Measures Of Body Fat Mass Research Articles

Measurement of Body Fat Mass, Fat-Free Mass, and Muscle Mass Measured using Bioelectric Impedance and Dual-Energy X-Ray Absorptiometry

In this research, we discussed the bone density by measuring the total bone mineral density, fat mass and lean mass in a sample of Mosul people, as soon as to compare the accuracy of the BIA approach to DXA in assessing total body compartments and segmental tissue mass. A cross sectional study conducted at DXA laboratory, Physiology Department, College of Medicine, Nineveh University, Mosul-Iraq. A total of 136 persons, 44 males and 92 women, recruited from reviewing of college Medical College Academic Centre and took part in the current study. A highly statistically significant association between BIA and DXA measures for TFM, TLM, and FFM was also found. BIA underestimates total fat mass by 7.24 kg than DXA. BIA approach overestimated muscle mass by 10.1 kg when compared to the DXA. BIA underestimates fat-free mass by 20.67 kg compared to DXA.

Novel associations between inflammation-related proteins and adiposity: A targeted proteomics approach across four population-based studies

Chronic low-grade inflammation has been proposed as a linking mechanism between obesity and the development of inflammation-related conditions such as insulin resistance and cardiovascular disease. Despite major advances in the last 2 decades, the complex relationship between inflammation and obesity remains poorly understood. Therefore, we aimed to identify novel inflammation-related proteins associated with adiposity. We investigated the association between BMI and waist circumference and 72 circulating inflammation-related proteins, measured using the Proximity Extension Assay (Olink Proteomics), in 3,308 participants of four independent European population-based studies (KORA-Fit, BVSII, ESTHER, and Bialystok PLUS). In addition, we used body fat mass measurements obtained by Dual-energy X-ray absorptiometry (DXA) in the Bialystok PLUS study to further validate our results and to explore the relationship between inflammation-related proteins and body fat distribution. We found 14 proteins associated with at least one measure of adiposity across all four studies, including four proteins for which the association is novel: DNER, SLAMF1, RANKL, and CSF-1. We confirmed previously reported associations with CCL19, CCL28, FGF-21, HGF, IL-10RB, IL-18, IL-18R1, IL-6, SCF, and VEGF-A. The majority of the identified inflammation-related proteins were associated with visceral fat as well as with the accumulation of adipose tissue in the abdomen and the trunk. In conclusion, our study provides new insights into the immune dysregulation observed in obesity that might help uncover pathophysiological mechanisms of disease development.

Body composition in patients with type 2 intestinal failure.

Measurement of body composition is a valuable clinical tool for nutrition assessments, but there are no data on the merits of assessment modalities in type 2 intestinal failure (IF). The aim of this study was to evaluate the prevalence of low muscle mass and quality in type 2 IF, comparing bioelectric impedance analysis (BIA) and computed tomography (CT) at the third lumbar vertebra level. Patients admitted with acute severe (type 2) IF to a national UK IF center who had BIA measurement and CT scan as part of routine care within 40 days of anthropometric measurement were included in this cross-sectional study. Data were also collected on patient demographics and clinical characteristics. Forty-four patients meeting inclusion criteria were included. Low muscle mass was detected in 37 out of 44 (84.1%) patients by CT scan and in 30 of out 44 (68.2%) by BIA. Low muscle quality was detected in 22 out of 44 (50%) patients by CT scan and in 40 out of 44 (90.1%) by BIA. Comparison of CT and BIA measurements showed a moderate correlation of muscle, Spearman ρ 0.65 (95% CI, 0.42-0.81; P < 0.001), and a strong correlation of body fat mass measurements, Spearman ρ 0.79 (95% CI, 0.62-0.89; P < 0.001). This is the first study to demonstrate that low muscle mass is common in patients with type 2 IF, regardless of body composition assessment modality. A larger cohort study is required to validate the impact of low muscle mass and quality on clinical outcomes and the role of targeted interventions to improve the care of patients with type 2 IF.

Standing 8-Electrode Bioelectrical Impedance Analysis as an Alternative Method to Estimate Visceral Fat Area and Body Fat Mass in Athletes.

