The Usefulness of an Alternative Diagnostic Method for Sarcopenia Using Thickness and Echo Intensity of Lower Leg Muscles in Older Males

Exploring the associations between skeletal muscle echogenicity and physical function in aging adults: A systematic review with meta-analyses

BACKGROUND

Assessment and quantification of skeletal muscle within the aging population is vital for diagnosis, treatment, and injury/disease prevention. The clinical availability of assessing muscle quality through diagnostic ultrasound presents an opportunity to be utilized as a screening tool for function-limiting diseases. However, relationships between muscle echogenicity and clinical functional assessments require authoritative analysis. Thus, we aimed to (a) synthesize the literature to assess the relationships between skeletal muscle echogenicity and physical function in older adults (≥60 years), (b) perform pooled analyses of relationships between skeletal muscle echogenicity and physical function, and (c) perform sub-analyses to determine between-muscle relationships.

METHODS

CINAHL, Embase, MEDLINE, PubMed, and Web of Science databases were systematically searched to identify articles relating skeletal muscle echogenicity to physical function in older adults. Risk-of-bias assessments were conducted along with funnel plot examination. Meta-analyses with and without sub-analyses for individual muscles were performed utilizing Fisher's Z transformation for the most common measures of physical function. Fisher's Z was back-transformed to Pearson's r for interpretation.

RESULTS

Fifty-one articles (n = 5095, female = ∼2759, male = ∼2301, 72.5 ± 5.8 years, mean ± SD (1 study did not provide sex descriptors)) were extracted for review, with previously unpublished data obtained from the authors of 13 studies. The rectus femoris (n = 34) and isometric knee extension strength (n = 22) were the most accessed muscle and physical qualities, respectively. The relationship between quadriceps echogenicity and knee extensor strength was moderate (n = 2924, r = -0.36 (95% confidence interval: -0.38 to -0.32), p < 0.001), with all other meta-analyses (grip strength, walking speed, sit-to-stand, timed up-and-go) resulting in slightly weaker correlations (r:  -0.34 to -0.23, all p < 0.001). Sub-analyses determined minimal differences in predictive ability between muscle groups, although combining muscles (e.g., rectus femoris + vastus lateralis) often resulted in stronger correlations with maximal strength.

CONCLUSION

While correlations are modest, the affordable, portable, and noninvasive ultrasonic assessment of muscle quality is a consistent predictor of physical function in older adults. Minimal between-muscle differences suggest that echogenicity estimates of muscle quality are systemic. Therefore, practitioners may be able to scan a single muscle to estimate full-body skeletal muscle quality/composition, while researchers should consider combining multiple muscles to strengthen the model.

Ultrasound-measured Quadriceps Muscle Thickness and Mortality in Older Patients With Heart Failure

BACKGROUND

Ultrasound might be helpful for muscle mass assessment in patients with heart failure (HF). We aimed to determine the feasibility and prognostic implications of ultrasound-measured quadriceps muscle thickness (QMT) in older patients with HF.

METHODS

This was a post hoc analysis of a multicentre prospective cohort study including patients hospitalized for HF aged 65 years and older. QMT at rest and during isometric contractions using ultrasound was measured with the patient in the supine position before discharge.

RESULTS

The interobserver agreement for measuring QMT was excellent, with intraclass correlation coefficients of 0.979 (95% confidence interval [CI], 0.963-0.988) at rest and 0.997 (95% CI, 0.994-0.998) during isometric contraction. The intraobserver reproducibility was also excellent (intraclass correlation coefficient > 0.92). Of the 595 patients (median age, 81 years; 56% male), median QMT at rest and during contraction were 18.9 mm and 24.9 mm, respectively. The patients were grouped according to sex-specific tertiles of height-adjusted QMT. During the median follow-up of 735 days, 157 deaths occurred, and Kaplan-Meier curve analysis showed that the lowest tertile of the height-adjusted QMT was associated with a higher mortality. Cox proportional hazard analysis revealed that thinner height-adjusted QMT was independently associated with higher mortality, even after adjusting for conventional risk factors (per 1 mm/m increase: hazard ratio, 0.94; 95% CI, 0.89-0.99; P = 0.030 [at rest] and hazard ratio, 0.94; 95% CI, 0.90-0.99; P = 0.015 [during isometric contraction]).

CONCLUSIONS

Ultrasound-measured QMT in older patients with HF is feasible, and thinner height-adjusted QMT at rest and during isometric contraction was independently associated with higher mortality.

The value of multi-modal ultrasound in the assessment of sarcopenia in maintenance hemodialysis patients

INTRODUCTION

Sarcopenia is one of the common complications in maintenance hemodialysis (MHD) patients and is associated with poor prognosis. We aimed to study the validity and reliability of ultrasound in the assessment of sarcopenia in MHD patients.

METHODS

MHD patients were categorized into the sarcopenia group and the non-sarcopenia group according to the diagnostic criteria of the Asian Working Group on Sarcopenia (AWGS) 2019. Ultrasonography of the left medial head of the gastrocnemius muscle was performed in MHD and healthy controls to obtain muscle thickness (MT), pinnation angle (PA), fascicle length (FL), cross-sectional area (CSA), echo intensity (EI), elastic modulus (E), shear wave velocity (SWV), and microvascular velocity (MV). Compare the differences in ultrasound parameters among different groups, and determine the cut-off values suitable for diagnosing sarcopenia in MHD patients.

RESULTS

The MT, CSA, PA, and MV in the sarcopenia group were lower than those in the non-sarcopenia group and the control group; while the EI was higher, the FL of the sarcopenia group was lower than that of the non-sarcopenia group, while the E and SWV of the sarcopenia group were higher than those of the control group. Receiver operating characteristic curve analyses indicated that ultrasound combined index had a good diagnostic value, model Y = 13.511-0.121*MT-0.609*CSA-0.172*PA+0.011*EI-2.205*MV(P < 0.05), with a cut-off value of 0.69.

