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PubMed1992

Predicting body composition from anthropometry and bioimpedance in marginally undernourished adolescents and young adults.

Body-composition prediction equations were developed using data from a sample of 201 female and male Guatemalan ladinos (ie, people of Amerindian-European descent) aged 11-25 y. Fat-free mass (FFM) values were estimated from body density by using the two-component model and age- and sex-specific values for the density of FFM. The root-mean-square error (RMSE) of the best model predicting FFM from a set of simple anthropometric variables was 1.59 kg for females and 1.90 kg for males. The addition of more extensive anthropometry to the set of candidate predictors reduced the RMSE to 1.42 kg for females and 1.88 kg for males. The subsequent addition of a bioelectrical impedance measure (Ht2/R) further reduced the RMSE to 1.32 kg for females and 1.82 kg for males. These results suggest that for a marginally undernourished population with relatively little body fat, simple anthropometrics are as useful as more sophisticated measures for the prediction of body composition.

Adolescent↗

PubMed1999

Body composition in 85 year-old women: effects of increased physical activity.

This study explores whether regular training alters body composition and resting metabolism in the very old. A total of 55 community-dwelling women, 85 years old, were enrolled in a training group (N = 22) and a control group (N = 33). Training was performed once a week for eight months, and consisted of various exercises with particular attention to movements important for everyday activities. Before, immediately after, and one year after cessation of training, body composition was evaluated both by an impedance measurement and a whole body scan by dual-photon X-ray absorptiometry. Resting metabolism, assessed as energy expenditure at rest, was measured with standardized protocols by analyzing oxygen consumption and carbon dioxide production. Height declined in both groups throughout the study. Immediately after the training period, body weight showed a trend towards reduced levels in the training group, and an opposite trend in the control group. The control group showed an increased body mass index (p < 0.05) related to an increase in fat mass immediately after the training period; these parameters were unaltered in the training group. A reduction in fat free mass (p < 0.05) and bone mineral content (p < 0.05), and unaltered energy expenditure at rest were evident in both groups during the course of the study. These results suggest that regular training can counteract the age-related accumulation of fat in the very old. Physical reactivation, therefore, may possess an important potential for reducing morbidity in the very old by lowering fat mass, and thereby reducing the risk of acquiring several age-related diseases.

Absorptiometry, Photon↗

PubMed1990

Resting metabolic rate and body composition of achondroplastic dwarfs.

Indirect calorimetry was used to measure resting metabolic rates (RMR), and densitometry and anthropometry were used to measure body fat and fat-free masses of 32 adults with very short stature. Twenty-seven of them were achondroplastic dwarfs. Their results were compared to those obtained from 103 lean and obese adults with normal heights. All 32 dwarfs had distinctly greater RMR per kg fat-free mass by densitometry than adults with average stature. However, there was a wide variation in the RMR among dwarfs, which was independent of leanness or obesity. In spite of increased RMR, obesity among dysplastic adult dwarfs was twice as prevalent as among average-height adults. Increased abdominal:hip ratios were prevalent among dwarfs, but these ratios do not reflect body fat. Body mass indices were worthless, and skinfold thicknesses and other anthropometric measurements were of very limited value in predicting the body fat of dwarfs. Although our new and specific equations for estimating RMR and body composition give reasonable values, we recommend that the caloric requirements and body compositional variables be measured if nutritional therapy is needed to induce weight loss or gain in Little People.

Achondroplasia↗

PubMed1990

Efficacy of the urea dilution technique in estimating empty body composition of pigs weighing 50 kilograms.

