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Steven B Heymsfield - One of the best experts on this subject based on the ideXlab platform.
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bioelectrical impedance analysis population reference values for phase angle by age and sex
The American Journal of Clinical Nutrition, 2005Co-Authors: Maria Cristina G Barbosasilva, Aluisio J D Barros, Jack Wang, Steven B Heymsfield, Richard N PiersonAbstract:Background: Phase angle is an indicator based on reactance and resistance obtained from bioelectrical impedance analysis (BIA). Although its biological meaning is still not clear, phase angle appears to have an important prognostic role. Objective: The aim of this study was to estimate population averages and SDs of phase angle that can be used as reference values. Design: BIA and other methods used to evaluate body composition, including Hydrodensitometry and total body water, were completed in 1967 healthy adults aged 18-94 y. Phase angle was calculated directly from body resistance and reactance, and fat mass (FM) was estimated from the combination of weight, Hydrodensitometry, and total body water by using the 3-compartment Siri equation. Phase angle values were compared across categories of sex, age, body mass index (BMI), and percentage FM. Results: Phase angle was significantly (P < 0.001) smaller in women than in men and was lower with greater age (P < 0.001). Phase angle increased with an increase in BMI and was significantly inversely associated with percentage fat in men. Phase angle was significantly predicted from sex, age, BMI, and percentage FM in multiple regression models. Conclusions: Phase angle differs across categories of sex, age, BMI, and percentage fat. These reference values can serve as a basis for phase angle evaluations in the clinical setting.
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Body composition in children and adults by air displacement plethysmography.
European Journal of Clinical Nutrition, 1999Co-Authors: Christopher Nuñez, Stanley Heshka, Aj Kovera, Angelo Pietrobelli, Mary Horlick, Jj Kehayias, Z. M. Wang, Steven B HeymsfieldAbstract:Objectives: Air displacement plethysmography (ADP) may provide a partial alternative to body density (Bd) and therefore body composition measurement compared to conventional Hydrodensitometry (Hd) in children. As there are no evaluation studies of ADP in children, this study had a two-fold objective: to compare Bd estimates by ADP and Hd; and to compare fat estimates by both ADP and Hd to fat estimates by another reference method, dual energy X-ray absorptiometry (DXA). Setting: Obesity Research Center, St. Luke’s=Roosevelt Hospital, New York, USA. Subjects: One hundred and twenty subjects (66 females=54 males) who ranged in age from 6 ‐ 86 y and in body mass index (BMI, kg=m 2 ) from 14.1 ‐ 40.0 kg=m 2 met study entry criteria. Study Design: Cross-sectional study of healthy children (age 19 y) and adult group for comparison to earlier studies. Each subject completed ADP, Hd, and DXA studies on the same day. Only subjects with subjectivelyjudged successful Hd studies were entered into the study cohort. Results: There was a high correlation between Bd by ADP and Hd (Bd Hda 0.11a 0.8966Bd ADP; ra 0.93, SEEa 0.008 g=cm 3 , P 0.9, P< 0.0001) with %fat by DXA in child and adult subgroups. Bland ‐ Altman analyses revealed no significant %fat bias by either ADP or Hd vs DXA in either children or adults, although a bias trend (Pa 0.11) was detected in the child subgroup. Conclusion: With additional refinements, the air displacement plethysmography system has the potential of providing an accurate and practical method of quantifying body fat in children as it now does in adults. Sponsorship: This study was in-part supported by NIH Grants RR00645, NIDDK 42618 and NIDDK 37352. Descriptors: air displacement plethysmography; body composition; Hydrodensitometry; children
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effects of gender body composition and menopause on plasma concentrations of leptin
The Journal of Clinical Endocrinology and Metabolism, 1996Co-Authors: Michael Rosenbaum, Steven B Heymsfield, Dympna Gallagher, M Nicolson, Jules Hirsch, Rudolph L LeibelAbstract:Circulating concentrations of leptin ([leptin]) vary directly with body mass index and percentage body fat, and may thus constitute an afferent limb of a system regulating body fatness. We tested the hypotheses that: 1) Plasma [leptin] vary more directly with absolute fat mass than with fractional body fatness per se: and 2). The relationship between fat mass and [leptin] is significantly affected by gender and by menopausal status. [Leptin] in the post-absorptive state was examined in 67 subjects (26 male, 20 premenopausal female, 21 postmenopausal females; 43 never-obese, 24 obese) at usual body weight. Body composition was determined by Hydrodensitometry, and [leptin] was determined by a double antibody ELISA assay. In male and pre-menopausal female subjects, subcutaneous adipose tissue aspirations were performed for determination of adipocyte volume by the osmium fixation method, and a 3 hour oral glucose tolerance tests was performed. At usual body weight, ([leptin]) was better correlated with absolu...
