Phase angle from bioelectrical impedance analysis is a useful indicator of muscle quality

Relationship of phase angle with postoperative pneumonia and survival prognosis in patients with esophageal cancer: A retrospective cohort study

OBJECTIVES

Phase angle (PhA), derived from bioelectrical impedance analysis (BIA), is an indicator of cell membrane health. Low PhA values reflect poor cellular function and low muscle mass. However, consensus regarding the appropriate cutoff value of PhA remains insufficient, and its impact on outcomes after esophagectomy in patients with esophageal malignancies is not well studied. We aimed to investigate whether preoperative PhA is associated with postoperative complication risk and survival prognosis and whether PhA decrease during the surgical preparation period is a prognostic factor in patients with esophageal cancer.

METHODS

This retrospective cohort study analyzed data from 194 patients who had undergone esophagectomy for esophageal malignancies. A PhA measured several days before surgery, with cutoff values of 5.0° for men and 4.2° for women, was used. The relationship between postoperative pneumonia and clinicopathological factors and between low PhA and postoperative outcomes and survival prognosis was investigated. The preoperative PhA decline and survival prognosis were analyzed in 134 patients whose PhA was measured twice before surgery.

RESULTS

Overall, 93 and 101 patients were classified into the low and high PhA groups, respectively. A multivariate analysis showed that a serum albumin level lower than 3.5 g/dL and low PhA were independent risk factors for pneumonia (odds ratio [OR] = 3.40, P = 0.03; OR = 3.42, P = 0.03, respectively). The low PhA group exhibited significantly higher intraoperative fluid balance (6.7 versus 6.0 mL/kg/h, P = 0.01) and a higher proportion of patients who failed to achieve early mobilization on the first postoperative day (46 versus 32%, P = 0.04) than did the high PhA group. Multivariate analysis using a Cox proportional hazards model revealed that low PhA was a poor survival prognostic factor, independent of the clinical stage of esophageal cancer (hazard ratio = 2.61, P < 0.01). In patients whose PhA was measured twice preoperatively, a decrease in PhA during the preoperative period was a significant indicator of poor survival (hazard ratio = 2.59, P < 0.01). The group with a decrease in PhA during the preoperative period had significantly fewer steps than the group with an increase in PhA (6220 ± 2880 versus 8200 ± 2850, P < 0.01).

CONCLUSIONS

Low PhA was a risk factor for postoperative pneumonia in patients who had undergone esophagectomy and was associated with poor survival prognosis. A decrease in PhA during the preoperative period was a significant poor prognostic factor. Increasing physical activity before surgery may lead to an increase in PhA. Thus, it is important to measure and evaluate PhA changes sequentially in patients with esophageal cancer.

Phase Angle Is a Potential Novel Early Marker for Sarcopenia and Cognitive Impairment in the General Population

BACKGROUND

Sarcopenia is associated with an increased risk for dementia. This study aimed to elucidate the relationship between sarcopenia-related indices and cognitive decline in the general population.

METHODS

This was a cross-sectional study involving 263 participants (163 men with a median age of 60 years [interquartile range = 53-70] and 100 women with a median age of 58 years [interquartile range = 49-68]) who underwent a general health examination. Sarcopenia-related indices included appendicular skeletal muscle mass (ASM)/height2, ASM/body mass index, handgrip strength (HGS), HGS/upper extremity skeletal muscle mass and phase angle (PhA). We examined the associations between these indices and cognitive function using the Japanese version of the Montreal Cognitive Assessment (MoCA-J).

RESULTS

Higher PhA, an indicator of muscle quality, was associated with a lower risk of mild cognitive impairment (MCI) in women (adjusted odds ratio = 0.28 [95% confidence interval, 0.10-0.78], p = 0.014), whereas the other sarcopenia-related indices showed no significant association with MCI in both sexes. The PhA of women was positively associated with the MoCA-J scores (β = 0.27, p = 0.005). Moreover, the PhA of women showed a positive correlation with cognitive subdomains, including memory (r = 0.22, p = 0.031), which is one of the earliest manifestations of cognitive impairment. The PhA in men was also positively correlated with memory (r = 0.24, p = 0.002).

CONCLUSIONS

PhA is a potentially novel index for detecting the risk of sarcopenia and cognitive decline in the general population.

Association between phase angle and hospital-associated disability in hospitalized patients in the internal medicine ward: A prospective observational study

OBJECTIVE

This study aimed to evaluate the association between the phase angle (PhA) and hospital-associated disability (HAD) in older patients admitted to an internal medicine ward.

METHODS

This was a prospective observational study in a single acute care hospital. HAD was defined as a decrease of at least five points in the Barthel index at discharge compared to pre-admission. Multiple logistic regression analysis was used to determine the association between PhA and HAD. The cut-off point for PhA was evaluated using a receiver operating characteristic curve.

RESULTS

This study included 215 patients (113 males; mean age: 80.8 years). The HAD incidence rate was 27.9 %. Multiple logistic regression analysis showed that PhA was associated with HAD (odds ratio: 3.47, 95 % confidence interval: 1.95-6.18, p < 0.001). The PhA cut-off points for predicting HAD were 3.7° for men and 3.6° for women.

CONCLUSION

PhA was associated with HAD in older patients admitted to the internal medicine ward and may be a useful indicator for predicting HAD.

Phase angle as an independent predictor of sarcopenia and glycemic control in older adults with type 2 diabetes: a cross-sectional observational study

Objectives

The global rise in type 2 diabetes mellitus (T2DM) poses challenges, particularly with the increasing burden of sarcopenia and poor glycemic control. Phase angle (PhA) is a promising biomarker for early detection and management of these conditions. This study aimed to evaluate PhA as an independent predictor of sarcopenia and glycemic control.

Methods

This cross-sectional study included older adults with T2DM hospitalized for diabetes education between April 2021 and March 2023. Measurements included PhA, muscle mass, body fat mass, grip strength, knee extension strength, physical function (Short Physical Performance Battery and 6-min walk distance), and glycemic control (fasting blood glucose and hemoglobin A1c [HbA1c]). Sarcopenia was defined as low muscle mass and physical function. Analyses included Pearson correlations, receiver operating characteristic curve analysis, and multivariate logistic regression.

Results

PhA was moderately correlated with muscle mass (r = 0.42, p < 0.001), grip strength (r = 0.43, p < 0.001), and body mass index (r = 0.27, p = 0.001), and inversely correlated with HbA1c (r = - 0.34, p < 0.001) and age (r = - 0.26, p = 0.003). PhA showed a strong predictive ability for sarcopenia (AUC = 0.83, 95% CI: 0.76-0.90, p < 0.001). Logistic regression indicated PhA as an independent predictor of sarcopenia (OR = 0.105, 95% CI: 0.031-0.353, p < 0.001) and glycemic control (OR = 0.380, 95% CI: 0.201-0.719, p = 0.003).

Conclusions

PhA is a non-invasive, practical tool for predicting sarcopenia and monitoring glycemic control. Routine integration of PhA could identify high-risk patients and guide interventions. Future research should validate its application in diverse settings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-025-01590-z.

The association of hemopexin, muscle quality, and sarcopenia in Japanese older adults with cognitive impairment: a cross-sectional study

OBJECTIVE

To examine the cross-sectional associations of hemopexin, muscle quality, and sarcopenia status with cognitive function among older Japanese adults with cognitive impairment, and to explore the potential sex-specific differences.

METHODS

A total of 580 older adults (372 women, 208 men; mean age 83.3 ± 6.2 years) who presented with cognitive impairment at the Kyoto Dementia Comprehensive Center between 2018 and 2022 were enrolled. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Hemopexin level was measured by enzyme-linked immunosorbent assay. Muscle quality was evaluated via phase angle (PhA) and grip strength, and sarcopenia status was defined using the Asian Working Group for Sarcopenia criteria. Multiple linear regression models, including sex-stratified analyses, were conducted to determine the relationships of these variables with MMSE scores.

RESULTS

Higher hemopexin levels (β = 1.19, p = 0.017), PhA (β = 0.59, p = 0.005), and grip strength (β = 0.14, p < 0.001) were independently associated with better MMSE scores, whereas sarcopenia was negatively linked to MMSE scores (β = - 2.28, p < 0.001). Notably, sex-stratified models indicated that hemopexin positively predicted MMSE scores in men but not in women; meanwhile, sarcopenia showed a stronger negative impact in women. Educational attainment also displayed a significant positive association with cognitive performance in both sexes.

CONCLUSIONS

In this cross-sectional study of older Japanese adults with cognitive impairment, hemopexin levels and muscle quality emerged as important correlates of cognitive function, particularly in men, while sarcopenia was negatively linked to cognition.

Phase angle: a novel application of bioelectrical impedance technology in osteoarthritis screening and diagnosis

Bioelectrical impedance technology (EBI) offers a non-invasive, cost-effective method for body composition assessment, showing promise in diagnosing and managing musculoskeletal disorders, particularly osteoarthritis (OA). OA is a major global health concern, notably affecting the knee and hip joints. Conventional imaging techniques like X-rays and MRI have limitations in early detection, as they cannot capture microscopic cartilage changes. Phase angle (PhA), an essential EBI parameter, is widely applied in evaluating sarcopenia, tumors, and body fluids, and is increasingly valuable in OA research. PhA reflects cellular health through cell membrane impedance, with studies showing that lower PhA levels correlate with OA severity and predict OA-related degeneration, supporting its role in early screening. Additionally, EBI holds potential for monitoring OA progression and evaluating treatment efficacy. This review summarizes recent advances in OA diagnosis with EBI, focusing on the applications of PhA and other bioimpedance parameters in screening, monitoring, and evaluation. Through systematic analysis, this review provides theoretical support for EBI's clinical use, highlighting its potential in OA prevention, diagnosis, and intervention. With continued technological progress, EBI is poised to become a critical tool in OA management, particularly for early diagnosis and personalized treatment.

