RESUMO
BACKGROUND: Glycogen storage disease type 5 (McArdle disease) leads to a deficiency in the activity of myophosphorylase resulting in an impaired glucose utilization. The disease can be caused by a variety of mutations in the PYGM gene, and its typical clinical manifestation is muscles weakness within the first three decades of life. CASE PRESENTATION: In this case report we present the diagnostic work-up of a physically active 78-year-old Caucasian patient suffering from a 2-year history of progressive camptocormia including clinical, radiologic, histological, and genetic tests. There was no history of neuro-muscular diseases in the family. Serum CK levels were moderately increased while other blood/urine parameters were normal. Magnetic resonance imaging showed fatty remodeling of the muscles of the back. Histochemical examination of a muscle biopsy revealed the absence of myophosphorylase activity, while gene analysis identified a known early-onset McArdle mutation in the PYGM gene. CONCLUSION: This case highlights that the clinical spectrum of PYGM gene mutation typically manifest during adolescence, but it is also a differential diagnosis in late onset muscle disorders and emphases the investigation of the role of ACE inhibitors in this disease.
Assuntos
Glicogênio Fosforilase Muscular , Doença de Depósito de Glicogênio Tipo V , Atrofia Muscular Espinal , Mutação , Curvaturas da Coluna Vertebral , Humanos , Doença de Depósito de Glicogênio Tipo V/genética , Doença de Depósito de Glicogênio Tipo V/diagnóstico , Doença de Depósito de Glicogênio Tipo V/complicações , Idoso , Curvaturas da Coluna Vertebral/genética , Masculino , Glicogênio Fosforilase Muscular/genética , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/diagnóstico , Imageamento por Ressonância Magnética , Músculo Esquelético/patologia , Músculo Esquelético/diagnóstico por imagem , Diagnóstico DiferencialRESUMO
Loss of glycogen myophosphorylase (PYGM) expression results in an inability to break down muscle glycogen, leading to McArdle disease-an autosomal recessive metabolic disorder characterized by exercise intolerance and muscle cramps. While previously considered relatively benign, this condition has recently been associated with pattern dystrophy in the retina, accompanied by variable sight impairment, secondary to retinal pigment epithelial (RPE) cell involvement. However, the pathomechanism of this condition remains unclear. In this study, we generated a PYGM-null induced pluripotent stem cell line and differentiated it into mature RPE to examine structural and functional defects, along with metabolite release into apical and basal media. Mutant RPE exhibited normal photoreceptor outer segment phagocytosis but displayed elevated glycogen levels, reduced transepithelial resistance, and increased cytokine secretion across the epithelial layer compared to isogenic WT controls. Additionally, decreased expression of the visual cycle component, RDH11, encoding 11-cis-retinol dehydrogenase, was observed in PYGM-null RPE. While glycolytic flux and oxidative phosphorylation levels in PYGM-null RPE were near normal, the basal oxygen consumption rate was increased. Oxygen consumption rate in response to physiological levels of lactate was significantly greater in WT than PYGM-null RPE. Inefficient lactate utilization by mutant RPE resulted in higher glucose dependence and increased glucose uptake from the apical medium in the presence of lactate, suggesting a reduced capacity to spare glucose for photoreceptor use. Metabolic tracing confirmed slower 13C-lactate utilization by PYGM-null RPE. These findings have key implications for retinal health since they likely underlie the vision impairment in individuals with McArdle disease.
Assuntos
Glucose , Células-Tronco Pluripotentes Induzidas , Epitélio Pigmentado da Retina , Células-Tronco Pluripotentes Induzidas/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Glucose/metabolismo , Humanos , Glicogênio Fosforilase/metabolismo , Glicogênio Fosforilase/genética , Diferenciação Celular , Doença de Depósito de Glicogênio Tipo V/metabolismo , Doença de Depósito de Glicogênio Tipo V/genética , Doença de Depósito de Glicogênio Tipo V/patologia , Glicogênio/metabolismo , Consumo de OxigênioRESUMO
The physiological function of muscle glycogen is to meet the energy demands of muscle contraction. The breakdown of glycogen occurs through two distinct pathways, primarily cytosolic and partially lysosomal. To obtain the necessary energy for their function, skeletal muscles utilise also fatty acids in the ß-oxidation. Ketogenesis is an alternative metabolic pathway for fatty acids, which provides an energy source during fasting and starvation. Diseases arising from impaired glycogenolysis lead to muscle weakness and dysfunction. Here, we focused on the lack of muscle glycogen phosphorylase (PYGM), a rate-limiting enzyme for glycogenolysis in skeletal muscles, which leads to McArdle disease. Metabolic myopathies represent a group of genetic disorders characterised by the limited ability of skeletal muscles to generate energy. Here, we discuss the metabolic aspects of glycogenosis with a focus on McArdle disease, offering insights into its pathophysiology. Glycogen accumulation may influence the muscle metabolic dynamics in different ways. We emphasize that a proper treatment approach for such diseases requires addressing three important and interrelated aspects, which include: symptom relief therapy, elimination of the cause of the disease (lack of a functional enzyme) and effective and early diagnosis.
