Prediction of DXA-determined whole body fat from skinfolds: importance of including skinfolds from the thigh and calf in young, healthy men and women

Measuring body composition in pediatric patients with complex diagnoses: Acceptability, practicality, and validation of different techniques

BACKGROUND

Body composition could help identify malnutrition in pediatric patients, but there is uncertainty over which techniques are most suitable and prevailing opinion that measurements are difficult to obtain in practice. This study examined the acceptability, practicality, reliability, and validity of different anthropometric and body composition measurements in patients with complex diagnoses in a tertiary pediatric hospital.

METHODS

A total of 152 children aged 5-18 years had weight, height, body mass index (BMI), mid-upper arm circumference (MUAC), 4-site skinfold thicknesses (SFT), bioelectrical impedance analysis (BIA), and dual-energy x-ray absorptiometry (DXA) assessed on admission and discharge. Acceptability was assessed in a continuous scale, practicality with number/percentage of successful measurements, reliability with intraclass correlation coefficients and coefficients of repeatability, and validity between "simpler" techniques and DXA with Bland-Altman analysis of agreement and Cohen kappa.

RESULTS

Techniques were overall acceptable. Measurements were successful in >50%, with patient refusal uncommon. Coefficients of repeatability were good (0.3 cm MUAC and height, 0.2 kg weight, and 1.0 mm SFTs). All techniques significantly overestimated DXA fat mass, but BMI and triceps SFT better identified abnormal fat mass (κ = 0.46 and 0.49). BIA fat-free mass was not significantly different from DXA, with substantial agreement between techniques (κ = 0.65).

CONCLUSION

Body composition by a range of techniques is acceptable, practical, and reliable in a diverse group of children with complex diagnoses. BIA seems a good alternative to DXA for assessing fat-free mass, triceps SFT, and BMI for fat mass but should be used with care as it could overestimate total fat mass in individuals.

Estimating fat-free mass in recreationally resistance-trained young men: Longitudinal and cross-sectional validation of different methods

Several techniques exist to measure fat-free mass (FFM). Accordingly, this study is based on data from our recent trial comparing the sensitivity of the main field methods available with that of dual-energy X-ray absorptiometry (DXA) as reference and analyzing the cross-sectional accuracy of these field methods in recreationally resistance-trained males. We hypothesized that the use of these techniques would lead to varying estimates of FFM compared with DXA. Participants (N = 23; 21.4 ± 3.3 years) completed a 10-week resistance training plus diet intervention designed to optimize hypertrophy. FFM was determined by bioelectrical impedance analysis (BIA), 23 anthropometric equations, and DXA. After the intervention, FFM increased significantly according to BIA and most anthropometric estimates, but this increase was not detected by 2 anthropometric equations or by DXA. Only 1 of these 2 equations showed significant correlation with DXA and no standardized or significant differences to this reference method, although it did display significant heteroscedasticity. In our cross-sectional analysis, only 1 anthropometric equation gave rise to good accuracy as confirmed by DXA. Our findings indicate that the use of different techniques to assess FFM gains in response to a hypertrophic intervention yields different results. BIA with general embedded equations should not be used to monitor a young male adult's body composition. To monitor FFM over time, we would recommend the Dunne et al. equation (2) as the most sensitive field method, and to assess FFM cross-sectionally, equation (1) of these authors is the most accurate field method.

The effect of combined β-lactoglobulin supplementation and resistance exercise training prior to limb immobilisation on muscle protein synthesis rates in healthy young adults: study protocol for a randomised controlled trial

BACKGROUND

The decline in skeletal muscle mass experienced following a short-term period (days to weeks) of muscle disuse is mediated by impaired rates of muscle protein synthesis (MPS). Previous RCTs of exercise or nutrition prehabilitation interventions designed to mitigate disuse-induced muscle atrophy have reported limited efficacy. Hence, the aim of this study is to investigate the impact of a complex prehabilitation intervention that combines β-lactoglobulin (a novel milk protein with a high leucine content) supplementation with resistance exercise training on disuse-induced changes in free-living integrated rates of MPS in healthy, young adults.

METHODS/DESIGN

To address this aim, we will recruit 24 healthy young (18-45 years) males and females to conduct a parallel, double-blind, 2-arm, randomised placebo-controlled trial. The intervention group will combine a 7-day structured resistance exercise training programme with thrice daily dietary supplementation with 23 g of β-lactoglobulin. The placebo group will combine the same training programme with an energy-matched carbohydrate (dextrose) control. The study protocol will last 16 days for each participant. Day 1 will be a familiarisation session and days 2-4 will be the baseline period. Days 5-11 represent the 'prehabilitation period' whereby participants will combine resistance training with their assigned dietary supplementation regimen. Days 12-16 represent the muscle disuse-induced 'immobilisation period' whereby participants will have a single leg immobilised in a brace and continue their assigned dietary supplementation regimen only (i.e. no resistance training). The primary endpoint of this study is the measurement of free-living integrated rates of MPS using deuterium oxide tracer methodology. Measurements of MPS will be calculated at baseline, over the 7-day prehabilitation period and over the 5-day immobilisation period separately. Secondary endpoints include measurements of muscle mass and strength that will be collected on days 4 (baseline), 11 (end of prehabilitation) and 16 (end of immobilisation).

DISCUSSION

This novel study will establish the impact of a bimodal prehabilitation strategy that combines ß-lactoglobulin supplementation and resistance exercise training in modulating MPS following a short-term period of muscle disuse. If successful, this complex intervention may be translated to clinical practice with application to patients scheduled to undergo, for example, hip or knee replacement surgery.

TRIAL REGISTRATION

NCT05496452. Registered on August 10, 2022.

PROTOCOL VERSION

16-12-2022/1.

Agreement between mechanical and digital skinfold callipers

Background: Skinfold callipers are often used in clinical practice to estimate subcutaneous adipose tissue thickness. Recently, LipoTool emerged as a potential digital system to measure skinfolds, however comparisons with competing equipment are lacking. Aim: The aim of this study was to test the agreement between two competing skinfold callipers (digital and mechanical). Methods: The sample included 22 healthy male adult participants. A certified observer measured eight skinfolds twice using different skinfold callipers (digital and mechanical). Differences between equipment were tested using Wilcoxon signed rank test The distribution of error was examined using the normality test Results: Differences between skinfold callipers were significantly in five skinfolds: triceps (Z  =  -3.546; P < 0.001), subscapular (Z  =  -3.984; P < 0.001), suprailiac (Z  =  3.024; P  =  0.002), supraspinale (Z  =  3.885; P < 0.001), abdominal (Z z = -2.937; P  =  0.003), thigh (Z  =  -2.224; P  =  0.026) and calf (Z  =  -2.052; P  =  0.040). Differences between callipers were constant. Conclusions: Mechanical and digital callipers tended to record different values of skinfold thickness. Clinical examination should consider equipment-related variation in fat mass estimation.

