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PubMed1994

Body composition and two-compartment model assumptions in male long distance runners.

Long distance running increases bone mineral mass, skeletal muscle weight, and extracellular fluid volume. Each of these changes may have an impact on classic two-compartment body composition methods that assume a constant fat-free body mass (FFM) density (1.100 g.cc-1), potassium content (65 mmol.kg-1 FFM), and hydration (0.73 kg H2O.kg-1 FFM). The aims of the present study were: to use newly developed multi-component methods to evaluate the validity of two-compartment methods in white male recreational long-distance runners (N = 10); and to compare the body composition of these runners to sedentary controls (N = 10) of similar age, body weight, and body mass index. Runners had a significantly smaller fraction of body weight as fat (P = 0.001) and a larger fraction of FFM as lower extremity skeletal muscle (P = 0.045) and bone (P = 0.049). Although FFM constituted a larger proportion of body weight in the runners, the fractional contributions of water, protein, and mineral were similar to those in the control group. There were no significant differences between the two groups in density of FFM, total body potassium/FFM, and total body water/FFM. New methods thus allow in-depth analyses of body composition in athletes, with results suggesting that classic two-compartment methods are valid in white recreational long-distance runners.

Absorptiometry, Photon↗
PubMed1998

Effect of growth hormone on height, weight, and body composition in Prader-Willi syndrome.

AIMS: To evaluate the effect of the administration of growth hormone on stature, body weight, and body composition in children aged between 4 and 10 years with Prader-Willi syndrome. METHODS: Height, weight, and skinfold thickness were recorded in 25 children using standard anthropometric techniques at recruitment, and six months later, shortly before the start of daily subcutaneous injections of growth hormone. Body composition was assessed via a measurement of total body water using stable isotopes. Measurements were repeated at the end of the six months of growth hormone administration. Measurements of height, weight, and skinfold thickness were expressed as standard deviation scores (SDSs). RESULTS: There was a significant reduction in the percentage of body fat after growth hormone treatment; height velocity doubled during treatment; body weight did not change significantly when expressed as an SDS. Skinfold thickness at both the triceps and subscapular site decreased in absolute terms and when expressed as an SDS. CONCLUSIONS: These results indicate sufficient potential benefit to justify a more prolonged trial of growth hormone treatment and an exploration of different dosage regimens in children with Prader-Willi syndrome.

Body Composition↗
PubMed1993

[Estimation of body composition in patients on dialysis by means of near-infrared interaction ].

Malnutrition and low serum albumin values predict increased mortality in uremic patients. Infrared interactance represents a novel approach to the estimation of body composition. We have examined total body fat, body water and fat-free weight in our male haemodialysis (n = 24) and peritoneal dialysis (n = 17) patients. There were no differences between the groups in a cross-sectional study. A longitudinal study showed a significant increase of total body fat (%) in the peritoneal dialysis patients after five months (mean values +/- SEM) (from 19.8 +/- 2.3 to 22.6 +/- 2.4, p < 0.05), and a significant decrease of body water (%) (from 59.9 +/- 1.5 to 58.2 +/- 1.6, p < 0.05). The difference in total body fat between the haemodialysis (n = 14) and peritoneal dialysis (n = 10) groups reached statistical significance (16.5 +/- 1.7 versus 22.6 +/- 2.4, p < 0.05). No difference was found in serum albumin. Infrared interactance has the capacity to characterize time-dependent differential changes of body composition in various dialysis modalities. Further studies are needed to describe the validity of the method for identification of patients with increasing malnutrition.

Aged↗
PubMed1995

Nutrients, body composition and exercise are related to change in bone mineral density in premenopausal women.

