Design and validation of a novel estimator of visceral adipose tissue area and comparison to existing adiposity surrogates

Investigating a novel surrogate indicator of adipose accumulation in relation to erectile dysfunction

INTRODUCTION

Although previous studies have linked obesity and erectile dysfunction, the novel surrogate indicators of adipose accumulation are more essential and dependable factors to consider. Therefore, the primary objective of the current investigation was to examine and clarify the association between metabolic score for visceral fat (METS-VF) and erectile dysfunction.

METHODS

Firstly, multivariate logistic regression analysis, smoothed curve fitting, and threshold effect analysis were employed to investigate the association between METS-VF and erectile dysfunction. Mediation analysis was also performed to evaluate the mediating role of homocysteine and inflammation. After that, subgroup analysis was carried out to examine the stability of the correlation of METS-VF with erectile dysfunction in various population settings. Furthermore, the area under the receiver operating characteristic (ROC) curve and eXtreme Gradient Boosting (XGBoost) algorithm were utilized to assess the capability of identifying METS-VF in comparison to the other four obesity-related indicators in identifying erectile dysfunction.

RESULTS

After adjusting for all confounding factors, METS-VF was strongly and favourablely correlated with erectile dysfunction. With each additional unit rise in METS-VF, the prevalence of erectile dysfunction increased by 141%. A J-shaped relationship between METS-VF and erectile dysfunction was discovered through smoothed curve fitting. Marital status, physical activity, and smoking status can potentially modify this association. This finding of the ROC curve suggests that METS-VF had a powerful identifying capacity for erectile dysfunction (AUC = 0.7351). Homocysteine and inflammation mediated 4.24% and 2.81%, respectively.

CONCLUSION

The findings of the current investigation suggest that METS-VF can be considered a dependable identifying indicator of erectile dysfunction.

Is Metabolic Score for Visceral Fat (METS-VF) a Better Index Than Other Adiposity Indices for the Prediction of Visceral Adiposity

Background

Visceral adiposity is an important risk factor for cardiometabolic diseases.

Objective

To determine whether the Metabolic Score for Visceral Fat (METS-VF) is more effective than other adiposity indices in predicting visceral fat area (VFA).

Methods

In this single-center and cross-sectional study, we included patients aged 20-50 years, without diabetes and coronary artery disease, who underwent computed tomography (CT) including the third lumbar vertebra. Age, blood pressure, waist circumference (WC), hip circumference, fasting lipids, and glucose were assessed. VFA was measured by cross-sectional examination of CT. The correlation of WC, body mass index (BMI), waist-hip ratio (WHR), lipid accumulation product (LAP), visceral adiposity index (VAI), a body shape index (ABSI), body roundness index (BRI), and METS-VF with VFA was analyzed by correlation analysis. The cut-off values and area under the curve (AUC) for identifying increased VFA (>130 cm2) were determined.

Results

We included 185 individuals with mean age 38.2 ± 8 and female predominance (58.4%). There was a significant positive correlation between all indices and VFA (p<0.001). ROC analysis revealed that METS-VF and WC demonstrated the highest predictive value for identifying increased VFA. In both men (p=0.001) and women (p<0.001), METS-VF (AUC 0.922 and 0.939, respectively) showed a significant superiority over ABSI (AUC 0.702 and 0.658, respectively), and VAI (AUC 0.731 and 0.725, respectively). Additionally, in women, its superiority over WHR (AUC 0.807) was also statistically significant (p=0.003). We identified a METS-VF cut-off point >6.4 in males >6.5 in females and WC cut-off point >88 cm in males (AUC 0.922), >90.5 cm in females (AUC 0.938).

Conclusion

METS-VF is strongly associated with visceral adiposity and better to predict increased VFA. However, its superiority over WC, BMI, BRI, and LAP was not significant. The results emphasize that WC is more appealing as screening indicator for visceral adiposity considering its easy use.

Clinical Trial Registry Name

Clinicaltrials.gov (http://www.clinicaltrials.gov).

Clinical Trial Registry Url

https://clinicaltrials.gov/ct2/show/NCT05648409.

Clinical Trial Registry Number

NCT05648409.

Sex-specific equations to estimate body composition: Derivation and validation of diagnostic prediction models using UK Biobank

BACKGROUND & AIMS

Body mass index and waist circumference are simple measures of obesity. However, they do not distinguish between visceral and subcutaneous fat, or muscle, potentially leading to biased relationships between individual body composition parameters and adverse health outcomes. The purpose of this study was to develop and validate prediction models for volumetric adipose and muscle.

