Visceral and subcutaneous fat quality and cardiometabolic risk

Associations between visceral adipose and renal artery calcification: Results from the multi-ethnic study of atherosclerosis

Background

Visceral adipose tissue (VAT) has been associated with higher levels of atherosclerosis. Renal artery calcification (RAC) secondary to atherosclerosis has been found to be associated with an increase in all-cause mortality.

Methods

1 978 participants underwent CT imaging to measure VAT and RAC. Rate ratio regression was used to estimate prevalence ratios (PRs) for the presence of RAC, while linear regression was used to estimate linear coefficients for the severity of RAC.

Results

1 196 participants had complete VAT and RAC measurements. In adjusted models, VAT area was not associated with RAC presence (PR 1.02, 95 % CI 0.89, 1.16, p = 0.80), while greater VAT density was inversely, but not significantly, associated with RAC presence (PR 0.89, 95 % CI 0.78, 1.02, p = 0.10). Among 354 participants with RAC > 0, VAT area was significantly associated with RAC severity (slope 63.32, 95 % CI 11.84, 114.81, p = 0.02), while VAT density was not associated (slope 9.78, 95 % CI -40.87, 60.44, p = 0.71).

Conclusions

VAT area and density are not significantly associated with RAC presence, while greater VAT area is significantly associated with RAC severity among those with RAC > 0. Our results are the first describing the relationship between VAT and RAC, and are in contrast to previous literature demonstrating a significant association between VAT and coronary artery calcification.

Automated CT segmentation for lower extremity tissues in lymphedema evaluation using deep learning

OBJECTIVES

Clinical assessment of lymphedema, particularly for lymphedema severity and fluid-fibrotic lesions, remains challenging with traditional methods. We aimed to develop and validate a deep learning segmentation tool for automated tissue component analysis in lower extremity CT scans.

MATERIALS AND METHODS

For development datasets, lower extremity CT venography scans were collected in 118 patients with gynecologic cancers for algorithm training. Reference standards were created by segmentation of fat, muscle, and fluid-fibrotic tissue components using 3D slicer. A deep learning model based on the Unet++ architecture with an EfficientNet-B7 encoder was developed and trained. Segmentation accuracy of the deep learning model was validated in an internal validation set (n = 10) and an external validation set (n = 10) using Dice similarity coefficient (DSC) and volumetric similarity (VS). A graphical user interface (GUI) tool was developed for the visualization of the segmentation results.

RESULTS

Our deep learning algorithm achieved high segmentation accuracy. Mean DSCs for each component and all components ranged from 0.945 to 0.999 in the internal validation set and 0.946 to 0.999 in the external validation set. Similar performance was observed in the VS, with mean VSs for all components ranging from 0.97 to 0.999. In volumetric analysis, mean volumes of the entire leg and each component did not differ significantly between reference standard and deep learning measurements (p > 0.05). Our GUI displays lymphedema mapping, highlighting segmented fat, muscle, and fluid-fibrotic components in the entire leg.

CONCLUSION

Our deep learning algorithm provides an automated segmentation tool enabling accurate segmentation, volume measurement of tissue component, and lymphedema mapping.

KEY POINTS

Question Clinical assessment of lymphedema remains challenging, particularly for tissue segmentation and quantitative severity evaluation. Findings A deep learning algorithm achieved DSCs > 0.95 and VS > 0.97 for fat, muscle, and fluid-fibrotic components in internal and external validation datasets. Clinical relevance The developed deep learning tool accurately segments and quantifies lower extremity tissue components on CT scans, enabling automated lymphedema evaluation and mapping with high segmentation accuracy.

Triglyceride-glucose index as an independent predictor of mortality in patients with chronic respiratory diseases

Objective

The consequences of chronic pulmonary illness are known to exacerbate in individuals with metabolic syndrome and insulin resistance. However, the relationship between triglyceride-glucose (TyG) index, a reliable alternative biomarker of metabolic dysfunction, and chronic respiratory diseases (CRDs) are inconclusive.

Research design and methods

Our research involved a total of 7,819 adult individuals diagnosed with CRDs who participated in the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2018. To assess the correlation between the TyG index and survival rates, we employed multivariable weighted Cox regression analysis, smoothing curve fitting, survival curve analysis and subgroup analysis to investigate the relationship.

Results

Higher TyG index among CRDs shown a substantial positive correlation with all-cause mortality after controlling for relevant confounders. The restricted cubic spline analysis showed a nonlinear relationship between the TyG score and all-cause mortality in CRDs. Patients with higher TyG indexes had a greater risk of all-cause mortality according to Kaplan-Meier survival curves.

Conclusion

The clinical relevance of the TyG index in predicting the life expectancy of individuals with CRDs is highlighted by our research. The TyG index can serve as a substitute biomarker for monitoring the wellbeing of the individuals with CRDs.

Association of Deep Learning-based Chest CT-derived Respiratory Parameters with Disease Progression in Amyotrophic Lateral Sclerosis

Background Forced vital capacity (FVC) is a standard measure of respiratory function in patients with amyotrophic lateral sclerosis (ALS) but has limitations, particularly for patients with bulbar impairment. Purpose To determine the value of deep learning-based chest CT-derived respiratory parameters in predicting ALS progression and survival. Materials and Methods This retrospective study included patients with ALS diagnosed between January 2010 and July 2023 who underwent chest CT at a tertiary hospital. Deep learning-based software was used to measure lung and respiratory muscle volume, normalized for height as the lung volume index (LVI) and respiratory muscle index (RMI). Differences in these parameters across King clinical stages were assessed using ordinal logistic regression. Tracheostomy-free survival was evaluated using Cox regression and time-dependent receiver operating characteristic analysis. Subgroup analysis was conducted for patients with bulbar impairment. In addition, a Gaussian process regressor model was developed to estimate FVC based on lung volume, respiratory muscle volume, age, and sex. Results A total of 261 patients were included in the study (mean age, 65.2 years ± 11.9 [SD]; 156 male patients). LVI and RMI decreased with increasing King stage (both P < .001). The high LVI and high RMI groups had better survival (both P < .001). After adjustment, LVI (hazard ratio [HR] = 0.998 [95% CI: 0.996, 1.000]; P = .021) and RMI (HR = 0.992 [95% CI: 0.988, 0.996]; P < .001) remained independent prognostic factors. In patients with bulbar impairment, LVI (HR = 0.998 [95% CI: 0.996, 1.000]; P = .029) and RMI (HR = 0.991 [95% CI: 0.987, 0.996]; P < .001) were independent prognostic factors. Time-dependent receiver operating characteristic curve analysis revealed no significant differences in survival prediction performance among LVI, RMI, and FVC. The Gaussian process regressor model estimated FVC with approximately 8% error. Conclusion The deep learning-derived CT metrics LVI and RMI reflected ALS stage, enabled FVC prediction, and supported assessment in patients with limited respiratory function. © RSNA, 2025 Supplemental material is available for this article. See also the editorial by Rahsepar and Bedayat in this issue.

Exploring the obesity paradox in chronic respiratory disease: the mediating effect of triglyceride-glucose index on mortality

Chronic respiratory diseases (CRD) are major contributors to mortality. The "obesity paradox" suggests that higher body mass index (BMI) may confer survival benefits in CRD patients. This study investigates the association between BMI and mortality risk in CRD patients, focusing on the mediating role of the triglyceride-glucose (TyG) index. A cross-sectional analysis of 7689 participants with CRD was conducted. Participants were categorized by BMI into <25.0, 25.0-29.9, 30.0-34.9, 35.0-39.9, and ≥40 kg/m2. Outcomes included all-cause mortality, cardiovascular disease (CVD) mortality, and non-CVD mortality. Cox regression models assessed associations, and mediation analysis evaluated the role of the TyG index. Among 7689 CRD patients, higher BMI was associated with lower all-cause mortality (HR for BMI 25.0-29.9: 0.81, 95% CI 0.70-0.94; HR for BMI 30.0-34.9: 0.72, 95% CI 0.61-0.85; HR for BMI 35.0-39.9: 0.72, 95% CI 0.59-0.88; HR for BMI ≥ 40: 0.82, 95% CI 0.66-1.02) and non-CVD mortality (HR for BMI 25.0-29.9: 0.77, 95% CI 0.65-0.91; HR for BMI 30.0-34.9: 0.65, 95% CI 0.54-0.79; HR for BMI 35.0-39.9: 0.66, 95% CI 0.52-0.83; HR for BMI ≥ 40: 0.69, 95% CI 0.53-0.89), but not CVD mortality. The TyG index mediated a significant proportion of the association between BMI and mortality (mediation effects: -22.39 to -18.49%). Kaplan-Meier survival curves and restricted cubic spline regression further illustrated the significant associations between BMI and all-cause mortality and non-CVD mortality, while no significant association was observed for CVD mortality. Higher BMI is associated with lower mortality risk in CRD patients, particularly for non-CVD causes, mediated by the TyG index. This highlights the potential role of insulin resistance in the "obesity paradox" and suggests that metabolic health interventions may improve outcomes in CRD.

Body composition metrics as a determinant of trastuzumab deruxtecan related toxicity and response

Body composition is an important predictor in cancer patients, with skeletal muscle loss and high adiposity associated with poorer prognosis. This study evaluated how body composition affects treatment efficacy in 48 women with metastatic breast cancer receiving trastuzumab deruxtecan. Using computed tomography, skeletal muscle, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were assessed within 60 days before initiating treatment. High SAT and VAT areas were significantly associated with a higher likelihood of dose reductions (Odds Ratio [OR] = 5.34, p = .032 and OR = 5.52, p = 0.032, respectively). Higher SAT areas correlated with a lower objective response rate (OR = 0.22, p = 0.047). Medium SAT and low/medium VAT densities increased the risk of dose reductions. A body mass index over 25 kg/m2 was linked to higher dose reductions (OR = 4.97, p = 0.016). These findings emphasize the need for personalized treatment strategies based on body composition.

"Weekend Warrior" Physical Activity and Adipose Tissue Deposition

BACKGROUND

Attaining guideline-recommended levels of physical activity is associated with substantially lower risk of cardiometabolic diseases.

