Dual-energy X-ray absorptiometry prediction of adipose tissue depots in children and adolescents

Uremic sarcopenia: the role of intramuscular adipose tissue as a potential early identifier

Introduction

Sarcopenia is a chronic pathological condition, first defined in 2010 and revised in 2018. The most recent definition of sarcopenia focuses mostly on "low muscle strength." A secondary form of sarcopenia is represented by uremic sarcopenia (US), a condition that characterizes end-stage kidney disease (ESKD) patients. The intramuscular adipose tissue (IMAT) seems to impact negatively on muscle strength, as it would seem to replace muscle fibers with a non-contractile component. The study aims to compare body composition parameters-both standardized and innovative-related to the diagnosis of US in hemodialysis (HD) patients, stratified by sarcopenia diagnosis. Furthermore, the different indices of sarcopenia are compared in order to evaluate their predictive capacity.

Methods

We analyzed 48 ESKD patients according to the sarcopenia diagnosis, obtained using dual-energy X-ray absorptiometry (DXA). Moreover, we assessed the presence of IMAT and calculated the sarcopenia index (SI).

Results

For the study, the enrolled population was divided according to the sarcopenia diagnosis: no sarcopenic patients had higher transferrin (p = 0.03), total proteins (p = 0.04), and azotemia pre-dialysis (p = 0.05) values. On the contrary, atherogenic indices were lower in no sarcopenic patients. Moreover, we observed an indirect correlation between the SI and parathyroid hormone (PTH) (p = 0.00138, R 2 = 0.54). Finally, we calculated the prevalence of sarcopenia and sarcopenia adjusted for IMAT. We showed a different prevalence between sarcopenia diagnosed with a standard index and an index adjusted for IMAT (p = 0.043). In conclusion, we believe that the most important result obtained is the indirect correlation between SI and PTH. These data corroborate the theories, in which PTH seems to play a central role in the cachexia genesis. Moreover, the SI adjusted for IMAT seems to be a more reliable parameter for the early identification of subjects at risk of developing US, allowing timely implementation of targeted therapeutic strategies.

Circadian misalignment impacts the association of visceral adiposity with metabolic syndrome in adolescents

STUDY OBJECTIVES

Although insufficient sleep is a risk factor for metabolic syndrome (MetS), the circadian timing of sleep (CTS) is also involved in cardiac and metabolic regulation. We examined whether delays and deviations in the sleep midpoint (SM), a measure of CTS, modify the association between visceral adipose tissue (VAT) and MetS in adolescents.

METHODS

We evaluated 277 adolescents (median 16 years) who had at least 5 nights of at-home actigraphy (ACT), in-lab polysomnography (PSG), dual-energy X-ray absorptiometry (DXA) scan, and MetS score data. Sleep midpoint (SM), sleep irregularity (SI), and social jetlag (SJL) were examined as effect modifiers of the association between VAT and MetS, including waist circumference, blood pressure, insulin resistance, triglycerides, and cholesterol. Linear regression models adjusted for demographics, ACT-sleep duration, ACT-sleep variability, and PSG-apnea-hypopnea index.

RESULTS

The association between VAT and MetS was significantly stronger (p-values for interactions < 0.001) among adolescents with a schooldays SM later than 4:00 (2.66 [0.30] points increase in MetS score), a SI higher than 1 hour (2.49 [0.30]) or a SJL greater than 1.5 hours (2.15 [0.36]), than in those with an earlier SM (<3:00; 1.76 [0.28]), lower SI (<30 minutes; 0.98 [0.70]), or optimal SJL (<30 minutes; 1.08 [0.45]).

CONCLUSIONS

A delayed sleep phase, an irregular sleep-wake cycle, and greater social jetlag on schooldays identified adolescents in whom VAT had a stronger association with MetS. Circadian misalignment is a risk factor that enhances the impact of visceral obesity on cardiometabolic morbidity and should be a target of preventative strategies in adolescents.

Reference Ranges of Body Composition Using Dual-Energy X-Ray Absorptiometry and Its Relation to Tri-Ponderal Mass Index

Introduction/background Increased body fat is related to obesity and its comorbidities later in life. To determine the amount of body fat in children and adolescents, reference intervals should be applied. Dual-energy X-ray absorptiometry (DXA) is a good tool for accurately measuring body composition. Methodology The body composition reference ranges in Korean children and adolescents were determined using nationally representative cross-sectional data. The performances of the body mass index (BMI) and tri-ponderal mass index (TMI) in measuring body fat were compared using the reference percentiles derived from this analysis. Results A total of 1,661 subjects (891 boys and men and 770 girls and women) were included. Age- and sex-specific percentiles and the corresponding LMS variables for DXA-assessed parameters for the whole body and the trunk were determined. The coefficients of determination of the whole body FM SDS and FMI SDS for the BMI SDS were 0.783 and 0.784, respectively, and those for the TMI SDS were 0.685 and 0.769, respectively. Conclusion Based on the reference values for body composition, the correlation coefficients of TMI for adjusted FM measured by DXA were comparable to those of BMI. TMI estimated body fat levels more accurately than BMI in this study population.

