Comparison of single- or multifrequency bioelectrical impedance analysis and spectroscopy for assessment of appendicular skeletal muscle in the elderly

The Influence of Physical, Mental, and Cognitive Factors on Health-Related Quality of Life among Community-Dwelling Older Adults: A Focus on Central Sensitization-Related Symptoms

Most older adults wish to maintain independence in their familiar communities. However, many experience pain and pain-related disabilities which reduce their health-related quality of life (HRQOL), leading to increased hospitalizations and mortality. This study aimed to determine the impact of physical, mental, and cognitive factors, particularly central sensitization-related symptoms (CSS), on the HRQOL of community-dwelling older adults. A total of 206 participants were included in the analysis, which measured HRQOL, basic attributes, physical functions and body pain, mental factors, cognitive factors, and CSS severity using validated tools. A correlation analysis was used to examine the association between HRQOL and each measure. Furthermore, multiple regression analysis (forced entry method) was performed to identify the factors influencing the HRQOL. The study found that pain intensity and CSS severity significantly influenced the HRQOL among community-dwelling older adults. The higher the pain intensity and CSS severity, the lower their HRQOL. The participants had mild pain and CSS, demonstrating the need to monitor, address, and treat even non-severe issues in community-dwelling older adults. This association, revealed for the first time in this study, suggests that approaches to reduce pain and CSS are important for maintaining and improving the HRQOL of community-dwelling older adults.

Segmental extracellular-to-intracellular water resistance ratio and physical function in older adults

OBJECTIVES

This study aimed to investigate the association between whole-body (WB), arm, and leg extracellular-to-intracellular water resistance (Recw/Ricw) ratios and various physical functions of each segment and muscle mass using segmental multifrequency bioelectrical impedance analysis.

METHODS

In total, 988 community-dwelling older adults were included in the analysis. Physical function was assessed using hand grip, 5-repetition sit-to-stand, 5-m habitual walk, Timed Up and Go, and single-leg balance with eyes open tests. Each segmental Recw/Ricw ratio and muscle mass were assessed at 5 and 250 kHz resistances using a segmental multifrequency bioelectrical impedance analysis device. Pearson's correlation between the segmental Recw/Ricw ratio and muscle mass and physical function was calculated, and the difference in correlation coefficients was tested using Bonferroni correction. Multiple linear regression analysis was conducted using physical function as the dependent variable and the segmental Recw/Ricw ratio as the independent variable, adjusting for sex, age, body mass index, and segmental muscle mass.

RESULTS

WB and leg Recw/Ricw ratios were significantly positively correlated with good hand grip performance, gait speed, mobility, balance, and standing power (p < 0.05), after adjusting for sex, age, body mass index, and muscle mass. Furthermore, the leg Recw/Ricw ratio was positively associated with lower extremity physical function compared with WB and arm Recw/Ricw ratios and muscle mass (p < 0.01). Conversely, WB muscle mass was more strongly related to grip strength than WB, arm, and leg Recw/Ricw ratios (p < 0.01).

CONCLUSIONS

The Recw/Ricw ratio is useful for identifying older adults with worse physical function. The Recw/Ricw ratio allows for easy and timely screening of older adults with worse physical function in clinical settings.

Novel Noninvasive Paraclinical Study Method for Investigation of Liver Diseases

Based on a prior university patent, the authors developed a novel type of bioimpedance-based test method to noninvasively detect nonalcoholic fatty liver disease (NAFLD). The development of a new potential NAFLD diagnostic procedure may help to understand the underlying mechanisms between NAFLD and severe liver diseases with a painless and easy-to-use paraclinical examination method, including the additional function to detect even the earlier stages of liver disease. The aim of this study is to present new results and the experiences gathered in relation to NAFLD progress during animal model and human clinical trials.

Comparison of Bioelectrical Impedance Indices for Skeletal Muscle Mass and Intracellular Water Measurements of Physically Active Young Men and Athletes

BACKGROUND

Bioelectrical impedance analysis (BIA) is a minimally invasive, safe, easy, and quick technology used to determine body composition.

OBJECTIVES

We compared the relationship among impedance indices obtained using single-frequency BIA, multi-frequency BIA, bioelectrical impedance spectroscopy (BIS), and skeletal muscle mass (SMM) of physically active young men and athletes using the creatine (methyl-d3) dilution method. We also compared the SMM and intracellular water (ICW) of athletes and active young men measured using a reference stable isotope dilution and BIS method, respectively.

METHODS

We analyzed data from 28 men (mean age, 20 ± 2 y) who exercised regularly. Single-frequency BIA at 5 kHz and 50 kHz (R5 and R50), multi-frequency BIA (R250-5), and BIS (RICW) methods of determining the SMM were compared. The deuterium and sodium bromide dilution methods of obtaining the total body water, ICW, and extracellular water measurements were also used, and the results were compared to those acquired using bioimpedance methods.

RESULTS

The correlation coefficients between SMM and L2/R5, L2/R50, L2/R250-5, and L2/RICW were 0.738, 0.762, 0.790, and 0.790, respectively (P < 0.01). The correlation coefficients between ICW and L2/R5, L2/R50, L2/R250-5, and L2/RICW were 0.660, 0.687, 0.758, and 0.730, respectively (P < 0.001). However, the correlation coefficients of L2/R50, L2/R250-5, and L2/RICW for SMM and ICW were not significantly different.

CONCLUSIONS

Our findings suggest that single-frequency BIA at L2/R50, multi-frequency BIA, and BIS are valid for assessing the SMM of athletes and active young men. Additionally, we confirmed that the SMM and ICW were correlated with single-frequency BIA, multi-frequency BIA, and BIS. Bioimpedance technologies may be dependable and practical means for assessing SMM and hydration compartment status of active young adult males; however, cross-validation is needed.

Investigating the impact of fluid status on the ultrasound assessment of muscle quantity and quality in the diagnosis of sarcopenia - a multidimensional cross-sectional study

BACKGROUND

Sarcopenia is a clinical manifestation of adverse ageing, characterised by progressive loss of muscle mass and function. Diagnosis requires assessment of muscle quantity and quality; ultrasound represents an emerging tool for this. However, ultrasound muscle assessment may be impacted by fluid balance. This is particularly important when assessing for acute sarcopenia in hospitalised patients, where fluid disturbance often occurs. The primary aim of this study was to characterise the impact of fluid status on ultrasound muscle assessment, such that this may be accounted for in sarcopenia diagnostics.

METHODS

This Multidimensional Cross-sectional study involved 80 participants, who were inpatients at QEHB, a large UK tertiary centre. Fluid status was evaluated clinically and quantified using Bioelectrical Impedance Analysis (BIA). Muscle quantity was measured using Bilateral Anterior Thigh Thickness (BATT) with Rectus Femoris (RF) echogenicity used to assesses muscle adiposity and hence provide an inverse measure of muscle quality.

RESULTS

A significant positive correlation was found between fluid status, measured using BIA, and BATT as a measure of muscle quantity, in males (rs = 0.662, p < 0.001) and females (rs = 0.638, p < 0.001). A significant negative correlation was found between fluid status and RF echogenicity (rs=-0.448, p < 0.001).

CONCLUSIONS

These findings demonstrate associations between fluid balance and ultrasound assessment of muscle quantity and quality. Given the emerging use of ultrasound muscle assessment in sarcopenia diagnosis, there is a need to account for this in clinical practice. Future research should focus on the development of a corrective equation allowing assessment of muscle quantity and quality which account for changes in fluid status, hence aiding accurate diagnosis of sarcopenia.

The role of bioelectrical phase angle in patients with heart failure

The most challenging feature of heart failure (HF) still remains the evaluation of congestion. Residual congestion at discharge and the difficulties in perfectly dosing therapies in order to balance the hydration status of the patient are the most worrisome issues when dealing with HF.The use of bioimpedance vector analysis (BIVA) might promote a different approach in the general management of patients with HF. BIVA is a reliable, fast, bedside tool able to assess the congestion status. It proved to be helpful to physicians for diagnosing congestive status, managing therapies, and providing prognostic information in the setting of HF.Bioelectrical Phase Angle (PhA) - as derived from equations related to the parameters of BIVA - recently surged as a possible biomarker for patients with HF. Studies provided data about the application of PhA in the clinical management and in the overall risk stratification of HF patients.Basically, the use of PhA might be considered as a holistic evaluation of patients with HF which includes the need for a multiparametric approach able to effectively depict the clinical status of patients. There is no definite biomarker able to comprehensively describe and identify all the features of HF patient, but scores based on molecules/techniques able to explore the different pathogenetic mechanisms of HF are desirable.The aim of this review was to provide a comprehensive evaluation of literature related to PhA role in HF and the impact of this biomarker on clinical management and risk stratification of HF patients.

