Phase Angle Is a Useful indicator for Muscle Function in Older Adults

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.

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.

Utilizing Lower Limb Phase Angle as a Functional Prognostic Indicator for Patients in Convalescent Rehabilitation Wards

Objectives

: This study aimed to investigate whether lower limb phase angle (LL-PA) at admission predicts functional outcomes in patients undergoing rehabilitation.

Methods

: In this retrospective study, we measured the LL-PA of 256 patients (mean age 74.09±12.86 years) admitted to a convalescent rehabilitation ward upon arrival. The primary outcomes at discharge were motor Functional Independence Measure (FIM) scores and walking independence. The secondary outcomes included a 10-m walking speed and Timed Up-and-Go test result.

Results

: The LL-PA independently predicted discharge motor FIM scores (β=0.323, P <0.001) and walking independence (odds ratio=3.302, 95% confidence interval: 1.714-6.360). The sex-specific cut-off value for predicting walking independence was 3.050° for men (sensitivity, 0.804; specificity, 0.853) and 2.650° for women (sensitivity, 0.769; specificity, 0.812).

Conclusions

: LL-PA at admission is a significant predictor of functional outcomes in patients undergoing rehabilitation, with potential utility in early prognostic assessments.

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.

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.

Association Between Phase Angle and Tongue Pressure in Older Inpatients with Connective Tissue Diseases

To investigate the association between tongue pressure (TP) and phase angle (PhA) in patients with connective tissue diseases (CTDs) aged 65 years or older. This retrospective cross-sectional study was conducted on 189 patients with CTDs who underwent hospital rehabilitation. TP was measured using a tongue pressure measuring device, and PhA was calculated from the bioimpedance analysis readings. Statistical analyses included multivariate linear regression with TP and receiver operating characteristic curves to determine PhA cutoff values indicative of low TP, defined as < 24.3 kPa for men and < 23.7 kPa for women. A total of 189 patients with CTDs (mean age 75 years; 49 men and 140 women; mean PhA 4.0°; mean TP 27.7 kPa) were included in the analysis. Fifty-five patients had low TP. Patients with low TP had lower PhA values than those with normal TP (mean PhA values 3.5° versus 4.3°). After adjusting for confounding factors, PhA (β = 0.387, p < 0.001) was significantly associated with TP. Cutoff values for PhA predicting low TP were identified as 3.9° for men and 3.5° for women. PhA is associated with TP, independent of other factors, in older inpatients with CTDs. The identified PhA cutoff values could enable the early detection of declining TP.

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.

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.

Phase angle as a marker of muscle quality: A systematic review and meta-analysis

BACKGROUND & AIMS

Phase angle (PhA) is a biomarker derived from raw bioelectrical impedance analysis (BIA) values: resistance (R) and reactance (Xc). PhA reflects cellular membrane integrity and, as a result, has been considered a marker of fluid distribution, making it a potential prognostic indicator. A growing body of research demonstrates independent associations between PhA and muscle strength, mass, and composition. In this context, PhA has the extra potential to serve as a marker of muscle quality. However, the evidence supporting its use for this purpose is not well established. This study aimed to investigate the relationship between PhA and markers of muscle quality.

METHODS

This systematic review and meta-analysis (Internal Prospective Register of Systematic Reviews - PROSPERO on a registration code: CRD42024507853) focused on observational studies assessing the relationship between PhA and markers of both concepts of muscle quality: the muscle quality index (MQI: strength by a unit of mass) and the muscle composition (i.e., skeletal muscle radiodensity [SMD], muscle echogenicity, muscle fat fraction, inter- and intramuscular adiposity). Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS) and Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2), while the certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Meta-analyses with a random-effects model were conducted.

RESULTS

Seventeen studies were included in this systematic review, encompassing 2710 participants. Meta-analyses demonstrated that PhA had a moderate positive correlation coefficient with SMD (4 studies, 924 participants; r = 0.54, 95 % confidence interval (CI) 0.38 to 0.69, heterogeneity (I2) = 92 %) and good accuracy (85 %) for classifying low SMD (2 studies, 390 participants; Area Under the Curve - AUCpooled 0.85, 95 % CI 0.78 to 0.92, I2 = 0 %). PhA was inversely-moderately correlated with muscle echogenicity (8 studies, 1401 participants; r = - 0.42, 95 % CI - 0.57 to - 0.24, I2 = 82 %) and positively-weakly correlated with MQI (2 studies, 191 participants; r = 0.36, 95 % CI 0.21 to 0.49, I2 = 17 %). All studies had a higher risk of bias. The certainty of evidence ranged from low to very low.

CONCLUSION

Despite technical challenges, this study demonstrates the potential of PhA as a surrogate marker for muscle quality, particularly expressing muscle composition (SMD). Future studies should utilize BIA with standardized protocols to potentially establish specific cutoff values for PhA, thereby enhancing its diagnostic accuracy and clinical applicability. These studies could additionally explore the mechanisms underlying the associations between PhA and muscle quality aspects. In cases where technical factors are not easily controlled, the use of standardized PhA (SPhA), which converts PhA into Z-scores, could be beneficial. Although this warrants investigation, this approach (SPhA) has the potential to account for variables such as age, sex, device differences, and health status.

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.

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 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.

Sex differences in reduction of trunk muscle mass related to falls and cognitive function during the COVID-19 pandemic in older adults

AIM

This study aimed to examine the influence of the COVID-19 pandemic on physical components and activity, and its relationship to physical performance in older adults.

METHODS

Sixty-seven participants aged 75 and older (81 ± 2 years, female: 66%), who underwent medical checkups continuously from 2018 to 2022 in one clinic, were enrolled. Muscle mass was assessed by the biometrical impedance analysis method, which was adjusted by height squared. Physical, oral, and cognitive performance data were obtained from Japanese standard questionnaires at medical checkups. Values obtained in 2018 and 2019 were defined as pre-pandemic, and those in 2021 and 2022 were defined as during the pandemic.

RESULTS

Body weight, grip strength, and skeletal mass index did not change from 2018 to 2022, but trunk muscle mass index decreased significantly. A difference in the trunk muscle mass index (TMI) was observed between 2022 and 2018/2019 in men; however, a significant difference was found between 2021 and 2022 in women. Compared with the pre-pandemic period, TMI during the pandemic decreased only in men. The difference in TMI between the pre-pandemic period and during the pandemic (ΔTMI) was significantly decreased in participants with low physical activity and poor oral performance before the pandemic, and in those with falls and poor cognitive function during the pandemic only in men.

CONCLUSION

Reduction of trunk muscle mass was related to falls and poor cognitive function during the COVID-19 pandemic in older male adults. These data suggest that the difference in response to the COVID-19 pandemic between men and women necessitates different types of support for older adults. Geriatr Gerontol Int 2024; 24: 1060-1066.