Optimizing Nutritional Care with Machine Learning: Identifying Sarcopenia Risk Through Body Composition Parameters in Cancer Patients-Insights from the NUTritional and Sarcopenia RIsk SCREENing Project (NUTRISCREEN)

Background/Objectives: Cancer and related treatments can impair body composition (BC), increasing the risk of malnutrition and sarcopenia, poor prognosis, and Health-Related Quality of Life (HRQoL). To enhance BC parameter interpretation through Bioelectrical Impedance Analysis (BIA), we developed a predictive model based on unsupervised approaches including Principal Component Analysis (PCA) and k-means clustering for sarcopenia risk in cancer patients at the Istituto Nazionale Tumori IRCCS "Fondazione G. Pascale" (Naples). Methods: Sarcopenia and malnutrition risks were assessed using the NRS-2002 and SARC-F questionnaires, anthropometric measurements, and BIA. HRQoL was evaluated with the EORTC QLQ-C30 questionnaire. PCA and clustering analysis were performed to identify different BC profiles. Results: Data from 879 cancer patients (mean age: 63 ± 12.5 years) were collected: 117 patients (13%) and 128 (15%) were at risk of malnutrition and sarcopenia, respectively. PCA analysis identified three main components, and k-means determined three clusters, namely HMP (High Muscle Profile), MMP (Moderate Muscle Profile), and LMP (Low Muscle Profile). Patients in LMP were older, with a higher prevalence of comorbidities, malnutrition, and sarcopenia. In the multivariable analysis, age, lung cancer site, diabetes, and malnutrition risk were significantly associated with an increased risk of sarcopenia; among the clusters, patients in LMP had an increased risk of sarcopenia (+62%, p = 0.006). Conclusions: The NUTRISCREEN project, part of the ONCOCAMP study (ClinicalTrials.gov ID: NCT06270602), provides a personalized nutritional pathway for early screening of malnutrition and sarcopenia. Using an unsupervised approach, we provide distinct BC profiles and valuable insights into the factors associated with sarcopenia risk. This approach in clinical practice could help define risk categories, ensure the most appropriate nutritional strategies, and improve patient outcomes by providing data-driven care.

Bioelectrical impedance analysis for measuring body composition and predicting low muscle mass in apparently healthy pediatric outpatients: a retrospective observational study

BACKGROUND

The bioelectrical impedance analysis-derived phase angle is a proposed indicator of sarcopenia in adults. This study assessed the body composition of pediatric outpatients without underlying medical conditions to evaluate the predictive value of the phase angle in identifying low muscle mass, a risk factor for pediatric sarcopenia.

METHODS

Analyses were performed separately for each sex among 480 pediatric outpatients aged 5-18 years. Body composition variables were compared between low and normal body mass index-for-age z-score (BMIz) groups, including correlation analysis between the phase angle and other variables. The receiver operating characteristic curves of the phase angle, body mass index, and fat-free mass index (FFMI) were compared to predict a severely low appendicular skeletal muscle mass index (ASMI), defined as an ASMI below - 1 or - 2 standard deviations based on sex- and ethnicity-specific reference curves derived from dual-energy X-ray absorptiometry.

RESULTS

The low BMIz group showed a greater prevalence of a low fat-mass percentage and severely low ASMI, accompanied by notable changes in fat mass, muscle mass, height-squared adjusted indices, body water, protein, visceral fat area, and the phase angle (P < 0.05) compared with the normal BMIz group. The phase angle exhibited moderate correlations (P < 0.001) with the FFMI and ASMI (positive) and the visceral fat area and the extracellular water/total body water (ECW/TBW) ratio (negative) but no or negligible correlation with fat mass, fat-mass percentage, the fat mass index, or minerals. The phase angle' area under the curve for predicting a severely low ASMI was 0.743-0.785 (sensitivity: 62.3-80.4%; specificity: 67.0-75.0%). The area under the curve of the FFMI was 0.853-0.931 (sensitivity: 78.4-92.9%; specificity: 79.6-87.1%).

CONCLUSIONS

Body composition can identify fat and muscle wasting in children with a normal BMIz. The phase angle moderately correlated with the FFMI, ASMI, visceral fat area, and ECW/TBW ratio. The phase angle is a reasonable, although not a surrogate, indicator of the sarcopenia risk in pediatric outpatients.

[Associations between phase angle measured by bioelectrical impedance and physical frailty, sarcopenia and comorbidity in older patients]

AIM

To evaluate the association between phase angle (PA), measured by electrical bioimpedance, and age, comorbidity, physical frailty, and sarcopenia in individuals over 50years old attending a falls clinic.

MATERIALS AND METHODS

Data were collected on demographics (age, sex), anthropometric measurements (body mass index [BMI]), comorbidity (CIRS-G score), physical frailty (SHARE-FI score), probable sarcopenia (by handgrip strength and 5 sit-to-stand test [5-STS]), and bioimpedance parameters (PA and sarcopenia as per Sergi's equation). Bivariate correlations and multiple linear regression models were applied to determine association.

RESULTS

The study included 107 patients (61 women) from the Falls and Syncope Unit, Mercer's Institute for Successful Ageing, St James' Hospital, Dublin; with a mean age of 69.8 years, PA of 4.7°, and BMI of 26.4kg/m2. PA demonstrated an inverse correlation with SHARE-FI (ρ: -0.23, P=.019), which remained significant after adjusting for age. PA was also inversely correlated with CIRS-G (ρ: -0.40, P<.001); in regression analysis, this association was independent of age (P<.001) and SHARE-FI (P=.539). PA was inversely associated with bioimpedance-confirmed sarcopenia (P=.002) and probable sarcopenia by handgrip strength (ρ: 0.25, P=.009) and 5-STS (ρ: -0.32, P=.001). Among patients with confirmed or probable sarcopenia (n=49), PA was inversely related to CIRS-G (P=.011), independent of age (P=.003) and SHARE-FI (P=.959).

CONCLUSIONS

PA decreases with age and is significantly influenced by comorbidities, but not by physical frailty. This relationship persists in patients with confirmed or probable sarcopenia, suggesting that PA could be a valuable marker for assessing the burden of comorbidities in these patients.

Application of bioelectrical impedance detection techniques: Cells and tissues

Pathological conditions in organisms often arise from various cellular or tissue abnormalities, including dysregulation of cell numbers, infections, aberrant differentiation, and tissue pathologies such as lung tumors and skin tumors. Thus, developing methods for analyzing and identifying these biological abnormalities presents a significant challenge. While traditional bioanalytical methods such as flow cytometry and magnetic resonance imaging are well-established, they suffer from inefficiencies, high costs, complexity, and potential hazards. To address these challenges, bioelectrical impedance detection technology, which leverages the electrical properties of biological cells and tissues to extract relevant biomedical information, has garnered considerable attention in the field of biological detection due to its affordability, convenience, non-invasiveness, and label-free nature. This article first provides a brief introduction to the principles of bioelectrical impedance and related detection techniques, as well as the equivalent circuit models and numerical simulation models developed at the cellular and tissue levels. Next, this article delves into the applications of bioelectrical impedance technology at the cellular level, including recent advancements in cell counting, classification, concentration detection, differentiation, and infection, thereby enriching previous literature reviews from a multicellular perspective. In addition, this article highlights the applications of bioelectrical impedance technology in relevant tissues including muscle, skin, lungs, and so on. Finally, the article explores the future opportunities and challenges of bioelectrical impedance detection and analysis technology, focusing on interdisciplinary research areas and data-driven intelligent analysis, offering researchers broader research directions and perspectives.

The usefulness of the updated bioelectrical impedance vector analysis references for assessing malnutrition, sarcopenia and predicting mortality in hospitalized patients

BACKGROUND & AIMS

The application of validated pre-screening tools is crucial in clinical practice to identify patients at risk for disease. Bioelectrical Impedance Vector Analysis (BIVA) has gained recognition as a qualitative method for monitoring body composition and assessing the health status of hospitalized patients. This study investigates the utility of updated BIVA reference standards in evaluating malnutrition, sarcopenia, and mortality among hospitalized individuals.

MATERIAL AND METHOD

This retrospective observational study included 2.872 patients admitted to Quironsalud Málaga Hospital between January 2019 and January 2024. Malnutrition and sarcopenia were diagnosed using the Global Leadership Initiative on Malnutrition (GLIM) and the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) guidelines. Mortality was defined as death within one year of their initial discharge or later admissions. BIVA was performed using the former and the new 50th, 75th, and 95th reference tolerance ellipses of general population.

RESULTS

BIVA revealed significant differences in bioimpedance vectors between malnourished (n = 1187, 544 women) and non-malnourished patients, sarcopenic (n = 136, 51 women) and non-sarcopenic patients, and non-survivors (n = 317, 160 women) compared to survivors. When previous BIVA references (Piccoli 1995) were applied, the bioimpedance vectors for malnourished, sarcopenic, and non-surviving patients fell within the 75th tolerance ellipses. However, with updated references, these vectors shifted rightward, moving outside the 75th and 95th tolerance ellipses. Univariate Cox analysis showed that participants with vectors outside the new 95th tolerance ellipses faced significantly higher mortality risk (HR = 6.22 [95 % CI 4.40-8.80], p < 0.001) and lower survival rates (log-rank test p < 0.001) compared to those within the 75th ellipses. These trends persisted even after adjusting for age, sex, and BMI (HR = 4.79 [95 % CI 3.29-6.97], p < 0.001). The new reference ellipses demonstrated greater prognostic accuracy compared to the older ones, emphasizing their value in identifying high-risk patients.

CONCLUSION

The implementation of BIVA with newly established reference tolerance ellipses significantly enhances the evaluation of body composition and overall health in hospitalized patients. These updated tolerance ellipses are instrumental in accurately identifying malnutrition, sarcopenia, and heightened mortality risks. The delineation of specific mortality risk zones underscores the potential of incorporating these advanced BIVA ellipses into routine pre-screening protocols, thereby optimizing clinical nutritional assessments and interventions.

The diagnostic performance of phase angle for sarcopenia among older adults: A systematic review and diagnostic meta-analysis

OBJECTIVE

Phase angle is a promising tool for diagnosing sarcopenia. This study aimed to summarize its diagnostic performance by performing a systematic review and meta-analysis.

METHODS

We conducted a systematic search of PubMed, Web of Science, Embase, and Scopus. The Quality Assessment of Diagnostic Accuracy Studies, Version 2, was used to evaluate the quality of the studies. A bivariate random effects model was employed for data synthesis, and diagnostic performance was reported in terms of pooled sensitivity, specificity, and the area under the summary receiver operating characteristic curve (AUC). Additionally, meta-regression, subgroup analyses, and sensitivity analyses were performed.