Effects of exercise programs on phase angle in older adults: A systematic review and meta-analysis

The purpose of this study was to calculate the effects of exercise programs on phase angle (PhA) in older people. A systematic review was undertaken in multiple electronic databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines for the purposes of selecting randomized controlled trials that measured the effects of the exercise programs on PhA in older adults on 31 March 2022. We carried out a random-effect meta-analysis for the effects of exercise programs on PhA. Additionally, we analysed the differences between subgroups in terms of weekly frequency, number of sets and repetitions, and duration of interventions. Studies were methodological assessed through the PEDro scale where one had excellent, ten had good, and three had poor methodological quality. For the purposes of the study, fourteen studies met the criteria for inclusion. However, four studies did not have enough information to be included in the quantitative analysis. The remaining ten articles revealed moderate effects on PhA in favour of intervention groups (p=0.009, SMD=0.72 [0.46-0.99], I2=54%). The meta-analysis also showed that interventions lasting twelve weeks are more successful in generating positive effects on PhA as opposed to eight weeks (SMD's=0.79 vs. 0.64, respectively). These results indicate that resistance training (RT) is an effective and safe to improve PhA in the older people, especially through RT programs lasting from eight to twelve weeks. A novel finding of this study was that RT is the most used type of exercise by authors when assessing the PhA in older adults.

External validation of BIA equations to estimate appendicular skeletal muscle mass in older adults: Importance of the bias analysis and derivation of correction factors to achieve agreement

There are several equations based on bioelectrical impedance analysis (BIA) to estimate with high precision appendicular skeletal muscle mass (ASM). However, most of the external validation studies have reported that these equations are inaccurate or biased when applied to different populations. Furthermore, none of the published studies has derived correction factors (CFs) in samples of community-dwelling older adults, and none of the published studies have assessed the influence of the dual-energy X-ray absorptiometry (DXA) model on the validation process. This study assessed the agreement between six BIA equations and DXA to estimate ASM in non-Caucasian older adults considering the DXA model and proposed a CF for three of them. This analysis included 547 non-institutionalized subjects over 60 years old from the northwest of Mexico who were physically independent and without cognitive impairment: 192 subjects were measured using DXA Hologic, while 355 were measured by DXA Lunar. The agreement between each of the equations and DXA was tested considering the DXA model used as a reference method for the design of each equation, using the Bland and Altman procedure, a paired t test, and simple linear regression as objective tests. This process was supported by the differences reported in the literature and confirmed in a subsample of 70 subjects measured with both models. Only six published BIA equations were included. The results showed that four equations overestimated ASM_DXA, and two underestimated it (p < 0.001, 95% CI for Kim's equation:−5.86-−5.45, Toselli's:−0.51-−0.15, Kyle's: 1.43–1.84, Rangel-Peniche's: 0.32–0.74, Sergi's: 0.83–1.23, and Yoshida's: 4.16–4.63 kg). However, Toselli's, Kyle's and Rangel-Peniche's equations were the only ones that complied with having a homogeneous bias. This finding allowed the derivation of CFs, which consisted of subtracting or adding the mean of the differences from the original equation. After estimating ASM applying the respective CF, the new ASM estimations showed no significant bias and its distribution remained homogeneously distributed. Therefore, agreement with DXA in the sample of non-Caucasian was achieved. Adding valid CFs to some BIA equations allowed to reduce the bias of some equations, making them valid to estimate the mean values of ASM at group level.

Bioelectrical impedance vector analysis and body composition in cervical spinal cord injury: A pilot study

Introduction

Body composition assessment in cervical spinal cord injury (c-SCI) individuals is important to monitor the fat free-mass (FFM) loss, due to immobilization, or gain, due to exercise practice. Single frequency bioelectrical impedance analysis (SF-BIA) is low in cost, simple and easy.

Objectives

The aims of this study are: to evaluate the concordance between the FFM values obtained using dual X-ray absorptiometry (DXA) and the three SF-BIA previous predictive equations; and to test the applicability of the bioelectrical impedance vector analysis (BIVA).

Methods

Twenty-three c-SCI males were divided into two groups: Physically active (PA; n = 13; at least 150 min/week) and non-active individuals (NPA) and were assessed by DXA and SF-BIA simultaneously.

Results

FFM values were similar between groups PA and NPA. Considering all participants, FFM values obtained by Kocina and Heyward (>11%) and Sun (<15.4%) predictive equations were different when compared to DXA (p < 0.01). However, Buchholz's et al. predictive equation showed FFM values similar to DXA, but presented poor concordance (<7%, p = 0.99; concordance coefficient = 0.85). BIVA showed consistency in ellipse distribution using FFM obtained using Buchholz et al. predictive equation.

Conclusions

The use of non-specific BIA equations can lead to misinterpretation in FFM values in male c-SCI individuals. Predictive equations for this group need to be developed.

Membrane capacitance and characteristic frequency are associated with contractile properties of skeletal muscle

The cell membrane capacitance (Cm) and characteristic frequencies (fc) of tissues can be obtained using segmental bioelectrical impedance spectroscopy (S-BIS). Higher Cm and lower fc are associated with a larger surface area of skeletal muscle fibers with T-tubules in the tissues. Muscle fiber membrane is one of the major physiological factors that influence surface electromyograms (EMGs) as well as the number of recruited motor units so that the amplitude of surface EMG may be correlated with Cm and fc. The aim of the current study was to examine the association of fc or Cm in the lower leg with contractile and neuromuscular properties in the plantar flexors. We analyzed data from 59 participants (29 women) aged 21-83 years. The Cm, fc, and intracellular water (ICW) in the lower leg were obtained using S-BIS. We measured electrical-evoked torque, maximal voluntary contraction (MVC) torque, and amplitude of EMG normalized by the M wave during MVC contraction. The high Cm group had a significantly lower fc and significantly higher MVC torque, estimated maximum torque, twitch torque, and root mean square (RMS) of EMG normalized by the M wave (EMG:M) in the musculus triceps surae compared to the low Cm group (P < 0.05). Cm was positively and fc was negatively correlated with the nRMS of EMG:M in the triceps surae (P < 0.05). S-BIS recordings can be used to detect changes in skeletal muscle membrane capacitance, which may provide insights into the number of T-tubules. The muscle capacitance measured with S-BIS can be predictive of muscle force generation.

Objective Physical Activity Levels, Sedentary Time, and Muscle Mass, Strength, and Function: Impact on Physical and Mental Health-Related Quality of Life in Older Adults

Limited physical activity, sedentary behavior, and reduction in muscle mass, strength, and function are accompanied by negative outcomes. The relationship between these factors and physical and mental health-related quality of life (HRQoL) has yet to be elucidated in continuing care retirement community (CCRC) residents. The current study investigated the relationships among physical activity, sedentary behavior, and muscle mass, strength, and function to physical and mental HRQoL. A sample of 105 CCRC residents participated in this cross-sectional correlational study. Findings demonstrated that low physical activity and muscle function were significantly associated with low physical HRQoL and explained 38% of the variance in physical HRQoL. Handgrip strength was significantly associated with low mental HRQoL and explained 8% of the variance in mental HRQoL. Older adults living in CCRCs may benefit from interventions targeting physical activity and the distinct muscle components of sarcopenia that have the potential to improve physical and mental HRQoL. [Research in Gerontological Nursing, 15(3), 131-139.].

Effect of semi-recumbent vibration exercise on muscle outcomes in older adults: a pilot randomized controlled clinical trial

Background

Many older adults with physical limitations living in residential care apartments are unable to exercise in a standing position and are at risk for declining in muscle function leading to falls and injury. Novel approaches to achieve exercise benefits are needed. The purpose of this study was to test the effect of semi-recumbent vibration exercise on muscle outcomes in older adults living in residential care apartment complexes (RCACs).

Methods

A randomized, crossover design was used to examine the effect of semi-recumbent vibration exercise on muscle function and mass among 32 RCAC residents (mean age 87.5 years) with physical limitations. Participants received a randomized sequence of two study conditions: sham or vibration for 8 weeks each separated by a 4-week washout. Before and after the 8 weeks of vibration treatment and sham treatment, muscle mechanography was used to assess muscle function including jump power, weight-corrected jump power, and jump height. Short physical performance battery (SPPB) and handgrip strength were also used to measure muscle function. Bioelectrical impedance spectroscopy was used to estimate skeletal muscle mass. The effect of the vibration treatment on muscle outcomes was analyzed through mixed effects linear regression models.

