Advances of pathogenesis and drug development in amyotrophic lateral sclerosis / 中国药理学通报

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting both upper and lower motor neurons. ALS patients develop progressive muscle atrophy, muscle weak and paralysis, finally died of respiratory failure. ALS is characterized by fast aggression and high mortality. What' s more, the disease is highly heterogeneous with unclear pathogenesis and lacks effective drugs for therapy. In this review, we summarize the main pathological mechanisms and the current drugs under development for ALS, which may provide a reference for the drug discovery in the future.

Association between skeletal muscle mass and metabolic syndrome in middle-aged and elderly community residents / 上海预防医学

ObjectiveTo explore the correlation between skeletal muscle mass and metabolic syndrome （MS） disease risk among middle-aged and elderly community residents in Urumqi， and to provide a theoretical basis for understanding the relationship between skeletal muscle mass and MS among middle-aged and elderly community residents in China. MethodsA total of 1 438 community residents ≥ 50 years old were selected as the research subjects from July 2018 to January 2019 in Urumqi. They were selected from a multi-ethnic natural population cohort in Xinjiang. Data were collected through questionnaires， physical examination， bioelectrical impedance analysis （BIA）， laboratory tests， etc. Skeletal muscle mass was evaluated using the limb skeletal muscle mass index （SMI） corrected for body weight； MS was defined as it at least includes three of the following： abdominal obesity， hypertension， hyperglycemia， high triglycerides and low high-density lipoprotein cholesterol. SMI was divided into four quantile arrays of Q1‒Q4. Trend χ2 test was applied to explore whether there was a correlation between SMI changes and MS. A multivariate logistic regression model was used to analyze whether there is a difference in the risk of MS between the higher SMI group （Q2， Q3， Q4） and the reference group Q1. ResultA total of 560 MS patients were detected in this study， with a prevalence rate of 38.94%. Among them， the prevalence rate of MS was 39.16% in males and 38.80% in females. The increase in male SMI grading level is not correlated with the prevalence of MS （trend P>0.05）； After adjusting for confounding factors （model 4）， the increase in SMI was still not related to the prevalence of MS （Ptrend=0.995）. There was no statistical difference in the risk of MS between the lowest quartile group Q1 and the highest quartile group Q4 （OR=1.01， 95%CI： 0.69‒1.78）. The prevalence of MS in women gradually decreased with the increase of SMI grading level （Ptrend<0.001）； After adjusting for confounding factors （model 4）， there was still a correlation between the increase of SMI and the prevalence of MS （Ptrend=0.005）. With the lowest quartile of SMI Q1 as the reference group， the risk of MS in Q2 （OR=0.63， 95%CI： 0.40‒1.00）， Q3 （OR=0.56， 95%CI： 0.34‒0.94）， Q4 （OR=0.42， 95%CI： 0.23‒0.76） decreased. ConclusionAn increase in skeletal muscle mass may be beneficial for preventing MS， especially among middle-aged and elderly female residents. Considering the intensification of aging in China and the close relationship between MS and related comorbidities， managing skeletal muscle mass may contribute to potential MS prevention.

Activation of Nrf2/HO-1/NQO1 Signaling Pathway by Shenqi Tangluo Pill Improves Oxidative Stress Injury of Skeletal Muscle of Type 2 Diabetes Mellitus Mice / 中国实验方剂学杂志

