Total-body skeletal muscle mass: development and cross-validation of anthropometric prediction models

Psychometric performance of the Romanian version of the SarQoL®, a health-related quality of life questionnaire for sarcopenia

Our study assessed the psychometric properties of the Romanian SarQoL^® questionnaire. Normal distribution and high internal consistency were found. Sarcopenic subjects reported a reduced global quality of life compared to non-sarcopenics. The Romanian version of the SarQoL^® questionnaire, conceptually and literally equivalent with the source instrument, is qualified in terms of psychometric properties.

PURPOSE/INTRODUCTION

We have recently provided a translated and culturally tailored version of the first quality of life (QoL) questionnaire specific for sarcopenia, the SarQoL^®, in Romanian language. The aim of this study was to assess the psychometric performances of the translated questionnaire.

METHODS

A total of 100 volunteers were enrolled in the study. Sarcopenia was diagnosed according to the algorithm proposed by the European Working Group on Sarcopenia in Older People (EWGSOP). To test the psychometric performance, discriminative power, internal consistency, floor and ceiling effects, and construct validity analyses were made. We assessed the correlation between SarQoL^® and similar/different domains of other two QoL questionnaires.

RESULTS

Sarcopenic subjects reported a reduced global QoL compared to non-sarcopenic individuals. Significantly (p = 0.018) higher total scores for non-sarcopenic subjects compared to those of sarcopenics indicate a good discriminative power of the Romanian questionnaire. Sarcopenic individuals had significantly lower scores in almost all domains. The Cronbach's alpha value of 0.946 indicates a high internal consistency. No floor or ceiling effects were found. A strong positive correlation was also found between similar domain scores from SF-36 and EQ-5D questionnaires with the Total SarQoL^® score. Moreover, lower scores of quality of life have been shown to be significantly associated with lower muscle strength, in univariate analyses, and lower gait speed, both in univariate and multivariate analyses.

CONCLUSIONS

Our results indicate that the Romanian version of the SarQoL^® questionnaire, qualified in terms of psychometric properties, could be a useful tool to assess the sarcopenia-related QoL among frail Romanian individuals.

Development and validation of anthropometric prediction equations for lean body mass, fat mass and percent fat in adults using the National Health and Nutrition Examination Survey (NHANES) 1999-2006

Quantification of lean body mass and fat mass can provide important insight into epidemiological research. However, there is no consensus on generalisable anthropometric prediction equations to validly estimate body composition. We aimed to develop and validate practical anthropometric prediction equations for lean body mass, fat mass and percent fat in adults (men, n 7531; women, n 6534) from the National Health and Nutrition Examination Survey 1999-2006. Using a prediction sample, we predicted each of dual-energy X-ray absorptiometry (DXA)-measured lean body mass, fat mass and percent fat based on different combinations of anthropometric measures. The proposed equations were validated using a validation sample and obesity-related biomarkers. The practical equation including age, race, height, weight and waist circumference had high predictive ability for lean body mass (men: R 2=0·91, standard error of estimate (SEE)=2·6 kg; women: R 2=0·85, SEE=2·4 kg) and fat mass (men: R 2=0·90, SEE=2·6 kg; women: R 2=0·93, SEE=2·4 kg). Waist circumference was a strong predictor in men only. Addition of other circumference and skinfold measures slightly improved the prediction model. For percent fat, R 2 were generally lower but the trend in variation explained was similar. Our validation tests showed robust and consistent results with no evidence of substantial bias. Additional validation using biomarkers demonstrated comparable abilities to predict obesity-related biomarkers between direct DXA measurements and predicted scores. Moreover, predicted fat mass and percent fat had significantly stronger associations with obesity-related biomarkers than BMI did. Our findings suggest the potential application of the proposed equations in various epidemiological settings.

Relation between functional mobility and dynapenia in institutionalized frail elderly

Objective

To investigate the relation between functional mobility and dynapenia in institutionalized frail elderly.

Methods

A descriptive, correlational study involving 26 institutionalized elderly men and women, mean age 82.3±6 years. The instruments employed were the Mini Mental State Examination, the Geriatric Depression Scale, the International Physical Activity Questionnaire, the Timed Up and Go test, a handgrip dynamometer and a portable dynamometer for large muscle groups (shoulder, elbow and hip flexors, knee extensors and ankle dorsiflexors).

Results

Significant negative correlation between functional mobility levels assessed by the Timed Up and Go test and dynapenia was observed in all muscle groups evaluated, particularly in knee extensors (r -0.65).

Conclusion

A significant negative correlation between muscle strength, particularly knee extensor strength, and functional mobility was found in institutionalized elderly. Data presented indicate that the higher the muscle strength, the shorter the execution time, and this could demonstrate better performance in this functional mobility test.

Reduction in skeletal muscle fibrosis of spontaneously hypertensive rats after laceration by microRNA targeting angiotensin II receptor

Regeneration of injured skeletal muscles is affected by fibrosis, which can be improved by the administration of angiotensin II (AngII) receptor (ATR) blockers in normotensive animals. However, the role of ATR in skeletal muscle fibrosis in hypertensive organisms has not been investigated yet. The tibialis anterior (TA) muscle of spontaneously hypertensive (SHR) and Wistar rats (WR) were lacerated and a lentivector encoding a microRNA targeting AngII receptor type 1 (At1) (Lv-mirAT1a) or control (Lv-mirCTL) was injected. The TA muscles were collected after 30 days to evaluate fibrosis by histology and gene expression by real-time quantitative PCR (RT-qPCR) and Western blot. SHR's myoblasts were analyzed by RT-qPCR, 48 h after transduction. In the SHR's TA, AT1 protein expression was 23.5-fold higher than in WR without injury, but no difference was observed in the angiotensin II receptor type 2 (AT2) protein expression. TA laceration followed by suture (LS) produced fibrosis in the SHR (23.3±8.5%) and WR (7.9±1.5%). Lv-mirAT1 treatment decreased At1 gene expression in 50% and reduced fibrosis to 7% 30 days after. RT-qPCR showed that reduction in At1 expression is due to downregulation of the At1a but not of the At1b. RT-qPCR of myoblasts from SHR transduced with Lv-mirAT1a showed downregulation of the Tgf-b1, Tgf-b2, Smad3, Col1a1, and Col3a1 genes by mirAT1a. In vivo and in vitro studies indicate that hypertension overproduces skeletal muscle fibrosis, and AngII-AT1a signaling is the main pathway of fibrosis in SHR. Moreover, muscle fibrosis can be treated specifically by in loco injection of Lv-mirAT1a without affecting other organs.

Timed Up and Go test as a sarcopenia screening tool in home-dwelling elderly persons

Abstract Objective: to evaluate the performance of the Timed Up and Go test (TUG) as a screening tool for sarcopenia in elderly persons living in a city in the south of Brazil. Method: A cross-sectional, home-based study was conducted with 322 elderly persons. The diagnosis of sarcopenia was based on the criteria proposed by the European Working Group on Sarcopenia in Older People (EGWSOP). A Receiver Operating Characteristic (ROC) curve was constructed to assess the discriminatory power of the TUG on sarcopenia screening. Results: With a cutoff point of 7.5 seconds, the test had an area under the curve (AUC) of 0.66 (CI 0.56-0.76; p=0.002) and adequate sensitivity and negative predictive values (88.9% and 93.2%, respectively). Conclusion: Due to its ease of use and rapid execution, in addition to its low cost, this test is useful for the screening of sarcopenia, especially among elderly persons with good physical and cognitive abilities. The early identification of individuals with probable sarcopenia may allow for preventive or directive interventions for the management of this geriatric syndrome.

