Interindividual variation in abdominal subcutaneous and visceral adipose tissue: influence of measurement site

Subcutaneous and Visceral Adipose Tissue Reference Values From the Framingham Heart Study Thoracic and Abdominal CT

BACKGROUND

Computed tomography (CT) captures the quantity, density, and distribution of subcutaneous and visceral (SAT and VAT) adipose tissue compartments. These metrics may change with age and sex.

OBJECTIVE

The study aims to provide age-, sex-, and vertebral level-specific reference values for SAT on chest CT and for SAT and VAT on abdomen CT.

MATERIALS AND METHODS

This secondary analysis of an observational study describes SAT and VAT measurements in participants of the Framingham Heart Study without known cancer diagnosis who underwent at least 1 of 2 CT examinations between 2002 and 2011. We used a previously validated machine learning-assisted pipeline and rigorous quality assurance to segment SAT at the fifth, eighth, and tenth thoracic vertebra (T5, T8, T10) and SAT and VAT at the third lumbar vertebra (L3). For each metric, we measured cross-sectional area (cm 2 ) and mean attenuation (Hounsfield units [HU]) and calculated index (area/height 2 ) (cm 2 /m 2 ) and gauge (attenuation × index) (HU × cm 2 /m 2 ). We summarized body composition metrics by age and sex and modeled sex-, age-, and vertebral level-specific reference curves.

RESULTS

We included 14,898 single-level measurements from up to 4 vertebral levels of 3797 scans of 3730 Framingham Heart Study participants (1889 [51%] male with a mean [standard deviation] age of 55.6 ± 10.6 years; range, 38-81 years). The mean VAT index increased with age from 65 (cm 2 /m 2 ) in males and 29 (cm 2 /m 2 ) in females in the <45-year-old age group to 99 (cm 2 /m 2 ) in males and 60 (cm 2 /m 2 ) in females in >75-year-old age group. The increase of SAT with age was less pronounced, resulting in the VAT/SAT ratio increasing with age. A free R package and online interactive visual web interface allow access to reference values.

CONCLUSIONS

This study establishes age-, sex-, and vertebral level-specific reference values for CT-assessed SAT at vertebral levels T5, T8, T10, and L3 and VAT at vertebral level L3.

Body composition assessment of people with overweight/obesity with a simplified magnetic resonance imaging method

To develop a simplified magnetic resonance imaging method (MRI) to assess total adipose tissue (AT) and adipose tissue free mass (ATFM) from three single MRI slices in people with overweight/obesity in order to implement body composition follow-up in a clinical research setting. Body composition of 310 participants (70 women and 240 men, age: 50.8 ± 10.6 years, BMI: 31.3 ± 5.6 kg.m^-2) was assessed with 3 single slices (T6-T7, L4-L5 and at mid-thigh) MRI. Multiple regression analysis was used to develop equations predicting AT and ATFM from these three single slices. Then we implemented a longitudinal phase consisting in a 2-month exercise training program during which we tested the sensitivity of these equations in a subgroup of participants with overweight/obesity (n = 79) by comparing the exercise-induced variations between predicted and measured AT and ATFM. The following equations: total AT = - 12.74105 + (0.02919 × age) + (4.27634 × sex (M = 0, F = 1)) + (0.22008 × weight) + (26.92234 × AT T6-T7) + (23.70142 × AT L4-L5) + (37.94739 × AT mid-thigh) and total ATFM = - 33.10721 + (- 0.02363 × age) + (- 3.58052 × sex (M = 0, F = 1)) + (30.02252 × height) + (0.08549 × weight) + (11.36859 × ATFM T6-T7) + (27.82244 × ATFM L4-L5) + (58.62648 × ATFM mid-thigh) showed an excellent prediction (adjusted R² = 97.2% and R² = 92.5%; CCC = 0.986 and 0.962, respectively). There was no significant difference between predicted and measured methods regarding the AT variations (- 0.07 ± 2.02 kg, p = 0.70) and the ATFM variations (0.16 ± 2.41 kg, p = 0.49) induced by 2-months of exercise training. This simplified method allows a fully accurate assessment of the body composition of people with obesity in less than 20 min (10 min for images acquisition and analysis, respectively), useful for a follow-up.

Fully automated CT-based adiposity assessment: comparison of the L1 and L3 vertebral levels for opportunistic prediction

PURPOSE

The purpose of this study is to compare fully automated CT-based measures of adipose tissue at the L1 level versus the standard L3 level for predicting mortality, which would allow for use at both chest (L1) and abdominal (L3) CT.

METHODS

This retrospective study of 9066 asymptomatic adults (mean age, 57.1 ± 7.8 [SD] years; 4020 men, 5046 women) undergoing unenhanced low-dose abdominal CT for colorectal cancer screening. A previously validated artificial intelligence (AI) tool was used to assess cross-sectional visceral and subcutaneous adipose tissue areas (SAT and VAT), as well as their ratio (VSR) at the L1 and L3 levels. Post-CT survival prediction was compared using area under the ROC curve (ROC AUC) and hazard ratios (HRs).

RESULTS

Median clinical follow-up interval after CT was 8.8 years (interquartile range, 5.2-11.6 years), during which 5.9% died (532/9066). No significant difference (p > 0.05) for mortality was observed between L1 and L3 VAT and SAT at 10-year ROC AUC. However, L3 measures were significantly better for VSR at 10-year AUC (p < 0.001). HRs comparing worst-to-best quartiles for mortality at L1 vs. L3 were 2.12 (95% CI, 1.65-2.72) and 2.22 (1.74-2.83) for VAT; 1.20 (0.95-1.52) and 1.16 (0.92-1.46) for SAT; and 2.26 (1.7-2.93) and 3.05 (2.32-4.01) for VSR. In women, the corresponding HRs for VSR were 2.58 (1.80-3.69) (L1) and 4.49 (2.98-6.78) (L3).

CONCLUSION

Automated CT-based measures of visceral fat (VAT and VSR) at L1 are predictive of survival, although overall measures of adiposity at L1 level are somewhat inferior to the standard L3-level measures. Utilizing predictive L1-level fat measures could expand opportunistic screening to chest CT imaging.

Risk factors for umbilical incisional hernia after laparoscopic colorectal surgery

BACKGROUND

Laparoscopic colorectal surgery (LCRS) requires a small laparotomy at the umbilicus. The wound is small and inconspicuous, but if the patient develops an umbilical incisional hernia (UIH), the wound is visible and the patient suffers from symptoms of discomfort. However, the incidence of UIH after LCRS and its risk factors are not well understood. The purpose of this study was to investigate the risk factors for UIH after LCRS for colorectal cancer.

METHODS

This was a single-centre retrospective study of 135 patients with colorectal cancer, conducted at our hospital from April 2013 to March 2019. The diagnosis of UIH was based on computed tomography and physical examination findings. Preoperative patient data such as enlargement of the umbilical orifice (EUO), subcutaneous fat thickness (SFT) and intraperitoneal thickness (IPT) were collected and analysed using univariate and multivariate analyses for the presence of risk factors for UIH.

RESULTS

A total of 135 patients who underwent LCRS were analysed. The incidence of UIH was 20.7%. Univariate analysis revealed significantly high body mass index (BMI) ≥ 25 (P = 0.032), EUO (P < 0.001), SFT ≥18 mm (P = 0.011), and IPT ≥61 mm (P < 0.01) in the UIH group. Multivariate analysis revealed significant differences in EUO (P < 0.001), SFT ≥18 mm (P = 0.046) and IPT ≥61 mm (P = 0.022).

CONCLUSION

EUO was the most important risk factor for UIH, followed by IPT and SFT. These findings are predictive indicators of the development of UIH after LCRS and can be assessed objectively and easily with preoperative computed tomography.

The role of fat distribution and inflammation in the origin of endometrial cancer, study protocol of the ENDOCRINE study

BACKGROUND

Obesity is a growing problem worldwide, especially in countries with improved socioeconomic circumstances. Also, in the Netherlands the incidence of overweight and obesity is rising. There is increasing evidence on the association between obesity and tumorigenesis. Of all cancer types, endometrial cancer (EC) has the strongest positive correlation with obesity. Obesity is generally defined as a body mass index (BMI) >30, yet does not cover the differences in fat distribution in visceral and subcutaneous compartments. Visceral fat is assumed to be relatively more metabolically active and likely negative prognostic biomarker in non-endometrioid EC. Whereas subcutaneous fat is mainly responsible for oestrogen production through increased aromatase activity.

OBJECTIVE

The aim of this study is to compare hormone levels and inflammatory markers after bilateral salpingo-oophorectomy (BSO) in obese and non-obese patients. Secondary objectives are to compare the effect of fat distribution and diagnosis (benign vs. EC) on the observed changes in hormone levels and inflammatory markers, and to compare the effect of BSO on menopausal complaints.

METHODS

Prospective multicentre observational cohort study. A total of 160 patients will be included, of which 80 patients with a normal BMI (18-25 kg/m2) and 80 patients with an obese BMI >32-35 kg/m2. Preoperative abdominal CT will be performed and fasting venous blood samples are obtained for hormone levels and inflammation markers analysis. During surgery, adipose tissue biopsies of subcutaneous and visceral (omental and intestinal epiploic fat) compartments will be collected and stored fresh frozen. In addition a fasting blood draw six weeks after surgery will be obtained. All subjects will fill in two questionnaires before surgery and one after surgery.

