Abdominal Visceral Adipose Tissue Volume Research Articles

Cardiovascular Significance and Genetics of Epicardial and Pericardial Adiposity

Epicardial and pericardial adipose tissue (EPAT) has been associated with cardiovascular diseases such as atrial fibrillation or flutter (AF) and coronary artery disease (CAD), but studies have been limited in sample size or drawn from selected populations. It has been suggested that the association between EPAT and cardiovascular disease could be mediated by local or paracrine effects. To evaluate the association of EPAT with prevalent and incident cardiovascular disease and to elucidate the genetic basis of EPAT in a large population cohort. A deep learning model was trained to quantify EPAT area from 4-chamber magnetic resonance images using semantic segmentation. Cross-sectional and prospective cardiovascular disease associations were evaluated, controlling for sex and age. Prospective associations were additionally controlled for abdominal visceral adipose tissue (VAT) volumes. A genome-wide association study was performed, and a polygenic score (PGS) for EPAT was examined in independent FinnGen cohort study participants. Data analyses were conducted from March 2022 to December 2023. The primary exposures were magnetic resonance imaging-derived continuous measurements of epicardial and pericardial adipose tissue area and visceral adipose tissue volume. Prevalent and incident CAD, AF, heart failure (HF), stroke, and type 2 diabetes (T2D). After exclusions, this study included 44 475 participants (mean [SD] age, 64.1 [7.7] years; 22 972 female [51.7%]) from the UK Biobank. Cross-sectional and prospective cardiovascular disease associations were evaluated for a mean (SD) of 3.2 (1.5) years of follow-up. Prospective associations were additionally controlled for abdominal VAT volumes for 38 527 participants. A PGS for EPAT was examined in 453 733 independent FinnGen cohort study participants. EPAT was positively associated with male sex (β = +0.78 SD in EPAT; P < 3 × 10-324), age (Pearson r = 0.15; P = 9.3 × 10-229), body mass index (Pearson r = 0.47; P < 3 × 10-324), and VAT (Pearson r = 0.72; P < 3 × 10-324). EPAT was more elevated in prevalent HF (β = +0.46 SD units) and T2D (β = +0.56) than in CAD (β = +0.23) or AF (β = +0.18). EPAT was associated with incident HF (hazard ratio [HR], 1.29 per +1 SD in EPAT; 95% CI, 1.17-1.43), T2D (HR, 1.63; 95% CI, 1.51-1.76), and CAD (HR, 1.19; 95% CI, 1.11-1.28). However, the associations were no longer significant when controlling for VAT. Seven genetic loci were identified for EPAT, implicating transcriptional regulators of adipocyte morphology and brown adipogenesis (EBF1, EBF2, and CEBPA) and regulators of visceral adiposity (WARS2 and TRIB2). The EPAT PGS was associated with T2D (odds ratio [OR], 1.06; 95% CI, 1.05-1.07; P =3.6 × 10-44), HF (OR, 1.05; 95% CI, 1.04-1.06; P =4.8 × 10-15), CAD (OR, 1.04; 95% CI, 1.03-1.05; P =1.4 × 10-17), AF (OR, 1.04; 95% CI, 1.03-1.06; P =7.6 × 10-12), and stroke in FinnGen (OR, 1.02; 95% CI, 1.01-1.03; P =3.5 × 10-3) per 1 SD in PGS. Results of this cohort study suggest that epicardial and pericardial adiposity was associated with incident cardiovascular diseases, but this may largely reflect a metabolically unhealthy adiposity phenotype similar to abdominal visceral adiposity.

Epicardial and pericoronary adipose tissue and coronary plaque burden in patients with Cushing's syndrome: a propensity score-matched study.

