Ultrasound imaging for measuring muscle and subcutaneous fat tissue thickness of the anterior thigh: A two-year longitudinal study in middle age

Background Ultrasound (US) imaging technique is widely used in research and clinical settings to assess the morphology and morphometry of neuromusculoskeletal structures. The technique has reported validity and reliability in measuring the size of various muscles under controlled conditions. The aim of the present study was to assess anterior thigh thickness using US imaging, in a healthy cohort of middle-aged older adults.Methods Participants included seventeen healthy older adults involved in regular moderate-vigorous activities (age range 39-66 years). US imaging scans of the anterior thighs two years since baseline measurements were performed. Images were analyzed off-line to compare US imaging measurements of muscle thickness and subcutaneous fat (SF) of the anterior thigh taken at baseline and after two years.Results There was no significant difference between muscle thickness measurements taken at baseline and after two years (Mean, standard deviation; baseline=2.80±0.71cm; follow-up=2.77±0.72cm, p=0.33). There was also no significant change in SF thickness (baseline=1.04±0.41cm; follow-up=1.06±0.40, p=0.33).Conclusions The results show there was no decline in anterior thigh muscle thickness or increase in SF in the healthy cohort studied using US imaging over a two-year period. These findings demonstrate the robustness of US imaging measurements over time.

SARC-F Questionnaire: Rapid and Easy Tool for Identifying Physical Limitations in Hemodialysis Patients

Background:SARC-F is a simple questionnaire for rapidly assessing physical function and screening for sarcopenia. This study aimed to determine whether the SARC-F questionnaire is useful for identifying impaired physical function and the risk of physical limitations in hemodialysis patients.Methods:This cross-sectional study included 281 patients undergoing hemodialysis at two dialysis units.SARC-F, handgrip strength, leg strength, one-leg standing time, usual gait speed, and short physical performance battery (SPPB) score were measured. Patients were classified according to the SARC-F score (SARC-F <4 and SARC-F ≥4), indicating the risk of sarcopenia. Furthermore, we defined physical limitations as handgrip strength of <26 kg for men and <18 kg for women, leg strength of <40%, usual gait speed of ≤0.8 m/s, and SPPB score of ≤8 points. To calculate the areas under the curves (AUCs) of the SARC-F score for physical limitations, receiver-operating characteristic curve analysis was performed.Results:SARC-F ≥4 was observed in 75 (26.7 %) hemodialysis patients. The SARC-F ≥4 group had a significantly lower handgrip and leg strength, shorter one-leg standing time, slower usual gait speed, and lower SPPB score than the SARC-F <4 group, even after adjusting for potential confounders (all P<0.001). Further, SARC-F demonstrated good accuracy in identifying the risk of physical limitations (all AUCs > 0.75).Conclusions:The SARC-F questionnaire is useful for screening impaired physical function and for identifying the risk of physical limitations in hemodialysis patients and can be easily and rapidly administered to this patient group in clinical practice.

The association between SARC-F status and quality of life in High Risk Foot Clinic patients

BackgroundHigh Risk Foot Clinic (HRFC) patients have foot ulceration commonly associated with poorer quality of life (QoL). A positive SARC-F test is predictive of sarcopenia. The objective of this study is to investigate whether SARC-F positive status is associated with lower QoL among attendees of HRFC, which is currently unknown. MethodsIn this cross-sectional study ambulatory HRFC patients were recruited at metropolitan tertiary referral hospital over one year. Demographics, comorbidities, SARC-F and EQ-5D-3L (EuroQol Group) outcomes were collected. Association between SARC-F status and EQ-5D visual analogue scale measurement, as well as individual EQ-5D-3L dimensions were investigated using, respectively, linear robust and ordinal logistic regression modelling. ResultsThe clinic was attended by 122 new patients, 85 of whom (69%) completed the questionnaires with no selection bias identified. 43/85 (51%) patients were SARC-F positive as indicated by a score of 4 or greater. No significant differences between SARC-F positive and negative patients were identified in age or diabetes status. SARC-F positive patients had consistently lower EQ-5D-3L visual analogue scale measurement [mean 5.3 (SD 2.0); median 5 (IQR: 4, 6.5)] compared to SARC-F negative patients [6.6 (SD 1.9); 7 (5.5, 7.5)], adjusted mean difference -1.2 (95%CI: -2.1, -0.4; p=0.007). SARC-F positive patients demonstrated consistent and statistically significantly worse EQ-5D-3L scores on mobility, personal care and usual activities, but not on anxiety/depression and pain/discomfort components. ConclusionsApproximately half of HRFC patients are SARC-F positive and exhibit significantly lower QoL as measured by EQ-5D-3L compared to SARC-F negative patients.