ObjectiveTo investigate the effect and mechanism of Shenqi Tangluo pill （SQTLP） on oxidative stress injury of skeletal muscle of type 2 diabetes mellitus （T2DM） mice based on nuclear factor erythroid 2-related factor 2 （Nrf2）/heme oxygenase-1 （HO-1）/NAD（P）H quinone oxidoreductase 1 （NQO1） pathway. MethodA total of 60 7-week-old male db/db mice ［specific pathogen-free （SPF） grade］ were selected and fed for one week for adaption. They were divided into the model control group， SQTLP low-， medium- and high-dose （19， 38， and 76 g·kg-1） groups and metformin group （0.26 g·kg-1） by gavage. Each group consisted of 12 mice. Twelve male db/m mice of the same age were selected as the blank group. The intervention was implemented continuously for 8 weeks. Fasting blood glucose （FBG） was detected. Fasting serum insulin （FINS） levels were detected by enzyme-linked immunosorbent assay （ELISA）， and the homeostasis model assessment-insulin resistance （HOMA-IR） index and the homeostasis model assessment-insulin sensitivity index （HOMA-ISI） were calculated. Oral glucose tolerance test （OGTT） and insulin tolerance test （ITT） were conducted. The activities of superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） and the contents of malondialdehyde （MDA） and reduced nicotinamide adenine dinucleotide phosphate （NADPH） in skeletal muscle tissues were detected by biochemical kits. Hematoxylin-eosin （HE） staining was used to observe the pathological changes in skeletal muscle tissues. The levels of reactive oxygen species （ROS） and 4-hydroxynonenal （4-HNE） in skeletal muscle tissue were detected by immunofluorescence （IF）. The expression levels of Nrf2， HO-1， NQO1 and glutamate-cysteine ligase catalytic subunit （GCLC） proteins in skeletal muscle tissues were detected by Western blot. ResultCompared with those in the blank group， FBG， FINS and HOMA-IR in the model group were significantly increased （P<0.05）， while HOMA-ISI was decreased （P<0.05）. The results of OGTT and ITT showed that blood glucose was significantly increased at all time points （P<0.05）， and glucose tolerance and insulin tolerance were significantly impaired. SOD and GSH-Px activities in skeletal muscle tissues were significantly decreased （P<0.05）， and MDA and NADPH contents were significantly increased （P<0.05）. In skeletal muscle tissues， the arrangement of muscle fibers was loose， the nucleus was disordered， and inflammatory cells were infiltrated. The expression levels of ROS and 4-HNE in skeletal muscle tissues were significantly increased （P<0.05）. The protein expression levels of Nrf2， HO-1， NQO1 and GCLC in skeletal muscle tissues were significantly decreased （P<0.05）. Compared with those in the model group， FBG， FINS and HOMA-IR in the metformin group were significantly decreased （P<0.05）， while HOMA-ISI was increased （P<0.05）. The results of OGTT and ITT showed that blood glucose in the metformin group was significantly decreased at all time points （P<0.05）. The activities of SOD and GSH-Px in skeletal muscle tissues were significantly increased （P<0.05）， while the contents of MDA and NADPH were significantly decreased （P<0.05）. No obvious abnormality was found in the skeletal muscle tissue of the metformin group. The expressions of ROS and 4-HNE in skeletal muscle tissues were decreased （P<0.05）. The protein expression levels of Nrf2， HO-1， NQO1 and GCLC in skeletal muscle tissues were significantly increased （P<0.05）. Compared with those in the model group， FBG， FINS and HOMA-IR in the SQTLP medium- and high-dose groups were significantly decreased （P<0.05）， while HOMA-ISI was increased （P<0.05）. The results of OGTT and ITT showed that the glucose tolerance and insulin tolerance of mice were improved in each dose group of SQTLP. The GSH-Px activity in the SQTLP low-dose group was significantly increased （P<0.05）， and the NADPH content was decreased （P<0.05）. The activities of SOD and GSH-Px in the SQTLP medium- and high-dose groups were significantly increased （P<0.05）， while the contents of MDA and NADPH were significantly decreased （P<0.05）. The skeletal muscle tissue injury of mice in each dose group of SQTLP was ameliorated to different degrees. In the SQTLP medium- and high-dose groups， the expressions of ROS and 4-HNE were decreased （P<0.05）， and the protein expression levels of Nrf2， HO-1， NQO1 and GCLC were significantly increased （P<0.05）. Compared with those in the SQTLP low-dose group， FBG and HOMA-IR in the SQTLP high-dose group were significantly decreased （P<0.05）， while HOMA-ISI was increased （P<0.05）. The results of OGTT and ITT showed that the SQTLP high-dose group significantly improved the glucose tolerance and insulin tolerance of mice. The activities of SOD and GSH-Px in skeletal muscle tissues were significantly increased （P<0.05）， while the contents of MDA and NADPH were significantly decreased （P<0.05）. No obvious abnormality was found in the skeletal muscle tissue， the expressions of ROS and 4-HNE were decreased （P<0.05）， and the protein expression levels of Nrf2， HO-1， NQO1 and GCLC were significantly increased （P<0.05） in the skeletal muscle tissue of the SQTLP high-dose group. ConclusionSQTLP can significantly improve IR in T2DM mice， and the mechanism is related to SQTLP activating the Nrf2/HO-1/NQO1 signaling pathway， promoting the expression of antioxidant enzymes， and thus improving the oxidative stress injury in the skeletal muscle.

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.