RESULTS

A total of 15 studies were included in this meta-analysis, involving 4,063 participants. The overall risk of bias in the included studies was high. The meta-analysis revealed that the pooled sensitivity and specificity across all studies were 0.74 [95 % confidence interval (CI): 0.71-0.78] and 0.75 (95 % CI: 0.70-0.79), respectively, with an AUC of 0.79 (95 % CI: 0.76-0.83). Meta-regression indicated that study design, country, population, sex-specificity, and age may influence the diagnostic performance of phase angle. The optimal diagnostic performance was observed in the cut-off interval of 4.20 to 4.50°.

CONCLUSION

The phase angle demonstrated moderate diagnostic performance for sarcopenia, and the possible cut-off interval is 4.20 to 4.50 °. However, large-scale, multicenter prospective studies are necessary to assess its clinical applicability at specific cut-off values.

Bioelectrical phase angle and impedance vectors are related to leg hip-femur density and bone geometry parameters in adolescent male soccer players

BACKGROUND

Bone geometry parameters are essential for evaluating bone health and fracture risk in soccer players, whose physical demands affect their bone characteristics. However, studies on adolescent soccer players linking raw bioelectrical data to bone data are lacking, in addition to potential discrepancies in phase angle (PhA) values obtained using single-frequency (SF-BIA) and multifrequency (MF-BIA) bioelectrical impedance devices.

AIMS

In this cross-sectional study, we aimed to compare raw bioelectrical impedance data (resistance (R), reactance (Xc), and PhA values) obtained using SF-BIA and MF-BIA devices and test the relationships among PhA and bioelectrical impedance vector analysis (BIVA) with bone mineral density (BMD), and leg hip-femur geometry (HF-G) parameters in adolescent male soccer players.

METHODS

Raw bioelectrical impedance data were assessed using the SF-BIA and MF-BIA devices at a frequency of 50 kHz. The HF-G parameters were obtained by dual-energy X-ray absorptiometry. BIVA was used to compare bone data considering BMD and HF-G median values.

RESULTS

Overall, 59 adolescent male soccer players participated in this study. Raw SF-BIA data had lower R values (-19.3 %, p < 0.001), but higher Xc (+5.3 %, p < 0.001) and PhA values (+20.3 %, p < 0.001) than when using MF-BIA data. PhA values obtained using SF-BIA (r = 0.27, p = 0.04) or MF-BIA (r = 0.43, p < 0.001) were positively correlated with total hip-femur BMD. Considering BIVA, the ellipses differed for the total BMD (p = 0.0018), neck BMD (p = 0.026), and cross-sectional area (p = 0.024).

CONCLUSION

The PhA and R values obtained using SF-BIA were higher than those obtained using MF-BIA, possibly because of the technological differences between the devices. However, the MF-BIA data suggests that PhA and BIVA can be used as tools for continuous use to warn of possible imbalances in bone tissue.

Raw bioelectrical impedance parameters and vector analysis in the screening of low muscle mass and low muscle mass associated with obesity in adult healthy subjects

The aim was to estimate the prevalence of low muscle mass (LMM) and low muscle mass associated with obesity (LMM-O) in healthy adult, and to verify the performance of raw bioelectrical impedance parameters (BIA) and vector analysis (BIVA) in the screening of this tow conditions. This is a cross-sectional study including 1025 healthy adults. Body composition was assessed by the BIA technique. The appendicular skeletal muscle mass index (ASMMI) and body fat percentage (BF%) were used for the screening of LMM and LMM-O. The raw BIA parameters were: resistance (R), reactance (Xc), phase angle (PhA), and impedance (Z). The vectors, R and Xc, were adjusted for height and projected on the RXc graph. Associations were checked by the correlation test, binary logistic regression, adjusted for age and body water, and ROC curve. LMM was found in 30.8% of the subjects, and 20.9 and 21.4% of the men and women were with LMM-O. PhA and R/H were the most powerful discriminators of LMM with a sensitivity of 62-100% and a specificity of 71-90%. Cutoff values of PhA ranged between 4.95° and 5.75° for women and men. The RXc graph was able to identify LMM subjects, with clustering on the right side: area of low cellularity, high R/H and low-phase angle. Traditional anthropometric indices were the least effective in identifying LMM-O. The BIVA approach, PhA, R and R/H are effective in the screening of LMM and LMM-O, irrespective of age, gender, intra- and extracellular hydration status.

Evaluation of sarcopenia and phase angle in elderly patients with Parkinson's Disease

PURPOSE

To investigate sarcopenia and related factors and to determine the disease-specific phase angle (PhA) cut-off score in detecting sarcopenia in elderly patients with Parkinson's Disease (PD).

METHODS

This cross-sectional study was conducted with 89 participants. The Mini-Nutritional Assessment (MNA), the Eating Attitude Test-10 (EAT-10), the Physical Activity Scale for The Elderly (PASE) questionnaire and the Hoehn-Yahr scale have been used. Additionally, anthropometric measurements were performed. The diagnosis of sarcopenia was based on the new consensus published by the European Working Group on Sarcopenia in Older People 2 (EWGSOP2). PhA has been performed by Bioelectrical Impedance Analysis (BIA) with Tanita MC 780®.

RESULTS

The mean age was of the participants 68.9 ± 6.4 years, and 57.3% were male. The prevalence of sarcopenia was 12.3%. PhA, malnutrition, age, disease severity, low calf circumference (CC), low body mass index (BMI), the difference between the pre-diagnosis and current weight loss, dopaminergic treatment, and low PASE score were associated with sarcopenia. The cut-off value of the PhA in terms of the ability to identify sarcopenia was <4.5o with a sensitivity of 53.3% and a specificity of 93.2% (p = 0.001). When we grouped the PhA of the patients according to this cut-off score, it was seen that 14.6% of them were sarcopenic. Age, disease severity, PASE score and hand grip strength were significantly related to both sarcopenia and PhA.

CONCLUSION

It is important to be aware of sarcopenia and related factors at an early stage in Parkinson's patients. Because of disease-related symptoms, it may be more appropriate to use a disease-specific PhA cut-off score in the definition of sarcopenia.

Exploring the significance of phase angle in diabetes management: a narrative review

Purpose

The phase angle is a mathematical concept representing the time relationship between two periodic waveforms, and has gained some importance for its potential clinical applications. The purpose of this review was to investigate the role of phase angle in diabetes mellitus.Studies have investigated the relationship between the phase angle and glycemic control, insulin resistance, and diabetes-related complications. Phase angle has demonstrated its potential as a prognostic marker for diabetic complications, enabling early identification and intervention. It might be beneficial for evaluating disease severity, monitoring treatment response, and predicting long-term results in diabetics.

Results and conclusion

Although the phase angle offers significant advantages, its clinical use in managing diabetes is still in its early stages, and there are certain issues that need to be resolved. Standardization of measurement techniques and interpretation criteria is essential to ensure consistency and comparability across studies and clinical settings. Investigating the role of phase angle in the treatment of diabetes provides significant knowledge about its potential as a non-invasive and informative parameter. Identifying the importance of phase angle in diabetes might help to improve risk stratification, treatment strategies, and patient outcomes. Additional research is required to determine its therapeutic value and discover the mechanisms underlying its association with diabetes and its complications.

Thirty-second chair stand test in older adults with chronic health conditions is associated with lower limb oxygen extraction capacity

BACKGROUND

The 30-s chair stand test (CS-30) is a well-known measure of muscle strength in older adults. However, factors other than muscle strength may also be involved in older adults with chronic health conditions who require support and care in daily living.

PURPOSE

To test the hypothesis that the CS-30 in older adults with chronic health conditions is associated with lower limb muscle oxygen extraction capacity.

METHODS

Twenty-seven older adults with chronic health conditions (those who needed support and care in daily living because of stroke, musculoskeletal disease, etc.) were recruited. Tissue and percutaneous oxygen saturations of the right vastus lateralis muscle were measured during CS-30 measurements, and muscle oxygen extraction rate (MOER) was calculated. Knee extension strength, skeletal muscle mass index (SMI), and phase angle (PhA) were measured. In a multiple regression analysis with CS-30 as the dependent variable, results were calculated for model 1 with SMI, PhA, and ΔMOER as independent variables and model 2 with knee extension muscle strength added to model 1.

RESULTS

Phase angle (model 1, β = 0.46, p = .014; model 2, β = 0.46, p = .016) and ΔMOER (model 1, β = 0.39, p = .032; model 2, β = 0.40, p = .039) were significantly associated in both models. Adjusted R2 was 0.26 (Model 1) and 0.23 (Model 2).

CONCLUSION

The CS-30 in older adults with chronic health conditions may be related to muscle oxygen extraction capacity. This indicates that CS-30 also considers lower limb endurance assessment in this population.

Factors influencing changes in body composition and nutritional status in patients with hyperacute stroke: prospective study

Background and aims

Muscle loss not only reduce the effectiveness of the recovery period of rehabilitation after stroke but also prolongs the length of hospital stay. Therefore, it is crucial to maintain muscle mass during the hyperacute phase of stroke. We aimed to investigate the factor that influence changes in muscle mass and quality in patients with hyperacute stroke by using a body composition analyzer.

Methods

Body composition assessment was performed on 156 patients admitted to the stroke care unit at the time of admission and 1 week later. Additionally, associations between rehabilitation intervention time, nutritional dosage and administration method, and stroke severity were examined to which factors were affecting body composition.

Results

Muscle mass and quality significantly decreased in both men (SMI: 7.41 ± 1.26 to 7.22 ± 1.23 kg/m2, p < 0.005, phA: 5.5 ± 1.24 to 5.31 ± 1.29 degree, p < 0.005) and women (SMI: 6.04 ± 1.30 to 5.08 ± 1.20 kg/m2, p < 0.005, phA: 4.58 ± 0.85 to4.18 ± 0.82 degree, p < 0.005)1 week after admission. Rehabilitation intervention time [odds ratio (OR) = 2.12; 95% CI: 1.28-4.47, p = 0.01], and high calorie dosage (OR = 1.53; 95% CI: 1.14-3.21, p = 0.03) significantly reduced the loss of muscle mass. However, stroke severity did not affect variations in body composition.

Conclusion

Deterioration in muscle mass and quality was observed during the hyperacute phase of stroke. The risk of muscle mass loss may be reduced with appropriate rehabilitation intervention and diet therapy from the early stage of hospitalization. Therefore, providing early rehabilitation intervention and nutritional management in the hospitalization phase are important to improve treatment effectiveness. In hyperacute stroke treatment, rehabilitation and nutritional administration should be provided as early as possible.