OBJECTIVES

Although physical activity commonly follows a weekend warrior pattern, in which most moderate-to-vigorous physical activity is concentrated in 1 to 2 days rather than spread more evenly across the week (regular), the effects of activity pattern on imaging-based biomarkers of cardiometabolic health are unknown.

METHODS

We analyzed 17,146 UK Biobank participants who wore accelerometers for 1 week, and later underwent cardiac magnetic resonance imaging. Activity was categorized as inactive, regular, or "weekend warrior". Associations between activity pattern and magnetic resonance imaging-derived visceral adipose tissue (VAT) and epicardial and pericardial adipose tissue (EPAT) were assessed using multiple linear regression adjusted for confounding factors.

RESULTS

Compared to inactive, VAT was progressively lower with weekend warrior (-0.71 L, 95% CI -0.78 to -0.64, P < 0.001) followed by regular activity (-0.96 L, 95% CI -1.04 to -0.88, P < 0.001). Observations were similar for EPAT (weekend warrior activity -2.84 cm2, 95% CI -3.20 to -2.49, P < 0.001; regular activity -3.62 cm2, 95% CI -4.03 to -3.20, P < 0.001). When compared directly, weekend warriors had modestly higher adipose tissue than regular activity (VAT difference 0.25 L, 95% CI 0.17-0.32, P < 0.001; EPAT 0.78 cm2, 95% CI 0.40-1.15, P < 0.001). No differences were observed after adjustment for total moderate-to-vigorous physical activity minutes (VAT 0.07 L, 95% CI -0.01 to 0.14, P = 0.09; EPAT 0.04 cm2, 95% CI -0.35 to 0.43, P = 0.84).

CONCLUSIONS

Guideline-adherent physical activity is associated with favorable quantitative measures of cardiometabolic health, with no differences based on activity pattern for a given activity volume.

Visceral Adipose Tissue is Associated with Recurrent Cardiovascular Events in Premature Coronary Artery Disease: Sub-analysis of the GEA study cohort

BACKGROUND

Visceral adipose tissue (VAT) has been related to coronary artery disease (CAD), but its association with recurrent major adverse cardiovascular events (MACE) in premature CAD (pCAD) has not been fully explored. Thus, we aimed to investigate the impact of VAT on recurrent MACE in patients with pCAD.

METHODS

This was a retrospective sub-analysis of 853 patients with pCAD from the GEA cohort study. VAT was measured by computed tomography at baseline. The primary outcome was the recurrence of MACE over 5 years of follow-up. Likewise, the association of VAT with non-fatal and fatal MACE was analyzed as a secondary outcome. Cox regression models were fitted and adjusted by confounders obtained at baseline to estimate adjusted hazard ratios (aHR).

RESULTS

The median age of the patients was 53 years, and 80% were male, with a median follow-up of 4.9 years. Overall, 10% of the patients had recurrent MACE (6.5% non-fatal and 3.6% fatal) with an incidence rate of 18.5 (95% CI: 18.0-19.0) events per 1,000 person-years. VAT was positively associated with MACE. Those in the upper tertile (VAT ≥ 194 cm²) had the highest risk for total (aHR: 2.71; 95% CI: 1.37-5.35; p=0.004) and non-fatal (aHR: 3.58; 95% CI: 1.49-8.61; p=0.004) MACE. Fatal MACE was not statistically associated (aHR: 2.13; 95% CI: 0.72-6.35; p=0.174).

CONCLUSION

Among patients with pCAD, VAT increased the risk of recurrent MACE despite adequate pharmacological treatment. These results suggest that VAT could be considered an emergent risk factor and a promising target for residual cardiovascular risk reduction.

Assessment of the Relationship between Pre-Existing Muscle Atrophy, Subcutaneous Fat Volume, and the Prognosis of COVID-19

Background: Coronavirus disease 2019 (COVID-19), with its rapid transmission and emergence, has become a major global public health concern. COVID-19 patients are at an increased risk of acute skeletal muscle loss and complications such as muscular weakness, depression, and anxiety. Furthermore, sarcopenia has been linked to COVID-19 vulnerability, hospitalization rates, and severity. This study aims to investigate the relationship between pre-existing sarcopenia, subcutaneous fat, and the prognosis of COVID-19. Methods: Patients over 18 with positive tests who had chest CT scans without underlying conditions were included in this cohort study. The ratio of muscle volume to the total body surface area was calculated. Patients were divided into four subgroups: outpatients, hospitalized, ICU admitted, and deceased. The initial muscle volume for each group was compared. Results: In total, 127 patients were included in the study, 63 (49%) of whom were male. The mean age of the patients was 51.8 ± 18.16 (from 23 to 87 years). In total, 27 patients (21.3%) were treated as outpatients, 49 patients (38.6%) were hospitalized, and 23 (18.1%) were admitted to the ICU. Twenty-eight patients (22%) died. The total muscle/surface area ratio was significantly associated with disease outcome and prognosis. The ratio was significantly lower in dead individuals (p = 0.017). Conclusions: Sarcopenia was discovered to be significantly associated with the severity of COVID-19 and a poor prognosis. Reducing the risk of severe COVID-19 is possible by identifying and managing sarcopenia-related risk factors.

Association of a composite trait for anthropometrics, adiposity and energy expenditure with cardiometabolic diseases: An age-stratified cohort and genetic risk score analysis

AIM

Various anthropometric measures capture distinct as well as overlapping characteristics of an individual's body composition. To characterize independent body composition measures, we aimed to reduce easily-obtainable individual measures reflecting adiposity, anthropometrics and energy expenditure into fewer independent constructs, and to assess their potential sex- and age-specific relation with cardiometabolic diseases.

METHODS

Analyses were performed within European ancestry participants from UK Biobank (N = 418,963, mean age 58.0 years, 56% women). Principal components (PC) analyses were used for the dimension reduction of 11 measures of adiposity, anthropometrics and energy expenditure. PCs were studied in relation to incident type 2 diabetes mellitus (T2D) and coronary artery disease (CAD). Multivariable-adjusted Cox regression analyses, adjusted for confounding factors, were performed in all and stratified by age. Genome-wide association studies were performed in half of the cohort (N = 156,295) to identify genetic variants as instrumental variables. Genetic risk score analyses were performed in the other half of the cohort stratified by age of disease onset (N = 156,295).

RESULTS

We identified two PCs, of which PC1 reflected lower overall adiposity (negatively correlated with all adiposity aspects) and PC2 reflected more central adiposity (mainly correlated with higher waist-hip ratio, but with lower total body fat) and increased height, collectively capturing 87.8% of the total variance. Similar to that observed in the multivariable-adjusted regression analyses, we found associations between the PC1 genetic risk score and lower risks of CAD and T2D [CAD cases <50 years, odds ratio: 0.91 (95% confidence interval 0.87, 0.94) per SD; T2D cases <50 years, odds ratio: 0.76 (0.72, 0.81)], which attenuated with higher age (p-values 8.13E-4 and 2.41E-6, respectively). No associations were found for PC2.

CONCLUSIONS

The consistently observed weaker associations of the composite traits with cardiometabolic disease suggests the need for age-specific cardiometabolic disease prevention strategies.

Visceral and subcutaneous adiposity and cardiovascular disease: Unravelling associations and prognostic value

AIM

The distribution pattern of abdominal adiposity may help determine cardiovascular disease (CVD). Waist circumference (WC) is the most common but imprecise method for measuring abdominal adiposity, as it fails to differentiate between visceral adipose tissue (VAT) and abdominal subcutaneous adipose tissue (ASAT). This study aimed to determine whether elevated VAT or ASAT provides greater prognostic value for CVD events compared to elevated WC in the general population using data from the UK Biobank.

MATERIALS AND METHODS

In this secondary analysis of UK Biobank study, 24 265 participants with available abdominal magnetic resonance imaging data were included. The primary outcome of the study was coronary heart disease (CHD), and secondary outcomes included stroke, heart failure (HF) and atrial fibrillation (AF). Cox regressions for VAT, ASAT and WC were examined in relation to the predefined outcomes on continuous scales using standard deviation (SD) changes and by categories of concordant and discordant values defined by medians.

RESULTS

During a mean follow-up period of 12.9 ± 1.8 years, 2641 participants developed CVD events (1296 CHD, 165 stroke, 286 HF and 894 AF) Each 1 SD increase in VAT yielded a hazard ratio (HR) of 1.15 (95% confidence interval [CI]: 1.09-1.22) for CHD risk, whereas ASAT had a HR of 1.10 (95% CI: 1.04-1.18). Further adjustment for WC eliminated the association between ASAT and CHD risk, in contrast to the association between VAT and CHD risk, which remained almost unaffected. Discordant VAT above the median with WC below presented a HR of 1.43 (95% CI: 1.15-1.78) for CHD, compared with concordant VAT and WC below the median. Similar results were found for discordant WC above the median with VAT below, with a HR of 1.46 (95% CI: 1.18-1.81). In contrast, discordant ASAT above the median with WC below was not associated with an increased risk of CHD. Similarly, discordant ASAT above the median with VAT below was not associated with an increased risk of CHD. Additionally, there was no observed association between VAT or ASAT and the risks of stroke, HF or AF after further adjustment for WC. Additionally, there was no observed association between VAT or ASAT and the risks of stroke, HF or AF after further adjustment for WC.

CONCLUSION

Incorporating VAT measurements alongside WC data improved the ability to identify individuals at high risk for CHD compared to using WC alone. Both VAT and WC proved to be more accurate indicators of CHD risk than ASAT. However, VAT alone did not fully account for the CHD risk associated with elevated WC levels. Neither VAT nor ASAT showed an association with the risk of stroke, HF and AF.

Glucose metabolism and radiodensity of abdominal adipose tissue: A 5-year longitudinal study in a large PET cohort

OBJECTIVE

18F-Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) allows noninvasive assessment of glucose metabolism and radiodensity in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). We aimed to address the effects of ageing and metabolic factors on abdominal adipose tissue.