DISCUSSION

We hypothesize that BMI, the type of fat distribution, and possibly the underlying pathology significantly influence in hormone levels, and systemic inflammation changes after BSO. Previous studies have found several clues for a relationship between obesity and endometrial cancer. We expect that our study will contribute to pinpoint the exact differences between 'healthy obesity' and 'unhealthy obesity' and will help to identify patients that are more at risk of developing cancer (or possibly suffer from other related problems such as cardiovascular problems e.g.).

How much abdominal fat do obese patients lose short term after laparoscopic sleeve gastrectomy? A quantitative study evaluated with MRI

Background

This study aimed to elucidate the changes in the amount of abdominal adipose tissue after laparoscopic sleeve gastrectomy in obese Chinese patients over a relatively short follow-up period and to analyze the differences in the effects of surgery between genders.

Methods

Ninety-one patients were enrolled in the study, including 18 males and 73 females. These patients underwent laparoscopic sleeve gastrectomy between November 2017 and November 2019. Before and short term after surgery, the areas of subcutaneous/visceral adipose tissue and the liver proton density fat fraction were calculated with upper abdominal magnetic resonance (MR) examinations.

Results

Approximately 100 days after surgery, the median values of weight loss and body mass index reduction were 23.1 kg and 8.1 kg/m², respectively. The patients achieved a greater absolute loss of subcutaneous adipose tissue index than of visceral adipose tissue index (3.2×10^-3 vs. 1.6×10^-3, P<0.001). The amount of weight loss, body mass index loss and absolute/relative reduction in visceral adipose tissue index were much greater in males than in females (31.7 vs. 21.7 kg, P<0.001; 9.8 vs. 7.9 kg/m², P=0.016; 2.5×10^-3 vs. 1.3×10^-3, P=0.007; 28.2% vs. 20.9%, P=0.029). There was a correlation between decreased amounts in subcutaneous and visceral adipose tissue in sum and weight loss (r=0.282, P=0.032). The absolute/relative reduction in visceral adipose tissue index was also correlated with absolute/relative reduction in liver proton density fat fraction (r=0.283, P=0.013; r=0.372, P=0.001).

Conclusions

The reductions in body weight and visceral fat were more significant in male patients. The sum of absolute reduction in subcutaneous and visceral fat deposits was correlated with weight loss, in all patients enrolled. For severely obese patients, an upper abdominal MR examination could assess the body tissue composition and how it changes after bariatric surgery.

Artificial intelligence-aided CT segmentation for body composition analysis: a validation study

Background

Body composition is associated with survival outcome in oncological patients, but it is not routinely calculated. Manual segmentation of subcutaneous adipose tissue (SAT) and muscle is time-consuming and therefore limited to a single CT slice. Our goal was to develop an artificial-intelligence (AI)-based method for automated quantification of three-dimensional SAT and muscle volumes from CT images.

Methods

Ethical approvals from Gothenburg and Lund Universities were obtained. Convolutional neural networks were trained to segment SAT and muscle using manual segmentations on CT images from a training group of 50 patients. The method was applied to a separate test group of 74 cancer patients, who had two CT studies each with a median interval between the studies of 3 days. Manual segmentations in a single CT slice were used for comparison. The accuracy was measured as overlap between the automated and manual segmentations.

Results

The accuracy of the AI method was 0.96 for SAT and 0.94 for muscle. The average differences in volumes were significantly lower than the corresponding differences in areas in a single CT slice: 1.8% versus 5.0% (p < 0.001) for SAT and 1.9% versus 3.9% (p < 0.001) for muscle. The 95% confidence intervals for predicted volumes in an individual subject from the corresponding single CT slice areas were in the order of ± 20%.

Conclusions

The AI-based tool for quantification of SAT and muscle volumes showed high accuracy and reproducibility and provided a body composition analysis that is more relevant than manual analysis of a single CT slice.

Quantification of Human Central Adipose Tissue Depots: An Anatomically Matched Comparison Between DXA and MRI

Excess visceral adipose tissue (VAT) and VAT volume relative to subcutaneous adipose tissue (SAT) are associated with elevated health risks. This study compares fat measurements by dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI). In total, 21 control subjects (Control) and 16 individuals with metabolic syndrome (MetSyn) were scanned by DXA and MRI. The region measured by MRI was matched to the android region defined by DXA, and MRI reproducibility was also evaluated. In addition, liver fat fraction was quantified via MRI and whole-body fat by DXA. VAT measurements are interchangeable between DXA and MRI in the Control (R = 0.946), MetSyn (R = 0.968), and combined cohort (R = 0.983). VAT/SAT ratio did not differ in the Control group (P = .10), but VAT/SAT ratio measured by DXA was significantly higher in the MetSyn group (P < .01) and the combined (P = .03) cohort. Intraobserver (ICC = 0.998) and interobserver (ICC = 0.977) reproducibility of MRI VAT measurements was excellent. Liver fat fraction by MRI was higher (P = .001) in MetSyn (12.4% ± 7.6%) than in controls (2.6% ± 2.2%), as was whole-body fat percentage by DXA (P = .001) between the MetSyn (42.0% ± 8.1%) and Control groups (26.7% ± 6.9%). DXA and MRI VAT are interchangeable when measured over an anatomically matched region of the abdomen, while SAT and VAT/SAT ratio differ between the 2 modalities.

Negative Energy Balance Induced by Exercise or Diet: Effects on Visceral Adipose Tissue and Liver Fat

The indisputable association between visceral adipose tissue (VAT) and cardiometabolic risk makes it a primary target for lifestyle-based strategies designed to prevent or manage health risk. Substantive evidence also confirms that liver fat (LF) is positively associated with increased health risk and that reduction is associated with an improved metabolic profile. The independent associations between reductions in VAT, LF, and cardiometabolic risk is less clear. In this narrative review, we summarize the evidence indicating whether a negative energy balance induced by either an increase in energy expenditure (aerobic exercise) or a decrease in energy intake (hypocaloric diet) are effective strategies for reducing both VAT and LF. Consideration will be given to whether a dose-response relationship exists between the negative energy balance induced by exercise or diet and reduction in either VAT or LF. We conclude with recommendations that will help fill gaps in knowledge with respect to lifestyle-based strategies designed to reduce VAT and LF.

Abdominal wall morphometric variability based on computed tomography: Influence of age, gender, and body mass index

INTRODUCTION

Ventral hernia surgery does not usually account for the individuality of the abdominal wall anatomy. This could be both because medical imaging is rarely performed before surgery and because data on abdominal wall variability are limited. The objective of the present study was to perform an exhaustive morphometric analysis of abdominal wall components based on computed tomography (CT) scans.

MATERIALS AND METHODS

A retrospective study was performed on 120 abdominopelvic CT scans of clinically normal adults aged 18-86 years equally divided between women and men and into four age groups. Each abdominal wall muscle was evaluated in terms of area, thickness, shape ratio, fat infiltration, and aponeuroses width. The influence of age, gender, and body mass index (BMI) was investigated, as well as muscular asymmetry.

RESULTS

The abdominal wall muscle area represented 8.5 ± 2.5% of the abdominal area. The internal oblique muscle had the largest area, the rectus abdominis was the thickest, the transversus abdominis was the narrowest and had the smallest area. The width of the linea alba was 20.3 ± 12.0 mm. The evolution of the abdominal wall with age was quantified, as well as the large differences between the sexes and BMI groups, resulting in strong correlations and highlighting the specific pattern of the transversus abdominis. The asymmetry of the left and right muscle areas oscillated around 17%.

CONCLUSIONS

The various components of the abdominal wall have been precisely described. Knowledge of their variability could be used to enhance the planning of ventral hernia surgery or to develop numerical modeling of the abdominal wall.

Measurement of Visceral Adipose Tissue in Persons With Spinal Cord Injury by Magnetic Resonance Imaging and Dual X-Ray Absorptiometry: Generation and Application of a Predictive Equation

PURPOSE

Dual energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) permits quantification of visceral adipose tissue (VAT). However, DXA has not been validated against MRI in persons with chronic spinal cord injury (SCI). A predictive equation was generated from the measurement of VAT by MRI, a "gold" standard to quantitate VAT, compared to that of DXA, a method with several practical advantages.

METHOD

DXA and MRI scans were performed in 27 participants with SCI. MRI multiaxial images were captured for VAT analysis. DXA-VAT was quantified at the android region (DXA-VAT_ANDROID-VOL) using enCore software. Android regions of DXA and MRI were matched using android height. Volumes of multiaxial MRI-VAT and subcutaneous adipose tissue (SAT) were quantified for the android region (MRI-VAT_ANDROID-VOL, MRI-SAT_ANDROID-VOL) and total trunk (MRI-VAT_ANDROID-VOL). Linear regression analysis was used to establish the proposed predication equations. The prediction equations were then applied to an independent sample that consisted of 98 participants with SCI. Bland-Altman analysis was used to determine the limits of agreement.

RESULTS

DXA-VAT_ANDROID-VOL predicted 92% of the variance in MRI-VAT_ANDROID-VOL (SEE = 252.5, p < 0.0005) and 85% of the variance in MRI-VAT_TRUNK-VOL (SEE = 1526.9, p < 0.0005). DXA-SAT_ANDROID-VOL predicted 81.5% of the variance in MRI-SAT_ANDROID-VOL (SEE = 458.2, p < 0.0005). Bland-Altman analysis revealed a high level of agreement between MRI-VAT_ANDROID-VOL and DXA-VAT_ANDROID-VOL (mean bias = 58.45 cm³). A predicted mean DXA-VAT_ANDROID-VOL of 995.2 cm³ was estimated as the population-specific cut-off point for high levels of VAT.