Results

Vibration exercise leads to better jump height (p < .05) compared to sham exercise but also poorer chair rise performance (p = 0.012). Other muscle functions tests and muscle mass parameters showed non-significant changes.

Conclusion

This small pilot study showed no conclusive results on the effect of semi-recumbent vibration exercise on muscle function and mass in older adults living in RCAC. However, the promising signals of improved jump performance could be used to power larger studies of longer duration with various vibration doses to determine the benefit of vibration exercise in this physically impaired, high-risk population with few exercise capabilities.

Trial registration

The study is registered at clinicaltrials.gov (NCT02533063; date of first registration 26/08/2015).

Comparison of Bioelectrical Impedance Analysis with DXA in Adolescents with Cystic Fibrosis before and after a Resistance Training Intervention

Background: The purpose of this pilot study was to compare body composition metrics obtained by two portable bioelectrical impedance analysis (BIA) devices with dual-energy X-ray absorptiometry (DXA) among adolescents with cystic fibrosis (CF) before and after a resistance exercise training program. Methods: Participants with CF were assessed using DXA, single-frequency BIA (SFBIA), and multiple-frequency BIA (MFBIA) to quantify percent body fat (%Fat), fat mass (FM), and fat-free mass (FFM) at baseline and after a home-based resistance training intervention comprised of 36, 1 h sessions completed in 12–14 weeks. Repeated measures analysis of variance, paired samples t-tests, Cohen’s d effect sizes, and Pearson’s correlations were used to compare differences between and within methods at baseline and post-intervention. Results: Ten participants (15.8 ± 2.2 yr, 60.1 ± 15.1 kg) completed the assessments. At baseline, both SFBIA and MFBIA scales significantly underestimated %Fat and FM and overestimated FFM, with small to moderate effect sizes. Post-intervention, small, non-significant differences were found between DXA and both BIA scales for all body composition metrics. Significant changes in %Fat and FFM were observed with DXA. MFBIA displayed less constant error than SFBIA when compared to DXA for pre- and post-intervention assessments for %Fat (MFBIA: pre and post −2.8 and −0.8 vs. SFBIA: −4.6 and −2.0), FM (−0.4 and −0.4 vs. −3.0 and −1.1), and FFM (+0.8 and +0.6 vs. +3.1 and +1.3). Near-perfect correlations were observed at both time points between DXA and each BIA scale. Conclusions: Portable BIA results should be interpreted with caution, and further validation studies in CF patients are needed prior to clinical use.

Malnutrition–Sarcopenia Syndrome and Self-Management Behaviors in Continuing-Care Retirement Community Residents

Malnutrition–sarcopenia syndrome (MSS) might put older adults at higher risk for disability, frailty, and mortality. This study examined the prevalence and association of the self-management-process factors (i.e., self-efficacy and aging expectations) and behaviors (protein and caloric intake and sedentary and physical-activity behaviors) to MSS among older adults living in continuing care retirement communities (CCRCs). Using a cross-sectional correlational design, data of 96 CCRC residents (82.4 ± 7.4 years) were analyzed. Muscle mass, strength, function, nutritional status, sedentary time, physical activity levels, protein and caloric intake, self-efficacy for physical activity, aging expectations, and physical and mental health-related quality of life were measured. Results show that 36 (37.5%) had sarcopenia, 21 (21.9%) had malnutrition risk, 13 (13.4%) had malnutrition, and 12 (12.5%) had MSS. We also found that high time spent in sedentary behaviors (OR = 1.041; 95% CI: 1.011–1.071) was associated with higher odds of having MSS and high expectations regarding aging (OR = 0.896; 95% CI: 0.806–0.997) were associated with less likelihood of having MSS. Findings suggest that CCRC residents should be screened for MSS. Self-management interventions that consider the self-management-process factors are needed to prevent MSS and mitigate its negative outcomes among CRCC residents.

Physical Activity and Sarcopenia in Community-Dwelling Older Adults with Long-Term Care Insurance

The present study aimed to clarify the difference in physical activity (PA) due to sarcopenia in community-dwelling older adults with long-term care insurance (LTCI). This was a cross-sectional study that investigated data of 97 consecutive community-dwelling older Japanese adults with LTCI who underwent rehabilitation at one day care center in Japan from November 2018 to May 2019. Sarcopenia was determined according to criteria of the Asian Working Group for Sarcopenia. Unpaired t-test, Mann-Whitney U test, chi-square test and analysis of covariance were used to compare participant characteristics and clinical parameters between the older adults with and without sarcopenia. A receiver operating characteristic (ROC) curve was constructed to determine the cut-off value of PA for sarcopenia. The sarcopenia group (n = 20) had significantly lower body mass index (BMI), skeletal muscle mass index, gait speed, and PA than those in the no sarcopenia group (n = 28) (p < 0.05). After adjustment for BMI and sex, the sarcopenia group showed significantly lower PA than the no sarcopenia group. Findings showed that the cut-off value of PA indicating sarcopenia by ROC curve analysis was 1494.4 steps/day (p < 0.05); this value may aid in identifying sarcopenia in older adults with LTCI.

Lymphedema Index Ratio As Predictive Factor of Treatment in Patients with Breast Cancer-Related Lymphedema

Background: This retrospective observational study aimed to evaluate the lymphedema index ratio to predict the effect of complex decongestive therapy (CDT) in patients with breast cancer-related lymphedema (BCRL) and to establish a lymphedema index ratio cutoff value for the extent of CDT effect. Materials and Methods: All 108 enrolled patients with BCRL underwent volume measurements and bioelectrical impedance analysis before and after CDT. The difference in percent excess volume (PEV) before and after CDT was defined as the therapeutic effect, and each patient was assigned to Groups A, B, or C based on therapeutic effects of 0%-5%, 5%-10%, and 10%-20%, respectively. Results: The mean lymphedema index ratios of Groups A, B, and C were 1.27, 1.38, and 1.46, respectively, with significant differences between the groups (p < 0.01). The cutoff lymphedema index ratio values for diagnosis between Groups A and B and between Groups B and C were 1.277 (sensitivity: 71.7%, specificity: 61.8%) and 1.357 (sensitivity: 76.9%, specificity: 62.1%), respectively. The Spearman coefficients for the linear relationship between lymphedema index ratio and initial PEV and between lymphedema index ratio and therapeutic effect were found to be significant at 0.615 and 0.360, respectively (p < 0.01). Conclusion: The results of this study found that the lymphedema index ratio may predict the volume reduction in patients with BCRL. A less reduction (therapeutic effect <5%) was predicted in patients with a lymphedema index ratio of <1.277, while a greater reduction (therapeutic effect >10%) was predicted in patients with a lymphedema index ratio of >1.357.

Raw bioelectrical impedance analysis variables (phase angle and impedance ratio) are significant predictors of hand grip strength in adolescents and young adults

OBJECTIVES

Musculoskeletal fitness and body composition are major components of health-related physical fitness that are expected to be linked to each other. The aim of this study was to explore the association of musculoskeletal fitness (expressed as hand grip strength [HGS]) and raw bioelectrical impedance analysis (BIA) variables and other predictors in the second and third decades of life.

METHODS

Four groups of healthy normal-weight and overweight participants were studied: 130 male adolescents (age 16.0 ± 1.1 y), 143 female adolescents (16.0 ± 0.9 y), 141 young men (25.5 ± 2.0 y), and 141 young women (25.2 ± 1.9 y). Raw BIA variables (impedance [Z] and phase angle [PhA]) for the whole body were measured at four frequencies (5, 50, 100, and 250 kHz), and HGS was measured in both upper limbs.

RESULTS

HGS was higher in males than females and higher in young men than male adolescents. A fairly strong correlation emerged in both genders between HGS and raw BIA variables-that is, bioimpedance index (height²/Z), PhA, and impedance ratios (Z at high frequency/Z at low frequency). In multiple regression analysis, bioimpedance index, PhA, and impedance ratio were more effective predictors of HGS than BIA-derived estimates of body composition or anthropometric variables such as height, weight, and body mass index. In both genders, HGS was significantly higher in young adults than in adolescents for the same PhA or impedance ratio.

CONCLUSIONS

This study provides some insight into the use of raw BIA variables and HGS in the first decades of life, suggesting a new approach for a reliable assessment of muscle quality in terms of both muscle structure and strength.

