Optimal cut-points of visceral adipose tissue areas for cardiometabolic risk factors in a Chinese population: a cross-sectional study

Association between visceral fat area and metabolic syndrome in individuals with normal body weight: insights from a Chinese health screening dataset

BACKGROUND

Metabolic syndrome (MetS) is increasingly diagnosed in individuals with normal body weight, and visceral fat emerges as a significant risk factor. However, the relationship between visceral fat area (VFA) and MetS within this population remains inadequately explored, and the diagnostic threshold for MetS in normal-weight individuals is yet to be established.

METHODS

This study used a cross-sectional design combined with longitudinal cohort analysis. Data were collected from 5,944 normal-weight participants who underwent health screenings at Henan Provincial People's Hospital of China between October 2018 and October 2024. VFA was measured via multislice computed tomography scanning, and VFA-based tertile categorization was applied among the participants. The relationship between VFA and MetS was examined using univariate and multivariate logistic regression analyses. Nonlinear relationship was investigated by restricted cubic spline (RCS) modeling, and diagnostic accuracy was determined by receiver operating characteristic (ROC) curve analysis. Furthermore, data from individuals who completed three or more screenings were used to construct Kaplan-Meier survival curves for MetS events, with significance tested using the log-rank method.

RESULTS

Among the individuals with a normal BMI, elevated VFA was associated with a high incidence of MetS. After the adjustment for confounders, VFA was significantly associated with MetS risk [odds ratio (OR) = 1.13, 95% confidence interval (CI): 1.12-1.25]. The subjects in the highest VFA tertile showed significantly elevated MetS risk (OR = 30.33; 95% CI: 19.00-48.43, P < 0.001) versus those in the lowest tertile. The RCS model demonstrated a nonlinear, positive association between VFA and MetS risk (P for nonlinearity < 0.001), with risk escalation slowing down when the VFA exceeded 100 cm². ROC analysis showed that VFA had the highest diagnostic accuracy for MetS compared with other abdominal fat measures (AUC = 0.844, sensitivity = 0.839, specificity = 0.793, and accuracy = 0.785). In a longitudinal subset of 398 normal-weight participants followed for 6 years, 106 MetS cases occurred, with cumulative incidence rising as VFA increased (log-rank test, P < 0.001).

CONCLUSION

VFA shows an independent, nonlinear, positive association with MetS risk among normal-weight individuals, with a threshold effect at 100 cm². VFA = 162.85 cm² may serve as an accurate and effective predictor for MetS in this population.

Effects of time-restricted feeding (TRF)-model of intermittent fasting on adipose organ: a narrative review

Time-restricted feeding (TRF), an intermittent fasting approach involving a shortened eating window within 24 h, has gained popularity as a weight management approach. This review addresses how TRF may favor fat redistribution and the function of the adipose organ. TRF trials (mainly 16:8 model, with a duration of 5-48 weeks) reported a significant weight loss (1.2-10.2%, ~ 1.4-9.4 kg), with a considerable decrease in total fat mass (1.6-21%, ~ 0.5-7 kg) and visceral adipose compartment (VAC, 11-27%) in overweight and obese subjects. Experimental TRF in normal-fed and obesogenic-diet-fed mice and rats (with a fasting duration ranging between 9 and 21 h within 1-17 weeks) reported a significant reduction in body weight (~ 7-40%), total fat mass (~ 17-71%), and intrahepatic fat (~ 25-72%). TRF also improves VAC and subcutaneous adipose compartment (SAC) function by decreasing adipocyte size, macrophage infiltration, M1-macrophage polarity, and downregulating inflammatory genes. In conclusion, beyond its effect on body weight loss, total fat mass, and intrahepatic fat accumulation, TRF favors adipose organ fat redistribution in overweight and obese subjects by decreasing VAC and improving the function of VAC and SAC.