DESIGN, PATIENTS AND MEASUREMENTS

We retrospectively analyzed data from 435 healthy men (mean 42.8 years) who underwent a health check-up programme twice, at baseline and the 5-year follow-up. The mean standardized uptake value (SUV) was measured using SAT and VAT and divided by the liver SUV. The mean Hounsfield units (HU) of the SAT and VAT were measured from the CT scans. The effects of clinical variable clusters on SUVR were investigated using Bayesian hierarchical modelling; metabolic cluster (BMI, waist-to-hip ratio, fat percentage, muscle percentage*-1, HOMA-IR), blood pressure (systolic, diastolic), glucose (fasting plasma glucose level, HbA1c) and C-reactive protein.

RESULTS

All the clinical variables changed during the 5-year follow-up period. The SUVR and HU of the VAT increased during follow-up; however, those of the SAT did not change. SUVR and HU were positively correlated with both VAT and SAT. SAT and VAT SUVR were negatively associated with metabolic clusters.

CONCLUSIONS

Ageing led to increased glucose metabolism and radiodensity in VAT, but not in SAT. VAT may reflect the ageing process more directly than SAT. Glucose metabolism was higher and radiodensity was lower in VAT than in SAT, probably owing to differences in gene expression and lipid density. Both glucose metabolism and radiodensity of VAT and SAT reflect metabolic status.

Micro/Nanobubble-Assisted Lipotransfer: In Vivo Evidence of Improved Graft Outcomes

OBJECTIVE

Retention rates of lipotransfer remain variable, with the underlying cause associated with tissue oxygenation and blood supply barriers. One promising new method of improving tissue oxygenation is micro/nanobubbles (MNBs), which are small gas bubbles (<100 μm) generated within a saline solution. MNBs are stable and carry a significant amount of oxygen, and because of their negatively charged surface characteristics, they are an ideal oxygen-delivery solution. Thus, we hypothesize that washing/oxygenating lipoaspirate tissue prior to transplantation in a micro/nanobubble saline solution will improve graft survival and quality compared to a saline control.

METHODS

Human lipoaspirate samples obtained from healthy donors were washed with an oxygenated MNB or saline wash. These samples were then injected into the dorsum of sixteen 6-week-old male BALB/c mice, where each mouse received one saline and one MNB-washed graft. At 2-, 4-, 8-, and 12-week time points, the explants were harvested and weighed, and gas pycnometry was performed to assess graft volume. The tissues were also subjected to hematoxylin and eosin (HE) staining and immunohistochemistry to detect perilipin and blood vessels (CD31). These stains, as well as adipocyte count and area quantifications, were analyzed using ImageJ.

RESULTS

HE staining revealed that the control group demonstrated notable adipocyte hypertrophy, while MNB-washed samples had evident adipocyte hyperplasia. This observation was confirmed by an analysis of variance (ANOVA), which showed that the control group had a larger average graft mass and volume (P < 0.01). MNB-washed grafts also exhibited significantly greater adipocyte counts and smaller adipocytes (P < 0.001). Perilipin staining was also greater in the MNB group at the 2- and 4-week time point indicating improved de novo adipogenesis following implantation. Lastly, CD31 staining revealed a significantly greater core vessel density and angiogenesis at the 4-week and 12-week time points (P < 0.01).

CONCLUSIONS

Our study demonstrates that MNBs enhance tissue quality as indicated by a significant increase in de novo adipogenesis, higher vessel density, and decreased adipocyte hypertrophy. Additional studies are needed to evaluate the clinical effectiveness. Nevertheless, incorporating MNBs into procedures holds great promise in tackling the ongoing challenge of inconsistent outcomes in lipotransfer.

The prognostic role of perirenal fat tissue in non-metastatic renal cell carcinoma

PURPOSE

The aim of this study was to evaluate the impact of perirenal fat volume and perirenal fat density on prognosis in surgically treated non-metastatic renal cell carcinomas (RCC).

METHODS AND MATERIALS

All consecutive patients who underwent partial or total nephrectomy surgery between March 2019 and December 2021 were assessed. Measurements of perirenal fat volume and perirenal fat density were performed on computed tomography (CT) images. The relationship between progression and perirenal fat parameters was evaluated using ROC analysis, Cox regression analysis, and Kaplan-Meier analysis.

RESULTS

In the study population comprising 118 patients diagnosed with RCC (74.6% male, mean age of 59.1 ± 11.8 years), the median follow-up duration was 43 months (interquartile range: 33-51 months). Perirenal fat volume (AUC: 0.669, 95% CI 0.538-0.799, p = 0.011) and perirenal fat density (AUC: 0.680, 95% CI 0.558-0.803, p = 0.007) demonstrated acceptable discrimination performance in predicting progression. There was a significant association between high perirenal fat volume and high perirenal fat density with poor progression-free survival (HR: 1.007, 95% CI 1.003-1.011, p = 0.001 vs. HR: 1.084, 95% CI 1.033-1.137, p = 0.001; respectively).

CONCLUSION

High perirenal fat volume and high perirenal fat density are independent predictors for poor progression-free survival. Perirenal fat parameters, easily obtainable from preoperative CT images, may serve as potential tools in predicting the prognosis of non-metastatic RCC.

Morphofunctional Assessment beyond Malnutrition: Fat Mass Assessment in Adult Patients with Phenylketonuria-Systematic Review

Morphofunctional assessment was developed to evaluate disease-related malnutrition. However, it can also be used to assess cardiometabolic risk, as excess adiposity increases this risk. Phenylketonuria (PKU) is the most prevalent inherited metabolic disease among adults, and obesity in PKU has recently gained interest, although fat mass correlates better with cardiometabolic risk than body mass index. In this systematic review, the objective was to assess whether adult patients with PKU have higher fat mass than healthy controls. Studies of adult PKU patients undergoing dietary treatment in a metabolic clinic reporting fat mass were included. The PubMed and EMBASE databases were searched. Relevance of articles, data collection, and risk of bias were evaluated by two independent reviewers. Ten articles were evaluated, six with a control group, including 310 subjects with PKU, 62 with mild hyperphenylalaninemia, and 157 controls. One study reported a significant and four a tendency towards an increased fat mass in all patients or only females with PKU. Limitations included not having a healthy control group, not reporting sex-specific results and using different techniques to assess fat mass. Evaluation of fat mass should be included in the morphofunctional assessment of cardiometabolic risk in adult patients with PKU.

Association of epicardial adipose tissue with early structural and functional cardiac changes in Type 2 diabetes

BACKGROUND

Dysregulated epicardial adipose tissue (EAT) may contribute to the development of heart failure in Type 2 diabetes (T2D). This study aimed to evaluate the associations between EAT volume and composition with imaging markers of subclinical cardiac dysfunction in people with T2D and no prevalent cardiovascular disease.

METHODS

Prospective case-control study enrolling participants with and without T2D and no known cardiovascular disease. Two hundred and fifteen people with T2D (median age 63 years, 60 % male) and thirty-nine non-diabetics (median age 59 years, 62 % male) were included. Using computed tomography (CT), total EAT volume and mean CT attenuation, as well as, low attenuation (Hounsfield unit range -190 to -90) EAT volume were quantified by a deep learning method and volumes indexed to body surface area. Associations with cardiac magnetic resonance-derived left ventricular (LV) volumes and strain indices were assessed using linear regression.

RESULTS

T2D participants had higher LV mass/volume ratio (median 0.89 g/mL [0.82-0.99] vs 0.79 g/mL [0.75-0.89]) and lower global longitudinal strain (GLS; 16.1 ± 2.3 % vs 17.2 ± 2.2 %). Total indexed EAT volume correlated inversely with mean CT attenuation. Low attenuation indexed EAT volume was 2-fold higher (18.8 cm3/m2 vs. 9.4 cm3/m2, p < 0.001) in T2D and independently associated with LV mass/volume ratio (ß = 0.002, p = 0.01) and GLS (ß = -0.03, p = 0.03).

CONCLUSIONS

Higher EAT volumes seen in T2D are associated with a lower mean CT attenuation. Low attenuation indexed EAT volume is independently, but only weakly, associated with markers of subclinical cardiac dysfunction in T2D.

Sarcopenia and adipose tissue evaluation by artificial intelligence predicts the overall survival after TAVI

Sarcopenia is a serious systemic disease that reduces overall survival. TAVI is selectively performed in patients with severe aortic stenosis who are not indicated for open cardiac surgery due to severe polymorbidity. Artificial intelligence-assisted body composition assessment from available CT scans appears to be a simple tool to stratify these patients into low and high risk based on future estimates of all-cause mortality. Within our study, the segmentation of preprocedural CT scans at the level of the lumbar third vertebra in patients undergoing TAVI was performed using a neural network (AutoMATiCA). The obtained parameters (area and density of skeletal muscles and intramuscular, visceral, and subcutaneous adipose tissue) were analyzed using Cox univariate and multivariable models for continuous and categorical variables to assess the relation of selected variables with all-cause mortality. 866 patients were included (median(interquartile range)): age 79.7 (74.9-83.3) years; BMI 28.9 (25.9-32.6) kg/m2. Survival analysis was performed on all automatically obtained parameters of muscle and fat density and area. Skeletal muscle index (SMI in cm2/m2), visceral (VAT in HU) and subcutaneous adipose tissue (SAT in HU) density predicted the all-cause mortality in patients after TAVI expressed as hazard ratio (HR) with 95% confidence interval (CI): SMI HR 0.986, 95% CI (0.975-0.996); VAT 1.015 (1.002-1.028) and SAT 1.014 (1.004-1.023), all p < 0.05. Automatic body composition assessment can estimate higher all-cause mortality risk in patients after TAVI, which may be useful in preoperative clinical reasoning and stratification of patients.

Skeletal muscle and visceral adipose radiodensities are pre-surgical, non-invasive markers of aggressive kidney cancer

INTRODUCTION

Most studies on body composition in kidney cancer have been conducted among patients with metastatic disease. Given that aggressive tumours can adversely impact body composition and even non-metastatic tumours can be aggressive, we evaluated associations between pre-surgical body composition features and tumour pathological features in patients with non-metastatic clear cell renal cell cancer (ccRCC).

