Low skeletal muscle mass and high visceral adiposity are associated with recurrence of acute cholecystitis after conservative management:A propensity score-matched cohort study

Background:Recurrent acute cholecystitis(RAC)can occur after non-surgical treatment for acute cholecystitis(AC),and can be more severe in comparison to the first episode of AC.Low skeletal muscle mass or adiposity have various effects in several diseases.We aimed to clarify the relationship between RAC and body parameters.Methods:Patients with AC who were treated at our hospital between January 2011 and March 2022 were enrolled.The psoas muscle mass and adipose tissue area at the third lumbar level were measured using computed tomography at the first episode of AC.The areas were divided by height to obtain the psoas muscle mass index(PMI)and subcutaneous/visceral adipose tissue index(SATI/VATI).According to median VATI,SATI and PMI values by sex,patients were divided into the high and low PMI groups.We performed propensity score matching to eliminate the baseline differences between the high PMI and low PMI groups and analyzed the cumulative incidence and predictors of RAC.Results:The entire cohort was divided into the high PMI(n=81)and low PMI(n=80)groups.In the propensity score-matched cohort there were 57 patients in each group.In Kaplan-Meier analysis,the low PMI group and the high VATI group had a significantly higher cumulative incidence of RAC than their counterparts(log-rank P=0.001 and 0.015,respectively).In a multivariate Cox regression analysis,the hazard ratios of low PMI and low VATI for RAC were 5.250(95%confidence interval 1.083-25.450,P=0.039)and 0.158(95%confidence interval:0.026-0.937,P=0.042),respectively.Conclusions:Low skeletal muscle mass and high visceral adiposity were independent risk factors for RAC.

Muscle Mass Is Associated with Depression in Adolescents and Young Adults

Background and Aims: The study aims to explore the association between body composition and depression in adolescents and young adults. Methods: A random cluster sampling method was used to select 41 age-matched indi-viduals (aged 11 - 30) as a non-depressive control group. The Department of Psychology at the Affiliated Hospital of Youjiang Medical University for Na-tionalities recruited 27 depressive patients within the same age range. Bioelec-trical impedance analysis measured body composition, while SCL-90, SAS, and SDS were employed for depression diagnosis. Logistic regression analysis was conducted to assess the relationship between body composition and de-pression scores. Results: The Depression Group exhibited higher levels of fat mass (p Conclusion: Depression is associated with age, gender, and muscle mass in adolescents and young people. Proper exercise and a healthy diet can increase muscle mass, thereby reducing fat mass and, as a result, reducing the prevalence of depression.

Possibilities of Assessing Respiratory Muscle Strength and Trunk Muscle Mass in the Prevention of Sarcopenia in Older People Living in the Community

Objective: The purpose of this study was to clarify the relationship between respiratory muscle strength and skeletal muscle mass (trunk, upper limbs, and lower limbs) in older people who were certified as requiring nursing or supportive care. Methods: Thirty-five older people (65 years or older) who were certified as requiring nursing care or support were included in the study. The subjects were divided into a non-sarcopenic group (n = 12) and a sarcopenic group (n = 23) according to the sarcopenia diagnostic criteria proposed by the Asian Working Group for Sarcopenia. Maximum inspiratory pressure, maximum expiratory pressure, skeletal muscle mass (trunk, upper and lower limbs), and hand grip strength were measured. Pearson’s correlation coefficient and multiple regression analysis were used for statistical processing. Results: In the non-sarcopenic group, both expiratory muscle strength and hand grip strength were correlated with skeletal muscle mass. In the sarcopenia group, expiratory muscle strength was not correlated with skeletal muscle mass, and only hand grip strength was correlated with upper limb muscle mass. Multiple regression analysis revealed that, in the non-sarcopenic group, trunk muscle mass was the primary factor in expiratory muscle strength and upper limb muscle mass was the primary factor in hand grip strength. In the sarcopenia group, upper limb muscle mass was found to be the main factor in hand grip strength. Conclusion: Our results highlight the importance of assessing expiratory muscle strength and trunk muscle mass before sarcopenia develops in older people who require support and nursing care.