Body Composition of Male Professional Soccer Players Using Different Measurement Methods: A Systematic Review and Meta-Analysis

The performance of male soccer players (MSP) depends on multiple factors such as body composition. The physical demands of modern soccer have changed, so the ideal body composition (BC) requirements must be adapted to the present. The aim of this systematic review and meta-analysis was to describe the anthropometric, BC, and somatotype characteristics of professional MSP and to compare the values reported according to the methods and equations used. We systematically searched Embase, PubMed, SPORTDiscus, and Web of Science following the PRISMA statement. Random-effects meta-analysis, a pooled summary of means, and 95% CI (method or equation) were calculated. Random models were used with the restricted maximum likelihood (REML) method. Seventy-four articles were included in the systematic review and seventy-three in the meta-analysis. After comparing the groups according to the assessment method (kinanthropometry, bioimpedance, and densitometry), significant differences were found in height, fat mass in kilograms, fat mass percentage, and fat-free mass in kilograms (p = 0.001; p < 0.0001). Taking into account the equation used to calculate the fat mass percentage and ∑skinfolds, significant differences were observed in the data reported according to groups (p < 0.001). Despite the limitations, this study provides useful information that could help medical technical staff to properly assess the BC of professional MSP, providing a range of guidance values for the different BC.

Criterion-Related Validity of Field-Based Methods and Equations for Body Composition Estimation in Adults: A Systematic Review

PURPOSE OF REVIEW

Overweight and obesity are associated to health prognosis. Therefore, body composition assessment is an important health outcome, especially in adult population. We analyzed the criterion-related validity of existing field-based methods and equations for body composition estimation in adults aged 19-64 years.

RECENT FINDINGS

One hundred studies met inclusion criteria. The field-based methods, waist circumference (WC), body adiposity index (BAI), and body mass index (BMI) are valid to indicate body adiposity. Likewise, several equations, including the classical Durnin/Womersley equation, Jackson/Pollock equation (males), and Jackson, Pollock, and Ward equation (females), are valid to estimate total body fat mass or body fat percentage. Anthropometric field methods can provide a simple, quick, and easy informative indicators of adiposity in adults. Classical equations, such as Durnin/Womersley equation, Jackson/Pollock equation, and Jackson, Pollock, and Ward equation, are still valid to estimate total body fat mass or body fat percentage in adult population. When choosing estimation equations, specific population characteristics, such as age, weight status, or race ethnicity, should be taken into account. (Trial Registration: Registered on PROSPERO (CRD42020194272)).

Development and Validation of an Anthropometric Equation to Predict Fat Mass Percentage in Professional and Semi-Professional Male Futsal Players

This study aimed to (i) characterise the body composition of professional and semi-professional male futsal players, (ii) assess the validity of commonly used equations to estimate FM%, (iii) develop and cross-validate a futsal-specific FM% prediction equation. In a cross-sectional design, 78 adult male futsal players were assessed for body mass, stature, skinfolds, and girths as per the International Society for the Advancement of Kinanthropometry protocol and completed a dual-energy X-ray absorptiometry (DXA) scan for reference body composition data. Using paired-sample t-tests, the FM% from the DXA and nine published equations were compared. New sport-specific models were developed by stepwise multiple regression. Existing equations were cross-validated using the least squares regression, concordance correlation coefficient, and the Bland−Altman analyses. New equations were further cross-validated using the PRESS approach. None of the existing equations accurately predicted the DXA-derived FM% (p < 0.001; R2 ≤ 0.76, SEE ≥ 1.59; CCC ≤ 0.83; bias = −8.2% to −1.3%, limited agreement, and varying trends). The novel Bettery® equation: −0.620 + (0.159 ∗ Σ4SKF [triceps, abdominal, iliac crest, and front thigh (mm)]) + (0.120 ∗ waist girth (cm)), demonstrated a high accuracy (R2 = 0.85, SEE = 1.32%), a moderate strength of agreement (CCC = 0.92), no bias (0.2%), good agreement (±2.5%), and no trend (r = −0.157; p = 0.170) against the DXA. The Bettery® equation is the first to allow for a valid and sport-specific assessment of FM% in male futsal players.

Predicting resting energy expenditure in people with chronic spinal cord injury

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

The aims of this study were (1) to validate the two recently developed SCI-specific REE equations; (2) to develop new prediction equations to predict REE in a general population with SCI.

SETTING

University, the Netherlands.

METHODS

Forty-eight community-dwelling men and women with SCI were recruited (age: 18-75 years, time since injury: ≥12 months). Body composition was measured by dual-energy X-ray absorptiometry (DXA), single-frequency bioelectrical impedance analysis (SF-BIA) and skinfold thickness. REE was measured by indirect calorimetry. Personal and lesion characteristics were collected. SCI-specific REE equations by Chun et al. [1] and by Nightingale and Gorgey [2] were validated. New equations for predicting REE were developed using multivariate regression analysis.

RESULTS

Prediction equations by Chun et al. [1] and by Nightingale and Gorgey [2] significantly underestimated REE (Chun et al.: -11%; Nightingale and Gorgey: -11%). New equations were developed for predicting REE in the general population of people with SCI using FFM measured by SF-BIA and Goosey-Tolfrey et al. skinfold equation (R² = 0.45-0.47; SEE = 200 kcal/day). The new equations showed proportional bias (p < 0.001) and wide limits of agreement (LoA, ±23%).

CONCLUSIONS

Prediction equations by Chun et al. [1] and by Nightingale and Gorgey [2] significantly underestimated REE and showed large individual variations in a general population with SCI. The newly developed REE equations showed proportional bias and a wide LoA (±23%) which limit the predictive power and accuracy to predict REE in the general population with SCI. Alternative methods for measuring REE need to be investigated.

Optimizing Field Body Fat Percentage Assessment in Professional Soccer Players

Body composition is a determinant of performance in soccer. To estimate the body fat percentage (%BF), dual energy X-ray absorptiometry (DXA) is effective though this method is expensive and not readily accessible. This study examines the validity of widely used field methods based on anthropometric data and bioelectrical impedance analysis (BIA). Participants were 21 male Spanish First Division soccer players aged between 22 and 35 years. In each participant, body fat mass was determined by BIA and using 18 anthropometric equations including skinfold (SKF) measurements. DXA was used as reference. Correlation with DXA measurements was excellent for all equations and separate SKF measurements yet only moderate for BIA. However, only the equation recently developed for use in soccer players based on iliac crest and triceps SKFs showed no significant or standardized differences with DXA-derived %BF and these measurements also had the lowest bias. Our findings suggest that when DXA is not available, the best field method for %BF assessment in footballers is the equation based on iliac crest and triceps SKF. As another good option, we propose the sum of triceps, subscapular, supraspinal, and abdominal SKFs, as this combination also showed good correlation with DXA.

