Predicting appendicular lean and fat mass with bioelectrical impedance analysis in older adults with physical function decline - The PROVIDE study

Skeletal muscle estimation: A review of techniques and their applications

Quantifying skeletal muscle size is necessary to identify those at risk for conditions that increase frailty, morbidity, and mortality, as well as decrease quality of life. Although muscle strength, muscle quality, and physical performance have been suggested as important assessments in the screening, prevention, and management of sarcopenic and cachexic individuals, skeletal muscle size is still a critical objective marker. Several techniques exist for estimating skeletal muscle size; however, each technique presents with unique characteristics regarding simplicity/complexity, cost, radiation dose, accessibility, and portability that are important factors for assessors to consider before applying these modalities in practice. This narrative review presents a discussion centred on the theory and applications of current non-invasive techniques for estimating skeletal muscle size in diverse populations. Common instruments for skeletal muscle assessment include imaging techniques such as computed tomography, magnetic resonance imaging, peripheral quantitative computed tomography, dual-energy X-ray absorptiometry, and Brightness-mode ultrasound, and non-imaging techniques like bioelectrical impedance analysis and anthropometry. Skeletal muscle size can be acquired from these methods using whole-body and/or regional assessments, as well as prediction equations. Notable concerns when conducting assessments include the absence of standardised image acquisition/processing protocols and the variation in cut-off thresholds used to define low skeletal muscle size by clinicians and researchers, which could affect the accuracy and prevalence of diagnoses. Given the importance of evaluating skeletal muscle size, it is imperative practitioners are informed of each technique and their respective strengths and weaknesses.

High-standard predictive equations for estimating body composition using bioelectrical impedance analysis: a systematic review

The appropriate use of predictive equations in estimating body composition through bioelectrical impedance analysis (BIA) depends on the device used and the subject's age, geographical ancestry, healthy status, physical activity level and sex. However, the presence of many isolated predictive equations in the literature makes the correct choice challenging, since the user may not distinguish its appropriateness. Therefore, the present systematic review aimed to classify each predictive equation in accordance with the independent parameters used. Sixty-four studies published between 1988 and 2023 were identified through a systematic search of international electronic databases. We included studies providing predictive equations derived from criterion methods, such as multi-compartment models for fat, fat-free and lean soft mass, dilution techniques for total-body water and extracellular water, total-body potassium for body cell mass, and magnetic resonance imaging or computerized tomography for skeletal muscle mass. The studies were excluded if non-criterion methods were employed or if the developed predictive equations involved mixed populations without specific codes or variables in the regression model. A total of 106 predictive equations were retrieved; 86 predictive equations were based on foot-to-hand and 20 on segmental technology, with no equations used the hand-to-hand and leg-to-leg. Classifying the subject's characteristics, 19 were for underaged, 26 for adults, 19 for athletes, 26 for elderly and 16 for individuals with diseases, encompassing both sexes. Practitioners now have an updated list of predictive equations for assessing body composition using BIA. Researchers are encouraged to generate novel predictive equations for scenarios not covered by the current literature.Registration code in PROSPERO: CRD42023467894.

Blood Selenium Concentrations Are Inversely Associated with the Risk of Undernutrition in Older Adults

BACKGROUND

Selenium is an essential trace element with an antioxidant and anti-inflammatory capacity that has been associated in experimental studies with beneficial effects on appetite control, the regulation of the gut microbiota, and control of the anabolic-catabolic balance. The main aim of the present study was to evaluate the association between circulating selenium concentrations and the risk of developing undernutrition in older adults.

METHODS

This was a cohort study with 1398 well-nourished community-dwelling individuals aged ≥ 65 years residing in Spain in 2017, who were followed for a mean of 2.3 years. Whole blood selenium was measured at baseline using inductively coupled plasma-mass spectrometry. Undernutrition was assessed at baseline and at follow-up, and defined as having at least one of the three GLIM phenotypic criteria (involuntary weight loss, a low body mass index, and a reduced muscle mass) and at least one of the two etiologic criteria (reduced food consumption or nutrient assimilation and inflammation/disease burden).

RESULTS

During the follow-up, 142 participants (11%) developed moderate undernutrition and 113 (8.8%) severe undernutrition. The standardized relative risks of moderate and severe undernutrition at the 75th percentile of Se levels versus the 25th were 0.90 and 0.70, respectively. In dose-response analyses, the risk of severe undernutrition decreased linearly with increasing selenium concentrations. This association was independent of protein intake or diet quality and was stronger among participants with a diagnosis of a musculoskeletal disorder.

CONCLUSIONS

The results suggest that an adequate dietary selenium status is needed to prevent undernutrition in older adults. Also, this may open the door for clinical trials with selenium supplementation, at doses considered as safe, to prevent undernutrition.

Nutritional Risk and Sarcopenia Features in Patients with Crohn's Disease: Relation to Body Composition, Physical Performance, Nutritional Questionnaires and Biomarkers

Patients with Crohn's disease (CD) face malnutrition risk, which, combined with inflammation, can lead to sarcopenia, associated with a worse prognosis. The purpose of the present study was to assess malnutrition and sarcopenia in patients with CD. Fifty-three patients (26 women) participated (38.1 ± 10.9 years, 79% in remission). Body composition, physical performance, nutritional questionnaires, and biomarkers were performed. Malnutrition was screened with the Mini Nutritional Assessment (MNA) and the Malnutrition Inflammation Risk Tool (MIRT) and was assessed with the Global Leadership Initiative on Malnutrition (GLIM) tool using etiologic along with three different phenotypic criteria: low Body Mass Index (BMI), low Calf Circumference (CC), and low Fat-Free Mass Index (FFMI). To find cases and evaluate sarcopenia, the Sarcopenia Questionnaire (SARC-F) and European Working Group on Sarcopenia2 (EWGSOP2) criteria were used. Malnutrition rates were 11.3% (n = 6), 7.5% (n = 4), and 5.6% (n = 3) based on low FFMI, CC, and BMI, correspondingly. Four (7%) patients had low Hand-Grip Strength (HGS), n = 8 (14.8%) had low Appendicular Lean Mass (ALM), and n = 3 (5.6%) had low gait speed. No-one had sarcopenia. A high albumin and triceps skinfold pattern, identified by principal component analysis, was related to reduced C-Reactive Protein (CRP) levels (B = -0.180, SE = 0.085, p = 0.045). In conclusion, based on the studied anthropometric, nutritional, and functional variables, CD patients were not diagnosed with sarcopenia in the present study. Body composition patterns were related to the inflammatory burden, underlying the interplay of inflammation and malnutrition, even in remission states. Further studies on older populations and during disease exacerbation are necessary to explore the potential link between CD, inflammation, and sarcopenia.

Prevalence and determinants of sarcopenia in community-dwelling older adults in Ireland

BACKGROUND

Data on the prevalence of sarcopenia among older adults in Ireland are lacking.

AIMS

To assess the prevalence and determinants of sarcopenia among community-dwelling older adults in Ireland.

METHODS

This cross-sectional analysis involved n = 308 community-dwelling adults aged ≥ 65 y living in Ireland. Participants were recruited via recreational clubs and primary healthcare services. Sarcopenia was defined according to the 2019 European Working Group on Sarcopenia in Older People (EWGSOP2) criteria. Skeletal muscle mass was estimated using bioelectrical impedance analysis, strength was measured via handgrip dynamometry, and physical performance was assessed using the Short Physical Performance Battery. Detailed information was collected on demographics, health, and lifestyle. Dietary macronutrient intake was measured via a single 24 h recall. Binary logistic regression was used to examine potential demographic, health, lifestyle, and dietary determinants of sarcopenia (where both probable and confirmed sarcopenia were combined).