Possible prediction of obesity-related liver disease in children and adolescents using indices of body composition

BACKGROUND

Diagnosis of nonalcoholic fatty liver disease in children and adolescents currently requires advanced or invasive technologies.

OBJECTIVES

We aimed to develop a method to improve diagnosis, using body composition indices and liver biochemical markers.

METHODS

To diagnose non-alcoholic fatty liver disease, 767 Danish children and adolescents underwent clinical examination, blood sampling, whole-body dual-energy X-ray absorptiometry scanning and proton magnetic resonance spectroscopy for liver fat quantification. Fourteen variables were selected as a starting point to construct models, narrowed by stepwise selection. Individuals were split into a training set for model construction and a validation test set. The final models were applied to 2120 Danish children and adolescents to estimate the prevalence.

RESULTS

The final models included five variables in different combinations: body mass index-standard deviation score, android-to-gynoid-fat ratio, android-regional fat percent, trunk-regional fat percent and alanine transaminase. When validated, the sensitivity and specificity ranged from 38.6% to 51.7% and 87.6% to 91.9%, respectively. The estimated prevalence was 24.2%-35.3%. Models including alanine transaminase alongside body composition measurements displayed higher sensitivity.

CONCLUSIONS

Body composition indices and alanine transaminase can be used to estimate non-alcoholic fatty liver disease, with 38.6%-51.7% sensitivity and 87.6%-91.9%, specificity, in children and adolescents with overweight (including obesity). These estimated a 24.2%-35.3% prevalence in 2120 patients.

Body fat indicators perform better than body mass index in identifying abnormal lipid profiles in boys but not in girls

BACKGROUND

BMI as a body weight indicator, may inadequately represent the biological effect of body fat on lipid profiles. This study aims to assess whether body fat indicators were superior to BMI for recognizing children with dyslipidemia.

METHODS

A nationwide cross-sectional study involving 8944 pediatric participants aged 6-18 years. Measures of fat mass index (FMI), fat mass percentage (FMP), BMI, and four lipid profiles were obtained.

RESULTS

Among boys, the standard multi-linear regression coefficients of FMI for TC, LDL-C, and TG were higher than those of BMI (P < 0.01), but not for HDL-C. Also, the prevalence ratios and area under curves (AUCs) of excess fat classified by FMI for specific abnormal lipid profiles (except for HDL-C) were greater than overweight classified by BMI. The AUCs for detecting children with abnormal TC, LDL-C, and TG of FMI-based excess fat were 3.9%, 5.6%, and 2.8% higher than those of BMI-based overweight, respectively, all P < 0.01. Among girls, the associations of BMI with lipid profiles were substantially similar to FMI. All these results were almost identical when FMP was used instead of FMI.

CONCLUSIONS

DXA measured body fat performs better than BMI in identifying abnormal lipid profiles in boys but not in girls.

Evidences of a New Psychobiotic Formulation on Body Composition and Anxiety

Background

Gut microbiota is implied in obesity, because of its ability to harvest energy from diet, and in the regulation of behavior. Given the link between gut microbiota, body composition, obesity, and anxiety, the aim of this study was to evaluate the effects of a new psychobiotic formulation.

Methods

Eligible patients were randomly divided into three groups: psychobiotics oral suspension group (POSG); dietary treatment group (DTG); combined treatment group (CTG). All subjects underwent body composition and psychological profile evaluation.

Results

Significant changes in body composition parameters in each group were relieved after all treatments. Hamilton anxiety rating scale (HAM-A) highlighted a significant reduction of the total score for all study population after treatments in POSG (p = 0.01) and CTG (p = 0.04). A reduction of HAM-A total score in anxious subjects in POSG or CTG and a significant reduction of positive subjects for HAM-A in POSG (p = 0.03) and in CDG (p = 0.01) were shown.

Discussion

Three-week intake of selected POS represents a good approach to solve problems related to obesity and behavior disorders. However, new clinical trials need to be performed on a larger population and for a longer period of treatment before definitive conclusions can be made. This trial is registered with NCT01890070.

