AI-based abdominal CT measurements of orthotopic and ectopic fat predict mortality and cardiometabolic disease risk in adults.

OBJECTIVES: To evaluate the utility of CT-based abdominal fat measures for predicting the risk of death and cardiometabolic disease in an asymptomatic adult screening population. METHODS: Fully automated AI tools quantifying abdominal adipose tissue (L3 level visceral [VAT] and subcutaneous [SAT] fat area, visceral-to-subcutaneous fat ratio [VSR], VAT attenuation), muscle attenuation (L3 level), and liver attenuation were applied to non-contrast CT scans in asymptomatic adults undergoing CT colonography (CTC). Longitudinal follow-up documented subsequent deaths, cardiovascular events, and diabetes. ROC and time-to-event analyses were performed to generate AUCs and hazard ratios (HR) binned by octile. RESULTS: A total of 9223 adults (mean age, 57 years; 4071:5152 M:F) underwent screening CTC from April 2004 to December 2016. 549 patients died on follow-up (median, nine years). Fat measures outperformed BMI for predicting mortality risk-5-year AUCs for muscle attenuation, VSR, and BMI were 0.721, 0.661, and 0.499, respectively. Higher visceral, muscle, and liver fat were associated with increased mortality risk-VSR > 1.53, HR = 3.1; muscle attenuation < 15 HU, HR = 5.4; liver attenuation < 45 HU, HR = 2.3. Higher VAT area and VSR were associated with increased cardiovascular event and diabetes risk-VSR > 1.59, HR = 2.6 for cardiovascular event; VAT area > 291 cm2, HR = 6.3 for diabetes (p < 0.001). A U-shaped association was observed for SAT with a higher risk of death for very low and very high SAT. CONCLUSION: Fully automated CT-based measures of abdominal fat are predictive of mortality and cardiometabolic disease risk in asymptomatic adults and uncover trends that are not reflected in anthropomorphic measures. CLINICAL RELEVANCE STATEMENT: Fully automated CT-based measures of abdominal fat soundly outperform anthropometric measures for mortality and cardiometabolic risk prediction in asymptomatic patients. KEY POINTS: Abdominal fat depots associated with metabolic dysregulation and cardiovascular disease can be derived from abdominal CT. Fully automated AI body composition tools can measure factors associated with increased mortality and cardiometabolic risk. CT-based abdominal fat measures uncover trends in mortality and cardiometabolic risk not captured by BMI in asymptomatic outpatients.

Age-adjusted Charlson comorbidity index and its association with body composition and overall survival in patients with colorectal cancer.

OBJECTIVE: To examine the relationship between the age-adjusted Charlson comorbidity index (A-CCI) with body composition and overall survival in patients newly diagnosed with colorectal cancer (CRC). RESEARCH METHODS AND PROCEDURES: In this cohort study, patients (≥ 18 years old) with CRC were followed for 36 months. Computed tomography images of the third lumbar were analyzed to determine body composition, including skeletal muscle area (SMA), skeletal muscle index (SMI), skeletal muscle radiodensity (SMD), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT). Phenotypes based on comorbidity burden assessed by A-CCI and body composition parameters were established. RESULTS: A total of 436 participants were included, 50% male, with a mean age of 61 ± 13.2 years. Approximately half of the patients (50.4%) had no comorbidity, and the A-CCI median score was 4 (interquartile range: 3-6). A higher A-CCI score was a risk factor for 36-month mortality (HR = 3.59, 95% CI = 2.17-5.95). Low SMA and low SMD were associated with a higher A-CCI. All abnormal phenotypes (high A-CCI and low SMA; high A-CCI and low SMD; high A-CCI and high VAT) were independently associated with higher 36-month mortality hazard (adjusted HR 5.12, 95% CI 2.73-9.57; adjusted HR 4.58, 95% CI 2.37-8.85; and adjusted HR 2.36, 95% CI 1.07-5.22, respectively). CONCLUSION: The coexistence of comorbidity burden and abnormal body composition phenotypes, such as alterations in muscle or fat compartments, may pose an additional risk of mortality in patients newly diagnosed with CRC. Early assessment and management of these phenotypes could be crucial in optimizing outcomes in such patients.

The association between the visceral to subcutaneous abdominal fat ratio and the risk of cardiovascular diseases: a systematic review.

