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PubMed1997

Whole body lean mass is altered by dexamethasone treatment through reductions in protein and energy utilization in piglets.

The objective of this study was to assess the effect of dexamethasone on growth, body composition and protein metabolism using the piglet as a model for rapidly growing premature infants. Seven-day-old male pigs (n = 18) were randomized to 0.5 mg/kg/day oral dexamethasone or placebo for 15 consecutive days. Weight and length gains and weight gained per energy or protein consumed were significantly lower in the dexamethasone group. Serum urea nitrogen was significantly higher in the dexamethasone group by day 15 of the study. No differences were observed between groups for urinary creatinine. The whole body percent lean mass was significantly lower and percent fat mass was significantly higher in the dexamethasone piglets, as measured by dual energy X-ray absorptiometry. In young piglets, dexamethasone, at doses similar to those in premature infants, induces protein catabolism, impairs growth and alters its composition.

Absorptiometry, Photon↗
PubMed2006

A daily comprehensive muscle training programme increases lean mass and spontaneous activity in children with Prader-Willi syndrome after 6 months.

UNLABELLED: The reduction of spontaneous physical activity (PA) and of muscle tissue are thought to be major causes of fat accretion and metabolic deterioration in Prader-Labhart-Willi syndrome (PWS). We investigated whether a generalized physical training programme in a home setting improves these parameters. The prospective study included 11 prepubertal children (mean age 8.7 years, range 5.9-11.8) with documented PWS and under continuous growth hormone treatment for at least 2.8 years. Seven children were enrolled in a training programme for several muscle groups during 4-10 minutes daily. Twelve matched children with PWS served as controls (average age 8.8 years, 6.1-11.3). Before and after training, at 6 months, PA was assessed by measuring walking distance by pedometer registration and by an activity score, and body composition by DEXA expressed as standard deviation scores (SDS) related to height. After training, lean mass (LM) increased from -1.83 to -1.48 SDS, p <0.05, whereas the controls showed no change. In the training group, walking distance and PA increased from 4.2 to 4.7 km/d and from 255 to 266 points, respectively, and these rises significantly exceeded those observed in controls. CONCLUSION: Children with PWS can be motivated by their families to follow a short daily training, which has general effects on PA and does increase, but not normalize LM.

Adiposity↗
PubMed2000

Effect of a hypocaloric diet, increased protein intake and resistance training on lean mass gains and fat mass loss in overweight police officers.

We compare the effects of a moderate hypocaloric, high-protein diet and resistance training, using two different protein supplements, versus hypocaloric diet alone on body compositional changes in overweight police officers. A randomized, prospective 12-week study was performed comparing the changes in body composition produced by three different treatment modalities in three study groups. One group (n = 10) was placed on a nonlipogenic, hypocaloric diet alone (80% of predicted needs). A second group (n = 14) was placed on the hypocaloric diet plus resistance exercise plus a high-protein intake (1.5 g/kg/day) using a casein protein hydrolysate. In the third group (n = 14) treatment was identical to the second, except for the use of a whey protein hydrolysate. We found that weight loss was approximately 2.5 kg in all three groups. Mean percent body fat with diet alone decreased from a baseline of 27 +/- 1.8 to 25 +/- 1.3% at 12 weeks. With diet, exercise and casein the decrease was from 26 +/- 1.7 to 18 +/- 1.1% and with diet, exercise and whey protein the decrease was from 27 +/- 1.6 to 23 +/- 1.3%. The mean fat loss was 2. 5 +/- 0.6, 7.0 +/- 2.1 and 4.2 +/- 0.9 kg in the three groups, respectively. Lean mass gains in the three groups did not change for diet alone, versus gains of 4 +/- 1.4 and 2 +/- 0.7 kg in the casein and whey groups, respectively. Mean increase in strength for chest, shoulder and legs was 59 +/- 9% for casein and 29 +/- 9% for whey, a significant group difference. This significant difference in body composition and strength is likely due to improved nitrogen retention and overall anticatabolic effects caused by the peptide components of the casein hydrolysate.