The efficacy of the urea dilution technique in estimating the empty body composition of pigs weighing 50 kg was evaluated in three trials using 17 contemporary (Large White X Landrace X Hampshire X Duroc) and 8 Nebraska Gene Pool X contemporary pigs. Blood samples were collected via ear catheter before infusion (-60, -30 and 0 min) and at various times (3 to 90 min) after urea infusion (2.16 mmol/kg live BW), and analyzed for plasma urea. Backfat thickness of live pigs from the contemporary line was measured ultrasonically. Pigs then were killed by euthanasic injection, and total bodies (with gastrointestinal contents removed) were analyzed for water, protein and fat. In Trials 1 and 2, there were linear relationships (P less than .001) between chemically determined body water and fat and between body water and protein. Urea space was related (P less than .05) to empty body components with few exceptions, but regression coefficients for urea space in Trial 3 were different from those of Trials 1 and 2. Inclusion of additional independent variables with urea space improved estimation of empty body components. Although backfat alone did not estimate empty body components (except fat) as well as urea space alone, the addition of other common independent variables resulted in better estimates using backfat than urea space. The results of this experiment indicate that the urea dilution technique can be used to estimate the body composition of growing pigs. However, the accuracy obtained depended on the population of pigs being investigated and was no greater than the accuracy with appropriate equations based on backfat.

Animal Feed↗

PubMed2004

Body composition in neonates: relationship between measured and derived anthropometry with dual-energy X-ray absorptiometry measurements.

This study examined the relationship between measured and derived anthropometric measurements with dual-energy X-ray absorptiometry measured lean and fat mass at 3.0 +/- 2.8 (SD) days in 120 neonates with birth weights appropriate (AGA; n=74), large (LGA; n=30); or small (SGA, n=16) for gestational age. Anthropometric measurements, including total body weight and length, and regional measurements, including circumferences of head, chest, abdomen, midarm, and midthigh and dynamic skinfold thickness (15 and 60 s) at tricep, subscapular, suprailiac, and midthigh, were performed. Derived anthropometry included muscle and fat areas, and ratios were calculated from direct measurements. The skinfold thickness measurements between 15 and 60 s were highly correlated (r=0.973-0.996, p <0.001 for all comparisons). Strong correlations existed within the four circumferences of trunk and extremities, the four skinfolds, and the ratios of weight to length and its higher powers. Weight and length accounted for >97% of the variance of lean mass in AGA and SGA infants and 46% of the variance in LGA infants and for 80, 82, and 84% of the variance of fat mass in SGA, AGA, and LGA infants, respectively, whereas midarm:head circumference ratio and arm muscle and fat areas are the most important derived anthropometry in the prediction for body composition. They independently accounted for up to 16.5 and 10.2%, respectively, of the variance in body composition depending on the state of in utero growth. Thus, total body weight and length and some selected regional and derived anthropometry accounted for the vast majority of the variance of body composition.

Absorptiometry, Photon↗

PubMedDate not supplied

[Nutritional status and body composition of two South American native populations -- Alto Xingu and Ikpeng].

OBJECTIVES: To assess the nutritional and body composition of two Brazilian indigenous populations by comparing their nutritional status. METHODS: 95 children from Alto Xingu and 69 from Ikpeng were evaluated, ages ranged from 24 to 117 months. The study was performed in the Xingu Indigenous Park. Data collected were: age, weight, height, skin folds, arm circumference, resistance and reactance. The z-scores were calculated and classified according to the parameters defined by the National Center for Health Statistics (NCHS 2000). Shortness was defined as length or stature below -2, underweight as body mass index below -2, and overweight as body mass index above 2. RESULTS: Among children from Alto Xingu, the prevalence of shortness was 8.4%, while among Ikpengs the prevalence was 37.7% (p < 0.001). Underweight was diagnosed in 12.5% of Ikpeng s children. Values of fat-free mass were greater for children from Alto Xingu and no case of obesity was found. CONCLUSION: In this study, Ikpeng's children showed higher incidences of short stature and low weight than the Altoxingu's children. Data regarding body composition have greater values among children from Alto Xingu, thus we conclude that nutritional status among children from Alto Xingu is better than the one found among the Ikpeng's children.

Anthropometry↗

PubMed1992

Sequence of changes in body composition induced by testosterone and reversal of changes after drug is stopped.

