Differential Characteristics of Skeletal Muscle in Community-Dwelling Older Adults

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72.5 ± 5.8 years, mean ± SD (1 study did not provide sex descriptors)) were extracted for review, with previously unpublished data obtained from the authors of 13 studies.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.

The use of portable A-mode ultrasound in appendicular lean mass measurements among older adults: a comparison study with dual-energy X-ray absorptiometry and handgrip strength

BACKGROUND/OBJECTIVES

Strength and muscle mass are key factors for the diagnosis of sarcopenia. The EWGSOP2 recommended using ultrasound (US) as a reliable device to measure muscle mass (MM), but A-mode US still needs to be validated for older adults. This study aimed to evaluate the association between measurements of muscle thickness (MT) by portable A-mode US and, muscle quantity by Dual-Energy X-ray absorptiometry (DXA) in older adults.

METHODS

Cross-sectional study, with 115 participants included. Muscle mass was assessed by DXA and MT of the biceps, triceps, anterior thigh, and calf by A-mode US and handgrip strength by a dynamometer.

RESULTS

The majority were women (n = 96; 83%), 69 ± 6 years. The MT sum (biceps, triceps, thigh, and calf) assessed by the US was not associated with the appendicular lean mass (ALM) assessed by DXA after controlling for sex and age (R2 = 0.524; p = 0.139; effect size = 0.53). The MT sum biceps and triceps was still significantly associated with MM arms/2 even when controlling for sex and age (which were also significant) (R2 = 0.551; p < 0.001; effect size = 0.56). The MT sum thigh and calf was not associated with MM legs/2 in adjusted models (R2 = 0.499; p = 0.688; effect size = 0.51).

CONCLUSIONS

This finding shows that the portable A-mode US may not be an appropriate method for estimating MM in extremities (the sum of arms and legs), but can be appropriate for estimating only MM arms in healthy older adults.

Quality of skeletal muscles during allogeneic stem-cell transplantation: a pilot study

OBJECTIVES

This study investigated the muscle fat fraction (FF) and muscle-related parameters before and after allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

Fat and water signals were derived from the in-phase and out-of-phase MR signal intensities of the pelvis and thigh using the two-point Dixon technique. They were analysed using Synapse Vincent, and muscle quality was evaluated using the FF. The muscle mass was assessed by measuring the thigh and gluteal muscle areas using a manual trace on the MR image. The association between the muscle FF and clinical data was retrospectively determined.

RESULTS

This study included 11 patients (6 males). Their mean age was 42.7 years, and eight had leukaemia. Eight were assessed at a mean of 65.4 days post-HSCT. The hip and thigh skeletal muscle FFs were not significantly different during HSCT. The grip and lower limb muscle strengths decreased significantly after HSCT. Patients with low FFs before transplantation tended to lose muscle strength, and the increase in FF and decrease of muscle strength were correlated.

CONCLUSIONS

Muscle strength and quantity decrease during the early phase after HSCT, especially in patients with low FF muscles. Therefore, interventions based on muscle quality and quantity are essential.

Evaluation of quadriceps muscle cross-sectional area using an ultrasonic diagnostic equipment with a wide field of view

Skeletal muscle index measurement via dual-energy X-ray absorptiometry or bioelectrical impedance analysis is used to evaluate muscle mass when diagnosing sarcopenia. However, inherent challenges exist with these methods. We previously focused on muscle mass evaluation in the quadriceps femoris by using computed tomography (CT). In this observational study, we utilized a new ultrasound device with a wide field of view that can obtain CT-like images and investigated its usefulness. Reproducibility was investigated by calculating the intra- and inter-examiner intraclass correlation coefficient (ICC) by using three examiners and performing five measurements in 12 participants. In 123 participants (48 men, 75 women, mean age 78.2 ± 8.1 years), we investigated the correlation between the quadriceps cross-sectional area measured with supine ultrasound and CT images as well as between supine and sitting ultrasound images. Unadjusted, age-adjusted, and age-sex-adjusted correlations were calculated. Reproducibility was excellent (intra-examiner ICC[1,1]: 0.978, 0.987, and 0.994; inter-examiner ICC[2,1]: 0.993). The unadjusted, age-adjusted, and age-sex-adjusted correlations between the quadriceps cross-sectional area measured using supine ultrasound and CT were 0.949, 0.940, and 0.894, respectively. For sitting ultrasound, the corresponding values were 0.958, 0.953, and 0.912, respectively. Correlations between the supine and sitting ultrasound measurements were also good, with corresponding values of 0.952, 0.945, and 0.904, respectively. The tested ultrasound device showed excellent measurement reproducibility and had good correlations with CT images. Further studies with an increased numbers of clinical cases and additional evaluations should allow the device to become a screening tool for diagnosing sarcopenia.

Effect of Phase Angle on Change in Quadriceps Muscle Strength 1 Year After Total Knee Arthroplasty: The Screening for People Suffering Sarcopenia in Orthopedic Cohort of Kobe Study

BACKGROUND

Phase angle (PhA) has been reported to be associated with quadriceps strength in patients who have knee osteoarthritis and were scheduled for total knee arthroplasty (TKA). The PhA can also be expected to predict the time course of quadriceps muscle strength loss and recovery. We aimed to investigate the relationship between the preoperative PhA and the time course of quadriceps muscle strength change in patients undergoing TKA.

METHODS

A prospective cohort study was conducted on patients scheduled for primary unilateral TKA. A total of 855 patents were included in the analysis. The PhA and quadriceps muscle strength of the operated knee were measured preoperatively and at 3, 6, and 12 months postoperatively. To analyze the effect of the preoperative PhA on the change in postoperative quadriceps muscle strength, a linear mixed model with the quadriceps muscle strength as a dependent variable with the preoperative PhA, evaluation period (dummy variable), and their product terms as independent variables was conducted after adjusting for preoperative covariates.

RESULTS

A statistically significant negative effect was present for a higher PhA, resulting in a greater decrease in quadriceps muscle strength between preoperative and 3 months postoperative (P = 0.012). In contrast, the effect was not statistically significant between 3 and 6 months postoperatively (P = 0.17). However, a statistically significant positive effect for a higher PhA resulting in a greater increase in quadriceps muscle strength was present between 6 and 12 months postoperatively (P = 0.027).

CONCLUSIONS

Preoperative PhA is a useful predictor of the quadriceps muscle strength change after TKA. These findings suggest that evaluating the preoperative PhA could aid in the development of targeted rehabilitation programs aimed at optimizing quadriceps muscle function in patients undergoing TKA.

Relationship between physical activity levels and changes in skeletal muscle characteristics in patients with stroke

PURPOSE

This study aimed to investigate the relationship between physical activity (PA) levels and short-term changes in skeletal muscle characteristics in patients with subacute hemiparetic stroke.

MATERIALS AND METHODS

This prospective observational study included 76 patients with stroke who received inpatient care in a convalescent rehabilitation ward. The PA level was measured as the duration of daily total PA (≥ 1.5 metabolic equivalents) using a triaxial accelerometer for 7 days after admission. The outcomes were changes in the quadriceps muscle quality and quantity on the affected and unaffected sides, as assessed by ultrasonography at admission and 1 month after admission.

RESULTS

Multiple regression analysis indicated that the duration of total PA was significantly associated with a percentage change in quadriceps muscle quality (p = 0.011) and quantity (p = 0.012) on the affected side. However, no significant relationship was observed between the muscle quality and quantity on the unaffected side.

CONCLUSIONS

The results revealed that PA was associated with changes in the quadriceps muscle quality and quantity on the affected side in patients with subacute hemiparetic stroke. These findings highlight the importance of promoting PA in stroke rehabilitation to improve muscle properties and functional outcomes.

