Role of Ultrasonography in Estimating Muscle Mass in Sarcopenic Obesity

Skeletal muscle as a pro- and anti-inflammatory tissue: insights from children to adults and ultrasound findings

Previously regarded as a movement and posture control agent, the skeletal muscle is now recognized as an endocrine organ that may affect systemic inflammation and metabolic health. The discovery of myokines such as IL-6, released from skeletal muscle in response to physical exercise, is now one of the most recent insights. Myokines are the mediators of the balance between the pro-inflammatory and anti-inflammatory responses. This underscores the muscle function as a determinant of good health and prevention of diseases. Advances in ultrasound technology improved evaluation of muscle thickness, composition, and determining fat distribution. Combining imaging with molecular biology, researchers discovered the complicated interplay between muscle function, cytokine production and general health effects.The production of myokines with exercise showcasing the adaptability of muscles to high-stress conditions and contributing to metabolism and inflammation regulation. These findings have significant implications in order to provide improvement in metabolic and inflammatory diseases.

Cutoff values for appendicular skeletal muscle mass using dual-energy x-ray absorptiometry in a reference group of Turkish adults

BACKGROUND

The aim of this study is to determine cutoff values for different appendicular skeletal muscle mass index (ASMI) methods measured by dual-energy x-ray absorptiometry (DXA) in a reference group of the Turkish population.

METHODS

Body composition analyses were performed with DXA, and appendicular skeletal muscle mass (ASM) was adjusted to body size as ASMI using height squared (ASM/ht2), weight (ASM/wt), and body mass index (BMI) (ASM/BMI). Sex-specific cutoff values were obtained as 1 and 2 standard deviations (SDs) below the mean values of ASM/ht2, ASM/wt, and ASM/BMI.

RESULTS

A total of 207 (106 women and 101 men) healthy adults were enrolled. Sex-specific cutoff values based on 1 SD below the mean values of ASM, ASM/ht2, ASM/BMI, and ASM/wt were 14.44, 5.45, 0.61, and 24.07 in women and 22.63, 7.22, 0.90, and 29.04 in men, respectively; 2 SDs below the mean values of ASM, ASM/ht2, ASM/BMI, and ASM/wt were 11.96, 4.65, 0.51, and 21.75 in women and 19.26, 6.40, 0.78, and 26.55 in men, respectively. ASM, ASM/BMI, ASM/ht2, and ASM/wt were statistically significant positively correlated with handgrip strength (r = 0.81, r = 0.78, r = 0.73, and r = 0.67, respectively; P < 0.001).

CONCLUSION

In this study, ASM/BMI was found to be the most suitable ASM adjustment method to predict muscle strength.

Uncovering sarcopenia and frailty in older adults by using muscle ultrasound-A narrative review

Muscle ultrasound is a valuable non-invasive and cost-effective method in assessing muscle mass and structure, both of which are significant indicators for the development of sarcopenia and frailty in elderly individuals. Sarcopenia refers to the loss of muscle mass and strength that occurs with age, whereas frailty is a complex geriatric syndrome characterized by reduced physical function and an increased susceptibility to negative health outcomes. Both conditions are prevalent in older adults and are associated with higher risks of falls, disability, and mortality. By measuring muscle size and structure and several other ultrasound parameters, including muscle thickness, cross-sectional area, echogenicity (brightness in the ultrasound image), pennation angle, and fascicle length ultrasound can assist in identifying sarcopenia and frailty in older adults. In addition, ultrasound can be used to evaluate muscle function such as muscle contraction and stiffness, which may also be affected in sarcopenia and frailty. Therefore, muscle ultrasound could lead to better identification and tracking of sarcopenia and frailty. Such advancements could result in the implementation of earlier interventions to prevent or treat these conditions, resulting in an overall improvement in the health and quality of life of the elderly population. This narrative review describes the benefits and challenges when using ultra-sound for the evaluation of frailty and sarcopenia.