Estimating thigh skeletal muscle volume using multi-frequency segmental-bioelectrical impedance analysis

Background

The primary aim of this study was to investigate whether using the extracellular water/intracellular water (ECW/ICW) index and phase angle combined with segmental-bioimpedance analysis (BIA) improved the model fitting of skeletal muscle volume (SMV) estimation. The secondary aim was to compare the accuracy of segmental-BIA with that of ultrasound for estimating the quadriceps SMV measured with MRI.

Methods

Seventeen young men (mean age, 23.8 ± 3.3 years) participated in the study. The T-1 weighted images of thigh muscles were obtained using a 1.5 T magnetic resonance imaging (MRI) scanner. Thigh and quadriceps SMVs were calculated as the sum of the products of anatomical cross-sectional area and slice thickness of 6 mm across all slices. Segmental-BIA was applied to the thigh region, and data on the 50-kHz bioelectrical impedance (BI) index, ICW index, ECW/ICW index, and phase angle were obtained. The muscle thickness index was calculated as the product of the mid-thigh muscle thickness, determined using ultrasound, and thigh length. The standard error of estimate (SEE) of the regression equation was calculated to determine the model fitting of SMV estimation and converted to %SEE by dividing the SEE values by the mean SMV.

Results

Multiple regression analysis indicated that the combination of 50-kHz BI and the ECW/ICW index or phase angle was a significant predictor when estimating thigh SMV (SEE = 7.9 and 8.1%, respectively), but were lower than the simple linear regression (SEE = 9.4%). The ICW index alone improved the model fitting for the estimation equation (SEE = 7.6%). The model fitting of the quadriceps SMV with the 50-kHz BI or ICW index was similar to that with the skeletal muscle thickness index measured using ultrasound (SEE = 10.8, 9.6 and 9.7%, respectively).

Conclusions

Combining the traditionally used 50-kHz BI index with the ECW/ICW index and phase angle can improve the model fitting of estimated SMV measured with MRI. We also showed that the model suitability of SMV estimation using segmental-BIA was equivalent to that on using ultrasound. These data indicate that segmental-BIA may be a useful and cost-effective alternative to the gold standard MRI for estimating SMV.

Validating muscle mass cutoffs of four international sarcopenia-working groups in Japanese people using DXA and BIA

BACKGROUND

The Asian Working Group for Sarcopenia (AWGS) 2019 recommended the use of dual-energy X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) to assess appendicular lean mass (ALM). AWGS, European Working Group on Sarcopenia in Older People 2 (EWGSOP2), Foundation for the National Institutes of Health Sarcopenia Project (FNIH), and International Working Group on Sarcopenia (IWGS) reported different cutoff values for sarcopenia. We aimed to validate these cutoff values in a Japanese population using DXA and two different devices of segmental multi-frequency BIA (MF-BIA).

METHODS

We examined the data of Japanese individuals aged 18-86 years using the DXA (n = 756) and two 8-electrode MF-BIA devices (InBody and TANITA MC) (n = 1884). To validate these cutoff values, we used a population aged 18-40 years, and calculated the 95% confidence intervals (CIs) of [mean-2SD].

RESULTS

In DXA, the 95%CIs of [mean-2SD] for ALM/Ht² were 5.2-5.8 and 6.6-7.3 kg/m² in women and men, respectively. The AWGS (<5.4 in women and <7.0 in men), and IWGS (≤5.67 in women and ≤7.23 in men) cutoffs were acceptable. Regarding TANITA MC, the 95%CIs of [mean-2SD] for ALM/Ht² were 5.6-6.0 and 6.9-7.4 kg/m² in women and men, respectively. The AWGS (<5.7 in women and <7.0 in men), EWGSOP2 (<6.0 in women and <7.0 in men), and IWGS cutoffs were acceptable. Regarding InBody, the 95%CIs of [mean-2SD] for ALM/Ht² were 4.8-5.2 and 6.4-6.8 kg/m² in young women and men, respectively. All cutoff values were too high compared to those measured by InBody. InBody and TANITA MC were highly correlated (P < 0.001), but the values by InBody were significantly lower than those by TANITA MC or DXA. Using Yamada's equation for InBody raw data, the AWGS, EWGSOP2, or IWGS cutoffs were acceptable. The BMI-adjusted muscle mass cutoff values were <0.60 and <0.82 m² in women and men, respectively. We also obtained the 20th percentile in older adult population (ALM/Ht² , <6.2 in women and <7.5 in men for TANITA MC; <5.4 in women and <7.0 in men for InBody).

CONCLUSIONS

The AWGS and IWGS cutoffs were valid for DXA, and the AWGS, IWGS, and EWGSOP2 cutoffs were valid for TANITA MC in Japanese population. Because the prevalence of sarcopenia is too low particularly in women when using those criteria, the 20th percentile might be a good alternative criteria. If the ALM original InBody values are used, the cutoffs should be <5.0 kg/m² in women and <6.6 kg/m² in men.

Relationship Between Bioelectrical Impedance Parameters and Appendicular Muscle Functional Quality in Older Adults from South-Western Poland

Purpose

The aim of this research was to assess the correlations between the impedance components and the appendicular skeletal muscle strength and functional quality indices in older adults. The use of the impedance parameters as potential identifiers characterizing the functional state of muscles could improve methods of monitoring “healthy ageing”.

Patients and Methods

A total of 346 subjectively healthy adults aged 50–83 years were subjected to tests. Body mass and height, hand grip strength and knee extensor strength were measured. Resistance, reactance and phase angle were measured using the bioelectrical impedance method. The relationship between the impedance parameters and the appendicular skeletal muscle strength and quality indices was evaluated using stepwise multiple regression.

Results

Participants aged ≥65 years were found to be characterized by lower values of the impedance parameters and the appendicular skeletal muscle strength and functional quality indices than participants 10 years younger. In both groups of sexes, the relative percentage differences in limb strength between the age groups were 3–6 times greater than the differences in appendicular skeletal muscle mass. Significant regression models for muscle strength and quality, with strong age, sex and reactance prediction and a weaker phase angle effect, were obtained.

Conclusion

The impedance components explain the part of changes in muscle strength which is independent of the decline in skeletal muscle mass. Phase angle and reactance can be suitable for diagnosing and preventing dangers connected with the decline in muscle quality, but it is necessary to establish their normalized reference values for older adults.

Validity of Bioimpedance Spectroscopy in the Assessment of Total Body Water and Body Composition in Wrestlers and Untrained Subjects

Bioimpedance spectroscopy (BIS) is an easy tool to assess hydration status and body composition. However, its validity in athletes remains controversial. We investigated the validity of BIS on total body water (TBW) and body composition estimation in Japanese wrestlers and untrained subjects. TBW of 49 young Japanese male subjects (31 untrained, 18 wrestlers) were assessed using the deuterium dilution method (DDM) and BIS. De Lorenzo’s and Moissl’s equations were employed in BIS for TBW estimation. To evaluate body composition, Siri’s 3-compartment model and published TBW/fat-free mass (FFM) ratio were applied in DDM and BIS, respectively. In untrained subjects, DDM and BIS with de Lorenzo’s equation showed consistent TBW estimates, whereas BIS with Moissl’s equation overestimated TBW (p < 0.001 vs. DDM). DDM and BIS with de Lorenzo’s equation estimated FFM and percent of fat mass consistently, whereas BIS with Moissl’s equation over-estimated and under-estimated them (p < 0.001 vs. DDM). In wrestlers, BIS with de Lorenzo’s and Moissl’s equations assessed TBW similarly with DDM. However, the Bland–Altman analysis revealed a proportional bias for TBW in BIS with de Lorenzo’s equation (r = 0.735, p < 0.001). Body composition assessed with BIS using both equations and DDM were not different. In conclusion, BIS with de Lorenzo’s equation accurately estimates the TBW and body composition in untrained subjects, whereas BIS with Moissl’s equation is more valid in wrestlers. Our results demonstrated the usefulness of BIS for assessing TBW and body composition in Japanese male wrestlers.

Relationship between oral function and life-space mobility or social networks in community-dwelling older people: A cross-sectional study

OBJECTIVES

This study aimed to clarify the relationship between oral function and life-space mobility or social networks in order to explore approaches that prevent a decline in oral function.

MATERIALS AND METHODS

A total of 113 community-dwelling older people (mean age; 75.7 ± 7.3 years) who participated in preventive long-term care projects aimed at the maintenance or improvement of physical and mental functions were included in this study. The life-space assessment (LSA) was used to evaluate life-space mobility, while the Lubben Social Network Scale-6 (LSNS-6) was employed to assess social networks. Oral function was measured by maximum voluntary tongue pressure, oral diadochokinesis, the repetitive saliva swallowing test, and lip pressure. Indices of frailty were grip strength and the Kihon Checklist score. Multiple regression analysis was performed to clarify whether the LSA, LSNS-6, and frailty are associated with oral function.