Adipose Tissue↗
PubMed2003

Effect of exogenous growth hormone and exercise on lean mass and muscle function in children with burns.

We tested the hypothesis that the administration of recombinant human growth hormone (rHGH) and exercise would increase lean body mass (LBM) and muscle strength in burned children to a greater extent than rHGH or exercise separately. Children, ages 7-17 yr, with >40% body surface area burned, were randomized into groups. One group (GHEX, n = 10) participated in a 12-wk in-hospital physical rehabilitation program supplemented with an exercise program and received 0.05 mg. kg(-1). day(-1) of rHGH. A second exercising group (SALEX, n = 13) received saline. A third group (GH, n = 10) received a similar dose of rHGH as GHEX and participated in a 12-wk, home-based physical rehabilitation program without exercise. The fourth group (Saline, n = 11) received saline and participated in a 12-wk, home-based physical rehabilitation program without exercise. The mean (+/-SE) percent change in lean body mass after 12 wk was not significantly different between GHEX (9.0 +/- 2.1%), SALEX (5.4 +/- 1.6%), and GH (5.8 +/- 1.8%) groups (P = 0.33). However, the mean percent change in muscle strength was significantly greater in the GHEX (36.2 +/- 5.4%) and SALEX (42.6 +/- 10.0%) groups than in the GH (-7.4 +/- 4.7%) or Saline (6.7 +/- 4.4%) groups (P = 0.008). In summary, rHGH GHEX, SALEX, and GH alone produced similar improvements in LBM. However, muscle strength was only increased via exercise.

Adolescent↗
PubMed1999

Nutritional requirements to increase lean mass.

If a physician determines that an athlete has the potential to increase lean body mass, the following components are necessary for success: appropriate progressive resistance-training program. Adequate rest and sleep. Adequate energy intake. Five to nine eating occasions a day. Increased amount of food if possible. High energy supplements. Adequate protein intake. [table: see text]

Body Composition↗
PubMed2003

Effect of dietary protein on lean body wasting in dogs: correlation between loss of lean mass and markers of proteasome-dependent proteolysis.

To determine the effect of dietary protein intake on lean body wasting in adult canines a study was undertaken to investigate the Ubiquitin Proteasome (UP) pathway and concurrent changes in lean and fat body mass of canines fed variable sources and concentrations of dietary protein. Purpose-bred, intact female canines (56) between the ages of 2 and 3 years were fed either 12 or 28% protein diet for 10 weeks. Each diet contained variable amounts of corn gluten meal and chicken protein sources in ratios of 100 : 0, 67 : 33, 33 : 67 and 0 : 100 per cent (w/w), respectively. All diets were isocaloric with calories coming from protein : fat : carbohydrate at the respective ratios of 12 : 40 : 48% for the 12% diets, and 28 : 40 : 32% for the 28% diets. Standard dual energy X-ray absorptiometry was performed to assess total body lean and fat mass at weeks 0 and 10 of the dietary trial. Muscle biopsies were also taken and processed for protein determination and standard gel electrophoresis with subsequent Western blotting for 20S proteasome and PA700 regulatory cap subunit p31. Statistical analysis revealed a moderate degree of correlation between increasing quantities of corn gluten, which is low in essential amino acids (i.e. lysine, tryptophan), and increasing loss of lean body mass over the 10-week study (R = 0.56). Furthermore, a moderate degree of correlation was observed between increasing concentrations of corn gluten protein and decreased expression of the p31 subunit of the 26S proteasome (R = 0.49). Additionally, the dogs consuming the 12% protein diets had a significant increase in fat mass regardless of the protein source. These findings suggest that lean body wasting in adult canines can be associated with the consumption of low protein diets consisting of predominantly corn gluten, which is likely due to imbalances or subclinical deficiencies of specific essential amino acids, and that low protein diets may augment accumulation of adipose tissue. Although the mechanisms remain unclear, alteration of molecular targets of skeletal muscle proteolysis, specifically involving the UP pathway occur.

Absorptiometry, Photon↗
PubMed2006

Measurement error of DXA: interpretation of fat and lean mass changes in obese and non-obese children.