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Doença de Depósito de Glicogênio Tipo V , Glicogênio , Glicogenólise , Músculo Esquelético , Humanos , Doença de Depósito de Glicogênio Tipo V/metabolismo , Doença de Depósito de Glicogênio Tipo V/genética , Glicogênio/metabolismo , Músculo Esquelético/metabolismo , Glicogênio Fosforilase Muscular/metabolismo , Glicogênio Fosforilase Muscular/genética , Animais , Glicogênio Fosforilase/metabolismoRESUMO
INTRODUCTION AND METHODS: Myophosphorylase deficiency, also known as McArdle disease or Glycogen Storage Disease type V (GSD-V), is an autosomal recessive metabolic myopathy that results in impaired glycogen breakdown in skeletal muscle. Despite being labelled as a "pure myopathy," cardiac involvement has been reported in some cases, including various cardiac abnormalities such as electrocardiographic changes, coronary artery disease, and cardiomyopathy. Here, we present a unique case of a 72-year-old man with GSD-V and both mitral valvulopathy and coronary artery disease, prompting a systematic review to explore the existing literature on cardiac comorbidities in McArdle disease. RESULTS: Our systematic literature revision identified 7 case reports and 1 retrospective cohort study. The case reports described 7 GSD-V patients, averaging 54.3 years in age, mostly male (85.7%). Coronary artery disease was noted in 57.1% of cases, hypertrophic cardiomyopathy in 28.5%, severe aortic stenosis in 14.3%, and genetic dilated cardiomyopathy in one. In the retrospective cohort study, five out of 14 subjects (36%) had coronary artery disease. DISCUSSION AND CONCLUSION: Despite McArdle disease primarily affecting skeletal muscle, cardiac involvement has been observed, especially coronary artery disease, the frequency of which was moreover found to be higher in McArdle patients than in the background population in a previous study from a European registry. Exaggerated cardiovascular responses during exercise and impaired glycolytic metabolism have been speculated as potential contributors. A comprehensive cardiological screening might be recommended for McArdle disease patients to detect and manage cardiac comorbidities. A multidisciplinary approach is crucial to effectively manage both neurological and cardiac aspects of the disease and improve patient outcomes. Further research is required to establish clearer pathophysiological links between McArdle disease and cardiac manifestations in order to clarify the existing findings.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Humanos , Doença de Depósito de Glicogênio Tipo V/complicações , Masculino , Idoso , Comorbidade , Doença da Artéria Coronariana , CardiopatiasRESUMO
In individuals with McArdle disease (IWMD), the ingestion of carbohydrates before exercise has previously been shown in laboratory studies to significantly decrease the exercising symptoms of the condition and increase exercise tolerance during the early stages of exercise. As a result, carbohydrate ingestion pre-exercise is currently included in management guidelines, and often advised by medical professionals treating the condition. The aim of the current study was to determine whether positive lab-based results for the ingestion of carbohydrate before exercise in laboratory studies are being effectively translated into practice and produce perceptions of the same positive outcomes in real-world settings (RWS). An online survey method was used to collect responses from 108 IWMD. Data collected on the amount and type of carbohydrate consumed prior to exercise found that most surveyed participants (69.6%) who supplied qualitative data (n = 45) consumed less than the 37 g currently recommended in management guidelines. Survey data also revealed a large variation in the type and amount of carbohydrate ingested when IWMDs are applying carbohydrate ingestion before exercise in RWS. Consistent with these findings, only 17.5% of participants stated that they found carbohydrate ingestion before exercise relieved or minimised their MD symptoms. Results suggest that positive lab-based findings (increased exercise tolerance) of carbohydrate ingestion before exercise are not being effectively translated to RWS for many IWMD. There is a need for improved patient education of IWMD on the application of carbohydrate ingestion before exercise in RWS.
