Comparison of anthropometric, area- and volume-based assessment of abdominal subcutaneous and visceral adipose tissue volumes using multi-detector computed tomography

Impact of pathologic body composition assessed by CT-based anthropometric measurements in adult patients with multiple trauma: a retrospective analysis

PURPOSE

In recent years, there has been mounting evidence on the clinical importance of body composition, particularly obesity and sarcopenia, in various patient populations. However, the relevance of these pathologic conditions remains controversial, especially in the field of traumatology. Computed tomography-based measurements allow clinicians to gain a prompt and thorough assessment of fat and muscle compartments in trauma patients. Our aim was to investigate whether CT-based anthropometric parameters of fat and muscle tissues show correlations with key elements of pre-hospital and clinical care in an adult population with multiple trauma.

METHODS

In this retrospective analysis we searched our institutional records of the German Trauma Registry (TraumaRegister DGU^®) from January 2008 to May 2014. Included were 297 adult trauma patients with multiple trauma who underwent a whole-body CT-scan on admission and were treated in an ICU. We measured anthropometric determinants of abdominal core muscle and adipose tissue using the digital imaging software OsiriX™. Multivariate linear and logistic regression analyses were conducted to unveil potential correlations.

RESULTS

None of the obesity-linked anthropometric parameters were associated with longer pre-hospital or initial ED treatment times. Obese patients were less frequently intubated at the site of the accident. Patients with increased abdominal fat tissue received on average lower volumes during fluid resuscitation in the pre-hospital phase but were not more often in shock on admission. During ED treatment, fluid resuscitation and transfusion volumes were not affected by abdominal fat tissue, although transfusion rates were higher in the obese. Furthermore, damage control surgeries took place less frequently in patients with increased abdominal fat tissue markers. Obesity parameters did not affect the prevalence of sepsis, although increased abdominal fat was associated with higher white blood cell counts on admission. Finally, there was no statistically significant correlation between sarcopenia or obesity markers and duration of mechanical ventilation, ICU length of stay or neurologic outcome.

CONCLUSION

CT-based assessment of abdominal fat and muscle mass is a simple method in revealing pathologic body composition in trauma patients. Our study suggests that obesity influences pre-hospital and ED treatment and early immune response in multiple trauma. Nevertheless, we could not demonstrate any significant effect of abdominal fat and muscle tissue parameters on the course of treatment, in particular the duration of mechanical ventilation, ICU length of stay and neurologic outcome.

Evaluation of visceral fat mass in dogs by computed tomography

In human medicine, computed tomography (CT) is the gold standard for visceral fat measurement. Research shows that the visceral fat area (VFA) of the umbilical slice is significantly correlated with the visceral fat volume (VFV). In veterinary medicine, however, few studies have evaluated visceral fat using CT. This study aimed to evaluate the visceral fat in dogs using CT images, and determine if the slice significantly correlated with VFV to simplify visceral fat measurements. This retrospective study includes data on 90 dogs that underwent whole-body CT scans for diagnostic purposes. VFV was calculated as the product of VFA and thickness in each CT slice; the correlation between VFV and VFA was analyzed at the level of each lumbar vertebra. Visceral fat percentage (VF%) was calculated as the ratio of the product of VFV and fat density to the body weight. Visceral fat area percentage (VFA%) was calculated as the ratio of VFA to the body area, and its correlation with the VF% and the body condition score (BCS) was analyzed. VFA was highly correlated with VFV at the level of each lumbar vertebra, with the highest correlation (r=0.964) at the L3 level. VFA% was significantly correlated with VF% (r=0.930) and weakly correlated with BCS (r=0.523). This study demonstrates that it is sufficient to use only the L3 slice for visceral fat evaluation and that the evaluation can be based on VFA% of the L3 level.

Obesity promotes resistance to anti-VEGF therapy in breast cancer by up-regulating IL-6 and potentially FGF-2

Anti-vascular endothelial growth factor (VEGF) therapy has failed to improve survival in patients with breast cancer (BC). Potential mechanisms of resistance to anti-VEGF therapy include the up-regulation of alternative angiogenic and proinflammatory factors. Obesity is associated with hypoxic adipose tissues, including those in the breast, resulting in increased production of some of the aforementioned factors. Hence, we hypothesized that obesity could contribute to anti-VEGF therapy's lack of efficacy. We found that BC patients with obesity harbored increased systemic concentrations of interleukin-6 (IL-6) and/or fibroblast growth factor 2 (FGF-2), and their tumor vasculature was less sensitive to anti-VEGF treatment. Mouse models revealed that obesity impairs the effects of anti-VEGF on angiogenesis, tumor growth, and metastasis. In one murine BC model, obesity was associated with increased IL-6 production from adipocytes and myeloid cells within tumors. IL-6 blockade abrogated the obesity-induced resistance to anti-VEGF therapy in primary and metastatic sites by directly affecting tumor cell proliferation, normalizing tumor vasculature, alleviating hypoxia, and reducing immunosuppression. Similarly, in a second mouse model, where obesity was associated with increased FGF-2, normalization of FGF-2 expression by metformin or specific FGF receptor inhibition decreased vessel density and restored tumor sensitivity to anti-VEGF therapy in obese mice. Collectively, our data indicate that obesity fuels BC resistance to anti-VEGF therapy via the production of inflammatory and angiogenic factors.

The effects of testosterone administration on muscle areas of the trunk and pelvic floor in hysterectomized women with low testosterone levels: proof-of-concept study

OBJECTIVE

The aim of this study was to determine the effect of testosterone administration on trunk and pelvic floor muscle area in women with low testosterone levels.

METHODS

Participants were hysterectomized women with total testosterone<31 ng/dL and/or free testosterone<3.5 pg/mL; participating in the Testosterone Dose Response in Surgically Menopausal Women (TDSM) trial. All participants received a standardized transdermal estradiol regimen during the 12-week run-in period, and were then randomized to receive weekly intramuscular injections of placebo, or 3, 6.25, 12.5, or 25 mg testosterone enanthate for 24 weeks. Muscle areas of the trunk and pelvis were measured at baseline and end of treatment using 1.5 Tesla magnetic resonance imaging. Total and free testosterone levels were measured by liquid chromatography-tandem mass spectrometry and equilibrium dialysis, respectively. Testosterone effect on muscle areas was analyzed using linear regression models.

RESULTS

A total of 24 women who had available baseline and posttreatment magnetic resonance imaging were included in the analysis. Increased cross-sectional areas of the paraspinal, psoas, and abdominal wall muscles were seen after testosterone administration. The estimated mean change (95% CI; P value) between treatment groups was 4.07 cm (1.26-6.88; P = 0.007) for paraspinal, 1.60 cm (0.10-3.09; P = 0.038) for psoas major, and 7.49 cm (1.96-13.02; P = 0.011) for abdominal wall muscles. Increases in psoas muscle area were significantly associated with changes in free testosterone concentrations. No significant changes in obturator internus and pelvic floor muscle areas were observed.

CONCLUSION

Short-term testosterone administration in women with low testosterone levels was associated with increased trunk muscle area.

Diagnostic Criteria for Obesity Disease in Cats

Accumulated visceral and subcutaneous fat masses were measured with computed tomography (CT) in cats with various body condition scores (BCS) from 5/9 to 9/9. BCS does not always reflect visceral fat accumulation which induces pro-inflammatory reactions. Obese cats with accumulated visceral fat showed low plasma adiponectin and high serum amyloid A (SAA) concentrations, an inflammatory marker. Based on the above results, new diagnostic criteria for obesity disease were established as follows. For overweight cats with high BCS of >7/9, showing two or more of the following three symptoms, low adiponectin concentrations, hyperlipidemia, and high SAA concentrations, categorizes them as having obesity disease. Cats with BCS 6/9-9/9, without inflammatory reactions, were classified as simple obesity, which is similar to metabolically healthy obesity (MHO) defined in human medicine. Simple obesity group showed significantly higher adiponectin concentrations than those in control group. The obesity disease group showed significantly higher plasma triglyceride (TG) and SAA concentrations and lower concentrations of adiponectin than the control group. Moreover, plasma glucose and malondialdehyde (MDA) concentrations in the obesity disease group were higher than those in healthy control group, although the differences were not statistically significant. Establishing criteria for obesity disease based on visceral fat accumulation and inflammation markers levels contributes to early and correct diagnosis of obesity in cats.

Evaluation of the Severity of Hyperlipidemia Pancreatitis Using CT-measured Visceral Adipose Tissue

BACKGROUND

Computed tomography-measured visceral adipose tissue (VAT) and the distribution of VAT are highly correlated with the severity and prognosis of acute pancreatitis (AP). To date, all available data are from the overall AP patient population; no subgroup analysis has been conducted to evaluate patients with moderately severe AP or patients with hyperlipidemia acute pancreatitis (HLAP) as independent populations. Currently, studies on the relationship between VAT and HLAP are lacking.

MATERIALS AND METHODS

A total of 235 patients with moderately severe AP or severe acute pancreatitis were divided into 2 groups according to whether hyperlipidemia was present: the HLAP group and the non-HLAP group. The general inpatient information was collected, and computed tomography was used to measure VAT, subcutaneous adipose tissue (SAT), total adipose tissue, and VAT/SAT (V/S). The data were subjected to t test, χ test, matrix scatter plot, logistic regression, and receiver operating characteristic analyses to evaluate the relationship between VAT and HLAP severity.

RESULTS

Significant differences were observed in VAT, SAT, total adipose tissue, and triglycerides (TGs) between the HLAP group and the non-HLAP group (P<0.001). Significant correlations were observed between VAT and body mass index (r=0.425, P=0.017) and between VAT and TG (r=0.367, P=0.042). In the HLAP group, VAT, V/S, TG, and local complications may have significant effects on disease severity. The receiver operating characteristic curves showed that VAT and V/S were more reliable than TGs in evaluating disease severity [area under the curve (AUC) of VAT: 0.819, P<0.001; AUC of V/S: 0.855, P<0.001; AUC of TG: 0.671, P=0.04]. Disease severity was reliably evaluated at 139 cm, the cut-off value of VAT. The cut-off value of V/S was 1.145; high V/S was associated with extended intensive care unit stay. VAT and its distribution had no significant effects on mortality.

CONCLUSIONS

For patients with moderately severe to severe HLAP, VAT was correlated with body mass index and TG. VAT and V/S were valuable factors for evaluating disease severity and prognosis. However, VAT had no effect on mortality, and VAT could not be used to evaluate patients with moderately severe to severe non-HLAP.