The Role of Ultrasound Muscle Parameters for Myosteatosis and Myofibrosis Measurement in Young, Older, and Obese Subjects

OBJECTIVES

The aim of the study was to compare quantitative and qualitative ultrasound parameters between healthy young adults and post-acute hospitalized older adults with and without physical disability, as well as between normal weight and overweight/obese persons.

DESIGN

Cross-sectional observational study.

SETTING AND PARTICIPANTS

A total of 120 individuals were recruited: 24 healthy young adults, 24 normal weight and 24 overweight/obese community-dwelling adults, and 48 post-acute hospitalized older adults with different degrees of functional autonomy.

METHODS

The rectus femoris cross-sectional area (CSA), subcutaneous adipose tissue (SCAT) thickness, echogenicity, strain elastography, and compressibility were measured with ultrasound echography.

RESULTS

Post-acute older adults with a good level of autonomy showed higher echogenicity, a higher compressibility index and elastometry strain, and lower rectus femoris thickness and CSA as compared with young persons. Post-acute individuals with physical disability showed lower echogenicity and a greater stiffness compared with their still autonomous counterparts. Normal weight individuals showed lower stiffness as evaluated with elastometry and a lower SCAT thickness, as compared with individuals with age-matched overweight or obesity. From multiple regression analyses, using CSA as an independent variable, an inverse association with female sex and age was observed, explaining 16% and 51% of variance. Echogenicity was directly associated with age (34% of variance) and with the Barthel index (6% of variance). Elastometry showed association with age and body mass index (BMI), 30% and 16% of variance, respectively. Considering compressibility as a dependent variable, a direct association with age and an inverse association with BMI were observed, with 5% and 11% of variance respectively.

CONCLUSIONS AND IMPLICATIONS

Muscle mass decreases with age and with physical disability. Echogenicity, which increases with age and disability level, seems to be associated with myofibrosis. Conversely, elastometry seems useful in the characterization of muscle quality in overweight or obese individuals and as a reliable indirect measure of myosteatosis.

Prevalence of nutrition disorders and nutrition-related conditions in older patients with Alzheimer's disease

BACKGROUNDS

Alzheimer's disease is frequently encountered with nutrition-related conditions such as malnutrition, sarcopenia, frailty, overnutrition, and micronutrient abnormalities in older patients. In this study, we aimed to evaluate the prevalence of nutrition disorders and nutrition-related conditions in the same patient group.

METHODS

A total of 253 older patients with Alzheimer's disease underwent comprehensive geriatric assessment, which included nutrition-related disorders, malnutrition via the Mini Nutritional Assessment-Short Form (MNA-SF), frailty via the Clinical Frailty Scale (CFS), and sarcopenia was diagnosed according to European Working Group on Sarcopenia in Older People-2 criteria.

RESULTS

The patients' mean age was 79.8 ± 6.5 years, and 58.1% were women. In our patients, 64.8% had malnutrition or were at risk of malnutrition; 38.3% had sarcopenia; 19.8% were prefrail; and 80.2% were frail. Malnutrition, frailty, and sarcopenia prevalence increased as the Alzheimer's disease stage progressed. Malnutrition was found to be significantly related with frailty scores via CFS (odds ratio [OR], 1.397; P = 0.0049) and muscle mass via fat-free mass index (FFMI) (OR, 0.793; P = 0.001). In logistic regression analysis, age, MNA-SF, and CFS were included in the model to detect the independent correlates of probable and confirmed sarcopenia. CFS was independently associated with probable and confirmed sarcopenia (OR, 1.822; P = 0.013; OR, 2.671; P = 0.001, respectively). Frailty was similarly related with FFMI (OR, 0.836; P = 0.031). Obesity was independently related with FFMI (OR, 0.688; P < 0.001).

CONCLUSION

In conclusion, nutrition disorders and nutrition-related conditions can present concurrently in patients with all stages of Alzheimer's disease; therefore, these frequent problems should be screened and diagnosed accordingly.

