Abdominal fat: standardized technique for measurement at CT

Visceral fat and clinical outcome in patients receiving first-line chemotherapy with bevacizumab for metastatic colorectal cancer

BACKGROUND

Visceral fat produces angiogenic factors such as vascular endothelial growth factor that promote tumoral growth. However, its influence on outcome for patients with advanced cancer treated with anti-angiogenic agents is controversial.

AIMS

The aim of this study was to determine whether visceral fat volume, visceral fat area and body mass index are associated with outcome in patients receiving first-line bevacizumab-based treatment for metastatic colorectal cancer.

METHODS

This multicenter prospective study included 103 patients with metastatic colorectal cancer who received first-line bevacizumab-based chemotherapy. Computed tomography was used to measure visceral fat volume and visceral fat area. Endpoints were tumoral response at 2 months, progression free survival and overall survival.

RESULTS

Visceral fat volume and visceral fat area, but not body mass index, were significantly associated with better outcome. Using sex-specific median values progression free survival was significantly longer in patients with high visceral fat volume (13.2 versus 9.4 months; p = 0.0043). In the same way, high visceral fat volume and visceral fat area were associated with a significantly better overall survival: 31.3 versus 20.5 months (p = 0.0072) and 29.3 versus 20.5 months (p = 0.0078), respectively. By multivariate analysis, visceral fat volume was associated with longer progression free survival and overall survival.

CONCLUSION

This study demonstrates that a high visceral fat volume is associated with better outcome in patients receiving first-line bevacizumab-based chemotherapy for metastatic colorectal cancer.

Pericardial Fat Is Associated With Less Severe Multiorgan Failure Over Time in Patients With Coronavirus Disease-19: The Maastricht Intensive Care COVID Cohort

PURPOSE

Pericardial fat (PF) and epicardial adipose tissue (EAT) may enhance the proinflammatory response in corona virus-19 (COVID-19) patients. Higher PF and EAT volumes might result in multiorgan failure and explain unfavorable trajectories.The aim of this study was to examine the association between the volume of PF and EAT and multiorgan failure over time.

MATERIALS AND METHODS

All mechanically ventilated COVID-19 patients with an available chest computed tomography were prospectively included (March-June 2020). PF and EAT volumes were quantified using chest computed tomography scans. Patients were categorized into sex-specific PF and EAT tertiles. Variables to calculate Sequential Organ Failure Assessment (SOFA) scores were collected daily to indicate multiorgan failure. Linear mixed-effects regression was used to investigate the association between tertiles for PF and EAT volumes separately and serial SOFA scores over time. All models were adjusted.

RESULTS

Sixty-three patients were divided into PF and EAT tertiles, with median PF volumes of 131.4 mL (IQR [interquartile range]: 115.7, 143.2 mL), 199.8 mL (IQR: 175.9, 221.6 mL), and 318.8 mL (IQR: 281.9, 376.8 mL) and median EAT volumes of 69.6 mL (IQR: 57.0, 79.4 mL), 107.9 mL (IQR: 104.6, 115.1 mL), and 163.8 mL (IQR: 146.5, 203.1 mL). Patients in the highest PF tertile had a statistically significantly lower SOFA score over time (1.3 [-2.5, -0.1], P =0.033) compared with the lowest PF tertile. EAT tertiles were not significantly associated with SOFA scores over time.

CONCLUSION

A higher PF volume is associated with less multiorgan failure in mechanically ventilated COVID-19 patients. EAT volumes were not associated with multiorgan failure.

Differentiation Between Ulcerative Colitis and Crohn's Disease Using Abdominal Computed Tomography in Patients With First-Time Inflammatory Bowel Disease

Background Ulcerative colitis (UC) and Crohn's disease (CD) are classified as inflammatory bowel diseases (IBDs). However, they have different pathogeneses and treatment strategies and need to be differentiated. Purpose To determine the feasibility of differentiating UC from CD in patients with first-time IBD based on simple abdominal computed tomography (CT) findings. Methods We conducted a retrospective study of patients diagnosed with IBD for the first time at our hospital between January and December 2021. Age, sex, white blood cell count, albumin concentration, C-reactive protein concentration, visceral fat area, subcutaneous fat area, and psoas major volume were extracted and used to differentiate the two groups. Results Forty-three patients were selected. Their mean age was 35.60 ± 17.19 years, and 32 were male, while 11 were female. The visceral fat cross-sectional area was 51.80 cm2 for UC and 21.10 cm2 for CD (p < 0.01). The subcutaneous fat cross-sectional area was 108.30 cm2 for UC and 66.30 cm2 for CD (p = 0.049). The total protein concentration was 6.15 g/L for UC and 6.60 g/L for CD (p = 0.012). Receiver operating characteristic curve analysis of the visceral and subcutaneous fat cross-sectional areas showed areas under the curve, 95% confidence intervals, sensitivities, and specificities of 0.750 and 0.675, 0.603-0.897 and 0.507-0.844, 0.810 and 1.00, and 0.591 and 0.409, respectively, at cutoffs of 26.53 and 36.6 cm2. Conclusions  The visceral and subcutaneous fat cross-sectional areas determined with simple abdominal CT can differentiate UC from CD in patients with first-time IBD.

A Review of the Paradigmatic Role of Adipose Tissue in Renal Cancer: Fat Measurement and Tumor Behavior Features

(1) Background: Renal-cell carcinoma (RCC) incidence has been steadily rising, with obesity identified as a potential risk factor. However, the relationship between obesity and RCC prognosis remains unclear. This systematic review aims to investigate the impact of different adipose tissue measurements on RCC behavior and prognosis. (2) Methods: A search of MEDLINE databases identified 20 eligible studies focusing on various fat measurements, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), perirenal adipose tissue (PRAT), and the Mayo adhesive probability (MAP) score. (3) Results: The review revealed conflicting findings regarding the association between adipose tissue measurements and RCC outcomes. While some studies suggested a protective role of certain fat deposits, particularly VAT, against disease progression and mortality, others reported contradictory results across different adipose metrics and RCC subtypes. (4) Conclusions: Methodological variations and limitations, such as retrospective designs and sample size constraints, pose challenges to standardization and generalizability. Further research is needed to understand these associations better and establish standardized approaches for adiposity assessment in RCC patients, which could inform clinical practice and therapeutic decision-making.

Comparison of robotic versus laparoscopic surgery for visceral obesity in mid-low rectal cancer: a propensity-matched analysis

Obesity is becoming more and more common, and measuring visceral fat area (VFA) is a useful diagnostic technique for visceral obesity (VO). The purpose of this research is to compare the surgical results of robotic versus laparoscopic rectal surgery, with a focus on assessing the benefits of the latter method for treating both VO and mid-low rectal cancer. Patients receiving laparoscopic or robotic anterior rectal excision at Northern Jiangsu People's Hospital's general surgery department were included in the retrospective analysis. 242 people in all took part in the study; 121 cases were assigned to the robotic surgery (RS) group and another 121 cases to the laparoscopic surgery (LS) group. In comparison to LS, our results show that RS led to a shorter period for the recovery of bowel function (p = 0.03), a shorter hospital stay (p < 0.001), a smaller intraoperative blood loss (p < 0.001), and a shorter time until the commencement of oral intake (p = 0.041). However, there were no statistically significant differences between the two groups in terms of the indices of histopathologic specimens, the proportion of temporary loop ileostomy, and the incidence of early postoperative problems (p > 0.05). When patients with VO undergo surgery for rectal cancer, RS has the added benefit of accelerating patient recovery while producing results that are similar to LS in the near run.

Changes in mesenteric fat thickness and its clinical impact in bariatric surgery

Obesity, especially central obesity is associated with increased risk of metabolic syndrome, non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus. The study aimed to investigate the associations of the changes of abdominal fat thicknesses with changes of anthropometric indexes and improvements of metabolic phenotypes in patients with obesity and T2DM before and after bariatric surgery. Between April 2016 and January 2017, 34 adult patients with concurrent obesity and T2DM scheduled for different bariatric surgeries were prospectively evaluated by ultrasound before and 1-year after bariatric surgery to determine abdominal fat thicknesses (mesenteric fat, preperitoneal fat and subcutaneous fat) and NAFLD. At 1 year, of the 25 patients that finished the study, significant decrease in mesenteric-fat-thickness was associated with significant reduction of obesity, that is, BMI (-24%, p < .001), remission of metabolic syndrome (32%, p = .008), NAFLD (60%, p < .001) and T2DM (44%, p < .001). Lower baseline mesenteric fat thickness was associated with remission of metabolic syndrome. Lower baseline mesenteric-fat-thickness may have the potential to predict metabolic syndrome remission after bariatric surgery.

