Validity of Skinfold Equations, Against Dual-Energy X-Ray Absorptiometry, in Predicting Body Composition in Adolescent Pentathletes

2017 ◽  
Vol 29 (2) ◽  
pp. 285-293
Author(s):  
Sidnei Jorge Fonseca-Junior ◽  
Aldair J. Oliveira ◽  
Luiz Lannes Loureiro ◽  
Anna Paola Trindade Pierucci
Keyword(s):  
Body Composition ◽  
Reference Method ◽  
Dual Energy ◽  
High Variability ◽  
The Body ◽  
Anthropometric Parameters ◽  
Predictive Equations ◽  
X Ray ◽  
Reference Equations ◽  
Mean Differences

Purpose:Body composition of adolescent athletes is often evaluated scientifically and in sports by using reference equations developed from nonathlete adolescent populations. The aim of this study was to analyze the validity of predictive equations based on skinfold measurements, as compared with dual-energy X-ray absorptiometry (DXA), to estimate body fat in adolescent modern pentathlon athletes.Methods:51 athletes, 27 male (mean age = 15.1 years; standard deviation, SD = 1.5 years) and 24 female (mean age = 14.2 years; SD = 2.5 years), were assessed using DXA, anthropometric parameters, sports practice anamnesis, and pubertal stages. Agreement between methods was tested with boxplots of mean comparisons using Student’s t test (p < .05), and Bland-Altman plots.Results:The body density equations of Durnin & Rahaman (1967) and Durnin & Womersley (1974) showed better agreement with DXA than the other predictive equations, for both females (difference between means=-2.03; 2SD = 8.44) and males (difference between means = 0.98; 2SD = 7.30). There were no mean differences between these equations and the reference method (DXA; p > .05), but they did display high variability (2SD).Conclusion:The high variability among results indicated imprecision. Predictive skinfold equations developed for nonathlete adolescents do not offer good validity for modern adolescent pentathlon athletes, and should be avoided.

In vivo assessment of body composition and growth potential of modern broiler using dual-energy X-ray absorptiometry

2020 ◽  
Vol 60 (16) ◽  
pp. 1959
Author(s):  
Camila Angelica Gonçalves ◽  
Nilva Kazue Sakomura ◽  
Miryelle Freire Sarcinelli ◽  
Letícia Graziele Pacheco ◽  
Letícia Soares ◽  
...  
Keyword(s):  
Body Composition ◽  
Growth Rates ◽  
Dual Energy ◽  
The Body ◽  
Growth Potential ◽  
Chemical Components ◽  
Potential Growth ◽  
X Ray ◽  
Growing Period

Context Genetic improvements in modern strains have led to continuous increments in broiler growth rates, which, as a consequence, have resulted in higher economic returns for broiler producers over the last decades. Aim The present study was conducted to characterise the potential growth of the body and feathers of Cobb 500, Hubbard Flex and Ross 308 male and female broilers, as well as to assess the changes in chemical composition that occur up to 16 weeks of age. Methods Birds were fed isoenergetic diets divided in four phases and formulated to marginally exceed the nutritional requirements of the strains throughout the growing period. They were maintained in a controlled environment so as not to limit growth. A dual energy X-ray absorptiometry (DXA) scanner was used to follow the in vivo body composition of 12 broilers of each strain and sex (total of 72 broilers), and the feather weight and composition was determined in four birds of each strain and sex selected at intervals during the growing period (total of 288 broilers) through comparative slaughter with later chemical analysis. Key results Parameters of Gompertz growth curve to describe the strains were estimated for body and feather weight as well as for the growth of their chemical components. Conclusion Differences in the growth rates between strains were evident, indicating the possible differences in selection methods used by geneticists in the different breeding companies. These genetic parameters would explain part of the variation on broiler´s performance which impacts on the way they should be fed and housed during growth. Implications The accurate description of genetic growth potential is useful information to be associated with factorial models that predict nutritional and feed intake requirements of birds. The main advantage of DXA technology is to decrease the variation of body deposition on the Gompertz model, resulting from the use of the same bird throughout its life. Despite the speed of obtaining chemical values of the body, the method is unsuitable for measuring the growth of feathers, which is also important data to be collected and related to the broiler strains.

scholarly journals Body composition in older community-dwelling adults with hip fracture: portable field methods validated by dual-energy X-ray absorptiometry

