Correlation analysis of dynamic changes of abdominal fat during rapid weight loss after bariatric surgery: A prospective magnetic resonance imaging study.

OBJECTIVE: The factors related to the changes in the liver and abdominal adipose tissue during the rapid weight loss after bariatric surgery remain uncertain. METHODS: This study included 44 participants who had undergone sleeve gastrectomy. The study aimed to analyze changes and correlations of body weight (BW), laboratory tests, and magnetic resonance imaging (MRI) indicators of the liver and abdominal adipose tissue conducted before and after bariatric surgery at 1, 3, and 6 months. RESULTS: Following a rapid weight loss within 6 months of surgery, there was a concurrent decrease in blood glucose, blood lipids, and fat content of the liver and abdomen and the changes showed a correlation. The change of BW (ΔBW) was positively correlated with the change of hepatic proton density fat fraction (ΔPDFF) in one and three months after surgery and was positively correlated with the change of abdominal visceral fat area (ΔAVFA) in six months after surgery, (P<0.05). In one month after surgery, ΔPDFF was positively correlated with the change of aspartate aminotransferase (ΔAST), change of alanine aminotransferase (ΔALT), and change of triglyceride glucose (ΔTYG) index (P<0.05). ΔPDFF was positively correlated with the change of hepatic native T1 values (P<0.001) and was moderately negatively correlated with the change of hepatic apparent diffusion coefficient (ΔADC) values in three months after surgery (P<0.05). CONCLUSION: ΔBW can serve as an indirect indicator for evaluating changes in liver fat fraction at 1 and 3 months after bariatric surgery and indicative of changes in visceral fat 6 months after surgery. ΔPDFF was positively correlated with ΔAST, ΔALT and ΔTYG index in 1 months after surgery.

AATCT-IDS: A benchmark Abdominal Adipose Tissue CT Image Dataset for image denoising, semantic segmentation, and radiomics evaluation.

BACKGROUND AND OBJECTIVE: The metabolic syndrome induced by obesity is closely associated with cardiovascular disease, and the prevalence is increasing globally, year by year. Obesity is a risk marker for detecting this disease. However, current research on computer-aided detection of adipose distribution is hampered by the lack of open-source large abdominal adipose datasets. METHODS: In this study, a benchmark Abdominal Adipose Tissue CT Image Dataset (AATCT-IDS) containing 300 subjects is prepared and published. AATCT-IDS publics 13,732 raw CT slices, and the researchers individually annotate the subcutaneous and visceral adipose tissue regions of 3213 of those slices that have the same slice distance to validate denoising methods, train semantic segmentation models, and study radiomics. For different tasks, this paper compares and analyzes the performance of various methods on AATCT-IDS by combining the visualization results and evaluation data. Thus, verify the research potential of this data set in the above three types of tasks. RESULTS: In the comparative study of image denoising, algorithms using a smoothing strategy suppress mixed noise at the expense of image details and obtain better evaluation data. Methods such as BM3D preserve the original image structure better, although the evaluation data are slightly lower. The results show significant differences among them. In the comparative study of semantic segmentation of abdominal adipose tissue, the segmentation results of adipose tissue by each model show different structural characteristics. Among them, BiSeNet obtains segmentation results only slightly inferior to U-Net with the shortest training time and effectively separates small and isolated adipose tissue. In addition, the radiomics study based on AATCT-IDS reveals three adipose distributions in the subject population. CONCLUSION: AATCT-IDS contains the ground truth of adipose tissue regions in abdominal CT slices. This open-source dataset can attract researchers to explore the multi-dimensional characteristics of abdominal adipose tissue and thus help physicians and patients in clinical practice. AATCT-IDS is freely published for non-commercial purpose at: https://figshare.com/articles/dataset/AATTCT-IDS/23807256.

Distinct subpopulations of human subcutaneous adipose tissue precursor cells revealed by single-cell RNA sequencing.