Evaluation of visceral adipose tissue thresholds for elevated metabolic syndrome risk across diverse populations: A systematic review

Beyond obesity, excess levels of visceral adipose tissue (VAT) significantly contribute to the risk of developing metabolic syndrome (MetS), although thresholds for increased risk vary based on population, regions of interest, and units of measure employed. We sought to determine whether a common threshold exists that is indicative of heightened MetS risk across all populations, accounting for sex, age, BMI, and race/ethnicity. A systematic literature review was conducted in September 2023, presenting threshold values for elevated MetS risk. Standardization equations harmonized the results from DXA, CT, and MRI systems to facilitate a comparison of threshold variations across studies. A total of 52 papers were identified. No single threshold could accurately indicate elevated risk for both males and females across varying BMI, race/ethnicity, and age groups. Thresholds fluctuated from 70 to 165.9 cm2, with reported values consistently lower in females. Generally, premenopausal females and younger adults manifested elevated risks at lower VAT compared to their older counterparts. Notably, Asian populations exhibited elevated risks at lower VAT areas (70-136 cm2) compared to Caucasian populations (85.6-165.9 cm2). All considered studies reported associations of VAT without accommodating covariates. No single VAT area threshold for elevated MetS risk was discernible post-harmonization by technology, units of measure, and region of interest. This review summarizes available evidence for MetS risk assessment in clinical practice. Further exploration of demographic-specific interactions between VAT area and other risk factors is imperative to comprehensively delineate overarching MetS risk.

Evaluation for Performance of Body Composition Index Based on Quantitative Computed Tomography in the Prediction of Metabolic Syndrome

Objective: We aimed to evaluate the performance of predicting metabolic syndrome (MS) using body composition indices obtained by quantitative computed tomography (QCT). Methods: In this cross-sectional study, data were collected from 4745 adults who underwent QCT examinations at a Chongqing teaching hospital between July 2020 and March 2022. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), total abdominal fat (TAT), abdominal muscle tissue (AMT), and liver fat content (LFC) were measured at the L2-L3 disc level using specialized software, and the skeletal muscle index (SMI) were calculated. The correlations between body composition indicators were analyzed using the Pearson correlation analysis. Receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) were used to assess these indicators' predictive potential for MS. Results: VAT and TAT exhibited the best predictive ability for MS, with AUCs of 0.797 [95% confidence interval (CI): 0.779-0.815] and 0.794 (95% CI: 0.775-0.812) in males, and 0.811 (95% CI: 0.785-0.836) and 0.802 (95% CI: 0.774-0.830) in females. The AUCs for VAT and TAT were the same but significantly higher than body mass index and other body composition measures. SAT also demonstrated good predictive power in females [AUC = 0.725 (95%CI: 0.692-0.759)] but fair power in males [AUC = 0.6673 (95%CI: 0.650-0.696)]. LFC showed average predictive ability, AMT showed average predictive ability in males but poor ability in females, and SMI had no predictive ability. Correlation analysis revealed a strong correlation between VAT and TAT (males: r = 0.95, females: r = 0.89). SAT was strongly correlated with TAT only in females (r = 0.89). In the male group, the optimal thresholds for VAT and TAT were 207.6 and 318.7 cm2, respectively; in the female group, the optimal thresholds for VAT and TAT were 128.0 and 269.4 cm2, respectively. Conclusions: VAT and TAT are the best predictors of MS. SAT and LFC can also be acceptable to make predictions, whereas AMT can only make predictions of MS in males.

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.

Serum triglyceride glucose index is a valuable predictor for visceral obesity in patients with type 2 diabetes: a cross-sectional study

BACKGROUND

Since the triglyceride glucose (TyG) index can reflect insulin resistance, it has been proven to be an efficient predictor of glycolipid-metabolism-related diseases. Therefore, this study aimed to investigate the predictive value of the TyG index for visceral obesity (VO) and body fat distribution in patients with type 2 diabetes mellitus (T2DM).

METHODS

Abdominal adipose tissue characteristics in patients with T2DM, including visceral adipose area (VAA), subcutaneous adipose area (SAA), VAA-to-SAA ratio (VSR), visceral adipose density (VAD), and subcutaneous adipose density (SAD), were obtained through analyses of computed tomography images at the lumbar 2/3 level. VO was diagnosed according to the VAA (> 142 cm² for males and > 115 cm² for females). Logistic regression was performed to identify independent factors of VO, and receiver operating characteristic (ROC) curves were used to compare the diagnostic performance according to the area under the ROC curve (AUC).