Age-dependent Changes in Skeletal Muscle Mass and Visceral Fat Area in a Chinese Population

Objective:The present study was conducted to demonstrate the age-dependent changes in skeletal muscle mass and visceral fat area in a population of Chinese adults aged 30-92 years old.Methods:A total of 6669 healthy Chinese men and 4494 healthy Chinese women aged 30-92 years old were assessed for their skeletal muscle mass and visceral fat area.Results:The results showed age-dependent decreases in the total skeletal muscle mass indexes in both men and women aged 40-92 years old as well as age-dependent increases in the visceral fat area in men aged 30-92 years old and in women aged 30-80 years old.Multivariate regression models showed that the total skeletal muscle mass index was positively associated with the body mass index and negatively associated with the age and visceral fat area in both sexes.Conclusion:The loss of skeletal muscle mass becomes obvious at approximately 50 years of age,and the visceral fat area commences to increase at approximately 40 years of age in this Chinese population.

Skeletal muscle mass and quality before preoperative chemotherapy influence postoperative long-term outcomes in esophageal squamous cell carcinoma patients

BACKGROUND Previous reports have focused on muscle mass as a prognostic factor in esophageal cancer.AIM To investigate how preoperative body type influences the prognosis of patients with esophageal squamous cell carcinoma who underwent neoadjuvant chemotherapy(NAC)and surgery.METHODS The subjects were 131 patients with clinical stage Ⅱ/Ⅲ esophageal squamous cell carcinoma who underwent subtotal esophagectomy after NAC.Skeletal muscle mass and quality were calculated based on computed tomography images prior to NAC,and their statistical association with long-term outcomes was examined retrospectively in this case-control study.RESULTS The disease-free survival rates in the low psoas muscle mass index(PMI)group vs the high PMI group were 41.3%vs 58.8%(P=0.036),respectively.In the high intramuscular adipose tissue content(IMAC)group vs the low IMAC group,the disease-free survival rates were 28.5%vs 57.6%(P=0.021),respectively.The overall survival(OS)rates for the low PMI group vs the high PMI group were 41.3%vs 64.5%(P=0.008),respectively,and for the high IMAC group vs the low IMAC group,they were 29.9%vs 61.9%(P=0.024),respectively.Analysis of the OS rate revealed significant differences in patients aged 60 years or older(P=0.018),those with pT3 or above disease(P=0.021),or those with lymph node metastasis(P=0.006),aside from PMI and IMAC.Multivariate analysis demonstrated that pT3 or above hazard ratio(HR):1.966,95%confidence interval(CI):1.089-3.550,(P=0.025),lymph node metastasis(HR:2.154,95%CI:1.118-4.148,P=0.022),low PMI(HR:2.266,95%CI:1.282-4.006,P=0.005),and high IMAC(HR:2.089,95%CI:1.036-4.214,P=0.022)were significant prognostic factors for esophageal squamous cell carcinoma.CONCLUSIONSkeletal muscle mass and quality before NAC in patients with esophageal squamous cellcarcinoma are significant prognostic factors for postoperative OS.

Comparison of the Two Algorithms of Skeletal Muscle Mass Index: An Observational Study in a Large Cohort of Chinese Adults

Objective: To compare the two skeletal muscle mass index (SMI) algorithms. One is SMM [SMM(%) = total skeletal muscle mass (kg)/body weight mass (kg) × 100%];and the other is SMH [SMH (kg/m2) = total skeletal muscle mass (kg)/height (m)2]. Methods: Body composition, body mass index (BMI) and body fat percentage (BFP) were estimated using a bioelectrical impedance analyzer. SMI was calculated by the two algorithms described above, and measurement parameters were stratified by age, BMI and levels of physical activity. Results: Levels of BMI, BFP, SMM and SMH differed significantly between the sexes. BMI and BFP were positively associated with age, while SMM was negatively associated with age (β = −0.2294, P < 0.001). Furthermore, SMM was determined to have a negative association with BMI (β = −0.5340, P < 0.001), while a positive association between SMH and BMI (β = 0.7930, P β = −0.9849, P β = −0.0642, P < 0.001) were negatively associated with BFP. In both men and women, SMM maintained the analogous correlation with other indicators. In the general population, SMM showed a gradual downward trend from low body weight to grade III obesity (F = 9528.32, P < 0.001), but SMH (F = 34395.46, P F = 9706.20, P < 0.001) had a reciprocal association. BMI, BFP and SMM differences were observed based on levels of physical activity (P < 0.001). However, there was no significant difference in SMH based on exercise (P > 0.05). Conclusions: SMM may be a more ideal and accurate clinical algorithm for SMI because it is more tightly associated with other body composition indices, as compared with SMH.