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.

Influence of epicardial adipose tissue inflammation and adipocyte size on postoperative atrial fibrillation in patients after cardiovascular surgery

Epicardial adipose tissue (EAT) is an active endocrine organ that is closely associated with occurrence of atrial fibrillation (AF). However, the role of EAT in the development of postoperative AF (POAF) remains unclear. We aimed to investigate the association between EAT profile and POAF occurrence in patients who underwent cardiovascular surgery. We obtained EAT samples from 53 patients to evaluate gene expression, histological changes, mitochondrial oxidative phosphorylation (OXPHOS) capacity in the EAT, and protein secretion in EAT-conditioned medium. EAT volume was measured using computed tomography scan. Eighteen patients (34%) experienced POAF within 7 days after surgery. Although no significant difference was observed in EAT profile between patients with and without POAF, logistic regression analysis identified that the mRNA expression levels of tumor necrosis factor-alpha (TNF-α) were positively correlated and adipocyte size in the EAT was inversely correlated with onset of POAF, respectively. Mitochondrial OXPHOS capacity in the EAT was not associated with POAF occurrence; however, it showed an inverse correlation with adipocyte size and a positive correlation with adiponectin secretion. In conclusion, changes in the secretory profile and adipocyte morphology of the EAT, which represent qualitative aspects of the adipose tissue, were present before the onset of AF.

Independent association of thigh muscle fat density with vascular events in Korean adults

BACKGROUND

We aimed to explore the associations between thigh muscle fat density and vascular events.

METHODS

A total of 3,595 adults (mean age, 57.2 years; women, 1,715 [47.7%]) without baseline cardiovascular events from the Korean Atherosclerosis Study-2 were included. Muscle and fat area at the mid-thigh level were measured by computed tomography (CT) using the following Hounsfield Unit range: 0-30 for low density muscle (LDM); 31-100 for normal density muscle (NDM); and - 250 to - 50 for fat.

RESULTS

During a median follow-up period of 11.8 (4.3-13.9) years, vascular events occurred in 11.6% of men and 5.9% of women. Individuals with vascular events had a larger LDM area (men: 48.8 ± 15.5 cm2 vs. 44.6 ± 14.5 cm2; women: 39.4 ± 13.2 cm2 vs. 35.0 ± 11.8 cm2, both P < 0.001) compared with those who did not have vascular events during the follow-up of at least 5 years. The LDM/NDM ratio was also independently associated with vascular events after adjusting for cardiometabolic risk factors. Moreover, the LDM/NDM ratio improved the prognostic value for vascular events when added to conventional risk factors.

CONCLUSIONS

The current study suggests that a higher thigh muscle fat infiltration is associated with an increased risk of developing vascular events among Korean adults.

The association between computed tomography attenuation value of renal angiomyolipoma associated with tuberous sclerosis complex and response to everolimus

BACKGROUND

The response to everolimus in patients with renal angiomyolipoma associated with tuberous sclerosis complex (TSC-RAML) varies among individuals. This study aims to identify potential factors associated with the response to everolimus.

METHOD

We retrospectively examined data encompassing age, gender, tumor size, computed tomography attenuation value (CT value), CT enhancement, and tumor reduction rate in patients with TSC-RAML undergoing everolimus in two previously registered clinical trials.

RESULT

A total of 33 participants (29.33 ± 6.63 years old, 20 females) were included. The correlation analysis conducted separately for tumors located in the left and right kidneys revealed significant negative correlations (P < 0.05) between tumor reduction rate and age, as well as tumor size. While significant positive correlations (P < 0.05) were observed between tumor reduction rate and unenhanced CT value as well as CT enhancement. Nonetheless, based on multiple linear regression analysis, unenhanced CT value emerged as the sole-independent predictor of tumor reduction rate among age, gender, tumor size, unenhanced CT value and CT enhancement for both left (coefficient = 0.00319, P < 0.0001) and right kidneys (coefficient = 0.00315, P = 0.0104). Notable reductions were observed in unenhanced CT value (- 3.81 vs - 24.70HU, P < 0.0001) and CT enhancement (48.16 vs 33.56HU, P < 0.0001) following a 3-month administration of everolimus. The decline in both unenhanced CT value and tumor size predominantly occurred within the initial 3 months, subsequently maintaining a relatively stable level throughout the treatment.

CONCLUSION

The unenhanced CT value of TSC-RAML showed an independent correlation with the response to everolimus, suggesting its potential as a predictor of everolimus efficacy in patients with TSC-RAML.

Time-Restricted Fasting Improves Liver Steatosis in Non-Alcoholic Fatty Liver Disease-A Single Blinded Crossover Trial

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with visceral adiposity. We assessed the effectiveness of time-restricted fasting (TRF) for 16 h daily without calorie restrictions compared to standard care (SC; diet and lifestyle advice) in improving visceral adiposity and steatosis via controlled attenuation parameter (CAP).

METHODS

In a prospective single-blind randomized controlled trial, 32 participants with NAFLD were randomly assigned to TRF or SC for 12 weeks. The secondary endpoints were changes in liver stiffness, anthropometry, blood pressure, and other metabolic factors.

RESULTS

Twenty-eight participants completed the first arm of the study (TRF = 14, SC = 14), with 23 completing the crossover arm (TRF = 10, SC = 13). The baseline demographics were similar between the groups. Intermittent fasting caused a significant decrease in hepatic steatosis (p = 0.038), weight (p = 0.005), waist circumference (p = 0.001), and BMI (p = 0.005) compared to standard care. Intermittent fasting also resulted in additional within-group changes that were not seen in the standard care intervention.

CONCLUSION

TRF offers superior improvements in patients with NAFLD, improving steatosis, weight, and waist circumference despite a lack of change in overall caloric intake. Time-restricted fasting should be considered as a primary weight loss intervention in the context of NAFLD.

TRIAL REGISTRATION

ACTRN12613000935730.

Functional Gastrointestinal Disorders and Abdominal Visceral Fat in Children and Adolescents

Purpose

Few reports have investigated the correlation between functional gastrointestinal disorders (FGIDs) and the degree of obesity in children and adolescents. Thus, this study aimed to examine the relationship between FGIDs and the degree of obesity in children and adolescents.

Methods

Children and adolescents (<19 years old) who had undergone abdominopelvic computed tomography and had been diagnosed with FGIDs from 2015 to 2016 were included in this retrospective case-control study in a ratio of 1:2. Abdominal visceral fat was measured using an image analysis software.

Results

The mean age of all 54 FGID patients was 12.9±3.4 years, and the male: female ratio was 1:1.2. We observed no difference in body mass index (BMI) between the FGID and control groups (19.5±4.6 vs. 20.6±4.3 kg/m2, p=0.150). However, the FGID group had less abdominal visceral fat than that of the control group (26.2±20.0 vs. 34.4±26.9 cm2, p=0.048). Boys in the FGID group had lower BMI (18.5±3.5 vs. 20.9±4.3 kg/m2, p=0.019) and less abdominal visceral fat (22.8±15.9 vs. 35.9±31.8 cm2, p=0.020) than those of boys in the control group. However, we found no difference in BMI (20.5±5.3 vs. 20.4±4.2 kg/m2, p=0.960) and abdominal visceral fat (29.0±22.9 vs. 33.1±22.1 cm2, p=0.420) between girls in both groups.

Conclusion

Our study revealed a difference in the relationship between FGID and the degree of obesity according to sex, which suggests that sex hormones influence the pathogenesis of FGIDs. Multicenter studies with larger cohorts are required to clarify the correlation between FGID subtypes and the degree of obesity.