Adipose-derived stem cells (ADSCs) play an important role in the differential capacity for excess energy storage between upper body abdominal (ABD) adipose tissue (AT) and lower body gluteofemoral (GF) AT. We cultured ADSCs from subcutaneous ABD AT and GF AT isolated from eight women with differential body fat distribution and performed single-cell RNA sequencing. Six populations of ADSCs were identified and segregated according to their anatomical origin. The three ADSC subpopulations in GF AT were characterized by strong cholesterol/fatty acid (FA) storage and proliferation signatures. The two ABD subpopulations, differentiated by higher expression of committed preadipocyte marker genes, were set apart by differential expression of extracellular matrix and ribosomal genes. The last population, identified in both depots, was similar to smooth muscle cells and when individually isolated and cultured in vitro they differentiated less than the other subpopulations. This work provides important insight into the use of ADSC as an in vitro model of adipogenesis and suggests that specific subpopulations of GF-ADSCs contribute to the more robust capacity for GF-AT to expand and grow compared with ABD-AT in women.NEW & NOTEWORTHY Identification of distinct subpopulations of adipose-derived stem cells (ADSCs) in upper body abdominal subcutaneous (ABD) and lower body gluteofemoral subcutaneous (GF) adipose tissue depots. In ABD-ADSCs, subpopulations are more committed to adipocyte lineage. GF-ADSC subpopulations are enriched for genes involved in lipids and cholesterol metabolism. Similar depot differences were found in stem cell population identified in freshly isolated stoma vascular fraction. The repertoire of ADSCs subpopulations was different in apple-shaped versus pear-shaped women.

DNA methylation promotes the expression of PPARγ transcript 1 at least in part by preventing NRF1 binding to the promoter P1 of chicken PPARγ gene.

Peroxisome proliferator-activated receptor gamma (PPARγ) is a master regulator of adipogenesis. Our previous study revealed that chicken PPARγ has 3 alternative promoters named as P1, P2, and P3, and the DNA methylation of promoter P3 was negatively associated with PPARγ mRNA expression in abdominal adipose tissue (AAT). However, the methylation status of promoters P1 and P2 is unclear. Here we assessed promoter P1 methylation status in AAT of Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF). The results showed that promoter P1 methylation differed in AAT between the lean and fat lines of NEAUHLF at 7 wk of age (p < 0.05), and AAT expression of PPARγ transcript 1 (PPARγ1), which was derived from the promoter P1, was greatly higher in fat line than in lean line at 2 and 7 wk of age. The results of the correlation analysis showed that P1 methylation was positively correlated with PPARγ1 expression at 7 wk of age (Pearson's r = 0.356, p = 0.0242), suggesting P1 methylation promotes PPARγ1 expression. To explore the underlying molecular mechanism of P1 methylation on PPARγ1 expression, bioinformatics analysis, dual-luciferase reporter assay, pyrosequencing, and electrophoresis mobility shift assay (EMSA) were performed. The results showed that transcription factor NRF1 repressed the promoter activity of the unmethylated P1, but not the methylated P1. Of all the 4 CpGs (CpG48, CpG49, CpG50, and CpG51), which reside within or nearby the NRF1 binding sites of the P1, only CpG49 methylation in AAT was remarkably higher in the fat line than in lean line at 7 wk of age (3.18 to 0.57, p < 0.05), and CpG49 methylation was positively correlated with PPARγ1 expression (Pearson's r = 0.3716, p = 0.0432). Furthermore, EMSA showed that CpG49 methylation reduced the binding of NRF1 to the P1. Taken together, our findings illustrate that P1 methylation promotes PPARγ1 expression at least in part by preventing NRF1 from binding to the promoter P1.

Comparison of abdominal adipose tissue versus body mass index (BMI) as a predictor of complications and survival in liver transplantation.

INTRODUCTION: Because of the obesity epidemic, more obese patients are on liver transplant (LT) waiting lists. The diseases associated with obesity may increase complications and limit survival after LT. However, there is no established measure or cut-off point to determine this impact and aid decision making. The aim of the present study is to evaluate obesity in patients undergoing LT via BMI and CT-based measurement of adipose tissue (AAT). These parameters will be used to predict the risk of postoperative complications and 5-year survival. METHODS: A retrospective, single-center study was carried out at a tertiary Spanish hospital, including all patients who received LT between January 2012 and July 2019 (n = 164). The patients were adults who underwent LT using the 'piggyback' technique, preserving the recipient vena cava. Visceral adipose tissue (VAT) and BMI were calculated to examine correlations with postoperative complications and 5-year survival. RESULTS: No significant association was found between postoperative complications by Comprehensive Complication Index, BMI, AAT/height, subcutaneous fat/height and VAT/height. Kaplan-Meier curves for 5-year survival compared LT recipients with BMI < 30.45 versus ≥30.45, with an estimated survival of 58.97 months versus 43.11 months, respectively (P < .001) (Fig. 3) and for LT recipients with an AAT/height <27.35 mm versus ≥27.35 mm, with an estimated survival of 57.69 months versus 46.34 months (P = .001). CONCLUSIONS: This study does not show a higher rate of postoperative complications in obese patients. There is a significantly lower long-term survival in patients with AAT/height ≥27.35 mm and BMI ≥ 30.45. BMI is a valid estimate of obesity and is predictive of survival.

