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BACKGROUND: Evidence suggested that abiotic airborne exposures may be associated with changes in body composition. However, more evidence is needed to identify key pollutants linked to adverse health effects and their underlying biomolecular mechanisms, particularly in sensitive older adults. OBJECTIVES: Our research aimed to systematically assess the relationship between abiotic airborne exposures and changes in body composition among healthy older adults, as well as the potential mediating mechanisms through the serum lipidome. METHODS: From September 2018 to January 2019, we conducted a monthly survey among 76 healthy adults (60-69 years old) in the China Biomarkers of Air Pollutant Exposure (BAPE) study, measuring their personal exposures to 632 abiotic airborne pollutions using MicroPEM and the Fresh Air wristband, 18 body composition indicators from the InBody 770 device, and lipidomics from venous blood samples. We used an exposome-wide association study (ExWAS) and deletion/substitution/addition (DSA) model to unravel complex associations between exposure to contaminant mixtures and body composition, a Bayesian kernel machine regression (BKMR) model to assess the overall effect of key exposures on body composition, and mediation analysis to identify lipid intermediators. RESULTS: The ExWAS and DSA model identified that 2,4,5-T methyl ester (2,4,5-TME), 9,10-Anthracenedione (ATQ), 4b,8-dimethyl-2-isopropyl-phenanthrene, and 4b,5,6,7,8,8a,9,10-octahydro-(DMIP) were associated with increased body fat mass (BFM), fat mass indicators (FMI), percent body fat (PBF), and visceral fat area (VFA) in healthy older adults [Bonferroni-Hochberg false discovery rate ([FDR.sub.BH]) < 0.05]. The BKMR model demonstrated a positive correlation between contaminants (anthracene, ATQ, copaene, di-epi-a-cedrene, and DMIP) with VFA. Mediation analysis revealed that phosphatidylcholine [PC, PC(16:1e/18:1), PC(16:2e/18:0)] and sphingolipid [SM, SM(d18:2/24.1)] mediated a significant portion, ranging from 12.27% to 26.03% (p-value DISCUSSION: Based on the evidence from multiple model results, ATQ and DMIP were statistically significantly associated with the increased VFA levels of healthy older adults, potentially regulated through lipid intermediators. These findings may have important implications for identifying potentially harmful environmental chemicals and developing targeted strategies for the control and prevention of chronic diseases in the future, particularly as the global population is rapidly aging. https://doi.org/10.1289/EHP13865, Introduction The global population is currently undergoing a notable aging trend, primarily driven by declining fertility rates and increased life expectancy. (1) This demographic shift is evident as the number [...]

Bioelectrical impedance analysis (BIA) is a body composition assessing technique for estimating body components; fat, and muscle mass, and body water (BW) by measuring the electrical resistance in ohm ([OMEGA]) of those components with response to the flow of a small electrical current through the body. Bioelectrical impedance analysis was used to investigate the relationships between segmental body composition, obesity and body mass index (BMI). The analysis in this study involved the use of InBody 370S equipment to conduct the body composition study of 48 adult participants (30 females and 18 males) at the Applied Science Private University (ASU) School of Pharmacy, Department of Clinical Nutrition and Dietetics, between October, 2019 and January, 2020, Jordan. Anthropometric parameters such as weight, height, body mass index (BMI), and waist-to-hip (W/H) ratio for each individual were measured. The values indicated that BMI of 26.5 for males and 25.42 for females and body composition such as body fat mass (BFM), protein, and visceral fat level (VFL) of females of BMI > 30 was 39.82 compared to 32.60 for males of the same category. The VFL for female individuals was higher than males (13.0 and 17.5) of the same BMI category. The results of BIA analysis, lean body mass, and body muscle mass were found to be significantly (p 30 was 39.82[+ or -]4.35 compared to 32.6[+ or -]3.67 for males of the same group. Additionally, the BFM (-3.86**), segmental muscle mass (SMM) was 0.784**, and total body water (TBW) of -0.658** were all indirectly correlated at (p Key words: BIA, obesity, segmental analysis, body composition, BMI, WHR, VFL, INTRODUCTION The use of body composition in assessing the nutritional status is largely recognized as an important tool in assessing changes in obesity occurrence among adults and children [1]. The [...]