BACKGROUND: Cardiovascular diseases (CVDs) are the primary cause of mortality globally. The prevalence of obesity is rising worldwide; there seems to be a significant positive association between obesity and CVDs. The distribution of fat in the abdominal area in the form of visceral (VAT) or subcutaneous adipose tissue (SAT) affects the risk of CVDs. The aim of the present study was to conduct a systematic review of the available literature regarding the association between the VAT-to-SAT ratio and CVDs. METHODS: A comprehensive search strategy was used to retrieve all human observational studies indexed in PubMed, Scopus and Google Scholar databases/search engines (from Jan 2000 up to Oct 2023). The VAT-to-SAT or SAT-to-VAT ratio was an independent variable and various cardiovascular diseases, including hypertension, atherosclerosis, coronary heart disease, cerebrovascular disease and heart failure, were considered as outcomes of interest. RESULTS: Out of 1173 initial studies, 910 papers were screened. Based on the inclusion criteria, 883 papers were excluded. Finally, 27 papers (18 cross-sectional and 9 cohort studies) published between 2010 and 2023 which met the inclusion criteria were reviewed. CONCLUSIONS: The distribution of abdominal fat seems to be associated with the risk of CVDs; the majority of the evidence suggests that a higher abdominal VAT-to-SAT ratio is associated with the development of CVDs. Therefore, this ratio can be used as a prognostic indicator for CVDs. TRIAL REGISTRATION: Not applicable.

Comprehensive analysis of changes in expression of lncRNA, microRNA and mRNA in liver tissues of chickens with high or low abdominal fat deposition.

1. The liver of chickens is a dominant lipid biosynthetic tissue and plays a vital role in fat deposition, particularly in the abdomen. To determine the molecular mechanisms involved in its lipid metabolism, the livers of chickens with high (H) or low (L) abdominal fat content were sampled and sequencing on long non-coding RNA (lncRNA), messenger RNA (mRNA) and small RNA (microRNA) was performed.2. In total, 351 expressed protein-coding genes for long non-coding RNA (DEL; 201 upregulated and 150 downregulated), 400 differentially expressed genes (DEG; 223 upregulated and 177 downregulated) and 10 differentially expressed miRNA (DEM; four upregulated and six downregulated) were identified between the two groups. Multiple potential signalling pathways related to lipogenesis and lipid metabolism were identified via pathway enrichment analysis. In addition, 173 lncRNA - miRNA - mRNA interaction regulatory networks were identified, including 30 lncRNA, 27 mRNA and seven miRNA.3. These networks may help regulate lipid metabolism and fat deposition. Five promising candidate genes and two lncRNA may play important roles in the regulation of adipogenesis and lipid metabolism in chickens.

Transcriptome analysis reveals FABP5 as a key player in the development of chicken abdominal fat, regulated by miR-122-5p targeting.

BACKGROUND: The development of abdominal fat and meat quality are closely related and can impact economic efficiency. In this study, we conducted transcriptome sequencing of the abdominal fat tissue of Gushi chickens at 6, 14, 22, and 30 weeks, and selected key miRNA-mRNA regulatory networks related to abdominal fat development through correlation analysis. RESULTS: A total of 1893 differentially expressed genes were identified. Time series analysis indicated that at around 6 weeks, the development of chicken abdominal fat was extensively regulated by the TGF-ß signaling pathway, Wnt signaling pathway, and PPAR signaling pathway. However, at 30 weeks of age, the apoptosis signaling pathway was the most significant, and correlation analysis revealed several genes highly correlated with abdominal fat development, including Fatty Acid Binding Protein 5 (FABP5). Based on miRNA transcriptome data, it was discovered that miR-122-5p is a potential target miRNA for FABP5. Cell experiments showed that miR-122-5p can directly target FABP5 to promote the differentiation of preadipocytes. CONCLUSION: The present study confirms that the key gene FABP5 and its target gene miR-122-5p are critical regulatory factors in the development of chicken abdominal fat. These results provide new insights into the molecular regulatory mechanisms associated with the development of abdomen-al fat in chickens.

Visceral adipose tissue is an independent predictor and mediator of the progression of coronary calcification: a prospective sub-analysis of the GEA study.

