Skeletal muscle mass adjusted by height correlated better with muscular functions than that adjusted by body weight in defining sarcopenia

Genetic Prediction of Osteoporosis by Anti-Müllerian Hormone Levels and Reproductive Factors in Women: A Mendelian Randomization Study

Previous observational studies have suggested that anti-Müllerian hormone (AMH) and reproductive factors are linked to reduced bone mineral density (BMD) and an increased risk of osteoporosis (OP) in women. However, related studies are limited, and these traditional observational studies may be subject to residual confounders and reverse causation, while also lacking a more comprehensive observation of various reproductive factors. Univariate and multivariate two-sample Mendelian randomization analyses were conducted to determine the causal associations of AMH levels and six reproductive factors with BMD and OP, using the random-effects inverse-variance weighted method. Heterogeneity was assessed using Cochran's Q-statistic, and sensitivity analyses were performed to identify causal correlations. Age at menarche (AAM) was negatively associated with total body BMD (TB-BMD) in females aged 45-60 and over 60 years, as well as with heel bone mineral density (eBMD). Conversely, age at natural menopause (ANM) was positively associated with TB-BMD in the same age ranges and with eBMD. ANM was only causally associated with self-reported OP and showed no significant correlation with definitively diagnosed OP. Neither AMH level nor other reproductive factors were significantly associated with a genetic predisposition to BMD at any age and OP. Later AAM and earlier ANM are significantly genetically causally associated with decreased BMD but not with OP. AMH levels, length of menstrual cycle, age at first birth, age at last birth, and number of live births, in terms of genetic backgrounds, are not causally related to BMD or OP.

Short-term mortality prediction in acute pulmonary embolism: Radiomics values of skeletal muscle and intramuscular adipose tissue

BACKGROUND

Acute pulmonary embolism (APE) is a potentially life-threatening disorder, emphasizing the importance of accurate risk stratification and survival prognosis. The exploration of imaging biomarkers that can reflect patient survival holds the potential to further enhance the stratification of APE patients, enabling personalized treatment and early intervention. Therefore, in this study, we develop computed tomography pulmonary angiography (CTPA) radiomic signatures for the prognosis of 7- and 30-day all-cause mortality in patients with APE.

METHODS

Diagnostic CTPA images from 829 patients with APE were collected. Two hundred thirty-four features from each skeletal muscle (SM), intramuscular adipose tissue (IMAT) and both tissues combined (SM + IMAT) were calculated at the level of thoracic vertebra 12. Radiomic signatures were derived using 10 times repeated three-fold cross-validation on the training data for SM, IMAT and SM + IMAT for predicting 7- and 30-day mortality independently. The performance of the radiomic signatures was then evaluated on held-out test data and compared with the simplified pulmonary embolism severity index (sPESI) score, a well-established biomarker for risk stratification in APE. Predictive accuracy was assessed by the area under the receiver operating characteristic curve (AUC) with a 95% confidence interval (CI), sensitivity and specificity.

RESULTS

The radiomic signatures based on IMAT and a combination of SM and IMAT (SM + IMAT) achieved moderate performance for the prediction of 30-day mortality on test data (IMAT: AUC = 0.68, 95% CI [0.57-0.78], sensitivity = 0.57, specificity = 0.73; SM + IMAT: AUC = 0.70, 95% CI [0.60-0.79], sensitivity = 0.74, specificity = 0.54). Radiomic signatures developed for predicting 7-day all-cause mortality showed overall low performance. The clinical signature, that is, sPESI, achieved slightly better performance in terms of AUC on test data compared with the radiomic signatures for the prediction of both 7- and 30-day mortality on the test data (7 days: AUC = 0.73, 95% CI [0.67-0.79], sensitivity = 0.92, specificity = 0.16; 30 days: AUC = 0.74, 95% CI [0.66-0.82], sensitivity = 0.97, specificity = 0.16).

CONCLUSIONS

We developed and tested radiomic signatures for predicting 7- and 30-day all-cause mortality in APE using a multicentric retrospective dataset. The present multicentre work shows that radiomics parameters extracted from SM and IMAT can predict 30-day all-cause mortality in patients with APE.

Associations between 3D surface scanner derived anthropometric measurements and body composition in a cross-sectional study

BACKGROUND

3D laser-based photonic scanners are increasingly used in health studies to estimate body composition. However, too little is known about whether various 3D body scan measures estimate body composition better than single standard anthropometric measures, and which body scans best estimate it. Furthermore, little is known about differences by sex and age.

METHODS

105 men and 96 women aged between 18 and 90 years were analysed. Bioelectrical Impedance Analysis was used to estimate whole relative fat mass (RFM), visceral adipose tissue (VAT) and skeletal muscle mass index (SMI). An Anthroscan VITUSbodyscan was used to obtain 3D body scans (e.g. volumes, circumferences, lengths). To reduce the number of possible predictors that could predict RFM, VAT and SMI backward elimination was performed. With these selected predictors linear regression on the respective body compositions was performed and the explained variations were compared with models using standard anthropometric measurements (Body Mass Index (BMI), waist circumference (WC) and waist-to-height-ratio (WHtR)).

RESULTS

Among the models based on standard anthropometric measures, WC performed better than BMI and WHtR in estimating body composition in men and women. The explained variations in models including body scan variables are consistently higher than those from standard anthropometrics models, with an increase in explained variations between 5% (RFM for men) and 10% (SMI for men). Furthermore, the explained variation of body composition was additionally increased when age and lifestyle variables were added. For each of the body composition variables, the number of predictors differed between men and women, but included mostly volumes and circumferences in the central waist/chest/hip area and the thighs.

CONCLUSIONS

3D scan models performed better than standard anthropometric measures models to predict body composition. Therefore, it is an advantage for larger health studies to look at body composition more holistically using 3D full body surface scans.

Cut-off points for low skeletal muscle mass in older adults: Colombia versus other populations

Background: The European Working Group on Sarcopenia in the Elderly defined sarcopenia as a geriatric syndrome with a diagnostic criteria of low skeletal muscle mass (LMM). Various sarcopenia consensuses recommend as cut-offs for LMM, the use of below 2 SDs from the mean skeletal muscle mass index (SMI) of a young reference group. Given the contrast between reported cut-offs, the objective of this study was to establish cut-offs for LMM from older adults in Manizales and compare them with those published in the literature. Methods: This was a prospective, cross-sectional analytical study in 237 healthy elderly patients from the city of Manizales, Colombia. Anthropometric measurements of weight, height and body mass index were estimated. The SMI was estimated with the Xitron Technologies bioimpedance meter using the Janssen formula. For the comparison of SMI cut-offs, studies that evaluated this parameter with bioelectrical impedance analysis (BIA) were taken into account, in addition to being obtained from the -2 SD from the sex-specific mean of a young reference group. Results: The cut-off points for SMI were 8.0 kg/m 2 for men and 6.1 kg/m 2 for women. There was a statistically significant difference when evaluating LMM from the cut-offs of the present study and those reported in Spain, Turkey, and Finland. The cut-off points of SMI derived from this sample of Colombian men and women may be adequate for the diagnosis in the Colombian geriatric population. However, we did not find significant differences when comparing the cut-offs for SMI from a population of older adults and young adults from the same city. Conclusions: The cut-off points of SMI by BIA derived from a sample of Colombian men and women may be adequate for the diagnosis of LMM in the Colombian geriatric population or populations with similar characteristics to those of the sample evaluated here.

Weight Status Prediction Using a Neuron Network Based on Individual and Behavioral Data

BACKGROUND

The worldwide epidemic of weight gain and obesity is increasing in response to the evolution of lifestyles. Our aim is to provide a new predictive method for current and future weight status estimation based on individual and behavioral characteristics.

METHODS

The data of 273 normal (NW), overweight (OW) and obese (OB) subjects were assigned either to the training or to the test sample. The multi-layer perceptron classifier (MLP) classified the data into one of the three weight statuses (NW, OW, OB), and the classification model accuracy was determined using the test dataset and the confusion matrix.

RESULTS

On the basis of age, height, light-intensity physical activity and the daily number of vegetable portions consumed, the multi-layer perceptron classifier achieved 75.8% accuracy with 90.3% for NW, 34.2% for OW and 66.7% for OB. The NW and OW subjects showed the highest and the lowest number of true positives, respectively. The OW subjects were very often confused with NW. The OB subjects were confused with OW or NW 16.6% of the time.

CONCLUSIONS

To increase the accuracy of the classification, a greater number of data and/or variables are needed.

Sex differences between the relationship of trunk muscle mass and whole body sagittal plane alignment in older adults

BACKGROUND

This study aimed to clarify sex differences in the relationship between trunk muscle mass, aging, and whole-body sagittal alignment.