Association between upper limb muscle quality and knee osteoarthritis in dynapenia: an observational cross-sectional study

Neurological and skeletal muscle properties are suggested causes of dynapenia. This study aimed to evaluate the relationship between upper limb muscle quality (grip strength/upper extremity muscle mass) and knee osteoarthritis in dynapenia, and to identify dynapenia-associated factors. Elderly individuals who responded to a public call for screening in Wakasa Town, Fukui Prefecture between June 2019 and November 2021 were included. The analysis included 433 participants (304 women aged 76.0 ± 7.1 years). Examination comprised (consecutively) a basic interview, physical function measurement, body composition measurement, and explanation of results. Dynapenia was observed in 67 patients. Binomial logistic regression analysis revealed that age, upper limb muscle quality score, and knee osteoarthritis were independent factors for dynapenia. Receiver operating characteristic analysis of the relationship between dynapenia and upper limb muscle quality showed an area under the curve of 0.806 (95% confidence interval: 0.658-0.953) for men (cut-off value, 14.3 kg/kg) and 0.849 for women (95% confidence interval: 0.858-0.968; cut-off value, 14.0 kg/kg). In conclusion, age, upper limb muscle quality, and knee osteoarthritis were independent factors of dynapenia. We demonstrated that upper limb muscle quality has good accuracy in detecting dynapenia in both men and women.

Association between oral frailty and sarcopenia among frailty clinic outpatients: A cross-sectional study

OBJECTIVES

In this study, we aimed to investigate the prevalence of oral frailty and explore its relationship with oral function and sarcopenia among older outpatients.

MATERIALS AND METHODS

In this cross-sectional study, we retrospectively included older patients who visited a frailty outpatient clinic. We assessed total oral frailty employing, among other measures, oral diadochokinesis (/ta/ sound) for tongue-lip movement and tongue pressure. Patients who did not meet the cut-off values for three or more of these were classified as having oral frailty. Sarcopenia was assessed according to Asian Working Group for Sarcopenia 2019 criteria and analyzed for the relationship with oral function.

RESULTS

The mean ± standard deviation age of the 111 patients was 77.2 ± 5.7 y; 63 were women (57%). Fifteen patients (14%) had either sarcopenia or dynapenia. The overall prevalence of oral frailty was 38%, with no significant difference in its prevalence between the sarcopenia/dynapenia group (44%) and the robust (no sarcopenia/dynapenia) group (35%). The following oral function assessments significantly differed between the sarcopenia/dynapenia group and the robust group: median (interquartile range) total oral frailty score, 2 (2-4) and 2 (1-3) (P = 0.019); tongue-lip motor function, 5.4 ± 1.2 and 5.9 ± 1.2 times/s (P = 0.049); and tongue pressure, 27.3 ± 8.5 kPa and 31.7 ± 8.0 kPa (P = 0.009).

CONCLUSIONS

Approximately 40% of patients exhibited a decline in oral function regardless of the presence of sarcopenia. Sarcopenia and dynapenia may particularly affect tongue function. Although assessing patients for sarcopenia is crucial, separate evaluations of oral function should also be considered.

Relationship between progressive improvement in gait ability one year after discharge and skeletal muscle characteristics of stroke survivors

BACKGROUND

The clinical importance of skeletal muscle characteristics for improving gait ability of stroke survivors is increasing. We aimed to examine the association between muscle quantity and quality at discharge and changes in gait independence at the time of 1 year after discharge in patients with stroke.

METHODS

This prospective observational study included 100 patients with stroke who were admitted to a convalescent rehabilitation ward. We defined muscle quantity and quality operationally as muscle thickness and echo intensity observed in ultrasonography images, respectively, and measured quadriceps muscle on the paretic and non-paretic sides at the time of discharge. The outcome measured in our study was changes in gait independence 1 year after discharge, as assessed by the Functional Independence Measure gait assessment tool score.

RESULTS

Among the study participants, 23 (23.0 %) were assessed to have reduced gait independence, while 77 (77.0 %) were evaluated to have improved or maintained gait independence. Our multivariate logistic regression analysis revealed that only muscle quantity on the paretic side was significantly associated with an improvement or maintenance of gait independence (odds ratios 3.32; 95 % confidence interval 1.01-10.95; p = 0.049).

CONCLUSIONS

Our findings revealed that an improvement in gait independence 1 year after discharge was influenced by quadriceps muscle quantity on the paretic side at the time of discharge in patients with subacute stroke. This finding highlights the importance of lower limb muscle quantity on the paretic side as a clinically significant factor that influences the improvement in gait ability after hospital discharge.

Usefulness of point of care ultrasound in older adults: a multicentre study across different geriatric care settings in Spain and the United Kingdom

BACKGROUND

Point of care ultrasound (POCUS) is an imaging technique performed bedside. To date, few published studies have reported the usefulness of multiorgan POCUS in Geriatrics. The objective of this study was to describe the utility of multiorgan POCUS in the care of older adults admitted to geriatric care settings.

METHODOLOGY

Observational retrospective study of patients admitted to geriatric settings in Spain and UK. Multiorgan POCUS was performed when there was a specific clinical suspicion or unexplained torpid clinical course despite physical examination and complementary tests. A geriatrician with a certificate degree in comprehensive ultrasound and long-standing experience in POCUS carried out POCUS. All patients underwent multiorgan POCUS in a cephalo-caudal manner.

RESULTS

Out of 368 patients admitted to geriatric units, 29% met the inclusion criteria. Average age was 85.9 years (SD ± 6.1). POCUS identified 235 clinically significant findings (2.2 per patient). Findings were classified as 37.9% confirmed diagnosis, 16.6% ruled out diagnosis, 14.9% unsuspected relevant diagnoses and 30.6% clinical follow-ups. POCUS findings led to changes in pharmacological and non-pharmacological treatment in 66.3 and 69.2% respectively, resulted in completion or avoidance of invasive procedures in 17.8 and 15.9%, respectively, facilitating early referrals to other specialities in 14.9% and avoiding transfers in 25.2% of patients.

CONCLUSION

Multiorgan POCUS is a tool that aids in the assessment and treatment of patients receiving care in geriatrics units. These results show the usefulness of POCUS in the management of older adults and suggest its inclusion in any curriculum of Geriatric Medicine speciality training.

The extracellular-to-total body water ratio reflects improvement in the activities of daily living in patients who experienced acute stroke

OBJECTIVES

To determine the relationship between bioelectrical impedance analysis (BIA) parameters, including the extracellular water-to-total body water ratio (ECW/TBW), and the activities of daily living (ADL) improvement, in patients who experienced acute stroke.

MATERIALS AND METHODS

This retrospective cohort study included 307 patients (mean age, 72 years; 39 % female) who experienced acute stroke and were admitted to the stroke unit of the Nippon Medical School Hospital (Bunkyo-ku, Tokyo, Japan) between April 2021 and March 2022. The Functional Independence Measure (FIM) was assessed at initial rehabilitation and discharge, and FIM effectiveness was calculated as ADL improvement in the participating acute care hospitals. BIA markers included the skeletal muscle mass index (SMI), phase angle (PhA), and ECW/TBW. Multiple linear regression models were used to estimate the relationship between the FIM effectiveness and each BIA marker.

RESULTS

The mean (±SD) FIM effectiveness was 0.45 ± 0.36. The proportions of low SMI (male, <7.0 kg/m2; female, <5.7 kg/m2) and low PhA (male <5.36 degrees, female <3.85 degrees), were 48.9 % and 43.3 %, respectively. In addition, the proportions of of low (<0.36), normal (0.36-0.40), and high (>0.4) ECW/TBW ratios were 1.3 %, 78.5 %, and 20.2 %, respectively. After adjustments for demographic and clinical variables, low PhA, low ECW/TBW, and high ECW/TBW were all significantly associated with FIM effectiveness (P < 0.05), with β coefficients of -0.126, -0.089, and -0.117, respectively.

CONCLUSIONS

Low and High ECW/TBW and low PhA levels were negatively correlated with improvements in ADL. The ECW/TBW ratio may be an additional indicator of rehabilitation trainability in patients who experience acute stroke.

Association between physical fitness tests and neuromuscular properties

PURPOSE

While various fitness tests have been developed to assess physical performances, it is unclear how these tests are affected by differences, such as, in morphological and neural factors. This study was aimed to investigate associations between individual differences in physical fitness tests and neuromuscular properties.

METHODS

One hundred and thirty-three young adults participated in various general physical fitness tests and neuromuscular measurements. The appendicular skeletal muscle mass (ASM) was estimated by bioelectrical impedance analysis. Echo intensity (EI) was evaluated from the vastus lateralis. During submaximal knee extension force, high-density surface electromyography of the vastus lateralis was recorded and individual motor unit firings were detected. Y-intercept (i-MU) and slope (s-MU) from the regression line between the recruitment threshold and motor unit firing rate were calculated.

