Measuring and Monitoring Skeletal Muscle Mass after Stroke: A Review of Current Methods and Clinical Applications

Association between changes in disease severity and physical function after surviving a critical illness: A multicentre retrospective observational study

BACKGROUND

Whilst disease severity can significantly impact functional outcomes, the ability to predict the scale of this impact has not been consistent.

AIM

We aimed to investigate whether changes in disease severity within the first 48 h of ICU admission are more strongly associated with physical dysfunction than a single-time assessment of disease severity at ICU admission.

METHODS

A multicentre retrospective study in seven tertiary ICUs in Japan, including all consecutive adult ICU patients (>48 h ICU stay) between September 2019 and February 2020. The primary outcome was physical function defined as the Barthel Index, which is an ordinal scale (0-100: larger indicates better function) to measure physical independence and performance. The association between Barthel Index score at hospital discharge and the Sequential Organ Failure Assessment (SOFA) scores, measured at ICU admission, the highest recorded score within 48 h of ICU admission, and the level of change between these two timepoints were investigated in multivariable analysis.

RESULTS

A total of 199 patients were included. Median SOFA score at ICU admission and the highest recorded score within the first 48 h were 6 (interquartile range: 5-10) and 8 (interquartile range: 6-11), respectively. A quarter of patients had a Barthel Index score of 60 or less at hospital discharge. The highest SOFA score within 48 h of ICU admission and the level of change in SOFA scores between ICU admission and the highest recorded score within 48 h were significantly associated with lower Barthel Index scores at hospital discharge. No significant association was identified with regard to Barthel Index scores and SOFA score at ICU admission. An increase in SOFA score of 1 or more within the first 48 h of ICU admission was the threshold to predict a Barthel Index score of 60 or less at hospital discharge. Larger changes in SOFA scores over the first 48 h of ICU admission were also significantly associated with smaller changes in Barthel Index scores from ICU discharge to hospital discharge.

CONCLUSIONS

The level of change in SOFA score between ICU admission and the highest recorded score within the first 48 h of ICU stay can more accurately predict the presence of physical dysfunction at hospital discharge than a single-time assessment of disease severity at ICU admission. The larger worsening in SOFA potentially indicates lower recovery after a critical illness.

Muscle mass as a modifier of stress response in acute ischemic stroke patients

Stroke triggers a systemic inflammatory response over the ensuing days after the cerebral insult. The age and comorbidities of the stroke population make them a vulnerable population for low muscle mass and sarcopenia, the latter being another clinical condition that is closely associated with inflammation, as shown by increased levels of pro-inflammatory biomarkers, including neutrophil-to-lymphocyte ratio (NLR). In this study, we evaluated the relationship between post-stroke NLR changes and muscle mass in a prospective cohort of acute ischemic stroke patients (n = 102) enrolled in the Muscle Assessment in Stroke Study Turkey (MASS-TR). Admission lumbar computed tomography images were used to determine the cross-sectional muscle area of skeletal muscles at L3 vertebra level and calculate the skeletal muscle index (SMI). The median (IQR) SMI was 44.7 (39.1-52.5) cm2/m2, and the NLR at admission and follow-up were 4.2 (3.0-10.5) and 9.4 (5.7-16.2), respectively. While there was no relationship between SMI and admission NLR, a significant inverse correlation was observed between SMI and follow-up NLR (r =  - 0.26; P = 0.007). Lower SMI remained significantly associated (P = 0.036) with higher follow-up NLR levels in multivariate analysis. Our findings highlight the importance of muscle mass as a novel factor related to the level of post-stroke stress response.

Improvements of mid-thigh circumferences following robotic rehabilitation in hemiparetic stroke patients

INTRODUCTION

Stroke has emerged as the leading cause of disability globally. The provision of long-term rehabilitation to stroke survivors poses a health care burden to many countries. Robotic devices have created a major turning point in stroke rehabilitation program. Currently, the anthropometric evidence to support the benefit of robotic rehabilitation (RR) among stroke patients is scarce. Therefore, the aim of this study was to evaluate the impact of RR on the mid-thigh circumferences of the paretic limbs in stroke patients.

METHODS

Twenty stroke patients from conventional rehabilitation (CR) (n = 10) and RR (n = 10) groups were recruited through a purposive sampling method. Patients in the CR group received a two-hour session of a five-day-a-week home-based CR program for 4 weeks. Patients in the RR group received a five-day-a-week of an hour combined physiotherapy and occupational therapy session and a one-hour robotic therapy session using the HAL® Cyberdyne lower-limb, for 4 weeks. The mid-thigh circumferences of both limbs were measured on day 1 (baseline), week 2 and week 4 of rehabilitation program.