CONCLUSIONS

Multi-modal ultrasound is a safe, non-invasive, and real-time imaging examination method, and can provide information on muscle structure, stiffness, and perfusion, which is expected to be a promising potential tool for predicting sarcopenia in MHD patients.

The Validity of Muscle Ultrasound in the Diagnostic Workup of Sarcopenia Among Older Adults: A Scoping Review

Purpose

Muscle ultrasound has emerged as a promising method in the diagnostic work-up of sarcopenia. The objective of this scoping review was to explore the validity of muscle ultrasound against the latest sarcopenia definitions among older adults.

Methods

We adhered to the PRISMA guidelines for scoping reviews. A systematic search of databases was performed by two independent reviewers. All articles comparing the performance of ultrasound to an internationally acknowledged sarcopenia definition among older adults (≥60 years) and published between 2019/01/01 (the year updated sarcopenia definitions were introduced) and 2023/11/15 were included. Data were extracted and collated by muscle and muscle parameters.

Results

Out of 2290 articles screened, six studies comprising 24 validity tests among a total of 1619 older adults (mean age 74.1 years, 52.2% female) were included. The validity tests investigated the rectus femoris (n = 7), biceps brachii (n = 5), gastrocnemius medialis (n = 4), tibialis anterior (n = 4), soleus (n = 3), and rectus abdominis (n = 1). The parameter muscle thickness (MT) (n = 14) was most commonly measured. The latest European and Asian sarcopenia definitions (EWGSOP2, AWGS2) were applied as reference standards in four validity tests each. None of the studies used the Sarcopenia Definition and Outcome Consortium (SDOC) criteria. The highest area under the curve AUC (0.92, 95% confidence interval [CI] 0.89-0.94) was found for the muscle thickness of the rectus femoris muscle. Due to substantial heterogeneity among the studies, pooling of data using a meta-analytic approach was not feasible.

Conclusion

Limited number of studies have examined the validity of muscle ultrasound for diagnosing sarcopenia based on recent definitions among older adults. Thereby, muscle thickness of the rectus femoris showed promising results regarding validity. Further studies are needed to investigate the validity of key muscles and to validate muscle ultrasound among older hospitalized patients.

Sonographic methods to predict type 2 diabetes patients with sarcopenia: B mode ultrasound and shear wave elastography

BACKGROUND

Type 2 diabetes accelerates the loss of muscle mass and strength. Sarcopenia is also one of the chronic complications of diabetes.

OBJECTIVE

To investigate the clinical value of B mode ultrasound (BMUS) and shear wave elastography (SWE) for predicting type 2 diabetic sarcopenia.

METHODS

We recorded Skeletal Muscle Mass Index (ASMI), grip strength, muscle thickness (MT), pinna angle (PA), fascicle length (FL), and the difference of Young's modulus in the relaxed states and tense states (ΔSWE). The correlations between clinical indicators and ultrasound characteristics were compared. A diagnostic model of sarcopenia was developed to assess the independent correlates and evaluate the diagnostic efficacy of sarcopenia.

RESULTS

ASMI was significantly and positively correlated with MT and ΔSWE (r = 0.826, 0.765, P < 0.01), and grip strength was significantly and positively correlated with MT and ΔSWE (r = 0.797, 0.818, P < 0.01). MT was the most significant predictor of sarcopenia (OR = 4.576, P < 0.001), and the cut-off value of MT was 11.4 mm (AUC: 0.952).

CONCLUSION

BMUS and SWE can quantitatively assess muscle mass and strength, and are effective methods to predict the occurrence of sarcopenia in elderly patients with type 2 diabetes.

Suitable ultrasound screening method for older adults with disability to identify low muscle mass

Objective

This study aimed to investigate the accuracy and consistency of different ultrasound protocols for the measurement of gastrocnemius muscle (GM) thickness and to identify a suitable ultrasound scheme that can be used to detect the low muscle mass in older with disability.

Materials and methods

In this cross-sectional study, each participant underwent three different ultrasound protocols for the measurement of the GM thickness, and each measurement was repeated three times. The three measurement schemes were as follows: method A, lying on the examination bed in a prone position with legs stretched and relaxed and feet hanging outside the examination bed; method B, lateral right side lying position with legs separated (left leg flexed and right leg in a relaxed state); and method C, right side lying position with legs together and lower limb muscles in a relaxed state. The low muscle mass was determined by averaging two or three measurements of the GM thickness determined using different sonographic protocols.

Results

The study included 489 participants. The difference in the prevalence of low muscle mass identified between two and three replicates of the same measurement protocol ranged from 0 to 1.3%. Considering the three repeated measurements of the method A as the reference, the area under the curve (AUC) in different measurement schemes were 0.977-1 and 0.973-1 in males and females, respectively. Furthermore, male and female Kappa values from low to high were 0.773, 0.801, 0.829, 0.839, and 0.967 and 0.786, 0.794, 0.804, 0.819, and 0.984, respectively.

Conclusion

Different ultrasound measurement protocols showed high accuracy and consistency in identifying low muscle mass. Repeating the measurements two or three times was found to be feasible.

Sarcopenia, More Than Just Muscle Atrophy: Imaging Methods for the Assessment of Muscle Quantity and Quality

BACKGROUND

Sarcopenia, a progressive reduction of muscle mass and function, is associated with adverse outcomes in the elderly. Sarcopenia and muscle atrophy are not equal processes. Low muscle strength in association with muscle quantity/quality reduction is currently the optimal method for assessing sarcopenia. There is a practical need for indirect measurement of muscle strength using state-of-the-art imaging techniques.