Performance Evaluation of a Semi-automated Method for [18F]FDG Uptake in Abdominal Visceral Adipose Tissue

PURPOSE

Severity of abdominal obesity and possibly levels of metabolic activity of abdominal visceral adipose tissue (VAT) are associated with an increased risk for cardiovascular disease (CVD). In this context, the purpose of the current study was to evaluate the reproducibility and repeatability of a semi-automated method for assessment of the metabolic activity of VAT using 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) positron emission tomography (PET)/x-ray computed tomography (CT).

PROCEDURES

Ten patients with lung cancer who underwent two baseline whole-body [¹⁸F]FDG PET/low-dose (LD) CT scans within 1 week were included. Abdominal VAT was automatically segmented using CT between levels L1-L5. The initial CT-based segmentation was further optimized using PET data with a standardized uptake value (SUV) threshold approach (range 1.0-2.5) and morphological erosion (range 0-5 pixels). The [¹⁸F]FDG uptake in SUV that was measured by the automated method was compared with manual analysis. The reproducibility and repeatability were quantified using intraclass correlation coefficients (ICCs).

RESULTS

The metabolic assessment of VAT on [¹⁸F]FDG PET/LDCT scans expressed as SUV_mean, using an automated method showed high inter and intra observer (all ICCs > 0.99) and overall repeatability (ICC = 0.98). The manual method showed reproducible inter observer (all ICCs > 0.92), but less intra observer (ICC = 0.57) and less overall repeatability (ICC = 0.78) compared with the automated method.

CONCLUSIONS

Our proposed semi-automated method provided reproducible and repeatable quantitative analysis of [¹⁸F]FDG uptake in VAT. We expect this method to aid future research regarding the role of VAT in development of CVD.

Pylorus-preserving gastrectomy for early cancer involving the upper third: can we go higher?

BACKGROUND

Pylorus-preserving gastrectomy (PPG) is commonly performed for early gastric cancer (EGC) located in middle third of the stomach. We investigated the surgical, oncological, and functional outcomes of PPG involving the upper third of stomach.

METHODS

We included all patients of the period 2013-2016 who underwent PPG, distal subtotal gastrectomy (DSG), and total gastrectomy (TG) for EGC involving the upper third by carefully defining the localization. Surgical, oncological, and functional outcome analyses included postoperative morbidity, lymph-node metastasis, tumor recurrence, postoperative body weight, body mass index, hemoglobin, total protein, albumin, quantification of intraabdominal fat, and gallstone development.

RESULTS

Overall, 288 cases were analyzed: 145 PPG, 61 DSG, and 82 TG. In the study period, patients potentially underwent PPG for EGC involving the upper third, if enough proximal remnant stomach was found whilst achieving a sufficient proximal margin. PPG resulted in less operation time (p < 0.001), less blood loss (p = 0.002) and lower postoperative morbidity compared to TG. For lymph-node (LN) stations being resected in all groups, no difference was found in number of resected LN. Recurrence-free survival was similar for all groups. PPG showed advantages regarding postoperative body weight, hemoglobin, total protein, albumin in postoperative 6 and 12 month follow-up. Lowest decrease of abdominal fat area after 12 months was seen for PPG. Gallstone incidence was significantly lower after PPG compared to TG (p < 0.001).

CONCLUSIONS

For EGC involving the upper third, PPG can be another good option with lower postoperative morbidity, better functional outcomes, and same oncological safety.

Impact of visceral adiposity on severity of acute pancreatitis: a propensity score-matched analysis

Background

The relationship between visceral adiposity and acute pancreatitis (AP) has not been completely elucidated. This study evaluated the significance of visceral adipose tissue (VAT) and the ratio of VAT to skeletal muscle tissue (VAT/SMT) in the prognosis of AP patients.

Methods

Based on a 1:2 propensity score matching, 306 hospitalized patients were enrolled in the study analysis from 2010 to 2017. VAT, subcutaneous adipose tissue (SAT), and SMT were measured using unenhanced computed tomography (CT). Cox proportional hazards models were applied for the analysis.

Results

VAT and the VAT/SMT ratio were significantly higher in the severe AP (SAP) and moderately severe AP (MSAP) groups compared to the mild AP (MAP) group (both p < 0.001). Intensive care transfer, AP severity, systemic complications, and prognostic scores (Acute Physiology and Chronic Health Evaluation II [APACHE-II] score ≥ 8, Ranson’s score ≥ 3, Bedside Index of Severity in Acute Pancreatitis [BISAP] score ≥ 3, and the systemic inflammatory response syndrome [SIRS] score ≥ 2) significantly correlated with VAT and the VAT/SMT ratio in AP patients. The multivariate adjusted hazard ratios (HRs) for VAT and the VAT/SMT ratio in the relationship of body parameters and AP mortality were 1.042 (95% confidence interval (CI), 1.019–1.066) and 7.820 (95% CI, 1.978–30.917), respectively. Compared with other prognostic scores, VAT had the highest area under the curve of receiver operating characteristics (ROC) (0.943, 95% CI, 0.909–0.976).

Conclusion

High VAT and VAT/SMT ratio are independent negative prognostic indicators of AP.

Trial registration

Clinical study registration number: NCT03482921. Date of registration: 03/23/2018.

Periatrial Fat Quality Predicts Atrial Fibrillation Ablation Outcome

Background Previous studies showed that the quantity of the left atrial (LA) periatrial fat tissue predicts recurrence after catheter ablation of atrial fibrillation (AF). We hypothesized that the quality of the LA periatrial fat tissue, measured by the mean computed tomography attenuation, predicts recurrence after AF ablation independent of the quantity of the LA periatrial fat tissue. Methods We included 143 consecutive patients with drug-refractory AF referred for the first catheter ablation of AF (62.2±10 years, 40% nonparoxysmal AF). All participants had a preablation cardiac computed tomography. We measured the quantity of the LA periatrial fat tissue by the area (millimeter square) and the quality by the mean computed tomography attenuation (Hounsfield units) in a standard 4-chamber view. Results Patients with AF recurrence after ablation (n=57) had a significantly larger fat area (167.6 [interquartile range, 124.1-255] versus 145.4 [95.6-229.3] mm²; P=0.018) and a higher fat attenuation (-92.0±9.8 versus -96.5±9.4 Hounsfield units; P=0.006) than those without recurrence (controls). LA fat attenuation was correlated with LA fat volume and LA bipolar voltage by invasive mapping and was associated with AF recurrence after adjusting for clinical risk factors, including body mass index, AF type, LA dimension, and fat area (hazard ratio, 2.65; P=0.001). Conclusions The quality of the LA periatrial fat tissue is an independent predictor of recurrence after the first AF ablation. Assessment of LA periatrial fat attenuation can improve AF ablation outcomes by refining patient selection.

Impact of body mass index and fat distribution on sex steroid levels in endometrial carcinoma: a retrospective study

Background

Obesity is an important cause of multiple cancer types, amongst which endometrial cancer (EC). The relation between obesity and cancer is complicated and involves alterations in insulin metabolism, response to inflammation and alterations in estradiol metabolism. Visceral obesity is assumed to play the most important role in the first two mechanisms, but its role in estradiol metabolism is unclear. Therefore, this retrospective study explores the relationship of body mass index (BMI), visceral fat volume (VAV) and subcutaneous fat volume (SAV) and serum levels of sex steroids and lipids in patients with endometrial cancer.

Methods

Thirty-nine postmenopausal EC patients with available BMI, blood serum and Computed Tomography (CT) scans were included. Serum was analyzed for estradiol, dehydroepiandrosterone sulfate (DHEAS), androstenedione, testosterone, cholesterol, triglycerides and high (HDL), low (LDL) and non-high density (NHDL) lipoprotein. VAV and SAV were quantified on abdominal CT scan images. Findings were interpreted using pearson correlation coefficient and linear regression with commonality analysis.

Results

Serum estradiol is moderately correlated with BMI (r = 0.62) and VAV (r = 0.58) and strongly correlated with SAV (r = 0.74) (p < 0.001 for all). SAV contributes more to estradiol levels than VAV (10.3% for SAV, 1.4% for VAV, 35.9% for SAV and VAV, p = 0.01). Other sex steroids and lipids have weak and moderate correlations with VAV or SAV.

Conclusions

This study shows that serum estradiol is correlated with BMI and other fat-distribution measures in postmenopausal endometrial cancer patients. Subcutaneous fat tissue contributes more to the estradiol levels indicating that subcutaneous fat might be relevant in endometrial cancer carcinogenesis.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5770-6) contains supplementary material, which is available to authorized users.

Effect of Abdominal Visceral Fat Change on the Regression of Erosive Esophagitis: A Prospective Cohort Study

Background/Aims

Although abdominal visceral fat has been associated with erosive esophagitis in cross-sectional studies, there are few data on the longitudinal effect. We evaluated the effects of abdominal visceral fat change on the regression of erosive esophagitis in a prospective cohort study.

Methods

A total of 163 participants with erosive esophagitis at baseline were followed up at 34 months and underwent esophagogastroduodenoscopy and computed tomography at both baseline and follow-up. The longitudinal effects of abdominal visceral fat on the regression of erosive esophagitis were evaluated using relative risk (RR) and 95% confidence intervals (CIs).

Results

Regression was observed in approximately 49% of participants (n=80). The 3rd (RR, 0.13; 95% CI, 0.02 to 0.71) and 4th quartiles (RR, 0.07; 95% CI, 0.01 to 0.38) of visceral fat at follow-up were associated with decreased regression of erosive esophagitis. The highest quartile of visceral fat change reduced the probability of the regression of erosive esophagitis compared to the lowest quartile (RR, 0.10; 95% CI, 0.03 to 0.28). Each trend showed a dose-dependent pattern (p for trend <0.001). The presence of baseline Helicobacter pylori increased the regression of erosive esophagitis (RR, 2.40; 95% CI, 1.05 to 5.48).

Conclusions

Higher visceral fat at follow-up and a greater increase in visceral fat reduced the regression of erosive esophagitis in a dose-dependent manner.

Liver Fat Is Associated With Markers of Inflammation and Oxidative Stress in Analysis of Data From the Framingham Heart Study

BACKGROUND & AIMS

Nonalcoholic fatty liver disease is an inflammatory condition that results in progressive liver disease. It is unknown if individuals with hepatic steatosis, but not known to have liver disease, have higher serum concentrations of markers of systemic inflammation and oxidative stress.