Assessment of Sarcopenia Using Muscle Ultrasound in Patients With Cirrhosis and Sarcopenic Obesity (AMUSE STUDY)

BACKGROUND AND AIMS

Sarcopenic obesity (SO) marks a confluence of 2 complex entities involving the muscle-liver-adipose tissue axis. Computed tomographic (CT) scan-derived skeletal muscle index (SMI) remains the gold standard for sarcopenia assessment in SO. However, it has intrinsic limitations of cost, radiation, and point of care applicability. We assessed the role of muscle ultrasound (US) in SO.

METHODS

A total of 52 patients with cirrhosis and obesity were assessed for sarcopenia using SMI. US assessment of thigh and forearm muscles was done to record quadriceps muscle thickness (QMT), quadriceps feather index (QMFI), forearm muscle thickness (FMT), and forearm feather index (FFI), respectively. Evaluated US parameters were correlated with SMI and assessed for diagnostic accuracy using the area under the curve.

RESULTS

A total of 40 (76.9%) males and 12 (23.1%) females [mean age: 50.9 y (43.8 to 53.5 y)] were included. QMT [0.45 cm/m 2 (0.42 to 0.48 cm/m 2 ) vs. 0.67 cm/m 2 (0.63 to 0.70 cm/m 2 )], QMFI [0.82 cm/m 2 (0.77 to 0.87 cm/m 2 ) vs. 1.12 cm/m 2 (1.06 to 1.19 cm/m 2 )], FMT [0.19 cm/m 2 (0.17 to 0.20 cm/m 2 ) vs. 0.25 cm/m 2 (0.23 to 0.27 cm/m 2 )], and FFI [0.38 cm/m 2 (0.35 to 0.412 cm/m 2 ) vs. 0.47 cm/m 2 (0.44 to 0.50 cm/m 2 )] were significantly lower in patients with SO ( P <0.01). A positive correlation with SMI was seen for all parameters in the entire cohort. The strongest correlation was exhibited by QMT ( r =0.70) and QMFI ( r =0.70) in males. The area under the curve of QMT, QMFI, FMT, and FFI were 0.98 (95% confidence interval: 0.96-1), 0.95 (0.89-1), 0.85 (0.75-0.96), and 0.80 (0.68-0.93), respectively.

CONCLUSIONS

US-based assessment of sarcopenia has excellent diagnostic accuracy and correlates well with computed tomography-SMI in patients with SO. US may serve as an easy-to-use, point of care tool for assessing sarcopenia in SO with the advantage of repeated sequential assessment.

Usefulness of Ultrasound in Assessing the Impact of Bariatric Surgery on Body Composition: a Pilot Study

BACKGROUND

Bariatric surgery (BS) has a significant impact on body composition. The purpose of the study is to evaluate the usefulness of musculoskeletal ultrasound (MUS) to bioelectrical impedance (BIA) in the follow-up of patients undergoing BS in terms of body composition and quality of life (QoL).

METHODS

This is a prospective pilot study including 32 subjects (75% female, mean age: 49.15 ± 1.9 years) who underwent BS. Fat mass (FM), lean mass (LM), and skeletal muscle index (SMI) were calculated by BIA. MUS measured subcutaneous fat (SF) and thigh muscle thickness (TMT) of the quadriceps. QoL was assessed by the Moorehead-Ardelt questionnaire. All these measurements were performed 1 month prior to BS and at 12-month follow-up.

RESULTS

The mean BMI decreased by 6.63 ± 1.25 kg/m² (p=0.001). We observed significant reductions in FM (p=0.001) and SF (p=0.007) and in LM (p=0.001) but not in SMI and TMT. We found a correlation between the FM and SF (pre-surgical, r=0.42, p=0.01; post-surgical, r=0.52, p=0.003) and between SMI and TMT (pre-surgical, r=0.35, p=0.04; post-surgical, r=0.38, p=0.03). QoL test showed significant improvement (p=0.001). In addition, a correlation between the QoL questionnaire and TMT post-surgery (r=0.91, p=0.019) was observed. However, we did not find any statistically significant correlation between QoL assessment and SMI or LM.