Relationship between sarcopenia and physical activity in older people: a systematic review and meta-analysis

Physical activity (PA) has been identified as beneficial for many diseases and health disorders, including sarcopenia. The positive influence of PA interventions on sarcopenia has been described previously on many occasions. Current reviews on the topic include studies with varied PA interventions for sarcopenia; nevertheless, no systematic review exploring the effects of PA in general on sarcopenia has been published. The main aim of this study was to explore the relationship between PA and sarcopenia in older people on the basis of cross-sectional and cohort studies. We searched PubMed, Scopus, EBSCOhost, and ScienceDirect for articles addressing the relationship between PA and sarcopenia. Twenty-five articles were ultimately included in the qualitative and quantitative syntheses. A statistically significant association between PA and sarcopenia was documented in most of the studies, as well as the protective role of PA against sarcopenia development. Furthermore, the meta-analysis indicated that PA reduces the odds of acquiring sarcopenia in later life (odds ratio [OR] =0.45; 95% confidence interval [CI] 0.37–0.55). The results of this systematic review and meta-analysis confirm the beneficial influence of PA in general for the prevention of sarcopenia.

Development and Validation of a Skinfold Model for Estimation of Body Density for a Safe Weight Reduction in Young Iranian Wrestlers

Background:

Adverse effects of excessive body mass reduction among wrestlers dictate minimum weight determination through body composition. Although skinfold equations are essential to estimate body composition in the field setting, they are mostly derived from Western societies and may lack generalizability to other populations.

Purpose:

Previously published skinfold equations lacked external validity in predicting body density of Iranian wrestlers. We aimed to derive a new anthropometric model specific to young Iranian male wrestlers.

Study design:

Cross-sectional cohort study.

Level of evidence:

Level 3.

Methods:

One hundred twenty-six Iranian male wrestlers with at least 1 year of experience and a mean age of 19 ± 4.0 years underwent underwater weight analysis for body density estimation and anthropometric measurements. The previously published equations were validated, followed by new regression modeling, using multivariable fractional polynomials, with body density as the criterion predicted by common anthropometric variables. The final model was validated throughout the modeling procedure using 1000 bootstrap replications.

Results:

The mean body fat percentage (%BF) was 12.6% (95% CI, 11.9%-13.4%), lower than that of previous studies. Six previously published equations each had significant deviations from the line of identity (all P < 0.001). The new prediction equation combined subscapular, tricipital, and midaxillary skinfolds and body mass index cubed to predict body density.

Conclusion:

The development of ethnicity-specific equations, using statistically unbiased and comprehensive validation methods, is imperative for body composition estimation to determine the minimum weight for regulation of health in athletes.

Clinical Relevance:

Using equations without external validation can bias the prediction of minimum weight, leading to unsafe weight reduction by athletes. Compared with a previous study, much lower mean %BF was found using an ethnicity-specific equation (12.6% vs 15.9%). This difference observed in %BF prediction could affect safe fat reduction in athletes.

Body mass-to-waist ratio strongly correlates with skeletal muscle volume in children

Purpose

We hypothesized that body mass-to-waist ratio is strongly associated with the total-body skeletal muscle volume (SMV) in children. The purpose of the present study was to examine this hypothesis.

Methods

By using magnetic resonance imaging, total-body SMV (SMV_MRI) was determined in 70 boys and 53 girls aged 6 to 12 years. Waist was measured at each of the level of umbilicus (Wumb) and the minimum circumference (Wmin), and the ratio of body mass to each of the two measured values was calculated (BM/Wumb and BM/Wmin, respectively). A single regression analysis was used to examine the relationships between SMV_MRI and either BM/Wumb or BM/Wmin. On the basis of the obtained regression equations, SMV_MRI was estimated and referred to as SMV_BM/Wumb or SMV_BM/Wmin.

Results

In both boys and girls, SMV_MRI was highly correlated to BM/Wumb (r = 0.937 for boys and r = 0.939 for girls, P < 0.0001) and BM/Wmin (r = 0.915 and 0.942, P < 0.0001). R² and the standard error of estimate for SMV_BM/Wumb were 0.878 and 706.2 cm³, respectively, in boys and 0.882 and 825.3 cm³, respectively, in girls, and those for SMV_BM/Wmin were 0.837 and 814.0 cm³, respectively, in boys and 0.888 and 804.1 cm³, respectively, in girls. In both boys and girls, there were no significant differences between SMV_MRI and either SMV_BM/Wumb or SMV_BM/Wmin, without systematic errors in Band-Altman plots. There was no significant effect of model on the absolute values of the residuals in both boys and girls.

Conclusion

The current results indicate that body mass-to-waist ratio can be a convenient outcome measure for assessing the total-body skeletal muscle volume in children.

Sarcopenia and physical independence in older adults: the independent and synergic role of muscle mass and muscle function

BACKGROUND

The loss of skeletal muscle mass (MM) or muscle function (MF) alone increases the risk for losing physical independence in older adults. We aimed to examine the independent and synergic associations of low MM and low MF, both criteria of sarcopenia, with the risk for losing projected physical independence in later life (+90 years old).

METHODS

Cross-sectional analyses were conducted in 3493 non-institutionalized older adults (1166 males). Physical independence was assessed with a 12-item composite physical function scale. Logistic regression was used to estimate the odds-ratio (OR) for being at risk for losing physical independence.

RESULTS

Approximately 30% of the participants were at risk for losing physical independence at 90 years of age. Independent analysis demonstrated that participants with low MM had 1.65 (95%CI: 1.27-2.31) increased odds for being at risk for losing physical independence and participants with low MF had 6.19 (95%CI 5.08-7.53) increased odds for being at risk. Jointly, having a low MM and a low MF increased the risk for losing physical independence to 12.28 (95%CI 7.95 to 18.96).

CONCLUSIONS

Although low MM represents a risk factor for losing physical independence, low MF seems to play a more dominant role in this relationship, with the presence of both sarcopenia criteria representing a substantial risk for losing physical independence in later life.

Association of insufficient physical activity with sarcopenia and sarcopenic obesity in individuals aged 50 years or more

ABSTRACT Objective: To analyze the association of insufficient physical activity in different domains with sarcopenia or sarcopenic obesity in patients aged ³50 years. Methods: The sample consisted of 770 males and females. Sarcopenia was diagnosed when the individual had: (1) low muscle mass and muscle strength; or (2) low walking speed and low muscle mass; sarcopenic obesity was diagnosed when individuals were at risk of obesity and sarcopenia. Muscle mass was given by a predictive equation, and then the muscle mass index (in kg/m²) was given by muscle mass divided by height squared. Muscle strength, in kg, was given by measuring handgrip strength with a digital dynamometer. The 4m walk test evaluated walking sped. Low muscle mass, muscle strength, and walking speed were defined as the respective values below the 25th percentile, and risk of obesity was defined as body mass index ³25kg/m2. Results: Habitual physical activity was investigated by a questionnaire. Insufficient leisure-time physical activity was associated with sarcopenia (OR=2.55; 95%CI=1.10-5.88). In addition, insufficient leisure-time physical activity (OR=4.75; 95%CI=1.64-13.72), leisure-time and commuting physical activities (OR=2.49; 95%CI=1.02-6.11, and habitual physical activity (OR=3.55; 95%CI=1.0-11.79) were associated with sarcopenic obesity. Conclusion: Insufficient physical activity is associated with sarcopenia or sarcopenic obesity in the study individuals aged ³50years.