Background/Objectives Seasonal variation in body mass is a model for the study of body mass regulation. Here a long-term study is presented on body mass, body composition, and activity-induced energy expenditure in a subject with a large seasonal variation in body mass of about 3.0 kg. Subject/Methods Body mass was assessed daily over >20 consecutive years. Daily assessment of activity-induced energy expenditure was performed over the last 10 years. Body composition was assessed monthly for 1 year in the middle and at the end of the observation interval. Additionally, data were compared with data on body composition, resting energy expenditure, and total daily energy expenditure of the same subject as a participant in published studies. Results Body mass showed a pronounced seasonal variation, associated with a synchronous variation in physical activity. Body mass peaked in the cold winter months when physical activity reached the lowest annual value and decreased to the lowest value in mid-summer when daily physical activity peaked. The seasonal variation in body mass consisted mainly of body fat. Longitudinally, over the past 8 years of the observation interval, average fat-free mass showed a decrease of 1.0 kg and fat mass increased 0.8 kg. Conclusions In a subject with a pronounced seasonal variation in physical activity, activity-induced variation in energy requirement was covered by an annual variation in body mass, mainly as fat. Maintenance of activity-induced energy expenditure did not protect against loss of fat-free body mass with advancing age., Author(s): Klaas R. Westerterp [sup.1] Author Affiliations: (1) NUTRIM, Maastricht University Medical Centre, Maastricht, The Netherlands Introduction Seasonal models represent valuable tools for the study of the mechanistic basis of [...]

Background Modern hemodialysis (HD) machines are able to measure ionic dialysance online and thereby continuously monitor Kt/V. The accuracy of measurement depends on the input of the correct urea distribution volume (V), available from anthropometric equations and body composition monitoring (BCM). The latter method, however, has not been validated in children. Methods We compared V determined by BCM to that calculated using four different anthropometric formulas (Morgenstern, Mellits and Cheek, Hume-Weyers and Watson equations) in 23 pediatric HD patients. We also compared online Kt/V using BCM-derived V with the Kt/V calculated from pre- and post-dialytic urea concentrations using the single-pool second-generation Daugirdas equation. Results The V calculated by the Morgenstern equation was similar to that derived by BCM, with a mean difference of -0.7 % (95 % limits of agreement -11.7 to 10.3 %). In contrast, the V calculated by the other equations was 5.4, 6.2 and 18 %, respectively higher than the BCM-derived V. The mean difference between Kt/V calculated using the Daugirdas equation and online Kt/V determination based on BCM-derived V data was 0.10 (95 % limits of agreement -0.50 to 0.70 %). Conclusions In our pediatric HD patients the V measured by BCM was in agreement with that calculated using the Morgenstern equation, which is the only equation which has been validated to date in children on dialysis. Online determination of Kt/V using a BCM-derived V largely agreed with that calculated by the Daugirdas equation. We therefore conclude that the former approach is suitable for frequent online assessment of dialytic small solute clearance., Author(s): Ariane Zaloszyc[sup.1] , Michel Fischbach[sup.1] , Betti Schaefer[sup.2] , Lorenz Uhlmann[sup.3] , Remi Salomon[sup.4] , Saoussen Krid[sup.4] , Claus Peter Schmitt[sup.2] Author Affiliations: (1) Nephrology Dialysis Transplantation Children's Unit, [...]

Common obesity-associated hepatic steatosis (nonalcoholic fatty liver disease (NAFLD)) and insulin resistance are mainly caused by dysfunctional adipose tissue. This adipose tissue dysfunction leads to increased delivery of NEFA and glycerol to the liver that (i) drives hepatic gluconeogenesis and (ii) facilitates the accumulation of lipids and insulin signaling inhibiting lipid intermediates. Dysfunctional adipose tissue can be caused by impaired lipid storage (overflow hypothesis, characterized by large visceral adipocytes) or increased lipolysis (due to impaired postprandial suppression of lipolysis in inflamed, insulin-resistant adipocytes). In line with the adipose tissue expandability hypothesis the amount and distribution of adipose tissue correlate with its dysfunction and thus with liver fat. This relationship is however modified by endocrine effects on lipid storage and lipolysis as well as dietary effects on hepatic lipogenesis and lipid oxidation. The association between body composition characteristics like visceral obesity or fat cell size and ectopic liver fat is modified by these influences. Phenotyping obesity according to metabolic risk should integrate body composition characteristics, endocrine parameters and information on diet., Author(s): Anja Bosy-Westphal [sup.1] , Wiebke Braun [sup.1] , Viktoria Albrecht [sup.1] , Manfred J. Müller [sup.1] Author Affiliations: (1) Institute for Human Nutrition and Food Science, Christian-Albrechts-University Kiel, Kiel, [...]