CONCLUSION

DXA-VAT_ANDROID-VOL may accurately predict MRI-VAT_ANDROID-VOL in persons with SCI. The ability of DXA to detect VAT changes in longitudinal studies in persons with SCI should be performed.

Reproducibility of semiautomated body composition segmentation of abdominal computed tomography: a multiobserver study

Background

Segmentation of computed tomography (CT) images provides quantitative data on body tissue composition, which may greatly impact the development and progression of diseases such as type 2 diabetes mellitus and cancer. We aimed to evaluate the inter- and intraobserver variation of semiautomated segmentation, to assess whether multiple observers may interchangeably perform this task.

Methods

Anonymised, unenhanced, single mid-abdominal CT images were acquired from 132 subjects from two previous studies. Semiautomated segmentation was performed using a proprietary software package. Abdominal muscle compartment (AMC), inter- and intramuscular adipose tissue (IMAT), visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were identified according to pre-established attenuation ranges. The segmentation was performed by four observers: an oncology resident with extensive training and three radiographers with a 2-week training programme. To assess interobserver variation, segmentation of each CT image was performed individually by two or more observers. To assess intraobserver variation, three of the observers did repeated segmentations of the images. The distribution of variation between subjects, observers and random noise was estimated by a mixed effects model. Inter- and intraobserver correlation was assessed by intraclass correlation coefficient (ICC).

Results

For all four tissue compartments, the observer variations were far lower than random noise by factors ranging from 1.6 to 3.6 and those between subjects by factors ranging from 7.3 to 186.1. All interobserver ICC was ≥ 0.938, and all intraobserver ICC was ≥ 0.996.

Conclusions

Body composition segmentation showed a very low level of operator dependability. Multiple observers may interchangeably perform this task with highly reproducible results.

Electronic supplementary material

The online version of this article (10.1186/s41747-019-0122-5) contains supplementary material, which is available to authorized users.

Sarcopenic obesity derived from PET/CT predicts mortality in lymphoma patients undergoing hematopoietic stem cell transplantation

BACKGROUND

Sarcopenic Obesity (SO) is associated with worse survival among chemotherapy recipients. Research on SO is scarce among lymphoma patients receiving Hematopoietic Stem Cell Transplantation (HSCT).

AIM

assess prevalence of SO pre-HSCT (T0) and 3 months post-HSCT (T1) in lymphoma patients and determine the power of SO at T0 and T1 in predicting survival.

METHODS

Consecutive patients (age ≥16 years) having B and T cell lymphoma who underwent SCT and who had PET/CT scan pre-SCT and 3 months post SCT were included in the study. A cross sectional image was analyzed at the level of the 3rd Lumber Vertebrae to assess body composition parameters.

RESULTS

93 patients [mean age: 38 (range: 17-70 years), 52 (55.9%) males, 45 (48%) Hodgkin and 48 (52%) Non-Hodgkin lymphoma, 81 (87%) autologous and 12 (13%) allogeneic SCT)] met the inclusion criteria. From T0 to T1, Sarcopenia rates increased (27% at T0 to 38% at T1, p = 0.013), Visceral adiposity decreased (46% at T0 to 30% at T1, p = 0.03) and SO decreased (42% at T0 to 20% at T1, p < 0.01). Length of stay, overall survival and progression free survival were significantly better in patients without sarcopenic obesity at T1. Cox-regression revealed SO at T1 was a risk factor for mortality [Adjusted Hazards Ratio = 8.2 (95% Confidence Interval: 1.9-36.2)].

CONCLUSION

Sarcopenic obesity, prevalent in 42% of patients pre-HSCT, decreased 3 months post HSCT as lymphoma patients lost skeletal muscle and visceral adipose tissues. SO at T1 was the most impactful risk factor for mortality.

Novel Body Shape Descriptors for Abdominal Adiposity Prediction Using Magnetic Resonance Images and Stereovision Body Images

OBJECTIVE

The purpose of this study was to design novel shape descriptors based on three-dimensional (3D) body images and to use these parameters to establish prediction models for abdominal adiposity.

METHODS

Sixty-six men and fifty-five women were recruited for abdominal magnetic resonance imaging (MRI) and 3D whole-body imaging. Volumes of abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured from MRI sequences by using a fully automated algorithm. The shape descriptors were measured on the 3D body images by using the software developed in this study. Multiple regression analysis was employed on the training data set (70% of the total participants) to develop predictive models for VAT and SAT, with potential predictors selected from age, BMI, and the body shape descriptors. The validation data set (30%) was used for the validation of the predictive models.

RESULTS

Thirteen body shape descriptors exhibited high correlations (P < 0.01) with abdominal adiposity. The optimal predictive equations for VAT and SAT were determined separately for men and women.

CONCLUSIONS

Novel body shape descriptors defined on 3D body images can effectively predict abdominal adiposity quantified by MRI.

Anthropometric dimensions provide reliable estimates of abdominal adiposity: A validation study

Abdominal fat accumulation is a major risk factor for cardiometabolic morbidity and mortality. The purpose of the study is to assess the possibility of developing accurate estimation equations based on body measurements to determine total abdominal (TFA), subcutaneous (SFA) and visceral fat area (VFA). Hungarian volunteers (n=198) aged between 20 and 81 years were enrolled in the study, which was conducted between July and November 2014. All persons underwent anthropometric measurements and computer tomographic (CT) scanning. Sex-specific multiple linear regression analyses were conducted in a subgroup of 98 participants to generate estimation models, then Bland-Altman's analyses were applied in the cross-validation group to compare their predictive efficiency. The variables best predicting VFA were hip circumference, calf circumference and waist-to-hip ratio (WHR) for males (R²=0.713; SEE=5602.1mm²) and sagittal abdominal diameter (SAD), WHR, thigh circumference and triceps skinfold for females (R²=0.845; SEE=3835.6mm²). The SFA prediction equation included SAD, thigh circumference and abdominal skinfold for males (R²=0.848; SEE=4124.1mm²), body mass index and thigh circumference for females (R²=0.861; SEE=5049.7mm²). Prediction accuracy was the highest in the case of TFA: hip circumference and WHR for males (R²=0.910; SEE=5637.2mm²), SAD, thigh circumference and abdominal skinfold for females (R²=0.915; SEE=6197.5mm²) were used in the equations. The results suggested that deviations in the predictions were independent of the amount of adipose tissue. Estimation of abdominal fat depots based on anthropometric traits could provide a cheap, reliable method in epidemiologic research and public health screening to evaluate the risk of cardiometabolic events.

Body composition measurement using computed tomography: Does the phase of the scan matter?

OBJECTIVES

The aim of this study was to determine, from the methodologic standpoint, the effect of the presence or absence of intravenous contrast on body composition variables obtained by analysis of computed tomography (CT) images.

METHODS

Triphasic abdominal (noncontrast, arterial phase, and portovenous phase contrast) CT scans from 111 patients were analyzed by two independent assessors at the third lumbar vertebral level using SliceOmatic software (version 5.0, TomoVision, Montreal, Canada). Variables included skeletal muscle index (SMI), fat and fat-free mass (FM and FFM, respectively), and mean skeletal muscle Hounsfield units (SMHU).

RESULTS

Mean SMHU was lowest in the noncontrast phase (29.4, standard deviation [SD] 8.9 HU), followed by arterial (32.4, SD 9.3 HU) then portovenous phases (34.9, SD 9.4 HU). The mean skeletal muscle attenuation was significantly different depending on the phase of the scan in which the images were obtained. Calculated FM was significantly lower in both arterial (28.6, SD 8.8 kg, P < 0.0001) and portovenous phase scans (28.5, SD 8.9 kg, P < 0.0001) when compared with noncontrast (29.2, SD 8.9 kg). The mean FFM was not significantly different as measured on noncontrast, arterial, or portovenous phase CT scans (48, SD 11.2; 48.1, SD 9.8; and 48.6, SD 10.2 kg, respectively). No difference was seen in SMI. Interobserver reliability was high.

CONCLUSIONS

The definition of myosteatosis should include a standardized phase of CT for analysis and this should be incorporated within its definition. However, as the magnitudes of the differences were relatively small, the effect of the phase of the scan on predicting outcome needs to be determined.

Automated quantification of abdominal adiposity by magnetic resonance imaging

OBJECTIVES

To develop a fully-automated algorithm to process axial magnetic resonance imaging (MRI) slices for quantifying abdominal visceral, subcutaneous and total adipose tissues, i.e., VAT, SAT, and TAT, without human intervention or prior knowledge.

MATERIALS AND METHODS

Fat regions in single MRI slice or sequence (20 slices) were identified with image processing techniques including region-growing, inhomogeneity correction, fuzzy c-means clustering, and active contours segmentation. The MR images of 85 subjects (60 males and 25 females), whose body mass index (BMI) values ranged from 19.96 to 40.35 kg/m2 , were analyzed using the fully-automated algorithm-the automatic method developed in the research and the widely used semi-automated software (sliceOmatic® Tomovision, Inc.)-the reference method.

RESULTS

The proposed automated method showed good performance against the reference method to quantify adipose tissues in both single umbilical slice and MRI sequence. The square of the Pearson correlation coefficients (R2 ) based on the results generated from the two methods for VAT/SAT/TAT were 0.977/0.998/0.997 for single slice data and 0.995/0.999/0.999 for volumetric data. The intra-class correlation of visceral adipose tissue (VAT) between the three operators was 0.939 in the reference method, which was improved to 0.999 in the automatic method. The adipose tissue measurements in the slice at Lumbar 3 vertebra have the highest correlation with the total fat volumes across the entire abdomen.