Dexa Body Composition Assessment in 10-11 Year Healthy Children

INTRODUCTION

Obesity is a growing health problem associated with metabolic derangements and cardiovascular disease. Accumulating evidence links the accumulation of visceral adipose tissue (VAT) to these obesity related health risks in adults. Childhood obesity is associated with a lifetime risk of cardiovascular disease and poses a serious challenge to future health care. In children, there is much less data on the prevalence and gender differences of visceral obesity than in adults. This study aims to provide reference values for VAT in children 10-11 years of age.

METHODS

In a cross-sectional study performed in the north western part of theNetherlands, healthy children of 10-11 years of age, were recruited from primary schools. Anthropometric data consisting of height, weight, waist circumference (WC) and BMI were measured. Body composition was measured using DXA, providing measures for bone mineral content, total fat mass (TFM), lean body mass (LBM) and VAT.

RESULTS

217 children were eligible for this study. Girls appeared to have a greater TFM (31.4% vs 27.5% of total body weight (TBW); P < .01) but lower VAT (0.3% vs 0.5% of TBW;P < .01) than boys, whereas boys had higher LBM (65.4% vs 69.3% TBW;P < .01). Median VAT area (cm2) was 41.1 for boys and 22.4 for girls (P < .01). Moderate to strong correlations were found for WC and BMI with VAT (boys: r = .664 and r = .630; Girls r = .699 and r = .546 respectively all P < .001).

DISCUSSION

This study shows gender specific differences in VAT percentiles in healthy non-obese 10-11 year old children as measured by DXA that may serve as reference values in children. Independent of BMI and WC, girls tend to have more TFM but less VAT and LBM than boys.

Body composition and functional assessment of nutritional status in adults: a narrative review of imaging, impedance, strength and functional techniques

The accurate and valid assessment of body composition is essential for the diagnostic evaluation of nutritional status, identifying relevant outcome measures, and determining the effectiveness of current and future nutritional interventions. Developments in technology and our understanding of the influences of body composition on risk and outcome will provide practitioners with new opportunities to enhance current practice and to lead future improvements in practice. This is the second of a two-part narrative review that aims to critically evaluate body composition methodology in diverse adult populations, with a primary focus on its use in the assessment and monitoring of under-nutrition. Part one focused on anthropometric variables [Madden and Smith (2016) J Hum Nutr Diet 29: 7-25] and part two focuses on the use of imaging techniques, bioelectrical impedance analysis, markers of muscle strength and functional status, with particular reference to developments relevant to practice.

Adding anthropometric measures of regional adiposity to BMI improves prediction of cardiometabolic, inflammatory and adipokines profiles in youths: a cross-sectional study

BACKGROUND

Paediatric research analysing the relationship between the easy-to-use anthropometric measures for adiposity and cardiometabolic risk factors remains highly controversial in youth. Several studies suggest that only body mass index (BMI), a measure of relative weight, constitutes an accurate predictor, whereas others highlight the potential role of waist-to-hip ratio (WHR), waist circumference (Waist C), and waist-to-height ratio (WHtR). In this study, we examined the effectiveness of adding anthropometric measures of body fat distribution (Waist C Z Score, WHR Z Score and/or WHtR) to BMI Z Score to predict cardiometabolic risk factors in overweight and obese youth. We also examined the consistency of these associations with the "total fat mass + trunk/legs fat mass" and/or the "total fat mass + trunk fat mass" combinations, as assessed by dual energy X-ray absorptiometry (DXA), the gold standard measurement of body composition.

METHODS

Anthropometric and DXA measurements of total and regional adiposity, as well as a comprehensive assessment of cardiometabolic, inflammatory and adipokines profiles were performed in 203 overweight and obese 7-17 year-old youths from the Paediatrics Clinic, Centre Hospitalier de Luxembourg.

RESULTS

Adding only one anthropometric surrogate of regional fat to BMI Z Score improved the prediction of insulin resistance (WHR Z Score, R(2): 45.9%. Waist C Z Score, R(2): 45.5%), HDL-cholesterol (WHR Z Score, R(2): 9.6%. Waist C Z Score, R(2): 10.8%. WHtR, R(2): 6.5%), triglycerides (WHR Z Score, R(2): 11.7%. Waist C Z Score, R(2): 12.2%), adiponectin (WHR Z Score, R(2): 14.3%. Waist C Z Score, R(2): 17.7%), CRP (WHR Z Score, R(2): 18.2%. WHtR, R(2): 23.3%), systolic (WHtR, R(2): 22.4%), diastolic blood pressure (WHtR, R(2): 20%) and fibrinogen (WHtR, R(2): 21.8%). Moreover, WHR Z Score, Waist C Z Score and/or WHtR showed an independent significant contribution according to these models. These results were in line with the DXA findings.

