| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Epidemiology, Demography and Biometry Program, National Institute on Aging, Bethesda, Maryland 20892; 2 Institute for Research in Extramural Medicine, Faculty of Medicine, Vrije Universiteit, 1081 BT Amsterdam, The Netherlands; 3 Department of Radiology, University of California, San Francisco, California 94105; and 4 Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
 |
ABSTRACT |
|---|
 TOP
 ABSTRACT
 INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
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 (R2 = 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 (R2 = 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.
computed tomography; elderly; multicompartment models
| |
INTRODUCTION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
DUAL-ENERGY X-ray absorptiometry (DEXA) is becoming increasingly popular for the measurement of soft tissue composition. Unlike most other body composition methods, DEXA is noninvasive and includes both regional and total body measurements as well as estimates of appendicular skeletal muscle mass (5, 7). Measurements of appendicular muscle mass by DEXA (or dual-photon absorptiometry) have previously been validated against criterion methods of the total body, including total body potassium counting (5, 7), total body nitrogen analysis (7), and computed tomography (CT) (17). However, no studies have directly compared appendicular skeletal muscle mass with regional criterion methods. Moreover, none of these studies have been carried out in elderly persons. Because of the interest in body composition in old age, especially the study of sarcopenia and the effect of intervention studies on muscle mass, accurate assessment of muscle mass by DEXA in older people is becoming more important.
In all previously mentioned DEXA validation studies, pencil-beam scanners were used. In these scanners the X-ray beam travels across the person in a rectilinear fashion, and a single detector is used to acquire the data. The newest generation of DEXA scanners uses a fan-beam X-ray source coupled with multiple detectors. These scanners have the advantage of a faster scanning speed, ~3-4 min compared with 15-25 min for a whole body scan, allowing the use of DEXA in large population studies and in subjects who have difficulty lying motionless on a flat hard surface for 20 min, such as frail older subjects and young children. However, validation studies directly comparing the newest fan-beam DEXA technology against other body composition techniques and against the pencil-beam technique are limited (4).
The aim of the present study was to examine the accuracy of the fan-beam DEXA technology for the estimation of total body fat-free mass (FFM) and leg muscle mass in men and women aged 70-79 yr. A four-compartment body composition model and multislice CT were used as the criterion methods for total body FFM and leg muscle mass, respectively.
| |
METHODS |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
Subjects. A total of 60 healthy adults, 30 men and 30 women, aged 70-79 yr, were recruited through flyers and advertisements in local newspapers. Study participants were recruited to represent a large body mass index (BMI) range: 25% of the study subjects had a BMI of <25 kg/m2, 50% with BMI of 25-30 kg/m2, and 25% with BMI of >30 kg/m2. Only Caucasians (n = 53) and African-Americans (n = 7) were included in the study. All measurements were performed in the morning after an overnight fast. After the blood draw for the determination of total body water, subjects were allowed to drink water and were provided a standard liquid meal. The experimental procedures were approved by the Human Investigation and Review Boards at the University of California at San Francisco and San Francisco State University. Written informed consent was obtained from all the subjects.
Anthropometry. Body weight was determined to the nearest 0.1 kg with subjects dressed in bathing suits, and height was measured to the nearest 0.1 cm using a stadiometer (Harpenden, Holtain, Wales, UK). BMI was calculated as weight (kg) divided by height (m) squared.
DEXA.
Body composition of all subjects was measured by DEXA using the
fan-beam technology (model QDR 4500A, Hologic, Waltham, MA). After
completion of the scans, the body composition results for the total
body were provided by the system's most recent software release,
version 8.21. Total body FFM was defined as lean soft tissue mass plus
total body bone mineral content (BMC). Muscle mass of the total leg,
total thigh, and small subregions at the midthigh and calf were also
assessed. For the total legs a region was defined by placing a
horizontal line at the lowest point of the ischial tuberosity as the
upper margin for the legs and a horizontal line at the ankle joint as
the lower margin for the legs. In this way the upper and lower margins
of the legs were similar to the ones used in the multislice CT
technique (see CT and Fig.
1). Total leg muscle mass was calculated as
follows (7): leg muscle mass = total leg mass 
(leg fat mass) (1.82 · leg BMC). Similarly,
muscle mass of the thighs was assessed, using the ischial tuberosity
and the knee joint as upper and lower margins, respectively.
Additionally, muscle mass at the midthigh (at one-half of the distance
from the knee joint to the top of femur) and at the calf (at two-thirds
of the distance from the ankle joint to the knee joint) was assessed by
using the smallest DEXA subregion possible, which consists of 3 pixels
or 3.96 cm. Triplicate scans of all 60 subjects without repositioning
revealed a coefficient of variation of 0.81% for total leg muscle mass
(0.81% for men and 0.83% for women). The interobserver coefficient of
variation for reading the scans of 20 subjects (10 men and 10 women)
was 1.4% for lean soft tissue mass of the total leg, 2.3% for the thigh, 4.3% for the midthigh subregion, and 1.3% for the calf subregion.
|
Four-compartment model. To validate the DEXA results for total body FFM, a four-compartment model was used as the criterion method (9). This model requires measurements of body density, total body water, total body bone mineral mass, and body weight, and it takes into account interindividual variations in the water content and mineral content of the FFM.