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Differences between young and old females in the five levels of body composition and their relevance to the two-compartment chemical model
Journal of Gerontology, 1994Co-Authors: Manolo Mazariegos, Jack Wang, Richard N Pierson, Zimian Wang, Dympna Gallagher, Richard N. Baumgartner, David B. Allison, Steven B HeymsfieldAbstract:BACKGROUND Body composition differs between young and old females, although the magnitude of these age-related changes remains uncertain. This uncertainty persists because methodology applied in earlier studies required assumptions that may be age-dependent and also because studies included young and old subjects who differed substantially in body size and health status. METHODS To resolve these earlier concerns we examined components at the atomic, molecular, cellular, tissue-system, and whole body levels of body composition in 19 weight- and height-matched pairs of young (age 19-35 yrs) and old (age > 65 yrs) healthy White females. Isotope dilution, dual photon, whole-body counting, Hydrodensitometry, and anthropometric methods were used either alone or in combination to produce multicomponent models. RESULTS Old females had significantly more fat, greater truncal skinfolds and circumferences, and significantly less fat-free body mass (FFM), total body potassium (TBK), total body water (TBW), and bone mineral than did their young matched counterparts. Skeletal muscle mass was less in the old females, although the magnitude of the difference from young females varied between the three indices examined. The main assumptions (i.e., TBW/FFM = 0.73 kg/kg and density of FFM = 1.100 g/cc) which the widely used two-compartment TBW and Hydrodensitometry methods are based on were not significantly different in young and old females. In contrast, the main assumed steady-state value for the two-compartment TBK method (TBK/FFM = 64.2 mmol/kg) was significantly lower (p < .001) in the old females. CONCLUSION New approaches thus allow for a critical reexamination of body composition in elderly subjects, and these methods also give new insight into less complex widely used body composition techniques.
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Skeletal differences between black and white men and their relevance to body composition estimates.
American Journal of Human Biology, 1994Co-Authors: Laura Gerace, Jack Wang, Richard N Pierson, Zimian Wang, David B. Allison, Antonios O. Aliprantis, Mary Russell, Kathleen M. Buhl, Steven B HeymsfieldAbstract:Skeletal differences exist between closely matched Black and White women, although it is unknown if similar differences also exist between Black and White men after controlling for age, body weight, and stature. The aim of this study was twofold: to test the hypothesis that Black men have greater bone mass, higher bone mineral density, and longer limbs compared to White men of similar age, weight, and height; and second, to establish if ethnic variation in skeletal characteristics has an impact on the models upon which three widely used methods for estimating total body fat are based. Twenty-four healthy Black men were matched by age (±5 years), height (±3 cm), and weight (±2 kg) to 24 healthy White men. Skeletal characteristics and body composition were studied using anatomical and compartment estimates derived by anthropometry, 3 H2 O dilution, Hydrodensitometry, whole-body 40 K counting, and dual photon systems. Black men had greater bone mineral mass (P = 0.007), higher bone density (P = 0.054), longer femurs (P = 0.002), longer anthropometric arm and thigh lengths (P = 0.001 and P = 0.002, respectively), lower spine to femur ratio (P = 0.004), and similar spine length (P = 0.271) compared to White men. Total body fat and fat-free body mass (FFM) were estimated in the men using a four-compartment model. Black and White men had similar total body fat, K (TBK), water (TBW), and FFM. Density of FFM and TBK/FFM were also similar between Black and White men, suggesting that current two-compartment Hydrodensitometry and TBK models for estimating fat may not require adjustments for ethnicity. The TBW/FFM ratio, which is the main assumed steady-state relation for the two-compartment TBW method of estimating fat, was modestly increased (P = 0.05) in Black men (x ± SD, 0.744 ± 0.018) compared to White men (0.732 ± 0.021). These results confirm that Black and White men differ significantly in some skeletal characteristics and these differences have implications in the study of both osteoporosis and human body composition. © 1994 Wiley-Liss, Inc.
Richard N Pierson - One of the best experts on this subject based on the ideXlab platform.
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bioelectrical impedance analysis population reference values for phase angle by age and sex
The American Journal of Clinical Nutrition, 2005Co-Authors: Maria Cristina G Barbosasilva, Aluisio J D Barros, Jack Wang, Steven B Heymsfield, Richard N PiersonAbstract:Background: Phase angle is an indicator based on reactance and resistance obtained from bioelectrical impedance analysis (BIA). Although its biological meaning is still not clear, phase angle appears to have an important prognostic role. Objective: The aim of this study was to estimate population averages and SDs of phase angle that can be used as reference values. Design: BIA and other methods used to evaluate body composition, including Hydrodensitometry and total body water, were completed in 1967 healthy adults aged 18-94 y. Phase angle was calculated directly from body resistance and reactance, and fat mass (FM) was estimated from the combination of weight, Hydrodensitometry, and total body water by using the 3-compartment Siri equation. Phase angle values were compared across categories of sex, age, body mass index (BMI), and percentage FM. Results: Phase angle was significantly (P < 0.001) smaller in women than in men and was lower with greater age (P < 0.001). Phase angle increased with an increase in BMI and was significantly inversely associated with percentage fat in men. Phase angle was significantly predicted from sex, age, BMI, and percentage FM in multiple regression models. Conclusions: Phase angle differs across categories of sex, age, BMI, and percentage fat. These reference values can serve as a basis for phase angle evaluations in the clinical setting.