Assuntos
Carboidratos da Dieta , Exercício Físico , Doença de Depósito de Glicogênio Tipo V , Humanos , Doença de Depósito de Glicogênio Tipo V/terapia , Carboidratos da Dieta/administração & dosagem , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Inquéritos e Questionários , Tolerância ao Exercício , Idoso , Adulto JovemRESUMO
INTRODUCTION: McArdle disease, or glycogen storage disease type V (GSD 5), is a rare metabolic myopathy linked to an autosomal recessive myophosphorylase deficiency. CASE REPORT: We report the case of a 17-year-old male patient who was referred to the emergency department for the management of acute inflammatory low back pain, without traumatic context, associated with an increase of CK at 66,336 UI/L (N<192UI/L) and a CRP at 202mg/L. The immunological assessment was negative and the spinal MRI showed images in favor of necrotizing fasciitis affecting the erector spinae muscles, among others. Faced with the description of difficulties in practicing physical activities since childhood and a non-ischaemic forearm exercise test showing no elevation in lactacidemia, genetic tests were carried out, finding two heterozygous variants in the PYGM gene: c.1963G>A (p.Glu655Lys) class 5 and c.2178-1G>A class 4, confirming the diagnosis of McArdle disease. DISCUSSION: GSD 5 is a disease characterized essentially by muscular fatigability during exercise. The case reported here is original in the clinical circumstances leading to the diagnosis, i.e., inaugural acute low back pain with rhabdomyolysis. This symptomatology had already been described before, but in a patient whose diagnosis was already known. Spinal MRI showed non-specific muscle inflammation and necrosis. Muscle biopsy only found necrosis but no pathological elements typical of the diagnosis. If the symptoms are suggestive, it may be preferable to directly perform a non-ischaemic forearm exercise test, in order to go directly to molecular genetic analysis. There is no specific curative treatment of GSD 5. However, some measures can be implemented to limit the symptoms, such as learning physical exercises, limiting intense efforts and adopting dietary recommendations.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Dor Lombar , Humanos , Doença de Depósito de Glicogênio Tipo V/diagnóstico , Doença de Depósito de Glicogênio Tipo V/complicações , Doença de Depósito de Glicogênio Tipo V/genética , Masculino , Dor Lombar/etiologia , Dor Lombar/diagnóstico , Adolescente , Doença AgudaAssuntos
Doença de Depósito de Glicogênio Tipo V , Doenças Retinianas , Humanos , Doenças Retinianas/diagnóstico , Doença de Depósito de Glicogênio Tipo V/diagnóstico , Doença de Depósito de Glicogênio Tipo V/complicações , Angiofluoresceinografia/métodos , Masculino , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Síndrome , FemininoRESUMO
BACKGROUND & AIMS: Ketone supplementation is gaining popularity. Yet, its effects on exercise performance when muscle glycogen cannot be used remain to be determined. McArdle disease can provide insight into this question, as these patients are unable to obtain energy from muscle glycogen, presenting a severely impaired physical capacity. We therefore aimed to assess the effects of acute ketone supplementation in the absence of muscle glycogen utilization (McArdle disease). METHODS: In a randomized cross-over design, patients with an inherited block in muscle glycogen breakdown (i.e., McArdle disease, n = 8) and healthy controls (n = 7) underwent a submaximal (constant-load) test that was followed by a maximal ramp test, after the ingestion of a placebo or an exogenous ketone ester supplement (30 g of D-beta hydroxybutyrate/D 1,3 butanediol monoester). Patients were also assessed after carbohydrate (75 g) ingestion, which is currently considered best clinical practice in McArdle disease. RESULTS: Ketone supplementation induced ketosis in all participants (blood [ketones] = 3.7 ± 0.9 mM) and modified some gas-exchange responses (notably increasing respiratory exchange ratio, especially in patients). Patients showed an impaired exercise capacity (-65 % peak power output (PPO) compared to controls, p < 0.001) and ketone supplementation resulted in a further impairment (-11.6 % vs. placebo, p = 0.001), with no effects in controls (p = 0.268). In patients, carbohydrate supplementation resulted in a higher PPO compared to ketones (+21.5 %, p = 0.001) and a similar response was observed vs. placebo (+12.6 %, p = 0.057). CONCLUSIONS: In individuals who cannot utilize muscle glycogen but have a preserved ability to oxidize blood-borne glucose and fat (McArdle disease), acute ketone supplementation impairs exercise capacity, whereas carbohydrate ingestion exerts the opposite, beneficial effect.