Wasting in Chronic Kidney Disease – a Complex Issue

Chronic kidney disease (CKD) has become a global health burden and is associated with increased morbidity and mortality. In particular, wasting is highly prevalent in later stages of the illness with muscle loss being a common problem. The aetiology and progression of this wasting is complex and multiple states have been identified linked to wasting in CKD. These include: ‘malnutrition’, ‘disease-related malnutrition’, ‘protein-energy wasting’, ‘cachexia’, ‘sarcopenia’, ‘frailty’ and ‘muscle wasting’. The purpose of this paper is to review these terms in the context of CKD. Common features include weight loss, loss of muscle mass and muscle function principally driven by CKD disease specific factors and inflammatory mediators. Disease-related malnutrition would appear to be a more appropriate term for CKD than malnutrition as it take in to consideration disease specific factors such as inflammation for example. Frailty is commonly associated with age-related decline in physiological function. Development of novel screening tools measuring across multiple domains of nutritional status, muscle and physical function may be useful in CKD. Research into potential treatments are currently underway with focus on multi-modal therapies including nutrition, resistance training and anabolic drugs such as myostatin blockade and selective androgen receptor modulators. A better understanding of different states and terms may help guide assessment and treatment opportunities for patients.

Pretiree lifestyles in relation to musculoskeletal health: cross-sectional data from the Geelong Osteoporosis Study

Background: What happens in the early-elderly ‘pretiree’ period potentially influences the divergent paths of healthy or unhealthy ageing. In this cross-sectional study, we aimed to profile musculoskeletal health and lifestyle behaviours for men and women in their late-fifties and sixties.Methods: For 482 participants from the Geelong Osteoporosis Study, we measured DXA-derived appendicular lean mass (rALM), bone mineral density (BMD) at the femoral neck and percentage body fat mass (%BF). Low-rALM and low-BMD referred to sex-specific T-scores<-1.0. Associations between exposures and low-rALM and/or low-BMD were explored using multivariable logistic regression.Results: Three-quarters of participants had high %BF, 98(20.3%) had low-rALM, 202(41.9%) had low-BMD and 63(13.1%) had both low-rALM and low-BMD. Eight-two (17.0%) were very active and one-third participated in sports/recreational activities. Most [n=416(87.8%)] met the recommended daily intake (RDI) for protein; only 119(25.1%) met the RDI for calcium. Less than 10% smoked and one-third exceeded recommended alcohol intakes. Independent of age, weight and sex, greater %BF and sedentary behaviour increased the likelihood of low-rALM; high-alcohol consumption increased the likelihood of low-BMD; and greater %BF increased the likelihood of low-rALM and low-BMD combined.Conclusions: One-half of participants had rALM and BMD in the normal range. Only a few were involved in resistance-training or weight-bearing exercise, despite having the capacity to be physically active. As sedentary lifestyles, excessive adiposity and high alcohol use were associated with low-rALM and/or low-BMD, we propose that these adverse factors be potential targets among pretirees to minimise their risk of entering old age with poor musculoskeletal health.