METHODS

The Resolve Cohort consists of 1239 patients with non-metastatic ccRCC who underwent nephrectomy at Memorial Sloan Kettering Cancer Center between 2000 and 2020. The cross-sectional areas and radiodensities of skeletal muscle, visceral adipose, and subcutaneous adipose tissues were determined from pre-surgical computed tomography (CT) scans at the third lumbar vertebrae using Automatica software. Pearson's correlation coefficients describe inter-relationships among BMI and body composition variables, while odds ratios (OR) and 95% confidence intervals (CI) estimate associations between continuous body composition features (per 1-standard deviation) and advanced stage (Stage III vs. Stages I-II) and high Fuhrman grade (Grades 3-4 vs. 1-2) from multivariable logistic regression models that considered the potential impact of biological sex, contrast enhanced CTs, and early age at onset of ccRCC.

RESULTS

The cohort was predominantly male (69%), white (89%), and had a median age of 58. The proportion of patients presenting with advanced stage and high-grade disease were 31% and 51%, respectively. In models that adjusted for demographics and all body composition variables simultaneously, decreasing skeletal muscle radiodensity (i.e., more fat infiltration) but increasing visceral adipose tissue radiodensity (i.e., more lipid depletion) were associated with advanced tumour features. Per 8.4 HU decrease in skeletal muscle radiodensity, the odds of presenting with advanced stage was 1.61 (95% CI: 1.34-1.93). Per 7.22 HU increase in visceral adipose tissue radiodensity, the odds of presenting with advanced stage was 1.45 (95% CI: 1.22-1.74). Skeletal muscle index (i.e., sarcopenia) was not associated with either tumour feature. Similar associations were observed for Fuhrman grade, a more direct marker of tumour aggressiveness. Associations did not differ by sex, contrast use, or age at onset of ccRCC.

CONCLUSIONS

Lipid infiltrated skeletal muscle, but lipid depleted visceral adipose tissue were independently associated with advanced tumour features in non-metastatic ccRCC. Findings highlight the importance of evaluating the full range of body composition features simultaneously in multivariable models. Interpreting pre-surgical CTs for body composition for patients may be a novel and non-invasive way to identify patients with aggressive renal tumours, which is clinically relevant as renal biopsies are not routinely performed.

White adipocyte dysfunction and obesity-associated pathologies in humans

The prevalence of obesity and associated chronic diseases continues to increase worldwide, negatively impacting on societies and economies. Whereas the association between excess body weight and increased risk for developing a multitude of diseases is well established, the initiating mechanisms by which weight gain impairs our metabolic health remain surprisingly contested. In order to better address the myriad of disease states associated with obesity, it is essential to understand adipose tissue dysfunction and develop strategies for reinforcing adipocyte health. In this Review we outline the diverse physiological functions and pathological roles of human white adipocytes, examining our current knowledge of why white adipocytes are vital for systemic metabolic control, yet poorly adapted to our current obesogenic environment.

Pre-operative visceral adipose tissue radiodensity is a potentially novel prognostic biomarker for early endoscopic post-operative recurrence in Crohn's disease

BACKGROUND

Evidence suggests inflammatory mesenteric fat is involved in post-operative recurrence (POR) of Crohn's disease (CD). However, its prognostic value is uncertain, in part, due to difficulties studying it non-invasively.

AIM

To evaluate the prognostic value of pre-operative radiographic mesenteric parameters for early endoscopic POR (ePOR).

METHODS

We conducted a retrospective cohort study of CD subjects ≥ 12 years who underwent ileocecal or small bowel resection between 1/1/2007 to 12/31/2021 with computerized tomography abdomen/pelvis ≤ 6 months pre-operatively and underwent ileocolonoscopy ≤ 15 months post-operatively. Visceral adipose tissue (VAT) volume (cm3), ratio of VAT:subcutaneous adipose tissue (SAT) volume, VAT radiodensity, and ratio of VAT:SAT radiodensity were generated semiautomatically. Mesenteric lymphadenopathy (LAD, largest lymph node > 10 mm) and severe vasa recta (VR) engorgement (diameter of the VR supplying diseased bowel ≥ 2 × VR supplying healthy bowel) were derived manually. The primary outcome was early ePOR (Rutgeert's score ≥ i2 on first endoscopy ≤ 15 months post-operatively) and the secondary outcome was ePOR severity (Rutgeert's score i0-4). Regression analyses were performed adjusting for demographic and disease-related characteristics to calculate adjusted odds ratio (aOR) and 95% confidence interval (CI).

RESULTS

Of the 139 subjects included, 45% of subjects developed early ePOR (n = 63). VAT radiodensity (aOR 0.59, 95%CI: 0.38-0.90) and VAT:SAT radiodensity (aOR 8.54, 95%CI: 1.48-49.28) were associated with early ePOR, whereas, VAT volume (aOR 1.23, 95%CI: 0.78-1.95), VAT:SAT volume (aOR 0.80, 95%CI: 0.53-1.20), severe VR engorgement (aOR 1.53, 95%CI: 0.64-3.66), and mesenteric LAD (aOR 1.59, 95%CI: 0.67-3.79) were not. Similar results were observed for severity of ePOR.

CONCLUSION

VAT radiodensity is potentially a novel non-invasive prognostic imaging marker to help risk stratify CD patients for POR.

Epigenetic Aging Is Associated With Measures of Midlife Muscle Volume and Attenuation in CARDIA Study

BACKGROUND

GrimAge acceleration (GAA), an epigenetic marker that represents physiologic aging, is associated with age-related diseases including cancer and cardiovascular diseases. However, the associations between GAA and muscle mass and function are unknown.

METHODS

We estimated measures of GAA in 1 118 Black and White participants from the Coronary Artery Risk Development in Young Adults (CARDIA) Study at exam years (Y) 15 (2000-2001) and 20 (2005-2006). Abdominal muscle composition was measured using CT scans at the Y25 (2010-2011) visit. We used multivariate regression models to examine associations of GAA estimates with muscle imaging measurements.

RESULTS

In the CARDIA study, each 1-year higher GAA was associated with an average 1.1% (95% confidence interval [CI]: 0.6%, 1.5%) higher intermuscular adipose tissue (IMAT) volume for abdominal muscles. Each 1-year higher GAA was associated with an average -0.089 Hounsfield unit (HU; 95% CI: -0.146, -0.032) lower lean muscle attenuation and an average -0.049 HU (95% CI: -0.092, -0.007) lower IMAT attenuation for abdominal muscles. Stratified analyses showed that GAA was more strongly associated with higher abdominal muscle IMAT volume in females and significantly associated with lower lean muscle attenuation for White participants only.

CONCLUSIONS

Higher GAA is associated with higher abdominal muscle IMAT volume and lower lean muscle attenuation in a midlife population.

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

CONTEXT

Compared with the relatively benign effects of increased subcutaneous adipose tissue (SAT), increased visceral adipose tissue (VAT) volume is a causal risk factor for hypertension, hyperlipidemia, type 2 diabetes, and cardiovascular disease. In rodents, increased VAT volume and triglyceride density and ectopic lipid accumulation in kidneys and liver have been induced by alterations in the gut microbiome. However, few studies have characterized these relationships in humans.

OBJECTIVE

To evaluate the tissue triglyceride content of VAT and SAT, liver, kidneys, and pancreas in male and female adults and assess associations with markers of glucose tolerance, serum insulin, and lipids and characteristics of the gut microbiome.

METHODS

Cross-sectional observational study of healthy human adults (n = 60) at a clinical research center. Body mass index (BMI), body composition, and oral glucose tolerance were assessed. Microbiome analysis was conducted on stool samples using 16S rRNA v3 amplicon sequencing. The triglyceride content of VAT, SAT, liver, kidney and pancreas were determined by assessing proton density fat fraction (PDFF) with magnetic resonance imaging (MRI).

RESULTS

Higher VAT PDFF and the ratio of VAT to SAT PDFF were related to higher BMI, HbA1c, HOMA-IR, non-high-density lipoprotein cholesterol, plasma triglycerides, low-density lipoprotein (LDL) cholesterol, and lower high-density lipoprotein (HDL) cholesterol. A higher VAT PDFF and VAT to SAT PDFF ratio were associated with lower alpha diversity and altered beta diversity of the gut microbiome. Differences in VAT were associated with higher relative abundance of the phylum Firmicutes, lower relative abundance of the phylum Bacteroidetes, and enrichment of the bacterial genera Dorea, Streptococcus, and Solobacterium.

CONCLUSION

VAT PDFF measured with MRI is related to impaired glucose homeostasis, dyslipidemia, and differences in the gut microbiome, independently of the total body fat percentage.

Abdominal adipose tissue and type 2 diabetic kidney disease: adipose radiology assessment, impact, and mechanisms

Diabetic kidney disease (DKD) is a significant healthcare burden worldwide that substantially increases the risk of kidney failure and cardiovascular events. To reduce the prevalence of DKD, extensive research is being conducted to determine the risk factors and consequently implement early interventions. Patients with type 2 diabetes mellitus (T2DM) are more likely to be obese. Abdominal adiposity is associated with a greater risk of kidney damage than general obesity. Abdominal adipose tissue can be divided into different fat depots according to the location and function, including visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), perirenal adipose tissue (PAT), and renal sinus adipose tissue (RSAT), which can be accurately measured by radiology techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI). Abdominal fat depots may affect the development of DKD through different mechanisms, and radiologic abdominal adipose characteristics may serve as imaging indicators of DKD risk. This review will first describe the CT/MRI-based assessment of abdominal adipose depots and subsequently describe the current studies on abdominal adipose tissue and DKD development, as well as the underlying mechanisms in patients of T2DM with DKD.

Adolescent and young adult Hodgkin lymphoma patients at risk for subcutaneous fat gain during early cancer treatment: a brief report

Computed tomography scans were assessed for subcutaneous fat area and density at thoracic vertebra 4 in 65 adolescent and young adult (AYA) patients with Hodgkin lymphoma. Subcutaneous fat was quantified over 3 timepoints; (1) baseline, (2) end of initial anthracycline treatment (EOT) and (3) 1 year. Fat area increased at EOT (62.3 ± 5.4 cm/m2 vs 53.5 ± 5.0 cm/m2, p < 0.01) and 1 year (65.8 ± 5.6 cm/m2 vs 53.5 ± 5.0 cm/m2, p < 0.01) compared to baseline. Fat density significantly decreased at EOT (-91.2 ± 1.4 HU vs -86.5 ± 1.4 HU, p < 0.01) and at 1 year (-90.3 ± 1.6 HU vs -86.5 ± 1.4 HU, p = 0.01) compared to baseline. Female, radiation receiving, and anthracycline dosage >250mg/m2subgroups experienced significant fat gain (p < 0.05 for all). Female AYA Hodgkin lymphoma patients receiving radiation, and/or high-dose anthracyclines may be at higher risk of subcutaneous fat gain during therapy.