RESULTS

Stepwise multiple regression analyses revealed that knee extension strength could be explained (adjusted R2 = 0.712) by ASM (β = 0.723), i-MU (0.317), EI (- 0.177), and s-MU (0.210). Five-sec stepping could be explained by ASM (adjusted R2 = 0.212). Grip strength, side-stepping, and standing broad jump could be explained by ASM and echo intensity (adjusted R2 = 0.686, 0.354, and 0.627, respectively). Squat jump could be explained by EI (adjusted R2 = 0.640). Counter-movement jump could be explained by EI and s-MU (adjusted R2 = 0.631). On the other hand, i-MU and s-MU could be explained by five-sec stepping and counter-movement jump, respectively, but the coefficients of determination were low (adjusted R2 = 0.100 and 0.045).

CONCLUSION

Generally developed physical fitness tests were mainly explained by morphological factors, but were weakly affected by neural factors involved in performance.

Assessing muscle architecture with ultrasound: implications for spasticity

Botulinum Neurotoxin Type A (BoNT-A) injections using Ultrasound (US) guidance have led to research evaluating changes in muscle architecture. Controversy remains as to what constitutes increased Echo-Intensity (EI) in spastic muscles and whether this may affect outcomes. We aim to provide a narrative review of US muscle architecture changes following Central Nervous System (CNS) lesions and explore their relationship to spasticity. Medline, CINAHL, and Embase databases were searched with keywords: ultrasonography, hypertonia, spasticity, fibrosis, and Heckmatt. Three physicians reviewed the results of the search to select relevant papers. Reviews identified in the search were used as a resource to identify additional studies. A total of 68 papers were included. Four themes were identified, including histopathological changes in spastic muscle, effects of BoNT-A on the muscle structure, available US modalities to assess the muscle, and utility of US assessment in clinical spasticity. Histopathological studies revealed atrophic and fibro-fatty changes after CNS lesions. Several papers described BoNT-A injections contributing to those modifications. These changes translated to increased EI. The exact significance of increased muscle EI remains unclear. The Modified Heckmatt Scale (MHS) is a validated tool for grading muscle EI in spasticity. The use of the US may be an important tool to assess muscle architecture changes in spasticity and improve spasticity management. Treatment algorithms may be developed based on the degree of EI. Further research is needed to determine the incidence and impact of these EI changes in spastic muscles.

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.

Associations Between Cognitive Function and Muscle Quality Among Community-Dwelling Older Adults: A Cross-Sectional Study

OBJECTIVE

To investigate whether muscle quality is related to cognitive function in older adults living in the community.

METHODS

The participants were 40 community-dwelling older adults without a diagnosis of dementia (mean age, 78.85 ± 6.40 years; 31 women). The dependent variable was the score on the mild cognitive impairment (MCI) index of the Japanese version of the Neurobehavioral Cognitive Status Examination Five (range: 0-6; higher scores indicate MCI or possible dementia).

RESULTS

Multiple regression with Bayesian statistics was performed for analysis of muscle quality, as indicated by echo intensity (EI), with skeletal muscle mass index, gait speed, physical activity level, age, and sex as covariates. EI was significantly associated with the MCI index (expected a posterior = 0.04 [95% Bayesian confidence interval: 0.01, 0.07], t = 2.47, β = 0.41, p = 0.019).

CONCLUSIONS

The results suggest that EI may be related to the cognitive function of older adults living in the community. Future studies should examine whether focusing on EI can help prevent cognitive decline among older adults..

Association between dynapenia and cognitive decline in community-dwelling older Japanese adults: The IRIDE Cohort Study

AIM

Muscle mass and strength correlate with cognitive function; however, it remains unclear whether dynapenia (i.e., muscle weakness with preserved muscle mass) is relevant. This study aimed to explore whether dynapenia is associated with global cognitive function in community-dwelling older Japanese adults.

METHODS

This cross-sectional study used data from the Integrated Research Initiative for Living Well with Dementia Cohort Study, which pooled data from five community-based geriatric cohorts. Dynapenia was defined as muscle weakness without muscle mass loss according to the Asian Working Group for Sarcopenia criteria. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). An ordered logistic regression analysis was conducted with dynapenia as the exposure and with cognitive decline stages, defined as an MMSE score of 27-30 for normal cognition, 24-26 for possible cognitive decline, and <24 for cognitive decline, as the outcome, stratified by sex and adjusted for age, muscle mass, education, alcohol consumption, smoking habits, living alone, and non-communicable diseases.

RESULTS

We analyzed data for 3338 participants (2162 female) with preserved muscle mass. Of these, 449 (13.5%) had dynapenia, and 79 (2.4%) exhibited cognitive decline. Multivariate odds ratios (95% confidence interval) for cognitive decline among those with dynapenia, compared with those without dynapenia, were 1.51 (1.02-2.24) for males and 2.08 (1.51-2.86) for females.

CONCLUSIONS

Muscle weakness is associated with cognitive decline, even in individuals with preserved muscle mass. Further studies are needed to better understand the association between muscle weakness and cognitive decline over time in order to develop dementia prevention strategies for those with dynapenia. Geriatr Gerontol Int 2024; 24: 123-129.

Relationship between cognitive function and phase angle measured with a bioelectrical impedance system

PURPOSE

The purpose of this study was to investigate the relationship between cognitive function and phase angle (PhA), an indicator of muscle quality.

METHODS

This cross-sectional study enrolled outpatients who visited a memory clinic at the Nagoya University hospital from January 2016 to June 2022. We enrolled 153 participants with body composition measurements. Inclusion criteria were a Mini-Mental State Examination score of 20-30 and a clinical diagnosis of Alzheimer's dementia (AD) or amnesic mild cognitive impairment (aMCI). The background characteristics of the participants were compared according to AD and aMCI. Next, linear regression analysis was performed with PhA as the objective variable. In addition, logistic regression analysis was performed for AD diagnosis.

RESULTS

PhA was lower in the AD group (P = 0.009). In linear regression analysis, PhA consistently decreased with worsening ADAS score. In logistic regression analysis, high PhA was associated with absence of AD. Gender-specific analyses showed these associations existed only in men.

CONCLUSIONS

Our study of patients with AD and aMCI found that PhA decreased with worsening of cognitive function. Compared with aMCI, AD was associated with significantly lower PhA. Our results strengthen the limited evidence in the literature showing that low muscle quality is associated with poor cognitive function.

Cross-sectional association of skeletal muscle mass and strength with dietary habits and physical activity among first-year university students in Japan: Results from the KEIJI-U study

OBJECTIVE

Recently, the high prevalence of young Japanese individuals who are underweight has received attention because of the potential risk for sarcopenia. The aim of this study was to examine the prevalence and characteristics of sarcopenia in Japanese youth.

METHODS

In this cross-sectional study, we measured skeletal muscle mass using a multifrequency bioelectrical impedance analysis device and handgrip strength (HGS) and administered questionnaires on dietary habits and physical activity in 1264 first-year university students ages 18 to 20 y (838 men and 426 women). Sarcopenia was confirmed based on the presence of both low skeletal muscle mass and weak muscle strength.

RESULTS

In all, 145 men (17%) and 69 women (16%) were diagnosed as underweight. Sarcopenia was diagnosed in 8 men (1%) and 5 women (1%). There was a significantly higher prevalence of low skeletal muscle mass index (SMI) and/or weak HGS in underweight individuals than in those in other body mass index (BMI) ranges. The multivariate analyses indicated that SMI and HGS were significantly associated with BMI in both sexes. Furthermore, after adjusting for BMI, both SMI and HGS were significantly associated with physical activity in men, and SMI was significantly associated with energy intake in women.

CONCLUSIONS

First-year university students showed a high incidence of being underweight with low SMI and/or weak HGS, but the prevalence of sarcopenia was low in both sexes. There may be sex differences in factors related to muscle mass and strength, but further research is needed to clarify this.