Association between dietary inflammatory index and phase angle in university employees: a cross-sectional study

Phase angle (PhA), measured by bioelectrical impedance analysis, indicates cellular health, integrity, and function. As inflammation can damage cells, phase angle may be useful in detecting inflammatory status early. The relationship between dietary inflammatory index (DII) and PhA has not been studied yet. Therefore, we aimed to examine this association in Iranian adults. This cross-sectional study included 206 university employees. Dietary intakes were assessed by using a validated 86-item food frequency questionnaire (FFQ). Anthropometric indices and blood pressure were measured. A short form of the validated International Physical Activity Questionnaire (IPAQ) was used for evaluating physical activity. The PhA was measured by the Body Composition Analyzer Mc780 MA device. The mean age of participants was 43.50 ± 8.82 years and the range of DII score was - 4.66 to 0 among them. The highest tertile of DII compared to the lowest tertile, showed greater weight, WC, HC, basal metabolic rate (BMR), and diastolic blood pressure. We found no significant association between DII and PhA (crude model: OR: 0.68; 95% CI 0.34, 1.33, fully-adjusted model: OR: 0.65; 95% CI 0.26, 1.64). Also, after BMI stratification this association remained (fully-adjusted: normal weight: OR: 0.61; 95% CI 0.11, 3.27; Overweight and obese: OR: 0.57; 95% CI 0.16, 1.98). Having a higher DII score was not associated with a lower PhA. Further well-controlled prospective studies are warranted.

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.

Phase angle: A robust predictor of malnutrition and poor prognosis in gastrointestinal cancer

OBJECTIVES

The aim of this study was to investigate the relationship among phase angle (PA), malnutrition, and prognosis in patients with gastrointestinal cancer.

METHODS

In total, 870 patients with gastrointestinal cancer were enrolled. Kaplan-Meier curves and Cox proportional hazards models were used to evaluate the association between PA and survival risk. Restricted cubic spline regression was used for flexibility analysis to explore sex-specific associations between PA and survival. Logistic regression was used to assess the relationships among PA, malnutrition, and cachexia.

RESULTS

Low PA was closely associated with poor physical conditions, diminished quality of life, and malnutrition. Patients with low PA had a significantly worse prognosis than those with high PA (60.6% versus 72.8%; log-rank P < 0.001). PA was suitable for the prognostic assessment of patients with advanced-stage tumors. Regardless of sex, patients with lower PA showed significantly poorer survival rates. Cox proportional hazards models identified PA as an independent predictor of prognosis in patients with gastrointestinal cancer (hazard ratio (HR)=0.534; 95% confidence interval (CI)=0.409-0.696, P < 0.001). Subgroup analysis indicated that a high PA was an independent risk factor affecting the prognoses of patients with esophageal, liver, and intrahepatic bile duct cancers. Interestingly, variations in PA had a more significant prognostic effect on survival in men than in women. The logistic regression model confirmed that PA is a valuable indicator for assessing malnutrition and cachexia in patients with gastrointestinal cancer. Among all body composition indicators, PA demonstrated the highest accuracy for prognostic prediction.

CONCLUSIONS

PA was identified as a robust predictor of malnutrition and poor prognosis in patients with gastrointestinal cancer.

Proposal and validation of an equation to identify sarcopenia using bioelectrical impedance analysis-derived parameters

OBJECTIVE

This study aimed to develop a simpler approach for diagnosing sarcopenia by using only bioelectrical impedance vector analysis parameters.

METHODS

The study design was a cross-sectional study. The research was conducted based on the Itabashi Longitudinal Study on Aging, a community-based cohort study, with data collected from the 2022 and 2023 surveys in Itabashi Ward, Tokyo, Japan. The development cohort consisted of 1146 participants from the 2022 survey, and the validation cohort included 656 participants from the 2023 survey. Both cohorts were comprised of community-dwelling older adults with similar inclusion criteria. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. The logistic model utilized height divided by impedance at 50 kHz and phase angle to establish a new regression equation to identify sarcopenia. Regression equations were generated for the development cohort and validated for the validation cohort. Discriminatory ability was assessed using the area under the receiver operating characteristic curve (AUC) for men and women.

RESULTS

The prevalence of sarcopenia was 20.7% and 14.8% in the development and validation cohort, respectively. The AUC (95% confidence interval) of the logistic model in discriminating sarcopenia was 0.92 (0.88, 0.95) for men and 0.82 (0.78, 0.86) for women in the development cohort and 0.85 (0.78, 0.91) for men and 0.90 (0.86, 0.95) for women in the validation cohort.

CONCLUSION

The study demonstrated that a simple formula using bioelectrical parameters at 50 kHz proved useful in identifying sarcopenia in the older adult population.

The Role of Combined Muscle Ultrasound and Bioimpedentiometry Parameters for Sarcopenia Diagnosis in a Population of Hospitalized Older Adults

BACKGROUND

For the study of quantitative and qualitative muscle parameters, ultrasound and bioelectric impedance analysis are reliable, non-invasive, and reproducible. The aim of this study was to test the combined role of those techniques for the diagnosis of sarcopenia in a population of hospitalized older males and females.

METHODS

A total of 70 subjects were recruited, including 10 healthy adults and 60 hospitalized elderly patients with a good level of independence and cooperation, with and without sarcopenia. The rectus femoris cross-sectional area (CSA), thickness, echogenicity, and compressibility were measured with ultrasound echography. The phase angles (PhAs) and skeletal muscle mass were calculated by bioimpedence analysis. The muscle quality index (MQI) was calculated as the product of CSA and PhA.

RESULTS

Muscle compressibility was greater and PhA was lower in sarcopenic when compared with non-sarcopenic subjects. The threshold values for sarcopenia diagnosis in both sexes of CSA, of PhA, and of the MQI were identified. The obtained CSA values showed an AUC of 0.852 for women and 0.867 for men, PhA of 0.792 in women and 0.898 in men, while MQI was 0.900 for women and 0.969 for men.

CONCLUSIONS

The newly calculated cut-off values of CSA, PhA, and MQI predicted the presence of sarcopenia with good sensitivity and specificity values. The use of the MQI proved to be more promising than the separate use of CSA and PhA in both male and female subjects.

Investigation of Skeletal Muscle Indices Affecting Anaerobic Thresholds after Acute Myocardial Infarction

OBJECTIVE

To investigate skeletal muscle indices influencing the anaerobic threshold (AT) measured by cardiopulmonary exercise testing (CPX).

METHODS

This study included 125 consecutive men (median age: 66.0 years) diagnosed with acute myocardial infarction who underwent CPX before discharge. Participants were categorized into two groups based on their AT: the AT-lowering and AT-maintaining groups, comprising those with AT <11 and ≥11 ml/min/kg, respectively. Skeletal muscle indices that influenced AT, strengths of such influences, and respective cutoff values were investigated using multiple logistic regression analysis, decision-tree analysis, and the random-forest method. Skeletal muscle indices included grip strength, knee extension strength, lower-limb skeletal muscle index, phase angle (PhA), lower-limb PhA, arm circumference (AC), and calf circumference.

RESULTS

Lower-limb PhA, AC, age, and body mass index (BMI) influenced AT (model X2 test: p <0.05; Hosmer-Lemeshow test: p = 0.98). Among the skeletal muscle indices, Gini impurity reduction was the highest in the lower-limb PhA. The cutoff values for AT were ≥4.0° for BMI <24 kg/m2 and ≥6.4° for BMI ≥24 kg/m2.

CONCLUSION

Lower-limb PhA was the most influential skeletal muscle index affecting AT. PhA measured using body composition analyzers is useful to identify exercise-limiting factors and determine the effectiveness of exercise because it can be easily performed shortly.