Inter-software and inter-scan variability in measurement of epicardial adipose tissue: a three-way comparison of a research-specific, a freeware and a coronary application software platform

OBJECTIVES

Epicardial adipose tissue (EAT) is a proposed marker of cardiovascular risk; however, clinical application may be limited by variability in post-processing software platforms. We assessed inter-vendor agreement of EAT volume (EATv) and attenuation on both contrast-enhanced (CE) and non-contrast CT (NCT) using a standard coronary CT reporting software (Vitrea), an EAT research-specific software (QFAT) and a freeware imaging software (OsiriX).

METHODS

Seventy-six consecutive patients undergoing simultaneous CE and NCT had complete volumetric EAT measurement. Between-software, within-software NCT vs. CE, and inter- and intra-observer agreement were evaluated with analysis by ANOVA (with post hoc adjustment), Bland-Altman with 95% levels of agreement (LoA) and intraclass correlation coefficient (ICC).

RESULTS

Mean EATv (freeware 53 ± 31 mL vs. research 93 ± 43 mL vs. coronary 157 ± 64 mL) and attenuation (freeware  - 72 ± 25 HU vs. research  - 75 ± 3 HU vs. coronary  - 61 ± 10 HU) were significantly different between all vendors (ANOVA p < 0.001). EATv was consistently higher in NCT vs. CE for all software packages, with most reproducibility found in research software (bias 26 mL, 95% LoA: 2 to 56 mL), compared to freeware (bias 11 mL 95% LoA: - 46 mL to 69 mL) and coronary software (bias 10 mL 95% LoA: - 127 to 147 mL). Research software had more comparable NCT vs. CE attenuation (- 75 vs. - 72 HU) compared to freeware (- 72 vs. - 57 HU) and coronary (- 61 vs.  - 39 HU). Excellent inter-observer agreement was seen with research (ICC 0.98) compared to freeware (ICC 0.73) and coronary software (ICC 0.75) with narrow LoA on Bland-Altman analysis.

CONCLUSION

There are significant inter-vendor differences in EAT assessment. Our study suggests that research-specific software has better agreement and reproducibility compared to freeware or coronary software platforms.

KEY POINTS

• There are significant differences between EAT volume and attenuation values between software platforms, regardless of scan type. • Non-contrast scans routinely have higher mean EAT volume and attenuation; however, this finding is only consistently seen with research-specific software. • Of the three analyzed packages, research-specific software demonstrates the highest reproducibility, agreement, and reliability for both inter-scan and inter-observer agreement.

Association Between Fat Depletion and Prognosis of Amyotrophic Lateral Sclerosis: CT-Based Body Composition Analysis

OBJECTIVE

The purpose of this study was to present the results of our investigation of the prognostic value of adipopenia and sarcopenia in patients with amyotrophic lateral sclerosis (ALS).

METHODS

Consecutive patients with ALS with abdominal computed tomography (CT) were retrospectively identified at a single tertiary hospital between January 2010 and July 2021. Deep learning-based volumetric CT body composition analysis software was used to obtain abdominal waist fat volume, fat attenuation, and skeletal muscle area at the L3 level, then normalized to the fat volume index (FVI) and skeletal muscle index (SMI). Adipopenia and sarcopenia were defined as the sex-specific lowest quartile and SMI reference values, respectively. The associations of CT-derived body composition parameters with clinical variables, such as body mass index (BMI) and creatinine, were evaluated by Pearson correlation analyses, and associations with survival were assessed using the multivariable Cox regression analysis.

RESULTS

Eighty subjects (40 men, 65.5 ± 9.4 years of age) were investigated (median interval between disease onset and CT examination = 25 months). The mean BMI at the CT examination was 20.3 ± 4.3 kg/m2 . The BMI showed a positive correlation with both FVI (R = 0.70, p < 0.001) and SMI (R = 0.63, p < 0.001), and the serum creatinine level was associated with SMI (R = 0.68, p < 0.001). After adjusting for sex, age, King's stage, BMI, creatinine, progression rate, and sarcopenia, adipopenia was associated with shorter survival (hazard ratio [HR] = 5.94, 95% confidence interval [CI] = 1.01, 35.0, p = 0.049). In a subgroup analysis for subjects with nutritional failure (stage 4a), the HR of adipopenia was 15.1 (95% CI = 2.45, 93.4, p = 0.003).

INTERPRETATION

Deep learning-based CT-derived adipopenia in patients with ALS is an independent poor prognostic factor for survival. ANN NEUROL 2023;94:1116-1125.

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 .

Genome-Wide Association Study of Pericardial Fat Area in 28 161 UK Biobank Participants

BACKGROUND Pericardial adipose tissue (PAT) is the visceral adipose tissue compartment surrounding the heart. Experimental and observational research has suggested that greater PAT deposition might mediate cardiovascular disease, independent of general or subcutaneous adiposity. We characterize the genetic architecture of adiposity-adjusted PAT and identify causal associations between PAT and adverse cardiac magnetic resonance imaging measures of cardiac structure and function in 28 161 UK Biobank participants. METHODS AND RESULTS The PAT phenotype was extracted from cardiac magnetic resonance images using an automated image analysis tool previously developed and validated in this cohort. A genome-wide association study was performed with PAT area set as the phenotype, adjusting for age, sex, and other measures of obesity. Functional mapping and Bayesian colocalization were used to understand the biologic role of identified variants. Mendelian randomization analysis was used to examine potential causal links between genetically determined PAT and cardiac magnetic resonance-derived measures of left ventricular structure and function. We discovered 12 genome-wide significant variants, with 2 independent sentinel variants (rs6428792, P=4.20×10-9 and rs11992444, P=1.30×10-12) at 2 distinct genomic loci, that were mapped to 3 potentially causal genes: T-box transcription factor 15 (TBX15), tryptophanyl tRNA synthetase 2, mitochondrial (WARS2) and early B-cell factor-2 (EBF2) through functional annotation. Bayesian colocalization additionally suggested a role of RP4-712E4.1. Genetically predicted differences in adiposity-adjusted PAT were causally associated with adverse left ventricular remodeling. CONCLUSIONS This study provides insights into the genetic architecture determining differential PAT deposition, identifies causal links with left structural and functional parameters, and provides novel data about the pathophysiological importance of adiposity distribution.

Associations of objectively measured physical activity, sedentary time and cardiorespiratory fitness with adipose tissue insulin resistance and ectopic fat

BACKGROUND/OBJECTIVES

Inadequate movement, excess adiposity, and insulin resistance augment cardiometabolic risk. This study examined the associations of objectively measured moderate-to-vigorous intensity physical activity (MVPA), sedentary time and cardiorespiratory fitness (CRF), with adipose tissue insulin resistance and ectopic fat.

METHODS

Data were combined from two previous experimental studies with community volunteers (n = 141, male = 60%, median (interquartile range) age = 37 (19) years, body mass index (BMI) = 26.1 (6.3) kg·m-2). Adipose tissue insulin resistance was assessed using the adipose tissue insulin resistance index (Adipo-IR); whilst magnetic resonance imaging (MRI) was used to measure liver, visceral (VAT) and subcutaneous abdominal adipose tissue (ScAT). Sedentary time and MVPA were measured via an ActiGraph GT3X+ accelerometer. Generalized linear models examined the association of CRF, MVPA, and sedentary time with Adipo-IR and fat depots. Interaction terms explored the moderating influence of age, sex, BMI and CRF.

RESULTS

After controlling for BMI and cardiometabolic variables, sedentary time was positively associated with Adipo-IR (β = 0.68 AU [95%CI = 0.27 to 1.10], P < 0.001). The association between sedentary time and Adipo-IR was moderated by age, CRF and BMI; such that it was stronger in individuals who were older, had lower CRF and had a higher BMI. Sedentary time was also positively associated with VAT (β = 0.05 L [95%CI = 0.01 to 0.08], P = 0.005) with the relationship being stronger in females than males. CRF was inversely associated with VAT (β = -0.02 L [95%CI = -0.04 to -0.01], P = 0.003) and ScAT (β = -0.10 L [95%CI = -0.13 to -0.06], P < 0.001); with sex and BMI moderating the strength of associations with VAT and ScAT, respectively.

CONCLUSIONS

Sedentary time is positively associated with adipose tissue insulin resistance which regulates lipogenesis and lipolysis. CRF is independently related to central fat storage which is a key risk factor for cardiometabolic disease.

Exercise-induced regulation of adipose tissue

Exercise induces various beneficial whole-body adaptations and can delay the onset of obesity, type 2 diabetes, and cardiovascular disease. While many of the beneficial effects of exercise on skeletal muscle and the cardiovascular system have been well established, recent studies have highlighted the role of exercise-induced improvements to adipose tissue that affect metabolic and whole-body health. Studies investigating exercise-induced adaptations of white adipose tissue (WAT) and brown adipose tissue (BAT) demonstrate modifications to glucose uptake, mitochondrial activity, and endocrine profile, and a beiging of WAT in rodents. This review discusses recent studies of the exercise-induced adaptations to WAT and BAT and their implications.

Periaortic adipose radiomics texture features associated with increased coronary calcium score-first results on a photon-counting-CT

BACKGROUND

Cardiovascular diseases remain the world's primary cause of death. The identification and treatment of patients at risk of cardiovascular events thus are as important as ever. Adipose tissue is a classic risk factor for cardiovascular diseases, has been linked to systemic inflammation, and is suspected to contribute to vascular calcification. To further investigate this issue, the use of texture analysis of adipose tissue using radiomics features could prove a feasible option.