Adipose tissue indices predict prognosis in hodgkin lymphoma.

INTRODUCTION BACKGROUND: This study evaluated the impact of adipose tissue indices on prognosis of HL. METHODS: Fifty-five patients with newly diagnosed Hodgkin Lymphoma were evaluated retrospectively for association with adipose tissue indices (total abdominal tissue volume, radiodensity, subcutaneous and visceral adipose tissue SUVmax value and prognostic factors for Hodgkin Lymphoma such as IPS-3, IPS-7, stage, sedimentation, progression free and overall survival. RESULTS: For IPS-3, SAT SUVmax and TAAT radiodensity were significantly increased in high-risk patients (2and 3) compared to group 0 and 1. For IPS-7, total abdominal adipose volume was significantly decreased in high-risk patients, SAT SUVmax significantly increased in high-risk patients and decreased in low-risk patients. In addition, SAT SUVmax was significantly increased in patients with high sedimentation rate, with B symptoms and who passed away during follow-up. SAT SUVmax showed moderate positive correlation with sedimentation, IPS-3, IPS-7, and stage. In addition, it was observed that TAAT radiodensity and SAT SUVmax were significantly better for determining prognosis than other adipose tissue indices. Roc analysis showed that the diagnostic value of all adipose tissue indices in predicting IPS-3 and IPS-7 prognoses were statistically significant. CONCLUSION: SAT SUVmax and TAAT radiodensity were two new and independent markers with diagnostic value in predicting prognosis.

Characteristics of Abdominal Visceral Adipose Tissue, Metabolic Health and the Gut Microbiome in Adults.

CONTEXT: Compared with the relatively benign effects of increased subcutaneous adipose tissue (SAT), increased visceral adipose tissue (VAT) volume is a causal risk factor for hypertension, hyperlipidemia, type 2 diabetes, and cardiovascular disease. In rodents, increased VAT volume and triglyceride density and ectopic lipid accumulation in kidneys and liver have been induced by alterations in the gut microbiome. However, few studies have characterized these relationships in humans. OBJECTIVE: To evaluate the tissue triglyceride content of VAT and SAT, liver, kidneys, and pancreas in male and female adults and assess associations with markers of glucose tolerance, serum insulin, and lipids and characteristics of the gut microbiome. METHODS: Cross-sectional observational study of healthy human adults (n = 60) at a clinical research center. Body mass index (BMI), body composition, and oral glucose tolerance were assessed. Microbiome analysis was conducted on stool samples using 16S rRNA v3 amplicon sequencing. The triglyceride content of VAT, SAT, liver, kidney and pancreas were determined by assessing proton density fat fraction (PDFF) with magnetic resonance imaging (MRI). RESULTS: Higher VAT PDFF and the ratio of VAT to SAT PDFF were related to higher BMI, HbA1c, HOMA-IR, non-high-density lipoprotein cholesterol, plasma triglycerides, low-density lipoprotein (LDL) cholesterol, and lower high-density lipoprotein (HDL) cholesterol. A higher VAT PDFF and VAT to SAT PDFF ratio were associated with lower alpha diversity and altered beta diversity of the gut microbiome. Differences in VAT were associated with higher relative abundance of the phylum Firmicutes, lower relative abundance of the phylum Bacteroidetes, and enrichment of the bacterial genera Dorea, Streptococcus, and Solobacterium. CONCLUSION: VAT PDFF measured with MRI is related to impaired glucose homeostasis, dyslipidemia, and differences in the gut microbiome, independently of the total body fat percentage.

Gender-specific associations between abdominal adipose mass and bone mineral density in the middle-aged US population.