To conduct a systematic literature review to identify studies that used indirect methods to assess body fat in healthy children. A systematic review was conducted according to the PRISMA guidelines. We conducted a search in the MEDLINE/PubMed, SciELO and Google Scholar databases. Studies in healthy children aged 0-9 years were eligible for inclusion. Studies were kept or excluded from the review according to eligibility criteria defined a priori. Two independent reviewers conducted all steps in the study selection. Initially, 11,246 articles were retrieved, with 3,593 duplicates. After applying the eligibility criteria, 22 articles were selected for review. The methodology of each study was analyzed by each reviewer individually. The indirect methods used to assess body fat in children included dual-energy X-ray absorptiometry (DXA) (14 articles), air-displacement plethysmography (five articles), multicomponent models (two articles), and total body water (one article). Most studies reported absolute (in kilograms) or relative (percentage) body fat measures. Only seven studies reported the fat mass index (FMI) (kg/m.sup.2). DXA was the indirect method most frequently used to assess body fat in healthy children. FMI was seldom reported., Author(s): Roberta de Vargas Zanini[sup.1] , Ina S. Santos[sup.1] , Maria Aurora D. Chrestani[sup.1] , Denise Petrucci Gigante[sup.1] Author Affiliations: (1) Programa de Pos-Graduação em Epidemiologia, Universidade Federal de Pelotas, [...]

We describe change in weight, midupper arm circumference (MUAC), arm muscle area (AMA) and arm fat area (AFA) in 1130 pregnant HIV-infected women with CD4 counts > 200 as part of the BAN Study (www. thebanstudy.org), a randomized, controlled clinical trial to evaluate antiretroviral and nutrition interventions to reduce mother-to-child transmission of HIV during breast feeding. In a longitudinal analysis, we found a linear increase in weight with a mean rate of weight gain of 0.27 kgs/week, from baseline (12 to 30 weeks gestation) until the last follow-up visit (32-38 weeks). Analysis of weight gain showed that 17.1% of the intervals between visits resulted in a weight loss. In unadjusted models, MUAC and AMA increased and AFA declined during late pregnancy. Based on multivariable regression analysis, exposure to the famine season resulted in larger losses in AMA [-0.08, 95% CI -0.14, -0.02; p = 0.01] while AFA losses occurred irrespective of season [-0.55, 95%: -0.95, -0.14, p = 0.01]. CD4 was associated with AFA [0.21, 95% CI 0.01, 0.41, p = .04]. Age was positively associated with MUAC and AMA. Wealth was positively associated with MUAC, AFA, and weight. While patterns of anthropometric measures among HIV-infected, pregnant women were found to be similar to those reported for uninfected women in sub-Saharan Africa, effects of the famine season among undernourished, Malawian women are of concern. Strategies to optimize nutrition during pregnancy for these women appear warranted. Keywords HIV * Pregnancy * Malawi * Seasonality * Body composition * MUAC, Introduction Maternal body composition and its changes during pregnancy have an impact on women's health and their birth outcomes. The interaction of HIV/AIDS disease progression and nutrition is well established [...]

The purpose of this investigation was to determine the effect of different lifting cadences on the ground reaction force (GRF) during the squat exercise. Squats performed with greater acceleration will produce greater inertial forces; however, it is not well understood how different squat cadences affect GRF. The hypotheses were that faster squat cadences would result in greater peak GRF and that the contributions of the body and barbell, both of equivalent mass, to total system inertial force would not be different. Six experienced male subjects (31 [+ or -] 4 years, 180 [+ or -] 9 cm, 88.8 [+ or -] 13.3 kg) performed 3 sets of 3 squats using 3 different cadences (fast cadence [FC] = 1-second descent/1-second ascent; medium cadence [MC] = 3-second descent/1-second ascent; and slow cadence [SC] = 4-second descent/2-second ascent) while lifting a barbell mass equal to their body mass. Ground reaction force and velocity sensor data were used to calculate inertial force contributions of both the body and barbell to total inertial force. Peak GRF were significantly higher in FC squats compared to MC (p = 0.0002) and SC (p = 0.0002). Ranges of GRF were also significantly higher in FC compared to MC (p < 0.05) and higher in MC compared to SC (p < 0.05). The inertial forces associated with the body were larger than those associated with the barbell, regardless of cadence. Faster squat cadences result in significantly greater peak GRF as a result of the inertia of the system. This study demonstrates that GRF was more dependent on descent cadence than on ascent cadence and that researchers should not use a single point on the body to approximate the location of the center of mass during squat exercise analysis. Key Words velocity, inertial forces, weight training, resistive exercise