METHODS

In this retrospective single-center study, 55 patients (mean age 56, 34 male, 21 female) were scanned on a first-generation photon-counting CT. On axial unenhanced images, periaortic adipose tissue surrounding the thoracic descending aorta was segmented manually. For feature extraction, patients were divided into three groups, depending on coronary artery calcification (Agatston Score 0, Agatston Score 1-99, Agatston Score ≥ 100). 106 features were extracted using pyradiomics. R statistics was used for statistical analysis, calculating mean and standard deviation with Pearson correlation coefficient for feature correlation. Random Forest classification was carried out for feature selection and Boxplots and heatmaps were used for visualization. Additionally, monovariable logistic regression predicting an Agatston Score > 0 was performed, selected features were tested for multicollinearity and a 10-fold cross-validation investigated the stability of the leading feature.

RESULTS

Two higher-order radiomics features, namely "glcm_ClusterProminence" and "glcm_ClusterTendency" were found to differ between patients without coronary artery calcification and those with coronary artery calcification (Agatston Score ≥ 100) through Random Forest classification. As the leading differentiating feature "glcm_ClusterProminence" was identified.

CONCLUSION

Changes in periaortic adipose tissue texture seem to correlate with coronary artery calcium score, supporting a possible influence of inflammatory or fibrotic activity in perivascular adipose tissue. Radiomics features may potentially aid as corresponding biomarkers in the future.

Obesity and the risk of cardiometabolic diseases

The prevalence of obesity has reached pandemic proportions, and now approximately 25% of adults in Westernized countries have obesity. Recognized as a major health concern, obesity is associated with multiple comorbidities, particularly cardiometabolic disorders. In this Review, we present obesity as an evolutionarily novel condition, summarize the epidemiological evidence on its detrimental cardiometabolic consequences and discuss the major mechanisms involved in the association between obesity and the risk of cardiometabolic diseases. We also examine the role of potential moderators of this association, with evidence for and against the so-called 'metabolically healthy obesity phenotype', the 'fatness but fitness' paradox or the 'obesity paradox'. Although maintenance of optimal cardiometabolic status should be a primary goal in individuals with obesity, losing body weight and, particularly, excess visceral adiposity seems to be necessary to minimize the risk of cardiometabolic diseases.

Elevated Chinese visceral adiposity index increases the risk of stroke in Chinese patients with metabolic syndrome

Introduction

Patients with Metabolic Syndrome (MetS) are considered at high-risk for incident stroke. An indicator of visceral adiposity dysfunction, the Chinese Visceral Adiposity Index (CVAI) is used to evaluate the dysfunction of visceral fat. Given the impact of visceral adiposity dysfunction on elevating cardiovascular hazards, this study aimed to examine the association between CVAI and stroke risk in MetS patients.

Method

Between November 2017 and December 2018, a total of 18,974 individuals aged ≥40 underwent standardized in-person clinical interviews in Hunan Province, with 6,732 meeting the criteria for MetS. After the baseline survey was completed, subsequent surveys were conducted biennially. The study was split into two stages performed at baseline and after two years. During the former, receiver-operating characteristic curves were used to assess the accuracy of using baseline CVAI in diagnosing MetS. After two years, we examined the association between CVAI and incident stroke in MetS patients using logistic regression, subgroup analysis, and restricted cubic spline (RCS) analysis.

Result

As evidenced by a higher AUC (AUC:0.741), CVAI demonstrated superior diagnostic performance relative to body mass index (AUC:0.631) and waist circumference (AUC:0.627) in diagnosing MetS. After a 2-year follow-up, 72 MetS patients had a stroke event. There was a robust positive correlation between incident stroke and CVAI in patients with MetS. Each 1 SD increase in CVAI was associated with a 1.52-fold higher risk of stroke after adjustment for confounding factors (aOR=1.52, 95%CI: 1.18-1.95). The RCS demonstrated a reduced risk of stroke for MetS patients when the CVAI was below 110.91. However, no significant correlation was detected between CVAI and stroke in non-MetS patients.

Conclusion

Our findings recommend CVAI as a superior screening tool for detecting MetS and suggest that reducing CVAI can mitigate the risk of stroke in patients with MetS.

Exploring the Diversity of Visceral, Subcutaneous and Perivascular Adipose Tissue in a Vascular Surgery Population

The prevalence of obesity has doubled, with a concomitant increase in cardiovascular disease. This study aimed to compare the characteristics of visceral, subcutaneous and peri-aortic adipose tissue determined with computed tomography (CT) scans and to correlate them with cardiovascular risk factors, anthropometric measures and medication. An observational and prospective study was conducted, and 177 subjects were included. Peri-aortic adipose tissue had the highest density, while the subcutaneous adipose tissue had the lowest. The density of subcutaneous adipose tissue differs from the density of visceral (p = 0.00) and peri-aortic adipose tissue (p = 0.00). Smokers/ex-smokers had a lower area (p = 0.00) and density (p = 0.02) of subcutaneous adipose tissue. Multiple linear regression analysis showed that sex was a predictor of subcutaneous adipose tissue area (β = -0.27, t = -3.12, p = 0.00) but smoking habits were not. After controlling for sex, we found that the association between smokers/ex-smokers and area of subcutaneous adipose tissue was lost, but the association with density persisted. Patients with hypertension had a higher visceral adipose tissue area, and this relationship was maintained even after adjusting for gender. Peri-aortic adipose tissue is similar to visceral and distinct from subcutaneous adipose tissue. Cardiovascular risk factors have different influences in distinct adipose compartments.

Accumulation in Visceral Adipose Tissue Over 6 Years Is Associated With Lower Paraspinal Muscle Density

CONTEXT

Visceral adipose tissue (VAT) has been recognized to be a metabolically active fat depot that may have paracrine effects on surrounding tissues, including muscle. Since many adults accumulate VAT as they age, the effect of changes in VAT on muscle is of interest.

OBJECTIVE

We determined the association between 6-year changes in VAT and paraspinal muscle density, an indicator of fatty infiltration.

METHODS

This study included 1145 participants from the Framingham Study third-generation cohort who had both quantitative computed tomography scans of the spine at baseline and 6-year's follow-up, on whom muscle density was measured along with VAT. We implemented multiple regression to determine the association of muscle density at follow-up as primary outcome measure with changes in VAT (follow-up minus baseline divided by 100), adjusting for VAT at baseline, age, sex, height, menopausal status, presence of diabetes, and physical activity. Analyses were performed in men and women separately.

RESULTS

After adjustment for covariates, individuals with the greatest accumulation of VAT over 6 years had significantly lower paraspinal density at the follow-up with an estimated 0.302 (95% CI, -0.380 to -0.224) and 0.476 (95% CI: -0.598 to -0.354) lower muscle density (HU) per 100-cm3 increase in VAT (both P values < .001) in men and women, respectively.

CONCLUSION

These results highlight that age-related accumulation of VAT in men and women is associated with lower muscle density. VAT may represent a modifiable risk factor for poor musculoskeletal outcomes with aging.

Evidence gaps on weight gain in people living with HIV: a scoping review to define a research agenda

BACKGROUND

Combined antiretroviral therapy (cART) dramatically improved survival in people living with HIV (PLWH) but is associated with weight gain (WG), raising concern for a possible obesity epidemic in PLWH. This scoping review aims to identify the gaps in the existing evidence on WG in PLWH and generate a future research agenda.

METHODS

This review was conducted according to the methodology for scoping studies and reported according to the PRISMA Extension for Scoping Review checklist. Articles published in English in the last 10 years indexed in Pubmed, WHO Global Index Medicus, or Embase were searched using specific queries focused on WG in PLWH.

RESULTS

Following the selection process, 175 included articles were reviewed to search for the available evidence on four specific topics: (I) definition of WG in PLWH, (II) pathogenesis of WG in PLWH, (III) impact of ART on WG, (IV) correlation of WG with clinical outcomes. A summary of the data enabled us to identify gaps and clearly define the following research agenda: (I) develop a data-driven definition of WG in PLWH and define noninvasive assessment methods for body weight and fat composition; (II) further investigate the interaction between HIV/cART and immunity, metabolism, and adipose tissue; (III) establish the specific role of individual drugs on WG; (IV) clarify the independent role of WG, cART, HIV, and metabolic factors on clinical events.

CONCLUSIONS

The proposed research agenda may help define future research and fill the knowledge gaps that have emerged from this review.

Development and validation of a preoperative nomogram for predicting the surgical difficulty of laparoscopic colectomy for right colon cancer: a retrospective analysis

BACKGROUND

In laparoscopic right hemicolectomy for right colon cancer, complete mesocolic excision is a standard procedure that involves extended lymphadenectomy and blood vessel ligation. This study aimed to establish a nomogram to facilitate evaluation of the surgical difficulty of laparoscopic right hemicolectomy based on preoperative parameters.

MATERIALS AND METHODS

The preoperative clinical and computed tomography-related parameters, operative details, and postoperative outcomes were analyzed. The difficulty of laparoscopic colectomy was defined using the scoring grade reported by Escal et al . with modifications. Multivariable logistic analysis was performed to identify parameters that increased the surgical difficulty. A preoperative nomogram to predict the surgical difficulty was established and validated.

RESULTS

A total of 418 consecutive patients with right colon cancer who underwent laparoscopic radical resection at a single tertiary medical center between January 2016 and May 2022 were retrospectively enrolled. The patients were randomly assigned to a training data set ( n =300, 71.8%) and an internal validation data set ( n =118, 28.2%). Meanwhile, an external validation data set with 150 consecutive eligible patients from another tertiary medical center was collected. In the training data set, 222 patients (74.0%) comprised the non-difficulty group and 78 (26.0%) comprised the difficulty group. Multivariable analysis demonstrated that adipose thickness at the ileocolic vessel drainage area, adipose area at the ileocolic vessel drainage area, adipose density at the ileocolic vessel drainage area, presence of the right colonic artery, presence of type III Henle's trunk, intra-abdominal adipose area, plasma triglyceride concentration, and tumor diameter at least 5 cm were independent risk factors for surgical difficulty; these factors were included in the nomogram. The nomogram incorporating seven independent predictors showed a high C-index of 0.922 and considerable reliability, accuracy, and net clinical benefit.

CONCLUSIONS

The study established and validated a reliable nomogram for predicting the surgical difficulty of laparoscopic colectomy for right colon cancer. The nomogram may assist surgeons in preoperatively evaluating risk and selecting appropriate patients.