PurposeTo investigate the potential of standing 8-electrode bioelectrical impedance analysis (BIA) for assessing visceral fat area (VFA) and body fat mass (BFM) in athletes.Materials and MethodsA total of 95 subjects (50 males and 45 females) were recruited. VFA and BFM measurements were obtained using three standing 8-electrode BIA devices, InBody230, InBody770, and IOI353. These acquired VFA and BFM were expressed as VFAIOI353, VFAInBody230, VFAInBody770 V, BFMIOI353, BFMInBody230, and BFMInBody770, respectively. As reference measurement, the VFA acquired from computer tomography (CT) was expressed as VFACT, and the BFM measured by dual-energy X-ray absorptiometry (DXA) was denoted as BFMDXA.ResultsThe coefficient of determination (r2) in regression analysis between the measurements by VFAIOI353, VFAInBody230, VFAInBody770 and VFACT were 0.425, 0.492, and 0.473, respectively. Also, the limits of agreement (LOA) obtained from Bland–Altman analysis were −25.18 to 56.62, −29.74 to 62.44, and −32.96 to 71.93 cm2. For BFM, r2 in regression analysis between the measurements by BFMIOI353, BFMInBody230, BFMInBody770 and BMFDXA were 0.894, 0.950, and 0.955, respectively; LOA were −7.21 to 5.75, −4.70 to 4.05, and −5.48 to 3.05 kg, respectively.ConclusionThe results showed when assessing BFM, these instruments delivered comparable measurements, and the degree of agreement ranged from excellent to moderate compared with the reference method. However, when assessing VFA, the agreements were weak. Therefore, the application of standing 8-electrode BIA devices for assessing athletes’ VFA still needs improvement.

Body Fat Mass is Better Indicator than Indirect Measurement Methods in Obese Children for Fatty Liver and Metabolic Syndrome

Introduction: To compare the bioelectric impedance analysis (BIA) with indirect measurement methods in the evaluation of obese children. To determine the diagnostic value of BIA in the fatty liver and metabolic syndrome (MS) in obese children. Population and methods: One hundred thirty-four obese children whom ≥10 years of age were prospectively assessment. All patients were evaluated by foot to foot BIA and indirect measurement methods. Blood biochemical parameters such as glucose, lipids and insulin levels were studied and oral glucose tolerance test was performed. Fatty liver was assessed by ultrasonography. Compared BIA records and indirect measurements findings according to fatty liver and MS. Results: The study included females/males: 77/57, mean age of 13.3 ± 2.2 years. Fatty liver was detected in 94 patients, MS was diagnosed in 58 cases. There were no gender difference in terms of fatty liver and MS. Fatty liver was seen more frequently in patients with metabolic syndrome than in those without metabolic syndrome (p &lt; 0.001). Fat Mass (FM) of ≥ 97th percentile was observed in 63% of the 94 patients with fatty liver versus 37.5% of 40 patients without fatty liver. A FM of ≥97th percentile was observed in 72% (n=42) of the 58 patients with metabolic syndrome, 42% (n=33) of 76 patients without MS. Body mass index, upper mid-arm circumference, waist circumference (WC), and hip circumference values were significantly increased in patients with fatty liver. There was a better correlation was determined between FM and FM Index with fatty liver compared to indirect measurement methods. BIA records were found moderately correlated with indirect measurements. Conclusion: Our results revealed that FM and FMI have a better correlated in obese children with fatty liver and metabolic syndrome than indirect measurement methods. The measurement of body FM by BIA can be used together with the indirect measurement methods to detect the fatty liver. FMI may be an alternative diagnostic criterion instead of WC for diagnosis of MS in children.