Effect of Zishenwan on Intestinal Barrier and Transcriptome of Skeletal Muscle of db/db Diabetic Mice / 中国实验方剂学杂志

ObjectiveTo explore the effect of Zishenwan on glucose and lipid metabolism in spontaneous type 2 diabetes （db/db） mice and investigate the underlying mechanism for improving diabetes based on intestinal barrier function and skeletal muscle transcriptome sequencing results. MethodLiquid chromatography-tandem mass spectrometry （LC-MS/MS） was used to analyze the components of Zishenwan. Sixteen 6-week-old db/db mice were divided into a model group and a Zishenwan group， while eight wild-type mice were assigned to the normal group. The Zishenwan group received oral administration of drugs for six weeks， during which fasting blood glucose， body weight， and food intake were measured. Serum total cholesterol （TC） and triglyceride （TG） levels were determined， and fasting insulin levels were measured to calculate the homeostatic model assessment of insulin resistance （HOMA-IR）. After the treatment， skeletal muscle and ileum tissues were collected， followed by hematoxylin-eosin （HE） staining. Immunohistochemistry was used to detect the expression of tight junction proteins occludin and zonula occludens-1 （ZO-1） in the ileum. Transcriptome sequencing was performed to detect the skeletal muscle transcriptome， and enrichment analysis was conducted for differentially expressed genes. ResultMultiple active components were identified in Zishenwan. Compared with the normal group， the model group showed increased fasting blood glucose， body weight， TC， TG， and HOMA-IR （P<0.01）. Compared with the model group， Zishenwan significantly reduced fasting blood glucose， body weight， TC， TG， and HOMA-IR in db/db mice （P<0.01）， while there was no statistically significant difference in food intake. Compared with the normal group， the model group exhibited lipid deposition in skeletal muscle， as well as structural changes in the ileum， with significant decreases in the protein expression levels of intestinal occludin and ZO-1 （P<0.01）. Compared with the model group， Zishenwan improved the pathological changes in skeletal muscle and ileum， and increased the protein expression of occludin and ZO-1 in the ileum （P<0.01）. Transcriptome analysis suggested that Zishenwan might improve skeletal muscle metabolism and increase insulin sensitivity in mice. ConclusionZishenwan can improve glucose and lipid metabolism in db/db mice， and this effect may be related to its protection of intestinal barrier function and transcriptional regulation of skeletal muscle metabolism-related genes.

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.

Association between appendicular skeletal muscle mass and ankle-brachial index in patients with type 2 diabetes / 中华健康管理学杂志

Objective:To assess the relationship between appendicular skeletal muscle mass (ASM) and ankle brachial index (ABI) among patients with type 2 diabetes.Methods:In this cross-sectional study, from July 2018 to March 2019, a total of 278 patients with type 2 diabetes treated in Zhongda Hospital were enrolled in this study, and there were 158 males and 120 females. General information and clinical biochemical parameters and ABI in the patients were collected. The appendicular muscle mass was quantitatively measured with body composition analyzer to achieve ASM. And the appendicular skeletal muscle mass index (ASMI), skeletal muscle index (SMI), and appendicular skeletal muscle mass/body mass index (ASM/BMI) were calculated respectively. Correlation analysis and multiple linear regression analyses with different adjustment models were conducted to analyze the correlation between ABI and above-mentioned indexes.Results:The Pearson correlation analysis showed that ABI had significant positive correlation with ASM, ASMI and ASM/BMI ( r=0.14, 0.13, 0.13, all P<0.05), but a marginal relation with SMI ( r=0.116, P=0.053). Multiple linear regression analysis suggested that ASMI ( β=0.053, 95% CI: 0.006-0.101, P=0.027) and AMI/ABI ( β=0.347, 95% CI: 0.040-0.654, P=0.027) were significantly related to ABI. Conclusion:ASM is positively associated with ABI in patients with type 2 diabetes.

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.