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Differences between young and old females in the five levels of body composition and their relevance to the two-compartment chemical model
Journal of Gerontology, 1994Co-Authors: Manolo Mazariegos, Jack Wang, Richard N Pierson, Zimian Wang, Dympna Gallagher, Richard N. Baumgartner, David B. Allison, Steven B HeymsfieldAbstract:BACKGROUND Body composition differs between young and old females, although the magnitude of these age-related changes remains uncertain. This uncertainty persists because methodology applied in earlier studies required assumptions that may be age-dependent and also because studies included young and old subjects who differed substantially in body size and health status. METHODS To resolve these earlier concerns we examined components at the atomic, molecular, cellular, tissue-system, and whole body levels of body composition in 19 weight- and height-matched pairs of young (age 19-35 yrs) and old (age > 65 yrs) healthy White females. Isotope dilution, dual photon, whole-body counting, Hydrodensitometry, and anthropometric methods were used either alone or in combination to produce multicomponent models. RESULTS Old females had significantly more fat, greater truncal skinfolds and circumferences, and significantly less fat-free body mass (FFM), total body potassium (TBK), total body water (TBW), and bone mineral than did their young matched counterparts. Skeletal muscle mass was less in the old females, although the magnitude of the difference from young females varied between the three indices examined. The main assumptions (i.e., TBW/FFM = 0.73 kg/kg and density of FFM = 1.100 g/cc) which the widely used two-compartment TBW and Hydrodensitometry methods are based on were not significantly different in young and old females. In contrast, the main assumed steady-state value for the two-compartment TBK method (TBK/FFM = 64.2 mmol/kg) was significantly lower (p < .001) in the old females. CONCLUSION New approaches thus allow for a critical reexamination of body composition in elderly subjects, and these methods also give new insight into less complex widely used body composition techniques.
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Skeletal differences between black and white men and their relevance to body composition estimates.
American Journal of Human Biology, 1994Co-Authors: Laura Gerace, Jack Wang, Richard N Pierson, Zimian Wang, David B. Allison, Antonios O. Aliprantis, Mary Russell, Kathleen M. Buhl, Steven B HeymsfieldAbstract:Skeletal differences exist between closely matched Black and White women, although it is unknown if similar differences also exist between Black and White men after controlling for age, body weight, and stature. The aim of this study was twofold: to test the hypothesis that Black men have greater bone mass, higher bone mineral density, and longer limbs compared to White men of similar age, weight, and height; and second, to establish if ethnic variation in skeletal characteristics has an impact on the models upon which three widely used methods for estimating total body fat are based. Twenty-four healthy Black men were matched by age (±5 years), height (±3 cm), and weight (±2 kg) to 24 healthy White men. Skeletal characteristics and body composition were studied using anatomical and compartment estimates derived by anthropometry, 3 H2 O dilution, Hydrodensitometry, whole-body 40 K counting, and dual photon systems. Black men had greater bone mineral mass (P = 0.007), higher bone density (P = 0.054), longer femurs (P = 0.002), longer anthropometric arm and thigh lengths (P = 0.001 and P = 0.002, respectively), lower spine to femur ratio (P = 0.004), and similar spine length (P = 0.271) compared to White men. Total body fat and fat-free body mass (FFM) were estimated in the men using a four-compartment model. Black and White men had similar total body fat, K (TBK), water (TBW), and FFM. Density of FFM and TBK/FFM were also similar between Black and White men, suggesting that current two-compartment Hydrodensitometry and TBK models for estimating fat may not require adjustments for ethnicity. The TBW/FFM ratio, which is the main assumed steady-state relation for the two-compartment TBW method of estimating fat, was modestly increased (P = 0.05) in Black men (x ± SD, 0.744 ± 0.018) compared to White men (0.732 ± 0.021). These results confirm that Black and White men differ significantly in some skeletal characteristics and these differences have implications in the study of both osteoporosis and human body composition. © 1994 Wiley-Liss, Inc.