RESULTS

The results of the Kihon Checklist showed that 63 participants (56%) were subjectively and at least slightly aware of a decline in oral function. LSA (B = 0.222, p < .001) and grip strength (B = 0.266, p = .003) associated with maximum voluntary tongue pressure. The goodness of fit of the predictive model was an adjusted R² value of .486. Other oral functions were not associated with any factors and the goodness of fit of the model was poor (Adjusted R²  < .1). LSNS-6 was not associated with any oral function.

CONCLUSIONS

Life-space mobility and grip strength were independent factors associating maximum voluntary tongue pressure, while social networks did not directly association oral function. This study suggests the necessity of a program that approaches both oral and physical functions through guidance for securing a certain amount of daily activity for older people at risk of or exhibiting a decline in maximum voluntary tongue pressure.

Estimation of skeletal muscle mass by bioimpedance and differences among skeletal muscle mass indices for assessing sarcopenia

BACKGROUND

It is crucial to assess age-related muscle mass changes and derived indices differences in geriatric medicine. We aimed to develop and validate four bioimpedance analysis (BIA) prediction equations against dual-energy X-ray absorptiometry (DEXA) and magnetic resonance image (MRI) in estimating skeletal muscle mass and to compare the differences among skeletal muscle mass indices, cutoff values, and corresponding prevalence rates of low muscle mass for assessing sarcopenia in Chinese adults.

METHODS

We measured the height (Ht), weight (Wt), appendicular lean mass (ALM) or skeletal muscle mass (ASM), total lean body mass (LBM) or skeletal muscle mass (TSM) obtained using DEXA or MRI, and a multi-frequency BIA (BCA _II;50, 250 kHz), in 371 adults aged 18.0-87.0 years. We also collected gender, age, Ht, Wt, and impedance indexes (Ht²/R₅₀, Ht²/R₂₅₀, R₅₀/Ht², R₂₅₀/Ht²) from 30,500 adults aged 18-96 years living in China. Multiple regression analyses were used to derive four prediction equations by BIA, and double cross-validation techniques and Bland-Altman analyses were used to test agreement. Various muscle mass indices and prevalence rates were depicted by line plots in regard to age trends.

RESULTS

Satisfactory results were found in the four prediction models as they had the larger R² (0.833-0.930) values and low SEE (1.409-2.335 kg) values. The predictive variables included impedance indexes (Ht²/R₅₀, R₅₀/Ht², R₂₅₀/Ht²), gender, age, Wt, and Ht. The corresponding prevalence rates of low muscle mass exhibited significant differences according to the various muscle mass indices adjusted for Ht, Wt, or body mass index (BMI), in addition to the cutoff values based on two standard deviations (2SD) of young people or the lower 20% of the study group.

CONCLUSIONS

The BIA equations have the potential to be applied as a practical method of quantifying skeletal muscle mass in Chinese adults. However, the operational methods that are most appropriate for determining the degree of low muscle mass that actually contributes to sarcopenia remains inconclusive.

Comparison of segmental lean tissue mass in individuals with spinal cord injury measured by dual energy X-ray absorptiometry and predicted by bioimpedance spectroscopy

STUDY DESIGN

Observational.

OBJECTIVES

To compare two methods for predicting segmental (arms, legs, trunk) lean tissue mass (LTM: non-bone fat-free mass) from bioimpedance spectroscopy (BIS) against LTM measured from dual energy X-ray absorptiometry (DXA) in individuals with acute spinal cord injury (SCI).

SETTING

Austin Health Victorian Spinal Cord Service, Victoria, Australia.

METHODS

Fourteen participants (two female), within 8 weeks of traumatic SCI had BIS measured following an overnight fast and within 24 h of DXA scanning. Total body fat-free mass (FFM, body weight minus fat mass) and segmental LTM were predicted from BIS using manufacturer's proprietary software and a previously established SCI-specific prediction method. Appendicular LTM (ALM) was calculated from the sum of the LTM of the arms and legs. Agreement and strength of relationships with DXA for predicted LTM measures using both approaches were assessed using Lin's concordance coefficient and limits of agreement analysis (LOA).

RESULTS

The BIS proprietary method performed better than the SCI-specific prediction method in predicting DXA LTM, demonstrating substantial concordance for total body FFM (rc = 0.80), ALM (rc = 0.78), arm (rc = 0.76) and leg LTM (rc = 0.65) and a smaller bias and LOA for ALM (+0.8 vs. -3.4 kg; LOA -4.9-6.4 vs. -11.9-5.1 kg), arm (+0.02 vs. -0.3 kg; LOA -1.1-1.1 kg vs. -2.2-1.6 kg) and leg (+0.4 vs. -1.4 kg; LOA -2.0-2.8 vs. -5.6-2.8) LTM.

CONCLUSIONS

BIS can be used to accurately predict total body FFM, segmental LTM and ALM in individuals with acute SCI.

Validation of a Multielectrode Bioelectrical Impedance Analyzer With a Dual-Energy X-Ray Absorptiometer for the Assessment of Body Composition in Older Adults

Changes in body composition are related to mobility, fall risk, and mortality, especially in older adults. Various devices and methods exist to measure body composition, but bioelectrical impedance analysis (BIA) has several advantages. The purpose of this study was to validate a common BIA device with a dual-energy X-ray absorptiometer (DXA) in older adults and develop prediction equations to improve the accuracy of the BIA measurements. The participants were 277 older adults (162 women and 115 men; age 73.9 ± 5.8 years) without a history of cancer and without a history of severe medical or mental conditions. Individuals fasted 12 hr before BIA and DXA measurement. The correlations between the two methods for appendicular lean mass (ALM), fat-free mass (FFM), and percentage body fat (%BF) were .86, .93, and .92, respectively, adjusting for age and sex. The mean percentage error (DXA-InBody) and mean absolute percentage error were -12% and 13% for ALM, -13% and 13% for FFM, and 16% and 17% for %BF. The prediction equations estimated ALM, FFM, and %BF; sex was coded as 1 for male and 0 for female: DXAALM=0.0673+(0.6732×BIAALM)+(2.33507×sex)+(0.13349×BMI),R2=.94; DXAFFM=0.72323+(0.72384×BIAFFM)+(3.675012×sex)+(0.2816×BMI),R2=.97; and DXA%BF=15.8896+(0.64694×BIA%BF) -(3.99945×sex)+(0.13824×BMI),R2=.91 Although highly correlated, BIA overestimated FFM, and ALM and underestimated %BF compared with DXA. An application of prediction equations eliminated the mean error and reduced the range of individual error across the sample. Prediction equations may improve BIA accuracy sufficiently to substitute for DXA in some cases.

The associations of body mass index, bioimpedance spectroscopy-based calf intracellular resistance, single-frequency bioimpedance analysis and physical performance of older people

BACKGROUND

Bioimpedance skeletal muscle indices (SMI) are used as a surrogate for skeletal muscle mass, but their associations with physical functioning and obesity need further evaluation.

AIMS

To compare the associations of body mass index (BMI), bioimpedance spectroscopy-based calf intracellular resistance (Cri-SMI), and single-frequency bioimpedance analysis (SF-SMI) indices with physical performance and the functioning of community-dwelling older people at risk of or already suffering from sarcopenia.

METHODS

Pre-intervention measurements of the screened subjects and the participants of the Porvoo sarcopenia trial (N = 428) were taken. Cri-SMI, whole-body SF-SMI, and BMI were related to hand-grip strength, walking speed, short physical performance battery (SPPB), and the physical component of the RAND-36.

RESULTS

Among the older people (aged 75-96), Cri-SMI correlated inversely with age (men r = - 0.113, p < 0.001; women r = - 0.287, p < 0.001), but positively with SPPB (r = 0.241, p < 0.001) and the physical component of the RAND-36 (r = 0.114, p = 0.024), whereas BMI was inversely associated with SPPB (r = - 0.133, p < 0.001) and RAND-36 (r = - 0.286, p < 0.001). After controlling for age, gender, and comorbidity, one unit of Cri-SMI (cm²/Ω) was associated with a 3.3-fold probability of good physical performance (SPPB ≥ 9 points, OR = 3.28, p < 0.001) and one unit of BMI (kg/m²) decreased the respective probability 4% (OR= 0.96, p = 0.065). Physical inactivity partly explained the negative association of BMI. When Cri-SMI and BMI were controlled for, a 1% difference in Cri-SMI was associated with a 0.7% (p < 0.001) higher probability of good performance, the respective figure being - 2.2% (p = 0.004) for BMI. The associations of SF-SMI with physical functioning indices were insignificant.

