Ângulo de fase como preditor de massa muscular em pacientes com doença inflamatória intestinal / Phase angle as a predictor of muscle mass in patients with inflammatory bowel disease

ABSTRACT Malnutrition/sarcopenia is frequent in patients with inflammatory bowel diseases (IBD), and results in muscle catabolism, impacting treatment response, postoperative complications, and quality of life. Objective: This study aims to assess whether the phase angle (PhA) is a parameter for predicting reduced muscle mass in patients with IBD. Methods: Adult patients with IBD were included in this cross-sectional study. For the estimation of muscle mass and the calculation of the PhA, we used bioelectrical impedance analysis (BIA). Crohn's disease (CD) and ulcerative colitis (UC) activity scores were defined using the Harvey-Bradshaw index and partial Mayo score, respectively. The area under the ROC curve was calculated to identify the PhA cut-off point for reduced muscle mass. Results: The sample consisted of 145 patients, with 39 (26.9%) with IBD in the active phase. There was a correlation of the PhA with skeletal muscle mass (SMM) (rs 0.35, P<0.001) and with the skeletal muscle mass index (SMI) (rs 0.427, P<0.001), and the associations remained in the most active form (moderate or severe) of IBD. The ROC curve analysis indicated that the cut-offs points of the PhA ≤5.042 for female and PhA ≤6.079 for male can be used to predict muscle mass reduction. Conclusion: The PhA can be considered a predictor of muscle mass reduction in IBD patients, and we can use it for screening and monitoring the evolution of malnutrition.

RESUMO A desnutrição/sarcopenia é frequente em pacientes com doenças inflamatórias intestinais (DII), resultando em catabolismo muscular, com impacto nas respostas aos tratamentos, complicações cirúrgicas e na qualidade de vida. Objetivo: Este estudo tem como objetivo, avaliar se o ângulo de fase (AF) é um parâmetro para a predição de redução de massa muscular em pacientes com DII. Métodos: Pacientes adultos com DII foram incluídos neste estudo transversal. A estimativa da massa muscular e o cálculo do AF foram realizados a partir do exame de bioimpedância elétrica (BIA). As atividades da doença de Crohn e retocolite ulcerativa foram definidas pelo índice Harvey-Bradshaw e escore parcial de Mayo, respectivamente. A área de curva ROC foi calculada para identificar o ponto de corte do AF para a massa muscular reduzida. Resultados: A amostra foi composta por 145 pacientes, sendo 39 (26.9%) com DII em fase ativa. Houve correlação do AF com massa muscular esquelética (MME) (rs 0.35, P<0.001) e com o índice de massa muscular esquelética (IMME) (rs 0.427, P<0.001), mantendo-se as associações na forma mais ativa (moderada ou grave) da DII. A análise da curva ROC indicou que os pontos de corte de AF ≤5.042 para mulheres e ≤6.079 para homens podem ser usados para prever a redução da massa muscular. Conclusão: O AF pode ser considerado um preditor de redução de massa muscular nos pacientes com DII e ser utilizado para triagem e acompanhamento da evolução da desnutrição.

Relationship between skeletal muscle mass loss and metabolic dysfunction-associated fatty liver disease among Chinese patients with metabolic dysregulation