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Body composition of humans: comparison of two improved four-compartment models that differ in expense, technical complexity, and radiation exposure
The American Journal of Clinical Nutrition, 1990Co-Authors: Steven B Heymsfield, Jack Wang, Steven W. Lichtman, Antonios O. Aliprantis, R N Baumgartner, Y. Kamen, Richard N PiersonAbstract:Multicompartment models are of growing importance in the study of body composition in humans. This study compares two improved four-compartment (water, protein, mineral, and fat) models that differ in expense, technological complexity, and radiation exposure. Primary data (from 31 subjects) for the first model were derived by dual-photon absorptiometry, 3H2O dilution, and Hydrodensitometry and for the second model by delayed and prompt gamma neutron-activation analysis and 3H2O dilution. Estimates of fat, protein, and mineral from the first model were highly correlated with those from the second model (r = 0.98, 0.72, and 0.94, respectively; all p less than 0.001). The proportions of body weight represented by water, protein, mineral, and fat for the simpler first model (0.532, 0.155, 0.048, and 0.265) were similar to compartment fractions provided by the more complex and costly second model (0.532, 0.143, 0.046, and 0.279). Multicompartment body composition models can thus be developed from increasingly available techniques that compare favorably with similar results derived from limited-access instrumentation.
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body composition of humans comparison of two improved four compartment models that differ in expense technical complexity and radiation exposure
The American Journal of Clinical Nutrition, 1990Co-Authors: Steven B Heymsfield, Jack Wang, Steven W. Lichtman, Antonios O. Aliprantis, R N Baumgartner, Y. Kamen, Richard N PiersonAbstract:Multicompartment models are of growing importance in the study ofbody composition in humans. This study compares two improved four-compartment (water, pro- tein, mineral, and fat) models that differ in expense, technologi- cal complexity, and radiation exposure. Primary data (from 31 subjects) for the first model were derived by dual-photon ab- sorptiometry, 3H2O dilution, and Hydrodensitometry and for the second model by delayed and prompty neutron-activation analysis and 3H20 dilution. Estimates offat, protein, and mm- eral from the first model were highly correlated with those from the second model (r = 0.98, 0.72, and 0.94, respectively; all p < 0.001). The proportions ofbody weight represented by water, protein, mineral, and fat for the simpler first model (0.532, 0. 155, 0.048, and 0.265) were similarto compartment fractions provided by the more complex and costly second model (0.532, 0. 143, 0.046, and 0.279). Multicompartment body composi- tion models can thus be developed from increasingly available techniques that compare favorably with similar results derived from limited-access instrumentation. Am J C/in Nutr 1990;52:52-8.
Giraldo Argenis - One of the best experts on this subject based on the ideXlab platform.
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Comparison of three bioimpedance techniques with Hydrodensitometry for assessment of body composition in young adult women
Universidad de Antioquia, 2017Co-Authors: Aristizábal, Juan Carlos, Giraldo ArgenisAbstract:Background: Bioimpedance measurement allows quick and safe estimation of the body composition. However, it remains controversial which bioimpedance measurement technique is more exact for calculating the fat mass percentage (%FM). Objective: To compare the %FM obtained with three bioimpedance techniques with Hydrodensitometry, as a reference method. Materials and methods: In 31 women, the %FM was assessed by Hydrodensitometry with simultaneous lung residual volume measurement and three bioimpedance techniques: hands-to-feet (8-electrodes), hand-to-foot (4-electrodes) and footto-foot (4-electrodes). Results: Average age and body mass index were 22.4 ± 2.8 years and 23.6 ± 3.3 kg/m2, respectively. There were no significant differences (p > 0.05) between the %FM obtained by Hydrodensitometry (31.4 ± 6.6) and hands-to-feet technique (31.9 ± 5.9). However, hand-to-foot and foot-to-foot techniques showed differences (p < 0.05) with the reference method of +1.4 % and -4.9%, respectively. There was a fair agreement between Hydrodensitometry and the results obtained with hands-to-feet (Bland-Altman: IC95 %: -6.6; 5.6) and hand-to-foot (Bland-Altman: IC95 %: -8.0; 5.2) techniques. The foot-to-foot measurement showed poor agreement with the reference method (Bland-Altman: IC95 %: -4.7; 14.4). Conclusions: In this group of young women with healthy body weight, the hands-to-feet bioimpedance technique generates body composition values closer to the Hydrodensitometry results as compared with the hand-to-foot and foot-to-foot techniques. Additionally, the hands-to-feet technique shows a slightly better agreement with Hydrodensitometry than the hand-to-foot and foot-to-foot techniques
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Comparación de la composición corporal de mujeres jóvenes obtenida por hidrodensitometría y tres técnicas de bioimpedancia