CONCLUSION

The fully-automated algorithm presented in the paper provides an accurate and reliable assessment of abdominal fat without human intervention. Am. J. Hum. Biol. 28:757-766, 2016. © 2016Wiley Periodicals, Inc.

Does exercise training affect resting metabolic rate in adolescents with obesity?

We evaluated the hypothesis that resistance exercise training performed alone or in combination with aerobic exercise training would increase resting metabolic rate (RMR) relative to aerobic-only and nonexercising control groups. Postpubertal adolescents (N = 304) aged 14-18 years with obesity (body mass index (BMI) ≥ 95th percentile) or overweight (BMI ≥ 85th percentile + additional diabetes risk factor(s)) were randomized to 4 groups for 22 weeks: Aerobic exercise training, Resistance exercise training, Combined aerobic and resistance exercise training, or Control. All participants received dietary counselling targeting a daily energy deficit of 250 kcal. RMR was measured by indirect calorimetry and body composition by magnetic resonance imaging. There was no significant change in RMR in any group, in spite of significant within-group increases in fat-free mass in the Aerobic, Resistance, and Combined exercise training groups. RMR at baseline and 6 months were Aerobic: 1972 ± 38 and 1990 ± 41; Resistance: 2024 ± 37 and 1992 ± 41; Combined: 2023 ± 38 and 1995 ± 38; Control: 2075 ± 38 and 2073 ± 39 kcal/day (p > 0.05). There were no between-group differences in RMR after adjustment for total body weight or fat-free mass between groups over time. Per-protocol analyses including only participants with ≥70% adherence, and analyses stratified by sex, also showed no within- or between-group differences in RMR. In conclusion, despite an increase in fat-free mass in all exercise groups, 6 months of aerobic, resistance, or combined training with modest dietary restriction did not increase RMR compared with diet only in adolescents with obesity.

Prepubertal children exposed to concentrated disadvantage: An exploratory analysis of inflammation and metabolic dysfunction

OBJECTIVE

It is unclear whether physiologic and metabolic biomarkers are associated with chronic stressors evidenced during early childhood.

METHODS

Cross-sectional data were obtained from a cohort of healthy, prepubertal (Tanner stage < 2) children (n = 96; age: 8.06 [7.8] years; M = 51 [53%]; F = 45 [47%]; African-American = 26 [27%]; Caucasian = 70 [73%]; with obesity = 21 [22%]; without obesity = 75 [78%]) from the MET study. Body mass index z-score (z_BMI), total body fat (BF), visceral adipose tissue (VAT), intrahepatic and intramyocellular lipids, and insulin resistance (HOMA-IR) were measured. Chronic stress was assessed using neighborhood concentrated disadvantage index (CDI) for the U.S. Census tracts in which participants resided. Spearman's rank correlations were used to examine relationships, accounting for sex and race.

RESULTS

CDI was not positively associated with inflammatory and metabolic markers of dysfunction. However, z_BMI (-0.234, P = 0.023), BF (-0.228, P = 0.028, n = 95), and VAT (-0.241, P = 0.042, n = 74) were significantly negatively associated with CDI. When stratifying by race, these relationships remained significant in Caucasian children only.

CONCLUSIONS

These findings suggest chronic stress during early childhood is not associated with inflammatory and metabolic biomarkers, typically observed in adults. Therefore, exposure to stress during this critical developmental period may remain latent and emerge during a later developmental stage.

Increased Abdominal Adiposity in Adolescents and Young Adults With Classical Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency

CONTEXT

Childhood obesity rates in congenital adrenal hyperplasia (CAH) exceed the high rates seen in normal children, potentially increasing their risk of cardiovascular disease (CVD). Abdominal adiposity, in particular visceral adipose tissue (VAT), is strongly associated with metabolic syndrome and CVD. However, it remains unknown whether VAT is increased in CAH.

OBJECTIVE

The objective of the study was to determine whether adolescents and young adults with classical CAH have more VAT and sc adipose tissue (SAT) than matched controls and whether VAT and SAT are associated with biomarkers of metabolic syndrome, inflammation, and hyperandrogenism in CAH.

DESIGN/SETTING

This was a cross-sectional study at a tertiary center.

PARTICIPANTS

CAH subjects (n = 28; 15.6 ± 3.2 y; 15 females) were matched for age, sex, ethnicity, and body mass index to healthy controls (n = 28; 16.7 ± 2.3 y; 15 females).

MAIN OUTCOME MEASURES

VAT and SAT, using computed tomography imaging and serum biomarkers associated with CVD risk, were measured. Data are reported as mean ± SD.

RESULTS

Both VAT (43.8 ± 45.5 cm(2)) and SAT (288.1 ± 206.5 cm(2)) were higher in CAH subjects than controls (VAT 26.4 ± 29.6 cm(2) and SAT 226.3 ± 157.5 cm(2); both P < .001). The VAT to SAT ratio was also higher in CAH subjects (0.15 ± 0.07) than controls (0.12 ± 0.06; P < .05). Within CAH, measures of obesity (waist to height ratio, fat mass) and inflammation (plasminogen activator inhibitor-1, high-sensitivity C-reactive protein, leptin) correlated strongly with VAT and SAT. In addition, homeostasis model assessment of insulin resistance, and low-density lipoprotein correlated with abdominal adiposity. There were no sex differences for VAT or SAT in CAH subjects.

CONCLUSIONS

CAH adolescents and young adults have increased abdominal adiposity, with a higher proportion of proinflammatory VAT than SAT. An improved understanding of the mechanism of obesity in CAH may lead to targeted prevention and therapeutics in this high-risk population.

Effects of aerobic and resistance training on abdominal fat, apolipoproteins and high-sensitivity C-reactive protein in adolescents with obesity: the HEARTY randomized clinical trial

OBJECTIVES

To investigate the effects of aerobic training, resistance training, or both on abdominal subcutaneous fat (subcutaneous adipose tissue (SAT)) (deep and superficial), visceral fat (visceral adipose tissue (VAT)), apolipoproteins A-1 and B (ApoA-1, ApoB), ApoB/ApoA-1 ratio and high-sensitivity C-reactive protein (HSCRP) in post-pubertal adolescents with obesity.

PARTICIPANTS

After a 4-week supervised moderate-intensity exercise run-in period, 304 postpubertal adolescents with overweight (body mass index (BMI) ⩾85th percentile for age and sex+diabetes risk factor) or obesity (⩾95th BMI percentile) aged 14-18 years were randomized to four groups for 22 weeks (5 months): aerobic training, resistance training, combined training or a non-exercising control.

METHODS

This study used a randomized controlled design. All groups received dietary counseling designed to promote healthy eating with a maximum daily energy deficit of 250 kcal. Abdominal fat (SAT and VAT) at the level of the fourth and fifth lumbar vertebrae (L4-L5) was measured by magnetic resonance imaging and ApoA-1, ApoB and HSCRP were measured after a 12-h fast at baseline and after 6 months.

RESULTS

Changes in SAT at L4-L5 were -16.2 cm(2) in aerobic (P=0.04 vs control), -22.7 cm(2) in resistance (P=0.009 vs control) and -18.7 cm(2) in combined (P=0.02 vs control). Combined training reduced ApoB levels from 0.81±0.02 to 0.78±0.02 g l(-1) (P=0.04 vs control) and ApoB/ApoA-1 ratio from 0.67±0.02 to 0.64±0.02 (P=0.02 vs control and P=0.04 vs aerobic). There were no significant differences in VAT, ApoA-1 or HSCRP levels between groups.

CONCLUSIONS

Aerobic and resistance training and their combination decreased abdominal SAT in adolescents with obesity. Combined training caused greater improvements in ApoB/ApoA-1 ratio compared with aerobic training alone.

Comparison of HOMA-IR, HOMA-β% and disposition index between US white men and Japanese men in Japan: the ERA JUMP study

AIMS/HYPOTHESIS

At the same level of BMI, white people have less visceral adipose tissue (VAT) and are less susceptible to developing type 2 diabetes than Japanese people. No previous population-based studies have compared insulin resistance and insulin secretion between these two races in a standardised manner that accounts for VAT. We compared HOMA-IR, HOMA of beta cell function (HOMA-β%) and disposition index (DI) in US white men and Japanese men in Japan.

METHODS

We conducted a population-based, cross-sectional study, comprising 298 white men and 294 Japanese men aged 40-49 years without diabetes. Insulin, glucose, VAT and other measurements were performed at the University of Pittsburgh. We used ANCOVA to compare geometric means of HOMA-IR, HOMA-β% and DI, adjusting for VAT and other covariates.

RESULTS

White men had higher HOMA-IR, HOMA-β% and DI than Japanese men, and the difference remained significant (p < 0.01) after adjusting for VAT (geometric mean [95% CI]): 3.1 (2.9, 3.2) vs 2.5 (2.4, 2.6), 130.8 (124.6, 137.3) vs 86.7 (82.5, 91.0), and 42.4 (41.0, 44.0) vs 34.8 (33.6, 36.0), respectively. Moreover, HOMA-IR, HOMA-β% and DI were significantly higher in white men even after further adjustment for BMI, impaired fasting glucose and other risk factors.