OBJECTIVE: --To study the changes in body composition produced by large doses of testosterone and reversal of changes when the drug is discontinued. DESIGN: --Weekly injections of testosterone enanthate were given to young adult male volunteers for 12 weeks. Repeated assays of lean body mass (LBM) by potassium 40 counting were made during this period and at intervals during the ensuing 5 to 6 months. PARTICIPANTS AND SETTING: --Subjects who were living on their own, who were known to be free of significant disease, and who volunteered as controls for a study of patients with neuromuscular disease. Assays were done in the Clinical Research Center. MAIN OUTCOME MEASURES: --Changes in body weight, LBM, and (by subtraction) body fat. RESULTS: --Testosterone treatment produced a progressive increase in LBM and a progressive decrease in body fat. Body composition reverted slowly toward normal when the injections were stopped; thus, the effects of testosterone lingered for some time. The magnitude of the observed changes in LBM was in keeping with the change in urinary creatinine excretion reported for these same subjects. CONCLUSION: --Testosterone is a powerful anabolic agent that also serves to reduce body fat content.

Adipose Tissue↗

PubMed2004

Physical frailty and body composition in obese elderly men and women.

OBJECTIVE: To evaluate the prevalence of frailty and interrelationships among body composition, physical function, and quality of life in community-dwelling obese elderly (OE) persons. RESEARCH METHODS AND PROCEDURES: Fifty-two OE, 52 nonobese frail, and 52 nonobese nonfrail subjects, matched for age and sex, were studied. Subjective and objective measures of functional status were evaluated by using the physical performance test, exercise stress test, lower extremity (LE) strength, gait speed, static and dynamic balance, functional status questionnaires, and health-related quality-of-life questionnaire (Medical Outcomes Short Form). Body composition was evaluated by using DXA, and muscle quality was evaluated by determining the ratio of LE strength to LE lean mass. RESULTS: Among OE subjects, 96% met our standard criteria for mild to moderate frailty. Compared with the nonobese nonfrail group, the OE and nonobese frail groups had lower and similar scores in physical performance test, peak aerobic power, and functional status questionnaire, and exhibited similar impairments in strength, walking speed, balance, and health-related quality of life. Although absolute fat-free mass (FFM) was greater, the percentage body weight as FFM and muscle quality was lower in the OE group than in the other two groups. DISCUSSION: Physical frailty, which predisposes to loss of independence, is common in community-living OE men and women. Physical frailty in OE subjects was associated with low percentage FFM, poor muscle quality, and decreased quality of life. These findings suggest that weight loss therapy may be particularly important in OE persons to improve physical function, in addition to improving the medical complications associated with obesity.

Aged↗

PubMed2000

In vivo determination of body composition of rats using magnetic resonance imaging.

Magnetic resonance imaging (MRI) has potential as an instrument to measure body composition because it can discriminate various soft tissues in vivo. These soft tissues include adipose tissue, muscle, organs, and brain. We report on preliminary studies using a 4.2-tesla MRI for measuring body composition in the mouse and rat. We employed image segmentation methods that include an image correction method, a necessary requirement when the images are taken in the presence of nonuniform radio-frequency (RF) coil response. The software for 3-D data segmentation, quantification, correction, image manipulation, and visualization has been developed as a research tool. This method currently is being validated.

Animals↗

PubMed2003

Exploration of a variation of the bottle buoyancy technique for the assessment of body composition.

Hydrostatic weighing has long been recognized as a reliable and valid method for the assessment of body composition. An alternative method known as bottle buoyancy (BB) was introduced by Katch, Hortobagyi, and Denahan in 1989. The purpose of this clinical investigation was to determine the accuracy of the BB technique using an 11-L container. Sixteen individuals (8 men, 8 women) were weighed hydrostatically using a chair/scale and the BB technique. The overall intraclass correlation coefficient for the two techniques was 0.9537. A 2-variable ANOVA was significant for gender but not for technique, and there was no interaction between variables. Thus, the BB technique appears to be an accurate substitute for the chair/scale technique for hydrostatic weighing. The BB method does not involve elaborate equipment and is portable. It could be improved with the use of multiple bottles of various volumes or a calibrated bottle to minimize the number of trials needed for accurate measurements. BB is a valuable, simple clinical tool for assessing body composition based on the principles of hydrostatic weighing and can be performed in any high school, college, or community swimming pool.