Sonographic muscle mass assessment in patients after cardiac surgery

BACKGROUND Patients undergoing cardiac surgery particularly those with comorbidities and frailty,experience frequently higher rates of post-operative morbidity,mortality and prolonged hospital length of stay.Muscle mass wasting seems to play important role in prolonged mechanical ventilation(MV)and consequently in intensive care unit(ICU)and hospital stay.AIM To investigate the clinical value of skeletal muscle mass assessed by ultrasound early after cardiac surgery in terms of duration of MV and ICU length of stay.METHODS In this observational study,we enrolled consecutively all patients,following their admission in the Cardiac Surgery ICU within 24 h of cardiac surgery.Bedside ultrasound scans,for the assessment of quadriceps muscle thickness,were performed at baseline and every 48 h for seven days or until ICU discharge.Muscle strength was also evaluated in parallel,using the Medical Research Council(MRC)scale.RESULTS Of the total 221 patients enrolled,ultrasound scans and muscle strength assessment were finally performed in 165 patients(patients excluded if ICU stay<24 h).The muscle thickness of rectus femoris(RF),was slightly decreased by 2.2%[(95%confidence interval(CI):-0.21 to 0.15),n=9;P=0.729]and the combined muscle thickness of the vastus intermedius(VI)and RF decreased by 3.5%[(95%CI:-0.4 to 0.22),n=9;P=0.530].Patients whose combined VI and RF muscle thickness was below the recorded median values(2.5 cm)on day 1(n=80),stayed longer in the ICU(47±74 h vs 28±45 h,P=0.02)and remained mechanically ventilated more(17±9 h vs 14±9 h,P=0.05).Moreover,patients with MRC score≤48 on day 3(n=7),required prolonged MV support compared to patients with MRC score≥49(n=33),(44±14 h vs 19±9 h,P=0.006)and had a longer duration of extracorporeal circulation was(159±91 min vs 112±71 min,P=0.025).CONCLUSION Skeletal quadriceps muscle thickness assessed by ultrasound shows a trend to a decrease in patients after cardiac surgery post-ICU admission and is associated with prolonged duration of MV and ICU length of stay.

Administration of soluble activin receptor 2B increases bone and muscle mass in a mouse model of osteogenesis imperfecta

Osteogenesis imperfecta（OI） comprises a group of heritable connective tissue disorders generally defined by recurrent fractures, low bone mass, short stature and skeletal fragility. Beyond the skeletal complications of OI,many patients also report intolerance to physical activity, fatigue and muscle weakness. Indeed, recent studies have demonstrated that skeletal muscle is also negatively affected by OI, both directly and indirectly. Given the well-established interdependence of bone and skeletal muscle in both physiology and pathophysiology and the observations of skeletal muscle pathology in patients with OI, we investigated the therapeutic potential of simultaneous anabolic targeting of both bone and skeletal muscle using a soluble activin receptor 2B（ACVR2B） in a mouse model of type Ⅲ OI（oim）. Treatment of 12-week-old oim mice with ACVR2 B for 4 weeks resulted in significant increases in both bone and muscle that were similar to those observed in healthy,wild-type littermates. This proof of concept study provides encouraging evidence for a holistic approach to treating the deleterious consequences of OI in the musculoskeletal system.