SUMMARY OBJECTIVE: The aim of this study was to explore the correlation between skeletal muscle content and the presence and severity of metabolic dysfunction-associated fatty liver disease in patients with metabolic dysregulation in China. METHODS: A cross-sectional study was conducted among patients from the endocrinology outpatient department at Ningbo First Hospital, in Ningbo, China, in April 2021. Adult patients with metabolic dysregulation who accepted FibroScan ultrasound were included in the study. However, those without clinical data on skeletal muscle mass were excluded. FibroScan ultrasound was used to noninvasively evaluate metabolic dysfunction-associated fatty liver disease. The controlled attenuation parameter was used as an evaluation index for the severity of liver steatosis. Bioelectrical impedance analysis was used to measure the skeletal muscle index. RESULTS: A total of 153 eligible patients with complete data were included in the final analysis. As the grading of liver steatosis intensifies, skeletal muscle index decreases (men: Ptrend<0.001, women: Ptrend=0.001), while body mass index, blood pressure, blood lipid, uric acid, aminotransferase, and homeostatic model assessment of insulin resistance increase (Ptrend<0.01). After adjusting for confounding factors, a negative association between skeletal muscle index and the presence of metabolic dysfunction-associated fatty liver disease was observed in men (OR=0.691, p=0.027) and women (OR=0.614, p=0.022). According to the receiver operating characteristic curve, the best cutoff values of skeletal muscle index for predicting the metabolic dysfunction-associated fatty liver disease presence were 40.37% for men (sensitivity, 87.5%; specificity, 61.5%) and 33.95% for women (sensitivity, 78.6%; specificity, 63.8%). CONCLUSION: Skeletal muscle mass loss among patients with metabolic dysregulation was positively associated with metabolic dysfunction-associated fatty liver disease severity in both sexes. The skeletal muscle index cutoff value could be used to predict metabolic dysfunction-associated fatty liver disease.

COVID-19 related to sarcopenia: Current perspectives on etiology, clinical implications, and nutritional rehabilitation

Sarcopenia is a progressive skeletal muscle disorder characterized by reduced strength and quality. Pathophysiological mechanisms, clinical aspects, and nutritional points were related to sarcopenia in COVID-19 found in skeletal muscle during and after the disease course, which corroborated the development of adverse events. Declining physical activity, insufficient protein intake, and worsened proinflammatory response have been shown to have negative consequences on muscle protein synthesis, potentiating the risk of acute sarcopenia. Obesity sarcopenia has also been shown to worsen the prognosis of patients with SARS-CoV-2. Nutritional rehabilitation is used to prevent or minimize the development of acute sarcopenia. Dietary recommendations include increased energy supply and protein intake of 1.2 to 2.0 g/kg of body weight. Evidence suggests that aging with sedentary behaviors, pathophysiological changes, and inflammation alter body composition. In addition, nutritional deficiencies are predictors and aggravators of acute sarcopenia in COVID-19.

Sarcopenia é um distúrbio progressivo do músculo esquelético caracterizado pela redução da força e qualidade. Mecanismos fisiopatológicos, aspectos clínicos e nutricionais foram relacionados à sarcopenia no COVID-19 encontrada no músculo esquelético, durante e após o curso da doença, o que corroborou para o desenvolvimento de eventos adversos. O declínio da atividade física, a ingestão insuficiente de proteínas e piora da resposta pró-inflamatória demonstraram ter consequências negativas na síntese de proteínas musculares, potencializando risco de sarcopenia. A obesidade sarcopênica também demonstrou piorar o prognóstico de pacientes infectados com SARS-CoV-2. A reabilitação nutricional pode prevenir ou minimizar o desenvolvimento de sarcopenia. As recomendações dietéticas incluem maior oferta de energia e maior ingestão de proteínas de 1,2 a 2,0 g/kg de peso corporal. Evidências sugerem que o envelhecimento com comportamentos sedentários, alterações fisiopatológicas e inflamação, alterações na composição corporal, deficiências nutricionais são preditores e agravantes da sarcopenia aguda na COVID-19.

Sarcopenia em pacientes de 40 a 64 anos hospitalizados por insuficiência cardíaca / Sarcopenia in patients aged 40­64 years hospitalized for heart failure