Clinical trial registration

https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000053017, identifier UMIN-CTR UMIN000046467.

Relationship between age and various muscle quality indices in Japanese individuals via bioelectrical impedance analysis (BIA)

BACKGROUND

Bioelectrical impedance analysis (BIA) is widely used as a convenient method of measuring body composition. The validity of the phase angle (PhA), impedance rate (IR), and resistance rate (RR) as indices of muscle quality using BIA has been suggested. This study aimed to investigate the relationship between these muscle quality indices and age, and to clarify their characteristics.

METHODS

The appendicular muscle mass (AMM), AMM corrected for body mass index (AMM/BMI), PhA, IR, and RR were determined using BIA in 1376 Japanese individuals (532 males and 844 females) aged 15-95 years. The PhA was determined from a 50-kHz current, and the IR and RR were determined from the impedance and resistance ratios between the 250- and 5-kHz currents.

RESULTS

AMM/BMI showed greater age-related changes than the other indices of muscle mass. Significant differences in PhA, IR, and RR were found for the whole body at age ≥ 50 years and for the lower limbs at age ≥ 30 years, compared to those in their 20 s. For the arms, age-related changes were small, and significant differences in PhA of females were only observed at aged ≥ 85 years, whereas significant differences in IR and RR were observed at aged ≥ 75 years, compared to those in their 20s.

CONCLUSION

These results suggest that although PhA, IR, and RR in the whole body and lower limbs showed age-related changes, the change in PhA in the upper body was small, especially in females. However, IR and RR in the upper limbs of females reflected age-related changes more than PhA.

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.

The correlation between serum alkaline phosphatase and grip strength in middle-aged and elderly people: NHANES 2011-2014

BACKGROUND

Serum alkaline phosphatase (ALP) plays a crucial role in bone and muscle health. Previous studies have demonstrated that serum alkaline phosphatase (ALP) is closely associated with muscle mass. Nevertheless, the association between serum alkaline phosphatase (ALP) and grip strength remains unclear. Therefore, the present study focused on exploring the association of serum ALP with grip strength in middle-aged and elderly people.

METHODS

We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey conducted from 2011 to 2014. A total of 3514 participants (1891 males and 1623 females) aged 40-80 years were included in this study. Serum ALP and pelvic grip strength were analyzed as independent and dependent variables, additional variables were the possible impact modifiers. weighted generalized linear models and stratified analysis by gender, age group, and race were applied to assess the relationship between serum ALP and grip strength. Smooth curve fitting and threshold effect analysis/saturation effect analysis were used to analyze the nonlinear relationship between the 2 variables.

RESULTS

In the gender-stratified subgroup analysis, we observed an inverse association between serum ALP and grip strength in both male and female. When stratified by age group, the association remained significant among participants 40-59 years of age, but not among those ≥ 60 years old. When stratified by race, the association remained significant among Non-Hispanic White and Non-Hispanic Black. It is noteworthy that serum ALP and grip strength showed a significant negative correlation among female aged 40-59 years, but not among female aged ≥ 60 years. Additionally, Smooth curve fitting showed that serum ALP had a nonlinear relationship with grip strength in male aged 40-59 years and male aged over 60 years, the inflection points are 54 IU and 97 IU respectively.

CONCLUSION

Our study revealed an inverse relationship between serum ALP and grip strength, this finding offers new insights and avenues for understanding how serum alkaline phosphatase affects skeletal muscle health.

Effects of outdoor play on body composition and physical performance in children: the Yamanashi Adjunct study of the Japan Environment and Children's Study

INTRODUCTION

Childhood is a pivotal developmental stage that substantially affects lifelong habits. Recent research has emphasized the vital role of outdoor play in children's mental and physical well-being. Despite the World Health Organization recommending 1 hour of daily physical activity for children, a knowledge gap exists regarding the specific link between children's physical performance, body composition (evaluated through bioelectrical impedance analysis [BIA]), and outdoor play habits.

METHODS

Utilizing data from the Japan Environment and Children's Study, a national birth cohort study, this study included 494 eight-year-old participants. The assessment included body composition (height, weight, body fat percentage, predicted muscle weight, and phase angle using BIA) and physical performance (50 m sprint, standing long jump, 20 m shuttle run, and handgrip strength). Parents provided information on children's outdoor playtime.

RESULTS

The group with more outdoor play demonstrated superior sports test results, particularly among boys. Girls engaged in increased outdoor play exhibited higher predicted muscle weights, whereas boys showed greater phase angles in the lower limbs. Handgrip strength correlated with phase angle and predicted muscle weight. Notably, the association between body composition and sports test results was more pronounced in boys than in girls, with phase angles exhibiting stronger links to running and jumping.

CONCLUSION

This pioneering study explored the relationship between outdoor play, body composition, and physical performance in children. Outdoor play positively correlated with improved sports performance, revealing sex disparities in body composition changes. Unlike previous studies focusing on general physical development, this study scrutinized specific physical functions, uncovering correlations between phase angle and muscle quality. Findings suggest that outdoor play positively impacts muscle quality, especially in boys, contributing to enhanced physical performance in children. Understanding these effects on body composition and physical activity is imperative for promoting children's health.

Decreased Lower Limb Phase Angle in Older People Is an Indicator of Standing and Gait Function, Regardless of Age

Background/Objectives: The phase angle (PhA), as measured using bioelectrical impedance analysis (BIA), indicates muscle mass and quality. However, its relationship with age-related muscle changes and motor function and effective BIA assessment/intervention sites remains unclear. Herein, we evaluated age-related changes in PhA, explored the relationship between PhA and muscle mass, and identified effective sites for BIA. Methods: We included 131 healthy community-dwelling adults divided into older (≥65 years) and control (≤65 years) groups. PhA and muscle mass were measured using BIA with a device determining electrical resistance by transmitting a weak alternating current <90 μA. Motor function was measured using ground reaction force index, gait function, and grip strength. The relationships between muscle mass, PhA, and motor function were analyzed. Results: All values, excluding upper limb muscle mass, were lower in the older group, as were the rates of change in muscle mass and PhA in the lower limbs vs. the upper limbs. Lower limb PhA showed negative and positive correlations with the Timed Up and Go test and standing function, respectively; it was significantly associated with all motor functions. Conclusions: Regardless of age, muscle mass and PhA measured by BIA were high and low in the lower limbs, respectively, and lower limb PhA was related to walking and standing function. The decrease in lower limb muscle mass and PhA may accelerate with age. Given global population aging, easy-to-assess lower limb PhA linked to the movements necessary for independent living may be an effective site for assessment and intervention in clinical practice.

The Impact of Photobiomodulation Therapy on Swelling Reduction and Recovery Enhancement in Total Knee Arthroplasty: A Randomized Clinical Trial

Background: Total knee arthroplasty (TKA) is commonly performed for severe osteoarthritis but often results in significant postoperative swelling and discomfort, impacting early rehabilitation. Photobiomodulation therapy (PBMT), utilizing low-level laser therapy (LLLT), has emerged as a potential adjunctive treatment to alleviate these symptoms. Methods: In this single-center, nonblinded prospective randomized clinical trial, conducted from May to July 2024, 30 patients undergoing primary TKA were enrolled and divided into two groups. Fifteen patients formed the control group receiving standard postoperative care, while the intervention group consisted of another 15 patients who received additional PBMT from the first to the fifth postoperative day (POD). The swelling was assessed using bioimpedance analysis, which offers a noninvasive, safe, and efficient method for assessing postoperative swelling by measuring tissue impedance, and functional outcomes were measured using the 2-min walk test (2MWT) and active range of motion (aROM). The study was registered with ClinicalTrials.gov (NCT06426251). Results: The PBMT group demonstrated significantly lower impedance, reactance, and phase angle ratios by POD6, suggesting reduced swelling compared to the control group. In the 2MWT, the PBMT group achieved a longer walking distance of 27 m, compared to 16 m in the control group. However, there were no significant differences in aROM or Visual Analogue Scale (VAS) pain scores between the groups. Conclusions: The findings indicate that PBMT effectively reduces postoperative swelling and enhances early mobility post-TKA. These benefits suggest that PBMT can be a valuable addition to conventional postoperative care, potentially accelerating functional recovery, and reducing rehabilitation time.

Six-month trajectory of phase angle after cardiovascular surgery and associated factors of the recovery during cardiac rehabilitation: A retrospective cohort study

BACKGROUND AND AIMS

Although the phase angle (PhA), a measure of frailty and sarcopenia, determined by bioelectrical impedance analysis has been reported as a prognostic factor after cardiovascular surgery, few studies have reported the trajectory of the PhA after discharge. In this study, we examined the trajectory of the PhA along with conventional physical function measures and explored the factors associated with recovery for 6 months after hospital discharge in patients who had undergone cardiovascular surgery.

METHODS

We included 116 patients who underwent elective cardiovascular surgery and cardiac rehabilitation after discharge. The PhA, physical function measures (grip strength, knee extension isometric muscle strength [KEIS], and usual gait speed), and Geriatric Nutritional Risk Index (GNRI) were assessed preoperatively, at discharge, and 3 and 6 months. Correlations between the PhA recovery rates and physical function and nutritional indices were assessed using Spearman's correlation analysis. Multivariate linear regression analysis was performed to examine the factors associated with recoveries of PhA and physical function indices (grip strength, KEIS, gait speed) after discharge.

RESULTS

Mean values of the PhA and physical function measurements and the GNRI score at discharge were lower than the preoperative values (PhA, -8.0 %; grip strength, -8.7 %; KEIS, -6.9 %; usual gait speed, -8.3 %; GNRI, -11 %). The grip strength, KEIS, and gait speed recovered to almost preoperative values 3 months after discharge. Values for the PhA and GNRI were still lower than preoperative values 3 months after discharge but had recovered to preoperative values at 6 months. The PhA was not significantly correlated with the recovery rates of the other indicators. Older age was negatively associated with PhA recovery rate, however, recovery rates decreased significantly with post-discharge physical activity.

CONCLUSIONS

In patients undergoing cardiovascular surgery, the PhA takes longer to recover than muscle strength or gait speed, requiring up to 6 months to recover to preoperative levels. Post-discharge interventions to increase daily physical activity may be an important method of speeding PhA recovery.