METHODS

Subjects aged 60-89 years who underwent musculoskeletal screening in 2018 were included in the study. Subject demographics, trunk muscle mass (TMM) measured by bioelectrical impedance analysis (BIA), and spinopelvic and lower extremity alignment parameters measured from standing radiographic images were investigated. Additionally, TMM was corrected for BMI (TMM/BMI). The relationship between trunk muscle and whole-body sagittal alignment was analyzed for each age group (young-old group (60-74 years) and old-old group (>75 years)) and sex.

RESULTS

A total of 281 (mean age 75.4 ± 6.7 years, 100 males and 181 females) were enrolled. The trunk muscle mass in both men and women significantly decreased with age. Regarding TMM/BMI, there was no significant difference in men, but there was a significant difference between females in the young-old and old-old groups (p < 0.001). TMM/BMI was significantly correlated with sagittal vertical axis (SVA) and knee flexion angle (KF) in both sexes. In females, TMM/BMI was significantly correlated with thoracic kyphosis in the young-old group, whereas in the old-old group, TMM/BMI was correlated with SVA, PI-LL, and KF.

CONCLUSIONS

TMM was related to trunk anteverion and lower extremity alignment in both sexes. However, the relationship between TMM on alignment differs between sexes. Thoracic hyperkyphosis in young-old adults indicated a decrease in muscle mass, which may be a sign of future malalignment.

Biochemical Markers of Musculoskeletal Health and Aging to be Assessed in Clinical Trials of Drugs Aiming at the Treatment of Sarcopenia: Consensus Paper from an Expert Group Meeting Organized by the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) and the Centre Académique de Recherche et d'Expérimentation en Santé (CARES SPRL), Under the Auspices of the World Health Organization Collaborating Center for the Epidemiology of Musculoskeletal Conditions and Aging

In clinical trials, biochemical markers provide useful information on the drug's mode of action, therapeutic response and side effect monitoring and can act as surrogate endpoints. In pharmacological intervention development for sarcopenia management, there is an urgent need to identify biomarkers to measure in clinical trials and that could be used in the future in clinical practice. The objective of the current consensus paper is to provide a clear list of biochemical markers of musculoskeletal health and aging that can be recommended to be measured in Phase II and Phase III clinical trials evaluating new chemical entities for sarcopenia treatment. A working group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) proposed classifying biochemical markers into 2 series: biochemical markers evaluating musculoskeletal status and biochemical markers evaluating causal factors. For series 1, the group agreed on 4 biochemical markers that should be assessed in Phase II or Phase III trials (i.e., Myostatin-Follistatin, Brain Derived Neurotrophic Factor, N-terminal Type III Procollagen and Serum Creatinine to Serum Cystatin C Ratio - or the Sarcopenia Index). For series 2, the group agreed on 6 biochemical markers that should be assessed in Phase II trials (i.e., the hormones insulin-like growth factor-1 (IGF-I), dehydroepiandrosterone sulphate, and cortisol, and the inflammatory markers C-reactive protein (CRP), interleukin-6 and tumor necrosis factor-α), and 2 in Phase III trials (i.e., IGF-I and CRP). The group also proposed optional biochemical markers that may provide insights into the mode of action of pharmacological therapies. Further research and development of new methods for biochemical marker assays may lead to the evolution of these recommendations.

Cross-sectional and longitudinal associations between body flexibility and sarcopenia

BACKGROUND

The associations between body flexibility and sarcopenia were not well understood. This study aimed to explore the cross-sectional and longitudinal associations of flexibility with sarcopenia.

METHODS

Our study selected participants aged 50-80 from the WELL-China cohort and the Lanxi cohort. Participants from the urban area of the Lanxi cohort were followed up 4 years later. Body flexibility was measured by the sit-and-reach test. Muscle mass was evaluated by dual-energy X-ray absorptiometry. Muscle strength was evaluated using handgrip strength. Sarcopenia was defined as having both low muscle mass and low muscle strength. We used multivariable logistic regressions to assess the cross-sectional associations of body flexibility with low muscle mass, low muscle strength and sarcopenia. We also used multivariable logistic regressions to explore the associations of baseline flexibility and 4-year changes in flexibility with incident low muscle mass, low muscle strength and sarcopenia.

RESULTS

A total of 9453 participants were enrolled in the cross-sectional study, and 1233 participants were included in the longitudinal analyses. In the cross-sectional analyses, compared with low body flexibility, high body flexibility was inversely associated with low muscle mass (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.50-0.68; P < 0.001), low muscle strength (OR, 0.62; 95% CI, 0.55-0.69; P < 0.001) and sarcopenia (OR, 0.52; 95% CI, 0.41-0.65; P < 0.001), and these associations did not differ in different age groups, sex or physical activity levels. In the longitudinal analyses, compared with participants with low body flexibility, participants with high body flexibility had lower risk of the incident low muscle strength (OR, 0.53; 95% CI, 0.38-0.74; P < 0.001) and sarcopenia (OR, 0.36; 95% CI, 0.21-0.61; P < 0.001), but not incident low muscle mass (OR, 0.59; 95% CI, 0.33-1.06; P = 0.076). Every 1-cm increase in flexibility during 4 years was associated with reduced risk of incident low muscle mass (OR, 0.96; 95% CI, 0.93-1.00; P = 0.025), low muscle strength (OR, 0.96; 95% CI, 0.94-0.98; P = 0.002) and sarcopenia (OR, 0.96; 95% CI, 0.93-0.99; P = 0.007).

CONCLUSIONS

High flexibility was associated with reduced risk of incident low muscle strength and sarcopenia. Increases in flexibility were associated with reduced risk of incident low muscle mass, low muscle strength and sarcopenia. Flexibility exercises and monitoring the dynamic change of flexibility might be helpful in preventing sarcopenia among adults aged 50 years or over.

Handgrip strength reference intervals in Swedish, young, healthy adults: The LBA study

OBJECTIVES

Handgrip strength (HGS) is a surrogate marker of general risk and nutritional status, frequently used in clinical practice. This study aimed to determine clinically useful reference intervals for healthy, young adults from Northern Europe.

METHODS

This cross-sectional study was conducted in central Sweden, recruiting 834 young, nonsmoking adults ages 18 to 26 y. Subjects responded to a questionnaire on general health status, medication (including contraceptives), exercise habits, and parental and their own country of birth. Anthropometry, bioimpedance analysis for determination of fat-free mass (FFM), and HGS was measured. Reference intervals were calculated as mean and standard deviation. Differences between men, women, and women using estrogen contraceptives were analyzed using an analysis of variance with Tukey's post hoc test. Associations between HGS and determinant variables were analyzed using Spearman and linear regressions.

RESULTS

Men and women differed in HGS, but no significant difference was found in average HGS based on contraceptive use in women. Mean HGS was 53 kg in men and 34 kg in women, with a range of 22 kg to 90 kg in men and 16 kg to 73 kg in women. Height correlated with HGS. Subjects with a body mass index (BMI) <20 had statistically significantly lower HGS than those in higher BMI groups. There was no statistically significant mean difference between the group of subjects with a BMI of 20 to 25 and those with BMI >25 in neither men nor women. HGS in both sexes showed a gradual increase through tertiles of FFM. In linear regression models, sex, height, and FFM were the main determinants of HGS.

CONCLUSIONS

In this study, we established reference intervals for HGS in healthy Swedish adults ages 18 to 26 y. As a surrogate marker of whole-body muscle mass, these reference intervals can be used in health assessments and the planning of health-promoting measures in the individual young adults. Differences in HGS based on height warrant height-specific reference intervals that should be established locally.

Ageing of skeletal muscle extracellular matrix and mitochondria: finding a potential link

Aim: To discuss the progress of extracellular matrix (ECM) characteristics, mitochondrial homeostasis, and their potential crosstalk in the pathogenesis of sarcopenia, a geriatric syndrome characterized by a generalized and progressive reduction in muscle mass, strength, and physical performance.Methods: This review focuses on the anatomy and physiology of skeletal muscle, alterations of ECM and mitochondria during ageing, and the role of the interplay between ECM and mitochondria in the pathogenesis of sarcopenia.Results: Emerging evidence points to a clear interplay between mitochondria and ECM in various tissues and organs. Under the ageing process, the ECM undergoes changes in composition and physical properties that may mediate mitochondrial changes via the systematic metabolism, ROS, SPARC pathway, and AMPK/PGC-1α signalling, which in turn exacerbate muscle degeneration. However, the precise effects of such crosstalk on the pathobiology of ageing, particularly in skeletal muscle, have not yet been fully understood.Conclusion: The changes in skeletal muscle ECM and mitochondria are partially responsible for the worsened muscle function during the ageing process. A deeper understanding of their alterations and interactions in sarcopenic patients can help prevent sarcopenia and improve its prognoses.

