scholarly journals Evaluation of a model for total body protein mass based on dual-energy X-ray absorptiometry: comparison with a reference four-component model

2001 ◽  
Vol 86 (1) ◽  
pp. 45-52 ◽  
Author(s):  
N. J. Fuller ◽  
J. C. K. Wells ◽  
M. Elia
Keyword(s):  
Dual Energy ◽  
Fat Free Mass ◽  
Component Model ◽  
Body Volume ◽  
Body Protein ◽  
X Ray ◽  
Protein Mass ◽  
Four Component Model ◽  
The Mean ◽  
Total Body

The aim of the present study was to evaluate a model of body composition for assessing total body protein (TBP) mass using dual-energy X-ray absorptiometry (DXA), with either measured or assumed total body water (TBW); it was intended to provide a less complex or demanding alternative technique to, for example, the four-component model (4-CM). The following measurements were obtained in healthy adults (n46) aged 18–62 years, and children (n30) aged 8–12 years: body weight (BWt), body volume (BV; under-water weighing), TBW (2H-dilution space or predicted using an assumed hydration fraction of fat-free mass (HFffm)), bone mineral content (BMC; DXA) and fat-free soft tissue (FFST; DXA). TBP was calculated using the 4-CM (TBP=3·050BWt-0·290TBW-2·734BMC-2·747BV) and the DXA model (TBP=FFST-0·2305BMC-TBW). DXA measurements were obtained using the Lunar DPX (Lunar Radiation Corporation, Madison, WI, USA) or Hologic QDR 1000/W (Hologic, Waltham, MA, USA). Precision of the DXA model for TBP with measured TBW (4·6–6·8 % mean TBP) was slightly worse than the 4-CM (4·0–5·4 %), whereas that modelled with assumed HFffmwas more precise (2·4–5·2 %) because it obviated imprecision associated with measuring TBW. Agreement between the 4-CM and DXA model with measured TBW was also worse (e.g. bias, 15 % of the mean; 95 % limits of agreement up to ±39 % for adults measured on the Lunar DPX) than when a constant for HFffmwas assumed (3·7 % and ±21 % respectively). Most of the variability in agreement between these various models was due to interpretation of biological factors, rather than to measurement imprecision. Therefore, the DXA model, which is less complex and demanding than the 4-CM, is of value for assessing TBP in groups of healthy subjects, but is of less value for individuals in whom there may be substantial differences from reference 4-CM estimates.

QDR 4500A DXA overestimates fat-free mass compared with criterion methods

2003 ◽  
Vol 94 (3) ◽  
pp. 959-965 ◽  
Author(s):  
Frances Tylavsky ◽  
Timothy Lohman ◽  
Barbara A. Blunt ◽  
Dale A. Schoeller ◽  
Thomas Fuerst ◽  
...  
Keyword(s):  
Lower Estimate ◽  
Dual Energy ◽  
Fat Free Mass ◽  
Component Model ◽  
Men And Women ◽  
Hydration Level ◽  
X Ray ◽  
Beam System ◽  
Four Component Model ◽  
Total Body

This study evaluated the accuracy with which the dual-energy X-ray absorptiometer (Hologic QDR 4500A) measured fat-free mass (FFM), fat mass (FM), and hydration of FFM. In a study of 58 men and women (ages 70–79 yr), the QDR 4500A was found to provide a systematically higher estimate of FFM and lower estimate of FM than a four-component model of body composition. A correction factor from this study was developed and applied to two other samples ( n = 13 and 37). We found mean corrected levels of FFM and FM to be equivalent to that obtained by the four-component model or total body water. In addition, the hydration of the corrected FFM was closer to the established hydration level in adult samples and that obtained from the four-component model. These findings suggest that the current calibration of the fan-beam system of the Hologic QDR 4500A provides an overestimate of FFM and underestimate of FM compared with reference methods.

Four-Component Model of Body Composition in Chronic Renal Failure Comprising Dual-Energy X-ray Absorptiometry and Measurement of Total Body Water by Deuterium Oxide Dilution

1996 ◽  
Vol 91 (6) ◽  
pp. 763-769 ◽  
Author(s):  
Graham Woodrow ◽  
Brian Oldroyd ◽  
John H. Turney ◽  
Peter S. W. Davies ◽  
Janice M. E. Day ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Total Body Water ◽  
Dual Energy ◽  
Body Water ◽  
Fat Free Mass ◽  
Component Model ◽  
X Ray ◽  
Four Component Model ◽  
Total Body