Body density was measured by using underwater weighing. Subjects wore a bathing suit. Water temperature was set at 32-35°C. When possible, 10 submersions with maximal exhalation were performed. The average of the five most consistent trials (difference 0.02 kg) was used. Before submersion, residual lung volume was measured by using a Collins Respirometer (model SVR/PLUS, Braintree, MA). With the mouthpiece in place, subjects were asked to breathe normally until the spirometer equilibrated for collection of data on functional residual capacity. After equilibration, subjects performed a forced inhalation followed by a forced exhalation for collection of inspiratory and expiratory reserve capacity data, respectively. Residual volume was calculated as functional residual capacity minus expiratory capacity. Three separate tests were performed, and the average was used to adjust body volume. Total body water was assessed by using deuterium dilution (13). Blood samples were collected before and at least 4 h after an exactly weighed oral dose of deuterium oxide (~4 g diluted in 50 ml of water) and stored frozen at20°C until analysis for deuterium.
Corrections were made for nonaqueous hydrogen exchange and water
density at body temperature. Total body water (kg) was calculated as
deuterium dilution space (liters)/1.046.
Total body mineral mass was calculated from measured total body bone
mineral content by the fan-beam DEXA technology, multiplied by 1.23 (9).
Body composition from the four-compartment model was calculated by
using the following formula (9): body fat (%) = [2.747/D 0.714W + 1.146M 2.0503] · 100, where D
is body density from underwater weighing, W is the water fraction of
the body (total body water/body weight), and M is the mineral fraction
of the body (total body mineral mass/body weight). FFM was calculated as body weight body fat. FFM was missing for two women who were not able to complete the underwater-weighing procedure.
CT.
CT of the legs was used to validate the measurements of leg muscle mass
by DEXA. Five cross-sectional images at anatomically defined locations
in the legs were made by using a GE-9800Q scanner. Each CT image was
completed at 120 kVp with a scanning time of 2 s at 70 mA. The
following anatomic locations were used (Fig. 1): ankle (at joint), calf
(at two-thirds of the distance between ankle joint and knee joint),
knee (7 mm above knee joint), midthigh (at one-half of the distance
between knee joint and top of femur), and upper thigh (lowest point of
the ischial tuberosity). Slice thickness was set at 10 mm for the upper
thigh, midthigh, and calf scans and at 5 mm for the knee and ankle
scans. A 40-cm field of view and 512 by 512 matrix (pixel size 0.78 mm)
was used for most persons. In heavier persons, a 48-cm field of view
(pixel size 0.93 mm) was used for the upper thigh scan. A standard soft tissue reconstruction algorithm was employed. A single observer analyzed all cross-sectional images. The external contours of the leg
were determined using a threshold of 224 Hounsfield units (HU),
and the external bone contours were derived at 150 HU. The resulting
contours were viewed and manually adjusted if they did not adequately
track the boundaries. The CT number intervals of this region were
determined by computing the histogram of the soft-tissue region,
detecting the adipose tissue and muscle peaks, and setting windows
around the peaks. To ensure the quality of the results, the calculated
contours of the adipose tissue and muscle distribution were overlaid on
the image. Intervals were adjusted manually if the areas were not
accurately depicted. The muscle volume bounded by two adjacent scans,
scan 1 and
2 (V1,2), is given by
V1,2 = D1,2 · (A1 + A2/2), where
D1,2 is the
distance in centimeters between images and
A1 and
A2 are the
cross-sectional muscle areas in square centimeters in the two images
(3, 17).
Statistical analysis. Data were analyzed by using SAS software (SAS Institute, Cary, NC). Results are presented as means ± SD. A P value of <0.05 was considered statistically significant. Total body FFM by fan-beam DEXA was compared with total body FFM from the four-compartment model by using linear regression analyses. The SE of the estimate (SEE) reported is the root mean square error. Absolute differences were tested by using paired t-tests. The method of Bland and Altman was used to compare fan-beam DEXA with the criterion method (2). This method was repeated after the exclusion of outliers, defined as those subjects for whom the difference between two methods was greater or smaller than two SD from the mean (2). Similarly, leg muscle mass measured by fan-beam DEXA was compared with muscle mass measured by CT. Reported correlation coefficients (r) are Pearson's product-moment correlations.
| |
RESULTS |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
The characteristics of the study population are shown in Table
1. The mean age of the study population was
73.7 yr, and the mean BMI was 27.4 kg/m2. Study participants covered
a broad range of BMI, from 17.5 to 39.8 kg/m2. Total body mass as measured
by fan-beam DEXA was highly correlated with body weight from the scale
in men and women (r = 0.999, P = 0.0001). However, DEXA total body
mass was statistically higher than body weight from the scale (1.1 ± 0.4 kg, P < 0.001).
|
Validation of total body FFM.
