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PubMed1997

Body composition by x-ray absorptiometry and bioelectrical impedance in female runners.

Body composition interests athletes since athletic performance is influenced by and dependent on the proportion and total amount of fat-free mass (FFM) and fat mass. The use of bioelectrical impedance (BIA) has increased recently since portable instruments make the measurements easy to execute and relatively inexpensive. The purpose of this study was to test the degree of relationship between FFM and fat mass calculated in elite female runners with 12 different BIA formulas reported in the literature and measured by dual-energy x-ray absorptiometry (DXA). The present study shows that body composition by BIA is valid in female runners. Prediction equations used to calculate FFM and fat mass must be appropriate for this population subgroup and validated against other methods, such as DXA and hydrodensitometry. Those formulas that performed well in the controls gave poor results in the female runner and vice versa. The below average fat mass noted in female runners suggests that prediction equations for untrained women with average fat mass are inappropriate. The formula by RJL Systems-2 for women: FFM = 5.091 + 0.6483.height2/resistance + 0.1996.weight gave best predictions of FFM in female runners. Further research is necessary to validate BIA prediction formulas in other athletes.

Absorptiometry, Photon↗

PubMed1994

Increased energy requirements and changes in body composition with resistance training in older adults.

Body composition and the components of energy metabolism were examined in 12 men and women, aged 56-80 y, before and after 12 wk of resistance training. Subjects were randomly assigned to groups that consumed diets that providing either 0.8 or 1.6 g protein.kg-1.d-1 and adequate total energy to maintain baseline body weight. Fat mass decreased 1.8 +/- 0.4 kg (P < 0.001) and fat-free mass (FFM) increased 1.4 +/- 0.4 kg (P < 0.01) in these weight-stable subjects. The increase in FFM was associated with a 1.6 +/- 0.4 kg increase in total body water (P < 0.01) but no significant change in either protein plus mineral mass or body cell mass. With resistance training, the mean energy intake required for body weight maintenance increased by approximately 15%. Increased energy expenditure included increased resting metabolic rate (P < 0.02) and the energy cost of resistance exercise. Dietary protein intake did not influence these results. Resistance training is an effective way to increase energy requirements, decrease body-fat mass, and maintain metabolically active tissue mass in healthy older people and may be useful as an adjunct to weight-control programs for older adults.

Adipose Tissue↗

PubMed2005

Body composition of children aged 1 to 12 years with biliary atresia or Alagille syndrome.

BACKGROUND: Growth and body composition have not been well described in older children with biliary atresia or Alagille syndrome living with their native liver. To optimize nutritional management of these conditions it is essential to understand the normal growth characteristics. OBJECTIVES: The purpose of this study was to evaluate and compare the growth and body composition of children, particularly school-age children, with biliary atresia and Alagille syndrome. METHODS: A single observer measured height, weight, arm anthropometry and skin fold thickness in subjects aged 1 to 12 years with biliary atresia or Alagille syndrome who had not undergone liver transplantation. RESULTS: Forty-six subjects (10 biliary atresia/36 Alagille syndrome) were assessed. Biliary atresia subjects were below average in height for age with normal weight and elevated body mass index. Mean fat stores were mildly depressed. The z-scores for body mass index and weight for age were inversely correlated with age. Alagille subjects were stunted and had low body weight and reduced fat and muscle stores. Body mass index z-score was inversely correlated with age despite improved cholestasis. CONCLUSIONS: Children with Alagille syndrome had significant growth deficits as measured by weight, height and upper arm anthropometry at all ages studied. In contrast, subjects with biliary atresia had normal weights and heights. However, body mass index and weight for age z-scores were lower in the older biliary atresia subjects. Few studies of anthropometry in biliary atresia or Alagille syndrome have included the school-aged child. This study addresses this gap in knowledge and provides baseline data for nutritional interventions in these patients.

Alagille Syndrome↗

PubMed1982

Growth and body composition of Mexican-American boys 9 through 14 years of age.