METHODS

The following provides a narrative, broad review of all current imaging techniques for evaluating muscles and identifying sarcopenia, including DEXA, CT, MRI, and high-resolution ultrasound, their main strengths, weaknesses, and possible solutions to problems regarding each technique.

RESULTS AND CONCLUSION

Well-recognized imaging methods for the assessment of muscle mass are explained, including evaluation with DEXA, CT, and MRI muscle quantity assessment, ultrasound evaluation of muscle thickness and CSA, and their correlations with established muscle mass calculation methods. A special focus is on imaging methods for muscle quality evaluation. Several innovative and promising techniques that are still in the research phase but show potential in the assessment of different properties of muscle quality, including MRI DIXON sequences, MRI spectroscopy, Diffusion Tensor Imaging, ultrasound echo intensity, ultrasound elastography, and speed-of-sound ultrasound imaging are briefly mentioned.

KEY POINTS

· Sarcopenia definition includes low muscle strength and low muscle quantity/quality.. · DEXA is a low-radiation method for whole-body composition measurement in a single image.. · CT has established cut-off values for muscle quality/quantity evaluation and sarcopenia diagnosis.. · MRI is the most sophisticated muscle quality assessment method capable of evaluating myosteatosis, myofibrosis, and microstructure.. · Ultrasound can evaluate muscle quality, including tissue architecture, and elasticity with excellent spatial resolution..

CITATION FORMAT

· Vasilevska Nikodinovska V, Ivanoski S, . Sarcopenia, More Than Just Muscle Atrophy: Imaging Methods for the Assessment of Muscle Quantity and Quality. Fortschr Röntgenstr 2023; 195: 777 - 789.

Evaluation of Hepatic/Renal and Splenic/Renal Echointensity Ratio Using Ultrasonography in Diabetic Nephropathy

The objective of this study is to assess the hepatic/renal and splenic/renal echointensity ratios in ultrasonography in patients with and without diabetic nephropathy. This retrospective study included patients with diabetes mellitus who underwent ultrasound examinations at our hospital between January 2023 and May 2023. Ultrasound examinations were conducted using renal cortical echogenicity and corticomedullary differentiation by using B-mode ultrasonography. The hepatic/renal and splenic/renal echo intensity ratios were compared among study groups (diabetic patients with diabetic nephropathy and without nephropathy). The diabetic nephropathy group exhibited significantly higher right renal echointensity and left renal echointensity compared to the non-nephropathic group. Additionally, the splenic/renal echointensity ratio and hepatic/renal echointensity ratio were significantly lower in the diabetic nephropathy group. Urinary microalbumin levels were significantly correlated with right renal echointensity (r = 0.65, p < 0.001) and left renal echointensity (r = 0.69, p < 0.001). There was also a significant inverse correlation between the urinary albumin and splenic/renal echointensity ratio (r = -0.58, p < 0.001). Ultrasonography, specifically the assessment of hepatic/renal and splenic/renal echointensity ratios, shows promise as a noninvasive and cost-effective method for evaluating morphological changes in the kidneys in patients with diabetic nephropathy. These findings suggest that ultrasonography can be a valuable tool for monitoring the progression of diabetic nephropathy and contributing to its early detection and management.

Reliability of Muscle Quantity and Quality Measured With Extended-Field-of-View Ultrasound at Nine Body Sites

OBJECTIVE

Measuring muscle quantity and quality is very important because the loss of muscle quantity and quality is associated with several adverse effects specifically in older people. Ultrasound is a method widely used to measure muscle quantity and quality. One problem with ultrasound is its limited field of view, which makes it impossible to measure the muscle quantity and quality of certain muscles. In this study, we aimed to evaluate the intra- and inter-rater reliability of extended-field-of-view (EFOV) ultrasound for the measurement of muscle quantity and quality in nine muscles of the limbs and trunk.

METHODS

Two examiners took two ultrasound EFOV images with a linear probe from each of the muscle sites. The intraclass correlation coefficient (ICC) was used, and the standard error of measurement and coefficient of variation were calculated.

RESULTS

Intra-rater reliability was good to excellent (ICC = 0.2-1.00) for all muscle measurements. The inter-rater reliability for most of the muscle measurements was good to excellent (ICC = 0.82-0.98). Inter-rater reliability was moderate (0.58-0.72) for some muscle quantity measurements of the tibialis anterior, gastrocnemius, rectus femoris, biceps femoris and triceps brachii muscles.

CONCLUSION

Muscle quantity and quality can be measured reliably using EFOV US.

Diagnostic test accuracy of ultrasound for sarcopenia diagnosis: A systematic review and meta-analysis