Association between segmental phase angles and functional independence measure scores in hospitalized adults following stroke: A retrospective cohort study

BACKGROUND

This study investigated the association between segmental phase angles and functional outcomes in patients after stroke, hypothesizing that increased segmental phase angle correlates with improved functional status.

METHODS

A retrospective cohort study of 1012 patients after stroke was conducted. Whole body and segmental phase angles were measured using bioelectrical impedance analysis within 3 days of admission. Our exposure of interest was segmental phase angle measured via a multifrequency bioelectrical impedance analyzer and calculated as phase angle = arctangent (Xc/R) × (180/π), where R is the resistance of the right half of the body and Xc is the reactance measured at 50 kHz. The primary outcomes were the motor subscale of the functional independence measure (FIM) at discharge and FIM change between admission and discharge. Secondary outcomes included FIM scores for specific activities. Multiple linear regression analysis was performed to assess associations.

RESULTS

Phase angles of the healthy upper and lower limbs demonstrated stronger associations with discharge FIM motor scores (β = 0.175 and β = 0.105, respectively) and FIM motor gain (β = 0.242 and β = 0.092, respectively) compared with whole body or paretic limb phase angles. Upper limb phase angles were more closely related to grooming and toileting abilities, whereas lower limb phase angles were associated with both toileting and locomotion at discharge.

CONCLUSION

Segmental phase angles, particularly those of the nonparetic limbs, are promising predictors of functional outcomes in patients after stroke. Assessing segmental phase angles may guide targeted interventions and rehabilitation strategies for improving specific activities of daily living.

Selective peroxisome proliferator-activated receptor-α modulator improves hypertriglyceridemia and muscle quality in patients with chronic kidney disease: A retrospective observational study

BACKGROUND & AIMS

Patients with chronic kidney disease (CKD) often have additional health problems, including sarcopenia and sarcopenic obesity. These conditions involve ectopic fat accumulation within muscles. This ectopic fat deposition reduces muscle quality, leading to weaker muscle strength and poorer physical performance. Persistent hypertriglyceridemia contributes to ectopic fat accumulation. Metabolic abnormalities, including dyslipidemia, are major factors in CKD development. Triglycerides (TG) and muscle quality are thus important factors in CKD management. Recently developed selective peroxisome proliferator-activated receptor α modulator (SPPARMα) hold promises for improving hypertriglyceridemia. However, their effectiveness and impact on muscle quality in CKD patients remain unclear. This study aimed to evaluate the effect of SPPARMα on muscle quality and its efficacy in CKD patients.

METHODS

This retrospective observational study involved CKD patients with dyslipidemia. We included patients who initiated medications for hypertriglyceridemia. We compared changes in lipid profiles, renal function, and muscle quality, assessed by phase angle, over six months between two groups: those receiving this type of medication and those receiving conventional treatment.

RESULTS

Among 245 patients diagnosed with CKD and hypertriglyceridemia, 52 started medications for hypertriglyceridemia. Of these, 26 received SPPARMα, and 26 received conventional lipid-lowering medications (statins, ezetimibe, eicosapentaenoic acid, and fibrates). SPPARMα significantly reduced TG (from 296.8 ± 106.1 to 153.0 ± 86.1, p < 0.001) without affecting glomerular filtration rate or urinary protein levels. Conventional treatment also improved TG (from 261.6 ± 89.5 to 173.6 ± 81.3, p < 0.001). Only patients treated with SPPARMα showed significant improvement in muscle quality. Their phase angle increased from 5.41 ± 0.6 to 5.55 ± 0.6 after six months of treatment (p < 0.05).

CONCLUSIONS

Our study demonstrates that the newly developed SPPARMα significantly lowers TG levels in CKD patients without harming their kidneys. Additionally, only patients treated with SPPARMα showed improvement in muscle quality. These findings suggest that SPPARMα may be a valuable treatment option for CKD patients with dyslipidemia, particularly those with low muscle quality.

Association between hypovitaminosis D and sarcopenic obesity in patients with chronic kidney disease stages 3 and 4

The relationship between sarcopenic obesity and hypovitaminosis D in individuals with chronic kidney disease is complex and has significant impacts on muscle and bone health. An observational, cross-sectional, and analytical study was conducted to analyze possible associations between serum vitamin D levels and sarcopenic obesity in patients with chronic kidney disease stages 3 and 4 in a cohort of patients under nephrology care. The presence of sarcopenic obesity was assessed using bioimpedance criteria, and vitamin D levels were measured and recorded for each patient. Statistically significant associations were found between sarcopenic obesity and suboptimal vitamin D levels (p < 0.005) as well as between severe sarcopenia and hypovitaminosis D (p < 0.05) in patients with chronic kidney disease stages 3 and 4. Patients with optimal levels of vitamin D showed better muscle quality and a lower prevalence of sarcopenia and severe sarcopenia. The findings suggest that vitamin D levels play a crucial role in muscle quality in patients with CKD stages 3 and 4. Maintaining optimal levels of vitamin D may help reduce the prevalence of sarcopenic obesity and improve quality of life in these patients.

Pre-stroke patient characteristics that influence skeletal muscle quality: A cross-sectional study

AIM

One of the parameters that is measurable using bioelectrical impedance is the phase angle (PhA), which is an indicator of skeletal muscle quality. The PhA reflects cellular health and nutritional status and is an important parameter for monitoring recovery after stroke. However, the factors affecting skeletal muscle quality remain unclear. Therefore, this study aimed to identify the factors associated with skeletal muscle quality in patients with acute stroke.

METHODS

A total of 505 consecutively hospitalized patients with acute stroke were included in this study. The primary outcome was the PhA measured by bioelectrical impedance analysis, which evaluates muscle quality. Multiple regression analysis was performed to identify the factors affecting PhA.

RESULTS

The mean age of the participants was 75.1 years, and 44% were female. The median National Institutes of Health Stroke Scale (NIHSS) score upon admission was 4, and the mean length of stay was 18 days. The mean PhA for skeletal muscle quality was 4.9° in males and 3.9° in females. Multiple regression analysis showed that age, sex, pre-stroke modified Rankin Scale (pre-mRS), Geriatric Nutritional Risk Index, type 2 diabetes mellitus, atrial fibrillation, and chronic kidney disease had independent effects on PhA (R2 = 0.575; P = 0.001). Age, pre-mRS, NIHSS, dementia, and PhA independently associated with functional independence measure at discharge (R2 = 0.657; P = 0.001).

CONCLUSIONS

This study identified determinants contributing to the deterioration of muscle quality upon admission in acute stroke patients. Further investigation is needed to ascertain whether modulation of these factors improves muscle quality. Geriatr Gerontol Int 2025; 25: 213-219.

Association between phase angle and all-cause mortality in adults aged 18-49 years: NHANES 1999-2004

Phase angle (PhA) is an indicator of nutritional status. The association between PhA and all-cause mortality has been confirmed in older adults, but no relevant studies have been conducted in adults aged 18-49 years. This study aimed to investigate the relationship between PhA and all-cause mortality in adults aged 18-49 years. Our study included 6338 adults aged 18-49 from the National Health and Nutrition Examination Survey (1999-2004). Kaplan-Meier (KM) curve, multiple Cox regression and stratified analyses were performed. These adults were divided into two groups based on the median PhA value (the low PhA group: PhA < 6.96°; the high PhA group: PhA ≥ 6.96°). During a median follow-up of 214 months, 307 all-cause deaths were recorded. The all-cause mortality rate was 5.07% in the low PhA group and 3.98% in the high PhA group. After full adjustment, a higher PhA value was significantly associated with reduced risk of all-cause mortality (HR = 0.73,95CI%:0.59-0.91, P = 0.005). Similarly, compared with those in the low PhA group, individuals in the high PhA group had a lower risk of all-cause mortality (HR = 0.67, 95% CI 0.46-0.98, P = 0.041). There was an interaction between smoking status and PhA (P for interaction = 0.029), with a statistically significant negative association between PhA and all-cause mortality in the non-smokers (HR:0.62, 95%CI:0.53-0.88, P = 0.003). In conclusion, there was a significant negative association between PhA and all-cause mortality in adults aged 18-49 years. The negative association was stronger in non-smokers.

Poor muscle quality: A hidden and detrimental health condition in obesity

Poor muscle quality (MQ) is a hidden health condition in obesity, commonly disregarded and underdiagnosed, associated with poor health-related outcomes. This narrative review provides an in-depth exploration of MQ in obesity, including definitions, available assessment methods and challenges, pathophysiology, association with health outcomes, and potential interventions. MQ is a broad term that can include imaging, histological, functional, or metabolic assessments, evaluating beyond muscle quantity. MQ assessment is highly heterogeneous and requires further standardization. Common definitions of MQ include 1) muscle-specific strength (or functional MQ), the ratio between muscle strength and muscle quantity, and 2) muscle composition (or morphological MQ), mainly evaluating muscle fat infiltration. An individual with obesity might still have normal or higher muscle quantity despite having poor MQ, and techniques for direct measurements are needed. However, the use of body composition and physical function assessments is still limited in clinical practice. Thus, more accessible techniques for assessing strength, muscle mass, and composition should be further explored. Obesity leads to adipocyte dysfunction, generating a low-grade chronic inflammatory state, which leads to mitochondrial dysfunction. Adipocyte and mitochondrial dysfunction result in metabolic dysfunction manifesting clinically as insulin resistance, dyslipidemia, and fat infiltration into organs such as muscle, which in excess is termed myosteatosis. Myosteatosis decreases muscle cell function and insulin sensitivity, creating a vicious cycle of inflammation and metabolic derangements. Myosteatosis increases the risk of poor muscle function, systemic metabolic complications, and mortality, presenting prognostic potential. Interventions shown to improve MQ include nutrition, physical activity/exercise, pharmacology, and metabolic and bariatric surgery.