RESULTS

The prevalence of EWGSOP2-defined probable sarcopenia was 20.8% and confirmed sarcopenia was 8.1% (5.8% had severe sarcopenia). Polypharmacy (OR 2.60, 95% confidence interval [CI] 1.3, 5.23), height (OR 0.95, 95% CI 0.91, 0.98), and Instrumental Activities Of Daily Living (IADL) score (OR 0.71, 95% CI 0.59, 0.86) were independently associated with sarcopenia (probable and confirmed combined). There were no independent associations between energy-adjusted macronutrient intakes, as determined by 24 h recall, and sarcopenia.

CONCLUSION

Sarcopenia prevalence within this sample of community-dwelling older adults in Ireland is broadly similar to other European cohorts. Polypharmacy, lower height, and lower IADL score were independently associated with EWGSOP2-defined sarcopenia.

Development and validation of bioelectrical impedance prediction equations estimating regional lean soft tissue mass in middle-aged adults

BACKGROUND/OBJECTIVES

Bioelectrical impedance (BIA) whole-body and regional raw parameters have been used to develop prediction models to estimate whole-body lean soft tissue (LSTM), with less attention being given to the development of models for regional LSTM. Therefore, we aimed to develop and validate BIA-derived equations predicting regional LSTM against dual x-ray absorptiometry (DXA) in healthy adults.

SUBJECTS/METHODS

149 adults were included in this cross-sectional investigation. Whole-body and regional LSTM were assessed by DXA, and raw bioelectrical parameters of distinct body regions were measured using a 50 kHz phase sensitive BIA analyzer. BIA-derived equations were developed using a stepwise multiple linear regression approach in 2/3 of the sample and cross-validated in the remaining sample.

RESULTS

Slopes and intercepts of predicted LSTM and DXA measured LSTM did not differ from 1 and 0, respectively, for each region (p ≥ 0.05), with the exception for the trunk (p < 0.05). The BIA-derived equations exhibited a strong relationship (p < 0.001) between the predicted and measured LSTM for each of the following body regions: right and left arms (R = 0.94; R = 0.96), right and left legs (R = 0.88; R = 0.88), upper body (R = 0.96), lower body (R = 0.89), right and left sides of the body (R = 0.94; R = 0.94), and trunk (R = 0.90). Agreement analyses revealed no associations between the differences and the means of the predicted and DXA-derived LSTM.

CONCLUSION

The developed BIA-derived equations provide a valid estimate of regional LSTM in middle-aged healthy adults, representing a cost-effective and time-efficient alternative to DXA for the assessment and identification of LSTM imbalances in both clinical and sport-specific contexts.

Sarcopenia screening in elderly with Alzheimer’s disease: performances of the SARC-F-3 and MSRA-5 questionnaires

Background

The 3-item SARC-F (SARC-F-3) and the 5-item Mini Sarcopenia Risk Assessment (MSRA-5) questionnaires have been recently proposed to screen elderly people regarding the risk of sarcopenia. However, no studies have investigated their performances in Alzheimer’s disease (AD).

Methods

We conducted a single-center observational study, including 130 consecutive AD patients (mean age: 70.71 ± 8.50 y, 54.6% women) who attended a center for neurodegenerative diseases. Sarcopenia was diagnosed using the European Working Group on Sarcopenia in Older People of 2010 (EWGSOP1) and of 2018 (EWGSOP2) criteria. Sensitivity, specificity, positive and negative likelihood ratio, and the area under the receiver operating characteristic curve (AUC) were used to assess the diagnostic performance of SARC-F-3 and MSRA-5.

Results

SARC-F-3 showed a sensitivity of 9.7%, a specificity of 82.8% and an AUC of 0.41 using EWGSOP1, whereas the sensitivity was of 16.7%, specificity of 84.7% and AUC of 0.58 using EWGSOP2. The MSRA-5 displayed a sensitivity of 3.2%, a specificity of 89.9% and an AUC of 0.41 using EWGSOP1, whereas sensitivity was of 0%, specificity of 91.1% and the AUC of 0.55 using EWGSOP2 criteria. The questionnaires showed a moderate agreement (Cohen's k = 0.53).

Conclusions

In our sample of AD patients, a sizable number of sarcopenic individuals were misidentified by SARC-F-3 and MSRA-5, making those questionnaires unsuitable for sarcopenia screening. Considering that sarcopenia has a high prevalence in dementia and that its correct and timely identification is paramount for optimal management of patients, the development and validation of an ad-hoc sarcopenia screening tool for AD patients is highly desirable.

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.

Bio-Electrical Impedance Analysis: A Valid Assessment Tool for Diagnosis of Low Appendicular Lean Mass in Older Adults?

Background

The diagnosis of sarcopenia is essential for early treatment of sarcopenia in older adults, for which assessment of appendicular lean mass (ALM) is needed. Multi-frequency bio-electrical impedance analysis (MF-BIA) may be a valid assessment tool to assess ALM in older adults, but the evidences are limited. Therefore, we validated the BIA to diagnose low ALM in older adults.

Methods

ALM was assessed by a standing-posture 8 electrode MF-BIA (Tanita MC-780) in 202 community-dwelling older adults (age ≥ 55 years), and compared with dual-energy X-ray absorptiometry (DXA) (Hologic Inc., Marlborough, MA, United States; DXA). The validity for assessing the absolute values of ALM was evaluated by: (1) bias (mean difference), (2) percentage of accurate predictions (within 5% of DXA values), (3) the mean absolute error (MAE), and (4) limits of agreement (Bland–Altman analysis). The lowest quintile of ALM by DXA was used as proxy for low ALM (< 22.8 kg for men, < 16.1 kg for women). Sensitivity and specificity of diagnosing low ALM by BIA were assessed.

Results

The mean age of the subjects was 72.1 ± 6.4 years, with a BMI of 25.4 ± 3.6 kg/m², and 71% were women. BIA slightly underestimated ALM compared to DXA with a mean bias of −0.6 ± 1.2 kg. The percentage of accurate predictions was 54% with a MAE of 1.1 kg, and limits of agreement were −3.0 to + 1.8 kg. The sensitivity for ALM was 80%, indicating that 80% of subjects who were diagnosed as low ALM according to DXA were also diagnosed low ALM by BIA. The specificity was 90%, indicating that 90% of subjects who were diagnosed as normal ALM by DXA were also diagnosed as normal ALM by the BIA.

Conclusion

This comparison showed a poor validity of MF-BIA to assess the absolute values of ALM, but a reasonable sensitivity and specificity to recognize the community-dwelling older adults with the lowest muscle mass.

Two-megahertz impedance index prediction equation for appendicular lean mass in Korean older people

Background

Whole-body bioelectrical impedance analysis (BIA) has been accepted as an indirect method to estimate appendicular lean mass (ALM) comparable to dual-energy X-ray absorptiometry (DXA). However, single or limited frequencies currently used for these estimates may over or under-estimate ALM. Accordingly, there is a need to measure the impedance parameter with appendicular lean-specific across multiple frequencies to more accurately estimate ALM. We aimed to validate muscle-specific frequency BIA equation for ALM using multifrequency BIA (MF-BIA) with DXA as the reference.