This study determined relationships among total energy intake, nutrient intake, body composition, exercise group status, and annual rates of change (slopes) in bone mineral density in 66 Caucasian premenopausal women (mean age, 34.4 +/- 2.7) taking calcium supplements. Body composition components measured by dual-energy X-ray absorptiometry included fat mass, soft tissue lean mass, and bone mineral density (g/cm2) of total body, spine (lumbar vertebrae 2-4), and three femur sites measured at baseline, 5, 12, and 18 mo. Nutrients were not significant variables in regression models predicting bone mineral density slopes (rates of change) at any femur site. The only significant variable in models predicting Ward's triangle bone mineral density slope was the initial fat mass and, for trochanter, exercise. Significant variables (P < 0.05) in models predicting total body bone mineral density slope included the initial fat mass and fat mass slope plus either vitamin A, carotene, fiber, magnesium, or phosphorus (R2 from 0.31 to 0.25) and fat mass slope plus sodium (R2 = 0.24). The significant variable in the model predicting L2-4 slope was energy intake (R2 = 0.17, P < 0.05). We conclude that nutrient intake, exercise, and body composition are related to bone mineral density rate of change and that relations among these variables vary by bone site.

Absorptiometry, Photon↗
PubMed2005

Effect of recombinant human growth hormone administration on body composition and vascular function and structure in old male Wistar rats.

The process of ageing affects negatively both cardiovascular system and body composition. On the other hand, the hormones of the somatotrophic axis, growth hormone (GH) and insulin-like growth factor-I (IGF-I), whose production is reduced by age, are involved in the regulation of the cardiovascular system. The aim of this study was to investigate the effect of GH on body composition, vascular function and structure in old male rats. Old (20 months) and adult (4 months) male Wistar rats were used. One group of old animals was treated with GH for 4 weeks. Periepididimary fat weight, Specific Gravity Index (SGI), dose responses to Acetylcholine (ACh), Isoproterenol (Iso), Phenylephrine (Phe) and ACh in the presence of NG-nitro-L: -arginine metylester (L-NAME; ACh + L-NAME), as well as vascular morphology in aortic rings, were studied. Old rats showed increased fat weight and decreased SGI as compared to adult animals. GH increased SGI and tended to reduce fat weight. Old rats showed an impairment in the vasodilator response to ACh and Iso; GH significantly improved the vasodilatation induced by Iso, whereas the response to ACh was not significantly enhanced by GH treatment. There were no significant differences between adult and old rats in the contractile response to Phe, and GH did not show any effect. Contraction induced by ACh + L-NAME was higher in old rats as compared to adults, and treatment with GH significantly reduced this response. Aortic media area was increased in old rats, and GH administration reduced this parameter. In conclusion, GH shows beneficial effects on body composition, as well as on vascular function and morphology in old male rats.

Acetylcholine↗
PubMed1995

Obesity in children: recent advances in energy metabolism and body composition.

In this paper we review recent advances in energy metabolism and body composition studies in prepubescent children and the relationship to childhood obesity. Our review on energy expenditure focusses on studies of total energy expenditure using doubly labeled water, the role of energy expenditure in the development of obesity, and the determinants of resting energy expenditure in children. The relatively few studies that have examined the regulation of energy and macronutrient intake in children are also reviewed. In terms of body composition, we focus on recent methodological studies that have developed existing techniques for application to the pediatric population, including dual energy X-ray absorptiometry and bioelectrical resistance. Lastly, we review existing information relating to measurement and alteration of body fat distribution in children.

Body Composition↗
PubMed2000

Body composition in healthy aging.

Health risks in elderly people cannot be evaluated simply in conventional terms of body fatness or fat distribution. Elderly people have less muscle and bone mass, expanded extracellular fluid volumes, and reduced body cell mass compared to younger adults. These nonfat components of body composition play critical roles, influencing cognitive and physical functional status, nutritional and endocrine status, quality of life, and comorbidity in elderly people. Different patterns of "disordered body composition" have different relationships to these outcomes and may require different, tailored approaches to treatment that combine various exercise regimens and dietary supplements with hormone replacement or appetite-stimulating drugs. Skeletal muscle atrophy, or "sarcopenia," is highly prevalent in the elderly population, increases with age, and is strongly associated with disability, independent of morbidity. Elders at greatest risk are those who are simultaneously sarcopenic and obese. The accurate identification of sarcopenic obesity requires precise methods of simultaneously measuring fat and lean components, such as dual-energy X-ray absorptiometry.