The growth status and densitometric estimates of body composition are considered in a cross-sectional sample of 95 Mexican-American boys, 9 through 14 years of age, from lower socioeconomic circumstances. A series of 19 measurements were taken on each boy, including measures of size, proportions, skeletal breadths, limb circumferences, skinfolds, and grip strength. Body density was determined by underwater weighing and residual volume was predicted. Density determinations were converted to percentage body fat using the average of two estimates from the equations of Brozek et al. (1963) and Siri (1956). Relative fatness was also converted to lean body mass and fat weight in kilograms. The growth status of the boys was compared to reference data for American White boys in the U. S. Health examination Survey. The Mexican-American boys are shorter and lighter than the reference data, and smaller in all anthropometric dimensions except skinfolds, which are variable. The subscapular and midaxillary skinfolds are similar in the two samples, while the triceps, medial calf, and suprailiac skinfolds are thinner in Mexican-American boys. Regressions of the four body composition estimates on age show significant age effects only for lean body mass and fat weight. Density and percentage fat do not vary significantly with age. Compared to samples of boys in the same age range, the Mexican-American boys generally have a greater body density. Correlations between skinfold thicknesses and body density are generally lower in the Mexican-American boys compared to other samples. Two equations for the prediction of body density in Mexican-American boys are offered.

Adipose Tissue↗

PubMed2006

Genome-wide linkage analysis to identify chromosomal regions affecting phenotypic traits in the chicken. II. Body composition.

Two informative chicken F(2) populations based on crosses between a broiler breeder male line and dams from genetically distinct, highly inbred (>99%) chicken lines, the Leghorn G-B2 and Fayoumi M15.2, have been used for genome-wide linkage and QTL analysis. Phenotypic data on 12 body composition traits (breast muscle weight, breast muscle weight percentage, abdominal fat weight, abdominal fat weight percentage, heart weight, heart weight percentage, liver weight, liver weight percentage, spleen weight, spleen weight percentage, and drumstick weight, and drumstick weight percentage) were collected. Birds were genotyped for 269 microsatellite markers across the genome. The QTL Express program was used to detect QTL for body composition traits. Significant levels were obtained using the permutation test. For the twelve traits, a total of 61 (Gga 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, 24, and Z) and 45 (Gga 1, 2, 3, 4, 6, 7, 8, 9, 10, 12, 15, 17, and E46) significant QTL were detected at the 5% chromosome-wise significance level, of which 19 and 11 were significant at the 5% genome-wise level for the broiler-Leghorn cross and broiler-Fayoumi cross, respectively. Phenotypic variation for each trait explained by all QTL across the genome ranged from 3.22 to 33.31% in the broiler-Leghorn cross and 4.83 to 47.12% in broiler-Fayoumi cross. Distinct QTL profiles between the 2 crosses were observed for most traits. Cryptic alleles were detected for each trait. Potential candidate genes within the QTL region for body composition traits at the 1% chromosome-wise significance level were identified from databases for future association study. The results of the current study will increase the knowledge of genetic markers associated with body composition traits and aid the process of identifying causative genes. Knowledge of beneficial genetic variation can be incorporated in breeding programs to enhance genetic improvement through marker-assisted selection in chickens.

Animals↗

PubMed1993

Body composition study in the elderly: comparison between tritium dilution method and dual photon absorptiometry.

BACKGROUND: The methods commonly employed in body composition study in elderly persons derive fat-free mass (FFM) by measures of total body water (TBW); these methods assume FFM hydration constant (TBW/FFM = 0.732). The aim of our study was to verify the accuracy of the TBW method in FFM estimation and to study the variability of fat-free mass hydration (TBW/FFM) in healthy elderly subjects. METHODS: We assessed FFM in 27 healthy old subjects (76 +/- 7 yrs) by dual photon absorptiometry (DPA) and by TBW measured by 3H2O. Furthermore, to verify the accuracy in FFM estimation by our methods, we measured resting metabolic rate (RMR) by indirect calorimetry. RESULTS: FFM hydration was 71.9 +/- 4.9 (range 63.6-80.4%), a range larger than that reported by direct chemical analysis in adults. The FFM hydration measured in our subjects was not different from the 73.2 value currently used in healthy adults. FFM values derived by TBW (assuming TBW/FFM = 0.732) were not significantly different from FFM measured by DPA. We correlated FFM with resting metabolic rate and found a similar correlation between RMR and FFM-DPA (r = .89, p < .001) and FFM-TBW (r = .85, p < .001). CONCLUSIONS: Both methods employed in our study have proved to be accurate in estimating FFM in elderly persons; particularly, the value of 0.732 assigned to FFM hydration to derive fat-free mass in adults can be employed also in body composition study of the elderly.