METHODS

Based on cross-sectional data of 18,457, 18,260, and 17,052 White adults from the UK Biobank, we developed sex-specific equations to estimate visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (ASAT), and total thigh fat-free muscle (FFM) volumes, respectively. Volumetric magnetic resonance imaging served as the reference. We used the least absolute shrinkage and selection operator and the extreme gradient boosting methods separately to fit three sequential models, the inputs of which included demographics and anthropometrics and, in some, bioelectrical impedance analysis parameters. We applied comprehensive metrics to assess model performance in the temporal validation set.

RESULTS

The equations that included more predictors generally performed better. Accuracy of the equations was moderate for VAT (percentage of estimates that differed <30% from the measured values, 70 to 78 in males, 64 to 69 in females) and good for ASAT (85 to 91 in males, 90 to 95 in females) and FFM (99 to 100 in both sexes). All the equations appeared precise (interquartile range of the difference, 0.89 to 1.76 L for VAT, 1.16 to 1.61 L for ASAT, 0.81 to 1.39 L for FFM). Bias of all the equations was negligible (-0.17 to 0.05 L for VAT, -0.10 to 0.12 L for ASAT, -0.07 to 0.09 L for FFM). The equations achieved superior cardiometabolic correlations compared with body mass index and waist circumference.

CONCLUSIONS

The developed equations to estimate VAT, ASAT, and FFM volumes achieved moderate to good performance. They may be cost-effective tools to revisit the implications of diverse body components.

Altered Visceral Adipose Tissue Predictors and Women’s Health: A Unicenter Study

(1) Background: The excess visceral adipose tissue (VAT) accumulation in women may reflect an early or advanced state of a metabolic disorder and a higher risk of cardiovascular disease than other types of obesity. This study aimed to determine the predictor variables (demographic information, anthropometric data, and blood biomarkers) for changes in VAT in adult women. (2) Methods: This cross-sectional study was conducted with women aged 18–59 years attending nutritional consultation at the Centro Universitário de Brasília (CEUB)’s nutrition school clinic, Brazil. All participants’ medical records were reviewed throughout the study and data of interest were collected. Various anthropometric measurements and biochemical exams were performed and analyzed in a univariate logistic regression model to identify the possible risk factors predictors for the presence of altered VAT. (3) Results: Our logistic regression model considered body mass index (BMI) greater than 25 kg/m², lipid accumulation product (LAP), and waist–hip ratio (WHR) as predictors of altered VAT. (4) Conclusion: LAP has a robust predictive capacity for changes in visceral fat in adult women, followed by WHR and BMI, making these variables effective in assessing the risk for changes in visceral fat and their inclusion essential in the individual and collective clinical practice.

Visceral Adipose Tissue Influence on Health Problem Development and Its Relationship with Serum Biochemical Parameters in Middle-Aged and Older Adults: A Literature Review

Background

The amount of visceral adipose tissue (VAT) tends to increase with age and is associated with several health problems, such as cardiometabolic diseases, increased infections, and overall mortality.

Objectives

This review provides a general assessment of how visceral adiposity correlates with the development of health problems and changes in serum biochemical parameters in middle-aged and older adults.

Methods

We searched specific terms in the Virtual Health Library (VHL) databases for VAT articles published in the English language between 2009 and 2019 related to older adults.

Results

The search found twenty-three publications in this period, of which nine were excluded. The publications had a population aged between 42 and 83 years and correlated the VAT area ratio with several comorbidities (such as pancreatitis, depression, cancer, and coronary heart disease) and serum biochemical parameters.

Conclusion

Further research on the association between visceral obesity and the emergence of health problems and the relationship between VAT and changes in serum biochemical parameters in older individuals should deepen the understanding of this connection and develop preventive actions.

Evaluation of the Value of Waist Circumference and Metabolomics in the Estimation of Visceral Adipose Tissue