Absorptiometry, Photon↗
PubMed2001

Gender differences in rhGH-induced changes in body composition in GH-deficient adults.

In GH-deficient adults, rhGH has pronounced effects on total body water, fat free mass, and fat mass. Recently, we observed a gender difference in IGF-I responsivity to rhGH that was sex steroid dependent. The aim of the present study was to assess the effect of rhGH therapy on body composition parameters with due attention to the gender differences in biological responsiveness to rhGH. Forty-four women [36.9 +/- 11.9 yr (mean +/- SD)] and 33 men (37.2 +/- 13.8 yr) with GH deficiency were studied every 6 months during 2 yr. The treatment goal was to achieve IGF-I levels within the age-adjusted normal range. Total body water, fat free mass, and fat mass were measured by bioimpedantiometry. To reach the treatment goal, the daily rhGH dose (IU/kg/d) had to be significantly higher in women than in men at all time intervals. During rhGH therapy, total body water and fat free mass increased significantly in both men and women (P < or = 0.01 by ANOVA), but changes were more pronounced in men. Fat mass decreased during rhGH treatment and reached its nadir at 6 months, which was more pronounced in men than in women (P = 0.02 by ANOVA). After the initial decrease, fat mass increased again and reached baseline values after 2 yr of treatment. In both men and women, the total body water and fat free mass increases were closely related to the IGF-I increments (P < 0.001 by Pearson's correlation test). The decrease in fat mass correlated significantly with the increase in IGF-I in men (r = -0.89, P < 0.001), not in women. Confirming our earlier data, IGF-I responsivity to rhGH was significantly higher in men than in women at all time intervals (P < 0.01 by ANOVA). Total body water and fat free mass responsivities were also higher in men than in women (P < 0.01 by ANOVA). In conclusion, gender differences in IGF-I responsivities to rhGH are accompanied by gender differences in the extent of body composition changes to rhGH. Probably because of these gender differences in IGF-I responsivity, the increases of total body water and fat free mass to rhGH replacement were greater in men than in women. Remarkably, however, in men, only total body water and fat free mass responses relative to changes in IGF-I increased during the 2 yr of rhGH therapy (P = 0.02 and 0.01, respectively, by ANOVA). In our opinion, this phenomenon might be explained by the increasing target organ sensitivity to IGF-I over time.

Adult↗
PubMed1992

Comparison of measures of body composition in a trial of low dose growth hormone replacement therapy.

OBJECTIVE: We assessed the effects of the administration of low dose growth hormone in growth hormone deficient adults on body composition and physical performance. We compared the validity of different measures of body composition in GH treated adults. DESIGN: An uncontrolled longitudinal study of eight patients with GH deficiency who were treated with 4 units of biosynthetic growth hormone (Norditropin), three times a week. Subjects were studied for 8 weeks. PATIENTS: Eight patients with acquired growth hormone deficiency as defined by < 5 mU/l GH following standard provocative investigations in whom other hormone replacement was optimized. MEASUREMENTS: IGF-I was measured on day 1 and after 4 and 8 weeks of treatment with recombinant human growth hormone. Body composition was estimated by dual energy X-ray absorptiometry, bioelectrical impedance, skinfold anthropometry, total body potassium measurement and by computerized tomography of a representative cross-sectional area of thigh on day 1 and following 8 weeks of treatment. Exercise capacity was measured on an electromechanical bicycle and palmar grip strength was measured using a Jamar dynamometer on day 1 and after 8 weeks. RESULTS: IGF-I increased significantly. Exercise capacity and maximum heart rate achieved on the electromechanical bicycle increased significantly. Grip strength did not change. There was a significant increase in fat-free mass and a decline in fat mass as shown by dual energy X-ray absorptiometry and bioelectrical impedance. However, this was not confirmed by other methods. No side-effects were noted. CONCLUSIONS: This study shows that a low dose of biosynthetic growth hormone can elevate IGF-I levels and have a pronounced physical impact in the growth hormone deficient adult without the side-effects seen at higher dosage schedules. Over a 2 month period the increase in fat-free mass may be due to an increase in total body water; however, the decline in fat mass is a genuine effect.