Validity and accuracy of body fat prediction equations using anthropometric measurements in children 7 – 10 years old

abstract Children with a deficit of growth because of perinatal malnutrition present specificities in the percentage of body fat (%BF) that could not be detected by previous fat mass-based equations. This study developed and validated predictive equations of the %BF derived from anthropometric variables in children aged 7 to 10 living in Northeast Brazil, using dual-energy x-ray absorptiometry (DXA) as a reference. Body composition data from 58 children were utilized. DXA was used as a reference. A stepwise (forward) multiple regression statistical model was used to develop the new equations. The Bland-Altman analysis (CI: 95%), paired Student's t-test, and the intraclass correlation coefficient (ICC) was used to validate and compare the developed equations. Two new equations were developed for either gender: boys: %BF: 13.642 + (1.527*BMI) + (-0.345*Height) + (0.875*Triceps) + (0.290* Waist Circumference) and girls: %BF: -13.445 + (2.061*Tight). The Bland-Altman analysis showed good agreement, with limits ranging from -1.33 to 1.24% for boys and -3.35 to 4.08% for girls. The paired Student’s t-test showed no difference between %BF-DXA and the two new equations (p> 0.05), and the ICC was 0.948 and 0.915, respectively. DXA-based anthropometric equations provide an accurate and noninvasive method to measure changes in the %BF in children.

Accuracy of bioelectrical impedance analysis and skinfold thickness in the assessment of body composition in people with chronic spinal cord injury

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

This study: (1) investigated the accuracy of bioelectrical impedance analysis (BIA) and skinfold thickness relative to dual-energy X-ray absorptiometry (DXA) in the assessment of body composition in people with spinal cord injury (SCI), and whether sex and lesion characteristics affect the accuracy, (2) developed new prediction equations to estimate fat free mass (FFM) and percentage fat mass (FM%) in a general SCI population using BIA and skinfolds outcomes.

SETTING

University, the Netherlands.

METHODS

Fifty participants with SCI (19 females; median time since injury: 15 years) were tested by DXA, single-frequency BIA (SF-BIA), segmental multi-frequency BIA (segmental MF-BIA), and anthropometry (height, body mass, calf circumference, and skinfold thickness) during a visit. Personal and lesion characteristics were registered.

RESULTS

Compared to DXA, SF-BIA showed the smallest mean difference in estimating FM%, but with large limits of agreement (mean difference = -2.2%; limits of agreement: -12.8 to 8.3%). BIA and skinfold thickness tended to show a better estimation of FM% in females, participants with tetraplegia, or with motor incomplete injury. New equations for predicting FFM and FM% were developed with good explained variances (FFM: R² = 0.94; FM%: R² = 0.66).

CONCLUSIONS

None of the measurement techniques accurately estimated FM% because of the wide individual variation and, therefore, should be used with caution. The accuracy of the techniques differed in different subgroups. The newly developed equations for predicting FFM and FM% should be cross-validated in future studies.

Examining Race-Related Error in Two-Compartment Models of Body Composition Assessment: A Systematic Review and Meta-Analysis

BACKGROUND

The Brozek and Siri formulas estimate relative adiposity (%Fat) from total body density (Db) using a 2-compartment (2C) model. Racial/ethnic differences in Db have been reported, along with subsequent errors in estimated %Fat.

OBJECTIVE

The primary aim of this systematic review and meta-analysis was to examine potential race/ethnic differences in the accuracy of the Brozek and Siri 2C formulas using aggregate-level data.

METHODS

Peer-reviewed studies available in English that provided 2C and 4C estimates of %Fat were located using searches of the PubMed (n = 150), Scopus (n = 170), and Web of Science (n = 138) online electronic databases. Random-effects models were used to determine potential differences between racial groups using a mean ES and 95% confidence intervals.

RESULTS

The cumulative results from 78 effects indicate that the relative accuracy of the Brozek equation did not vary between racial groups (between group p = 0.053). In contrast, the Siri equation slightly underestimated %Fat for Asian adults (ESWMD = -1.40%, 95%CI -2.33% to -0.46%; p = 0.004) and Black adults (ESWMD = -1.10%, 95%CI -2.11% to -0.08%; p = 0.034), with no significant differences observed in Hispanic adults (ESWMD = 0.64%, 95%CI -1.02% to 2.31%; p = 0.448) and White adults (ESWMD = 0.08%, 95%CI -0.42% to 0.57%; p = 0.766) (between group p = 0.019).

CONCLUSION

Small, but statistically significant, error was found between racial groups when estimating %Fat using the 2C Siri equation when compared to 4C models. However, the observed error due to race/ethnicity appears to be of little clinical or practical significance when using either equation.

Anthropometric Prediction of DXA-Measured Percentage of Fat Mass in Athletes With Unilateral Lower Limb Amputation

To date there is no anthropometric equation specific to athletes with unilateral lower limb amputation to estimate the percentage of fat mass (%FM). This study investigated the accuracy of a set of anthropometric equations validated on able-bodied populations to predict the %FM assessed by-means of dual-energy x-ray absorptiometry (DXA) in athletes with unilateral lower limb amputation. Furthermore, a predictive anthropometric equation specific to athletes with unilateral lower limb amputation was developed from skinfold thickness measurements using DXA as the reference method for the estimation of the %FM. Twenty-nine white male athletes with unilateral lower limb amputation underwent a DXA scan and an anthropometric assessment on the same day. The %FM, calculated through several existing anthropometric equations validated upon able-bodied populations, was compared with the DXA-measured %FM (%FM_DXA). Accuracy and agreement between the two methods was computed with two-tailed paired-sample t-test, concordance correlation coefficient, reduced major axis regression and Bland-Altman analysis. A stepwise multiple regression analysis with the %FM_DXA as the dependent variable and age and nine skinfold thicknesses as potential predictors was carried out and validated using a repeated 10-fold cross-validation. A linear regression analysis with the sum of nine skinfolds as the independent variable was also carried out and validated using a repeated 10-fold cross-validation. The results showed that the anthropometric equations validated on able-bodied populations are inaccurate in the estimation of %FM_DXA with an average bias ranging from 0.51 to -13.70%. Proportional bias was also found revealing that most of the anthropometric equations considered, tended to underestimate/overestimate the %FM_DXA as body fat increased. Regression analysis produced two statistically significant models (P < 0.001 for both) which were able to predict more than 93% of total variance of %FM_DXA from the values of four skinfold measurements (i.e., thigh, abdominal, subscapular and axillary skinfold measurements) or from the sum of 9 skinfolds. Repeated cross-validation analysis highlighted a good predictive performance of the proposed equations. The predictive equations proposed in this study represent a useful tool for clinicians, nutritionists, and physical conditioners to evaluate the physical and nutritional status of athletes with unilateral lower limb amputation directly in the field.