Epicardial adipose tissue density is a better predictor of cardiometabolic risk in HFpEF patients: a prospective cohort study

BACKGROUND

Epicardial adipose tissue (EAT) accumulation is associated with multiple cardiometabolic risk factors and prognosis of heart failure with preserved ejection fraction (HFpEF). The correlation between EAT density and cardiometabolic risk and the effect of EAT density on clinical outcome in HFpEF remain unclear. We evaluated the relationship between EAT density and cardiometabolic risk factors, also the prognostic value of EAT density in patients with HFpEF.

METHODS

We included 154 HFpEF patients who underwent noncontrast cardiac computed tomography (CT) and all patients received follow-up. EAT density and volume were quantified semi-automatically. The associations of EAT density and volume with cardiometabolic risk factors, metabolic syndrome and the prognostic impact of EAT density were analyzed.

RESULTS

Lower EAT density was associated with adverse changes in cardiometabolic risk factors. Each 1 HU increase in fat density, BMI was 0.14 kg/m² lower (95% CI 0.08-0.21), waist circumference was 0.34 cm lower (95% CI 0.12-0.55), non-HDL-cholesterol was 0.02 mmol/L lower (95% CI 0-0.04), triglyceride was 0.03 mmol/L lower (95% CI 0.01-0.04), fasting plasma glucose was 0.05 mmol/L lower (95% CI 0.02-0.08), TyG index was 0.03 lower (95% CI 0.02-0.04), Log₂(TG/HDL-C) was 0.03 lower (95% CI 0.02-0.05), METS-IR was 0.36 lower (95% CI 0.23-0.49), MetS Z-score was 0.04 lower (95% CI 0.02-0.06), and Log₂(CACS + 1) was 0.09 lower (95% CI 0.02-0.15). After adjusting for BMI and EAT volume, the associations of non-HDL-cholesterol, triglyceride, fasting plasma glucose, insulin resistance indexes, MetS Z-score, and CACS with fat density remained significant. The area under the curve (AUC) for the presence and severity of metabolic syndrome was greater in EAT density than volume (AUC: 0.731 vs 0.694, 0.735 vs 0.662, respectively). Over a median follow-up of 16 months, the cumulative incidence of heart failure readmission and composite endpoint increased with lower level of EAT density (both p < 0.05).

CONCLUSIONS

EAT density was an independent impact factor of cardiometabolic risk in HFpEF. EAT density might have better predictive value than EAT volume for metabolic syndrome and it might have prognostic value in patients with HFpEF.

Greater aortic perivascular adipose tissue density is associated with aging, aortic stiffness, and central blood pressure in humans

Aging results in aortic perivascular adipose tissue (aPVAT)-mediated aortic stiffening in preclinical animal models to promote cardiovascular dysfunction. We hypothesized that greater human aPVAT density will be associated with aging, higher aortic stiffness, and blood pressure (BP). Fourteen apparently healthy adults (6 M/8 F, age range 20-79 yr) were recruited for this study. Aortic stiffness, assessed by carotid-femoral pulse wave velocity (cfPWV), resting aortic BP via pulse wave analysis, and aPVAT and abdominal visceral adipose tissue (VAT) density by computed tomography attenuation were acquired. aPVAT and epididymal (visceral) fat from young (4-6 mo) and old (27-29 mo) mice were used for ex vivo-conditioned media intrinsic mechanical stiffness experiments. Compared with younger adults, older adults had higher cfPWV (8.6 ± 0.4 vs. 6.2 ± 0.6 m/s, P < 0.05) and greater aPVAT attenuation (-80.2 ± 2.0 vs. -95.9 ± 1.5 HU, P < 0.05), but not VAT attenuation (P > 0.05). aPVAT-conditioned media from old mice compared with young mice increased intrinsic mechanical stiffness of the aorta (4,519 ± 510 vs. 2,325 ± 563 kPa, P < 0.05), which was not observed with epididymal fat-conditioned media from old mice (P > 0.05). aPVAT, but not VAT density, was positively associated with age (r = 0.89), cfPWV (r = 0.56), resting augmentation index normalized to heart rate 75 (AIxHR75; r = 0.67), aortic systolic BP (r = 0.58), and aortic pulse pressure (PP; r = 0.59; P < 0.05, all) and were independent of VAT density (P < 0.05, all). These data herein provide evidence for aPVAT as a novel fat depot and therapeutic target to lower aortic stiffness and future cardiovascular disease risk with aging in humans.NEW & NOTEWORTHY Aortic perivascular adipose tissue (aPVAT) promotes age-related aortic stiffening in preclinical animal models, but the relation between aPVAT density and cardiovascular function in adults is unknown. We demonstrate that aPVAT, but not abdominal visceral adipose tissue density, is positively associated with aging, aortic stiffness, and higher resting aortic blood pressure in apparently healthy adults. These findings provide novel evidence for aPVAT as a viable therapeutic target for improving cardiovascular function in humans.

Association Between Perivascular Adipose Tissue Density and Atherosclerosis in the Descending Thoracic Aorta

Radiodensity measured by computed tomography (CT) in Hounsfield Units (HU) is emerging as a clinical tool for detecting perivascular adipose tissue (PVAT) inflammation. In the present study, we hypothesized that PVAT radiodensity might predict the risk of descending thoracic aorta atherosclerosis. A total of 73 subjects who underwent CT angiography to investigate aortic disease were retrospectively analyzed. PVAT radiodensity, aortic complex plaque (ACP), mean plaque-burden score (MPBS), and plaque density were measured, and the association between them was analyzed. Perivascular adipose tissue radiodensity (HU) in patients with different aortic plaques grades (grade 1, 2, 3, and 4) were -93.71 ± 2.50, -93.63 ± 3.93, -90.24 ± 4.49, and -89.90 ± 5.18, respectively, and the difference was significant (P = .010). In the regression analysis, PVAT radiodensity was an independent predictor of ACP, with an OR of 1.263. In the linear analysis, PVAT radiodensity was an independent predictor of MPBS, with a β-coefficient of .073. In the univariate analysis, only the PVAT radiodensity was significantly associated with plaque density, with a β-coefficient of -1.666. In conclusion, PVAT density was independently related to descending thoracic aorta atherosclerosis.

Changes in abdominal fat depots after bariatric surgery are associated with improved metabolic profile

BACKGROUND AND AIMS

Obesity associated with a change in the quantity and quality of fat depots. Using computed tomography (CT), we analyzed abdominal fat depots in patients with obesity after bariatric surgery according to their metabolic health status.

METHODS AND RESULTS

We recruited 79 individuals with metabolically unhealthy obesity before bariatric surgery and compared them with age-sex matched healthy controls. The volume and fat attenuation index (FAI) of fat depots were measured using CT scans that were conducted prior to and a year after bariatric surgery. 'Metabolically healthy' was defined as having no hypertension, normal fasting glucose and a waist-to-hip ratio of <1.05 for men and <0.95 for women. Individuals who achieved a metabolic health status conversion (MHC) (n = 29, 37%)-from unhealthy to healthy-were younger (p < 0.001) as compared to individuals without MHC. Pre-surgery BMI and reduction of BMI did not differ between the two groups (p = 0.099, p = 0.5730). Bariatric surgery reduced the volume and increased the FAI of fat depots. Baseline lower abdominal periaortic adipose tissue (AT) volume (p = 0.014) and great percent reduction in renal sinus AT volume after surgery (p = 0.019) were associated with MHC after surgery. Increased intraperitoneal AT FAI (p = 0.031) was also associated with MHC.

CONCLUSION

MHC was not associated with improvement in general obesity, based on indicators such as reduction of BMI after surgery. Weight reduction induced specific abdominal fat depot changes measured by CT are positively associated with MHC.

Exercise-induced intertissue communication: adipose tissue and the heart

Exercise leads to numerous beneficial whole-body effects and can protect against the development of obesity, cardiometabolic, and neurodegenerative diseases. Recent studies have highlighted the importance of inter-organ crosstalk with a focus on secretory factors that mediate communication among organs, including adipose tissue and the heart. Studies investigating the effects of exercise on brown adipose tissue (BAT) and white adipose tissue (WAT) demonstrated that adipokines are released in response to exercise and act on the heart to decrease inflammation, alter gene expression, increase angiogenesis, and improve cardiac function. This review discusses the exercise-induced adaptations to BAT and WAT and how these adaptations affect heart health and function, while highlighting the importance of tissue crosstalk.

Abdominal Fat Characteristics and Mortality in Rectal Cancer: A Retrospective Study

The aim of this study was to evaluate the association of adipose tissue characteristics with survival in rectal cancer patients. All consecutive patients, diagnosed with stage II-IV rectal cancer between 2010-2016 using baseline unenhanced Computed Tomography (CT), were included. Baseline total, subcutaneous and visceral adipose tissue areas (TAT, SAT, VAT) and densities (TATd, SATd, VATd) at third lumbar vertebra (L3) were retrospectively measured. The association of these tissues with cancer-specific and progression-free survival (CCS, PFS) was assessed by using competitive risk models adjusted by age, sex and stage. Among the 274 included patients (median age 70 years, 41.2% females), the protective effect of increasing adipose tissue area on survival could be due to random fluctuations (e.g., sub-distribution hazard ratio-SHR for one cm2 increase in SAT = 0.997; 95%confidence interval-CI = 0.994-1.000; p = 0.057, for CSS), while increasing density was associated with poorer survival (e.g., SHR for one Hounsfield Unit-HU increase in SATd = 1.03, 95% CI = 1.01-1.05, p = 0.002, for CSS). In models considering each adipose tissue area and respective density, the association with CSS tended to disappear for areas, while it did not change for TATd and SATd. No association was found with PFS. In conclusion, adipose tissue density influenced survival in rectal cancer patients, raising awareness on a routinely measurable variable that requires more research efforts.

Adipose tissue radiodensity and mortality among patients with nonmetastatic breast cancer

BACKGROUND & AIMS

Computed tomography (CT) scans can measure quantity and distribution of adipose tissue, which are associated with breast cancer prognosis. As a novel prognostic marker, radiodensity of adipose tissue has been examined in multiple cancer types, but never in breast cancer. Lower density indicates larger adipocytes with greater lipid content, whereas higher density can reflect inflammation, fibrosis, vascularity, or even metabolic changes; and both may impact breast cancer prognosis.