Physical activity and calorie intake mediate the relationship from depression to body fat mass among female Mexican health workers

BackgroundDepression is a foremost cause of morbidity throughout the world and the prevalence of depression in women is about twice as high as men. Additionally, overweight and obesity are major global health concerns. We explored the relationship between depression and body fat, and the role of physical activity and diet as mediators of this relationship in a sample of 456 adult female Mexican health workers.MethodLongitudinal and cross-sectional analyses using data from adult women of the Health Workers Cohort Study (HWCS) Measures of body fat mass (kg from DEXA), dietary intake (kcal from FFQ), leisure time activity (METs/wk) and depression (CES-D) were determined in two waves (2004–2006 and 2010–2011). We explored the interrelation between body fat, diet, leisure time, physical activity, and depression using a cross-lagged effects model fitted to longitudinal data. We also fitted a structural equations model to cross-sectional data with body fat as the main outcome, and dietary intake and physical activity from leisure time as mediators between depression and body fat.ResultsBaseline depression was significantly related to higher depression, higher calorie intake, and lower leisure time physical activity at follow-up. From our cross-sectional model, each standard deviation increase in the depression score was associated with an average increase of 751 ± 259 g (± standard error) in body fat through the mediating effects of calorie intake and physical activity.ConclusionsThe results of this study show how depression may influence energy imbalance between calories consumed and calories expended, resulting in higher body fat among those with a greater depression score. Evaluating the role of mental conditions like depression in dietary and physical activity behaviors should be positioned as a key research goal for better designed and targeted public health interventions.Trial registrationThe HealthWorkers Cohort Study (HWCS) has been approved by the Institutional IRB. Number: 2005–785-012.

Predicting body fat percentage from anthropometric and laboratory measurements using artificial neural networks

Purpose of the researchObesity is a major public health problem with rapidly growing prevalence and serious associated health risks. Characterized by excess body fat, the accurate measurement of obesity is a non-trivial question. Widely used indicators, such as the body mass index often poorly predict actual risk, but the direct measurement of body fat mass is complicated. The aim of the present research is to investigate how well can body fat percentage be predicted from easily measureable data: age, gender, weight, height, waist circumference and different laboratory results. For that end, linear regression, feedforward neural networks and support vector machines are applied on the data of a representative US health survey (n=862) using adult males. Optimal parameters are chosen and bootstrap validation is used to get realistic error estimates. ResultsNo methods can well predict the body fat percentage, but support vector machines slightly outperformed feedforward neural networks and linear regression (root mean square error 0.0988±0.00288, 0.108±0.00928 and 0.107±0.012 respectively). ConclusionEven this best performance means that soft computing methods had an R2 of 44%, but this slight advantage is balanced by the fact that regression models are clinically interpretable.

Associations of maternal obesity and excessive weight gain during pregnancy with subcutaneous fat mass in infancy

BackgroundNot much is known about the associations of maternal obesity and excessive gestational weight gain with body fat in infancy. ObjectiveTo examine the associations of maternal pre-pregnancy body mass index and gestational weight gain with infant subcutaneous fat. MethodsIn a population-based prospective cohort study among 845 mothers and their infants, we obtained maternal pre-pregnancy body mass index and measured maternal weight during pregnancy. At 1.5, 6 and 24months, we estimated infant total subcutaneous fat (sum of biceps, triceps, suprailiacal and subscapular skinfold thicknesses) and central-to-total subcutaneous fat ratio (sum of suprailiacal and subscapular skinfold thicknesses/total subcutaneous fat). ResultsMaternal body mass index was positively associated with higher infant body mass index from 6months onwards. Maternal body mass index was not associated with infant subcutaneous fat measures at 1.5 or 6months. A 1-standard deviation scores (SDS) higher maternal body mass index was associated with a 0.09 (95% Confidence Interval 0.01, 0.17) SDS higher infant total subcutaneous fat at 24months, but not with central-to-total subcutaneous fat ratio. No associations were present for maternal total or period-specific gestational weight gain with infant fat. ConclusionMaternal body mass index was positively associated with infant body mass index and total subcutaneous fat in late infancy. Maternal total and period-specific gestational weight gain were not associated with infant body fat mass measures.

Diet-induced modifications to milk composition have long-term effects on offspring growth in rabbits.