CONCLUSIONS

Our results suggest that MUS can be complementary to BIA for the evaluation and the follow-up of body composition after BS. TMT of quadriceps can provide relevant information about regional sarcopenia and has a significant correlation with QoL.

Changes in muscle quality identified by shear-wave elastography and association with sarcopenia

BACKGROUND AND AIMS

This study aimed to investigate the potential role of shear-wave elastography (SWE) in evaluating muscle quality and assess its association with muscle strength and mass.

METHODS

A total of 129 patients aged 18-87 years were included. Patients aged >65 years underwent comprehensive geriatric assessment. Anthropometric measurements, assessment of physical performance, muscle strength (handgrip strength [HGS]), muscle mass (B-mode muscle ultrasonography), and muscle quality (identified via SWE) were performed for all patients.

RESULTS

The median (interquartile range) age of participants was 69 (59-76) years and 62% (n = 80) were female. According to HGS, patients were divided into normal and low HGS groups, and there were 85 (65.9%) and 44 (34.1%) patients in each group, respectively. The median average value of SWE measurement (V_mean ) of the rectus femoris (RF) in passive stretching was significantly lower in the low HGS group. In regression analyses, V_mean was significantly associated with HGS independently of age, sex, and body mass index. Optimal cutoff values of the V_mean value (m/s) of RF in passive stretching for predicting low HGS were ≤2.62 for male (area under the curve [AUC], 0.882; 95% CI, 0.705-0.938; P = <0.0001), and ≤2.52 for female (AUC, 0.719; 95% CI, 0.605-0.833; P = 0.002).

CONCLUSION

To the best of our knowledge, this is the first study revealing SWE is a good predictor of muscle strength, and it could be a useful tool for evaluating muscle quality in clinical practice. Further randomized controlled studies are needed to confirm the presented cutoff values.

Determination gender-based hybrid artificial intelligence of body muscle percentage by photoplethysmography signal

BACKGROUND AND OBJECTIVE

Muscle mass is one of the critical components that ensure muscle function. Loss of muscle mass at every stage of life can cause many adverse effects. Sarcopenia, which can occur in different age groups and is characterized by a decrease in muscle mass, is a critical syndrome that affects the quality of life of individuals. Aging, a universal process, can also cause loss of muscle mass. It is essential to monitor and measure muscle mass, which should be sufficient to maintain optimal health. Having various disadvantages with the ordinary methods used to estimate muscle mass increases the need for the new high technology methods. This study aims to develop a low-cost and trustworthy Body Muscle Percentage calculation model based on artificial intelligence algorithms and biomedical signals.

METHODS

For the study, 327 photoplethysmography signals of the subject were used. First, the photoplethysmography signals were filtered, and sub-frequency bands were obtained. A quantity of 125 time-domain features, 25 from each signal, have been extracted. Additionally, it has reached 130 features in demographic features added to the model. To enhance the performance, the spearman feature selection algorithm was used. Decision trees, Support Vector Machines, Ensemble Decision Trees, and Hybrid machine learning algorithms (the combination of three methods) were used as machine learning algorithms.

RESULTS

The recommended Body Muscle Percentage estimation model have the perfomance values for all individuals R=0.95, for males R=0.90 and for females R=0.90 in this study.

CONCLUSION

Regarding the study results, it is thought that photoplethysmography-based models can be used to predict body muscle percentage.