Methods

195 community-dwelling Korean older people (94 men and 101 women) aged 70 ~ 92y participated in this study. ALM was measured by DXA and bioimpedance measures at frequencies of 5 kHz ~ 3 MHz were assessed for independent predictive variables. Regression analyses were used to find limb-specific frequencies of bioimpedance, to develop the ALM equations and to conduct the internal cross-validation. The six published equations and the final equation of MF-BIA were externally cross-validated.

Results

195 participants completed the measurements of MF-BIA and DXA. Using bivariate regression analysis, the 2 MHz impedance index explained R² = 91.5% of variability (P < 0.001) in ALM and predictive accuracy of standard error of estimate (SEE) was 1.0822 kg ALM (P < 0.001). Multiple stepwise regression analysis obtained in the development group had an adjusted R² of 9.28% (P < 0.001) and a SEE of 0.97 kg ALM. The cross-validation group had no significant difference between the measured ALM and the predicted ALM (17.8 ± 3.9 kg vs. 17.7 ± 3.8 kg, P = .486) with 93.1% of R² (P < 0.001) and 1.00 kg ALM of total error. The final regression equation was as follows: ALM = 0.247ZI_@2 MHz + 1.254SEX_M1F0 + 0.067Xc_@5 kHz + 1.739 with 93% of R² (P < 0.001), 0.97 kg ALM of SEE (Subjective Rating as “excellent” for men and “very good” for women). In the analysis of the diagnostic level for sarcopenia of the final regression, the overall agreement was 94.9% (k = 0.779, P < 0.001) with 71.4% of sensitivity, 98.8% of specificity, 91.3 of positive prediction value and 95.3% of negative prediction value.

Conclusion

The newly developed appendicular lean-specific high-frequency BIA prediction equation has a high predictive accuracy, sensitivity, specificity, and agreement for both individual and group measurements. Thus, the high-frequency BIA prediction equation is suitable not only for epidemiological studies, but also for the diagnosis of sarcopenia in clinical settings.

Using accelerometers in the assessment of sarcopenia in older adults attending a day hospital service in Ireland

Objectives:

The aim of this study was to describe the associations between sarcopenia and variables derived from wrist accelerometry in community-dwelling older adults attending a day hospital service in Ireland.

Methods:

An observational cross-sectional study was carried out using a consecutive series of older adults attending a day hospital service. Sarcopenia was diagnosed using the latest European Working Group of Sarcopenia in Older People guidelines. Accelerometers were worn by each participant for a 7-day period on their non-dominant wrist.

Results:

Thirty-eight out of forty-one participants (93%) met the accelerometer wear time criterion and were included in statistical analyses. Included participants had a mean age of 81.1 years (standard deviation 6.2). Both sarcopenia (Grip) and sarcopenia (Lower limb) were associated with increased time spent in low physical activity and reduced average of Kcals per hour. Only sarcopenia (Lower limb) was associated with increased time in sedentary behaviour as well as reduced number of steps taken in a week.

Conclusions:

Accelerometer data can be used in an older day hospital population to track physical activity levels and sedentary behaviours. The assessment tool used to assess muscle strength and the cut-off criteria for physical activity behaviour influences the association with sarcopenia.

Bioelectrical impedance analysis as an alternative to dual-energy x-ray absorptiometry in the assessment of fat mass and appendicular lean mass in patients with obesity

OBJECTIVE

Obesity is a challenge for bioelectrical impedance analysis (BIA) estimations of skeletal muscle and fat mass (FM), and none of the equations used for appendicular lean mass (ALM) have been developed for people with obesity. By using different equations and proposing a new equation, this study aimed to assess the estimation of FM and ALM using BIA compared with dual-energy x-ray absorptiometry (DXA) as a reference method in a cohort of people with severe obesity.

METHODS

This cross-sectional study compared a multifrequency BIA (TANITA MC-780A) versus DXA for body composition assessment in adult patients with severe obesity (body mass index [BMI] of >35 kg/m²). Comparisons between measured (DXA) and predicted (BIA) data for FM and ALM were performed using the original proprietary equations of the device and the equations proposed by Kyle, Sergi, and Yamada. Bland-Altman plots were drawn to evaluate the agreement between DXA and BIA, calculating bias and limits of agreement (LOA). Reliability was analyzed using intraclass correlation coefficient (ICC). Stepwise multiple regression analysis was used to derive a new equation to predict ALM in patients with obesity and was validated in a subsample of our cohort.

RESULTS

In this study, 115 patients (72.4% women) with severe obesity (mean BMI of 46.1 [5.2] kg/m²) were included (mean age 43.5 [8.6] y). FM_DXA was 61.4 (10.1) kg, FM_BIA was 57.9 (10.3) kg, and ICC was 0.925 (P < 0.001). Bias was -3.4 (4.4) kg (-5.2%), and LOA was -14.0, +7.3 kg. Using the proprietary equations, ALMDXA was 21.8 (4.7) kg and ALMBIA was 29.0 (6.8) kg with an ICC 0.868, bias +7.3 (4.0) kg (+34.1%) and LOA -0.5, +15.1. When applying other equations for ALM, the ICC for Sergi, et al. was 0.880, the ICC for Kyle, et al. was 0.891, and the best ICC estimation for Yamada, et al. was 0.914 (P < 0.001). Bias was +2.8 (2.8), +4.1 (2.9), and +2.7 (2.8) kg, respectively. The best-fitting regression equation to predict ALM_DXA in our population derived from a development cohort (n = 77) was: ALM = 13.861 + (0.259 x H2/Z) - (0.085 x age) - (3.983 x sex [0 = men; 1 = women]). When applied to our validation cohort (n = 38), the ICC was 0.864, and the bias was the lowest compared with the rest of the equations +0.3 (+0.5) kg (+2.7%) LOA -5.4, +6.0 kg.

CONCLUSION

BIA using multifrequency BIA in people with obesity is reliable enough for the estimation of FM, with good correlation and low bias to DXA. Regarding the estimation of ALM, BIA showed a good correlation with DXA, although it overestimated ALM, especially when proprietary equations were used. The use of equations developed using the same device improved the prediction, and our new equation showed a low bias for ALM.

Sarcopenia measured with paraspinous muscle using computed tomography for predicting prognosis in elderly pneumonia patients

Background:

In the elderly, diagnostic findings of pneumonia are often atypical. Computed tomography was recommended for the diagnosis of pneumonia in elderly patients. Recently, the usage of computed tomography as a screening tool for pneumonia in emergency departments has increased. Sarcopenia is defined as the loss of skeletal muscle mass and strength with aging. In this study, the association between sarcopenia and prognosis measured through computed tomography was evaluated compared to CURB-65.

Methods:

This study was conducted on patients diagnosed with pneumonia through computed tomography from 1 March 2018 to 31 March 2020. The paraspinous muscle size and attenuation were measured at a level located at the T12 pedicle level on axial computed tomography images. Paraspinous muscle size was presented as paraspinous muscle index. Differences in the prognostic performance among the paraspinous muscle size and attenuation, and CURB-65 were evaluated by the area under the receiver operating characteristic curve.

Results:

A total of 509 patients were included and 132 patients (25.9%) were admitted to the ICU, and 58 patients (11.4%) died in hospital. Paraspinous muscle index was the significant factor for predicting in-hospital mortality and ICU admission. The area under the receiver operating characteristic value of paraspinous muscle index for prediction of mortality was 0.738 and CURB-65 was 0.707. The area under the receiver operating characteristic of paraspinous muscle index and CURB-65 for predicting ICU admission were 0.766 and 0.704, respectively.