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Glicogênio , Humanos , Glicemia , Suplementos Nutricionais , Cetonas , Músculos , Estudos Cross-OverRESUMO
McArdle disease is an autosomal recessive inherited disease caused by pathogenic variants in the PYGM gene, resulting in virtual absence of the myophosphorylase enzyme in skeletal muscle. Patients experience physical activity intolerance, muscle pain, and muscle fatigue. This study aimed to investigate other fatigue domains with the Multidimensional Fatigue Inventory (MFI-20) along with an investigation of potential contributing factors, including relevant disease and lifestyle-related factors. We conducted a survey in an international cohort of patients with McArdle disease. The survey included questions on demographics and McArdle disease-related symptoms, and the questionnaires: MFI-20, Insomnia Severity Index (ISI), and International Physical Activity Questionnaire Short-Form (IPAQ-SF). One hundred seventy-four responses were included in the data analyses. We found relatively high fatigue scores in all five domains (general fatigue (12.9 ± 2.2), mental fatigue (10.1 ± 4.1), physical fatigue (13.7 ± 4.1), reduced activity (12.1 ± 4.1), and reduced motivation (10.4 ± 3.4)). Fatigue associated with McArdle symptom severity (p < 0.005), lower levels of physical activity (assessed by IPAQ-SF) (p < 0.05), and poor sleep (assessed by ISI) (p < 0.05). These findings call for clinical focus and future research into fatigue, sleep and mental health in patients with McArdle disease.
Assuntos
Glicogênio Fosforilase Muscular , Doença de Depósito de Glicogênio Tipo V , Humanos , Doença de Depósito de Glicogênio Tipo V/complicações , Doença de Depósito de Glicogênio Tipo V/genética , Doença de Depósito de Glicogênio Tipo V/diagnóstico , Glicogênio Fosforilase Muscular/genética , Músculo Esquelético/patologia , Inquéritos e Questionários , InternetRESUMO
BACKGROUND: Glycogen storage disease type 5 (GSD) is an autosomal recessive inherited metabolic myopathy caused by a deficiency of the enzyme muscle glycogen phosphorylase. Individuals with GSD5 experience physical activity intolerance. OBJECTIVE: This patient-led study aimed to capture the daily life experiences of GSD5, with a focus on adapting to and coping with their physical activity intolerance. METHODS: An online survey was composed in close collaboration with patient organizations. It consisted of customized and validated questionnaires on demographics, general health and comorbidities, physical activity, psychosocial well-being and functioning, pain, fatigue and adapting to and coping with GSD5. RESULTS: One hundred sixty-two participants (16 countries) participated. The majority, nâ=â86 (69%) were from the Netherlands, USA or UK. We observed a high rate of misdiagnosis prior to GSD5 diagnosis (49%), surprisingly a relatively high proportion had not been diagnosed by DNA testing which is the gold standard. Being diagnosed had a strong impact on emotional status, daily life activities and important life choices. A large proportion had not received any rehabilitation (41%) nor medical treatment (57%) before diagnosis. Engagement in vigorous and moderate physical activity was reduced. Health related quality of life was low, most likely related to low physical health. The median Fatigue Severity Score was 4.3, indicating moderate to severe fatigue. Participants themselves had found various ways to adapt to and cope with their disability. The adaptations concerned all aspect of their life, including household chores, social and physical activities, and work. In addition to lack of support, participants reported limited availability of information sources. CONCLUSION: Participants have provided guidance for newly diagnosed people, including the advice to accept one's limited abilities and maintain an active lifestyle. We conclude that adequate counseling on ways of adapting and coping is expected to increase both health-related quality of life and physical activity.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Humanos , Qualidade de Vida/psicologia , Dor , Exercício Físico , Fadiga/etiologiaRESUMO