Adult↗

PubMed2001

Alterations in body composition and fat distribution in growth hormone-deficient prepubertal children during growth hormone therapy.

Growth hormone (GH) deficiency in children results in increased body fat, reduced fat-free mass (FFM) including muscle (protein) and bone, and abdominal obesity. Thus, proper GH secretion likely has major developmental influences on later health risks including cardiovascular diseases and osteoporosis. However, the in vivo control of the development of the body composition and fat distribution by GH has not yet been accurately investigated using children with GH deficiency as a model. We determined the effect of GH therapy (GH replacement, n = 3; GH + physiologic cortisol and thyroxine replacement, n = 3) on body composition, the proportional composition of the FFM, and body fat distribution in GH-deficient prepubertal children compared with healthy control children (n = 6) not treated with GH. The GH-deficient and control children were initially matched for gender, bone age, and weight. As assessed by a 4-compartment model, GH therapy reduced percent body fat during the first 3 months of therapy but not thereafter. This change was primarily due to FFM, which increased 3-fold more in the GH-deficient group and accounted for 91.5% of the increase in body weight. Fat mass increased in the controls but was unchanged in the GH-deficient group. Therapy temporarily increased the proportional contribution of water to the FFM, decreased the proportion of mineral, and slightly increased the proportion of protein. Using magnetic resonance imaging (MRI), abdominal visceral fat was reduced in the GH-deficient group and unchanged in the controls. Abdominal subcutaneous fat measured in the same image was not changed. The abdominal and suprailiac skinfold thicknesses also were not decreased in the GH-deficient group. In conclusion, within 1 to 3 months, GH therapy accelerates lean tissue accrual, especially the water and protein components, but has a smaller effect on reducing fat mass. GH therapy has site-specific effects on reducing abdominal adiposity.

Abdomen↗

PubMed2000

Changes in body composition during the initial hours of life in breast-fed healthy term newborns.

Newborns usually lose 5-10% of their initial weight during the first 4 days of life. Our aim, using bioelectrical impedance (BI), was to study the body composition of healthy term newborns and the nature of the changes which accompany this physiological weight loss. Forty-three healthy term newborns, all with adequate weight for their gestational age, were studied during the first 3 days of life. Weight and BI were taken on the 1st, 2nd, and 3rd days of life, always at the same time of the day. Total body water (TBW), percentage of total body mass hydration (%TBW), and amount of body solids were calculated. Average weight at birth was 3,297+/-381 g, length 50.04+/-1.75 cm, and gestational age 39.9+/-0.84 weeks. Weight, TBW, and body solids decreased progressively during the first 3 days of life (p<0.000). By day 3, weight loss represented 5.67+/-1.98% of birth weight, but %TBW increased slightly (1.72%; p<0.000). These results suggest that, during physiological weight loss, body composition modifications are produced in the term newborn by a decrease in TBW and loss of body solids. The level of body hydration increases slightly, since the loss of body solids is greater than the loss of TBW. The use of BI can help us in the study of body composition and the short- and/or long-term changes produced therein, in the newborn.

Adult↗

PubMedDate not supplied

Effects of Pseudomonas colonization on body composition and resting energy expenditure in children with cystic fibrosis.