Table 2 shows the measurement of total body
FFM by fan-beam DEXA vs. the criterion method. The two measurements
were positively associated with an explained variance of 98%
(R2 = 0.98, Fig.
2A). FFM
measured by DEXA was higher than the criterion method for the complete
study group (1.8 kg) and for men (1.8 kg) and women (1.9 kg)
separately. With use of the Bland and Altman procedure (2), no
association was observed between the mean and the difference of the two
methods (r = 0.09, P = 0.5; Fig. 2B).
|
|
Validation of leg muscle mass and thigh muscle mass.
To examine whether the CT and DEXA methods measured the same amount of
total mass, estimates of total leg mass and total thigh mass were
compared. The results showed a good agreement between the two methods
(total leg R2 = 0.98, difference 0.4 ± 0.7 kg,
P = 0.0001; total thigh
R2 = 0.98, difference +0.0 ± 0.5 kg, P = 0.44).
|
|
|
Validation of muscle mass at the midthigh and calf subregions. A good agreement between the DEXA and CT method was observed for total mass at the midthigh subregion (R2 = 0.94, difference 0.11 ± 0.07 kg, P = 0.0001) and at the calf subregion (R2 = 0.86, difference 0.00 ± 0.06 kg, P = 0.9).
Muscle mass by fan-beam DEXA was positively associated with muscle mass by CT at both subregions (Fig. 3, C and D, Table 4). The explained variance was lower for the calf (R2 = 0.86) than for all other muscle mass comparisons (R2 = 0.94-0.96). At the midthigh subregion, DEXA muscle mass was significantly higher than the CT values. After the exclusion of several outliers [defined as those subjects for whom the difference between the 2 methods was greater or smaller than 2 SDs from the mean (Fig. 4C)], the overestimation was not associated with the level of muscle mass. Muscle mass at the calf subregion was similar between DEXA and CT, with a positive association between the overestimation and the level of muscle mass (r = 0.28, P = 0.03, Fig. 4D). However, after exclusion of one outlier this association became statistically nonsignificant.
|
| |
DISCUSSION |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
The results of the present study show that the fan-beam DEXA technology is a promising body composition method for measuring total body FFM and leg skeletal mass in elderly men and women. The study used a four-compartment model as the criterion method for FFM, which is considered the gold standard for body composition because it takes into account individual and age-related variations in the water content and mineral content of the FFM (9). This DEXA validation study is unique in that it used multislice CT to allow direct validation of skeletal muscle mass at four different regions of the leg, showing high correlations and a good agreement between the two methods.
Absolute differences in FFM between DEXA and the four-compartment model were small but statistically significant. We compared our findings with the results of other studies in which FFM from DEXA was compared with FFM from underwater weighing (6, 15, 18), FFM from total body potassium (6, 12), or FFM from total body water (12, 18). In these studies that all used pencil-beam DEXA scanners, the absolute differences ranged from 0.1 to 2.9 kg, and reported SEEs were 1.9 and 2.3 kg. The observed mean difference of 1.8 ± 1.6 kg FFM and SEE of 1.6 kg FFM in our study are comparable and suggest similar performance of the fan-beam scanner compared with the pencil-beam scanners.
Because of the shape of the fan-beam X-ray, an inherent magnification of scanned structures occurs, increasing as the distance from the X-ray source decreases. This magnification error has been shown to affect measurements of bone area and parameters of hip geometry (11) and may affect the accuracy of the fan-beam DEXA technology for measuring soft tissue composition. The DEXA 4500A scanner measures the distance of each pixel to the X-ray source. The most recent software release (v8.21), which was used in the present study, uses this measured distance in its mathematical models to calculate and adjust for the magnification error of each pixel. The close agreement between the fan-beam DEXA values and the criterion methods, even on small subregions of the leg, suggest that this adjustment is successful and that the fan-beam can be used to estimate FFM and muscle mass in older subjects.
The estimation of muscle mass by DEXA and by CT, and the comparison between the two methods, requires several assumptions. Some of the assumptions necessary for the estimation of muscle mass from DEXA, the interpolation of multiple CT slices, the estimation of the nonfat content of adipose tissue, and the estimation of wet bone mass are discussed below.
Appendicular skeletal muscle mass can be obtained from DEXA by assuming that all nonfat and nonbone tissue is muscle mass (7). This assumption is likely to be valid in the arms and legs and is most likely to be valid at the regions in between joints such as the midthigh and the calf, where the amount of tendons and cartilage is small. For this reason DEXA muscle mass was compared with CT, not only for the total leg and the total thigh but also for smaller regions at the midthigh and the calf. Indeed, the comparisons at the calf subregion showed a slightly better agreement than at the other sites. However, the R2 for the subregions were slightly lower, which might be explained by the increased variability in placing these small subregions when reading and analyzing the DEXA scans. The assumption that all nonfat and nonbone tissue is muscle mass also implies that skin is included in the DEXA muscle mass estimates. Skin tissue was not included in the CT muscle mass estimates. This difference may partly explain the overestimation of DEXA muscle mass vs. CT muscle mass as observed in our study.