McArdle's disease (Glycogen storage disease type V) is a rare inherited autosomal recessive disease involving defect in enzyme, glycogen phosphorylase (PYGM) which results in accumulation of glycogen mainly affecting skeletal muscles. It commonly presents in childhood and rarely in adults with symptoms like exercise intolerance, muscle weakness, cramps and fatigue. Herein, we report an unusual case of a 22 years old male in Pakistan with probable McArdle's Disease presenting with repeated episodes of generalized cramping muscle pain, exercise intolerance and haematuria. The diagnostic approach to identifying this disease as well as the differentials of other rare types of skeletal muscle disorders that should be kept in mind while dealing with a similar clinical picture, irrespective of the age of presentation, have been discussed.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Humanos , Masculino , Adulto Jovem , Adulto , Doença de Depósito de Glicogênio Tipo V/complicações , Doença de Depósito de Glicogênio Tipo V/diagnóstico , Músculo Esquelético , Debilidade Muscular/etiologia , Fadiga , Cãibra Muscular/etiologiaRESUMO
Compartment syndrome (CS) is a medical emergency that occurs secondary to excessively high pressures within a confined fibro-osseous space, resulting in reduced perfusion and subsequent tissue injury. CS can be divided into acute forms, most commonly due to trauma and considered an orthopaedic emergency, and chronic forms, most commonly presenting in athletes with recurrent exercise-induced pain. Downstream pathophysiological mechanisms are complex but do share commonalities with mechanisms implicated in genetic neuromuscular disorders. Here we present 3 patients with recurrent CS in the context of a RYR1-related disorder (n = 1) and PYGM-related McArdle disease (n = 2), two of whom presented many years before the diagnosis of an underlying neuromuscular disorder was suspected. We also summarize the literature on previously published cases with CS in the context of a genetically confirmed neuromuscular disorder and outline how the calcium signalling alterations in RYR1-related disorders and the metabolic abnormalities in McArdle disease may feed into CS-causative mechanisms. These findings expand the phenotypical spectrum of RYR1-related disorders and McArdle disease; whilst most forms of recurrent CS will be sporadic, above and other genetic backgrounds ought to be considered in particular in patients where other suggestive clinical features are present.
Assuntos
Síndromes Compartimentais , Fibromialgia , Doença de Depósito de Glicogênio Tipo V , Doenças Neuromusculares , Humanos , Doença de Depósito de Glicogênio Tipo V/diagnóstico , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Síndromes Compartimentais/etiologia , Síndromes Compartimentais/genética , Doenças Neuromusculares/diagnóstico , Doenças Neuromusculares/genética , Doenças Neuromusculares/complicações , Fibromialgia/complicaçõesRESUMO
McArdle disease is a glycogen storage disease that results in rhabdomyolysis during intense exercise. A number of different triggers have been described. We evaluated a patient with McArdle disease who presented with rhabdomyolysis after recreational scuba diving. There was no concern for barotrauma or decompression sickness. His symptoms resolved with standard-of-care management for non-diving-related rhabdomyolysis. Features of his experience provoked questions about the diving-related factors contributing to his presentation. We present the case and explore possible mechanisms of diving-related injury in patients with McArdle disease, including the possible effects of hyperoxia, hyperbaria, hypothermia and strenuous activity.