CONCLUSIONS/INTERPRETATION

The higher VAT-adjusted DI in white men than Japanese men may partly explain lower susceptibility of white people than Japanese people to developing type 2 diabetes. The results, however, should be interpreted with caution because the assessment of insulin indices was made using fasting samples and adjustment was not made for baseline glucose tolerance. Further studies using formal methods to evaluate insulin indices are warranted.

Relationship of circulating adipokines to body composition in pregnant women

Circulating adipokines are associated with physiological and pathophysiological processes in both obesity and pregnancy. Obesity in pregnancy increases the risk of pregnancy complications and the majority of research uses body mass index (BMI) to assess fatness. Specific fat compartments are associated with obesity-induced health risks yet it is not known how abdominal fat mass in pregnancy is related to circulating adipokines. Plasma leptin, resistin, visfatin, and adiponectin were measured by immunoassay in healthy pregnant women of normal weight (BMI 18.5-24.9; n = 17) and overweight/obese pregnant women (BMI 25.0-40, n = 21) in the third trimester. Total body and abdominal subcutaneous and visceral fat mass were measured at 1-3 weeks postpartum. Overweight/obese women had greater total body fat (t = -6.210, P < 0.001) and abdominal subcutaneous fat (t = -5.072, P < 0.001) than normal-weight women while there was no difference in abdominal visceral fat. Overweight/obese women had higher leptin (66.3 ± 34.2 vs. 35.7 ± 19.3 ng/mL, P < 0.001) compared to normal-weight women. Leptin was associated with total body fat (r = 0.782, P < 0.001) and resistin was associated with abdominal visceral fat (r = 0.452, P = 0.045). No significant correlations were observed between adiponectin or visfatin and any measure of body composition. In pregnant women, resistin has the potential to be a circulating biomarker for visceral fat, an ectopic fat compartment. These observational data may provide insight for the pathophysiological roles of adipokines and the impact of visceral fat in pregnant women.

Reproducibility and validity of ultrasound for the measurement of visceral and subcutaneous adipose tissues

BACKGROUND

Ultrasound represents a low-cost and widely available field method for assessing visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) but its measurement properties are uncertain. The aim of the current study was to examine the reproducibility and validity of ultrasound to quantify abdominal fat compartments.

METHODS

In two study centers, VAT and SAT thicknesses were quantified by ultrasound two times by two observers each among 127 adults aged 20-70 years. In a separate sample of 30 adults, the ultrasound method was validated by comparing VAT and SAT thicknesses with VAT and SAT areas at vertebrae L2/L3 as obtained by a single magnetic resonance imaging (MRI) slice.

RESULTS

For VAT, the intra-rater reproducibility values for observers 1 and 2 were r=0.996 (95% CI=0.994-0.997) and r=0.999 (95% CI=0.999-0.999), respectively. For SAT, the intra-rater reproducibility values were r=0.992 (95% CI=0.989-0.994) and r=0.993 (95% CI=0.990-0.995), respectively. The inter-rater reproducibility values for VAT and SAT were r=0.998 (95% CI=0.997-0.999) and r=0.990 (95% CI=0.986-0.993), respectively. For VAT and SAT, the correlation coefficients between ultrasound and MRI measurements were r=0.898 (P<0.001) and r=0.705 (P<0.001), respectively.

CONCLUSION

Ultrasound provides reproducible and valid estimates of VAT and SAT and represents a useful method to assess abdominal fat in large scale epidemiologic studies.

Persistent apparent pancreatic β-cell defects in premenarchal PCOS relatives

CONTEXT

Polycystic ovary syndrome confers an increased risk for type 2 diabetes in affected women as early as adolescence. First-degree relatives (FDRs) of affected women are at increased risk for associated reproductive and metabolic phenotypes.

OBJECTIVE

We sought to prospectively assess insulin sensitivity and secretion and to measure reproductive hormone levels using sensitive techniques.

DESIGN, SETTING, AND PARTICIPANTS

Twelve premenarchal FDR girls and 10 control girls of comparable age, Tanner stage, and body mass index were studied at an academic medical center.

INTERVENTIONS

Frequently sampled intravenous glucose tolerance tests and oral glucose tolerance tests were performed.

MAIN OUTCOME MEASURES

Reproductive hormone levels, lipid profiles, glucose tolerance, and frequently sampled iv glucose tolerance test parameters of insulin sensitivity and secretion were investigated.

RESULTS

Disposition index (DI), insulin secretion corrected for insulin sensitivity, was decreased in FDR compared with control girls at baseline (P = .01), independent of dysglycemia. Decreases in DI persisted in FDR girls during the 2-year follow-up (P = .003). T levels were increased (P = .02) in FDR compared with control girls at baseline, but this difference did not persist because T levels increased in control girls.

CONCLUSIONS

DI is decreased in peripubertal FDR girls, and this decrease persists as puberty progresses. These findings suggest that β-cell dysfunction is an early defect in glucose homeostasis preceding decompensation in glucose tolerance in FDR girls. T levels were increased in FDR girls earlier than previously reported, but these changes did not persist, suggesting an earlier onset of pubertal increases in glandular androgen secretion in FDR girls.

Ectopic cardiovascular fat in middle-aged men: effects of race/ethnicity, overall and central adiposity. The ERA JUMP study

BACKGROUND/OBJECTIVES

Higher volumes of ectopic cardiovascular fat (ECF) are associated with greater risk of coronary heart disease (CHD). Identifying factors that are associated with ECF volumes may lead to new preventive efforts to reduce risk of CHD. Significant racial/ethnic differences exist for overall and central adiposity measures, which are known to be associated with ECF volumes. Whether racial/ethnic differences also exist for ECF volumes and their associations with these adiposity measures remain unclear.

SUBJECTS/METHODS

Body mass index (BMI), computerized tomography-measured ECF volumes (epicardial, pericardial and their summation) and visceral adipose tissue (VAT) were examined in a community-based sample of 1199 middle-aged men (24.2% Caucasians, 7.0% African-Americans, 23.6% Japanese-Americans, 22.0% Japanese, 23.2% Koreans).

RESULTS

Significant racial/ethnic differences existed in ECF volumes and their relationships with BMI and VAT. ECF volumes were the highest among Japanese-Americans and the lowest among African-Americans. The associations of BMI and VAT with ECF differed by racial/ethnic groups. Compared with Caucasians, for each 1-unit increase in BMI, African-Americans had lower, whereas Koreans had higher increases in ECF volumes (P-values<0.05 for both). Meanwhile, compared with Caucasians, for each 1-unit increase in log-transformed VAT, African-Americans, Japanese-Americans and Japanese had similar increases, whereas Koreans had a lower increase in ECF volumes (P-value<0.05).

CONCLUSIONS

Racial/ethnic groups differed in their propensity to accumulate ECF at increasing level of overall and central adiposity. Future studies should evaluate whether reducing central adiposity or overall weight will decrease ECF volumes more in certain racial/ethnic groups. Evaluating these questions might help in designing race-specific prevention strategy of CHD risk associated with higher ECF.

Abdominal adipose tissue distribution on MRI and diabetes

RATIONALE AND OBJECTIVES

To introduce a simple magnetic resonance imaging (MRI) protocol for quantitative assessment of intraperitoneal, retroperitoneal, and subcutaneous adipose tissue (AT) and to compare AT distribution between diabetic and nondiabetic individuals.

MATERIALS AND METHODS

Thirty-eight consecutive male diabetic patients (group A) and 38 males (who matched for body mass index [BMI]) without metabolic syndrome (group B) underwent abdominal MRI with a three-dimensional spoiled gradient echo T1-weighted sequence. The amounts of intraperitoneal, retroperitoneal, and subcutaneous AT were calculated on a workstation, after manual anatomic segmentation and were correlated with 10 anthropometric measurements. Pearson product-moment correlation coefficients were used for correlation of AT volumes with anthropometric measurements, Wilcoxon test to compare AT measurements between automatic and manual technique used, and unpaired t test to compare volumes of AT compartments between group A and B.

RESULTS

Diabetic patients exhibited larger amount of intraperitoneal and retroperitoneal AT than normal individuals at all levels (t = 2.02,P < .05). Among anthropometric measurements, the waist circumference, BMI, and body fat percentage exhibited the best correlations with intraperitoneal and retroperitoneal AT (group A (r) = 0.88/0.78/0.0.69 and group B (r) = 0.91/0.87/0.81). The L2-L5 set of images was found to be the most representative of the amount of AT volumes.

CONCLUSIONS

Amount and distribution of AT can be accurately and easily assessed on MRI. Quantification of intraabdominal AT may promote the role of imaging in the study of metabolic syndrome.

Changes in liraglutide-induced body composition are related to modifications in plasma cardiac natriuretic peptides levels in obese type 2 diabetic patients

Background and aims

Liraglutide treatment can improve glycemic control with a concomitant weight loss, but the underlying mechanism on weight loss is not completely understood. Cardiac natriuretic peptides (NPs) can resist body fat accumulation through increasing adipocytes lypolysis. In this study, we tested the hypothesis that liraglutide-induced weight loss was associated with increased plasma NPs concentrations.

Methods

Thirty-one outpatients with type 2 diabetes (T2D) treated with metformin and other oral antidiabetic drugs except for thiazolidinediones (TZDs) were subcutaneously administered with liraglutide for 12 weeks. Body composition, abdominal visceral adipose tissue areas (VAT) and subcutaneous adipose tissue areas (SAT) were assessed at pre- and post-treatment by dual-energy X-ray absorptiometry (DXA) scanning and abdominal computerized tomography (CT). Plasma atrial natriuretic peptides (ANP) and B-type ventricular natriuretic peptides (BNP) concentrations were tested by commercial ELISA Kit quantitatively.

