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Body composition and bone mineral density changes during a premier league season as measured by dual-energy X-ray absorptiometry
E. Egan, J. Wallace, T. Reilly, P. Chantler and J. Lawlor
An evaluation of lean body mass in the Spanish population using X-ray absorptiometry (DXA)
S. Aguado, R. Rodríguez and L. Gómez-Pellico
Half-body scans are a valid alternative to whole-body scans when estimating body composition by dual-energy X-ray absorptiometry
C.P. Wilson, R.M. Petri and B.A. Gower
Dual-energy X-ray absorptiometry: validity of the Lunar Prodigy fan-beam system for body composition measurement in pediatrics
Hongchan Lee, Jack Wang, Dympna Gallagher, Stanley Heshka, Wei Shen, Earle Chambers, Steven B. Heymsfield and ZiMian Wang
Equations for classifying overweight in children: a comparison
R.J. Hill, A.J. Murphy, H.M. Buntain and P.S.W. Davies
Self-reported height and weight in an adult Indian population in comparison with measured height and weight
K.S. Reddy and K.K.R. Reddy
International Journal of Body Composition Research 2006 Vol. 4 No. 2: 61-66
E. Egan, J. Wallace, T. Reilly, P. Chantler and J. Lawlor
Research Institute for Sport and Exercise Sciences , Liverpool John Moores University , Liverpool , UK .
Body composition was repeatedly assessed in 28 male Premier League football players using dual-energy xray absorptiometry (DXA). Assessments were performed at the beginning (T1) and end (T2) of 6 weeks of pre-season training, 29 weeks later during the competitive phase (T3) and at the beginning (T4) and end (T5) of a 6-week pre-season training phase the following year. Total mass, body fat per cent, and fat mass decreased ( P < 0.05) during the pre-season phase of the first year (T1-T2); body fat per cent and fat mass decreased ( P < 0.05) and fat-free soft tissue mass increased significantly ( P < 0.05) during the same phase of the following year (T4-T5). Total mass, body fat percent and fat mass increased ( P < 0.05) between the end of the pre-season (T2) and the middle of the competitive season (T3). Total body mass, body fat percent and fat mass were not significantly different mid-way through the competitive phase from the beginning of the pre-season phase (T1-T3; P > 0.05). There were no further changes in total mass, body fat percent, fat mass or lean mass between the middle (T3) of the competitive season and the next measurements (T4; P > 0.05). Values were not different at the beginning of the second year of pre-season training (T4) than they were at the beginning of the first year (T1; P > 0.05). Body composition changes reflected seasonal shifts in emphasis of training. Positive changes in body composition observed pre-season were lost by the middle of the competitive season, but were restored in the subsequent start of pre-season training.
International Journal of Body Composition Research 2006 Vol. 4 No. 2: 67-74
S. Aguado, R. Rodríguez and L. Gómez-Pellico
Department of Human Anatomy and Embryology, School of Medicine, University of Alcalá , Alcalá de Henares ( Madrid ), Spain .
Knowledge of the relationship between muscle mass and morpho-functional variables is one of the foremost requirements in gaining knowledge of the constitutional structure of the human body. In the awareness that the development of the muscle system is associated with that of the skeletal system, and that there are differences between genders and between age groups, this survey aimed to study the amount of lean mass, ie muscle mass in the Spanish population in both sexes and for each age-group (sample divided into five-year age groups, from 0 to 80 years of age). We took a population sample of 1120 subjects, which we divided into 16 groups. A total body scan was performed in each subject by means of dual-energy X-ray absorptiometry (DXA). Lean body mass was analysed both for the whole body and for specific body areas (arms, legs and trunk). For total lean mass gender differences were more significant between ages 11 and 80 ( P = 0.001), values being always higher in men. In women, lean mass increased up to age 15 years, while in men this increase continued till age 20. The trend of lean mass of the different body areas was comparable to that of the total body in both sexes.
Key words: dual energy X ray absorptiometry, age, body composition, muscle mass.
International Journal of Body Composition Research 2006 Vol. 4 No. 2: 75-80
C.P. Wilson, R.M. Petri and B.A. Gower
Department of Nutrition Sciences, Division of Physiology and Metabolism,
University of Alabama at Birmingham , Birmingham , AL , USA .
The purpose of this study was to determine if half-body scans can be used as an alternative to whole-body scans for the measurement of bone mineral density (BMD), bone mineral content (BMC), percent body fat (%BF), tissue mass, fat mass (FM), and lean tissue mass (LTM) by dual-energy X-ray absorptiometery (DXA). Non-obese, apparently healthy, subjects ( n =15) were recruited. Each subject underwent two scans on the Lunar Prodigy DXA. The first scan was a whole-body (WB) scan, which was analyzed for body composition using the 'Standard' analysis program. The patient was then re-positioned so that their left arm, from the shoulder joint to the finger tips, was outside the instrument scanning range. This scan was then analyzed using two separate approaches; the first, 'Right Side' (RS), involved a standard analysis of the whole body. Subsequently, data from only the right side of the body were doubled and used in statistical analyses. The second, 'Region-of-Interest' (ROI), involved a custom analysis that entailed manually placing a box around the right side of the body. Paired t -tests indicated that ROI differed significantly from WB for determination of %BF, FM, and LTM ( P < 0.05 for all). LTM was under-estimated by ROI, whereas %BF and FM were overestimated. Similarly, linear regression analysis indicated that ROI significantly under-estimated LTM (intercept = -2.4 kg; P < 0.05). Bland-Altman plots confirmed that ROI consistently under-estimated LTM, and over-estimated both %BF and FM, across the range of values; no bias was detected. In contrast, RS did not differ from WB with respect to any outcome. We conclude that the RS method is a valid alternative to WB for analysis of DXA scans; this approach may be useful for analysis of scans from individuals who are too large to fit within the instrument scanning range.