BACKGROUND: To determine the extent and effects of increased metabolic demand represented by Pseudomonas colonization on body composition and resting energy expenditure in children with cystic fibrosis (CF). METHODS: The study comprised 18 stable children with CF, of whom 10 (6 male/4 female) were colonized with Pseudomonas species and 8 (4 male/4 female) were not. The groups were of similar age range and genotype. Measured resting energy expenditure (REE) was performed by open circuit indirect calorimetry and compared with predicted REE calculated from standard equations. Body composition was determined by dual-energy x-ray absorptiometry, including lean body mass (LBM), fat mass (FM), bone mineral density (BMD), and anterior-posterior spine density (APS); these were compared using z-scores. Routine pulmonary function testing assessed forced vital capacity, forced expiratory volume in 1 second (FEV1), and forced expiratory flow over middle half of vital capacity (FEF25% to 75%); these were compared as percent predicted. RESULTS: As expected, results of pulmonary function testing showed significant deterioration among the children colonized with Pseudomonas species when compared with the children who were not, while standard anthropometry showed no differences in weight, height, or weight-for-height percentile and respective z-scores. Although a trend of lower LBM was noted among the children colonized with Pseudomonas species, no significant differences were found between these children and children who were not colonized with Pseudomonas species when z-scores for LBM, FM, BMD, or APS were compared during body composition analysis. In addition, neither REE as kilocalories per day (kcal/d) nor REE expressed as a percent predicted by standard equations discriminated between subgroups of children colonized with Pseudomonas species and children who were not. However, metabolic demand, expressed as resting energy expenditure in kilocalories per kilogram (kcal/kg) of LBM (REE/LBM), revealed significant differences between children colonized with Pseudomonas species and children who were not (75.4+/-4.4 vs 58.6+/-2.9 kcal/kg, p < .05). CONCLUSIONS: The effect of Pseudomonas colonization on metabolic demand in children with CF can be accurately assessed by expressing resting energy expenditure as kilocalorie per kilogram of LBM, the active metabolic component of the body. The 50% increase in REE/LBM seen in the children colonized with Pseudomonas species represents the metabolic demand from the inflammatory burden and work of breathing resulting from the effects of the Pseudomonas colonization. The trend of a lower LBM in the children colonized with Pseudomonas species makes this finding even more dramatic.

Absorptiometry, Photon↗

PubMed2004

Effects of oral contraceptives on body composition and physical performance in female athletes.

Menstrual disturbances are common among female athletes, and oral contraceptives (OCs) are often recommended as estrogen substitution. However, there is little information about the effects of OC use in athletes, and there is great concern that OCs might impair physical performance. The aim of this study was to investigate the effects of OC use on body composition and physical performance in female athletes. Twenty-six endurance athletes (13 with oligo-/amenorrhea and 13 regularly menstruating athletes) and 12 sedentary controls were examined before and after 10 months of treatment with a low dose, monophasic, combined OC. Significant changes in body composition were recorded in the athletes, but not in the controls. There was an increase in weight and fat mass only in athletes with oligo-/amenorrhea. These changes were associated with a decrease in ovarian androgens. OC treatment also increased bone mineral density, with the largest increase in athletes with a low bone mineral density at baseline. Despite significant changes in body composition, little impact on physical performance was recorded. We have demonstrated that OC treatment in female athletes has predominantly beneficial effects on body composition without adverse effects on physical performance and could be used for the prevention of osteoporosis in athletic amenorrhea. However, it cannot be excluded that a marked increase in fat mass might have unfavorable effects for athletic performance in individual women.

Adolescent↗

PubMed1986

Photon activation analysis as a new technique for body composition studies.

A study was undertaken to demonstrate the usefulness of the recently developed photon activation analysis (PAA) technique for in vivo body composition studies. PAA can be used for direct measurement of total-body oxygen, nitrogen, and carbon. Sequential measurements were made on rats fed diets of 0%, 4.2%, or 20% protein for 6 1/2 wk, and significant changes in body composition were noted. In addition, rats of different ages, strains, nutritional states, and degrees of obesity were included in a comparison of PAA results in vivo with results from chemical analysis after sacrifice of the animals. High positive correlations were found between PAA measurements of carbon and chemical analysis measurements of fat and between PAA measurements of oxygen and chemical analysis measurements of total-body water. A low positive correlation was found between PAA measurements of nitrogen and chemical analysis measurements of protein.

Activation Analysis↗

PubMed2000

Genome-wide scan for body composition in pigs reveals important role of imprinting.