To assess coronary inflammation by measuring the volume and density of the epicardial adipose tissue (EAT), perivascular fat attenuation index (FAI) and coronary plaque burden in patients with Cushing's syndrome (CS) based on coronary computed tomography angiography (CCTA). This study included 29 patients with CS and 58 matched patients without CS who underwent CCTA. The EAT volume, EAT density, FAI and coronary plaque burden were measured. The high-risk plaque (HRP) was also evaluated. CS duration from diagnosis, 24-h urinary free cortisol (UFC), and abdominal visceral adipose tissue volume (VAT) of CS patients were recorded. The CS group had higher EAT volume (146.9 [115.4, 184.2] vs. 119.6 [69.0, 147.1] mL, P = 0.006), lower EAT density (- 78.79 ± 5.89 vs. - 75.98 ± 6.03 HU, P = 0.042), lower FAI (- 84.0 ± 8.92 vs. - 79.40 ± 10.04 HU, P = 0.038), higher total plaque volume (88.81 [36.26, 522.5] vs. 44.45 [0, 198.16] mL, P = 0.010) and more HRP plaques (7.3% vs. 1.8%, P = 0.026) than the controls. The multivariate analysis suggested that CS itself (β [95% CI], 29.233 [10.436, 48.03], P = 0.014), CS duration (β [95% CI], 0.176 [0.185, 4.242], P = 0.033), and UFC (β [95% CI], 0.197 [1.803, 19.719], P = 0.019) were strongly associated with EAT volume but not EAT density, and EAT volume (β [95% CI] - 0.037[- 0.058, - 0.016], P = 0.001) not CS was strongly associated with EAT density. EAT volume, FAI and plaque burden increased (all P < 0.05) in 6 CS patients with follow-up CCTA. The EAT volume had a moderate correlation with abdominal VAT volume (r = 0.526, P = 0.008) in CS patients. Patients with CS have higher EAT volume and coronary plaque burden but less inflammation as detected by EAT density and FAI. The EAT density is associated with EAT volume but not CS itself.

Eliminating exogenous insulin therapy in patients with type 2 diabetes by duodenal ablation and GLP-1RA decreases risk scores for cardiovascular events

IntroductionDuodenal Mucosal Resurfacing (DMR) is an endoscopic ablation technique aimed at improving glycaemia and metabolic health in patients with type 2 diabetes mellitus (T2DM). DMR has an insulin sensitizing effect in patients with T2DM. Reducing hyperinsulinemia can improve cardiovascular health. In the INSPIRE trial, we combined a single DMR with a glucagon-like-peptide-1 receptor agonist (GLP-1RA) and demonstrated elimination of insulin treatment in 69% of patients at 6 months and 53% of patients at 18 months while improving glycaemic control and metabolic health. We hypothesized that this treatment approach is associated with improved cardiovascular health, by reducing hyperinsulinemia.MethodsBefore and 6 months after starting the combination treatment to replace insulin, the following assessments were performed to evaluate cardiovascular health: magnetic resonance imaging (MRI) to measure abdominal visceral adipose tissue volume, ambulatory 24 h blood pressure (ABPM) analysis, postprandial insulin and triglycerides, fasting lipid panel and urine microalbumin. The Atherosclerotic Cardiovascular Disease (ASCVD) score was calculated to estimate 10-year risk of cardiovascular disease or stroke and the diabetes lifetime-perspective prediction (DIAL) score was calculated to estimate years free of cardiovascular disease.ResultsSix months after replacing exogenous insulin by DMR and GLP-1RA, visceral adipose tissue decreased significantly by 24%. Postprandial triglyceride and insulin concentrations decreased significantly (p < 0.001), as did total cholesterol (from median 3.64 (IQR 3.34–4.89) to 3.48 (3.18–3.97) mmol/l, p = 0.008), LDL (from median 1.92 (IQR 1.49–2.30) to 1.79 (1.49–2.08 mmol/l, p = 0.044), and urine microalbumin (from median 7 (IQR 3–27) to 4 (3–8) mg/l, p = 0.018). All daytime blood pressure values decreased significantly. The ASCVD 10-year risk score decreased (from median 13.6 (IQR 5.7–26.0) to 11.5 (4.2–22.5) %, p = 0.030)) and the DIAL score increased (from median 82 (IQR 81–83) to 83 (81–84) years, (p = 0.039)).DiscussionThe combination of DMR and GLP-1RA to replace insulin therapy in patients with T2DM is associated with a positive effect on multiple parameters of cardiovascular health. Taken together, they show a pattern of overall improvement in cardiovascular health, as evidenced by decreased risk scores for cardiovascular complications. However, it is not yet clear whether these improvements will translate into a true reduction in cardiovascular events.