Information on reproducibility of dual-energy X-ray absorptiometry (DXA) measurements is essential because DXA is frequently used by clinicians and researchers to assess body composition changes. We estimated measurement error and absolute and relative smallest detectable differences (SDDs) for fat, lean, and bone mass in children. The SDD is the change necessary to be confident that the change is not a consequence of measurement error. Duplicate whole body DXA (Hologic QDR 4500A, Hologic Inc., Waltham, MA) scans were obtained on 32 obese and 34 non-obese children ages 6-19 yr. Absolute (kg) and relative (coefficient of variation) measurement error and SDD were calculated. Absolute SDDs for fat and lean were higher for obese (1.39 and 1.30 kg, respectively) than for non-obese children (0.42 and 0.47 kg, respectively). The %SDD for fat was lower for obese (3.58%) than non-obese children (5.24%), but for lean the %SDD was higher for obese (2.60%) than non-obese children (1.32%). The SDDs for bone mass were similar for obese and non-obese children. An obese child must lose or gain more absolute fat and lean mass than a non-obese child to be confident that the change is not a reflection of measurement error. Overall, SDD values for fat, lean, and bone mass are low.

Absorptiometry, Photon↗
PubMed1984

[Hypocaloric and high-protein diet in obese patients: changes in the lean mass].

We have followed for 40 days seven hospitalized, young (age, mean SD : 33 +/- 8 yrs), and moderately obese (W/H : 35 +/- 3.92) women. During the first 5 days (DO to D5) they received a diet similar to their customary home-diet; from D6 to D40, their daily caloric intake was adjusted to 3,41 +/- 0.13 MJ (816 +/- 30 kcal). This diet comprised 21 p. 100 of sugars, 35 p. 100 of lipids, 1.57 +/- 0.09 g proteins per kg ideal body weight. Five seven-day periods have been studied. On the first day of each period, we recorded body weight and measured plasma albumin, pre albumin, retinol binding protein, complement (CH50 and C3) C peptide (in the fasting state and after glucagon stimulation), and thyroid hormones (T3 and rT3). On each of the 35 days of this study, total nitrogen was measured (Kjeldahl's method) in food, urine and faeces. On D0 and D41 lean and fat body masses were evaluated through measurements of total water (dilution of tritiated water) and of skin fold thickness respectively. From D0 to D40, the average weight loss was 8.76 +/- 1.86 kg; the cumulated nitrogen balances were negative in 6 patients and positive in one, with variations from one period to another and from one patient to another. Plasma proteins and hormones did not vary significantly. Changes in lean mass were comprised between + 0,7 and -- 1,6 kg in spite of the fact that all patients received the same caloric and protein intake.

Adolescent↗
PubMed2003

Importance of lean mass in the interpretation of total body densitometry in children and adolescents.

OBJECTIVE: Most studies that use total body dual energy x-ray absorptiometry (DEXA) in children rely on areal bone mineral density (BMD=bone mineral content [BMC]/bone area [BA]) and compare the output with age- and sex-specific normative data. Because this approach is prone to size-related misinterpretation, this study focuses on the interrelations among BMC, body size (height), and lean tissue mass (LTM). STUDY DESIGN: This cross-sectional study presents normative total body LTM data in relation to height and BMC for 459 healthy white subjects (249 female), 3 to 30 years of age. Guidelines for DEXA interpretation in children are provided and illustrated for patients with growth hormone deficiency (n=5) and anorexia nervosa (n=5). RESULTS: LTM/height tended to be greater in male than in girls. The BMC/LTM ratio was greater in female than in boys (P<.001), even after adjustment for age and height. Sex-specific reference curves were created for LTM/height, the BMC/LTM ratio, BA/height, and BMC/BA. CONCLUSIONS: We recommend that total body DEXA in children should be interpreted in 4 steps: (1) BMD or BMC/age, (2) height/age, (3) LTM/height, and (4) BMC/LTM ratio for height. This allows differentiation of the origin of a low BMD or BMC/age, for example, short stature and primary, secondary, and mixed bone defects.

