Financial impact of sarcopenia or low muscle mass - A short review

Effects of soy protein-rich meals on muscle health of older adults in long-term care: A randomized clinical trial

OBJECTIVE

This study investigated the effects of a soy protein-rich meal intervention on the muscle health of older adults in long-term care facilities.

METHODS

A 12-week single-center randomized controlled trial with a control-group and open-label design was conducted. Eighty-four older adults from a long-term care facility participated in the study. The chefs at the facility cooked three meals using soy protein-rich recipes designed by dieticians. For 12 weeks, the intervention group participants consumed three meals with 30 g of soy protein (10 g/meal) per day, and the control group participants maintained their habitual diets.

RESULTS

The 84 participants (mean age, 84.9 ± 7.0 years; 61.9% female) were randomly assigned to an intervention group (43 participants) and a control group (41 participants). The intervention group exhibited significant increases in several lean mass indicators, namely soft lean mass (mean, 1.43 kg; 95% confidence interval [CI]: 0.20-1.65 kg), skeletal muscle mass (mean, 1.20 kg; 95% CI: 0.43-1.96 kg), appendicular skeletal muscle mass (mean, 0.79 kg; 95% CI: 0.07-1.52 kg), and skeletal muscle index (mean, 0.37 kg/m2; 95% CI: 0.05-0.68 kg/m2) (all P < 0.05). These changes were not observed in the control group (all P > 0.05). Notably, calf circumference decreased significantly in the control group (mean, -0.98 cm; 95% CI: -1.61 to -0.36 cm) but was maintained in the intervention group. The differences in the calf circumference and 6-m walk performance of the two groups were significant (P < 0.05).

CONCLUSIONS

The 12-week soy protein-rich meal intervention improved the muscle mass and 6-m walk performance of older adults in a long-term care facility.

The nutritional support to prevent sarcopenia in the elderly

Sarcopenia has been described as a muscle disease, with multiple adverse consequences on human health. Recommendations aimed at supporting awareness, prevention, early detection and treatment of this disease are needed. This review focuses on the epidemiology, pathophysiology and early detection of elderly sarcopenia. As far as treatment is concerned, physical activity and nutritional support are specifically evaluated. An individually tailored resistance exercise training program appears to be crucial for a positive outcome of the sarcopenia prevention and treatment. The nutritional intervention is mostly based on the supplementation with high-quality proteins (i.e., whey protein) in order to increase the intake of essential amino acids and in particular of leucine. In addition, of relevant importance appears to be the supplementation with vitamin D, with omega-3 fatty acids and probiotics. This review evaluates the results of the most qualified studies on the nutritional supplementation of sarcopenic elderly subjects and shows that promising results have been achieved in community elderly subjects, or subjects followed in rehabilitation centers and in nursing homes, with additional resistance exercise programs.

The diagnostic performance of Cr/CysC for sarcopenia and its predictive value on clinical outcomes in hospitalized older patients: a prospective cohort study

PURPOSE

The utilization of the creatinine-to-cystatin C ratio (Cr/CysC) represents an innovative method for predicting sarcopenia. Our objectives encompassed the evaluation of sarcopenia diagnostic accuracy for Cr/CysC, SARC-F, SARC-CalF, the combination of Cr/CysC and SARC-CalF, and the Ishii score, as well as an exploration of the predictive value of Cr/CysC concerning clinical outcomes within hospitalized older individuals.

METHODS

We employed receiver operating characteristic (ROC) curves and calculated areas under the curves (AUCs) to assess the diagnostic accuracy. Furthermore, we applied univariate and multivariate Cox proportional-hazard models to calculate the hazard ratio (HR) and 95% confidence interval (CI) of risk factors affecting prognosis.

RESULTS

Our study included 312 participants, comprising 167 men and 145 women, with an average age of 71 years. Among males, the AUCs for Cr/CysC, SARC-F, SARC-CalF, the combination of Cr/CysC and SARC-CalF, and the Ishii score were 0.717 [95% CI 0.642-0.784], 0.669 (95% CI 0.592-0.739), 0.845 (95% CI 0.781-0.896), 0.882 (95% CI 0.823-0.926), and 0.938 (95% CI 0.890-0.969), respectively. In females, the AUCs for Cr/CysC, SARC-F, SARC-CalF, the combination of Cr/CysC and SARC-CalF, and the Ishii score were 0.706 (95% CI 0.625-0.779), 0.631 (95% CI 0.547-0.710), 0.763 (95% CI 0.686-0.830), 0.789 (95% CI 0.714-0.853), and 0.898 (95% CI 0.837-0.942), respectively. After adjusting for age, sex, physical exercise, smoking, drinking, hypertension, coronary heart disease (CHD), chronic obstructive pulmonary disease (COPD), chronic kidney disease (CKD), and cancer, sarcopenia identified by Cr/CysC (adjusted HR = 2.176, 95% CI 1.062-4.460, P = 0.034) was independently associated with poor overall survival in hospitalized older patients.

CONCLUSIONS

Cr/CysC has satisfactory diagnostic accuracy for sarcopenia diagnosis and predictive value for poor outcomes in hospitalized older patients. The combination of Cr/CysC and SARC-CalF may provide a more accurate screening for sarcopenia and the Ishii score may be the most accurate clinical method for detecting sarcopenia.

Mitochondrial involvement in sarcopenia

Sarcopenia lowers the quality-of-life for millions of people across the world, as accelerated loss of skeletal muscle mass and function contributes to both age- and disease-related frailty. Physical activity remains the only proven therapy for sarcopenia to date, but alternatives are much sought after to manage this progressive muscle disorder in individuals who are unable to exercise. Mitochondria have been widely implicated in the etiology of sarcopenia and are increasingly suggested as attractive therapeutic targets to help restore the perturbed balance between protein synthesis and breakdown that underpins skeletal muscle atrophy. Reviewing current literature, we note that mitochondrial bioenergetic changes in sarcopenia are generally interpreted as intrinsic dysfunction that renders muscle cells incapable of making sufficient ATP to fuel protein synthesis. Based on the reported mitochondrial effects of therapeutic interventions, however, we argue that the observed bioenergetic changes may instead reflect an adaptation to pathologically decreased energy expenditure in sarcopenic muscle. Discrimination between these mechanistic possibilities will be crucial for improving the management of sarcopenia.

Effect of sarcopenia on survival in patients after pancreatic surgery: a systematic review and meta-analysis

Background

Numerous studies have reported sarcopenia to be associated with unfavorable outcomes in patients who have undergone pancreatectomy. Therefore, in this meta-analysis, we examined the relationship between sarcopenia and survival after pancreatic surgery.

Methods

PubMed, Embase, and Cochrane Library were searched for studies that examined the association between sarcopenia and survival after pancreatic surgery from the inception of the database until June 1, 2023. Hazard ratio (HR) for overall survival (OS) and/or progression-free survival (PFS) of sarcopenia and pancreatic surgery were extracted from the selected studies and random or fixed-effect models were used to summarize the data according to the heterogeneity. Publication bias was assessed using Egger's linear regression test and a funnel plot.

Results

Sixteen studies met the inclusion criteria. For 13 aggregated univariate and 16 multivariate estimates, sarcopenia was associated with decreased OS (univariate analysis: HR 1.69, 95% CI 1.48-1.93; multivariate analysis: HR 1.69; 95% CI 1.39-2.05, I2 = 77.4%). Furthermore, sarcopenia was significantly associated with poor PFS of pancreatic resection (Change to univariate analysis: HR 1.74, 95% CI 1.47-2.05; multivariate analysis: HR 1.54; 95% CI 1.23-1.93, I2 = 63%).

Conclusion

Sarcopenia may be a significant prognostic factor for a shortened survival following pancreatectomy since it is linked to an elevated risk of mortality. Further studies are required to understand how sarcopenia affects long-term results after pancreatic resection.Systematic review registrationRegistration ID: CRD42023438208 https://www.crd.york.ac.uk/PROSPERO/#recordDetails.

Association of depression with incident sarcopenia and modified effect from healthy lifestyle: The first longitudinal evidence from the CHARLS

BACKGROUND

The prospective association of depression with incident sarcopenia remains unknown, as does whether such an association is modified by a healthy lifestyle. Thus, the goal of this study was to determine whether depression is independently related to the risk of developing sarcopenia and to detect the effect of a healthy lifestyle on its modification.

METHODS

The prospective study included 9486 participants from the China Health and Retirement Longitudinal Study who were followed from 2011 to 2015. We calculated a lifestyle score based on body mass index, drinking, smoking, social activities, and sleeping time. Cox proportional hazards regression models with hazard ratios (HRs) and 95 % confidence intervals were used to estimate the effect of depression on the risk of sarcopenia and the modification effect of lifestyle (CIs).

RESULTS

During a mean of 3.53 years of follow-up, 1373 individuals developed sarcopenia. After adjusting for confounding factors, depression was significantly associated with a higher risk of incident sarcopenia (HR = 1.34; 95 % CI: 1.19, 1.50). In addition, we observed that individuals adhering to a healthy lifestyle had an 18 % lower risk of sarcopenia onset, compared with individuals with an unhealthy lifestyle.

LIMITATIONS

We couldn't completely rule out potential residual bias due to its observational design. Second, ascertainment of the history of diseases in CHARLS was based on self-reported information, which may introduce recall bias or misclassification.

CONCLUSIONS

Depression was associated with a higher risk of sarcopenia in Chinese adults, and such a risk may be alleviated by adhering to a healthy lifestyle.

Association of high-sensitivity cardiac troponin T with all-cause and cardiovascular mortality in older adults with low lean mass: A 14.6-year longitudinal study

BACKGROUND

Current evidence on the association between high-sensitivity cardiac troponin T (hs-cTnT) levels and mortality in elderly sarcopenic patients is limited. This study aimed to investigate the association of serum hs-cTnT concentrations with all-cause and cardiovascular mortality in older adults with low lean mass (LLM) and without baseline cardiovascular disease.

METHODS

This prospective cohort study included 369 older adults (representing 3.2 million people) from the National Health and Nutrition Examination Survey 1999-2004. Individuals were linked to national death records until 31 December 2019. The weighted Kaplan-Meier analysis, Cox proportional hazards models, restricted cubic spline models, stratified analysis, interaction analysis, and sensitivity analysis were performed to examine the association between hs-cTnT levels and mortality in older adults with LLM.