Conclusion:

As a method of measuring sarcopenia, paraspinous muscle index was superior to CURB-65 in elderly pneumonia patients. The use of computed tomography in predicting prognosis for elderly pneumonia patients will ease the economic burden.

Disease-Related Malnutrition and Sarcopenia Predict Worse Outcome in Medical Inpatients: A Cohort Study

(1) Background: Both sarcopenia and disease-related malnutrition (DRM) are unfortunately underdiagnosed and undertreated in our Western hospitals, which could lead to worse clinical outcomes. Our objectives included to determine the impact of low muscle mass (MM) and strength, and also DRM and sarcopenia, on clinical outcomes (length of stay, death, readmissions at three months, and quality of life). (2) Methodology: Prospective cohort study in medical inpatients. On admission, MM and hand grip strength (HGS) were assessed. The Global Leadership Initiative on Malnutrition (GLIM) criteria were used to diagnose DRM and EWGSOP2 for sarcopenia. Assessment was repeated after one week and at discharge. Quality of life (EuroQoL-5D), length of stay (LoS), readmissions and mortality are reported. (3) Results: Two hundred medical inpatients, median 76.0 years-old and 68% with high comorbidity. 27.5% met GLIM criteria and 33% sarcopenia on admission, increasing to 38.1% and 52.3% on discharge. Both DRM and sarcopenia were associated with worse QoL. 6.5% died and 32% readmission in 3 months. The odds ratio (OR) of mortality for DRM was 4.36 and for sarcopenia 8.16. Readmissions were significantly associated with sarcopenia (OR = 2.25) but not with DRM. A higher HGS, but not MM, was related to better QoL, less readmissions (OR = 0.947) and lower mortality (OR = 0.848) after adjusting for age, sex, and comorbidity. (4) Conclusions: In medical inpatients, mostly polymorbid, both DRM but specially sarcopenia are associated with poorer quality of life, more readmissions, and higher mortality. Low HGS proved to be a stronger predictor of worse outcomes than MM.

Predictive equation for assessing appendicular lean soft tissue mass using bioelectric impedance analysis in older adults: Effect of body fat distribution

BACKGROUND

Low muscle mass is associated with sarcopenia and increased mortality. Muscle mass, especially that of the limbs, is commonly estimated by dual-energy X-ray absorptiometry (DXA) or bioimpedance analysis (BIA). However, BIA-based predictive equations for estimating lean appendicular soft tissue mass (ALST) do not take into account body fat distribution, an important factor influencing DXA and BIA measurements.

OBJECTIVES

To develop and cross-validate a BIA-based equation for estimating ALST with DXA as criterion, and to compare our new formula to three previously published models.

METHODS

One-hundred eighty-four older adults (140 women and 44 men) (age 71.5 ± 7.3 years, body mass index 27.9 ± 5.3 kg/m²) were recruited. Participants were randomly split into validation (n = 118) and cross-validation groups (n = 66). Bioelectrical resistance was obtained with a phase-sensitive 50 kHz BIA device.

RESULTS

A BIA-based model was developed for appendicular lean soft tissue mass [ALST (kg) = 5.982 + (0.188 × S² / resistance) + (0.014 × waist circumference) + (0.046 × Wt) + (3.881 × sex) - (0.053 × age), where sex is 0 if female or 1 if male, Wt is weight (kg), and S is stature (cm) (R² = 0.86, SEE = 1.35 kg)]. Cross validation revealed r² of 0.91 and no mean bias. Two of three previously published models showed a trend to significantly overestimate ALST in our sample (p < 0.01).

CONCLUSIONS

The new equation can be considered valid, with no observed bias and trend, thus affording practical means to quantify ALST mass in older adults.

The effect of different measurement modalities in the association of lean mass with mortality: A systematic review and meta-analysis

OBJECTIVES

Lean mass is commonly measured by 3 modalities, dual energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and computerized tomography (CT). CT is considered the most accurate, while lean mass measured by DXA and BIA often consists of non-muscle compartment, and hence considered less accurate when compared with CT. It remains unclear if the association of lean mass with mortality would differ using different measurement modalities.

METHODS

A systematic review and meta-analysis of lean mass and mortality was conducted. The analysis was stratified by different measurement modalities and health conditions. Pooled hazard ratios were estimated using a random effects model.

RESULTS

This meta-analysis included 188 studies with 98 468 participants. Reduced lean mass measured by BIA, DXA, and CT, was associated with increased risk of mortality with a hazard ratio (HR) of 1.35 (95% CI, 1.21-1.49), 1.18 (95% CI, 1.06-1.30), and 1.44 (95% CI, 1.32-1.57), respectively. Similarly, low lean mass defined by BIA-, DXA-, and CT-measurement was associated with increased risk of mortality, with an HR of 1.81 (95% CI, 1.56-2.10), 1.44 (95% CI, 1.29-1.60), and 1.78 (95% CI, 1.64-1.93).

CONCLUSIONS

Reduced and low lean mass were robustly associated with increased mortality in studies using different measurement modalities.

Prevalence of sarcopenia and associated factors in older adults attending a day hospital service in Ireland

Aim

The aim of this study was to describe the prevalence and associated factors of sarcopenia in community-dwelling older adults attending a day hospital service in Ireland, using the latest European Working Group of Sarcopenia in Older People (EWGSOP) guidelines.

Findings

The prevalence of sarcopenia in older adults attending a day hospital service in Ireland was 27–37% and varied depending on the strength test used. Sarcopenia was associated with older age, female gender, reduced BMI, reduced calf circumference, frailty, malnutrition, and reduced gait speed, irrespective of how muscle strength was assessed.

Message

Further consideration on the assessment of sarcopenia needs to be considered, regarding the use of muscle strength assessment, whether to assess upper limb, lower limb, or both.

Purpose

Sarcopenia is a muscle disease that is linked to the effects of ageing, chronic diseases, physical inactivity, and poor nutrition. In Ireland, there is a lack of readily available information on sarcopenia in older adults. The aim of this study was to describe the prevalence and associated factors of sarcopenia in community-dwelling older adults attending a day hospital service in Ireland, using the European Working Group of Sarcopenia in Older People (EWGSOP) guidelines.

Methods

An observational cross-sectional study was conducted, where a consecutive series of older adults attending a day hospital service were invited to participate. The measure of primary interest was the diagnosis of sarcopenia using the EWGSOP 2019 guidelines. We also collected other Comprehensive Geriatric Assessment measures including cognition, nutrition, frailty and physical activity.

Results

A total of 134 participants took part in the study. The mean age was 81.7 (SD ± 7.1). Sixty-one percent (N = 82) were female. The prevalence of sarcopenia ranged from 27 to 37% depending on the assessment tool used to assess muscle strength. Sarcopenia was associated with older age, frailty, reduced nutritional state, poor physical performance and reduced anthropometric measures, irrespective of how muscle strength was measured. Independently associated factors differed depending on muscle strength test, except for older age.

Conclusion

The prevalence of sarcopenia in the day hospital ranged from 27 to 37%. The assessment tool used to assess muscle strength influenced both the prevalence and associated factors of sarcopenia, suggesting scope for further research.

Validity of Bioimpedance Equations to Evaluate Fat-Free Mass and Muscle Mass in Severely Malnourished Anorectic Patients

BACKGROUND

Bioelectrical impedance analysis (BIA) is a simple and rapid technique to measure body composition (BC). Validity of BIA in patients with low body mass index (BMI) remains controversial. We assessed the validity of several BIA equations to evaluate fat-free mass (FFM), fat mass (FM) and muscle mass in patients with anorexia nervosa (AN) by using dual X ray absorptiometry (DXA) as reference.

