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PubMed1992

Estimation of changes in genetic parameters in selected lines of mice using REML with an animal model. 2. Body weight, body composition and litter size.

Restricted Maximum Likelihood (REML) with an animal model was used to estimate genetic parameters of body weight, body consumption and litter size of lines of mice selected for 20 generations on an index of lean mass at 10 weeks in males, highly correlated with body weight, and for a further 18 generations on body weight at 10 weeks in males and females. Univariate and multivariate estimates of heritability were about 0.5 and those of common environment correlations were about 0.25 for both body weight and composition. Body weight and fat pad weight had genetic and phenotypic correlations of about 0.5. The heritability estimate of litter size was about 0.15 from univariate analysis, rather lower from multivariate, and the estimate of its genetic correlation with body weight was about 0.25. There were reductions in heritability of both body weight and litter size in later generations, even though full pedigrees were fitted and inferences made to the base population, but a plateau in response to selection for increased body weight could not be explained by a complete attenuation of genetic variance.

Animals↗

PubMed2003

Body composition and energy expenditure in Duchenne muscular dystrophy.

OBJECTIVE: To investigate the relationship between resting energy expenditure (REE) and body composition in Duchenne Muscular Dystrophy (DMD). DESIGN: An observational study. SETTING: University Research Centre. SUBJECTS: Nine Duchenne children (age range 6-12 y), mean relative weight 128%, agreed to undergo the investigation and all of them completed the study; INTERVENTIONS: Assessment of body composition (total body fat and skeletal muscle mass) by magnetic resonance imaging and resting energy expenditure by indirect calorimetry. MAIN OUTCOME MEASURES: Fat mass (FM; kg and percentage weight), fat-free mass (FFM; kg and percentage weight), muscle mass (kg and percentage weight), resting energy expenditure (kJ/kg body weight and kJ/kg fat-free mass). RESULTS: : In Duchenne children fat mass averages 32% and total skeletal muscle mass 20% of body weight. Resting energy expenditure per kg of body weight falls within the normal range for children of the same age range, while when expressed per kg of FFM is significantly higher than reference values. No relationship was found between REE and total skeletal muscle mass. CONCLUSIONS: Our results do not demonstrate a low REE in DMD boys; on the contrary REE per kg of FFM is higher than normal, probably due to the altered FFM composition. We suggest that the development of obesity in DMD children is not primarily due to a low REE but to other causes such as a reduction in physical activity and or overfeeding.

Body Composition↗

PubMed2000

Indirect estimates of body composition are useful for groups but unreliable in individuals.

OBJECTIVE: To assess the usefulness of the body mass index (BMI) in identifying individuals classified as overweight or obese based on estimates of body fat percentage (BF%) obtained by the deuterium dilution (BF%DD) method. In addition, to assess the accuracy of bioelectrical impedance analysis (BIA) and skinfold thickness (SFT) measurements in the estimation of body composition of Australians at the individual and group level. DESIGN: Cross-sectional study. SUBJECTS: One hundred and seventeen healthy Australian volunteers of European descent, comprising of 51 males and 66 females, ranging in age from 19 to 77 y. MEASUREMENTS: BMI was calculated from body weight and height. Fat-free mass (FFM) was estimated from measures of total body water (TBW) using deuterium dilution (FFM(DD)), SFT using the equations of Durnin and Womersley (Br J Nutr 1974; 32: 77-97) (FFM(SFT)), and BIA using the equations of Lukaski et al (J Appl Physiol 1986; 60: 1327-1332) (FFM(Lu)), Segal et al (Am J Clin Nutr 1988; 47: 7-14) (FFM(Se)) and Heitmann (Eur J Clin Nutr 1990; 44: 831-837) (FFM(He)). Estimates of fat mass (FM) were calculated as the difference between body weight and FFM, while BF% was calculated by expressing FM as a percentage of body weight. RESULTS: BMI had poor sensitivity and positive predictive value in identifying individuals as being overweight/obese as classified by BF%DD. Furthermore, estimates of FFM (and hence FM) from BIA or SFT could not be used interchangeably with DD, without the risk of considerable error at the individual level. At the group level errors were relatively smaller, though statistically significant. While FFM(SFT) could be corrected by the addition of the bias (1.2 kg in males and 0.8 kg in females), no simple correction was possible with BIA estimates of FFM for any of the equations used. However, an accurate prediction of FFM(DD) was possible from the combination of FFM(He), biceps SFT and mid-arm circumference in both males and females. The bias of this prediction was small (<0.15 kg), statistically non-significant in both sexes, and unrelated to the mean FFM obtained by the two methods. The revision of Heitmann's estimate of FFM using anthropometric variables described in this study had the best sensitivity (79%), specificity (96%) and positive predictive value (92%) in identifying overweight/obese individuals in comparison to the other equations tested. CONCLUSION: BMI was a poor surrogate for body fatness in both males and females. The currently recommended equations for the prediction of body composition from SFT and BIA provided inaccurate estimates of FFM both at the individual and group level as compared to estimates from DD. However, Heitmann's equations, when combined with measures of the biceps SFT and mid-arm circumference, provided better estimates of FFM both at the individual and group level.