Visceral adipose tissue (VAT) is a strong prognostic factor for cardiovascular disease and a potential target for cardiovascular risk stratification. Because VAT is difficult to measure in clinical practice, we estimated prediction models with predictors routinely measured in general practice and VAT as outcome using ridge regression in 2,501 middle-aged participants from the Netherlands Epidemiology of Obesity study, 2008-2012. Adding waist circumference and other anthropometric measurements on top of the routinely measured variables improved the optimism-adjusted R2 from 0.50 to 0.58 with a decrease in the root-mean-square error (RMSE) from 45.6 to 41.5 cm2 and with overall good calibration. Further addition of predominantly lipoprotein-related metabolites from the Nightingale platform did not improve the optimism-corrected R2 and RMSE. The models were externally validated in 370 participants from the Prospective Investigation of Vasculature in Uppsala Seniors (PIVUS, 2006-2009) and 1,901 participants from the Multi-Ethnic Study of Atherosclerosis (MESA, 2000-2007). Performance was comparable to the development setting in PIVUS (R2 = 0.63, RMSE = 42.4 cm2, calibration slope = 0.94) but lower in MESA (R2 = 0.44, RMSE = 60.7 cm2, calibration slope = 0.75). Our findings indicate that the estimation of VAT with routine clinical measurements can be substantially improved by incorporating waist circumference but not by metabolite measurements.

Visceral adiposity index outperforms common anthropometric indices in predicting 10-year diabetes risk: Results from the ATTICA study

BACKGROUND

Visceral adiposity index (VAI) is a novel marker of visceral adipose tissue accumulation and dysfunction. The study aim was to explore the association of VAI with the 10-year type 2 diabetes mellitus (T2DM) incidence in apparently healthy individuals and compare its T2DM predictive ability against common anthropometric indices.

METHODS

In 2001 to 2002, the ATTICA study (Greece) recruited a random sample of 1514 and 1528 CVD-free men (18-87 years old) and women (18-89 years old), respectively. Sociodemographic, lifestyle, clinical, and biochemical characteristics of participants were measured at baseline, and the 10-year follow-up was performed during 2011 to 2012. After excluding participants with diabetes at baseline and participants without complete follow-up information regarding diabetes status and/or baseline VAI values, the working sample consisted of 1049 participants. In this sample, the predictive value of baseline VAI value was studied in relation to 10-year diabetes incidence.

RESULTS

One hundred thirty-three incident cases of diabetes were documented (10-year incidence: 12.7%). In the fully adjusted model, VAI significantly increased diabetes risk by 22% (OR per 1-unit increase =1.22; 95%CI, 1.09-1.37). Markers of oxidative stress and inflammation were found to, at least partly, mediate this relationship. Also, a moderating effect of menstruation status was revealed among women. VAI showed the highest predictive ability and contributed the most, along with waist-to-height ratio, to the correct classification of participants who developed diabetes.

CONCLUSIONS

The present findings suggest that VAI may be a useful index for predicting long-term diabetes development and may exhibit better predictive ability to commonly used anthropometric indices.

Metabolic Score for Visceral Fat (METS-VF), a novel estimator of intra-abdominal fat content and cardio-metabolic health

BACKGROUND & AIMS

Intra-abdominal and visceral fat (VAT) are risk factors for the development of cardio-metabolic comorbidities; however its clinical assessment is limited by technology and required expertise for its assessment. We aimed to develop a novel score (METS-VF) to estimate VAT by combining the non-insulin-based METS-IR index, waist-height ratio (WHtr), age and sex.

METHODS

We developed METS-VF in a sample of 366 individuals with Dual X-ray absorptiometry (DXA). METS-VF was modeled using non-linear regression and validated in two replication cohorts with DXA (n = 184, with n = 118 who also had MRI) and bio-electrical impedance (n = 991). We also assessed METS-VF to predict incident type 2 diabetes (T2D) and arterial hypertension independent of body-mass index (BMI) in our Metabolic Syndrome Cohort (n = 6144).

RESULTS

We defined METS-VF as: 4.466 + 0.011*(Ln(METS-IR))³ + 3.239*(Ln(WHtr))³ + 0.319*(Sex) + 0.594*(Ln(Age)). METS-VF showed better performance compared to other VAT surrogates using either DXA (AUC 0.896 95% CI 0.847-0.945) or MRI (AUC 0.842 95% CI 0.771-0.913) as gold standards. We identified a METS-VF cut-off point >7.18 in healthy patients which has 100% sensitivity (95% CI 76.8-100) and 87.2% specificity (95% CI 79.1-93.0) to identify increased VAT (>100 cm²). METS-VF also had adequate performance in subjects with metabolically-healthy obesity. Finally, in our metabolic syndrome cohort, subjects in the upper quintiles of METS-VF (>7.2) had 3.8 and 2.0-fold higher risk of incident T2D and hypertension, respectively (p < 0.001). This effect was independent of BMI for both outcomes.

CONCLUSION

METS-VF is a novel surrogate to estimate VAT, which has better performance compared to other surrogate VAT indexes and is predictive of incident T2D and hypertension. METS-VF could be a useful tool to assess cardio-metabolic risk in primary care practice and research settings.