The objective of this study was to compare the fatty acid (FA) composition of intramuscular fat from the LM of 3 divergent breeds of cattle: Angus (AN, n = 9), Brahman (BR, n = 7), and Romosinuano (RM, n = 11). Cattle were blocked by breed and finished 129 d before slaughter in one year and 157 d in the next year. Longissimus muscle samples were collected from each carcass between the 10th and 13th ribs, trimmed of external fat, frozen in liquid nitrogen, homogenized, and used for fat extraction, using a modified Folch procedure. Extracted fat was analyzed for FA by using a GLC system with an HP-88 capillary column. Fatty acid composition was expressed using both a normalized percentage (%) and gravimetric calculation (mg/g of fresh muscle tissue) in relation to degree of saturation, which was determined using a saturation index (ratio of total SFA to total unsaturated FA). Crude fat determination revealed that LM from AN purebred cattle had the greatest amount of intramuscular fat (7.08%; P = 0.001). Although intramuscular fat of LM from RM contained a reduced percentage of total SFA (P = 0.002) compared with AN, it had the greatest percentage of total PUFA (P < 0.001 and P = 0.020). The percentages of total MUFA were similar among the 3 breeds (P = 0.675). The gravimetric calculation, a measure of actual FA concentration, showed significantly greater concentrations of SFA (26.67 mg/g), MUFA (26.50 mg/g), and PUFA (2.37 mg/g) in LM from AN cattle, as compared with LM from BR and RM cattle (P < 0.001). Interestingly, BR purebreds had the least PUFA concentration (1.49 mg/g; P < 0.001) in the LM, although their intramuscular fat content was similar to that of RM (P = 0.924). Regardless of breed, the MUFA proportion was always the greatest (47.58%; P _< 0.005), whereas PUFA was the least contributor to FA composition (1.49 to 2.37 mg/g and 4.36 to 8.78%; P < 0.001). Beef LM fatty acid composition was characterized by palmitic and oleic acids being the most abundant FA (P < 0.001). These results suggested a genetic variation in FA synthesis and deposition among breeds that influenced both marbling and its composition. Key words: Angus, Brahman, cattle breed, fatty acid, intramuscular fat, Romosinuano doi: 10.2527/jas.2009-1951

Growth hormone receptor gene--disrupted (GHR-/-) mice exhibit increased life span and adipose tissue mass. Although this obese phenotype has been reported extensively for young adult male GHR-/- mice, data for females and for other ages in either gender are lacking. Thus, the purpose of this study was to evaluate body composition longitudinally in both male and female GHR-/- mice. Results show that GHR-/- mice have a greater percent fat mass with no significant difference in absolute fat mass throughout life. Lean mass shows an opposite trend with percent lean mass not significantly different between genotypes but absolute mass reduced in GHR-/- mice. Differences in body composition are more pronounced in male than in female mice, and both genders of GHR-/- mice show specific enlargement of the subcutaneous adipose depot. Along with previously published data, these results suggest a consistent and intriguing protective effect of excess fat mass in the subcutaneous region. Key Words: Body composition--Growth hormone--Obesity--Adipose depots--Gender differences. doi: 10.1093/gerona/glp175

The application of advanced methods and techniques and their continuous development enable detailed body composition analyses (BCAs) and modeling of body composition at different levels (e.g., at atomic, molecular, organ-tissue and whole body level). Functional body composition integrates body components into regulatory systems (e.g., on energy balance). Regulation of body weight is closely linked to the mass and function of individual body components. Fat mass is part of the energy intake regulatory feedback system. In addition, fat-free mass (FFM) and fat mass are both determinants of resting energy expenditure (REE). Up to 80% of the variance in energy intake and energy expenditure is explained by body composition. A deviation from normal associations between body components and function suggests a metabolic disequilibrium (e.g., in the REE-FFM relationship or in the plasma leptin-fat mass association) that may occur in response to weight changes and diseases. The concept of functional body composition adds to a more sophisticated view on nutritional status and diseases, as well as to a characterization of biomedical traits that will provide functional evidence relating genetic variants. doi:10.1038/ejcn.2009.55; published online 22 July 2009 Keywords: body composition analysis; resting energy expenditure; weight loss; weight gain; energy balance; clinical nutrition, Introduction Recent methodological and technological advances enable (1) an accurate and detailed body composition analysis (BCA) as well as (2) the development of new models and concepts in body composition [...]

Objective: To validate the Tanita BC-418MA Segmental Body Composition Analyser and four-site skinfold measurements for the prediction of total body water (TBW), percentage fat-free mass (%FFM) and percentage body fat (%BF) in a population of rural Gambian children. Subjects/Methods: One hundred and thirty-three healthy Gambian children (65 males and 68 females). FFM estimated by the inbuilt equations supplied with the Tanita system was assessed by comparison with deuterium oxide dilution and novel prediction equations were produced. Deuterium oxide dilution was also used to develop equations for %BF based on four-site skinfolds (biceps, triceps, subscapular and suprailiac). Results: The inbuilt equations underestimated FFM compared to deuterium oxide dilution in all the sex and age categories (P Conclusions: These data suggest that the Tanita instrument may be a reliable field assessment technique in African children, when using population and gender-specific equations to convert impedance measurements into estimates of FFM. doi:10.1038/sj.ejcn.1602830; published online 11 July 2007 Keywords: body composition; bioelectrical impedance; skinfolds; deuterium oxide dilution; children; Gambia, Introduction In children, body composition is a sensitive indicator of current health (Hill, 1992) and nutritional status (Shephard, 1994). An increased proportion of fat mass and a decreased proportion of [...]