BACKGROUND: Coronary artery calcium (CAC) improves cardiovascular event prediction. Visceral adipose tissue (VAT) is a cardiometabolic risk factor that may directly or through its related comorbidities determine the obesity-related risk. A clinical VAT estimator could allow an efficient evaluation of obesity-related risk. We aimed to analyze the effect of VAT and its related cardiometabolic risk factors on CAC progression. METHODS: CAC was quantified at baseline and after 5 years by computed tomography (CT), determining its progression. VAT and pericardial fat were measured by CT and estimated by a clinical surrogate (METS-VF). Considered cardiometabolic risk factors were: peripheral insulin resistance (IR), HOMA-IR, adipose tissue IR (ADIPO-IR), and adiponectin. Factors independently associated to CAC progression were analyzed by adjusted Cox proportional hazard models, including statin use and ASCVD risk score as covariates. We performed interaction and mediation models to propose possible pathways for CAC progression. RESULTS: The study included 862 adults (53 ± 9 years, 53% women), incidence CAC progression rate: 30.2 (95% CI 25.3-35.8)/1000 person-years. VAT (HR: 1.004, 95% CI 1.001-1.007, p < 0.01) and METS-VF (HR: 1.001, 95% CI 1.0-1.001, p < 0.05) independently predicted CAC progression. VAT-associated CAC progression risk was evident among low-risk ASCVD subjects, and attenuated among medium-high-risk subjects, suggesting that traditional risk factors overcome adiposity in the latter. VAT mediates 51.8% (95% CI 44.5-58.8%) of the effect attributable to IR together with adipose tissue dysfunction on CAC progression. CONCLUSIONS: This study supports the hypothesis that VAT is a mediator of the risk conferred by subcutaneous adipose tissue dysfunction. METS-VF is an efficient clinical surrogate that could facilitate the identification of at-risk adiposity subjects in daily clinical practice.

Visceral fat percentage for prediction of outcome in uterine cervical cancer.

OBJECTIVE: The prognostic role of adiposity in uterine cervical cancer (CC) is largely unknown. Abdominal fat distribution may better reflect obesity than body mass index. This study aims to describe computed tomography (CT)-assessed abdominal fat distribution in relation to clinicopathologic characteristics, survival, and tumor gene expression in CC. METHODS: The study included 316 CC patients diagnosed during 2004-2017 who had pre-treatment abdominal CT. CT-based 3D segmentation of total-, subcutaneous- and visceral abdominal fat volumes (TAV, SAV and VAV) allowed for calculation of visceral fat percentage (VAV% = VAV/TAV). Liver density (LD) and waist circumference (at L3/L4-level) were also measured. Associations between CT-derived adiposity markers, clinicopathologic characteristics and disease-specific survival (DSS) were explored. Gene set enrichment of primary tumors were examined in relation to fat distribution in a subset of 108 CC patients. RESULTS: High TAV, VAV and VAV% and low LD were associated with higher age (≥44 yrs.; p ≤ 0.017) and high International Federation of Gynecology and Obstetrics (FIGO) (2018) stage (p ≤ 0.01). High VAV% was the only CT-marker predicting high-grade histology (p = 0.028), large tumor size (p = 0.016) and poor DSS (HR 1.07, p < 0.001). Patients with high VAV% had CC tumors that exhibited increased inflammatory signaling (false discovery rate [FDR] < 5%). CONCLUSIONS: High VAV% is associated with high-risk clinical features and predicts reduced DSS in CC patients. Furthermore, patients with high VAV% had upregulated inflammatory tumor signaling, suggesting that the metabolic environment induced by visceral adiposity contributes to tumor progression in CC.

High Visceral-To-Subcutaneous Fat Ratio Is Associated with an Increased Risk of Gastroesophageal Reflux Disease in Nonobese Adults.