Introdução: a insuficiência cardíaca (IC) e a sarcopenia são condições prevalentes e inter-relacionadas, figurando como importantes causas de limitações funcionais. Objetivo: avaliar critérios de sarcopenia, e suas relações com parâmetros cardiometabólicos, em pacientes de 40 a 64 anos hospitalizados por IC. Metodologia: estudo de corte transversal com caráter analítico envolvendo indivíduos com IC confirmada. A massa muscular apendicular (MMA) foi avaliada através da absorciometria por raios-X de dupla energia (DXA), considerando-se baixa MMA mulheres com MMA/altura² <5,5 kg/m² ou MMA/índice de massa corporal (IMC) <0,512 e homens com MMA/altura² <7,0 kg/m² ou MMA/IMC <0,789. Baixa força de preensão manual (FPM) foi considerada quando <16 kg em mulheres e <27 kg em homens. Resultados: avaliou-se 109 pacientes (50,5% mulheres), com mediana de idade de 58 anos. Constatou-se baixa MMA em 41,3% e baixa FPM em 64,2%, não havendo correlação significativa entre FPM e MMA em nenhum dos gêneros. Baixa MMA se associou ao gênero masculino (68,9% versus 35,9%; p=0,001), a maiores idades (60,0 [53,0-63,0] versus 57,0 [51,3-60,0] anos; p=0,039) e maiores níveis séricos de paratormônio (48,0 [30,5-94,4] versus 29,9 [23,0-54,1] pg/mL; p=0,009). Baixa FPM se associou a maior sintomatologia cardíaca (75,7% com baixa FPM tinham classificação funcional da New York Heart Association III-IV, versus 51,3% daqueles com FPM normal; p=0,009). Conclusões: há uma relevante prevalência de sarcopenia em pacientes de 40 a 64 anos hospitalizados por IC, observando-se maior frequência de baixa MMA nos homens, associação entre baixa FPM e sintomatologia cardíaca, e maiores níveis de paratormônio naqueles com perda muscular.

Introduction: heart failure (HF) and sarcopenia are prevalent and interrelated conditions, being important causes of functional limitations. Objective: to evaluate sarcopenia criteria, and their relationship with cardiometabolic parameters, in patients aged 40­64 years hospitalized for HF. Methodology: Cross-sectional study including patients with established HF. Appendicular skeletal muscle mass (ASMM) was assessed using dual-energy X-ray absorptiometry (DXA), considering low ASMM women with ASMM/height² <5.5 kg/m² or ASMM/body mass index (BMI) <0.512 and men with ASMM/height² <7.0 kg/m² or ASMM/BMI <0.789. Low handgrip strength (HGS) was considered when <16 kg in women and <27 kg in men. Results: we evaluated 109 patients (50.5% women), with a median age of 58 years. Low ASMM was found in 41.3% and low HGS in 64.2%, with no significant correlation between HGS and ASMM in either gender. Low ASMM was associated with male gender (68.9% versus 35.9%; p=0.001), older age (60.0 [53.0-63.0] versus 57.0 [51.3-60, 0] years; p=0.039) and higher serum parathyroid hormone (48.0 [30.5-94.4] versus 29.9 [23.0-54.1] pg/mL; p=0.009). Low HGS was associated with greater cardiac symptoms (75.7% with low HGS had a New York Heart Association III-IV functional classification, versus 51.3% of those with normal HGS; p=0.009). Conclusions: there is a relevant prevalence of sarcopenia in patients aged 40­64 years hospitalized for HF, observing a higher frequency of low ASMM in men, an association between low HGS and cardiac symptoms, and higher levels of parathyroid hormone in those with muscle wasting.

Predictive factors of the contracture test for diagnosing malignant hyperthermia in a Brazilian population sample: a retrospective observational study

Abstract Introduction Malignant Hyperthermia (MH) is a pharmacogenetic, hereditary and autosomal dominant syndrome triggered by halogenates/succinylcholine. The In Vitro Contracture Test (IVCT) is the gold standard diagnostic test for MH, and it evaluates abnormal skeletal muscle reactions of susceptible individuals (earlier/greater contracture) when exposed to caffeine/halothane. MH susceptibility episodes and IVCT seem to be related to individual features. Objective To assess variables that correlate with IVCT in Brazilian patients referred for MH investigation due to a history of personal/family MH. Methods We examined IVCTs of 80 patients investigated for MH between 2004‒2019. We recorded clinical data (age, sex, presence of muscle weakness or myopathy with muscle biopsy showing cores, genetic evaluation, IVCT result) and IVCT features (initial and final maximum contraction, caffeine/halothane concentration triggering contracture of 0.2g, contracture at caffeine concentration of 2 and 32 mmoL and at 2% halothane, and contraction after 100 Hz stimulation). Results Mean age of the sample was 35±13.3 years, and most of the subjects were female (n=43 or 54%) and MH susceptible (60%). Of the 20 subjects undergoing genetic investigation, 65% showed variants in RYR1/CACNA1S genes. We found no difference between the positive and negative IVCT groups regarding age, sex, number of probands, presence of muscle weakness or myopathy with muscle biopsy showing cores. Regression analysis revealed that the best predictors of positive IVCT were male sex (+12%), absence of muscle weakness (+20%), and personal MH background (+17%). Conclusions Positive IVCT results have been correlated to male probands, in accordance with early publications. Furthermore, normal muscle strength has been confirmed as a significant predictor of positive IVCT while investigating suspected MH cases.