Exploring the Associations Between Non-Traditional Lipid Parameters and Epicardial Adipose Tissue Volume

The aim of this retrospective study was to determine the relationship between non-traditional lipid parameters and epicardial adipose tissue (EAT). A total of 770 patients with coronary computed tomography angiography examinations were included. The non-traditional lipid parameters included the atherogenic index of plasma (AIP), the atherogenic coefficient (AC), monocyte to high-density lipoprotein cholesterol (HDL-C) ratio (MHR), and lipoprotein combined index (LCI). To investigate the association between non-conventional lipid markers and the EAT-volume (EAT-v), a univariate and multivariate analyses were conducted. The receiver operating characteristic (ROC) analysis was used to compare the predictive ability among the four non-traditional lipid parameters. In the univariate analysis, we identified factors that might have effects on EAT-v (all P<.05) and adjusted for these in the multivariate analysis. We found that except for MHR, other non-traditional lipid parameters were still associated with high EAT-v after adjustment (all P<.05). In the ROC analysis, the area under the curve (AUC) of AIP was greater than that of other non-traditional lipid parameters and lipid profiles. There was an association between both non-traditional lipid parameters and EAT-v. After adjustment, the AIP remained an independent predictor of EAT-v and it outperformed other non-traditional lipid parameters.

Strong impact of sarcopenic state defined by skeletal muscle mass index on postoperative complication of Crohn's disease patients

Background

Malnutrition impacts the clinical course of Crohn's disease; however, there is little evidence of its influence on perioperative adverse events. We assessed whether nutritional indicators are associated with postoperative complications in surgical treatment of Crohn's disease.

Methods

137 patients with Crohn's disease who underwent surgical treatment between January 2011 and December 2020 were included. Skeletal muscle index was calculated by a single CT slice. We analyzed the risk factors for adverse events.

Results

37 % of patients had postoperative complications. Adverse events occurred more frequently in patients with high serum C-reactive protein, low serum albumin, prognostic nutritional index <38.3, skeletal muscle index <38.9 cm2/m2, abdominoperineal resection, long surgical duration, and mass hemorrhage. Among patients with skeletal muscle index <38.9 cm2/m2, patients who experienced adverse events had higher visceral fat index compared with those who did not (0.85 vs. 0.45, P = 0.04). Multivariate analysis revealed that skeletal muscle index <38.9 cm2/m2 and low serum albumin were the independent risk factors for postoperative complications (Odds ratio, 2.85; 95 % confidence interval, 1.13-7.16; P = 0.03, 2.62; 1.09-6.26; P = 0.03, respectively). Separated by sex, low serum albumin (<3.5 and <2.8 g/dL, male and female, respectively) and skeletal muscle index (<38.9 and <36.6 cm2/m2, male and female, respectively) were statistically related to postoperative complications.

Conclusions

Skeletal muscle index is the most useful nutritional predictor of postoperative complications in Crohn's disease patients among other nutritional indices. We believe that these patients are at high risk of postoperative complications and need appropriate nutritional support in the perioperative period.

Fat Hounsfield Unit Reference Interval Derived through an Indirect Method

BACKGROUND

In vivo Hounsfield Unit (HU) values have traditionally been determined using direct CT image measurements. These measurements are dependent on the window/level used to examine the CT image and the individual conducting the fat tissue tracing.

METHODS

Using an indirect method, a new reference interval (RI) is proposed. A total of 4000 samples of fat tissues were collected from routine abdominal CT examinations. A linear regression equation was then calculated using the linear part of the cumulative frequency plot of their average values.

RESULTS

The regression function for total abdominal fat was determined to be y = 35.376*x - 123.48, and a 95% confidence RI of -123 to -89 was computed. A significant difference of 3.82 was observed between the average fat HU values of visceral and subcutaneous areas.

CONCLUSIONS

Using statistical methods and the in vivo measurements of patient data, a series of RIs were determined for fat HU that is consistent with theoretical values.

Assessment of epicardial adipose tissue on virtual non-contrast images derived from photon-counting detector coronary CTA datasets

OBJECTIVES

To assess epicardial adipose tissue (EAT) volume and attenuation of different virtual non-contrast (VNC) reconstructions derived from coronary CTA (CCTA) datasets of a photon-counting detector (PCD) CT-system to replace true non-contrast (TNC) series.

METHODS

Consecutive patients (n = 42) with clinically indicated CCTA and coronary TNC were included. Two VNC series were reconstructed, using a conventional (VNC_Conv) and a novel calcium-preserving (VNC_PC) algorithm. EAT was segmented on TNC, VNC_Conv, VNC_PC, and CCTA (CTA_-30) series using thresholds of -190 to -30 HU and an additional segmentation on the CCTA series with an upper threshold of 0 HU (CTA₀). EAT volumes and their histograms were assessed for each series. Linear regression was used to correlate EAT volumes and the Euclidian distance for histograms. The paired t-test and the Wilcoxon signed-rank test were used to assess differences for parametric and non-parametric data.

RESULTS

EAT volumes from VNC and CCTA series showed significant differences compared to TNC (all p < .05), but excellent correlation (all R² > 0.9). Measurements on the novel VNC_PC series showed the best correlation (R² = 0.99) and only minor absolute differences compared to TNC values. Mean volume differences were -12%, -3%, -13%, and +10% for VNC_Conv, VNC_PC, CTA_-30, and CTA₀ compared to TNC. Distribution of CT values on VNC_PC showed less difference to TNC than on VNC_Conv (mean attenuation difference +7% vs. +2%; Euclidean distance of histograms 0.029 vs. 0.016).

CONCLUSIONS

VNC_PC-reconstructions of PCD-CCTA datasets can be used to reliably assess EAT volume with a high accuracy and only minor differences in CT values compared to TNC. Substitution of TNC would significantly decrease patient's radiation dose.

KEY POINTS

• Measurement of epicardial adipose tissue (EAT) volume and attenuation are feasible on virtual non-contrast (VNC) series with excellent correlation to true non-contrast series (all R²>0.9). • Differences in VNC algorithms have a significant impact on EAT volume and CT attenuation values. • A novel VNC algorithm (VNC_PC) enables reliable assessment of EAT volume and attenuation with superior accuracy compared to measurements on conventional VNC- and CCTA-series.

Myocardial fat accumulation is associated with cardiac dysfunction in patients with type 2 diabetes, especially in elderly or female patients: a retrospective observational study

BACKGROUND

Ectopic fat is fat that accumulates in or around specific organs or compartments of the body including myocardium. The clinical features of type 2 diabetes patients with high fat accumulation in the myocardium remain unknown. Moreover, little is known about the influence of myocardial fat accumulation in type 2 diabetes on coronary artery disease and cardiac dysfunction. We aimed to clarify the clinical features, including cardiac functions, of type 2 diabetes patients with myocardial fat accumulation.

METHODS

We retrospectively enrolled type 2 diabetes patients who underwent ECG-gated coronary computed tomography angiography (CCTA) and abdominal computed tomography (CT) scan examinations within 1 year of CCTA from January 2000 to March 2021. High fat accumulation in the myocardium was defined as the low mean myocardial CT value of three regions of interest, and the associations between CT values and clinical characteristics or cardiac functions were assessed.

RESULTS

In total, 124 patients were enrolled (72 males and 52 females). The mean age was 66.6 years, the mean BMI was 26.2 kg/m², the mean ejection fraction (EF) was 67.6%, and the mean myocardial CT value was 47.7 Hounsfield unit. A significant positive correlation was found between myocardial CT value and EF (r = 0.3644, p = 0.0004). The multiple regression analyses also showed that myocardial CT value was independently associated with EF (estimate, 0.304; 95% confidence interval (CI) 0.092 to 0.517; p = 0.0056). Myocardial CT value showed significant negative correlations with BMI, visceral fat area and subcutaneous fat area (r = - 0.1923, - 0.2654, and -0.3569, respectively, p < 0.05). In patients who were ≥ 65 years or female, myocardial CT value showed significant positive correlations with not only EF (r = 0.3542 and 0.4085, respectively, p < 0.01) but also early lateral annular tissue Doppler velocity (Lat e') (r = 0.5148 and 0.5361, respectively, p < 0.05). The multiple regression analyses showed that myocardial CT value was independently associated with EF and Lat e' in these subgroups (p < 0.05).