OBJECTIVES: The relationship between abdominal adipose tissue and osteoporosis is poorly understood. The purpose of this study was to examine the associations of abdominal adipose tissue with bone mineral density (BMD) among a nationally representative sample of US middle-aged adults. MATERIAL AND METHODS: This study included 1498 participants from the National Health and Nutrition Examination Survey 2013-2014 and 2017-2018. Dual-energy x-ray absorptiometry was used to measure BMD at the lumbar spine and femoral neck, as well as to assess abdominal adipose mass by categorizing total adipose tissue (TAT) into visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Linear regression was used to assess the relationship between abdominal adipose tissue and BMD, and logistic regression and generalized additive model were used to assess the associations of abdominal adipose tissue with the development of low BMD. RESULTS: In our study, men accounted for 51.3%, and the mean age and body mass index for men and women were 49.3 and 49.6 years, and 23.9 and 28.3 kg/m2, respectively. In the univariate model, we found that abdominal adipose mass was positively associated with BMD at femoral neck and spine in both genders. In the multivariate model, among men, a negative correlation was observed between TAT and SAT and BMD at the femoral neck. Additionally, higher masses of TAT, SAT, and VAT were found to significantly increase the risk of low BMD at both the femoral neck and lumbar spine. In contrast, there was no significant association between abdominal adipose mass and BMD in middle-aged women, regardless of menopausal status. CONCLUSIONS: Our finding suggested that abdominal adipose tissue, regardless of its location (SAT or VAT), may have a negative impact on BMD in middle-aged men independently of body weight, but this relationship was not observed in women. Further research is needed to confirm these findings and investigate potential mechanisms underlying these associations.

Association between body fat composition and hyperhomocysteinemia in the analysis of the baseline data of the Northwest China Natural Population Cohort: Ningxia Project (CNC-NX).

The authors conducted an observational study to explore the association between body fat composition and the risk of hyperhomocysteinemia (HHcy) and their combined effect on the risk of developing cardiovascular disease (CVD). Adults aged 18-74 years from the Northwest China Natural Population Cohort: Ningxia Project (CNC-NX) were recruited in this study. Association between body fat composition and HHcy was evaluated by logistic regression model. Restricted cubic spline was used to find nonlinear association. The impact of the interaction between HHcy and body fat composition on CVD was evaluated using the addition interaction model and mediation effect model. In total, 16 419 participants were included in this research. Body fat percentage, visceral fat level, and abdominal fat thickness were positively associated with overall HHcy (p for trend < .001). Adjusted odds ratios (ORs) in quarter 4 were 1.181 (95% CI: 1.062, 1.313), 1.202 (95% CI: 1.085, 1.332), and 1.168 (95% CI: 1.055, 1.293) for body fat percentage, visceral fat level, and abdominal fat thickness, respectively, compared with those in quarter 1. Subgroup analysis indicated age, estimated glomerular filtration rate (eGFR), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and CVD were the interaction factors of body fat percentage, visceral fat level, abdominal fat thickness with HHcy (all p for interaction < .05). ORs of CVD were higher in participants with HHcy and high body fat. Body fat composition was positively associated with HHcy, indicating that reducing body, abdominal, and visceral fat content may lower the risk of HHcy and CVD.

Comparison of CT and Dixon MR Abdominal Adipose Tissue Quantification Using a Unified Computer-Assisted Software Framework.

PURPOSE: Reliable and objective measures of abdominal fat distribution across imaging modalities are essential for various clinical and research scenarios, such as assessing cardiometabolic disease risk due to obesity. We aimed to compare quantitative measures of subcutaneous (SAT) and visceral (VAT) adipose tissues in the abdomen between computed tomography (CT) and Dixon-based magnetic resonance (MR) images using a unified computer-assisted software framework. MATERIALS AND METHODS: This study included 21 subjects who underwent abdominal CT and Dixon MR imaging on the same day. For each subject, two matched axial CT and fat-only MR images at the L2-L3 and the L4-L5 intervertebral levels were selected for fat quantification. For each image, an outer and an inner abdominal wall regions as well as SAT and VAT pixel masks were automatically generated by our software. The computer-generated results were then inspected and corrected by an expert reader. RESULTS: There were excellent agreements for both abdominal wall segmentation and adipose tissue quantification between matched CT and MR images. Pearson coefficients were 0.97 for both outer and inner region segmentation, 0.99 for SAT, and 0.97 for VAT quantification. Bland-Altman analyses indicated minimum biases in all comparisons. CONCLUSION: We showed that abdominal adipose tissue can be reliably quantified from both CT and Dixon MR images using a unified computer-assisted software framework. This flexible framework has a simple-to-use workflow to measure SAT and VAT from both modalities to support various clinical research applications.