RESULTS

During 4697 person-years of follow-up (median duration, 14.6 years), 228 (65.6%) deaths were documented, including 56 (15.8%) deaths from cardiovascular disease. Individuals with a hs-cTnT level of ≥14 ng/L had 2.1- and 4.4-fold higher risks of all-cause and cardiovascular mortality, respectively. Compared with the lowest quartile, the fourth quartile of hs-cTnT levels was significantly associated with 3.1- and 6.4-fold higher risks of all-cause and cardiovascular mortality, respectively. Each one standard deviation increase in natural log-transformed hs-cTnT levels significantly and linearly increased the risks of all-cause and cardiovascular mortality by 39% and 61%, respectively. Stratified and sensitivity analyses confirmed the robustness of the association.

CONCLUSIONS

In this nationally representative cohort of US older adults with LLM, higher serum hs-cTnT concentrations were significantly associated with increased risks of all-cause and cardiovascular mortality.

Association between lean muscle mass and treatment-resistant late-life depression in the IRL-GRey randomized controlled trial

OBJECTIVE

To investigate the relationship between lean muscle mass and treatment response in treatment-resistant late-life depression (TR-LLD). We hypothesized that lower lean muscle mass would be associated with older age, higher physical comorbidities, higher depressive symptom severity, and poorer treatment response.

DESIGN

Secondary analysis of a randomized, placebo-controlled trial.

SETTING

Three academic hospitals in the United States and Canada.

PARTICIPANTS

Adults aged 60+ years with major depressive disorder who did not remit following open treatment with venlafaxine extended-release (XR) (n = 178).

MEASUREMENTS

We estimated lean muscle mass using dual-energy X-ray absorptiometry (DEXA) scans prior to and following randomized treatment with aripiprazole or placebo added to venlafaxine XR. Multivariate regressions estimated influence of demographic and clinical factors on baseline lean muscle mass, and whether baseline lean muscle mass was associated with treatment response, adjusted for treatment arm.

RESULTS

Low lean muscle mass was present in 22 (12.4%) participants. Older age and female sex, but not depressive symptom severity, were independently associated with lower lean muscle mass at baseline. Marital status, baseline depressive symptom severity, and treatment group were associated with improvement of depressive symptoms in the randomized treatment phase. Baseline lean muscle mass was not associated with improvement, regardless of treatment group.

CONCLUSION

As expected, older age and female sex were associated with lower lean muscle mass in TR-LLD. However, contrary to prior results in LLD, lean muscle mass was not associated with depression severity or outcome. This suggests that aripiprazole augmentation may be useful for TR-LLD, even in the presence of anomalous body composition.clinicaltrials.gov Identifier: NCT00892047.

A bidirectional Mendelian randomization study of sarcopenia-related traits and inflammatory bowel diseases

Background

There is increasing evidence pointing to a close relationship between sarcopenia and inflammatory bowel disease. However, it remains unclear whether or in which direction causal relationships exist, because these associations could be confounded.

Methods

We conducted a two-sample bidirectional mendelian randomization analysis using data from European genome-wide association studies of the appendicular lean mass(n = 450,243), walking pace(n = 459,915), grip strength (left hand, n = 461,026; right hand, n = 461,089), inflammatory bowel disease (25,042 patients and 34,915 controls), ulcerative colitis (12,366 patients and 33,609 controls), and Crohn's disease (12,194 patients and 28,072 controls) to investigate the causal relationship between sarcopenia-related traits and inflammatory bowel disease and its subtypes on each other. The inverse-variance weighted method was used as the primary analysis method to assess the causality, and a comprehensive sensitivity test was conducted.

Results

Genetically predicted appendicular lean mass was significantly associated with inflammatory bowel disease (OR = 0.916, 95%CI: 0.853-0.984, P = 0.017), ulcerative colitis (OR =0.888, 95%CI: 0.813-0.971, P = 0.009), and Crohn's disease (OR = 0.905, 95%CI: 0.820-0.999, P = 0.049). Similar results also revealed that the usual walking pace was causally associated with Crohn's disease (OR = 0.467, 95%CI: 0.239-0.914, P = 0.026). Reverse mendelian randomization analysis results found that genetic susceptibility to inflammatory bowel disease, and Crohn's disease were associated with lower appendicular lean mass. A series of sensitivity analyses ensured the reliability of the present research results.

Conclusion

The mendelian randomization study supports a bidirectional causality between inflammatory bowel disease, Crohn's disease and appendicular lean mass, but no such bidirectional causal relationship was found in ulcerative colitis. In addition, genetically predicted usual walking pace may reduce the risk of Crohn's disease. These findings have clinical implications for sarcopenia and inflammatory bowel disease management.

Performance Evaluation of Machine Learning Algorithms for Sarcopenia Diagnosis in Older Adults

BACKGROUND

Sarcopenia is a progressive and generalized skeletal muscle disorder. Early diagnosis is necessary to reduce the adverse effects and consequences of sarcopenia, which can help prevent and manage it in a timely manner. The aim of this study was to identify the important risk factors for sarcopenia diagnosis and compare the performance of machine learning (ML) algorithms in the early detection of potential sarcopenia.

METHODS

A cross-sectional design was employed for this study, involving 160 participants aged 65 years and over who resided in a community. ML algorithms were applied by selecting 11 features-sex, age, BMI, presence of hypertension, presence of diabetes mellitus, SARC-F score, MNA score, calf circumference (CC), gait speed, handgrip strength (HS), and mid-upper arm circumference (MUAC)-from a pool of 107 clinical variables. The results of the three best-performing algorithms were presented.

RESULTS

The highest accuracy values were achieved by the ALL (male + female) model using LightGBM (0.931), random forest (RF; 0.927), and XGBoost (0.922) algorithms. In the female model, the support vector machine (SVM; 0.939), RF (0.923), and k-nearest neighbors (KNN; 0.917) algorithms performed the best. Regarding variable importance in the ALL model, the last HS, sex, BMI, and MUAC variables had the highest values. In the female model, these variables were HS, age, MUAC, and BMI, respectively.

CONCLUSIONS

Machine learning algorithms have the ability to extract valuable insights from data structures, enabling accurate predictions for the early detection of sarcopenia. These predictions can assist clinicians in the context of predictive, preventive, and personalized medicine (PPPM).

Chronic inflammation does not mediate the effect of adiposity on grip strength: results from a multivariable Mendelian randomization study

The relationship between adiposity and grip strength (GS) is complex. We investigated whether one pathway through which adiposity affects GS was via chronic inflammation. 367,583 UK Biobank participants had body mass index (BMI), waist-hip-ratio (WHR), C-reactive protein (CRP) and GS data. Univariable Mendelian randomization (MR) and multivariable Mendelian randomization (MVMR) analyses (using inverse variance weighted (IVW) weighted median estimates (WME) and MR-Egger models) estimated total, direct and indirect effects of adiposity traits on GS using genetic instruments for BMI and WHR (exposures) and CRP (mediator). Observational findings suggested higher BMI was associated with stronger grip, e.g., in males, per standard deviation (SD) higher BMI, GS was higher by 0.48 kg (95% confidence interval(CI):0.44,0.51), independent of CRP. For males MR estimates were directionally consistent; for females, estimates were consistent with the null. Observational findings for WHR suggested that higher WHR was associated with weaker grip. In multivariable MR-IVW analyses, effects in males were consistent with the null. In females, there were consistent effects such that higher WHR was associated with stronger grip, e.g., 1-SD higher WHR was associated with 1.25 kg (MVMR-Egger; 95% CI:0.72,1.78) stronger grip, independent of CRP. Across sexes and adiposity indicators, CRP's mediating role was minor. Greater adiposity may increase GS in early old age, but effects vary by sex and adiposity location. There was no evidence that inflammation mediated these effects.

Low lean mass with obesity in older adults with hypertension: prevalence and association with mortality rate

BACKGROUND

The influence of sarcopenic obesity (SO) on overall survival in older adults with hypertension has not been addressed. The aim of this study was to investigate the prevalence and mortality predictive value of various body composition phenotypes, focusing mainly on SO, in older adults with hypertension.

METHODS

We included 1105 hypertensive patients aged ≥ 60 years from the National Health and Nutrition Examination Survey 1999-2004. Sarcopenia was broadly defined based on low lean mass (LLM; as measured by dual-energy X-ray absorptiometry), and was defined using appendicular lean mass (ALM) divided by height squared (ALM/height2), weight (ALM/weight), and body mass index (BMI; ALM/BMI), respectively. Obesity was defined as BMI ≥ 30 kg/m2, body fat percentage ≥ 30/42%, or waist circumference ≥ 102/88 cm. The prevalence of LLM with obesity was estimated according to each ALM index (ALMI). Multivariable Cox regression analysis and sensitivity analysis were used to examine the association between various body composition phenotypes and all-cause mortality.

RESULTS

In older adults with hypertension, the prevalence of LLM with obesity by the ALM/height2 index (9.8%) was lower relative to the ALM/weight (11.7%) and ALM/BMI indexes (19.6%). After a median follow-up of 15.4 years, 642 deaths occurred. In the fully adjusted models, LLM with obesity was significantly associated with a higher risk of all-cause mortality (hazard ratio [HR] 1.69, 95% confidence interval [CI] 1.14-2.49, P = 0.008; HR 1.48, 95% CI 1.04-2.10, P = 0.028; HR 1.30, 95% CI 1.02-1.66, P = 0.037; respectively) compared with the normal body phenotype, with no statistical differences found in individuals with LLM or obesity alone. Sensitivity analysis confirmed the robustness of the results.

CONCLUSIONS

The prevalence of LLM with obesity markedly differed in older adults with hypertension according to the 3 different ALMIs, varying from 9.8%, 11.7%, to 19.6%. Patients with both LLM and obesity had a higher risk of all-cause mortality. Further large, prospective, cohort studies are warranted to validate these findings and uncover underlying mechanisms.

Association between digestive diseases and sarcopenia among Chinese middle-aged and older adults: a prospective cohort study based on nationally representative survey

Objectives

Patients with digestive diseases frequently suffer from dyspepsia and malabsorption, which may lead to muscle loss due to malnutrition. However, it is not clear whether digestive diseases are associated with sarcopenia. This study aims to explore the longitudinal association between digestive diseases and sarcopenia in middle-aged and older adults based on a nationally representative survey from China.

Methods

We used a prospective cohort study including 7,025 middle-aged and older adults aged ≥45 years from the 2011 to 2015 waves China Health and Retirement Longitudinal Study (CHARLS). Digestive diseases were identified using self-report. The assessment of sarcopenia was based on the Asian Working Group for Sarcopenia 2019 Consensus and included three components of muscle strength, physical performance, and muscle mass. Cox hazards regression was used to examine the association between digestive diseases and sarcopenia.