Muscle ultrasound is an emerging tool for diagnosing sarcopenia. This review aims to summarize the current knowledge on the diagnostic test accuracy of ultrasound for the diagnosis of sarcopenia. We collected data from Ovid Medline, Embase and the Cochrane Central Register of Controlled Trials. Diagnostic test accuracy studies using muscle ultrasound to detect sarcopenia were included. Bivariate random-effects models based on sensitivity and specificity pairs were used to calculate the pooled estimates of sensitivity, specificity and the area under the curves (AUCs) of summary receiver operating characteristic (SROC), if possible. We screened 7332 publications and included 17 studies with 2143 participants (mean age range: 52.6-82.8 years). All included studies had a high risk of bias. The study populations, reference standards and ultrasound measurement methods varied across the studies. Lower extremity muscles were commonly studied, whereas muscle thickness (MT) was the most widely measured parameter, followed by the cross-sectional area (CSA). The MTs of the gastrocnemius, rectus femoris, tibialis anterior, soleus, rectus abdominis and geniohyoid muscles showed a moderate diagnostic accuracy for sarcopenia (SROC-AUC 0.83, 8 studies; SROC-AUC 0.78, 5 studies; AUC 0.82, 1 study; AUC 0.76-0.78, 2 studies; AUC 0.76, 1 study; and AUC 0.79, 1 study, respectively), whereas the MTs of vastus intermedius, quadriceps femoris and transversus abdominis muscles showed a low diagnostic accuracy (AUC 0.67-0.71, 3 studies; SROC-AUC 0.64, 4 studies; and AUC 0.68, 1 study, respectively). The CSA of rectus femoris, biceps brachii muscles and gastrocnemius fascicle length also showed a moderate diagnostic accuracy (AUC 0.70-0.90, 3 studies; 0.81, 1 study; and 0.78-0.80, 1 study, respectively), whereas the echo intensity (EI) of rectus femoris, vastus intermedius, quadriceps femoris and biceps brachii muscles showed a low diagnostic accuracy (AUC 0.52-0.67, 2 studies; 0.48-0.50, 1 study; 0.43-0.49, 1 study; and 0.69, 1 study, respectively). The combination of CSA and EI of biceps brachii or rectus femoris muscles was better than either CSA or EI alone for diagnosing sarcopenia. Muscle ultrasound shows a low-to-moderate diagnostic test accuracy for sarcopenia diagnosis depending on different ultrasound parameters, measured muscles, reference standards and study populations. The combination of muscle quality indicators (e.g., EI) and muscle quantity indicators (e.g., MT) might provide better diagnostic test accuracy.

Usefulness of muscle ultrasound in appendicular skeletal muscle mass estimation for sarcopenia assessment

The measurement of skeletal muscle mass is essential for the diagnosis of sarcopenia. Muscle ultrasonography has emerged as a useful tool for evaluating sarcopenia because it can be used to assess muscle quality and quantity. This study investigated whether muscle ultrasonography is effective for estimating appendicular skeletal muscle mass (ASM) and screening for sarcopenia. This study prospectively enrolled 212 healthy volunteers aged 40-80 years. ASM was measured using the bioelectrical impedance analysis. Muscle thickness (MT) and echo-intensity (EI) were measured in four muscles (biceps brachii, BB; triceps brachii, TB; rectus femoris, RF; biceps femoris, BF) on the dominant hand. A hold-out cross-validation method was used to develop and validate the ASM prediction equation. In the model development group, the ASM prediction equations were deduced as follows: estimated ASM for men (kg) = 0.167 × weight (kg) + 0.228 × height (cm) + 0.143 × MT of BF (mm)- 0.822 × EI to MT ratio of BB- 28.187 (R2 = 0.830) and estimated ASM for women (kg) = 0.115 × weight + 0.215 × height (cm) + 0.139 × MT of RF-0.638 × EI to MT ratio of BB- 23.502 (R2 = 0.859). In the cross-validation group, the estimated ASM did not significantly differ from the measured ASM in both men (p = 0.775; intraclass correlation coefficient [ICC] = 0.948) and women (p = 0.516; ICC = 0.973). In addition, multiple logistic regression analysis revealed that the ratios of EI to MT in the BF and RF muscles in men and MT in the BB muscle in women could be valuable parameters for sarcopenia screening. Therefore, our study suggests that muscle ultrasound could be an effective tool for estimating ASM and screening sarcopenia.

The Muscle Thickness Assessment Using Ultrasonography is a Useful Alternative to Skeletal Muscle Mass by Bioelectrical Impedance Analysis

Purpose

Muscle mass, a key index for the diagnosis of sarcopenia, is currently assessed using the appendicular skeletal muscle mass index (ASMI) by bioelectrical impedance analysis (BIA). Muscle thickness (MT) assessed by ultrasonography (US) may be a better determinant and/or predictor of muscle condition than ASMI. Thus, we compared it to the ASMI determined by the BIA.

Patients and Methods

Our study included 165 ambulatory older adults (84 males, 81 females, mean age: 76.82 years). The ASMI by the BIA method, MT by US, and the distribution of body mass index (BMI) and body fat percentage (BFP) were examined using defined values for men and women. These were used as the basis for examining the association of MT and ASMI with handgrip strength (HGS), leg muscle strength (LMS), gait speed (GS), and echo intensity (EI). We compared HGS, LMS, GS, and EI for high and low ASMI among lower BMI or BFP. The same was also done for MT assessed by US.

Results

MT, as well as ASMI, was strongly associated with HGS and LMS. There was a correlation between MT and GS and EI but not between ASMI and GS and EI. There were significant differences in the prevalence between high ASMI and high MT or low ASMI and low MT in those with lower BMI or BFP. In non-overweight participants, HGS, LMS, GS, and EI were significantly higher in those with high MT than in those with low MT; however, there were no significant differences in them between those with high and low ASMI.

Conclusion

In the non-overweight group, the MT assessment by US showed a stronger relationship to muscle strength and muscle quality than the ASMI assessment by BIA. The MT assessment using US is a useful alternative to BIA-assessed ASMI, especially in non-overweight participants.

Subcutaneous Fat Thickness of the Lower Limb is Associated with Trunk Muscle Mass in Patients with Hepatocellular Carcinoma: A Simple Assessment for Sarcopenia Using Conventional Ultrasonography

OBJECTIVE

Trunk muscle mass can be evaluated by skeletal muscle index (SMI), which is a prognostic factor in patients with hepatocellular carcinoma (HCC); however, this requires the use of computed tomography, and a simpler assessment for trunk muscle mass is urgently needed. We aimed to examine whether an association between SMI and lower extremity compartments including muscle and subcutaneous fat thickness of lower limbs (SFT-LL) could be identified by means of ultrasonography in patients with HCC.