Measurement of skeletal muscle volume is useful for predicting prognosis in patients with liver cirrhosis

BACKGROUND

Hepatic venous pressure gradient (HVPG) and the model for end-stage liver disease (MELD) score were previously reported as prognostic factors for outcome in patients with liver cirrhosis (LC), and recently, the presence of sarcopenia was reported to be an indicator of worse prognosis in these patients.

AIM

This retrospective study aimed to clarify the importance of sarcopenia as a prognostic factor in patients with LC.

MATERIAL AND METHODS

The MELD-Na score, HVPG, and skeletal muscle index (SMI) were measured in 202 patients between January 2013 and August 2020. We performed linear regression analysis between HVPG and SMI and calculated suitable cutoff values of HVPG for predicting presarcopenia and of HVPG, ΔSMI (i.e. the decrease in SMI per year, for predicting survival). Overall survival rates with the HVPG and ΔSMI cutoff values were compared by Kaplan-Meier estimates and log-rank tests. Prognostic factors for survival were analyzed by Cox regression univariate and multivariate analyses.

RESULTS

In total, 71% (143/202) of patients presented with presarcopenia. Linear regression showed a significantly negative correlation between HVPG and SMI. Survival was significantly worse in the group with presarcopenia than in the group without. Survival was worse also in the group with an HVPG value ≥ 15 and ΔSMI ≥ -2.4. Cox regression multivariate analyses showed that MELD-Na score, HVPG, HVPG ≥ 15, ΔSMI, and ΔSMI ≥ -2.4 were independent prognostic factors.

CONCLUSION

Skeletal muscle volume, especially ΔSMI, has a prognostic value equivalent to that of the MELD-Na score and HVPG.

Bioelectrical impedance analysis to estimate one-repetition maximum measurement of muscle strength for leg press in healthy young adults

Resistance training (RT) progress is determined by an individual's muscle strength, measured by one-repetition maximum (1RM). However, this evaluation is time-consuming and has some safety concerns. Bioelectrical impedance analysis (BIA) is a valid and easy-to-use method to assess skeletal muscle mass (SMM). Although BIA measurements are often correlated with muscle strength, few studies of 1RM for RT and BIA measurements are available. This observational study examined the relationship between 1RM and BIA measurements and developed BIA-based prediction models for 1RM. Thirty-five healthy young Japanese adults were included. SMM and the skeletal muscle mass index (SMI) were measured using the BIA device. In addition, dominant-leg 1RM was measured using a unilateral leg-press (LP) machine. The correlations between BIA measurements and 1RM were calculated, and simple regression analyses were performed to predict 1RM from the BIA variables. The results showed significant correlations between 1RM and dominant-leg SMM (R = 0.845, P = 0.0001) and SMI (R = 0.910, P = 0.0001). The prediction models for 1RM for LP derived from SMM of the dominant leg and SMI were Y = 8.21x + 8.77 (P = 0.0001), R² = 0.73, and Y = 15.53x - 36.33 (P = 0.0001), R² = 0.83, respectively. Our results indicated that BIA-based SMI might be used to predict 1RM for LP accurately.

MIF1 and MIF2 Myostatin Peptide Inhibitors as Potent Muscle Mass Regulators

The use of peptides as drugs has progressed over time and continues to evolve as treatment paradigms change and new drugs are developed. Myostatin (MSTN) inhibition therapy has shown great promise for the treatment of muscle wasting diseases. Here, we report the MSTN-derived novel peptides MIF1 (10-mer) and MIF2 (10-mer) not only enhance myogenesis by inhibiting MSTN and inducing myogenic-related markers but also reduce adipogenic proliferation and differentiation by suppressing the expression of adipogenic markers. MIF1 and MIF2 were designed based on in silico interaction studies between MSTN and its receptor, activin type IIB receptor (ACVRIIB), and fibromodulin (FMOD). Of the different modifications of MIF1 and MIF2 examined, _Ac-MIF1 and _Ac-MIF2-_NH2 significantly enhanced cell proliferation and differentiation as compared with non-modified peptides. Mice pretreated with _Ac-MIF1 or _Ac-MIF2-_NH2 prior to cardiotoxin-induced muscle injury showed more muscle regeneration than non-pretreated controls, which was attributed to the induction of myogenic genes and reduced MSTN expression. These findings imply that _Ac-MIF1 and _Ac-MIF2-_NH2 might be valuable therapeutic agents for the treatment of muscle-related diseases.

Population-based cohort imaging: skeletal muscle mass by magnetic resonance imaging in correlation to bioelectrical-impedance analysis

BACKGROUND

Skeletal muscle mass is subjected to constant changes and is considered a good predictor for outcome in various diseases. Bioelectrical-impedance analysis (BIA) and magnetic resonance imaging (MRI) are approved methodologies for its assessment. However, muscle mass estimations by BIA may be influenced by excess intramuscular lipids and adipose tissue in obesity. The objective of this study was to evaluate the feasibility of quantitative assessment of skeletal muscle mass by MRI as compared with BIA.

METHODS

Subjects from a population-based cohort underwent BIA (50 kHz, 0.8 mA) and whole-body MRI including chemical-shift encoded MRI (six echo times). Abdominal muscle mass by MRI was quantified as total and fat-free cross-sectional area by a standardized manual segmentation-algorithm and normalized to subjects' body height² (abdominal muscle mass indices: AMMI_MRI ).

RESULTS

Among 335 included subjects (56.3 ± 9.1 years, 56.1% male), 95 (28.4%) were obese (BMI ≥ 30 kg/m² ). MRI-based and BIA-based measures of muscle mass were strongly correlated, particularly in non-obese subjects [r < 0.74 in non-obese (P < 0.001) vs. r < 0.56 in obese (P < 0.001)]. Median AMMI_Total(MRI) was significantly higher in obese as compared with non-obese subjects (3246.7 ± 606.1 mm² /m² vs. 2839.0 ± 535.8 mm² /m² , P < 0.001, respectively), whereas the ratio AMMI_Fat-free /AMMI_Total (by MRI) was significantly higher in non-obese individuals (59.3 ± 10.1% vs. 53.5 ± 10.6%, P < 0.001, respectively). No significant difference was found regarding AMMI_{Fat-free(MRI)} (P = 0.424). In analyses adjusted for age and sex, impaired glucose tolerance and measures of obesity were significantly and positively associated with AMMI_Total(MRI) and significantly and inversely with the ratio AMMI_{Fat-free(MRI)} /AMMI_Total(MRI) (P < 0.001).

CONCLUSIONS

MRI-based assessment of muscle mass is feasible in population-based imaging and strongly correlated with BIA. However, the observed weaker correlation in obese subjects may explain the known limitation of BIA in obesity and promote MRI-based assessments. Thus, skeletal muscle mass parameters by MRI may serve as practical imaging biomarkers independent of subjects' body weight.

Impact of Sarcopenia and Myosteatosis in Non-Cirrhotic Stages of Liver Diseases: Similarities and Differences across Aetiologies and Possible Therapeutic Strategies

Sarcopenia is defined as a loss of muscle strength, mass and function and it is a predictor of mortality. Sarcopenia is not only a geriatric disease, but it is related to several chronic conditions, including liver diseases in both its early and advanced stages. Despite the increasing number of studies exploring the role of sarcopenia in the early stages of chronic liver disease (CLD), its prevalence and the relationship between these two clinical entities are still controversial. Myosteatosis is characterized by fat accumulation in the muscles and it is related to advanced liver disease, although its role in the early stages is still under researched. Therefore, in this narrative review, we firstly aimed to evaluate the prevalence and the pathogenetic mechanisms underlying sarcopenia and myosteatosis in the early stage of CLD across different aetiologies (mainly non-alcoholic fatty liver disease, alcohol-related liver disease and viral hepatitis). Secondly, due to the increasing prevalence of sarcopenia worldwide, we aimed to revise the current and the future therapeutic approaches for the management of sarcopenia in CLD.

The Correlation of Serum Myostatin Levels with Gait Speed in Kidney Transplantation Recipients

The primary role of myostatin is to negatively regulate skeletal muscle growth. The gait speed is a noninvasive, reliable parameter that predicts cardiovascular risk and mortality. This study evaluated the relationship between serum myostatin concentrations and gait speeds in patients who had undergone kidney transplantation (KT). A total of 84 KT recipients were evaluated. A speed of less than 1.0 m/s was categorized into the low gait speed group. We measured serum myostatin concentrations with a commercial enzyme-linked immunosorbent assay. KT recipients in the low gait speed group had significantly older age, as well as higher body weight, body mass index (BMI), skeletal muscle index, serum triglyceride levels, glucose levels, and blood urea nitrogen levels, lower estimated glomerular filtration rates and serum myostatin levels, a higher percentage of steroid use, and a lower proportion of mycophenolate mofetil use. Multivariable logistic regression analysis revealed that lower myostatin levels and lower frequency of mycophenolate mofetil use were independently associated with low gait speed. In multivariable stepwise linear regression analysis, myostatin levels were positively correlated with gait speeds, and age and BMI were negatively correlated with gait speeds. In the study, serum myostatin levels were significantly lower in the low gait speed group. Subjects in the low gait speed group also had greater BMI and older age.