It has been clearly demonstrated that the maternal nutritional status during pregnancy and lactation has long-term effects on offspring health. In mammals, milk represents the first maternal support provided to the newborns so that its composition may play a major role in long-term programming. We therefore assessed the effects of maternal high-fat/high-sugar obesogenic (OD) or control (CD) diets on offspring growth and adiposity in the rabbit. Between 7 and 20 wk of age, the BW gain of OD milk-fed rabbits was higher than that of CD milk-fed rabbits ( < 0.05). Body fat mass measurements at 21 wk of age revealed a significant increase in body adiposity as a function of milk ingested during the neonatal period, in both female and male offspring ( < 0.05). A marked weight gain difference was observed according to the milk in both female and male offspring. Moreover, we investigated the composition in major proteins and leptin levels in milk from OD or CD diet-fed dams. Liquid chromatography-mass spectrometry analysis of individual CD skimmed milk samples enabled identification and quantification of the rabbit main milk proteins and of their main phosphorylated isoforms at 2 different stages of lactation (3 and 10 d). Here we show that the OD diet induced a reduction in the whey acidic protein content concomitantly with both an increase in serum albumin and lactoferrin contents and in the phosphorylated isoforms of the main milk proteins. Furthermore, a sharp rise in leptin levels was observed in the milk of OD diet-fed dams on Day 10 of lactation when compared with CD diet animals ( < 0.05). Taken together, these findings provide evidence that lactation is a critical window of development during which exposure to a deleterious diet is highly detrimental to long-term outcomes. Moreover, these insights suggest that it may be possible to prevent at least some of the adverse effects of inadequate maternal nutrition on the long-term metabolic outcomes of the offspring through nutritional interventions applied during the lactation period.

The effects of fat distribution and some adipokines on insulin resistance.

The risk of developing insulin resistance and metabolic syndrome is particularly high in central obesity. In this study we evaluated the effects of fat distribution and some adipokines on insulin resistance in prediabetic patients. Eighty-seven age- and sex-matched patients were divided into three groups according to their 75-gram oral glucose tolerance test results as follows: impaired fasting glucose group, impaired glucose tolerance group, and normal glucose tolerance group. Fasting insulin levels were measured. Homeostatic model assessment of insulin resistance was calculated. Body fat mass measurements were assessed by bioelectric impedance analyser and abdominal fat thicknesses (subcutaneous, visceral, and preperitoneal) by ultrasonography. The fasting serum levels of several adipokines [adiponectin, leptin, resistin, vaspin, visfatin, retinol-binding protein-4 (RBP-4), tumour necrosis factor-alpha (TNF-alpha)] were measured by ELISA method. The mean body mass index, fat mass measurements, and abdominal fat thicknesses of the groups were similar. There were no differences between groups in terms of the mean fasting insulin, vaspin, RBP-4, leptin, resistin, and TNF-alpha. In comparison of the prediabetic and normal groups, the levels of adiponectin (p < 0.001) and visfatin (p < 0.001) were lower in the prediabetic group. Furthermore, we found that high body mass index (p < 0.01) and fat mass (p < 0.01) and low adiponectin (p < 0.05) levels have roles in the development of insulin resistance in the prediabetic group. We suggested that in the prediabetic period not only obesity but also decreased adiponectin levels play some role in the pathogenesis of insulin resistance. (Endokrynol Pol 2016; 67 (3): 277-282).

Elevated serum advanced glycation endproducts in obese indicate risk for the metabolic syndrome: a link between healthy and unhealthy obesity?

Although obesity can predispose to the metabolic syndrome (MS), diabetes, and cardiovascular disease, not all obese subjects develop MS, hence the need for new indicators of risk for this syndrome. Advanced glycation end products (AGEs) correlate with factors involved in the MS, including inflammation and insulin resistance (IR). Because AGEs can be derived from food and are modifiable, it is important to determine whether they are a risk factor for MS. The objective of this study was to assess the association of endogenous and exogenous AGEs with MS criteria. The following data were collected in a cross-sectional study of subjects with and without the MS: serum AGEs (sAGEs) and mononuclear cell AGEs, metabolites, pro- and antiinflammatory markers, body fat mass measures, including abdominal magnetic resonance imaging, and caloric and dietary AGE (dAGE) consumption. The study was conducted in the general community. Participants included 130 MS and 139 non-MS subjects of both sexes, older than 50 years. sAGEs ((ϵ)N-carboxymethyllysine, methylglyoxal) were markedly elevated in obese persons with more than one other MS criteria but not in obese without MS criteria. sAGEs directly correlated with markers of IR (HOMA) and inflammation (leptin, TNFα, RAGE) and inversely with innate defenses (SIRT1, AGE receptor 1 [AGER1], glyoxalase-I, adiponectin). sAGEs correlated with dAGEs but not with calories, nutrient consumption, or fat mass measures. Consumption of dAGE, but not of calories, was markedly higher in MS than in non-MS. High sAGEs, a modifiable risk factor for IR, may indicate risk for the MS, type 2 diabetes, and cardiovascular disease. High dietary AGE consumption and serum AGE levels may link healthy obesity to at-risk obesity.