Effects of different time point rolling massager on inflammation in rabbits with skeletal muscle injury / 国际中医中药杂志

Objective:To observe the effects of rolling method massager on local tissue morphology, tissue and serum TNF-α and IL-1β in rabbits with skeletal muscle injury at different time points; To investigate the mechanism of temporal effect of rolling method action on skeletal muscle injury.Methods:Totally 72 New Zealand rabbits were divided into blank group, model group and rolling method treatment group according to random number table method, with 24 rabbits in each group. Rabbits in each group were divided into 1 d, 3 d, 5 d, 7 d, 9 d and 11 d subgroups according to the time point of injury, with 4 rabbits in each group. Blunt contusion was used to model the model group and the rolling method treatment group. Each subgroup of the rolling method treatment group was subjected to rolling method intervention for 3 d, using a homemade rolling method massager, 2 times/d, 3 min/time. At 24 h after the completion of the intervention, the histomorphological changes were observed by HE staining, and the TNF-α and IL-1β contents in serum and damaged skeletal muscle tissues were detected by ELISA.Results:Compared with the blank group, the inflammatory cell infiltration in the model group was obvious, edema was severe, and myofibers were broken; the inflammatory cell infiltration in the 1 d rolling method treatment group was intensified, myocytes were apoptotic, and myofibers were broken and necrosed more seriously; the inflammation in the 7 d rolling method treatment group was obviously improved with the best effect, and the difference with normal healthy muscle tissue was smaller. After modeling, TNF-α and IL-1β levels in skeletal muscle tissues and serum TNF-α levels were higher in the 3 d model group than in the 1 d model group ( P<0.05). Compared with the blank group, TNF-α and IL-1β levels in skeletal muscle tissues and serum increased in each subgroup of the model group and each subgroup of the rolling method treatment group ( P<0.01); Compared with the 1 d model group, TNF-α and IL-1β levels in skeletal muscle tissues and serum TNF-α levels increased in the 1 d rolling method treatment group. The levels of TNF-α and IL-1β in the 3 d, 5 d, 7 d, 9 d and 11 d rolling method treatment group were lower than those in the model group subgroup ( P<0.05). TNF-α and IL-1β levels in skeletal muscle tissues and serum TNF-α levels were higher in the 1 d, 3 d and 5 d rolling method treatment group than in the 7 d rolling method treatment group ( P<0.05). TNF-α levels in skeletal muscle tissues were higher in the 1 d and 3 d rolling method treatment group than in the 7 d rolling method treatment group ( P<0.05). Conclusion:The inflammatory factors in the rolling treated group were significantly higher at 1 d after skeletal muscle injury, indicating that treatment with the rolling method was inappropriate at this time; seven days after injury, the application of rolling method can reduce the inflammatory effect, accelerate the repair of skeletal muscle, and improve the quality of functional recovery.

Six-week Aerobic Exercise Improves Oxidative Damage of Skeletal Muscles and Promotes Myokine Production in Atherosclerotic Mice / 中国生物化学与分子生物学报

Atherosclerosis involving peripheral arteries can cause skeletal muscle lesions, in which oxidative damage is an important manifestation, and atherosclerosis also reduces the production and secretion of beneficial myokines. Irisin, musclin and β-aminoisobutyric acid (BAIBA) are thought to be involved in improving atherosclerosis. However, the molecular mechanism of atherosclerosis-induced skeletal muscle lesions and the effects of aerobic exercise training on the oxidative damage of skeletal muscle and myokine production remain unclear. In this study, apolipoprotein E knockout (ApoE

Interleukin-6 in Skeletal Muscle Mass Regulation / 中国生物化学与分子生物学报

Interleukin-6 (IL-6) is a spreading pleiotropic cytokine, with both anti-inflammatory and proinflammatory effects. It not only participates in the body immune responses but also is involved in the biological regulative processes among different organs, tissues, and cells. IL-6 has both anti-inflammatory and pro-inflammatory effects. In the early stage of pathogen infection, IL-6 plays an anti-inflammatory role in the body, and its level is moderately increased in the body to resist inflammation and maintain internal homeostasis. However, a large amount of IL-6 release can cause excessive inflammation and trigger other pathological changes in the body. Il-6 also has the dual effect of stimulating the synthesis and degradation of skeletal muscle protein in regulating skeletal muscle mass. As an important locomotive organ, skeletal muscle is also one of the key targets of IL-6. IL-6 takes part in the biological control of skeletal muscle hypertrophy through regulating muscle satellite cell proliferation and differentiation under specific stresses. In addition IL-6 is also associated with skeletal muscle atrophy induced by aging and other pathological stresses. In addition, during exercise stress, skeletal muscle can also serve as an endocrine organ to secrete and release IL-6 that facilitates the "crosstalk" between skeletal muscle and other organs or tissues. As IL-6 plays as a versatile role in our body, this paper reviews the research progress of the mechanism of IL-6 in the regulation of skeletal muscle mass, which may provide theoretical support for revealing the molecular mechanism of skeletal muscle stresses and adaptations.

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.