CONCLUSIONS

Independent of each other, Cri-SMI was positively and BMI was inversely associated with the physical performance and functioning of community-dwelling older people who were at risk of or already suffering from sarcopenia. We found no association between SF-SMI and physical functioning.

Variable selection and importance in presence of high collinearity: an application to the prediction of lean body mass from multi-frequency bioelectrical impedance

In prediction problems both response and covariates may have high correlation with a second group of influential regressors, that can be considered as background variables. An important challenge is to perform variable selection and importance assessment among the covariates in the presence of these variables. A clinical example is the prediction of the lean body mass (response) from bioimpedance (covariates), where anthropometric measures play the role of background variables. We introduce a reduced dataset in which the variables are defined as the residuals with respect to the background, and perform variable selection and importance assessment both in linear and random forest models. Using a clinical dataset of multi-frequency bioimpedance, we show the effectiveness of this method to select the most relevant predictors of the lean body mass beyond anthropometry.

Comprehensive geriatric intervention in community-dwelling older adults: a cluster-randomized controlled trial

BACKGROUND

In longevity societies, one of the most serious social issues is sarcopenia and/or frailty. Preventing them is important for maintaining independence and quality of life in the older population. This study investigated the effect of a self-monitoring comprehensive geriatric intervention programme (CGIP) on physical function and muscle size in community-dwelling older adults. We compared the effects of a CGIP using weekly class-styled (CS) sessions and a home-based (HB) programme.

METHODS

The 526 participants were randomized into one of two groups (CS 251, HB 275) based on their residential districts. We conducted a 12 week CGIP, which consisted of low-load resistance exercise, physical activity increments, oral function improvements, and a nutritional guide. All participants were encouraged to attend two 90 min lectures that included instructions on the CGIP. They were provided with exercise materials (triaxial-accelerometers/pedometers, ankle weights, and elastic bands) and diary logs. The CS group attended 90 min weekly sessions and independently executed the programme on other days, whereas the HB group only received instructions on how to execute the programme. Physical functions, such as knee extension strength (KES), normal and maximum walking speed, the timed up-and-go test, and anterior thigh muscle thickness (MT), were measured and analysed using intention-to-treat analysis before and after the 12 week intervention.

RESULTS

Of the 526 participants identified, 517 (CS 243 age 74.0 ± 5.4 women 57.2%, HB 274 age 74.0 ± 5.6 women 58.8%) were enrolled. Nine (CS 8, HB 1) were excluded from the analysis because they did not participate in the pre-intervention measurements. Both interventions significantly improved KES (CS 18.5%, HB 10.6%), normal walking speed (CS 3.7%, HB 2.8%), and MT (CS 3.2%, HB 3.5%). Greater improvement of KES was observed in the CS group (P = 0.003). Maximum walking speed (CS 4.7%, HB 1.8%; P = 0.001) and timed up-and-go (CS -4.7%, HB -0.2%; P < 0.001) significantly improved in the CS group only.

CONCLUSIONS

The intervention was effective in preventing sarcopenia and/or frailty. Most physical functions and MT improved after both interventions. The HB intervention is cost-effective and may help prevent sarcopenia and/or frailty in the large older population.

Relationship Between Physical Fitness at the End of Preseason and the Inseason Game Performance in Japanese Female Professional Baseball Players

Watanabe, Y, Yamada, Y, Yoshida, T, Matsui, T, Seo, K, Azuma, Y, Hiramoto, M, Miura, Y, Fukushima, H, Shimazu, A, Eto, T, Saotome, H, Kida, N, and Morihara, T. Relationship between physical fitness at the end of preseason and the inseason game performance in Japanese female professional baseball players. J Strength Cond Res 33(6): 1580-1588, 2019-This study examined anthropometric and fitness profiles of Japanese female professional baseball players and investigated the relationship between players' physical fitness and inseason game performance. Fifty-seven players who were registered in the Japan Women's Baseball League (JWBL) participated. Height, body mass, grip strength, back strength, knee extension and flexion strength, hamstring extensibility, vertical jump height, and horizontal jump distance were measured at preseason (February and March) in 2013. Game performance during the 2013 season (March-November) was obtained from official JWBL statistics. Vertical jump height showed significant positive correlations with individual performance records (e.g., total bases [r = 0.551], slugging percentage [r = 0.459], and stolen bases [r = 0.442]). Similar relationships were observed between horizontal jump distance and performance statistics in most cases. By contrast, grip, back, and lower-limb strength, as well as hamstring extensibility were not significantly correlated with game performance. Stepwise regression analysis selected vertical jump height as an independent variable, significantly correlating with several game performance measures (e.g., total bases: adjusted R = 0.257). Also, vertical jump height and body mass index were identified as independent variables significantly associated with stolen bases (adjusted R = 0.251). Maximal jump performance, rather than simple isometric muscle strength or flexibility, is a good performance test that can be used at the end of preseason to predict inseason batting and stolen base performance. Our findings demonstrate the importance of constructing preseason training programs to enhance lower-limb muscular power that is linked to successful inseason performance in female baseball players.

Bioimpedance analysis and physical functioning as mortality indicators among older sarcopenic people

OBJECTIVES

To assess the prognostic significance of various characteristics and measurements of sarcopenia and physical functioning on all-cause mortality among home-dwelling older people with or at-risk of sarcopenia.

DESIGN

Cross-sectional and longitudinal analyses.

SETTING

Porvoo sarcopenia trial in open care.

PARTICIPANTS

Community-dwelling people aged 75 and older (N = 428, of which 182 were re-examined at one year) with four years of follow-up.

MEASUREMENTS

Body mass index (BMI), physical functioning (physical component of the RAND-36) and physical performance tests (Short Physical Performance Battery (SPPB)), hand grip strength, walking speed, Charlson Comorbity Index, bioimpedance-based surrogates for muscle mass: Single Frequency Skeletal Muscle Index (SF-SMI), and Calf Intracellular Resistance Skeletal Muscle Index (CRi-SMI). Date of death was retrieved from central registers. Survival analyses were performed using Life-Table analyses and Cox models.

RESULTS

Most test variables (except BMI) were associated with four-year mortality in a dose-dependent fashion. After controlling for age, gender and co-morbidity, physical performance and functioning (both SPPB and RAND-36), muscle strength (hand grip strength) and CRi-SMI appeared to be independent mortality risk indicators (p < 0.001) whereas SF-SMI was not. When CRi-SMI values were grouped by gender-specific cut-off points, the probability of surviving for four years decreased by 66% among the older people with low CRi-SMI (HR = 0.34, 95%CI 0.15-0.78, p = 0.011). When low CRi-SMI was further controlled for SPPB, the prognostic significance remained significant (HR = 0.55, 95%CI 0.33-0.92, p = 0.021). After controlling for age, gender, comorbidity, and CRi-SMI, the physical component of the RAND-36 (p = 0.007), SPPB (p < 0,001) and hand grip strength (p = 0.009) remained significant mortality predictors. Twelve-month changes were similarly associated with all-cause mortality during the follow-up period.

CONCLUSION

CRi-SMI, muscle strength, physical performance and physical functioning are each strong independent predictors of all-cause mortality among home-dwelling older people. Compared to these indicators, BMI seemed to be clearly inferior. Of two bioimpedance-based muscle indices, CRi SMI was better predictor of mortality than SF-SMI. In this regard, muscle mass, muscle strength and physical performance are all suitable targets for the prevention of sarcopenia-related over-mortality.

Sarcopenia Indicators as Predictors of Functional Decline and Need for Care among Older People

OBJECTIVES

Sarcopenia is associated with poor health outcomes. We examined the relative roles of muscle mass, strength, physical performance and obesity as health predictors among older sarcopenic people.

DESIGN AND PARTICIPANTS

This prospective study examined community-dwelling people aged 75+ (N=262).

SETTING

Porvoo Sarcopenia and Nutrition Trial.

MEASUREMENTS

We collected demographic data and medical history by postal questionnaire including RAND-36 at baseline and at four years and measured BMI, Short Physical Performace Battery (SPPB), hand-grip strength, cognition and two surrogate measures of muscle mass; the Single Frequency Skeletal Muscle Index (SF-SMI) and the Calf Intracellular Resistance Skeletal Muscle Index (CRi-SMI).