Masseter muscle parameters can function as an alternative for skeletal muscle mass assessments on cross-sectional imaging at lumbar or cervical vertebral levels

BACKGROUND

Patients with head and neck cancer are at increased risk of developing low skeletal muscle mass (SMM), which is associated with adverse treatment outcomes and prognosis. Low SMM is most commonly assessed by the skeletal muscle cross sectional area (CSA) at the third lumbar vertebra (L3) or more recently the third cervical vertebra (C3). L3 is not routinely imaged and C3 may be impacted by disease or treatment. As an alternative we analyzed masseter muscle characteristics and their relationship with L3 and C3 skeletal muscle CSA and overall survival (OS).

METHODS

In this single-center retrospective study, 99 patients with head and neck cancer who underwent whole body FDG-PET/CT-scans were reviewed. Of these patients, L3 CSA, C3 CSA, masseter CSA, masseter thickness, masseter volume, masseter Hounsfield Unit values, lumbar skeletal muscle index (LSMI), cervical skeletal muscle index (CSMI), and masseter skeletal muscle index (MSMI) were recorded and correlated with each other and with OS.

RESULTS

We included 72 male and 27 female patients. The masseter muscle parameters differed significantly between sexes. The Spearman correlation coefficients for C3 CSA-Masseter volume and L3 CSA-Masseter volume were 0.639 and 0.531 (P<0.001) respectively. In multivariate analysis low MSMI was a predictor of OS (HR 2.227, P=0.009).

CONCLUSIONS

There is a moderate to strong association between the masseter muscle volume (MV) and C3 CSA and L3 CSA. MSMI predicts OS. Further research should investigate the relationship between muscle function and masseter muscle parameters and impacting factors on masseter muscle dimensions.

Comparison of appendicular lean mass indices for predicting physical performance in Korean hemodialysis patients: A cross-sectional study

ABSTRACT

Few studies have examined the optimal adjustment indices for predicting low muscle strength or physical performance in hemodialysis (HD) patients. Thus, the present study aimed to identify optimal adjustment indices for predicting strength and/or physical performance in HD patients.Our study was performed at an HD center (n = 84). Appendicular lean mass (ALM; kg) was calculated using dual-energy X-ray absorptiometry. ALM were adjusted to body weight, height2 (Ht2), body surface area, or body mass index. Physical performance tests (sit-to-stand test performed 5 times test, sit-to-stand for 30 second test, 6-minute walk test, timed up and go test, gait speed, hand grip strength, average steps per day (AST), and short physical performance battery) were also evaluated. Participants with a below median value for each physical performance test were defined as the low group.The mean participant age was 55.6 ± 12.8 years; 44 (52.4%) were men. The univariate analysis revealed a significant difference in ALM/Ht2 values between the low and normal physical performance group in all physical performance tests except short physical performance battery. The multivariate analysis revealed a significant difference in ALM/Ht2 between the low and normal physical performance groups in hand grip strength, 5 times sit-to-stand test, sit-to-stand for 30-second test, and AST. In women on HD, most indices were not associated with physical performance or strength.We demonstrated that, in men on HD, ALM/Ht2 may be the most valuable among various variables adjusted for ALM for predicting physical performance or strength.

Impact of Different Operational Definitions of Sarcopenia on Prevalence in a Population-Based Sample: The Salus in Apulia Study

Background: In 2010, the European Working Group on Sarcopenia in Older People (EWGSOP1) issued its first operational definition to diagnose sarcopenia. This was updated in 2019 with a revised sequence of muscle mass and muscle strength (EWGSOP2). The aim of the study was to investigate the impact of these different operational definitions on sarcopenia prevalence in a representative population-based sample. Methods: For each algorithm, the prevalence of sarcopenia-related categories was calculated and related to sociodemographic and lifestyle variables, anthropometric parameters, and laboratory biomarkers. The present analysis used data from the Salus in Apulia Study (Italy, 740 subjects, mean age 75.5 ± 5.9 years, 54% women). Results: The application of the EWGSOP1 adapted algorithm resulted in 85% [95% confidence intervals (CI): 82–88%] non-sarcopenic subjects, 10% (95% CI: 8–12%) pre-sarcopenic subjects, and 5% (95% CI: 3–7%) sarcopenic/severe sarcopenic subjects. The sarcopenia-related categories were inversely related to weight and body mass index (BMI), particularly in overweight/obese subjects, and these categories showed favorable metabolic biomarkers. The EWGSOP2 algorithm yielded 73% (95% CI: 69–76%) non-sarcopenic subjects, 24% (95% CI: 21–27%) probably sarcopenic subjects, and 4% (95% CI: 2–5%) sarcopenic subjects. Conclusions: The present study identified BMI as a potential confounder of the prevalence estimates of sarcopenia-related categories in population-based settings with different EWGSOP operational definitions.

Related factors for preserving firefighter's pulmonary function

Background

Firefighters are constantly exposed to harmful substances in the respiratory tract and require management measures. We comprehensively compared factors affecting the lung function of firefighters to identify management measures that can reduce the deterioration of lung function.

Methods

A cross-sectional study was conducted in 1,108 male firefighters. Subjects were surveyed with self-written questionnaires that included a history of smoking, number of workouts per week, work department, and medical history, including diseases that could affect lung function. Body mass index was calculated using an automatic body measurement instrument and body fat, body fat percentage, muscle mass, and skeletal muscle mass were measured using Inbody 770. Based on the body weight obtained from body measurements, skeletal muscle mass height-adjusted skeletal muscle index (hSMI) compared to height was determined. For lung function, forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), FEV₁/FVC, and peak expiratory flow (PEF) were measured using a spirometer HI-801. Analysis of variance and independent t-tests were performed for univariate analysis of factors that could affect lung function, and multiple regression analysis was performed for multivariate analysis.

Results

When the factors relating lung function were analyzed using regression analysis, FEV₁ was negatively correlated with age, body fat percentage, and duty year, positively with height and hSMI. FVC increased with height and hSMI, decreased with age, body fat percentage, and duty year. FEV₁/FVC was related with age, height, body fat percentage and working history. Height and muscle mass were analyzed as related factors on PEF. When the analysis was conducted on firefighters who exercised more than 3 times a week, working history had lower relation with FEV₁ and body fat percentage had no relation with FEV₁/FVC.

Conclusion

We suggest management measures to reduce body fat percentage and increase skeletal muscle mass to maintain lung function in firefighters.

Prevalence of sarcopenia in older Chinese adults: a systematic review and meta-analysis

OBJECTIVE

This meta-analysis was conducted to estimate the overall prevalence of sarcopenia in older Chinese adults.

DESIGN

Systematic review and meta-analysis.

PARTICIPANTS

A literature research was conducted using the PubMed, Web of Science, China National Knowledge Infrastructure, CQVIP and Wanfang databases. The following search terms in the abstract were used: "sarcopenia" in combination with the terms "prevalence," "epidemiology" and "China." All studies published from January 2010 to November 2020 were included. The random-effect model was used to estimate the prevalence of sarcopenia. The sex-specific prevalence of sarcopenia at a 95% CI was also calculated using different criteria for defining sarcopenia.

PRIMARY OUTCOME MEASURES

The overall prevalence of sarcopenia in older Chinese adults.

RESULTS

In total, 23 articles were included in this meta-analysis involving 21 564 participants. On the basis of the Asian Working Group for Sarcopenia criterion, the overall prevalence of sarcopenia among the elderly in China was 14% (95% CI 11% to 18%); the prevalence was higher in Chinese women than in men (15% vs 14%).

CONCLUSIONS

This systematic review is the first estimation of the pooled prevalence of sarcopenia in older Chinese adults. Our results suggest that China has a large number of patients with sarcopenia. These findings would be useful for sarcopenia prevention in China. There is a high degree of heterogeneity, and although there are a large number of cases and could be an emerging public health issue, more research is required to make these claims.

PROSPERO REGISTRATION NUMBER

CRD42020223405.