Two genetic lines with different lean gains were evaluated for various body measurements and indices of lean tissue in barrows and gilts from 20 to 125 kg of BW. One genetic line was identified as the low-lean line [280 g of fat-free lean (FFL)/d], and the second line was the high-lean line (375 FFL gained/d). The experiment was conducted as a completely randomized design using a 2 x 2 x 5 factorial arrangement of treatments in 6 replicates (n = 120 pigs). The 2 genetic lines and sexes were provided ad libitum access to corn-soybean mixtures that met or exceeded their required amino acid requirements for their respective lean gain potentials. Six pigs of each sex and genetic line were slaughtered initially and at 25-kg of BW intervals to 125 kg of BW. Pigs slaughtered were measured for height, width, and length using metal calipers. Backfat and LM area were measured using real-time ultrasound, with backfat depth also measured using A-mode ultrasound technology. Longissimus muscle area and backfat thickness at the 10th rib were measured on the chilled carcass. Data was analyzed using the MIXED procedure of SAS, with the animal as the experimental unit. Shoulders (P < 0.05) and lumbars (P < 0.05) were wider in the low-lean genetic line and in barrows. Gilts and the high-lean genetic line had less backfat and greater LM areas than the low-lean genetic line. As BW increased, there was a greater increase in FFL tissue and lower backfat depths in the high-lean vs. the low-lean genetic line. This resulted in a greater divergence of measurement values as BW increased. Femur weight, length, and cortical wall thickness were greater in the high-lean genetic line, but the differences were not significant. The high-lean genetic line had a greater (P < 0.01) organic matrix content in the femur and less ash, resulting in a lower percentage of bone ash (P < 0.01). The results indicate that differences occurred phenotypically between pigs having more muscle (wider hams) or more fat (wider shoulder and lumbar). As BW increased, the high-lean pigs had an increase in lean tissue, particularly after 75 kg of BW, and less backfat and less bone mineralization, whereas the low-lean line pigs had increased backfat and greater bone mineralization. Real-time ultrasound measurements using various formulas to estimate lean tissue produced values close to those determined from carcass measurements at 100 and 125 kg of BW. Key words: body composition, carcass, growth, pig

Barrows and gilts of 2 genetic lines with differing lean gain potentials (high-lean = 375 g of fat-free lean/d; low-lean = 280 g of fat-free lean/d) were used to determine tissue and organ weights and compositions from 20 to 125 kg of BW. The experiment was a 2 (genetic line) x 2 (sex) x 5 (BW) factorial arrangement of treatments in a completely randomized design conducted with 2 groups of pigs in 6 replicates (n = 120 pigs). Six pigs from each sex and genetic line were slaughtered at 20 kg of BW and at 25 kg of BW intervals to 125 kg of BW. At slaughter, the internal tissues and organs were weighed. Loin and ham muscles were dissected from the carcass and trimmed of skin and external fat, and the ham was deboned. Residuals from the loin and ham were combined with the remaining carcass. Body components were ground, and their compositions were determined. The results demonstrated that tissue weights increased (P < 0.01) as BW increased. Loin and ham muscle weights increased but at a greater rate in the high-lean line and in gilts resulting in genetic line x BW and sex x BW interactions (P < 0.01). Liver and heart expressed on a BW or a percentage of empty BW basis increased at a greater rate in the high-lean line resulting in a genetic line x BW interaction (P < 0.01). Liver and intestinal tract weights were heavier in barrows than in gilts, significant only at 45 (P < 0.05), 75 (P < 0.01), and 100 (P < 0.05) kg of BW. Loin and ham muscles from the high-lean genetic line and gilts had greater (P < 0.01) water, protein, and ash contents compared with the low-lean genetic line and barrows resulting in genetic line x BW and sex x BW interactions (P < 0.01). The remaining carcass (minus loin and ham muscles) had greater (P < 0.01) amounts of water and protein, and less (P < 0.01) fat in the high-lean genetic line and gilts. The high-lean genetic line and gilts had more total body water, protein, and ash, but less body fat, with these differences diverging as BW increased, resulting in a genetic line x BW interaction (P < 0.01). The results indicated that liver and heart weights were greater in high-lean pigs, reflecting the greater amino acid metabolism, whereas the liver and intestinal tract weights were greater in barrow than gilts, reflecting their greater feed intakes and metabolism of total nutrients consumed. Key words: body composition, genetic, growth, pig, tissue development

The relationship between macronutrient composition of the body and mate attraction signals in Texas field crickets, Gryllus texensis, is analyzed.