Increased intramuscular adipose tissue of the quadriceps at admission is more strongly related to activities of daily living recovery at discharge compared to muscle mass loss in older patients with aspiration pneumonia

BACKGROUND

Recent studies reported that an increase in intramuscular adipose tissue of the quadriceps in older patients negatively affects the recovery of activities of daily living (ADL) more than the loss of muscle mass. However, whether intramuscular adipose tissue of the quadriceps in older patients with aspiration pneumonia is related to ADL recovery remains unclear. This study aimed to determine the relationship between intramuscular adipose tissue of the quadriceps and ADL recovery in older patients with aspiration pneumonia.

METHODS

Thirty-nine older inpatients who were diagnosed with aspiration pneumonia participated in this prospective study. The main outcome of this study was ADL at discharge. ADL were assessed using the Barthel Index (BI). The intramuscular adipose tissue and muscle mass of the quadriceps were evaluated at admission using echo intensity and muscle thickness observed on ultrasound images. A multiple linear regression analysis was performed to confirm whether the quadriceps echo intensity was related to the BI score at discharge, even after adjusting for confounding factors.

RESULTS

The medians [interquartile range] of the BI score at admission and discharge were 15.0 [0.0-35.0] and 20.0 [5.0-55.0], respectively. The BI score at discharge was significantly higher than that at admission (p = 0.002). The quadriceps echo intensity (β =  - 0.374; p = 0.036) and BI score at admission (β = 0.601; p < 0.001) were independently and significantly related to the BI score at discharge (R2 = 0.718; f2 = 2.546; statistical power = 1.000). In contrast, the quadriceps thickness (β =  - 0.216; p = 0.318) was not independently and significantly related to the BI score at discharge.

CONCLUSIONS

Increased intramuscular adipose tissue of the quadriceps at admission is more strongly and negatively related to ADL recovery at discharge than the loss of muscle mass among older patients with aspiration pneumonia. Interventions targeting the intramuscular adipose tissue of the quadriceps may improve ADL among these patients.

Motor unit firing patterns in older adults with low skeletal muscle mass

Muscular dysfunctions involving a decline in muscle strength are often induced by loss of muscle mass in older adults. Understanding neural activation in older adults in addition to muscular characteristics may be important to prevent such age-related dysfunctions. This study aimed to investigate the difference in motor unit firing patterns between community-dwelling older individuals with normal and low skeletal muscle mass. Sixty-six older adults (62-90 years) performed muscle strength and function tests. On conducting high-density surface electromyography of the vastus lateralis, individual motor unit firing properties were assessed. Individual motor units were divided into three different recruitment threshold groups and their firing rates were compared. The skeletal muscle quantity and quality were assessed using bioimpedance methods and ultrasound images. They were divided into two groups according to sarcopenia criteria: a normal group (n = 39) and presarcopenia group with low skeletal muscle mass but normal physical functions (n = 21). Skeletal muscle mass and muscle thickness were greater and echo intensity was lower in the normal group than presarcopenia group. Motor units in normal older adults fired at different rates with a hierarchy depending on their recruitment threshold, observed as a normal phenomenon. However, motor units in the presarcopenia group fired without showing the hierarchical pattern. The results suggest that older adults with low skeletal muscle mass exhibited an abnormal neural input pattern, in addition to declines in muscle quantity and quality.

Relationship between quadriceps muscle computed tomography measurement and motor function, muscle mass, and sarcopenia diagnosis

Background

The quadriceps muscle is one of the human body's largest and most clinically important muscles and is evaluated using mid-thigh computed tomography (CT); however, its relationship with motor function and sarcopenia remains unclear. Herein, we investigated the relationship between the cross-sectional area (CSA) of the quadriceps muscle, CT attenuation value (CTV), dual-energy X-ray absorptiometry muscle mass measurements, and muscle strength and motor function to evaluate the relationship between muscle mass loss and motor function decline, determine the diagnostic ability for sarcopenia, and confirm the usefulness of quadriceps muscle CT evaluation.

Methods

A total of 472 middle-aged and older community dwellers (254 men and 218 women) aged ≥40 years (mean age: 62.3 years) were included in this study. The quantity and quality of the quadriceps muscle were assessed using CSA and CTV (CSA×CTV) as a composite index multiplied by quality and quantity. Age-adjusted partial correlations by sex with eight motor functions (knee extension muscle strength, power, normal walking speed, fast walking speed, grip strength, sit-up ability, balance ability, and reaction time) were evaluated, including correction methods for height, weight, and body mass index (BMI). Further, the accuracy of sarcopenia diagnosis was evaluated using appendicular muscle mass with dual-energy X-ray absorptiometry measurements, grip strength, and walking speed as the gold standard, and receiver operating characteristic curves were plotted to evaluate diagnostic performance.

Results

In men, CSA and CSA×CTV were significantly associated with seven of the eight motor functions (p<0.05), excluding only balance ability. BMI-corrected CSA was significantly correlated with all eight motor functions in men and women (p<0.05). In the diagnosis of sarcopenia based on skeletal muscle index, CSA (area under the curve (AUC) 0.935) and CSA×CTV (AUC 0.936) and their correction by height (CSA/height (AUC 0.917) and CSA×CTV/height (AUC 0.920)) were highly accurate and useful for diagnosis in men but moderately accurate in women (CSA (AUC 0.809), CSA×CTV (AUC 0.824), CSA/height (AUC 0.799), CSA×CTV/height (AUC 0.814)).

Conclusion

The present results showed that a single CT image of the quadriceps muscle at the mid-thigh is useful for diagnosing sarcopenic changes, such as loss of muscle mass, muscle weakness, and muscle function.

Echo Intensity of Gastrocnemius Is Independently Associated with 6-Minute Walking Distance in Male Patients with Peripheral Arterial Disease

Background and Objectives: This study aimed to examine the differences in the thickness and echo intensity (EI) of the gastrocnemius muscle measured via ultrasonography between healthy adults and patients with peripheral arterial disease (PAD) and to determine the associations of gastrocnemius thickness (GT) and EI within a 6 min walking distance (6MD) in patients with PAD. Materials and Methods: This cross-sectional study targeted 35 male patients with PAD (mean age, 73.7 years; mean body mass index [BMI], 23.5 kg/m2) and age- and gender-matched 73 male healthy adults (mean age, 73.2 years; mean BMI, 23.3 kg/m2). The gastrocnemius thickness (GT) and EI were measured using ultrasound. Both legs of patients with PAD were classified based on higher and lower ankle brachial pressure index (ABI), and the GTs and EIs with higher and lower ABI were compared with those of healthy adults. Multiple regression analysis incorporated 6MD as a dependent variable and each GT and EI with higher and lower ABI, age, and BMI as independent variables. Results: This study showed that GT was considerably greater in healthy adults than in both legs with higher and lower ABI (median values, 13.3 vs. 11.3 vs. 10.7, p < 0.01), whereas EI was lower in healthy adults than in the lower ABI leg (72.0 vs. 80.8 vs. 83.6, p < 0.05). The 6MD was shown to be substantially related to EI in both legs with higher and lower ABIs (p < 0.01) but not in the GT. Conclusions: In patients with PAD, the GT was lower, and EI was higher than in healthy adults. In addition, EIs in both legs with higher and lower ABIs were independently associated with 6MD in male PAD patients. This study showed that the EI measured via ultrasonography could become an important indicator for treatments for patients with PAD.

Usefulness of muscle echo intensity for evaluating functional performance in the older population: A scoping review

Muscle echo intensity, as measured by ultrasonography, could be used as a new marker of functional performance in older populations. This scoping review aimed to present evidence on the utility of muscle echo intensity as determined by ultrasonography for assessing functional performance in older adults. The eligibility criterion included observational studies that investigated the associations between muscle echo intensity and functional performance in older adults. Terms, such as "echo intensity" and "older adults", were searched for in databases, such as PubMed, Web of Science, the Cochrane database of systematic reviews, and the Cumulative Index of Nursing and Allied Health Literature, in April 2021. Two independent reviewers screened and extracted the data; 46 papers, of which almost one-third were Japanese, were subsequently identified for inclusion. The representative functional performances included in this review were muscle strength, gait speed, sit-to-stand test results, and timed up-and-go test results. Poor to moderate associations were found between muscle echo intensity and functional performance; however, heterogeneities were observed in the characteristics of study participants. Moreover, the accurate effect size and causal inferences between muscle echo intensity and functional performance remained unclear. Further longitudinal studies are needed to determine these causal inferences.