2012 ◽  
Vol 109 (7) ◽  
pp. 1219-1229 ◽  
Author(s):  
Anthony M. Villani ◽  
Michelle Miller ◽  
Ian D. Cameron ◽  
Susan Kurrle ◽  
Craig Whitehead ◽  
...  
Keyword(s):  
Body Composition ◽  
Hip Fracture ◽  
Dual Energy ◽  
Community Dwelling ◽  
Fat Free Mass ◽  
Muscle Area ◽  
Field Methods ◽  
Predictive Equations ◽  
X Ray ◽  
Post Surgery

Ageing is associated with weight loss and subsequently poor health outcomes. The present study assessed agreement between two field methods, bioelectrical impedance spectroscopy (BIS) and corrected arm muscle area (CAMA) for assessment of body composition against dual-energy X-ray absorptiometry (DXA), the reference technique. Agreement between two predictive equations estimating skeletal muscle mass (SMM) from BIS against SMM from DXA was also determined. Assessments occurred at baseline < 14 d post-surgery (n 79), and at 6 months (6M; n 75) and 12 months (12M; n 63) in community-living older adults after surgical treatment for hip fracture. The 95 % limits of agreement (LOA) between BIS and DXA, CAMA and DXA and the equations and DXA were assessed using Bland–Altman analyses. Mean bias and LOA for fat-free mass (FFM) between BIS and DXA were: baseline, 0·7 ( − 10·9, 12·4) kg; 6M, − 0·5 ( − 20·7, 19·8) kg; 12M, 0·1 ( − 8·7, 8·9) kg and for SMM between CAMA and DXA were: baseline, 0·3 ( − 11·7, 12·3) kg; 6M, 1·3 ( − 4·5, 7·1) kg; 12M, 0·9 ( − 5·4, 7·2) kg. Equivalent data for predictive equations against DXA were: equation 1: baseline, 15·1 ( − 9·5, 20·6) kg; 6M, 17·1 ( − 12·0, 22·2) kg; 12M, 17·5 ( − 13·0, 22·0) kg; equation 2: baseline, 12·6 ( − 7·3, 19·9) kg; 6M, 14·4 ( − 9·7, 19·1) kg; 12M, 14·8 ( − 10·7, 18·9) kg. Proportional bias (BIS: β = − 0·337, P< 0·001; CAMA: β = − 0·294, P< 0·001) was present at baseline but not at 6M or 12M. Clinicians should be cautious in using these field methods to predict FFM and SMM, particularly in the acute care setting. New predictive equations would be beneficial.

scholarly journals Verification of precision, accuracy, and characteristics of dual-energy X-ray absorptiometry and nuclear magnetic resonance in the analysis of mouse body composition

2020 ◽  
Author(s):  
Kyung-Wan Baek ◽  
Ji-Seok Kim ◽  
Jin Sung Park ◽  
So-Jeong Kim ◽  
Yong-Chan Ha ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Body Composition ◽  
Magnetic Resonance ◽  
Dual Energy ◽  
The Body ◽  
Experimental Animals ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
Measurement Efficiency ◽  
Nuclear Magnetic

Abstract Background: As an instrument for measuring body composition in experimental animals, dual-energy X-ray absorptiometry (DXA) is ideal for accuracy, cost, and measurement efficiency. However, there is too little insight into the effectiveness of the various aspects of applying DXA to experimental animals. Therefore, we investigated whether to compare and verify the precision and accuracy of DXA and nuclear magnetic resonance (NMR) animal body composition analyzers. We used 30 ICR mice in the study. First, in order to evaluate the reproducibility of DXA and NMR, we did repeated measurements by repositioning each mouse in anesthesia and euthanasia states. Subsequently, the accuracy of each device was evaluated by comparing the weight measured before the experiment, the weight of the tissue extracted from the mice after the experiment, and the measured DXA and NMR. In addition, when measuring the body composition of animals, we compared the time and the measurable body composition parameters and summarized the advantages and disadvantages of the two devices.Results: Compared to NMR, DXA had the advantage of a fast measurement of bone composition and rapid image analysis. In addition, DXA showed a higher correlation (> 95%) with FM, body weight, and fBMC baseline than did NMR (> 85%).Conclusion: In conclusion, DXA was confirmed to have higher precision and measurement accuracy than did NMR. Therefore, DXA is an effective method for evaluating the body composition of experimental animals.