Stress perception among the elderly and its effect on some muscle strength parameters

Background: With improvement in living conditions in the population and the availability of treatments for various communicable and non-communicable diseases, the life expectancy and consequently the elderly population have increased. Stress leads to mental and physical problems. Aim and Objective: The aim of this study was to assess the effect of stress on muscle functions in the elderly. Materials and Methods: One hundred apparently healthy persons (50 males and 50 females) took part in the study. Perceived stress scale was used to measure their level of stress. Maximum voluntary contraction (MVC) and endurance time were measured with the help of a handgrip dynamometer. Results: The elderly population sample in our study showed a moderate level of stress, but there was no significant difference between the three age groups under study. Conclusion: A significant positive correlation between MVC and stress level was observed in our study subjects.

NEDD4-1 deficiency impairs satellite cell function during skeletal muscle regeneration

Background Satellite cells are tissue-specific stem cells primarily responsible for the regenerative capacity of skeletal muscle. Satellite cell function and maintenance are regulated by extrinsic and intrinsic mechanisms, including the ubiquitin-proteasome system, which is key for maintaining protein homeostasis. In this context, it has been shown that ubiquitin-ligase NEDD4-1 targets the transcription factor PAX7 for proteasome-dependent degradation, promoting muscle differentiation in vitro. Nonetheless, whether NEDD4-1 is required for satellite cell function in regenerating muscle remains to be determined. Results Using conditional gene ablation, we show that NEDD4-1 loss, specifically in the satellite cell population, impairs muscle regeneration resulting in a significant reduction of whole-muscle size. At the cellular level, NEDD4-1-null muscle progenitors exhibit a significant decrease in the ability to proliferate and differentiate, contributing to the formation of myofibers with reduced diameter. Conclusions These results indicate that NEDD4-1 expression is critical for proper muscle regeneration in vivo and suggest that it may control satellite cell function at multiple levels.

Cholic and deoxycholic acids induce mitochondrial dysfunction, impaired biogenesis and autophagic flux in skeletal muscle cells

Background Skeletal muscle is sensitive to bile acids (BA) because it expresses the TGR5 receptor for BA. Cholic (CA) and deoxycholic (DCA) acids induce a sarcopenia-like phenotype through TGR5-dependent mechanisms. Besides, a mouse model of cholestasis-induced sarcopenia was characterised by increased levels of serum BA and muscle weakness, alterations that are dependent on TGR5 expression. Mitochondrial alterations, such as decreased mitochondrial potential and oxygen consumption rate (OCR), increased mitochondrial reactive oxygen species (mtROS) and unbalanced biogenesis and mitophagy, have not been studied in BA-induced sarcopenia. Methods We evaluated the effects of DCA and CA on mitochondrial alterations in C2C12 myotubes and a mouse model of cholestasis-induced sarcopenia. We measured mitochondrial mass by TOM20 levels and mitochondrial DNA; ultrastructural alterations by transmission electronic microscopy; mitochondrial biogenesis by PGC-1α plasmid reporter activity and protein levels by western blot analysis; mitophagy by the co-localisation of the MitoTracker and LysoTracker fluorescent probes; mitochondrial potential by detecting the TMRE probe signal; protein levels of OXPHOS complexes and LC3B by western blot analysis; OCR by Seahorse measures; and mtROS by MitoSOX probe signals. Results DCA and CA caused a reduction in mitochondrial mass and decreased mitochondrial biogenesis. Interestingly, DCA and CA increased LC3II/LC3I ratio and decreased autophagic flux concordant with raised mitophagosome-like structures. In addition, DCA and CA decreased mitochondrial potential and reduced protein levels in OXPHOS complexes I and II. The results also demonstrated that DCA and CA decreased basal, ATP-linked, FCCP-induced maximal respiration and spare OCR. DCA and CA also reduced the number of cristae. In addition, DCA and CA increased the mtROS. In mice with cholestasis-induced sarcopenia, TOM20, OXPHOS complexes I, II and III, and OCR were diminished. Interestingly, the OCR and OXPHOS complexes were correlated with muscle strength and bile acid levels. Conclusion Our results showed that DCA and CA decreased mitochondrial mass, possibly by reducing mitochondrial biogenesis, which affects mitochondrial function, thereby altering potential OCR and mtROS generation. Some mitochondrial alterations were also observed in a mouse model of cholestasis-induced sarcopenia characterised by increased levels of BA, such as DCA and CA.