DNA catabolites in triathletes: effects of supplementation with an aronia-citrus juice (polyphenols-rich juice)

In this study we analyzed whether our aronia-citrus juice (ACJ, the composition is based on a mixture of 95% citrus juice with 5% of Aronia melanocarpa juice), rich in polyphenols, and physical exercise had an effect on seven catabolites of DNA identified in plasma and on a urine isoprostane (8-iso-PGF2α). Sixteen elite triathletes on a controlled diet for triathlon training (45 days) were used in this clinical trial. Our results show a decrease in the 8-hydroxy-2'-deoxyguanosine concentration due to chronic physical exercise. The ACJ intake and physical exercise maintained the guanosine-3',5'-cyclic monophosphate plasmatic concentrations and decreased the concentration of 8-hydroxyguanine as well as urinary values of 8-iso-PGF2α. Finally, we observed a significant increase in the 8-nitroguanosine levels in triathletes after ACJ intake, compared to the placebo stage. It is concluded that the combination of the intake of ACJ, rich in polyphenolic compounds, with adequate training was able to influence the plasmatic and urinary values of oxidative stress biomarkers. This suggests a positive effect on the oxidative damage and potential associations with DNA repair mechanisms.

Concurrent agreement between an anthropometric model to predict thigh volume and dual-energy X-Ray absorptiometry assessment in female volleyball players aged 14-18 years

Background

A variety of performance outputs are strongly determined by lower limbs volume and composition in children and adolescents. The current study aimed to examine the validity of thigh volume (TV) estimated by anthropometry in late adolescent female volleyball players. Dual-energy X-ray absorptiometry (DXA) measures were used as the reference method.

Methods

Total and regional body composition was assessed with a Lunar DPX NT/Pro/MD+/Duo/Bravo scanner in a cross-sectional sample of 42 Portuguese female volleyball players aged 14–18 years (165.2 ± 0.9 cm; 61.1 ± 1.4 kg). TV was estimated with the reference method (TV-DXA) and with the anthropometric method (TV-ANTH). Agreement between procedures was assessed with Deming regression. The analysis also considered a calibration of the anthropometric approach.

Results

The equation that best predicted TV-DXA was: -0.899 + 0.876 × log₁₀ (body mass) + 0.113 × log₁₀ (TV-ANTH). This new model (NM) was validated using the predicted residual sum of squares (PRESS) method (R²_PRESS = 0.838). Correlation between the reference method and the NM was 0.934 (95%CI: 0.880–0.964, S_y∙x = 0.325 L).

Conclusions

A new and accurate anthropometric method to estimate TV in adolescent female volleyball players was obtained from the equation of Jones and Pearson alongside with adjustments for body mass.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0730-7) contains supplementary material, which is available to authorized users.

The Spanish "Century XXI" academy for developing elite level basketballers: design, monitoring and training methodologies

OBJECTIVES

The XXI Century Academy was a 6-year state-initiated intervention program that served as an alternative to basketball clubs for players in the u-14 and u-18 age groups in Spain, under guidelines established by the Spanish Basketball Federation. It was an important and unique project on talent development in basketball. To the best of the authors' knowledge, no evidence has been reported on long-term athlete development programs in basketball worldwide. The main aim of this report is to describe the design and evaluation methods used for the XXI Century Academy as a long-term intervention program in the elite Spanish Basketball Academy, aiming to prepare basketball players to compete at the elite level.

METHODS

The monitoring time lasted from 1996 to 2001. A total of 55 players were assigned to the intervention groups based on age, position, maturation level, and country of origin. During this process, participants competed in up to two categories in addition to playing competitive official matches worldwide in international tournaments in their categories and with the national team in the European and World Championships (u-14 - u-18). Participants included 1 NBA player, 3 national A Team players, 10 ACB (First Spanish League) players, 5 LEB (second League) players and 39 LEB-2 EBA (third League) players. Assessments took place in a High-Performance Sports Center (CPT FADURA-GETXO- Basque Government, Getxo, Vizcaya, Spain) and consisted of health questionnaires, anthropometric measures, blood parameters, maturation level, birth age, fitness tests, training volume and intensity, physical activity, technical and tactical training, dietary intake, supplementation and injuries. Each player was assessed 4 times per year (September, December, April, June) for 4 years (16 data points).

RESULTS

This is a purely methodological paper describing the design and evaluation methods used in the XXI Century Project, which will be used as a basis for future reporting of results. Therefore, the results of the project will be reported in subsequent publications.

CONCLUSION

The viability of the Century XXI Project protocols has been described. This national project of training in basketball closely replicates the physical and technical match-play conditions for professionals and may constitute a useful training tool.

Is adductor pollicis muscle thickness a good predictor of lean mass in adults?

BACKGROUND & AIMS

Lean mass (LM) is an important parameter in clinical outcomes, which highlights the necessity of reliable tools for its estimation. The adductor pollicis muscle thickness (APMT) is easily accessible and suffers minimal interference from the adjacent subcutaneous fat tissue.

OBJECTIVE

To assess the relationship between the APMT and LM in a sample of Southern Brazilian adults.

METHODS

Participants were adults from the 1982 Pelotas (Brazil) Birth Cohort. LM was measured by dual energy X-ray absorptiometry (DXA). LM and lean mass index (LMI - LM divided by the square of height - kg/m(2)) were the outcomes. APMT was measured using a skinfold caliper. The mean of three measurements in the non-dominant hand was used in the analyses. APMT was described according to socio-demographic characteristics and nutritional status. The relationship between APMT and both LM and LMI was evaluated by correlation coefficient and linear regression using APMT as a single anthropometric parameter and also in addition to BMI.

RESULTS

APMT was assessed in 3485 participants. APMT was higher in males, non-whites, less-schooled and obese individuals. APMT was moderately correlated to LM and LMI (ranged from 0.44 to 0.57). Correlation coefficients were higher for LMI as outcome and in females (LM: 0.51 and LMI: 0.57). APMT explained 19% and 26% of the variance in LM in males and females, respectively, whereas it explained 26% and 33% of the variance in LMI. APMT increased the prediction for LM in 3 and 4 percentage points in males and females, in comparison to explained by BMI. BMI explained 48% and 59% of the variance of LMI in males and females whereas APMT increased it to 51% and 62% for both sexes, respectively.

CONCLUSIONS

Results were not good enough to promote the APMT as a single predictor of LM or LMI in epidemiological studies. APMT has a little predictive capacity in estimating LM or LMI when BMI is also considered.

[Equations for the evaluation of body composition in children and adolescents]

Body mass index (BMI) is widely used in the world, despite caveats concerning its interpretation in relation to gender, age, and race. BMI reading is normally standardized, potentially producing error in the results and classification of nutritional status. Body composition provides more relevant information than BMI: fat mass and lean mass are the main indices. This paper reviews existing equations and proposes the simplest ones and those with the lowest estimation error to replace or complement BMI and improve interpretation of nutritional status and physical activity.