Assessment and risk prediction of frailty using texture-based muscle ultrasound image analysis and machine learning techniques

The purpose of this study was to evaluate texture-based muscle ultrasound image analysis for the assessment and risk prediction of frailty phenotype. This retrospective study of prospectively acquired data included 101 participants who underwent ultrasound scanning of the anterior thigh. Participants were subdivided according to frailty phenotype and were followed up for two years. Primary and secondary outcome measures were death and comorbidity, respectively. Forty-three texture features were computed from the rectus femoris and the vastus intermedius muscles using statistical methods. Model performance was evaluated by computing the area under the receiver operating characteristic curve (AUC) while outcome prediction was evaluated using regression analysis. Models developed achieved a moderate to good AUC (0.67 ≤ AUC ≤ 0.79) for categorizing frailty. The stepwise multiple logistic regression analysis demonstrated that they correctly classified 70-87% of the cases. The models were associated with increased comorbidity (0.01 ≤ p ≤ 0.18) and were predictive of death for pre-frail and frail participants (0.001 ≤ p ≤ 0.016). In conclusion, texture analysis can be useful to identify frailty and assess risk prediction (i.e. mortality) using texture features extracted from muscle ultrasound images in combination with a machine learning approach.

Association of sarcopenia, pre-sarcopenia, and dynapenia with the onset and progression of locomotive syndrome in Japanese older adults: a cross-sectional study

BACKGROUND

Sarcopenia commonly occurs in older adults with motor disorders requiring long-term care, and the clinical features of sarcopenia are associated with locomotive syndrome. Dynapenia is the age-related loss of muscle strength. However, the association of sarcopenia and dynapenia with the onset and progression of locomotive syndrome in older adults remains unknown. The current study aimed to determine the association of sarcopenia, pre-sarcopenia, and dynapenia with the onset and progression of locomotive syndrome in Japanese older adults.

METHODS

This study included older females (n = 264, 73.9 ± 5.8 years) and males (n = 92, 76.3 ± 6.1 years). Sarcopenia was defined as low muscle function and mass; pre-sarcopenia was defined as low muscle mass with normal muscle function; and dynapenia was defined as low muscle function without low muscle mass. Locomotive syndrome (stage 0-2) severity was determined using the stand-up test, the two-step test, and the 25-question geriatric locomotive function scale. Logistic regression analysis was performed to determine the relationship between sarcopenia category and locomotive syndrome stages.

RESULTS

Age (1.208, 95% confidence interval (CI) 1.124-1.298), sex (2.455, 95% CI 1.241-4.856), and BMI (1.211, 95% CI 1.077-1.361) were significant variables for determining locomotive syndrome stage ≥ 1, whereas pre-sarcopenia (0.543, 95% CI 0.331-0.891) and sarcopenia (1.664, 95% CI 1.005-2.755) were significant variables for determining locomotive syndrome stage 2.

CONCLUSIONS

Only sarcopenia was associated with locomotive syndrome progression, while low muscle mass or low muscle function was not associated with locomotive syndrome. Gaining muscle mass accompanied by an increased muscle function for older adults is warranted to prevent locomotive syndrome progression in the super-aged society.

Suggestions on the ideal method of conducting community screenings for older adults

BACKGROUND/OBJECTIVES

Since dementia and frailty lead to a reduced quality of life and risk of needing long-term care in the older adults, we hypothesized that evaluations related to dementia and frailty would be useful and of high interest in screening for the older adults. Therefore, we conducted a community screening incorporating multiple simple evaluations related to dementia and frailty. In addition to various functional evaluations, we investigated interest in tests, thoughts on the disease, and the relationships between subjective (i.e., how one feels about oneself) and objective evaluations (i.e., the results of tests and rating scales). The purpose of this study was to examine the thoughts regarding tests and diseases and the functions that make it difficult to accurately perceive changes by oneself, and to obtain suggestions on the ideal method of community screening for the older adults.

SUBJECTS/METHODS

The participants were 86 people aged 65 and over living in Kotoura Town who participated in the community screening, for which we obtained background information and body measurements. We also assessed physical, cognitive and olfactory function, evaluated nutritional status, and we administered a questionnaire (interest in tests, thoughts on dementia and frailty, and a subjective functional evaluation).

RESULTS

Regarding interest in tests, the participants answers were highest for physical, cognitive and olfactory function, in that order (68.6%, 60.5%, and 50.0%, respectively). In the survey on thoughts on dementia and frailty, 47.6% of participants felt that people with dementia were viewed with prejudice, and 47.7% did not know about frailty. Regarding the relationship between subjective and objective evaluations, only the assessment of cognitive function did not show a correlation between both evaluations.

CONCLUSIONS

From the viewpoint of the participants' degree of interest in and the need for accurate evaluations through objective examination, the findings suggest that the assessment of physical and cognitive function may be beneficial as a screening tool for older adults. Objective evaluation is essential, particularly for assessing cognitive function. However, approximately half the participants believed people with dementia were viewed with prejudice and did not know about frailty, which may lead to barriers to testing and low interest. The importance of increasing the participation rate in community screening through disease-related educational activities was suggested.

Muscle strength rather than appendicular skeletal muscle mass might affect spinal sagittal alignment, low back pain, and health-related quality of life

Sarcopenia is defined as decreasing in muscle strength and mass, and dynapenia is defined as decreasing in muscle strength and maintained muscle mass. This study elucidated the prevalence and characteristics of sarcopenia and dynapenia and evaluate in elderly spinal disorders patients. 1039 spinal disorders patients aged ≥ 65 years were included. We measured age, grip strength, muscle mass, spinal sagittal alignment parameters, low back pain (LBP) scores and health-related quality of life (HR-QoL) scores. Based on the previous reports, patients were categorised into normal group: NG, pre-sarcopenia group: PG, dynapenia group: DG, and sarcopenia group: SG. Pre-sarcopenia, dynapenia, and sarcopenia were found in 101 (9.7%), 249 (19.2%), and 91 (8.8%) patients, respectively. The spinal sagittal alignment parameters, trunk muscle mass, LBP, and HR-QoL scores were significantly worse in DG and SG compared with those in PG and NG. Spinal alignment, trunk muscle mass, and clinical outcomes, including LBP and HR-QoL scores, were maintained in the PG and poor in the DG and SG. Thus, intervention for muscle strength may be a treatment option for changes of spinal sagittal alignment and low back pain.

The impact of acute skeletal muscle loss after gastrointestinal cancer surgery on physical function

INTRODUCTION

Significant skeletal muscle loss occurs commonly after cancer surgery; however, the impact of postoperative acute skeletal muscle loss on physical function remains poorly understood.

OBJECTIVE

To determine the impact of surgery-associated acute skeletal muscle wasting on physical function in the early postoperative period in patients with gastrointestinal cancer.

DESIGN

A single-center retrospective observational study.

SETTING

General hospital.

PATIENTS

Hospitalized patients with gastrointestinal cancer who were admitted for surgery.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

The main outcome was the partial correlation between postoperative changes in skeletal muscle index (SMI) and physical function such as handgrip strength, gait speed, and 6-minute walk test.

RESULTS

A total of 69 patients (41 male and 28 female) with a mean age of 70.5 years were included. SMI was significantly correlated with physical function, such as handgrip strength (r = 0.757, p < .001), maximum gait speed (r = 0.318, p = .008), and 6-minute walk test (r = 0.365, p = .002) before surgery. In contrast, partial correlation analysis between the absolute changes in SMI and physical function after controlling for SMI and each physical function before surgery showed no significant correlation. Multivariable linear regression analyses also showed that postoperative change in SMI was not significantly associated with the postoperative change in physical function but it was associated with the length of stay after surgery, SMI at admission, and absolute change in body fat percentage.

CONCLUSIONS

The absolute change in SMI during the early postoperative period was not linearly correlated with the degree of decline in physical function. Further studies are necessary to investigate the effects of the respective changes in skeletal muscle mass and physical function on clinical outcomes.