METHODS

Sixteen BIA equations developed for FFM and appendicular lean mass (ALM) were applied on electrical data measured by BIA in AN patients with BMI <16 kg/m². BIA and DXA were done the same day after overnight fasting. Results were compared with the Bland-Altman method, Pearson correlation and a Lin concordance test.

RESULTS

Data from 115 female AN patients (14.6 ± 1.2 kg/m^²; 32.3 ± 14.5 years) were included. FM and FFM assessed by DXA were, respectively, 4.2 ± 2.4 kg and 35.5 ± 3.8 kg. The best results were obtained with Sun's equation: respectively for FM and FFM, Bland Altman bias at 0.548 and 0.706 kg, Pearson correlation r at 0.86 and 0.86 and Lin concordance coefficient at 0.81 and 0.84. However, confidence intervals (CI) at 95% were high (-2.73-3.83 kg for FM; -4.55-3.13 kg for FFM). Other equations also showed high 95% CI. Accuracy was acceptable for Sun and Bedogni equations for FFM (approximately 66%) but very low for FM prediction considering all equations (<15%). Concerning ALM evaluated at 14.88 ± 2.04 kg by DXA, only Scafoglieri and Yoshida equations showed acceptable values: bias (-0.2 and 2.8%), Pearson r (0.89 and 0.86), Lin concordance coefficient (0.82 and 0.82) and accuracy (83.5 and 82.6%). Confidence intervals at 95% were high for both equations (-2.1-2.0 for Scafoglieri equation and -1.6-2.4 for Yoshida equation).

CONCLUSION

In AN patients with BMI < 16 kg/m², no BIA equation tested was adapted to evaluate BC at the individual level.

Prediction Equations of the Multifrequency Standing and Supine Bioimpedance for Appendicular Skeletal Muscle Mass in Korean Older People

Bioimpedance analysis (BIA) has been demanded for the assessment of appendicular skeletal muscle mass (ASM) in clinical and epidemiological settings. This study aimed to validate BIA equations for predicting ASM in the standing and supine positions; externally to cross-validate the new and published and built-in BIA equations for group and individual predictive accuracy; and to assess the overall agreement between the measured and predicted ASM index as sarcopenia diagnosis. In total, 199 healthy older adults completed the measurements of multifrequency BIA (InBody770 and InBodyS10) and dual-energy X-ray absorptiometry (DXA). Multiple regression analysis was used to validate the new multifrequency bioelectrical impedance analysis (MF-BIA) prediction equations. Each MF-BIA equation in the standing and supine position developed in the entire group included height²/resistance, sex, and reactance as predictors (R² = 92.7% and 92.8%, SEE = 1.02 kg and 1.01 kg ASM for the standing and supine MF-BIA). The new MF-BIA equations had a specificity positive predictive value and negative predictive value of 85% or more except for a sensitivity of about 60.0%. The new standing and supine MF-BIA prediction equation are useful for epidemiological and field settings as well as a clinical diagnosis of sarcopenia. Future research is needed to improve the sensitivity of diagnosis of sarcopenia using MF-BIA.

Associations Between Serum GDF15 Concentrations, Muscle Mass, and Strength Show Sex-Specific Differences in Older Hospital Patients

Aging is accompanied by a progressive decline of muscle mass and strength and also higher levels of circulating cytokines such as growth differentiation factor 15 (GDF15). Studies evaluating the association of GDF15 with muscle mass and strength are rare. In this analysis, we investigated GDF15 concentrations and their relationship with muscle mass and strength in older men compared with women. GDF15 serum concentrations were measured in 103 (60 years and older) hospital patients and an age-matched control group with an immunosorbent assay. Skeletal muscle mass was determined with the bioelectrical impedance analysis. Grip strength and knee extension strength were assessed and normalized for height. Associations between GDF15 concentrations and muscle mass and strength were evaluated with general linear models. Male patients showed higher levels of GDF15 compared with female patients (p = 0.021). Elevated GDF15 concentrations were associated with lower measures of muscle mass, exclusively in men, after adjustment for age and number of drugs per day. Our results indicate sex differences between associations of GDF15 with muscle mass and strength parameters in a cohort of older hospital patients.

Comparison of Three Nutritional Screening Tools with the New Glim Criteria for Malnutrition and Association with Sarcopenia in Hospitalized Older Patients

The integrated assessment of nutritional status and presence of sarcopenia would help improve clinical outcomes of in-hospital aged patients. We compared three common nutritional screening tools with the new Global Leadership Initiative on Malnutrition (GLIM) diagnostic criteria among hospitalized older patients. To this, 152 older patients were assessed consecutively at hospital admission by the Malnutrition Universal Screening Tool (MUST), the Subjective Global Assessment (SGA), and the Nutritional Risk Screening 2002 (NRS-2002). A 46% prevalence of malnutrition was reported according to GLIM. Sensitivity was 64%, 96% and 47%, and specificity was 82%, 15% and 76% with the MUST, SGA, and NRS-2002, respectively. The concordance with GLIM criteria was 89%, 53% and 62% for the MUST, SGA, and NRS-2002, respectively. All the screening tools had a moderate value to diagnose malnutrition. Moreover, patients at high nutritional risk by MUST were more likely to present with sarcopenia than those at low risk (OR 2.5, CI 1.3-3.6). To conclude, MUST is better than SGA and NRS-2002 at detecting malnutrition in hospitalized older patients diagnosed by the new GLIM criteria. Furthermore, hospitalized older patients at high risk of malnutrition according to MUST are at high risk of presenting with sarcopenia. Nutritional status should be determined by MUST in older patients at hospital admission, followed by both GLIM and the European Working Group on Sarcopenia in Older People (EWGSOP2) assessment.

Think Globally, Act Locally: The Importance of Population-Specific Bioelectrical Impedance Analysis Prediction Equations for Muscle Mass Assessment

BACKGROUND

Bioelectrical impedance analysis (BIA) is a convenient muscle assessment method, but its accuracy highly depends on population-specific aspects of the adopted equation. We aimed to develop appendicular lean mass (ALM) prediction models for older South Americans and to compare their performances to those of reference equations in the same sample.

METHODS

Cross-sectional evaluation of 192 community-dwelling Brazilian subjects ≥60 years old from the COMO VAI?

STUDY

Using measurements from single-frequency and multifrequency devices (BIASF and BIAMF, respectively), new ALM prediction equations were developed (reference method: dual-energy x-ray absorptiometry [DXA]). Validity was assessed by bootstrapping. Four previously established equations were also tested, and the performances were compared using Bland-Altman analysis.

RESULTS

Stepwise variable selection produced the following equations: ALM_SF-BIA = (2.08 × sex) + (0.04 × weight) + (0.24 × RI₅₀ ) + (0.07 × Xc₅₀ ) - 0.16; ALM_MF-BIA = (1.85 × sex) + (0.03 × weight) + (0.31 × RI₅₀ ) + (0.04 × Xc₅₀ ) + (0.01 × Z₅ ) - 8.16, where ALM is estimated in kg; female sex = 0 and male sex = 1; weight is measured in kg; RI₅₀ is the resistance index at 50 kHz measured in cm² /Ω); Xc₅₀ is the reactance at 50 kHz measured in Ω; and Z₅ is impedance at 5 kHz measured in Ω. The equations explained, respectively, 89% and 90% of the variability of ALM_DXA in our sample, and their estimates were not significantly different from DXA measurements. Bland-Altman analysis revealed accurate and unbiased performances for both models, with similar limits of agreement (BIA_SF : ±2.58 kg; BIA_MF : ±2.48 kg), and their validity was considered adequate by the bootstrap method. The reference equations, however, systematically overestimated ALM in our sample.