Clinical significance of sarcopenia in patients undergoing treatment for gastric cancer

SUMMARY OBJECTIVE: The aim of this study was to investigate the impact of sarcopenia on prognosis in patients with gastric cancer in order to explore the relationship between sarcopenia and postoperative complications as well as durations of hospital stay and intensive care unit. METHODS: A total of 175 patients who visited the oncology clinic between 2017 and 2022 with respect to their radiological images, demographic data, and laboratory parameters were perused. The OsiriX software was used to measure the skeletal muscle area that was divided by the body height in order to obtain the skeletal muscle index. RESULTS: A total of 50.28% of 175 patients (41 females and 134 males, with a mean age of 63.5 years) who met the inclusion criteria in the study were sarcopenic. Significant differences appeared between sarcopenic and non-sarcopenic patients with respect to durations of both hospital stay (p<0.01) and intensive care unit stay (p<0.01) (multivariate analysis). Furthermore, patients with sarcopenia had significantly frequent postoperative complications in comparison with those without sarcopenia. Among the patients with sarcopenia, decreased levels of hemoglobin and albumin as well as lymphocytes were encountered in terms of inflammatory markers; nevertheless, no significant differences were determined among other inflammatory markers. CONCLUSION: In patients undergoing treatment for gastric cancer, sarcopenia increases postoperative complications and prolongs hospital and intensive care stays during the treatment process.

Exosome-mediated regulatory mechanisms in skeletal muscle: a narrative review / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Skeletal muscle plays a paramount role in physical activity, metabolism, and energy balance, while its homeostasis is being challenged by multiple unfavorable factors such as injury, aging, or obesity. Exosomes, a subset of extracellular vesicles, are now recognized as essential mediators of intercellular communication, holding great clinical potential in the treatment of skeletal muscle diseases. Herein, we outline the recent research progress in exosomal isolation, characterization, and mechanism of action, and emphatically discuss current advances in exosomes derived from multiple organs and tissues, and engineered exosomes regarding the regulation of physiological and pathological development of skeletal muscle. These remarkable advances expand our understanding of myogenesis and muscle diseases. Meanwhile, the engineered exosome, as an endogenous nanocarrier combined with advanced design methodologies of biomolecules, will help to open up innovative therapeutic perspectives for the treatment of muscle diseases.

Porcine skeletal muscle development regulated by MicroRNA: a review / 生物工程学报

The growth and development of skeletal muscle is an important factor affecting pork production and quality, which is elaborately regulated by many genetic and nutritional factors. MicroRNA (miRNA) is a non-coding RNA with a length of about 22 nt, which binds to the 3'UTR sequence of the mRNA of the target genes, and consequently regulates its post-transcriptional expression level. In recent years, a large number of studies have shown that miRNAs are involved in various life processes such as growth and development, reproduction, and diseases. The role of miRNAs in the regulation of porcine skeletal muscle development was reviewed, with the hope to provide a reference for the genetic improvement of pigs.