Absorptiometry, Photon↗
PubMed2005

Body fat distribution, body composition, and respiratory function in elderly men.

BACKGROUND: Most population studies have reported weak or nonsignificant associations between body mass index (BMI; in kg/m2) and lung function. OBJECTIVE: This study focused on the distinct effects of fat distribution and body composition on lung function and examined these relations in elderly men. DESIGN: The study was a cross-sectional evaluation of 2744 men aged 60-79 y who were free of cardiovascular disease and cancer and were drawn from general practices in 24 British towns. Anthropometric and body-composition [including fat mass (FM), fat-free mass (FFM), and percentage body fat (%BF) evaluated with bioelectric impedance] measurements were made, and lung function was examined by using spirometry. RESULTS: Height-standardized forced expiratory volume in 1 s (FEV1) was diminished only in lean (BMI < 22.5) and obese (BMI > or = 30) men, but forced vital capacity (FVC) tended to decrease with increasing BMI (P < 0.01). All other measures of adiposity [ie, waist circumference (WC), waist-hip ratio (WHR), FM, and %BF] were significantly and inversely related to FEV1 and FVC after adjustment for confounders, including age and cigarette smoking (all: P < 0.05). This was seen both in nonobese (BMI < 30) and obese men. FFM was positively associated with FEV1 (P = 0.03) and to a lesser extent with FVC. Higher BMI and FFM were both associated with reduced odds of a low FEV1-FVC ratio (ie, <70%). CONCLUSION: Total body fat and central adiposity are inversely associated with lung function, but increased FFM reflecting increases in muscle mass is associated with increased lung function and lower odds of low FEV1:FVC in the elderly.

Adipose Tissue↗
PubMed1984

Age, body weight and body composition requirements for the onset of sexual maturity of dwarf and normal chickens.

Comparisons of age, food intake, body weight and body composition at the onset of sexual maturity were made between dwarf and normal chickens from lines selected for high or low juvenile body weight. At the same age birds which had started to lay were significantly heavier and contained significantly more abdominal and carcass fat than those which were not laying. Differences between normal and dwarf pullets within lines varied with genetic background, indicating differences between lines in meeting a body weight or a body composition requirement, or both, for the onset of sexual maturity.

Adipose Tissue↗
PubMed1998

The influence of maternal passive and light active smoking on intrauterine growth and body composition of the newborn.

OBJECTIVE: To assess the influence of passive and light active smoking on the reduction of intrauterine growth of the foetus and on modifications in the body composition of the newborn. DESIGN: Random. SETTING: Full term newborn infants at the Department of the Pediatric and Gynaecological Divisions of the City Major Hospital, Chair of Paediatrics, Verona University. SUBJECTS: One hundred and twelve mothers selected after having completed a questionnaire on smoking habits during pregnancy. One hundred and twelve newborn infants were divided into three groups: Group 1: non-smoking and non-exposed mothers; Group 2: non-smoking but exposed mothers; Group 3: light smoking mothers (under 10 cigarettes/d, whether or not also exposed to passive smoking). Examination within 24 h of birth established the anthropometric measurements and estimates of body composition through indices or equations. RESULTS: Newborns of groups 2 and 3 had a statistically significant reduction of fat mass and most anthropometric measurements: fat mass according to Dauncey (P < 0.001), birth-weight (P < 0.013), crownheel length (P < 0.000), upper- and lower-arm length (P < 0.000) and circumference (P < 0.002), triceps skinfold and sum of all skinfolds (P < 0.004). Student t-test, between groups 2 and 3, did not evidence intergroup differences. CONCLUSIONS: Exposure of the foetus to passive and/or light active smoking involves a reduction of most auxiological parameters and not only weight. As regards body composition, smoking appears to reduce fat mass. The prevention of smoking during pregnancy is therefore extremely important, as intrauterine growth seems to be negatively influenced not only by active smoking, but also by passive and light active smoking.