Association between grip strength and electrical properties measured by bioimpedance spectroscopy in women with dementia aged 77 to 97 years living in group homes

Electrical properties estimated from the electrical resistance of the human body can serve as indicators of muscle tissue status and the risk of developing sarcopenia; however, to date, at least to the best of our knowledge, no studies have performed such an assessment in older individuals with advanced dementia. The present study examined the associations between grip strength, body composition and electrical properties using bioimpedance spectroscopy (BIS) in women aged 77-97 years residing in dementia group homes. A total of 33 participants were enrolled with an average age of 88.1±5.2 years; 57.6% of the participants had moderate or severe dementia. The resistance values of the participants were measured in the whole body, upper limbs and lower limbs using BIS, and their body composition, muscle mass index and electrical properties were estimated as indicators of muscle quality. In addition, grip strength was measured and the participants were classified into three groups (high, low and non-measurable) according to their cognitive function. The effect size (partial eta-squared and Cohen's d) was also evaluated. The Shapiro-Wilk test was used to assess the distribution of each variable; variables with non-normal distributions were analyzed following log transformation. Continuous variables were analyzed using a one-way analysis of variance and the Tukey-Kramer post hoc test was used. The post hoc sample size (statistical power: 1-β) analysis revealed a power of ~80% (i.e., 76.1-88.7%), considering the minimum power for sufficient participants. No differences were found in body composition or muscle mass index among the three grip strength groups. As regards the upper limbs, the electrical properties of the characteristic frequencies were significant (P=0.006; effect size, large), and the membrane capacitance (P=0.005; effect size, large) was significantly higher in the high-dose group than in the other groups. A significant association was detected among grip strength, upper limb characteristic frequency and membrane capacitance. Hence, electrical properties may be an indicator of muscle quality in older women identified as needing care for dementia.

New Perspectives for Low Muscle Mass Quantity/Quality Assessment in Probable Sarcopenic Older Adults: An Exploratory Analysis Study

BACKGROUND

Low muscle mass quantity/quality is needed to confirm sarcopenia diagnosis; however, no validated cut-off points exist. This study aimed to determine the diagnostic accuracy of sarcopenia through muscle mass quantity/quality parameters, using the bioimpedance analysis (BIA), isokinetic, and ultrasound tools in probable sarcopenic community-dwelling older adults (≥60 years). Also, it aimed to suggest possible new cut-off points to confirm sarcopenia diagnosis.

METHODS

A cross-sectional exploratory analysis study was performed with probable sarcopenic and non-sarcopenic older adults. BIA, isokinetic, and ultrasound parameters were evaluated. The protocol was registered on ClinicalTrials.gov (NCT05485402).

RESULTS

A total of 50 individuals were included, 38 with probable sarcopenia (69.63 ± 4.14 years; 7 men and 31 women) and 12 non-sarcopenic (67.58 ± 4.54 years; 7 men and 5 women). The phase angle (cut-off: 5.10° men, p = 0.003; 4.95° women, p < 0.001), peak torque (cut-off: 66.75 Newtons-meters (N-m) men, p < 0.001; 48.35 N-m women, p < 0.001), total work (cut-off: 64.00 Joules (J) men, p = 0.007; 54.70 J women, p = 0.001), and mean power (cut-off: 87.8 Watts (W) men, p = 0.003; 48.95 W women, p = 0.008) in leg extension, as well as the the forearm muscle thickness (cut-off: 1.41 cm (cm) men, p = 0.017; 0.94 cm women, p = 0.041), had great diagnostic accuracy in both sexes.

CONCLUSIONS

The phase angle, peak torque, total work, and mean power in leg extension, as well as forearm muscle thickness, had great diagnostic accuracy in regard to sarcopenia, and the suggested cut-off points could lead to the confirmation of sarcopenia diagnosis, but more studies are needed to confirm this.

Association between phase angle and clinical outcomes in patients with lumbar spinal stenosis from the preoperative to 12-month postoperative period: A prospective observational study

No reports of longitudinal studies on phase angle (PhA) in lumbar spinal stenosis (LSS) exist, and its association with postoperative clinical outcomes is unclear. We longitudinally investigated PhA in patients with LSS preoperatively to 12 months postoperatively and determined the association between PhA and the Japanese Orthopedic Association (JOA) score. This prospective observational study included patients who underwent consecutive surgical treatments for clinically and radiologically defined LSS. Outcome measures including walking speed, Timed Up and Go test (TUG), JOA score, and PhA based on bioelectrical impedance analysis were measured preoperatively and at 3, 6, and 12 months postoperatively. Correlations between PhA and the JOA score and motor function were analyzed. The effect of PhA on JOA scores was evaluated using mixed-effect models for repeated measurements (MMRM). Eighty-nine patients were included at baseline, and 85, 85, and 78 patients were analyzed at 3, 6, and 12 months postoperatively, respectively. PhA was 3.9 ± 0.8 (p = 0.086), 4.0 ± 0.8 (p = 0.644), and 4.1 ± 0.9 (p = 0.791) at 3, 6, and 12 months postoperatively and 4.2 ± 0.8 at baseline. PhA was significantly correlated with the JOA score (p < 0.01) and walking speed and TUG results (p < 0.01) at all assessment points. In the MMRM, PhA was associated with the JOA score at all assessment points. Changes in postoperative JOA scores after lumbar spine surgery are associated with PhA at each assessment time point. PhA may be a useful postoperative clinical indicator after surgery for LSS.

Calculation of trunk muscle mass and trunk muscle quality indices for walking independence in asian patients with hip fractures

BACKGROUND & AIMS

This study aimed to investigate the association between trunk muscle mass and muscle quality, as evaluated by bioelectrical impedance analysis (BIA), and the ability to walk independently in patients with hip fractures. Cutoff values for quantitative and qualitative indicators of the trunk muscles were also calculated.

METHODS

This study included 181 patients with hip fractures who were admitted to a convalescent rehabilitation ward. Trunk muscle mass and phase angle of the participants were evaluated on admission. The phase angle in this study was defined as the trunk muscle quality index (TMQI). Patients were classified into the independent (functional independence measure [FIM]-walk score ≥6; n = 101) and non-independent (FIM-walk score ≤5; n = 80) walking groups according to the FIM mobility scores at discharge.

RESULTS

The independent group had a higher FIM gain than the non-independent group (37.0 ± 13.6 vs. 27.1 ± 13.5, p < 0.001). Logistic regression analysis showed that the trunk muscle mass index (TMI) and TMQI were associated with the ability to walk independently. Furthermore, cutoff values of TMI and TMQI for male and female to estimate the ability to walk independently were 6.5 kg/m2 and 5.7 kg/m2, and 4.5° and 3.4°, respectively.

CONCLUSION

TMI and TMQI are related to the ability to walk independently in patients with hip fractures. These results suggest the importance of improving trunk muscle mass and muscle quality during rehabilitation of patients with hip fractures.

Low Phase Angle and Skeletal Muscle Index Increase Hospital-Acquired Infections During Stroke Rehabilitation

OBJECTIVES

Sarcopenia is common in patients with stroke and may increase the risk of medical complications such as infection. However, assessing sarcopenia in stroke patients with consciousness disturbance, aphasia or severe paralysis is challenging. This study aimed to investigate whether a combined assessment of phase angle (PhA) and skeletal muscle index (SMI), estimated using bioelectrical impedance analysis, was associated with 2 common nosocomial infections, hospital-acquired pneumonia (HAP) and urinary tract infection (UTI), during inpatient stroke rehabilitation.