Body Fat Assessment in International Elite Soccer Referees

Soccer referees are a specific group in the sports population that are receiving increasing attention from sports scientists. A lower fat mass percentage (FM%) is a useful parameter to monitor fitness status and aerobic performance, while being able to evaluate it with a simple and quick field-based method can allow a regular assessment. The aim of this study was to provide a specific profile for referees based on morphological and body composition features while comparing the accuracy of different skinfold-based equations in estimating FM% in a cohort of soccer referees. Forty-three elite international soccer referees (age 38.8 ± 3.6 years), who participated in the 2018 Russian World Cup, underwent body composition assessments with skinfold thickness and dual-energy X-ray absorptiometry (DXA). Six equations used to derive FM% from skinfold thickness were compared with DXA measurements. The percentage of body fat estimated using DXA was 18.2 ± 4.1%, whereas skinfold-based FM% assessed from the six formulas ranged between 11.0% ± 1.7% to 15.6% ± 2.4%. Among the six equations considered, the Faulkner's formula showed the highest correlation with FM% estimated by DXA (r = 0.77; R² = 0.59 p < 0.001). Additionally, a new skinfold-based equation was developed: FM% = 8.386 + (0.478 × iliac crest skinfold) + (0.395 × abdominal skinfold, r = 0.78; R² = 0.61; standard error of the estimate (SEE) = 2.62 %; p < 0.001). Due to these findings, national and international federations will now be able to perform regular body composition assessments using skinfold measurements.

Subcutaneous Adipose Tissue in Female Volleyball Players: Is It Related with Performance Indices?

Background and objectives: The aim of the present study was to examine subcutaneous adipose tissue distribution in female volleyball players with regards to (a) variation by anatomical site, (b) differences among age groups and playing positions, and (c) physiological characteristics associated with performance. Materials and Methods: Participants were adolescent (n = 89, age 15.6 ± 0.9 years, mean ± standard deviation) and adult female volleyball players (n = 78, 24.8 ± 5.3 years), who performed a series of anthropometric and performance tests including skinfold thickness in 10 sites, Abalakov jump (AJ) and handgrip test (HG). Results: Chin had the smallest thickness, and iliac crest and abdomen the largest. The largest correlations of skinfold thickness were shown with regards to AJ ad HG. Coefficient of variations in skinfold thickness correlated with performance indices with small magnitude. Triceps and chin were the most frequent predictors of performance indices. The anatomical site of skinfold was near the active muscle groups related to performance in HG. Conclusions: In conclusion, performance indices such AJ and HG were related with thickness of specific skinfolds and with the variation of thickness by anatomical site (i.e., the less the variation, the better the performance). Considering the relevance of specific skinfolds (e.g., triceps and chin) for performance, their further use would be recommended for purposes of training monitoring, volleyball players’ selection and talent identification.

Does caffeine ingestion before a short-term sprint interval training promote body fat loss?

We investigated the effect of caffeine ingestion combined with a 2-wk sprint interval training (SIT) on training-induced reductions in body adiposity. Twenty physically-active men ingested either 5 mg/kg of cellulose as a placebo (PLA, n=10) or 5 mg/kg of caffeine (CAF, n=10) 60 min before each SIT session (13×30 s sprint/15 s of rest). Body mass and skinfold thickness were measured pre- and post-training. Energy expenditure was measured at rest, during exercise, and 45 min after exercise in the first SIT session. Body fat was similar between PLA and CAF groups at pre-training (P>0.05). However, there was a significant decrease in body fat after training in the CAF group (−5.9±4.2%, P<0.05) but not in PLA (1.5±8.0%, P>0.05). There was no difference in energy expenditure at rest and during exercise between PLA and CAF groups (P>0.05), but the post-exercise energy expenditure was 18.3±21.4% greater in the CAF than in the PLA group (P<0.05). In conclusion, caffeine ingestion before SIT sessions induced a body fat loss that may be associated with higher post-exercise energy expenditure.

Ageing influences the relationship of circulating miR-33a and miR- 33b levels with insulin resistance and adiposity

OBJECTIVE

The identification of circulating microRNAs related to abnormal metabolic function may be useful in the context of ageing, adiposity and insulin resistance. The miR-33 a/b has been shown to control the expression of genes involved in fatty acid biosynthesis, impaired metabolism and insulin resistance. In this study, we aimed to identify differences in circulating miR-33 a/b levels according to age-related metabolic impairment and increased adiposity.

METHODS

This study included 80 individuals (30.2% with obesity, 70% females) classified according to insulin resistance (Stern's criteria) and age [young (20-39 years) and senior (40-59 years)]. Body fat was evaluated using bioelectrical impedance, biochemical markers by colorimetric, enzymatic and immuno-turbidimetry methods. TaqMan measures of circulating miR-33 a and miR-33 b with quantitative reverse transcription polymerase chain reaction in serum were assessed in association with clinical outputs.

RESULTS

Circulating miR-33 a and miR-33 b levels showed significant association with fatness, the lipid profile and biomarkers of impaired glucose metabolism. Both miR-33 a and miR-33 b were associated with visceral adiposity index in non-insulin resistance and insulin resistance individuals. More important, for miR-33 a circulating levels in senior group, receiver operating characteristic curve analyses showed area under the curve 0.804 ( p = 0.010; 95% confidence interval = 0.655-0.952).

CONCLUSION

Ageing influenced the relationship of circulating miR-33 a and miR-33 b with insulin resistance and increased adiposity.

Comparison of Transcranial Motor Evoked Potential Amplitude Responses Between Intramuscular and Subcutaneous Needles in Proximal Thigh Muscle

PURPOSE

Successful intraoperative neurophysiological monitoring is predicated on the presence of adequate baseline-evoked potentials. We have observed that transcranial motor evoked potentials (TcMEPs) yield more robust responses in the distal muscles compared with proximal muscles. One possible explanation is the distance from the needle to the muscle generator. In this study, we investigate whether TcMEP amplitudes from the rectus femoris muscle are affected by changes in needle length.

METHODS

We analyzed rectus femoris TcMEP responses in surgical patients undergoing lumbar spinal surgery. Needles of two different sizes were placed simultaneously. A shorter 13-mm subcutaneous needle was inserted into the rectus femoris muscle subcutaneous group in addition to a longer 25-mm intramuscular needle (intramuscular group). Each limb was used as an independent control. Transcranial motor evoked potential amplitude responses were obtained using both needles, and statistical analysis was calculated using the Wilcoxon signed-rank test for paired data. Secondary analysis was performed to correlate between TcMEP amplitude and skinfold thickness.

RESULTS

Twenty-eight TcMEP responses from the rectus femoris (14 patients) were analyzed. We observed that TcMEP amplitude responses were higher in the intramuscular needle group compared with the subcutaneous group (N = 28, P < 0.0001). There was a mean difference of 604 μV between the intramuscular versus subcutaneous group (median 184 μV). There was also a significant correlation between TcMEP amplitude and skinfold thickness.