Results

The prevalence of digestive diseases and the incidence of sarcopenia in middle-aged and older adults were 22.6% (95% CI = 21.6-23.6%) and 8.5% (95% CI = 7.8-9.1%). After adjusting for 15 covariates composed of three sets (demographic characteristics, lifestyles, and health status), digestive diseases were associated with a higher risk of sarcopenia (HR = 1.241, 95% CI = 1.034-1.490, P < 0.05). The associations were more pronounced among men, older adults aged 60-79, rural residents, and married people. In addition, the association between digestive diseases and sarcopenia was robust in the sensitivity analysis.

Conclusion

Digestive diseases were associated with an increased risk of sarcopenia in middle-aged and older adults aged ≥45 years. Early intervention of digestive diseases may help to reduce the incidence of sarcopenia in middle-aged and older adults.

Cost-effectiveness analysis of sarcopenia management interventions in Iran

OBJECTIVES

Identification the optimal management intervention of sarcopenia is a concern of health systems. We aimed to analyze the cost-effectiveness of sarcopenia management strategies in Iran.

METHODS

We constructed a lifetime Markov model based on natural history. The strategies comparedincluded exercise training, nutritional supplements, whole body vibration (WBV), and various exercise interventions and nutritional supplement combinations. A total of 7 strategies was evaluated in addition to the non-intervention strategy. Parameter values were extracted from primary data and the literature, and the costs and Quality-adjusted life years (QALYs) were calculated for each strategy. Deterministic and probabilistic sensitivity analysis, including the expected value of perfect information (EVPI), was also performed to determine the robustness of the model. Analyses were performed using the 2020 version of TreeAge Pro software.

RESULTS

All seven strategies increased lifetime effectiveness (QALYs). The protein and Vitamin D₃ (P + D) strategy had the highest effectiveness values among all strategies. After removing the dominated strategies, the estimated ICER for the P + D compared to Vitamin D₃ alone (D) strategy was calculated as $131,229. Considering the cost-effectiveness threshold ($25,249), base-case results indicated that the D strategy was the most cost-effective strategy in this evaluation. Sensitivity analysis of model parameters also demonstrated the robustness of results. Also, EVPI was estimated at $273.

CONCLUSIONS

Study results, as the first economic evaluation of sarcopenia management interventions, showed that despite the higher effectiveness of D + P, the D strategy was the most cost-effective. Completing clinical evidence of various intervention options can lead to more accurate results in the future.

Can artificial intelligence simplify the screening of muscle mass loss?

Background

Sarcopenia is a risk factor for morbidity and preventable mortality in old age, with consequent high costs for the national health system. Its diagnosis requires costly radiological examinations, such as the DEXA, which complicate screening in medical centers with a high prevalence of sarcopenia.

Objectives

Developing a nearly zero-cost screening tool to emulate the performance of DEXA in identifying patients with muscle mass loss. This can crucially help the early diagnosis of sarcopenia at large-scale, contributing to reduce its prevalence and related complications with timely treatments.

Methods

We exploit cross-sectional data for about 14,500 patients and 38 non-laboratory variables from successive NHANES over 7 years (1999-2006). Data are analyzed through a state-of-the-art artificial intelligence approach based on decision trees.

Results

A reduced number of anthropometric parameters allows to predict the outcome of DEXA with AUC between 0.92 and 0.94. The most complex model derived in this paper exploits 6 variables, related to the circumference of key corporal segments and to the evaluation of body fat. It achieves an optimal trade-off sensitivity of 0.89 and a specificity of 0.82. Restricting exclusively to variables related to lower limb, we obtain an even simpler tool with only slightly lower accuracy (AUC 0.88-0.90).

Conclusions

Anthropometric data seem to contain the entire informative content of a more complex set of non-laboratory variables, including anamnestic and/or morbidity factors. Compared to previously published screening tools for muscle mass loss, the newly developed models are less complex and achieve a better accuracy. The new results might suggest a possible inversion of the standard diagnostic algorithm of sarcopenia. We conjecture a new diagnostic scheme, which requires a dedicated clinical validation that goes beyond the scope of the present study.

An elusive consensus definition of sarcopenia impedes research and clinical treatment: A narrative review

The definition of sarcopenia, the age-related loss of muscle mass, has evolved since the term's inception and yet there is no consensus. Many of the identified definitions of sarcopenia centre their criteria around the loss of muscle mass, loss of function, and weakness. Common variables to various definitions of sarcopenia are appendicular lean soft tissue mass (often called muscle mass), grip strength, and gait speed. However, a lack of consensus remains among operational definitions and diagnostics for this newly recognized disease and may be attributed to the absence of appropriate tools that accurately measure the outcomes of interest, such as skeletal muscle instead of lean mass. In this narrative review, we describe the evolution of the consensus groups' definition of sarcopenia, address the need for more accurate measures of muscle mass and function, and effective, low-cost treatments (i.e., resistance training and diet) for this disease. Consensus on what constitutes sarcopenia is critical to propel research in the field and, importantly, provide what prognostic value a sarcopenia diagnosis provides and how such a patient would be treated.

A systematic review and meta-analysis of the prevalence and correlation of mild cognitive impairment in sarcopenia

Sarcopenia is a progressive skeletal muscle disorder involving the loss of muscle mass and function, associated with an increased risk of disability and frailty. Though its prevalence in dementia has been studied, its occurrence in mild cognitive impairment (MCI) has not been well established. As MCI is often a prelude to dementia, our study aims to investigate the prevalence of MCI among individuals with sarcopenia and to also ascertain whether sarcopenia is independently associated with MCI. The Cochrane Library, PubMed, Ovid, Embase and Web of Science were systematically searched for articles on MCI and/or sarcopenia published from inception to 1 February 2022. We reviewed the available literature on the number of individuals with MCI and/or sarcopenia and calculated odds ratios (ORs) of sarcopenia in MCI and MCI in sarcopenia, respectively. Statistical analyses were performed using the meta package in Stata, Version 12.0. A total of 13 studies and 27 428 patients were included in our analysis. The pooled prevalence of MCI in participants with sarcopenia was 20.5% (95% confidence interval [CI]: 0.140-0.269) in a total sample of 2923 cases with a high level of heterogeneity (P < 0.001; I²  = 95.4%). The overall prevalence of sarcopenia with MCI was 9.1% (95% CI: 0.047-0.134, P < 0.001; I²  = 93.0%). For overall ORs, there were 23 364 subjects with a mean age of 73 years; the overall adjusted OR between MCI and sarcopenia was 1.46 (95% CI: 1.31-1.62). Slight heterogeneity in both adjusted ORs (P = 0.46; I²  = 0%) was noted across the studies. The prevalence of MCI is relatively high in patients with sarcopenia, and sarcopenia may be a risk factor for MCI.

A bi-directional Mendelian randomization study of sarcopenia-related traits and type 2 diabetes mellitus

BACKGROUND

Previous studies have reported an association between sarcopenia and type 2 diabetes mellitus (T2DM), but causation was prone to confounding factors. A more robust research approach is urgently required to investigate the causal relationship between sarcopenia and T2DM.

METHODS

The bi-directional two-sample MR study was carried out in two stages: Sarcopenia-related traits were investigated as exposure while T2DM was investigated as an outcome in the first step, whereas the second step was reversed. The GWAS summary data for hand-grip strength (n = 256,523), appendicular lean mass (ALM, n = 450,243), and walking pace (n = 459,915) were obtained from the UK Biobank. T2DM data were obtained from one of the biggest case-control studies on diabetes (DIAGRAM; n = 180,834 cases and 492,191 controls), which was published in 2022. The inverse-variance weighted (IVW) approach was used to obtain MR estimates, and various sensitivity analysis was also performed.

RESULTS

Low hand-grip strength had a potential causal relationship with an increased incidence of T2DM (OR = 1.109; 95% CI, 1.008-1.222; p = 0.0350). T2DM risk was reduced by increasing ALM and walking pace: A 1 kg/m² increase in ALM decreased the risk of T2DM by 10.2% (OR = 0.898; 95% CI, 0.830-0.952; p < 0.001). A 1 m/s increase in walking pace decreased the risk of T2DM by 90.0% (OR = 0.100; 95% CI, 0.053-0.186; p < 0.001). The relationship was bidirectional, with T2DM as a causative factor of sarcopenia-related traits (p < 0.05) except for ALM (β = 0.018; 95% CI, -0.008 to -0.044; p = 0.168).

CONCLUSIONS

Hand-grip strength and T2DM had a potential bidirectional causal relationship, as did walking pace and T2DM. We suggest that sarcopenia and T2DM may mutually have a significant causal effect on each other.

Effect of flavonoids on skeletal muscle mass, strength and physical performance in middle-aged and older adults with or without Sarcopenia: A meta-analysis of randomized controlled trials

The role of flavonoids in regulating the synthesis and function of skeletal muscles is increasingly recognized. However, randomized controlled trials have yielded inconsistent results on the influence of flavonoids on human muscular parameters. Therefore, we performed a meta-analysis to evaluate the possible effects of flavonoids on sarcopenia-related parameters in middle-aged and elderly people. Eligible literature and randomized controlled trials reports have been extensively searched from PubMed, Cochrane Library, Web of Science, and EMBASE databases until April 2022. A total of 20 articles involving 796 participants were available for the meta-analysis. There were significant benefits for participants in appendicular muscle mass gain (SMD = 0.29; 95% CI: 0.07, 0.52; P = 0.01) and 6-min walk distance (SMD = 0.37; 95% CI: 0.01, 0.73; P = 0.05). A subgroup analysis indicated that flavonoid significantly improves appendicular muscle mass (SMD = 0.50; 95% CI: 0.21, 0.80; P < 0.01) and Timed-Up and Go test (SMD = −0.47; 95% CI: −0.85, −0.09; P = 0.02) in Sarcopenia population. Our results provide insight into the effects of flavonoids on skeletal muscle mass and gait speed for those without exercise. However, there was no significant improvement in the subjects' muscle strength.

Diagnostic and prognostic value of the Creatinine/Cystatin C ratio for low muscle mass evaluation among US adults

Background

Identifying patients with low muscle mass is crucial for the diagnosis of sarcopenia. Although the Creatinine/Cystatin C (Cr/CysC) is recommended as a simplified indicator to identify patients with low muscle mass, its ability to assess muscle mass and predict a poor prognosis has not been validated. We aimed to determine the diagnosis value of Cr/CysC for low muscle mass and examine the association of Cr/CysC with mortality.