RESULTS

Adjusted for age and gender, independent outdoors mobility was predicted positively by baseline physical functioning scores in RAND-36 (p<0.001), the SPPB (p<0.001), the two-minute step test (p<0.001), and grip strength (p=0.023), as well as CRi-SMI (p<0.001). However, the prediction was negative in BMI (p<0.001) and the Charlson co-morbidity Index (p= 0.004). Similar associations were found when the physical component RAND-36 was used as an outcome measure. The use of home care was predicted by high co-morbidity (p=0.057) and low scores in RAND-36 (p<0.001), SPPB (p<0.001) and the two-minute step test (p<0.001), and low CRi-SMI (p<0.001). CRi-SF was a more consistent predictor than SF-SMI, which was partly masked by BMI. Controlled for age, gender and comorbidity, a 10% difference in CRi-SMI was associated with a 4% higher probability (p=0.019) of independently living at home, whereas the respective figures for SF-SMI and BMI were -18% (p=0.098) and -14% (p=0.088).

CONCLUSIONS

In contrast to SF-SMI, high CRi-SMI appeared to indicate good prognosis and less need of care, independently of BMI.

Could bioelectric impedance spectroscopy (BIS) measured appendicular intracellular water serve as a lean mass measurement in sarcopenia definitions? A pilot study

DXA lean mass measurement for sarcopenia diagnosis is not always possible. Bioelectric impedance spectroscopy (BIS), a portable technology, is a potential alternative to DXA-measured lean mass. This pilot study explores the possibility and proposes an arbitrarily chosen potential cut-point for appendicular intracellular water corrected by height (aICW/ht²).

INTRODUCTION

Sarcopenia definitions often include DXA lean mass measurement. However, DXA is not always available. We explored the potential of a less-expensive mobile method, bioelectric impedance spectroscopy (BIS), to assess lean mass for sarcopenia determination. We hypothesized that BIS-measured appendicular intracellular water (aICW/ht²) would correlate with DXA-measured appendicular lean mass (ALM)/ht² and with functional parameters. If so, establishing an aICW/ht² cut-point in sarcopenia definitions may be feasible.

METHODS

Sixty-one community-dwelling women, mean age 79.9, had BIS and DXA lean mass, grip strength, gait speed, and jumping mechanography assessments. BIS aICW was calculated using limb length and intracellular water resistance. aICW/ht² was compared to DXA-measured ALM/ht² by linear regression. The European Working Group ALM/ht² and an exploratory aICW/ht² cut-point were utilized.

RESULTS

In this cohort, ALM/ht² and aICW/ht² were moderately correlated, R² = 0.55, p < 0.0001. Lean mass was low in 7 and normal in 44 by BIS and DXA. Those with low aICW/ht² had lower grip strength (p = 0.04) and jump power (p = 0.0002) than those with normal aICW/ht² and ALM/ht². Subjects with low ALM/ht² had lower jump power (p = 0.0006) but were not different in gait speed or grip strength.

CONCLUSIONS

BIS aICW is correlated with DXA-measured ALM directly, and when height adjusted. An aICW/ht² cut-point of 6.5 L/m² identified 70% of women with low ALM/ht². Women with low lean mass by DXA and BIS had poorer function measured by jump power. These pilot data support further evaluation of BIS measurement inclusion into sarcopenia definitions.

Dilution of oral D3 -Creatine to measure creatine pool size and estimate skeletal muscle mass: development of a correction algorithm

BACKGROUND

Muscle mass can be measured directly in vivo by isotope dilution, using Creatine-(methyl-d3 ) monohydrate (D3 -Cr) by mouth followed by measurement of the steady-state enrichment of D3 -creatinine (D3 -Crn) in urine. Isotope dilution methods require knowledge of the amount of tracer delivered to the pool of interest. In a subset of human subjects, a small amount of orally administered D3 -Cr 'spills' into urine after absorption and prior to transport into skeletal muscle cells. The objectives were to develop a method to correct for spillage to compare the estimate of muscle mass by D3 -Cr dilution to other assessments of fat-free mass.

METHODS

Subjects (19 males, 23-81 years old; 20 females, 20-77 years old) ingested a single dose of 60 mg D3 -Cr and urine was collected prior to and daily for 4 days following the dose. Fasting morning urine samples was assessed for D3 -Cr, total Cr, D3 -Crn, and total Crn concentrations, as well as isotopic enrichments of D3 -Crn, by LC/MS. The 24-h urine collections over 3 days after the dose of D3 -Cr were also performed to determine D3 -Cr spillage. Total body water, fat mass, and fat-free mass were assessed by bioelectrical impedance spectroscopy (BIS).

RESULTS

Spillage of D3 -Cr in the urine was greater in women than men. D3 -Crn enrichment and the ratio of Cr/Crn were used in an algorithm to calculate Cr pool size and muscle mass. Specifically, an algorithm was developed for the estimation of spillage based on the relationship between the fasting Cr/Crn ratio and the cumulative proportion of the D3 -Cr dose excreted over 3 days based on 24-h urine collections. Muscle mass corrected using the algorithm based on fasting urine levels correlated (r = 0.9967, P < 0.0001) with that corrected by measuring D3 -Cr dose excreted. Muscle mass measured by D3 -Crn enrichment also correlated (r = 0.8579, P < 0.0001, algorithm corrected) with that measured by 24-h Crn excretion. Muscle mass measured by D3 -Cr dilution method correlated with intracellular water by BIS, whether using spillage corrected by the algorithm (r = 0.9041, P < 0.0001) or measured by 3 day D3 -Cr losses (r = 0.91, P < 0.0001) and similarly correlated with fat-free mass by BIA (r = 0.8857 and 0.8929, P < 0.0001, respectively).

CONCLUSIONS

The D3 -Cr dilution method is further validated here as a non-invasive, easy-to-use test for measuring muscle mass. The technical issue of D3 -Cr spillage can be corrected for with a simple algorithm based on fasting spot urine samples. Muscle mass by Cr dilution potentially has broad applications in clinical and research settings.

Comprehensive geriatric intervention program with and without weekly class-style exercise: research protocol of a cluster randomized controlled trial in Kyoto-Kameoka Study

Objective

The number of long-term care (LTC) users and the associated expenditures in Japan are increasing dramatically. The national government recommends LTC prevention through activation of communities. However, there is no clear evidence of the effect of population-based comprehensive geriatric intervention program (CGIP) for restraints of LTC users and the associated expenditures in the future. The aims of the current paper are to describe the study protocol and progress of a cluster randomized controlled trial (RCT) with a CGIP in Kameoka City.

Methods

The cluster RCT involved random allocation of regions as intervention (n=4,859) and nonintervention (n=7,195). Participants were elderly persons aged ≥65 years without LTC certification who had responded to a mailing survey. The residents living in intervention regions were invited to a physical check-up, and 1,463 people participated (30.3%). These individuals were invited to the CGIP, and 526 accepted. The CGIP comprised instructions on: 1) low-load resistance training using bodyweight, ankle weights, and elastic bands; 2) increasing daily physical activity; 3) oral motor exercise and care; and 4) a well-balanced diet based on a program from Ministry of Health, Labour and Welfare. We allocated the intervention regions randomly into home-based self-care program alone (HB group, 5 regions, n=275) and home-based program+weekly class-style session (CS group, 5 regions, n=251). We evaluated the effects of the CGIP at 12 weeks and at 12 or 15 months on physical function, and are conducting follow-up data collection for an indefinite period regarding LTC certification, medical costs, and mortality.

Results and discussion

The study was launched with good response rates in each phase. Participants of both groups significantly increased their step counts by ~1,000 per day from the baseline during the CGIP. This RCT will provide valuable information and evidence about effectiveness of a community-based CGIP.

Light rhythmic exercise with dietary milk fat globule membrane improves physical fitness in an elderly Japanese population: a double-blind randomized placebo-controlled trial

This study aimed to investigate the efficacy of home-based, light gymnastic exercise plus dietary milk fat globule membrane (MFGM) intake on physical fitness of an elderly Japanese sample in a pilot, double-blind, randomized, placebo-controlled trial. Seventy-one subjects (male, n = 13; female, n = 58) were randomly assigned into two groups: placebo (n = 35 [male, n = 6; female, n = 29]) and MFGM group (n = 36 [male, n = 7; female, n = 29]). The intervention was eight weeks. Subjects ingested either MFGM (1 g/day) or placebo tablets daily and engaged in an exercise program daily. Physical function tests were performed at baseline and after four and eight weeks. Foot tapping and open–close stepping scores significantly increased from baseline to eight weeks in the MFGM group. Study results suggest daily MFGM ingestion might further enhance the effects of light-intensity exercise in healthy elderly people.