METHODS

We retrospectively enrolled male patients with HCC (n=30). Trunk muscle mass was evaluated by SMI using computed tomography. Ultrasonography was used for assessment of muscle and SFT-LL. Factors associated with SMI were evaluated by decision-tree analysis.

RESULTS

There was no significant correlation between SMI and muscle thickness of lower limbs. However, a significant correlation was seen between SMI and left SFT-LL (r=0.406, P=0.026). In decision-tree analysis for SMI, left SFT-LL was selected as the initial split variable with an optimal cut-off value of 5 mm. In patients with left SFT-LL ≥ 5 mm, SMI was 39.4±3.4 cm²/m², whereas SMI was 31.6±6.3 cm²/m² in patients with left SFT-LL <5 mm.

CONCLUSION

Left SFT-LL evaluated by ultrasonography was associated with SMI. Thus, ultrasonography may be a useful tool to evaluate trunk muscle mass. Moreover, left SFT-LL may be a useful indicator of sarcopenia in patients with HCC.

Influence of Subcutaneous Adipose Tissue and Skeletal Muscle Thickness on Rectus Femoris Echo Intensity in Younger and Older Males and Females

OBJECTIVES

Ultrasound measurements of muscle echo intensity are commonly used surrogates of muscle composition (eg, intramuscular adipose tissue). However, given that soundwaves are increasingly attenuated with tissue depth, the interpretation of echo intensity may be confounded by adipose and skeletal muscle thickness. Our objectives are to compare the associations between adipose or muscle tissue thickness and rectus femoris echo intensity in younger and older males and females.

METHODS

Participants included in this analysis were derived from 3 previously published cohorts of younger (<45 years) and older (≥60 years) males and females. Ultrasound images of the rectus femoris were evaluated for muscle thickness, echo intensity, and subcutaneous adipose tissue thickness.

RESULTS

Older adults (n: 49 males, 19 females) had a higher body mass index (P = .001) compared with younger adults (n: 37 males, 49 females). Muscle thickness was negatively associated with echo intensity in older males (r = -0.59) and females (r = -0.53), whereas no associations were observed in younger males (r = 0.00) or females (r = -0.11). Subcutaneous adipose tissue thickness displayed no associations with echo intensity in any group.

CONCLUSIONS

Despite the known influence of subcutaneous adipose tissue thickness on beam attenuation, we observed no association with muscle echo intensity, indicating that adipose tissue correction may be required to better understand muscle echo intensity across differences in adiposity. The negative associations between muscle thickness and echo intensity in older, but not younger adults, suggests these associations may be related to the co-occurrence of skeletal muscle atrophy and intramuscular adipose tissue infiltration with advancing age.

Influence of subcutaneous adipose thickness and dominance on reliability of quadriceps muscle quality in healthy young individuals

BACKGROUND

Echo intensity (EI) can be useful to check muscle quality and has been widely used to identify tissue damage. In the clinical and sports context, it has been used to identify metabolic disorders and training muscle performance.

OBJECTIVE

To determine whether subcutaneous adipose thickness (SAT) influences the inter-session EI reliability of the quadriceps femoris and whether EI is influenced by dominance in young healthy subjects.

DESIGN

All procedures were approved by the local Institutional Research Ethics Committee (project number 2.620.204). This is a cross-sectional study where 19 healthy young individuals volunteered.

METHOD

The individuals were assessed at two time points by an experienced examiner. Imaging of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles were performed bilaterally by ultrasonography. EI and SAT analysis was performed using ImageJ®software.

RESULTS/FINDINGS

Inter-session intraclass correlation coefficient (ICC) for EImeasured showed moderate reliability for RF (R = 0.578; P = 0.038) and VL (R = 0.735; P = 0.004) and low for VM (R = 0.402; P = 0.142). When corrected by SAT, inter-session (EIcorrected), ICC values showed good reliability for RF (R = 0.826; P < 0.001) and VM (R = 0.765; P = 0.002) and excellent for VL (R = 0.909; P < 0.001). Considering inter-side reliability, Student's paired t-test demonstrated no difference for EImeasured (P > 0.283), EIcorrected (P > 0.127), and SAT (P > 0.356).

CONCLUSIONS

SAT influenced the inter-session reliability values of EI in all muscles evaluated. Although they showed similarity, EI values were not influenced by dominance in young healthy subjects.

Resistance training with or without nutritional supplementation showed no influence on muscle thickness in old-institutionalized adults: a secondary analysis of the Vienna Active Ageing Study

BACKGROUND

Resistance training and protein supplementation are recommended strategies to combat sarcopenia.

AIM

Quantification of muscle thickness (MT) by musculoskeletal ultrasound is a promising method to follow changes in skeletal muscles. The aim of this study was to investigate the effect of six months of resistance training with or without nutritional supplementation on MT of M. quadriceps in institutionalized old adults.

DESIGN

This is a prospective, randomized, multi-arm parallel and controlled intervention study.

SETTING

This study was conducted in five different retirement care facilities.

POPULATION

Institutionalized individuals (mean age 82.6±6.2 years) were randomly assigned to an elastic band resistance training (N.=41), training with nutritional supplementation (N.=36) or control group (N.=40).

METHODS

Health status and handgrip strength were investigated at baseline. MT of all parts of M. quadriceps of the left leg was assessed using musculoskeletal ultrasound at baseline and after six months. Linear regression models adjusted for age, BMI and sex were calculated to investigate the influence of baseline characteristics on MT. Multivariable regression analyses were performed for investigation of study intervention on MT. Follow-up examinations were performed after 12 and 18 months.