Adipose Tissue↗

PubMed1991

Evaluation of growth and changes in body composition following neonatal diagnosis of cystic fibrosis.

Early deficits in nutritional status that might require specific treatment and early response to nutritional therapy were studied longitudinally in 25 infants with cystic fibrosis (CF) diagnosed by neonatal screening, using anthropometric and research body composition methodology, and evaluation of pancreatic function. At the time of confirmed diagnosis (mean 5.4 weeks), body mass, length, total body fat (TBF), and total body potassium (TBK) were all significantly reduced. Following diagnosis and commencement of therapy there was a normalization of weight, length, and TBK by 6-12 months of age, indicating catch-up growth. But in some individuals the response was incomplete, and as a group, mean total body fat remained significantly lower than normal at 1 year of age. Seven of 25 (28%) were pancreatic sufficient at diagnosis, and all but one had evidence of declining pancreatic function requiring the institution of pancreatic enzyme therapy during the next 1-9 months. The median age of commencement of enzyme therapy was 10 weeks (range 5 weeks to 11 months). These longitudinal assessments emphasize the dynamic changes occurring in absorptive function, body composition, and nutritional status following neonatal diagnosis of cystic fibrosis and may reflect previously described abnormalities of energy metabolism in this age group. Abnormal body composition is evident in most CF infants following diagnosis by neonatal screening but pancreatic damage may still be evolving. We suggest that early active nutritional therapy and surveillance for changes in pancreatic function are warranted in CF infants diagnosed by neonatal screening.

Body Composition↗

PubMed2005

Child temperament does not predict adolescent body composition in girls.

OBJECTIVES: Our previous cross-sectional analysis of MIT Growth and Development (MIT) Study girls showed that activity temperament, as assessed by a nine-item temperament questionnaire, was related to body composition and nonresting energy expenditure (NREE). In girls with lower levels of physical activity, having a high activity temperament was associated with a higher NREE. Percentage body fat was lower in girls with high vs low activity temperament. Based on these results, we hypothesized that, especially in girls with declining levels of physical activity over adolescence, high activity temperament in childhood would be protective against increased adiposity during adolescence. We tested this hypothesis with longitudinal data from the MIT study. DESIGN, SETTING, AND PARTICIPANTS: A total of 196 nonobese premenarcheal girls 8-12 y old were enrolled between 1990 and 1993. Girls were followed until 4 y postmenarche; average duration of follow-up was 7 y. MEASURES: Activity temperament was assessed at baseline by the girls' mothers with questions modified from those developed by Thomas and Chess that tapped predilection for movement. Temperament, the stylistic component of behavior, is considered relatively stable within an individual. Body composition was assessed by total body water at baseline and study completion (4 y postmenarche), and by bioelectrical impedance (BIA) annually. Physical activity was assessed annually by questionnaire, and by activity diary at baseline only. RESULTS: Child activity temperament was not associated with percentage body fat at 4 y postmenarche in multivariate regression models controlling for baseline percentage body fat, physical activity, parental obesity status, age at menarche, age at baseline, and race-ethnicity. Body composition of girls with low and high activity temperaments who reported declining levels of physical activity over adolescence was not statistically significantly different at study completion. In longitudinal models of percentage body fat by BIA, high activity temperament was not associated with lower adiposity. CONCLUSION: Although high activity temperament was associated cross-sectionally with lower percentage body fat and higher NREE, we did not find evidence to support our hypothesis that high child activity temperament would be protective for increased adiposity prospectively in our cohort of girls followed over the adolescent period.