Absorptiometry, Photon↗
PubMed1985

Assessment of cellular mass and lean body mass by noninvasive nuclear techniques.

With the nuclear techniques employed in this study, it has been possible to measure total body potassium (TBK), lean body mass (LBM), and body cell mass (BCM). The latter two are derived independently of TBK. LBM is derived from the sum of total body water (TBW), total body protein, and bone mineral ash measurements. The BCM value is, in turn, based on the difference between the LBM (as measured above) and the sum of the extracellular water and extracellular solids. It was demonstrated in 123 normal individuals that, although the TBK/LBM ratio decreases with age, the TBK/BCM ratio does not change significantly with age. It can be deduced that the ratio of TBK to intracellular water should be relatively constant with age. This relative constancy with age was demonstrated independently with the absolute measurements of TBK and intracellular water in normal individuals. Because the BCM is physiologically and chemically more homogeneous than LBM and because it reflects the actively metabolizing cellular compartment more accurately than LBM, it is the preferred parameter to be used for reference or normalization in body composition studies. For most applications, BCM is readily derived from TBK measurement by either whole body counting or isotope dilution techniques.

Adult↗
PubMed2006

Increased neonatal fat mass, not lean body mass, is associated with maternal obesity.

OBJECTIVE: The purpose of this study was to compare body composition measures in neonates of women who were overweight/obese (body mass index, > or = 25 kg/m2) versus women who were lean/average (body mass index, < 25 kg/m2), all of whom had normal glucose tolerance levels. STUDY DESIGN: Seventy-six neonates (34 female and 42 male) of singleton pregnancies of pregravid overweight/obese women and 144 neonates (67 female and 77 male) of lean/average women were assessed with anthropometric measures and total body electrical conductivity evaluation of body composition at birth. RESULTS: There was a borderline increase in birthweight (3436 +/- 567 g vs 3284 +/- 534 g; P = .051) but not lean body mass (3020 +/- 410 g vs 2950 +/- 400 g; P = .23) in the overweight/obese versus lean/average weight groups. However, there were significant increases in percent body fat (11.6% +/- 4.7% vs 9.7 +/- 4.3%; P = .003) and fat mass (420 +/- 220 g vs 380 +/- 170 g; P = .01) in neonates of overweight/obese women versus lean/average weight women. CONCLUSION: Overweight/obese women with normal glucose tolerance levels have neonates who are heavier than lean/average weight women because of increased adiposity. We speculate that this increased obesity in offspring of obese women with normal glucose tolerance levels is a significant risk for adolescent obesity and components of the metabolic syndrome.

Adiposity↗
PubMed2000

Regional body composition changes in women after 6 months of periodized physical training.

Data are lacking regarding regional morphological changes among women after prolonged physical training. This study employed dual-energy X-ray absorptiometry to assess changes in whole body and regional (i.e., trunk, legs, arms) fat mass, lean mass, and bone mineral content body composition adaptations in 31 healthy women pre-, mid-, and post-6 mo of periodized physical training. These results were compared with those of 1) a control group of women who had not undergone the training program and were assessed pre- and post-6 mo and 2) a group of 18 men that was tested only once. Additionally, magnetic resonance imaging was used to assess changes in muscle morphology of the thigh in a subset of 11 members of the training group. Physical training consisted of a combination of aerobic and resistance exercise in which the subjects engaged for 5 days/wk for 24 wk. Overall, the training group experienced a 2.2% decrease, a 10% decrease, and a 2.2% increase for body mass, fat mass, and soft tissue lean mass, respectively. No changes in bone mineral content were detected. The women had less of their soft tissue lean mass distributed in their arms than did the men, both before and after the women were trained. Novel to this study were the striking differences in the responses in the tissue composition of the arms (31% loss in fat mass but no change in lean mass) compared with the legs (5.5% gain in lean mass but no change in fat mass). There was a 12% fat loss in the trunk with no change in soft tissue lean mass. Dual-energy X-ray absorptiometry and magnetic resonance imaging fat mass measurements showed good agreement (r = 0. 72-0.92); their lean mass measurements were similar as well, showing approximately 5.5% increases in leg lean tissue. These findings show the importance of considering regional body composition changes, rather than whole body changes alone when assessing the effects of a periodized physical training program.