RESULTS

A total of 976 patients were included in this study. VO patients showed significantly higher TyG values than non-VO patients in males (9.74 vs. 8.88) and females (9.59 vs. 9.01). The TyG index showed significant positive correlations with VAA, SAA, and VSR and negative correlations with VAD and SAD. The TyG index was an independent factor for VO in both males (odds ratio [OR] = 2.997) and females (OR = 2.233). The TyG index ranked second to body mass index (BMI) for predicting VO in male (AUC = 0.770) and female patients (AUC = 0.720). Patients with higher BMI and TyG index values showed a significantly higher risk of VO than the other patients. TyG-BMI, the combination index of TyG and BMI, showed significantly higher predictive power than BMI for VO in male patients (AUC = 0.879 and 0.835, respectively) but showed no significance when compared with BMI in female patients (AUC = 0.865 and 0.835, respectively).

CONCLUSIONS

. TyG is a comprehensive indicator of adipose volume, density, and distribution in patients with T2DM and is a valuable predictor for VO in combination with anthropometric indices, such as BMI.

Association of Periaortic Fat and Abdominal Visceral Fat with Coronary Artery Atherosclerosis in Chinese Middle Aged and Elderly Patients Undergoing Computed Tomography Coronary Angiography

Background and Aims:

Coronary artery disease (CAD) is usually caused by atherosclerosis, which is associated with general obesity and stronger associations with localized ectopic fat depots have been reported. We measured body ectopic fat distribution in Chinese patients to determine the association with coronary artery atherosclerosis (CA).

Methods:

Patients undergoing coronary computed tomography angiography (CCTA) who agreed to participate in the study (n = 750, 50.4% men, mean age 64.8 years) had cardiovascular disease and risk assessment. Body ectopic fat depots were measured from CT and their association with CA, determined from CCTA, was evaluated by univariate and multivariate logistic regression models.

Results:

CAD with CA (CAD-CA) was present in 57.2% of participants with CAD of moderate/severe CA (CAD-msCA) present in 23.5% and both were significantly more frequent in men than in women. Overall, men had greater body mass index (BMI) but there was no difference in waist circumference (WC) between genders. However, significantly higher visceral adipose tissue (VAT) and periaortic fat volume (PAFV) were observed in men, whereas women had significantly higher abdominal subcutaneous adipose tissue (SAT). With increasing age, there was a significant decline in BMI, WC and SAT in men, but a significant increase of WC and VAT, PAFV and epicardial fat volume (EFV) in women. A high proportion of non-calcified plaques was observed in CAD-CA, 55.3% in CAD of minimal/mild CA (CAD-mmCA) with 38.7% exclusively non-calcified plaques, and 59.7% in CAD-msCA with multiple type plaques containing non-calcified ones. Multivariate logistic regression showed a significant association of PAFV with CAD-CA and CAD-msCA that was independent of general obesity and clinical risk factors, and independent of abdominal obesity in the highest PAFV quartile patients. VATA was associated with an increased prevalence of CAD-msCA in the patients in the upper 2 VATA quartiles that was independent of clinical risk factors and both general and abdominal obesity.

Conclusions:

We found age and gender differences of body ectopic fat distribution in Chinese patients with higher VAT and PAFV in men and higher SAT in women. With increased age, there was a decline of WC and SAT in men but not in women and an increase in WC, VAT and PAFV in women but not in men. PAFV was significantly associated with overall CAD-CA and CAD-msCA, while VAT was associated with CAD-msCA.

Measurement of visceral fat and abdominal obesity by single-frequency bioelectrical impedance and CT: a cross-sectional study

OBJECTIVES

The measurement of visceral fat (VF) is clinically important for the identification of individuals at high risk of visceral obesity-related health conditions. Bioelectrical impedance analysis (BIA) is a widely available and frequently used body composition assessment method, but there have been few validation studies for the measurement of VF. This validation study investigated agreement between BIA and CT for the assessment of VF in adults.

DESIGN

Cross-sectional study.

SETTING

Between 2015 and 2016 in China.

PARTICIPANTS

A total of 414 adults (119 men and 295 women) aged 40-82 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

CT-visceral fat area (VFA) was derived at the L2-3 and umbilicus level and VFA cut-offs for visceral obesity applied. BIA measurements of visceral fat level were compared with CT VFA findings using scatter plots and receiver operator characteristic (ROC) curves.

RESULTS

Scatter plots showed poor agreement between BIA and CT-derived visceral fat measurements in both sexes (R=0.387-0.636). ROC curves gave optimum figures for sensitivity and specificity of 65% and 69% in women and 76% and 70% in men, respectively, for BIA to discriminate between adults with normal levels of VF and those with visceral obesity determined by CT.

CONCLUSION

BIA has limited accuracy for the assessment of VF in adults in practice when compared with the criterion method.