Urinary Creatinine-Skeletal Muscle Mass Method:A Prediction Equation Based on Computerized Axial Tomography

A classic body composition method is estimation of total body skeletal muscle mass (SM, kg) from 24 h urinary creatinine excretion (Cr, g). Two types of prediction equations were suggested: one assumes a constant SM/Cr ratio; and the other assumes a highly variable SM/Cr ratio. We explored these two extreme possibilities by measuring SM with whole-body computerized axial tomography and collecting Cr during meat-free dietary conditions in 12 healthy young men. Prediction equations were developed in the men that fit these two equation types, SM = 21.8×Cr (SD and CV of SM/Cr ratio, 1.3 kg and 6.0%,respectively) and SM = 18.9 × Cr + 4.1 (r = 0.92, p = 2.55 × 10-5, and SEE = 1.9 kg). The validity of each model is reviewed. This is the first investigation of Cr-SM method using modern techniques for quantifying total body SM mass

Prognostic value of computed tomography derived skeletal muscle mass index in lung cancer:A meta-analysis

BACKGROUND The prognostic role of the skeletal muscle mass index(SMI)derived from computed tomography(CT)imaging been well verified in several types of cancers.However,whether the SMI could serve as a reliable and valuable predictor of long-term survival in lung cancer patients remains unclear.AIM To identify the prognostic value of the CT-derived SMI in lung cancer patients.METHODS The PubMed,Web of Science,and Embase electronic databases were searched up to November 5,2021 for relevant studies.The Reference Citation Analysis databases were used during the literature searching and selection.Hazard ratios(HRs)and 95%confidence intervals(CIs)were calculated to assess the association of the SMI with the overall survival(OS)of lung cancer patients.All statistical analyses were performed with STATA 12.0 software.RESULTS A total of 12 studies involving 3002 patients were included.The pooled results demonstrated that a lower SMI was significantly related to poorer OS(HR=1.23,95%CI:1.11-1.37,P<0.001).In addition,the subgroup analyses stratified by treatment(nonsurgery vs surgery),tumor stage(advanced stage vs early stage),and tumor type(non-small cell lung cancer vs lung cancer)showed similar results.CONCLUSION The CT-derived SMI is a novel and valuable prognostic indicator in lung cancer and might contribute to the clinical management and treatment of lung cancer patients.

Loss of skeletal muscle mass is not specific to type 2 diabetes

Skeletal muscle is a massive insulin-sensitive tissue in the body.Loss of muscle mass is associated with mitochondrial dysfunction,and is often a result of diabetes.Insulin deficiency or insulin resistance can only be seen as reduced skeletal muscle mass.Diabetes is caused by insulin deficiency or insulin resistance;however,insulin resistance is not unique to diabetics.Insulin resistance also exists in many diseases.

Relationship between Muscle Strength, Muscle Mass and BMD in Postmenopausal Female of Zhuang in Guangxi Province of China

Objective: To explore the correlation between muscle strength, muscle mass and bone mineral density (BMD) in Zhuang female population, body composition analysis and grip strength, and to analyze the possible influencing factors of BMD. Methods: 182 postmenopausal women were selected from Guangxi Province of China. Broadband ultrasound attenuation (BUA) was used to evaluate BMD. Grip dynamometer to assess muscle strength. Height, weight and muscle mass of each part were measured by body composition measuring instrument. Body mass index (BMI), skeletal muscle mass index (SMI) and limb skeletal muscle mass (SM) were calculated according to the measurement results. Results: BUA, grip strength and SMI in postmenopausal women of Zhuang nationality showed a decreasing trend with age (p p p r = 0.305, p Conclusion: With the increase of age, the decline rate of muscle strength of postmenopausal Zhuang women in Guangxi is slower than that of BMD and muscle mass. SM can better reflect the BMD level of the body than SMI, and the LSM is the main influencing factor of BMD.