Maximal oxygen uptake is proportional to muscle fiber oxidative capacity, from chronic heart failure patients to professional cyclists

V̇o2 max during whole body exercise is presumably constrained by oxygen delivery to mitochondria rather than by mitochondria's ability to consume oxygen. Humans and animals have been reported to exploit only 60-80% of their mitochondrial oxidative capacity at maximal oxygen uptake (V̇o2 max). However, ex vivo quantification of mitochondrial overcapacity is complicated by isolation or permeabilization procedures. An alternative method for estimating mitochondrial oxidative capacity is via enzyme histochemical quantification of succinate dehydrogenase (SDH) activity. We determined to what extent V̇o2 max attained during cycling exercise differs from mitochondrial oxidative capacity predicted from SDH activity of vastus lateralis muscle in chronic heart failure patients, healthy controls, and cyclists. V̇o2 max was assessed in 20 healthy subjects and 28 cyclists, and SDH activity was determined from biopsy cryosections of vastus lateralis using quantitative histochemistry. Similar data from our laboratory of 14 chronic heart failure patients and 6 controls were included. Mitochondrial oxidative capacity was predicted from SDH activity using estimated skeletal muscle mass and the relationship between ex vivo fiber V̇o2 max and SDH activity of isolated single muscle fibers and myocardial trabecula under hyperoxic conditions. Mitochondrial oxidative capacity predicted from SDH activity was related (r(2) = 0.89, P < 0.001) to V̇o2 max measured during cycling in subjects with V̇o2 max ranging from 9.8 to 79.0 ml·kg(-1)·min(-1) V̇o2 max measured during cycling was on average 90 ± 14% of mitochondrial oxidative capacity. We conclude that human V̇o2 max is related to mitochondrial oxidative capacity predicted from skeletal muscle SDH activity. Mitochondrial oxidative capacity is likely marginally limited by oxygen supply to mitochondria.

The Relationship of Physical Activity and Anthropometric and Physiological Characteristics to Bone Mineral Density in Postmenopausal Women

The aim of this study is to investigate the relationship of physical activity and anthropometric and physiological characteristics to bone mineral density (BMD) in postmenopausal women. Ninety-seven postmenopausal women with an average age of 50.71 ± 6.86 yr were selected to participate in this study. After completing consent forms and the questionnaire on physical activity, the amounts of calcium and 25-hydroxyvitamin D levels in participants' blood were measured by blood tests. The BMDs of the subjects in the lumbar spine (L2-L4) and hip were measured by dual-energy X-ray absorptiometry device and the results were recorded. Also, anthropometric characteristics including height, weight, body fat percentage, body mass index, waist-to-hip ratio (WHR), digit ratio (2D:4D), skeletal muscle mass index, hand and calf circumferences and physiological parameters, including handgrip strength, quadriceps isotonic extension strength and balance of the subjects, were measured. The results showed that the 2D:4D ratio and skeletal muscle mass index had a significantly positive relationship with BMD of the lumbar spine (p ≤ 0.05) and the hip (p ≤ 0.05). Also, there was a negative relationship between the BMD of lumbar spine and hip and WHR (p ≤ 0.05). Moreover, there was a positive relationship between the calf circumferences and lumbar spine BMD (p ≤ 0.05). Contrary to this, there was no significant relationship between the calf circumference and the hip BMD, and between hand circumference with lumbar spine and hip BMD (p > 0.05). Results of physiological indices showed a significant positive relationship between physical activity, handgrip strength, quadriceps isotonic extension strength, standing on 1 foot with the lumbar spine and hip BMD (p ≤ 0.05). But the relationship was not observed between BMD and the ability to squat down on the floor (p > 0.05). Based on these results, it seemed that we can use some physiological and anthropometric indices that are important determinants of BMD and risk of osteoporosis in postmenopausal women.

Factors associated with skeletal muscle mass, sarcopenia, and sarcopenic obesity in older adults: a multi-continent study

BACKGROUND

The aim of this study was to evaluate the factors associated with low skeletal muscle mass (SMM), sarcopenia, and sarcopenic obesity using nationally representative samples of people aged ≥65 years from diverse geographical regions of the world.

METHODS

Data were available for 18 363 people aged ≥65 years who participated in the Collaborative Research on Ageing in Europe survey conducted in Finland, Poland, and Spain, and the World Health Organization Study on global AGEing and adult health survey conducted in China, Ghana, India, Mexico, Russia, and South Africa, between 2007 and 2012. A skeletal muscle mass index (SMI) was created to reflect SMM. SMM, SMI, and percent body fat (%BF) were calculated with specific indirect population formulas. These estimates were based on age, sex, weight, height, and race. Sarcopenia and sarcopenic obesity were defined with specific cut-offs.

RESULTS

The prevalence of sarcopenia ranged from 12.6% (Poland) to 17.5% (India), and that of sarcopenic obesity ranged from 1.3% (India) to 11.0% (Spain). Higher %BF was associated with lower SMM in all countries, and with sarcopenia in five countries (p < 0.001). Compared to high levels of physical activity, low levels were related with higher odds for sarcopenia [OR 1.36 (95%CI 1.11-1.67)] and sarcopenic obesity [OR 1.80 (95%CI 1.23-2.64)] in the overall sample. Also, a dose-dependent association between higher numbers of chronic diseases and sarcopenic obesity was observed.

CONCLUSIONS

Physical activity and body composition changes such as high %BF are key factors for the prevention of sarcopenia syndrome.

New ultrasonography-based method for predicting total skeletal muscle mass in male athletes

[Purpose] This study aimed 1) to assess whether a prediction model for whole body skeletal muscle mass that is based on a sedentary population is applicable to young male athletes, and 2) to develop a new skeletal muscle mass prediction model for young male athletes. [Subjects and Methods] The skeletal muscle mass of 61 male athletes was measured using magnetic resonance imaging (MRI) and estimated using a previous prediction model (Sanada et al., 2006) with B-mode ultrasonography. The prediction model was not suitable for young male athletes, as a significant difference was observed between the means of the estimated and MRI-measured skeletal muscle mass. Next, the same subjects were randomly assigned to a development or validation group, and a new model specifically relevant to young male athletes was developed based on MRI and ultrasound data obtained from the development group. [Results] A strong correlation was observed between the skeletal muscle mass estimated by the new model and the MRI-measured skeletal muscle mass (r=0.96) in the validation group, without significant difference between their means. No bias was found in the new model using Bland-Altman analysis (r=−0.25). [Conclusion] These results validate the new model and suggest that ultrasonography is a reliable method for measuring skeletal muscle mass in young male athletes.

The core musculature in male prepubescent tennis players and untrained counterparts: a volumetric MRI study

The effects of exercise on the core musculature have not been investigated in prepubescents. The main purpose of the present study was to determine the volume and degree of asymmetry of rectus abdominis, obliques and transversus abdominis, quadratus lumborum, iliopsoas, gluteus and paravertebralis muscles in prepubescent tennis players and in untrained boys. The muscle volume was determined using magnetic resonance imaging (MRI) in 7 male prepubescent tennis players and 10 untrained controls (mean age 11.0 ± 0.8 years, Tanner 1-2). After accounting for height and body weight as covariates, the tennis players had 14-34% greater volume than the controls in all the muscles analysed (P < 0.05) except in paravertebralis, dominant quadratus lumborum and non-dominant gluteus, which had similar volumes in both groups (P = NS). Compared to controls, the tennis players displayed a greater degree of asymmetry in quadratus lumborum and rectus abdominis (3% vs. 15%, P < 0.01 and 8% vs. 17%, P = 0.06, respectively). The level of asymmetry of obliques and transversus abdominis, iliopsoas, gluteus and paravertebralis muscles was similar in both groups (P = NS). In conclusion, tennis playing at prepubertal ages induces a selective hypertrophy of the core musculature and exaggerates the degree of asymmetry of quadratus lumborum and rectus abdominis compared to untrained boys.