Grupo de Investigación en Fisiología y Bioquímica - Physis, 2017Co-Authors: Aristizábal Rivera, Juan Carlos, Giraldo ArgenisAbstract:Antecedentes: existe controversia sobre la exactitud de las técnicas de bioimpedancia para calcular el porcentaje de grasa corporal (%GC). Objetivo: comparar el %GC obtenido por tres técnicas de bioimpedancia con la hidrodensitometría como método de referencia. Metodología: en 31 mujeres se midió el %GC por hidrodensitometría con medición simultánea del volumen residual pulmonar, y por las técnicas de bioimpedancia manos-pies (8-electrodos), mano-pie (4-electrodos) y pie-pie (4-electrodos). Resultados: el promedio de edad fue 22,4 ± 2,8 años y el del índice de masa corporal 23,6 ± 3,3 kg/m2. No hubo diferencias (p > 0,05) en el %GC obtenido por hidrodensitometría y por la técnica manos-pies (31,4 ± 6,6 % y 31,9 ± 5,9 %, respectivamente). Las técnicas mano-pie y pie-pie presentaron diferencias (p 0.05) between the %FM obtained by Hydrodensitometry (31.4 ± 6.6) and hands-to-feet technique (31.9 ± 5.9). However, hand-to-foot and foot to-foot techniques showed differences (p < 0.05) with the reference method of +1.4 % and -4.9%, respectively. There was a fair agreement between Hydrodensitometry and the results obtained with hands-to-feet (Bland-Altman: IC95 %: -6.6; 5.6) and hand-to-foot (Bland-Altman: IC95 %: -8.0; 5.2) techniques. The foot-to-foot measurement showed poor agreement with the reference method (Bland-Altman: IC95 %: -4.7; 14.4). Conclusions: In this group of young women with healthy body weight, the hands-to-feet bioimpedance technique generates body composition values closer to the Hydrodensitometry results as compared with the hand-to-foot and foot-to-foot techniques. Additionally, the hands-to-feet technique shows a slightly better agreement with Hydrodensitometry than the hand-to-foot and foot-to-foot techniques
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Comparison of body composition assessment by bioimpedance versus Hydrodensitometry in women 38 to 60 years old from Medellin-Colombia
Grupo de Investigación en Fisiología y Bioquímica - Physis, 2015Co-Authors: Aristizábal Rivera, Juan Carlos, Olaya Ramírez, Sara M., Giraldo ArgenisAbstract:Antecedentes: la bioimpedancia es un método de estimación de la composición corporal rápido, económico y portátil. Objetivo: comparar la composición corporal obtenida por bioimpedancia e hidrodensitometría en mujeres de Medellín-Colombia. Materiales y métodos: se evaluó el porcentaje de grasa corporal de 50 voluntarias. Se utilizó como método de referencia la hidrodensitometría con medición simultánea del volumen residual pulmonar. Se midió la bioimpedancia mano-pie y se estimó el porcentaje de grasa corporal con las ecuaciones de Kotler y Sun. La bioimpedancia pie-pie se midió con báscula Tanita. El análisis estadístico empleó t-student pareada, error estándar del estimado y prueba Bland-Altman. Resultados: el porcentaje de grasa corporal obtenido por hidrodensitometría fue (33,3±5,6). Sun y Kotler estimaron porcentajes de grasa similares (p>0,05) a la hidrodensitometría (34,0±4,8 y 34,4±6,0, respectivamente). Tanita estimó un porcentaje de grasa diferente al método de referencia (30,1±5,8, p=0,000). La bioimpedancia presentó un bajo grado de acuerdo con la hidrodensitometría: Sun (BlandAltman: -0,73 IC95%: -9,9; 8,4), Kotler (Bland-Altman: -1,1 IC95%: -10,7; 8,5) y Tanita (Bland-Altman: 3,2 IC95%: -5,8; 12,2). Conclusiones: las ecuaciones de Sun y Kotler estiman de forma adecuada el porcentaje de grasa corporal grupal, pero presentan poca concordancia con la hidrodensitometría en la estimación de la composición corporal individual. La báscula Tanita presentó las mayores diferencias con la hidrodensitometría en la estimación del porcentaje de grasa corporal grupal e individual.Background: Body composition assessment by bioimpedance is non-invasive, inexpensive and portable. Objective: To assess the validity of bioimpedance to estimate fat mass percentage (%FM) in women. Materials and methods: This is a cross-sectional study with a sample of 50 women, 38 to 60 years old. Hydrodensitometry with simultaneous measurement of the lung residual volume was used as the reference method. The %FM was assessed by the bioimpedance hand-to-feet technique using the equations of Sun and Kotler. A Tanita body composition scale was used to estimate the %FM with the bioimpedance feet-to-feet technique. Results: The %FM estimated by Sun (34,0±4,8) and Kotler (34,4±6,0) were not different (p>0,05) from the %FM obtained by Hydrodensitometry (33,3±5,6). The %FM estimated by Tanita differed from the reference method (30,1±5,8, p=0,000). BIA equations and Tanita showed low agreement with Hydrodensitometry: Sun (Bland-Altman: -0,73 CI95%: -9,9; 8,4), Kotler (Bland-Altman: -1,1 CI95%: -10,7; 8,5) and Tanita (Bland-Altman: 3,2 CI95%: -5,8; 12,2). Conclusions: In this specific population of women, hand-to-feet bioimpedance with Sun and Kotler equations accurately estimated the %FM of the whole group, but these equations lacked validity to assess the individual %FM. The Tanita body composition scale lacked validity to assess both; individual and group %FM
Vivian H Heyward - One of the best experts on this subject based on the ideXlab platform.