A Combined Region- and Pixel-Based Deep Learning Approach for Quantifying Abdominal Adipose Tissue in Adolescents Using Dixon Magnetic Resonance Imaging.

BACKGROUND: The development of adipose tissue during adolescence may provide valuable insights into obesity-associated diseases. We propose an automated convolutional neural network (CNN) approach using Dixon-based magnetic resonance imaging (MRI) to quantity abdominal subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in children and adolescents. METHODS: 474 abdominal Dixon MRI scans of 136 young healthy volunteers (aged 8-18) were included in this study. For each scan, an axial fat-only Dixon image located at the L2-L3 disc space and another image at the L4-L5 disc space were selected for quantification. For each image, an outer and an inner region around the abdomen wall, as well as SAT and VAT pixel masks, were generated by expert readers as reference standards. A standard U-Net CNN architecture was then used to train two models: one for region segmentation and one for fat pixel classification. The performance was evaluated using the dice similarity coefficient (DSC) with fivefold cross-validation, and by Pearson correlation and the Student's t-test against the reference standards. RESULTS: For the DSC results, means and standard deviations of the outer region, inner region, SAT, and VAT comparisons were 0.974 ± 0.026, 0.997 ± 0.003, 0.981 ± 0.025, and 0.932 ± 0.047, respectively. Pearson coefficients were 1.000 for both outer and inner regions, and 1.000 and 0.982 for SAT and VAT comparisons, respectively (all p = NS). CONCLUSION: These results show that our method not only provides excellent agreement with the reference SAT and VAT measurements, but also accurate abdominal wall region segmentation. The proposed combined region- and pixel-based CNN approach provides automated abdominal wall segmentation as well as SAT and VAT quantification with Dixon MRI and enables objective longitudinal assessment of adipose tissues in children during adolescence.

Association Between Abdominal Adipose Tissue Distribution and Risk of Endometrial Cancer: A Case-Control Study.

Background: Obesity contributes to endometrial cancer (EC). However, it is not clear whether the distribution of adipose tissue affects the occurrence of endometrial carcinoma. This study aimed to evaluate the relationship between abdominal adipose tissue distribution and EC. Methods: We designed a case-control study with 115 women with EC and a control group. The total abdominal adipose tissue, visceral adipose tissue, and subcutaneous adipose tissue were measured by single slice computerized tomography at the level of umbilicus. Univariate and multivariate logistic regression models were used to calculate odds ratios (ORs) for the risk of EC associated with adipose tissue distribution. Furthermore, we analyzed the correlation between adipose tissue distribution and clinicopathologic features of endometrial carcinoma. Results: Multivariate analysis showed that a larger visceral adipose tissue ratio was associated with an increased risk of EC after adjusting for body mass index (BMI) and diabetes (OR = 1.046, 95% confidence interval = [1.008-1.079]). The ratio of International Federation of Obstetrics and Gynecology (FIGO) stage I and type I EC was higher in EC patients with larger visceral adipose tissue (84.5% vs 63.2%, P = .009; 91.4% vs 75.4%, P = .021). There was a higher positive ratio of progesterone receptor in EC patients with a larger subcutaneous adipose tissue area (91.2% vs 77.6%; P = .044). Conclusions: Higher visceral adipose tissue ratio, independent of BMI, was associated with an increased risk of EC. Therefore, this study demonstrated that women with normal BMI, but abnormal abdominal adipose tissue distribution, have an increased risk for EC.

RNA-seq Based Transcriptome Analysis Reveals The Cross-Talk of Macrophage and Adipocyte of Chicken Subcutaneous Adipose Tissue during The Embryonic and Post-Hatch Period.