Skeletal muscle mass and body fat in relation to successful ageing of older adults: The multi-national MEDIS study

BACKGROUND

The determinants that promote successful ageing still remain unknown. The aim of the present work was to evaluate the role of skeletal muscle mass and body fat percentage (BF%), in the level of successful ageing.

METHODS

during 2005-2011, 2663 older (aged 65-100 years) from 21 Mediterranean islands and the rural Mani region (Peloponnesus) of Greece were voluntarily enrolled in the study. Appendicular skeletal muscle mass (ASM), skeletal muscle mass index (SMI) and BF% were calculated using population formulas. Dietary habits, energy intake, expenditure and energy balance were derived throughout standard procedures. A successful ageing index ranging from 0 to 10 was used.

RESULTS

The mean ASM mass was 24±6.0kg, the SMI was 0.84±0.21 and the BF% was 44%. Females had lower SMI and higher BF% in comparison with males, respectively [(SMI: 0.66±0.09 vs. 1.03±0.11; BF%: 51% vs. 34%, (p<0.001)]. High successful agers had better rates in ASM (p=0.01), SMI (p<0.001) and BF% (p<0.001), compared with the medium and low successful ones. Changes in SMI [b-coefficient (95% CI):2.14 (1.57 to 2.71)] were positively associated with successful ageing, while changes in BF% [b-coefficient (95% CI): -0.04 (-0.05 to -0.03)] were inversely associated with successful ageing. Results from sensitivity analysis showed that the effects of variations on body composition were consistent, less pronounced in the positive energy balance group and more pronounced among the oldest old.

CONCLUSIONS

Body composition changes seem to be associated with lower quality of life in the older adults, as measured through successful ageing.

Existe associação entre massa e força muscular esquelética em idosos hospitalizados?

Resumo Introdução: Massa e força muscular esquelética são variáveis que contribuem para o diagnóstico de sarcopenia. Objetivo: Avaliar a associação entre força e massa muscular esquelética em idosos hospitalizados. Método: Estudo transversal, realizado em hospital privado na cidade de Salvador-BA. Foram incluídos idosos ≥60 anos, entre o 1o e o 5o dia de internação hospitalar e que estivessem sem sedação e/ou drogas vasoativas. A massa muscular foi obtida por meio de equação antropométrica e a variável força por meio da força de preensão palmar. Fraqueza muscular foi identificada se <20 kgf para mulheres e <30 kgf para homens e a massa muscular reduzida quando o índice de massa muscular foi ≤8,9 kg/m2 para homens e ≤6,37 kg/m2 para mulheres. A correlação de Pearson foi utilizada para avaliar a relação entre massa e força e a acurácia para avaliar a capacidade da massa predizer força. Resultados: Entre os 110 idosos avaliados, houve moderada correlação entre massa e força (R=0,691; p=0,001). Entretanto, a acurácia foi fraca da massa para predizer força muscular (acurácia=0,30; IC 95% = 0,19-0,41; p=0,001). Os idosos com fraqueza eram mais velhos que os sem fraqueza, sem diferença nas outras variáveis. Conclusão: Existe uma relação linear entre massa e força muscular esquelética, porém a massa não prediz força, o que sugere que as duas medidas continuem sendo realizadas de forma independente.

Evaluation of the site specificity of acute disuse muscle atrophy developed during a relatively short period in critically ill patients according to the activities of daily living level: A prospective observational study

INTRODUCTION

In critically ill patients, excessive bed rest and immobilisation have been shown to cause disuse muscle atrophy, which contributes to prolonged hospitalisation and decreased activity of daily living (ADL) levels. However, the degree and site specificity of acute disuse muscle atrophy in critically ill patients during a relatively short intensive care unit (ICU) stay have not been fully elucidated.

METHODS

Critically ill patients, who required bed rest on ICU admission, were eligible for this study. The degree of skeletal muscle atrophy was evaluated on the day of, and 72 and 144h after ICU admission by measuring the limb circumference in ADL-dependent or -independent patients separately at five different sites: the midpoint of the upper limb between the acromion and the olecranon, the maximum diameter of the triceps surae in the lower leg, and three different sites in the thigh at 5, 10, and 15cm above the superior pole of the patella. Value of the limb circumference was presented as a percentage relative to the baseline (median).

RESULTS

In ADL-dependent patients, limb circumferences at all five sites were decreased significantly at 144h compared with the baseline (98.9-100% in the upper limbs, 97.1-97.2% in the lower legs, and 96.5-99.1% in the thighs), but not at 72h. In contrast, the limb circumferences at almost all sites decreased significantly at both 72 and 144h (100% in the upper limbs, 94.5-94.7% in the lower legs, and 89.7-94.7% in the thighs), compared with the baseline in ADL-independent patients. Muscle atrophy was greater at the four different lower-limb sites compared to the upper limb during 144h in the ICU in the ADL-independent, but not in the ADL-dependent patients.

CONCLUSIONS

Compared to ADL-dependent patients, ADL-independent patients are prone to develop muscle weakness, especially in the lower limbs.

Relationships between maximal strength, muscle size, and myosin heavy chain isoform composition and postactivation potentiation

The purpose of this study was to examine the relationships between maximal voluntary postactivation potentiation (PAP) and maximal knee extensor torque, quadriceps cross-sectional area (CSA) and volume, and type II myosin heavy chain (MHC) isoform percentage in human skeletal muscle. Thirteen resistance-trained men completed a test protocol consisting of 2 isokinetic knee extensions at 180°·s(-)(1) performed before and 1, 4, 7, and 10 min after the completion of 4 maximal knee extensions at 60°·s(-)(1) (i.e., a conditioning activity (CA)). Magnetic resonance imaging and muscle microbiopsy procedures were completed on separate days to assess quadriceps CSA and volume and MHC isoform content. Maximal voluntary PAP response was assessed as the ratio of the highest knee extensor torques measured before and after the CA. There were large to very large correlations between maximal voluntary PAP response and maximal knee extensor torque (r = 0.62) and quadriceps CSA (r = 0.68) and volume (r = 0.63). Nonetheless, these correlations were not statistically significant after adjusting for the influence of type II MHC percentage using partial correlation analysis. By contrast, the strongest correlation was observed for type II MHC percentage (r = 0.77), and this correlation remained significant after adjusting for the other variables. Maximal voluntary PAP response is strongly correlated with maximal knee extensor torque and quadriceps CSA and volume, but is mostly clearly associated with the type II myosin isoform percentage in human skeletal muscle.

Lipidomic approach in young adult triathletes: effect of supplementation with a polyphenols-rich juice on neuroprostane and F2-dihomo-isoprostane markers

With adequate training, our juice rich in polyphenolic compounds has been able to influence the excretion values of oxidative stress biomarkers associated with the central nervous system.

"Chair Stand Test" as Simple Tool for Sarcopenia Screening in Elderly Women

OBJECTIVES

To investigate the association between sarcopenia and "chair stand test" performance, and evaluate this test as a screening tool for sarcopenia in community-dwelling elderly women.

DESIGN

Cross-sectional Survey.

PARTICIPANTS

173 female individuals, aged ≥ 60 years and living in the urban area of the municipality of Lafaiete Coutinho, Bahia's inland, Brazil.

MEASUREMENTS

The association between sarcopenia (defined by muscle mass, strength and/or performance loss) and performance in the "chair stand test" was tested by binary logistic regression technique. The ROC curve parameters were used to evaluate the diagnostic power of the test in sarcopenia screening. The significance level was set at 5 %.