CONCLUSIONS

Higher TcMEP amplitude responses are seen with longer needles compared with shorter needles placed in the same rectus femoris muscle. Transcranial motor evoked potential baselines may be optimized using longer needles. Skinfold thickness can be a good marker to determine appropriate needle size.

Accuracy of Anthropometric Equations for Estimating Body Fat in Professional Male Soccer Players Compared with DXA

Background

There are several published anthropometric equations to estimate body fat percentage (BF%), and this may prompt uncertainty about their application.

Purpose

To analyze the accuracy of several anthropometric equations (developed in athletic [AT] and nonathletic [NAT] populations) that estimate BF% comparing them with DXA.

Methods

We evaluated 131 professional male soccer players (body mass: 73.2 ± 8.0 kg; height: 177.5 ± 5.8 cm; DXA BF% [median, 25th–75th percentile]: 14.0, 11.9–16.4%) aged 18 to 37 years. All subjects were evaluated with anthropometric measurements and a whole body DXA scan. BF% was estimated through 14 AT and 17 NAT anthropometric equations and compared with the measured DXA BF%. Mean differences and 95% limits of agreement were calculated for those anthropometric equations without significant differences with DXA.

Results

Five AT and seven NAT anthropometric equations did not differ significantly with DXA. From these, Oliver's and Civar's (AT) and Ball's and Wilmore's (NAT) equations showed the highest agreement with DXA. Their 95% limits of agreement ranged from −3.9 to 2.3%, −4.8 to 1.8%, −3.4 to 3.1%, and −3.9 to 3.0%, respectively.

Conclusion

Oliver's, Ball's, Civar's, and Wilmore's equations were the best to estimate BF% accurately compared with DXA in professional male soccer players.

Body Fat Measurements in Singaporean Adults Using Four Methods

Few studies have been conducted to measure body composition in Asian populations. In this study, we determined the percent body fat (PBF) by using dual-energy X-ray absorptiometry (DEXA), air-displacement plethysmography (ADP or BOD POD), bioelectrical impedance analysis (BIA) and skinfold (SKF) in 445 healthy Singaporean adults. We observed that the BOD POD, BIA and SKF estimates of PBF were highly correlated with that from DEXA (as a reference method) among Singaporean adults. However, they all underestimated PBF (differences of 3.9% for BOD POD, 5.6% for BIA and 12.5% for SKF). Our results filled a gap in the literature by testing the relationships between DEXA and BOD POD, BIA and SKF in a large sample with a wide range of body mass index (BMI) from 16.1 to 37.5 kg/m² and age from 21 to 69.2 years. The differences of PBF measured by different methods were dependent on age, gender and ethnicity. No significant difference was observed between DEXA and BOD POD in men aged > 40 or in BMI tertile 3. However, the mean difference between DEXA and BOD POD was significant in women. Different measuring methods of estimating PBF therefore must be cautiously interpreted.

Protein Supplementation Does Not Further Increase Latissimus Dorsi Muscle Fiber Hypertrophy after Eight Weeks of Resistance Training in Novice Subjects, but Partially Counteracts the Fast-to-Slow Muscle Fiber Transition

The response to resistance training and protein supplementation in the latissimus dorsi muscle (LDM) has never been investigated. We investigated the effects of resistance training (RT) and protein supplementation on muscle mass, strength, and fiber characteristics of the LDM. Eighteen healthy young subjects were randomly assigned to a progressive eight-week RT program with a normal protein diet (NP) or high protein diet (HP) (NP 0.85 vs. HP 1.8 g of protein·kg⁻¹·day⁻¹). One repetition maximum tests, magnetic resonance imaging for cross-sectional muscle area (CSA), body composition, and single muscle fibers mechanical and phenotype characteristics were measured. RT induced a significant gain in strength (+17%, p < 0.0001), whole muscle CSA (p = 0.024), and single muscle fibers CSA (p < 0.05) of LDM in all subjects. Fiber isometric force increased in proportion to CSA (+22%, p < 0.005) and thus no change in specific tension occurred. A significant transition from 2X to 2A myosin expression was induced by training. The protein supplementation showed no significant effects on all measured outcomes except for a smaller reduction of 2X myosin expression. Our results suggest that in LDM protein supplementation does not further enhance RT-induced muscle fiber hypertrophy nor influence mechanic muscle fiber characteristics but partially counteracts the fast-to-slow fiber shift.

Dual-Energy X-Ray Absorptiometry, Skinfold Thickness, and Waist Circumference for Assessing Body Composition in Ambulant and Non-Ambulant Wheelchair Games Players

Field-based assessments provide a cost-effective and accessible alternative to dual-energy X-ray absorptiometry (DXA) for practitioners determining body composition in athletic populations. It remains unclear how the range of physical impairments classifiable in wheelchair sports may affect the utility of field-based body composition techniques. The present study assessed body composition using DXA in 14 wheelchair games players who were either wheelchair dependent (non-walkers; n = 7) or relied on a wheelchair for sports participation only (walkers; n = 7). Anthropometric measurements were used to predict body fat percentage with existing regression equations established for able-bodied persons by Sloan and Weir, Durnin and Womersley, Lean et al, Gallagher et al, and Pongchaiyakul et al. In addition, linear regression analysis was performed to calculate the association between body fat percentage and BMI, waist circumference, sum of 6 skinfold thickness and sum of 8 skinfold thickness. Results showed that non-walkers had significantly lower total lean tissue mass (46.2 ± 6.6 kg vs. 59.4 ± 8.2 kg, P = 0.006) and total body mass (65.8 ± 4.2 kg vs. 79.4 ± 14.9 kg; P = 0.05) than walkers. Body fat percentage calculated from most existing regression equations was significantly lower than that from DXA, by 2 to 9% in walkers and 8 to 14% in non-walkers. Of the anthropometric measurements, the sum of 8 skinfold thickness had the lowest standard error of estimation in predicting body fat content. In conclusion, existing anthropometric equations developed in able-bodied populations substantially underestimated body fat content in wheelchair athletes, particularly non-walkers. Impairment specific equations may be needed in wheelchair athletes.

Commingling effect of gynoid and android fat patterns on cardiometabolic dysregulation in normal weight American adults

AIM

To determine the independent and commingling effect of android and gynoid percent fat (measured using Dual Energy X-Ray Absorptiometry) on cardiometabolic dysregulation in normal weight American adults.

METHODS

The 2005-2006 data (n=1802) from the United States National Health and Nutritional Examination Surveys (NHANES) were used in this study. Associations of android percent fat, gynoid percent fat and their joint occurrence with risks of cardiometabolic risk factors were estimated using prevalence odds ratios from logistic regression analyses.