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Comparison of air-displacement plethysmography, Hydrodensitometry, and dual X-ray absorptiometry for assessing body composition of children 10 to 18 years of age.
Annals of the New York Academy of Sciences, 2006Co-Authors: D. W. Lockner, Vivian H Heyward, R N Baumgartner, K. A. JenkinsAbstract:Abstract: Body density (Db) of 54 boys and girls 10–18 years of age (13.9 ± 2.4 years) was measured in an air-displacement plethysmograph, the BOD POD®, and compared to Db determined by Hydrodensitometry (HW). Both Db values were converted to percent body fat (%BF) using a two-component model conversion formula and compared to %BF determined by dual energy X-ray absorptiometry (DXA). Body density estimated from the BOD POD (1.04657 ± 0.01825 g/cc) was significantly higher than that estimated from HW (1.04032 ± 0.01872 g/cc). The relative body fat calculated from the BOD POD (23.12 ± 8.39 %BF) was highly correlated but, on average, 2.9% BF lower than %BF DXA. Average %BF estimates from HW and DXA were not significantly different. Despite consistently underestimating the %BF of children, the strong relationship between DXA and the BOD POD suggests that further investigation may improve the accuracy of the BOD POD for assessing body composition in children.
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techniques of body composition assessment a review of laboratory and field methods
Research Quarterly for Exercise and Sport, 1999Co-Authors: Dale R Wagner, Vivian H HeywardAbstract:Abstract Body composition is one of the major health-related components of fitness. Thus, it is important for health and fitness professionals to have a general understanding of the most commonly used techniques for assessing body composition. This review presents the developmental background and underlying principles and theory of four laboratory (Hydrodensitometry, air displacement plethysmography, isotope dilution, and dual-energy x-ray absorptiometry) and four field (bioelectrical impedance analysis, near-infrared interactance, skinfolds, and anthropometry) methods of body composition assessment. In addition to a description of the methods, the validity, and reliability, strengths, and limitations of each measurement tool are examined. Highlights of the laboratory methods include the relatively new Bod Pod® air displacement device, which is a promising assessment tool more convenient than Hydrodensitometry but still lacking substantial validity testing and the ability of dual-energy x-ray absorptiomet...
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Evaluation of body composition. Current issues.
Sports Medicine, 1996Co-Authors: Vivian H HeywardAbstract:In the selection of body composition field methods and prediction equations, exercise and health practitioners must consider their clients’ demographics. Factors, such as age, gender, level of adiposity, physical activity and ethnicity influence the choice of method and equation. Also, it is important to evaluate the relative worth of prediction equations in terms of the criterion method used to derive reference measures of body composition for equation development. Given that Hydrodensitometry, hydrometry and dual-energy x-ray absorptiometry are subject to measurement error and violation of basic assumptions underlying their use, none of these should be considered as a ‘gold standard’ method for in vivo body composition assessment.
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Evaluation of Body Composition
Sports Medicine, 1996Co-Authors: Vivian H HeywardAbstract:In the selection of body composition field methods and prediction equations, exercise and health practitioners must consider their clients’ demographics. Factors, such as age, gender, level of adiposity, physical activity and ethnicity influence the choice of method and equation. Also, it is important to evaluate the relative worth of prediction equations in terms of the criterion method used to derive reference measures of body composition for equation development. Given that Hydrodensitometry, hydrometry and dual-energy x-ray absorptiometry are subject to measurement error and violation of basic assumptions underlying their use, none of these should be considered as a ‘gold standard’ method for in vivo body composition assessment. Reference methods, based on whole-body, 2-component body composition models, are limited, particularly for individuals whose fat-free body (FFB) density and hydration differ from values assumed for 2-component models. Use of field method prediction equations developed from 2-component model (Siri equation) reference measures of body composition will systematically underestimate relative body fatness of American Indian women, Black men and women, and Hispanic women because the average FFB density of these ethnic groups exceeds the assumed value (1.1 g/ml). Thus, some researchers have developed prediction equations based on multicomponent model estimates of body composition that take into account interindividual variability in the water, mineral, and protein content of the FFB. One multicomponent model approach adjusts body density (measured via Hydrodensitometry) for total body water (measured by hydrometry) and/or total body mineral estimated from bone mineral (measured via dual-energy x-ray absorptiometry). Skinfold (SKF), bioelectrical impedance analysis (BIA), and near-infrared interactance (NIR) are 3 body composition methods used in clinical settings. Unfortunately, the overwhelming majority of field method prediction equations have been developed and cross-validated for White populations and are based on 2-component model reference measures. Because ethnicity may affect the composition of the FFB and regional fat distribution, race-specific prediction equations may need to be developed for some ethnic groups. To date, race-specific SKF (American Indian women, Black men, and Asian adults), BIA (American Indian women and Asian adults), and NIR (American Indian women and White women) equations have been developed. However, these equations need to be cross-validated on additional samples from these ethnic groups. In summary , research strongly suggests that multicomponent models need to be used in order to quantify differences in FFB composition due to ethnicity so that accurate SKF, BIA, and NIR prediction equations can be developed. Assessment of body composition in vivo may be enhanced by using advanced technologies such as dual-energy x-ray absorptiometry and hydrometry to refine Hydrodensitometry. Practitioners should carefully select and use only those prediction equations that have been developed and cross-validated for specific ethnic groups. Additional research is needed to test the accuracy and applicability of previously published prediction equations for the American Indian, Asian, Black, and Hispanic populations.