Assuntos
Barotrauma , Doença da Descompressão , Mergulho , Doença de Depósito de Glicogênio Tipo V , Rabdomiólise , Humanos , Mergulho/efeitos adversos , Mergulho/lesões , Doença da Descompressão/complicações , Doença de Depósito de Glicogênio Tipo V/complicações , Doença de Depósito de Glicogênio Tipo V/diagnóstico , Barotrauma/complicações , Rabdomiólise/etiologia , Rabdomiólise/complicaçõesRESUMO
BACKGROUND: McArdle disease is caused by myophosphorylase deficiency leading to blocked glycogenolysis in skeletal muscle. Consequently, individuals with McArdle disease have intolerance to physical activity, muscle fatigue, and pain. These symptoms vary according to the availability of alternative fuels for muscle contraction. In theory, a modified ketogenic diet (mKD) can provide alternative fuels in the form of ketone bodies and potentially boost fat oxidation. METHODS: This randomized, single-blind, placebo-controlled, cross-over study aimed to investigate if a mKD improves exercise capacity in individuals with McArdle disease. Participants were randomized to follow a mKD (75-80% fat, 15% protein, 5-10% carbohydrates) or placebo diet (PD) first for three weeks, followed by a wash-out period, and then the opposite diet. The primary outcome was change in heart rate during constant-load cycling. Secondary outcomes included change in plasma metabolites, perceived exertion, indirect calorimetry measures, maximal exercise capacity, and patient-reported outcomes. RESULTS: Fifteen out of 20 patients with genetically verified McArdle disease completed all study visits, and 14 were included in the data analyses. We found that the mKD induced a metabolic shift towards increased fat oxidation (â¼60% increase), and a 19-fold increase in plasma ß-hydroxybutyrate (p < 0.05). The mKD did not improve heart rate responses during constant-load cycling but did improve patient-reported outcomes and maximal exercise capacity (â¼20% increase) compared to the PD. CONCLUSION: The mKD did not alleviate all McArdle disease-related symptoms but did induce some positive changes. To date, no satisfactory treatment options exist other than exercise training. To that end, a mKD can be a possible nutritional strategy for some individuals with McArdle disease who are motivated to undertake a restrictive diet. CLINICAL TRIAL REGISTRATION: clinical trials.gov: NCT04044508.
Assuntos
Dieta Cetogênica , Doença de Depósito de Glicogênio Tipo V , Humanos , Doença de Depósito de Glicogênio Tipo V/metabolismo , Estudos Cross-Over , Método Simples-Cego , Músculo Esquelético , Corpos Cetônicos/metabolismoRESUMO
McArdle disease is an inherited myopathy that autosomal recessive inheritance and is also known as glycogen storage disease type 5. Myoglobinuria, increase in serum CK level and darkening of urine color secondary to myoglobinuria are typical. Patients may have symptoms associated with increased rhabdomyolysis secondary acute renal failure or hyperkalemia after long and strenuous exercise periods. Today, many studies in the literature have shown that transplantation is superior to dialysis in patients with end-stage renal disease. Our case is a 53-year-old male patient with the diagnosis of McArdle syndrome who was going to have a kidney transplant. The patient had essential hypertension and history of HBsAg+. Total intravenous anesthesia technique was chosen as the anesthesia technique because inhaled anesthetic agents may trigger malignant hyperthermia in the patient. We didn't experience any perioperative complications in our patient. In conclusion, renal transplantation performed with total intravenous in a McArdle syndrome patient may be a simple and effective technique.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Transplante de Rim , Mioglobinúria , Masculino , Humanos , Pessoa de Meia-Idade , Doença de Depósito de Glicogênio Tipo V/complicações , Rim , Anestesia GeralRESUMO
BACKGROUND: The European registry for individuals with GSD5 and other muscle glycogenosis (EUROMAC) was launched to register rare muscle glycogenosis in Europe, to facilitate recruitment for research trials and to learn about the phenotypes and disseminate knowledge about the diseases. A network of twenty collaborating partners from eight European countries and the US contributed data on rare muscle glycogenosis in the EUROMAC registry. METHODS: Following the initial report on demographics, neuromuscular features and comorbidity (2020), we here present the data on social participation, previous and current treatments (medication, supplements, diet and rehabilitation) and limitations. Furthermore, the following questionnaires were used: Fatigue severity scale (FSS), WHO Disability Assessment Scale (DAS 2.0), health related quality of life (SF36) and International Physical Activity Questionnaire (IPAQ). RESULTS: Of 282 participants with confirmed diagnoses of muscle glycogenosis, 269 had GSD5. Of them 196 (73%) completed all questionnaires; for the others, the data were incomplete. The majority, 180 (67%) were currently working. Previous medical treatments included pain medication (23%) and rehabilitation treatment (60%). The carbohydrate-rich diet was reported to be beneficial for 68%, the low sucrose diet for 76% and the ketogenic diet for 88%. Almost all participants (93%) reported difficulties climbing stairs. The median FSS score was 5.22, indicating severe fatigue. The data from the WHODAS and IPAQ was not of sufficient quality to be interpreted. CONCLUSIONS: The EUROMAC registry have provided insight into the functional and social status of participants with GSD5: most participants are socially active despite limitations in physical and daily life activities. Regular physical activity and different dietary approaches may alleviate fatigue and pain.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Doença de Depósito de Glicogênio , Humanos , Qualidade de Vida , Participação Social , Estado Funcional , FadigaRESUMO