The role and regulatory mechanism of tissue and organ crosstalk on skeletal muscle development: a review / 生物工程学报

Skeletal muscle is one of the most important organs in animal, and the regulatory mechanism of skeletal muscle development is of great importance for the diagnosis of muscle-related diseases and the improvement of meat quality of livestock. The regulation of skeletal muscle development is a complex process, which is regulated by a large number of muscle secretory factors and signaling pathways. In addition, in order to maintain steady-state and maximum use of energy metabolism in the body, the body coordinates multiple tissues and organs to form the complex and sophisticated metabolic regulation network, which plays an important role for the regulation of skeletal muscle development. With the development of omics technologies, the underlying mechanism of tissue and organ communication has been deeply studied. This paper reviews the effects of crosstalk among adipose tissue, nerve tissue and intestinal tissue on skeletal muscle development, with the aim to provide a theoretical basis for targeted regulation of skeletal muscle development.

Is the myonuclear domain ceiling hypothesis dead?

Muscle fibres are multinuclear cells, and the cytoplasmic territory where a single myonucleus controls transcriptional activity is called the myonuclear domain (MND). MND size shows flexibility during muscle hypertrophy. The MND ceiling hypothesis states that hypertrophy results in the expansion of MND size to an upper limit or MND ceiling, beyond which additional myonuclei via activation of satellite cells are required to support further growth. However, the debate about the MND ceiling hypothesis is far from settled, and various studies show conflicting results about the existence or otherwise of MND ceiling in hypertrophy. The aim of this review is to summarise the literature about the MND ceiling in various settings of hypertrophy and discuss the possible factors contributing to a discrepancy in the literature. We conclude by describing the physiological and clinical significance of the MND ceiling limit in the muscle adaptation process in various physiological and pathological conditions.

Association of the appendicular skeletal muscle mass to fat mass ratio in early pregnancy with the risk of development of gestational diabetes mellitus / 中华临床营养杂志

Objective:To assess the association of appendicular skeletal muscle mass(ASM) to fat mass(FM) ratio in early pregnancy with the risk of gestational diabetes mellitus (GDM).Methods:A total of 468 pregnant women who visited the Nutritional Department of Peking Union Medical College Hospital or Shunyi Maternal and Child Care Service Center in 2018 and 2019 were recruited. Detailed information and clinical data were collected. The body components were measured using the bioelectrical impedance analysis (BIA) method during early pregnancy (< 14 weeks) and the ASM to FM ratio was calculated. The patients were divided into the GDM group and normal glucose tolerance (NGT) group according to the results of the oral glucose tolerance test (OGTT) performed during 24-28 weeks. Binary logistics regression was used to explore the correlation between the ASM/FM ratio and the risk of GDM. The receiver operator characteristic (ROC) curve of subjects was used to evaluate the predictive value of ASM/FM ratio for GDM and the cut-off value was reported.Results:Compared to the NGT group, the ASM and FM in early pregnancy in the GDM group were significantly higher, while the ASM/FM ratio was significantly lower. A lower ASM/FM ratio in early pregnancy was one of the risk factors of developing GDM. The cut-off value of the ASM/FM ratio was 0.809. The area under the ROC curve for predicting GDM increased from 68.1% to 72.3% when ASM/FM ratio was incorporated, with a significant difference by Delong test ( P = 0.006). Conclusion:Inadequate muscle mass would increase the risk of GDM and the ASM/FM ratio could serve as a predictor of GDM.

Research progress on the skeletal muscle mitochondrial alterations and the treatment in cancer cachexia / 中华临床营养杂志

Cancer cachexia is a multifactorial syndrome characterized by the continuous loss of skeletal muscle. The pathogenic mechanism of cancer cachexia remains unknown, and the effectiveness of routine nutritional therapy is limited. The mitochondrial disorder is demonstrated to play an important role in the mechanism of tumor-induced skeletal muscle atrophy, including alterations to the mitochondrial ultrastructure, biogenesis, dynamics, mitophagy, and functions. Interventions targeting mitochondrial alterations provide a potential solution to cancer cachexia and represent a new focus in this research field.