Methods

In this cohort study we analyzed data from the National Health and Nutrition Examination Survey from 1999 to 2002. Follow-up was conducted up to December, 2015. Appendicular skeletal mass was calculated based on dual-energy X-ray absorptiometry (DXA) scans. Low muscle mass was defined referring to five international diagnostic criteria. The diagnostic value of Cr/CysC as a replacement indicator of muscle mass was measured using area under the curve, positive percent agreement, negative percent agreement and kappa. Cox proportional hazards regression models were developed to examine the association between Cr/CysC and risk of mortality.

Results

This cohort study of 3,741 adults comprised 1,823 females (48.73%), with a weighted mean (SE) age of 44.46 (0.43) years. The positive percent agreement of Cr/CysC for the diagnosis of low muscle mass was poor (40.23–58.74%), except for Foundation of the National Institute of Health (FNIH) criteria (80.90–58.97%). But the negative percent agreement of Cr/CysC for the diagnosis of low muscle mass was high (males: 62.15–88.17%; females: 55.26–82.30%). Moreover, the risk of death was reduced by 2% per 0.01 unit increase in Cr/CysC (aHR, 0.98; 95% CI, 0.98–0.99, P < 0.001).

Conclusions

Cr/CysC performed well not only in identifying non-sarcopenia cases, especially when based on FNIH diagnostic criteria, but also in revealing a positive association with higher risk of mortality. The optimal cut-off values for Cr/CysC were <1.0 in males and <0.8 in females. Expanding the use of Cr/CysC would allow for early and targeted treatment of sarcopenia.

Lifetime body mass index and grip strength at age 46 years: the 1970 British Cohort Study

BACKGROUND

Ongoing rises in obesity prevalence have prompted growing concerns about potential increases in the burden of age-related musculoskeletal conditions including sarcopenia and sarcopenic obesity. This is of particular concern for future generations of older adults who have lived more of their lives in an obesogenic environment than current generations of older adults. We aimed to study longitudinal associations between body mass index (BMI) and grip strength in midlife using data from a large population-based sample, the 1970 British Cohort Study (BCS70).

METHODS

BCS70 participants with valid measures of maximum grip strength at age 46 years were included in analyses [3671 males (49%) and 3876 females (51%)]. Using sex-specific linear regression models, we examined associations of (i) BMI at ages 10, 16, 30, and 46 years; (ii) body fat percentage (BF%) and waist-hip ratio at age 46 years; (iii) BMI gains between 10-16, 16-30, and 30-46; and (iv) age at onset of obesity, with grip strength.

RESULTS

At age 46 years, mean (standard deviation) grip strength was 48.10 kg (8.98) in males and 29.61 kg (5.81) in females. Higher BMI at all ages was associated with stronger grip, and the scale of associations was greater in males than females from age 16 onwards (P_{sex interactions}  < 0.01). For example, in fully adjusted models, a 1 standard deviation increase in BMI at age 16 was associated with mean differences in grip strength at age 46 years of 1.41 kg (95% confidence interval: 1.07, 1.75) in males and 0.72 kg (0.53, 0.91) in females. Higher BF% at age 46 was also associated with stronger grip in both sexes. Greater gains in BMI between ages 10 and 16 were associated with stronger grip in both sexes, but subsequent gains in BMI were only associated with stronger grip in males. Associations of greater length of exposure to obesity and stronger grip were also more consistent among males than females. For example, in fully adjusted models, mean grip strength at age 46 years of males and females who had been obese since age 10 or 16 years was 4.39 kg (1.85, 6.93) and 1.25 kg (-0.18, 2.69) higher than males and females who had never been obese, respectively.

CONCLUSIONS

Higher BMI from childhood onwards is associated with stronger grip at age 46 years. This suggests that, at this age, anabolic effects of fat on muscle are outweighing the catabolic effects thought to lead to the manifestation of sarcopenic obesity later in life, especially among men. Midlife may be an optimal time to intervene to prevent sarcopenic obesity.

Associations between childhood and adulthood socioeconomic position and grip strength at age 46 years: findings from the 1970 British Cohort Study

BACKGROUND

Muscle weakness is a key criterion for important age-related conditions, including sarcopenia and frailty. Research suggests lower childhood socioeconomic position (SEP) may be associated with muscle weakness in later life but there is little evidence on associations in younger adults closer to peak muscle strength. We aimed to examine relationships between indicators of SEP in childhood and adulthood and grip strength at age 46y.

METHODS

We examined 7,617 participants from the 1970 British Cohort Study with grip strength measurements at 46y. We used sex-specific linear regression models to test associations between five different indicators of SEP in childhood and adulthood (paternal occupational class and parental education levels at age 5 and own occupational class and education level at age 46) and maximum grip strength. Models were adjusted for birth weight, BMI in childhood and adulthood, adult height, disability in childhood, leisure-time physical activity in childhood and adulthood, sedentary behaviour in childhood and adulthood, occupational activity and smoking at age 46.

RESULTS

Among women, lower SEP in childhood and adulthood was associated with weaker grip strength even after adjustments for covariates. For example, in fully-adjusted models, women whose mothers had no qualifications at age five had mean grip strength 0.99 kg (95% CI: -1.65, -0.33) lower than women whose mothers were educated to degree and higher. Among men, lower levels of father's education and both adult SEP indicators were associated with stronger grip. The association between own occupational class and grip strength deviated from linearity; men in skilled-manual occupations (i.e. the middle occupational group) had stronger grip than men in the highest occupational group (Difference in means: 1.33 kg (0.60, 2.06)) whereas there was no difference in grip strength between the highest and lowest occupational groups. Adjustment for occupational activity largely attenuated these associations.

CONCLUSION

Findings highlight the need to identify age and sex-specific interventions across life to tackle inequalities in important age-related conditions related to weakness.

Bibliometric Analysis of the Knowledge Base and Future Trends on Sarcopenia from 1999–2021

Sarcopenia is characterized by progressive loss of muscle mass and function, and it is becoming a serious public health problem with the aging population. However, a comprehensive overview of the knowledge base and future trends is still lacking. The articles and reviews with “sarcopenia” in their title published from 1999 to 2021 in the SCIE database were retrieved. We used Microsoft Excel, VOSviewer, and CiteSpace to conduct a descriptive and bibliometric analysis. A total of 3582 publications were collected, from 4 published in 2000 increasing dramatically to 850 documents in 2021. The USA was the most productive country, with the most citations. The Catholic University of the Sacred Heart and Landi F were the most influential organization and author in this field, respectively. The core journal in this field was the Journal of Cachexia Sarcopenia and Muscle. According to the analysis of keywords and references, we roughly categorized the main research areas into four domains as follows: 1. Definition and diagnosis; 2. Epidemiology; 3. Etiology and pathogenesis; 4. Treatments. Comparing different diagnostic tools and the epidemiology of sarcopenia in different populations are recent hotspots, while more efforts are needed in the underlying mechanism and developing safe and effective treatments. In conclusion, this study provides comprehensive insights into developments and trends in sarcopenia research that can help researchers and clinicians better manage and implement their work.

Adiposity and grip strength: a Mendelian randomisation study in UK Biobank

BACKGROUND

Muscle weakness, which increases in prevalence with age, is a major public health concern. Grip strength is commonly used to identify weakness and an improved understanding of its determinants is required. We aimed to investigate if total and central adiposity are causally associated with grip strength.

METHODS

Up to 470,786 UK Biobank participants, aged 38-73 years, with baseline data on four adiposity indicators (body mass index (BMI), body fat percentage (BF%), waist circumference (WC) and waist-hip-ratio (WHR)) and maximum grip strength were included. We examined sex-specific associations between each adiposity indicator and grip strength. We explored whether associations varied by age, by examining age-stratified associations (< 50 years, 50-59 years, 60-64 years,65 years +). Using Mendelian randomisation (MR), we estimated the strength of the adiposity-grip strength associations using genetic instruments for each adiposity trait as our exposure.

RESULTS

In males, observed and MR associations were generally consistent: higher BMI and WC were associated with stronger grip; higher BF% and WHR were associated with weaker grip: 1-SD higher BMI was associated with 0.49 kg (95% CI: 0.45 kg, 0.53 kg) stronger grip; 1-SD higher WHR was associated with 0.45 kg (95% CI:0.41 kg, 0.48 kg) weaker grip (covariate adjusted observational analyses). Associations of BMI and WC with grip strength were weaker at older ages: in males aged < 50 years and 65 years + , 1-SD higher BMI was associated with 0.93 kg (95% CI: 0.84 kg, 1.01 kg) and 0.13 kg (95% CI: 0.05 kg, 0.21 kg) stronger grip, respectively. In females, higher BF% was associated with weaker grip and higher WC was associated with stronger grip; other associations were inconsistent.

CONCLUSIONS

Using different methods to triangulate evidence, our findings suggest causal links between adiposity and grip strength. Specifically, higher BF% (in both sexes) and WHR (males only) were associated with weaker grip strength.

Whey Protein, Leucine- and Vitamin-D-Enriched Oral Nutritional Supplementation for the Treatment of Sarcopenia

Sarcopenia has been recognized as a muscle disease, with adverse consequences on health. Updated recommendations, aimed at increasing awareness of sarcopenia and its accompanying risks, have been produced to urge the early detection and treatment of this disease. Recommended treatment is based on an individually tailored resistance exercise training program, the optimization of protein intake using high-quality protein sources (i.e., whey protein) in order to provide a high amount of essential amino acids—particularly leucine—and addressing vitamin D deficiency/insufficiency. The purpose of this review is to collate and describe all of the relevant efficacy studies carried out with a muscle-targeted oral nutritional supplementation (MT-ONS)—namely a whey-protein-based, leucine- and vitamin D-enriched formula aimed at optimizing their intake and satisfying their requirements—in different patient populations and clinical settings in order to determine if there is enough evidence to recommend prescription for the treatment of sarcopenia or its prevention in high-risk patient populations. Trials using a MT-ONS with or without a concomitant physical exercise program were systematically searched (up to June 2021), and those addressing relevant endpoints (muscle mass, physical performance and function) were critically reviewed. In total, 10 articles providing efficacy data from eight trials were identified and narratively reviewed. As far as older patients with sarcopenia are concerned, MT-ONS has been pertinently tested in six clinical trials (duration 4–52 weeks), mostly using a high-quality randomized controlled trial design and demonstrating efficacy in increasing the muscle mass and strength, as well as the physical performance versus iso-caloric placebo or standard practice. Consistent results have been observed in various clinical settings (community, rehabilitation centers, care homes), with or without adjunctive physical exercise programs. A positive effect on markers of inflammation has also been shown. A muscle-protein-sparing effect, with benefits on physical performance and function, has also been demonstrated in patients at risk of losing skeletal muscle mass (three trials), such as older patients undergoing weight loss or intensive rehabilitation programs associated with neurological disability (Parkinson’s disease). MT-ONS has demonstrated not only a significant efficacy in clinical variables, but also a positive impact on healthcare resource consumption in the rehabilitation setting (length of stay and duration of rehabilitation). In summary, MT-ONS, alone or in association with an appropriate exercise program, is an effective therapy for older patients with sarcopenia and should be offered as a first-line treatment, not only to improve clinical outcomes but also to reduce healthcare resource consumption, particularly in patients admitted to a rehabilitation center.