DESIGN

Single-center retrospective observational study.

SETTINGS AND PARTICIPANTS

A total of 1068 patients with stroke admitted to a rehabilitation hospital between January 2016 and September 2019 were analyzed.

METHODS

The study variables included demographic characteristics, comorbidities, stroke severity, blood chemistry and urine analysis, SMI, and PhA obtained using bioelectrical impedance analysis. Patients were classified as normal, low PhA only, low SMI only, and low PhA + SMI. Multivariate Cox proportional analysis was used to determine the variables associated with HAP and UTI.

RESULTS

A combination of low PhA + SMI was observed in 429 (40.2%) patients. Over a median follow-up duration of 46 days, HAP occurred in 187 patients (17.5%) and UTI occurred in 155 patients (14.5%). The low PhA + SMI group showed a significantly higher incidence of HAP and UTI than the normal group (32.6% vs 4.6%, P < .001, for HAP; 20.7% vs 6.2%, P < .001, for UTI). In multivariate Cox analyses, low PhA and SMI were associated with significantly higher rates of HAP [hazard ratio (HR) 3.36, 95% CI 1.796-6.304, P < .001] and UTI (HR 1.71, 95% CI 1.002-2.947, P < .05) after adjusting for confounding variables.

CONCLUSIONS AND IMPLICATIONS

Combination of low PhA + SMI was independently associated with a higher risk of HAP and UTI in stroke patients who underwent inpatient rehabilitation. Measuring PhA and SMI using bioelectrical impedance analysis might be helpful in establishing care plans in these population.

Association between bone health and dynapenic obesity in postmenopausal women

AIM

The combination of dynapenia (age-related muscle weakness) and obesity is referred to as dynapenic obesity. We examined the associations between dynapenic obesity and cortical bone thickness and trabecular bone density.

METHODS

The participants were 797 community-dwelling postmenopausal women (with an average age of 62.5 years) who were stratified into normopenia without obesity, dynapenia without obesity (dynapenia), normopenia with obesity (obesity) and dynapenia with obesity (dynapenia obesity) groups based on their grip strength and body fat percentage. Cortical bone thickness and trabecular bone density were measured using ultrasonic bone densitometry. The participants were further divided into those with low cortical bone thickness and low trabecular bone density. Logistic regression analysis was used to identify associated factors.

RESULTS

Individuals with dynapenia (odds ratio [OR] 1.77, 95% confidence interval [CI] 1.16-2.68), obesity (OR 2.46, 95% CI 1.62-3.75) and dynapenic obesity (OR 4.07, 95% CI 2.44-6.79) all significantly increased the odds of low cortical bone thickness. Conversely, the odds of low trabecular bone density were significantly lower in the obesity group (OR 0.65, 95% CI 0.43-0.99) and dynapenic obesity group (OR 0.60, 95% CI 0.37-0.97).

CONCLUSIONS

Dynapenic obesity was found to be associated with cortical bone thinning that might compromise bone health. Postmenopausal women with dynapenic obesity might need to be closely monitored for preserving bone health. Geriatr Gerontol Int 2024; 24: 378-384.

Relationship between phase angle and lower-extremity function in older adults: Itabashi Longitudinal Study on Aging

OBJECTIVE

Evaluating muscle quality instead of its mass has gained attention in diagnosing sarcopenia. The aim of this study was to examine whether phase angle (PhA) as a bioelectrical impedance analysis (BIA)-derived muscle quality indicator is associated with overall lower extremity function better than appendicular skeletal muscle mass index (ASMI) in community-dwelling older adults.

METHODS

This cross-sectional study used data from the Itabashi Longitudinal Study on Aging, a community-based cohort study. A sex-stratified multivariate logistic regression analysis was conducted using PhA and ASMI as exposures, and low physical function defined as short physical performance battery score <10 as the outcome, adjusted for age, being overweight, knee pain, and non-communicable diseases. Discrimination of low physical function was compared using the receiver operating characteristic curve.

RESULTS

This study included 1464 participants (age 76 [73-80] y; 757 women), with 58 men (8%) and 66 women (9%) exhibiting low physical function. The multivariate odds ratio (OR; 95% confidence interval [CI]) for low physical function among the highest quartile, compared with the lowest quartile were significant in PhA in multiple sites (e.g., OR, 0.09; 95% CI, 0.03-0.32] for men and 0.12; 95% CI, 0.04-0.33 for women in the left leg) but not in ASMI (OR, 0.51; 95% CI, 0.19-1.34 for men and 0.56; 95% CI, 0.21-1.47 for women). Legs and whole-body PhA outperformed the ASMI in discriminating low physical function (P < 0.001).

CONCLUSION

PhA reflected physical function better than ASMI; using PhA instead of ASMI in BIA-based morphometric evaluation may add information on low physical function and enhance the diagnostic value of sarcopenia.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association of resting energy expenditure with phase angle in hospitalized older patients: a cross-sectional analysis

BACKGROUND/OBJECTIVES

Resting energy expenditure (REE) constitutes the largest component of total energy expenditure and undergoes an age-related decline that is unexplained by decreased fat-free mass. Phase angle (PhA) is a cellular health indicator that is possibly associated with REE. We investigated the association of REE and PhA in hospitalized older adults.

SUBJECTS/METHODS

This single-center, cross-sectional analysis utilized the baseline data from a prospective longitudinal study and included 131 eligible patients aged ≥70 years. The REE was measured using indirect calorimetry, and PhA and body composition were assessed using bioelectrical impedance. The association between REE, PhA, and body composition was examined, and REE was compared using previously reported PhA cutoff values.

RESULTS

In this cohort with a mean (±standard deviation) age of 87.4 (±7.0) years, 34.4% of the participants were men. REE and PhA correlated strongly (r: 0.562, p < 0.001) and significantly after adjusting for age and sex (r: 0.433, p < 0.001). Multivariate analysis showed a significant independent association between REE and PhA and skeletal muscle mass (standardized β [95% CI]; 28.072 [2.188-53.956], p = 0.035) without any significant interaction between PhA and age on REE. The low PhA group had a significantly lower REE (kcal/day; 890 [856-925] vs. 1077 [1033-1122], p < 0.001), and this remained significant after adjusting for age, sex, and skeletal muscle mass index.

CONCLUSIONS

PhA is associated with REE in older adults. Adjusting REE calculation algorithms based on PhA values and correcting predicted REE according to PhA may aid in determining more accurate energy requirements.

Validation of bioimpedance phase angle in lower extremity of male patients with chronic spinal cord injury

[Purpose] This study aimed to evaluate the relationship between lower extremity phase angle and muscle thickness/echo intensity in males with chronic spinal cord injury. It also compared bioelectrical impedance analysis measurements to investigate skeletal muscle degeneration between individuals with spinal cord injury and healthy controls. [Participants and Methods] This cross-sectional study included 12 male patients with chronic spinal cord injury and 14 healthy male controls. We used bioelectrical impedance analysis and ultrasonography to measure the lower extremity phase angle and muscle thickness/echo intensity of the rectus femoris muscle, respectively. We also compared the bioelectrical impedance analysis measurements between individuals with spinal cord injury and healthy controls. [Results] Lower extremity phase angle was strongly correlated with muscle thickness and echo intensity of the rectus femoris muscle in individuals with spinal cord injury. All measures differed significantly between individuals with spinal cord injury and healthy controls. [Conclusion] These findings suggest that lower extremity phase angle is a valuable skeletal muscle indicator in spinal cord injury. Furthermore, bioelectrical impedance analysis revealed degeneration of the lower extremity skeletal muscles in individuals with chronic spinal cord injury.