Aging↗

PubMedDate not supplied

Comparison of total parenteral nutrition and an oral, semielemental diet on body composition, physical function, and nutrition-related costs in patients with malabsorption due to acquired immunodeficiency syndrome.

BACKGROUND: The nutrition management of patients with malabsorption syndromes due to acquired immunodeficiency syndrome (AIDS) is problematic. The aim of this study was to compare the effects of total parenteral nutrition (TPN) and an oral, semielemental diet (SED) on body weight, body composition, quality of life, survival, and medical costs in AIDS patients with malabsorption. METHODS: This was a prospective, randomized, open-label study performed in outpatients. Twenty-three AIDS subjects (TPN group, 12; SED group, 11) with cryptosporidiosis, microsporidiosis, or malabsorption of unknown cause were randomized and followed. Subjects were prescribed equivalent amounts of formulas of similar composition for 3 months. Monthly estimations of caloric intake, body weight, body composition by bioimpedance analysis, and quality of life were recorded. Nutritional variables were analyzed by repeated-measures analysis of covariance, with the baseline measure as the covariate. Nutrition-related medical costs, survival, and indices of absorptive and immune function were compared, RESULTS: Subjects had lost an average of 1.5 and 1.0 kg body wt/mo for TPN and SED during the 6 months before study entry (p < not significant). The TPN group consumed more total calories than the SED group (p < .05). Weight change during therapy was significantly different from pretreatment in both groups (p < .01 for TPN, p = .023 for SED). The TPN group gained more weight than the SED group (p = .057) and significantly more fat (p = .02), but the changes in body cell mass were similar in the two groups. Changes in weight and body composition correlated with caloric intake but not the mode of feeding. The SED group scored significantly better than the TPN group on a physical functioning subscale of quality of life (p < .01). Survival was similar in the two groups. TPN therapy cost almost four times more than SED. Peripheral blood CD4+ lymphocyte numbers were unaffected by either therapy. Intestinal function was not affected by either therapy. CONCLUSIONS: An oral SED may reverse weight loss and wasting in AIDS patients with malabsorption.

Acquired Immunodeficiency Syndrome↗

PubMed2002

Effects of functional electrical stimulation training for six months on body composition and spasticity in motor complete tetraplegic spinal cord-injured individuals.

The effect of functional electrical stimulation (FES) training on body composition, assessed by computed tomography, and the effect of spasticity, assessed by both objective and subjective measures, are evaluated. Fifteen motor-complete spinal-cord-injured men participated in the study. Eight of the 15 subjects undertook FES cycling 3 times weekly for 6 months. Whole body computed tomography scans evaluated changes in body composition. Simultaneous Modified Ashworth Scale and electromyography (EMG) measurements, resistive torque (Kin-Com) and EMG measurements, and self-ratings with Visual Analogue Scale during four consecutive days were used to evaluate changes in spasticity. Lower extremity muscle volume increased by an average of 1300 cm3 (p < 0.001) in the training group compared to the control group, who experienced no change. Otherwise no changes in body composition were seen. Significant correlations (Spearman) were found between individual EMG activity recordings and movement-provoked Modified Ashworth Scale ratings in 26% of the test situations, irrespective of group and time. The objective and subjective evaluation of movement-provoked passive (viscoelastic) and active (spasticity-related) resistance remained unchanged.