The Pro12Ala Polymorphism of the Peroxisome Proliferator-Activated Receptor Gamma Gene Modifies the Association of Physical Activity and Body Mass Changes in Polish Women.

Peroxisome proliferator-activated receptor γ is a key regulator of adipogenesis, responsible for fatty acid storage and maintaining energy balance in the human body. Studies on the functional importance of the PPARG Pro12Ala polymorphic variants indicated that the observed alleles may influence body mass measurements; however, obtained results were inconsistent. We have decided to check if body mass changes observed in physically active participants will be modulated by the PPARG Pro12Ala genotype. The genotype distribution of the PPARG Pro12Ala allele was examined in a group of 201 Polish women measured for selected body mass variables before and after the completion of a 12-week training program. The results of our experiment suggest that PPARG genotype can modulate training-induced body mass measurements changes: after completion of the training program, Pro12/Pro12 homozygotes were characterised by a greater decrease of body fat mass measurements in comparison with 12Ala allele carriers. These results indicate that the PPARG 12Ala variant may impair the training-induced positive effects on body mass measurements; however, the detailed mechanism of such interaction remained unclear and observed correlation between PPARG genotype and body mass differential effects should be interpreted with caution.

Waist circumference and dual-energy X-ray absorptiometry measures of overall and central obesity are similarly associated with systemic oxidative stress in women

Growing evidence suggests that overall and abdominal obesity might lead to oxidative stress (OxS), which, in turn, plays a key role in the pathogenesis of a wide spectrum of diseases. In this study, for the first time, we compared the correlations of indirect, i.e. anthropometric, and direct, by dual energy X-ray absorptiometry (DXA), measures of body fat with circulatory OxS markers in women. To address this issue, we assessed central and total body fat mass (FM) by DXA, and serum levels of advanced oxidation protein products (AOPP), thiols and hydroperoxides in 275 healthy women (age 21–65 years; body mass index [BMI] 21.1–32.0 kg/m2; waist circumference [WC] 60.1–109.9 cm). Among the markers considered in the study, only hydroperoxides levels, i.e. by-products of lipid peroxidation, were significantly (p < 0.05 for all) and positively correlated to body fat accumulation after controlling for confounding factors. In particular, this marker was found to be similarly associated with DXA-derived total FM, total FM % and trunk FM as well as with WC. Of note, hydroperoxides appeared to be correlated with abdominal but not with general obesity, as classified according to standard WC and BMI cut-offs, respectively. In conclusion, taken together our data demonstrated that, at least in women, the measurement of body FM by DXA has no advantage over the simpler and cheaper WC with regard to their associations with systemic OxS markers. Moreover, WC emerged as a superior potential predictor of OxS compared to the other most commonly used anthropometric measures (including BMI and waist to hip ratio).

Superiority of skinfold measurements and waist over waist-to-hip ratio for determination of body fat distribution in a population-based cohort of Caucasian Dutch adults