RESULTS

The results revealed no statistically significant difference in the mid-thigh circumferences between the paretic (F1.05,9.44 = 1.96, p = 0.20), and the normal (F1.05,9.44 = 1.96, p = 0.20) sides in the CR group (n = 10). For the comparison between the paretic and normal sides in the RR group (n = 10), the paretic mid-thigh circumferences revealed significant time effect results (F2,18 = 11.91, p = 0.001), which were due to changes between baseline and week 2, and baseline and week 4 measurements. Interestingly, the normal mid-thigh circumferences also revealed a significant time effect (F2,18 = 6.56, p = 0.007), which is due to changes between baseline and week 4. One-way analysis of variance was employed to compare the mean average between groups due to the difference in the baseline measurements of the mid-thigh circumferences between the paretic side of the CR and the RR groups. With this adjustment, the average means mid-thigh circumferences after 4 weeks of therapy were shown to be significantly different between the CR and RR groups (F1,18 = 12.49, p = 0.02).

CONCLUSION

Significant increments in the mid-thigh circumferences following RR were seen in the paretic limbs of stroke patients. Hence, this study may provide some insights into further potential research related to the benefits of RR in stroke patients.

Improvement of muscle quality assessed using the phase angle is influenced by recovery of knee extension strength in patients with hip fractures

BACKGROUND AND AIMS

Studies reported that knee extension strength on the operated side in patients with hip fractures was not recovered to the level on the non-operated side 6 months after surgery or later. In a cross-sectional study, we revealed that a reduction in isometric knee extension muscle strength on the operated side in patients with hip fractures approximately 6 months after surgery was associated with not only a reduction in skeletal muscle mass but also a reduction in muscle quality, characterized by a reduction in the phase angle (PhA). Furthermore, the mechanisms of knee extension strength improvement can be clarified in more detail using the minimal significant change as the index of recovery. However, no longitudinal studies have examined the factors for knee extension strength improvement based on the minimal significant change in patients with hip fractures 6 months after surgery. This study aimed to longitudinally examine the factors influencing the recovery of knee extension strength based on the minimal significant change in patients with hip fractures between 2 weeks and approximately 6 months after surgery.

METHODS

In this study, the outcomes used were basic and medical information, PhA, skeletal muscle index (SMI), pain, one-leg standing time, movement control during one-leg standing, and walking speed. For PhA, SMI, pain, one-leg standing time, movement control during one-leg standing, and walking speed, the amount of change was calculated by subtracting the data at 2 weeks from the data at 6 months. Group classification was determined by dividing the patients into two groups using a previous study as a reference: recovery group if the knee extension strength value approximately 6 months after surgery minus that 2 weeks after surgery was ≥3.3 kgf and non-recovery group if the value was <3.3 kgf. Logistic regression analysis was performed to explore the association between the recovery and non-recovery groups.

RESULTS

The recovery group contained 55 patients, while the non-recovery group comprised 35 patients. The only significant factor associated with knee extension muscle strength in the recovery group was the amount of change in PhA. The odds ratio for the amount of change in PhA was 2.26. The discrimination rate of the model was 62.5%.

CONCLUSIONS

Our results suggest that recovery of knee extension strength in patients with hip fractures after surgery was mainly because of improvements in muscle quality, not improvements in muscle mass or pain.

Utility of Lean Body Mass Equations and Body Mass Index for Predicting Outcomes in Critically Ill Adults with Sepsis: A Retrospective Study

Lean body mass is a significant component of survival from sepsis. Several equations can be used for calculating lean body mass based on age, sex, body weight, and height. We hypothesized that lean body mass is a better predictor of outcomes than the body mass index (BMI). This study used a multicenter cohort study database. The inclusion criteria were age ≥18 years and a diagnosis of sepsis or septic shock. BMI was classified into four categories: underweight (<18.5 kg/m2), normal (≥18.5-<25 kg/m2), overweight (≥25-<30 kg/m2), and obese (≥30 kg/m2). Four lean body mass equations were used and categorized on the basis of quartiles. The outcome was in-hospital mortality among different BMI and lean body mass groups. Among 85,558 patients, 3916 with sepsis were included in the analysis. Regarding BMI, in-hospital mortality was 36.9%, 29.8%, 26.7%, and 27.9% in patients who were underweight, normal weight, overweight, and obese, respectively (p < 0.01). High lean body mass did not show decreased mortality in all four equations. In critically ill patients with sepsis, BMI was a better predictor of in-hospital mortality than the lean body mass equation at intensive care unit (ICU) admission. To precisely predict in-hospital mortality, ICU-specific lean body mass equations are needed.