Adult↗

PubMedDate not supplied

[Effect of time of administration of food supplement amino acids on protein utilization and the body composition of rats].

The effect of administration of amino acids enriching the diet on protein utilization and rat body composition was investigated. Net protein utilization (NPU) of the diet enriched by tryptophane, lysine or sulphur-containing amino acids comprised 0.408, 0.335 and 0.664. Changes in the time of administering the amino acids allowed NPU to be attained as 0.445, 0.352 and 0.716, respectively. It has been also shown that the time of administering the amino acids produces an effect on the rat body composition. The lowest fat content was recorded in the body with tryptophane given one hour before feeding the main diet, with lysine and sulphur-containing amino acids given one and two hours after feeding the main diet.

Amino Acids↗

PubMed2001

Group- and sex-specific effects of age, body composition and pulse rate on blood pressure variability in some cross-cultural populations of Visakhapatnam District; South India.

BACKGROUND: Hypertension is becoming a major public health problem in developing countries. Blood pressure tends to vary cross-culturally and is influenced by various factors including age, body composition and pulse rate. This paper reports the influence of age, body composition and pulse rate on blood pressure variability. DESIGN: The data were collected from 1316 individuals (646 men and 670 women) belonging to two tribes (Khondh and Valmiki) inhabiting hilly tribal area and two castes (Wadabalija and Settibalija) from both rural and urban areas from Visakhapatnam district, Andhra Pradesh, India. RESULTS: There are considerable ethnic differences in blood pressure and body composition variables. Age contributes significantly to the variance in blood pressure in these populations. However the influence of age is less pronounced in Khondh, a primitive/unacculturized tribe, while age exerts a profound effect on blood pressure variability in Valmiki, an acculturizing tribe. Further, the effect of age is more pronounced on systolic than on diastolic pressure and it contributes more to the blood pressure of women than men. The subcutaneous fatness measures (sum of three trunk skin fold thicknesses and sum of three extremities skin fold thicknesses) are significant predictors of both systolic and diastolic blood pressure in Khondh, Valmiki and Wadabalija, while body mass index (BMI) is an important predictor of both systolic and diastolic blood pressure in Settibalija. Pulse rate is often found to influence blood pressure of women. CONCLUSION: The age-associated variability of blood pressure confirms the proposition that variability is high in adverse environment, when modernization/acculturization is taken to represent environmental adversity. Apart from the influence of age, body composition/adiposity contributes significantly to the blood pressure variability.

Age Factors↗

PubMed1996

Insulin sensitivity, lipids, and body composition in childhood: is "syndrome X" present?