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Body composition of Native-American women estimated by dual-energy X-ray absorptiometry and Hydrodensitometry.
Human Body Composition, 1993Co-Authors: Virginia L. Hicks, Vivian H Heyward, Richard N. Baumgartner, Andrew J. Flores, Lisa M. Stolarczyk, Elizabeth A. WotrubaAbstract:Variation in the relative amounts and densities of bone mineral and water in the fat-free body (FFB) will alter the density of the FFB. This produces a systematic error in estimating %BF when equations based on the two-component model1,2 are applied. Depending on the population studied, the theoretical error for estimating %BF from total body density (Db) could be as much as 2–4% BF due to interindividual variability in the densities and relative proportions of mineral, water, and protein comprising the fat-free mass (FFM).3 Within a homogeneous population, the %BF prediction error has been estimated at 2.77% due to biological variation of the density of the fat-free body.3
Jack Wang - One of the best experts on this subject based on the ideXlab platform.
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bioelectrical impedance analysis population reference values for phase angle by age and sex
The American Journal of Clinical Nutrition, 2005Co-Authors: Maria Cristina G Barbosasilva, Aluisio J D Barros, Jack Wang, Steven B Heymsfield, Richard N PiersonAbstract:Background: Phase angle is an indicator based on reactance and resistance obtained from bioelectrical impedance analysis (BIA). Although its biological meaning is still not clear, phase angle appears to have an important prognostic role. Objective: The aim of this study was to estimate population averages and SDs of phase angle that can be used as reference values. Design: BIA and other methods used to evaluate body composition, including Hydrodensitometry and total body water, were completed in 1967 healthy adults aged 18-94 y. Phase angle was calculated directly from body resistance and reactance, and fat mass (FM) was estimated from the combination of weight, Hydrodensitometry, and total body water by using the 3-compartment Siri equation. Phase angle values were compared across categories of sex, age, body mass index (BMI), and percentage FM. Results: Phase angle was significantly (P < 0.001) smaller in women than in men and was lower with greater age (P < 0.001). Phase angle increased with an increase in BMI and was significantly inversely associated with percentage fat in men. Phase angle was significantly predicted from sex, age, BMI, and percentage FM in multiple regression models. Conclusions: Phase angle differs across categories of sex, age, BMI, and percentage fat. These reference values can serve as a basis for phase angle evaluations in the clinical setting.
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Differences between young and old females in the five levels of body composition and their relevance to the two-compartment chemical model
Journal of Gerontology, 1994Co-Authors: Manolo Mazariegos, Jack Wang, Richard N Pierson, Zimian Wang, Dympna Gallagher, Richard N. Baumgartner, David B. Allison, Steven B HeymsfieldAbstract:BACKGROUND Body composition differs between young and old females, although the magnitude of these age-related changes remains uncertain. This uncertainty persists because methodology applied in earlier studies required assumptions that may be age-dependent and also because studies included young and old subjects who differed substantially in body size and health status. METHODS To resolve these earlier concerns we examined components at the atomic, molecular, cellular, tissue-system, and whole body levels of body composition in 19 weight- and height-matched pairs of young (age 19-35 yrs) and old (age > 65 yrs) healthy White females. Isotope dilution, dual photon, whole-body counting, Hydrodensitometry, and anthropometric methods were used either alone or in combination to produce multicomponent models. RESULTS Old females had significantly more fat, greater truncal skinfolds and circumferences, and significantly less fat-free body mass (FFM), total body potassium (TBK), total body water (TBW), and bone mineral than did their young matched counterparts. Skeletal muscle mass was less in the old females, although the magnitude of the difference from young females varied between the three indices examined. The main assumptions (i.e., TBW/FFM = 0.73 kg/kg and density of FFM = 1.100 g/cc) which the widely used two-compartment TBW and Hydrodensitometry methods are based on were not significantly different in young and old females. In contrast, the main assumed steady-state value for the two-compartment TBK method (TBK/FFM = 64.2 mmol/kg) was significantly lower (p < .001) in the old females. CONCLUSION New approaches thus allow for a critical reexamination of body composition in elderly subjects, and these methods also give new insight into less complex widely used body composition techniques.