Characteristics of Body Composition and Relationship between Muscle Mass and Muscle Strength among Elderly Women in Different Age Groups

Age-related changes in the body composition of older adults differ among age groups. The purpose of the present study was to clarify the characteristics of body compositions in young (age, 65 - 74 years;yE group) and old (age, ≥75 years;oE group) elderly women, and compare the relationship between muscle mass and strength in elderly women with that in young women for preventing motor function loss in older adults. A total of 30 elderly and 45 young women aged ≥ 65 and 19 - 22 years, respectively, participated in this study. The participants underwent body composition measurement via bioelectrical impedance analysis and examinations of handgrip and leg muscle strength. The age-related body composition changes varied among age groups. Compared with young women, fat-free mass (FFM) in the yE group did not decrease significantly;however, fat mass (FM) and waist-hip ratio (WHR) were significantly greater. Compared with the yE group, decreases in FFM, FM, and WHR in the oE group were significant;furthermore, the decrease in FM measurements was attributed to the loss of FM in the trunk and limbs (upper and lower). The measurement results suggested that the greater FM decrease in the oE group was characterized by decreases in both visceral and subcutaneous fat. In the yE group, the muscle mass was comparable to that in young women;however, there was a remarkable reduction in the lower-limb muscle mass (9% - 10%). In the oE group, muscle mass was reduced in all body parts, including upper and lower limbs and trunk. In young women, significant positive correlations between muscle mass and muscle strength in the upper and lower limbs were observed. No such correlations in the lower limbs were found in elderly women, indicating that muscle mass is not proportionally reflected in muscle strength. In conclusion, for improving and maintaining the health of elderly women, especially those above the age of 75 years, it is important to maintain muscle mass, including muscle strength, and prevent the loss of muscle quality.

Associations of muscle mass,strength,and quality with all-cause mortality in China:a population-based cohort study

Background It remains unclear about the association of muscle mass,strength,and quality with death in the general Chinese population of diverse economical and geographical backgrounds.The present study aimed to comprehensively examine such associations across different regions in China.Methods Based on the China Kadoorie Biobank study,the present study included 23,290 participants who were aged 38 to 88 years and had no prevalent cardiovascular diseases or cancer.Muscle mass and grip strength were measured using calibrated instruments.Arm muscle quality was defined as the ratio of grip strength to arm muscle mass.Low muscle mass,grip strength,and arm muscle quality were defined as the sex-specific lowest quintiles of muscle mass index,grip strength,and arm muscle quality,respectively.Cox proportional hazards models yielded hazard ratios(HRs)and 95%confidence intervals(CIs)for risks of all-cause mortality in relation to muscle mass,strength,and quality.Results During a median follow-up of 3.98 years,739 participants died.The HR(95%CI)of all-cause mortality risk was 1.28(1.08–1.51)for low appendicular muscle mass index,1.38(1.16–1.62)for low total muscle mass index,1.68(1.41–2.00)for low grip strength,and 1.41(1.20–1.66)for low arm muscle quality in models adjusted for sociodemographic characteristics,lifestyle factors,and medical histories.Conclusion Low muscle mass,grip strength,and arm muscle quality are all associated with short-term increased risks of mortality,indicating the importance of maintaining normal muscle mass,strength,and quality for general Chinese adults.

Longitudinal Changes in Sarcopenia Criteria in Older Men with Low Skeletal Muscle Mass Index:A 2-Year Observational Study

Purpose Declines in muscle mass and function are inevitable during the aging process.However,what is the“normal age appropriate”decline of muscle mass and function?Further,is this decline uniform for muscle mass versus functions or between different functional abilities?Using recognized Sarcopenia criteria[i.e.skeletal muscle mass index(SMI)defined as appendicular skeletal muscle mass/height(kg/m^(2)),handgrip strength,gait velocity],the aim of the present project was to determine corresponding changes in community-dwelling men 70 years+with low SMI over a 2-year period.Methods One hundred and seventy-seven(177)men within the lowest SMI quartile of a recent epidemiologic study(n=965)were included in the 2-year follow-up analysis.Muscle mass was determined via direct-segmental,multi-frequency Bio-Impedance-Analysis,handgrip strength was tested with a Jamar hand-dynamometer and habitual gait speed was assessed with photo sensors applying the 10 m protocol.Results SMI,handgrip strength and gait velocity all declined significantly(P<0.001;effect size,d′0.39-1.17),however,with significantly higher reductions(P<0.001)in functional compared with morphologic Sarcopenia criteria(P≤0.006).Less expected,handgrip strength featured a fourfold higher decline compared with gait velocity(−12.8±10.9%versus−3.5±9.0%).Conclusion We provided evidence for significant non-uniform changes of Sarcopenia criteria in a cohort of community dwell-ing men 70 years+with low SMI.We doubt that this result might be a particularity of the selected cohort;however,studies with other(older)cohorts should address this issue in more depth.Of practical relevance,our data further give implications for the prioritization of interventions that address Sarcopenia criteria in older community-dwelling men.