Muscle wasting diseases has two distinct trajectories on the 3-dimensional age-BMI-peak VO2 scatterplot

Background: Frailty and sarcopenia are age-related morbid states, and a low body mass index (BMI) is a characteristic of frailty and cachexia. However, no common index for assessing these three muscle wasting states is available, making it difficult to understand the relationship among them. Peak oxygen uptake (peak VO2), an index of life expectancy, may be a useful common index. Therefore, this study aimed to investigate the relationship among sarcopenia, frailty, and cachexia using age, BMI, and peak VO2. Methods: Participants were 175 Japanese community dwelling older adults (58 men, 117 women; 77.6 years). We assessed biochemical, physiological, and physical factors, and symptoms associated with frailty, and cachexia. Peak VO2 was assessed with a cardiopulmonary exercise test. Participants were classified into five groups: robust, pre-frail, frail, sarcopenia, and cachexia. We compared the groups by age, BMI, and peakVO2 with average values and 95% confidence intervals (CIs).Results: 17% (n=30) of participants were classified as robust, 40% (n=70) as pre-frail, 12% (n=21) as sarcopenia, 25% (n=44) as frail, and 6% (n=10) as cachexia. Significant differences were found in age (robust vs. frail, pre-frail vs. frail), BMI (robust vs. cachexia, pre-frail vs. cachexia, frail vs. cachexia), and peak VO2 (robust vs. frail, robust vs. cachexia, pre-frail vs. cachexia) with average values and 95% CIs. Three dimensions among age, BMI and peak VO2 revealed two trajectories (from robust to frailty via pre-frailty, and from robust to cachexia via sarcopenia) among muscle wasting diseases.Conclusions: This study revealed two trajectories among muscle wasting diseases.

Resistance Training Frequency Confers Greater Muscle Quality in Aged Individuals: A Brief NHANES Report

Background: Sarcopenia, the age-related decline in skeletal muscle mass, results in a loss of strength and functional capacity, which subsequently increases the risk of disease, disability frailty, and all-cause mortality. Skeletal muscle quality (MQ), i.e., strength per unit muscle mass, is the ability of muscle to perform its functions, and evidence indicates it is a more influential variable underlying age-related declines in muscle function than losses in muscle mass. Resistance training (RT) is known for enhancing skeletal MQ, improving health span, and reducing mortality; however, to the best of our knowledge, no studies have examined the relationship between RT frequency and MQ in an aged population. Thus, this study was designed to test the hypothesis that greater MQ in older individuals is associated with RT frequency. Methods: Utilizing data from 2,391 older adults in the National Health and Nutrition Survey (NHANES; 1999-2002), a secondary analysis of data was performed to see if an association existed between RT frequency and MQ in persons aged 55 years and older. Data were analyzed using analysis of covariance (ANCOVA) with three different models. Individuals were stratified into two groups based on how many days per week they performed RT: Insufficient (i.e., < two days per week) or sufficient (≥ two days per week). Muscle quality was calculated by taking the average peak force (Newtons) obtained from an isokinetic dynamometer and dividing it by lean mass, excluding bone mineral content (grams), obtained from dual-energy X-ray absorptiometry. The alpha level was set at <0.05. Results: For persons aged 55 and over, a statistically significant association was found between sufficient RT and greater MQ in both unadjusted as well as adjusted models that accounted for various demographic, behavioral, and clinical characteristics (p<0.05 for all). However, when limited to those 65 and older, no statistically significant associations were observed between sufficient RT and greater MQ (p>0.05 for all). When partitioned according to those 55 to 64 years of age and those 55 to 79 years, a statistically significant association was again observed (p<0.05 for all). No statistically significant associations were observed for individuals 65-79 years of age or those 80 years of age and older (p>0.05 for all). Conclusions: Sufficient amounts of RT are associated with greater MQ in selected older individuals. A need exists for future randomized controlled trials that examine the dose-response relationship between resistance training and MQ in older adults.

The Role of Systemic Inflammation in Cancer-Associated Muscle Wasting and Rationale for Exercise as a Therapeutic Intervention