RESULTS

Android-gynoid percent fat ratio was more highly correlated with cardiometabolic dysregulation than android percent fat, gynoid percent fat or body mass index. Commingling of android and gynoid adiposities was associated with much greater odds of cardiometabolic risk factors than either android or gynoid adiposities. Commingling of android and gynoid adiposities was associated with 1.75 (95% confidence interval (CI)=1.42-2.93), 1.48 (95% CI=1.32-1.91), 1.61 (95% CI=1.50-1.89), 3.56 (95% CI=2.91-4.11) and 1.86 (95% CI=1.49-1.96) increased odds of elevated glucose, elevated blood pressure, elevated low-density lipoprotein-cholesterol, elevated triglyceride and low high-density lipoprotein-cholesterol, respectively.

CONCLUSIONS

Normal weight subjects who present with both android and gynoid adiposities should be advised of the associated health risks. Both android and gynoid fat accumulations should be considered in developing public health strategies for reducing cardiometabolic disease risk in normal weight subjects.

Novel equations to predict body fat percentage of Brazilian professional soccer players: A case study

This study analyzed classical and developed novel mathematical models to predict body fat percentage (%BF) in professional soccer players from the South Brazilian region using skinfold thicknesses measurement. Skinfolds of thirty one male professional soccer players (age of 21.48 ± 3.38 years, body mass of 79.05 ± 9.48 kg and height of 181.97 ± 8.11 cm) were introduced into eight mathematical models from the literature for the prediction of %BF; these results were then compared to Dual-energy X-ray Absorptiometry (DXA). The classical equations were able to account from 65% to 79% of the variation of %BF in DXA. Statistical differences between most of the classical equations (seven of the eight classic equations) and DXA were found, rendering their widespread use in this population useless. We developed three new equations for prediction of %BF with skinfolds from: axils, abdomen, thighs and calves. Theses equations accounted for 86.5% of the variation in %BF obtained with DXA.

Percent body fat prediction equations for 8- to 17-year-old American children

BACKGROUND

Percent body fat equations are usually developed in specific populations and have low generalizability.

OBJECTIVES

To use a nationally representative sample of the American youth population (8-17 years old) from the 1999-2004 National Health and Nutrition Examination Survey data to develop gender-specific percent body fat equations.

METHODS

Percent body fat equations were developed for girls and boys using information on weight, height, waist circumference, triceps skin-folds, age, race/ethnicity and menses status compared to dual-emission X-ray absorptiometry. Terms were selected using forward and backward selection in regression models in a 2/3 development sample and were cross-validated in the remaining sample. Final coefficients were estimated in the full sample.

RESULTS

Final equations included ten terms in girls and eight terms in boys including interactions with age and race/ethnicity. In the cross-validation sample, the adjusted R2 was 0.818 and the root mean squared error was 2.758 in girls. Comparable estimates in boys were 0.893 and 2.525. Systematic bias was not detected in the estimates by race/ethnicity or by body mass index categories.

CONCLUSION

Gender-specific percent body fat equations were developed in youth with a strong potential for generalizability and utilization by other investigators studying adiposity-related issues in youth.

Head fat is a novel method of measuring metabolic disorder in Chinese obese patients

BACKGROUND

Body adiposity, especially ectopic fat accumulation, has a range of metabolic and cardiovascular effects. The aim of this study was to investigate the association between head fat and metabolic values in Chinese obese patients.

METHODS

Data of this cross-sectional study from 66 obese patients were collected. Fat distribution was measured by dual-energy X-ray absorptiometry, and data of body weight, body mass index (BMI), neck circumference (NC), waist circumference (WC), hip circumference (HC), visceral index, basal metabolism (BM), glucose metabolism, lipid levels, uric acid (UA) had been collected.

RESULTS

1) Head fat was significantly associated with BMI, WC, HC, visceral index, BM, total fat and total fat excluding head fat in both males and females (p<0.05). Head fat was positively correlated with upper limb fat, trunk fat, weight, fasting plasma C peptide, fasting plasma insulin and UA in women(p<0.05), and the association was not statistically significant in male (p>0.05). Head fat was positively corrected with NC in males (p<0.05) but not females (p>0.05). There was no significant correlation between head fat and fasting plasma glucose, total choleslerolemia, triglyceridemia, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and free fat acid in either gender (p>0.05). 2) Receiver operating characteristic analysis showed that a head fat of 1925.6 g and a head fat of 1567.85 g were the best cut-off values to determine subjects with low high-density lipoprotein cholesterol and hyperuricemia respectively.

CONCLUSIONS

Head fat accumulation was closely associated with increased body fat, hyperinsulinemia, hyperuricemia, and impared lipid profile, suggesting it might be used as an indicator for dyslipidemia and hyperuricemia.

Increase in subcutaneous adipose tissue and fat free mass in women with polycystic ovary syndrome is related to impaired insulin sensitivity

OBJECTIVES

The present study was performed to search whether subcutaneous and whole body adipose tissue increase and they relate to measures of insulin sensitivity in women with polycystic ovary syndrome (PCOS).

MATERIALS AND METHODS

52 women with PCOS and 53 healthy controls, all with similar age and body mass index participated in the study. A skinfold caliper device was used to measure biceps, triceps, subscapular and suprailiac skinfold thickness (SFT). Mid-upper arm circumference (MUAC) was measured using a tape measure. Body fat distributions were determined by bioelectrical impedance analysis. Insulin resistance score was computed with the HOMA formula. Plasma adiponectin was measured by EIA.

RESULTS

SFT in all defined areas, MUAC, total body and trunk fat free mass, and HOMA score were higher in women with PCOS compared with healthy women, while adiponectin level was significantly lower. SFT values correlated positively with HOMA score, and negatively with blood adiponectin level. Regression analysis indicated, SFT in triceps and supscapular areas, trunk fat mass, trunk fat ratio, fat free mass and trunk fat free mass values as the most powerful predictors of HOMA score.

CONCLUSIONS

The present study showed that SFT in different body regions and fat-free tissue mass are increased in women with PCOS, with a significant relation to impaired insulin sensitivity.

Comparison between dual-energy X-ray absorptiometry and skinfolds thickness in assessing body fat in anorexia nervosa before and after weight restoration

BACKGROUND & AIMS

The aim of the study was to evaluate the correspondence between body fat mass composition (percentage) measured with dual-energy X-ray absorptiometry (DXA) and estimated by means of skinfold thicknesses (ST) measurement in patients with anorexia nervosa (AN), before and after weight gain.

METHODS

Percentage body fat (%BF) was measured with DXA and estimated by ST measurements using Siri, Brozek, and Heyward equations in 27 adult patients with AN before and after weight gain (pre- and post-treatment) achieved with inpatient treatment and in 42 healthy age-matched controls.

RESULTS

Due to Lohman criteria and Bland Altman plot there is no correspondence between the %BF measured with DXA and the %BF estimated by predictive equations based on ST measurements in patients with AN before and after weight gain, with the exception of Brozek equation which showed a mild agreement in pre-treatment AN. However, a correspondence was observed between the two procedures in healthy controls.