INTRODUCTION: Abdominal obesity increases the risk of gastroesophageal reflux disease (GERD). This study aimed to determine the association between GERD and abdominal fat area quantified by computed tomography (CT). METHODS: We analyzed the effect of abdominal fat area on gastroesophageal reflux symptoms and erosive esophagitis using logistic regression models in 5,338 participants who underwent abdominal fat measurement CT and screening esophagogastroduodenoscopy. RESULTS: Participants with reflux symptoms and erosive esophagitis were diagnosed in 1,168 (21.9%) and 671 (12.5%), respectively. Multivariate analysis showed that subcutaneous and visceral fat areas were significantly associated with reflux symptoms and erosive esophagitis. The adjusted odds ratio (OR) in the fourth quartile of visceral fat area compared with that in the lowest quartile was 1.98 (95% confidence interval (CI) 1.63-2.39) for reflux symptoms and 2.33 (95% CI 1.80-3.01) for erosive esophagitis. Visceral fat area had a stronger effect in the younger age-group. In the group <50 years, the adjusted OR in fourth quartile of visceral fat area was 2.70 (95% CI 1.86-3.94) for reflux symptoms and 3.59 (95% CI 2.22-5.80) for erosive esophagitis. High visceral-to-subcutaneous fat ratio (VSR) increased the risk of reflux symptoms and erosive esophagitis in participants with body mass index <25 kg/m2 and normal waist circumference. CONCLUSION: Subcutaneous and visceral fat areas were associated with an increased risk of reflux symptoms and erosive esophagitis. High VSR increased the risk of reflux symptoms and erosive esophagitis in participants with normal body weight and waist circumference.

Clinical characteristics and predictive factors of postoperative intra-abdominal abscess after distal pancreatectomy.

PURPOSE: The postoperative mortality rate of distal pancreatectomy is lower than that of pancreaticoduodenectomy, although persistent complications may occur after distal pancreatectomy. Fluid collection (FC) is frequently observed after distal pancreatectomy; however, FC may occasionally progress to postoperative intra-abdominal abscess (PIAA), which requires conservative or progressive interventional treatment. This study aimed to compare the status between patients with or without PIAA, identify predictive factors for PIAA and clinically relevant postoperative pancreatic fistula, and investigate the clinical characteristics of patients with PIAA with interventional drainage. METHODS: We retrospectively reviewed data of patients who underwent distal pancreatectomy between January 2012 and December 2019 at two high-volume centers, where hepatobiliary-pancreatic surgeries were performed by expert specialist surgeons. Logistic regression analysis was performed to determine the predictive factors for PIAA. RESULTS: Overall, 242 patients were analyzed, among whom 49 (20.2%) had PIAA. The median postoperative period of PIAA formation was 9 (range: 3-49) days. Among the 49 patients with PIAA, 25 (51.0%) underwent percutaneous ultrasound, computed tomography, or endoscopic ultrasound-guided interventions for PIAA. In the univariate analysis, preoperative indices representing abdominal fat mass (i.e., body mass index, subcutaneous fat area, and visceral fat area) were identified as predictive factors for PIAA; in the multivariate analysis, C-reactive protein (CRP) level (continuous variable) on postoperative day (POD) 3 (odds ratio: 1.189, 95.0% confidence interval: 1.111 - 1.274; P < 0.001) was the only independent and significant predictive factor for PIAA. CONCLUSIONS: CRP level on POD 3 was an independent and significant predictive factor for PIAA after distal pancreatectomy.

Evaluation of the relationship between abdominal fat distribution and osteoporotic vertebral compression fracture with MRI.

OBJECTIVE: This study was carried out to investigate the effects of abdominal subcutaneous adiposity and visceral adiposity on osteoporotic compression fractures. MATERIAL AND METHODS: The study group consisted of a total of 152 individuals aged 50-80 years; 76 were included in the vertebral fracture group and 76 in the healthy control group, whose bone mineral density was calculated. In order to determine the distribution of abdominal fat in both groups, four different measurements, i.e., sagittal abdominal diameter (SAD), abdominal diameter (AD), ventral subcutaneous thickness (VST), and dorsal subcutaneous thickness (DST), were made using lumbar magnetic resonance imaging (MRI). The visceral fat ratio (VFR) was also calculated based on these measurements. RESULTS: There was a significant difference between the patient and control groups in VST and DST values, both when gender distribution was and was not taken into account (p < 0.006 for all cases). There was no significant difference between the patient and control groups in SAD and AS values, both when only female patients were considered, and gender distribution was not taken into account (p > 0.25 for all cases). On the other hand, in the analysis, when only male patients were considered, the SAD and AD values of the patient group were found to be significantly lower than those of the control group (p = 0.046 and p = 0.048, respectively). CONCLUSION: In conclusion, the study findings indicated that high SAD values in the male gender and high VST and DST values in both genders were associated with low lumbar vertebral fracture risk.