Adipose Tissue↗
PubMed2000

Lipid and lipoprotein profiles, cardiovascular fitness, body composition, and diet during and after resistance, aerobic and combination training in young women.

The purpose of this study was to evaluate the effects of various modes of training on the time-course of changes in lipoprotein-lipid profiles in the blood, cardiovascular fitness, and body composition after 16 weeks of training and 6 weeks of detraining in young women. A group of 48 sedentary but healthy women [mean age 20.4 (SD 1) years] were matched and randomly placed into a control group (CG, n = 12), an aerobic training group (ATG, n = 12), a resistance training group (RTG, n = 12), or a cross-training group that combined both aerobic and resistance training (XTG, n = 12). The ATG, RTG and XTG trained for 16 weeks and were monitored for changes in blood concentrations of lipoprotein-lipids, cardiovascular fitness, body composition, and dietary composition throughout a 16 week period of training and 6 weeks of detraining. The ATG significantly reduced blood concentrations of triglycerides (TRI) (P < 0.05) and significantly increased blood concentrations of high-density lipoprotein-cholesterol (HDL-C) after 16 weeks of training. The correlation between percentage fat and HDL-C was 0.63 (P < 0.05), which explained 40% of the variation in HDL-C, while the correlation between maximal oxygen uptake (VO2max) and HDL-C was 0.48 (P < 0.05), which explained 23% of the variation in HDL-C. The ATG increased VO2max by 25% (P < 0.001) and decreased percentage body fat by 13% (P < 0.05) after 16 weeks. Each of the alterations in the ATG had disappeared after the 6 week detraining period. The concentration of total cholesterol (TC), TRI, HDL-C and low density lipoprotein-cholesterol in the blood did not change during the study in RTG, XTG and CG. The RTG increased upper and lower body strength by 29% (P < 0.001) and 38%, respectively. The 6 week detraining strength values obtained in RTG were significantly greater than those obtained at baseline. The XTG increased upper and lower body strength by 19% (P < 0.01) and 25% (P < 0.001), respectively. The 6 week detraining strength values obtained in XTG were significantly greater than those obtained at baseline. The RTG, XTG and CG did not demonstrate any significant changes in either VO2max, or body composition during the training and detraining periods. The results of this study suggest that aerobic-type exercise improves lipoprotein-lipid profiles, cardiorespiratory fitness and body composition in healthy, young women, while resistance training significantly improved upper and lower body strength only.

Adult↗
PubMed2000

Effects of the Zimbabwe Defence Forces training programme on body composition and reproductive hormones in male army recruits.

OBJECTIVES: To investigate the effects of a four month endurance training programme on body composition and reproductive hormone levels. DESIGN: PRE and POST training comparative study. SETTING: Zimbabwe Military Academy, Gweru, Zimbabwe. SUBJECTS: 77 male recruit volunteers participating in the Zimbabwe Defence Forces cadet training programme. MAIN OUTCOME MEASURES: Percent body fat, fat free mass, body mass index, total serum testosterone, luteinising hormone (LH) and follicle stimulating hormone (FSH) compared using the paired t-test. RESULTS: There was a significant decrease in all parameters measured after four months of endurance training. Decreases in body composition parameters were 54% in percent body fat, 6% in fat free mass, and 13% in body mass index. There was a dramatic 58% drop in testosterone, 60% drop in LH and 15% drop in FSH after four months of endurance training. CONCLUSIONS: The Zimbabwe Defence Forces cadet training programme, an endurance training programme induces a state of negative energy balance in trainees. This results in a decrease in % body fat and body mass index due to utilisation of fat stores as a source of energy and a decrease in fat free mass due to gluconeogenic utilisation of muscle protein as energy source for muscle activity. There is impaired hypothalamic-pituitary-testicular axis function as evidenced by the state of hypogonadal-hypogonadism (low testosterone, LH and FSH). This may be attributed to: 1. gonadotrophin releasing hormone pattern generator malfunction due to the stress of intense physical activity and 2. withdrawal of energy expenditure from reproductive machinery as a way of conserving energy for more vital processes in the prevailing state of energy starvation.