CONCLUSIONS

Patients with type 2 diabetes, especially in elderly or female patients, who had more myocardial fat had more severe left ventricular systolic and diastolic dysfunctions. Reducing myocardial fat accumulation may be a therapeutic target for type 2 diabetes patients.

Visceral Obesity as a Predictor of Postoperative Complications After Pancreaticoduodenectomy

INTRODUCTION

Obesity is associated with increased morbidity and mortality post surgery. The measurement of visceral obesity can predict postoperative outcomes after pancreaticoduodenectomy.

METHODS

This is a prospective observational study. Visceral obesity was calculated by measuring the fat thickness in the retro-renal area by using a computed tomography scan. Visceral obesity was defined as retro-renal fat thickness (RRFT) of ≥ 2 cm. Patients were divided into two groups: Group-A (RRFT < 2 cm, non-obese) and Group-B (RRFT > 2 cm, obese). Demographic, clinical, and intraoperative variables were correlated with postoperative outcomes.

RESULTS

Fifty-six patients were included in the study. Thirty-two patients were included in Group-A, and 24 patients were included in Group-B. The two groups had comparable outcomes. A total of 21 patients in Group-A (65.62%) and 17 patients in Group-B (70.83%) had comorbidities, including diabetes mellitus, hypertension, and coronary disease (p=0.680). American Society of Anesthesiologists (ASA) grading was comparable (p=0.927). BMI was also comparable (p=0.354). Type of pancreaticoduodenectomy, pancreatic texture, pancreatic duct diameter, and technique of pancreaticojejunostomy anastomosis were comparable. The mean operative time was longer in Group-B (362 ± 36.2 min vs. 298 ± 45.2 min) (p=0.001). Intraoperative blood loss was more in Group-B (312 ± 36.8 ml vs. 267 ± 23.7 ml) (p=0.001). The rates of postoperative pancreatic fistula and delayed gastric emptying were comparable (p=0.402 and p=0.134, respectively). The length of hospital stay was longer in patients in Group-B (p=0.004). There was one death in Group-B (obese group).

CONCLUSION

Visceral obesity is a risk factor for postoperative complications after a pancreaticoduodenectomy.

Automated volume measurement of abdominal adipose tissue from entire abdominal cavity in Dixon MR images using deep learning

The purpose of this study was to realize an automated volume measurement of abdominal adipose tissue from the entire abdominal cavity in Dixon magnetic resonance (MR) images using deep learning. Our algorithm involves a combination of extraction of the abdominal cavity and body trunk regions using deep learning and extraction of a fat region based on automatic thresholding. To evaluate the proposed method, we calculated the Dice coefficient (DC) between the extracted regions using deep learning and labeled images. We also compared the visceral adipose tissue (VAT) and subcutaneous adipose tissue volumes calculated by employing the proposed method with those calculated from computed tomography (CT) images scanned on the same day using the automatic calculation method previously developed by our group. We implemented our method as a plug-in in a web-based medical image processing platform. The DCs of the abdominal cavity and body trunk regions were 0.952 ± 0.014 and 0.995 ± 0.002, respectively. The VAT volume measured from MR images using the proposed method was almost equivalent to that measured from CT images. The time required for our plug-in to process the test set was 118.9 ± 28.0 s. Using our proposed method, the VAT volume measured from MR images can be an alternative to that measured from CT images.

Muscle and visceral fat infiltration: A potential mechanism to explain the worsening of obstructive sleep apnea with age

STUDY OBJECTIVES

Aging is a major risk factor for obstructive sleep apnoea (OSA) and is associated with increased upper airway collapsibility, but the mechanisms are largely unknown. We hypothesized that the increase in OSA severity and upper airway collapsibility with age are partially mediated by upper airway, visceral and muscle fat infiltration.

METHODS

Male subjects underwent full polysomnography, upper airway collapsibility determination (Pcrit) after sleep induction with midazolam, upper airway and abdominal computed tomography. Tongue and abdominal muscle fat infiltration were assessed by the determination of muscle attenuation with computed tomography.

RESULTS

Eighty-four males with a wide range of age (47 ± 13 years, range 22-69 years) and apnea-hypopnea index (AHI) (30 [14-60] events/h, range 1-90 events/h), were studied. Younger and older males were grouped according to the mean age. Despite similar body mass-index (BMI), older subjects had higher AHI, higher Pcrit, larger neck and waist circumference, higher visceral and upper airway fat volumes (P < 0.01) as compared to younger subjects. Age was associated with OSA severity, Pcrit, neck and waist circumference, upper airway fat volume and visceral fat (P < 0.05), but not with BMI. Older subjects had lower tongue and abdominal muscle attenuation as compared to younger subjects (P < 0.001). Age was inversely associated with tongue and abdominal muscle attenuation, indicating muscle fat infiltration.

CONCLUSIONS

The associations between age, upper airway fat volume, visceral and muscle fat infiltration may help to explain the worsening of OSA and increased upper airway collapsibility with aging.

CT volumetric analysis permits comparison of tongue size and tongue fat in different canine brachycephalic and mesaticephalic breeds

While macroglossia is a newly accepted component of brachycephalic obstructive airway syndrome (BOAS) in dogs, macroglossia with increased tongue fat is a well-known cause for obstructive sleep apnea (OSA) in people, and targeted reduction procedures such as midline glossectomy are used to treat people with OSA. While midline glossectomy has been described in dogs, tissue contributions to macroglossia have not been characterized. The purpose of this retrospective, descriptive, case-control study was to describe and compare volumetric dimensions of the tongue and tongue fat in brachycephalic (BC) and mesaticephalic (MC) dogs using CT images. Data collected included head and neck CT images from 17 BC and 18 control MC dogs. Multiplanar reformatted and 3D reconstructed images were created using image segmentation and specialized visualization software to calculate volumetric dimensions of the total tongue, tongue fat, and tongue muscle. Rostral and caudal topographical distributions of fat were compared. Total tongue and tongue muscle volume (P < 0.0001) and tongue fat volume (P = 0.01) normalized to body weight (BW) were greater in BC dogs. More fat was localized in the caudal tongue in both groups (P < 0.04). In regression analysis, BC conformation and increased weight were significant predictors of increased tongue fat volume. As in people, increased tongue fat may contribute to macroglossia and sleep-disordered breathing in BC dogs. Use of CT volumetry to identify tongue fat deposits may permit targeted surgical reduction of tongue volume in BC dogs and contribute substantially to treatment of BOAS.

Computed tomography-based body composition is associated with adverse clinical outcomes among older patients with sepsis in the emergency department

PURPOSE

To investigate the association between body composition and adverse clinical outcomes in older patients with sepsis in the emergency department.

METHODS

Body composition, including the skeletal muscle area, skeletal muscle index (SMI), mean skeletal muscle density (SMD), and intramuscular fat area, was measured at the level of the third lumbar vertebra (L3) on abdominal computed tomography scans. Clinical outcomes included 90-day mortality, 90-day readmission, and discharge to long-term care. According to sex-specific cut-off values of L3 SMI and SMD, patients were divided into low SMI, low SMD, both low SMI and low SMD, and neither low SMI nor low SMD groups.

RESULTS

In total, 443 patients were included, 162 (36.6%) of whom died. Lower SMI and SMD, as continuous variables, were independent risk factors for 90-day mortality (adjusted hazard ratio [HR] = 0.947 and 0.963, respectively, both p < 0.001). Cut-off values of L3 SMI and L3 SMD were 32.24 cm²/m² and 30.01 HU for men and 28.28 cm²/m² and 28.20 HU for women, respectively. The both low SMI and low SMD group had an increased risk of 90-day mortality (adjusted HR=3.059, p < 0.001), 90-day readmission (adjusted odds ratio [OR]=2.859, p = 0.006), and discharge to long-term care (adjusted OR = 2.814, p = 0.007).

CONCLUSIONS

Lower muscle mass and muscle quality, as measured by skeletal muscle index and density, were independent risk factors for mortality among older patients with sepsis in the emergency department. Furthermore, patients with both low muscle mass and quality had an increased risk of mortality, readmission, and discharge to long-term care.

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.