Protein is an important body component for monitoring growth, development, and nutritional status. We previously developed a total body potassium (TBK, in mmol) and bone mineral (Mo, in kg) model for predicting total body protein (TBPro, in kg) in adults (TBPro = 0.00252 x TBK + 0.732 x Mo). However, the applicability of the TBK-Mo model for children is unknown. The study aims were to develop a TBK- independent 6-component (6-C) TBPro approach as the criterion, and then to validate the TBK-Mo model in children. The following measurements were made in adolescents and children (n = 62, 38 boys and 24 girls, aged 5-17 y): body weight (BW, in kg), body volume (BV, in liters) by air displacement plethysmography, total body water (TBW, in kg) by [sup.2][H.sub.2]O dilution, Mo by dual-energy X-ray absorptiometry, and TBK by whole-body counting. A 6-C model was derived as TBPro = 2.922 x BW - 0.301 x TBW - 2.039 x Mo - 2.632 x BV. The TBPro estimates did not differ between the 6-C and TBK-Mo models (mean [+ or -] SD, 0.20 [+ or -] 0.86 kg). There was a significant correlation between TBPro by the 6-C and TBK-Mo models (r = 0.94, P < 0.001). Bland-Altman analysis indicated that the differences between TBPro by 6-C and TBK-Mo models were not significantly correlated with the mean TBPro estimates by the 2 models (r = 0.032, P > 0.05). The TBK-Mo model can thus be used to estimate TBPro in healthy adults, adolescents, and children >5 y old. KEY WORDS: * nutritional assessment * body composition * bone mineral * whole-body counting

Objective. Pediatricians are encountering body composition information more frequently, with percentage of body fat (%BF) measurement receiving particular attention as a result of the obesity epidemic. One confounding issue is that different methods may yield different %BF results in the same person. The objective of this study was to compare dual-energy X-ray absorptiometry (DXA) with the criterion 4-compartment model (4-CM) for measurement of %BF in a large pediatric cohort and to assist pediatricians in appropriate interpretation of body composition information by recognizing differences between techniques. Methods. Height, weight, anthropometrics, body density by underwater weighing, total body water by deuterium dilution, and bone mineral content and %BF by DXA (Lunar DPX/DPX-L) were measured in 411 healthy subjects, aged 6 to 18 years. Values for %BF by 4-CM and DXA were compared using regression analysis. Results. The mean [+ or -] standard deviation values for %BF by DXA (22.73% [+ or -] 11.23%) and by 4-CM (21.72% [+ or -] 9.42%) were different, but there was a strong relationship between the 2 methods ([R.sup.2] = 0.85). DXA underestimated %BF in subjects with lower %BF and overestimated it in those with higher %BF. The relationship between the 2 methods was not affected by gender, age, ethnicity, pubertal stage, height, weight, or body mass index. The standard error of the estimate was 3.66%. Conclusion. This analysis demonstrates a predictable relationship between DXA and 4-CM for %BF measurement. Because of its ease of use, consistent relationship with 4-CM, and availability, we propose that DXA has the capacity for clinical application including prediction of metabolic abnormalities associated with excess %BF in pediatrics. Pediatrics 2004;113:1285-1290; body composition, percentage of body fat, obesity, pediatrics, children, adolescents, 4-compartment model, DXA. ABBREVIATIONS. DXA, dual-energy X-ray absorptiometry; %BF, percentage of body fat; 4-CM, 4 compartment model; TBW, total body water; [D.sub.b], body density; M, total body bone mineral content; UWW, underwater weighing; CV, coefficient of variation; BMI, body mass index., In the midst of an epidemic of pediatric obesity (1-3) and concerns about immediate and long-term complications, (3-10) pediatricians are increasingly confronted with body composition information. This information is encountered [...]