Absorptiometry, Photon↗
PubMed2004

The metabolic syndrome in obese postmenopausal women: relationship to body composition, visceral fat, and inflammation.

The purpose of this study was to investigate whether aerobic fitness, body composition, body fat distribution, and inflammation are different in obese postmenopausal women with and without the metabolic syndrome (MS), and whether the severity of MS is associated with these characteristics. Fifty-eight women (age, 59 +/- 1 yr; body mass index, 33.0 +/- 0.6 kg/m2)completed testing of maximal aerobic capacity, body composition (fat mass, lean mass, and percent body fat), body fat distribution (sc and visceral fat areas, and regional adipocyte sizes), and inflammation (C-reactive protein, IL-6, and TNF-alpha,and their soluble receptors). Lean mass (44.4 +/- 0.9 vs. 41.2 +/- 0.9 kg; P < 0.05), visceral fat area (180 +/- 10 vs. 135 +/- 7 cm2; P <0.001), and plasma soluble TNF receptor 1 (sTNFR1; 860 +/- 25 vs. 765 +/- 42 pg/ml; P < 0.05) were higher in women with the MS(n = 27) than in those without the MS (n = 31). The number of MS components was directly related to weight, body mass index, fat mass, lean mass, visceral fat area, and plasma sT-NFR1. We conclude that obese older women with the MS are characterized by high lean mass, high visceral fat, and elevated sTNFR1, and the severity of the MS is associated with body composition, visceral adiposity, and inflammation.

Adipose Tissue↗
PubMed2005

The combination of dietary conjugated linoleic acid and treadmill exercise lowers gain in body fat mass and enhances lean body mass in high fat-fed male Balb/C mice.

Nearly half of the U.S. adult population is overweight or obese, which may be related to increased energy intake combined with lack of physical activity. Obesity increases the risk of several chronic diseases including diabetes, coronary heart disease, hypertension, and stroke. Conjugated linoleic acids (CLA) were shown to decrease fat and increase lean mass in several animal studies. However, the effects of CLA in combination with exercise (Ex) on body composition have not been studied in an animal model. We examined the effect of a low concentration of either safflower oil as control (0.5%) or mixed isomers of CLA (0.4%) along with treadmill exercise on body composition in male Balb/C mice fed a high-fat diet (20% corn oil) in a 2 x 2 factorial design. CLA consumption lowered change in fat mass (P < 0.001) confirming the results of other studies, and change in fat mass decreased further (P < 0.001) with CLA and exercise. Change in lean mass did not increase with exercise alone; it increased, although not significantly, with CLA alone and increased significantly (P < 0.05) due to the combination of CLA and exercise. This effect was accompanied by decreased serum leptin levels and lower leptin mRNA expression in peritoneal fat (P < 0.001). Serum insulin, glucose, tumor necrosis factor (TNF)-alpha, and interleukin-6 were lower in CLA-fed mice than in controls (P < 0.05), whereas serum TNF-alpha was increased by exercise (P < 0.05). Exercise increased oxygen consumption and energy expenditure when measured under resting conditions (P < 0.05). In summary, the combination of dietary CLA and exercise decreased fat mass and increased lean mass in mice fed a high-fat diet, and these effects may be related in part to decreased serum leptin and exercise-induced increases in oxygen consumption and energy expenditure.

Adipose Tissue↗
PubMed1982

[Relationship between blood pressure and weight characteristics in childhood and adolescence. II.--Blood pressure, fatness, lean body mass and non lean body mass (author's transl)].