Association between abdominal obesity and diabetic retinopathy in patients with diabetes mellitus: A systematic review and meta-analysis

OBJECTIVE

Previous studies have reported different opinions regarding the association between abdominal obesity and diabetic retinopathy (DR) in patients with diabetes mellitus (DM). In this study, we aimed to investigate this problem through a systematic review and meta-analysis to provide a basis for clinical interventions.

METHODS

A comprehensive search was conducted in the PubMed, Embase, and Web of Science databases up to May 1, 2022, for all eligible observational studies. Standardized mean differences (SMD) and 95% confidence intervals (CI) were evaluated using a random-effects model in the Stata software. We then conducted, publication bias assessment, heterogeneity, subgroup and sensitivity analyses.

RESULTS

A total of 5596 DR patients and 17907 non-DR patients were included from 24 studies. The results of the meta-analysis of abdominal obesity parameters showed statistically significant differences between DR and non-DR patients in both type 1 and type 2 diabetes. Waist circumference (WC) was higher in patients with DR than in the non-DR patients. In the waist-hip ratio (WHR) subgroup, the level of WHR was higher in patients with DR than that in non-DR patients. The association between abdominal obesity and mild to moderate nonproliferative DR or vision-threatening DR groups did not show any statistical difference. Subgroup analysis according to ethnicity showed that Caucasians had higher levels of combined abdominal obesity parameters than Asians.

CONCLUSION

We found that abdominal obesity measured by WC and WHR is associated with DR in patients with type 1 and type 2 diabetes. This association is stronger in Caucasians than in Asians, where isolated abdominal obesity might be more related to DR. However, no correlation was found between abdominal obesity and varying degrees of diabetic retinopathy. Further prospective cohort studies with larger sample sizes are yet to be conducted to clarify our findings.

On the relationship between CT measured abdominal fat parameters and three metabolic risk biomarkers

Introduction: Cardiovascular diseases are the leading cause of morbidity and mortality worldwide, and there is a need for the development of adjacent markers to assess cardiovascular risk. In this study, we examined the relationship between the areas of abdominal fat compartments, as measured by computed tomography (CT)-based planar measurements, and laboratory-validated cardiovascular risk markers.

Methods: Fat distribution was measured on CT scans in 252 patients (M: F = 1.13) who underwent routine abdominal CT, using in-house and commercially available software. The included laboratory parameters were glucose, triglycerides, and the triglycerideglucose index.

Results: The visceral abdominal fat (VAF) area and VAF percentage were lower in females compared to the VAF area and VAF percentage in males, (p=0.001, and p<0.001 respectively). However, the total abdominal fat (TAF) area was not significantly different between genders. Visceral fat and triglyceride levels showed a weakly positive connection for females (r=0.447, p=0.002) but not for males (r=0.229, p=0.09). The glucose levels had a weak correlation with CT calculated abdominal fat parameters, with the strongest statistically significant correlation value being with TAF for females (r=0.331, p=0.003).

Conclusions: Areas of abdominal fat compartments correlate with metabolic parameters in the blood, and in the future, their assessment might be considered when constructing risk scores. Visceral fat content assessment for every abdominal computed tomography procedure might become a surrogate marker for cardio-vascular risk estimation after defining clear cut-off values and image analysis parameters.

A simple and reproducible measure of adipose depots with non-contrast post-mortem computed tomography

Background and aim

Obesity is associated with an increase in different adipose depots. The anatomic distribution of internal adipose confers different risks. Recently, significant interest has emerged in the expansion of epicardial adipose tissue (EAT) as a mediator of adverse cardiovascular events. Often, post-mortem examination remains the best method of investigating morphological changes in health and disease. This study aimed to develop a simple, reproducible, and non-invasive protocol for the measurement of internal adiposity using post-mortem computed tomography (PMCT).

Patients and methods

101 consecutive post-mortem subjects underwent non-contrast computed tomography scans. Measurements were performed using the open-source software 3D Slicer by a non-expert researcher. An expert radiologist and cardiologist verified the abdominal and cardiac sites of adiposity, respectively. We aimed to develop a protocol to measure total EAT, sub-depots of EAT, extra-pericardial adipose, visceral and subcutaneous adipose, and suprasternal adipose.

Results

We found excellent reproducibility for our measures of total EAT, anterior right atrial EAT, extra-pericardial adipose, and visceral adipose tissue, with intraclass correlations between 0.82 and 0.99 for each measure. Due to a lack of suitable anatomical boundaries, other sub-depots of EAT, including in the interventricular groove, were not reproducible.

Conclusions

Quantification of total EAT and anterior right atrial EAT are readily reproducible using 3D Slicer on post-mortem CT. They can be reliably measured by non-expert researchers with a small amount of training, and therefore be used to investigate morphological changes in adiposity in health and disease.

18F-FDG uptake of visceral adipose tissue on preoperative PET/CT as a predictive marker for breast cancer recurrence

Glucose utilization by visceral adipose tissue (VAT) reflects inflammatory activity, which also promotes tumor growth and carcinogenesis. The effect of metabolically active VAT on survival outcomes in breast cancer is unknown. We investigated survival outcomes in patients with breast cancer based on the standardized uptake value (SUV) of VAT (SUVmean-VAT) using ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT). A total of 148 patients with breast cancer were divided into high- and low groups according to their SUVmean-VAT and SUVmax-tumor. Clinical characteristics and survival outcomes were compared between the groups. High SUVmean-VAT was associated with poor recurrence-free survival (RFS; hazard ratio [HR], 2.754; 95% confidence interval [CI], 1.090-6.958, p = 0.032) and distant metastasis-free survival (DMFS; HR, 3.500; 95% CI, 1.224-10.01, p = 0.019). Multivariate analysis showed that high SUVmean-VAT was a significant factor for poor RFS and poor DMFS (p = 0.023 and 0.039, respectively). High SUVmax-tumor was significantly associated with short RFS (p = 0.0388). Tumors with a high SUV tended to have a short DMFS, although the difference was not significant (p = 0.0718). Our findings showed that upregulated glucose metabolism in the VAT measured using ¹⁸F-FDG PET/CT may be a prognostic biomarker for adverse outcomes in breast cancer.

Identifying sex differences in predictors of epicardial fat cell morphology

Predictors of overall epicardial adipose tissue deposition have been found to vary between males and females. Whether similar sex differences exist in epicardial fat cell morphology is currently unknown. This study aimed to determine whether epicardial fat cell size is associated with different clinical measurements in males and females. Fat cell sizes were measured from epicardial, paracardial, and appendix adipose tissues of post-mortem cases (N= 118 total, 37 females). Epicardial, extra-pericardial, and visceral fat volumes were measured by computed tomography from a subset of cases (N= 70, 22 females). Correlation analyses and stepwise linear regression were performed to identify predictors of fat cell size in males and females. Median fat cell sizes in all depots did not differ between males and females. Body mass index (BMI) and age were independently predictive of epicardial, paracardial, and appendix fat cell sizes in males, but not in females. Epicardial and appendix fat cell sizes were associated with epicardial and visceral fat volumes, respectively, in males only. In females, paracardial fat cell size was associated with extra-pericardial fat volume, while appendix fat cell size was associated with BMI only. No predictors were associated with epicardial fat cell size in females at the univariable or multivariable levels. To conclude, no clinical measurements were useful surrogates of epicardial fat cell size in females, while BMI, age, and epicardial fat volume were independent, albeit weak, predictors in males only.

Effects of exercise combined with diet intervention on body composition and serum biochemical markers in adolescents with obesity: a systematic review and meta-analysis

BACKGROUND

This systematic review aims to evaluate the effects of exercise combined with diet (ECWD), exercise alone, diet alone, and no intervention on body composition and serum biochemical markers in adolescents with obesity to provide reference for solving the metabolic disorders of adolescents caused by obesity.

CONTENTS

Studies published before January 5, 2021 were retrieved from PubMed, Web of Science, Ovid, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang data, VIP database, and SinoMed. Randomized controlled trials with an age between 10 and 20 years, body mass index (BMI) ≥28 kg/m² or ≥95th percentiles, no history of endocrine and metabolic diseases, heart disease, hematologic disease, and so on before the trial were included.