To determine which anthropometric measurement is the most reliable alternative for fat distribution as measured by dual-energy X-ray absorptiometry (DXA). Population-based survey carried out in Amsterdam, The Netherlands. A total of 376 individuals (200 women) with a mean age of 36.5 years and mean body mass index (BMI) of 24.0 (+/-3.1) kg/m2 underwent various anthropometric and DXA measurements of central (CFM) and peripheral fat mass (PFM). Furthermore, for the assessment of apple-shaped body composition, CFM-to-PFM ratio was calculated. Anthropometric measurements were waist and hip circumference, waist-to-hip ratio (WHR), BMI, waist/length and the skinfold thickness of biceps, triceps, suprailiacal (SI), subscapular (SS) and upper leg. We determined whether equations of combined anthropometrics were even more reliable for the assessment of fat mass. In both women and men, reliable alternatives for CFM are central skinfolds and waist (Pearson's correlation (r) >or= 0.8). Peripheral skinfolds are the best predictors of PFM (r >or= 0.8). In contrast, WHR correlated only marginally with any of the DXA measurements. Equations based on several anthropometric variables correlate with CFM even better (R2 >or= 0.8). CFM-to-PFM ratio has the highest correlation with the ratio (SS+SI)/BMI in women (r = 0.66) and waist/length in men (r = 0.71). Equations are reasonable alternatives of CFM-to-PFM ratio (R2 >or= 0.5). Waist and skinfolds are reliable alternatives for the measurement of body fat mass in a cohort of Caucasian adults. WHR is not appropriate for the measurement of fat distribution.

Evaluation of metabolic risk markers in polycystic ovary syndrome (PCOS). Adiponectin, ghrelin, leptin and body composition in hirsute PCOS patients and controls

Polycystic ovary syndrome (PCOS) patients are abdominally obese and are at increased risk of developing the metabolic syndrome. Low adiponectin and ghrelin levels in PCOS patients could be caused by insulin resistance as well as high testosterone levels. Adiponectin and ghrelin levels were evaluated in 51 hirsute PCOS patients referred to the outpatient clinic of an academic, tertiary care medical centre and in 63 weight-matched female controls. Relationships between adiponectin, ghrelin, leptin, body composition, testosterone and insulin were examined. Measurements of body composition including waist-hip-ratio (WHR), body mass index (BMI) and whole body dual-energy X-ray absorptiometry scan measures of body fat mass. Measurements of fasting levels of adiponectin, ghrelin, leptin, androgen status, oestradiol, lipid variables and insulin during follicular phase. Adiponectin levels were significantly decreased in obese PCOS patients compared with weight-matched controls (geometric mean (-2 to 2 s.d.) 5.3 (2.5-11.1) vs 7.3 (3.0-17.4) mg/l, P<0.05). Mean ghrelin was significantly lower in hirsute PCOS patients than in controls (0.6 (0.3 to 1.4) vs 0.8 (0.4 to 1.7) microg/l, P<0.001) and this remained significant after subdividing subjects according to waist circumference and BMI. During multiple regression analysis, testosterone correlated positively with adiponectin and negatively with ghrelin independent of BMI, WHR and total fat mass. Obese hirsute PCOS patients demonstrated significantly lower adiponectin levels than weight-matched controls suggesting a very high risk for the metabolic syndrome. Furthermore, ghrelin levels were decreased in hirsute PCOS patients and showed a significant, negative correlation with testosterone independent of body composition.

Regional Differences in Adipose Tissue Metabolism in Women

Studies comparing adipose tissue metabolism in central versus peripheral fat depots have generated equivocal data. We examined whether regional differences in abdominal subcutaneous and omental adipose tissue metabolism in women exist and whether they persist across the spectrum of body fatness and abdominal adiposity values. We measured adipocyte size; lipoprotein lipase (LPL) activity; and basal, isoproterenol-, forskolin-, and dibutyryl cAMP-stimulated lipolysis in adipose tissue or mature adipocytes isolated from the omental and subcutaneous fat depots in a sample of 55 healthy women undergoing elective gynecological surgery. Measures of body fat mass and body fat distribution were also obtained by dual-energy X-ray absorptiometry and computed tomography. Subcutaneous adipocytes were significantly larger than omental adipocytes (P < 0.0001). LPL activity expressed as a function of cell number was significantly higher in subcutaneous versus omental adipose tissue (P < 0.0001). Basal, isoproterenol-stimulated, dibutyryl cAMP-stimulated (10(-3) mol/l) and forskolin-stimulated (10(-5) mol/l) lipolysis (expressed as a function of cell number) were all significantly higher in subcutaneous versus omental adipocytes (P < 0.05 to P < 0.0001). However, the response of omental adipocytes to lipolytic stimuli tested (fold increase over basal level) was significantly greater in magnitude compared with subcutaneous adipocytes (P < 0.01). These differences were relatively constant across total body fat mass and visceral adipose tissue area tertiles. In conclusion, compared with adipocytes from the omental fat compartment, subcutaneous adipocytes are larger, have higher LPL activity, and are more lipolytic on an absolute basis, which may reflect a higher fat storage capacity in this depot in women. In contrast, omental adipocytes display greater relative responsiveness to both adrenergic receptor-and postreceptor-acting agents compared with subcutaneous adipocytes. Overall and visceral obesity have only minor effects on regional differences in adipose tissue metabolism.