The role of imprinting in body composition was investigated in an experimental cross between Chinese Meishan pigs and commercial Dutch pigs. A whole-genome scan revealed significant evidence for five quantitative trait loci (QTL) affecting body composition, of which four were imprinted. Imprinting was tested with a statistical model that separated the expression of paternally and maternally inherited alleles. For back fat thickness, a paternally expressed QTL was found on Sus scrofa chromosome 2 (SSC2), and a Mendelian-expressed QTL was found on SSC7. In the same region of SSC7, a maternally expressed QTL affecting muscle depth was found. Chromosome 6 harbored a maternally expressed QTL on the short arm and a paternally expressed QTL on the long arm, both affecting intramuscular fat content. The individual QTL explained from 2% up to 10% of the phenotypic variance. The known homologies to human and mouse did not reveal positional candidate genes. This study demonstrates that testing for imprinting should become a standard procedure to unravel the genetic control of multifactorial traits.

Adipose Tissue↗

PubMed1999

Body composition in renal transplant patients: bioimpedance analysis compared to isotope dilution, dual energy X-ray absorptiometry, and anthropometry.

Whether multifrequency bioelectrical impedance analysis (MF-BIA), a relatively new method for measuring body composition, is also applicable for accurate body composition measurements in renal transplant (RTx) patients is not known. Therefore, the use of MF-BIA is validated in 77 RTx patients with a stable renal function at least 2 yr posttransplantation. MF-BIA is compared to isotope dilution techniques for measurement of body water compartments, and to dual energy x-ray absorptiometry (DEXA) and anthropometry for measurement of fat and fat free mass. Finally, DEXA and anthropometry are compared to each other. Method agreement is assessed by intraclass correlation coefficients (ICC) and plotted by Bland and Altman analysis. MF-BIA significantly underestimates total body water (TBW, 0.7+/-2.1 L) and overestimates the extracellular water (ECW, 3.3+/-1.8 L) compared to isotope dilution; the ICC between both techniques is 0.943 for TBW and 0.846 for ECW. The percentage body fat (BF) measured by MF-BIA is significantly higher than both BF measured by DEXA (3.4+/-4.7%) or by anthropometry (5.5+/-5.2%). The ICC between MF-BIA and DEXA is 0.887 and between MF-BIA and anthropometry 0.856. BF measured by DEXA is significantly higher than BF measured by anthropometry (2.1+/-4.4%); their ICC is 0.913. In conclusion, MF-BIA seems to be suitable for measurement of TBW in RTx patients; however, method agreement between isotope dilution and MF-BIA for the measurement of ECW is not satisfactory. In the assessment of fat and fat free mass, the reliability of MF-BIA appears to be questionable. Method agreement between DEXA and anthropometry seems to be slightly better.

Absorptiometry, Photon↗

PubMed2002

Body-composition measurements as predictors of glucose and insulin abnormalities in HIV-positive men.

BACKGROUND: Fat redistribution and metabolic abnormalities are seen increasingly in HIV-positive patients. However, the degree to which abnormalities in fat distribution predict glucose and insulin concentrations in these patients remains unknown. OBJECTIVE: We determined how well measurements of fat distribution derived from anthropometry, dual-energy X-ray absorptiometry, and computed tomography predicted hyperinsulinemia in HIV-positive men. DESIGN: Body-composition data were analyzed in 41 HIV-positive men (21 with fat redistribution and 20 without) and 20 HIV-negative control subjects matched for age and body mass index (BMI). Multivariate modeling was performed to determine the effects of body composition on fasting insulin and insulin area under the curve (AUC) during standard glucose tolerance testing. RESULTS: WHR was superior to other body-composition measures in predicting fasting hyperinsulinemia and was a strong predictor of insulin AUC in HIV-positive men. Fasting insulin increased by 77.4 pmol/L for each 0.1-unit change in WHR (95% CI: 18.6, 136.1; P = 0.011), overall r(2) = 0.415 in a model also including age, BMI, and protease inhibitor use. Measures of intraabdominal and subcutaneous fat did not predict fasting hyperinsulinemia but were independent predictors of insulin AUC in multivariate modeling. The ratio of visceral to subcutaneous abdominal fat predicted the largest degree of variance in insulin AUC. CONCLUSIONS: Fat redistribution contributes to hyperinsulinemia in HIV-positive men, independent of BMI and protease inhibitor use. WHR is an integrated index of body-composition changes and strongly predicts both fasting hyperinsulinemia and insulin AUC in HIV-positive men.

Adipose Tissue↗