SUMMARY

Fifteen of the 50,155 studies met the criteria. Meta-analysis showed that ECWD was more effective in reducing BMI (kg/m²) (-2.45 kg/m², 95% CI: -3.06; -1.85) and fat thickness of back (-13.77 mm, 95% CI: -15.92; -11.62), abdomen (-11.56 mm, 95% CI: -14.04; -9.09), and upper arm (-14.81 mm, 95% CI: -16.74; -12.89) than other interventions; in reducing body fat (-7.03 kg, 95% CI: -9.77; -4.29) and thigh circumference (-4.05 cm, 95% CI: -5.58; -2.52), ECWD and diet alone were more effective than exercise alone; ECWD and exercise alone were more effective in reducing waist circumference (-6.05 cm, 95% CI: -8.37; -3.72), waist-to-hip ratio (WHR; -0.06, 95% CI: -0.11; -0.01), upper arm circumference (-2.57 cm, 95% CI: -3.70; -1.45), triglycerides (TG; -0.30 mmol/L, 95% CI: -0.45; -0.14), total cholesterol (TC; -0.30 mmol/L, 95% CI: -0.59; -0.01), and low density lipoprotein (LDL; -0.22 mmol/L, 95% CI: -0.40; -0.04) than diet alone. ECWD also had effects on tumor necrosis factor-α (TNF-α), interleukin-6, leptin, and so on.

OUTLOOK

ECWD is more effective than exercise alone, diet alone, or no intervention in solving the problems of body shape and metabolic disorder of adolescents with obesity.

Quality measures for fully automatic CT histogram-based fat estimation on a corpse sample

In a previous article a new algorithm for fully automatic 'CT histogram based Fat Estimation and quasi-Segmentation' (CFES) was validated on synthetic data, on a special CT phantom, and tested on one corpse. Usage of said data in FE-modelling for temperature-based death time estimation is the investigation's number one long-term goal. The article presents CFES's results on a human corpse sample of size R = 32, evaluating three different performance measures: the τ-value, measuring the ability to differentiate fat from muscle, the anatomical fat-muscle misclassification rate D, and the weighted distance S between the empirical and the theoretical grey-scale value histogram. CFES-performance on the sample was: D = 3.6% for weight exponent α = 1, slightly higher for α ≥ 2 and much higher for α ≤ 0. Investigating τ, S and D on the sample revealed some unexpected results: While large values of τ imply small D-values, rising S implies falling D and there is a positive linear relationship between τ and S. The latter two findings seem to be counter-intuitive. Our Monte Carlo analysis detected a general umbrella type relation between τ and S, which seems to stem from a pivotal problem in fitting Normal mixture distributions.

Deep learning-based fully automated body composition analysis of thigh CT: comparison with DXA measurement

OBJECTIVES

To compare volumetric CT with DL-based fully automated segmentation and dual-energy X-ray absorptiometry (DXA) in the measurement of thigh tissue composition.

METHODS

This prospective study was performed from January 2019 to December 2020. The participants underwent DXA to determine the body composition of the whole body and thigh. CT was performed in the thigh region; the images were automatically segmented into three muscle groups and adipose tissue by custom-developed DL-based automated segmentation software. Subsequently, the program reported the tissue composition of the thigh. The correlation and agreement between variables measured by DXA and CT were assessed. Then, CT thigh tissue volume prediction equations based on DXA-derived thigh tissue mass were developed using a general linear model.

RESULTS

In total, 100 patients (mean age, 44.9 years; 60 women) were evaluated. There was a strong correlation between the CT and DXA measurements (R = 0.813~0.98, p < 0.001). There was no significant difference in total soft tissue mass between DXA and CT measurement (p = 0.183). However, DXA overestimated thigh lean (muscle) mass and underestimated thigh total fat mass (p < 0.001). The DXA-derived lean mass was an average of 10% higher than the CT-derived lean mass and 47% higher than the CT-derived lean muscle mass. The DXA-derived total fat mass was approximately 20% lower than the CT-derived total fat mass. The predicted CT tissue volume using DXA-derived data was highly correlated with actual CT-measured tissue volume in the validation group (R² = 0.96~0.97, p < 0.001).

CONCLUSIONS

Volumetric CT measurements with DL-based fully automated segmentation are a rapid and more accurate method for measuring thigh tissue composition.

KEY POINTS

• There was a positive correlation between CT and DXA measurements in both the whole body and thigh. • DXA overestimated thigh lean mass by 10%, lean muscle mass by 47%, but underestimated total fat mass by 20% compared to the CT method. • The equations for predicting CT volume (cm³) were developed using DXA data (g), age, height (cm), and body weight (kg) and good model performance was proven in the validation study.

Evaluation of risk factors and diseases associated with metabolic and atherosclerotic disorders in different abdominal fat distribution patterns assessed by CT-scan

INTRODUCTION

Obesity is defined as an increase in body fat composition.

High Visceral Fat is Associated with a Worse Survival after Liver Resection for Intrahepatic Cholangiocarcinoma

The impact of body composition (BC) on the prognosis of resected intrahepatic cholangiocarcinoma (ICC) has been poorly studied. Aims: i) to evaluate the prevalence of low muscle mass (MM) in patients; ii) to assess the impact of BC on patient overall survival (OS) and disease-free survival (DFS), and iii) on the incidence of postoperative complications. All consecutive patients who underwent liver resection for ICC between 2004 and 2016 and who had preoperative CT scans were included. Ninety-three patients were included. Sixty percent (55/91) had low total MM. On multivariable analysis, high visceral fat (HR 2.48, CI95% [1.63; 3.77], p < 0.0001), nodules >1 (HR 3.15 [1.67; 5.93], p = 0.0004), involvement adjacent organ (HR 6.67 [1.88; 23.69], p = 0.003), and postoperative sepsis (HR 3.04 [1.54; 5.99], p = 0.0013) were independently associated with OS. High visceral fat (HR 2.10 [1.31; 3.38], p = 0.002], nodules >1 (HR 3.01, [1.49; 6.10], p = 0.002), postoperative sepsis (HR 5.16 [2.24; 11.89], p = 0.0001), ASA score (p = 0.02) and perineural invasion (HR 3.30 [1.62; 6.76], p = 0.001) were independently associated with lower DFS. Conclusion: 60% of ICC patients had low MM before surgery. High visceral fat, but not muscle mass, was an independent prognostic factor for poor OS and DFS in European patients with resected ICC.

Visceral adipose volume is correlated with surgical tissue fibrosis in Crohn's disease of the small bowel

Background

This study explored the diagnostic performance of visceral adiposity to predict the degree of intestinal inflammation and fibrosis.

Methods

The patients with Crohn’s disease (CD) who underwent surgical small bowel resection at the First Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between January 2007 and December 2017 were enrolled. We evaluated the intestinal imaging features of computed tomography enterography (CTE), including mesenteric inflammatory fat stranding, the target sign, mesenteric hypervascularity, bowel wall thickening, lymphadenopathy, stricture diameter, and maximal upstream diameter. We used A.K. software (Artificial Intelligence Kit, version 1.1) to calculate the visceral fat (VF) and subcutaneous fat (SF) volumes at the third lumbar vertebra level. Pathological tissue information was recorded. Diagnostic models were established based on the multivariate regression analysis results, and their effectiveness was evaluated by area under the curve (AUC) and decision curve analyses.

Results

Overall, 48 patients with CD were included in this study. The abdominal VF/SF volume ratio (odds ratio, 1.20; 95% confidence interval, 1.05–1.38; P = 0.009) and the stenosis diameter/upstream intestinal dilatation diameter (ND) ratio (odds ratio, 0.90; 95% confidence interval, 0.82–0.99; P = 0.034) were independent risk factors for the severe fibrosis of the small intestine. The AUC values of the VF/SF ratio, the ND ratio, and their combination were 0.760, 0.673, and 0.804, respectively. The combination of the VS/SF volume ratio and ND ratio achieved the highest net benefit on the decision curve.

Conclusion

The VF volume on CTE can reflect intestinal fibrosis. The combination of the VF/SF volume ratio and ND ratio of CD patients assessed using CTE can help predict severe fibrosis stenosis of the small intestine.