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.

The Efficacy of Biological Disease-modifying Antirheumatic Drugs on Sarcopenia in Patients with Rheumatoid Arthritis

Objective Sarcopenia is characterized by a loss of muscle mass and strength, which leads to frailty and mortality. Rheumatoid arthritis (RA) is considered to be a cause of sarcopenia. The present study assessed the effectiveness of biological disease-modifying antirheumatic drugs (bDMARDs) on sarcopenia. Methods This was a prospective cohort study including 48 patients [11 men, 37 women; 67.5 (57.0-74.8) years old] with RA who started bDMARDs in Niigata Rheumatic Center. We monitored the physical ability, nutritional status and body composition at the baseline, 6 months and 12 months. The physical activity was measured by the Health Assessment Questionnaire (HAQ) and 10-m walking test (10MWT). The nutritional status was assessed by the controlling nutrition status (CONUT) score. Results Among the 48 patients who started bDMARDs, 21 were classified as having sarcopenia. The physical activity and nutritional status were significantly ameliorated after 12 months of bDMARDs. The body composition analysis showed a significant increase in the body weight but no significant increase in the skeletal muscle mass index. The proportion of patients diagnosed with sarcopenia decreased significantly after 12 months of bDMARDs (43.8% vs. 27.1%, p=0.039). Among the 21 patients who were diagnosed with sarcopenia when starting bDMARDs, the skeletal muscle index was significantly increased after 12 months of bDMARDs. [5.22 (4.76-5.43) kg/m² vs. 5.44 (4.84-5.77), p=0.039]. Conclusion Biologics may be useful in the treatment of sarcopenia through mechanisms such as improving the disease activity, physical activity and nutritional status.

Muscular Echo-Intensity of the Quadriceps by Ultrasound Is More Related to Improvement of Gait Independence than Muscle Thickness in Older Inpatients

OBJECTIVES

This study aimed to examine whether the decrease in muscular echo-intensity of the quadriceps by ultrasound in older inpatients is related to the improvement of gait independence than the increase of muscle thickness.

DESIGN

Longitudinal study.

SETTING

Hospital-based study.

PARTICIPANTS

This study included 171 inpatients aged ≥ 65 years (median age: 84.0 [77.0-88.0], 56.1% female). Patients who were able to walk independently at hospital admission were excluded from the study.

MEASUREMENTS

Improvement of gait independence during hospital stay was assessed using the change in Functional Independence Measure (FIM) gait score (i.e., FIM gait score at hospital discharge minus FIM gait score at hospital admission) and FIM gait score at hospital discharge. Muscular echo-intensity and muscle thickness of the quadriceps were assessed at hospital admission and discharge using ultrasound images, respectively. Muscular echo-intensity has been shown to be mainly related to intramuscular adipose tissue. Multiple linear regression analysis was performed to identify the factors independently associated with the change in FIM gait score and FIM gait score at discharge.

RESULTS

Change in quadriceps echo-intensity was independently and significantly associated with the change in FIM gait score (β = -0.22, p = 0.017) and FIM gait score at hospital discharge (β = -0.21, p = 0.017). In contrast, change in quadriceps thickness was not independently and significantly associated with the change in FIM gait score (β = 0.16, p = 0.050) and FIM gait score at hospital discharge (β = 0.15, p = 0.050).

CONCLUSIONS

Our study indicates that a decrease in muscular echo-intensity of the quadriceps by ultrasound is more related to the improvement of gait independence than an increase of muscle thickness in older inpatients. Intervention for intramuscular adipose tissue of the quadriceps may be important for improving gait independence in older inpatients.

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.

Machine learning-based muscle mass estimation using gait parameters in community-dwelling older adults: A cross-sectional study

BACKGROUND

Loss of skeletal muscle mass is associated with numerous factors such as metabolic diseases, lack of independence, and mortality in older adults. Therefore, developing simple, safe, and reliable tools for assessing skeletal muscle mass is needed. Some studies recently reported that the risks of the incidence of geriatric conditions could be estimated by analyzing older adults' gait; however, no studies have assessed the association between gait parameters and skeletal muscle loss in older adults. In this study, we applied machine learning approach to the gait parameters derived from three-dimensional skeletal models to distinguish older adults' low skeletal muscle mass. We also identified the most important gait parameters for detecting low muscle mass.

METHODS

Sixty-six community-dwelling older adults were recruited. Thirty-two gait parameters were created using a three-dimensional skeletal model involving 10-meter comfortable walking. After skeletal muscle mass measurement using a bioimpedance analyzer, low muscle mass was judged in accordance with the guideline of the Asia Working Group for Sarcopenia. The eXtreme gradient boosting (XGBoost) model was applied to discriminate between low and high skeletal muscle mass.

RESULTS

Eleven subjects had a low muscle mass. The c-statistics, sensitivity, specificity, precision of the final model were 0.7, 59.5%, 81.4%, and 70.5%, respectively. The top three dominant gait parameters were, in order of strongest effect, stride length, hip dynamic range of motion, and trunk rotation variability.

CONCLUSION

Machine learning-based gait analysis is a useful approach to determine the low skeletal muscle mass of community-dwelling older adults.

Gait Characteristics of Dynapenia, Sarcopenia, and Presarcopenia in Community-Dwelling Japanese Older Women: A Cross-Sectional Study

Age-related decline in skeletal muscle mass and function are risk factors for reduced walking ability. This study aimed to understand the characteristic gait parameters of presarcopenia (low muscle mass only), dynapenia (low muscle function only), and sarcopenia (low muscle mass and function), which have differing skeletal muscle characteristics. Skeletal muscle mass, grip strength, and gait parameters (walking speed, cadence, step length, step width, gait angle, foot angle, stance time, swing time, and double stance time) were evaluated in 307 older Japanese women. Low muscle function was determined by grip strength and normal walking speed. Participants were assessed and divided into the normal (60.9%, n = 187), presarcopenia (25.7%, n = 79), dynapenia (5.2%, n = 16), and sarcopenia (8.1%, n = 25) groups. When compared to the normal group, the sarcopenia group had significantly slower walking speed and shorter step length (p < 0.05); the dynapenia group had significantly slower walking speed, smaller cadence, shorter step length, wider step width, and longer stance time (p < 0.05); and the presarcopenia group showed no differences. Skeletal muscle function may therefore be more strongly related to reduced walking function in older adults than body composition factors. The decrease in walking function was most pronounced in older women with dynapenia.

Combined effect of lower muscle quality and quantity on incident falls and fall-related fractures in community-dwelling older adults: A 3-year follow-up study

OBJECTIVE

Falls and fractures are serious geriatric adverse events worldwide, and skeletal muscle is considered to be a key factor in these incidents. The objective of this study was to investigate the combined effect of lower muscle quality and quantity on the incidence of falls and fall-related fractures in a 3-year follow-up period among community-dwelling older adults.

METHODS

We recruited community-dwelling adults aged 65 years and older who were living independently in 2018. A total of 773 older participants were analyzed in this study. The outcomes were incident falls and fall-related fractures during the 3-year follow-up period. At baseline, we assessed muscle quality and quantity using ultrasonography, and we categorized the participants into four groups based on their combination of poor/better muscle quality and poor/better muscle quantity. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of the relationships among items in the four groups and the time to incident falls and fall-related fractures.

RESULTS

During the 3-year follow-up period, 178 participants (23.0 %) had a fall incident and 51 participants (6.6 %) had fall-related fractures. Older adults with lower muscle quality and quantity had significantly elevated risks of incident falls according to multivariate analyses using older adults with better muscle quality and quantity as the reference (adjusted HR: 1.54 [95 % CI 1.06-2.23]). However, there were no significant differences in fall-related fractures among the four groups.

CONCLUSION

We found that lower muscle quality and quantity led to higher incidents of falls; thus, identifying community-dwelling older adults with lower muscle quality and quantity is necessary to provide them fall preventive measures and maybe to reduce fall-related outcomes.

Relationships between cystatin C and creatinine‐based eGFR with low tongue pressure in Japanese rural community‐dwelling older adults

Background

Sarcopenia is prevalent in patients with chronic kidney disease (CKD), which is defined as a low estimated glomerular filtration rate (eGFR). It has been reported that oral hypofunction characterized by decreased tongue pressure is related to sarcopenia. Although there are several previous reports regarding the association of renal dysfunction with oral hypofunction characterized by low tongue pressure, the association between tongue pressure and renal function is not fully understood.