Progressive skeletal muscle wasting in cancer cachexia involves a process of dysregulated protein synthesis and breakdown. This catabolism may be the result of mal-nutrition, and an upregulation of both pro-inflammatory cytokines and the ubiquitin proteasome pathway (UPP), which can subsequently increase myostatin and activin A release. The skeletal muscle wasting associated with cancer cachexia is clinically significant, it can contribute to treatment toxicity or the premature discontinuation of treatments resulting in increases in morbidity and mortality. Thus, there is a need for further investigation into the pathophysiology of muscle wasting in cancer cachexia to develop effective prophylactic and therapeutic interventions. Several studies have identified a central role for chronic-systemic inflammation in initiating and perpetuating muscle wasting in patients with cancer. Interestingly, while exercise has shown efficacy in improving muscle quality, only recently have investigators begun to assess the impact that exercise has on chronic-systemic inflammation. To put this new information into context with established paradigms, here we review several biological pathways (e.g. dysfunctional inflammatory response, hypothalamus pituitary adrenal axis, and increased myostatin/activin A activity) that may be responsible for the muscle wasting in patients with cancer. Additionally, we discuss the potential impact that exercise has on these pathways in the treatment of cancer cachexia. Exercise is an attractive intervention for muscle wasting in this population, partially because it disrupts chronic-systemic inflammation mediated catabolism. Most importantly, exercise is a potent stimulator of muscle synthesis, and therefore this therapy may reverse muscle damage caused by cancer cachexia.

Profiles Associated with Sarcopenia in Hepatoma Patients Underwent Transcatheter Arterial Chemoembolization: A Data-Mining Analysis

Background & Aims: Sarcopenia is a prognostic factor in patients with hepatocellular carcinoma (HCC). Transcatheter arterial chemoembolization (TACE) may aggravate sarcopenia because of post-embolization syndrome. The aims of this study are to investigate changes in skeletal muscle mass after TACE and its risk profiles in patients with HCC.Methods: We enrolled 104 HCC patients (age 73.5 [41.0-88.0] years, female/male 35/69, body mass index 22.4 [16.0-32.7]). Changes in skeletal muscle mass were evaluated by Δskeletal muscle index (SMI) using computed tomography before and after TACE. Factors correlated with ΔSMI were evaluated. Independent factors and profiles associated with a decrease in SMI were evaluated by multivariate analysis and decision-tree analysis, respectively.Results: SMI was significantly decreased after TACE in patients with HCC (32.8 vs. 30.6 cm2/m2; P=0.0001). However, there was no significant correlation between the ΔSMI and other variables including Δalbumin. In the logistic regression analysis, no factor was significantly associated with a decrease in SMI. In the decision-tree analysis, sex was selected as the initial split and, in female, 74% of subjects showed a decrease in SMI. While, in male, an estimated glomerular filtration rate (eGFR) ≤81.7 ml/min/1.73 m2 was the second split; of these patients, 74% of subjects had a decreased SMI.Conclusions: We demonstrated that skeletal muscle mass was decreased after TACE in patients with HCC. “female” and “male who had a lower eGFR” were profile for a decrease in skeletal muscle mass. Thus, such patients who have HCC treated with TACE may benefit from preventive treatment for sarcopenia.

Race and socioeconomic effect on sarcopenia and sarcopenic obesity in the Louisiana Osteoporosis Study (LOS)

BACKGROUNDSarcopenia and sarcopenic obesity are emerging public health issues. True prevalence rates are unknown and estimates differ substantially between studies. No large-scale single study has compared prevalence rates between whites, blacks, Asians, and Hispanics, as we intend to do here. This study also examined the effects of race and socioeconomic factors on sarcopenia and sarcopenic obesity. METHODSThis study included 10,325 participants from Louisiana. Appendicular lean mass, measured through DXA scans, was divided by height squared (ASM/h2) to define sarcopenia. Sarcopenic obesity was defined as sarcopenia plus obesity (waist-to-hip ratio). RESULTSOverall sarcopenia and sarcopenic obesity rates were 17.6% and 7.0% for males, and 13.7% and 2.5% for females, respectively. The highest sarcopenia and sarcopenic obesity rates were found in Asian males (40.6%, 14.4%) and females (30.1%, 8.0%). The lowest sarcopenic obesity rates were observed in black males (3.7%) and females (0.9%). We found significant associations with sarcopenic obesity in males for age, race, and income; in females, for age, race, and education. CONCLUSIONSUnder one diagnostic definition, the prevalence of sarcopenia and sarcopenic obesity is highest among Asians and lowest amongst blacks. Income and education had significant associations with sarcopenia and sarcopenic obesity, in males and females, respectively.