RESULTS

Handgrip strength of both hands was significantly correlated with MT of M. vastus lateralis. Moreover, the sum of regularly taken medication was significantly correlated to MT of all parts of quadriceps. Six months of training or nutritional supplementation was not able to alter MT. However, participants with lower baseline MT values or a higher number of diseases and medications at baseline showed significant higher increases in MT after intervention.

CONCLUSIONS

Resistance training using elastic bands with or without nutritional supplementation did not alter MT of M. quadriceps of old institutionalized individuals. However, baseline values and health status had a significant influence on the training effect.

CLINICAL REHABILITATION IMPACT

As old individuals are very heterogenic according to their health and muscle status; further studies might focus on individualizing training regimes with particular emphasize on accompanied diseases and medications of this population.

Influence of ultrasound focus depth on the association between echo intensity and intramuscular adipose tissue

INTRODUCTION/AIMS

Attenuation of the US wave is a serious limitation of echo intensity (EI) on B-mode ultrasound (US). The aim of this study was to determine if the focus depth of US images influences the depth-dependent attenuation of EI and the relationship between EI and intramuscular adipose tissues (IntraMAT).

METHODS

The rectus femoris (RF) and vastus intermedius (VI) of the right thigh were studied in 135 adults (92 older, 43 younger). The EI on US images was measured at three focus depth conditions: top of the image, center of the RF, and center of the VI. The depth of the region of interest (ROI) was measured. Using water and fat images based on the two-point Dixon technique with 3.0 T MRI scanner, IntraMAT was calculated.

RESULTS

The correlation between EI and IntraMAT was stronger in the focus RF and VI conditions than in the focus top condition and stronger for RF than for VI. The depth of the ROI influenced the IntraMAT-adjusted residual EI more in the focus top condition than in the focus RF and VI conditions, and influenced VI more strongly than it did RF.

DISCUSSION

This study showed that by mitigating EI attenuation, EI with a focus depth adjusted to the ROI reflected IntraMAT more accurately than that without adjustment. However, it may not completely prevent the potential influence of depth-dependent attenuation of EI, especially for deeper muscles such as the VI. This article is protected by copyright. All rights reserved.

Age-related changes in swallowing muscle intramuscular adipose tissue deposition and related factors

OBJECTIVES

To investigate age-related changes in the intramuscular adipose tissue (IAT) of the tongue and geniohyoid muscle (GHM) and associated factors.

DESIGN

Exploratory cross-sectional study.

SETTING AND PARTICIPANTS

This study included 89 participants recruited from a health survey, which included 38 younger adults (age range, 20-63 years) and 51 older adults (age range, 65-87 years).

MEASUREMENTS

Age, body mass index, body fat, lean body mass, skeletal muscle mass index, trunk muscle mass index, tongue pressure, jaw opening force, and oral diadochokinesis were assessed. The cross-sectional area (CSA) and echo intensity (EI) of the tongue and GHM were measured using ultrasonography. IAT was assessed according to EI values. The factors related to the IAT of each muscle were examined using multiple regression analysis. We also investigated the correlation of IAT with factors related to oral function and systemic and morphological factors.

RESULTS

Neither the EI of the tongue nor that of the GHM had a significant correlation with factors related to oral function and systemic factors. In the multiple regression analysis, significant explanatory variables for EI of the tongue and GHM were age (β = 0.14, P = 0.019; tongue and β = 0.13, P = 0.017; GHM) and the CSA of each muscle (β = -0.01, P = 0.042; tongue and β = -0.04, P = 0.003; GHM). EI was positively associated with age and negatively associated with muscle CSA.

CONCLUSION

Age-related changes in the IAT show the same trend for both the tongue and GHM, unlike age-related changes in muscle mass. The IATs of the tongue and GHM were not significantly correlated with oral function and systemic factors. Therefore, EI may not be a useful index for the functional evaluation of the tongue and GHM.

Post-acute sequelae of SARS-CoV-2 infection (PASC): a protocol for a multidisciplinary prospective observational evaluation of a cohort of patients surviving hospitalisation in Sao Paulo, Brazil

INTRODUCTION

COVID-19 may lead to persistent and potentially incapacitating clinical manifestations (post-acute sequelae of SARS-CoV-2 infection (PASC)). Using easy-to-apply questionnaires and scales (often by telephone interviewing), several studies evaluated samples of COVID-19 inpatients from 4 weeks to several months after discharge. However, studies conducting systematic multidisciplinary assessments of PASC manifestations are scarce, with thorough in-person objective evaluations restricted to modestly sized subsamples presenting greatest disease severity.

METHODS AND ANALYSES

We will conduct a prospective observational study of surviving individuals (above 18 years of age) from a cohort of over 3000 subjects with laboratory-confirmed COVID-19 who were treated as inpatients at the largest academic health centre in Sao Paulo, Brazil (Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo). All eligible subjects will be consecutively invited to undergo a 1-2-day series of multidisciplinary assessments at 2 time-points, respectively, at 6-9 months and 12-15 months after discharge. Assessment schedules will include detailed multidomain questionnaires applied by medical research staff, self-report scales, objective evaluations of cardiopulmonary functioning, physical functionality and olfactory status, standardised neurological, psychiatric and cognitive examinations, as well as diagnostic laboratory, muscle ultrasound and chest imaging exams. Remaining material from blood tests will be incorporated by a local biobank for use in future investigations on inflammatory markers, genomics, transcriptomics, peptidomics and metabolomics.

ETHICS AND DISSEMINATION

All components of this programme have been approved by local research ethics committees. We aim to provide insights into the frequency and severity of chronic/post-COVID multiorgan symptoms, as well as their interrelationships and associations with acute disease features, sociodemographic variables and environmental exposures. Findings will be disseminated in peer-reviewed journals and at scientific meetings. Additionally, we aim to provide a data repository to allow future pathophysiological investigations relating clinical PASC features to biomarker data extracted from blood samples.