Preoperative Body Composition Correlates with Postoperative Muscle Volume and Degeneration after Total Hip Arthroplasty

Impaired muscle recovery after total hip arthroplasty (THA) may affect gait and activities of daily living. Bioelectrical impedance analysis (BIA) can assess body composition and muscle volume, and computed tomography (CT) can assess muscle volume and the fatty degeneration of muscle. This study aimed to explore the effectiveness of BIA, and the correlation between preoperative body composition and postoperative muscle volume and degeneration after THA using BIA and CT. Thirty-eight patients who underwent THA and had BIA and CT performed pre- and postoperatively were retrospectively assessed. The BIA-derived measurements of preoperative body composition (fat mass index, fat-free mass index, and phase angle) were correlated with the CT-derived measurements (pre- and postoperative muscle volume and gluteus maximus and quadriceps Hounsfield Units of the affected hip). The preoperative fat mass index negatively correlated with the postoperative muscle volume of the gluteus maximus (p = 0.02) and quadriceps (p < 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.03). The preoperative fat-free mass index positively correlated with the postoperative muscle volume of the quadriceps (p = 0.02). The preoperative phase angle positively correlated with the postoperative muscle volume of the quadriceps (p = 0.001) and the Hounsfield Units of the gluteus maximus (p = 0.03) and quadriceps (p = 0.001). In patients who underwent THA, preoperative body composition correlated with postoperative muscle volume and the fatty degeneration of the affected lower limb. Preoperative body composition may help predict postoperative muscle volume and fatty degeneration and thus, postoperative recovery.

Sedentary Behavior and Phase Angle: An Objective Assessment in Physically Active and Inactive Older Adults

The purpose of the present study was to investigate the associations of the objectively assessed total sedentary behavior (SB) amount and SB patterns with phase angle (PhA) in older populations and to conduct a comparison analysis for those who are physically active (meet 150 min/week) and inactive (less than 150 min/week). During May to August 2023, a convenience sampling was used to recruit older adults (aged ≥ 65 years) living in a community in Taiwan. The total SB amount (minutes/day), SB patterns (including SB bouts and breaks), and physical activity were assessed by a triaxial accelerometer. A multifrequency bioelectrical impedance analyzer (BIA) was used to measure PhA. Multiple linear regression analysis was employed to examine the associations between SB and PhA in the total number of participants and stratified in the physically active and inactive groups. For the whole sample (n = 166; mean age: 72.1 ± 5.5 years), the total SB amount and patterns of SB were not associated with PhA. For those physically active, the total SB amount and SB patterns were not associated with PhA. Among those physically inactive, the total SB amount was negatively related to PhA (B: -0.059, 95% CI: -0.118, 0.000). This study underscores the importance of minimizing the total SB amount in physically inactive older adults, providing evidence for future interventions targeting SB and PhA in this population.

Associations of Lower-Limb Phase Angle with Locomotion and Motor Function in Japanese Community-Dwelling Older Adults

Whole-body phase angle (PhA) is associated with motor function and geriatric diseases. However, it was unclear which parts of the upper- or lower-limb PhA were involved. This study investigated the differences in the PhA of the upper and lower extremities and their relationships with frailty, locomotive syndrome indices, and motor function in community-dwelling older adult participants. This study was a cross-sectional observational study. In 69 community-dwelling older adults, the PhA at each measurement site (whole body, upper limbs, and lower limbs), motor function, Kihon Checklist (KCL), and 25-Geriatric Locomotive Function Scale (GLFS-25) were measured. This study examined differences in each PhA and its relationship with motor function and geriatric diseases. Multiple regression analysis was performed using GLFS-25 as the dependent variable and sex and lower-limb PhA as independent variables. In this cohort (mean age: 72.3 ± 5.7 years; 18 males and 51 females), lower-limb PhA was significantly lower than upper-limb PhA. Unlike other PhAs, lower-limb PhA was related to grip strength, TUG, F/w, and GLFS-25. Multiple regression analysis showed that the lower-limb PhA was independently related to GLFS-25. Cellular health of the lower extremity is associated with gait, standing function, and indicators of locomotive syndrome.

Skeletal muscle quality, measured via phase angle, and cardiorespiratory fitness in patients with obesity and heart failure with preserved ejection fraction

OBJECTIVES

Cardiorespiratory fitness (CRF) is influenced by body composition quantity and quality in heart failure with preserved ejection fraction (HFpEF) and obesity. Bioelectrical impedance analysis (BIA) provides a noninvasive quantitative and qualitative body composition assessment. The aim of this study was to determine the role of phase angle (PhA), a BIA-measure of skeletal muscle quality and body cell mass, on CRF in patients with obesity and HFpEF.

METHODS

Fifty-nine consecutive outpatients with HFpEF underwent cardiopulmonary exercise testing to measure CRF. Single-frequency segmental BIA was used to measure PhA and body composition quantity. Resting Doppler echocardiography and biomarkers were measured to assess cardiac function and systemic inflammation.

RESULTS

Compared with patients with lower PhA, patients with higher PhA (above mean 5.8°) presented a greater absolute peak oxygen consumption (VO2; 1.83 [1.3-2.1] versus 1.39 [1.1-1.6] L/min, P = 0.003), VO2 peak adjusted for body weight (17.5 [12.3-18.1] versus 13.3 [12.7-15.2] mL/kg/min, P = 0.040), and a lower edema index (48.7 [2.9] versus 51.4% [2.7], P < 0.001) and N-terminal pro-B-type natriuretic peptide (NT-proBNP; 64 [50-121] versus 183 [68-343.5] pg/dL, P < 0.001). In the overall sample, PhA was correlated with absolute VO2 peak (r = 0.468, P < 0.001), VO2 peak adjusted for body weight (r = 0.368, P = 0.004), VO2 peak adjusted for fat-free mass (r = 0.315, P = 0.015), edema index (r = -0.508, P < 0.001), and NT-proBNP (r = -0.579, P < 0.001). PhA remained a significant predictor for CRF even after adjustment for potential confounders and HFpEF severity.

CONCLUSION

In patients with obesity and HFpEF, a greater PhA is an independent predictor for favorable CRF.

Phase angle is associated with frailty in community-dwelling older adults

OBJECTIVES

Frailty is a geriatric syndrome associated with adverse outcomes. Malnutrition and sarcopenia are conditions intertwined with frailty. Phase angle (PhA), used to evaluate nutritional status and sarcopenia, shows the cell membrane integrity and is closely related to clinical outcomes and mortality in many chronic conditions. The aim of this study was to evaluate the relationship between PhA and frailty in community-dwelling older adults.

METHODS

The study included 299 older adults admitted to a geriatric outpatient clinic. A comprehensive geriatric assessment was performed on all participants. Frailty was evaluated via the Clinical Frailty Scale, ≥4 levels were accepted as living with frailty. All participants underwent bioelectrical impedance analysis, and PhA was recorded for each participant.