CONCLUSION

The proposed equations might represent practical options to estimate ALM in older noninstitutionalized South Americans. Further external validation, though, is required to verify the reproducibility of our findings.

Equation models developed with bioelectric impedance analysis tools to assess muscle mass: A systematic review

BACKGROUND & AIMS

This systematic review aims to systematically assess and summarize the equation models developed to estimate muscle mass with bioelectric impedance analysis (BIA) instruments against a reference instrument (DXA, MRI, CT-scan, Ultrasonography), in order to help researchers and clinicians choose the most adapted equation, depending on the device and the population in question.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement was followed. Medline (via Ovid) and Scopus were searched in January 2019 for observational (transversal, longitudinal, retrospective) studies developing an equation prediction model to validate BIA against another reference method for the assessment of muscle mass. Study selection and data extraction was performed independently by two researchers. Methodological quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool.

RESULTS

25 studies matched the inclusion criteria and were included in the present systematic review. Among them, 10 studies proposed an equation for subjects aged 65 years and older, 9 for adults, 4 for infants and 2 did not report the age of the population. A large heterogeneity was observed regarding the brand and type of BIA as well as the administration protocol (mode, frequency, number of electrodes, administration position and empty bladder/stomach or not). Most of the studies used DXA as the reference instrument, except 4 that used MRI. In each of the included papers authors provided, through simple or multiple regression, a predictive equation for muscle mass. BIA resistance index, sex, weight, age, BIA reactance and height were most frequently included as predictive variables. The majority of the equations developed explained more than 80% of the variance between both instruments. Out of the 25 equations available, only 9 were also validated in another population within the same paper.

CONCLUSION

This systematic review of the literature offers clinicians and researchers the opportunity to verify the existence of a prediction equation when using a BIA device for estimating muscle mass. This will help them to obtain a valid estimation of muscle mass in a specific population and with a specific instrument. If the equation exists and has been validated by a study free of high risk of bias, it's use is recommended because the development of a new equation in the same context seems redundant and undesirable. If a validation has not been carried out for a specific brand of BIA, reference method or population, we recommend the development and cross-validation of a new equation.

Milk and resistance exercise intervention to improve muscle function in community-dwelling older adults at risk of sarcopenia (MIlkMAN): protocol for a pilot study

INTRODUCTION

Sarcopenia is a progressive muscle disorder characterised by decline in skeletal muscle mass, strength and function leading to adverse health outcomes, including falls, frailty, poor quality of life and death. It occurs more commonly in older people and can be accelerated by poor diet and low physical activity. Intervention studies incorporating higher dietary protein intakes or protein supplementation combined with resistance exercise (RE) have been shown to limit muscle function decline. However, less is known about the role of whole foods in reducing the risk of sarcopenia. Milk is a source of high-quality nutrients, which may be beneficial for skeletal muscle. This pilot study examines the feasibility and acceptability of milk consumption with RE to improve muscle function in community-dwelling older adults at risk of sarcopenia.

METHODS AND ANALYSIS

30 older adults aged ≥65 years will be randomly allocated to three groups: 'whole milk+RE', 'skimmed milk+RE' or 'control drink+RE'. Assessments will take place in participants' homes, including screening (milk allergies, grip strength, walking speed), baseline and postintervention health and function. All participants will undertake a structured RE intervention twice a week for 6 weeks at a local gym, followed by the consumption of 500 mL of whole or skimmed milk (each ~20 g of protein) or an isocaloric control drink and another 500 mL at home. Participants' views about the study will be assessed using standardised open-ended questions. The primary outcomes include feasibility and acceptability of the intervention with recruitment, retention and intervention response rates. Analyses will include descriptive statistics, exploration of qualitative themes and intervention fidelity.

ETHICS AND DISSEMINATION

Outputs include pilot data to support funding applications; public involvement events; presentation at conferences and peer-reviewed publication.

TRIAL REGISTRATION NUMBER

ISRCTN13398279; Pre-results.

A Vitamin D, Calcium and Leucine-Enriched Whey Protein Nutritional Supplement Improves Measures of Bone Health in Sarcopenic Non-Malnourished Older Adults: The PROVIDE Study

Alterations in musculoskeletal health with advanced age contribute to sarcopenia and decline in bone mineral density (BMD) and bone strength. This decline may be modifiable via dietary supplementation. To test the hypothesis that a specific oral nutritional supplement can result in improvements in measures of bone health. Participants (n 380) were participants of the PROVIDE study, a 13-week, multicenter, randomized, controlled, double-blind, 2 parallel-group study among non-malnourished older participants (≥ 65 years) with sarcopenia [determined by Short Physical Performance Battery (SPPB; 0-12) scores between 4 and 9, and a low skeletal muscle mass index (SMI; skeletal muscle mass/BW × 100) ≤ 37% in men and ≤ 28% in women using bioelectric impedance analysis] Supplementation of a vitamin D, calcium and leucine-enriched whey protein drink that comprises a full range of micronutrients (active; 2/day) was compared with an iso-caloric control. Serum 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), biochemical markers of bone formation (osteocalcin; OC, procollagen type 1 amino-terminal propeptide; P1NP) and resorption (carboxy-terminal collagen crosslinks; CTX), insulin like growth factor 1 (IGF-1) and total-body BMD were analysed pre- and post-intervention. Serum 25(OH)D concentrations increased from 51.1 ± 22.9 nmol/L (mean ± SD) to 78.9 ± 21.1 nmol/L in the active group (p < 0.001 vs. control). Serum PTH showed a significant treatment difference (p < 0.001) with a decline in the active group, and increase in the control group. Serum IGF-1 increased in the active group (p < 0.001 vs. control). Serum CTX showed a greater decline in the active group (p = 0.001 vs. control). There were no significant differences in serum OC or P1NP between groups during the intervention. Total body BMD showed a small (0.02 g/cm²; ~ 2%) but significant increase in the active group after supplementation (p = 0.033 vs. control). Consuming a vitamin D, calcium and leucine-enriched whey protein supplement for 13 weeks improved 25(OH)D, suppressed PTH and had small but positive effects on BMD, indicative of improved bone health, in sarcopenic non-malnourished older adults.