Progress in the effect of fluorosis on skeletal muscle and its related molecular mechanisms / 中华地方病学杂志

Fluoride has dual health effects. Proper amount of fluoride plays an important role in bone development, prevention of dental caries and nervous system activity. Excessive fluoride causes chronic systemic diseases with dental fluorosis and skeletal fluorosis as the main symptoms. Fluorosis causes morphological and structural changes and function damage in skeletal muscle. Low concentration of fluoride induces muscle canal hypertrophy in skeletal muscle, while high concentration of fluoride leads to skeletal muscle atrophy by causing a series of signal pathway abnormalities. Abnormal changes in phosphatidylinositol-3-hydroxykinase/protein kinase B (PI3K/Akt) signal pathway, oxidative stress, and ubiquitin-proteasome pathway all play important roles in skeletal muscle injury caused by fluorosis. In this paper, the effect of fluoride on skeletal muscle and its related molecular mechanisms are reviewed.

The CB1 cannabinoid receptor regulates autophagy in the tibialis anterior skeletal muscle in mice

The endocannabinoid system (ECS) regulates energy metabolism, has been implicated in the pathogenesis of metabolic diseases and exerts its actions mainly through the type 1 cannabinoid receptor (CB1). Likewise, autophagy is involved in several cellular processes. It is required for the normal development of muscle mass and metabolism, and its deregulation is associated with diseases. It is known that the CB1 regulates signaling pathways that control autophagy, however, it is currently unknown whether the ECS could regulate autophagy in the skeletal muscle of obese mice. This study aimed to investigate the role of the CB1 in regulating autophagy in skeletal muscle. We found concomitant deregulation in the ECS and autophagy markers in high-fat diet-induced obesity. In obese CB1-KO mice, the autophagy-associated protein LC3 II does not accumulate when mTOR and AMPK phosphorylation levels do not change. Acute inhibition of the CB1 with JD-5037 decreased LC3 II protein accumulation and autophagic flux. Our results suggest that the CB1 regulates autophagy in the tibialis anterior skeletal muscle in both lean and obese mice.

An Unresolving Case of Pyomyositis: A Case Report

@#Pyomyositis which is also known as myositis tropicans is a rare condition where there is bacterial infection of the skeletal muscle. Its manifestation includes pain and tenderness of the affected muscle and general infective symptoms. It commonly occurs in immunocompromised individuals and patients with previous history of trauma to the affected muscle. We report a case of a 16-year-old boy with history of underlying bronchial asthma who presented with multiple abscesses. He underwent multiple operations to drain the infection and targeted antibiotic therapy subsequently. Despite undergoing surgical debridement, drainage and antibiotic treatment, he was still having repeated bouts of fever and his inflammatory markers were not reducing. He was then diagnosed with concurrent pulmonary tuberculosis infection which subjected him to an immunosuppressed state thus arising to the condition of pyomyositis and unresolving fever. The patient then made prompt improvement when the underlying cause of immunosuppression; pulmonary tuberculosis was treated as well.

Effects of sarcopenia on the occurrence of overt hepatic encephalopathy in patients with liver cirrhosis / 中华消化杂志