Methods

This cross‐sectional study included 68 men aged 79.0 ± 4.8 years and 145 women aged 77.3 ± 5.4 years from a rural area in Hyogo Prefecture, Japan. We examined the relationships between cystatin C‐based CKD (CKDcys), creatinine‐based CKD (CKDcre), ratio of cystatin C‐based GFR (eGFRcys) divided by creatinine‐based GFR (eGFRcre): eGFRcys/eGFRcre, and tongue pressure in community‐dwelling older adults.

Results

Tongue pressure was significantly lower in participants with CKDcys than in those without CKDcys in men and women. However, there were no significant differences in tongue pressure with or without CKDcre. Tongue pressure was significantly lower in participants with eGFRcys/eGFRcre <1.0, than in those with eGFRcys/eGFRcre ≧ 1.0 in men. According to the receiver operating characteristic analysis, the optimal cut‐off value of tongue pressure for the presence of CKDcys was 36.6kPa, area under the curve (AUC) 0.74 (specificity 54.8%, sensitivity 84.6%) in men and 31.8kPa, AUC 0.65 (specificity 67.3%, sensitivity 60.5%) in women.

Conclusions

CKDcys but not CKDcre is associated with low tongue pressure. In addition, a lower eGFRcys/eGFRcre ratio is a useful screening marker of low tongue pressure in community‐dwelling older adults.

Cognitive function is associated with home discharge in subacute stroke patients: a retrospective cohort study

Aim

To investigate the cognitive function and its relation to the home discharge of patients following subacute stroke.

Methods

This retrospective cohort study included 1,229 convalescent patients experiencing their first subacute stroke. We determined discharge destination and demographic and clinical information. We recorded the following measurement scores: Mini-Mental State Examination (MMSE) score, Stroke Impairment Assessment Set score, grip strength, and Functional Independence Measure (FIM). We performed a multivariable logistic regression analysis with the forced-entry method to identify factors related to home discharge.

Results

Of the 1,229 participants (mean age: 68.7 ± 13.5 years), 501 (40.8%), 735 (59.8%), and 1,011 (82.3%) were female, had cerebral infarction, and were home discharged, respectively. Multivariable logistic regression analysis revealed that age (odds ratio [OR], 0.93; 95% confidence interval [CI], 0.91 – 0.96; P < 0.001), duration from stroke onset to admission (OR, 0.98; 95% CI, 0.96 – 0.99; P = 0.003), living situation (OR, 4.40; 95% CI, 2.69 – 7.20; P < 0.001), MMSE score at admission (OR, 1.05; 95% CI, 1.00 – 1.09; P = 0.035), FIM motor score at admission (OR, 1.04; 95% CI, 1.01 – 1.06; P = 0.001), and FIM cognitive score at admission (OR, 1.08; 95% CI, 1.04 – 1.13; P < 0.001) were significantly associated with home discharge.

Conclusions

MMSE at admission is significantly associated with home discharge in patients with subacute stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02745-8.

Association of strength, power, and function with muscle thickness, echo intensity, and lean tissue in older males

Dual-energy X-ray absorptiometry (DXA) appendicular lean tissue is used to screen older adults for sarcopenia. However, emerging data indicates that ageing-related muscle atrophy largely occurs within specific muscles, which may be masked using appendicular lean tissue. Comparisons between appendicular lean tissue and site-specific measures of muscle in relation to strength and physical function are needed to advance our understanding of these features in the context of poor muscle function in aged adults. Our primary objective was to compare correlations between lean tissue and site-specific muscle characteristics in relation to strength and physical function in older males. Older males (≥65 years) were evaluated for muscle strength, physical function (6-minute walk and 30-second sit-to-stand), and muscle size (appendicular and site-specific) and composition (echo intensity) using DXA and ultrasound. Of the 32 older males (75.4 ± 7.9 years), 12 had low appendicular lean tissue. All DXA and ultrasound muscle characteristics were associated (r = 0.39 to 0.83, p < 0.05) with torque or power producing capabilities. Except for the knee flexors, no differences in correlation coefficients were observed between muscle thickness or regional lean tissue in relation to muscle strength. Neither DXA nor ultrasound muscle characteristics were associated with physical function. In older males, ultrasound-based muscle thickness and DXA lean tissue provided similar associations with strength. Novelty: Lean tissue and muscle thickness provide similar associations with strength. Muscle thickness can distinguish low and normal appendicular lean tissue in older adults.

Body Composition Characteristics of Community-Dwelling Older Adults With Dynapenia or Sarcopenia

This study aimed to determine the differences in muscle and fat masses of the arm and leg between older adults with dynapenia, sarcopenia, or presarcopenia and normal individuals. The percent body fat, lean body mass, and skeletal mass index were measured with bioelectrical impedance analysis. Muscle function was evaluated using grip strength and walking speed. Participants were classified into four categories. Dynapenia was defined as low muscle function with normal muscle mass. Sarcopenia was defined as the presence of both low muscle mass and low muscle function. Presarcopenia was defined as low muscle mass with normal muscle function. Control was defined as normal muscle mass and function. Multivariate analyses of variance were performed separately for women and men to test the main effect of sarcopenia category on body composition. Among the 356 enrolled participants, 270 were women, and 86 were men. In older women, the dynapenia and sarcopenia groups had significantly less muscle mass in the leg than the control group. In older men, the dynapenia group demonstrated a higher body fat mass in the leg than the control group. These results suggest that different strategies are necessary to prevent dynapenia in women and men.

The relationship between dynapenia and vitamin D level in geriatric women with type 2 diabetes mellitus

Objective

In this study, we examined the possible relationship between dynapenia and vitamin D (VD) levels in geriatric women with type 2 diabetes mellitus (T2DM).

Methods

One hundred and twenty-two geriatric female patients aged 65-80 years with a diagnosis of T2DM were included in this prospective study. Physical examinations of the patients were performed, and biochemical tests were analyzed. The muscle strength of the patients was measured with a hand dynamometer. Dynapenia was defined as low grip strength with normal skeletal muscle mass index. In muscle strength measurements, for female patients, over 20 kg was accepted as normal and below 20 kg as decreased muscle strength. Patients were separated into three groups as <10 ng/ml, 10-30 ng/ml, and >30 ng/ml according to VD levels; according to the status of dynapenia, they were divided into two groups as dynapenic and non-dynapenic. By comparing all these parameters between these groups, the relationship between VD level and dynapenia was evaluated. In statistical analysis, significance was accepted as p<0.05.

Results

While 54 of the patients (44.3%) met the dynapenia criterion, 68 patients (55.7%) were non-dynapenic. Patients were first compared according to their dynapenia status. VD level was significantly lower in the dynapenic group (p<0.05). In the correlation analysis, a moderate positive correlation was found between muscle strength and VD (p=0.033, r: 0.23). The patients were then compared according to the VD groups. In the VD insufficient group, muscle strength (p=0.015), body mass index (p=0.025), systolic blood pressure (p<0.01), and glucose (p<0.01) were statistically significantly higher.

Conclusion

In the present study, we found a considerable relationship between VD levels and dynapenia in geriatric women with T2DM.

Prediction Model including Gastrocnemius Thickness for the Skeletal Muscle Mass Index in Japanese Older Adults

Non-invasive and easy alternative methods to indicate skeletal muscle mass index (SMI) have not been established when dual energy X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) cannot be performed. This study aims to construct a prediction model including gastrocnemius thickness using ultrasonography for skeletal muscle mass index (SMI). Total of 193 Japanese aged ≥65 years participated. SMI was measured by BIA, and subcutaneous fat thickness and gastrocnemius thickness in the medial gastrocnemius were measured by using ultrasonography, and age, gender and body mass index (BMI), grip strength, and gait speed were collected. The stepwise multiple regression analysis was conducted, which incorporated SMI as a dependent variable and age, gender, BMI, gastrocnemius thickness, and other factors as independent variables. Gender, BMI, and gastrocnemius thickness were included as significant factors, and the formula: SMI = 1.27 × gender (men: 1, women: 0) + 0.18 × BMI + 0.09 × gastrocnemius thickness (mm) + 1.3 was shown as the prediction model for SMI (R = 0.89, R2 = 0.8, adjusted R2 = 0.8, p < 0.001). The prediction model for SMI had high accuracy and could be a non-invasive and easy alternative method to predict SMI in Japanese older adults.