Absorptiometry, Photon↗

PubMed2001

Body composition and anthropometry in bodybuilders: regional changes due to nandrolone decanoate administration.

The purpose of the present study was to investigate regional changes in body composition and anthropometric variables induced by nandrolone decanoate in bodybuilders. In a randomized, double blind, placebo controlled design 16 subjects received weekly intramuscular injections containing 200 mg nandrolone decanoate (ND) or placebo. Composition of total body and body parts were assessed using dual energy X-ray absorptiometry (DEXA), skinfolds and circumferences. Measurements were performed at baseline, after 8 weeks ND administration period and 6 weeks after drug withdrawal. DEXA revealed that total body mass (from 76.16 +/- 2.70 to 78.73 +/- 4.07 kg, p<0.5) and bone-free lean mass (from 59.54 +/- 2.36 to 63.06 +/- 2.99 kg, p < 0.025) increased significantly during ND administration whereas bone mineral mass remained unchanged. Six weeks after drug cessation bone-free lean mass was still increased compared to baseline levels. During ND administration significant increments of bone-free lean mass of the trunk (+ 2.03 kg) and legs (+ 1.08 kg) could be observed. Percentage fat of the legs decreased during the drug intervention period (-1.9%) and remained lowered six weeks after drug withdrawal. No alteration in any variable of the arms was observed. Skinfolds did not change during the entire study period in both groups. After 8 weeks ND administration circumference of the neck was increased (+0.9 cm) significantly although all circumferences underwent non-significant gains. In conclusion, the intramuscular administration of nandrolone decanoate (200 mg per week) during eight weeks induced an increase of body weight and bone-free lean body mass in bodybuilders that was mainly situated in the trunk and legs as determined by DEXA. The changes in the trunk were reflected in the circumferences but not the alterations in the legs. Skinfolds were not able to detect changes of fat mass of body parts. DEXA revealed that total fat mass and total percentage fat remained unaffected by drug administration while percentage fat of the legs decreased and remained lowered after drug cessation. These data indicate that changes of the composition of body parts induced by ND are elucidated less accurately by circumferences or skinfolds rather than by DEXA.

Absorptiometry, Photon↗

PubMed1983

Changes in body composition and muscle protein degradation during nutritional supplementation in nutritionally growth-retarded children with cystic fibrosis.

Changes in body composition and muscle protein degradation were studied in seven nutritionally growth-retarded children with cystic fibrosis (CF) before and after nutritional supplementation and in eight healthy children who served as controls. Supplemental feedings consisted of a peptide formula that increased dietary protein and energy intakes approximately 20-40% over a 6-month period, delivered either as oral supplement or overnight intragastric feeding. Body composition was assessed by anthropometric data and measurements of whole body potassium (40K) and creatinine excretion. Muscle protein degradation was measured by urinary 3-methylhistidine excretion, an index of myofibrillar protein catabolism. Compared with controls, CF children had significantly reduced body mass, body fat, and muscle mass, and a significantly increased rate of myofibrillar protein degradation. With nutritional supplementation, significant catch-up weight gain and improved linear growth were observed with evidence of accretion of lean body mass and muscle mass, and in all but one severely malnourished patient with progressive disease, there was normalization of the high rate of muscle protein degradation. Thus, this form of nutritional therapy has significant benefits in terms of body protein accretion and myofibrillar protein degradation.

Adolescent↗

PubMed1993

Relationships and independence of body composition, sex hormones, fat distribution and other cardiovascular risk factors in overweight postmenopausal women.