METHODS

We collected data from 2482 participants from the Framingham Heart Study (mean age, 51 ± 11 y; 51% women) who underwent computed tomography and measurement of 14 serum markers of systemic inflammation. Heavy alcohol users were excluded. The liver:phantom ratio (a continuous parameter of liver attenuation relative to a calibration phantom) was used to identify individuals with radiographic evidence of liver fat. Primary covariates included age, sex, smoking, alcohol, aspirin use, hypertension, dyslipidemia, diabetes, and cardiovascular disease. Body mass index and visceral fat were secondary covariates. We used multivariable linear regression models to assess the association between liver fat and systemic inflammatory markers.

RESULTS

In multivariable-adjusted models, liver fat was associated with the following inflammatory markers: high-sensitivity C-reactive protein (P < .001), urinary isoprostanes (P < .001), interleukin 6 (P < .001), intercellular adhesion molecule 1 (P < .001), and P-selectin (P = .002). Additional adjustment for body mass index or visceral fat attenuated the results slightly, although all associations remained statistically significant (P for all ≤ .01).

CONCLUSIONS

In a community-based cohort, individuals with hepatic steatosis without known liver disease had higher mean serum concentrations of systemic markers of inflammation. Studies are needed to determine whether treatment of hepatic steatosis reduces systemic inflammation.

Intra-abdominal fat measurement by ultrasonography: association with anthropometry and metabolic syndrome in adolescents

OBJECTIVE

To associate intra-abdominal fat thickness measured by ultrasonography to the factors related to metabolic syndrome and to determine cutoff points of intra-abdominal fat measurement associated with a greater chance of metabolic syndrome in adolescents.

METHODS

This was a cross-sectional study, with 423 adolescents from public schools. Intra-abdominal fat was measured by ultrasonography. Anthropometric data were collected, and biochemical analyses were performed.

RESULTS

Intra-abdominal fat was measured by ultrasonography, showing a statistically significant association with the diagnosis of metabolic syndrome (p=0.037), body mass index (p<0.001), elevated triglyceride levels (p=0.012), decreased plasma HDL levels (p=0.034), and increased systemic blood pressure values (p=0.023). Cutoff values of intra-abdominal fat thickness measurements were calculated by ultrasound to estimate the individuals most likely to develop metabolic syndrome. In the logistic regression models, the cutoff values that showed the highest association with metabolic syndrome in males were 4.50, 5.35, 5.46, 6.24, and 6.50cm for the ages of 14, 15, 16, 17, and 18/19 years, respectively. In the female gender, the cutoff values defined for the same age groups were 4.46, 4.55, 4.45, 4.90, and 6.46cm. In an overall analysis using the ROC curve, without gender and age stratification, the cut-off of 3.67cm showed good sensitivity, but low specificity.

CONCLUSION

Ultrasonography is a useful method to estimate intra-abdominal adipose tissue in adolescents, which is associated with the main factors related to obesity and metabolic syndrome.

Increased Diet Quality is Associated with Long-Term Reduction of Abdominal and Pericardial Fat

OBJECTIVE

This study examined the longitudinal associations between genetic risk, change in diet quality, and change in visceral adipose tissue (ΔVAT), abdominal subcutaneous adipose tissue (ΔSAT), and pericardial adipose tissue (ΔPAT).

METHODS

A total of 1,677 Framingham Heart Study participants who had ectopic fat depots measured using computed tomography were analyzed. Diet quality was quantified using a Mediterranean-style diet score (MDS) and genetic risk by depot-specific genetic risk scores (GRSs).

RESULTS

Per SD improvement in MDS, there was 50 cm³ (95% CI: 14-86; P = 0.007) less fat accumulation in VAT, 52 cm³ (95% CI: 12-92; P = 0.01) less fat accumulation in SAT, and 1.3 cm³ (95% CI: 0.1-2.4; P = 0.04) less fat accumulation in PAT. No association was observed between GRSs and ΔVAT or ΔSAT. Each 1-SD increase in the PAT GRS was associated with a 1.2-cm³ (95% CI: 0.1-2.3; P = 0.03) increase in ΔPAT. In participants with higher PAT GRS, those with ΔMDS ≥ 0 had a favorable change in PAT compared with the counterparts with ΔMDS < 0 (P = 0.008).

CONCLUSIONS

Longitudinal improvements in diet quality are associated with less ectopic fat accumulation. This study suggests that diet quality may play a critical role in improving ectopic adiposity profiles.

Amygdalar Metabolic Activity Independently Associates With Progression of Visceral Adiposity

CONTEXT

Epidemiologic data link psychological stress to adiposity. The underlying mechanisms remain uncertain.

OBJECTIVES

To test whether (i) higher activity of the amygdala, a neural center involved in the response to stress, associates with greater visceral adipose tissue (VAT) volumes and (ii) this association is mediated by increased bone marrow activity.

SETTING

Massachusetts General Hospital, Boston, Massachusetts.

PATIENTS

Two hundred forty-six patients without active oncologic, cardiovascular, or inflammatory disease who underwent clinical 18F-fluorodeoxyglucose positron emission tomography/computed tomography imaging were studied. VAT imaging was repeated ∼1 year later in 68 subjects.

DESIGN

Metabolic activity of the amygdala (AmygA), hematopoietic tissue activity, and adiposity volumes were measured with validated methods.

MAIN OUTCOME MEASURE

The relationship between AmygA and baseline and follow-up VAT.

RESULTS

AmygA associated with baseline body mass index (standardized β = 0.15; P = 0.01), VAT (0.19; P = 0.002), and VAT/subcutaneous adipose tissue ratio (0.20; P = 0.002), all remaining significant after adjustment for age and sex. AmygA also associated with bone marrow activity (0.15; P = 0.01), which in turn associated with VAT (0.34; P < 0.001). Furthermore, path analysis showed that 48% of the relationship between AmygA and baseline VAT was mediated by increased bone marrow activity (P = 0.007). Moreover, AmygA associated with achieved VAT after 1 year (P = 0.02) after adjusting for age, sex, and baseline VAT.

CONCLUSIONS

These results suggest a neurobiological pathway involving the amygdala and bone marrow linking psychosocial stress to adiposity in humans. Future studies should test whether targeting this mechanism attenuates adiposity and its complications.

Visceral obesity and short-term outcomes after laparoscopic rectal cancer resection

BACKGROUND

Complications after rectal resection are frequent. Recently, methods to assess visceral obesity (VO) have become available as an alternative to measurement of body mass index (BMI). The aim of this study was to examine the association between visceral fat volume (VFV) and the short-term outcomes after laparoscopic low anterior resection (LLAR) in patients with rectal cancer.

METHODS

We studied a consecutive series of patients undergoing LLAR at Bispebjerg University Hospital from 01.01.2013 to 01.01.2016. Preoperative VFV was calculated from abdominal CT scans using an automatic segmentation tool. The primary outcome was anastomotic leakage (AL). Secondary outcomes included conversion to open surgery, number of lymph nodes harvested, the rates of 30-day complications as well as reoperations, and 1-year survival.

RESULTS

A total of 102 patients were included. VO was defined as a VFV above the 75 percentile. Thirteen (12.7%) patients developed AL, four (15.4%) of whom were in the VO group (p = 0.900). At least one postoperative complication developed in 38 (37.3%) patients, with no significant difference between the VO and non-VO patients after univariable analysis (42.3% vs. 35.4%, p = 0.702) or multivariable adjustment (OR 1.01, 95% CI 0.38-2.65, p = 0.984). VO was significantly associated with an increased incidence of conversion to open surgery (OR 4.30, 95% CI 1.29-14.86, p = 0.018). There was a significant difference in the number of harvested lymph nodes between the two groups (mean 23.5 vs. 29.1, p = 0.045).

CONCLUSIONS

In this study on patients undergoing laparoscopic rectal resection, VO was not associated with development of AL or other complications. However, we found that visceral obesity was associated with an increased risk of conversion to open surgery.

Preoperative Visceral Adiposity and Muscularity Predict Poor Outcomes after Hepatectomy for Hepatocellular Carcinoma

OBJECTIVE

Visceral adiposity, defined as a high visceral-to-subcutaneous adipose tissue area ratio (VSR), has been shown to be associated with poor outcomes in several cancers. However, in the surgical field, the significance of visceral adiposity remains controversial. The present study investigated the impact of visceral adiposity as well as sarcopenic factors (low muscularity) on outcomes in patients undergoing hepatectomy for hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

This retrospective study analyzed data from 606 patients undergoing hepatectomy for HCC at our institution between April 2005 and March 2016. Using preoperative plain computed tomography imaging at the level of the third lumbar vertebra, visceral adiposity, skeletal muscle mass, and muscle quality were evaluated by the VSR, skeletal muscle mass index (SMI), and intramuscular adipose tissue content (IMAC), respectively. The impact of these parameters on outcomes after hepatectomy for HCC was analyzed.

RESULTS

The overall survival rate was significantly lower among patients with a high VSR (p < 0.001) than among patients with a normal VSR. Similarly, the recurrence-free survival rate was significantly lower among patients with a high VSR (p = 0.016). A high VSR, low SMI, and high IMAC contributed to an increased risk of death (p < 0.001) and HCC recurrence (p < 0.001) in an additive manner. Multivariate analysis showed that not only preoperative low muscularity but also visceral adiposity was a significant risk factor for mortality (hazard ratio [HR] = 1.566, p < 0.001) and HCC recurrence (HR = 1.329, p = 0.020) after hepatectomy for HCC.

CONCLUSIONS

Preoperative visceral adiposity, as well as low muscularity, was closely related to poor outcomes after hepatectomy for HCC. It is crucial to establish a new strategy including perioperative nutritional interventions with rehabilitation for better outcomes after hepatectomy for HCC.

Application of a novel sex independent anthropometric index, termed angle index, in relation to type 2 diabetes: a Trinidadian case-control study

OBJECTIVE

To develop a novel sex independent anthropometric index, termed as angle index, related to type 2 diabetes.

DESIGN

Case-control.

PARTICIPANTS

The study comprised 121 participants and were divided into two groups. One group had no form of diabetes and served as controls (n=50). The other group had the condition of type 2 diabetes (n=71). 31% (n=37) of the subjects were male and 69% (n=84) were female. 62% (n=75) of the subjects were of East Indian ethnicity, 28% (n=34) were of African ethnicity and 10% (n=12) were of mixed ethnicity.

SETTING

Participants of the study were from the island of Trinidad, located in the Caribbean. Patients in the study were selected at random from hospital records.