Usefulness of Muscle Ultrasound to Study Sarcopenic Obesity: A Pilot Case-Control Study

Background and objectives: Sarcopenic obesity (SO) is an emerging problem, especially in candidates for bariatric surgery (BS). We hypothesized that musculoskeletal ultrasound (MUS), a simple and accessible method, could be a reliable index of SO. Materials and Methods: A cross-sectional pilot study including 122 subjects (90 cases and 32 controls, 73% female, mean age: 51.2 years) who underwent BS was conducted at University Hospital Mútua Terrassa. The lean mass (LM) was calculated by bioelectrical impedance analysis (BIA) and the thigh muscle thickness (TMT) by MUS. To identify the subjects with SO by BIA, we used skeletal muscle index (SMI). The validity of MUS was determined using the ROC curve. Results: The mean BMI in the obesity group was 44.22 kg/m2. We observed a correlation between the LM and SMI assessed by BIA and the TMT assessed by MUS (R = 0.46, p < 0.001). This correlation was maintained at significant levels in the SO group (n = 40): R = 0.79; p = 0.003). The TMT assessed by MUS was able to predict SMI using BIA (AUC 0.77; 95% CI: 0.68242 to 0.84281). The optimal cut-off point for maximum efficiency was 1.57 cm in TMT (sensitivity = 75.6% and specificity = 71.1%). Conclusions: The TMT of the quadriceps assessed by US is a useful tool for identifying subjects with SO. Larger studies to validate this simple low-cost screening strategy are warranted.

[Assessment and technical monitoring of nutritional status of patients in intensive and intermediate care units : Position paper of the Section Metabolism and Nutrition of the German Interdisciplinary Association for Intensive and Emergency Medicine (DIVI)]

Die Erhebung des Ernährungsstatus zum Zeitpunkt der Aufnahme im Intensiv- oder Intermediate Care Bereich hat sowohl prognostische als auch therapeutische Relevanz im Hinblick auf die Planung einer individualisierten medizinischen Ernährungstherapie (engl. „medical nutrition therapy“, MNT). Diese Planung wird im Rahmen der Erstversorgung eines vital bedrohlichen Krankheitsbilds nachvollziehbar nicht priorisiert, jedoch im weiteren Verlauf häufig auch oft nicht mehr angemessen durchgeführt. Vor allem bei längerer Verweildauer besteht das Risiko einer Mangelernährung mit Aufbau eines kumulativen, prognoserelevanten Makro- und/oder Mikronährstoffdefizits. Bisher gibt es für Patient*innen auf Intensiv- und Intermediate Care Einheiten keine strukturierten Empfehlungen zur Erhebung des Ernährungsstatus. Das vorliegende Positionspapier der Sektion Metabolismus und Ernährung der Deutschen Interdisziplinären Vereinigung für Intensiv- und Notfallmedizin (DIVI) beinhaltet konsensbasierte Empfehlungen zur Erfassung und zum apparativen Monitoring des Ernährungsstatus von Patient*innen auf Intensiv- und Intermediate Care Stationen. Diese Empfehlungen ergänzen die aktuelle S2k-Leitlinie „Klinische Ernährung in der Intensivmedizin“ der Deutschen Gesellschaft für Ernährungsmedizin (DGEM) und der DIVI.

Ultrasound Assessment of Sarcopenia in Patients With Sarcoidosis

OBJECTIVES

Sarcoidosis can cause sarcopenia like other chronic diseases. Ultrasonography is a simple method, which has been used frequently in recent years. We aimed to evaluate the sarcoidosis patients with ultrasonography for sarcopenia and to compare the results of ultrasonography with the accepted standard method, bioelectrical impedance analysis (BIA).

METHODS

BIA and handgrip test were applied to all patients diagnosed with sarcoidosis. The patients were classified according to the presence of probable sarcopenia with their handgrip results and the presence of sarcopenia with the appendicular skeletal muscle mass index calculated with using BIA. Ultrasonography was applied to each patient and the thickness of seven different muscle groups of the patients were evaluated. The ability of muscle thickness values measured by ultrasonography to predict sarcopenia was compared with the reference standard test BIA.