The relationships and independence of body composition, sex hormones, fat distribution and other cardiovascular risk factors were studied in 121 overweight postmenopausal women. Body composition and fat distribution were directly measured by dual energy X-ray absorptiometry (DXA); other parameters were waist-to-hip ratio (WTH), sex hormone binding globulin (SHBG), testosterone, androstenedione (A), oestradiol (E2), and lipids and lipoproteins; cigarette and alcohol consumption were recorded. SHBG was correlated with the fat distribution by DXA and WTH (r = -0.35, P < 0.01) and A with the fat mass (r = -0.3, P < 0.01). SHBG had a negative and alcohol and cigarette consumption a positive, independent relationship to a central fat distribution (by DXA and WTH, respectively) (P < 0.01). SHBG (r = 0.23, P < 0.05), fat distribution (WTH) and A (r = -0.2 to -0.3, P < 0.01) were correlated with high density lipoprotein cholesterol (HDL-C). However, only fat distribution (WTH) and A were independently related to HDL-C (P < 0.05). Fat distribution (WTH) and SHBG were independently related to triglycerides (P < 0.05), whereas fat distribution (by DXA) and E2 were independently associated with total cholesterol and low density lipoprotein cholesterol (LDL-C) (P < 0.05). Thus, in overweight postmenopausal women, androgenicity and cigarette and alcohol consumption were independently positively related to a central fat distribution. Furthermore, atherogenic levels of lipids and lipoproteins were independently related to a central fat distribution, androgenicity and low levels of oestrogens.

Absorptiometry, Photon↗

PubMed1993

Relationships among swimming performance, body composition and somatotype in competitive collegiate swimmers.

Relationships were determined between sprint swimming performance and estimates of body composition and somatotype components in competitive collegiate swimmers. Forty-three women and 31 men underwent anthropometric and hydrodensitometric measurements at the beginning of a competitive season. There were significant partial correlations (swim stroke was partialed out) between swimming performance (time in a competitive 100-yard swim of each swimmer's major competitive stroke) and height (-0.466, p < 0.01), the mesomorphic (0.404, p < 0.01) and ectomorphic (-0.398, p < 0.01) components of somatotype, percent body fat (0.351, p < 0.05), and fat-free weight (-0.332, p < 0.05) among the women, but no significant correlations among the men. Twenty-three of the women and 21 of the men were also measured and timed at the end of the competitive season. Again, there were significant (p < 0.01) partial correlations (season and stroke were partialed out) between swimming performance and height (-0.766), fat-free weight (-0.657), body weight (-0.437), and the ectomorphic (-0.441) and mesomorphic (0.392, p < 0.01) components of somatotype in women, but no significant correlations among the men. These findings indicate that measurements of body composition and somatotype may be predictors of swimming performance in women but not in men.

Adipose Tissue↗

PubMed2005

Improvement of fitness, body composition, and insulin sensitivity in overweight children in a school-based exercise program: a randomized, controlled study.

BACKGROUND: Obesity and poor physical fitness constitute a health problem affecting an increasing number of children. Causes include a pervasive "toxic" environment that facilitates increased caloric intake and reduced physical activity. An effective strategy for prevention and treatment of childhood obesity likely includes a collaborative effort in the school setting. OBJECTIVE: To determine whether a school-based fitness program can improve body composition, cardiovascular fitness level, and insulin sensitivity in overweight children. DESIGN: Fifty overweight middle school children with a body mass index (BMI) above the 95th percentile for age were randomized to lifestyle-focused, fitness-oriented gym classes (treatment group) or standard gym classes (control group) for 9 months. Children underwent evaluation of fasting insulin and glucose levels, body composition by means of dual energy absorptiometry, and maximum oxygen consumption (V0(2)max) treadmill testing at baseline (before the school year) and at end of the school year. SETTINGS: Rural middle school and an academic children's hospital. MAIN OUTCOME MEASURES: Baseline test results for cardiovascular fitness, body composition, and fasting insulin and glucose levels. RESULTS: At baseline, there were no differences between groups before intervention (values for age, 12 +/- 0.5 years [all results, mean +/- SD]; BMI [calculated as weight in kilograms divided by the square of height in meters], 31.0 +/- 3.7; percentage of body fat, 36.5% +/- 4.6%; lean body mass, 41.4 +/- 8.6 kg; and V0(2)max, 31.5 +/- 5.1 mL/kg per minute). Compared with the control group, the treatment group demonstrated a significantly greater loss of body fat (loss, -4.1% +/- 3.4% vs -1.9% +/- 2.3%; P = .04), greater increase in cardiovascular fitness (V0(2)max, 2.7 +/- 2.6 vs 0.4 +/- 3.3 mL/kg per minute; P<.001), and greater improvement in fasting insulin level (insulin level, -5.1 +/- 5.2 vs 3.0 +/- 14.3 microIU/mL [-35.4 +/- 36.1 vs 20.8 +/- 99.3 pmol/L]; P = .02). CONCLUSIONS: Children enrolled in fitness-oriented gym classes showed greater loss of body fat, increase in cardiovascular fitness, and improvement in fasting insulin levels than control subjects. The modification to the school physical education curriculum demonstrates that small but consistent changes in the amount of physical activity has beneficial effects on body composition, fitness, and insulin levels in children. Partnering with school districts should be a part of a public health approach to improving the health of overweight children.