Techniques for Undertaking Dual-Energy X-Ray Absorptiometry Whole-Body Scans to Estimate Body Composition in Tall and/or Broad Subjects

2012 ◽  
Vol 22 (5) ◽  
pp. 313-322 ◽  
Author(s):  
Alisa Nana ◽  
Gary J. Slater ◽  
Will G. Hopkins ◽  
Louise M. Burke
Keyword(s):  
Body Composition ◽  
Dual Energy ◽  
The Body ◽  
Whole Body ◽  
Whole Body Scan ◽  
Body Scan ◽  
Physically Active ◽  
X Ray ◽  
Scanning Area ◽  
Dxa Scans

Dual-energy X-ray absorptiometry (DXA) is becoming a popular tool to measure body composition, owing to its ease of operation and comprehensive analysis. However, some people, especially athletes, are taller and/or broader than the active scanning area of the DXA bed and must be scanned in sections. The aim of this study was to investigate the reliability of DXA measures of whole-body composition summed from 2 or 3 partial scans. Physically active young adults (15 women, 15 men) underwent 1 whole-body and 4 partial DXA scans in a single testing session under standardized conditions. The partial scanning areas were head, whole body from the bottom of the chin down, and right and left sides of the body. Body-composition estimates from whole body were compared with estimates from summed partial scans to simulate different techniques to accommodate tall and/or broad subjects relative to the whole-body scan. Magnitudes of differences in the estimates were assessed by standardization. In simulating tall subjects, summation of partial scans that included the head scan overestimated whole-body composition by ~3 kg of lean mass and ~1 kg of fat mass, with substantial technical error of measurement. In simulating broad subjects, summation of right and left body scans produced no substantial differences in body composition than those of the whole-body scan. Summing partial DXA scans provides accurate body-composition estimates for broad subjects, but other strategies are needed to accommodate tall subjects.

scholarly journals Evaluation of the body adiposity index against dual‐energy X‐ray absorptiometry for assessing body composition in children and adolescents

2020 ◽  
Author(s):  
Tatianny Cesário ◽  
Paulo Francisco Almeida‐Neto ◽  
Dihogo Gama Matos ◽  
Jonathan Wells ◽  
Felipe J. Aidar ◽  
...  
Keyword(s):  
Body Composition ◽  
Children And Adolescents ◽  
Dual Energy ◽  
The Body ◽  
Body Adiposity Index ◽  
X Ray ◽  
Adiposity Index ◽  
Body Adiposity

scholarly journals Techniques for the study of energy balance in man

2003 ◽  
Vol 62 (2) ◽  
pp. 529-537 ◽  
Author(s):  
Marinos Elia ◽  
Rebecca Stratton ◽  
James Stubbs
Keyword(s):  
Body Composition ◽  
Measurement Error ◽  
Energy Balance ◽  
Energy Intake ◽  
Dual Energy ◽  
The Body ◽  
Fat Free Mass ◽  
Whole Body ◽  
X Ray ◽  
Body Segments

Energy balance can be estimated in tissues, body segments, individual subjects (the focus of the present article), groups of subjects and even societies. Changes in body composition in individual subjects can be translated into changes in the energy content of the body, but this method is limited by the precision of the techniques. The precision for measuring fat and fat-free mass can be as low as 0.5 kg when certain reference techniques are used (hydrodensitometry, air-displacement plethysmography, dual-energy X-ray absorptiometry), and approximately 0.7 kg for changes between two time points. Techniques associated with a measurement error of 0.7 kg for changes in fat and fat-free mass (approximately 18MJ) are of little or no value for calculating energy balance over short periods of time, but they may be of some value over long periods of time (18 MJ over 1 year corresponds to an average daily energy balance of 70 kJ, which is <1% of the normal dietary energy intake). Body composition measurements can also be useful in calculating changes in energy balance when the changes in body weight and composition are large, e.g. >5–10 kg. The same principles can be applied to the assessment of energy balance in body segments using dual-energy X-ray absorptiometry. Energy balance can be obtained over periods as short as a few minutes, e.g. during measurements of BMR. The variability in BMR between individuals of similar age, weight and height and gender is about 7–9%, most of which is of biological origin rather than measurement error, which is about 2%. Measurement of total energy expenditure during starvation (no energy intake) can also be used to estimate energy balance in a whole-body calorimeter, in patients in intensive care units being artificially ventilated and by tracer techniques. The precision of these techniques varies from 1 to 10%. Establishing energy balance by measuring the discrepancy between energy intake and expenditure has to take into consideration the combined validity and reliability of both components. The measurement error for dietary intake may be as low as 2–3% in carefully controlled environments, in which subjects are provided only with certain food items and bomb calorimetry can be undertaken on duplicate samples of the diet. Reliable results can also be obtained in hospitalised patients receiving enteral tube feeding or parenteral nutrition as the only source of nutrition. Unreliability increases to an unknown extent in free-living subjects eating a mixed and varied diet; thus, improved methodology is needed for the study of energy balance.