Syndrome X, or the syndrome of insulin resistance, is a cluster of related metabolic abnormalities of hyperinsulinemia, glucose intolerance, increased very low density lipoprotein (VLDL), decreased high density lipoprotein (HDL), and hypertension in nonobese adults and plays an important role in the genesis of cardiovascular disease. The aim of the present study was to examine the relationships among insulin sensitivity, plasma lipid levels, and body composition in the pediatric age group to determine whether these associations are present in childhood. Twenty healthy Caucasian Tanner stage I (TI) children (age, 10.7 +/- 0.3 yr; body mass index, 18.9 +/- 0.8 kg/m2) and 22 pubertal Tanner stage II-IV (TII-IV) adolescents (age, 14.0 +/- 0.3 yr; body mass index, 20.0 +/- 0.4 kg/m2) were studied. In vivo insulin-mediated glucose disposal (Rd) was evaluated during a 40 mu/m2. min hyperinsulinemic-euglycemic clamp. Body composition was assessed isotopically by the H218O dilution principle. Fasting blood was obtained for cholesterol, triglyceride (TG), VLDL, low density lipoprotein (LDL), and HDL determinations. In both groups, the strongest correlation of Rd was with percent body fat (%BF) (TI: r = -0.82; P < 0.001; TII-IV: r = -0.73; P < 0.001). In addition, in TI, Rd was correlated with TG (r = 0.64; P = 0.001), VLDL (r = 0.64; P = 0.001), and diastolic blood pressure (r = -0.50; P = 0.01). There were no such correlations in TII-IV. In TI, % BF correlated positively with LDL and negatively with TG and VLDL. In TII-IV, % BF correlated positively with cholesterol and LDL. After correcting for %BF, partial correlation analysis revealed no relationship between Rd and lipid levels in either group. This suggests that the relationship of insulin sensitivity to lipid levels was secondary to the effect of body composition on lipid levels. However, regardless of body composition, the basal insulin level was correlated with TG (r = 0.38; P = 0.04) and VLDL (r = 0.40; P = 0.04) in TII-IV subjects. We conclude that 1) the primary correlate of insulin sensitivity is %BF in both prepubertal and pubertal subjects, with no relationship to plasma lipids; 2) in prepubertal children, diastolic blood pressure is negatively correlated with insulin sensitivity and positively with insulin levels, independent of adiposity; and 3) after the onset of puberty, basal insulin levels are positively correlated with VLDL and TG regardless of the degree of adiposity. This observation could be a very early manifestation of the genesis of syndrome X in childhood.

Adipose Tissue↗

PubMed1998

Preliminary evidence that DEXA provides an accurate assessment of body composition.

It was previously found that dual-energy X-ray absorptiometry (DEXA) underestimated central body fat. The purposes of this study were to determine whether an updated version (enhanced version 5.64) of the analysis program corrected this problem (experiment 1) and to compare body composition assessed by DEXA and hydrodensitometry (HD) in women (n = 225) and men (n = 110) across a 21- to 81-yr age range (experiment 2). For experiment 1, 10 subjects underwent DEXA procedures in a control condition and with packets of lard positioned over either the thighs or the truncal region. DEXA accurately quantified the additional mass as approximately 96% fat, regardless of position. For experiment 2, DEXA yielded higher (P < 0.001) estimates of fatness than did HD (32.1 +/- 12.0 vs. 31.2 +/- 10.1%). The mean difference between the two methods was similar in young, middle-aged, and older subjects, but was different in men (HD-DEXA, 1.6 +/- 3.4% of body wt) than in women (-2.1 +/- 3.8% of body wt). Correcting the density of fat-free mass for variance in the bone mineral fraction of fat-free mass reduced the difference between the methods in men from 1.6 +/- 3.4 to -0.7 +/- 2.9% but widened it in women from -2.1 +/- 3.8 to -3.5 +/- 3.4%. A second correction procedure that adjusted for variance in water, protein, and mineral fractions of fat-free mass eliminated the differences in estimates of fat content by DEXA and HD in both men (21.1 +/- 9.3 vs. 20.6 +/- 8.4%, respectively) and women (37.5 +/- 9.3 vs. 36.8 +/- 8.0%, respectively). These results provide encouraging, but not definitive, evidence that the assessment of body composition by DEXA is accurate under the specified conditions.

Absorptiometry, Photon↗

PubMed1997

Bone mineralization and body composition in young patients with celiac disease.

