title: A multi-parametric protocol to study exercise intolerance in McArdle's disease.
abstract: McArdle's disease is the most common metabolic myopathy of muscle carbohydrate metabolism, due to deficiency of myophosphorylase and alteration of glycogen breakdown in muscle. The clinical manifestations usually begin in young adulthood, with exercise intolerance, exercise-induced muscle cramps, pain and recurrent episodes of myoglobinuria. Many patients experience the second wind phenomenon, characterized by an improved tolerance for aerobic exercise approximately after eight minutes of motor activity, secondary to the increased availability of blood glucose and free fatty acids associated to an enhanced glucose uptake by muscle cells. In this study, we aimed to test a multi-parametric protocol in order to detect the impairment of muscular metabolism and motor performance in patients with McArdle's disease. We enrolled 5 patients and 5 age-matched healthy subjects, that were evaluated by: (01) monitoring of physical activity with an electronic armband; (02) testing of cardiopulmonary, metabolic and respiratory responses to exercise with a cardiopulmonary exercise test and analyzing muscle fatigue during exercise test by surface electromyography (04) evaluating blood lactate and oxidative stress biomarkers at rest and during exercise. The patients were tested at baseline and after three days of carbohydrate-rich diet integrated with tricarboxylic acid cycle intermediate and creatine. The multiparametric protocol proved to be useful to detect the oxidative capacity impairment and the second wind phenomenon of patients. We did not observe any significant differences of muscle metabolic response during the exercise test after three days of carbohydrate-rich diet.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Ricci
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Bertolucci
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Logerfo
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Costanza
authors.initials: C
authors.lastname: Simoncini
authors.affiliation: Department of Internal Medicine, University of Pisa, Pisa, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Papi
authors.affiliation: Department of Internal Medicine, University of Pisa, Pisa, Italy.
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Franzoni
authors.affiliation: II Orthopedic and Traumatologic Clinic, University of Pisa, Pisa, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Dell'Osso
authors.affiliation: Pathological Anatomy, Department of Surgical, Medical and Molecular Pathology and Critical Area, University of Pisa, Pisa, Italy.
authors.forename: Adele
authors.initials: A
authors.lastname: Servadio
authors.affiliation: SOD Dietologia Universitaria, Medicina Generale I, AOU Pisana, Pisa, Italy.
authors.forename: Maria Chiara
authors.initials: MC
authors.lastname: Masoni
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Siciliano
mesh_terms: D000328:Adult; D004734:Energy Metabolism; D005080:Exercise Test; D005260:Female; D006012:Glycogen Storage Disease Type V / Q000378:metabolism* / Q000503:physiopathology*; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation; D018384:Oxidative Stress
chemical_list: D007773:Lactates
keywords: McArdle disease; muscle exercise; myophosphorylase deficiency