Measurement of body fat mass in vivo: from two-compartment techniques to neutron activation analysis and DXA

Measurement of body fat mass in vivo: from two-compartment techniques to neutron activation analysis and DXA

Serum leptin and insulin in paediatric end-stage liver disease and following successful orthotopic liver transplantation.

Leptin, the product of the ob gene, is a postulated feedback regulator of adiposity with appetite suppressant and catabolic effects. Catabolic states are associated with decreased body fat mass as a result of both nutritional and metabolic perturbation. Low serum leptin has been described previously in a number of catabolic states. It has been unclear whether the observed changes in leptin are a cause or consequence of changes in adiposity. Paediatric end-stage liver disease (ESLD) is characterized by decreased body fat mass and poor linear growth. Successful treatment by orthotopic liver transplantation (OLT) is accompanied by increase in fat mass. We investigated the hypothesis that serum leptin would be low in paediatric ESLD and that increase in body fat mass post-OLT would result in increased serum leptin. Serum leptin and insulin were measured by radioimmunoassay in children with ESLD before and after successful OLT and in age-matched controls. Twenty-four children with ESLD attending the outpatient department of King's College Hospital, London and 10 age-matched controls. Anthropometric measurements were performed according to standard techniques and standard deviation (SDS) derived from population standards. Serum leptin and insulin were measured by radioimmunoassay. Serum leptin pre-OLT, leptin (4.06 micrograms/l, [3.45, 5.68] median, with 25th and 75th interquartile ranges) was significantly lower than controls (6.62 micrograms/l, [4.33, 8.05], P = 0.02). Following OLT, serum leptin fell to levels which were significantly lower than pre-OLT values (3.32 micrograms/l, [2.30, 3.99], P = 0.01). There was no significant difference between boys and girls either pre-OLT (boys; 3.64 micrograms/l, [2.45, 5.57], girls; 4.14 micrograms/l, [3.18, 5.65]) or post-OLT (boys; 3.32 micrograms/l, [2.93, 3.62], girls; 3.69 micrograms/l, [2.23, 4.63]. Neither the age at OLT nor the age at the time of blood sampling was correlated with serum leptin pre-OLT or post-OLT. Pre-OLT the children were significantly malnourished with low measures of body fat mass (mid-arm circumference (MAC) SDS -1.90 [-4.67, -1.07]; triceps skinfold thickness (TSF) SDS -1.53, [-2.23, -0.23]; body mass index (BMI) 16.2, [15.5, 16.9]). Three months post-OLT, there were significant improvements in MAC SDS (-0.77, [-1.08, -0.20], P = 0.02) and TSF SDS (-0.41, [-1.95, -0.38], P = 0.003), but no significant change in BMI (15.9 [15.3, 16.7], P = 0.41. Pre-OLT, log serum leptin did not correlate with BMI, MAC SDS or TSF SDS. In contrast, post-OLT, there was a positive correlation between log serum leptin and BMI (r = 0.59, P = 0.003), MAC SDS (r = 0.49, P = 0.01) and TSF SDS (r = 0.41, P = 0.05). BMI also correlated with log serum leptin in the control children (r = 0.64, P = 0.04). Serum leptin is low in children with end-stage liver disease but does not show the expected correlation with measures of body fat mass. Surprisingly, following orthotopic liver transplantation serum leptin falls significantly despite significant increases in measures of body fat mass (triceps skinfold thickness standard deviation scores, mid-arm circumference standard deviation scores). Orthotopic liver transplantation restores the expected correlation of serum leptin with measures of body fat mass within the treatment group. The elevation of serum leptin above predicted levels in paediatric end-stage liver disease offers a mechanism for the anorexia and cachexia characteristic of this disease.