OBJECTIVES: The aim of the study was to establish whether body composition in patients with celiac disease is normal and influenced by the age at diagnosis or by the duration of the gluten free diet. METHODS: A group of 66 children with celiac disease and 76 healthy controls were studied by dual energy x-ray absorptiometry. We compared celiac patients with the control group, and within the celiac disease group, we compared patients with different age at diagnosis (28 diagnosed in the first 24 months vs 38 later) and with different duration of the diet (16 in gluten free diet for less than 12 months, 11 for less than 24 months, and 39 for more than 24 months). RESULTS: Overall we did not find any significant difference in body composition between overall celiac patients and controls. However the fat mass, the body mass index, and the spine bone mineral density values in late diagnosed celiac patients were significantly lower than in early diagnosed patients (significance values were p < 0.009; p < 0.002; p < 0.002, respectively). Patients on diet for less than 12 months showed significantly lower bone mineral content and density than those on diet for more than 24 months (significance values were, respectively, p < 0.011 and p < 0.022). Spine mineral density was the only parameter significantly influenced both by age at diagnosis (p < 0.03) and duration of gluten free diet (p < 0.008). CONCLUSIONS: Only an early diagnosis of celiac disease in pediatric age and a strict gluten free diet, lasting more than 12 months, allow celiac patients to reach a normal mineralization.

Absorptiometry, Photon↗

PubMed2003

The impact of nutrition support on body composition in cancer outpatients receiving radiotherapy.

This study investigated the change in body composition in 36 cancer outpatients receiving radiotherapy to the head and neck area (mean age: 63 +/- 15 years) randomised to receive either nutrition intervention (NI; n=15) or usual care (UC; n=21). Body weight and composition were measured at the commencement of radiotherapy and 3 months later. The UC group lost significantly more weight; mean decrease = 4.3 kg, than the NI group: mean decrease = 1.1 kg (t((30))=-2.5, p=0.019). Fat-free mass loss was significantly higher in the UC group with a mean loss of 2.2 kg versus 0.3 kg in the NI group (t((30))=- 2.3, p=0.029). Body composition as measured by foot-to-foot bioelectrical impedance analysis provides more information than weight alone and can allow for tailoring of NI.

Adipose Tissue↗

PubMed2000

Body composition of growing and adult cats as measured by use of dual energy X-ray absorptiometry.

BACKGROUND AND PURPOSE: Total body scans were performed on 89 domestic cats of various ages, using dual energy x-ray absorptiometry (DEXA) to determine body composition, including fat, lean, and bone mineral content. Bone mineral density results from scans also are presented. METHODS: This cross sectional study included data for cats from a closed colony and from privately owned cats. Data were grouped by age and were analyzed by sex and reproductive status to provide information as to the rate of growth of the individual components of body composition. RESULTS: The results indicate that the rate of accretion of bone mineral, fat, and lean tissue differs throughout maturation and by sex. Regressions are provided to highlight age- and sex-related differences. CONCLUSIONS: The results of this study emphasize the benefits of examining the growth of each component of body composition when studying the effects of nutrition, disease processes, or therapeutic interventions.

Absorptiometry, Photon↗

PubMed2000

Conjugated linoleic acid supplementation in humans: effects on body composition and energy expenditure.

Recent animal studies have demonstrated that dietary conjugated linoleic acid (CLA) reduces body fat and that this decrease may be due to a change in energy expenditure. The present study examined the effect of CLA supplementation on body composition and energy expenditure in healthy, adult women. Seventeen women were fed either a CLA capsule (3 g/d) or a sunflower oil placebo for 64 d following a baseline period of 30 d. The subjects were confined to a metabolic suite for the entire 94 d study where diet and activity were controlled and held constant. Change in fat-free mass, fat mass, and percentage body fat were unaffected by CLA supplementation (0.18+/-0.43 vs. 0.09+/-0.35 kg; 0.01+/-0.64 vs. -0.19+/-0.53 kg; 0.05+/-0.62 vs. -0.67+/-0.51%, placebo vs. CLA, respectively). Likewise, body weight was not significantly different in the placebo vs. the CLA group (0.48+/-0.55 vs. -0.24+/-0.46 kg change). Energy expenditure (kcal/min), fat oxidation, and respiratory exchange ratio were measured once during the baseline period and during weeks 4 and 8 of the intervention period. At all three times, measurements were taken while resting and walking. CLA had no significant effect on energy expenditure, fat oxidation, or respiratory exchange ratio at rest or during exercise. When dietary intake was controlled, 64 d of CLA supplementation at 3 g/d had no significant effect on body composition or energy expenditure in adult women, which contrasts with previous findings in animals.