PRIMARY OUTCOME MEASURE

It was hypothesised that the mean angle index of patients with type 2 diabetes would be higher than the mean angle index of patients without type 2 diabetes.

RESULTS

Patients with type 2 diabetes had a significantly higher angle index value as compared with controls (p<0.001). Angle index was the superior sex independent anthropometric index in relation to type 2 diabetes (area under the curve=0.72; p<0.001) as compared with other sex independent variables. Angle index correlated with glycated haemoglobin (rs=0.28, p=0.003) and fasting blood glucose (rs=0.31, p=0.001) levels. Patients with type 2 diabetes were four times more likely to have an angle index greater than 184° (OR 4.2, 95% CI 1.8 to 9.9) as compared with controls.

CONCLUSION

Angle index was a superior sex independent index for discriminating between patients with and without type 2 diabetes, as compared with waist circumference, abdominal volume index, conicity index, blood pressure readings, triglyceride levels and very low-density lipoprotein levels.

Quantification of body-torso-wide tissue composition on low-dose CT images via automatic anatomy recognition

PURPOSE

Quantification of body composition plays an important role in many clinical and research applications. Radiologic imaging techniques such as Dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and computed tomography (CT) imaging make accurate quantification of the body composition possible. However, most current imaging-based methods need human interaction to quantify multiple tissues. When dealing with whole-body images of many subjects, interactive methods become impractical. This paper presents an automated, efficient, accurate, and practical body composition quantification method for low-dose CT images.

METHOD

Our method, named automatic anatomy recognition body composition analysis (AAR-BCA), aims to quantify four tissue components in body torso (BT) - subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), bone tissue, and muscle tissue - from CT images of given whole-body positron emission tomography/computed tomography (PET/CT) acquisitions. AAR-BCA consists of three key steps - modeling BT with its ensemble of key objects from a population of patient images, recognition or localization of these objects in a given patient image I, and delineation and quantification of the four tissue components in I guided by the recognized objects. In the first step, from a given set of patient images and the associated delineated objects, a fuzzy anatomy model of the key object ensemble, including anatomic organs, tissue regions, and tissue interfaces, is built where the objects are organized in a hierarchical order. The second step involves recognizing, or finding roughly the location of, each object in any given whole-body image I of a patient following the object hierarchy and guided by the built model. The third step makes use of this fuzzy localization information of the objects and the intensity distributions of the four tissue components, already learned and encoded in the model, to optimally delineate in a fuzzy manner and quantify these components. All parameters in our method are determined from training datasets.

RESULTS

Thirty-eight low-dose CT images from different subjects are tested in a fivefold cross-validation strategy for evaluating AAR-BCA with a 23-15 train-test dataset division. For BT, over all objects, AAR-BCA achieves a false-positive volume fraction (FPVF) of 3.7% and false-negative volume fraction (FNVF) of 3.8%. Notably, SAT achieves both a FPVF and FNVF under 3%. For bone tissue, it achieves a FPVF and a FNVF both under 3.5%. For VAT tissue, the FNVF of 4.8% is higher than for other objects and so also for muscle (4.7%). The level of accuracy for the four tissue components in individual body subregions mostly remains at the same level as for BT. The processing time required per patient image is under a minute.

CONCLUSIONS

Motivated by applications in cancer and systemic diseases, our goal in this paper was to seek a practical method for body composition quantification which is automated, accurate, and efficient, and works on BT in low-dose CT. The proposed AAR-BCA method toward this goal can quantify four tissue components including SAT, VAT, bone tissue, and muscle tissue in the body torso with under 5% overall error. All needed parameters can be automatically estimated from the training datasets.

Quantification of visceral adipose tissue by computed tomography and magnetic resonance imaging: reproducibility and accuracy

Objective

To evaluate the feasibility of quantifying visceral adipose tissue (VAT) on computed tomography (CT) and magnetic resonance imaging (MRI) scans, using freeware, as well as calculating intraobserver and interobserver reproducibility.

Materials and Methods

We quantified VAT in patients who underwent abdominal CT and MRI at our institution between 2010 and 2015, with a maximum of three months between the two examinations. A slice acquired at the level of the umbilicus was selected. Segmentation was performed with the region growing algorithm of the freeware employed. Intraobserver and interobserver reproducibility were evaluated, as was the accuracy of MRI in relation to that of CT.

Results

Thirty-one patients (14 males and 17 females; mean age of 57 ± 15 years) underwent CT and MRI (mean interval between the examinations, 28 ± 12 days). The interobserver reproducibility was 82% for CT (bias = 1.52 cm²; p = 0.488), 86% for T1-weighted MRI (bias = −4.36 cm²; p = 0.006), and 88% for T2-weighted MRI (bias = −0.52 cm²; p = 0.735). The intraobserver reproducibility was 90% for CT (bias = 0.14 cm²; p = 0.912), 92% for T1-weighted MRI (bias = −3,4 cm²; p = 0.035), and 90% for T2-weighted MRI (bias = −0.30 cm²; p = 0.887). The reproducibility between T1-weighted MRI and T2-weighted MRI was 87% (bias = −0.11 cm²; p = 0.957). In comparison with the accuracy of CT, that of T1-weighted and T2-weighted MRI was 89% and 91%, respectively.

Conclusion

The program employed can be used in order to quantify VAT on CT, T1-weighted MRI, and T2-weighted MRI scans. Overall, the accuracy of MRI (in comparison with that of CT) appears to be high, as do intraobserver and interobserver reproducibility. However, the quantification of VAT seems to be less reproducible in T1-weighted sequences.

Amygdalar activity predicts future incident diabetes independently of adiposity

While it is established that psychosocial stress increases the risk of developing diabetes mellitus (DM), two key knowledge gaps remain: 1) the neurobiological mechanisms that are involved in mediating that risk, and 2) the role, if any, that adiposity plays in that mechanism. We tested the hypotheses that: 1) metabolic activity in the amygdala (AmygA), a key center involved in the neurobiological response to stress, associates with subsequent DM risk, and 2) this association is independent of adiposity. AmygA and adipose tissue volumes were measured, and serial blood assessments for DM were obtained in 232 subjects who underwent combined ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) imaging. Higher baseline AmygA predicted subsequent, new-onset DM, independently of adiposity and other DM risk factors. Furthermore, higher adiposity only increased DM risk in the presence of higher AmygA. In a separate cross-sectional cohort, higher AmygA associated with higher insulin resistance. Accordingly, the current study shows, for the first time, that activity in a stress-responsive neural region predicts the onset of DM. Further, we observed that this neurobiological activity acts independently of, but also synergistically with adiposity to increase DM risk. These findings suggest novel therapeutic targets to help manage and possibly prevent DM.

Changes of computed tomography-based body composition after adrenalectomy in patients with endogenous hypercortisolism

CONTEXT

Data on longitudinal changes of computed tomography (CT)-determined visceral fat area (VFA), skeletal muscle area (SMA) and skeletal muscle radiodensity (SMD) after adrenalectomy are limited in patients with hypercortisolism.

OBJECTIVE

To examine the association of severity of cortisol excess and improvement of CT-based muscle and fat parameters after adrenalectomy.

DESIGN

Retrospective observational cohort study.

PATIENTS

One hundred thirty-four patients with overt Cushing's syndrome (CS; n = 39), mild autonomous cortisol excess (MACE; n = 57), or nonfunctioning adrenal tumour (NFAT; n = 38) at a tertiary endocrinology institution between 2006 and 2017 were included.

MEASUREMENTS

Changes in CT-determined VFA, visceral-to-subcutaneous fat ratio (VSR), SMA, skeletal muscle index (SMI), and SMD measured at the third lumbar vertebra (L3).

RESULTS

At baseline, CS patients had higher VFA, lower SMA, SMI and SMD values, compared to NFAT or MACE patients. Compared to NFAT, significant decreases in VFA and increases in SMA, SMI and SMD was observed in CS 1 year after adrenalectomy. In MACE, adjusted mean changes of SMD but not VFA, SMA or SMI differ significantly compared to NFAT (+8.9% vs -3.4%, P = 0.032). In a multivariate linear regression model, the increase by 1 μg/dL of post-dexamethasone serum cortisol at baseline was independently associated with greater reduction of VFA (-3.95%), VSR (-3.07%), and increase in SMD (+0.92%, P < 0.05 for all) after adrenalectomy.

CONCLUSIONS

The severity of cortisol excess was associated with greater improvement of L3 VFA, VSR and SMD 1 year after adrenalectomy. These CT-based markers may allow more objective assessment of treatment benefit at earlier stage.

The Characteristics Of Abdominal Fat Distribution In Japanese Adolescents With Type 2 Diabetes Mellitus

PURPOSE

The aim was to investigate the characteristics of abdominal fat distribution in Japanese adolescents with type 2 diabetes mellitus.

PATIENTS AND METHODS

Eighty-six Japanese adolescents with simple obesity or type 2 diabetes mellitus treated between 2002 and 2018 were included. The subjects were classified into the simple obesity group (SO group, n=38) and type 2 diabetes mellitus group (DM group, n=23) by matching average age and gender ratio. The metabolic parameters VFA, SFA, and V/S ratio were compared between the 2 groups. Multivariate logistic regression analysis was performed to identify clinical factors associated with type 2 diabetes mellitus. Linear regression analysis was performed between hemoglobin A1c (HbA1c) and visceral fat area (VFA), subcutaneous fat area (SFA), or VFA-to-SFA ratio (V/S ratio) among all enrolled subjects. Finally, correlation analyses were performed to determine the relationships between VFA, SFA, and V/S ratio and metabolic parameters of the DM group. For the metabolic parameters, serum lipids, alanine aminotransferase (ALT), and HbA1c were measured without fasting. The VFA and SFA at umbilical level were investigated using computed tomography.

RESULTS

VFA and V/S ratio in DM group were higher than those in SO group (p=0.04 and p<0.01, respectively). SFA in DM group was lower than that in SO group (p<0.01). VFA and SFA, and non-high density lipoprotein (HDL) cholesterol were identified as being independently associated with type 2 diabetes mellitus (odds ratio, 1.05, 0.98, and 1.04, respectively, p<0.05). HbA1c was correlated with VFA and V/S ratio (p<0.01). In DM group, VFA and SFA were positively correlated with systolic blood pressure (p<0.01), ALT (p<0.05), total cholesterol (p<0.05), and non-HDL cholesterol (p<0.01); however, V/S ratio was not correlated.