The relationship between adiposity and blood pressure has been studied among 17,067 healthy children aged 4 to 18 years old. The correlation of blood pressure with fatness, expressed as non lean body mass, is smaller than the correlation with lean body mass, especially in boys. Blood pressure association with lean body mass strongly increases during puberty growth in boys. These data suggest that during adolescence blood pressure association with weight is mainly due to growth and physical-maturation and that fatness has less influence. A careful analysis of somatic features of adolescents with high blood pressure seems necessary before advocating and improved system of weight control. Preference of blood pressure reference to height is again strengthened.

Adolescent↗
PubMed2006

Body composition and cardiovascular risk in hemodialysis patients.

Death rate is unacceptably elevated in end-stage renal disease patients treated with hemodialysis. Excessive body fat, or obesity, is the well-known risk factor for cardiovascular disease and other health problems in the general population. However, hemodialysis patients with a higher body mass index (BMI) have a lower risk of death, as shown by many studies. There are several explanations for the paradox of BMI in dialysis patients. First, although body mass is composed of fat mass and fat-free mass (lean mass), it is unknown which is more important, fat mass or lean mass, in predicting outcome of hemodialysis patients. Second, it is also possible that functions of adipose tissue are altered in renal failure so that accumulation of body fat leads to less atherogenicity and beneficial properties become predominant. Third, an increased fat mass may be protective against death after harmful events. In this article, we explore these possibilities using either the data of our own cohort of hemodialysis patients or the existing registry data of Japan. We conclude that in hemodialysis patients, fat mass rather than lean mass plays a protective role against mortality, that the fat mass-adipocytokine relationship is altered, and that a low BMI is associated with increased risk of fatality after cardiovascular events rather than the risk of occurrence of such events.

Adiponectin↗
PubMed1995

Age-related changes of whole skeleton and body composition in healthy men.

We examined age-related changes of the entire skeleton and its major anatomical areas (spine, trunk, pelvis, arms, legs) in 139 healthy males (19-99 years of age) and evaluated the influence of lean mass and fat mass on these changes. The population studied was stratified according to their ages referred in decades. Bone mineral density (BMD) and body composition (fat mass, lean mass) were measured by Lunar DPX. A negative linear correlation between BMD values and age was observed. The overall bone loss from the young to the aged was statistically significant for all skeletal sites, with a lower level of significance for the spinal area: BMD percentage decrease ranged from 19.4% for the pelvis to 9% for the spine. Peak bone mass was observed in the first decade (19-29 years of age). Soft tissue increased until the fifth and sixth decades, followed by a gradual decrease. Lean mass declined in a uniform way from the first to the last decades. BMD values were significantly related to lean mass, but there were no correlations with the fat mass. Lean body mass was significantly related to BMD/height, index of "true" volumetric density. Multiple regression analysis confirmed that in males the principal determinant of total body bone density is fat-free mass.

Absorptiometry, Photon↗
PubMed2005

Simulated high altitude selectively decreases protein intake and lean mass gain in rats.

The aim of this study was to find out whether high altitude (HA)-induced hypophagia was macronutrient-specific using a self-selection procedure. Body composition was assessed by dual X-ray absorptiometry before and after exposure and by dissection at the end of the experiment. Energy intake, macronutrient selection, body composition, plasma insulin and leptin concentrations were measured in rats (FHx) exposed 16 h daily for 10 days to hypobaric hypoxia (HH) simulating an altitude of 5500 m. Rats were fasted during the exposure to HH and had access to food only during the 8 h of normoxia in their active period. This group was compared to control group (C) with ad libitum access to food and a group of rats submitted only to the 16-h fast (FNx). Results showed that sustained hypophagia was specific to protein (55 +/- 5% of C, P < .05), whereas after a decline, carbohydrate intake reached its basal level on the 5th day. HH dramatically reduced fat-free mass gain (P < .05 and P < .0001 compared to C and FNx, respectively). Plasma leptin concentrations at the onset of the period of access to food were not significantly different from those of controls. Across groups, leptin was positively correlated with fat mass (r = .71, P < .001) and negatively with energy intake (r = -.52, P < .05), more specifically with protein intake (r = -.57, P < .05). These results suggest that HA leads to a reduced preference for protein impairing fat-free mass gain and that leptin may contribute to this hypophagia.

Altitude↗