TRIAL REGISTRATION NUMBER

RBR-8z7v5wc; Pre-results.

Relationship between longitudinal changes in skeletal muscle characteristics over time and functional recovery during intensive rehabilitation of patients with subacute stroke

BACKGROUND

Stroke is a disease that easily impairs skeletal muscle characteristics, resulting in low quantity, low quality, and poor strength. However, the recovery process of skeletal muscles in patients with stroke is not well established.

OBJECTIVES

We aimed to determine the longitudinal changes in skeletal muscle characteristics in patients with stroke during intensive rehabilitation and examine their relationship with functional recovery.

METHODS

Eighty-five patients with stroke were prospectively recruited. We defined muscle quantity and quality as ultrasonographic muscle thickness and echo intensity, respectively, and muscle strength as knee extension strength. These skeletal muscle characteristics were compared at four time points: on admission, after 2 weeks, after 4 weeks, and at discharge. We also explored the relationship between changes in skeletal muscle characteristics and functional recovery.

RESULTS

Non-paretic knee extension torque (F = 5.838, P = .001), paretic quadriceps thickness (F = 2.943, P = .039), and paretic tibialis anterior thickness (F = 4.654, P = .004) improved over time, and changes in the paretic side quadriceps thickness were significantly associated with recovery for balance ability (odds ratio, 1.05; 95% confidence interval, 1.00-1.09; P = .048).

CONCLUSIONS

The present study revealed that knee extension muscle strength on the non-paretic side and quadriceps and tibialis anterior thickness on the paretic side significantly improved over time and that changes in the paretic side quadriceps thickness were associated with the recovery of balance ability.

Cut-off Values for Lower Limb Muscle Thickness to Detect Low Muscle Mass for Sarcopenia in Older Adults

Purpose

Ultrasound-based prediction methods for the detection of low muscle mass for sarcopenia in older adults have been explored previously; however, the muscle that most accurately predicts it is unclear. This study aimed to clarify prediction accuracy and cut-off values for ultrasound-derived thigh and lower leg muscle thickness (MT) to detect low skeletal muscle mass index (SMI) in older adults and to estimate cut-off values based on two standard deviations (SD) below younger adult means for the corresponding muscles as an early detection tool for site-specific low muscle mass.

Methods

This study included 204 community-dwelling older (64 males, 140 females, mean age: 75.4 years) and 59 younger (31 males, 28 females, mean age: 22.3 years) adults. The MT of the rectus femoris, vastus intermedius, gastrocnemius, and soleus muscles was measured using ultrasound; SMI was measured using bioelectrical impedance analysis.

Results

The prevalence of a low SMI among older adults was 20.3% (n=13) for males and 21.4% (n=30) for females. The receiver operating characteristic analysis revealed that the total MT for the four muscles measured presented the highest area under the curve (AUC) value to predict low SMI for males (0.849) and females (0.776). The AUC value was the highest for the total MT of the gastrocnemius and soleus muscles for males and the gastrocnemius for females (0.836, 0.748; cut-off value: 5.67 cm, 1.42 cm, respectively). Muscle-specific differences between the low SMI-predicting and SD-based cut-off values were observed. The SD-based value for the rectus femoris (1.85 cm) was substantially higher than the low SMI-predicting value (1.51 cm) in males.

Conclusion

Ultrasound measurement of lower leg muscles may be a simple, robust measure to detect low muscle mass for sarcopenia. Additionally, cut-off values for site-specific muscle mass loss may not always agree with those for whole-limb muscle mass loss.

Calf circumference positively correlates with calf muscle thickness and negatively correlates with calf subcutaneous fat thickness and percent body fat in non-obese healthy young adults

BACKGROUND

Calf circumference is measured for assessing sarcopenia, nutrition status, percent body fat or obesity. However, there has been no study that investigated the relationship between calf circumference and calf subcutaneous fat tissue thickness. Therefore, the purpose of this study was to investigate the relationship between calf circumference, calf muscle thickness, and calf subcutaneous fat tissue thickness in nonobese healthy young adults.

METHODS

The study participants were non-obese 22 women (20.1 ± 0.8 years) and 21 men (20.0 ± 0.8 years). The right calf circumference was measured in prone position at the point where the circumference was maximal by visual recognition using a measuring tape. Then, thickness of calf subcutaneous fat tissue and calf muscles were measured with an ultrasonic diagnostic equipment.

RESULTS

There was a positive relationship between calf circumference and calf muscle thickness both in women (r = 0.58, P < 0.01) and men (r = 0.46, P < 0.05), negative relathionship between calf circumference and calf subcutaneous fat tissue thickness both in women (r = -0.43, P < 0.05) and men (r = -0.67, P < 0.001), no correlation between calf circumference and percent body fat both in women (r = 0.04, P = 0.87) and men (r = 0.41, P = 0.06), and a negative relationship between calf subcutaneous fat tissue thickness and percent body fat both in women (r = -0.48, P < 0.05) and men (r = -0.46, P < 0.05).

CONCLUSIONS

Our present study showed that a larger calf indicated larger calf muscle thickness, and largely different from previous studies, a lower calf subcutaneous fat tissue thickness. That is because when the calf circumference increases, calf subcutaneous fat tissue thickness should be thinner to keep the percent body fat equal in non-obese healthy young adults. The finding will help to get a better understanding of the nature of the calf.

Utility of Ultrasound as a Valid and Accurate Diagnostic Tool for Sarcopenia: Sex-Specific Cutoff Values in Chronic Kidney Disease

OBJECTIVES

Patients with chronic kidney disease (CKD) have aberrant changes in body composition, including low skeletal muscle mass, a feature of "sarcopenia." The measurement of the (quadriceps) rectus femoris (RF) cross-sectional area (CSA) is widely used as a marker of muscle size. Cutoff values are needed to help discriminate the condition of an individual's muscle (eg, presence of sarcopenia) quickly and accurately. This could help distinguish those at greater risk and aid in targeted treatment programs.