Metabolomics Coupled with Pathway Analysis Provides Insights into Sarco-Osteoporosis Metabolic Alterations and Estrogen Therapeutic Effects in Mice

Postmenopausal osteoporosis (PMOP) and sarcopenia are common diseases that predominantly affect postmenopausal women. In the occurrence and development of these two diseases, they are potentially pathologically connected with each other at various molecular levels. However, the application of metabolomics in sarco-osteoporosis and the metabolic rewiring happening throughout the estrogen loss-replenish process have not been reported. To investigate the metabolic alteration of sarco-osteoporosis and the possible therapeutical effects of estradiol, 24 mice were randomly divided into sham surgery, ovariectomy (OVX), and estradiol-treated groups. Three-dimensional reconstructions and histopathology examination showed significant bone loss after ovariectomy. Estrogen can well protect against OVX-induced bone loss deterioration. UHPLC-Q-TOF/MS was preformed to profile semi- polar metabolites of skeletal muscle samples from all groups. Metabolomics analysis revealed metabolic rewiring occurred in OVX group, most of which can be reversed by estrogen supplementation. In total, 65 differential metabolites were identified, and pathway analysis revealed that sarco-osteoporosis was related to the alterations in purine metabolism, glycerophospholipid metabolism, arginine biosynthesis, tryptophan metabolism, histidine metabolism, oxidative phosphorylation, and thermogenesis, which provided possible explanations for the metabolic mechanism of sarco-osteoporosis. This study indicates that an UHPLC-Q-TOF/MS-based metabolomics approach can elucidate the metabolic reprogramming mechanisms of sarco-osteoporosis and provide biological evidence of the therapeutical effects of estrogen on sarco-osteoporosis.

The effect of long chain omega-3 polyunsaturated fatty acids on muscle mass and function in sarcopenia: A scoping systematic review and meta-analysis

BACKGROUND & AIMS

Sarcopenia is characterized by the progressive loss of skeletal muscle mass and function, which reduces mobility and quality of life. Risk factors for sarcopenia include advanced age, physical inactivity, obesity, and chronic diseases such as cancer or rheumatoid arthritis. Omega-3 long chain polyunsaturated fatty acids (LC PUFAs) might be associated with a reduction in risk of sarcopenia due to their anti-inflammatory effects.

METHODS

We conducted a systematic review and meta-analysis to quantify the effects of omega-3 LC PUFAs on muscle mass, volume and function parameters. The National Library of Medicine's MEDLINE/PubMed database was searched on 9th October 2020 for randomized controlled trials that used omega-3 LC PUFAs as an intervention with muscle-related endpoints. A snowballing search to identify additional studies was completed on 23rd April 2021. The meta-analysis was conducted using meta-essentials worksheet 3. Bias was assessed using the Jadad scale.

RESULTS

123 studies were identified with the systematic searches. Most studies were performed in disease populations, such as cancer or chronic obstructive pulmonary disease (COPD), or in healthy individuals after a fatiguing exercise bout. The endpoints lean body mass, skeletal muscle mass, mid-arm muscle circumference, handgrip strength, quadriceps maximal voluntary capacity (MVC), and 1-repetition maximum chest press were selected for meta-analysis based on the number of available studies; thus 66 studies were included in the quantitative synthesis. Using a random effects model and 2-tailed p-value, there was a significant relationship in favor of omega-3 LC PUFA supplementation for lean body mass (effect size 0.27, 95%CI 0.04 to 0.51), skeletal muscle mass (effect size 0.31, 95%CI 0.01 to 0.60) and quadriceps MVC (effect size 0.47, 95%CI 0.02 to 0.93).

CONCLUSION

The results indicate that there is a positive effect of omega-3 LC PUFA supplementation on overall body muscle mass and strength. Small study size and heterogeneity limit the applicability of these findings for sarcopenia prevention. Larger trials in populations at risk of sarcopenia would strengthen the evidence base.

Sarcopenia affects activities of daily living recovery and hospitalization costs in older adults in convalescent rehabilitation wards

PURPOSE

This study aimed to investigate the impact of sarcopenia on activities of daily living (ADL) recovery and hospitalization costs in older patients admitted to convalescent rehabilitation wards.

METHODS

This prospective cohort study included 104 patients aged ≥ 65 years who were admitted to convalescent rehabilitation wards. The primary outcome was ADL recovery as evaluated by the Functional Independence Measure (FIM) efficiency during hospitalization, and the secondary outcome was hospital-related costs. Univariate and multivariate analyses were performed to identify whether sarcopenia was associated with FIM-motor efficiency and hospitalization costs.

RESULTS

Among the patients, 68.3% were females, and the mean age was 82.3 ± 8.3 years. The prevalence of sarcopenia was 73.1%. The FIM-motor efficiency score was significantly lower in patients with sarcopenia (median 0.38; interquartile range 0.27-0.52) than in those without sarcopenia (median 0.55; interquartile range 0.34-0.87) (P = 0.009). Hospitalization costs were higher in patients with sarcopenia (32,813 ± 15,184 dollars) than in those without sarcopenia (26,879 ± 10,248 dollars) (P = 0.058). Multivariate analysis showed that sarcopenia was independently associated with FIM-motor efficiency (standardized β =  - 0.236, P = 0.014, R2 = 0.40) and hospitalization costs (standardized β = 0.15, P = 0.027, R2 = 0.70) after adjusting for confounding factors.

CONCLUSION

We found that sarcopenia reduces the FIM-motor efficiency and increases direct hospitalization costs in older patients admitted to convalescent rehabilitation wards. Therefore, it is necessary to design interventions to prevent sarcopenia and improve the efficiency of ADL recovery and reduce direct hospitalization cost.

Prevalence of low muscle mass and associated factors in community-dwelling older adults in Singapore

The population is rapidly aging worldwide, and there is an age-related decline in muscle mass. Therefore, it is important to examine the prevalence and associated factors of low appendicular skeletal muscle mass index (ASMI) in older adults. The objectives of this cross-sectional study were (i) to determine the prevalence of low ASMI (ASM/height²) and (ii) to identify factors associated with low ASMI. This study included 1211 community-dwelling adults aged ≥ 65 years. Low ASMI was defined as < 7.0 kg/m² in males and < 5.7 kg/m² in females (bioelectrical impedance analysis). Gender-specific cut-off values of calf circumference for low ASMI were determined. The prevalence of low ASMI in the overall cohort was 59.9%, i.e., 57.0% among males and 61.8% among females, with no significant difference between genders (P = 0.1068). The prevalence of low ASMI was 81.3% in individuals at risk of malnutrition compared to 20.6% in their counterparts with normal nutritional status (P < 0.0001). Participants with low ASMI were older, had lower physical activity scores, and greater likelihood of hospitalization in prior 6 months compared with normal ASMI (all P < 0.0001). Low ASMI was associated with risk of malnutrition (odds ratio: 3.58 for medium risk, odds ratio: 12.50 for high risk), older age, smoking, drinking, smaller calf circumference, and lower bone mass (all P ≤ 0.0328). Cut-off values of calf circumference for low ASMI for males was 33.4 cm and for females was 32.2 cm. In conclusion, we found that low ASMI was highly prevalent among community-dwelling older adults at risk of malnutrition. Other significant factors associated with low ASMI were age, smoking, drinking, calf circumference, and bone mass. Screening community-dwelling older adults for risk of malnutrition can prevent or delay onset of low ASMI.

Immediate Effects of Whole-Body Vibration Associated with Squatting Exercises on Hemodynamic Parameters in Sarcopenic Older People: A Randomized Controlled Trial

Whole-body vibration (WBV) exercises have recently been introduced as a nonpharmacological therapeutic strategy for sarcopenic older people. The present study aimed to evaluate the effect of WBV exercise on hemodynamic parameters in sarcopenic older people. Forty older people, divided into groups of nonsarcopenic (NSG = 20) and sarcopenic (SG = 20), participated in the study and were cross randomized into two interventions of eight sets of 40 s each, these being squatting with WBV and squatting without WBV. Heart rate (HR), peak heart rate (peak HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), mean arterial pressure (MAP), and subjective perception of effort (SPE), were assessed at baseline, during, and after a single WBV session. The HR, peak HR, and DP variables were similar at baseline between groups. WBV exercise increased all the hemodynamic parameters both during and immediately after the intervention, in both groups (SG and NSG). The MAP values were similar at baseline between groups; however, in the NSG there was a significant increase during and immediately after the squatting with WBV intervention (p < 0.05). The HR behavior, in both groups, showed that there was an increase in HR after the first set of exercises with vibration and this increase was maintained until the final set. The absence of adverse effects of WBV exercise on the cardiovascular system and fatigue suggests this exercise modality is adequate and safe for sarcopenic older people.

Associations of Physical Activity and Exercise with Health-related Outcomes in Patients with Melanoma During and After Treatment: A Systematic Review

Purpose:

Although exercise medicine is recommended to counter treatment-related side-effects and improve health-related outcomes of patients affected by different cancers, no specific recommendations exist for patients with melanoma. As a result, we systematically examined the current evidence regarding the effects of physical activity and exercise on objectively-measured and patient-reported outcomes among patients with melanoma.

Methods:

Searches were conducted in PubMed, CINAHL, EMBASE, SPORTDiscus, and Web of Science databases. This review included published data involving physical activity or exercise and objectively-measured or patient-reported outcomes of patients with cutaneous melanoma. The quality of included studies was assessed using the McMaster University Critical Appraisal Tool for Quantitative Studies.