Is sarcopenia effective on survival in patients with metastatic gastric cancer?

BACKGROUND Sarcopenia is a progressively diminishing state characterized by the reduction of muscle mass and density,which is frequently observed in malignancies of solid organs.AIM To assess how sarcopenia affects the overall survival of individuals who have been diagnosed with metastatic gastric cancer.METHODS The study retrospectively included individuals who had been diagnosed with metastatic gastric cancer between January 2008 and December 2020.Sarcopenia was identified through the calculation of the average Hounsfield units(HUAC)using computed tomography(CT)images taken at the time of diagnosis in patients.RESULTS A total of 118 patients with metastatic gastric cancer were evaluated.Sarcopenia was detected in 29 patients(24.6%).The median survival of all patients was 8(1-43)mo.The median survival of patients with sarcopenia was 2 mo,while it was 10 mo for those without sarcopenia(P<0.001).A significant relationship was found between sarcopenia and survival.CONCLUSION Sarcopenia has been observed to impact survival outcomes in various types of solid tumor cancers.Sarcopenic patients can be identified in a short time,easily and inexpensively,by HUAC measurements from CT images used for diagnosis,and survival could be promoted with nutritional support.

Associations between Geriatric Nutrition Risk Index,bone mineral density and body composition in type 2 diabetes patients

BACKGROUND Type 2 diabetes mellitus(T2DM),a fast-growing issue in public health,is one of the most common chronic metabolic disorders in older individuals.Osteoporosis and sarcopenia are highly prevalent in T2DM patients and may result in fractures and disabilities.In people with T2DM,the association between nutrition,sarcopenia,and osteoporosis has rarely been explored.AIM To evaluate the connections among nutrition,bone mineral density(BMD)and body composition in patients with T2DM.METHODS We enrolled 689 patients with T2DM for this cross-sectional study.All patients underwent dual energy X-ray absorptiometry(DXA)examination and were categorized according to baseline Geriatric Nutritional Risk Index(GNRI)values calculated from serum albumin levels and body weight.The GNRI was used to evaluate nutritional status,and DXA was used to investigate BMD and body composition.Multivariate forward linear regression analysis was used to identify the factors associated with BMD and skeletal muscle mass index.RESULTS Of the total patients,394 were men and 295 were women.Compared with patients in tertile 1,those in tertile 3 who had a high GNRI tended to be younger and had lower HbA1c,higher BMD at all bone sites,and higher appendicular skeletal muscle index(ASMI).These important trends persisted even when the patients were divided into younger and older subgroups.The GNRI was positively related to ASMI(men:r=0.644,P<0.001;women:r=0.649,P<0.001),total body fat(men:r=0.453,P<0.001;women:r=0.557,P<0.001),BMD at all bone sites,lumbar spine(L1-L4)BMD(men:r=0.110,P=0.029;women:r=0.256,P<0.001),FN-BMD(men:r=0.293,P<0.001;women:r=0.273,P<0.001),and hip BMD(men:r=0.358,P<0.001;women:r=0.377,P<0.001).After adjustment for other clinical parameters,the GNRI was still significantly associated with BMD at the lumbar spine and femoral neck.Additionally,a low lean mass index and higherβ-collagen special sequence were associated with low BMD at all bone sites.Age was negatively correlated with ASMI,whereas weight was positively correlated with ASMI.CONCLUSION Poor nutrition,as indicated by a low GNRI,was associated with low levels of ASMI and BMD at all bone sites in T2DM patients.Using the GNRI to evaluate nutritional status and using DXA to investigate body composition in patients with T2DM is of value in assessing bone health and physical performance.