Hepatic steatosis is associated with abnormal hepatic enzymes, visceral adiposity, altered myocardial glucose uptake measured by 18F-FDG PET/CT

BackgroundNonalcoholic fatty liver disease (NAFLD) is a multisystem disease that affects the liver and a variety of extra-hepatic organ systems. This study aimed to investigate the relationship between hepatic steatosis and glucose metabolism in liver and extra-hepatic tissues and organs.MethodsThe whole body 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) images of 191 asymptomatic tumor screening patients were retrospectively analyzed. Patients with the ratio of spleen/liver CT densities > 1.1 were defined to have NAFLD, and their clinical symptoms, laboratory markers, FDG uptake in a variety of tissues and organs including heart, mediastinal blood pool, liver, spleen, pancreas, and skeletal muscle, as well as abdominal adipose tissue volumes including visceral adipose tissue (VAT) volume and subcutaneous adipose tissue (SAT) volume were compared with those of the non-NAFLD patients and used to analyze the independent correlation factors of NAFLD.ResultsAmong the 191 patients, 33 (17.3%) were NAFLD, and 158 (82.7%) were non-NAFLD. There was no significant correlation between the mean standardized uptake value (SUVmean) and CT density of liver as well as the ratio of spleen/liver CT densities. Hepatic steatosis, but not FDG intake, was more significant in NAFLD patients with abnormal liver function than those with normal liver function. Compared with the non-NAFLD patients, NAFLD patients had significantly reduced myocardial glucose metabolism, but significantly increased mediastinal blood pool, spleen SUVmean and abdominal adipose tissue volumes (including VAT and SAT volumes) (P < 0.05). Multivariate regression analysis showed that elevated serum ALT, increased abdominal VAT volume, and decreased myocardial FDG uptake were independent correlation factors for NAFLD. Further studies showed that hepatic steatosis and myocardial FDG uptake were mildly linearly correlated (r = 0.366 with hepatic CT density and − 0.236 with the ratio of spleen/liver CT densities, P < 0.05).ConclusionsNAFLD is a systemic disease that can lead to the change of glucose metabolism in some extra-hepatic tissues and organs, especially the myocardium.

Novel artificial neural network and linear regression based equation for estimating visceral adipose tissue volume.

There is a growing interest in fast and reliable assessment of abdominal visceral adipose tissue (VAT) volume for risk stratification of metabolic disorders. However, imaging based measurement of VAT is costly and limited by scanner availability. Therefore, we aimed to develop equations to estimate abdominal VAT volume from simple anthropometric parameters and to assess whether linear regression based equations differed in performance from artificial neural network (ANN) based equations. MRI-measured abdominal VAT volumes and anthropometric parameters of 5772 subjects (White ethnicity, age 45-76 years, 52.7% females) were obtained from the UK Biobank. Subjects were divided into the derivation sample (n=5195) and the validation sample (n=577). Basic models (age, sex, height, weight) and expanded models (basic model+waist circumference and hip circumference) were constructed from the derivation sample by linear regression and ANN respectively. Performance of the linear regression and ANN based equations in the validation sample were compared and estimating accuracies were evaluated by receiver-operating characteristic curves (ROC). The basic and expanded equations based on linear regression and ANN demonstrated the adjusted coefficient of determination (R2) ranging from 0.71 to 0.78, with bias ranging from less than 0.001L-0.07L in comparison with MRI-measured VAT. Both basic and expanded ANN based equations demonstrated slightly higher adjusted R2 and lower error measurements than linear regression equations. However, no statistical difference was found between linear regression equations and their ANN based counterparts in ROC analysis. Both linear regression and ANN based expanded equations presented higher estimating accuracies (76.9%-90.1%) than the basic equations (74.5%-87.5%) in ROC analysis. We present equations based on linear regression and artificial neural networks to estimate abdominal VAT volume by simple anthropometric parameters for middle-aged and elderly White population. These equations can be used to estimate VAT volume in general practice as well as population-based studies.

Equation to estimate visceral adipose tissue volume based on anthropometry for workplace health checkup in Japanese abdominally obese men.