Prevalence and Risk Factors of Sarcopenia among Older Adults Aged ≥65 Years Admitted to Daycare Centers of Taiwan: Using AWGS 2019 Guidelines

Sarcopenia is a geriatric syndrome which is likely to cause disability, body unbalance, and mortality and thus can lead to heavy healthcare expenditure and caregiver burden. Although some studies have addressed the prevalence of sarcopenia for older adults, there are limited studies conducted in daycare centers. The present study aimed to (i) estimate the prevalence of sarcopenia and (ii) explore associated factors of sarcopenia and standing balance among older adults admitted to daycare centers in Taiwan. The cross-sectional study collected data on demographics, health status, handgrip strength, gait speed (GS), skeletal muscle mass, Taiwan-Mini Nutritional Assessment Short-Form (TW-MNA-SF), and Short Physical Performance Battery from daycare centers in northern Taiwan. The definition of sarcopenia followed the Asian Working Group for Sarcopenia 2019 guidelines. Among 173 participants ≥65 year-old, 50.9% had confirmed sarcopenia, 47.4% possible sarcopenia, and 1.7% normal. Results showed that calf circumference, TW-MNA-SF, dementia, and body mass index (BMI) were associated with sarcopenia. Moreover, BMI, GS, and sarcopenia were associated factors of standing balance. The study estimated a high prevalence of sarcopenia in daycare centers and identified some significant factors of sarcopenia and standing balance. Early nutritional and physiotherapy interventions could benefit older adults to prevent sarcopenia or unbalance.

Skeletal muscle mass at C3 may not be a strong predictor for skeletal muscle mass at L3 in sarcopenic patients with head and neck cancer

PURPOSE

To evaluate the feasibility of using skeletal muscle mass (SMM) at C3 (C3 SMM) as a diagnostic marker for sarcopenia in head and neck cancer (HNC) patients.

METHODS

We evaluated 165 HNC patients and 42 healthy adults who underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography scans. The paravertebral muscle area at C3 and skeletal muscle area at L3 were measured by CT. Pearson's correlation was used to assess the relationship between L3 and C3 SMMs. The prediction model for L3 SMM was developed by multiple linear regression. Then the correlation and the agreement between actual and predicted L3 SMMs were assessed. To evaluate the diagnostic value of C3 SMM for sarcopenia, the receiver operating characteristics (ROC) curves were analyzed.

RESULTS

Of the 165 HNC patients, 61 (37.0%) were sarcopenic and 104 (63.0%) were non-sarcopenic. A very strong correlation was found between L3 SMM and C3 SMM in both healthy adults (r = 0.864) and non-sarcopenic patients (r = 0.876), while a fair association was found in sarcopenic patients (r = 0.381). Prediction model showed a very strong correlation between actual SMM and predicted L3 SMM in both non-sarcopenic patients and healthy adults (r > 0.9), whereas the relationship was moderate in sarcopenic patients (r = 0.7633). The agreement between two measurements was good for healthy subjects and non-sarcopenic patients, while it was poor for sarcopenic patients. On ROC analysis, predicted L3 SMM showed poor diagnostic accuracy for sarcopenia.

CONCLUSIONS

A correlation between L3 and C3 SMMs was weak in sarcopenic patients. A prediction model also showed a poor diagnostic accuracy. Therefore, C3 SMM may not be a strong predictor for L3 SMM in sarcopenic patients with HNC.

Suboptimal Tongue Pressure Is Associated with Risk of Malnutrition in Community-Dwelling Older Individuals

The tongue plays an important role in swallowing, and its dysfunction theoretically leads to inadequate oral intake and subsequent malnutrition. This study aimed to explore how different levels of tongue pressure are related to malnutrition among community-dwelling older individuals. The target population was community-dwelling adults aged ≥ 65 years. Tongue pressure was measured using the Iowa Oral Performance Instrument, whereas the mini nutrition assessment (MNA) test was administered to determine the nutritional status. A full MNA score of less than 24 points was defined as risk of malnutrition. Multivariate logistic regression analyses were conducted to calculate the odds ratio (OR) of risk of malnutrition among different quartiles of tongue pressure. Among the 362 participants, 26 (7.1%) were classified as having risk of malnutrition. Body weight, body mass index, handgrip strength, skeletal muscle mass index, sum MNA score, and serum levels of albumin were lower in the malnutrition risk groups than in the normal nutrition status group. A positive correlation was identified between tongue pressure and the MNA score (r = 0.143, p < 0.01). Treating the subgroup of the highest quartile of tongue pressure as the reference, the crude odds ratio (OR) of having risk of malnutrition was 5.37 (95% CI, 1.14–25.28) in the subgroup at the third quartile, 3.10 (95% CI, 0.60–15.84) in the subgroup at the second quartile, and 3.95 (95% CI, 0.81–19.15) in the subgroup at the lowest quartile. After adjustment for age and sex, the subgroup in the third quartile still presented with a significantly higher risk (OR, 4.85; 95% CI, 1.02–22.99) of risk of malnutrition. Compared with the subgroup at the highest quartile of tongue pressure, the crude OR for all the subgroups in the lower three quartiles was 4.17 (95% CI, 0.96–18.04), showing borderline significance (p = 0.05). In conclusion, we found hints for an association between decreased tongue pressure and an increased risk of malnutrition in community-dwelling older individuals. Older people with suboptimal tongue pressure should undergo a thorough assessment of their nutritional status and swallowing function for the early identification of subclinical malnutrition and dysphagia.

Sarcopenia Is Associated With Increased Risks of Rotator Cuff Tendon Diseases Among Community-Dwelling Elders: A Cross-Sectional Quantitative Ultrasound Study

Backgrounds: Recently, the association between sarcopenia and various musculoskeletal disorders, such as lumbar spine stenosis and fibromyalgia, has been highlighted. However, the relationship between sarcopenia and rotator cuff tendon diseases has rarely been investigated. This study aimed to evaluate whether sarcopenia was associated with shoulder pain and to determine whether rotator cuff tendons differed in echotexture between the sarcopenic and non-sarcopenic populations.

Methods: The thickness and echogenicity ratio of the tendon vs. the overlying muscle (ER_TM) or subcutaneous tissue (ER_TT) were measured using high-resolution ultrasonography in 56 sarcopenic patients and 56 sex- and age- matched controls. The association between ultrasound measurements of the rotator cuff tendon complex and sarcopenia was investigated using the generalized estimating equation (GEE).

Results: The sarcopenic group had an increased prevalence of shoulder pain. Based on the GEE analysis, sarcopenia was significantly associated with an increase in supraspinatus tendon thickness (β coefficient = 0.447, p < 0.001) and a decrease in the ER_TM for the biceps long head and rotator cuff tendons. A negative trend of association was observed between sarcopenia and ER_TT in the supraspinatus tendons (β coefficient = −0.097, p = 0.070). Nevertheless, sarcopenia was not associated with an increased risk of rotator cuff tendon tears.

Conclusions: Patients with sarcopenia have a higher risk of shoulder pain. A consistent tendinopathic change develops in the supraspinatus tendons in sarcopenic patients. However, sarcopenia is less likely to be associated with serious rotator cuff pathology, such as tendon tears. Prospective cohort studies are warranted to explore the causal relationship between sarcopenia and shoulder disorders.

The Prevalence of Sarcopenia in Chinese Older Adults: Meta-Analysis and Meta-Regression

Sarcopenia, with risk factors such as poor nutrition and physical inactivity, is becoming prevalent among the older population. The aims of this study were (i) to systematically review the existing data on sarcopenia prevalence in the older Chinese population, (ii) to generate pooled estimates of the sex-specific prevalence among different populations, and (iii) to identify the factors associated with the heterogeneity in the estimates across studies. A search was conducted in seven databases for studies that reported the prevalence of sarcopenia in Chinese older adults, aged 60 years and over, published through April 2020. We then performed a meta-analysis to estimate the pooled prevalence, and investigated the factors associated with the variation in the prevalence across the studies using meta-regression. A total of 58 studies were included in this review. Compared with community-dwelling Chinese older adults (men: 12.9%, 95% CI: 10.7-15.1%; women: 11.2%, 95% CI: 8.9-13.4%), the pooled prevalence of sarcopenia in older adults from hospitals (men: 29.7%, 95% CI:18.4-41.1%; women: 23.0%, 95% CI:17.1-28.8%) and nursing homes (men: 26.3%, 95% CI: 19.1 to 33.4%; women: 33.7%, 95% CI: 27.2 to 40.1%) was higher. The multivariable meta-regression quantified the difference of the prevalence estimates in different populations, muscle mass assessments, and areas. This study yielded pooled estimates of sarcopenia prevalence in Chinese older adults not only from communities, but also from clinical settings and nursing homes. This study added knowledge to the current epidemiology literature about sarcopenia in older Chinese populations, and could provide background information for future preventive strategies, such as nutrition and physical activity interventions, tailored to the growing older population.