1. Assessment of nutrition in patients with chronic renal failure by body composition measurement techniques may be affected by variable hydration. 2. This study aimed to derive a four-component model of body composition (consisting of fat, protein, total body water and body mineral) from a combination of dual-energy X-ray absorptiometry and total body water measured by deuterium oxide dilution, allowing assessment of body protein stores without the effect of variation in hydration. Patients with chronic renal failure on haemodialysis, peritoneal dialysis and conservative treatment and a control group were studied. Patients with chronic renal failure were at an ‘ideal’ state of hydration on clinical assessment. 3. Hydration was defined by total body water as a percentage of fat-free mass measured by dual-energy X-ray absorptiometry, and no differences were found between chronic renal failure subgroups and control subjects (except in the female undialysed chronic renal failure subgroup). Hydration was significantly correlated with percentage total body fat in the control groups but not in patients with chronic renal failure. 4. Lean tissue measured by dual-energy X-ray absorptiometry was significantly reduced in three of the six chronic renal failure groups compared with control subjects (male and female patients on haemodialysis and female patients on peritoneal dialysis). Protein estimated from the four-component model failed to detect these abnormalities. 5. Lean tissue measured by dual-energy X-ray absorptiometry in normal subjects strongly correlated with fat-free mass measured by total body potassium in normal subjects (male r = 0.91; female r = 0.89, both P < 0.0001). The correlation of protein estimated from the four-component model with fat-free mass measured by total body potassium was far weaker in male control subjects (r = 0.51, P < 0.05) and not significant in female control subjects (r = 0.38, P not significant). In the normal subjects protein estimated from the four-component model showed a much greater variation from protein estimated by total body potassium than did protein estimated simply as 27% of dual-energy X-ray absorptiometry fat-free mass minus total body mineral. 6. Hydration in patients with chronic renal failure in whom fluid balance is believed to be normal on clinical criteria does not differ from that in normal subjects. The combined model of dual-energy X-ray absorptiometry and total body water is not a useful method for the measurement of body protein.

Four-component model for the assessment of body composition in humans: comparison with alternative methods, and evaluation of the density and hydration of fat-free mass

1992 ◽  
Vol 82 (6) ◽  
pp. 687-693 ◽  
Author(s):  
N. J. Fuller ◽  
S. A. Jebb ◽  
M. A. Laskey ◽  
W. A. Coward ◽  
M. Elia
Keyword(s):  
Body Composition ◽  
Skinfold Thickness ◽  
Dual Energy ◽  
Fat Free Mass ◽  
Component Model ◽  
Alternative Methods ◽  
X Ray ◽  
Four Component Model ◽  
Deuterium Dilution ◽  
Component Models

1. Body composition was assessed in 28 healthy subjects (body mass index 20–28 kg/m2) by dual-energy X-ray absorptiometry, deuterium dilution, densitometry, 40K counting and four prediction methods (skinfold thickness, bioelectrical impedance, near-i.r. interactance and body mass index). Three- and four-component models of body composition were constructed from combinations of the reference methods. The results of all methods were compared. Precision was evaluated by analysis of propagation of errors. The density and hydration fraction of the fat-free mass were determined. 2. From the precision of the basic measurements, the propagation of errors for the estimation of fat (± sd) by the four-component model was found to be ± 0.54 kg, by the three-component model, ± 0.49 kg, by deuterium dilution, ± 0.62 kg, and by densitometry, ± 0.78 kg. Precision for the measurement of the density and hydration fraction of fat-free mass was ± 0.0020 kg/l and ± 0.0066, respectively. 3. The agreement between reference methods was generally better than between reference and alternative methods. Dual-energy X-ray absoptiometry predicted three- and four-component model body composition slightly less well than densitometry or deuterium dilution (both of which greatly influence these multi-component models). 4. The hydration fraction of fat-free mass was calculated to be 0.7382 ± 0.0213 (range 0.6941–0.7837) and the density of fat-free mass was 1.1015 ± 0.0073 kg/1 (range 1.0795–1.1110 kg/1), with no significant difference between men and women for either. 5. The results suggest that the three- and four-component models are not compromised by errors arising from individual techniques. Dual-energy X-ray absorptiometry would appear to be a suitable alternative method for the assessment of body composition in these healthy adults. The traditional mean value assumed for density of the fat-free mass in classic densitometry (1.1 kg/l) appears to be appropriate, and the mean hydration fraction was close to values which are generally applied to the fat-free mass (0.72–0.73). Despite concealing considerable inter-individual variation, these mean values may be applied to groups with characteristics similar to those in this study. Finally, with the notable exception of skinfold thickness, bedside prediction methods show poor agreement with both the three- and the four-component models.