Usefulness of body composition assessment by bioelectrical impedance vector analysis in subacute post-stroke patients in rehabilitation

Bioelectrical Impedance Vector Analysis (BIVA) is a valuable tool for evaluating hydration and body composition, but its application in subacute post-stroke patients remains unexplored. This study aimed to fill this gap by analyzing BIVA in a cohort of 87 subacute post-stroke patients (42 women, mean age 69 ± 12) undergoing rehabilitation. At admission (T0), diagnosis of malnutrition with GLIM criteria and of sarcopenia with EWGSOP2 was done, and patients were analyzed with BIVA. The change in modified Barthel Index (mBIT1-mBIT0) was assessed to evaluate the improvement in functional recovery. BIVA revealed that both adult patients (< 65 years, n = 29) and elderly patients (≥ 65 years, n = 58) exhibited high body fluid overload and low muscle mass. Additionally, BIVA revealed a significant rightward shift of the bioimpedance vectors in malnourished (n = 37) versus non-malnourished patients (T2 = 56.9, p < 0.001, D = 1.68) and in sarcopenic (n = 24) versus non-sarcopenic patients (T2 = 36.4, p < 0.001, D = 1.5). Lastly, the BIVA distinguished patients with greater improvement (n = 53) from patients with lower improvement (n = 34) (T2 = 10.6, p = 0.007, D = 0.7). In conclusion, BIVA is an effective, easy-to-use tool for evaluating hydration, nutritional status, and recovery in post-stroke rehabilitation.

Association between phase angle and daily creatinine excretion changes in critically ill patients: an approach to muscle mass

Assessing muscle mass in critically ill patients remains challenging. This retrospective cohort study explores the potential of phase angle (PA°) derived from bioelectrical impedance analysis (BIA) as a surrogate marker for muscle mass monitoring by associating it with daily creatinine excretion (DCE), a structural and metabolic muscle mass marker. In 20 ICU patients, we observed a linear relationship between PA° and DCE at initial (S1) and follow-up (S2) points, with Rho values of 0.78 and 0.65, respectively, as well as between their percentage changes (Rho = 0.80). Multivariate analysis confirmed a strong association between changes in PA° and DCE (adjusted R2 of 0.73), while changes in the extracellular water to total body water (ECW/TBW) ratio showed no significant association. This study establishes a relationship between a BIA-derived independent-weight parameter and DCE, highlighting the potential of PA° for muscle mass monitoring during acute changes, such as those seen in ICU settings. Integrating PA° into clinical practice could provide a non-invasive and reliable tool to enhance muscle assessment and support targeted interventions in critically ill patients.

Development and clinical application of bioelectrical impedance analysis method for body composition assessment

Obesity, which is characterized by excessive body fat, increases the risk of chronic diseases, such as type 2 diabetes, cardiovascular diseases, and certain cancers. Sarcopenia, a decline in muscle mass, is also associated with many chronic disorders and is therefore a major concern in aging populations. Body composition analysis is important in the evaluation of obesity and sarcopenia because it provides information about the distribution of body fat and muscle mass. It is also useful for monitoring nutritional status, disease severity, and the effectiveness of interventions, such as exercise, diet, and drugs, and thus helps assess overall health and longevity. Computed tomography, magnetic resonance imaging, and dual-energy X-ray absorptiometry are commonly used for this purpose. However, they have limitations, such as high cost, long measurement time, and radiation exposure. Instead, bioelectrical impedance analysis (BIA), which was introduced several decades ago and has undergone significant technological advancements, can be used. It is easily accessible, affordable, and importantly, poses no radiation risk, making it suitable for use in hospitals, fitness centers, and even at home. Herein, we review the recent technological developments and clinical applications of BIA to provide an updated understanding of BIA technology and its strengths and limitations.

Effects of muscle quantity, muscle quality, and phase angle on whole-body reaction time in 5164 adults aged 20-91 years

PURPOSE

Muscle quantity, defined as appendicular lean mass (ALM); muscle quality, defined as the ratio of muscle strength to ALM; and bioelectrical impedance analysis (BIA)-derived phase angle (PhA) are determinants of physical performance. We examined whether muscle quality indices were significant predictors of the whole-body reaction time (WBRT) in healthy female and male adults aged 20-91 years.

METHODS

Data from 5164 adults (2869 women and 2295 men; mean age ± standard deviation, 60.9 ± 15.6 years) were analyzed. Height and weight were measured, and body mass index was calculated. ALM was estimated using a previously validated 8-electrode multi-frequency BIA. PhA was measured at 50 kHz using a BIA device. Knee extension strength (KES), leg extension power (LEP), and flexibility were examined. The ALM to weight (ALM/weight), KES to ALM (KES/ALM), and LEP to KES (LEP/KES) ratios were calculated. In the WBRT test, participants were asked to stand on a force plate and jump upright as quickly as possible in response to a light stimulus. The WBRT was divided into the response initiation and motion execution phases.

RESULTS

ALM/weight, KES/ALM, LEP/KES, PhA, and flexibility were significant independent predictors of WBRT and the time of the motion execution phase (p < 0.001). However, PhA was not a significant predictor of the time of response initiation phase.

CONCLUSION

Muscle quantity (ALM/weight), muscle quality (KES/ALM and LEP/KES), PhA, and flexibility are determinants of WBRT test performance, particularly in the motion execution phase.

Associations of socio-demographic, anthropometric and behavioural factors with phase angle in older adults: a cross-sectional study in Taiwan

OBJECTIVE

Phase angle (PhA) is a prognostic factor for predicting and monitoring geriatric syndromes. However, multiple factors associated with increased PhA values as an outcome remain unclear in the older population. This study aimed to examine the association of socio-demographic, anthropometric and behavioural factors with PhA among older Taiwanese adults.

DESIGN

This cross-sectional study was conducted between May and August 2023.

SETTING

The study was carried out in northern Taiwan, specifically Taipei city and Yilan county.

PARTICIPANTS

Participants aged ≥65 years who were able to walk independently and had no artificial implants, such as cardiac pacemakers or joint replacements, were recruited using convenience sampling. A total of 198 participants were initially recruited for this study.

PRIMARY OUTCOME MEASURES

Data on socio-demographic and behavioural variables were collected using self-administered questionnaires. Anthropometric variables and PhA were measured using a multi-frequency bioelectrical impedance analyser (MC-780MA, TANITA). PhA was categorised into 'high' and 'low' using gender-specific cut-off points. A logistic regression analysis was performed.

RESULTS

A total of 152 participants (mean age: 72.0±5.5 years; 121 women (79.6%)) were included. Male (OR=0.72, 95% CI=0.02 to 0.33), unmarried (OR=0.22, 95% CI=0.06 to 0.82) and unemployed older adults (OR=0.16, 95% CI=0.03 to 0.87) were less probable to achieve high PhA values. After adjusting for potential confounders, older individuals with an increased body mass index (BMI) (OR=2.56, 95% CI=1.61 to 4.07) and greater muscle mass (OR=1.34, 95% CI=1.12 to 1.60) may have higher PhA values, whereas those with a greater fat mass may have lower PhA values (OR=0.61, 95% CI=0.48 to 0.78). No significant associations were observed between behavioural factors and PhA values.

CONCLUSIONS

The interventions designed to improve PhA should prioritise strategies tailored to male, unmarried or unemployed older adults, as well as those with low BMI, low muscle mass and high fat mass. Future studies with larger sample sizes are needed to confirm and strengthen our findings.

Prevalence and associated body composition factors of sarcopenia in community-dwelling older adults

BACKGROUND

The objective of this investigation was to examine the frequency and determinants related to body composition of sarcopenia among aging individuals residing in the Beijing community through implementation of the diagnostic criteria for sarcopenia outlined by the 2019 Asian Working Group for Sarcopenia (AWGS).

METHODS

A cross-sectional examination employing multistage cluster sampling was conducted on a sample consisting of 933 individuals aged 50 years or above. The study utilized the AWGS 2019 criteria for muscle mass, muscle strength, and physical function to gauge sarcopenia. In addition, data on demographic characteristics, anthropometry, and body composition were collected. Logistic regression analysis was carried out to ascertain the relationships between sarcopenia and correlated factors.

RESULTS

The study found that the overall prevalence of sarcopenia was 8.3%. Sex (p < 0.001) and body mass index (BMI p < 0.001) were determined to have a significant association with the occurrence of sarcopenia. The adjusted analyses demonstrated that with each standard deviation increase in fat-free mass index (OR = 0.02 (0.01-0.05), of 95%), skeletal muscle mass (OR = 0.17 (0.12-0.25), of 95%), and other body composition indicators (including total body water 0.26 (0.2-0.35), intracellular water 0.1 (0.06-0.17), protein 0.01 (0-0.02), soft lean mass 0.35 (0.28-0.44), BMI 0.58 (0.51-0.67), body cell mass 0.21 (0.15-0.29), OR < 0.60, of 95%), the risk of sarcopenia decreased by more than 40%. Certain straightforwardly accessible anthropometric indices such as upper arm circumference (correlation coefficient 0.94 (0.9-0.97), 0.97 (0.95-1), 1.01 (0.99-1.03), respectively, of 95%), waist circumference (0.94(0.92-0.96), 1.01 (0.99-1.03), 1.02 (1-1.03), of 95%), hip circumference (0.93 (0.9-0.96), 0.99 (0.97-1.02), 1.02 (1-1.04), of 95%), waist-to-hip ratio (0.93 (0.87-1), 1.04 (1-1.08), 1 (0.97-1.03), of 95%), body fat percentage (1 (0.98-1.02), 1.02(1-1.04), 1.01 (0.99-1.02), of 95%), and phase angle (0.91 (0.89-0.93), 0.96 (0.94-0.98), 0.99 (0.98-1), of 95%) exhibited substantial correlation with skeletal muscle index, muscle strength or physical performance. However, no noteworthy link between sarcopenia and most variables associated with physical function was discovered.

CONCLUSIONS

The findings of the study highlight the prevalence of sarcopenia among the aging residents of Beijing. Certain easily measured anthropometric indices demonstrated strong correlation with muscle strength or physical performance, thereby providing an avenue for screening and diagnosing sarcopenia in older people who may not be able to undergo grip strength or physical function assessments. To investigate causal relationships, future studies employing longitudinal or interventional designs with a more comprehensive population are warranted.

Limited predictive value of bioelectrical phase angle for the development of sarcopenia in older Europeans

BACKGROUND

Despite the emerging interest in phase angle (PhA), a non-invasive marker of cell hydration and nutritional status, no previous study has reported the prospective association between PhA and incident sarcopenia. Therefore, the aim of our study was to evaluate the association of baseline PhA in older subjects without sarcopenia with the development of new sarcopenia as outcome.