Results

Following 12-week liraglutide treatment, body weight, waist circumference, total fat and lean mass, fat percentage, SAT and VAT areas were significantly reduced from baseline. Concurrently, plasma ANP and BNP levels were significantly increased following 12-week liraglutide treatment. There were significant correlations between the reductions in body compositions and the increases in both plasma ANP and BNP levels.

Conclusions

There were significant correlations between increases in both plasma ANP and BNP levels and changes in liraglutide-induced body composition. Our data implied that increases in plasma NPs may add a novel dimension to explain how liraglutide induces weight loss.

Validation of the measurement of intra-abdominal fat between ultrasound and CT scan in women with obesity and infertility

OBJECTIVE

To compare the means and changes over time of intra-abdominal fat (IAF) and subcutaneous abdominal fat (SAF) measured by abdominal ultrasound (US) and computerized tomography (CT).

DESIGN AND METHODS

Prospective cohort study of 53 women with obesity and infertility undergoing a lifestyle program.

RESULTS

The Pearson's correlation between IAF measurement by US compared to CT was good at baseline, month 3 and 6 (all r ≥ 0.72). The correlation of SAF measurement by US compared to CT was reasonable at baseline (r = 0.54; 95%CI 0.30-0.78) and weak at month 3 and 6 (all r ≤ 0.39). The correlation between the changes in IAF over 3 and 6 months by US compared to CT was reasonable and significant respectively (all r > 0.48). US could not measure the changes of SAF over time. The Bland-Altman plot showed good agreement between US and CT for IAF measurements (-1.1 [95%CI -3.9-1.6] cm lower mean in US) at baseline. For changes of IAF over time, mean estimates were in agreement.

CONCLUSION

In women with obesity and infertility, measuring IAF by US is in good agreement with the CT scan methodology but the measurement of SAF by US is unreliable.

Relationships between visceral adipose tissue measurement site and the metabolic syndrome in the Korean population

SUMMARY

OBJECTIVE

Visceral adipose tissue (VAT) is presumed to play an important role in the development of metabolic syndrome (MS). The purpose of this study was to evaluate the influence of measurement location of VAT on the cardiometabolic risk factors and the MS in the Korean population.

METHODS

To assess abdominal fat distribution, 5 single-slice computed tomography (CT) images were obtained in 470 healthy subjects. The five CT images were obtained at the intervertebral space from L1 to S1 using known anatomical landmarks. Multiple logistic regression analysis was performed to assess the relationship between regional adipose tissue areas and MS.

RESULTS

All risk factors were more closely correlated with VAT than subcutaneous adipose tissue (SAT), except waist circumference and blood pressure. Images located at L2-L3 or L3-L4 provided high correlations between VAT area and all cardiometabolic risk factors. The highest adjusted odds (per SD) between VAT and MS were the L2-L3 image in men (OR 4.53) and the L1-L2 in women (OR 4.87), which was higher than measures at L4-L5 (OR 3.22 in men, OR 4.71 in women). However, differences in OR between L1-L2 VAT (OR 4.87) and L4-L5 (OR 4.71) were not great in women.

CONCLUSIONS

The results of this study suggest that VAT has a stronger association with MS than ASAT in Korean population regardless of measurement site, and an image located in the upper abdomen (L2-L3 or L3-L4) would be a better predictor of the relationship between VAT and MS in Korean men.

Inverse correlation of serum inflammatory markers with metabolic parameters in healthy, Black and White prepubertal youth

OBJECTIVE

To examine for the first time the associations between pro-inflammatory cytokines and obesity-related metabolic biomarkers in, exclusively prepubertal, otherwise healthy obese and non-obese Black and White children, 7-9 years of age.

DESIGN AND METHODS

Body mass index (BMI), homeostasis model assessment-estimated insulin resistance, visceral adipose tissue and subcutaneous adipose tissue (SAT (magnetic resonance imaging)); total body fat (dual-energy X-ray absorptiometry), ectopic, intrahepatic lipid (IHL) and intramyocellular lipid (IMCL) fat (proton magnetic resonance spectroscopy) and serum levels of interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor alpha (TNF-α) and monocyte chemoattractant protein-1 were measured in 40 obese and non-obese children. Relationships between inflammatory cytokines and obesity were assessed by analysis of variance and Spearman's rank correlation.

RESULTS

Significant inverse correlations were found between BMI z-score, SAT, total BF, and IHL and levels of TNF-α (Spearman's ρ=-0.36, -0.39, -0.43 and -0.39, respectively; P<0.05). Levels of IL-8 were significantly and inversely correlated with IMCL (-0.39; P=0.03) and remained significant after adjusting for race. IMCL was inversely associated with TNF-α only after adjusting for race (-0.37; P=0.04).

CONCLUSIONS

Relationships between pro-inflammatory and metabolic markers commonly observed in adults are reversed in healthy, Black and White children before puberty. Prospective studies are warranted to determine how these inverse relationships modify chronic disease risk later in life.

Skeletal muscle predicts ventilator-free days, ICU-free days, and mortality in elderly ICU patients

INTRODUCTION

As the population ages, the number of injured elderly is increasing. We sought to determine if low skeletal muscle mass adversely affected outcome in elderly patients following trauma.

METHODS

Patients ≥ 65 years of age with an admission abdominal computed tomography scan and requiring intensive care unit (ICU) stay at a Level I trauma center in 2009-2010 were reviewed. Muscle cross-sectional area at the 3rd lumbar vertebra was quantified and muscle index, a normalized measure of muscle mass, was calculated and related to clinical parameters including ventilator-free days, ICU-free days, and mortality. Using previously established sex-specific, muscle index cut-points, patients were then categorized as sarcopenic or non-sarcopenic and differences in clinical outcomes between these two groups were also compared. We also examined muscle index as a continuous variable relative to the same clinical outcomes.

RESULTS

There were 149 severely injured elderly patients (median age 79 years) enrolled in this study of which 71% were sarcopenic. Of the patients who were sarcopenic, 9% were underweight, 44% normal weight, and 47% overweight/obese as per body mass index (BMI) classifications. The overall mortality rate was 27% and univariate analysis demonstrated higher mortality among those who were sarcopenic (32% vs. 14%, P = 0.018). After controlling for age, sex, and injury severity, multiple logistic regression demonstrated that increased muscle index was significantly associated with decreased mortality (OR per unit muscle index = 0.93, 95% CI: 0.875-0.997, P = 0.025). In addition, multivariate linear regression showed that sarcopenia, but not muscle index, was associated with decreased ventilator-free (P = 0.004) and ICU-free days (P = 0.002). Neither BMI, serum albumin nor total adipose tissue on admission were indicative of survival, ventilator-free or ICU-free days.

CONCLUSIONS

Sarcopenia is highly prevalent in the elderly population with traumatic injuries. Traditional measures of nutritional assessment, such as BMI and serum albumin, do not accurately predict outcome in the injured elderly. Sarcopenia, however, represents a potential new predictor for mortality, discharge disposition, and ICU utilization. Measurement of muscularity allows for the early identification of at-risk patients who may benefit from aggressive and multidisciplinary nutritional and rehabilitative strategies.

Measuring visceral and hepatic fat in clinical practice and clinical research

OBJECTIVE

To review how visceral and hepatic fat are measured in clinical practice and clinical research.

METHODS

We examine different methods employed to assess visceral and hepatic fat in the literature.

RESULTS

Fat in the human body is located in 2 main compartments: subcutaneous and visceral, which also includes liver fat. Visceral and liver fats are associated with the metabolic complications of obesity like hypertension, diabetes, and atherosclerosis. Therefore, there is a need to detect those fats early in life before the development of cardiometabolic syndrome (CMS). Many modalities have been proposed to measure visceral and liver fat. Indirect measurements can be done through waist circumference (WC), dual-energy X-ray absorptiometry (DEXA), ultrasound, and bioelectric impedance, whereas direct methods include computed tomography (CT) and magnetic resonance imaging (MRI). An ideal measurement method should be noninvasive, reliable, suitable for all body sizes, widely available, cost and time effective, show low variability, and have no or limited radiation exposure.

CONCLUSION

Measuring visceral and liver fat is not a straightforward procedure in clinical practice or research; several variables may affect measure accuracy and validity.

Ethnic difference in liver fat content: a cross-sectional observation among Japanese American in Hawaii, Japanese in Japan, and non-Hispanic whites in United States

BACKGROUND

We recently reported that Japanese had higher liver fat at a lower level of BMI compared with non-Hispanic whites (NHW).

OBJECTIVE

We hypothesize that ethnic difference in fat storage capacity contributes to this ethnic difference in liver fat.

DESIGN

To examine this, we assessed liver fat among 244 Japanese-American aged 40-49, using regional computed-tomography images, along with metabolic variables.

RESULTS

Despite the similar BMI between Japanese-Americans and NHW men, Japanese-Americans had more liver fat (liver to spleen attenuation ratio: 1.03 ± 0.22 for Japanese-Americans, and 1.07 ± 0.15 for NHW men; p < 0.05) and tended to have a greater disposition for fatty liver with an increase in BMI than NHW, indicating a clear difference between the two groups. In addition, liver fat is less in Japanese-Americans compared with Japanese men (1.03 ± 0.22 vs. 1.01 ± 0.16; p < 0.05), despite of a much higher BMI. These ethnic differences support the hypothesis that higher fat storage capacity indeed seems to be associated with less liver fat. In all the groups, liver fat content strongly correlated with triglycerides, homeostasis model assessment-insulin resistance, and C-reactive protein (CRP). Nevertheless, these metabolic variables were worse in Japanese-Americans, despite of less liver fat, compared with Japanese. Moreover, CRP levels were least among Japanese with highest liver fat, and highest among NHW men with least liver fat, despite of a strong positive association between CRP and fatty liver within each population.