Muscle quality improvement in subacute post-stroke patients after rehabilitation: Usefulness of segmental phase angle from bioelectrical impedance analysis

BACKGROUND & AIMS

During stroke rehabilitation, the whole-body Phase Angle (PhA) from Bioelectrical Impedance Analysis (BIA) is measured to assess whole-body muscle quality, which reflects cellular integrity and function. The segmental BIA is a valuable method for assessing the body composition of specific body segments, such as the arms, legs, and hemisoma. After a stroke insult, patients frequently experience hemiparesis, and segmental PhA from segmental BIA appears to be an appropriate parameter for examining the muscle quality of affected and unaffected limbs separately. This study aims to investigate whether segmental PhA is more informative than whole-body PhA in (a) assessing the deterioration of muscle quality in post-stroke patients and (b) monitoring its recovery following rehabilitative treatment.

METHODS

This longitudinal study recruited subacute post-stroke patients who were admitted to our rehabilitation center. At admission, demographic, anamnestic, and clinical information, such as the presence of comorbidities, were recorded. BIA was used to evaluate the whole-body PhA and segmental PhA of the affected and unaffected hemisoma, arms, and legs at admission (T0) and after a six-week rehabilitation program (T1). The modified Barthel Index (mBI), Fugl-Meyer Assessment for the Upper Extremity (FMA-UE), and Motricity Index of the Upper (MI-UE) and Lower (MI-LE) Extremities were evaluated at T0 and T1 to determine the patient's Activity of Daily Living (ADL) performance, upper limb motor performance, and upper and lower limb muscle strength, respectively.

RESULTS

We evaluated segmental and whole-body BIA in 70 subacute post-stroke patients (women n = 34, ischemic n = 56, mean age 70 ± 11) at T0 and T1. Whole-body PhA values of the patients were below the normal range. Considering segmental data, the affected hemisoma, arm, and leg had considerably lower PhA values as compared to the unaffected body segments. Furthermore, at T1, the PhA values of all affected body segments improved, while those of the unaffected ones and whole-body PhA did not. At both T0 and T1, the segmental PhA values of the affected body segments showed to be related with all clinical outcome measures, while whole-body PhA correlated only with mBI.

CONCLUSIONS

This study emphasizes the significance of measuring segmental PhA in hemiparetic subacute stroke patients undergoing rehabilitation treatment. Segmental PhA is a more accurate parameter to evaluate rehabilitation treatment in patients with hemiparesis because it can distinguish affected from unaffected body segments, hence facilitating accurate monitoring of muscle quality improvements resulting from a rehabilitation program.

A baseline sarcopenia index based on creatinine/cystatin C for the prediction of stroke recurrence and mortality in older survivors of first ischemic strokes

Objective

Older adults individuals have a higher risk of stroke recurrence, leading to high mortality and disability rates, which, in turn, hinders the achievement of healthy aging. This study aimed to assess the utility of a baseline sarcopenia index (SI) based on serum creatinine (Cr)/cystatin C (CysC) as a prognostic marker for the risk of stroke recurrence and mortality in first-ever ischemic stroke older survivors (ISOS).

Materials and methods

Data were obtained from an ischemic stroke cohort study. The baseline information was collected from medical records and face-to-face interviews with patients admitted between January 2010 and June 2016. Follow-up information was obtained from telephone interviews every 3 months to determine stroke recurrence and survival status. The SI was calculated from the Cr and CysC values in the medical records as Cr/CysC × 100. Using the first quantile of the SI as the cut-off value, the study participants were divided into the low muscle-mass group (low SI) and the high muscle-mass group (high SI). Cox regression analysis was used to assess the association between SI and recurrence and mortality.

Results

A total of 415 first-ever ISOS were enrolled, including 242 (58.31%) male and 173 (41.69%) female participants. In the high-SI group, the relapse and mortality rates were lower than those in the low-SI group (relapse: 20.58% vs. 30.77%; mortality:13.5% vs. 29.81%). After adjusting for confounding factors, the high-SI group was found to have a lower risk of relapse and mortality than the low-SI group (relapse: HR = 0.571; mortality: HR = 0.294).