Objective:To investigate the risk factors of overt hepatic encephalopathy (OHE) in patients with liver cirrhosis, and to clarify the effect of sarcopenia on OHE.Methods:Based on the liver cirrhosis cohort established by our research group, from January 1, 2013 to December 31, 2017, 480 patients diagnosed with liver cirrhosis and underwent upper abdominal computed tomography were selected from 3 centers, including the Second Affiliated Hospital of Naval Medical University (Shanghai Changzheng Hospital), Shanghai East Hospital Affiliated to Tongji University, and Shandong Provincial Hospital. The L3 skeletal muscle index (L3-SMI) <44.77 cm 2/m 2 for males and L3-SMI <32.50 cm 2/m 2 for females were used as the diagnostic criterion for sarcopenia. The clinical data of all the patients were collected, including baseline medical history, age, serum total bilirubin, serum levels of aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT), albumin, sodium, prothrombin time (PT), international normalized ratio (INR), hemoglobin, platelet count, etc, as well as Child-Pugh classification of liver function, and model for end-stage liver disease (MELD) score. Independent sample t test, rank sum test, and chi-square test were used for statistical analysis. Binary logistic regression analysis was used to analyze the independent risk factors for OHE in patients with liver cirrhosis, and Kaplan-Meier method was used to analyze the effect of sarcopenia on the incidence of OHE in patients with liver cirrhosis. Results:After 2 years of follow-up, the incidence of OHE was 16.2% (78/480). The age, serum total bilirubin level, AST, GGT, PT, INR, Child-Pugh score, and MELD score of OHE patients were all higher than those of non-OHE patients ((59.67±10.30) years old vs. (53.41±12.06) years old, 35.25 μmol/L(20.10 μmol/L, 60.53 μmol/L) vs. 22.70 μmol/L(15.10 μmol/L, 35.20 μmol/L), 40.00 U/L(27.25 U/L, 61.00 U/L) vs. 33.00 U/L(24.75 U/L, 47.00 U/L), 52.50 U/L(26.25 U/L, 86.75 U/L) vs. 34.50 U/L(22.00 U/L, 73.00 U/L), (17.71±3.52) s vs. (15.50±2.98) s, 1.50±0.34 vs. 1.31±0.29, 8.95±2.19 vs.7.20±1.94, 13.56±4.42 vs.11.42±3.92), while serum albumin, serum sodium and platelet count of OHE patients were all lower than those of non-OHE patients ((29.72±5.55) g/L vs. (33.19±5.89) g/L, 139.00 mmol/L(136.00 mmol/L, 142.00 mmol/L)vs.140.00 mmol/L (138.00 mmol/L, 142.00 mmol/L), 60.00×10 9/L(43.75×10 9/L, 90.25×10 9/L) vs. 80.00×10 9/L(56.00×10 9/L, 131.00×10 9/L)), and the differences were statistically significant ( t=-4.77; Z=-4.10, -3.13, -2.24; t=-5.19, -4.71, -6.57, -3.98, 4.99; and Z=2.44 and 3.48; all P<0.05). The proportions of ascites, hepatic encephalopathy, hepatorenal syndrome, spontaneous bacterial peritonitis at baseline, and the incidence of sarcopenia in OHE patients were all higher than those in non-OHE patients (82.1%, 64/78 vs. 63.7%, 256/402; 41.0%, 32/78 vs. 3.5%, 14/402; 5.1%, 4/78 vs. 1.0%, 4/402; 14.1%, 11/78 vs. 2.5%, 10/402; 37.2%, 29/78 vs. 19.7%, 79/402), and the L3-SMI of OHE patients was lower than that of non-OHE patients ((43.14±8.97) cm 2/m 2 vs. (46.29±8.49) cm 2/m 2), and the differences were statistically significant ( χ2=9.11, 101.97, 4.52, 18.38, 10.53; t=2.86; all P<0.05). The results of binary logistic regression analysis indicated that platelet count ( OR=0.995, 95% confidence interval (95% CI) 0.991 to 1.000, P=0.038), L3-SMI ( OR=0.959, 95% CI 0.922 to 0.997, P=0.035) and hepatic encephalopathy ( OR=14.724, 95% CI 6.741 to 32.161, P<0.001) were independent influencing factors for OHE in patients with liver cirrhosis. The incidence of OHE in patients with sarcopenia was higher than that of patients without sarcopenia (26.9%, 29/108 vs. 13.2%, 49/372), and the difference was statistically significant ( χ2=10.53, P=0.001). The results of Kaplan-Meier analysis demonstrated that patients with sarcopenia were more likely to develop OHE ( P<0.001). Conclusion:Sarcopenia is closely correlated to OHE and is an independent predictor of OHE in patients with liver cirrhosis.

Research progress on the effect of exercise rehabilitation on skeletal muscle in patients with heart failure / 中华全科医师杂志

Heart failure(HF) can adversely affect various peripheral tissues in the body, including the skeletal muscle. HF leads to pathological changes in skeletal muscle, causing structural damage, functional impairment and atrophy of the skeletal muscle, which may eventually develope into cardiac cachexia. The skeletal muscle atrophy is also a prominent symptom of cachexia in HF patients, and it is also an independent risk factor of mortality in the patients. While exercise rehabilitation may attenuate skeletal muscle atrophy and improve the quality of life in HF patients. This article reviews the recent progress on the effect and related mechanisms of exercise rehabilitation on skeletal muscle atrophy in patients with HF.