Results:

Six studies including 882 patients with melanoma were included. Studies presented heterogeneity of design with 2 cross-sectional surveys, 2 retrospective analyses, and 2 non-randomized intervention trials. No statistically significant change in quality of life, fatigue, physical function, cardiorespiratory fitness, body composition, psychological distress, cognitive function, or treatment-related side-effects were attributable to physical activity or exercise. Importantly, physical activity or exercise during melanoma treatment or into survivorship did not adversely impact patients/survivors.

Conclusion:

In summary, physical activity or exercise did not adversely impact quality of life, objectively-measured or patient-reported outcomes in patients with melanoma. In addition, there is a paucity of quality studies examining the effects of physical activity or exercise on patients with melanoma throughout the cancer care continuum.

Dynapenia Rather Than Sarcopenia Is Associated with Metabolic Syndrome in Patients with Chronic Liver Diseases

We aimed to examine the association between sarcopenia-related factors and metabolic syndrome (Met-S) in patients with chronic liver diseases (CLDs, n = 582, average age = 59.5 years, 290 males, 168 liver cirrhosis cases). Met-S was determined based on the Japanese criteria. Sarcopenia was determined based on grip strength (GS) and skeletal muscle index (SMI) by bioelectrical impedance analysis. Our cohort was divided into the four groups: (A) sarcopenia (n = 44), (B) dynapenia (n = 45), (C) presarcopenia (n = 112), and (D) the control (n = 381). Impacts of GS and SMI on Met-S were investigated. In males, waist circumference (WC) ≥ 85 cm was observed in 199 patients (68.6%), while in females, WC ≥ 90 cm was observed in 94 patients (32.2%). Met-S was identified in 109 patients (18.7%). The proportion of Met-S in the group A, B, C and D were 18.2%, 48.9%, 8.0%, and 18.4% (A vs. B, p = 0.0033; B vs. C, p < 0.0001; C vs. D, p = 0.0081; A vs. C, p = 0.0867; A vs. D, p = 1.000, B vs. D, p < 0.0001; overall p value < 0.0001). Multivariate analysis revealed that age, gender, and group B (dynapenia) were significant factors linked to the presence of Met-S. In conclusion, dynapenia rather than sarcopenia is associated with Met-S in CLD patients.

Impact of Physical Inactivity on the Risk of Disability and Hospitalization in Older Patients with Advanced Lung Cancer

Purpose

This prospective observational study aimed to explore the influence of physical inactivity during initial chemotherapy on the risk of disability and hospitalization in later life among older patients with advanced non-small-cell lung cancer (NSCLC).

Patients and Methods

Patients aged 70 or above who were scheduled to receive first-line chemotherapy for newly diagnosed advanced NSCLC were recruited for the study. An electronic pedometer was used to measure daily steps; based on the change rate (cutoff: −12.5%) from pretreatment to 12 ± 4 weeks after enrolment, patients were classified as active or inactive. The Barthel Index estimated activities of daily living. We compared disability-free survival time, mean cumulative functions of hospital stays, and medical costs, between the active and inactive groups.

Results

Among the 29 patients enrolled, 21 were evaluable. Compared with active patients (n = 11), inactive patients (n = 10) showed shorter disability-free survival (6.4 vs 19.9 months, p < 0.05) and tended to have longer hospital stays (23.7 vs 6.3 days/person) and higher inpatient care cost (¥1.6 vs ¥0.3 million/person [US$16,000 vs US$3000/person]) during the first year.

Conclusion

Physical inactivity during initial chemotherapy may be a risk factor for developing disability and requiring hospitalization in later life for older patients with advanced NSCLC. Our findings may indicate the need for lifestyle interventions with multidisciplinary teams, which include physicians, nurses, and physiotherapists, for older patients with advanced lung cancer during an active cancer treatment. A large-sample-sized study is needed to validate our findings.

Association of sarcopenia with mortality and end-stage renal disease in those with chronic kidney disease: a UK Biobank study

BACKGROUND

Sarcopenia, a degenerative and generalized skeletal muscle disorder involving the loss of muscle function and mass, is an under-recognized problem in clinical practice, particularly in chronic kidney disease (CKD). We aimed to investigate the prevalence of sarcopenia in individuals with CKD, its risk factors, and its association with all-cause mortality and progression to end-stage renal disease (ESRD).

METHODS

UK Biobank participants were grouped according to the presence of CKD (defined as an estimated glomerular filtration rate <60 mL/min/1.73 m² ) and as having probable (low handgrip strength), confirmed (plus low muscle mass), and severe sarcopenia (plus poor physical performance) based on the 2019 European Working Group of Sarcopenia in Older People and Foundation for the National Institutes of Health criteria. Risk factors were explored using logistic regression analysis. Survival models were applied to estimate risk of mortality and ESRD.

RESULTS

A total of 428 320 participants, of which 8767 individuals with CKD (46% male, aged 62.8 (standard deviation 6.8) years, median estimated glomerular filtration rate 54.5 (interquartile range 49.0-57.7) mL/min/1.72 m² ) were included. Probable sarcopenia was present in 9.7% of individuals with CKD compared with 5.0% in those without (P < 0.001). Sarcopenia was associated with being older; inflammation; poorer renal function; and lower serum albumin, total testosterone, and haemoglobin. The largest risk factors for sarcopenia were having three or more comorbidities (odds ratio: 2.30; 95% confidence interval: 1.62 to 3.29; P < 0.001) and physical inactivity: participants in the highest quartile of weekly activity were 43% less likely to have sarcopenia compared to the lowest quartile (odds ratio: 0.57; 0.42 to 0.76; P < 0.001). Participants with CKD and sarcopenia had a 33% (7% to 66%; P = 0.011) higher hazard of mortality compared with individuals without. Sarcopenic CKD individuals had a 10 year survival probability of 0.85 (0.82 to 0.88) compared with 0.89 (0.88 to 0.30) in those without sarcopenia, an absolute difference of 4%. Those with sarcopenia were twice as likely to develop ESRD (hazard ratio: 1.98; 1.45 to 2.70; P < 0.001).

CONCLUSIONS

Participants with reduced kidney function are at an increased risk of premature mortality. The presence of sarcopenia increases the risk of mortality and ESRD. Appropriate measurement of sarcopenia should be used to identify at-risk individuals. Interventions such as physical activity should be encouraged to mitigate sarcopenia.

Can High-Intensity Interval Training Promote Skeletal Muscle Anabolism?

Exercise training in combination with optimal nutritional support is an effective strategy to maintain or increase skeletal muscle mass. A single bout of resistance exercise undertaken with adequate protein availability increases rates of muscle protein synthesis and, when repeated over weeks and months, leads to increased muscle fiber size. While resistance-based training is considered the 'gold standard' for promoting muscle hypertrophy, other modes of exercise may be able to promote gains in muscle mass. High-intensity interval training (HIIT) comprises short bouts of exercise at or above the power output/speed that elicits individual maximal aerobic capacity, placing high tensile stress on skeletal muscle, and somewhat resembling the demands of resistance exercise. While HIIT induces rapid increases in skeletal muscle oxidative capacity, the anabolic potential of HIIT for promoting concurrent gains in muscle mass and cardiorespiratory fitness has received less scientific inquiry. In this review, we discuss studies that have determined muscle growth responses after HIIT, with a focus on molecular responses, that provide a rationale for HIIT to be implemented among populations who are susceptible to muscle loss (e.g. middle-aged or older adults) and/or in clinical settings (e.g. pre- or post-surgery).

CT-determined sarcopenia as a predictor of post-operative outcomes in patients undergoing an emergency laparotomy

PURPOSE

Emergency laparotomy has a high reported thirty-day mortality, ranging from 11 to 15%. Current peri-operative risk assessment tools may poorly estimate the risk of perioperative mortality. We sought to determine if CT-determined sarcopenia may be a useful predictor of post-operative outcomes in patients undergoing an emergency laparotomy.

METHODS

A retrospective review of a prospectively maintained database of consecutive adult patients who underwent an emergency laparotomy at our institution was performed. Post-operative mortality (90-day mortality), admission to HDU or ICU and APACHE-II scores were recorded for these patients. Sarcopenia was calculated by determining psoas area and density at the level of the third lumbar vertebra. The lowest quartile was determined to be sarcopenic. Univariate statistical analysis investigated associations between sarcopenia and these outcome measures.

RESULTS

Eighty patients were included in the study following application of exclusion criteria. Thirty-eight were male. The 90-day mortality rate was 11%. Compared to their non-sarcopenic counterparts, sarcopenic patients were significantly more likely to have died by 90 days post-operatively (χ² = 9.51, p = 0.002) and to require admission to either the HDU or ICU in the post-operative period (χ² = 10.62, p = 0.001).

CONCLUSIONS

CT determined sarcopenia is significantly associated with 90-day mortality and post-operative admission to HDU or ICU in patients undergoing an emergency laparotomy. The future development of a validated scoring tool incorporating sarcopenia could help to better select out those patients who will require higher levels of post-operative care as well as identifying those for whom surgery may not confer a survival benefit and be deemed futile.

Role of fibro-adipogenic progenitor cells in muscle atrophy and musculoskeletal diseases

Maintaining muscle mass is clinically important as muscle helps to regulate metabolic systems of the body as well as support activities of daily living that require mobility, strength, and power. Losing muscle mass decreases an individual's independence and quality of life, and at the same time increases the risk of disease burden. Fibro-adipogenic progenitor (FAP) cells are a group of muscle progenitor cells that play an important role in muscle regeneration and maintenance of skeletal muscle fiber size. These important functions of FAPs are mediated by a complex secretome that interacts in a paracrine manner to stimulate muscle satellite cells to divide and differentiate. Dysregulation of FAP differentiation leads to fibrosis, fatty infiltration, muscle atrophy, and impaired muscle regeneration. Functional deficits in skeletal muscle resulting from atrophy, fibrosis, or fatty infiltration will reduce biomechanical stresses on the skeleton, and both FAP-derived adipocytes and FAPs themselves are likely to secrete factors that can induce bone loss. These findings suggest that FAPs represent a cell population to be targeted therapeutically to improve both muscle and bone health in settings of aging, injury, and disease.