Body Composition↗

PubMed1997

Energy expenditure and body composition in children with Crohn's disease: effect of enteral nutrition and treatment with prednisolone.

BACKGROUND: Malnutrition and growth retardation are common complications of Crohn's disease in children. The contribution of resting energy expenditure (REE) to malnutrition is unclear. AIMS: To characterise the REE and body composition in children with Crohn's disease and compare them with normal controls and patients with anorexia nervosa; to compare the effects of prednisolone and enteral nutrition on energy expenditure and body composition. SUBJECTS: Twenty four children with Crohn's disease, 19 malnourished females with anorexia nervosa, and 22 healthy control subjects were studied. METHODS: In children with Crohn's disease measurements were done when the disease was acute and repeated at one and three months after treatment with either prednisolone or enteral nutrition. Resting energy expenditure was measured by indirect calorimetry and body composition by anthropometry, bioelectrical impedance analysis, total body potassium, H218O, and bromide space studies. RESULTS: Body weight and ideal body weight were significantly lower in patients with Crohn's disease than in healthy controls. Lean tissue was depleted and there was an increase in extracellular water. Per unit of lean body mass, there was no difference between REE in patients with Crohn's disease and controls, whereas patients with anorexia nervosa had significantly reduced REE. With enteral nutrition all body compartments and REE increased significantly (p < 0.001). In a subgroup of age-matched men there was a significant increase in height after three months of enteral nutrition compared with prednisolone (p < 0.01). Those treated with steroids did not show a significant change in height but did show an increase in all body compartments. However, intracellular water as well as lean body mass accretion were significantly higher in the enteral nutrition group than in the prednisolone group. CONCLUSIONS: Despite being malnourished, children with Crohn's disease fail to adapt their REE per unit of lean body mass. This might be a factor contributing to their malnutrition. Lean tissue accretion is higher in patients treated with enteral nutrition than in those treated with prednisolone.

Adolescent↗

PubMed2004

Birth weight, weight at 1 y of age, and body composition in older men: findings from the Hertfordshire Cohort Study.

BACKGROUND: Size in early life is related to adult body mass index, and early environmental influences have been proposed to have lifelong consequences for obesity. However, body mass index also reflects fat-free mass, and few studies have examined the relation between size in early life and direct measures of body composition in older people. OBJECTIVE: We investigated the associations of birth weight and weight at 1 y of age with body composition in older men. DESIGN: We carried out a retrospective cohort study in Hertfordshire, United Kingdom. Men who were born between 1931 and 1939 and for whom there were records of birth weight and weight at 1 y of age (n = 737) participated in the study. The main outcome measures were adult body mass index, fat-free mass, and fat mass. RESULTS: Birth weight was significantly and consistently positively associated with adult body mass index and fat-free mass but not with measures of adult fat mass. In contrast, weight at 1 y of age was associated with adult body mass index, fat-free mass, and fat mass. CONCLUSIONS: The consistently reported positive relation between birth weight and adult body mass index may reflect prenatal and maternal influences on fat-free mass rather than on fat mass in older people. The postnatal environment may be more influential than prenatal factors in the development of obesity in later life.

Adipose Tissue↗

PubMed2000

The effects of Tribulus terrestris on body composition and exercise performance in resistance-trained males.