Prevalence and outcome of sarcopenia in non-alcoholic fatty liver disease

BACKGROUND Nonalcoholic fatty liver disease(NAFLD)includes a spectrum of conditions,progressing from mild steatosis to advanced fibrosis.Sarcopenia,characterized by decreased muscle strength and mass,shares common pathophysiological traits with NAFLD.An association exists between sarcopenia and increased NAFLD prevalence.However,data on the prevalence of sarcopenia in NAFLD and its impact on the outcomes of NAFLD remain inconsistent.AIM To analyze the prevalence and outcomes of sarcopenia in patients with NAFLD.METHODS We conducted a comprehensive search for relevant studies in MEDLINE,Embase,and Scopus from their inception to June 2023.We included studies that focused on patients with NAFLD,reported the prevalence of sarcopenia as the primary outcome,and examined secondary outcomes,such as liver fibrosis and other adverse events.We also used the Newcastle-Ottawa scale for quality assessment.RESULTS Of the 29 studies included,the prevalence of sarcopenia in NAFLD varied widely(1.6%to 63.0%),with 20 studies reporting a prevalence of more than 10.0%.Substantial heterogeneity was noted in the measurement modalities for sarcopenia.Sarcopenia was associated with a higher risk of advanced fibrosis(odd ratio:1.97,95%confidence interval:1.44-2.70).Increased odds were consistently observed in fibrosis assessment through biopsy,NAFLD fibrosis score/body mass index,aspartate aminotransferase to alanine aminotransferase ratio,diabetes(BARD)score,and transient elastography,whereas the fibrosis-4 score showed no such association.Sarcopenia in NAFLD was associated with a higher risk of steatohepatitis,insulin resistance,cardiovascular risks,and mortality.CONCLUSION This systematic review highlights the critical need for standardized diagnostic criteria and measurement methods for sarcopenia in NAFLD patients.The variability in study designs and assessment methods for sarcopenia and liver fibrosis may account for the inconsistent findings.This review demonstrates the multidimensional impact of sarcopenia on NAFLD,indicating its importance beyond liver-related events to include cardiovascular risks,mortality,and metabolic complications.

Role of metabolic stress for enhancing muscle adaptations: Practical applications

Metabolic stress is a physiological process that occurs during exercise in response to low energy that leads to metabolite accumulation [lactate, phosphate inorganic(Pi) and ions of hydrogen(H^+)] in muscle cells.Traditional exercise protocol(i.e., Resistance training) has an important impact on the increase of metabolite accumulation, which influences hormonal release, hypoxia, reactive oxygen species(ROS) production and cell swelling.Changes in acute exercise routines, such as intensity, volume and rest between sets, are determinants for the magnitude of metabolic stress, furthermore, different types of training, such as lowintensity resistance training plus blood flow restriction and high intensity interval training, could be used to maximize metabolic stress during exercise.Thus, the objective of this review is to describe practical applications that induce metabolic stress and the potential effects of metabolic stress to increase systemic hormonal release, hypoxia, ROS production, cell swelling and muscle adaptations.

Muscle hypertrophy in transgenic mice due to over-expression of porcine myostatin mutated at its cleavage site

Myostatin, a member of the transforming growth factor beta（TGF-β） superfamily, is a dominant inhibitor that acts to limit skeletal muscle growth and development. In this study, we generated transgenic mice that express porcine myostatin containg mutations at its cleavage site（RSRR） to evaluate its effect on muscle mass. Results showed that the weight of four skeletal muscles including gastrocnemius, rectus femoris, tibialis anterior, and pectoralis increased by 17.83 and 28.39%, 21.76 and 28.70%, 34.31 and 41.62%, 53.21 and 27.54% in transgenic male and female mice, respectively, compared to their corresponding non-transgenic control mice. Measurement of muscle fiber size and number indicated that the mean myofiber size increased by 50.73 and 61.30% in transgenic male and female mice respectively compared to the non-transgenic controls. However, there was no difference in the number of myofiber between transgenic and non-transgenic male mice. These results clearly demonstrated that the increase in skeletal muscle mass in transgenic mice is caused by hypertrophy instead of hyperplasia.