Variants in NEB and RIF1 genes on chr2q23 are associated with skeletal muscle index in Koreans: genome-wide association study

Although skeletal muscle plays a crucial role in metabolism and influences aging and chronic diseases, little is known about the genetic variations with skeletal muscle, especially in the Asian population. We performed a genome-wide association study in 2,046 participants drawn from a population-based study. Appendicular skeletal muscle mass was estimated based on appendicular lean soft tissue measured with a multi-frequency bioelectrical impedance analyzer and divided by height squared to derive the skeletal muscle index (SMI). After conducting quality control and imputing the genotypes, we analyzed 6,391,983 autosomal SNPs. A genome-wide significant association was found for the intronic variant rs138684936 in the NEB and RIF1 genes (β = 0.217, p = 6.83 × 10^–9). These two genes are next to each other and are partially overlapped on chr2q23. We conducted extensive functional annotations to gain insight into the directional biological implication of significant genetic variants. A gene-based analysis identified the significant TNFSF9 gene and confirmed the suggestive association of the NEB gene. Pathway analyses showed the significant association of regulation of multicellular organism growth gene-set and the suggestive associations of pathways related to skeletal system development or skeleton morphogenesis with SMI. In conclusion, we identified a new genetic locus on chromosome 2 for SMI with genome-wide significance. These results enhance the biological understanding of skeletal muscle mass and provide specific leads for functional experiments.

A Comprehensive Review Evaluating the Impact of Protein Source (Vegetarian vs. Meat Based) in Hepatic Encephalopathy

Hepatic encephalopathy (HE) is a common neurological consequence in patients with cirrhosis and has a healthcare burden of USD 5370 to 50,120 per patient annually. HE significantly hampers the quality of life and is a major cause of morbidity and mortality. Patients with cirrhosis are at a high risk for protein-calorie malnutrition due to altered metabolism. Current evidence has changed the old belief of protein restriction in patients with cirrhosis and now 1.2 to 1.5 g/kg/day protein intake is recommended. Case series and studies with small numbers of participants showed that a vegetarian protein diet decreases the symptoms of HE when compared to a meat-based diet, but the evidence is limited and requires further larger randomized controlled trials. However, vegetable or milk-based protein diets are good substitutes for patients averse to meat intake. Branch chain amino acids (BCAA) (leucine, isoleucine and valine) have also been shown to be effective in alleviating symptoms of HE and are recommended as an alternative therapy in patients with cirrhosis for the treatment of HE. In this review, we provide an overview of current literature evaluating the role of protein intake in the management of HE in cirrhosis.

Effect of antioxidant supplementation on skeletal muscle and metabolic profile in aging mice

Aging induces drastic changes in muscle mass and function (sarcopenia); however, the detailed mechanisms underlying sarcopenia remain poorly understood. Recent studies suggested that age-related increases in oxidative stress induce muscle atrophy. In this study, we investigated the effect of 6-month supplementation of antioxidants, specifically piceatannol (PIC) and enzymatically modified isoquercitrin (EMIQ), on age-related physiological changes, including skeletal muscle weight and quality, in 25-month-old (OLD) mice, compared to in 4-month-old (young, YNG) C57BL/6J mice. Muscle weight corrected by body weight significantly declined in OLD mice, compared to in YNG mice. The control OLD mice also showed changes in the expression of genes related to muscle fiber type, reduced locomotor activity, and increased oxidative stress markers in blood. Consistent with the muscle weight and quality changes, whole-body fat oxidation during sedentary conditions and exercise periods in control OLD mice was significantly lower than that in YNG mice. Interestingly, compared to the control OLD mice, the PIC- or EMIQ-fed OLD mice showed higher fat oxidation. Furthermore, EMIQ, but not PIC, increased locomotor activity, the expression of genes encoding antioxidant enzymes, and suppressed the carbonylated protein in the skeletal muscle of OLD mice. These results suggested that chronic antioxidant intake could alleviate aging-related muscle function changes.

Obesity and muscle may have synergic effect more than independent effects on brain volume in community-based elderly

OBJECTIVE

To evaluate the individual and combined effects of obesity and muscle mass on brain volume in a community-dwelling healthy older population.

METHODS

One thousand two hundred nine participants (M:F = 574:635, mean age 63.6 ± 6.9 years) were included. The cross-sectional area of visceral fat (VF), the height-adjusted appendicular skeletal muscle mass (ASM/height²), and the ratio of thigh muscle to visceral fat (TM/VF) represented obesity, muscle mass, and their integrated value, respectively. Linear regression analysis was performed to establish associations between 215 brain compartment volumes and VF, ASM/height², and TM/VF after adjusting for covariates.

RESULTS

On regression analysis, TM/VF had a positive correlation to the volumes of temporal lobe and cerebellum. TM/VF was associated with volumes of 10 subcompartments. TM/VF was positively correlated with the volumes of left entorhinal cortex, right temporal pole and inferior temporal gyrus related to cognition (p < 0.05, respectively), and the volumes of cerebellum and right pallidum related to movement (p < 0.05, respectively). However, VF had a negative correlation to temporal lobe volume and ASM/height² had no significant correlation to any of the brain lobes. VF and ASM/height² were correlated with volumes of 5 subcompartments and one subcompartment, respectively, CONCLUSIONS: TM/VF reflects the integrated effect of obesity and muscle mass and is associated with the volume of more brain regions compared to indices of obesity or muscle mass alone. The positive effect of muscle mass and the negative effect of obesity change the volumes of brain regions related to cognition and movement which were not significantly affected by obesity or muscle mass alone.

KEY POINTS

• If obesity and muscle mass were considered together, we could find more significant brain volume changes which were not found in obesity or muscle alone. • The ratio of thigh muscle to visceral fat was positively correlated with the volumes of entorhinal cortex, temporal pole, and inferior temporal gyrus related to cognition. • The ratio of thigh muscle to visceral fat was positively correlated with the volumes of cerebellum and pallidum related to movement.

A Critical Appraisal of the Definition of Sarcopenia in Patients with Non-Alcoholic Fatty Liver Disease: Pitfall of Adjusted Muscle Mass by Body Weight

Traditionally, sarcopenia has defined as amount of absolute muscle mass adjusted by height in the elderly people. However, relative muscle mass adjusted by weight has been used extensively in most non-alcoholic fatty liver disease (NAFLD) studies. Here, we attempted to investigate the pitfall of adjusted muscle mass by weight to evaluate association between sarcopenia and NAFLD. Adult subjects (n = 1343) who underwent a health check-up were finally included for analysis. The weight-adjusted skeletal muscle mass index (wSMI) and height-adjusted SMI (hSMI) calculated by dividing the total appendicular skeletal muscle (ASM) by weight or the square of height, respectively. Prevalence of sarcopenia defined by wSMI in the NAFLD group was significantly higher than in the control group (1.3% vs. 8.8%, p < 0.001). However, there was no difference in the prevalence of sarcopenia defined by hSMI between the control and NAFLD groups (2.0% vs. 0.8%, p = 0.055). Since body weight was the most potent independent risk factor for NAFLD in multivariable logistic regression analysis, abnormal rates (<-1 SD) of almost all parameters increased in the NAFLD population, after weight adjustment. However, abnormal rates of non-metabolic parameter did not increase in NAFLD, after height adjustment. Only metabolic parameters showed relationship with NAFLD, after height adjustment. As NAFLD is highly associated with body weight, careful attention should be given in the case of studying the relationship of NAFLD with sarcopenia adjusted by body weight.

Grip Strength and Demographic Variables Estimate Appendicular Muscle Mass Better Than Bioelectrical Impedance in Taiwanese Older Persons

OBJECTIVES

This study aimed to develop an equation model combining physical fitness and anthropometric parameters and compare its results with those of bioelectrical impedance analysis (BIA)-measured lean mass (LM) using dual-energy X-ray absorptiometry (DXA)-measured appendicular muscle mass (AMM) as reference.

DESIGN

Observational analysis.

SETTING AND PARTICIPANTS

Healthy community-dwelling older subjects.

METHODS

A total of 1020 participants were randomly allocated to the development group (development group, n = 510) or the cross-validation group (validation group, n = 510). Body composition was measured using both DXA and BIA, and physical fitness parameters, including grip strength, timed stepping test, sit-to-stand test, flexibility, and walking speed were also assessed. A prediction equation model of AMM by stepwise linear regression analysis that included or excluded 1 independent variable at each step, based on the P value of significance (P < .05), was developed.

RESULTS

Using weight, sex, height, and handgrip strength as independent variables, the equation AMM = -9.833 + 0.397 × weight (kg) + 4.433 × sex + 0.121 × height (cm) + 0.061 × handgrip strength (kg) best predicts DXA-measured AMM (adjusted R² = 0.914, SEE = 2.062, P < .001). The predicted AMM was more highly correlated with DXA-measured AMM than the commonly used BIA-measured LM (R²= 0.9158 and 0.8427, respectively, both P < .001). Using DXA-measured AMM as reference, the Bland-Altman plot showed mean differences of -0.03 kg and -0.12 kg, with limits of agreement of -3.98 to 3.92 kg and -5.97 to 5.73 kg for the predicted AMM and BIA-measured AMM, respectively.