CONCLUSIONS

Our data supporting the use of ST measurements do not appear to be an alternative to DXA in estimating body fat percentage, before and after weight gain in patients with AN.

Ketogenic diet does not affect strength performance in elite artistic gymnasts

BACKGROUND

Despite the increasing use of very low carbohydrate ketogenic diets (VLCKD) in weight control and management of the metabolic syndrome there is a paucity of research about effects of VLCKD on sport performance. Ketogenic diets may be useful in sports that include weight class divisions and the aim of our study was to investigate the influence of VLCKD on explosive strength performance.

METHODS

8 athletes, elite artistic gymnasts (age 20.9 ± 5.5 yrs) were recruited. We analyzed body composition and various performance aspects (hanging straight leg raise, ground push up, parallel bar dips, pull up, squat jump, countermovement jump, 30 sec continuous jumps) before and after 30 days of a modified ketogenic diet. The diet was based on green vegetables, olive oil, fish and meat plus dishes composed of high quality protein and virtually zero carbohydrates, but which mimicked their taste, with the addition of some herbal extracts. During the VLCKD the athletes performed the normal training program. After three months the same protocol, tests were performed before and after 30 days of the athletes' usual diet (a typically western diet, WD). A one-way Anova for repeated measurements was used.

RESULTS

No significant differences were detected between VLCKD and WD in all strength tests. Significant differences were found in body weight and body composition: after VLCKD there was a decrease in body weight (from 69.6 ± 7.3 Kg to 68.0 ± 7.5 Kg) and fat mass (from 5.3 ± 1.3 Kg to 3.4 ± 0.8 Kg p < 0.001) with a non-significant increase in muscle mass.

CONCLUSIONS

Despite concerns of coaches and doctors about the possible detrimental effects of low carbohydrate diets on athletic performance and the well known importance of carbohydrates there are no data about VLCKD and strength performance. The undeniable and sudden effect of VLCKD on fat loss may be useful for those athletes who compete in sports based on weight class. We have demonstrated that using VLCKD for a relatively short time period (i.e. 30 days) can decrease body weight and body fat without negative effects on strength performance in high level athletes.

Running speed during training and percent body fat predict race time in recreational male marathoners

BACKGROUND

Recent studies have shown that personal best marathon time is a strong predictor of race time in male ultramarathoners. We aimed to determine variables predictive of marathon race time in recreational male marathoners by using the same characteristics of anthropometry and training as used for ultramarathoners.

METHODS

Anthropometric and training characteristics of 126 recreational male marathoners were bivariately and multivariately related to marathon race times.

RESULTS

After multivariate regression, running speed of the training units (β = -0.52, P < 0.0001) and percent body fat (β = 0.27, P < 0.0001) were the two variables most strongly correlated with marathon race times. Marathon race time for recreational male runners may be estimated to some extent by using the following equation (r (2) = 0.44): race time ( minutes) = 326.3 + 2.394 × (percent body fat, %) - 12.06 × (speed in training, km/hours). Running speed during training sessions correlated with prerace percent body fat (r = 0.33, P = 0.0002). The model including anthropometric and training variables explained 44% of the variance of marathon race times, whereas running speed during training sessions alone explained 40%. Thus, training speed was more predictive of marathon performance times than anthropometric characteristics.

CONCLUSION

The present results suggest that low body fat and running speed during training close to race pace (about 11 km/hour) are two key factors for a fast marathon race time in recreational male marathoner runners.

Generalised equations for the prediction of percentage body fat by anthropometry in adult men and women aged 18-81 years

Anthropometric data indicate that the human phenotype is changing. Today's adult is greater in stature, body mass and fat mass. Accurate measurement of body composition is necessary to maintain surveillance of obesity within the population and to evaluate associated interventions. The aim of the present study was to construct and validate generalised equations for percentage body fat (%BF) prediction from anthropometry in 1136 adult men and women. Reference values for %BF were obtained using dual-energy X-ray absorptiometry. Skinfold thickness (SF) at ten sites and girth (G) at seven sites were measured on 736 men and women aged 18-81 years (%BF 5·1-56·8%). Quantile regression was employed to construct prediction equations from age and log-transformed SF and G measures. These equations were then cross-validated on a cohort of 400 subjects of similar age and fatness. The following generalised equations were found to most accurately predict %BF: Men: (age x 0·1) + (logtricepsSF x 7·6) + (logmidaxillaSF x 8·8) + (logsuprspinaleSF x 11·9) - 11·3 (standard error of the estimate: 2·5%, 95% limits of agreement: - 4·8, + 4·9) Women: (age x 0·1) + (logabdominalG x 39·4) + (logmidaxillaSF x 4·9) + (logbicepsSF x 11·0) + (logmedialcalfSF x 9·1) - 73·5 (standard error of the estimate: 3·0%, 95% limits of agreement: - 5·7, + 5·9) These generalised anthropometric equations accurately predict %BF and are suitable for the measurement of %BF in adult men and women of varying levels of fatness across the lifespan.

A negative relationship between leg length and leg cross-sectional areas in adults

OBJECTIVES

These were to examine the relationship between leg cross-sectional areas (CSAs) and leg length while making allowance for other factors, such as fatness and the load on the legs.

METHODS

Body mass, stature, and sitting height were directly measured and volumes and leg CSAs were obtained by 3D scanning for 155 men and 162 women. Leg CSAs were regressed simultaneously on upper body mass and leg length.

RESULTS

With allowance made for positive correlations with upper body mass, leg CSAs showed a negative correlation with leg length (P = 0.00006-0.027).

CONCLUSION

There is a negative correlation between leg lengths and CSAs that is largely obscured by other influences.

Predictive equations for body fat and abdominal fat with DXA and MRI as reference in Asian Indians

OBJECTIVE

To develop accurate and reliable equations from simple anthropometric parameters that would predict percentage of total body fat (%BF), total abdominal fat (TAF), subcutaneous abdominal adipose tissue (SCAT), and intra-abdominal adipose tissue (IAAT) with a fair degree of accuracy.

METHODS AND PROCEDURES

Anthropometry, %BF by dual-energy X-ray absorptiometry (DXA) in 171 healthy subjects (95 men and 76 women) and TAF, IAAT, and SCAT by single slice magnetic resonance imaging (MRI) at L3-4 intervertebral level in 100 healthy subjects were measured. Mean age and BMI were 32.2 years and 22.9 kg/m(2), respectively. Multiple regression analysis was used on the training data set (70%) to develop equations, by taking anthropometric and demographic variables as potential predictors. Predicted equations were applied on validation data set (30%).