To obtain muscle mass of the total leg and the total thigh by CT, we
interpolated the information of five or three slices, respectively. A
linear relationship between the slices was assumed because the use of
more complicated mathematical procedures has been shown to produce
similar results (8). The difference between the DEXA and CT results for
total leg muscle mass and total thigh muscle mass was positively
associated with the mean of the DEXA and CT results. Because this
association was only observed at these two sites that required the
greatest interpolation, and not for muscle mass at the midthigh and
calf subregions where only one CT slice was used, we tried to test the
assumption of linearity between CT slices. The amount of lean
soft-tissue mass of the legs by DEXA was measured in four study
participants (2 men and 2 women) using 25-31 subregions with a
width of 3 pixels, going from the level of the ischial tuberosity (Fig.
5, region 0) down to the ankle joint. Figure 5 suggests that
the assumption of a linear relation between two adjacent CT slices in
the leg seems justified. However, because of the interpolation
procedure, the possibility of bias in the muscle mass estimates by CT
for the total leg and the total thigh cannot be excluded. Increasing the number of CT slices may reduce this potential bias.
|
In this study it was assumed that 20% of adipose tissue consists of nonfat components including water, proteins and minerals. This estimate was based on chemical analyses of fat biopsies in 16 men and women (16). In the literature the nonfat fraction within adipose tissue ranges between 32 (10) and 14% (1), suggesting the value of 20% used here is a reasonable estimate. However, whether the value changes with age or adiposity, or whether the value is different between men and women, is not known.
In the approach by Heymsfield et al. (7), the bone mass is assumed to be 1.82 · BMC. The amount of bone mass by DEXA for the total legs was 1.3 ± 0.3 kg in this study. However, bone mass estimated from the CT data (total mass minus adipose tissue mass minus muscle tissue mass) was 3.8 ± 0.8 kg, which was statistically significantly larger than the DEXA estimate (P = 0.0001). These data suggest that the value of 1.82 · BMC currently used in the DEXA equations might underestimate bone mass. This underestimation of the bone component may partly explain the overestimation of DEXA muscle mass vs. CT muscle mass as observed in our study.
In conclusion, the results of this cross-sectional validation study in 60 elderly men and women suggest that the fan-beam DEXA technology offers considerable promise for the assessment of fat-free body mass and leg muscle mass among elderly subjects. The short scanning time, only 3-4 min for a whole body scan, can substantially reduce scanning and technician costs and makes DEXA a more feasible body composition method. However, whether the fan-beam DEXA technology can accurately measure change in body composition over time cannot be concluded from this study. Longitudinal validation studies are needed to provide such evidence.
| |
ACKNOWLEDGEMENTS |
|---|
The authors thank the technicians at the Department of Radiology (University of California, San Francisco), Marialice Kern and Alice Yee for conducting the underwater-weighing measurements, and Dr. D. A. Schoeller for conducting the total body water measurements.
| |
FOOTNOTES |
|---|
The Health, Aging, and Body Composition Study
Dual-Energy X-ray
Absorptiometry and Body Composition Working Group consists of Jane
Cauley, Maurice Dockrell, Jay Everhart, Tom Fuerst, Tamara Harris, Jean
Langlois, Michael Nevitt, Loran Salamone, Fran Tylavsky, Marjolein
Visser, Rena Wing, and consultants Tom Kelly and Timothy Lohman.
This study was supported by National Institute on Aging Grants NO1-AG-6-2106, NO1-AG-6-2103, NO1-AG-6-2101, and by Hologic Inc.
The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.
Address for reprint requests and other correspondence: M. Visser, Institute for Research in Extramural Medicine, Faculty of Medicine, Vrije Universiteit, Van der Boechorststraat 7, 1081 BT Amsterdam, The Netherlands (E-mail: m.visser.emgo{at}med.vu.nl).
Received 2 February 1999; accepted in final form 15 June 1999.
| |
REFERENCES |
|---|
|
TOP
ABSTRACT
INTRODUCTION
METHODS
RESULTS
DISCUSSION
REFERENCES
|
|---|
1.
Armellini, F.,
L. Scalfi,
S. Castelli,
A. Mino,
and
O. Bosello.
Relationship between hydration of lean body mass and visceral adipose tissue. A clinical study of women.
Int. J. Obes. Relat. Metab. Disord.
20:
37-40,
1996[Medline].
2.
Bland, J. M.,
and
D. G. Altman.
Statistical methods for assessing agreement between two methods of clinical measurement.
Lancet
1:
307-310,
1986[Medline].
3.
Chowdhury, B.,
L. Sjöström,
M. Alpsten,
J. Kostanty,
H. Kvist,
and
R. Lofgren.
A multicompartment body composition technique based on computerized tomography.
Int. J. Obes.
18:
219-234,
1994.
4.
Clasey, J. L.,
M. L. Hartman,
J. Kanaley,
L. Wideman,
C. D. Teates,
C. Bouchard,
and
A. Weltman.
Body composition by DXA in older adults: accuracy and influence of scan mode.