Adolescent↗
PubMed1983

Effects of androgenic-anabolic steroids on neuromuscular power and body composition.

The effects of androgenic-anabolic steroids on neuromuscular power and body composition were studied in nine volunteers experienced with progressive-resistance weight training. By use of double-blind procedures, testosterone cypionate, nandrolone decanoate, and sesame oil (placebo) were administered in a repeated-measures design that counterbalanced treatment order. Duration of each treatment condition was 3 wk. Supplemental protein was provided, and dietary records were maintained throughout the study. Subjects were trained with progressive-resistance weight-training exercises. Isokinetic dynamometer testing revealed that peak torque output was not significantly changed between treatments in 7 out of 10 isolated-joint actions. The hydrostatic weighing results revealed insignificant differences in lean body mass and percent body fat. Significant changes in some treatment means of three peak torque output tests were insufficient to identify any consistent treatment alterations. Since protein and caloric intake was sufficient to elicit anabolic effects from the steroid treatments and weight-training program, the lack of significant results could not be attributed to dietary considerations. Subjects reported subjective feelings of increased strength after administration of anabolic agents, which may partially account for their widespread use. In conclusion, anabolic steroids did not substantially change body composition or the objective power measurements used in this study.

Adult↗
PubMed2001

Accuracy and precision of dual-energy X-ray absorptiometry for body composition measurements in rhesus monkeys.

Accuracy of body composition measurements by dual-energy X-ray absorptiometry (DXA) was compared with direct chemical analysis in 10 adult rhesus monkeys. DXA was highly correlated (r-values > 0.95) with direct analyses of body fat mass (FM), lean mass (LM) and lumbar spine bone mineral content (BMC). DXA measurements of total body BMC were not as strongly correlated (r-value = 0.58) with total carcass ash content. DXA measurements of body FM, LM and lumbar spine BMC were not different from data obtained by direct analyses (P-values > 0.30). In contrast, DXA determinations of total BMC (TBMC) averaged 15%, less than total carcass ash measurements (P = 0.002). In conclusion, this study confirms the accurate measurement of fat and lean tissue mass by DXA in rhesus monkeys. DXA also accurately measured lumbar spine BMC but underestimated total body BMC as compared with carcass ash determinations.

Absorptiometry, Photon↗
PubMed1979

Body composition during nutritional repletion of severely undernourished men.

Body composition was studied in severely undernourished adult male inhabitants of a rural area of Colombia to evaluate the extent and the time course of the changes occurring upon nutritional repletion. During a 45-day basal period on a low (26g/day) protein diet containing adequate calories, body fat depots increased significantly (mean +/- SD = +3.02 +/- 2.9 kg), and there was a significant decrease in cell hydration from 81.8 to 76.4% (-5.4 +/- 9.1%). Upon protein repletion (100 g/day), cell hydration decreased significantly to 71.4%, while body cell mass increased markedly (9.0 +/- 1.1 kg). During protein repletion, muscle cell mass increased significantly (+5.5 +/- 0.6 kg) and rapidly, while the increase in nonmuscle cells (+3.5 +/- 3.8 kg) and specifically in red cell mass lagged behind. With repletion, the changes in the absolute values for plasma volume (+0.4 +/- 0.13 liters) were significant, but those in extracellular fluid volume (-0.7 +/- 1.9 liters) were not. Thus, the major compositional changes observed occurred in the body fat and the body cell mass components; these occurred independently of each other.

Adipose Tissue↗