The purpose of this study was to determine the effects of the herbal preparation Tribulus terrestris (tribulus) on body composition and exercise performance in resistance-trained males. Fifteen subjects were randomly assigned to a placebo or tribulus (3.21 mg per kg body weight daily) group. Body weight, body composition, maximal strength, dietary intake, and mood states were determined before and after an 8-week exercise (periodized resistance training) and supplementation period. There were no changes in body weight, percentage fat, total body water, dietary intake, or mood states in either group. Muscle endurance (determined by the maximal number of repetitions at 100-200% of body weight) increased for the bench and leg press exercises in the placebo group (p <.05; bench press +/-28.4%, leg press +/-28.6%), while the tribulus group experienced an increase in leg press strength only (bench press +/-3.1%, not significant; leg press +/-28.6%, p <.05). Supplementation with tribulus does not enhance body composition or exercise performance in resistance-trained males.

Adult↗

PubMed2006

Insulin resistance and body composition in Turner syndrome: Effect of sequential change in the route of estrogen administration.

The aim of the present study was to examine the impact of sequential change in the route of estrogen administration on body composition and insulin resistance in patients with Turner syndrome (TS) using cyclical hormone replacement therapy (HRT) with conjugated equine estrogens (CEE) plus medroxyprogesterone acetate (MPA). We carried out a self-controlled study of nine non-obese patients with TS, with an average age of 23 +/- 4.9 years. Body mass index (BMI), waist-to-hip ratio (WHR), fasting glycemia, insulin tolerance (glucose disappearance constant during an insulin tolerance test, kITT) and body composition (dual-energy X-ray absorptiometry) were studied after 1 year's use of CEE plus MPA and repeated after 1 year's use of 17beta-estradiol gel with the same schedule of MPA administration. We did not observe any difference between the oral and percutaneous HRT with regard to BMI, WHR and insulin tolerance (kITT: 4.9 +/- 1.5 vs. 5.3 +/- 1.5%/min, p = 0.8). During administration of the 17beta-estradiol gel a tendency to increased total lean mass (p = 0.054) was observed. We conclude that sequential change in the route of estrogen administration in TS patients using cyclical HRT with CEE and MPA does not affect insulin resistance, although use of percutaneous 17beta-estradiol gel seems to exert favorable changes in body composition.

Adolescent↗

PubMed1997

Characteristics of body composition and muscle strength in college Sumo wrestlers.

The purpose of this study was to investigate the characteristics of body composition and force generation capacity in college Sumo wrestlers (N=13, age=19.8+/-0.3 yr, stature= 178.5+/-1.6 cm, body mass = 111.2+/-3.8 kg, X+/-SE) in comparison with untrained males (N=18, 20.3+/-0.2 yr, 170.1+/-1.7 cm, 59.2+/-1.4 kg). The Sumo wrestlers had significantly higher average values in relative fat mass (24.8+/-1.0%) and fat-free mass (83.3+/-2.0 kg), estimated by an underwater weighing method, than the untrained subjects (relative fat mass = 12.9+/-0.1 %, fat-free mass = 51.5+/-1.3 kg). Moreover, the Sumo wrestlers had 1.7 to 1.9 times greater cross-sectional areas (CSAs) of elbow flexors and extensors and knee extensors, determined by a B-mode ultrasound technique, compared to those of the untrained subjects. Force values produced during elbow flexion and extension and knee extensions tasks under isokinetic contraction mode at constant velocities of 1.05, 3.14 and 5.24 rad x s(-1) were significantly higher in the Sumo wrestlers than in the untrained subjects. The force value in all test conditions was significantly correlated to the related-muscle CSA, r=0.611-0.910 (p<0.05). The difference between the two groups in force per unit CSA (F x CSA[-1]) during elbow flexion was not significant at all test velocities. However, the Sumo wrestlers showed significantly lower F x CSA(-1) values in elbow extension at 5.24 rad x s(-1) and in knee extension at all test velocities. Thus, the body composition of the Sumo wrestlers was characterized by a high fat content and a large fat-free mass. Moreover, the Sumo wrestlers had considerably larger muscle CSAs of limbs than the untrained subjects. For the Sumo wrestlers, however, force output of the muscles with a pennate structure were not proportional to their CSAs, particularly in knee extensors.