With high fecundity and short production cycle, poultry is one of the important sources of meat. During the embryonic and post-hatch period, the higher death rate caused huge economic losses in poultry production. Our previous study showed that chick subcutaneous adipose tissue is an important energy supply tissue besides yolk. Therefore, the metabolic mechanism of subcutaneous adipose tissue in chicks could provide a new perspective of brooding. The objectives of the current study were to evaluate the differences between chick subcutaneous adipose tissue and abdominal adipose tissue before and after hatching and reveal the cross-talk of different cells within the chick subcutaneous adipose tissue. The results of RNA-seq and weighted gene co-expression network analysis (WGCNA) of chick subcutaneous and abdominal adipose tissues showed that the function of chick subcutaneous tissue was related to immunoreaction, and macrophage could be the major immune infiltration cell type in chicken subcutaneous adipose tissue, which were also verified by qPCR, HE stain, and IHC. The results of free fatty acids (FFAs)-induced the cross-talk between macrophages and adipocytes showed that FFAs-Ccl2 (chicken CCL26) axis could have an important role in lipid transportation in adipose tissue. The results of Oil Red O and Nile red stain demonstrated that macrophages have the ability to absorb FFAs quickly. Interestingly, according to the genomic organization of CCL family with representative vertebrate species, we found that chicken CCL26 could be the major chemokine in chicken adipocyte as the status of CCL2 in mammal adipocyte. In conclusion, we demonstrate that FFA-induced Ccl2 (chicken CCL26) secretion is crucial in determining fat depot-selective adipose tissue macrophage (ATM) infiltration, which could be an important medium of lipid transportation in chicken subcutaneous adipose tissue. These findings may have multiple important implications for understanding macrophage biology with chick subcutaneous adipose tissue and provide theoretical basis for lipid metabolism in poultry brooding.

An effective automatic segmentation of abdominal adipose tissue using a convolution neural network.

BACKGROUND AND AIMS: Computer-aided diagnosis and prognosis rely heavily on fully automatic segmentation of abdominal fat tissue using Emission Tomography images. The identification of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in abdomen fat faces two main challenges: (1) the great difficulties in comparison to multi-stage semantic segmentation (VAT and SAT), and (2) the subtle differences due to the high similarity of the two classes in abdomen fat and complicated VAT distribution. METHODS: In this research, we built an automated convolutional neural network (A-CNN) for segmenting Abdominal adipose tissue (AAT) from radiology images. RESULTS: We developed a point-to-point design for the A-CNN learning process, wherein the representing features might be learned together with a hybrid feature extraction technique. We tested the proposed model on a CT dataset and evaluated it to existing CNN models. Furthermore, our suggested approach, A-CNN, outperformed existing deep learning methods regarding segmentation outcomes, notably in the AAT segment. CONCLUSIONS: Proposed method is extremely fast with remarkable performance on limited-scale low dose CT-scanning and demonstrates the strength in providing an efficient computer-aimed tool for segmentation of AAT in the clinic.

Association of the Kynurenine Pathway of Tryptophan Metabolism With Human Immunodeficiency Virus-Related Gut Microbiota Alterations and Visceral Adipose Tissue Accumulation.

BACKGROUND: The aim of the study was to investigate the association between human immunodeficiency virus (HIV)-related gut microbiota changes, alterations in the kynurenine (Kyn) pathway of tryptophan (Trp) metabolism, and visceral adipose tissue in the context of HIV infection. METHODS: Three hundred eighty-three people with HIV (PWH) were included from the Copenhagen comorbidity in HIV infection (COCOMO) study. Gut microbiota composition was analyzed by 16S ribosomal ribonucleic acid sequencing. Plasma metabolites were analyzed by liquid chromatography-tandem mass spectrometry. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas were measured by single-slice computed tomography (CT) scan (4th lumbar vertebra). RESULTS: The HIV-related gut microbiota alterations were associated with lower Trp (ß -.01; 95% confidence interval [CI], -0.03 to -0.00) and higher Kyn-to-Trp ratio (ß 0.03; 95% CI, 0.01-0.05), which in turn was associated with higher VAT-to-SAT ratio (ß 0.50; 95% CI, 0.10-0.90) and larger VAT area (ß 30.85; 95% CI, 4.43-57.28). In mediation analysis, the Kyn-to-Trp ratio mediated 10% (P = .023) of the association between the VAT-to-SAT ratio and HIV-related gut microbiota. CONCLUSIONS: Our data suggest HIV-related gut microbiota compositional changes and gut microbial translocation as potential drivers of high Kyn-to-Trp ratio in PWH. In turn, increased activity in the Kyn pathway of Trp metabolism was associated with larger visceral adipose tissue area. Taken together, our findings suggest a possible role for this pathway in the gut-adipose tissue axis in the context of HIV infection.