RESULTS

The model showed that the time spent for the "chair stand test" was positively associated (OR = 1.08; 95% CI = 1.01 - 1.16, p = 0.024) to sarcopenia, indicating that, for each 1 second increment in the test performance, the sarcopenia's probability increased by 8% in elderly women. The cut-off point that showed the best balance between sensitivity and specificity was 13 seconds.

CONCLUSION

The performance of "chair stand test" showed predictive ability for sarcopenia, being an effective and simple screening tool for sarcopenia in elderly women. This test could be used for screening sarcopenic elderly women, allowing early interventions.

Identifying Low Muscle Mass in Patients with Hip Fracture: Validation of Biolectrical Impedance Analysis and Anthropometry Compared to Dual Energy X-ray Absorptiometry

BACKGROUND

Older hip fracture patients often have reduced muscle mass, which is associated with adverse outcomes. Dual energy X-ray absorptiometry (DXA) can determine muscle mass, but is not practical in the acute phase. We investigated bioelectrical impedance analysis (BIA) and anthropometry compared against DXA for detecting low muscle mass in hip fracture patients.

METHODS

This was a cross-sectional validation study at two Norwegian hospitals on 162 hip fracture patients aged ≥ 65 years. Appendicular lean mass (ALM) was determined by DXA, BIA and anthropometry 3 months after hip fracture. ALM by BIA was calculated by the Kyle, Janssen, Tengvall and Sergi equations, and ALM by anthropometry by the Heymsfield and Villani equations. The area under the receiver operating characteristic curve (AUC) was used to compare BIA and anthropometry for determining low ALM (≤5.67 kg/m2 for women and ≤7.25kg/m2 for men).

RESULTS

Mean age was 79 years (SD 7.9), 74% were female. Mean ALM by DXA was 14.8 kg (SD 2.3) for women and 20.8 kg (SD 4.2) for men and 45% of women and 60% of men had low ALM. BIA (Kyle) in women (AUC 0.81, 95% confidence interval 0.72-0.89) and BIA (Sergi) in men (AUC 0.89, 95% CI 0.80-0.98) were best able to discriminate between low and normal ALM. Anthropometry (Heymsfield) was less accurate than BIA in women (AUC 0.64, 95% CI 0.54-0.75), and equal to BIA in men (AUC 0.72, 95% CI 0.72 0.56-0.87).

CONCLUSION

BIA (Sergi, Kyle and Tengvall) and anthropometry (Heymsfield) can identify low muscle mass in hip fracture patients.

Nutrition and physical activity for the prevention and treatment of age-related sarcopenia

Sarcopenia, defined as loss of skeletal muscle mass and function, is associated with adverse outcomes such as physical disability, impaired quality of life and increased mortality. Several mechanisms are involved in the development of sarcopenia. Potentially modifiable factors include nutrition and physical activity. Protein metabolism is central to the nutritional issues, along with other potentially modifying nutritional factors as energy balance and vitamin D status. An increasing but still incomplete knowledge base has generated recent recommendations on an increased protein intake in the elderly. Several factors beyond the total amount of protein consumed emerge as potentially important in this context. A recent summit examined three hypotheses: (1) A meal threshold; habitually consuming 25-30 g protein at breakfast, lunch and dinner provides sufficient protein to effectively stimulate muscle protein anabolism; (2) Protein quality; including high-quality protein at each meal improves postprandial muscle protein synthesis; and (3) performing physical activity in close temporal proximity to a high-quality protein meal enhances muscle anabolism. Optimising the potential for muscle protein anabolism by consuming an adequate amount of high-quality protein at each meal, in combination with physical activity, appears as a promising strategy to prevent or delay the onset of sarcopenia. However, results of interventions are inconsistent, and well-designed, standardised studies evaluating exercise or nutrition interventions are needed before guidelines can be developed for the prevention and treatment of age-related sarcopenia.

The science of badminton: game characteristics, anthropometry, physiology, visual fitness and biomechanics

Badminton is a racket sport for two or four people, with a temporal structure characterized by actions of short duration and high intensity. This sport has five events: men's and women's singles, men's and women's doubles, and mixed doubles, each requiring specific preparation in terms of technique, control and physical fitness. Badminton is one of the most popular sports in the world, with 200 million adherents. The decision to include badminton in the 1992 Olympics Game increased participation in the game. This review focuses on the game characteristics, anthropometry, physiology, visual attributes and biomechanics of badminton. Players are generally tall and lean, with an ectomesomorphic body type suited to the high physiological demands of a match. Indeed, a typical match characteristic is a rally time of 7 s and a resting time of 15 s, with an effective playing time of 31%. This sport is highly demanding, with an average heart rate (HR) of over 90% of the player's maximal HR. The intermittent actions during a game are demanding on both the aerobic and anaerobic systems: 60-70% on the aerobic system and approximately 30% on the anaerobic system, with greater demand on the alactic metabolism with respect to the lactic anaerobic metabolism. The shuttlecock has an atypical trajectory, and the players perform specific movements such as lunging and jumping, and powerful strokes using a specific pattern of movement. Lastly, badminton players are visually fit, picking up accurate visual information in a short time. Knowledge of badminton can help to improve coaching and badminton skills.

The role of muscle mass and body fat on disability among older adults: A cross-national analysis

BACKGROUND

The aim of this study was to evaluate the association of sarcopenia and sarcopenic obesity with disability among older adults (≥65years old) in nine high-, middle- and low-income countries from Asia, Africa, Europe, and Latin America.

METHODS

Data were available for 53,289 people aged ≥18years who participated in the Collaborative Research on Ageing in Europe (COURAGE) survey conducted in Finland, Poland, and Spain, and the WHO Study on global AGEing and adult health (SAGE) survey conducted in China, Ghana, India, Mexico, Russia, and South Africa, between 2007 and 2012. Skeletal muscle mass, skeletal muscle mass index, and percent body fat were calculated with specific population formulas. Sarcopenia and sarcopenic obesity were defined by specific cut-offs used in previous studies. Disability was assessed with the WHODAS 2.0 score (range 0-100) with higher scores corresponding to higher levels of disability. Multivariable linear regression analysis was conducted with disability as the outcome.

RESULTS

The analytical sample consisted of 18,363 people (males; n=8116, females; n=10247) aged ≥65years with mean (SD) age 72.9 (11.1) years. In the fully-adjusted overall analysis, sarcopenic obesity was associated with greater levels of disability [b-coefficient 3.01 (95% CI 1.14-4.88)]. In terms of country-wise analyses, sarcopenia was associated with higher WHODAS 2.0 scores in China [b-coefficient 4.56 (95% CI: 3.25-5.87)], Poland [b-coefficient 6.66 (95% CI: 2.17-11.14)], Russia [b-coefficient 5.60 (95% CI: 2.03-9.16)], and South Africa [b-coefficient 7.75 (95% CI: 1.56-13.94)].

CONCLUSIONS

Prevention of muscle mass decline may contribute to reducing the global burden of disability.

Frequency of sarcopenia and associated factors among hospitalized elderly patients

Background

Sarcopenia is an important public health problem that affects mainly elders, and has negative consequences, such as disability and even death. Due to the lack of studies evaluating sarcopenia in elderly persons hospitalized in Brazil, the aim of the present study was to describe the frequency of sarcopenia and associated factors among elders in a hospital in the city of Salvador - Brazil.