Using the Updated EWGSOP2 Definition in Diagnosing Sarcopenia in Spanish Older Adults: Clinical Approach

Recently the European Working Group on Sarcopenia in Older People (EWGSOP2) has updated diagnostic criteria for sarcopenia, which consist of one or more measures of muscle strength, muscle mass, and physical performance, plus an initial screening test called SARC-F. The main objective was to compare the number of cases of sarcopenia, using the different measurements and screening options. A cross-sectional study was conducted on Spanish older adults (n = 272, 72% women). Combining the different measures proposed by the steps described in the EWGSOP2 algorithm, 12 options were obtained (A-L). These options were studied in each of the three models: (1) using SARC-F as initial screening; (2) not using SARC-F; and (3) using SARC-CalF instead of SARC-F. A χ2 independence test was statistically significant (χ2(6) = 88.41, p < 0.001), and the association between the algorithm used and the classification of sarcopenia was moderate (Cramer's V = 0.226). We conclude that the different EWGSOP2 measurement options imply case-finding differences in the studied population. Moreover, when applying the SARC-F, the number of people classified as sarcopenic decreases. Finally, when SARC-CalF is used as screening, case finding of sarcopenic people decreases. Thus, clinical settings should consider these outcomes, since these steps can make preventive and therapeutic interventions on sarcopenia vary widely.

Comparison of calorie and nutrient intake among elderly with and without sarcopenia: A systematic review and meta-analysis

CONTEXT

Sarcopenia, besides having an impact on functional capacity, has been associated with increased hospitalization and mortality, and stands out as an essential cause of disability among older people.

OBJECTIVE

We conducted a systematic review and meta-analysis of published studies comparing the calories and nutrients ingested by elderly people with and without sarcopenia.

DATA SOURCES

MEDLINE/PubMed, Scopus, LILACS, Cochrane Library, and Scielo databases were searched.

STUDY SELECTION

Studies comparing calories and nutrient intake among elderly people diagnosed with sarcopenia and people without sarcopenia were included.

DATA ANALYSIS

Mean differences and 95% confidence intervals (CIs) were calculated, and heterogeneity was assessed using I2 test.

RESULTS

A total of 23 studies fulfilled the inclusion criteria. The average number of calories and nutrients ingested were significantly lower in elderly study participants with sarcopenia compared with those without sarcopenia. The meta-analyses showed that the average number of calories ingested (n = 19 studies; mean difference, -156.7 kcal; 95%CI, -194.8 to -118.7) were significantly lower in those with sarcopenia than in elderly participants without sarcopenia. Compared to those without sarcopenia, elderly people with sarcopenia consumed lower amounts of proteins; carbohydrates; saturated fatty acids; vitamins A, B12, C, and D; and minerals such as calcium, magnesium, sodium, and selenium.

CONCLUSIONS

The evidence so far available suggests a difference in caloric, macronutrient (ie, proteins, carbohydrates, saturated fatty acids), and micronutrient (ie calcium, magnesium, sodium, selenium, and vitamins A, B12, C, and D) intake among the elderly with and without sarcopenia. Additional studies are needed to define the best interventions to improve the consumption of calories and nutrients by the aging population.

Animal Protein versus Plant Protein in Supporting Lean Mass and Muscle Strength: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Although animal protein is usually considered to be a more potent stimulator of muscle protein synthesis than plant protein, the effect of protein source on lean mass and muscle strength needs to be systematically reviewed. This study aimed to examine potential differences in the effect of animal vs. plant protein on lean mass and muscle strength, and the possible influence of resistance exercise training (RET) and age. The following databases were searched: PubMed, Embase, Scopus and CINAHL Plus with Full Text, and 3081 articles were screened. A total of 18 articles were selected for systematic review, of which, 16 were used for meta-analysis. Total protein intakes were generally above the recommended dietary allowance at the baseline and end of intervention. Results from the meta-analyses demonstrated that protein source did not affect changes in absolute lean mass or muscle strength. However, there was a favoring effect of animal protein on percent lean mass. RET had no influence on the results, while younger adults (<50 years) were found to gain absolute and percent lean mass with animal protein intake (weighted mean difference (WMD), 0.41 kg; 95% confidence interval (CI) 0.08 to 0.74; WMD 0.50%; 95% CI 0.00 to 1.01). Collectively, animal protein tends to be more beneficial for lean mass than plant protein, especially in younger adults.

Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes

BACKGROUND

Sarcopenia is a disease associated with aging and a negative prognosis. Consensus-based treatment consists in targeting muscle mass and function through physical exercise, optimization of protein intake, and vitamin D supplementation, but evidence is lacking. We evaluated the safety and efficacy of a muscle-targeted nutritional support on the outcome of a physical exercise rehabilitation programme.

METHODS

In a single-site, double-blind, randomized, controlled trial (NCT03120026; May 2017 to December 2018), old (≥65 years) adults [N = 140 (63% female patients; age, 81 ± 6 years)] without severe cognitive impairment, who were found to have sarcopenia by European Working Group on Sarcopenia in Older People 2010 criteria and hospitalized for physical rehabilitation, were randomized to receive until discharge (for at least 4 weeks and up to 8 weeks) a whey protein-based nutritional formula enriched with leucine and vitamin D or an iso-caloric control formula twice daily in addition to a standard hospital diet. The primary endpoint was the change in 4 m gait speed per month. Key secondary endpoints addressed the change in physical performance: chair-stand test, timed up and go test, and short physical performance battery. Other secondary outcomes were the change in functional status, muscle strength and mass, cognitive status, and quality of life. The proportion of patients who improved their rehabilitation intensity profile and overall economic benefits (using length of stay and duration of rehabilitation as surrogate measures) were also evaluated.

RESULTS

A total of 161 patients were screened and 140 were randomized to study interventions. Thirteen patients (experimental, n = 6; placebo, n = 7) discontinued the intervention because they disliked the product and intention-to-treat analyses were based on patients reassessed at discharge [n = 127 (66% female patients; age, 81 ± 6 years)]. Supplementation with the experimental formula (n = 64) resulted in greater increase in mean gait speed {0.061 m/s/month [95% confidence interval (CI), 0.043 to 0.080]} than placebo [n = 63; -0.001 m/s/month (95%CI, -0.008 to 0.006)]: mean difference, 0.063 m/s/month (95%CI, 0.043 to 0.082) (P < 0.001). A significant effect was also found for muscle mass (P < 0.03) and all key secondary outcomes, functional and cognitive endpoints (P < 0.001 for all). Supplementation resulted also in higher proportion of patients improving their rehabilitation intensity profile (P = 0.003) and being discharged home (P = 0.002); shorter rehabilitation (P < 0.001); and hospital stay (P < 0.001).

CONCLUSIONS

In old adults with sarcopenia admitted to hospital for rehabilitation the consumption of a whey protein-based nutritional formula enriched with leucine and vitamin D improved physical performance and function, as well as muscle mass, and reduced the intensity and costs of care.

Effects of vibration therapy on muscle mass, muscle strength and physical function in older adults with sarcopenia: a systematic review and meta-analysis

Background

Sarcopenia, a progressive loss of muscle mass and function with advancing age, is a prevalent condition among older adults. As most older people are too frail to do intensive exercise and vibration therapy has low risk and ease of participation, it may be more readily accepted by elderly individuals. However, it remains unclear whether vibration therapy would be effective among older adults with sarcopenia. This systematic review and meta-analysis examined the effect of vibration therapy including local vibration therapy and whole-body vibration therapy, for enhancing muscle mass, muscle strength and physical function in older people with sarcopenia.

Methods

A systematic literature search was conducted in March 2019 in the following 5 electronic databases: PubMed, CINAHL, Embase, PEDro, and the Cochrane Central Register of Controlled Trials, with no restriction of language or the year of publication. Randomized controlled trials and quasi-experimental studies examining effects of vibration therapy on muscle mass, muscle strength or physical function in older adults with sarcopenia were included in this systematic review. Two reviewers independently assessed the methodological quality of the selected studies.

Results

Of the 1972 identified studies, seven publications from six studies involving 223 participants were included in this systematic review. Five of them conducted whole-body vibration therapy, while two conducted local vibration therapy. A meta-analysis of randomized controlled studies indicated that muscle strength significantly increased after whole-body vibration therapy (SMD 0.69, 95% CI 0.28 to 1.11, I² = 0%, P = 0.001) and local vibration therapy (SMD 3.78, 95% CI 2.29 to 5.28, P < 0.001). Physical performance measured by the sit-to-stand test and the timed-up-and-go test were significantly improved after the intervention (SMD -0.79, 95% CI − 1.21 to − 0.37, I² = 0%, P < 0.001) and SMD -0.83, 95% CI − 1.56 to − 0.11, I² = 64%, P = 0.02, respectively).

Conclusion

Vibration therapy could be a prospective strategy for improving muscle strength and physical performance in older adults with sarcopenia. However, due to the limited number of the included studies, caution is needed when interpreting these results. More well-designed, large sample size studies should be conducted to further explore and validate the benefits of vibration therapy for this population.

Feasibility and acceptability of a milk and resistance exercise intervention to improve muscle function in community-dwelling older adults (MIlkMAN): Pilot study

Background

Dietary protein supplementation combined with resistance exercise (RE) may counteract declines in muscle strength, mass, and function (sarcopenia), but the role of whole foods rich in protein, such as milk, is less well understood. In the MIlkMAN study, we aimed to examine the feasibility and acceptability of milk+RE as an intervention for muscle function in community-dwelling older adults, and provide exploratory pilot data for future substantive research in population at risk of sarcopenia.

Methods

In a parallel groups design, 30 older adults (71.7±3.6 years; 12 women) were randomised into three groups: WM (whole milk 3.6% fat)+RE, SM (skimmed milk 0.3% fat)+RE, and C (isocaloric carbohydrate drink)+RE. RE was performed twice-weekly over 6 weeks in a community gym, followed by the consumption of 500 ml of milk (~20 g protein) or carbohydrate drink immediately after exercise and a further 500 ml at home within the following 4–5 hours. The feasibility and acceptability of the study was determined by calculating recruitment and attendance rates, compliance with the intervention, rating participants’ experiences, and recording adverse health events.

Results

The response rate was 49% (out of 400 invitations sent), and the recruitment rate was 73.2% (30 participants recruited out of 41 screened for eligibility). Twenty-nine participants completed the intervention—an attendance rate of 97.1%; 89.7% rated their experience as ‘excellent’/very good’. Compliance with taking the drinks was 97.1% (WM), 98.3% (SM), and 95.0% (C); 93.1% rated their drink intake as ‘easy’/’very easy’ with no adverse effects. Collection of exploratory pilot data to inform future trials was successful. Mean change in grip strength, 5-chair rises, and gait speed were 0.9±3.4 kg, 1.8±2.2 s, 0.1±0.1 m/s, respectively with no differences between the groups.

Conclusions

This community-based milk+RE intervention was feasible and acceptable to older adults. The study successfully collected pilot data for future substantive research.