RESULTS

The prevalence of frailty among the participants was 53%. The median PhA was lower in patients living with frailty than in those who were robust (5.10 [4.55-7.80] and 5.90 [3.90-6.90] degrees, respectively, and P = 0.014). Multivariable regression analysis showed that PhA was also associated with frailty in both sexes (odds ratio [OR], 0.920; P = 0.034 for men; OR, 0.81; P = 0.005 for women, respectively) independent of age, handgrip strength, nutritional status, body mass index, living alone, and burden of morbidities.

CONCLUSION

PhA calculated with bioelectrical impedance analysis was significantly associated with frailty. Further research with large samples is needed to determine whether PhA demonstrates potential utility as a biomarker for frailty.

Change in phase angle is associated with improvement in activities of daily living and muscle function in patients with acute stroke

PURPOSE

The phase angle (PhA) is a simple index that reflects nutritional status and muscle quality. This study aimed to investigate the association between PhA changes and activities of daily living (ADL), muscle strength, and muscle mass in patients with acute stroke.

METHODS

This retrospective, observational, cross-sectional study included patients hospitalized for acute stroke. The primary outcome was functional independence measure (FIM) of motor gain. The secondary outcomes were changes in handgrip strength and skeletal muscle mass index (SMI) during hospitalization. Multivariate analysis was used to examine whether PhA changes were associated with outcomes, after adjusting for potential confounders.

RESULTS

Hundred and sixty one subjects (mean age 74.6 years, 92 men) were included in the study. Multivariate analysis showed that PhA change was significantly and positively correlated with the gain in FIM motor scores, both for men (β = 0.634, p < 0.001) and women (β = 0.660, p < 0.001). Furthermore, there were significant associations between PhA change and changes in handgrip strength for men (β = 0.222, p = 0.030) and women (β = 0.491, p < 0.001), as well as SMI for men (β = 0.556, p < 0.001) and women (β = 0.290, p = 0.025).

CONCLUSIONS

An increased phase angle was positively associated with ADL, muscle strength, and muscle mass at discharge in patients with acute stroke.

Association between disability in activities of daily living and phase angle in hemodialysis patients

BACKGROUND

Disability in activities of daily living (ADL) significantly increases the risk of mortality among patients undergoing hemodialysis. Malnutrition and decreased exercise capacity are closely correlated with ADL disability. Phase angle (PhA) has been proposed as a measure of nutritional status and exercise capacity. This study aims to investigate the prevalence of ADL disability in hemodialysis patients and its association with PhA.

METHODS

A prospective, observational study was conducted, involving hemodialysis patients treated between November 2019 and January 2020 in an affiliated hospital of Chinese university. ADL was measured using both basic ADL (BADL) scales and instrumental ADL (IADL) scales. PhA measurements were obtained using a BIA device while the patients were in the supine position after dialysis.

RESULTS

A total of 237 hemodialysis patients with a mean age of 60.01 ± 13.55 years were included in this study. The prevalence of disability in ADL was 43.5%. Multivariable analysis results showed a robust association between low PhA and disability in both BADL and IADL (for each unit decrease in PhA: odds ratio 4.83 [95% CI: 2.56-9.0], and 3.57 [95% CI: 2.14-5.95], respectively). The optimal cut-off values of PhA for disability in BADL and IADL were 4.8 and 5.4, with the area under the ROC curve (AUC) were 0.783 (0.727, 0.835) and 0.799 (0.743, 0.848), respectively.

CONCLUSIONS

Low PhA is strongly associated with disability in ADL in hemodialysis patients. These findings suggest that PhA may serve as a potentially objective measure of ADL disability in hemodialysis patients.

Prevalence of Sarcopenia and Dynapenia and Related Clinical Outcomes in Patients with Type 1 Diabetes Mellitus

BACKGROUND

Sarcopenia has recently been recognized as a complication of diabetes. However, there are few results about the prevalence of sarcopenia and dynapenia and the related clinical outcomes in type 1 diabetes mellitus (T1DM). Our objectives were to evaluate the prevalence of sarcopenia and dynapenia and to determine whether there are any associations with disease-related factors in people with T1DM.

METHODS

A cross-sectional study was conducted in people with T1DM. We assessed appendicular skeletal mass index (ASMI) using bioimpedance 50 Hz (Nutrilab Akern). Muscle function was assessed through handgrip strength (HGS) using a Jamar dynamometer. Sarcopenia was defined as a low HGS with low ASMI, whereas dynapenia was defined as low HGS with a normal ASMI. We used HGS data from the Spanish population percentile table and a cut-off point at p5 as dynapenia. The association of clinical, metabolic, and lifestyle variables with sarcopenia and dynapenia was studied.

RESULTS

This study included 62 T1DM patients (66% females, mean age of 38 ± 14 years, body mass index (BMI) of 24.9 ± 4.7 kg/m2). The prevalence of sarcopenia and dynapenia was 8% and 23%, respectively. In our sample, there were more men in the sarcopenic and dynapenic groups. The sarcopenic group showed a significantly higher mean HbA1c value. Lower diabetes duration, PREDIMED score, BMI, and muscle mass measures (fat-free mass index (FFMI), ASMI, and body cell mass index (BCMI)) were significantly associated with sarcopenia. Decreased diabetes duration, PREDIMED score, phase angle (PhA), and HGS values showed a significant association with dynapenia.

CONCLUSIONS

The prevalence of sarcopenia and dynapenia was high in people with T1DM in our study. Specifically, the proportion of dynapenia was quite high. HGS and ASMI are practical tools for the assessment of muscle health status in T1DM, and low values are associated with poor glycemic control, underweight, and low adherence to the Mediterranean diet. Thus, dynapenia may predict accelerated muscle aging in T1DM.

Application of digitization and visualization-based muscle strength measurement in ischemic stroke patients with motor dysfunction

Ischemic stroke stands as a prevalent neurological ailment, where a paucity of methodologies exists for the assessment of functional outcomes post-stroke. Our objective was the development of a WeChat applet for the evaluation of muscle strength and the subsequent evaluation of its validity in ischemic stroke patients experiencing motor dysfunction. The assessment encompassed Lovett and NIHSS, followed by muscle strength values (MSV) and muscle strength ratios (MSR). These metrics were then scrutinized in relation to NIHSS and Lovett, followed by examination of their interrelationships. We enrolled a cohort of 157 patients, with an average age of 65 years, consisting of 96 males and 61 females. Lovett scores in the range of 2-4 and NIHSS scores spanning from 0 to 3 were found to correspond to specific values of MSV and MSR, respectively. Upon conducting correlation analysis, we noted that both MSV and MSR exhibited significant positive correlations with Lovett scores and NIHSS. Remarkably, the correlation of MSR with Lovett scores or NIHSS surpassed that of MSV. The WeChat applet offers a means of digitization and visualization of muscle strength. It correlates well with Lovett score and NIHSS, especially MSR. This bears potential significance in guiding the rehabilitation of stroke patients.

Do metal implants for total hip arthroplasty affect bioelectrical impedance analysis? A retrospective study

BACKGROUND

Evaluation of body composition after total hip arthroplasty (THA) is essential because it can be used to evaluate muscle and functional recovery. Muscle volume and degeneration are evaluated using computed tomography (CT). However, CT evaluation of muscle volume has several limitations, such as radiation exposure and high medical cost. Bioelectrical impedance analysis (BIA) has gained attention for resolving these limitations of CT. BIA takes advantage of the microelectric current; thus, metal implants may affect the results. Therefore, this study aimed to elucidate the effects of metal implants on BIA after THA.