Methods

This cross-sectional study included 110 hospitalized elderly patients in a multi-specialty hospital in Salvador-BA, Brazil. Inclusion criteria: were elders aged ≥60 years between the first and fifth day of hospitalization; who were able to walk without external assistance; with medical permission to walk, and who did not take vasoactive and inotropic drugs. The diagnosis of sarcopenia was determined by combining the reduction in skeletal muscle mass with muscle weakness (women, <20 kg; men, <30 kg) and/or poor physical performance (gait speed ≤0.8 m/s). To obtain reduced skeletal muscle mass, the skeletal muscle mass index ≤6.37 kg/m² for women and ≤8.90 kg/m² for men was used. Cognitive function, Charlson index, admission profile (clinical and surgical), smoking, falls suffered in the last year and physical inactivity prior to admission were also evaluated. The frequency of sarcopenia was described in percentages with their respective confidence intervals and logistic regression was performed for multivariate analysis of factors associated with sarcopenia.

Results

Among the 110 patients included, the frequency of sarcopenia was 21.8%, with 10.0% being of the severe type. There was a predominance of clinical profile (59.1%), such as heart disease (20.0%), pneumonia (13.6%) and skin infections (9.1%), with a Charlson index of 5.4 ± 1.8. The factors associated with sarcopenia were age (OR = 1.14; 95% CI = 1.06 to 1.23), clinical profile on admission (OR = 5.15; 95% CI = 1.16–22.9) and smoking (OR = 7.8; 95% CI = 1.53–39.9).

Conclusions

The frequency of sarcopenia in elderly hospitalized patients was high (1 in 5 elderly) and anthropometric equation can be a viable and inexpensive alternative to screening and programming intervention in this population.

Accuracy of the Timed Up and Go test for predicting sarcopenia in elderly hospitalized patients

OBJECTIVES

The ability of the Timed Up and Go test to predict sarcopenia has not been evaluated previously. The objective of this study was to evaluate the accuracy of the Timed Up and Go test for predicting sarcopenia in elderly hospitalized patients.

METHODS

This cross-sectional study analyzed 68 elderly patients (≥60 years of age) in a private hospital in the city of Salvador-BA, Brazil, between the 1st and 5th day of hospitalization. The predictive variable was the Timed Up and Go test score, and the outcome of interest was the presence of sarcopenia (reduced muscle mass associated with a reduction in handgrip strength and/or weak physical performance in a 6-m gait-speed test). After the descriptive data analyses, the sensitivity, specificity and accuracy of a test using the predictive variable to predict the presence of sarcopenia were calculated.

RESULTS

In total, 68 elderly individuals, with a mean age 70.4±7.7 years, were evaluated. The subjects had a Charlson Comorbidity Index score of 5.35±1.97. Most (64.7%) of the subjects had a clinical admission profile; the main reasons for hospitalization were cardiovascular disorders (22.1%), pneumonia (19.1%) and abdominal disorders (10.2%). The frequency of sarcopenia in the sample was 22.1%, and the mean length of time spent performing the Timed Up and Go test was 10.02±5.38 s. A time longer than or equal to a cutoff of 10.85 s on the Timed Up and Go test predicted sarcopenia with a sensitivity of 67% and a specificity of 88.7%. The accuracy of this cutoff for the Timed Up and Go test was good (0.80; IC=0.66-0.94; p=0.002).

CONCLUSION

The Timed Up and Go test was shown to be a predictor of sarcopenia in elderly hospitalized patients.

Dietary intake habits and controlled training on body composition and strength in elite female volleyball players during the season

The purpose of this study was to assess dietary intake of elite female volleyball players (EFVPs, n = 22) during the first 11 weeks of the competitive season. Further, we compared findings for total energy intake and specific macronutrient distribution with the established recommendations for high-intensity athletes. Subjects also engaged in periodized training and we assessed changes in body composition (BC) and strength. Twenty-two EFVPs had dietary intake (7-day dietary recall and food-frequency questionnaire), BC (body mass index (BMI), body fat percentage, fat mass, muscle mass), and 1-repetition maximum (1RM) strength (bench press, military press, back squat, power clean, clean and jerk, pull-over) assessed at baseline (T0, before preseason) and 11 weeks later (T11). Athletes consumed less total kilocalories and carbohydrates (CHO) compared with established recommendations (total kilocalories: 40.7 ± 5.2 kcal/(kg · day)(-1) vs.

RECOMMENDATIONS

50-80 kcal/(kg · day)(-1); CHO: 4.3 ± 0.6 g/(kg · day)(-1) vs.

RECOMMENDATIONS

5-8 g/(kg · day)(-1)). Further, subjects consumed greater protein (2.1 ± 0.4 g/(kg · day)(-1)) compared with recommendations (1.6-1.8 g/(kg · day)(-1)) and greater fat (36.1 ± 4.6% of total kilocalories) than recommendations (20%-35% of total kilocalories). There were improvements (p < 0.05) in BC from T0-T11 (body fat percentage: 17.9% ± 4.2%-16.8% ± 3.6%, -4.7% ± 7.4%; fat mass: 12.7 ± 4.2-11.9 ± 3.8 kg, -4.0% ± 9.2%; muscle mass: 42.8% ± 3.4%-43.3% ± 3.0%, +1.3 ± 3.1%) and 1RM strength (bench press: 39.1 ± 4.5-43.4 ± 4.9 kg; +11.4% ± 9.3%; clean and jerk: 29.7 ± 6.3-34 ± 5.8 kg; +17.7% ± 23.8%); however, there was no change (p > 0.05) in BMI or military press and pull-over. Back squat (p = 0.054; +33.0% ± 83.7%) and power clean (p = 0.056; +26.2% ± 49.0%) increases approached significance. Our findings indicate that EFVPs improved BC and strength despite a dietary intake different from recommendations. This is possibly due to different substrate utilization during exercise in females versus males, thus new recommendations should be considered for high-intensity athletes, which are sex-specific.

The multidomain mobility lab in older persons: from bench to bedside. The assessment of body composition in older persons at risk of mobility limitations

With body composition it is possible to divide human body in compartments on the basis of different physical properties. The two level body composition model subdividing the whole body in fat mass and fat free mass is the most used in epidemiological and clinical studies in the elderly. Body composition techniques may be used to study ageing process. Changes in body composition occur as part of the normal ageing process and are associated with important effects on health and function. It has been shown that body composition changes with aging, with an increase in fat mass and a decrease in muscle mass, have important consequences on health and physical disability. Moreover body fat distribution changes with adverse metabolic profiles and increased cardiovascular risk. The purpose of this review is to describe the basic principles and techniques for fat free mass and fat mass evaluation, highlighting the advantages and limitations of different available body composition methods.

Appendicular skeletal muscle in hospitalised hip-fracture patients: development and cross-validation of anthropometric prediction equations against dual-energy X-ray absorptiometry

BACKGROUND

accurate and practical assessment methods for assessing appendicular skeletal muscle (ASM) is of clinical importance for the diagnosis of geriatric syndromes associated with skeletal muscle wasting.

OBJECTIVES

the purpose of this study was to develop and cross-validate novel anthropometric prediction equations for the estimate of ASM in older adults post-surgical fixation for hip fracture, using dual-energy X-ray absorptiometry (DEXA) as the criterion measure.

SUBJECTS

community-dwelling older adults (aged ≥65 years) recently hospitalised for hip fracture.

SETTING

participants were recruited from hospital in the acute phase of recovery.

DESIGN

validation measurement study.