Conclusion

The SI was predictive of the long-term prognosis of IS recurrence and mortality in first-ever ISOS. After discharge, in addition to conventional medication, it is recommended that patients with low SI values actively receive treatment for sarcopenia to reduce the risk of stroke recurrence and mortality and promote healthy aging.

Validity of sarcopenia diagnosis defined by calf circumference for muscle mass to predict functional outcome in patients with acute stroke

OBJECTIVE

This study examined the association between sarcopenia diagnosed by defining muscle mass with calf circumference and physical function at hospital discharge in patients with acute stroke and to perform a comparison with sarcopenia diagnosis according to the Asian Working Group for Sarcopenia.

RESEARCH METHODS & PROCEDURES

This retrospective cohort study included patients with acute stroke. We calculated the calf circumference cut-off value defining low skeletal muscle index for the Asian Working Group for Sarcopenia diagnostic criteria and used a combination of low calf circumference and low grip strength to define sarcopenia-calf circumference. A combination of low skeletal muscle index and low grip strength defined sarcopenia-Asian Working Group for Sarcopenia. Associations between sarcopenia-calf circumference, sarcopenia-Asian Working Group for Sarcopenia, and Functional Independence Measure motor score were evaluated using multiple regression analysis.

RESULTS

The study included 308 patients (198 men; mean age, 73.2 years). Sarcopenia-calf circumference prevalence was 24.7% in men and 46.4% in women. In men, sarcopenia-calf circumference (β=-0.178; 95% CI: -0.284, -0.073; p=0.001) and sarcopenia-Asian Working Group for Sarcopenia (β=-0.228; 95% CI: -0.330, -0.127; p<0.001) were significantly associated with Functional Independence Measure motor score at discharge.

CONCLUSIONS

Sarcopenia diagnosed by defining muscle mass with calf circumference was negatively associated with physical function at discharge in male patients with acute stroke. Sarcopenia diagnosed using Asian Working Group for Sarcopenia criteria was superior to sarcopenia-calf circumference for predicting physical function at discharge. Our findings suggest that the use of CC enables assessment of sarcopenia even at facilities where muscle mass measurements may be difficult.

The Assessment of the Risk of Malnutrition (Undernutrition) in Stroke Patients

Malnutrition is common in stroke patients, as it is associated with neurological and cognitive impairment as well as clinical outcomes. Nutritional screening is a process with which to categorize the risk of malnutrition (i.e., nutritional risk) based on validated tools/procedures, which need to be rapid, simple, cost-effective, and reliable in the clinical setting. This review focuses on the tools/procedures used in stroke patients to assess nutritional risk, with a particular focus on their relationships with patients' clinical characteristics and outcomes. Different screening tools/procedures have been used in stroke patients, which have shown varying prevalence in terms of nutritional risk (higher in rehabilitation units) and significant relationships with clinical outcomes in the short- and long term, such as infection, disability, and mortality. Indeed, there have been few attempts to compare the usefulness and reliability of the different tools/procedures. More evidence is needed to identify appropriate approaches to assessing nutritional risk among stroke patients in the acute and sub-acute phase of disease or during rehabilitation; to evaluate the impact of nutritional treatment on the risk of malnutrition during hospital stay or rehabilitation unit; and to include nutritional screening in well-defined nutritional care protocols.

Current practice and barriers in the implementation of ultrasound-based assessment of muscle mass in Japan: A nationwide, web-based cross-sectional study

Muscle mass is an important factor for surviving an illness. Ultrasound has gained increased attention as a muscle mass assessment method because of its noninvasiveness and portability. However, data on the frequency of ultrasound-based muscle mass assessment are limited, and there are some barriers to its implementation. Hence, a web-based cross-sectional survey was conducted on healthcare providers in Japan, which comprised four parts: 1) participant characteristics; 2) general muscle mass assessment; 3) ultrasound-based muscle mass assessment; and 4) the necessity of, interest in, and barriers to its implementation. Necessity and interest were assessed using an 11-point Likert scale, whereas barriers were assessed using a 5-point Likert scale, in which “Strongly agree” and “Agree” were counted for the analysis. Of the 1,058 responders, 1,026 participants, comprising 282 physicians, 489 physical therapists, 84 occupational therapists, 120 nurses, and 51 dieticians, were included in the analysis. In total, 93% of the participants were familiar with general muscle mass assessment, and 64% had conducted it. Ultrasound-based muscle mass assessment was performed by 21% of the participants. Necessity and interest scored 7 (6–8) and 8 (7–10), respectively for ultrasound-based muscle mass assessment. The barriers to its implementation included lack of relevant education (84%), limited staff (61%), and absence of fixed protocol (61%). Regardless of the necessity of and interest in ultrasound-based muscle mass assessment, it was only conducted by one-fifth of the healthcare providers, and the most important barrier to its implementation was lack of education.