METHODS

Transverse images of the RF were obtained by B-mode 2-dimensional ultrasound imaging. Sarcopenic levels of muscle mass were defined by established criteria (1, appendicular skeletal muscle mass [ASM]; 2, ASM/height² ; and 3, ASM/body mass index) based on the ASM and total muscle mass measured by a bioelectrical impedance analysis. The discriminative power of RF-CSA was assessed by receiver operating characteristic curves, and optimal cutoffs were determined by the maximum Youden index (J).

RESULTS

One hundred thirteen patients with CKD (mean age [SD], 62.0 [14.1] years; 48% male; estimated glomerular filtration rate, 38.0 [21.5] mL/min/1.73m² ) were included. The RF-CSA was a moderate predictor of ASM (R² = 0.426; P < .001) and total muscle mass (R² = 0.438; P < .001). With a maximum J of 0.47, in male patients, an RF-CSA cutoff of less than 8.9 cm² was deemed an appropriate cutoff for detecting sarcopenic muscle mass. In female patients, an RF-CSA cutoff of less than 5.7 cm² was calculated on the basis of ASM/height² (J = 0.71).

CONCLUSIONS

Ultrasound may provide a low-cost and simple means to diagnose sarcopenia in patients with CKD. This would allow for early management and timely intervention to help mitigate the effects in this group.

Frailty and Sarcopenia in Patients Pre- and Post-Liver Transplant

Greater than half of patients with decompensated liver disease suffer from frailty and/or sarcopenia, which can lead to increased pre- and post-liver transplant morbidity and mortality. Although frailty and sarcopenia can impact patients with end-stage liver disease in similar ways, they are unique clinical entities with differing underlying etiologies. Early assessment and identification of frailty and sarcopenia in patients is critical to guide clinical decision-making regarding transplantation and to implement nutritional and exercise-based treatment regiments. Nonetheless, accurate diagnosis and, in particular, predicting patients that will develop frailty and/or sarcopenia remains challenging, and the success of clinical interventions is limited.

Echo intensity as an indicator of skeletal muscle quality: applications, methodology, and future directions

PURPOSE

This narrative review provides an overview of the current knowledge of B-mode ultrasound-derived echo intensity (EI) as an indicator of skeletal muscle quality.

METHOD

PubMed and Google Scholar were used to search the literature. Advanced search functions were used to find original studies with the terms 'echo intensity' and/or 'muscle quality' in the title and/or abstract. Publications that conceptually described muscle quality but did not include measurement of EI were not a focus of the review.

RESULT

Importantly, the foundational premise of EI remains unclear. While it is likely that EI reflects intramuscular adiposity, data suggesting that these measurements are influenced by fibrous tissue is limited to diseased muscle and animal models. EI appears to show particular promise in studying muscular aging. Studies have consistently reported an association between EI and muscle function, though not all chronic interventions have demonstrated improvements. Based on the existing literature, it is unclear if EI can be used as a marker of muscle glycogen following exercise and nutritional interventions, or if EI is influenced by hydration status. Inconsistent methodological approaches used across laboratories have made comparing EI studies challenging. Image depth, rest duration, participant positioning, probe tilt, and the decision to correct for subcutaneous adipose tissue thickness are all critical considerations when interpreting the literature and planning studies.

CONCLUSION

While some areas show conflicting evidence, EI shows promise as a novel tool for studying muscle quality. Collaborative efforts focused on methodology are necessary to enhance the consistency and quality of the EI literature.

Asian Working Group for Sarcopenia: 2019 Consensus Update on Sarcopenia Diagnosis and Treatment

Clinical and research interest in sarcopenia has burgeoned internationally, Asia included. The Asian Working Group for Sarcopenia (AWGS) 2014 consensus defined sarcopenia as "age-related loss of muscle mass, plus low muscle strength, and/or low physical performance" and specified cutoffs for each diagnostic component; research in Asia consequently flourished, prompting this update. AWGS 2019 retains the previous definition of sarcopenia but revises the diagnostic algorithm, protocols, and some criteria: low muscle strength is defined as handgrip strength <28 kg for men and <18 kg for women; criteria for low physical performance are 6-m walk <1.0 m/s, Short Physical Performance Battery score ≤9, or 5-time chair stand test ≥12 seconds. AWGS 2019 retains the original cutoffs for height-adjusted muscle mass: dual-energy X-ray absorptiometry, <7.0 kg/m2 in men and <5.4 kg/m2 in women; and bioimpedance, <7.0 kg/m2 in men and <5.7 kg/m2 in women. In addition, the AWGS 2019 update proposes separate algorithms for community vs hospital settings, which both begin by screening either calf circumference (<34 cm in men, <33 cm in women), SARC-F (≥4), or SARC-CalF (≥11), to facilitate earlier identification of people at risk for sarcopenia. Although skeletal muscle strength and mass are both still considered fundamental to a definitive clinical diagnosis, AWGS 2019 also introduces "possible sarcopenia," defined by either low muscle strength or low physical performance only, specifically for use in primary health care or community-based health promotion, to enable earlier lifestyle interventions. Although defining sarcopenia by body mass index-adjusted muscle mass instead of height-adjusted muscle mass may predict adverse outcomes better, more evidence is needed before changing current recommendations. Lifestyle interventions, especially exercise and nutritional supplementation, prevail as mainstays of treatment. Further research is needed to investigate potential long-term benefits of lifestyle interventions, nutritional supplements, or pharmacotherapy for sarcopenia in Asians.