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Skeletal differences between black and white men and their relevance to body composition estimates.
American Journal of Human Biology, 1994Co-Authors: Laura Gerace, Jack Wang, Richard N Pierson, Zimian Wang, David B. Allison, Antonios O. Aliprantis, Mary Russell, Kathleen M. Buhl, Steven B HeymsfieldAbstract:Skeletal differences exist between closely matched Black and White women, although it is unknown if similar differences also exist between Black and White men after controlling for age, body weight, and stature. The aim of this study was twofold: to test the hypothesis that Black men have greater bone mass, higher bone mineral density, and longer limbs compared to White men of similar age, weight, and height; and second, to establish if ethnic variation in skeletal characteristics has an impact on the models upon which three widely used methods for estimating total body fat are based. Twenty-four healthy Black men were matched by age (±5 years), height (±3 cm), and weight (±2 kg) to 24 healthy White men. Skeletal characteristics and body composition were studied using anatomical and compartment estimates derived by anthropometry, 3 H2 O dilution, Hydrodensitometry, whole-body 40 K counting, and dual photon systems. Black men had greater bone mineral mass (P = 0.007), higher bone density (P = 0.054), longer femurs (P = 0.002), longer anthropometric arm and thigh lengths (P = 0.001 and P = 0.002, respectively), lower spine to femur ratio (P = 0.004), and similar spine length (P = 0.271) compared to White men. Total body fat and fat-free body mass (FFM) were estimated in the men using a four-compartment model. Black and White men had similar total body fat, K (TBK), water (TBW), and FFM. Density of FFM and TBK/FFM were also similar between Black and White men, suggesting that current two-compartment Hydrodensitometry and TBK models for estimating fat may not require adjustments for ethnicity. The TBW/FFM ratio, which is the main assumed steady-state relation for the two-compartment TBW method of estimating fat, was modestly increased (P = 0.05) in Black men (x ± SD, 0.744 ± 0.018) compared to White men (0.732 ± 0.021). These results confirm that Black and White men differ significantly in some skeletal characteristics and these differences have implications in the study of both osteoporosis and human body composition. © 1994 Wiley-Liss, Inc.
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Body composition of humans: comparison of two improved four-compartment models that differ in expense, technical complexity, and radiation exposure
The American Journal of Clinical Nutrition, 1990Co-Authors: Steven B Heymsfield, Jack Wang, Steven W. Lichtman, Antonios O. Aliprantis, R N Baumgartner, Y. Kamen, Richard N PiersonAbstract:Multicompartment models are of growing importance in the study of body composition in humans. This study compares two improved four-compartment (water, protein, mineral, and fat) models that differ in expense, technological complexity, and radiation exposure. Primary data (from 31 subjects) for the first model were derived by dual-photon absorptiometry, 3H2O dilution, and Hydrodensitometry and for the second model by delayed and prompt gamma neutron-activation analysis and 3H2O dilution. Estimates of fat, protein, and mineral from the first model were highly correlated with those from the second model (r = 0.98, 0.72, and 0.94, respectively; all p less than 0.001). The proportions of body weight represented by water, protein, mineral, and fat for the simpler first model (0.532, 0.155, 0.048, and 0.265) were similar to compartment fractions provided by the more complex and costly second model (0.532, 0.143, 0.046, and 0.279). Multicompartment body composition models can thus be developed from increasingly available techniques that compare favorably with similar results derived from limited-access instrumentation.
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body composition of humans comparison of two improved four compartment models that differ in expense technical complexity and radiation exposure
The American Journal of Clinical Nutrition, 1990Co-Authors: Steven B Heymsfield, Jack Wang, Steven W. Lichtman, Antonios O. Aliprantis, R N Baumgartner, Y. Kamen, Richard N PiersonAbstract:Multicompartment models are of growing importance in the study ofbody composition in humans. This study compares two improved four-compartment (water, pro- tein, mineral, and fat) models that differ in expense, technologi- cal complexity, and radiation exposure. Primary data (from 31 subjects) for the first model were derived by dual-photon ab- sorptiometry, 3H2O dilution, and Hydrodensitometry and for the second model by delayed and prompty neutron-activation analysis and 3H20 dilution. Estimates offat, protein, and mm- eral from the first model were highly correlated with those from the second model (r = 0.98, 0.72, and 0.94, respectively; all p < 0.001). The proportions ofbody weight represented by water, protein, mineral, and fat for the simpler first model (0.532, 0. 155, 0.048, and 0.265) were similarto compartment fractions provided by the more complex and costly second model (0.532, 0. 143, 0.046, and 0.279). Multicompartment body composi- tion models can thus be developed from increasingly available techniques that compare favorably with similar results derived from limited-access instrumentation. Am J C/in Nutr 1990;52:52-8.