Correlation of Body Composition via Bioelectrical Impedance Analysis and Motor Function and Recovery of Upper Extremity in Patients Undergoing Stroke Rehabilitation

Bioelectrical impedance analysis (BIA) has been used to investigate the body compositions and predict functional outcomes in patients with stroke, while the role of BIA to predict motor function or recovery in stroke has not been clarified. This study aimed to investigate relationship between body composition measured by BIA and upper limb motor function and recovery. Body compositions (soft tissue lean mass, phase angle, body fat mass and body water) of fifty patients who are admitted to the stroke rehabilitation unit were segmentally analyzed via BIA. The motor recovery of upper extremity (UE) was evaluated via Fugl-Meyer Assessment (UE-FMA) at the time of transfer and discharge. Correlations between body composition and UE-FMA at discharge were analyzed using Spearman correlation coefficient. Multiple regression analysis was used to determine the regression between body composition and motor function and recovery. The Δ Phase angle, the difference of both sides was significantly linearly inversely correlated with UE-FMA at discharge. However, in multiple regression analysis, body compositions including phase angle did not significantly predict motor function at discharge or motor recovery. The Δ Phase angle is related to the severity of upper limb motor function at discharge in subacute stroke patients, and further studies are needed to determine its value as a predictor for motor recovery.

Accuracy of Calf Circumference Measurement, SARC-F Questionnaire, and Ishii's Score for Screening Stroke-Related Sarcopenia

Objective

The purpose of this study was to investigate the accuracy of sarcopenia diagnosis in patients with stroke using calf circumference (CC), SARC-F questionnaire, and Ishii's score in comparison with the Asian Working Group for Sarcopenia 2019 (AWGS) sarcopenia diagnostic criteria.

Materials and Methods

In this cross-sectional study, a total of 364 consecutive patients with stroke were enrolled and evaluated with the CC measurement, SARC-F questionnaire, and Ishii's score. The diagnostic accuracy was analyzed.

Results

Based on the AWGS criteria, sarcopenia was present in 180 (49.5%) patients, with an age range of 49-74 (mean 63 ± 14.7) years. In all patients, the cutoff value of CC in the accuracy of diagnosing sarcopenia was 30.5 cm, with an AUC of 0.85, sensitivity of 81.8%, specificity of 90.1%, Kappa value of 0.72, and Youden index of 0.72. In the accuracy of diagnosing sarcopenia in all patients, Ishii's score had a cutoff value of 118, AUC of 0.78, sensitivity of 90.1%, specificity of 36.0%, Kappa value of 0.4, and Youden index of 0.55. For accuracy of diagnosing sarcopenia, the SARC-F questionnaire had a cutoff value of 5, AUC of 0.731, sensitivity of 94.7%, specificity of 40%, Kappa value of 0.34, and Youden index of 0.41.

Conclusions

Based on the AWGS criteria, calf circumference measurement has the optimal performance in screening stroke-related sarcopenia compared with the SARC-F questionnaire and Ishii's score. In patients with stroke, the cutoff value of calf circumference for sarcopenia is < 31 cm in men and 30 cm in women, and with an AUC of 0.85.

Temporal Muscle and Stroke-A Narrative Review on Current Meaning and Clinical Applications of Temporal Muscle Thickness, Area, and Volume

BACKGROUND

Evaluating muscle mass and function among stroke patients is important. However, evaluating muscle volume and function is not easy due to the disturbances of consciousness and paresis. Temporal muscle thickness (TMT) has been introduced as a novel surrogate marker for muscle mass, function, and nutritional status. We herein performed a narrative literature review on temporal muscle and stroke to understand the current meaning of TMT in clinical stroke practice.

METHODS

The search was performed in PubMed, last updated in October 2021. Reports on temporal muscle morphomics and stroke-related diseases or clinical entities were collected.