Validity of fan-beam dual-energy X-ray absorptiometry for measuring fat-free mass and leg muscle mass

1999 ◽  
Vol 87 (4) ◽  
pp. 1513-1520 ◽  
Author(s):  
Marjolein Visser ◽  
Thomas Fuerst ◽  
Thomas Lang ◽  
Loran Salamone ◽  
Tamara B. Harris ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Dual Energy ◽  
Fat Free Mass ◽  
Elderly Persons ◽  
X Ray ◽  
Total Body Fat ◽  
The Mean ◽  
Leg Muscle ◽  
The Difference ◽  
Total Body

The aim of the study was to examine the accuracy of fan-beam dual-energy X-ray absorptiometry (DEXA) for measuring total body fat-free mass (FFM) and leg muscle mass (MM) in elderly persons. Participants were 60 men and women aged 70–79 yr and with a body mass index of 17.5–39.8 kg/m2. FFM and MM at four leg regions were measured by using DEXA (Hologic 4500A, v8.21). A four-compartment body composition model (4C) and multislice computed tomography (CT) of the legs were used as the criterion methods for FFM and MM, respectively. FFM by DEXA was positively associated with FFM by 4C ( R 2 = 0.98, SE of estimate = 1.6 kg). FFM by DEXA was higher [53.5 ± 12.0 (SD) kg] than FFM by 4C (51.6 ± 11.9 kg; P < 0.001). No association was observed between the difference and the mean of the two methods. MM by DEXA was positively associated with CT at all four leg regions ( R 2 = 0.86–0.96). MM by DEXA was higher than by CT in three regions. The results of this study suggest that fan-beam DEXA offers considerable promise for the measurement of total body FFM and leg MM in elderly persons.

In vivo validation of whole body composition estimates from dual-energy X-ray absorptiometry

1997 ◽  
Vol 83 (2) ◽  
pp. 623-630 ◽  
Author(s):  
Barry M. Prior ◽  
Kirk J. Cureton ◽  
Christopher M. Modlesky ◽  
Ellen M. Evans ◽  
Mark A. Sloniger ◽  
...  
Keyword(s):  
Body Composition ◽  
Dual Energy ◽  
Component Model ◽  
Whole Body ◽  
Body Density ◽  
X Ray ◽  
Athletic Status ◽  
Musculoskeletal Development ◽  
Four Component Model ◽  
The Difference

Prior, Barry M., Kirk J. Cureton, Christopher M. Modlesky, Ellen M. Evans, Mark A. Sloniger, Michael Saunders, and Richard D. Lewis. In vivo validation of whole body composition estimates from dual-energy X-ray absorptiometry. J. Appl. Physiol. 83(2): 623–630, 1997.—We validated whole body composition estimates from dual-energy X-ray absorptiometry (DEXA) against estimates from a four-component model to determine whether accuracy is affected by gender, race, athletic status, or musculoskeletal development in young adults. Measurements of body density by hydrostatic weighing, body water by deuterium dilution, and bone mineral by whole body DEXA were obtained in 172 young men ( n = 91) and women ( n = 81). Estimates of body fat (%Fat) from DEXA (%FatDEXA) were highly correlated with estimates of body fat from the four-component model [body density, total body water, and total body mineral (%Fatd,w,m); r = 0.94, standard error of the estimante (SEE) = 2.8% body mass (BM)] with no significant difference between methods [mean of the difference ± SD of the difference = −0.4 ± 2.9 (SD) % BM, P = 0.10] in women and men. On the basis of the comparison with %Fatd,w,m, estimates of %FatDEXA were slightly more accurate than those from body density ( r = 0.91, SEE = 3.4%; mean of the difference ± SD of the difference = −1.2 ± 3.4% BM). Differences between %FatDEXA and %Fatd,w,m were weakly related to body thickness, as reflected by BMI ( r= −0.34), and to the percentage of water in the fat-free mass ( r = −0.51), but were not affected by race, athletic status, or musculoskeletal development. We conclude that body composition estimates from DEXA are accurate compared with those from a four-component model in young adults who vary in gender, race, athletic status, body size, musculoskeletal development, and body fatness.