CONCLUSIONS

Fat content in the liver is intermediate for Japanese-Americans compared with Japanese and NHW men, which supports the hypothesis of less fat storage capacity among Japanese, closely linked to ethnic difference in predisposition to fatty liver.

Pathophysiology of human visceral obesity: an update

Excess intra-abdominal adipose tissue accumulation, often termed visceral obesity, is part of a phenotype including dysfunctional subcutaneous adipose tissue expansion and ectopic triglyceride storage closely related to clustering cardiometabolic risk factors. Hypertriglyceridemia; increased free fatty acid availability; adipose tissue release of proinflammatory cytokines; liver insulin resistance and inflammation; increased liver VLDL synthesis and secretion; reduced clearance of triglyceride-rich lipoproteins; presence of small, dense LDL particles; and reduced HDL cholesterol levels are among the many metabolic alterations closely related to this condition. Age, gender, genetics, and ethnicity are broad etiological factors contributing to variation in visceral adipose tissue accumulation. Specific mechanisms responsible for proportionally increased visceral fat storage when facing positive energy balance and weight gain may involve sex hormones, local cortisol production in abdominal adipose tissues, endocannabinoids, growth hormone, and dietary fructose. Physiological characteristics of abdominal adipose tissues such as adipocyte size and number, lipolytic responsiveness, lipid storage capacity, and inflammatory cytokine production are significant correlates and even possible determinants of the increased cardiometabolic risk associated with visceral obesity. Thiazolidinediones, estrogen replacement in postmenopausal women, and testosterone replacement in androgen-deficient men have been shown to favorably modulate body fat distribution and cardiometabolic risk to various degrees. However, some of these therapies must now be considered in the context of their serious side effects. Lifestyle interventions leading to weight loss generally induce preferential mobilization of visceral fat. In clinical practice, measuring waist circumference in addition to the body mass index could be helpful for the identification and management of a subgroup of overweight or obese patients at high cardiometabolic risk.

The association between measurement sites of visceral adipose tissue and cardiovascular risk factors after caloric restriction in obese Korean women

Quantities as well as distributions of adipose tissue (AT) are significantly related to cardiovascular disease (CVD) risk factors and can be altered with caloric restriction. This study investigated which cross-sectional slice location of AT is most strongly correlated with changes in CVD risk factors after caloric restriction in obese Korean women. Thirty-three obese pre-menopausal Korean women (32.4 ± 8.5 yrs, BMI 27.1 ± 2.3 kg/m(2)) participated in a 12 weeks caloric restriction program. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured using computed tomography (CT) scans at the sites of L2-L3, L3-L4, and L4-L5. Fasting serum levels of glucose, insulin, triglyceride, total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), leptin and homeostasis model assessment-insulin resistance (HOMA-IR) were observed. Pearson's partial correlation coefficients were used to assess the relationship between AT measurement sites and changes in CVD risk factors after calorie restriction. When calories were reduced by 350 kcal/day for 12 weeks, body weight (-2.7%), body fat mass (-8.2%), and waist circumference (-5.8%) all decreased (P < 0.05). In addition, following caloric restriction, serum levels of glucose (-4.6%), TC (-6.2%), LDL-C (-5.3%), leptin (-17.6%) and HOMA-IR (-18.2%) decreased significantly (P < 0.05) as well. Changes in VAT at the level of L3-L4 were significantly greater than those at other abdominal sites, and these changes were correlated with changes in TC (P < 0.05), LDL-C (P < 0.001), SBP (P < 0.001) and HOMA-IR (P < 0.01). These results show that VAT at L3-L4 had a stronger correlation with CVD risk factors than with other AT measurement sites after caloric restriction.

VAT=TAAT-SAAT: innovative anthropometric model to predict visceral adipose tissue without resort to CT-Scan or DXA

OBJECTIVE

To investigate whether a combination of a selected but limited number of anthropometric measurements predicts visceral adipose tissue (VAT) better than other anthropometric measurements, without resort to medical imaging.

HYPOTHESIS

Abdominal anthropometric measurements are total abdominal adipose tissue indicators and global measures of VAT and SAAT (subcutaneous abdominal adipose tissue). Therefore, subtracting the anthropometric measurement the more correlated possible with SAAT while being the least correlated possible with VAT, from the most correlated abdominal anthropometric measurement with VAT while being highly correlated with TAAT, may better predict VAT.

DESIGN AND METHODS

BMI participants' range was from 16.3 to 52.9 kg m(-2) . Anthropometric and abdominal adipose tissues data by computed tomography (CT-Scan) were available in 253 patients (18-78 years) (CHU Nord, Marseille) and used to develop the anthropometric VAT prediction models.

RESULTS

Subtraction of proximal thigh circumference from waist circumference, adjusted to age and/or BMI, predicts better VAT (Women: VAT = 2.15 × Waist C - 3.63 × Proximal Thigh C + 1.46 × Age + 6.22 × BMI - 92.713; R(2) = 0.836. Men: VAT = 6 × Waist C - 4.41 × proximal thigh C + 1.19 × Age - 213.65; R(2) = 0.803) than the best single anthropometric measurement or the association of two anthropometric measurements highly correlated with VAT. Both multivariate models showed no collinearity problem. Selected models demonstrate high sensitivity (97.7% in women, 100% in men). Similar predictive abilities were observed in the validation sample (Women: R(2) = 76%; Men: R(2) = 70%). Bland and Altman method showed no systematic estimation error of VAT.

CONCLUSION

Validated in a large range of age and BMI, our results suggest the usefulness of the anthropometric selected models to predict VAT in Europides (South of France).

Best single-slice measurement site for estimating visceral adipose tissue volume after weight loss in obese, Japanese men

BACKGROUND

Although the measurement site at L4-L5 for visceral adipose tissue (VAT) has been commonly accepted, some researchers suggest that additional upper sites (i.e., L1-L2 and L2-L3) are useful for estimating VAT volume. Therefore, determining the optimum measurement site remains challenging and has become important in determining VAT volume. We investigated the influence of a single-slice measurement site on the prediction of VAT volume and changes in VAT volume in obese Japanese men.

METHODS

Twenty-four men, aged 30-65 years with a mean BMI of 30 kg/m2, were included in a 12-week weight loss program. We obtained continuous T1-weighted abdominal magnetic resonance images from T9 to S1 with a 1.5-T system to measure the VAT area. These VAT areas were then summed to determine VAT volume before and after the program.

RESULTS

Single-slice images at 3-11 cm above L4-L5 had significant and high correlations with VAT volume at baseline (r=0.94-0.97). The single-slice image with the highest correlation coefficient with respect to VAT volume was located at 5 cm above L4-L5 (r=0.97). The highest correlation coefficient between the individual changes in VAT area and changes in VAT volume was located at 6 cm above L4-L5 (r=0.90).

CONCLUSIONS

Individual measurement sites have different abilities to estimate VAT volume and changes in VAT volume in obese Japanese men. Best zone located at 5-6 cm above L4-L5 may be a better predictor of VAT volume than the L4-L5 image in terms of both baseline and changes with weight loss.

Nutcracker and SMA syndromes: What is the normal SMA angle in children?

OBJECTIVE

The nutcracker and superior mesenteric artery (SMA) syndromes are rare conditions where the left renal vein or duodenum may be compressed by an unusually acute angle between the SMA and aorta, although the normal angle in children is unknown. We measured the SMA angle to define the normal range in children.

METHODS

We retrospectively measured SMA angles, left renal vein (LRV) distance, and duodenal distance (DD) in 205 consecutive pediatric abdominal CT. Total and visceral intra-abdominal fat at the level of the umbilicus were also assessed.

RESULTS

Mean SMA angle was 45.6±19.6° (range 10.6-112.9°), mean LRV distance was 8.6±3.9mm (range 2.0-28.6mm) and mean DD was 11.3±4.8mm (range 3.6-35.3mm). There was a significant but weak correlation between %visceral fat volume (%VF) and SMA angle (R=0.30; p<0.001), LRV distance (R=0.37, p<0.001) and DD (R=0.32; p<0.001).

CONCLUSION

There is a wide range of SMA angle, LRV and DD in normal children, which correlated weakly with visceral fat volume. Using a definition of SMA angle <25° would diagnose 9.3% of asymptomatic children with nutcracker syndrome, and using a DD definition of <8mm would diagnose 20% with SMA compression. Our findings suggest exercising caution when attributing these rare syndromes to an absolute SMA angle.