Simple radiologic assessment of visceral obesity and prediction of surgical morbidity in endometrial cancer patients undergoing laparoscopic aortic lymphadenectomy: A reliability and accuracy study.

AIM: To evaluate the reliability of sagittal abdominal diameter (SAD)-a surrogate of visceral obesity-in magnetic resonance imaging, and its accuracy to predict the surgical morbidity of aortic lymphadenectomy. METHODS: We conducted a multicenter reliability (phase 1) and accuracy (phase 2) cohort study in three Spanish referral hospitals. We retrospectively analyzed data from the STELLA-2 randomized controlled trial that included high-risk endometrial cancer patients undergoing minimally invasive surgical staging. Patients were classified into subgroups: conventional versus robotic-assisted laparoscopy, and transperitoneal versus extraperitoneal technique. In the first phase, we measured the agreement of three SAD measurements (at the umbilicus, renal vein, and inferior mesenteric artery) and selected the most reliable one. In phase 2, we evaluated the diagnostic accuracy of SAD to predict surgical morbidity. Surgical morbidity was the main outcome measure, it was defined by a core outcome set including variables related to blood loss, operative time, surgical complications, and para-aortic lymphadenectomy difficulty. RESULTS: In phase 1, all measurements showed good inter-rater and intra-rater agreement. Umbilical SAD (u-SAD) was the most reliable one. In phase 2, we included 136 patients. u-SAD had a good diagnostic accuracy to predict surgical morbidity in patients undergoing transperitoneal laparoscopic lymphadenectomy (0.73 in ROC curve). It performed better than body mass index and other anthropometric measurements. We calculated a cut-off point of 246 mm (sensitivity: 0.56, specificity: 0.80). CONCLUSIONS: u-SAD is a simple, reliable, and potentially useful measurement to predict surgical morbidity in endometrial cancer patients undergoing minimally invasive surgical staging, especially when facing transperitoneal aortic lymphadenectomy.

Adiposity in the older population and the risk of dementia: The Rotterdam Study.

INTRODUCTION: We determined associations of total and regional adiposity with incident dementia among older adults. METHODS: Within the population-based Rotterdam Study, adiposity was measured as total, android, and gynoid fat mass using dual-energy X-ray absorptiometry in 3408 men and 4563 women, every 3 to 6 years between 2002 and 2016. Incident dementia was recorded until 2020. RESULTS: Higher adiposity measures were associated with a decreased risk of dementia in both sexes. After excluding the first 5 years of follow-up, only the association of gynoid fat among women remained significant (hazard ratio 0.85 [95% confidence interval 0.75-0.97] per standard deviation increase). No major differences in trajectories of adiposity measures were observed between dementia cases and dementia-free controls. DISCUSSION: Higher total and regional fat mass related to a decreased risk of dementia. These results may be explained by reverse causality, although a protective effect of adiposity cannot be excluded. HIGHLIGHTS: Total and regional adiposity were assessed using dual-energy X-ray absorptiometry scans in 7971 older adults. All adiposity measures were associated with a decreased risk of dementia. The results suggest a beneficial effect of gynoid fat on the risk of dementia in women. Reverse causation and competing risk may explain these inverse associations.

Assessment of the Efficacy of Cryolipolysis on Abdominal Fat Deposits: A Prospective Study.

BACKGROUND: Cryolipolysis is a non-invasive and efficacious procedure for body contouring. The effectiveness of cryolipolysis has been demonstrated on multiple areas of the body, but on a limited number of subjects. The aim of this study is to demonstrate the effectiveness and the safety of cryolipolysis in the lower abdomen adipose tissue thickness reduction. METHODS: A prospective study on 60 healthy women was carried out using CryoSlim Hybrid device. Each patient underwent two cryolipolysis sessions centered on the abdominal area. The primary endpoint was to decrease the thickness of the abdominal fat deposits. The change in the abdominal circumference and the thickness of the subcutaneous fat layer were assessed. Patient satisfaction and tolerance of the procedure were also taken into account. RESULTS: A significant reduction of the abdominal circumference and subcutaneous fat layer thickness was observed. The mean decrease in abdominal circumference was 2.10 cm (3.1%) 3 months after the procedure and 4.03 cm (5.8%) 6 months after the procedure. The mean decrease in fat layer thickness was 1.25 cm (43.81%) 3 months after the procedure and 1.61 cm (41.73%) 6 months after the procedure. No major adverse events were noted. All patients were very satisfied, and minimal pain was reported. CONCLUSIONS: Cryolipolysis is an effective technique to treat abdominal localized fat deposits. No major adverse events have been described for this procedure. Our promising results should encourage further studies aimed at optimizing the efficacy of the procedure without a considerable increase in the risks. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266 .