Bioelectric Impedance Vector Analysis (BIVA) in Breast Cancer Patients: A Tool for Research and Clinical Practice

Background and objectives: Body composition assessment can provide information associated with breast cancer patients’ (BCP) prognosis, that can lead interventions to improve survival outcomes. The aim of this study was to evaluate the effect of an individualized nutrition intervention program on breast cancer patients using bioelectrical impedance vector analysis (BIVA). Materials and Methods: This is a pretest-posttest study in recently diagnosed nonmetastatic BCP undergoing antineoplastic treatment, free of co-morbidities and dietary supplementation. Body composition was assessed at baseline and 6 months after an individualized nutrition intervention program, by dual-energy X-ray absorptiometry and BIVA. According to BIVA, each participant was located in the bivariate tolerance ellipses for Mexican population (50%, 75%, and 95%). In clinical practice, the 50% and 75% ellipses are considered within normality ranges. Results: Nine nonmetastatic BCP completed the intervention and were included in the analysis. After the intervention, they decreased by 5.8 kg of body weight (IQR, 3–6; p < 0.05), 3.8 kg of fat mass (IQR, 0.1–4.2; p < 0.05), and 1.4 kg of fat-free mass (IQR, −0.1 to 4; p < 0.05) while appendicular skeletal muscle mass remained unchanged (−0.2 kg, IQR, −0.8 to 2.3; p = 0.4). Using BIVA at baseline, five participants were among the 50% and 75% ellipses, mainly located in the area corresponding to edema and low lean tissue, two in the cachexia quadrant and two in the athletic quadrant (≥95% ellipse). After 6 months of intervention, six out of nine participants were in the athletic quadrant and eight of nine BCP were above the 5° phase angle cut-off point. One patient initially presented cachexia (≥95% ellipse); at postintervention her vector changed to the 50% ellipse. Conclusions: An individualized nutrition intervention program designed for nonmetastatic BCP was effective to improve the nutritional status of BCP as assessed by BIVA, therefore BIVA can be a useful tool to monitor changes in nonmetastatic BCP body composition in research and clinical practice.

Prevalence of sarcopenia and 9-year mortality in nursing home residents

BACKGROUND

Sarcopenia is a progressive loss of muscle mass, strength, and function. It is linked to functional decline, and secondary to this, to nursing home admission.

AIMS

To look into the prevalence of sarcopenia in a nursing home population and to gain insight into the relation of sarcopenia with mortality in this cohort.

METHODS

A longitudinal cohort follow-up started in October 2007 in 52 nursing homes in Belgium. Following data were procured: anthropometrics (weight/length), body composition (muscle mass through bio-impedance absorptiometry, BIA), functional status (Katz), nutritional status (mini-nutritional assessment-short form, MNA), and a number of laboratory parameters.

RESULTS

In total, 745 residents were included. Mean age was 84.6 ± 7.2 years. Mean follow-up time was 1632 ± 1026 days. In total, 17% had severe sarcopenia, 45% had moderate sarcopenia, and 38% had no sarcopenia. Following items were significant (p < 0.05) on univariate analysis with mortality as outcome: sarcopenia, gender, BMI, skeletal muscle mass, age, MNA, and functional level. In multivariate analysis, only MNA, skeletal muscle mass, and age were still significant. Odds ratio for skeletal muscle mass was 1.171 for the highest percentile group, 2.277 for the middle percentile group, and 4.842 for the lowest percentile group.

DISCUSSION

The prevalence of sarcopenia was higher than in comparative literature, for which there are a few hypotheses. Cut-off values for sarcopenia using BIA for specific cohorts need to be re-evaluated.

CONCLUSIONS

It seems to remain useful to screen for muscle mass in institutionalized elderly, because there is a clear and significant correlation with long-term mortality.

Predictors of Discordance in the Assessment of Skeletal Muscle Mass between Computed Tomography and Bioimpedance Analysis

Computed tomography (CT) and bioimpedance analysis (BIA) can assess skeletal muscle mass (SMM). Our objective was to identify the predictors of discordance between CT and BIA in assessing SMM. Participants who received a comprehensive medical health check-up between 2010 and 2018 were recruited. The CT and BIA-based diagnostic criteria for low SMM are as follows: Defined CT cutoff values (lumbar skeletal muscle index (LSMI) <1 standard deviation (SD) and means of 46.12 cm²/m² for men and 34.18 cm²/m² for women) and defined BIA cutoff values (appendicular skeletal muscle/height² <7.0 kg/m² for men and <5.7 kg/m² for women). A total of 1163 subjects were selected. The crude and body mass index (BMI)-adjusted SMM assessed by CT were significantly associated with those assessed by BIA (correlation coefficient = 0.78 and 0.68, respectively; p < 0.001). The prevalence of low SMM was 15.1% by CT and 16.4% by BIA. Low SMM diagnosed by CT was significantly associated with advanced age, female gender, and lower serum albumin level, whereas low SMM diagnosed by BIA was significantly associated with advanced age, female gender, and lower BMI (all p < 0.05). Upon multivariate analysis, age >65 years, female and BMI <25 kg/m² had significantly higher risks of discordance than their counterparts (all p < 0.05). We found a significant association between SMM assessed by CT and BIA. SMM assessment using CT and BIA should be interpreted cautiously in older adults (>65 years of age), female and BMI <25 kg/m².

Bioelectrical impedance analysis in the assessment of sarcopenia

PURPOSE OF REVIEW

Bioelectrical impedance analysis (BIA) is an accepted technique to estimate low muscle mass for sarcopenia diagnosis. However, muscularity assessment from BIA relies on prediction equations, estimating different compartments according to the calibration method. Low muscle mass can be defined using different approaches.

RECENT FINDINGS

There is a lack of standardization on how low muscularity is defined in the context of sarcopenia. Recent studies have shown discrepant results for the estimation of low muscle mass when different prediction equations are used in the same BIA device. Different sarcopenia prevalence rates are observed if different definitions are used to identify low muscle mass. Most of the studies using BIA for diagnosing sarcopenia use the incorrect combination of specific population cut-off or a different device from the original equation.

SUMMARY

The lack of standardization of BIA use for assessing muscularity results in a wide range of sarcopenia prevalence rates among studies, even when conducted in the same population. As BIA equations and cut-off values are population and device-specific, results should be interpreted with caution when data from different devices are applied in equations or using cut-off values from a different population.

Prevalence of sarcopenia in systemic sclerosis: assessing body composition and functional disability in patients with systemic sclerosis

OBJECTIVE

We analyzed the prevalence of sarcopenia among systemic sclerosis (SSc) patients with respect to quality of life, disability, organ involvement, and muscle function.

METHODS

A total of 129 patients who met the ACR/EULAR 2013 classification criteria were included. Body composition was measured using bioelectric impedance analysis. Sarcopenia was defined according to the criteria of the European Working Group on Sarcopenia in Older People. Handgrip and knee extension strength and pulmonary peak flow were measured. Physical function was assessed with the Short Form-36 Health Survey and Scleroderma Health Assessment Questionnaire.

RESULTS

Sarcopenia was prevalent in 22.5% of patients. There were significant differences between patients with and without sarcopenia regarding handgrip strength (11.5 [2.0-30.0] versus 18.0 [1.0-41.0] kilogram force [kgf]; P <0.001) and knee extension strength (11.0 [3.5-32.5] versus 17.5 [3.5-88.0] kgf; P = 0.006), physical function (38.8 [9.9-85.0] versus 48.8 [0-88.0]; P = 0.032) and number of immunosuppressants (2 [0-4] versus 1 [0-5]; P = 0.009). There were no differences regarding age (57.0 [32.0-83.0] versus 60.5 [28.0-82.0] years; P = 0.350) and disease duration (8 [1-27] versus 7 [0-34] years; P = 0.350).

CONCLUSIONS

Sarcopenia is common in patients with SSc and is associated with physical impairment that affects everyday life and participation in work. Interestingly, although age is the main risk factor for sarcopenia in the general population, it did not differ between sarcopenic and non-sarcopenic SSc patients in our study. Instead, the number of immunosuppressive drugs was significantly higher among sarcopenic patients.

Sarcopenia in Parkinson Disease: Comparison of Different Criteria and Association With Disease Severity

OBJECTIVES

In Parkinson disease (PD), sarcopenia may represent the common downstream pathway that from motor and nonmotor symptoms leads to the progressive loss of resilience, frailty, and disability. Here we (1) assessed the prevalence of sarcopenia in older adults with PD using 3 different criteria, testing their agreement, and (2) evaluated the association between PD severity and sarcopenia.