METHODS

Six-hundred ninety-six subjects without sarcopenia aged ≥75 years enrolled in an international multicenter observational study were included. Sarcopenia was assessed according to the revised EWGSOP2 criteria at baseline and in follow-up visits at 12 and 24 months. Muscle strength was assessed through the handgrip strength test using a hydraulic grip strength dynamometer, muscle mass was assessed by bioimpedance analysis (BIA) and appendicular skeletal muscle mass (ASMM) was estimated. Physical performance was assessed by Short Physical Performance Battery (SPPB).

RESULTS

Participants who developed sarcopenia were older, less educated, had higher prevalence of osteoporosis, and lower baseline cognitive function, SPPB, handgrip strength and ASMM than those without sarcopenia. Baseline PhA was significantly lower in subjects developing sarcopenia. Nevertheless, after adjusting for all potential covariates including baseline components of sarcopenia in multiple logistic regression, neither PhA as continuous variable nor different levels of PhA were any more significant predictors of sarcopenia.

CONCLUSIONS

As an indicator of cells function, PhA could be a potential useful early marker in identifying older people at risk of developing sarcopenia but its practical applicability remains uncertain with the present data.

Quality of Life and non-motor symptoms Improvement in Parkinson's Disease through Nutritional Intervention: a Case Study

Non-motor symptomatology in Parkinson's disease (PD) is related to patients' quality of life (QoL). The Non-Motor Symptoms Scale (NNMS) assesses QoL by investigating numerous domains including nutritional status, which is represented by domain 6. Patients with PD commonly suffer from dysphagia, and consequently malnutrition, leading to sarcopenia and increasing motor deficits in relation to loss of muscle mass and energy deficit. The impact of dysphagia on PD patients' health status, makes it necessary to study the effectiveness of specific nutritional programs in addressing feeding needs, with the goal to improve clinical outcomes and the patient's perception of their QoL. The 'Weancare' Program was trialed on an 84-year-old PD patient suffering from dysphagia and the Tower of Pisa Syndrome. The first assessment of the patient showed an early overall deteriorating condition, particularly under a nutritional point of view. The patient was assessed before and after the intervention considering serological tests, and the QoL through the New Non-Motor Symptoms Scale (NNMS). We found a beneficial impact of the 'Weancare' program on the patient significantly improving the non-motor symptomatology and QoL and the investigated outcomes, enhancing a better subjective experience of mealtime lived by the patient.

Correlation between Phase Angle and the Number of Medications in Older Inpatients: A Cross-Sectional Study

BACKGROUND

Muscle weakness in older adults elevates mortality risk and impairs quality of life, with the phase angle (PhA) indicating cellular health. Polypharmacy, common in geriatric care, could influence PhA. This investigates whether the number of medications and polypharmacy with PhA as a biomarker of muscle quality in older inpatients aged ≥65 and determines the extent to which multiple medications contribute to the risk of reduced muscle quality.

METHODS

This retrospective cross-sectional study analyzed data from older inpatients requiring rehabilitation. PhA was measured using bioelectrical impedance analysis. The number of medications taken by each patient was recorded at admission. Polypharmacy was defined as the concurrent use of five or more medications at admission.

RESULTS

In this study of 517 hospitalized older adults (median age 75 years; 47.4% men), 178 patients (34.4%) were diagnosed with sarcopenia. Polypharmacy was present in 66% of patients. The median PhA was 4.9° in men and 4.3° in women. Multivariate linear regression analysis was performed separately for men and women. In men, PhA was negatively correlated with the number of medications (β=-0.104, p=0.041) and polypharmacy (β=-0.045, p=0.383). In women, PhA was negatively correlated with the number of medications (β=-0.119, p=0.026) and polypharmacy (β=-0.098, p=0.063). Analyses were adjusted for age, body mass index, sarcopenia, C-reactive protein, and hemoglobin levels.

CONCLUSION

The number of medications at admission negatively impacted PhA in older inpatients, highlighting the importance of reviewing prescribed drugs and their interactions.

Improved trunk muscle quality in patients with stroke increases improvements in activities of daily living

BACKGROUND

This study aimed to determine whether an increased trunk muscle quality index (TMQI) is associated with activities of daily living (ADL) in patients ≥ 65 years of age with cerebral infarction in a convalescent rehabilitation ward.

METHODS

This retrospective observational study included patients aged ≥ 65 years who were admitted for post-stroke rehabilitation in Okinawa, Japan, between May 2018 and December 2022. The TMQI was calculated at admission and discharge using bioelectrical impedance analysis. Patients were divided into two groups based on the change in the TMQI during hospitalization: increase-in-TMQI and no-increase-in-TMQI groups. Multiple regression analysis was employed to explore the impact of increased TMQI on functional independence measure (FIM) -motor gain.

RESULTS

We included a total of 315 patients (79.1 ± 7.9 years of age, 51.7% men) in our analyses. Over half (165 [52.4%]) of the patients exhibited an increase in TMQI scores, and 150 (47.6%) patients did not exhibit an increase. No significant difference was observed in motor FIM score and motor FIM gain at admission and discharge between the groups with and without increased TMQI. Increased TMQI was independently associated with increased FIM-motor gain (adjusted R2 = 0.340 and R2 = 0.357, coefficient = 1.736, 95% confidence interval: 0.52-2.95, P = 0.005).

CONCLUSIONS

The results of this study suggest that increased TMQI has a positive effect on the recovery of physical function in patients with stroke. Further prospective studies are needed to elucidate the relationship between increased TMQI and ADL.

Phase angle is a useful predicting indicator for protein-energy wasting and cardiovascular risk among maintenance hemodialysis patients

Protein-energy wasting (PEW) is a major contributor to the high mortality among maintenance hemodialysis (MHD) patients. Cardiovascular disease (CVD) is the leading cause of death in dialysis patients, and PEW can significantly increase cardiovascular mortality in MHD patients. Previous studies have confirmed that PA may be a good objective indicator for determining the nutritional status and prognosis of MHD patients. Our study aimed to determine the predictive value of phase angle (PA) as detected by bioelectrical impedance analysis (BIA) on PEW and cardiovascular (CV) risk among MHD patients. Our retrospective observational study involved 161 adult patients with HD. The Cardiovascular risk score is a risk model based on the Japan Dialysis Outcome and Practice Patterns Study (J-DOPPS). We established LASSO logistic regression analysis model to identify key parameters related to body composition that can predict PEW in MHD patients. The area under the curve (AUC) values for PA, appendicular skeletal muscle mass index (ASMI), body cell mass (BCM), and mid-arm circumference (MAC) in predicting PEW in male MHD patients were relatively large, with 0.708, 0.674, 0.663, and 0.735, respectively. The predicted PEW values of these parameters were slightly lower in female patients than in men. We incorporated PA, ASMI, BCM, and MAC into a model that predicted the incidence of PEW in maintenance hemodialysis patients using LASSO technology. We discovered that the model predicted a greater AUC of PEW occurrence than any single factor, 0.877 for men and 0.76 for women. The results of the univariate logistic regression analysis showed that the low PA tertile array group had a greater incidence of PEW than the high PA group (P < 0.001). Additionally, we also found that lower PA was associated with higher CV risk scores. The PA detected by bioelectrical impedance analysis could predict the risk of PEW and cardiovascular events among patients with MHD. When used in conjunction, PA, ASMI, BCM, and MAC have a high diagnostic efficacy for PEW in patients on maintenance hemodialysis.

Dysphagia and Body Composition in Cornelia de Lange Syndrome

BACKGROUND/OBJECTIVES

Limited research had investigated nutritional status in patients with Cornelia de Lange Syndrome (CdLS) (OMIM 122470, 300590, 300882, 610759, 620568 and 614701). Body composition assessed via bioelectric impedance (BIA) is a particularly under-explored issue. In this cross-sectional study, we hypothesize that body composition imbalance is frequent in CdLS and may be associated with dysphagia. We aimed to determine dysphagia prevalence in CdLS. Dysphagia may be a sign or a complication of GERD (gastroesophageal reflux disease), which is the most frequent gastroenterological disorder in CdLS patients; Methods: Fourteen Polish patients with a clinical or genetic diagnosis of CdLS were included in the study. We performed body composition analysis via bioelectric impedance taking into account the phase angle (PhA) and Body Cell Mass (BCM) in patients who cooperated and were able to sit still. The patients' caregivers completed the pediatric version of the Eating Assessment Tool (PEDI-EAT-10). Based on the questionnaire scoring, we divided the patients into dysphagic and non-dysphagic groups. Body compartments of those two groups were compared. Statistical correlations between PhA and the PEDI-EAT-10 score were calculated; Results: Eleven of the fourteen CdLS patients had abnormalities in the BIA analysis in terms of fat mass (FM), fat free mass (FFM) and skeletal muscle mass (SMM). Six patients had excessive FM and four patients were deficient in FM. Two had deficiency in FFM and two had excessive FFM. We noted prevalence of dysphagia at 28.57%, with four patients having an PEDI-EAT-10 score higher or equal to 3, categorized as dysphagic. The dysphagic and non-dysphagic groups were not significantly different in terms of the proportion of patients with FM, FFM, SMM and BCM in the small cohort presented here. A statistically significant inverse correlation was found between the PhA and PEDI-EAT-10 score (rho = -0.72; p = 0.003); Conclusions: CdLS patients require investigation for dysphagia and nutritional status imbalance, as they are both frequent in this syndrome. The most prevalent are abnormalities in FM, both excess and deficit. PhA deviations observed in the bioimpedance study deepen with the severity of dysphagia. These findings require further investigation in a larger cohort.

The Diagnostic Accuracy and Cutoff Value of Phase Angle for Screening Sarcopenia: A Systematic Review and Meta-Analysis

OBJECTIVES

Phase angle (PhA) declines with age and is a reliable marker for muscle function, making it a potential screening indicator for sarcopenia. However, studies examined the reliability and validity of PhA for detecting sarcopenia, yielding inconsistent results. This meta-analysis aimed to evaluate the accuracy and cutoff value of PhA for screening sarcopenia and examine the potential confounding factors.

DESIGN

This is a meta-analysis.

SETTING AND PARTICIPANTS

PubMed, Embase, and Cochrane Library were searched up to September 18, 2023. Eighteen studies (6184 participants) were included reporting the diagnostic accuracy of PhA for screening sarcopenia.