Adult↗

PubMed1988

Changes in body composition in children following kidney transplantation.

Rapid weight gain has been observed following kidney transplantation. To determine the accompanying changes in body composition, we studied 8 patients (7 females, 1 male) aged 3-17.5 years who underwent renal transplantation. Body composition measurements included weight, height, triceps skinfold thickness, total body potassium, total body water, and extracellular water. Excessive weight gain was observed in most of the patients. Weight as a percentage of ideal weight for height increased from 96.0 +/- 13.8 to 116.3 +/- 13.0% (p less than 0.01). This was accompanied by a gain in fat mass in the first 3 months and a subsequent increase in lean body mass in the next 3 months. Extracellular water was increased before transplantation (32.9 +/- 6.5% of body weight) and returned to normal (27.3 +/- 8.6%) 3 months after transplantation (p less than 0.01). The weight gain following kidney transplantation in children resulted mainly from increases in adipose tissue and lean body mass, and was not related to water retention.

Adolescent↗

PubMed1988

Changes in body composition during refeeding of patients with anorexia nervosa.

Changes in body composition were studied in 13 girls with anorexia nervosa before and during 2 months of refeeding. Fat body mass and fat-free body mass were derived from skin-fold measurements. Total body potassium was measured by whole body counter, and intracellular water was calculated from it. Extracellular water was measured as the bromide space after oral bromide administration. A gradual increase was noted in weight, fat body mass, fat-free body mass, and total body potassium during refeeding. Extracellular water was expanded on admission and increased in all patients in the first weeks of treatment; later it fell to normal. Most of the changes in fat-free body mass over the first weeks of refeeding could be accounted for by an expansion in extracellular water. Particular care must therefore be taken with fluid balance during the first few weeks of refeeding.

Adipose Tissue↗

PubMed1996

Effects of gender, body composition, and menopause on plasma concentrations of leptin.

Circulating concentrations of leptin ([leptin]) vary directly with body mass index and percentage body fat, and may thus constitute an afferent limb of a system regulating body fatness. We tested the hypotheses that: 1) Plasma [leptin] vary more directly with absolute fat mass than with fractional body fatness per se: and 2). The relationship between fat mass and [leptin] is significantly affected by gender and by menopausal status. [Leptin] in the post-absorptive state was examined in 67 subjects (26 male, 20 premenopausal female, 21 postmenopausal females; 43 never-obese, 24 obese) at usual body weight. Body composition was determined by hydrodensitometry, and [leptin] was determined by a double antibody ELISA assay. In male and pre-menopausal female subjects, subcutaneous adipose tissue aspirations were performed for determination of adipocyte volume by the osmium fixation method, and a 3 hour oral glucose tolerance tests was performed. At usual body weight, ([leptin]) was better correlated with absolute fat mass than with body mass index (BMI) or percentage body fat. BMI and % body fat did not account for any of the variance in [leptin] beyond that attributable to FM, per se. The regression equations relating FM to [leptin] did not differ significantly between obese and never-obese subjects. [Leptin] and fasting serum insulin concentrations were significantly correlated in males only. [Leptin] was significantly higher in pre- and post-menopausal females compared to males, even when [leptin] was corrected for differences in body composition (pre-menopausal females > post-menopausal females > males). While plasma [leptin], corrected for FM, declines significantly in women post-menopause, this decline is not sufficient to account for the striking sexual dimorphism in the relationship of leptin to fat mass. This sexual dimorphism is apparently also due, in part, to a suppressive effect of circulating androgens on [leptin].

Adipose Tissue↗