DESIGN

Cross-sectional, observation study.

SETTING

Geriatric day hospital.

PARTICIPANTS

Older adults with idiopathic PD.

MEASUREMENTS

Body composition was evaluated through dual energy x-ray absorptiometry. Handgrip strength and walking speed were measured. Sarcopenia was operationalized according to the Foundation for the National Institutes of Health, the European Working Group on Sarcopenia in Older Persons, and the International Working Group. Cohen k statistics was used to test the agreement among criteria.

RESULTS

Among the 210 participants (mean age 73 years; 38% women), the prevalence of sarcopenia was 28.5%-40.7% in men and 17.5%-32.5% in women. The prevalence of severe sarcopenia was 16.8%-20.0% in men and 11.3%-18.8% in women. The agreement among criteria was poor. The highest agreement was obtained between the European Working Group on Sarcopenia in Older Persons (severe sarcopenia) and International Working Group criteria (k = 0.52 in men; k = 0.65 in women; P < .01 for both). Finally, severe sarcopenia was associated with PD severity (odds ratio 2.30; 95% confidence interval 1.15-4.58).

CONCLUSIONS

Sarcopenia is common in PD, with severe sarcopenia being diagnosed in 1 in every 5 patients with PD. We found a significant disagreement among the 3 criteria evaluated, in detecting sarcopenia more than in ruling it out. Finally, sarcopenia is associated with PD severity. Considering its massive prevalence, further studies should address the prognosis of sarcopenia in PD.

Validation of equations and proposed reference values to estimate fat mass in Chilean university students

OBJECTIVES

(i) To propose regression equations based on anthropometric measures to estimate fat mass (FM) using dual energy X-ray absorptiometry (DXA) as reference method, and (ii)to establish population reference standards for equation-derived FM.

MATERIAL AND METHODS

A cross-sectional study on 6,713 university students (3,354 males and 3,359 females) from Chile aged 17.0 to 27.0years. Anthropometric measures (weight, height, waist circumference) were taken in all participants. Whole body DXA was performed in 683 subjects. A total of 478 subjects were selected to develop regression equations, and 205 for their cross-validation. Data from 6,030 participants were used to develop reference standards for FM. Equations were generated using stepwise multiple regression analysis. Percentiles were developed using the LMS method.

RESULTS

Equations for men were: (i) FM=-35,997.486 +232.285 *Weight +432.216 *CC (R²=0.73, SEE=4.1); (ii)FM=-37,671.303 +309.539 *Weight +66,028.109 *ICE (R2=0.76, SEE=3.8), while equations for women were: (iii)FM=-13,216.917 +461,302 *Weight+91.898 *CC (R²=0.70, SEE=4.6), and (iv) FM=-14,144.220 +464.061 *Weight +16,189.297 *ICE (R²=0.70, SEE=4.6). Percentiles proposed included p10, p50, p85, and p95.

CONCLUSION

The developed equations provide valid and accurate estimation of FM in both sexes. The values obtained using the equations may be analyzed from percentiles that allow for categorizing body fat levels by age and sex.

Measurement of lean body mass using bioelectrical impedance analysis: a consideration of the pros and cons

The assessment of body composition has important applications in the evaluation of nutritional status and estimating potential health risks. Bioelectrical impedance analysis (BIA) is a valid method for the assessment of body composition. BIA is an alternative to more invasive and expensive methods like dual-energy X-ray absorptiometry, computerized tomography, and magnetic resonance imaging. Bioelectrical impedance analysis is an easy-to-use and low-cost method for the estimation of fat-free mass (FFM) in physiological and pathological conditions. The reliability of BIA measurements is influenced by various factors related to the instrument itself, including electrodes, operator, subject, and environment. BIA assumptions beyond its use for body composition are the human body is empirically composed of cylinders, FFM contains virtually all the water and conducting electrolytes in the body, and its hydration is constant. FFM can be predicted by BIA through equations developed using reference methods. Several BIA prediction equations exist for the estimation of FFM, skeletal muscle mass (SMM), or appendicular SMM. The BIA prediction models differ according to the characteristics of the sample in which they have been derived and validated in addition to the parameters included in the multiple regression analysis. In choosing BIA equations, it is important to consider the characteristics of the sample in which it has been developed and validated, since, for example, age- and ethnicity-related differences could sensitively affect BIA estimates.

Bioelectrical impedance analysis for diagnosing sarcopenia and cachexia: what are we really estimating?

As reference methods are not available for identifying low skeletal muscle mass in clinical practice, the European Group on Sarcopenia in Older People the Asian Working Group for Sarcopenia and the International Consensus for Cancer Cachexia guidelines accept bioelectrical impedance analysis (BIA) as an option for sarcopenia and cachexia assessment. Using different BIA equations, several components that represent 'muscularity' can be assessed. Total skeletal muscle mass or appendicular skeletal muscle mass normalized in relation to height (skeletal muscle mass index or appendicular skeletal muscle index, respectively) is the most common term used in the consensus. These terms are similar, but they should not be used as synonymous. Both terms can be used to define sarcopenia, but adequate equations and cut-off values should be used according to the studied population. However, there is a disagreement between the sarcopenia definition assessed by using BIA from the European Group on Sarcopenia in Older People and Cachexia Consensus, and this can lead to an overestimation of sarcopenia and, consequently, cachexia. An effort should be made to standardize the terminology employed by the Societies to define low muscularity and sarcopenia by using BIA. Future validation studies may show the need for specific cut-off values for each population using this method.

Effectiveness of a multicomponent exercise program in the attenuation of frailty in long-term nursing home residents: study protocol for a randomized clinical controlled trial

BACKGROUND

There is increasing evidence suggesting that cognition and physical frailty interact within a cycle of decline associated with aging which has been called cognitive frailty. Exercise programs have demonstrated to be an effective tool to prevent functional and cognitive decline during aging, but little is known about their potential to restore or maintain functionality in individuals that require long-term nursing care. Besides, WHO has recently highlighted the importance of introducing systematic musculoskeletal health programs for older people living in residential care, as they represent a particularly vulnerable group for the development of noncommunicable diseases.

METHODS

This is a multicentre randomized controlled trial. 114 participants will be randomly allocated to a usual care group or to an intervention group. Inclusion criteria are as follows: ≥ 70 years, ≥ 50 on the Barthel Index, ≥ 20 on MEC-35 who are capable to stand up and walk independently for 10 m. Subjects in the intervention group will add to the activities scheduled for the control group the participation in a 6 months long multicomponent exercise program designed to improve strength, balance and walking retraining. Study assessments will be conducted at baseline and at 3 and 6 months. The primary outcome is change in function assessed by Short Physical Performance Battery and secondary outcomes include other measurements to assess all together the condition of frailty, which includes functionality, sedentary behaviors, cognitive and emotional status and biological markers. The present study has been approved by the Committee on Ethics in Research of the University of the Basque Country (Humans Committee Code M10/2016/105; Biological Samples Committee Code M30/2016/106).

DISCUSSION

Results from this research will show if ageing related functional and cognitive deterioration can be effectively prevented by physical exercise in institutionalized elders. It is expected that the results of this research will guide clinical practice in nursing home settings, so that clinicians and policymakers can provide more evidence-based practice for the management of institutionalized elder people.

TRIAL REGISTRATION

The protocol has been registered under the Australian and New Zealand Clinical Trials Registry (ANZCTR) with the identifier: ACTRN12616001044415 .