Relationship of aging, skeletal muscle mass, and tooth loss with masseter muscle thickness

Background

Previous studies have reported a relationship between masseter muscle thickness and tooth loss or limb muscle thickness. However, it is not yet known whether masseter muscle thickness is related to appendicular skeletal muscle mass, and grip strength. The purpose of this study was to determine which of the two variables—tooth loss or appendicular skeletal muscle mass index—is more strongly related to masseter muscle thickness, and to identify a suitable indicator of decreasing masseter muscle thickness in healthy elderly individuals.

Methods

Grip strength, walking speed, body weight, skeletal muscle mass index, tooth loss, and masseter muscle thickness at rest and during contraction were determined in 97 community-dwelling elderly individuals aged ≥65 years (men: 44, women: 53). Masseter muscle thickness was chosen as the dependent variable, while age, skeletal muscle mass index, body weight, grip strength, and tooth loss were chosen as the independent variables. Multiple regression analysis was conducted using the stepwise regression method.

Results

In men, grip strength was the only independent predictor of masseter muscle thickness at rest. Tooth loss and grip strength were independent predictor of masseter muscle thickness during contraction. In women, tooth loss was the independent predictor of masseter muscle thickness both at rest and during contraction, while grip strength and body weight were the independent predictor of masseter muscle thickness at rest only.

Conclusions

We confirmed that in healthy elderly individuals, tooth loss has a stronger relationship with masseter muscle thickness than aging and skeletal muscle mass index do. Masseter muscle thickness in both elderly men and women is also associated with grip strength, suggesting that grip strength can be used as an indicator of masseter muscle thickness in this population.

Comparison of muscle/lean mass measurement methods: correlation with functional and biochemical testing

DXA-measured lean mass is often used to assess muscle mass but has limitations. Thus, we compared DXA lean mass with two novel methods-bioelectric impedance spectroscopy and creatine (methyl-d3) dilution. The examined methodologies did not measure lean mass similarly and the correlation with muscle biomarkers/function varied.

INTRODUCTION

Muscle function tests predict adverse health outcomes better than lean mass measurement. This may reflect limitations of current mass measurement methods. Newer approaches, e.g., bioelectric impedance spectroscopy (BIS) and creatine (methyl-d3) dilution (D3-C), may more accurately assess muscle mass. We hypothesized that BIS and D3-C measured muscle mass would better correlate with function and bone/muscle biomarkers than DXA measured lean mass.

METHODS

Evaluations of muscle/lean mass, function, and serum biomarkers were obtained in older community-dwelling adults. Mass was assessed by DXA, BIS, and orally administered D3-C. Grip strength, timed up and go, and jump power were examined. Potential muscle/bone serum biomarkers were measured. Mass measurements were compared with functional and serum data using regression analyses; differences between techniques were determined by paired t tests.

RESULTS

Mean (SD) age of the 112 (89F/23M) participants was 80.6 (6.0) years. The lean/muscle mass assessments were correlated (.57-.88) but differed (p < 0.0001) from one another with DXA total body less head being highest at 37.8 (7.3) kg, D3-C muscle mass at 21.1 (4.6) kg, and BIS total body intracellular water at 17.4 (3.5) kg. All mass assessment methods correlated with grip strength and jump power (R = 0.35-0.63, p < 0.0002), but not with gait speed or repeat chair rise. Lean mass measures were unrelated to the serum biomarkers measured.

CONCLUSIONS

These three methodologies do not similarly measure muscle/lean mass and should not be viewed as being equivalent. Functional tests assessing maximal muscle strength/power (grip strength and jump power) correlated with all mass measures whereas gait speed was not. None of the selected serum measures correlated with mass. Efforts to optimize muscle mass assessment and identify their relationships with health outcomes are needed.

Muscle glycogen depletion does not alter segmental extracellular and intracellular water distribution measured using bioimpedance spectroscopy

Although each gram of glycogen is well known to bind 2.7-4.0 g of water, no studies have been conducted on the effect of muscle glycogen depletion on body water distribution. We investigated changes in extracellular and intracellular water (ECW and ICW) distribution in each body segment in muscle glycogen-depletion and glycogen-recovery condition using segmental bioimpedance spectroscopy technique (BIS). Twelve male subjects consumed 7.0 g/kg body mass of indigestible (glycogen-depleted group) or digestible (glycogen-recovered group) carbohydrate for 24 h after a glycogen-depletion cycling exercise. Muscle glycogen content using ¹³C-magnetic resonance spectroscopy, blood hydration status, body composition, and ECW and ICW content of the arm, trunk, and leg using BIS were measured. Muscle glycogen content at the thigh muscles decreased immediately after exercise (glycogen-depleted group, 71.6 ± 12.1 to 25.5 ± 10.1 mmol/kg wet wt; glycogen-recovered group, 76.2 ± 16.4 to 28.1 ± 16.8 mmol/kg wet wt) and recovered in the glycogen-recovered group (72.7 ± 21.2 mmol/kg wet wt) but not in the glycogen-depleted group (33.2 ± 12.6 mmol/kg wet wt) 24 h postexercise. Fat-free mass decreased in the glycogen-depleted group ( P < 0.05) but not in the glycogen-recovered group 24 h postexercise. However, no changes were observed in ECW and ICW content at the leg in both groups. Our results suggested that glycogen depletion per se does not alter body water distribution as estimated via BIS. This information is valuable in assessing body composition using BIS in athletes who show variable glycogen status during training and recovery. NEW & NOTEWORTHY Segmental bioimpedance spectroscopy analysis reveals the effect of muscle glycogen depletion on body segmental water distribution in controlled conditions. Despite the significant difference in the muscle glycogen levels at the leg, no difference was observed in body resistance and the corresponding water content of the extracellular and intracellular compartments.

Glucose-independent segmental phase angles from multi-frequency bioimpedance analysis to discriminate diabetes mellitus

We investigated segmental phase angles (PAs) in the four limbs using a multi-frequency bioimpedance analysis (MF-BIA) technique for noninvasively diagnosing diabetes mellitus. We conducted a meal tolerance test (MTT) for 45 diabetic and 45 control subjects stratified by age, sex and body mass index (BMI). HbA1c and the waist-to-hip-circumference ratio (WHR) were measured before meal intake, and we measured the glucose levels and MF-BIA PAs 5 times for 2 hours after meal intake. We employed a t-test to examine the statistical significance and the area under the curve (AUC) of the receiver operating characteristics (ROC) to test the classification accuracy using segmental PAs at 5, 50, and 250 kHz. Segmental PAs were independent of the HbA1c or glucose levels, or their changes caused by the MTT. However, the segmental PAs were good indicators for noninvasively screening diabetes In particular, leg PAs in females and arm PAs in males showed best classification accuracy (AUC = 0.827 for males, AUC = 0.845 for females). Lastly, we introduced the PA at maximum reactance (PAmax), which is independent of measurement frequencies and can be obtained from any MF-BIA device using a Cole-Cole model, thus showing potential as a useful biomarker for diabetes.

Muscle Mass, Quality, and Composition Changes During Atrophy and Sarcopenia

Skeletal muscle mass (SMM) and muscle strengh reach their peak in 20s to 40s of age in human life and then decrease with advancing age. The decrease rate of muscle strength or power was twice to four times as large as that of the SMM. Thus, the normalized muscle force (muscle strength divided by SMM) also decreases in aging. It depends on the number of factors in skeletal muscle tissues and neuromuscular system. In human study, SMM cannot be measured directly without dissection so that all of the methodologies are indirect methods to assess SMM, even computing tomography or magnetic resonance imaging. Dual-energy X-ray absorptiometry, ultrasonography, anthropometry, and bioelectrical impedance analysis (BIA) are used as secondary indirect methods to estimate SMM. Recent researches show muscle composition changes in aging, and in particular, the ratio of muscle cell mass (MCM) against SMM decrease and relative expansion of extracellular water (ECW) and extracellular space is observed with advancing age and/or decrease of physical function. The intracellular water (ICW) and ECW estimated by segmental bioelectrical impedance spectroscopy or multifrequency BIA are good biomarkers of the ratio of MCM against SMM in limbs. The BIS and other state-of-the-art technology for assessment of muscle mass, quality, and composition are useful to fully understand the muscle atrophy in a living organism.