Estimation of visceral fat area using criteria for metabolic syndrome: A cross-sectional study

BACKGROUND AND AIMS

The aim of this study was to calculate the visceral fat area (VFA) based on the criteria for metabolic syndrome (MetS).

METHODS

A multiple regression analysis was performed to determine the estimated VFA using data from Japanese participants (2315 men and 1684 women). Receiver operating characteristic curve (ROC) analyses were performed to determine the optimal estimated VFA cutoff for the diagnosis of central obesity. The cutoff was also applied to a second cohort to validate the model.

RESULTS

The estimated VFA was calculated using the MetS criteria, age, and body mass index (adjusted coefficient of determination = 0.682 for men and 0.726 for women). The area under the ROC curve for waist circumference, VFA, and estimated VFA were 0.669, 0.741, and 0.749, respectively, for men and 0.711, 0.787, and 0.803, respectively, for women. The optimal cutoffs for estimated VFA were 128.1 cm² for men and 82.2 cm² for women. Multivariate logistic regression for heart disease revealed that estimated VFA, rather than waist circumference, was associated with a high risk of heart disease.

CONCLUSION

The estimated VFA is a better index of central obesity than waist circumference and VFA for the diagnosis of MetS.

Utilizing Computed Tomography to Analyze the Morphomic Change between Patients with Localized and Metastatic Renal Cell Carcinoma: Body Composition Varies According to Cancer Stage

Background: This study aimed to elucidate the change of body composition in different clinical stages of renal cell carcinoma (RCC) by analyzing computed tomography (CT) images. Methods: We enrolled patients diagnosed with RCC in a tertiary medical center who did not mention body weight loss or symptoms of cachexia. We grouped patients into those with localized RCC and those with metastatic RCC. Analyses of the volume of skeletal muscles tissue (SMT), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) calculated based on CT images were performed and included subgroup analyses by sex and age. The correlation between tumor size and body composition in localized RCC was also examined. Results: A total of 188 patients were enrolled in this study. There was significantly lower VAT (p = 0.015) in the metastatic group than in the localized group. SAT, body weight, and body mass index (BMI) were not significantly different between these two groups. In the subgroup analysis, a significant difference in SMT and VAT was noted in the male and younger subgroups but not in the female and older subgroups. Regarding primary tumor size in localized RCC, VAT was significantly higher in patients with larger tumors (p = 0.003). Conclusions: In localized RCC, VAT volume was significantly larger in those with large primary tumor size. However, the VAT was significantly lower in those with metastatic status comparing to those with localized disease. The clinical course of cancers closely correlates with body composition.

Visceral Fat Area Measured by Abdominal Bioelectrical Impedance Analysis in School-Aged Japanese Children

Abdominal bioelectrical impedance analysis (aBIA) has been in use to measure visceral fat area (VFA) in adults. Accurately measuring visceral fat using aBIA in children is challenging. Forty-six school-aged Japanese children aged 6–17 years (25 boys and 21 girls) were included in this study. All were measured, and their VFA obtained using aBIA (VFA-aBIA) and abdominal computed tomography (CT) (VFA-CT) were compared. VFA-aBIA was corrected using the Passing–Bablok method (corrected VFA-aBIA). The relationships between corrected VFA-aBIA and obesity-related clinical factors were analyzed, including non-alcoholic fatty liver disease (NAFLD) and serum leptin and adiponectin levels. Boys had higher VFA-CT than girls (p = 0.042), although no significant differences were found in their waist circumference, waist-to-height ratio, and body mass index. The corrected VFA-aBIA using y = 9.600 + 0.3825x (boys) and y = 7.607 + 0.3661x (girls) correlated with VFA-CT in both boys and girls. The corrected VFA-aBIA in patients with NAFLD was higher than that in those without NAFLD. Serum leptin and adiponectin levels were positively and negatively correlated with corrected VFA-aBIA, respectively. In conclusion, corrected VFA-aBIA was clearly correlated with VFA-CT and was related to NAFLD and serum leptin and adiponectin levels in school-aged Japanese children.

Metabolik sendromda visseral ve subkutan yağ miktari ve hepatosteatozun bilgisayarli tomografi ile kantitatif değerlendirilmesi

Purpose: We aimed to evaluate visceral and subcutaneous fat tissue and its association with hepatosteatosis on computed tomography (CT) scans to determine cut-off criteria for metabolic syndrome, measure abdominal obesity directly based on the visceral fat tissue area (VFTA) rather than indirectly based on waist circumference and obtain supportive findings by density measurements in addition to the VFTA measurements.Materials and Methods: The Hounsfield unit (HU) values, visceral, subcutaneous fat areas and HU values of 108 patients diagnosed with metabolic syndrome (MS) were determined according to the National Cholesterol Education Program Adult Treatment Panel III 2001 Criteria by retrospectively analyzing their abdominal CT images taken for various reasons. The relationships of the obtained values with each other and to MS were evaluated.Results: The strongest predictor of MS was VFTA, and 156.47 cm² was the most significant value with 74.1% sensitivity and 58.6% specificity. An HU value of -102.99 for visceral fat tissue density (VFTD) was found as the second most significant finding with 75% sensitivity and 57.6% specificity. The VFTA values of the patients with hepatosteatosis were higher, and increased VFTA values were associated with lower VFTD values.Conclusion: The most important supportive finding was the demonstration of the possibility of measuring abdominal obesity, which has an important place among criteria, directly by measuring VFTA, rather than indirectly based on waist circumference. 

A low subcutaneous fat mass is a risk factor for the development of inguinal hernia after radical prostatectomy

PURPOSE

Inguinal hernia (IH) after radical prostatectomy (RP) is a complication that impairs quality of life; however, the factors contributing to IH after RP remain unclear. Therefore, we herein attempted to identify the factors responsible for the development of IH after RP.

METHODS

We reviewed 622 patients who underwent laparoscopic or robot-assisted laparoscopic RP at our hospital between December 2011 and April 2020. The total fat area and visceral fat area were calculated at the level of the umbilicus using computed tomography, and the subcutaneous fat area (SFA) was calculated by subtracting the visceral fat area from the total fat area. The psoas muscle area was measured at the third lumbar vertebrae level using computed tomography to calculate the psoas muscle mass index, which is used in sarcopenia as an index of muscle mass. We investigated the risk factors for IH after laparoscopic or robot-assisted laparoscopic RP.

RESULTS

IH developed in 88 patients (16.7%). Fifty-seven of these patients underwent hernia repair at our hospital, and 56 (98.2%) had indirect hernias. A multivariate analysis identified SFA (odds ratios: 0.383, p < 0.001) as an independent predictor for the development of IH. Two-year IH-free survival rates were 77.3% in the small SFA group (SFA < 123 cm²) and 88.7% in the large SFA group (SFA ≥ 123 cm²) (p < 0.001).

CONCLUSION

Subcutaneous fat was associated with the development of IH, particularly indirect IH, after laparoscopic or robot-assisted laparoscopic RP. An indirect IH prevention technique needs to be considered, particularly for patients with less subcutaneous fat.

Value-added Opportunistic CT Screening: State of the Art

Opportunistic CT screening leverages robust imaging data embedded within abdominal and thoracic scans that are generally unrelated to the specific clinical indication and have heretofore gone largely unused. This incidental imaging information may prove beneficial to patients in terms of wellness, prevention, risk profiling, and presymptomatic detection of relevant disease. The growing interest in CT-based opportunistic screening relates to a confluence of factors: the objective and generalizable nature of CT-based body composition measures, the emergence of fully automated explainable AI solutions, the sheer volume of body CT scans performed, and the increasing emphasis on precision medicine and value-added initiatives. With a systematic approach to body composition and other useful CT markers, initial evidence suggests that their ability to help radiologists assess biologic age and predict future adverse cardiometabolic events rivals even the best available clinical reference standards. Emerging data suggest that standalone "intended" CT screening over an unorganized opportunistic approach may be justified, especially when combined with established cancer screening. This review will discuss the current status of opportunistic CT screening, including specific body composition markers and the various disease processes that may be impacted. The remaining hurdles to widespread clinical adoption include generalization to more diverse patient populations, disparate technical settings, and reimbursement.