Muscle Mass Loss in the Older Critically Ill Population: Potential Therapeutic Strategies

Skeletal muscle plays a critical role in everyday life, and its age-associated reduction has severe health consequences. The pre-existing presence of sarcopenia, combined with anabolic resistance, protein undernutrition, and the pro-catabolic/anti-anabolic milieu induced by aging and exacerbated in critical care, may accelerate the rate at which skeletal muscle is lost in patients with critical illness. Advancements in intensive care unit (ICU)-care provision have drastically improved survival rates; therefore, attention can be redirected toward other significant issues affecting ICU patients (e.g., length of stay, days on ventilation, nosocomial disease development, etc.). Thus, strategies targeting muscle mass and function losses within an ICU setting are essential to improve patient-related outcomes. Notably, loading exercise and protein provision are the most compelling. Many older ICU patients seldom meet the recommended protein intake, and loading exercise is difficult to conduct in the ICU. Nevertheless, the incorporation of physical therapy (PT), neuromuscular electrical stimulation, and early mobilization strategies may be beneficial. Furthermore, a number of nutrition practices within the ICU have been shown to improve patient-related outcomes ((e.g., feeding strategy [i.e., oral, early enteral, or parenteral]), be hypocaloric (∼70%-80% energy requirements), and increase protein provision (∼1.2-2.5 g/kg/d)). The aim of this brief review is to discuss the dysregulation of muscle mass maintenance in an older ICU population and highlight the potential benefits of strategic nutrition practice, specifically protein, and PT within the ICU. Finally, we provide some general guidelines that may serve to counteract muscle mass loss in patients with critical illness.

Assessment of body composition and impact of sarcopenia and sarcopenic obesity in patients with gastric cancer

Malnutrition is a critical problem in patients with gastric cancer (GC); however, no universally accepted marker that is convenient for clinical use has been defined. Recently, body composition has attracted considerable attention as a means to assess nutrition status in patients with cancer. The clinical role of skeletal muscle mass has also been increasingly recognized. In patients with GC, sarcopenia, which is the loss of skeletal muscle mass, was found to be significantly associated with increased post-surgical complications including hospital stay, healthcare costs, and poor survival. In addition, sarcopenic obesity, which combines the health risks of obesity and sarcopenia, is recognized as a strong risk factor for poor short- and long-term outcomes following gastrectomy. The mechanism linking sarcopenia to worse postoperative outcomes remains unclear; however, skeletal muscle has been found to act as an endocrine organ that produces substances affecting the immune system. In addition, sarcopenia was reported to be associated with toxicity and termination of chemotherapy. Patients with sarcopenia may be unable to react appropriately to the stress of gastrectomy and perioperative chemotherapy. To improve the short- and long-term outcomes of patients with GC and sarcopenia, adequate energy and protein intake are necessary during resistance training. In the present study, we performed a literature review and presented a method to evaluate body composition, the relationship between skeletal muscle mass and GC, and perioperative nutrition and exercise therapy for patients with sarcopenia.

PHD1 controls muscle mTORC1 in a hydroxylation-independent manner by stabilizing leucyl tRNA synthetase

mTORC1 is an important regulator of muscle mass but how it is modulated by oxygen and nutrients is not completely understood. We show that loss of the prolyl hydroxylase domain isoform 1 oxygen sensor in mice (PHD1^KO) reduces muscle mass. PHD1^KO muscles show impaired mTORC1 activation in response to leucine whereas mTORC1 activation by growth factors or eccentric contractions was preserved. The ability of PHD1 to promote mTORC1 activity is independent of its hydroxylation activity but is caused by decreased protein content of the leucyl tRNA synthetase (LRS) leucine sensor. Mechanistically, PHD1 interacts with and stabilizes LRS. This interaction is promoted during oxygen and amino acid depletion and protects LRS from degradation. Finally, elderly subjects have lower PHD1 levels and LRS activity in muscle from aged versus young human subjects. In conclusion, PHD1 ensures an optimal mTORC1 response to leucine after episodes of metabolic scarcity.

mTORC1 is an important regulator of muscle mass. Here, the authors show that the PHD1 controls muscle mass in a hydroxylation-independent manner. PHD1 prevents the degradation of leucine sensor LRS during oxygen and amino acid depletion to ensure effective mTORC1 activation in response to leucine.

Validation of the Danish SARC-F in Hospitalized, Geriatric Medical Patients

OBJECTIVES

Validation of the Danish version of the SARC-F (Strength, Assistance in walking, Rise from a chair, Climb stairs, and Falls) for hospitalized geriatric medical patients, compared against the original EWGSOP (European Working Group on Sarcopenia in Older People) and revised EWGSOP2 definition for sarcopenia. Additionally, investigation of the ability of SARC-F to individually identify low strength/function and muscle mass.

DESIGN

Cross-sectional analysis of data from an RCT.

SETTING

Hospital, Medical Department.

PARTICIPANTS

122 geriatric medical patients (65.6% women) ≥ 70 years of age with mixed medical conditions.

MEASUREMENTS

SARC-F screening, diagnostic assessment of sarcopenia (hand-grip strength, muscle mass measured by dual-frequency bio-impedance analysis, and 4-m usual gait speed).

RESULTS

The prevalence of risk of sarcopenia (SARC-F ≥ 4) was 48.3%, while it was diagnosed in 65.8% and 21.7%, with EWGSOP and EWGSOP2, respectively. The sensitivity, specificity, positive predictive value, negative predictive value according to EWGSOP were 50.0 %, 53.7 %, 67.2% and 36.1%, while they were 53.8 %, 53.2 %, 24.1% and 80.6%, according to EWGSOP2 (all participants). The ability of SARC-F to predict reduced strength, function, and muscle mass was modest. There was a significant negative linear, yet weak, relationship between total SARC-F score and hand-grip strength (R2=0.033) and 4-m gait speed (R2=0.111), but not muscle mass (R2=0.004).

CONCLUSION

SARC-F does not seem to be a suitable screening tool for identifying and excluding non-sarcopenic geriatric patients. Furthermore, the SARC-F score was more strongly correlated with reduced muscle strength and physical function than with low muscle mass.

Muscle weakness assessment in older intensive care unit patients

INTRODUCTION: After long periods of hospitalization, older adults may develop muscle weakness that can affect their functional independence after discharge. OBJECTIVE: To assess muscle weakness in older patients admitted to an ICU. METHOD: This cross-sectional, descriptive study with a quantitative approach assessed functional independence with the Katz Index and post-ICU muscle strength with a handgrip strength (HS) test and the Medical Research Council (MRC) sum-score. The sample consisted of 60 patients with an average age of 76 (60–99) years, 36 (60%) of whom were female. RESULTS: Post-ICU, 86.7% of the patients were functionally dependent. Female patients had significantly lower HS than males: 7 (0–24) vs. 17 (1–37) (p < 0.001). Female patients who received mechanical ventilation (MV) or sedation had significantly lower HS and MRC scores than those who did not (p < 0.001): HS MV 1 (0–13) vs. 11 (0–24) p < 0.001; MRC MV 35 (14–48) vs. 43 (27–57) p < 0.001; HS sedation 0 (0–12) vs. 9 (0–24) p < 0.001; MRC sedation 34 (14–36) vs. 42 (22–57) p < 0.001, respectively. Finally, there was an inversely proportional correlation between HS, MRC scores, and ICU length of stay, Spearman’s rho = -0.267 (p = 0.0039) and Spearman’s rho = -0.347 (p = 0.007), respectively. CONCLUSION: Older women who received mechanical ventilation and sedation have lower muscle strength than those who did not. As the ICU length of stay increases, muscle strength decreases.

Machine Learning for Automatic Paraspinous Muscle Area and Attenuation Measures on Low-Dose Chest CT Scans

RATIONALE AND OBJECTIVES

To develop and evaluate an automated machine learning (ML) algorithm for segmenting the paraspinous muscles on chest computed tomography (CT) scans to evaluate for presence of sarcopenia.

MATERIALS AND METHODS

A convolutional neural network based on the U-Net architecture was trained to perform muscle segmentation on a dataset of 1875 single slice CT images and was tested on 209 CT images of participants in the National Lung Screening Trial. Low-dose, noncontrast CT examinations were obtained at 33 clinical sites, using scanners from four manufacturers. The study participants had a mean age of 71.6 years (range, 70-74 years). Ground truth was obtained by manually segmenting the left paraspinous muscle at the level of the T12 vertebra. Muscle cross-sectional area (CSA) and muscle attenuation (MA) were recorded. Comparison between the ML algorithm and ground truth measures of muscle CSA and MA were obtained using Dice similarity coefficients and Pearson correlations.

RESULTS

Compared to ground truth segmentation, the ML algorithm achieved median (standard deviation) Dice scores of 0.94 (0.04) in the test set. Mean (SD) muscle CSA was 14.3 (3.6) cm2 for ground truth and 13.7 (3.5) cm2 for ML segmentation. Mean (SD) MA was 41.6 (7.6) Hounsfield units (HU) for ground truth and 43.5 (7.9) HU for ML segmentation. There was high correlation between ML algorithm and ground truth for muscle CSA (r2 = 0.86; p < 0.0001) and MA (r2 = 0.95; p < 0.0001).

CONCLUSION

The ML algorithm for measurement of paraspinous muscles compared favorably to manual ground truth measurements in the NLST. The algorithm generalized well to a heterogeneous set of low-dose CT images and may be capable of automated quantification of muscle metrics to screen for sarcopenia on routine chest CT examinations.

An Innovative AAL System Based on IoT Technologies for Patients with Sarcopenia

Sarcopenia is a highly prevalent, age-related muscle disorder associated with adverse outcomes. It is very important from a medical point of view to periodically monitor patients at risk of developing sarcopenia in order to early detect its onset or progression through objective and specific indicators. Today, the emerging Internet of Things (IoT)-enabling technologies allow us to create innovative, wearable, and non-invasive systems that can offer useful clinical support in this area. This work is focused on the use of combined hardware and software technologies, enabling the IoT, in order to monitor people suffering from sarcopenia by offering a high value-added service in the field of the Ambient Assisted Living (AAL). In addition to the description of the proposed system architecture, a validation of the entire system is also included, from both a performance and a functional point of view. Test beds have been carried out by using the independent replications method, and all measurements related to the identified sarcopenia parameters are characterized by a 95% confidence interval with a 5% maximum relative error. The implementation of these technologies as a supporting clinical tool used in a specific setting could significantly impact the life and independence of the sarcopenic frail elderly population.