Med. Sci. Sports Exerc.
29:
560-567,
1997[Medline].
5.
Fuller, N. J.,
M. A. Laskey,
and
M. Elia.
Assessment of the composition of major body regions by dual-energy X-ray absorptiometry (DEXA), with special reference to limb muscle mass.
Clin. Physiol.
12:
253-266,
1992[Medline].
6.
Haarbo, J.,
A. Gotfredsen,
C. Hassager,
and
C. Christiansen.
Validation of body composition by dual-energy X-ray absorptiometry (DEXA).
Clin. Physiol.
11:
331-341,
1991[Medline].
7.
Heymsfield, S. B.,
R. Smith,
M. Aulet,
B. Bensen,
S. Lichtman,
J. Wang,
and
R. N. Pieerson.
Appendicular skeletal muscle mass: measurement by dual-energy absorptiometry.
Am. J. Clin. Nutr.
52:
214-218,
1990
8.
Kvist, H.,
L. Sjöström,
and
U. Tylén.
Adipose tissue volume determinations in women by computed tomography: technical considerations.
Int. J. Obes.
10:
53-67,
1986[Medline].
9.
Lohman, T. G.,
and
S. B. Going.
Multicomponent models in body composition research: opportunities and pitfalls.
In: Human Body Composition, edited by K. J. Ellis,
and J. D. Eastman. New York: Plenum, 1993, p. 53-58.
10.
Martin, A. D.,
M. Z. Daniel,
D. T. Drinkwater,
and
J. P. Clarys.
Adipose tissue density, estimated adipose lipid fraction and whole body adiposity in male cadavers.
Int. J. Obes.
18:
79-83,
1994.
11.
Pocock, N. A.,
K. A. Noakes,
Y. Majerovic,
and
M. R. Griffits.
Magnification error of femoral geometry using fan-beam densitometers.
Calcif. Tissue Int.
60:
7-9,
1997.
12.
Rosenfalck, A. M.,
T. Almdal,
A. Gotfredsen,
L. L. Højgaard,
and
J. Hilsted.
Validity of dual X-ray absorptiometry scanning for determination of body composition in IDDM patients.
Scand. J. Clin. Lab. Invest.
55:
691-699,
1995[Medline].
13.
Schoeller, D. A.,
E. Van Santen,
D. W. Peterson,
W. Dietz,
J. Jaspan,
and
P. D. Klein.
Total body water measurement in humans with 18O and 2H labeled water.
Am. J. Clin. Nutr.
33:
2686-2693,
1980
14.
Snyder, W. S.,
M. J. Cook,
E. S. Nasset,
L. R. Karhansen,
G. P. Howells,
and
I. H. Tipton.
Report of the Task Group on Reference Man. Oxford, UK: Pergamon, 1975.
15.
Van Loan, M. D.,
and
P. L. Mayclin.
Body composition assessment: dual-energy X-ray absorptiometry (DEXA) compared to reference methods.
Eur. J. Clin. Nutr.
46:
125-130,
1992[Medline].
16.
Wang, J.,
and
R. N. Pierson, Jr.
Disparate hydration of adipose and lean tissue require a new model for body water distribution in man.
J. Nutr.
106:
1687-1693,
1976.
17.
Wang, Z.,
M. Visser,
R. N. Baumgartner,
D. Kotler,
D. Gallagher,
and
S. B. Heymsfield.
Skeletal muscle mass: evaluation of neutron activation and dual-energy X-ray absorptiometry methods.
J. Appl. Physiol.
80:
824-831,
1996
18.
Wellens, R.,
W. C. Chumlea,
S. Guo,
A. F. Roche,
N. V. Reo,
and
R. M. Siervogel.
Body composition in white adults by dual-energy X-ray absorptiometry, densitometry, and total body water.
Am. J. Clin. Nutr.