Preoperative prediction of early recurrence of HBV-related hepatocellular carcinoma (≤5†cm) by visceral adipose tissue index.

Background: This study aimed to investigate whether visceral adipose tissue index (VATI) is a significant risk factor for the early recurrence (ER) of HBV-related hepatocellular carcinoma (HCC) (≤5 cm) after hepatectomy. Methods: The recruited cohort patients who were positive for hepatitis B virus, presented with surgically confirmed HCC (≤5 cm) from Army Medical University (internal training cohort: n = 192) and Chongqing Medical University (external validation group: n = 46). We measured VATI, subcutaneous adipose tissue index (SATI) via computed tomography (CT). ER was defined as recurrence within 2 years after hepatectomy. The impact of parameters on outcome after hepatectomy for HCC was analyzed. Results: Univariate analysis showed that alpha-fetoprotein levels (p = 0.044), body mass index (BMI) (p < 0.001), SATI (p < 0.001), and VATI (p < 0.001) were significantly different between ER and non-ER groups in internal training cohort. Multivariate analysis identified VATI as an independent risk factor for ER (odds ratio = 1.07, 95% confidence interval: 1.047-1.094, p < 0.001), with a AUC of 0.802, based on the cut-off value of VATI, which was divided into high risk (≥37.45 cm2/m2) and low risk (<37.45 cm2/m2) groups. The prognosis of low risk group was significantly higher than that of high risk group (p < 0.001). The AUC value of VATI in external validation group was 0.854. Conclusion: VATI was an independent risk factor for the ER, and higher VATI was closely related to poor outcomes after hepatectomy for HBV-related HCC (≤5 cm).

Predictive value of preoperative abdominal adipose tissue measurement for early recurrence after resection of hepatocellular carcinoma / 中华消化外科杂志

Objective:To investigate the predictive value of preoperative abdominal adipose tissue measurement for early recurrence after resection of hepatocellular carcinoma (HCC).Methods:The retrospective case-control study was conducted. The clinicopathological data of 238 patients with HCC who underwent surgical resection from January 2018 to January 2020 in 2 medical centers in China were collected, including 46 cases in the First Affiliated Hospital of Chongqing Medical University and 192 cases in the First Affiliated Hospital of Army Medical University. There were 207 males and 31 females, aged 51(48,65)years. All patients underwent abdominal computed tomography (CT) and/or magnetic resonance imaging (MRI) before surgery. Observation indicators: (1) measure-ment of abdominal adipose tissue; (2) follow-up; (3) analysis of influencing factors for early recurrence after resection of HCC; (4) prediction of early recurrence after resection of HCC. Follow-up was conducted by outpatient examinations and telephone interview to detect the postoperative survival of patients up to February 2022. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was performed by the t test. Measurement data with skewed distribution was represented by M(range) or M( Q1, Q3), and comparison between groups was performed by the Mann-Whitney U test. Count data were expressed as absolute numbers or percen-tages, and the chi-square test was used for comparison between groups. Univariate analysis was conducted using the corresponding statistical methods based on data type. Multivariate analysis was performed using the Logistic regression model advance method. The receiver operating characteristic curve was drawn, and the area under curve was used to evaluate the efficacy. Results:(1) Measure-ment of abdominal adipose tissue. Of the 238 patients, the total abdominal adipose tissue, visceral adipose tissue, subcutaneous adipose tissue, total adipose tissue index, visceral adipose tissue index, subcutaneous adipose tissue index were 292(198,355)cm 2, 153(99,194)cm 2, 128(95,154)cm 2, 106(76,130)cm 2/m 2, (57±27)cm 2/m 2, 46(34,58)cm 2/m 2 for 139 patients with early postoperative recur-rence, versus 174(114,251)cm 2, 78(50,110)cm 2, 88(55,127)cm 2, 64(42,91)cm 2/m 2, (30±16)cm 2/m 2, 31(19,46) cm 2/m 2 for 99 patients without early recurrence, respectively, showing significant diffe-rences between them ( Z=?7.39, ?7.87, ?5.03, ?7.25, t=?9.46, Z=?5.00, P<0.05). (2) Follow-up. All the 238 patients were followed up according to the plan. The survival time of 238 patients was 26(8,44)months. The survival time was 11(5,18)months for patients with postoperative early recur-rence, versus 36(32,43)months for patients without early recurrence, respectively. (3) Analysis of influencing factors for early recurrence after resection of HCC. Results of univariate analysis showed that body mass index, total adipose tissue, visceral adipose tissue, subcutaneous adipose tissue, total adipose tissue index, visceral adipose tissue index and subcutaneous adipose tissue index were related factors for early recurrence after resection of HCC ( t=?5.88, Z=?7.39, ?7.87, ?5.03, ?7.25, t=?9.46, Z=?5.00, P<0.05). Results of multivariate analysis showed that visceral adipose tissue index was an independent influencing factor for early recurrence after resection of HCC ( odds ratio=1.06, 95% confidence interval as 1.04?1.08, P<0.05). (4) Prediction of early recurrence after resection of HCC. According to the results of multivariate analysis, the receiver operating characteris-tic curve showed that the area under curve of visceral adipose tissue index was 0.80 (95% confidence interval as 0.75?0.86, P<0.05), with the sensitivity and specificity as 75.5% and 71.7%. Conclusions:Visceral adipose tissue index is an independent influencing factor for early recurrence after resection of HCC. The risk of early recurrence increases with the increase of visceral adipose tissue index.