METHODS

Two groups of patients were assessed (Group 1: 70 patients who underwent unilateral THA and BIA; Group 2: 35 patients who underwent THA and BIA before and after THA). Electric impedance (resistance and reactance) of the operated and non-operated lower limbs was compared in Group 1. The pre- and post-operative impedances of the torso and operated ipsilateral limbs were compared in Group 2.

RESULTS

Regarding electric impedance in Group 1, no significant differences were observed in electrical resistance and reactance between the operated and non-operated lower limbs. Concerning electric impedance in Group 2, postoperative electric resistance of the torso was significantly lower than that preoperatively. However, no significant difference was seen in electric resistance and reactance of the operated ipsilateral limbs preoperatively and postoperatively.

CONCLUSIONS

Electrical resistance and reactance of the limbs did not change significantly after THA. BIA is useful for measuring body composition after THA.

Phase angle and body composition: A scoping review

The aim of the study was to map evidence on the association between phase angle (PhA) and body composition in populations healthy and clinical populations). A systematic search for information regarding the topic was conducted in nine electronic databases (CINAHL, LILACS, PubMed, SciELO, Scopus, SPORTDiscus, Science Direct, MEDLINE and Web of Science) between October and November 2021. Studies with different designs, which allowed extracting information about the relationship between PhA and body composition (body cell mass [BCM], muscle tissue, bone mineral content, lean mass, total fat mass, visceral fat, and lean soft tissue mass [LSTM]) were included. Of the total of 11,913 initially identified studies, 59 were included after reading titles, abstracts, full texts and references. Most studies (40.67%; n = 24) presented data from Brazilian samples. With regard to the design of studies, 15 (25.42%) had longitudinal design. The age group of studies was wide, with studies involved 3-year-old children and 88-year-old adults. Body fat mass was evaluated by 31 studies (52.54%) in which 11 observed inverse relationships, nine studies showed direct relationships and 11 observed no relationship. Regarding lean mass, muscle mass, and fat-free mass components, most studies observed direct relationship with PhA (n = 37; 86.04%). It could be concluded that the phase angle was directly associated with lean mass and muscle mass in different age groups (children, adolescents, adults and older adults) and in people with different health diagnoses (HIV, cancer, hemodialysis, sarcopenia and without the diagnosis of diseases). Regarding body fat and the other investigated components, there is not enough evidence to establish the direction of associations.

Phase angle as a key marker of muscular and bone quality in community-dwelling independent older adults: A cross-sectional exploratory pilot study

The aim of the present cross-sectional exploratory pilot study was to analyze the ability of the Phase Angle (PhA) to predict physical function, muscle strength and bone indicators, upon adjusting for potential confounders [age, sex, lean mass, and body mass index (BMI)]. This study included 56 physically independent older adults (age, 68.29 ± 3.01 years; BMI, 28.09 ± 4.37 kg/m2). A multi-frequency segmental bioelectrical impedance analysis was used to measure PhA at 50 KHz. Additionally, physical function was assessed through four functional capacity tests [30-sec chair-stand; seated medicine ball throw (SMBT); timed up & go; and 6-min walking test (6 MWT)], muscle strength through the handgrip test (dominant side) and maximal isokinetic strength of the dominant knee flexor and extensor. Moreover, bone indicators and body composition were assessed through the dual energy X-ray absorptiometry. PhA was significantly associated with SMBT (r = 0.375, effect size (ES) = moderate); 6 MWT (r = 0.396, ES = moderate); 30-sec chair-stand (rho = 0.314, ES = moderate); knee extension (rho = 0.566, ES = large) and flexion (r = 0.459, ES = moderate); handgrip (rho = 0.432, ES = moderate); whole-body bone mineral content (BMC) (r = 0.316, ES = moderate); femoral neck BMC (r = 0.469, ES = moderate); and femoral neck bone mineral density (BMD) (rho = 0.433, ES = moderate). Additionally, the results of multiple regression analysis demonstrated that PhA is significantly associated with SMBT (p < 0.001; R2 = 0.629), 6 MWT (p = 0.004; R2 = 0.214), knee extension (p < 0.001; R2 = 0.697), knee flexion (p < 0.001; R2 = 0.355), handgrip test (p < 0.001; R2 = 0.774), whole-body BMC (p < 0.001; R2 = 0.524), femoral neck BMC (p = 0.001; R2 = 0.249), and femoral neck BMD (p = 0.020; R2 = 0.153). The results of the preliminary analysis suggested that PhA is linked to muscle strength and some factors related to physical function and bone quality in community-dwelling older adults.

Not only muscle mass but also muscle quality is associated with knee extension muscle strength in patients with hip fractures

Our results revealed that the decrease in isometric knee extension muscle strength on the operated and nonoperated sides in patients with hip fractures was associated with not only a decrease in skeletal muscle mass but also a decrease in muscle quality, characterized by a decreased PhA.

PURPOSE

This study aimed to assess the relationship between isometric knee extension muscle strength on the operated or nonoperated sides and PhA in patients with hip fractures at approximately 6 months postoperatively.

METHODS

This study was a cross-sectional study. Skeletal muscle index (SMI), PhA, knee extension muscle strength on the operated and nonoperated sides, and other physical function variables were assessed at approximately 6 months postoperatively. To identify predictors of knee extension muscle strength on the operated and nonoperated sides, hierarchical multiple regression analysis was performed.

RESULTS

A total of 90 patients with hip fractures were included (mean age, 80.1 ± 6.9 years). SMI (0.45) and PhA on the operated side (0.27) were the significant associated factors extracted for isometric knee extension muscle strength on the operated side (standardized partial regression coefficients), independent of age, sex, and body mass index (BMI). Movement control during one-leg standing on the nonoperated side (0.26), SMI (0.32), and PhA on the nonoperated side (0.40) were the significant associated factors extracted for isometric knee extension muscle strength on the nonoperated side, independent of age, sex and BMI.

CONCLUSIONS

Our results revealed that the decrease in isometric knee extension muscle strength on the operated and nonoperated sides in patients with hip fractures at approximately 6 months postoperatively was associated with not only a decrease in skeletal muscle mass but also a decrease in muscle quality, characterized by a decreased PhA.

Interaction Effect of Phase Angle and Age on Femoral Neck Bone Mineral Density in Patients with Non-Dialysis Chronic Kidney Disease Stage 5

Background: Low bone mass is common in malnourished patients with chronic kidney disease (CKD) and can lead to a higher risk of fractures. Elderly and CKD patients have the same risk factors for protein-energy wasting, sarcopenia, and osteoporosis. Here, we investigated the association between phase angle (PhA) and bone mineral density (BMD) in dialysis-naïve patients with CKD stage 5 (CKD5) and identified a statistical relationship between PhA and age, which affects bone density. Methods: Bio-impedance spectroscopy for evaluating body composition and PhA and dual-energy X-ray absorptiometry for determining the BMD were simultaneously performed in 167 consecutive patients (mean age, 59.65 ± 13.98 years; women, 40.1%). Two-way analysis of variance (ANOVA) was conducted to assess the potential interaction effect of PhA and age on femoral neck BMD (FN-BMD). Results: Our results showed that PhA and age were independently associated with FN-BMD and T-score in multiple linear regressions analyses. A significant interaction effect of PhA and age on FN-BMD was found on two-way ANOVA (p = 0.028). The average BMD values for the first and second tertiles of the PhA were higher in the young versus elderly group, whereas patients in the elderly group had higher BMD in the third tertiles. Conclusions: A relationship was noted between PhA and BMD in patients with advanced-stage CKD. The effect of PhA level on FN-BMD differed between elderly and young patients. Our study suggested that higher PhA levels could be a marker explaining the maintenance of good bone health in elderly patients with CKD5. Further longitudinal analyses are needed to determine whether PhA predicts the risk of CKD-MBD-related fractures during CKD progression.