It is well-established that oral sucrose ingested shortly before exercise improves early exercise tolerance in individuals with McArdle disease. This is by supplying blood-borne glucose for muscle metabolism to compensate for the blocked glycogenolysis. The present study investigated if individuals with McArdle disease could benefit further from repeated sucrose ingestion during prolonged exercise. In this double-blind, placebo-controlled, cross-over study, the participants were randomized to ingest either sucrose or placebo first and subsequently the opposite on two separate days. The participants ingested the drink 10 min before and thrice (after 10, 25, and 40 min) during a 60-min submaximal exercise test on a cycle ergometer. The primary outcome was exercise capacity as indicated by heart rate (HR) and perceived exertion (PE) responses to exercise. Secondary outcomes included changes in blood metabolites, insulin and carbohydrate, and fatty acid oxidation rates during exercise. Nine participants with McArdle disease were included in the study. We confirmed improvement of exercise capacity with oral sucrose vs. placebo during early exercise (pre-second wind) indicated by lower peak HR and PE (p < 0.02). We found no further beneficial effect with repeated sucrose versus placebo ingestion during prolonged exercise, as indicated by no difference in HR or PE post-second wind (p > 0.05). Glucose, lactate, insulin, and carbohydrate oxidation rates increased, and fatty acid oxidation decreased with sucrose versus placebo (p ≤ 0.0002). We can conclude that repeated sucrose ingestion is not recommended during prolonged exercise. This finding can prevent excessive caloric intake and reduce the risk of obesity and insulin resistance.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Insulinas , Humanos , Doença de Depósito de Glicogênio Tipo V/metabolismo , Estudos Cross-Over , Sacarose/uso terapêutico , Glucose , Glicemia/metabolismo , Ácido Láctico , Ácidos Graxos , Insulinas/uso terapêutico , Método Duplo-CegoRESUMO
A 40-year-old Syrian man presented to the emergency department with a 5-day history of anuria. He had previously excreted dark urine. Major rhabdomyolysis and crush kidney were found, meaning that hemodialysis was immediately initiated. A detailed patient history in the patient's mother tongue revealed indications of metabolic myopathy. The PYGM-associated glycogen storage disease type V (McArdle disease) was confirmed by next generation sequencing panel diagnostics. The most important treatment approach is to avoid rhabdomyolysis through only moderate physical exertion.
Assuntos
Doença de Depósito de Glicogênio Tipo V , Erros Inatos do Metabolismo , Doenças Musculares , Rabdomiólise , Masculino , Humanos , Adulto , Rabdomiólise/diagnóstico , Doença de Depósito de Glicogênio Tipo V/complicações , Doenças Musculares/complicações , Esforço Físico , Erros Inatos do Metabolismo/complicaçõesRESUMO
Metabolic myopathies are rare inherited disorders that deserve more attention from neurologists and pediatricians. Pompe disease and McArdle disease represent some of the most common diseases in clinical practice; however, other less common diseases are now better-known. In general the pathophysiology of metabolic myopathies needs to be better understood. Thanks to the advent of next-generation sequencing (NGS), genetic testing has replaced more invasive investigations and sophisticated enzymatic assays to reach a final diagnosis in many cases. The current diagnostic algorithms for metabolic myopathies have integrated this paradigm shift and restrict invasive investigations for complicated cases. Moreover, NGS contributes to the discovery of novel genes and proteins, providing new insights into muscle metabolism and pathophysiology. More importantly, a growing number of these conditions are amenable to therapeutic approaches such as diets of different kinds, exercise training protocols, and enzyme replacement therapy or gene therapy. Prevention and management-notably of rhabdomyolysis-are key to avoiding serious and potentially life-threatening complications and improving patients' quality of life. Although not devoid of limitations, the newborn screening programs that are currently mushrooming across the globe show that early intervention in metabolic myopathies is a key factor for better therapeutic efficacy and long-term prognosis. As a whole NGS has largely increased the diagnostic yield of metabolic myopathies, but more invasive but classical investigations are still critical when the genetic diagnosis is unclear or when it comes to optimizing the follow-up and care of these muscular disorders.