Sex differences in intraorgan fat levels and hepatic lipid metabolism: implications for cardiovascular health and remission of type 2 diabetes after dietary weight loss.

AIMS/HYPOTHESIS: Type 2 diabetes confers a greater relative increase in CVD risk in women compared with men. We examined sex differences in intraorgan fat and hepatic VLDL1-triacylglycerol (VLDL1-TG) export before and after major dietary weight loss. METHODS: A group with type 2 diabetes (n = 64, 30 male/34 female) and a group of healthy individuals (n = 25, 13 male/12 female) were studied. Intraorgan and visceral fat were quantified by magnetic resonance and VLDL1-TG export by intralipid infusion techniques. RESULTS: Triacylglycerol content of the liver and pancreas was elevated in people with diabetes with no sex differences (liver 16.4% [9.3-25.0%] in women vs 11.9% [7.0-23.1%] in men, p = 0.57, and pancreas 8.3 ± 0.5% vs 8.5 ± 0.4%, p = 0.83, respectively). In the absence of diabetes, fat levels in both organs were lower in women than men (1.0% [0.9-1.7%] vs 4.5% [1.9-8.0%], p = 0.005, and 4.7 ± 0.4% vs 7.6 ± 0.5%, p< 0.0001, respectively). Women with diabetes had higher hepatic VLDL1-TG production rate and plasma VLDL1-TG than healthy women (559.3 ± 32.9 vs 403.2 ± 45.7 mg kg-1 day-1, p = 0.01, and 0.45 [0.26-0.77] vs 0.25 [0.13-0.33] mmol/l, p = 0.02), whereas there were no differences in men (548.8 ± 39.8 vs 506.7 ± 29.2 mg kg-1 day-1, p = 0.34, and 0.72 [0.53-1.15] vs 0.50 [0.32-0.68] mmol/l, p = 0.26). Weight loss decreased intraorgan fat and VLDL1-TG production rates regardless of sex, and these changes were accompanied by similar rates of diabetes remission (65.4% vs 71.0%) and CVD risk reduction (59.8% vs 41.5%) in women and men, respectively. CONCLUSIONS/INTERPRETATION: In type 2 diabetes, women have liver and pancreas fat levels as high as those of men, associated with raised hepatic VLDL1-TG production rates. Dynamics of triacylglycerol turnover differ between sexes in type 2 diabetes and following weight loss. These changes may contribute to the disproportionately raised cardiovascular risk of women with diabetes.

Differential regulation of intramuscular fat and abdominal fat deposition in chickens.

BACKGROUND: Chicken intramuscular fat (IMF) content is closely related to meat quality and performance, such as tenderness and flavor. Abdominal fat (AF) in chickens is one of the main waste products at slaughter. Excessive AF reduces feed efficiency and carcass quality. RESULTS: To analyze the differential deposition of IMF and AF in chickens, gene expression profiles in the breast muscle (BM) and AF tissues of 18 animals were analyzed by differential expression analysis and weighted co-expression network analysis. The results showed that IMF deposition in BM was associated with pyruvate and citric acid metabolism through GAPDH, LDHA, GPX1, GBE1, and other genes. In contrast, AF deposition was related to acetyl CoA and glycerol metabolism through FABP1, ELOVL6, SCD, ADIPOQ, and other genes. Carbohydrate metabolism plays an essential role in IMF deposition, and fatty acid and glycerol metabolism regulate AF deposition. CONCLUSION: This study elucidated the molecular mechanism governing IMF and AF deposition through crucial genes and signaling pathways and provided a theoretical basis for producing high-quality broilers.

Two-dimensional CT measurements enable assessment of body composition on head and neck CT.