RESULTS

Forty patients (women/men = 31/9) were included in our study. The mean age was 53.2 ± 12.5 years. A statistically significant positive correlation was observed between handgrip strength and gastrocnemius medialis (GM), rectus femoris (RF) cross-sectional area, rectus abdominis (RA), external oblique (EO), transversus abdominus (TA), and diaphragm thicknesses. Therefore, there was a significant correlation between fat free mass index with RA, EO, and TA muscles. According to the ROC analysis, statistically significant muscle groups predicting sarcopenia were found as GM, RF cross-sectional area, EO, and IO. Again, according to the ROC analysis, it was seen that the thicknesses of GM, RA, EO, IO, and TA muscles corrected for BMI predicted probable sarcopenia with quite high sensitivity and specificity.

CONCLUSIONS

Muscle thicknesses measured by ultrasonography are helpful for the diagnosis of sarcopenia that may develop in chronic diseases such as sarcoidosis. Further studies with higher number of patients are needed to validate the results of the present pilot study.

Global Leadership Initiative on Malnutrition criteria with different muscle assessments including muscle ultrasound with hospitalized internal medicine patients

BACKGROUND

The aim of this study is to identify cutoff values for muscle ultrasound (US) to be used in Global Leadership Initiative on Malnutrition (GLIM) criteria, and to define the effect of reduced muscle mass assessment on malnutrition prevalence at hospital admission.

METHODS

A total of 118 inpatients were enrolled in this cross-sectional study. Six different muscles were evaluated by US. Following defining thresholds for muscle US to predict low muscle mass measured by bioelectrical impedance analysis, malnutrition was diagnosed by GLIM criteria with seven approaches, including calf circumference, mid-upper arm circumference (MAC), handgrip strength (HGS), skeletal muscle index (SMI), rectus femoris (RF) muscle thickness, and cross-sectional area (CSA) in addition to without using the reduced muscle mass criterion.

RESULTS

The median age of patients was 64 (18-93) years, 55.9% were female. RF muscle thickness had moderate positive correlations with both HGS (r = 0.572) and SMI (r = 0.405). RF CSA had moderate correlation with HGS (r = 0.567) and low correlation with SMI (r = 0.389). The cutoff thresholds were 11.3 mm (area under the curve [AUC] = 0.835) and 17 mm (AUC = 0.737) for RF muscle thickness and 4 cm² (AUC = 0.937) and 7.2 cm² (AUC = 0.755) for RF CSA in females and males, respectively. Without using the reduced muscle mass criterion, malnutrition prevalence was 46.6%; otherwise, it ranged from 47.5% (using MAC) to 65.2% (using HGS).

CONCLUSIONS

Muscle US may be used in GLIM criteria. However, muscle US needs a standard measurement technique and specific cutoff values in future studies.

New insights on how and where to measure muscle mass

PURPOSE OF REVIEW

This article will discuss different muscle mass assessment methods and emphasize their highlights.

RECENT FINDINGS

Several measurement techniques can be used to evaluate muscle mass, recognized as important prognostic markers for adverse functional and clinical outcomes. Choosing the best method depends on the knowledge regarding their theoretical and practical limitations and the purpose of the assessment. Image techniques are considered the gold standards, with good accuracy and precision, but not always available in clinical settings. A new biological technique, the D3-creatinine dilution, can provide not only direct information about muscle mass but also shows a strong association with physical function. With the advancement of the use of the computed tomography (CT) images to assess skeletal muscle mass, mainly in patients with cancer, the assessment of skeletal muscle radiodensity (SMD), as a marker of muscle quality, may provide additional information regarding the association between muscle composition, muscle function and prognosis. Additional muscle function assessment can improve the risk prediction in several clinical situations.

SUMMARY

The use of the best tool for the muscle mass assessment should be performed carefully among the various methodologies, according to their characteristics and clinical situation.