High visceral to subcutaneous fat area ratio predicts early postoperative small bowel obstruction after surgery for colorectal cancer

PURPOSE

Risks for postoperative small bowel obstruction have been demonstrated in several reports, most of which indicated male sex was a risk factor, but with the reason remaining unknown. We tested the hypothesis that it could be because males have more visceral fat than females. This prospective observational study aims to examine risks of early postoperative small bowel obstruction (EPSBO) after colorectal cancer surgery and the association between visceral to subcutaneous fat area ratio (V/S ratio) and EPSBO.

METHODS

Four hundred and seventy-four patients who underwent colectomy for colorectal cancer in our hospital were enrolled in this study. The influence of several factors including V/S ratio on the development of EPSBO was analyzed.

RESULTS

Thirty-one of the 474 patients (6.5%) developed EPSBO. EPSBO occurred more frequently in males (p = 0.03) and cases who developed postoperative anastomotic leakage (p < 0.001) or wound infection (p = 0.02). Higher V/S ratio was strongly related to male sex (p < 0.001). Multivariate analysis revealed higher V/S ratio (OR 2.25; p = 0.049) and anastomotic leakage (OR 5.86; p < 0.001) were independent risk factors for EPSBO.

CONCLUSION

Higher V/S ratio was significantly related to EPSBO, suggesting that one of the reasons EPSBO was more likely to occur in males because they have more visceral fat than females. Preoperative identification of this risk factor could help us watch out for this potential complication.

A preliminary coronary computed tomography angiography-based study of perivascular fat attenuation index: relation with epicardial adipose tissue and its distribution over the entire coronary vasculature

OBJECTIVES

To investigate the perivascular fat attenuation index (FAI) in association with epicardial adipose tissue (EAT) parameters and its distribution over the entire coronary vasculature in patients with known or suspected coronary artery disease (CAD).

METHODS

Patients with known or suspected CAD who underwent coronary computed tomography angiography from January 1, 2019, to June 1, 2019, were retrospectively included. The perivascular FAI was quantified on four main epicardial coronary arteries and seven coronary segments. Moreover, EAT density and volume were measured.

RESULTS

We included 192 consecutive patients (55 without coronary plaque [mean age 46.4 ± 13.2 years, 69.1% male] and 137 with coronary plaque [mean age 57.9 ± 13.0 years, 84.7% male]). EAT density was lower than perivascular FAI in both groups, but they exhibited substantial correlation (- 83.33 ± 4.54 vs. - 78.22 ± 6.52 HU, p < 0.001; r = 0.667 in plaque- patients and - 83.11 ± 4.48 vs. - 77.81 ± 5.63 HU, p < 0.001; r = 0.778 in plaque+ patients). The left main coronary artery had the highest perivascular FAI, followed by the left circumflex artery. The perivascular FAI in proximal segments was significantly higher compared to that in distal segments (all p < 0.05). Furthermore, the presence of plaque did not alter perivascular FAI on the patient or segmental level.

CONCLUSION

The perivascular FAI was significantly higher than EAT density and correlated substantially with EAT density. The perivascular FAI distribution over the entire coronary tree varied and prompted for vessel-specific or segment-specific thresholds to determine abnormal perivascular FAI in practice.

KEY POINTS

• The perivascular FAI correlated well with EAT density and had higher values than EAT density. • The distributions of perivascular FAI differ between coronary vessels or segments; considering segment and vessel confounding factors while conducting a perivascular FAI study is necessary. • No significant difference of perivascular FAI was observed between patients without and with coronary plaque, nor between coronary segments without plaque and those with plaque.

Myosteatosis in Cirrhosis: A Review of Diagnosis, Pathophysiological Mechanisms and Potential Interventions

Myosteatosis, or pathological excess fat accumulation in muscle, has been widely defined as a lower mean skeletal muscle radiodensity on computed tomography (CT). It is reported in more than half of patients with cirrhosis, and preliminary studies have shown a possible association with reduced survival and increased risk of portal hypertension complications. Despite the clinical implications in cirrhosis, a standardized definition for myosteatosis has not yet been established. Currently, little data exist on the mechanisms by which excess lipid accumulates within the muscle in individuals with cirrhosis. Hyperammonemia may play an important role in the pathophysiology of myosteatosis in this setting. Insulin resistance, impaired mitochondrial oxidative phosphorylation, diminished lipid oxidation in muscle and age-related differentiation of muscle stem cells into adipocytes have been also been suggested as potential mechanisms contributing to myosteatosis. The metabolic consequence of ammonia-lowering treatments and omega-3 polyunsaturated fatty acids in reversing myosteatosis in cirrhosis remains uncertain. Factors including the population of interest, design and sample size, single/combined treatment, dosing and duration of treatment are important considerations for future trials aiming to prevent or treat myosteatosis in individuals with cirrhosis.

Effects of Synbiotic Preparation Containing Lactobacillus gasseri BNR17 on Body Fat in Obese Dogs: A Pilot Study

Simple Summary

The present study evaluated the effectiveness of a synbiotic preparation containing L. gasseri BNR17 on body fat in obese dogs. Body weight and the body condition score showed a significant reduction after 10 weeks of synbiotic preparation administration compared with those at baseline (0-week). The subcutaneous fat mass at the level of the third lumbar vertebra and its proportion, compared with the body mass, reduced significantly after 10 weeks of synbiotic preparation administration, compared with those at baseline. Following synbiotic supplementation, microbiome analysis revealed increased microbial diversity, and functional analysis of the microbiota showed an increased abundance of carbohydrate and lipid metabolism. Based on these results, we consider that synbiotic preparation containing L. gasseri BNR17 may play a role in reducing body fat and resolving obesity.

Abstract

Obesity is an important health concern in humans and dogs. It can cause a variety of secondary problems, including low bacterial diversity. Several approaches have been tried to solve this problem; one of them is probiotic supplementation. Lactobacillus gasseri BNR17 is derived from breast milk and has been proven to be effective for obesity in humans. However, there have been no studies using a synbiotic preparation containing L. gasseri BNR17 for obesity management in dogs. Therefore, the present study evaluated the effectiveness of a synbiotic preparation containing L. gasseri BNR17 in reducing body fat in obese dogs. A group of obese dogs were fed a synbiotic preparation for 10 weeks. Obesity variables included body weight, body condition score, subcutaneous fat thickness, subcutaneous fat mass and proportion of the fat mass. In addition, feces collected at 0-week and 10-week time points were analyzed for the intestinal microbiome. Results showed a significant decrease in body weight, body condition score, and subcutaneous fat mass and proportion at the level of the third lumbar vertebra. Diversity and functional analysis of the microbiota in obese dogs showed increased microbial diversity, and increased abundance of metabolism of carbohydrate, and lipid after supplementation with a synbiotic preparation. This study was conducted as a pilot study, and the results demonstrated that a synbiotic preparation containing L. gasseri BNR17 may play a role in reducing body fat and resolving the obesity in dogs.

HELICAL COMPUTERIZED TOMOGRAPHY CAN MEASURE SUBCUTANEOUS, VISCERAL AND TOTAL FAT AREAS?

Background:

Abdominal obesity or android obesity, that is, the increase in adipose tissue in the abdominal region, is considered a risk factor for several morbidities. Different ways of quantifying it have been proposed, one method is the measurement of the abdominal fat area by computed tomography.

Aim:

To establish correspondence between the groups defined by degree of obesity in relation to the total, subcutaneous and visceral fat area.

Methods:

Cross-sectional observational study carried out through the analysis of tomographic examinations. Horos v3.3.5 medical image visualization software was used, with abdominal tomography in a single cut including the L4 vertebral body and the umbilical scar, to obtain the areas of total, visceral and subcutaneous fat.

Results:

Of the 40 patients, 10 had grade II obesity, 23 grade III and 7 superobese. The amount of total fat showed an increase in relation to the degree of obesity. Visceral fat did not show significant differences between the degrees of obesity, but the data showed a lower average in the group of obesity grade II. The area of subcutaneous fat, as well as total fat, showed an increase in its measurements, according to the progression of the patients’ BMI, but there was no statistical significance in this difference between the groups of grade II and super-obese individuals.

Conclusion:

The area of total and subcutaneous fat showed an increase in its measurements according to the progression of the BMI groups, which did not happen with visceral fat.