Density of the fat-free mass and estimates of body composition in male weight trainers

1996 ◽  
Vol 80 (6) ◽  
pp. 2085-2096 ◽  
Author(s):  
C. M. Modlesky ◽  
K. J. Cureton ◽  
R. D. Lewis ◽  
B. M. Prior ◽  
M. A. Sloniger ◽  
...  
Keyword(s):  
White Men ◽  
Dual Energy ◽  
Fat Free Mass ◽  
Whole Body ◽  
Body Density ◽  
X Ray ◽  
Musculoskeletal Development ◽  
Four Component Model ◽  
Weight Trainers ◽  
Deuterium Dilution

The purpose of this study was to determine whether the assumed density and composition of the fat-free mass (FFM) and estimates of percent fat (%Fat) from body density by use of the Siri equation (%Fatd) are valid in weight trainers with high musculoskeletal development. Measures of body density by underwater weighing (Db), body water by deuterium dilution, and bone mineral by whole body dual-energy X-ray absorptiometry were obtained in young white men: 14 weight trainers with high musculoskeletal development and 14 non-weight-training controls with average musculoskeletal development. %Fatd was significantly higher (P < or = 0.05) than %Fat estimated from body density, water, and mineral (%Fatd,w,m) by use of a four-component model in weight trainers (17.3 +/- 4.6 vs. 13.2 +/- 5.1%) but not in controls (14.8 +/- 3.1 vs. 14.2 +/- 3.6%). The greater discrepancy between %Fatd and %Fatd,w,m was explained by lower density of fat-free mass (Dffm) in weight trainers (1.089 +/- 0.005 g/ml) than in controls (1.099 +/- 0.007 g/ml). The lower Dffm in the weight trainers was due to higher water (74.8 +/- 1.2 vs. 72.6 +/- 20%) and lower mineral (5.3 +/- 0.6 vs. 5.9 +/- 0.4%) and protein (19.9 +/- 1.4 vs. 21.5 +/- 1.9%) fractions of the FFM. We conclude that, in young white men with high musculoskeletal development, Dffm is lower than the assumed value of 1.1 g/ml and %Fat is overestimated from Db by use of the Siri equation.

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.

Fat-Free Mass and Percent Body Fat Assessments by Dual-Energy X-ray Absorptiometry, Densitometry and Total Body Water

1993 ◽  
pp. 71-74
Author(s):  
Rita Wellens ◽  
Alex F. Roche ◽  
Shumei Guo ◽  
William C. Chumlea ◽  
Roger M. Siervogel
Keyword(s):  
Body Fat ◽  
Total Body Water ◽  
Dual Energy ◽  
Body Water ◽  
Fat Free Mass ◽  
Percent Body Fat ◽  
X Ray ◽  
Total Body

Alterations in growth and body composition during puberty. I. Comparing multicompartment body composition models

1997 ◽  
Vol 83 (3) ◽  
pp. 927-935 ◽  
Author(s):  
James N. Roemmich ◽  
Pamela A. Clark ◽  
Arthur Weltman ◽  
Alan D. Rogol
Keyword(s):  
Body Composition ◽  
Bioelectrical Impedance ◽  
Dual Energy ◽  
Fat Free Mass ◽  
Mineral Density ◽  
Field Methods ◽  
X Ray ◽  
The Mean ◽  
Pubertal Boys ◽  
Better Than

Roemmich, James N., Pamela A. Clark, Arthur Weltman, and Alan D. Rogol. Alterations in growth and body composition during puberty. I. Comparing multicompartment body composition models. J. Appl. Physiol. 83(3): 927–935, 1997.—A four-compartment (4C) model of body composition was used as a criterion to determine the accuracy of three-compartment (3C) and two-compartment (2C) models to estimate percent body fat (%BF) in prepubertal and pubertal boys (genital I & II, n = 17; genital III & IV, n = 7) and girls (breast I & II, n = 8; breast III & IV, n = 15). The 3C water-density (3C-H2O) and 3C mineral-density models, dual-energy X-ray absorptiometry, the Lohman age-adjusted equations, the Slaughter et al. skinfold equations, and the Houtkooper et al. and Boileau bioelectrical impedance equations were evaluated. Agreement with the 4C model increased with the number of compartments (i.e., body water, bone mineral) measured. Except for the 3C-H2O model, the limits of agreement were large and did not perform well for individuals. The mean %BF by dual-energy X-ray absorptiometry (23.6%) was greater than that of the criterion 4C method (21.7%). For the field methods, the Slaughter et al. skinfold equations performed better than did the Houtkooper et al. and Boileau bioimpedance equations. The hydration of the fat-free mass decreased (genital I & II = 75.7%, genital III & IV = 74.8%, breast I & II = 75.5%, breast III & IV = 74.4%) and the mineral content increased (genital I & II = 4.9%, genital III & IV = 5.0%, breast I & II = 5.1%, breast III & IV = 5.7%) with maturation. The density of the fat-free mass also increased (genital I & II = 1.084 g/ml, genital III & IV = 1.087 g/ml, breast I & II = 1.086 g/ml, breast III & IV = 1.091 g/ml) with maturation. All of the models reduced the %BF overprediction of the Siri 2C model, but only the 4C and 3C-H2O models should be used as criterion methods for body composition validation in children and adolescents.

Sign in / Sign up

Export Citation Format

Share Document