CONCLUSIONS

Adding anthropometric measures of regional adiposity to BMI Z Score improves the prediction of cardiometabolic, inflammatory and adipokines profiles in youth.

Magnetic resonance imaging-measured bone marrow adipose tissue area is inversely related to cortical bone area in children and adolescents aged 5-18 years

Previous studies have shown an inverse correlation between bone marrow adipose tissue and bone mineral density in cancellous bone; however, such relationships in cortical bone are less studied, especially in children. A total of 185 healthy children and adolescents (76 females and 109 males, aged 5-18 years) were included in this study. Right femoral bone marrow adipose tissue area (BMA), right femoral cortical bone area (CBA), subcutaneous adipose tissue, visceral adipose tissue, and skeletal muscle were accessed by whole-body magnetic resonance imaging. In regression analysis with CBA as the dependent variable and BMA as the independent variable, BMA negatively contributed to CBA after adjusting for weight and total body fat or subcutaneous adipose tissue, visceral adipose tissue, and skeletal muscle (β = -0.201 to -0.272, p < 0.001). These results suggest an inverse relationship between BMA and CBA in children and adolescents after adjustment of body weight or body composition. The data support the hypothesis that a competitive relationship exists between bone and marrow fat in cortical bone and is consistent with a similar finding in cancellous bone in previous studies. Future research is needed to clarify the role of marrow fat in childhood fractures that are related to cortical bone quality.

Yeast hydrolysate can reduce body weight and abdominal fat accumulation in obese adults

OBJECTIVE

The aim of this study was to examine the effect of yeast hydrolysate on the abdominal fat in obese humans.

METHODS

We observed the effects of yeast hydrolysate that had a molecular weight below 10 kDa on the anti-abdominal fat accumulation in obese men and women ages 20 to 50 y for 10 wk. The abdominal fat mass was assessed by computed tomographic scans.

RESULTS

By the sixth week, the reductions in energy intake in the yeast group (yeast hydrolysate 1 g/d) were significantly greater than those in the control group (placebo 1 g/d) (P < 0.05). The body weight and body mass index (BMI) were significantly reduced by week 10 compared with baseline in the yeast group, and these differences were significantly greater than those in the control group: body weight 0.83 kg versus -2.60 k g (P < 0.001), BMI 0.29 kg/m(2) versus -0.90 kg/m(2) (P < 0.001). Despite the increased loss of body weight in the yeast group, lean body mass did not significantly differ between the two groups. Body fat mass in the control group did not significantly change between baseline and week 10. However, the yeast group lost a significant amount of body fat mass after 10 wk of treatment (P < 0.01). The differences in abdominal fat thickness and abdominal circumference between the two groups were significant after 10 wk of treatment (P < 0.001). The total abdominal fat area in the yeast group was significantly lower than in the control group after 10 wk of treatment (-7.06 cm(2) versus -17.34 cm(2); P < 0.01).

CONCLUSIONS

Yeast hydrolysate can reduce body weight and the accumulation of abdominal fat without an adverse effect on lean body mass in obese adults, regardless of sex, via the reduction of energy intake.

Assessment of regional adipose tissue depots: a DXA and CT comparison in cadavers of elderly persons

OBJECTIVE

Since dual energy X-ray absorptiometry (DXA) cannot distinguish between different adipose tissue (AT) deposits, it remains unclear how DXA-derived body composition variables relate to anatomical tissue (sub)compartments. The aim of the present study was to compare and relate regional DXA variables with absolute tissue masses obtained by computer tomography (CT) scanning of the lower limbs in elderly persons.

METHODS

Eleven well-preserved white Caucasian adults (seven male and four female cadavers) with a median age of 79.0 years (ranging from 68 to 96 years) were fully scanned with DXA and CT. Separate densities of skin tissue, AT, muscle tissue and bone were obtained by hydrostatic weighing.

RESULTS

The leg DXA-variables were significantly related (rho-values between 0.60 and 0.98, P < 0.01) to CT-derived tissue counterparts, but showed significant systematic differences except for subcutaneous AT mass (P = 0.773). After controlling for other AT depots, fat as measured by DXA (fat(DXA)) related only to intermuscular AT (rho = 0.82, P < 0.01) in males and to subcutaneous AT (rho = 0.84, P < 0.05) in females.

CONCLUSION

Although significantly interrelated, DXA and CT variables should not be used interchangeably since they have different quantitative and physiological significance. Our results suggest that fat(DXA) represents different parts of AT depots in elderly men and women. Since DXA is not appropriate for assessing tissue variability cautious clinical interpretation is warranted.