includes disorders of mitochondrial oxidative phosphorylation (mitochondrial myopathies, MM), fatty acid oxidation (FAOD), Pompe disease and generation of glycolytic substrates (muscle glycogenosis, GSDs) from muscle glycogen. At large, these disorders are amenable to treatment including exercise and dietary treatment and/or vitamins cofactors supplementation.
There is a lack of non-invasive biomarkers which could be used to monitor treatment effectiveness. Traditionally, maximal oxygen consumption (VO2 max), quality of life questionnaire, dual-energy x-ray absorptiometry (DXA/DEXA), muscle biopsies, blood lactate and creatine kinase are used as a surrogate biomarker but have a limited validity to assess response to therapeutic interventions in patients with myopathies. The ultimate goal is to established a platform for clinical trials using minimally invasive tests to evaluate energy metabolism in patients with metabolic myopathies in response to therapeutic interventions, such as physiotherapy exercise program. These minimally invasive tests could be used to develop a platform for clinical trials for patients with muscle disease.
The main aim (objective) of this study is to assess the benefit of an intervention: a 12 weeks at-home physiotherapy exercises program for metabolic myopathies by measuring different outcomes pre and post therapeutic intervention using minimally-invasive tests. The investigators will administer a 12-week at-home physiotherapy exercises program to 3 metabolic myopathies pediatric patients between age 10 and 18 years.
The following outcomes will be measured pre and post intervention:
The secondary aim (objective) of this study is to show that a glucose breath test measuring glucose oxidation (in mg/kg/min) and a doubly labelled water \& urine test measuring total energy expenditure (in kcal) are outcomes that can be used in clinical trials to evaluate therapeutic interventions, along VO2 max, DXA and quality of life questionnaires. In that regard, this is a proof-of-concept study with the aim to describe the two biomarkers results in response to a therapeutic intervention in comparison to VO2-max and DXA scan and quality of life and clinical questionnaire in 3 participants.
The study design is n of 1 and will compare results of the tests pre and post therapeutic interventions in the same patients.
The glucose breath test: for the glucose oxidation (in mg/kg/min) measured by 13C glucose oxidation, results will be plotted as repeated measurements (3 times pre and post-intervention) for each individual participant. Repeat measurements will reduce the intra-individual variability. A 12 weeks at-home physiotherapy exercise protocol has been developed by the investigator team physician and kinesiologists experienced with exercise, children and metabolic myopathies. The therapeutic intervention, a 12 weeks at-home physiotherapy exercises program performed at least 5 times per week, under virtual supervision 3 times per week by a kinesiologist, contains the same type of exercises that are normally prescribed to this population on a clinical basis. All patients will perform the same program to reduce inter-variability.
In parallel, clinical methods such as VO2max, PedsQL and DXA will be measured pre- (baseline) and post-intervention evaluation. The investigators consulted a BCCHRI statistician with regard to the data analysis. Statistical analysis will include the intra-individual data analysis (n=1 study design) and will compare - using a Paired T test -the pre- and post- intervention data obtained from the two stable isotope tracer methods, VO2 max, DXA and quality of life questionnaires. The results of these tests will also be descriptively analyzed and the pre and post-intervention results will be plotted graphically.
The results of this proof of concept study will inform a larger scale project that was initially planned.
University of British Columbia is the lead sponsor of 1,309 studies on the registry; 253 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 1 (17%) have results posted.
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Exclusion Criteria:
Experiment piece 1: 3 study days (pre-physio intervention) - single oral dose of unlabeled glucose and U-13C-glucose isotope. 3 study days (post-physio intervention) - single oral dose of unlabeled glucose and U-13C-glucose isotope. Both in mg/kg/min.
Dietary Supplement: 13C-Glucose Breath Test
Experiment piece 2: 1 study day (pre-physio intervention) - single oral dose of doubly labelled water (2H218O) isotope. 1 study days (post-physio intervention) - single oral dose of doubly labelled water (2H218O) isotope. Assess free-living total energy expenditure (in kcal).