Bioelectrical impedance analysis-derived phase angle predicts sarcopenia in patients on maintenance hemodialysis

BACKGROUND

This study aimed to investigate the association between phase angle (PhA) and sarcopenia and evaluate its performance as a sarcopenia predictor in patients receveing maintenance hemodialysis (MHD).

METHODS

All enrolled patients underwent handgrip strength (HGS) and the 6-m walk test, and muscle mass was measured using bioelectrical impedance analysis. Sarcopenia was diagnosed according to the diagnostic criteria of the Asian Sarcopenia Working Group. Logistic regression analysis was used to evaluate the PhA as an independent predictor of sarcopenia after adjusting for confounding factors. The receiver operating characteristic (ROC) curve was used to analyze the predictive value of PhA in sarcopenia.

RESULTS

Two hundred forty-one patients receiving hemodialysis were enrolled in this study, and the prevalence of sarcopenia was 28.2%. Patients with sarcopenia presented a lower PhA value (4.7° vs 5.5°; P < 0.001), lower muscle mass index (6.0 vs 7.2 [kg/m² ]; P < 0.001), lower HGS (19.7 vs 26.0 [kg]; P < 0.001), and lower walk speed (0.83 ± 0.27 vs 0.92 ± 0.23 [m/s]; P = 0.007) than patients without sarcopenia. The odds of patients receiving MHD presenting with sarcopenia increased as PhA decreased, even after adjustment (odds ratio = 0.39; 95% CI, 0.18-0.85; P = 0.019). ROC analysis revealed that the best cutoff value of PhA for sarcopenia was 4.95° in patients receiving MHD.

CONCLUSION

PhA may be a useful and simple predictor for predicting patients undergoing hemodialysis who are at risk of sarcopenia. To further facilitate the application of PhA in the diagnosis of sarcopenia, more research need to be conducted.

Association of phase angle with sarcopenia in chronic musculoskeletal pain patients: a retrospective study

BACKGROUND

In chronic musculoskeletal pain patients, detection of sarcopenia is of significant clinical interest. Phase angle, which can be measured through bioelectrical impedance analysis (BIA), can detect sarcopenia; however, the evidence in chronic musculoskeletal pain patients is limited. This study aimed to assess the relationship between phase angle and sarcopenia in patients with chronic musculoskeletal pain. Our hypothesis was that phase angle would be a useful indicator to identify sarcopenia in patients with chronic musculoskeletal pain.

METHODS

A total of 190 patients (51 men and 139 women) with chronic musculoskeletal pain were included in this retrospective cross-sectional study. Patient data of backgrounds, numeric rating scale score for pain, skeletal muscle index, and phase angle assessed using BIA were retrospectively reviewed. Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria 2019.

RESULTS

A total of 51 patients (26.7%), including 10 men (19.6%) and 41 women (29.5%), were diagnosed with sarcopenia. Phase angle, sarcopenia-related factors, age, and body mass index (BMI) differed significantly in patients with and without sarcopenia. On multiple logistic regression analysis, the prevalence of sarcopenia was significantly correlated with phase angle and BMI. The areas under the curve exhibited high accuracy in discriminating sarcopenia in men and moderate accuracy in both sexes and in women.

CONCLUSIONS

Phase angle may be a valid discriminator of sarcopenia in patients with chronic musculoskeletal pain.

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

OBJECTIVE

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

RESEARCH METHODS & PROCEDURES

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

RESULTS

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

CONCLUSIONS

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

Cross-sectional and longitudinal study of the relationship between phase angle and physical function in older adults

AIM

Although the validity of the assessment in older adults has been supported by several studies, cross-sectional and longitudinal relationships between phase angle (PhA) and physical function by sex have not been clarified. This study aimed to examine (i) cross-sectional relationships and (ii) longitudinal relationships between PhA and physical function in older adults.

METHODS

A total of 816 and 445 community-dwelling older adults were included in cross-sectional and longitudinal analyses, respectively. We evaluated their physical function using grip strength, 5-repetition sit-to-stand test (5-STS), 5-meter habitual walk, Timed Up and Go test (TUG), single-leg balance with eyes open, and sit-and-reach test. A multifrequency bioelectrical impedance analyzer was used to determine the PhA at 50 kHz as well as the participants' body composition.

RESULTS

In the cross-sectional analysis, a higher PhA was significantly associated with higher grip strength, sit-and-reach, single-leg balance with eyes open, 5-STS and lower TUG in women, as well as higher grip strength, single-leg balance with eyes open, lower 5-STS and TUG in men, adjusting for age, body mass index and muscle mass. In the longitudinal analysis, there was a significant interaction between PhA and year in the TUG test (B = -0.08; 95% CI, -0.136 to -0.025; P = 0.005) in men. There was no significant interaction between the PhA value and year for the other physical functions.

CONCLUSIONS

The PhA is a useful indicator for assessing physical function in both older men and women. Furthermore, the PhA may be able to predict mobility limitation in older men. Geriatr Gerontol Int 2023; 23: 141-147.

Effects of muscle mass and muscle quality estimated by phase angle on functional outcomes in older patients undergoing rehabilitation: A prospective cohort study

BACKGROUND

Both skeletal muscle mass and muscle quality are important predictors of poor prognosis in older patients. However, the effects of muscle mass and muscle quality estimated by the phase angle (PhA) on functional outcomes in older patients undergoing rehabilitation have yet to be reported. This study aimed to investigate whether appendicular skeletal muscle index (SMI) and muscle quality estimated by PhA were independently associated with activities of daily living (ADL) and physical function in older patients undergoing rehabilitation.

METHODS

This prospective cohort study included older patients in a subacute rehabilitation hospital (n = 443). Baseline SMI and PhA were measured using bioelectrical impedance analysis, and low SMI or low PhA were determined using each cutoff value. The primary outcomes were ADL abilities measured using the functional independence measure for motor function (FIM-M) score and physical function measured using the short physical performance battery (SPPB) score at hospital discharge. Association between low SMI and low PhA and FIM-M or SPPB scores at discharge were determined using multiple regression analysis adjusted for confounding factors.

RESULTS

There were significant differences between the normal- and low-PhA groups in the FIM-M and SPPB scores at discharge (P < 0.001). In multiple regression analysis, low PhA was independently associated with FIM-M (β = -0.109, P = 0.013) and SPPB scores (β = 0.535, P < 0.001) at discharge; however, low SMI was not independently associated with these functional outcomes.

CONCLUSION

Decreased muscle quality estimated by the PhA was independently associated with poor ADL abilities and poor physical function in older patients undergoing rehabilitation.