OBJECTIVES: The aim of this study was to evaluate whether simple 2D measurements in axial slices of head and neck CT examinations correlate with generally established measurements of body composition in abdominal CT at the height of the third lumbar vertebra and thus allow for an estimation of muscle and fat masses. METHODS: One hundred twenty-two patients who underwent concurrent CT of the head and neck and the abdomen between July 2016 and July 2020 were retrospectively included. For a subset of 30 patients, additional bioelectrical impedance analysis (BIA) was available. Areas of paraspinal muscles at the height of the third (C3) and fifth cervical vertebrae (C5) as well as the total cross-sectional area at the height of C3 and at the submandibular level were correlated with the results of abdominal measurements and BIA. Furthermore, intra- and interreader variabilities of all measurements were assessed. RESULTS: Regarding adipose tissue, good correlations were found between the total cross-sectional area of the patient's body at the submandibular level and at the height of C3 between both abdominal measurements and BIA results (r = 0.8-0.92; all p < 0.001). Regarding muscle, the total paraspinal muscle area at the height of C3 and C5 showed strong correlations with abdominal measurements and moderate to strong correlations with BIA results (r = 0.44-0.80; all p < 0.001), with the muscle area on C5 yielding slightly higher correlations. CONCLUSIONS: Body composition information can be obtained with comparable reliability from head and neck CT using simple biplanar measurements as from abdominal CT. KEY POINTS: • The total paraspinal muscle area at the height of C3 and C5 correlates strongly with abdominal muscle mass. • The total cross-sectional area at the submandibular level and at the height of C3 shows good correlations with abdominal fat mass. • The described measurements facilitate a rapid, opportunistic assessment of relevant body composition parameters.

Abdominal periaortic and renal sinus fat attenuation indices measured on computed tomography are associated with metabolic syndrome.

OBJECTIVES: To investigate the association between abdominal periaortic (APA) and renal sinus (RS) fat attenuation index (FAI) measured on MDCT and metabolic syndrome in non-obese and obese individuals. METHODS: Visceral, subcutaneous, RS, and APA adipose tissue were measured in preoperative abdominal CT scans of individuals who underwent donor nephrectomy (n = 84) or bariatric surgery (n = 155). FAI was defined as the mean attenuation of measured fat volume. Participants were categorized into four groups: non-obese without metabolic syndrome (n = 64), non-obese with metabolic syndrome (n = 25), obese without metabolic syndrome (n = 21), and obese with metabolic syndrome (n = 129). The volume and FAI of each fat segment were compared among the groups. Receiver operator characteristics curve analysis was used to assess the association between the FAIs and metabolic syndrome. RESULTS: FAIs of all abdominal fat segments were significantly lower in the obese group than in the non-obese group (p < 0.001). RS, APA, and the visceral adipose tissue FAIs were significantly lower in participants with metabolic syndrome than in those without metabolic syndrome in the non-obese group (p < 0.001, p = 0.006, and p < 0.001, respectively). The area under the curve for predicting metabolic syndrome was significantly higher for APA FAI (0.790) than subcutaneous, visceral, and RS FAI in all groups (0.649, 0.647, and 0.655, respectively). CONCLUSION: Both metabolic syndrome and obesity were associated with lower RS and APA adipose tissue FAI, and APA FAI performed best for predicting metabolic syndrome. KEY POINTS: • The volume and FAI of RS, APA, and visceral adipose tissue showed opposite trends with regard to metabolic syndrome or obesity. • Both metabolic syndrome and obesity were associated with lower RS FAI and APA FAI. • APA FAI performed best for predicting metabolic syndrome among FAIs of abdominal fat segments.

Abdominal adipose tissue quantification and distribution with CT: prognostic value for surgical and oncological outcome in patients with rectal cancer.