METHODS

Pooled accuracy [ie, the computed area under the curve value (AUC)] and cutoff value interval for screening sarcopenia were estimated using a random-effects model. Meta-regression analyses were conducted to identify sources of heterogeneity.

RESULTS

The AUC value was 0.81. Pooled sensitivity and specificity were 80% and 70%. The calculated 95% CI of the cutoff value of PhA for screening sarcopenia falls between 4.54° and 5.25°. The results of meta-regression analyses showed that ethnicity, body mass index (BMI), health status, and diagnostic criteria were the main factors affecting the diagnostic accuracy for screening sarcopenia (with all P values < 0.01).

CONCLUSION AND IMPLICATIONS

PhA may serve as a robust screening tool for sarcopenia, and the recommended cutoff interval falls between 4.54° and 5.25°. Ethnicity, BMI, health status, and diagnostic criteria can affect PhA's efficacy in sarcopenia screening.

Association between longitudinal changes in phase angle and mortality rate in adults critically ill with COVID-19: A retrospective cohort study

BACKGROUND

Phase angle (PhA) obtained by bioelectrical impedance analysis (BIA) works as a predictor of clinical outcomes. Specific cutoff values for longitudinal changes and their relationship with clinical outcomes are still undetermined for patients with critical illness. Thus, the aim of this study was to analyze the association between longitudinal changes in PhA during intensive care unit (ICU) stay and all-cause 90-day mortality in patients critically ill with COVID-19.

METHODS

This was a retrospective cohort study of adults critically ill with COVID-19 undergoing invasive mechanical ventilation with a length of stay >14 days. BIA was performed at ICU admission and at days 7 and 14 of ICU stay; PhA and hydration parameters were collected. Differences between survivors and nonsurvivors were assessed. Longitudinal changes were evaluated using repeated-measures analysis of variance. A receiver operating characteristics curve for PhA declined (%) during the first 14 days, and all-cause 90-day mortality was performed. Survival probability was reported using hazard ratios (HR).

RESULTS

One-hundred nine patients were included. The change in the value of PhA was close to 17.1%. Nonsurvivors had a higher prevalence of individuals with a decrease in PhA >22.2% (area under the curve = 0.65) in the first 14 days in comparison with survivors (70% vs 34.8%, P < 0.01). PhA decrease >22.2% at 14 days was a significant predictor of all-cause 90-day mortality (HR = 2.2, 95% CI 1.71-3.6, P = 0.04).

CONCLUSION

Changes in PhA are associated with all-cause 90-day mortality. Future studies should be directed to interventions to prevent changes in this nutrition marker.

Association between phase angle and sarcopenia in patients with connective tissue diseases

BACKGROUND AND AIMS

Early detection and management of sarcopenia in patients with connective tissue diseases (CTDs) are essential. However, the relationship between the phase angle and sarcopenia in patients with CTDs is unknown. This study investigated the association between the phase angle and sarcopenia in patients with (CTDs) and determined the optimal phase angle cutoff values for the early detection of sarcopenia.

METHODS

A retrospective cross-sectional study was conducted in 279 hospitalized patients with CTDs undergoing rehabilitation (median age 73.3 years; 80 men and 199 women). Bioimpedance analysis was used to measure the phase angle, and sarcopenia was assessed according to the Asian Working Group for Sarcopenia criteria.

RESULTS

Sarcopenia was identified in 134 patients (36 men and 98 women). Patients with sarcopenia had a significantly smaller phase angle than those without sarcopenia. Multivariate analysis revealed that phase angle was significantly associated with sarcopenia after adjusting for confounding factors in each sex. The optimal phase angle cutoff value for identifying sarcopenia was 4.6° for men and 4.3° for women, with area under the curve values of 0.795 and 0.754, respectively.

CONCLUSION

Phase angle is a valuable marker for identifying sarcopenia in patients with CTDs. The established phase angle cutoff values of 4.6° in men and 4.3° in women can facilitate the early detection and management of sarcopenia.

Comparison of the utility of SARC-F, SARC-CalF, and calf circumference as screening tools for sarcopenia in patients with osteoporosis

AIM

Patients with osteoporosis who also have sarcopenia are at a high risk for falls and fractures. Early detection of sarcopenia is crucial for these patients. This study aimed to compare the effectiveness of SARC-F, SARC-CalF, and calf circumference (CC) as screening tools for sarcopenia in patients with osteoporosis.

METHODS

This cross-sectional study was retrospectively conducted on patients who attended the outpatient clinic for Osteoporosis and Sarcopenia at Kyoto Medical Center. Sarcopenia was determined based on low skeletal muscle mass and weak handgrip strength. Sensitivity and specificity analyses were conducted on SARC-F, SARC-CalF, and CC. The diagnostic utility of these three tools was compared using the receiver-operating characteristic (ROC) curves and the area under the ROC curves (AUC).

RESULTS

A total of 225 patients (men/women: 33/192) with a median age of 69.0 years (interquartile range: 61.0‒75.0) were enrolled. The prevalence of sarcopenia was found to be 11.6%. CC had the highest sensitivity (80.8%), while SARC-F had the highest specificity (93.0%) for detecting sarcopenia. ROC analysis revealed that all three tools had significant potential for sarcopenia diagnosis, with SARC-CalF having the highest AUC compared to SARC-F and CC (0.753 vs. 0.619 and 0.700). A multivariate logistic regression, incorporating other confounders as explanatory variables, revealed that SARC-CalF was independently related to sarcopenia (odds ratio: 14.80, 95% confidence interval: 3.83-57.30, p < 0.001).

CONCLUSION

In patients with osteoporosis, SARC-CalF is more effective in the early detection of sarcopenia than SARC-F and CC.

Motor function is related to the lower phase angle than to muscle mass of the lower limbs in older females with hip osteoarthritis: a cross-sectional observational study

BACKGROUND

Muscle mass and phase angle (PhA) can be measured using multi-frequency bioelectrical impedance analysis (BIA). Osteoarthritis of the hip (OAhip) causes decreased muscle mass and PhA in the deformed lower limb. However, previous studies have not accounted for the influence of sex, and thus, the relationship between muscle mass, PhA, and motor function remains unclear. This study aimed to elucidate the relationship between PhA, an index of muscle mass and quality measured using BIA, and motor function during gait and standing in female patients with OAhip.

METHODS

Muscle mass and PhA of patients with OAhip were measured using BIA. Motor function was evaluated using the Timed Up and Go test, ground reaction/weight, rate of force development/weight, and load ratio between the osteoarthritic (OA) and contralateral sides when standing up. The difference between the OA side and the contralateral lower limb was tested to clarify the characteristics of the deformed lower limb. The relationship between each motor function was determined using a partial correlation coefficient with age as a control variable and multiple regression analysis with each motor function as the dependent variable and age, OA-side muscle mass/body weight ratio, and PhA as independent variables.

RESULTS

This study involved 60 patients with OAhip (age 65.6 ± 7.6 years, height 154.2 ± 6.0 cm, weight 56.8 ± 10.5 kg) scheduled for unilateral total hip arthroplasty. Muscle mass, PhA, and lower limb load ratio were significantly decreased in the lower limbs on the OA side. Furthermore, using a partial correlation coefficient with age as a control variable, PhA showed significant correlations with motor functions related to standing up and walking, and multiple regression analysis revealed that PhA was independently related to each motor function.

CONCLUSIONS

Evaluation and interventions that consider muscle quality rather than muscle mass are important.

Muscle Strength and Phase Angle Are Potential Markers for the Efficacy of Multidisciplinary Weight-Loss Program in Patients with Sarcopenic Obesity

Background/Objectives: Traditional weight-loss methods often result in the loss of both fat and muscle mass. For individuals with sarcopenic obesity (SO), additional muscle loss can exacerbate sarcopenia, leading to further declines in muscle strength and function, ultimately worsening quality of life. To mitigate this risk, weight-loss strategies should emphasize the preservation and building of muscle mass through adequate protein intake and tailored resistance training. This study aimed to evaluate changes in SO status following a 4-week multidisciplinary weight-loss intervention program in hospitalized patients with obesity. Methods: This study included adult patients with obesity (BMI > 30 kg/m2, aged 18-90 years). The SO diagnosis was performed using the handgrip strength (HGS) test and skeletal muscle mass (SMM) by bioelectrical impedance analysis (BIA) according to ESPEN/EASO-2022 guidelines. Results: A total of 2004 patients were enrolled, 64.8% female, with a mean age of 56 (±14) years and a BMI of 40.7 (±6.48) kg/m2. SO was present in 9.38% (188 patients) at baseline. At discharge, 80 patients (42.55%) were no longer classified as sarcopenic and showed significant improvements in HGS. The likelihood of resolving SO was not modified in patients with only phase angle (PhA) improvement (p-value = 0.141). Patients with HGS increment had a 65% probability to be No-SO at discharge and this probability, with the concomitant PhA increment, rose to 93% (p-value < 0.0001), indicating that functional changes and good nutrition status are crucial in improvement of SO. Muscle mass (MM) and SMMI remained unchanged in the studied cohort. Conclusions: Improvements in HGS and the PhA are potential markers for the efficacy of weight-loss programs tailored to patients with SO. These findings suggest that specific interventions focusing on these markers could be beneficial in managing SO patients.

Association between phase angle and level of independence in daily living among institutionalized super older females requiring nursing care

[Purpose] This study aimed to clarify the association between phase angle (PhA) and the level of independence in daily living among institutionalized super older females requiring nursing care. [Participants and Methods] This three-facility cross-sectional study enrolled 173 nursing home residents (mean age 91.0 years, standard deviation 4.9 years) divided into five groups, from 80+ to 100+ years of age, in 5-year increments. PhA, skeletal muscle mass index, body fat percentage, body mass index, and Barthel Index were measured in the five groups. We measured the relationship between age and PhA and analyzed partial correlation coefficients using these items. The adjusted variables differed significantly among the five groups. [Results] The overall PhA was 2.91 degrees, with a 2.36-degree PhA in patients aged >100 years. Age differences were found between the PhA and the Barthel Index. A significant correlation (0.66) was identified between the PhA and the Barthel Index. The age-adjusted partial correlation coefficient between the PhA and the Barthel Index was 0.56, indicating a moderately significant positive correlation. [Conclusion] This study identified an association between PhA and independence in daily living among female nursing home residents aged 80-107 years, indicating that the PhA is an excellent indicator of physical condition.