CONCLUSION

Abdominal fat distribution in Japanese adolescents with type 2 diabetes mellitus was different from those with simple obesity and might associate with glucose and lipid metabolism.

Association between carbohydrate intake and body composition: The Korean National Health and Nutrition Examination Survey

OBJECTIVE

Several studies have investigated the effects of dietary carbohydrate intake on body composition. However, the results are controversial and few studies have been conducted on an Asian population. The aim of this study was to investigate whether dietary carbohydrate intake is associated with body composition in Korean adults.

METHODS

The present study used data from the Korean National Health and Nutrition Examination Survey, a cross-sectional survey of Korean civilians, conducted from 2008 to 2011. The study analyzed 9594 participants. Carbohydrate intake was defined as the proportion of energy consumed from carbohydrate. Waist circumference, body mass index, and lean and fat mass using a whole-body dual-energy x-ray absorptiometry scanner were measured as body composition parameters.

RESULTS

After adjusting for age, household income, smoking, alcohol consumption, physical activity, history of diabetes, hypertension, dyslipidemia, and intake of energy and fiber per day, the proportion of carbohydrate intake was positively correlated with total limb lean mass in men (β = 0.141, P = 0.046), and in women, the proportion of carbohydrate intake was positively associated with appendicular skeletal muscle mass index (β = 0804, P = 0.003) but negatively associated with trunk fat percentage (β = -0.075, P = 0.026). Total limb lean mass and appendicular skeletal muscle mass index in women showed an increasing trend as the proportion of carbohydrate intake increased.

CONCLUSIONS

No positive association was found between the proportion of carbohydrate intake and any measure of obesity or body fat mass in either men or women. Further studies are needed to evaluate the effects of quantity and quality of carbohydrate intake on body composition.

Relationship Between Visceral Obesity and Postoperative Inflammatory Response Following Minimally Invasive Esophagectomy

BACKGROUND

Esophagectomy for esophageal cancer is one of the most invasive surgeries. However, the factors influencing postoperative systemic inflammatory response following esophagectomy have not been elucidated. Recently, visceral fat has been shown to play an important role in both chronic and acute inflammation. In this study, we assessed the relationship between visceral obesity and postoperative inflammatory response following minimally invasive esophagectomy (MIE).

METHODS

Visceral fat area (VFA) was measured using computed tomography in 152 patients undergoing MIE for esophageal cancer. We assessed perioperative serum C-reactive protein (CRP) levels preoperatively and on postoperative days (PODs) 1-5 and analyzed the relationship between VFA and perioperative serum CRP levels.

RESULTS

VFA was positively associated with preoperative serum CRP level (P < 0.001). Univariate analysis revealed that VFA was significantly associated with increased serum CRP levels on PODs 1-5 (P < 0.001 for each day), whereas multivariate analysis revealed that it was independently associated with increased serum CRP levels on PODs 1-4 (P = 0.033, 0.035, 0.001, and 0.006, respectively). Similar results were observed in patients who did not have postoperative infectious complications, such as pneumonia, anastomotic leak, and surgical site infection. VFA was not an independent risk factor for the occurrence of these postoperative infectious complications.

CONCLUSIONS

Visceral obesity might be associated with chronic inflammation in patients with esophageal cancer and promote postoperative inflammatory response following MIE.

Blood steroids are associated with prognosis and fat distribution in endometrial cancer

BACKGROUND

Despite being a hormone dependent cancer, there is limited knowledge regarding the relation between level of steroids in blood and prognosis for endometrial cancer (EC) patients.

METHODS

In this study we investigated plasma levels of 19 steroids using liquid-chromatography tandem mass-spectrometry in 38 postmenopausal EC patients, 19 with long, and 19 with short survival. We explored if estradiol levels were associated with specific abdominal fat distribution patterns and if transcriptional alterations related to estradiol levels could be observed in tumor samples.

RESULTS

The plasma steroid levels for DHEA, DHEAS, progesterone, 21 OH progesterone and E1S were significantly increased (all p < 0.05) in patients with long survival compared to short. Estradiol levels were significantly positively correlated with visceral fat percentage (p = 0.035), and an increased expression of genes involved in estrogen related signaling was observed in tumors from patients with high estradiol levels in plasma.

CONCLUSION

Several of the identified plasma steroids represent promising biomarkers in EC patients. The association between increased estradiol levels and a high percentage of visceral fat indicates that visceral fat is a larger contributor to estradiol production compared to subcutaneous fat in this population.

Integrating genetic, transcriptional, and biological information provides insights into obesity

Objective:

Indices of body fat distribution are heritable, but few genetic signals have been reported from genome-wide association studies (GWAS) of computed tomography (CT) imaging measurements of body fat distribution. We aimed to identify genes associated with adiposity traits and the key drivers that are central to adipose regulatory networks.

Subjects:

We analyzed gene transcript expression data in blood from participants in the Framingham Heart Study, a large community-based cohort (n up to 4,303), as well as implemented an integrative analysis of these data and existing biological information.

Results:

Our association analyses identified unique and common gene expression signatures across several adiposity traits, including body mass index, waist-hip ratio, waist circumference, and CT-measured indices, including volume and quality of visceral and subcutaneous adipose tissues. We identified six enriched KEGG pathways and two co-expression modules for further exploration of adipose regulatory networks. The integrative analysis revealed four gene sets (Apoptosis, p53 signaling pathway, Proteasome, Ubiquitin mediated proteolysis) and two co-expression modules with significant genetic variants and 94 key drivers/genes whose local networks were enriched with adiposity-associated genes, suggesting that these enriched pathways or modules have genetic effects on adiposity. Most identified key driver genes are involved in essential biological processes such as controlling cell cycle, DNA repair and degradation of regulatory proteins and are cancer related.

Conclusion:

Our integrative analysis of genetic, transcriptional and biological information provides a list of compelling candidates for further follow-up functional studies to uncover the biological mechanisms underlying obesity. These candidates highlight the value of examining CT-derived and central adiposity traits.

Higher visceral fat area/subcutaneous fat area ratio measured by computed tomography is associated with recurrence and poor survival in patients with mid and low rectal cancers

PURPOSE

Obesity is thought to influence postoperative complications and recurrence of mid and low rectal cancer (MLRC) because of intraoperative technical difficulties. However, few reports have described the relationship between obesity indices and the clinical outcomes of MLRC. This study aimed to investigate the association between visceral obesity on computed tomography (CT) and oncolofical outcomes after surgery for MLRC and identify the obesity index that most accurately reflects clinical outcomes.

METHODS

We investigated 125 patients who underwent curative resection for MLRC between 2004 and 2010. Visceral fat area (VFA) was defined as the umbilicus-level intra-abdominal adipose tissue area measured by CT. Body mass index (BMI), total fat area, VFA, subcutaneous fat area (SFA) and VFA/SFA ratio (V/S ratio) were analysed.

RESULTS

The median follow-up time was 60.3 months (range, 38.2-122.6 months). Recurrence was detected in 28 (22.4%) patients. Among the various obesity indices, recurrence was significantly associated with V/S ratio only (1.02 ± 0.45 versus 0.86 ± 0.34; P = 0.046). Stage, preoperative carcinoembryonic antigen level, V/S ratio, lymphatic invasion and perineural invasion were significantly associated with recurrence on univariate analysis, while only V/S ratio (P = 0.019; 95% confidence interval, 1.22 to 9.09) was significantly associated with recurrence on multivariate analysis. Disease-free and overall survival of the obese group (V/S ratio > 1.0) were shorter than those of the non-obese group.

CONCLUSIONS

V/S ratio is the optimal obesity index for predicting stage I-III MLRC recurrence.

Muscles of the trunk and pelvis are responsive to testosterone administration: data from testosterone dose-response study in young healthy men

Testosterone dose-dependently increases appendicular muscle mass. However, the effects of testosterone administration on the core muscles of the trunk and the pelvis have not been evaluated. The present study evaluated the effects of testosterone administration on truncal and pelvic muscles in a dose-response trial. Participants were young healthy men aged 18-50 years participating in the 5α-Reductase (5aR) Trial. All participants received monthly injections of 7.5 mg leuprolide acetate to suppress endogenous testosterone production and weekly injections of 50, 125, 300, or 600 mg of testosterone enanthate and were randomized to receive either 2.5 mg dutasteride (5aR inhibitor) or placebo daily for 20 weeks. Muscles of the trunk and the pelvis were measured at baseline and the end of treatment using 1.5-Tesla magnetic resonance imaging. The dose effect of testosterone on changes in the psoas major muscle area was the primary outcome; secondary outcomes included changes in paraspinal, abdominal, pelvic floor, ischiocavernosus, and obturator internus muscles. The association between changes in testosterone levels and muscle area was also assessed. Testosterone dose-dependently increased areas of all truncal and pelvic muscles. The estimated change (95% confidence interval) of muscle area increase per 100 mg of testosterone enanthate dosage increase was 0.622 cm² (0.394, 0.850) for psoas; 1.789 cm² (1.317, 2.261) for paraspinal muscles, 2.530 cm² (1.627, 3.434) for total abdominal muscles, 0.455 cm² (0.233, 0.678) for obturator internus, and 0.082 cm² (0.003, 0.045) for ischiocavernosus; the increase in these volumes was significantly associated with the changes in on-treatment total and free serum testosterone concentrations. In conclusion, core muscles of the trunk and pelvis are responsive to testosterone administration. Future trials should evaluate the potential role of testosterone administration in frail men who are predisposed to falls and men with pelvic floor dysfunction.

High Density of Periaortic Adipose Tissue in Abdominal Aortic Aneurysm

OBJECTIVES

Perivascular adipose tissue (PVAT) is currently seen as a paracrine organ that produces vasoactive substances, including inflammatory agents, which may have an impact on the vasculature. In this study PVAT density was quantified in patients with an aortic aneurysm and compared with those with a non-dilated aorta. Since chronic inflammation, as the pathway to medial thinning, is a hallmark of abdominal aortic aneurysms (AAAs), it was hypothesised that PVAT density is higher in AAA patients.

METHODS

In this multicentre retrospective case control study, three groups of patients were included: non-treated asymptomatic AAA (n = 140), aortoiliac occlusive disease (AIOD) (n = 104), and individuals without aortic pathology (n = 97). A Hounsfield units based analysis was performed by computed tomography (CT). As a proxy for PVAT, the density of adipose tissue 10 mm circumferential to the infrarenal aorta was analysed in each consecutive CT slice. Intra-individual PVAT differences were reported as the difference in PVAT density between the region of the maximum AAA diameter (or the mid-aortic region in patients with AIOD or controls) and the two uppermost slices of infrarenal non-dilated aorta just below the renal arteries. Furthermore, subcutaneous (SAT) and visceral (VAT) adipose tissue measurements were performed. Linear models were fitted to assess the association between the study groups, different adipose tissue compartments, and between adipose tissue compartments and aortic dimensions.