OBJECTIVES: Obesity is a known factor of poor surgical and oncological outcomes in patients who undergo surgery for colorectal cancer. There are physiological differences between abdominal visceral and subcutaneous adipose tissue. Evaluation of its quantity and distribution is possible with routine clinical imaging techniques, such as computed tomography. The goal of this study was to explore the associations and find correlations of fat measurements and distribution with surgical morbidity, long-term mortality and disease progression in patients who underwent surgery for rectal cancer. METHODS: Patients who underwent rectal cancer resection between 2006 and 2016 were included in this retrospective study. Computed tomography fat area measurements were assessed on preoperative computed tomography scans and were compared with postoperative outcomes (local and general complications), long-term survival and oncological response. RESULTS: Of 202 patients included, 50 (25%) died with a median survival time of 34 months, and 152 (75%) were still alive at the end of the study. Death and disease progression were significantly associated with a high intermuscular/subcutaneous fat ratio at the L4-L5 level, with a cut-off established at 0.12 (p < 0.05). Patients with a low (< 1.15) subcutaneous/visceral fat ratio at the L2-L3 level experienced significantly more local complications (p < 0.05). CONCLUSIONS: This study suggests that patients with a low subcutaneous fat area/visceral fat area ratio had more local postoperative complications and that a high intermuscular fat area/subcutaneous fat area ratio was associated with worse survival outcomes, as well as a high postoperative complication rate. KEY POINTS: • A low subcutaneous/visceral fat ratio seems to be associated with more local postsurgery complications in patients with rectal cancer, while a high intermuscular/subcutaneous fat ratio seems to be associated with worse survival and oncological outcomes. • A high intermuscular/subcutaneous fat ratio seems to be associated with worse survival outcomes or progressing disease, as well as a higher postoperative complication rate. • Computed tomography abdominal fat area measurements are correlated with one another on multiple anatomical levels.

Amyloid deposit corresponds to technetium-99m-pyrophosphate accumulation in abdominal fat of patients with transthyretin cardiac amyloidosis.

BACKGROUND: Radionuclide imaging using bone-avid tracers plays a critical role in diagnosing transthyretin cardiac amyloidosis (ATTR-CA), but technetium-99m-pyrophosphate (PYP) rarely allows the detection of extracardiac amyloid infiltration. We retrospectively investigated the frequency of PYP uptake in the subcutaneous abdominal fat of patients with ATTR-CA and its relevance to the results of fine-needle aspiration biopsy (FNAB) of this tissue. METHODS: Chest-centered images of PYP scintigraphy were obtained 2 h after the intravenous injection of the tracer (20 mCi), and the frequency of PYP uptake in the subcutaneous abdominal fat was evaluated. Amyloid deposits of fat smears taken by subcutaneous abdominal fat FNAB were assessed by Congo red staining. RESULTS: Twenty-four patients with ATTR-CA were included. Ten (41.7%) patients showed some PYP uptake in the subcutaneous abdominal fat (positive PYP group), and 14 patients did not (negative PYP group). Amyloid deposits were detected by subcutaneous abdominal fat FNAB in 7/10 patients (70.0%) of the positive PYP group versus 0/14 patients (0%) of the negative PYP group, and the difference was significant. CONCLUSIONS: In patients with ATTR-CA, abnormal PYP uptake in the subcutaneous abdominal fat could reflect the regional amyloid deposition confirmed by FNAB of this tissue.

Ultra-processed foods and obesity and adiposity parameters among children and adolescents: a systematic review.

PURPOSE: According to the NOVA classification, ultra-processed foods are products made through physical, biological and chemical processes and typically with multiple ingredients and additives, in which whole foods are mostly or entirely absent. From a nutritional point of view, they are typically energy-dense foods high in fat, sugar, and salt and low in fiber. The association between the consumption of ultra-processed food and obesity and adiposity measurements has been established in adults. However, the situation remains unclear in children and adolescents. METHODS: We carried out a systematic review, in which we summarize observational studies investigating the association between the consumption of ultra-processed food, as defined by NOVA classification, and obesity and adiposity parameters among children and adolescents. A literature search was performed using PUBMED and Web of Science databases for relevant articles published prior to May 2021. RESULTS: Ten studies, five longitudinal and five cross-sectional, mainly conducted in Brazil, were included in this review. Four longitudinal studies in children with a follow-up longer than 4 years found a positive association between the consumption of ultra-processed food and obesity and adiposity parameters, whereas cross-sectional studies failed to find an association. CONCLUSION: These data suggest that a consistent intake of ultra-processed foods over time is needed to impact nutritional status and body composition of children and adolescents. Further well-designed prospective studies worldwide are needed to confirm these findings considering country-related differences in dietary habits and food production technologies.