scholarly journals Comparison of a GE Lunar DPX-IQ and a Norland XR-26 dual energy X-ray absorptiometry scanner for body composition measurements in pigs – <i>in vivo</i>

2010 ◽  
Vol 53 (2) ◽  
pp. 162-175 ◽  
Author(s):  
D. Lösel ◽  
P. Kremer ◽  
E. Albrecht ◽  
A. M. Scholz
Keyword(s):  
Body Composition ◽  
Bone Mineral ◽  
Performance Testing ◽  
Dual Energy ◽  
The Body ◽  
Fat Percentage ◽  
Mineral Density ◽  
X Ray ◽  
And Performance

Abstract. In the context of future growth and performance testing, this study compares corresponding body composition results measured by two dual energy X-ray absorptiometry systems. To test the capability of each device to detect differences among experimental groups widely varying in body composition, 77 pigs from 6 purebred/crossbred groups were used for the experiment. Each pig was scanned consecutively on a Norland XR-26 and on a GE Lunar DPX-IQ. Coefficients of determination were: R²=0.92 for bone mineral content (BMC), R²=0.90 for bone mineral density (BMD), R²=0.94 for lean mass (LEAN), R²=0.92 for fat mass (FAT), R²=0.88 for lean percentage (%LEAN) and fat percentage (%FAT). However, Norland yielded larger values for %FAT and smaller values for %LEAN, BMC, and BMD than Lunar (P<0.001) with the extent of deviation depending on the specific trait and on the breeding group. The deviation in BMC was greater than the deviation in BMD, suggesting different bone detecting algorithms. Both systems revealed similar differences among the breeding groups, and ranked them in the same order based on numerical values. Differences in calibration, bone detection, and software algorithms, however, require a prior crosscalibration to make the body composition data from both systems directly comparable. Finally, they can be used across research centres for the determination of relative and absolute body composition differences among animal groups and individuals.

Validity of the 4-compartment model using dual energy X-ray absorptiometry-derived body volume in overweight individuals

2018 ◽  
Vol 43 (7) ◽  
pp. 742-746 ◽  
Author(s):  
Malia N.M. Blue ◽  
Katie R. Hirsch ◽  
Eric T. Trexler ◽  
Abbie E. Smith-Ryan
Keyword(s):  
Body Composition ◽  
Total Error ◽  
Bioelectrical Impedance ◽  
Compartment Model ◽  
Dual Energy ◽  
Body Volume ◽  
Fat Percentage ◽  
X Ray ◽  
Total Body ◽  
Mean Differences

The purpose of the present study was to assess the validity of dual-energy X-ray absorptiometry (DXA) to estimate body volume (BV) for use in a 4-compartment (4C) body composition model in an overweight/obese population. Body composition of 61 overweight/obese adults (age: 37.3 ± 10.0 years; height: 170.2 ± 9.5 cm; body mass: 97.1 ± 17.4 kg) was measured by 2 methods: a criterion 4C model and a DXA-derived BV 4C model. For both models, bioelectrical impedance spectroscopy was used to estimate total body water; total body bone mineral content was measured by a full-body DXA scan. For the criterion 4C model, BV was derived from air displacement plethysmography; for the DXA-4C model, BV was derived from previously published coefficients. Total error (TE) and standard error of the estimate (SEE) values for BV (TE = 1.11 L; SEE = 0.01 L) and body fat percentage (%fat) (TE = 2.92%; SEE = 0.32%) represented good to very good agreement between models. The DXA-derived measures of body composition (BV: 96.6 ± 18.1 L; %fat: 39.5% ± 8.1%; fat mass: 38.5 ± 11.9 kg), were significantly greater (p < 0.001) than 4C criterion measures (BV: 95.7 ± 17.6 L; %fat: 37.0% ± 7.6%; FM: 36.0 ± 10.8 kg) with the exception of lean mass, which was significantly lower (p < 0.001; DXA-4C: 58.2 ± 11.2 kg; criterion 4C: 60.7 ± 12.0 kg). Although small statistically significant mean differences were observed, TE and SEE results support the use of the DXA-4C method, which requires less time and equipment, for valid estimates of body composition in overweight/obese individuals.

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