59:
547-555,
1994
This article has been cited by other articles:
|
|
 |
|
  M. J Delmonico, T. B Harris, M. Visser, S. W. Park, M. B Conroy, P. Velasquez-Mieyer, R. Boudreau, T. M Manini, M. Nevitt, A. B Newman, et al. Longitudinal study of muscle strength, quality, and adipose tissue infiltration Am. J. Clinical Nutrition, December 1, 2009; 90(6): 1579 - 1585. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. W. Park, B. H. Goodpaster, J. S. Lee, L. H. Kuller, R. Boudreau, N. de Rekeneire, T. B. Harris, S. Kritchevsky, F. A. Tylavsky, M. Nevitt, et al. Excessive Loss of Skeletal Muscle Mass in Older Adults With Type 2 Diabetes Diabetes Care, November 1, 2009; 32(11): 1993 - 1997. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. S. Lee, M. Visser, F. A. Tylavsky, S. B. Kritchevsky, A. V. Schwartz, N. Sahyoun, T. B. Harris, A. B. Newman, and for the Health ABC study Weight Loss and Regain and Effects on Body Composition: The Health, Aging, and Body Composition Study J Gerontol A Biol Sci Med Sci, April 14, 2009; (2009) glp042v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Misra, M. A. Bredella, P. Tsai, N. Mendes, K. K. Miller, and A. Klibanski Lower growth hormone and higher cortisol are associated with greater visceral adiposity, intramyocellular lipids, and insulin resistance in overweight girls Am J Physiol Endocrinol Metab, August 1, 2008; 295(2): E385 - E392. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Pacifico, C. Anania, J. F Osborn, E. Ferrara, E. Schiavo, M. Bonamico, and C. Chiesa Long-term effects of Helicobacter pylori eradication on circulating ghrelin and leptin concentrations and body composition in prepubertal children Eur. J. Endocrinol., March 1, 2008; 158(3): 323 - 332. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. K Houston, B. J Nicklas, J. Ding, T. B Harris, F. A Tylavsky, A. B Newman, J. S. Lee, N. R Sahyoun, M. Visser, S. B Kritchevsky, et al. Dietary protein intake is associated with lean mass change in older, community-dwelling adults: the Health, Aging, and Body Composition (Health ABC) Study Am. J. Clinical Nutrition, January 1, 2008; 87(1): 150 - 155. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Fantin, V. D. Francesco, G. Fontana, A. Zivelonghi, L. Bissoli, E. Zoico, A. Rossi, R. Micciolo, O. Bosello, and M. Zamboni Longitudinal Body Composition Changes in Old Men and Women: Interrelationships With Worsening Disability J. Gerontol. A Biol. Sci. Med. Sci., December 1, 2007; 62(12): 1375 - 1381. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Chen, Z. Wang, T. Lohman, S. B. Heymsfield, E. Outwater, J. S. Nicholas, T. Bassford, A. LaCroix, D. Sherrill, M. Punyanitya, et al. Dual-Energy X-Ray Absorptiometry Is a Valid Tool for Assessing Skeletal Muscle Mass in Older Women J. Nutr., December 1, 2007; 137(12): 2775 - 2780. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. D Hansen, D. A Williamson, T. P Finnegan, B. D Lloyd, J. N Grady, T. H Diamond, E. U. Smith, T. M Stavrinos, M. W Thompson, T. H Gwinn, et al. Estimation of thigh muscle cross-sectional area by dual-energy X-ray absorptiometry in frail elderly patients Am. J. Clinical Nutrition, October 1, 2007; 86(4): 952 - 958. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. J. Prior, S. M. Roth, X. Wang, C. Kammerer, I. Miljkovic-Gacic, C. H. Bunker, V. W. Wheeler, A. L. Patrick, and J. M. Zmuda Genetic and environmental influences on skeletal muscle phenotypes as a function of age and sex in large, multigenerational families of African heritage J Appl Physiol, October 1, 2007; 103(4): 1121 - 1127. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. W. Park, B. H. Goodpaster, E. S. Strotmeyer, L. H. Kuller, R. Broudeau, C. Kammerer, N. de Rekeneire, T. B. Harris, A. V. Schwartz, F. A. Tylavsky, et al. Accelerated Loss of Skeletal Muscle Strength in Older Adults With Type 2 Diabetes: The Health, Aging, and Body Composition Study Diabetes Care, June 1, 2007; 30(6): 1507 - 1512. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. H. Goodpaster, S. W. Park, T. B. Harris, S. B. Kritchevsky, M. Nevitt, A. V. Schwartz, E. M. Simonsick, F. A. Tylavsky, M. Visser, A. B. Newman, et al. The loss of skeletal muscle strength, mass, and quality in older adults: the health, aging and body composition study. J. Gerontol. A Biol. Sci. Med. Sci., October 1, 2006; 61(10): 1059 - 1064. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. F. Reinking Exercise-Related Leg Pain in Female Collegiate Athletes: The Influence of Intrinsic and Extrinsic Factors Am. J. Sports Med., September 1, 2006; 34(9): 1500 - 1507. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. W. Park, B. H. Goodpaster, E. S. Strotmeyer, N. de Rekeneire, T. B. Harris, A. V. Schwartz, F. A. Tylavsky, and A. B. Newman Decreased Muscle Strength and Quality in Older Adults With Type 2 Diabetes: The Health, Aging, and Body Composition Study Diabetes, June 1, 2006; 55(6): 1813 - 1818. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. LeMaitre, S. Harris, J. Hannan, K. A.A. Fox, and M. A. Denvir Maximum oxygen uptake corrected for skeletal muscle mass accurately predicts functional improvements following exercise training in chronic heart failure Eur J Heart Fail, May 1, 2006; 8(3): 243 - 248. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. B. Newman, V. Kupelian, M. Visser, E. M. Simonsick, B. H. Goodpaster, S. B. Kritchevsky, F. A. Tylavsky, S. M. Rubin, T. B. Harris, and on Behalf of the Health, Aging and Body Compositio Strength, But Not Muscle Mass, Is Associated With Mortality in the Health, Aging and Body Composition Study Cohort J. Gerontol. A Biol. Sci. Med. Sci., January 1, 2006; 61(1): 72 - 77. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. B Newman, J. S. Lee, M. Visser, B. H Goodpaster, S. B Kritchevsky, F. A Tylavsky, M. Nevitt, and T. B Harris Weight change and the conservation of lean mass in old age: the Health, Aging and Body Composition Study Am. J. Clinical Nutrition, October 1, 2005; 82(4): 872 - 878. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Misra, K. K. Miller, K. Kuo, K. Griffin, V. Stewart, E. Hunter, D. B. Herzog, and A. Klibanski Secretory dynamics of ghrelin in adolescent girls with anorexia nervosa and healthy adolescents Am J Physiol Endocrinol Metab, August 1, 2005; 289(2): E347 - E356. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A Schoeller, F. A Tylavsky, D. J Baer, W. C Chumlea, C. P Earthman, T. Fuerst, T. B Harris, S. B Heymsfield, M. Horlick, T. G Lohman, et al. QDR 4500A dual-energy X-ray absorptiometer underestimates fat mass in comparison with criterion methods in adults Am. J. Clinical Nutrition, May 1, 2005; 81(5): 1018 - 1025. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Misra, K. K. Miller, C. Almazan, M. Worley, D. B. Herzog, and A. Klibanski Hormonal Determinants of Regional Body Composition in Adolescent Girls with Anorexia Nervosa and Controls J. Clin. Endocrinol. Metab., May 1, 2005; 90(5): 2580 - 2587. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. K. Petrella, J.-s. Kim, S. C. Tuggle, S. R. Hall, and M. M. Bamman Age differences in knee extension power, contractile velocity, and fatigability J Appl Physiol, January 1, 2005; 98(1): 211 - 220. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. E. Bolton, A. A. Ionescu, K. M. Shiels, R. J. Pettit, P. H. Edwards, M. D. Stone, L. S. Nixon, W. D. Evans, T. L. Griffiths, and D. J. Shale Associated Loss of Fat-free Mass and Bone Mineral Density in Chronic Obstructive Pulmonary Disease Am. J. Respir. Crit. Care Med., December 15, 2004; 170(12): 1286 - 1293. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Misra, A. Aggarwal, K. K. Miller, C. Almazan, M. Worley, L. A. Soyka, D. B. Herzog, and A. Klibanski Effects of Anorexia Nervosa on Clinical, Hematologic, Biochemical, and Bone Density Parameters in Community-Dwelling Adolescent Girls Pediatrics, December 1, 2004; 114(6): 1574 - 1583. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Sergi, L. Lupoli, S. Volpato, R. Bertani, A. Coin, E. Perissinotto, I. Calliari, E. M. Inelmen, L. Busetto, and G. Enzi Body Fluid Distribution in Elderly Subjects with Congestive Heart Failure Ann. Clin. Lab. Sci., October 1, 2004; 34(4): 416 - 422. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Misra, K. K. Miller, C. Almazan, K. Ramaswamy, W. Lapcharoensap, M. Worley, G. Neubauer, D. B. Herzog, and A. Klibanski Alterations in Cortisol Secretory Dynamics in Adolescent Girls with Anorexia Nervosa and Effects on Bone Metabolism J. Clin. Endocrinol. Metab., October 1, 2004; 89(10): 4972 - 4980. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Misra, K. K. Miller, D. B. Herzog, K. Ramaswamy, A. Aggarwal, C. Almazan, G. Neubauer, J. Breu, and A. Klibanski Growth Hormone and Ghrelin Responses to an Oral Glucose Load in Adolescent Girls with Anorexia Nervosa and Controls J. Clin. Endocrinol. Metab., April 1, 2004; 89(4): 1605 - 1612. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. M. Modlesky, C. S. Bickel, J. M. Slade, R. A. Meyer, K. J. Cureton, and G. A. Dudley Assessment of skeletal muscle mass in men with spinal cord injury using dual-energy X-ray absorptiometry and magnetic resonance imaging J Appl Physiol, February 1, 2004; 96(2): 561 - 565. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Misra, K. K. Miller, J. Bjornson, A. Hackman, A. Aggarwal, J. Chung, M. Ott, D. B. Herzog, M. L. Johnson, and A. Klibanski Alterations in Growth Hormone Secretory Dynamics in Adolescent Girls with Anorexia Nervosa and Effects on Bone Metabolism J. Clin. Endocrinol. Metab., December 1, 2003; 88(12): 5615 - 5623. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Visser, D. J. H. Deeg, and P. Lips Low Vitamin D and High Parathyroid Hormone Levels as Determinants of Loss of Muscle Strength and Muscle Mass (Sarcopenia): The Longitudinal Aging Study Amsterdam J. Clin. Endocrinol. Metab., December 1, 2003; 88(12): 5766 - 5772. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. de Rekeneire, H. E. Resnick, A. V. Schwartz, R. I. Shorr, L. H. Kuller, E. M. Simonsick, B. Vellas, and T. B. Harris Diabetes Is Associated With Subclinical Functional Limitation in Nondisabled Older Individuals: The Health, Aging, and Body Composition study Diabetes Care, December 1, 2003; 26(12): 3257 - 3263. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. B. Newman, C. L. Haggerty, S. B. Kritchevsky, M. C. Nevitt, and E. M. Simonsick Walking Performance and Cardiovascular Response: Associations With Age and Morbidity--The Health, Aging and Body Composition Study J. Gerontol. A Biol. Sci. Med. Sci., August 1, 2003; 58(8): M715 - 720. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Misra, L. A Soyka, K. K Miller, S. Grinspoon, L. L Levitsky, and A. Klibanski Regional body composition in adolescents with anorexia nervosa and changes with weight recovery Am. J. Clinical Nutrition, June 1, 2003; 77(6): 1361 - 1367. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Visser, M. Pahor, F. Tylavsky, S. B. Kritchevsky, J. A. Cauley, A. B. Newman, B. A. Blunt, and T. B. Harris One- and two-year change in body composition as measured by DXA in a population-based cohort of older men and women J Appl Physiol, June 1, 2003; 94(6): 2368 - 2374. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. L. Herbst, B. D. Anawalt, J. K. Amory, A. M. Matsumoto, and W. J. Bremner The Male Contraceptive Regimen of Testosterone and Levonorgestrel Significantly Increases Lean Mass in Healthy Young Men in 4 Weeks, but Attenuates a Decrease in Fat Mass Induced by Testosterone Alone J. Clin. Endocrinol. Metab., March 1, 2003; 88(3): 1167 - 1173. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Tylavsky, T. Lohman, B. A. Blunt, D. A. Schoeller, T. Fuerst, J. A. Cauley, M. C. Nevitt, M. Visser, and T. B. Harris QDR 4500A DXA overestimates fat-free mass compared with criterion methods J Appl Physiol, March 1, 2003; 94(3): 959 - 965. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A Tylavsky, T. G Lohman, M. Dockrell, T. Lang, D. A Schoeller, J. Y Wan, T. Fuerst, J. A Cauley, M. Nevitt, and T. B Harris Comparison of the effectiveness of 2 dual-energy X-ray absorptiometers with that of total body water and computed tomography in assessing changes in body composition during weight change Am. J. Clinical Nutrition, February 1, 2003; 77(2): 356 - 363. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Marquis, R. Debigare, Y. Lacasse, P. LeBlanc, J. Jobin, G. Carrier, and F. Maltais Midthigh Muscle Cross-Sectional Area Is a Better Predictor of Mortality than Body Mass Index in Patients with Chronic Obstructive Pulmonary Disease Am. J. Respir. Crit. Care Med., September 15, 2002; 166(6): 809 - 813. [Abstract] [Full Text]
|
|
|
|
|
|
J. Kim, Z. Wang, S. B Heymsfield, R. N Baumgartner, and D. Gallagher Total-body skeletal muscle mass: estimation by a new dual-energy X-ray absorptiometry method Am. J. Clinical Nutrition, August 1, 2002; 76(2): 378 - 383. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Sergi, A. Coin, M. Bussolotto, P. Beninca, G. Tomasi, C. Pisent, S. Peruzza, E. M. Inelmen, and G. Enzi Influence of Fat-Free Mass and Functional Status on Resting Energy Expenditure in Underweight Elders J. Gerontol. A Biol. Sci. Med. Sci., May 1, 2002; 57(5): M302 - 307. [Abstract] [Full Text]
|
|
|
|
|
|
A. Y. McDermott, A. Shevitz, T. Knox, R. Roubenoff, J. Kehayias, and S. Gorbach Effect of highly active antiretroviral therapy on fat, lean, and bone mass in HIV-seropositive men and women Am. J. Clinical Nutrition, November 1, 2001; 74(5): 679 - 686. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. M. Prior, C. M. Modlesky, E. M. Evans, M. A. Sloniger, M. J. Saunders, R. D. Lewis, and K. J. Cureton Muscularity and the density of the fat-free mass in athletes J Appl Physiol, April 1, 2001; 90(4): 1523 - 1531. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P Tothill, W J Hannan, and S Wilkinson Comparisons between a pencil beam and two fan beam dual energy X-ray absorptiometers used for measuring total body bone and soft tissue Br. J. Radiol., February 1, 2001; 74(878): 166 - 176. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. M. Salamone, T. Fuerst, M. Visser, M. Kern, T. Lang, M. Dockrell, J. A. Cauley, M. Nevitt, F. Tylavsky, and T. G. Lohman Measurement of fat mass using DEXA: a validation study in elderly adults J Appl Physiol, July 1, 2000; 89(1): 345 - 352. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
) and women (
). Solid line, line of equality.
B: difference in fat-free body mass
between fan-beam DEXA and a 4-compartment model plotted against the
mean. Solid line, mean difference; dashed lines, limits of agreement
(±2 SDs).
) and
2 women (
). Symbols indicate location of CT
slices.