The Appropriateness Criteria of Abdominal Fat Measurement at the Level of the L1-L2 Intervertebral Disc in Patients With Obesity.

Background: In this study, we proposed to use MR images at L1-L2 (lumbar) intervertebral disc level to measure abdominal fat area in patients with obesity. The quantitative results would provide evidence for the individualized assessment of the severity of obesity. Methods: All patients in the IRB-approved database of Beijing Friendship Hospital who underwent bariatric surgery between November 2017 and November 2019 were recruited. We retrospectively reviewed upper abdominal magnetic resonance (MR) data before surgery. We analyzed the correlation and consistency of the area of abdominal subcutaneous adipose tissue (ASAT) and visceral adipose tissue (VAT) measured at the L1-L2 and L2-L3 levels on MR images. We randomly distributed the cases into prediction model training data and testing data at a ratio of 7:3. Results: Two hundred and forty-five subjects were included. The ASAT and VAT results within the L1-L2 and L2-L3 levels were very similar and highly correlated (maleASAT: r=0.98, femaleASAT: r=0.93; maleVAT: r=0.91, femaleVAT: r=0.88). There was no substantial systematic deviation among the results at the two levels, except for the ASAT results in males. The intraclass correlation coefficients (ICCs) were 0.91 and 0.93 for maleASAT and femaleASAT, and 0.88 and 0.87 for maleVAT and femaleVAT, respectively. The ASAT/VAT area at the L2-L3 level was well predicted. The coefficient ß of linear regression that predicted L2-L3 ASAT from L1-L2 ASAT was 1.11 for males and 0.99 for females. The R-squares were 0.97 and 0.91, respectively. For VAT prediction, the coefficient ß was 1.02 for males and 0.96 for females. The R-squares were 0.82 and 0.77, respectively. Conclusion: For patients with obesity, the L1-L2 intervertebral disc level can be used as the substitution of L2-L3 level in abdominal fat measurement.

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.

Relationship Between Non-Alcoholic Fatty Liver Disease and Abdominal and Pericardial Adipose Tissue in Middle-Aged and Elderly Subjects.

OBJECTIVE: The present study aimed to explore the relationship between non-alcoholic fatty liver disease (NAFLD) and abdominal and pericardial adipose tissue in middle-aged and elderly subjects. METHODS: Between July 2019 and July 2020, 471 subjects attending the Health Care Medical Department of Peking Union Medical College Hospital for a medical examination were enrolled in the study. The volume and distribution of abdominal adipose tissue together with the volume of pericardial adipose tissue were calculated according to the results of the abdominal computed tomography. The differences between subjects with NAFLD and the normal population were analyzed. RESULTS: The volume of pericardial adipose tissue, abdominal visceral and subcutaneous adipose tissue, the total volume of abdominal adipose tissue, and volume of pelvic visceral adipose tissue were all significantly increased in subjects with NAFLD. For every 100 cm3 increase in the volume of abdominal visceral adipose tissue, the incidence of developing NAFLD increased by 9.4%. According to the results of the receiver operating curve, the cut-off point of abdominal visceral adipose tissue for the diagnosis of NAFLD was 2691.1 cm3. CONCLUSION: Overall, the risk of NAFLD increases significantly with the increase in the volume of adipose tissue.