Adipose Tissue↗

PubMed1993

Association among serum lipid and lipoprotein concentrations and physical activity, physical fitness, and body composition in young children.

OBJECTIVE: To examine the relationships among indicators of physical activity, physical fitness, and body composition with serum lipid and lipoprotein levels in young children. DESIGN: Cross-sectional and 1-year prospective cohort. SETTING: Studies of Child Activity and Nutrition (SCAN) program, Galveston, Tex. SUBJECTS: One hundred twenty-three 4- or 5-year-old black, Hispanic (of Mexican origin), and white children. MEASUREMENTS: Body composition, resting heart rate, and cardiovascular fitness variables and serum lipid and lipoprotein levels were measured at age 3 or 4 years (study year 1) and at age 4 or 5 years (study year 2), and day-long heart rate was measured and the Children's Activity Rating Scale was administered between study years 1 and 2. RESULTS: Year-1 waist/hip ratios were inversely correlated with total serum cholesterol (TSC) and low-density lipoprotein (LDL) levels. Mean activity level was inversely correlated with waist/hip ratios. On the basis of multiple regression analysis, the sum of seven skin-fold measurements, height, and gender explained 15.4% of the variation in triglyceride levels. The sum of seven skin-fold measurements was inversely correlated with the high-density lipoprotein (HDL) level. Resting heart rate, waist/hip ratio, and the slope of the exercise heart rate during fitness testing explained 19.5% of the variation in the concentration of an HDL subclass, HDL2. These children's levels of physical activity were associated with higher fitness levels. Year-1 waist/hip ratios and year-2 sum of seven skin-fold measurements were positively correlated with the LDL/HDL and TSC/HDL ratios. CONCLUSION: Higher levels of cardiovascular fitness and lower levels of fatness were associated with more favorable serum lipid and lipoprotein levels in these young children. Physical activity appeared to have an indirect association with serum lipid and lipoprotein values through its relationship with higher fitness levels and lower levels of fatness.

Activities of Daily Living↗

PubMed1984

Evaluation of an in vivo prompt gamma neutron activation facility for body composition studies in critically ill intensive care patients: results on 41 normals.

A programme of metabolic and nutritional research is being undertaken in critically ill patients requiring intensive care. Central to this research is the measurement of the three nutritionally important compartments of body composition, protein, fat, and water by a combination of tritium dilution and prompt gamma in vivo neutron activation analysis (IVNAA). In this paper a calibration technique is presented that enables absolute estimates of total body nitrogen (TBN) to be made using prompt gamma IVNAA in critically ill patients with gross abnormalities in body composition, especially in their state of hydration. This technique, which is independent of skinfold anthropometry and does not make a priori assumptions about the ratios of major body compartments, has been applied to 41 normal volunteers and the derived values for nitrogen compared with values obtained by applying three currently used calibration methods to the same experimental data; the other methods are used at centers which also measure nitrogen by prompt gamma IVNAA. Close agreement is obtained between the four calibration methods, with correlation coefficients relative to the Auckland technique of 0.999, 0.998, and 0.994. In addition, the measured values of TBN are compared to values obtained for the same group of volunteers using sets of empirical equations from two centers, one of which uses prompt gamma IVNAA (Brookhaven National Laboratory, Long Island, USA) and the other delayed gamma IVNAA (Leeds, Britain). The empirical equations relate TBN in normal people to age, height, weight and sex. The mean ratios of experimental to predicted TBN (with SEMs) are 1.013 +/- 0.017 and 1.002 +/- 0.014, respectively. Mean values of the ratio of TBN to fat-free mass (0.0340 +/- 0.0004) and of total body water to fat-free mass (0.716 +/- 0.002) agree closely with values reported elsewhere for normals by a variety of techniques including chemical analysis. Finally, TBN results based on the four different calibration methods are presented for five surgical patients, demonstrating the importance of the calibration method on estimates of TBN in patients with abnormal body composition. It is concluded that this technique will provide accurate estimates of the total body content of protein, water, and fat in intensive care patients.

Activation Analysis↗