RESULTS

Multiple regression analysis revealed the best equation for predicting %BF to be: %BF = 42.42 + 0.003 x age (years) + 7.04 x gender (M = 1, F = 2) + 0.42 x triceps skinfold (mm) + 0.29 x waist circumference (cm) + 0.22 [corrected] x weight (kg) - 0.42 x height (cm) (R (2) = 86.4%). The most precise predictive equation for estimating IAAT was: IAAT (mm(2)) = -238.7 + 16.9 x age (years) + 934.18 x gender (M = 1, F = 2) + 578.09 x BMI (kg/m(2)) - 441.06 x hip circumference (cm) + 434.2 x waist circumference (cm) (R (2) = 52.1%). SCAT was best predicted by: SCAT (mm(2)) = -49,376.4 - 17.15 x age (years) + 1,016.5 x gender (M = 1, F = 2) +783.3 x BMI (kg/m(2)) + 466 x hip circumference (cm) (R (2) = 67.1).

DISCUSSION

We present predictive equations to quantify body fat and abdominal adipose tissue sub-compartments in healthy Asian Indians. These equations could be used for clinical and research purposes.

Relationship between thigh skinfold measurement, hand grip strength, and trunk muscle endurance: differences between the sexes

This study was conducted to examine the relationship between thigh skinfold measurement, hand grip strength, and trunk muscle endurance and compare this relationship in men and women. The current study included 200 healthy subjects (111 women and 89 men), with a mean age of 31.58+/-13.78 y. Trunk muscle endurance was evaluated with the use of curl-up, horizontal side bridge, and static back endurance tests. Significant differences were found between women and men in performance of the curl-up and horizontal side bridge tests (P<.05); however, no significant difference was found between the sexes in the static back endurance test scores (P>or=.05). The investigators discerned a significant negative correlation between thigh skinfold measurements and all trunk muscle endurance tests in female patients (curl-up, r=-.501; horizontal side bridge, r=-.454; static back, r=-.479; P<.05). A rather weak correlation was found in male patients (curl-up, r=-.348; horizontal side bridge, r=-.182; static back, r=-.330; P<.05). On the other hand, no significant correlation was found between hand grip strength and trunk muscle endurance test scores in female patients (P>or=.05), although a significant positive correlation was found in male patients in curl-up and side bridge test results (curl-up, r=.319; horizontal side bridge, r=.307; static back, r=.123; P<.05). The results of this study suggest that women have lower endurance test scores compared with men. The investigators detected the presence of a significant negative correlation between thigh skinfold measurement and trunk muscle endurance tests in both men and women and concluded that there is a positive significant relationship between hand grip strength, curl-up, and horizontal side bridge tests. Additional studies are needed to evaluate the relationship between muscle endurance and physical characteristics as they relate to the sex of the individual.

Suprailiac or Abdominal Skinfold Thickness Measured with a Skinfold Caliper as a Predictor of Body Density in Japanese Adults

Measurement of subcutaneous fat thickness with a skinfold caliper is a simple and inexpensive technique for assessment of body composition, but is influenced by the skin site or the obesity level. The resulting measurement errors may influence the prediction accuracy of body density. We therefore aimed to clarify the characteristics of measurement errors with a skinfold caliper and to determine useful measurement sites for the prediction of body density in Japanese adults of wide-ranging age and obesity levels. The present study included 126 Japanese male and 77 female subjects ranging from 21 to 81 years old. They were divided into a "non-obese group" and an "obese group", based on the Japanese criteria of obesity (BMI > or = 25 kg/m(2)). Subcutaneous fat thickness was measured at 14 sites with a skinfold caliper and ultrasound. Percent body fat was measured by dual-energy x-ray absorptiometry, and body density was calculated using Brozek's formula. Sex and obesity level differences in the measurement error of skinfolds (ultrasound minus skinfold caliper measurements) were examined by 2 x 2 ANOVA (sex and obesity groups) for each site. The relationship between body density and the systematic error was examined. We developed an accurate prediction equation for body density with smaller measurement and systematic errors. Although measurement errors in skinfold thickness tended to increase with increasing obesity levels, the influence was smaller for the abdominal and suprailiac skinfolds compared with other sites. Measurement of suprailiac or abdominal skinfold thickness is useful to accurately estimate body density in Japanese adults.

Pharmacological approaches to ameliorating catabolic conditions

PURPOSE OF REVIEW

Nutritional debilitation is among the most devastating and life-threatening aspect of various diseases. It arises from a complex interaction between the illness and the host. This process includes cytokine production, release of lipid-mobilizing and proteolysis-inducing factors, and alterations in intermediary metabolism. As a result, many patients develop cachexia with progressive body fat and muscle tissue wasting with associated worsening of their clinical status and a lower quality of life. In this review, up-to-date information about different approaches to pharmacologic management of cachexia will be addressed.

RECENT FINDINGS

Until recently, the two major options for pharmacological therapy were either progestational agents or corticosteroids. Knowledge of the mechanisms of cachexia, however, has led to newer therapeutic interventions for treating several aspects of the syndrome. These include antiserotonergic agents, branched-chain amino acids, eicosapentaenoic acid, cannabinoids, melatonin, and thalidomide--all of which act on the feeding-regulatory circuitry to increase appetite and inhibit illness-derived catabolic factors.

SUMMARY

Information from this review will guide health care providers in limiting weight loss and improving performance status of cachectic patients through pharmacological therapy, with the hope that such therapy will extend patients' survival and improve their qualities of life.

Changes in performance, skinfold thicknesses, and fat patterning after three years of intense athletic conditioning in high level runners

OBJECTIVES

To determine if the changes in specific skinfold sites induced by intense athletic conditioning over a three year period were associated with changes in running performance in high level athletes.

METHODS

Thirty seven top class runners (eight male and five female sprint trained, 16 male and eight female endurance trained) volunteered to participate in the study. The athletes were divided into class A (n = 18) and class B (n = 17), with class A having the best performance. Biceps, triceps, subscapular, pectoral, iliac crest, abdominal, front thigh, and medial calf skinfold thickness and the best running performance were recorded at the beginning and after one, two, and three years of training. A one way analysis of variance and a linear regression analysis were conducted to determine changes and association between performance and skinfold thicknesses. Analyses were controlled for sex, sprint event or endurance event, and class.

RESULTS

Training resulted in a significant increase in performance and decreases in sum of six skinfolds, abdominal, front thigh, and medial calf skinfolds, and the ratio of extremity to trunk skinfolds (E/T, Sigmatriceps, front thigh, medial calf/Sigmasubscapular, iliac crest, abdominal). There were no significant differences in body weight. Except for the abdominal skinfold, there was no significant difference in trunk skinfolds. Significant differences in these changes were observed by sex for E/T, which decreased and increased in male and female runners respectively, and by class. Class B runners significantly improved performance, with decreased skinfold thicknesses in the lower limb. There were no significant changes in performance or skinfold thicknesses in class A runners. Improvements in performance were consistently associated with a decrease in the lower limb skinfolds.

CONCLUSIONS

On the basis of these findings, anthropometric assessment of top class athletes should include an evaluation of all skinfolds. The loss of body fat appears to be specific to the muscular groups used during training. The lower limb skinfolds may be particularly useful predictors of running performance.