In order to provide data with which to challenge a model of metabolism of lactating sows, we conducted a study to determine milk production and body and mammary composition in sows consuming a range of energy and amino acid intakes and nursing 11 to 12 pigs. Sows (2nd through 4th parity) consumed the same ration during gestation and consumed 6.1 kg/ d (as-fed) for a 20 d lactation. Litter size was standardized at 12 pigs within 3 d of farrowing. Diets were formulated to provide three different amounts of protein intake and two different amounts of fat intake. Protein intakes of sows in high (HP), medium (MP), and low protein (LP) treatment groups were 863, 767, and 678 g/d with 59, 53, and 47 g/d lysine at two levels of fat intake, 117 (LF) and 410 g/d (HF). Number of pigs weaned per litter was 11.4 [+ or -] 0.5 and milk production and litter weight gain was less (P < 0.01) in the last week of lactation for sows consuming the least protein. Medium and low protein intakes increased (P < 0.05) loss of body lean and protein. Change in carcass protein during lactation was -1.4, -3.0, -2.2, -1.2, -1.9 and -2.1 kg (SD 2.6) for sows fed HPLF, MPLF, LPLF, HPHF, MPHF, and LPHF. Body fat (carcass and visceral) change was 0.4, -3.7, -4.1, -0.3, 3.4, and -1.3 kg (SD 6.6) in HPLF, MPLF, LPLF, HPHF, MPHF, and LPHF groups. Total amount of mammary parenchyma increased more (P < 0.05) in sows fed a higher fat diet. These data are consistent with general knowledge of changes in body composition in lactation of sows. However, changes in body protein and fat were correlated across treatments and different from that reported for sows nursing smaller litters. These data help our quantitative understanding of nutrient flux in sows nursing large litters and allow a severe challenge of existing models of metabolism in sows. Key Words: Amino Acids, Fats, Lactation, Metabolism, Simulation Models, Sows

Although lipid excess can impair [beta]-cell function in vitro, short-term high-fat feeding in normal rats produces insulin resistance but not hyperglycemia. This study examines the effect of long-term (10-mo) high polyunsaturated fat feeding on glucose tolerance in Wistar rats. The high fat-fed compared with the chow-fed group was 30% heavier and 60% fatter, with approximately doubled fasting hyperinsulinemia (P < 0.001) but only marginal fasting hyperglycemia (7.5 [+ or -] 0.1 vs. 7.2 [+ or -] 0.1 mmol/l, P < 0.01). Insulin sensitivity was ~67% lower in the high-fat group (P < 0.01). The acute insulin response to intravenous arginine was approximately double in the insulin-resistant high-fat group (P < 0.001), but that to intravenous glucose was similar in the two groups. After the intravenous glucose bolus, plasma glucose decline was slower in the high fat-fed group, confirming mild glucose intolerance. Therefore, despite severe insulin resistance, there was only a mildly elevated fasting glucose level and a relative deficiency in glucose-stimulated insulin secretion; this suggests that a genetic or congenital susceptibility to [beta]-cell impairment is required for overt hyperglycemia to develop in the presence of severe insulin resistance. insulin secretion; arginine; long-chain acyl-coenzyme A; body composition; glucose tolerance

Two experiments, each with 39 high-lean-gain potential barrows, were conducted to evaluate the organ weights, body chemical composition, and tissue accretion rates of pigs fed corn-soybean meal diets (CONTROL) and low-protein diets supplemented with crystalline lysine, threonine, tryptophan, and methionine either on an ideal protein basis (IDEAL) or in a pattern similar to that of the control diet (AACON). Amino acids were added on a true ileally digestible basis. The initial and final BW were, respectively, 31.5 and 82.3 kg in Exp. 1 and 32.7 and 57.1 kg in Exp. 2, and pigs were fed for 55 and 27 d in Exp. 1 and 2, respectively. In Exp. 1, the CONTROL and IDEAL diets were offered on an ad libitum basis, or by feeding 90 or 80% of ad libitum intake. In Exp. 2, the CONTROL, IDEAL, and AACON diets were offered on an ad libitum basis, or by feeding 80% of the ad libitum intake. Three pigs were killed at the start of the experiments and three from each treatment were killed at the end of each experiment to determine body chemical composition. In both trials, the whole-body protein concentration (g/kg) and the accretion rates of protein (g/d) were greater (P < 0.05) for pigs fed the CONTROL than for pigs fed the IDEAL and AACON diets. In Exp. 1, pigs fed the CONTROL diet had a trend (P < 0.10) for greater water and lower lipid concentration and had greater (P < 0.05) water and ash accretion rates. Whole-body protein concentration was greatest (P < 0.05) in pigs fed at 80% of ad libitum, but protein, water, and ash accretion rates were greatest (P < 0.05) in pigs allowed ad libitum access to feed. In summary, pigs fed the IDEAL and the AACON diets had less protein in the body and lower protein accretion rates than pigs fed the CONTROL diet. It seems that reductions in protein deposition in pigs fed the IDEAL and AACON diets may have been due to a deficiency of one or more essential amino acids or possibly to increases in the NE for metabolic processes leading to increases in adipose tissue deposition. Key Words: Amino Acids, Body Composition, Growth, Pigs