Dietary Supplement: Doubly labelled water & urine test
Performed once by all participants, in between the pre- and post-intervention experiments described in the other arms.
Other: 12-week Physiotherapy Intervention
Experiment piece 3: 1 study day (pre-intervention) and 1 study day (post-intervention). Exercise test: Maximum oxygen consumption (VO2 max) (in ml/kg/min).
Diagnostic Test: Clinical Assessments - Exercise Test
Experiment piece 3: 1 study day (pre-intervention) and 1 study day (post-intervention). Muscle content test: Muscle mass measured by Dual-Energy X-ray Absorptiometry (DXA/DEXA) (in grams).
Diagnostic Test: Clinical Assessment - Muscle Content
Experiment piece 3: 1 study day (pre-intervention) and 1 study day (post-intervention). Quality of life questionnaire test: Quality of life measure by pediatric quality of life questionnaire (PedsQL).
Diagnostic Test: Clinical Assessment - Quality of Life
A 12 week at-home physiotherapy exercises program performed at least 5 times per week, under virtual supervision 3 times per week by a kinesiologist, contains the same type of exercises that are normally prescribed to this population on a clinical basis. All patients will perform the same program to reduce inter-variability.
Experiment piece 1: Oral glucose isotope is administered to fasted participants on pre and post-intervention study days. Breath is collected over a 4-hour period following ingestion. Other Names: • D-glucose (Thermo Scientific™ NERL™ Trutol™)
Experiment piece 2: 1 study day pre and post-intervention fasted participants ingest a single oral dose of doubly labelled water (2H218O) isotope. 4 urine samples are collected over a 4 hour period following isotope administration, and once a day over 14 days. DLW is a safe and minimally invasive technique, considered the gold standard for precise measurement energy expenditure in humans. It involves enriching the body water with heavy hydrogen and oxygen (2H218O). The method is based on the principle that the 2H2 derived from body water is eliminated only as water (2H2O), while 18O is eliminated as both water (H2 18O) and carbon dioxide (C18O2).
Experiment piece 3: Using a well-established clinical method VO2 max, once pre and post-intervention to assess for body composition (oxygen consumption during exercise).
Experiment piece 3: Using a well-established clinical method, DXA, once pre and post-intervention to assess for body muscle content (lean muscle mass)
Experiment piece 3: Using a well-established clinical survey, PedsQL, once pre and post-intervention to assess for participants perception of quality of life.
Glucose Oxidation
Breath samples will be collected during the 3 pre and post-intervention study days to measure the rate of oxidation of 13C glucose (mg/kg/min).
Time frame: 4 Hours
Doubly Labeled Water Free-living Total Energy Expenditure
Energy expenditure can be calculated by measuring the difference in elimination rates of the heavy hydrogen and heavy oxygen in urine. The elimination rate is assessed from urine collected at the beginning and end of the observation period (\~ 2 weeks). The 18O and 2H concentrations in urine are measured using isotope ratio mass spectrometry (IRMS). Assessed once pre- and post-intervention for free-living total energy expenditure (in kcal).
Time frame: 14 Days
Clinical Assessments - Exercise Test
Exercise test: Maximal Oxygen Consumption (VO2 max) (ml/kg/min) during monitored exercise. Assessed once pre- and post-intervention.
Time frame: 1-2 Hours
Clinical Assessments - Muscle Content
Muscle content test: Lean muscle mass measured by Dual-Energy X-ray Absorptiometry (DXA/DEXA) (grams). Assessed once pre- and post-intervention.
Time frame: 1 Hour
Clinical Assessments - Quality of Life
Quality of life questionnaire test: Quality of life measure by the pediatric quality of life questionnaire (PedsQL) to assess for participants perceived mental, physical and emotional health. Assessed once pre- and post-intervention.
Time frame: 30 minutes
Plan to share: Undecided
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University of British Columbia