RESULTS

Four studies reported on TMT and subarachnoid hemorrhage, two studies on intracerebral hemorrhage, two studies on ischemic stroke, two studies on standard TMT values, and two studies on nutritional status. TMT was reported as a prognostic factor for several diseases, a surrogate marker for skeletal muscle mass, and an indicator of nutritional status. Computed tomography, magnetic resonance imaging, and ultrasonography were used to measure TMT.

CONCLUSIONS

TMT is gradually being used as a prognostic factor for stroke or a surrogate marker for skeletal muscle mass and nutritional status. The establishment of standard methods to measure TMT and large prospective studies to further investigate the relationship between TMT and diseases are needed.

Bite Force, Thickness, and Thermographic Patterns of Masticatory Muscles Post-Hemorrhagic Stroke

OBJECTIVE

Stroke is a neurological deficit of cerebrovascular origin, considered a 21st-century epidemic that causes functional changes in the human body. This study aimed to evaluate the stomatognathic system of patients after hemorrhagic stroke through the bite force, thickness, and skin temperature in the region of the masseter and temporalis muscles.

MATERIAL AND METHODS

Twenty-four subjects were divided into groups: post-hemorrhagic stroke; with right side of the affected body (n = 12) and without the neurological disorder (n = 12). Maximum molar bite force was verified using a digital dynamometer. Muscle thickness was measured using ultrasound images obtained at rest and during maximal voluntary contraction of the masseter and temporalis muscles. Thermographic camera was used to record the thermographic patterns of the masseter and temporalis muscles. Data were subjected to Student's t-test (P < .05).

RESULTS

The maximum molar bite force showed significant differences in the right (P = .04) and left (P = .03) sides, with a reduction in force in the post-hemorrhagic stroke group on the affected and unaffected sides. There was a significant difference (P < .05) in the thickness of the left temporal muscle at mandibular rest (P = .01) between groups. The post-hemorrhagic stroke group clinically presented greater muscle thickness in almost 100% of the muscles evaluated in both clinical conditions. There were no significant differences in skin temperature in the masseter and temporal muscles between the groups.

CONCLUSIONS

Our results suggest functional changes in the stomatognathic system of subjects after a hemorrhagic stroke, especially concerning molar bite force and masticatory muscle thickness in the temporal muscle (unaffected side).

Ultrasound assessment of muscle mass has potential to identify patients with low muscularity at intensive care unit admission: A retrospective study

BACKGROUND & AIMS

Muscle mass is an important biomarker of survival from a critical illness; however, there is no widely accepted method for routine assessment of low muscularity at intensive care unit (ICU) admission. We hypothesize that ultrasound-based partial muscle mass assessments can reflect the trunk muscle mass. Therefore, we aimed to investigate whether ultrasound muscle mass measurements could reflect trunk muscle mass and identify patients with low muscularity.

METHODS

We performed a retrospective analysis of prospectively obtained ultrasound data at ICU admission. We included patients who underwent computed tomography (CT) imaging at the third lumbar vertebra (L3) within 2 days before and 2 days after ICU admission. Primary outcomes included the correlation between the femoral muscle mass measurements using ultrasound and the cross-sectional area (CSA) at L3 obtained by CT. Low muscularity was defined as a skeletal muscle index of 36.0 cm²/m² for males and 29.0 cm²/m² for females. Secondary outcomes included the correlation with the ultrasound measurements of the biceps brachii muscle mass and diaphragm thickness.

RESULTS

Among 133 patients, 89 underwent CT imaging, which included the L3. The patient mean age was 72 ± 13 years, and 60 patients (67%) were male. The correlation between the femoral muscle ultrasound and CT was ρ = 0.57 (p < 0.01, n = 89) and ρ = 0.48 (p < 0.01, n = 89) for quadriceps muscle layer thickness and rectus femoris muscle CSA, and these had the discriminative power to assess low muscularity, with the areas under the curve of 0.84 and 0.76, respectively. The ultrasound measurements of the biceps brachii muscle mass and diaphragm thickness were correlated with CT imaging [ρ = 0.57-0.60 (p < 0.01, n = 52) and ρ = 0.35 (p < 0.01, n = 79)].

CONCLUSIONS

Ultrasound measurements of muscle mass were correlated with CT measurements, and the measurements of femoral muscle mass were useful to assess low muscularity at ICU admission.

TRIAL REGISTRATION

UMIN000044032 (retrospectively registered on April 25, 2021).