Differences in lower limb muscle strength and balance ability between sarcopenia stages depend on sex in community-dwelling older adults

AIM

This study aimed to compare motor function between sarcopenia stages with respect to sex in community-dwelling older adults.

METHODS

The participants, comprising 2107 community-dwelling older adults (738 men and 1369 women), were classified into 4 groups and the groups were operationally defined-normal, low muscle mass, low physical function, and sarcopenia groups. Lower limb muscle strength and balance ability were assessed for evaluating motor function. To compare motor function between sarcopenia stages, an analysis of covariance adjusted for age and body mass index was performed.

RESULTS

Lower limb muscle strengths were significantly lower not only in the sarcopenia group but also in the low muscle mass and low physical function groups than that in the normal group in both men and women. Low hip abductor muscle strength was observed in the low physical function group compared to the low muscle mass group in women, but not in men. Timed Up and Go test results in the sarcopenia and low function groups was lower than in the normal and low muscle mass groups for men and women. One-leg standing in the low physical function group was lower than that in the normal group, only for women.

CONCLUSIONS

Reduced motor function was observed not only in older people with sarcopenia but also in older people with only low muscle mass or low physical function, and the decline in lower limb muscle strength and balance ability in the low function group were greater in older women than in older men.

Risk Factor Analysis for Fat Infiltration in the Lumbar Paraspinal Muscles in Patients With Lumbar Degenerative Diseases

Introduction

This study aimed to investigate factors related to fat infiltration in patients with lumbar degenerative diseases (lumbar disc herniation and/or spinal stenosis), examining a wide range of potential risk variables.

Materials and methods

We studied consecutive adult patients who underwent posterior lumbar spinal surgery for degenerative diseases at our hospital between July 2013 and June 2017. Preoperative magnetic resonance imaging was used to evaluate the presence or absence of fat infiltration at the level of the L4-5 lumbar paraspinal muscles using Kjaer’s evaluation method. Patients without fat infiltration (0%–10%) were rated as grade 0, grade 1 for moderate fat infiltration (10%–50%), and grade 2 for severe fat infiltration (>50%). Patients were then divided into two groups: Group A (without fat infiltration, grade 0) and Group B (with fat infiltration, grade 1 or 2). Detailed patient clinical data were collected and analyzed.

Results

A total of 205 consecutive patients were enrolled; 54 (26.3%) patients were assigned to Group A and 151 (73.7%) to Group B. Logistic regression analysis revealed two independent risk factors for fat infiltration of the lumbar paraspinal muscles: female sex and older age (P < .001).

Discussion

Fat infiltration of the lumbar paraspinal muscles is reported to be associated with the development of pain and dysfunction of the lumbar region and postoperative complications of spinal instrumented fusion surgery. To the best of our knowledge, no previous studies have identified female sex and older age as independent risk factors for fat infiltration in the lumbar paraspinal muscles using multivariate analysis.

Conclusions

Female sex and older age were independent risk factors for fat infiltration in the lumbar paraspinal muscles. The results of the current study may provide useful information for the study of preventive measures for fat infiltration.

Diagnostic Performance of Muscle Echo Intensity and Fractal Dimension for the Detection of Frailty Phenotype

To determine the relationship between muscle echo intensity (EI) and fractal dimension (FD), and the diagnostic performance of both ultrasound parameters for the identification of frailty phenotype. A retrospective interpretation of ultrasound scans from a previous cohort (November 2014-February 2015) was performed. The sample included healthy participants <60 years old, and participants ≥60 divided into robust, pre-frail, and frail groups according to Fried frailty criteria. A region of interest of the rectus femoris from the ultrasound scan was segmented, and histogram function was applied to obtain EI. For fractal analysis, images were processed using two-dimensional box-counting techniques to calculate FD. Statistical analyses were performed with diagnostic performance tests. A total of 102 participants (mean age 63 ± 16, 57 men) were evaluated. Muscle fractal dimension correlated with EI (r = .38, p < .01) and showed different pattern in the scatter plots when participants were grouped by non-frail (control + robust) and frail (pre-frail + frail). The diagnostic accuracy for EI to categorize frailty was of 0.69 (95%CI: 0.59-0.78, p = .001), with high intra-rater (ICC: 0.98, 95%CI: 0.98-0.99); p < .001) and inter-rater (ICC: 0.89, 95%CI: 0.75-0.95; p < .001) reliability and low measurement error for both parameters (EI: -0.18, LOA95%: -10.8 to 10.5; FD: 0.00, LOA95%: -0.09 to 0.10) in arbitrary units. The ROC curve combining both parameters was not better than EI alone (p = .18). Muscle FD correlated with EI and showed different patterns according to frailty phenotype, with EI outperforming FD as a possible diagnostic tool for frailty.

Associations of alpha-actinin-3 genotype with thigh muscle volume and physical performance in older adults with sarcopenia or pre-sarcopenia

BACKGROUND

This cross-sectional study aimed to investigate the relationship of the ACTN3 genotype with thigh muscle volume and physical performance in older adults with sarcopenia or pre-sarcopenia.

METHODS

Data from 64 older Japanese adults (mean age 74.4 ± 6.9 years, women 71.9%) with sarcopenia or pre-sarcopenia were analyzed. Sarcopenia and pre-sarcopenia were defined using the Asian Working Group for Sarcopenia. We collected oral mucosa samples to determine the ACTN3 genotype. Thigh muscle volumes were measured using magnetic resonance imaging. Physical performance was assessed using the usual and maximum gait speed, timed up and go test, and five-repetition sit-to-stand test. Muscle strength was assessed using grip strength.

RESULT

The ACTN3 genotype proportions were 20.3% for RR, 51.6% for RX, and 28.1% for XX. Participants with the RR genotype showed greater thigh muscle volume/ht² compared to those with the RX and XX ACTN3 genotypes (p < 0.05). The multiple linear regression analysis revealed that RX (p < 0.01) and XX (p < 0.01) ACTN3 genotypes, compared to RR, were associated with lower thigh muscle volume/ht² and with age, sex (reference; men), weight and maximum walking speed. There was no significant difference between physical performance and muscle strength between the ACTN3 genotypes.

CONCLUSION

The ACTN3 genotype of the X allele was associated with decreased thigh muscle volume compared to the ACTN3 genotype of RR in older adults with sarcopenia or pre-sarcopenia.

Comparisons of muscle thicknesses, echo intensities, and motor functions between community-dwelling older Japanese adults with and without diabetes

BACKGROUND

Individuals with diabetes tend to show decreased muscle volume and motor function compared to those without diabetes. Ultrasound is a non-invasive and potentially safe method to assess muscle function in patients with diabetes; however, the characteristics of muscle thickness and quality, measured by ultrasound, in individuals with diabetes are unclear.

METHODS

This study included 825 community-dwelling older individuals who underwent the Otassha Study comprehensive health survey. We measured the muscle thicknesses and echo intensities of rectus femoris and vastus intermedius; motor function, assessed using knee extension strength; one-leg standing balance; normal walk; fastest walk; timed up-and-go test; and grip strength. Participants were stratified by sex and categorized into those with and without diabetes. We examined inter-group differences in measured values.

RESULTS

Only knee extension strength showed significantly lower values in men with diabetes than in those without diabetes. Echo intensities and motor function significantly differed between women with and without diabetes. In adjusted multiple comparisons p values, echo intensities and grip strength significantly differed only in women with diabetes, unlike men with diabetes. Echo intensity of the rectus femoris was significantly higher in women with diabetes than in those without diabetes after adjusting for confounders, but similar to that in men.

CONCLUSION

We observed the deterioration of knee extension strength in men and women with diabetes compared to that in those without diabetes; however, the effects on muscle quality were inconsistent between the sexes. Our study suggested recommending exercise programs, especially for older women with diabetes.