Byline: D. Nakaoka (1), T. Sugimoto (1), H. Kaji (1), M. Kanzawa (1), S. Yano (1), M. Yamauchi (1), T. Sugishita (1), K. Chihara (1) Keywords: Key words:Albumin -- Body composition -- Bone mineral density -- Fracture -- Osteoporosis -- Postmenopausal women Abstract: The present study analyzed the factors that determine bone mineral density (BMD) and predict spinal fracture risk in postmenopausal Japanese women. Two hundred and five postmenopausal Japanese women aged 48--84 years (mean age 64 years) were enrolled in the cross-sectional study. BMD of the lumbar spine, femoral neck and total body as well as body composition were measured by dual-energy X-ray absorptiometry (DXA). Mid-radial BMD was measured by single-photon absorptiometry. We also determined serum levels of insulin-like growth factor (IGF)-I, IGF binding protein-2, -3 and osteocalcin as well as urinary levels of pyridinoline (Pyr), deoxy-Pyr (D-Pyr) and growth hormone. Multiple regression analysis revealed that lean body mass (LBM) was positively correlated with BMD at all sites. In contrast, femoral neck BMD was highly related to fat mass as well as LBM, although fat mass was not an independent correlate of total body and mid-radial BMD. LBM and urinary D-Pyr were crucial determinants at all sites except the mid-radius in stepwise regression analysis. Fat mass and serum IGF-I were determinants of femoral neck and mid-radial BMD, respectively. In terms of reproductive history, parity affected lumbar BMD. Factors affecting BMD differed according to the site. On the other hand, lumbar BMD as well as serum levels of IGF-I and albumin were selected as predictors of spinal fracture risk in multiple logistic regression analysis. Lumbar BMD, serum IGF-I and LBM were selected in women with lumbar BMD above 0.727 g/cm.sup.2. In conclusion, the present study indicates that LBM is a more important determinant of BMD than fat mass at any site except the femoral neck. Age, serum IGF-I and urinary D-Pyr were also determinants of BMD, dependent on the regions measured. Lumbar BMD and LBM as well as serum levels of IGF-I and albumin were useful markers which predicted the risk of osteoporotic spinal fractures in postmenopausal Japanese women. Author Affiliation: (1) Third Division, Department of Medicine, Kobe University School of Medicine, Kobe, Japan, JP Article note: Received: 6 June 2000 / Accepted: 11 January 2001

This article examines the effects of high altitude on body composition by investigating anthropometric and body composition variables of adult males in the Peruvian Andes. The Quechua subjects are shorter in relation to body weight and have lower presence of adiposity than do other ethnicities in the region, due to stresses of the high altitude environment.

Byline: K. Nezu (1), M. Yoshikawa (2), T. Yoneda (2), K. Kushibe (1), T. Kawaguchi (1), M. Yasukawa (1), A. Kobayashi (2), H. Takenaka (2), A. Fukuoka (2), N. Narita (2), S. Taniguchi (1) Keywords: Key words: Emphysema--Lung volume reduction surgery--Nutritional status--Body composition analysis--Bioelectrical impedance analysis. Abstract: The aim of this study was to examine the short-term effect of lung volume reduction surgery (LVRS) on body composition and other nutritional indicators in 28 patients with emphysema underwent thoracoscopic LVRS. Functional tests, body weight (BW), and body composition were measured before and 6 months after surgery. Mean daily caloric intake (CI) was estimated by 3-day dietary record as well. Fat-free mass (FFM) and fat mass (FM) were assessed by bioelectrical impedance analysis (BIA). FEV.sub.1.0 and Vo .sub.2max have improved after LVRS by 35.2% and 23.8%, respectively. Preoperatively, 75% of patients were underweight (% ideal body weight (%IBW) &lt 90) with the mean %IBW at 84.5%. BW, CI, and FFM increased significantly after LVRS, whereas FM was unchanged. The change in BW correlated significantly with the change in FEV.sub.1.0, MVV, and Vo .sub.2max (p &lt 0.01) but not with CI. Bilateral LVRS results in an increase in FFM and functional improvement for underweight patients with severe emphysema, and it may contribute to the improvement in maximal exercise capacity. Author Affiliation: (1) Department of Surgery III, Nara Medical University, Nara 634-8522, Japan, JP (2) Second Department of Internal Medicine, Nara Medical University, Nara 634-8522, Japan, JP Article note: Accepted for publication: 12 December 2000

Changes in body weight and composition in response to the metabolic load imposed by lactation are highly variable among and within diverse populations. In most reports, rates of weight loss did not differ between lactating and nonlactating women. Despite differences in the hormonal milieu between lactating and nonlactating women, only subtle short-term differences were observed in postpartum changes in body composition. Regional patterns of fat deposition and mobilization did not differ between lactating and nonlactating women in most studies. Changes in body composition during lactation are responses to a sequence of complex neuroendocrine and biochemical stimuli that may be significantly modified by environmental factors. Gestational weight gain was the strongest determinant of postpartum weight and fat mass change, which supports the premise that biological mechanisms are aimed at restoring prepregnancy body weight and composition. KEY WORDS: lactation; body composition; anthropometry; fat-free mass; fat mass