METHODS

We included 2868 nonmetastatic patients with breast cancer diagnosed between January 2005 and December 2013 at Kaiser Permanente Northern California, an integrated healthcare system. From CT scans at diagnosis, we assessed the radiodensity of subcutaneous (SAT) and visceral adipose tissue (VAT) at the third lumbar vertebra and categorized their radiodensity into three levels: low (<1 standard deviation [SD] below the mean), middle (mean ± 1 SD), and high (>1 SD above the mean). Using multivariable Cox proportional hazards regression with adjustment for clinicopathological characteristics including body mass index, we calculated hazard ratios (HRs [95% confidence intervals]) for the associations of adipose tissue radiodensity with overall mortality and breast-cancer-specific mortality.

RESULTS

Median age at diagnosis of breast cancer was 56.0 years, most (63.3%) were non-Hispanic White and nearly half (45.6%) were stage II. Compared to middle SAT radiodensity, high SAT radiodensity was significantly associated with increased risk of overall mortality (HR: 1.45 [1.15-1.81]), non-significantly with breast-cancer-specific mortality (HR: 1.32 [0.95-1.84]). Neither low SAT radiodensity nor high or low VAT radiodensity was significantly associated with overall or breast-cancer-specific mortality.

CONCLUSIONS

High radiodensity of SAT at diagnosis of nonmetastatic breast cancer was associated with increased risk of overall mortality, independent of adiposity and other prognostic factors. Considering both radiodensity and quantity of adipose tissue at different locations could deepen understanding of the role of adiposity in breast cancer survival.

Development of automated segmentation of visceral adipose tissue in computed tomography

PURPOSE

Imaging modalities such as computed tomography (CT) or magnetic resonance imaging have been used to measure adiposity. However, manual segmentation of visceral adipose tissue (VAT) in the entire abdomen is laborious and time-consuming. We aimed to develop a new method for accurate visceral fat segmentation by automatically dividing the three anatomical compartments of the lung, soft tissue, and post-vertebral spaces.

METHODS

To automatically separate visceral fat, a three-step process was performed that sequentially divided tissues and regions in a three-dimensional CT image. Manual segmentation was performed in 99 individuals who underwent 18-fluoro-2-deoxyglucosepositron emission tomography/CT for cancer screening between January 2010 and December 2018 to validate the automated segmentation. The similarity index and Pearson's correlation analysis were performed to compare automated segmentation with manual segmentation. Clinical data, such as weight, height, and glucose and insulin levels, were measured. Pearson's correlation analysis was performed to investigate the association between the two methods.

RESULTS

VAT volume of automated segmentation (3,594.6 ± 1,776.5 cm³) strongly correlated with that of manual segmentation (3,375.7 ± 1567.5 cm³) (r = 0.9676, p < 0.0001). The similarity index positively correlated with the VAT volume (r = 0.6396, p < 0.0001) and negatively correlated with the mean Hounsfield units (HU) (r = -0.4328, p < 0.0001). Bland-Altman plots are presented with 5.1 % for VAT volume and 7.1 % for mean HU were outside 1.96 standard deviation from the mean value.

CONCLUSION

We developed an automated segmentation method for VAT in the entire abdomen. This automated segmentation method is feasible for measuring the VAT volume and VAT HU. This method could be employed in daily clinical practice to provide more detailed information about VAT.

The effects of high-intensity interval training and moderate-intensity continuous training on visceral fat and carotid hemodynamics parameters in obese adults

Objectives

The present study aimed to examine the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on visceral fat and hemodynamic parameters in obese adults.

Methods

Fifty-two males were included in this study and divided into three groups: HIIT group (n = 21, age = 20.86 ± 1.62 years, BF (%) = 30.10 ± 5.02), MICT group (n = 22, age = 20.76 ± 1.14 years, BF (%) = 30.19 ± 5.76), and control group (CON) (n = 9, age = 21.38 ± 1.77 years, BF (%) = 30.40 ± 5.10). The HIIT and MICT groups received the exercise intervention three to four times per week for eight weeks (HIIT: exercise intensity 80–95% HRmax, circuit; MICT: exercise intensity 60–70% HRmax, running), and the control (CON) group received health education and guidance without exercise intervention. The body compositions and serum lipid indexes were tested to calculated LAP and VAI. The color doppler ultrasound diagnostic technology was used to test the artery diameter and blood velocity before and after the intervention. Based on the test data, MATLAB software and Womersley theory were used to calculate the hemodynamic parameters of the common carotid artery, including wall shear stress, flow rate, blood pressure, oscillatory shear index, elasticity modulus, dynamic resistance, artery diameter, arterial stiffness, circumferential strain and pulsatility index.

Results

We found that lipid accumulation product (LAP) was significantly decreased in both the HIIT group (p < 0.01) and MICT (p < 0.05) group but not in the CON group (p > 0.05). In contrast, visceral adiposity index (VAI) decreased in both the HIIT and MICT groups and increased in the CON group, although the difference among groups was not significant (p > 0.05). After 8 weeks of intervention, the blood velocity and wall shear stress were greater after HIIT and MICT intervention (p < 0.01). Artery diameter, oscillatory shear index, arterial stiffness, and pulsatility index decreased significantly, and circumferential strain increased significantly in the HIIT group (all, p < 0.01, p < 0.05) but not in the MICT group (p > 0.05). Dynamic resistance was significantly decreased in the MICT group. There was no difference in the CON group after the period of intervention (all, p > 0.05). LAP was positively related to artery diameter (r = 0.48, p = 0.011), blood pressure (r = 0.46, p = 0.002), flow rate (r = 0.31, p = 0.04), oscillatory shear index (r = 0.44, p = 0.03), and elasticity modulus (r = 0.33, p = 0.029) but inversely related to circumferential strain (r = −0.36, p = 0.028). The VAI was also positively associated with artery diameter (r = 0.33, p = 0.03), elasticity modulus (r = 0.38, p = 0.009), and arterial stiffness (r = 0.39, p = 0.012). In addition, the VAI was negatively correlated with the circumferential strain (r = −0.33, p = 0.04).

Conclusion

The present study demonstrated that both HIIT and MICT exercises for 8 weeks could effectively enhance visceral fat indices and partial hemodynamic parameters. Therefore, HIIT and MICT exert important effects on reducing fat content and improving hemodynamic environment. But HIIT on oscillatory shear index, arterial stiffness, circumferential strain, and pulsatility index was superior to MICT. In addition, there are close correlations between visceral fat and partial hemodynamic parameters of the common carotid artery.

Maternal High-Fat Diet Programs White and Brown Adipose Tissues In Vivo in Mice, with Different Metabolic and Microbiota Patterns in Obesity-Susceptible or Obesity-Resistant Offspring

Maternal obesity causes metabolic dysfunction in the offspring, including dysbiosis, overeating, obesity, and type 2 diabetes. Early-life phases are fundamental for developing subcutaneous (SAT) and brown adipose tissues (BAT), handling energy excesses. Imaging of ¹⁸F-fluorodeoxyglucose by positron emission tomography (PET) and radiodensity by computerized tomography (CT) allows assessing adipose tissue (AT) whitening and browning in vivo and the underlying metabolic efficiency. Our aim was to examine these in vivo traits in SAT and BAT concerning gut microbiota composition in 1- and 6-month-old mice born to normal (NDoff) and high-fat diet-fed dams (HFDoff), accounting for body weight responses. We found low radiodensity (high lipids) in HFDoff SAT at 1 month, relating to an increased abundance of Dorea genus in the caecum and activation of the fatty acid biosynthetic pathway. Instead, low BAT radiodensity and glucose uptake were seen in adult HFDoff. Glucose was shifted in favor of BAT at 1 month and SAT at 6 months. In adults, unclassified Enterococcaceae and Rikenellaceae, and Bacillus genera were negatively related to BAT, whereas unclassified Clostridiales genera were related to SAT metabolism. Stratification of HFDoff based on weight-response, namely maternal induced obesity (MIO-HFDoff) or obesity-resistant (MIOR-HFDoff), showed sex dimorphism. Both subgroups were hyperphagic, but only obese mice had hyper-leptinemia and hyper-resistinemia, together with BAT dysfunction, whereas non-obese HFDoff had hyperglycemia and SAT hypermetabolism. In the caecum, unclassified Rikenellaceae (10-fold enrichment in MIO-HFDoff) and Clostridiales genera (4-fold deficiency in MIOR-HFDoff) were important discriminators of these two phenotypes. In conclusion, SAT whitening is an early abnormality in the offspring of HFD dams. In adult life, maternal HFD and the induced excessive food intake translates into a dimorphic phenotype involving SAT, BAT, and microbiota distinctively, reflecting maternal diet*sex interaction. This helps explain inter-individual variability in fetal programming and the higher rates of type 2 diabetes observed in adult women born to obese mothers, supporting personalized risk assessment, prevention, and treatment.

Empagliflozin Treatment Attenuates Hepatic Steatosis by Promoting White Adipose Expansion in Obese TallyHo Mice

Sodium-glucose co-transporters (SGLTs) serve to reabsorb glucose in the kidney. Recently, these transporters, mainly SGLT2, have emerged as new therapeutic targets for patients with diabetes and kidney disease; by inhibiting glucose reabsorption, they promote glycosuria, weight loss, and improve glucose tolerance. They have also been linked to cardiac protection and mitigation of liver injury. However, to date, the mechanism(s) by which SGLT2 inhibition promotes systemic improvements is not fully appreciated. Using an obese TallyHo mouse model which recapitulates the human condition of diabetes and nonalcoholic fatty liver disease (NAFLD), we sought to determine how modulation of renal glucose handling impacts liver structure and function. Apart from an attenuation of hyperglycemia, Empagliflozin was found to decrease circulating triglycerides and lipid accumulation in the liver in male TallyHo mice. This correlated with lowered hepatic cholesterol esters. Using in vivo MRI analysis, we further determined that the reduction in hepatic steatosis in male TallyHo mice was associated with an increase in nuchal white fat indicative of "healthy adipose expansion". Notably, this whitening of the adipose came at the expense of brown adipose tissue. Collectively, these data indicate that the modulation of renal glucose handling has systemic effects and may be useful as a treatment option for NAFLD and steatohepatitis.