Impaired insulin sensitivity and elevated ectopic fat in healthy obese vs. nonobese prepubertal children

Insulin sensitivity is impaired and ectopic fat (accretion of lipids outside of typical adipose tissue depots) increased in obese adults and adolescents. It is unknown how early in life this occurs; thus, it is important to evaluate young children to identify potential factors leading to the development of metabolic syndrome. We examined an ethnically diverse cohort of healthy, exclusively prepubertal children (N = 123; F = 57, M = 66; age 8.04 ± 0.77 years) to examine differences in insulin sensitivity and ectopic and visceral fat deposition between obese and nonobese youth. Obesity was categorized by age- and sex-adjusted BMI z-scores (nonobese = z-score <2 (N = 94) and obese = z-score ≥2 (N = 29)). Insulin sensitivity was assessed by both a frequently sampled intravenous glucose tolerance test (S(i)) and the homeostatic model assessment of insulin resistance (HOMA(IR)). Intramyocellular lipids (IMCLs) from soleus and intrahepatic lipids (IHLs) were assessed by magnetic resonance spectroscopy, visceral adipose tissue (VAT) by magnetic resonance imaging, and total body fat by dual-energy X-ray absorptiometry. We also examined serum lipids (total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol) and blood pressure (diastolic and systolic). Obese children exhibited significantly lower S(i) (5.9 ± 5.98 vs. 13.43 ± 8.18 (mµ/l)(-1)·min(-1), P = 0.01) and HDL-C and higher HOMA(IR) (1.68 ± 1.49 vs. 0.63 ± 0.47, P < 0.0001), IMCL (0.74 ± 0.39 vs. 0.44 ± 0.21% water peak, P < 0.0001), IHL (1.49 ± 1.13 vs. 0.54 ± 0.42% water peak, P < 0.0001), VAT (20.16 ± 8.01 vs. 10.62 ± 5.44 cm(2), P < 0.0001), total cholesterol, triglycerides, low-density lipoprotein cholesterol, and systolic blood pressure relative to nonobese children. These results confirm significantly increased ectopic fat and insulin resistance in healthy obese vs. nonobese children prior to puberty. Excessive adiposity during early development appears concomitant with precursors of type 2 diabetes and the metabolic syndrome.

Differential effect of gender on hepatic fat

BACKGROUND

There are discrepant data on whether men or women have a higher risk for hepatic steatosis.

OBJECTIVE

To examine the influence of gender on hepatic adiposity in teenagers and young adults.

MATERIALS AND METHODS

We measured subcutaneous abdominal fat (SAF), intra-abdominal fat (IAF) and hepatic tissue density (a surrogate measure of hepatic fat) using CT in 505 healthy teenagers and young adults (254 males, 251 females; ages 15-22.9 years).

RESULTS

Overall, compared to men, women had higher values of SAF (P < 0.0001) but similar measures of IAF and liver tissue density (P = 0.09 and 0.92, respectively). However, when compared to overweight/obese men, overweight/obese women had strikingly similar IAF values (P = 0.85) but lower hepatic fat (P = 0.009). Multiple regression analyses indicated that, after adjusting for age and SAF, IAF independently predicted hepatic density in males (P < 0.0001) but not in females (P = 0.36). Hepatic fat increased with body mass in males from lean to overweight and obese (P < 0.0001) but not in females (P > 0.05).

CONCLUSION

When compared to overweight and obese young women, overweight and obese young men are at greater risk for hepatic steatosis, independent of IAF.

Measurement site of visceral adipose tissue and prediction of metabolic syndrome in youth

OBJECTIVE

It is unknown whether measurement site of visceral adipose tissue (VAT) influences the relationship between VAT and associated health risk in youth and if so, whether ethnic differences exist in this relationship. We examined the influence of the measurement site of VAT on the relationships between VAT and metabolic syndrome (MetS) in African-American (AA) and American-White (AW) youth.

SUBJECTS

Healthy AA (n = 54) and AW (n = 54) children and adolescents (age: 8-18 yr; BMI: 15.3-42.5 kg/m(2)).

MEASUREMENTS

VAT mass was derived using a series of five transverse images measured by magnetic resonance imaging, extending from 5 cm below to 15 cm above L4-L5. MetS was defined using a modified IDF criteria.

RESULTS

In AA, VAT measure at 5 cm above L4-L5 (R(2) = 0.93) was most strongly (p < 0.05) correlated with VAT mass and was a significantly (p < 0.05) stronger correlate as compared to L4-L5 (R(2) = 0.84). In AW, VAT measures at 5 cm (R(2) = 0.93) and 10 cm (R(2) = 0.93) above L4-L5 were most strongly (p < 0.05) correlated with VAT mass; however, these were not stronger correlates as compared to L4-L5 (R(2) = 0.91). In AW, all VAT measures were significantly (p < 0.05) associated with an increased odds ratio (OR) for prevalent MetS, wherein the VAT mass [OR = 5.32(1.9-15.0)] and VAT at L4-L5[OR = 5.99(1.9-18.4)] were most strongly associated with MetS. In contrast, only VAT at 10 cm above L4-L5 [OR = 4.39 (1.1-18.1)] was significantly (p < 0.05) associated with MetS in AA.

CONCLUSION

In AA and AW youth, the measurement site for VAT has impact on the estimation of total VAT and the magnitude of the association with obesity-related health risks.

Effect of gender on intra-abdominal fat in teenagers and young adults

BACKGROUND

Adult men accumulate greater intra-abdominal fat (IAF) than adult women, a difference closely related to gender differences in cardiometabolic disease risk in the elderly. However, the time when this gender difference appears is a matter of controversy.

OBJECTIVE

We examine the influence of gender on IAF deposition in lean, overweight and obese teenagers and young adults.

MATERIALS AND METHODS

We measured subcutaneous abdominal fat (SAF) and IAF in 505 healthy sexually mature teenagers and young adults (254 males, 251 females; 15-22 years) using a single CT scan at the level of the umbilicus.

RESULTS

Regardless of body size, young females had greater SAF values than young males. Although lean females had higher IAF values than lean males (13.7 ± 7.8 vs. 11.2 ± 5.4; P = 0.001), overweight and obese females and males had strikingly similar IAF values (23.4 ± 11.1 vs. 23.1 ± 9.5; P = 0.88 and 36.5 ± 20.4 vs. 38.8 ± 13.2; P = 0.59, respectively). In contrast, the ratio of IAF/SAF was greater in males than females, except in the very obese. Multiple regression analysis indicated that while gender was a strong predictor of SAF in lean and overweight subjects (P's < 0.0001), it did not influence IAF after adjusting for height and weight (P = 0.35 and 0.65, respectively) in overweight and obese subjects.

CONCLUSION

Overweight and obese young women have similar absolute amounts of IAF as young men.

Influence of motor complete spinal cord injury on visceral and subcutaneous adipose tissue measured by multi-axial magnetic resonance imaging

OBJECTIVE

Abdominal obesity conveys substantial health risks, in association with high levels of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and an increased proportion of VAT to SAT. The purposes were to determine the influence of spinal cord injury (SCI) on the associations between single axial cross-sectional area (CSA) slices and the average CSA or volumes of VAT and SAT across multi-axial slices of magnetic resonance imaging (MRI); and the relationships relative to the whole body composition and anthropometrics.

METHODS

Thirteen healthy male participants with traumatic motor complete SCI underwent fast spin-echo MRI to measure VAT and SAT across multi-axial slices, followed by dual-energy X-ray absorptiometry to measure whole body fat-free mass (FFM) and fat mass (FM). Waist circumference (WC) was also measured in the seated position.

RESULTS

The trunk CSAs of VAT and SAT were 99 +/- 51 and 164 +/- 69 cm2, respectively, and the ratio of VAT to SAT was 0.68 +/- 0.33. The CSAs of VAT and SAT at a single slice strongly predicted the average CSA and modestly predicted the volumes across multi-axial slices. VAT and SAT represented 5.7 +/- 1.8% and 9.7 +/- 3.2% of the total body FM, respectively. Percent body FFM was negatively related to VAT and SAT volumes, but not to a single axial CSA.

CONCLUSION

A single slice CSA can modestly predict the volume of multi-axial slices in individuals with SCI, yet it is not related to any of the body composition variables. Increased percent FFM is associated with a reduction in VAT and SAT volumes measured across multi-axial slices. The ratio of VAT to SAT is greater than 0.4, suggesting that individuals with SCI are at high risk of developing metabolic sequelae.

Weight-loss diet alone or combined with resistance training induces different regional visceral fat changes in obese women

BACKGROUND

Quantification of abdominal fat and its regional distribution has become increasingly important in assessing the cardiovascular risk.

OBJECTIVE

To examine the effects of 16 weeks of a hypocaloric diet with a caloric restriction of 500 Kcal per day (WL) or the same dietary intervention plus resistance training (WL+RT) on regional variation of abdominal visceral (visceral adipose tissue (VAT)) and subcutaneous (subcutaneous adipose tissue (SAT)) fat loss. Second, to identify the single-image that best represents total magnetic resonance imaging measurements of total VAT and SAT volume before and after WL or WL+RT intervention.

DESIGN

A total of 34 obese (body mass index: 30-40 kg m(-2)) women, aged 40-60 years, were randomized to three groups: a control group (C; n = 9), a diet group (WL; n = 12) and a diet plus resistance training group (WL+RT; n = 13) with the same caloric restriction as group WL and a 16-week supervised whole-body RT of two sessions per week.

RESULTS

WL+RT programs lead to significant changes in the location of highest mean VAT area from L3-L4 to L2-L3 discal level from pre- to post- intervention, whereas after WL the greatest relative VAT losses were located at L5-S1. Similar decreases in the SAT areas at all discal levels were observed after WL and WL+RT.

CONCLUSION

Different weight loss regimes may lead to different distribution of VAT. Sites located significantly above (cranial to) L4-L5 (that is, ∼ 5-6 cm above L4-L5 or at L2-L3 discal level) provided superior prediction of total abdominal VAT volume, whereas more caudal slices provide better prediction of subcutaneous fat, not only before but also after either WL or WL+RT.