CONCLUSIONS AND IMPLICATIONS

The proposed equation offers a practical alternative method for estimating AMM that is less facility-dependent and more easy to use and affordable than instrumental studies.

A method for scoring the cell type-specific impacts of noncoding variants in personal genomes

Here we use the expression and accessibility data from a diverse set of cell types to learn a model for the dependence of the accessibility of a regulatory element on its DNA sequence and TF expression. Using GTEx samples with WGS data, we show that the noncoding variants predicted to affect accessibility are more strongly associated with the expression of nearby genes. To interpret a personal genome, we combine the sequence information with context-specific TF expression to prioritize variants and regulatory elements in any genomic region of interest. This approach should be helpful in the study of risk loci previously identified by GWAS. Results from analysis of height and WGS data from the GTEx project support this hypothesis.

A person’s genome typically contains millions of variants which represent the differences between this personal genome and the reference human genome. The interpretation of these variants, i.e., the assessment of their potential impact on a person’s phenotype, is currently of great interest in human genetics and medicine. We have developed a prioritization tool called OpenCausal which takes as inputs 1) a personal genome and 2) a reference context-specific TF expression profile and returns a list of noncoding variants prioritized according to their impact on chromatin accessibility for any given genomic region of interest. We applied OpenCausal to 6,430 samples across 18 tissues derived from the GTEx project and found that the variants prioritized by OpenCausal are highly enriched for eQTLs and caQTLs. We further propose a strategy to integrate the predicted open scores with genome-wide association studies (GWAS) data to prioritize putative causal variants and regulatory elements for a given risk locus (i.e., fine-mapping analysis). As an initial example, we applied this method to a GWAS dataset of human height and found that the prioritized putative variants and elements are correlated with the phenotype (i.e., heights of individuals) better than others.

Myostatin as a Biomarker of Muscle Wasting and other Pathologies-State of the Art and Knowledge Gaps

Sarcopenia is a geriatric syndrome with a significant impact on older patients’ quality of life, morbidity and mortality. Despite the new available criteria, its early diagnosis remains difficult, highlighting the necessity of looking for a valid muscle wasting biomarker. Myostatin, a muscle mass negative regulator, is one of the potential candidates. The aim of this work is to point out various factors affecting the potential of myostatin as a biomarker of muscle wasting. Based on the literature review, we can say that recent studies produced conflicting results and revealed a number of potential confounding factors influencing their use in sarcopenia diagnosing. These factors include physiological variables (such as age, sex and physical activity) as well as a variety of disorders (including heart failure, metabolic syndrome, kidney failure and inflammatory diseases) and differences in laboratory measurement methodology. Our conclusion is that although myostatin alone might not prove to be a feasible biomarker, it could become an important part of a recently proposed panel of muscle wasting biomarkers. However, a thorough understanding of the interrelationship of these markers, as well as establishing a valid measurement methodology for myostatin and revising current research data in the light of new criteria of sarcopenia, is needed.

Impact of Grip Strength in Patients with Unresectable Hepatocellular Carcinoma Treated with Lenvatinib

Although sarcopenia is characterized by a loss of muscle strength and skeletal muscle mass, few studies have evaluated the effect of muscle strength on hepatocellular carcinoma (HCC) patients. We evaluated the impact of sarcopenia-related factors (grip strength (GS) and the skeletal muscle index (SMI)) on the survival among lenvatinib-treated unresectable HCC (u-HCC) patients. This single-center cohort study was conducted at a university hospital. The study population included 63 lenvatinib-treated u-HCC patients managed between April 2018 and April 2020. A decreased GS and decreased SMI were found in 21 (33.3%) and 22 (34.9%) patients, respectively. The overall survival (OS) of the normal GS group was significantly higher than that of the decreased GS group, while that of the normal and decreased SMI groups did not differ markedly. There were no significant differences in the progression-free survival between the normal GS and decreased GS groups or the normal SMI and decreased SMI groups. A multivariate Cox proportional hazards model showed that modified albumin-bilirubin-grade (mALBI) 2b (hazard ratio (HR) 4.39) and a decreased GS (HR 3.55) were independently associated with an increased risk of poor prognosis. In addition to the hepatic functional reserve, a decreased GS was a poor prognostic factor in lenvatinib-treated u-HCC patients.

Effectiveness of early versus delayed exercise and nutritional intervention on segmental body composition of sarcopenic elders - A randomized controlled trial

BACKGROUND & AIMS

Although resistance training with nutritional support is considered the best treatment option for sarcopenia, the importance of home-based exercise should not be overlooked. For managing sarcopenia, a fundamental issue is whether home-based exercise or a supervised training program should be administered first. Therefore, the present trial aimed to compare the effect of early versus delayed exercise intervention with nutritional support on the physical performance and body composition of sarcopenic elders.

METHODS

The study was a randomized controlled trial using a parallel-group design. Each group received two therapeutic periods lasted 12 weeks with an interval of 2 weeks in between. Physical performance and body composition were assessed at baseline and immediately following the end of the first and second phases. One phase included hospital-based resistance training and nutritional support (amino acid, calcium, and vitamin D3), whereas the other phase included home-based exercise. In the early intervention group, supervised exercise and nutrition supplementation were administered first followed by home-based exercise, whereas the sequence was reversed in the delayed intervention group. The influence of intervention sequence on the outcome variables was examined using a 3∗2 repeated-measures analysis of variance. The primary endpoints were defined as changes in lean mass and related physical function (grip strength and gait speed) over 12 and 26 weeks of interventions.

RESULTS

A total of 57 sarcopenic elders were randomly assigned to the early (n = 29) and delayed (n = 28) intervention groups. Among the primary endpoints, the only significant group-time interaction was recognized on the changes of lower extremity lean mass (p = 0.039). The early intervention was associated with an earlier increase in lower extremity lean mass (770.8 g, 95% confidence interval (CI), 564.8 g-976.9 g) than delayed intervention (294.2 g, 95% CI, -42.13 to 630.5 g) which was evident from the between-group comparison between baseline and the 1st follow-up (p = 0.016). No significant effect of group-time interaction was observed on the physical performance and other components of body composition.

CONCLUSIONS

Early exercise and nutritional intervention may be helpful in an earlier restoration of lower extremity muscle mass but not physical function in sarcopenic elders. When designing a rehabilitation program for patients with sarcopenia, resistance training with nutrition support can be prescribed first for the rapid enlargement of the muscle volume, and structuralized home-based exercise can be administered subsequently to preserve the prior intervention effect.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02779088).

The Quantitative Skeletal Muscle Ultrasonography in Elderly with Dynapenia but not Sarcopenia Using Texture Analysis

(1) Background: Dynapenia is defined as lower muscle strength alone. Only a few studies have investigated muscle quality in subjects with dynapenia. (2) Methods: The muscle quality, characterized by texture parameters of biceps brachii, triceps brachii, rectus femoris, and medial gastrocnemius muscles, were collected using ultrasonography. The risk of dynapenia was assessed by the multiple logistic regression model. (3) Results: There were a total of 36 participants (72.7 ± 5.8 yrs, 1:1 case-control matched). The values of texture parameters of autocorrelation (AUT) and sum variance (SVAR) in all four muscles were higher in the dynapenia group significantly (p < 0.05). AUT and SVAR had the significant associations for dynapenia in biceps (dds ratio[OR]:2.51, 95% CI = 1.25–5.07 for AUT; OR = 1.45, 95% CI:1.1–1.91 for SVAR), triceps (OR: 2.48, 95% CI = 1.60–5.3 for AUT; OR: 1.57, 95% CI = 1.08–2.28 for SVAR), and rectus femoris (OR: 1.58, 95% CI = 1.01–2.46 for AUT; OR: 1.2, 95% CI = 1.0–1.44 for SVAR). The areas under the receiver-operating curves of all texture parameters was between 0.84–0.94 after adjusting confounding factors. (4) Conclusions: The muscle quality in the dynapenia can be detected by the texture-feature quantitative ultrasound. Ultrasound measurement in the aging muscle might be promising, and further studies should validate its application in the context of dynapenia.