RESULTS

AAA patients presented higher intra-individual PVAT differences, with higher PVAT density around the aneurysm sac than the healthy neck. This association persisted after adjustment for cardiovascular risk factors and diseases and other fat compartments (β = 13.175, SE 4.732, p = .006). Furthermore, intra-individual PVAT differences presented the highest correlation with aortic volume that persisted after adjustment for other fat compartments, body mass index, sex, and age (β = 0.566, 0.200, p = .005).

CONCLUSION

The results suggest a relation between the deposition of PVAT and AAA pathophysiology. Further research should explore the exact underlying processes.

Analysis of the Correlation Between Central Obesity and Abdominal Aortic Diseases

BACKGROUND

Atherosclerosis and abdominal aortic aneurysms (AAAs) have several similar risk factors but different pathogenesis. Inflammation of the arteries is common to both. Central obesity can act as an endocrine organ through the secretion of inflammatory cytokines, and the perivascular fat has a local effect that could contribute to diseases of the abdominal aorta. Although the relation between central obesity and atherosclerosis occlusive arterial disease has been demonstrated, the correlation with AAA has conflicting results. The aim of this study was to analyze the correlation between central obesity and the presence of abdominal aortic diseases using computed tomography.

METHODS

Six hundred thirty-nine consecutive patients classified into 3 groups (AAA, aortic atherosclerotic occlusive disease (AAOD), and without aortic disease [control group]) who underwent computed tomography had the aorta diameter, the visceral fat area (VFA), and the subcutaneous fat area (SFA) measured at the level of third and fourth lumbar vertebrae.

RESULTS

VFA showed no difference between the groups. SFA was lower in atherosclerotic group (AAOD) than control (P < 0.01 in general and P < 0.04 in male). In AAA group, we found in men that the first tertile of aorta diameter had higher VFA than third tertile (P = 0.02).

CONCLUSIONS

There was no difference in VFA between patients in AAA, AAOD, and without aortic disease groups. In men with aneurysm, there was an inverse relationship between VFA and aortic diameter. In AAOD, visceral to subcutaneous ratio is higher due to lower SFA.

Visceral and Intrahepatic Fat Are Associated with Cardiometabolic Risk Factors Above Other Ectopic Fat Depots: The Framingham Heart Study

BACKGROUND

We examined the associations among 8 different fat depots accumulated in various anatomic regions and the relationship between these fat depots and multiple cardiometabolic risk factors.

METHODS

Participants were from the Framingham Heart Study Offspring and Third Generation who also participated in the multidetector computed tomography substudy in 2002-2005. Exposures were multidetector computed tomography-derived fat depots, including abdominal subcutaneous adipose tissue, abdominal visceral adipose tissue, intramuscular fat, intrathoracic fat, pericardial fat, thoracic periaortic fat, intrahepatic fat, and renal sinus fat. Multivariable-adjusted regression analyses with a forward selection procedure were performed to identify the most predictive fat depots.

RESULTS

Of 2529 participants, 51.9% were women (mean age, 51.1 years). Visceral adipose tissue had the strongest correlations with each of the other fat measures (range, 0.26-0.77) and with various cardiometabolic risk factors (range, -0.34 to 0.39). As determined by the selection models, visceral adipose tissue was the only fat depot that was associated with all cardiometabolic risk factors evaluated in this study (all P<.05). Selection models also showed that subcutaneous adipose tissue and intrahepatic fat were associated with cardiometabolic risk factors related to the traits of dysglycemia, dyslipidemia, and hypertension (all P<.05). However, only associations with visceral adipose tissue and intrahepatic fat persisted after further adjustment for body mass index and waist circumference.

CONCLUSIONS

Visceral adipose tissue and intrahepatic fat were consistent correlates of cardiometabolic risk factors, above and beyond standard anthropometric indices. Our data provide important insights for understanding the associations between variations in fat distribution and cardiometabolic abnormalities.

DXA-measured visceral fat mass and lean body mass reflect abnormal metabolic phenotypes among some obese and nonobese Chinese children and adolescents

BACKGROUND AND AIM

The exact constellation of body composition characteristics among metabolically unhealthy obese (MUO) and nonobese (MUNO) children and adolescents remains unclear. The purpose of this study was to identify the major body composition determinants of metabolically unhealthy phenotypes among Chinese children and adolescents.

METHODS AND RESULTS

We used data from a cross-sectional survey in 2015 that included 1983 children and adolescents aged 6-18 years. Subjects were classified into two phenotypes based on a combination of body mass index (BMI) and metabolic syndrome components. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Among all boys and among adolescent boys, those with MUNO phenotypes displayed significantly higher indices of body composition except for fat mass (FM) percentage and trunk-to-legs FM ratio compared with the metabolically healthy nonobese phenotype (all P < 0.05). MUO individuals had higher arm FM, lean body mass (LBM), and trunk lean mass compared to metabolically healthy obese individuals (all P < 0.05). Visceral fat mass (VFM) and BMI were the major independent determinants of MUNO (VFM, 6- to 9-year-old boys, OR = 1.02, 95% CI = 1.00-1.03, P = 0.021; BMI, 6- to 9-year-old girls, OR = 1.90, 95% CI = 1.31-2.84, P = 0.001; and adolescent boys, OR = 1.34, 95% CI = 1.23-1.44, P < 0.001). LBM was the major independent predictor of MUO among adolescent boys (OR = 1.90, 95% CI = 1.03-1.17, P = 0.003).

CONCLUSIONS

Among children and adolescents, the metabolically unhealthy phenotype was associated with excess of body composition, but with significant differences observed based on age and sex. VFM and LBM derived by DXA can predict the metabolically unhealthy phenotype effectively in specific sex and age groups.

Automatic Measurement of the Total Visceral Adipose Tissue From Computed Tomography Images by Using a Multi-Atlas Segmentation Method

BACKGROUND

The visceral adipose tissue (VAT) volume is a predictive and/or prognostic factor for many cancers. The objective of our study was to develop an automatic measurement of the whole VAT volume using a multi-atlas segmentation (MAS) method from a computed tomography.

METHODS

A total of 31 sets of whole-body computed tomography volume data were used. The reference VAT volume was defined on the basis of manual segmentation (VATMANUAL). We developed an algorithm, which measured automatically the VAT volumes using a MAS based on a nonrigid volume registration algorithm coupled with a selective and iterative method for performance level estimation (SIMPLE), called VATMAS_SIMPLE. The results were evaluated using intraclass correlation coefficient and dice similarity coefficients.

RESULTS

The intraclass correlation coefficient of VATMAS_SIMPLE was excellent, at 0.976 (confidence interval, 0.943-0.989) (P < 0.001). The dice similarity coefficient of VATMAS_SIMPLE was also good, at 0.905 (SD, 0.076).

CONCLUSIONS

This newly developed algorithm based on a MAS can measure accurately the whole abdominopelvic VAT.

Longitudinal Associations of Pericardial and Intrathoracic Fat With Progression of Coronary Artery Calcium (from the Framingham Heart Study)

Cross-sectional studies have shown that pericardial fat is associated with atherosclerotic burden above and beyond generalized and central adiposity. Whether pericardial fat is longitudinally associated with coronary artery calcium (CAC) has not been firmly established. We examined the associations between cardiac ectopic fat including pericardial and intrathoracic fat with CAC progression and incidence in a community-based study setting. Study participants were from the Framingham Heart Study Offspring and Third Generation Cohorts who underwent multidetector computed tomography at 2 consecutive examinations (2002 to 2005 and 2008 to 2011) for the assessment of CAC. Multivariable-adjusted regression models were used to evaluate the associations between cardiac ectopic fat with CAC. Nonlinear associations were also examined. We included 1,732 participants (49.6% women, mean age 49.9 years). Of the 1,024 participants with a CAC score = 0 at baseline, 197 individuals developed a CAC score > 0 (19.2%) during 6.1 years of follow-up. The remaining 708 participants with a CAC score > 0 at baseline were eligible for CAC progression analysis. We identified nonlinear association between pericardial fat and CAC progression. Higher pericardial fat was associated with higher CAC progression only for those participants with pericardial fat higher than the median value (β = 56.0, p = 0.04). Intrathoracic fat was linearly associated with CAC progression (β = 23.0, p = 0.02). However, all of these associations did not persist after additional adjustment for body mass index, abdominal visceral adipose tissue, or waist circumference (all p ≥ 0.14). Neither pericardial nor intrathoracic fat were associated with CAC incidence (all p ≥ 0.33). Overall, both of the cardiac ectopic fat measures were longitudinally associated with CAC progression.

High visceral fat percentage is associated with poor outcome in endometrial cancer

Despite evidence of increased endometrial cancer (EC) risk in obese women, the impact of obesity on clinical and histological phenotype is poorly understood. This study explored abdominal fat volumes and fat distribution quantified by computed tomography (CT), in relation to tumor characteristics and outcome. 227 EC patients with preoperative abdominal CT scans were included. Total abdominal fat volume (TAV), subcutaneous abdominal fat volume (SAV) and visceral abdominal fat volume (VAV) were quantified, and visceral fat percentage calculated (VAV%=[VAV/TAV]x100). Waist circumference (WC) and liver density (LD) were measured, and body mass index (BMI) calculated. Data for estrogen, progesterone and androgen receptor (ERα/PR/AR) expression by immunohistochemistry were available for 149 tumors, and global gene expression data for 105 tumors. High BMI, TAV, SAV, VAV and WC, and low LD, were associated with low grade endometrioid tumors and PR and AR positivity (all p≤0.03). High VAV% was associated with high age (p<0.001), aneuploidy (p=0.01) and independently predicted reduced disease-specific survival (HR 1.05, 95% CI 1.00-1.11, p=0.041). Tumors from patients with low VAV% showed enrichment of gene sets related to immune activation and inflammation. In conclusion, high VAV% independently predicts reduced EC survival. Tumors arising in patients with low VAV% show enrichment of immune and inflammation related gene sets, suggesting that the global metabolic setting may be important for tumor immune response.