MEASUREMENTS

a total of 79 hip fracture patients were involved in the development of the regression models (MD group). A further 64 hip fracture patients also recruited in the early phase of recovery were used in the cross-validation of the regression models (CV group). Multiple linear regression analyses were undertaken in the MD group to identify the best performing prediction models. The linear coefficient of determination (R(2)) in addition to the standard error of the estimate (SEE) were calculated to determine the best performing model. Agreement between estimated ASM and ASMDEXA in the CV group was assessed using paired t-tests with the 95% limits of agreement (LOA) assessed using Bland-Altman analyses.

RESULTS

the mean age of all the participants was 82.1 ± 7.3 years. The best two prediction models are presented as follows: ASMPRED-EQUATION_1: 22.28 - (0.069 * age) + (0.407 * weight) - (0.807 * BMI) - (0.222 * MAC) (adjusted R(2): 0.76; SEE: 1.80 kg); ASMPRED-EQUATION_2: 16.77 - (0.036 * age) + (0.385 * weight) - (0.873 * BMI) (adjusted R(2): 0.73; SEE: 1.90 kg). The mean bias from the CV group between ASMDEXA and the predictive equations is as follows: ASMDEXA - ASMPRED-EQUATION_1: 0.29 ± 2.6 kg (LOA: -4.80, 5.40 kg); ASMDEXA - ASMPRED-EQUATION_2: 0.13 ± 2.5 kg (LOA: -4.77, 5.0 kg). No significant difference was observed between measured ASMDEXA and estimated ASM (ASMDEXA: 16.4 ± 3.9 kg; ASMPRED-EQUATION_1: 16.7 ± 3.2 kg (P = 0.379); ASMPRED-EQUATION_2: 16.6 ± 3.2 kg (P = 0.670)).

CONCLUSIONS

we have developed and cross-validated novel anthropometric prediction equations against DEXA for the estimate of ASM designed for application in older orthopaedic patients. Our equation may be of use as an alternative to DEXA in the diagnosis of skeletal muscle wasting syndromes. Further validation studies are required to determine the clinical utility of our equation across other settings, including hip fracture patients admitted from residential care, and also with a longer-term follow-up.

Derivation and validation of simple equations to predict total muscle mass from simple anthropometric and demographic data

BACKGROUND

Muscle mass reflects and influences health status. Its reliable estimation would be of value for epidemiology.

OBJECTIVE

The aim of the study was to derive and validate anthropometric prediction equations to quantify whole-body skeletal muscle mass (SM) in adults.

DESIGN

The derivation sample included 423 subjects (227 women) aged 18-81 y with a body mass index (BMI; in kg/m(2)) of 15.9-40.8. The validation sample included 197 subjects (105 women) aged 19-83 y with a BMI of 15.7-36.4. Both samples were of mixed ethnic/racial groups. All underwent whole-body magnetic resonance imaging to quantify SM (dependent variable for multiple regressions) and anthropometric variables (independent variables).

RESULTS

Two prediction equations with high practicality and optimal derivation correlations with SM were further investigated to assess agreement and bias by using Bland-Altman plots and validated in separate data sets. Including race as a variable increased R(2) by only 0.1% in men and by 8% in women. For men: SM (kg) = 39.5 + 0.665 body weight (BW; kg) - 0.185 waist circumference (cm) - 0.418 hip circumference (cm) - 0.08 age (y) (derivation: R(2) = 0.76, SEE = 2.7 kg; validation: R(2) = 0.79, SEE = 2.7 kg). Bland-Altman plots showed moderate agreement in both derivation and validation analyses. For women: SM (kg) = 2.89 + 0.255 BW (kg) - 0.175 hip circumference (cm) - 0.038 age (y) + 0.118 height (cm) (derivation: R(2) = 0.58, SEE = 2.2 kg; validation: R(2) = 0.59, SEE = 2.1 kg). Bland-Altman plots had a negative slope, indicating a tendency to overestimate SM among women with smaller muscle mass and to underestimate SM among those with larger muscle mass.

CONCLUSIONS

Anthropometry predicts SM better in men than in women. Equations that include hip circumference showed agreement between methods, with predictive power similar to that of BMI to predict fat mass, with the potential for applications in groups, as well as epidemiology and survey settings.

Prediction equation for lower limbs lean soft tissue in circumpubertal boys using anthropometry and biological maturation

Lean soft tissue (LST), a surrogate of skeletal muscle mass, is largely limited to appendicular body regions. Simple and accurate methods to estimate lower limbs LST are often used in attempts to partition out the influence of body size on performance outputs. The aim of the current study was to develop and cross-validate a new model to predict lower limbs LST in boys aged 10–13 years, using dual-energy X-ray absorptiometry (DXA) as the reference method. Total body and segmental (lower limbs) composition were assessed with a Hologic Explorer-W QDR DXA scanner in a cross-sectional sample of 75 Portuguese boys (144.8±6.4 cm; 40.2±9.0 kg). Skinfolds were measured at the anterior and posterior mid-thigh, and medial calf. Circumferences were measured at the proximal, mid and distal thigh. Leg length was estimated as stature minus sitting height. Current stature expressed as a percentage of attained predicted mature stature (PMS) was used as an estimate of biological maturity status. Backward proportional allometric models were used to identify the model with the best statistical fit: ln (lower limbs LST)  = 0.838× ln (body mass) +0.476× ln (leg length) – 0.135× ln (mid-thigh circumference) – 0.053× ln (anterior mid-thigh skinfold) – 0.098× ln (medial calf skinfold) – 2.680+0.010× (percentage of attained PMS) (R = 0.95). The obtained equation was cross-validated using the predicted residuals sum of squares statistics (PRESS) method (R²_PRESS = 0.90). Deming repression analysis between predicted and current lower limbs LST showed a standard error of estimation of 0.52 kg (95% limits of agreement: 0.77 to −1.27 kg). The new model accurately predicts lower limbs LST in circumpubertal boys.

Lack of association of body composition and functionality variables with metabolic syndrome in the elderly

BACKGROUND

The aging process causes alterations in body composition (decrease in lean mass and increase in fat mass), diminution of functionality (strength, mobility, and physical performance), and an increased prevalence of chronic diseases such as metabolic syndrome and obesity. The aim of this study was to investigate the association of body composition and functionality with metabolic syndrome in the elderly.

METHODS

A cross-sectional study was conducted in the Outpatient Clinic of the Geriatric Service of Hospital São Lucas of Pontifical Catholic University of Rio Grande do Sul (PUCRS) involving 74 patients (14 males and 60 females). The patients were separated into two groups: Group 1=elderly with metabolic syndrome [through the National Cholesterol Education Program Adult Treatment Panel III (NECP ATP III) criteria; n=34], group 2=elderly without metabolic syndrome (n=40). The variables evaluated included age, gender, body composition (circumferences, skinfold thickness, BMI, muscle and fat thickness and muscle mass), functional variables [hand grip strength, Timed Up and Go Test (TUGT), and Sit-to-Stand Test].

RESULTS

The results showed that elderly individuals with metabolic syndrome had a higher mean of the anthropometric measures (except abdominal skinfold thickness) compared to subjects without metabolic syndrome (P<0.005). We observed significant differences for muscle mass index (higher, P=0.029), TUGT (longer time, P=0.008), and hand grip strength (lower, P=0.015) in elderly with metabolic syndrome compared with subjects without metabolic syndrome. However, when these variables were adjusted for gender, age, and body mass index (BMI), none showed a significant association with metabolic syndrome.

CONCLUSION

We did not observe associations among metabolic syndrome, body composition, and functionality variables.