Key words: body composition, dual-energy X-ray absorptiometry, percent fat, fat mass, lean tissue mass
International Journal of Body Composition Research 2006 Vol. 4 No. 2: 81-86
Hongchan Lee, Jack Wang, Dympna Gallagher, Stanley Heshka, Wei Shen, Earle Chambers, Steven B. Heymsfield 1 and ZiMian Wang
Obesity Research Center , St. Luke's-Roosevelt Hospital, Institute of Human Nutrition , Columbia University , and 1 Merck & Co., Inc. Rahway NJ , USA .
The aim of this study was to establish the accuracy of GE's Lunar Prodigy fan beam DXA system in pediatric subjects by comparison of percent body fat estimates to reference values provided by a multicomponent body-composition model based on measured body weight, body volume, total-body water, and bone mineral. Subjects were 53 healthy children and adolescents, ages 5-17 years, who were scanned in one of three modes based on body size, thin (n = 22), standard (n = 27), and thick (n = 4). The subject pool for thick mode was small and their inclusion was only relevant for the pooled analyses. For the pooled subjects, the two %fat estimates were strongly associated (r = 0.98, P <0.001, SEE = 2.29%), although there was a tendency for DXA to progressively overestimate adiposity in heavier individuals compared with the multicomponent model. Bland-Altman analysis showed a non-significant bias between %fat difference measured by the two methods and the mean values in thin mode (r = 0.11, P >0.05) and standard mode (r = 0.24, P >0.05), respectively. In a multiple regression analysis with multi-component %fat as the dependent variable and DXA %fat as the independent variable, measurement method and scan mode contributed significantly. Our findings support the clinical and research application of this new fan-beam DXA system for cross-sectional and longitudinal evaluation of body composition. However, caution should be used when comparing %fat estimates obtained with the Prodigy fan-beam system to those acquired by other fanbeam DXA systems.
Key words: DXA scan mode; multicomponent model; percent body fat.
International Journal of Body Composition Research 2006 Vol. 4 No. 2: 87-94
R.J. Hill 1 , A.J. Murphy 1 , H.M. Buntain 2 and P.S.W. Davies 1
1 Children's Nutrition Research Centre, Discipline of Paediatrics and Child Health, University of Queensland , Royal Children's Hospital, Herston , Queensland , Australia ; 2 Department of Respiratory Medicine, Royal Children's Hospital, Herston , Queensland, Australia ; Discipline of Paediatrics and Child Health, University of Queensland, Royal Children's Hospital, Herston , Queensland , Australia
The aim of this study was to compare percent fat mass and hence, classification of overweight calculated from three prediction equations with that measured using isotope dilution as a reference. Body composition data were collected from 113 normal, healthy, Australian children. Deuterium dilution was used to measure total body water and impedance was measured using a hand-to-foot bioelectrical impedance device. Two impedance prediction equations and one anthropometric prediction equation were used to calculate percent fat mass. Predicted percent fat mass was compared with that measured using deuterium dilution and children were classified as overweight according to body fatness associated with cardiovascular risk factors. Classifications of overweight were also made based on BMI and accepted cut-off values. Percent fat mass predicted by Sun et al. was not significantly different from that measured via total body water, however, all equations tested misclassified the number of subjects that were overweight compared with deuterium dilution. BMI cut-off values under-classified the number of subjects that were overweight. While Sun et al. showed good agreement with the reference method, its use is potentially limited by the need for technical equipment for its calculation. Equations which rely on anthropometric variables, for example BMI, in their calculation have potentially more widespread usage, however, BMI, while simple to use and correlates well with body fatness, is a reflection of overall body size rather than specific body fatness, and it is elevated body fatness per se rather than overweight for height that is a risk factor for disease.
Key words : body composition; isotope labelling; bioelectrical impedance; body mass index; prediction equations
International Journal of Body Composition Research 2006 Vol. 4 No. 2: 95-98
K.S. Reddy and K.K.R. Reddy
Department of Anthropology, Sri Venkateswara University , Tirupati, Andhra Pradesh , India .
In order to evaluate the accuracy of the prevalence of obesity from self-reported height and weight in an adult Indian population 348 healthy subjects (214 males and 134 females) aged between 20 to 60 years were randomly screened. Information on individual history, socio-economic status, physical activity and self-reported height and weight was procured. Further, height and weight were measured according to a standard protocol. Both genders underestimated their body image except height in females, and the mean measured (true) BMI was greater than estimated BMI (from self-reported height and weight) with the difference being 0.27 kg/m 2 in males and 0.59 kg/m 2 in females ( P < 0.05). Prediction equations that explained 60 to 90% (males) and 50 to 75% (females) of the difference between self-reported and measured body image included age and self-reported height and weight only. Since under-reporting of height and weight resulted in BMI estimates with relatively low error it appears that self-reporting of height and weight can be useful for the monitoring of obesity prevalence in India .
Key words: Height, weight, body mass index, socio-economic status, obesity prevalence.