Abdominal fat distribution measured using computed tomography is associated with an increased risk of colorectal adenoma in men

A few studies have shown inconsistent results regarding the association between the visceral fat proportion and colorectal adenomas. We aimed to investigate the association between abdominal fat distribution measured by computed tomography (CT) and colon adenoma.A total of 336 participants underwent physical examination, blood tests, colonoscopy, and abdominal computed tomography at Chung-Ang University Hospital. The associations between the obesity indicies (body mass index, visceral fat area (VFA), subcutaneous fat area (SFA), VFA-to-SFA ratio (VFA/SFA), and colorectal adenomas were evaluated.Of 309 subjects, 119 patients (38.5%) had colorectal adenoma. Mean age and fasting plasma glucose were higher in the patients with colorectal adenoma (P < .05, respectively). The mean VFA (153.3 cm vs 131.4 cm, P < .01) and VFA/SFA (1.07 vs 0.92, P < .05) were higher in the adenoma group than in the nonadenoma group. Males had higher mean VFA and VFA/SFA (P < .001). The mean VFA, SFA, and VFA/SFA were not associated with the location, size, number, and advancement of colorectal adenoma. In multivariate analysis, colorectal adenoma was significantly associated with VFA rather than VFA/SFA. In addition, colorectal adenoma was significantly associated with VFA rather than VFA/SFA in the men. The VFA, SFA, and VFA/SFA were not associated with colorectal adenoma in the women.The VFA measured by using a CT scan was positively associated with the presence of colorectal adenoma, especially in men. Furthermore, average risk men with large visceral fat volume should be examined carefully in screening colonoscopy.

Development and validation of a rapid and robust method to determine visceral adipose tissue volume using computed tomography images

BACKGROUND

Visceral adiposity is a risk factor for many chronic diseases. Existing methods to quantify visceral adipose tissue volume using computed tomographic (CT) images often use a single slice, are manual, and are time consuming, making them impractical for large population studies. We developed and validated a method to accurately, rapidly, and robustly measure visceral adipose tissue volume using CT images.

METHODS

In-house software, Medical Executable for the Efficient and Robust Quantification of Adipose Tissue (MEERQAT), was developed to calculate visceral adipose tissue volume using a series of CT images within a manually identified region of interest. To distinguish visceral and subcutaneous adipose tissue, ellipses are drawn through the rectus abdominis and transverse abdominis using manual and automatic processes. Visceral and subcutaneous adipose tissue volumes are calculated by counting the numbers of voxels corresponding to adipose tissue in the region of interest. MEERQAT's ellipse interpolation method was validated by comparing visceral adipose volume from 10 patients' CT scans with corresponding results from manually delineated scans. Accuracy of visceral adipose quantification was tested using a phantom consisting of animal fat and tissues. Robustness of the method was tested by determining intra-observer and inter-observer coefficients of variation (CV).

RESULTS

The mean difference in visceral adipose tissue volume between manual and elliptical delineation methods was -0.54 ± 4.81%. In the phantom, our measurement differed from the known adipose volume by ≤ 7.5% for all scanning parameters. Mean inter-observer CV for visceral adipose tissue volume was 0.085, and mean intra-observer CV for visceral adipose tissue volume was 0.059.

CONCLUSIONS

We have developed and validated a robust method of accurately and quickly determining visceral adipose tissue volume in any defined region of interest using CT imaging.

Assessing genetic and environmental influences on epicardial and abdominal adipose tissue quantities: a classical twin study

BACKGROUND/OBJECTIVES

Various adipose tissue compartments play an important role in the development of cardiometabolic diseases. The quantity of different fat compartments is influenced by genetic and environmental factors. The aim of our study was to evaluate the magnitude of genetic and environmental effects on epicardial, subcutaneous and visceral adipose tissue (EAT, SAT and VAT) quantities in a cohort of adult twin pairs.

SUBJECTS/METHODS

In this cross-sectional study we investigated adult twins (57 monozygotic (MZ) and 33 dizygotic (DZ) same-gender twin pairs; 180 twin subjects). We measured EAT volume using electrocardiogram-gated native computed tomography (CT) scan of the heart, and abdominal SAT and VAT areas were quantified between the third and fourth lumbar vertebra on native CT images. We calculated genetic and environmental impact on the size of various adipose tissue compartments by analyzing co-twin correlations in MZ and DZ pairs separately, and furthermore by using genetic structural equation models.

RESULTS

In co-twin analysis, MZ twins had stronger correlations than DZ twins for EAT (r_MZ=0.81, r_DZ=0.32), similar to SAT and VAT quantities (r_MZ=0.80, r_DZ=0.68 and r_MZ=0.79, r_DZ=0.48, respectively). In multi-trait model fitting analysis, the overall contribution of genetic factors to EAT, SAT and VAT volumes were 80%, 78% and 70%, whereas environmental factors were 20%, 22% and 30%, respectively. Common pathway model analyses indicated that none of the EAT, SAT and VAT phenotypes was independent of the other two.

CONCLUSIONS

Genetic factors have substantial influence, while environmental factors have only a modest impact on EAT volume, abdominal SAT and VAT quantities. There is a considerable amount of common genetic background influencing the quantities of all three adipose tissue compartments.

Upper Body Subcutaneous Fat Is Associated with Cardiometabolic Risk Factors

BACKGROUND

Upper body subcutaneous fat is a distinct fat depot that may confer increased cardiometabolic risk. We examined the cross-sectional associations between upper body subcutaneous fat volume and cardiometabolic risk factors.

METHODS

Participants were patients from the Framingham Heart Study who underwent multi-detector computed tomography between 2008 and 2011. Sex-specific multivariable-adjusted regression analyses were conducted. Covariates included age, ethnicity, smoking status, alcohol intake, physical activity, postmenopausal status, and hormone replacement therapy. Additional models included adjustment for body mass index (BMI), neck circumference, or abdominal visceral adipose tissue.

RESULTS

There were 2306 participants (mean age 60 years, 54.4% women) included. Mean upper body subcutaneous fat was 309.9 cm³ in women and 345.6 cm³ in men. Higher upper body subcutaneous fat volume was associated with adverse cardiometabolic risk factors. In women and men, each additional 50-cm³ increment in upper body subcutaneous fat was associated with a 3.23 and 2.65 kg/m² increase in BMI; 2.16 and 0.88 mm Hg increase in systolic blood pressure; 2.53 and 1.66 mg/dL increase in fasting plasma glucose; 0.12 and 0.11 mg/dL increase in log triglycerides; and 4.17 and 3.68 mg/dL decrease in high-density lipoprotein cholesterol, respectively (all P ≤.008). Similar patterns were observed with prevalent cardiometabolic risk factors. These associations remained significant after additional adjustment for BMI, neck circumference, or abdominal visceral adipose tissue.

CONCLUSIONS

Higher upper body subcutaneous fat is cross-sectionally associated with adverse cardiometabolic risk factors. Our findings underscore the importance of subcutaneous adiposity in the upper body region that may provide a better understanding of the pathogenic properties of obesity in the development of cardiometabolic sequelae.

Association of built environment characteristics with adiposity and glycaemic measures

OBJECTIVE

This study examined the cross-sectional and longitudinal relationships of built environment characteristics with adiposity and glycaemic measures.

METHOD

Longitudinal study sample consisted of 4,010 Framingham Heart Study Offspring (baseline: 1998-2001; follow-up: 2005-2008) and Generation Three (baseline: 2002-2005; follow-up: 2008-2011) participants (54.8% women, baseline mean age 48.6 years). Built environment characteristics (intersection density, greenspace, recreation land and food stores) at baseline were collected. Adiposity and glycaemic measures (body mass index [BMI], waist circumference, abdominal subcutaneous and visceral adipose tissue, and fasting plasma glucose) at baseline and changes during 6.4-year follow-up were measured.

RESULTS

In cross-sectional models, higher intersection density and food store density (total food stores, fast food restaurants and supermarkets) were linearly associated with higher BMI (all p < 0.05). Higher greenspace was associated with lower BMI, waist circumference, fasting plasma glucose, prevalent obesity and prevalent diabetes (all p < 0.05). Longitudinally, higher intersection density and food store density, and lower greenspace were associated with smaller increases in abdominal visceral adipose tissue (all p < 0.05). Higher densities of intersections, fast food restaurants and supermarkets were associated with smaller increases in fasting plasma glucose (all p < 0.05).

CONCLUSIONS

Collectively, built environment characteristics are associated with adiposity and glycaemic traits, suggesting the potential mechanisms by which built environment influences cardiometabolic health.

Association of Changes in Abdominal Fat Quantity and Quality With Incident Cardiovascular Disease Risk Factors

BACKGROUND

Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) are associated with adverse cardiometabolic risk profiles.

OBJECTIVES

This study explored the degree to which changes in abdominal fat quantity and quality are associated with changes in cardiovascular disease (CVD) risk factors.

METHODS

Study participants (n = 1,106; 44.1% women; mean baseline age 45.1 years) were drawn from the Framingham Heart Study Third Generation cohort who participated in the computed tomography (CT) substudy Exams 1 and 2. Participants were followed for 6.1 years on average. Abdominal adipose tissue volume in cm(3) and attenuation in Hounsfield units (HU) were determined by CT-acquired abdominal scans.

RESULTS

The mean fat volume change was an increase of 602 cm(3) for SAT and an increase of 703 cm(3) for VAT; the mean fat attenuation change was a decrease of 5.5 HU for SAT and an increase of 0.07 HU for VAT. An increase in fat volume and decrease in fat attenuation were associated with adverse changes in CVD risk factors. An additional 500 cm(3) increase in fat volume was associated with incident hypertension (odds ratio [OR]: 1.21 for SAT; OR: 1.30 for VAT), hypertriglyceridemia (OR: 1.15 for SAT; OR: 1.56 for VAT), and metabolic syndrome (OR: 1.43 for SAT; OR: 1.82 for VAT; all p < 0.05). Similar trends were observed for each additional 5 HU decrease in abdominal adipose tissue attenuation. Most associations remained significant even after further accounting for body mass index change, waist circumference change, or respective abdominal adipose tissue volumes.

CONCLUSIONS

Increasing accumulation of fat quantity and decreasing fat attenuation are associated with worsening of CVD risk factors beyond the associations with generalized adiposity, central adiposity, or respective adipose tissue volumes.