Association between Geriatric Nutrition Risk Index and Skeletal Muscle Mass Index with Bone Mineral Density in Post-Menopausal Women Who Have Undergone Total Thyroidectomy

Background: Osteoporosis is highly prevalent in postmenopausal women and may result in fractures and disabilities. Total thyroidectomy has also been associated with loss of bone mass. The aim of this cross-sectional study was to evaluate associations among nutritional status, skeletal muscle index and markers of bone turnover to bone mineral density in postmenopausal women who had undergone total thyroidectomy. Methods: Fifty postmenopausal women who had undergone total thyroidectomy were included. Body composition was measured using dual-energy X-ray absorptiometry (DXA). The Geriatric Nutritional Risk Index (GNRI) was calculated using baseline body weight and serum albumin level. Skeletal muscle mass index was calculated as the appendicular skeletal muscle mass (ASM) divided by the height squared and assessed using DXA. Results. Multivariate stepwise linear regression analysis showed that a low GNRI was significantly associated with low lumbar spine bone mineral density (BMD) and T-score, and that a low ASM/height² was significantly associated with low femoral neck BMD and T-score. A low vitamin D level was significantly associated with low femoral neck BMD and T-score and low total hip BMD and T-score. A high bone alkaline phosphatase (ALP) level was significantly associated with low femoral neck T-score and low total hip BMD and T-score. A low insulin-like growth factor-1 (IGF-1) was significantly associated with low total hip BMD and T-score. Conclusion: In the postmenopausal women who had undergone total thyroidectomy in this study, BMD was positively associated with GNRI, skeletal muscle mass index, and levels of vitamin D and serum IGF-1, and inversely associated with bone ALP level. Nutritional status, skeletal muscle mass index and bone turnover biomarkers can be used to early identify patients with a high risk of osteoporosis in this high-risk group.

Sarcopenia increases 1-year mortality after surgical resection of hepatocellular carcinoma

BACKGROUND

Liver resection is a well-recognized modality for hepatocellular carcinoma. Cirrhotic patients are more prone to adverse consequences after liver resection. This work assesses the prognostic significance of sarcopenic hepatocellular carcinoma cases for whom surgical resection was performed.

METHODS

The present prospective work included 52 cirrhotic cases. Computed tomography scans were used to determine the skeletal muscle index (SMI) at the plane of the third lumbar vertebra (L3). L3 SMI was used for the definition of sarcopenia. The primary outcome measure was the predictive value of sarcopenia for 1-year post-hepatectomy mortality.

RESULTS

Sarcopenia was diagnosed in 27 patients (51.9%). All patients had a Child-Turcotte-Pugh score A. At a 1-year follow-up, 20 cases died; that is the 1-year mortality rate was 38.5%. Sarcopenia was more commonly associated with older age and non-viral causes of cirrhosis. The risk of 1-year mortality is 7.6 times higher in sarcopenic patients with a risk ratio of 3.7 (95% confidence interval 1.4-9.6).

CONCLUSION

Sarcopenia diagnosed using L3 SMI is an independent prognostic factor for 1-year deaths in cases with hepatic malignancy with Child-Turcotte-Pugh score A undergoing surgical resection.

Dynamics of Anthropometric Indices in a Large Paired Cohort With 10 Years of Follow-Up: Paving the Way to Sarcopenic Obesity

Introduction: Paired cohort investigations assessing the evolution of anthropometric indices are scarce. Here we assessed the 10-year evolution of BMI, total body fat, and lean body mass in 50,019 participants aged 18-90 years at the time of first assessment. Material and Methods: A retrospective cohort study using an electronic database that contains anonymized, longitudinal data from Primary Care medical records covering the 2007-2008 and 2017-2018 periods. Total body fat was estimated using the Clínica Universidad de Navarra-Body Adiposity Estimator formula, and the Hume formula was applied to estimate lean body mass. Results: The mean BMI of participants <60 years old in the 2007-2008 period increased significantly, from 27.5 to 28.3 kg/m² (p < 0.001). However, the BMI of older subjects decreased during the next decade, from 28.9 to 28.3 kg/m² (p < 0.001). The estimated total body fat showed a continuous progressive increase over all ages. Finally, lean body mass showed a progressive increase until the 40s, with a plateau between 40-45 years old and an uninterrupted decrease until older ages. Also, subjects who increased their BMI by 2 kg/m² during the 10-year period were mainly women and younger at baseline, with a lower initial BMI and total body fat in comparison with those who experienced a BMI decrease of ≥2.0 kg/m². Conclusion: The evolutions of BMI and the estimated body compositions reported here confirm that the adverse decrease in lean body mass begins in middle age. The proportion of older subjects is important when evaluating overweight and obesity prevalence in cross-sectional studies.

Deterioration of Brain Neural Tracts in Elderly Women with Sarcopenia

OBJECTIVES

Sarcopenia is known to be associated with increased stiffness in brain arteries, which causes deterioration in brain structure and function. In this study, the authors evaluated the deterioration of neural tracts using diffusion tensor tractography (DTT) in elderly women with sarcopenia and investigated whether deterioration of neural tracts is consistent with clinical findings.

METHODS

Twenty elderly women with sarcopenia were recruited. Muscle mass was measured by dual energy x-ray absorptiometry. Hand-grip power and gait speed were also assessed. Memory function was evaluated using the Seoul Neuropsychological Screening Battery. Additionally, using DTT-Studio software, the authors evaluated eight neural tracts: the corticospinal tract (CST), corticoreticular pathway, fornix, cingulum, superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and optic radiation. The authors measured the DTT parameters (fractional anisotropy [FA] and fiber volume [FV]) for each neural tract.

RESULTS

The FA and FV values were decreased in all the evaluated neural tracts, compared with those of the 20 normal comparison subjects. The FVs of the CST were significantly correlated with the hand-grip power of elderly women with sarcopenia. The FVs of the fornix and cingulum in elderly women with sarcopenia were significantly correlated with their memory function.

CONCLUSION

The authors found that the neural tracts in elderly women with sarcopenia were extensively deteriorated, and their hand-grip power and memory function were associated with related neural tracts. The DTT seems to be a useful tool for evaluating structural changes in the brains of people with sarcopenia.

Prognostic and predictive implications of sarcopenia in Western patients undergoing gastric resections for carcinoma of the stomach

INTRODUCTION

Sarcopenia is highly prevalent in patients with gastrointestinal malignancies, including gastric cancer, but there is a lack of adequate data from Western populations.

METHODS

Computed tomography scans of 138 Caucasian patients subject to stomach resections due to gastric adenocarcinoma between 2012 and 2015 were reviewed to evaluate the impact of sarcopenia. The definition of sarcopenia was based on the lumbar skeletal muscle index (SMI) using cut-off values formulated by the international consensus definitions of sarcopenia (SMI <52.4 cm² /m² for men and <38.5 cm² /m² for women).

RESULTS

Sixty (43%) of 138 patients were sarcopenic. Sarcopenia was associated with postoperative morbidity (43% vs 23%; P = .011), major postoperative complications (Clavien-Dindo ≥3a; 36% vs 21%; P = .035), and reoperations (23% vs 9%; P = .020). Patients with sarcopenia also had prolonged postoperative hospital stay (8.0 vs 6.5 days; P = .010). The overall median survival of patients with sarcopenia was significantly lower than those with normal skeletal muscles (11.0 vs 36.7 months; P = .005) and sarcopenia remained an independent prognostic factor with an odds ratio of 1.94 (95% confidence interval, 1.08 to 3.48; P = .026).

CONCLUSION

Sarcopenia, defined by SMI, is associated with an increased risk of postoperative morbidity and impaired long-term survival.

Association of different bioimpedanciometry estimations of muscle mass with functional measures

AIM

To investigate the muscle mass adjustment technique that best correlates with functional measures.

METHODS

A cross-sectional study was designed. Community-dwelling older adults aged ≥60 years were assessed for body composition and functional measures between November 2012 and July 2017 in the geriatric outpatient clinic of a university hospital. Body composition was assessed with bioimpedance analysis. Skeletal muscle mass (SMM) was adjusted by height² , weight or body mass index (BMI). Functional and disability measures included handgrip strength assessed by a Jamar hydraulic hand dynamometer, gait speed by 4-m usual gait speed, frailty by the Fatigue, Resistance, Ambulation, Illnesses and Loss of Weight scale score, activities of daily living (ADL) and instrumental ADL scores. Nutrition was evaluated by the Mini Nutritional Assessment - Short Form.

RESULTS

A total of 1437 older adults (458 men, 979 women) with a mean age of 74.6 ± 7.0 years were included. The prevalences of low muscle mass were 2.4%, 47.8% and 20.3% when SMM was adjusted by height² , weight and BMI, respectively. Multivariate analyses adjusted for age, number of diseases, drugs and the Mini Nutritional Assessment - Short Form score revealed that when the SMM was adjusted by BMI, low muscle mass showed better associations with grip strength, gait speed, ADL, instrumental ADL and frailty than the height² or the weight-adjusted SMM.

CONCLUSIONS

SMM adjustment by BMI to designate low muscle mass was better associated with functional and disability measures than adjustment by height² and weight. The present results put forward the SMM index (by BMI) as the best adjustment method for SMM. These findings might be relevant for defining both sarcopenia and malnutrition. Geriatr Gerontol Int 2019; 19: 593-597.