Visceral Adipose Tissue Volume and the Occurrence of Colorectal Adenoma in Follow-up Colonoscopy for Screening and Surveillance

Whether obesity accelerates adenoma recurrence is not yet clear; therefore, we analyzed the risk factors for adenoma occurrence at follow-up colonoscopy, with a focus on visceral adiposity. In total, 1516 subjects underwent index colonoscopy, computed tomography, and questionnaire assessment from February to May 2008; 539 subjects underwent follow-up colonoscopy at the National Cancer Center at least 6 mo after the index colonoscopy. The relationships between the presence of adenoma at follow-up colonoscopy and anthropometric obesity measurements, including body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT) volume, and subcutaneous adipose tissue (SAT) volume, were analyzed. 188 (34.9%) had adenomatous polyps at follow-up colonoscopy. Multivariate analysis revealed that VAT volume ≥ 1000 cm³ and BMI ≥ 30 kg/m² were related to the presence of adenoma at follow-up colonoscopy (VAT volume 1000-1500 cm³: odds ratio [OR] = 2.13(95% confidence interval, CI = 1.06-4.26), P = 0.034; VAT volume ≥ 1000 cm³: OR = 2.24(95% CI = 1.03-4.88), P = 0.043; BMI ≥ 30 kg/m²: OR = 4.22(95% CI = 1.12-15.93), P = 0.034). In contrast, BMI 25-29.9 kg/m², SAT volume, and WC were not associated with the presence of adenoma at follow-up colonoscopy. In conclusion, excess VAT can contribute to the development and growth of new colorectal adenomas, and is a better predictor of colorectal adenoma occurrence at follow-up colonoscopy than BMI, WC, and SAT volume.

Increased Ratio of Visceral to Subcutaneous Adipose Tissue in Septic Patients Is Associated With Adverse Outcome

OBJECTIVES

Visceral and subcutaneous adipose tissue may contribute differentially to the septic inflammatory response. Accordingly, we tested the hypothesis that the ratio of visceral to subcutaneous adipose tissue is associated with altered sepsis outcome.

DESIGN

A retrospective analysis from a cohort of sepsis patients admitted between 2004 and 2009.

SETTING

A mixed medical-surgical ICU at St. Paul's Hospital in Vancouver, Canada.

PATIENTS

Patients older than 16 years old who had sepsis and underwent abdominal CT scan (n = 257) for clinical reasons.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We measured the visceral adipose tissue and subcutaneous adipose tissue areas and calculated the visceral adipose tissue-to-subcutaneous adipose tissue ratio. Visceral adipose tissue/subcutaneous adipose tissue was not correlated with body mass index (r = -0.015, p = NS) and therefore provides additional unique information independent of body mass index. Sepsis patients with higher visceral adipose tissue/subcutaneous adipose tissue had greater 90-day mortality than patients with lower visceral adipose tissue/subcutaneous adipose tissue (log-rank test, linear-by linear association p < 0.005). After adjustment for significant covariates using Cox regression, increased visceral adipose tissue/subcutaneous adipose tissue quartile was significantly associated with increased 90-day mortality with hazard ratios of 2.01 (95% CI, 1.01-3.99) for the third visceral adipose tissue/subcutaneous adipose tissue quartile compared with the first quartile and 2.32 (95% CI, 1.15-4.69) for the highest visceral adipose tissue/subcutaneous adipose tissue quartile when compared with the first quartile. Increased mortality for patients with higher visceral adipose tissue/subcutaneous adipose tissue was found for both patients with body mass index less than 25 kg/m (p = 0.004) and for body mass index greater than or equal to 25 kg/m (p = 0.023). Furthermore, we found significantly greater need for mechanical ventilation, renal replacement therapy, and ICU stay in patients in the highest visceral adipose tissue/subcutaneous adipose tissue quartile. The ratio of proinflammatory (interleukin-8) to anti-inflammatory (interleukin-10) plasma cytokine levels was greater in patients with higher visceral adipose tissue/subcutaneous adipose tissue than in those with lower visceral adipose tissue/subcutaneous adipose tissue (p = 0.043).

CONCLUSIONS

Visceral obesity, defined by a high visceral adipose tissue-to-subcutaneous adipose tissue ratio, contributes to adverse outcome in sepsis patients perhaps because of a greater pro- versus anti-inflammatory response.

Impact of Skeletal Muscle Mass Index, Intramuscular Adipose Tissue Content, and Visceral to Subcutaneous Adipose Tissue Area Ratio on Early Mortality of Living Donor Liver Transplantation

BACKGROUND

Skeletal muscle depletion has been shown to be an independent risk factor for poor survival in various diseases. However, in surgery, the significance of other body components including visceral and subcutaneous adipose tissue remains unclear.

METHODS

This retrospective study included 250 adult patients undergoing living donor liver transplantation (LDLT) between January 2008 and April 2015. Using preoperative plain computed tomography imaging at the third lumbar vertebra level, skeletal muscle mass, muscle quality, and visceral adiposity were evaluated by the skeletal muscle mass index (SMI), intramuscular adipose tissue content (IMAC), and visceral to subcutaneous adipose tissue area ratio (VSR), respectively. The cutoff values of these parameters were determined for men and women separately using the data of 657 healthy donors for LDLT between 2005 and 2016. Impact of these parameters on outcomes after LDLT was analyzed.

RESULTS

VSR was significantly correlated with patient age (P = 0.041), neutrophil-lymphocyte ratio (P < 0.001), body mass index (P < 0.001), and SMI (P = 0.001). The overall survival probability was significantly lower in patients with low SMI (P < 0.001), high IMAC (P < 0.001), and high VSR (P < 0.001) than in each respective normal group. On multivariate analysis, low SMI (hazard ratio [HR], 2.367, P = 0.002), high IMAC (HR, 2.096, P = 0.004), and high VSR (HR, 2.213, P = 0.003) were identified as independent risk factors for death after LDLT.

CONCLUSIONS

Preoperative visceral adiposity, as well as low muscularity, was closely involved with posttransplant mortality.

Perirenal fat thickness measured with computed tomography is a reliable estimate of perirenal fat mass

Deposition of perirenal adipose tissue has been associated with adverse renal and cardiovascular events. We compared various methods to measure perirenal adipose tissue using computerized tomography (CT)-scan and performed correlations with anthropometric measures associated with renal and cardiovascular events. Voluntary overweight and obese subjects undergoing a CT-scan for diagnostic purposes were included in the study. Perirenal adipose tissue volume, adipose tissue area of the renal sinus and perirenal fat thickness were manually measured bilaterally. The intra- and inter-observer coefficient correlations and the correlation between the diverse measures of renal adipose tissue, subcutaneous (SC-)fat and anthropometrics measures were analyzed using Pearson's correlation tests. The forty included patients (24 men, 16 women) had a mean age of 57.6 ± 18.1 years and a mean body mass index of 28.9 ± 2.9 kg/m². Despite comparable waist circumference, women had a greater SC-fat thickness compared to men, and therefore a smaller amount of visceral fat, as well as smaller perirenal fat volumes. Perirenal fat thickness was better correlated with perirenal fat volume than adipose area of the renal sinus (p <0.02). The adipose area of the renal sinus did not correlate with any anthropometric measures. In women, perirenal fat volume and thickness showed a negative correlation with SC-fat thickness and no correlation with waist circumference. In men, perirenal fat volume and thickness showed a positive correlation with waist circumference and no correlation with subcutaneous fat thickness. In conclusion, perirenal fat thickness measured with CT-scan at the level of the renal veins is a simple and reliable estimate of perirenal fat volume, that correlated negatively with SC-fat in women and positively with waist circumference in men. The adipose area of the renal sinus did not correlate with any anthropometric measure.

Relation of Iliac Artery Calcium With Adiposity Measures and Peripheral Artery Disease

Arterial calcification is associated with cardiovascular morbidity and mortality. To improve the understanding of the pathogenesis involved with iliac artery calcium (IAC), we sought to examine the associations between the burden of IAC with adiposity measures and peripheral artery disease (PAD). Participants (n = 1,236, 52% women, mean age 60 years) were drawn from the Framingham Heart Study Offspring cohort who underwent multidetector computed tomography. The extent of IAC was quantified based on calcified atherosclerotic plaques detected in the iliac arteries. High IAC was defined based on gender-specific 90th percentile cut-off points from a healthy referent subsample. PAD is defined as an ankle-brachial index < 0.9, intermittent claudication, and/or history of lower extremity revascularization. The association between PAD and IAC was assessed using multivariable-adjusted logistic regression models. The burden of high IAC was 20.5% in women and 25.5% in men. High IAC was not associated with generalized (body mass index) or area-specific (waist circumference, and volumes of thoracic periaortic, abdominal subcutaneous, and visceral adipose tissue) adiposity measures (all p ≥0.22). High IAC was associated with increased odds of PAD (odds ratio 10.36, 95% confidence interval 4.28 to 25.09). This association persisted even after additionally adjusting for coronary artery calcium (odds ratio 11.25, 95% confidence interval 4.29 to 29.53). Burden of IAC was associated with an increased risk of PAD.

Effect of abdominal visceral fat on the development of new erosive oesophagitis: a prospective cohort study

OBJECTIVES

Although abdominal visceral fat has been associated with erosive oesophagitis in cross-sectional studies, there are no data that describe its longitudinal effects. We aimed to evaluate the longitudinal effects of abdominal visceral fat on the development of new erosive oesophagitis in patients who did not have erosive oesophagitis at baseline.

MATERIALS AND METHODS

This was a single-centre prospective study. A total of 1503 participants without erosive oesophagitis at baseline were followed up for 34 months and they underwent oesophagogastroduodenoscopy and computed tomography at both baseline and during follow-up. The longitudinal effects of abdominal visceral fat on the development of new erosive oesophagitis were evaluated using odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

New oesophagitis developed in 83 patients. Compared with the first quartile, the third (OR=3.96, 95% CI: 1.54-10.18) and the fourth (OR=4.67, 95% CI: 1.79-12.23) of baseline visceral fat quartiles, the third (OR=3.03, 95% CI: 1.14-8.04) and the fourth (OR=7.50, 95% CI: 2.92-19.25) follow-up visceral fat quartiles, and the fourth visceral fat change quartile (OR=2.76, 95% CI: 1.47-5.21) were associated with increased development of new erosive oesophagitis, and the P value for each trend was less than 0.001. New erosive oesophagitis was inversely related to the follow-up Helicobacter pylori status and it was associated positively with the presence of a hiatal hernia and smoking during follow-up, but it was not associated with reflux symptoms, the H. pylori status, presence of a hiatal hernia or smoking at baseline.

CONCLUSION

Higher level of visceral fat at baseline and follow-up visceral fat, and greater changes in the visceral level were associated linearly with the development of new erosive oesophagitis in this longitudinal study.