The purpose of this study was to develop a new equation model for predicting abdominal visceral adipose tissue (VAT) volume using anthropometric values for workplace health checkup and to clarify the association between metabolic risk factors and measured and predicted VAT volumes. Two hundred sixty male workers (200 for derivation group and 60 for validation group) participated in the cross-sectional study. The anthropometric variables and VAT volume were measured with 24 consecutive magnetic resonance images. Measurements in the validation group also included metabolic risk factors, i.e. blood pressure, HDL cholesterol, triglyceride, fasting glucose and HbA1c. Using multiple regression analyses for the derivation group, we determined the best prediction equation for abdominal VAT volume with a variance of 47% as follows: 47.03 age+117.79 BMI+74.18 waist circumference −8,792.7. In our validation group, the correlation coefficient between the measured and predicted VAT volumes was 0.74 (p<0.01). Furthermore, blood pressure, fasting glucose and HbA1c correlated with both measured and predicted VAT volumes. This study suggests that the equation model has potential to assess VAT accumulation levels in workers health checkup where CT and MRI are not available.

Vitamin D Receptor Gene Polymorphisms Are Associated with Abdominal Visceral Adipose Tissue Volume and Serum Adipokine Concentrations but Not with Body Mass Index or Waist Circumference in African Americans: The Jackson Heart Study

Background: The biological actions of vitamin D are mediated through the vitamin D receptor (VDR). Single-nucleotide polymorphisms (SNPs) in the VDR gene have been previously associated with adiposity traits. However, to our knowledge, few studies have included direct measures of adiposity and adipokine concentrations.Objective: We examined the association of tagging SNPs in the VDR gene with multiple adiposity measures, including waist circumference (WC), body mass index (BMI), body fat percentage, subcutaneous and visceral adipose tissue (VAT) volume, and serum adipokine (adiponectin and leptin) concentrations in adult African Americans (AAs).Methods: Data from 3020 participants (61.9% women; mean age, 54.6 y) from the Jackson Heart Study were used for this analysis. Forty-five tag SNPs were chosen with the use of genotype data from the International HapMap project. We used linear regression to test the associations of imputed VDR SNPs with each of the traits, adjusted for age, sex, educational status, physical activity, smoking, alcohol intake, serum vitamin D concentration, European ancestry, and multiple testing.Results: The G allele of the SNP rs4328262 remained associated with increased VAT volume after multiple testing correction (β = 45.7; P < 0.001). The A allele of another SNP (rs11574070) was nominally associated with body fat percentage (β = 0.96; P = 0.002). None of the VDR SNPs analyzed showed any link with WC or BMI. The A allele of rs2228570 (β = 0.08; P = 0.001) for men and the T allele of rs2853563 (β = 0.04; P < 0.001) for women remained positively associated with serum adiponectin concentrations after multiple testing correction.Conclusion: Although we did not find any association for anthropometric measures, we did observe associations of VDR variants with serum adipokines and with the more metabolically active fat, VAT. Therefore, our findings demonstrate a possible role of VDR variants in regulating adipose tissue activity and adiposity among AAs.

Best single-slice location to measure visceral adipose tissue on paediatric CT scans and the relationship between anthropometric measurements, gender and VAT volume in children.

Visceral adipose tissue (VAT) is a significant risk factor for obesity-related metabolic diseases. This study investigates (1) the best single CT slice location for predicting total abdominal VAT volume in paediatrics and (2) the relationship between waist circumference (WC), sagittal diameter (SD), gender and VAT volume. A random sample of 130 paediatric abdomen CT scans, stratified according to age and gender, was collected. Three readers measured VAT area at each intervertebral level between T12 and S1 using ImageJ analysis (National Institute of Health, Bethesda, MD) software by thresholding -190 to -30 HU and manually segmenting VAT. Single-slice VAT measurements were correlated with total VAT volume to identify the most representative slice. WC and SD were measured at L3-L4 and L4-L5 slices, respectively. Regression analysis was used to evaluate WC, SD and gender as VAT volume predictors. Interviewer and intraviewer reliability were excellent (intraclass correlation coefficient = 0.99). Although VAT measured at multiple slices correlated strongly with abdominal VAT, only one slice in females at L2-L3 and two slices in males at L1-L2 and L5-S1 were strongly correlated across all age groups. Linear regression analysis showed that WC was strongly correlated with VAT volume (beta = 0.970, p < 0.001). Single-slice VAT measurements are highly reproducible. Measurements performed at L2-L3 in females and L1-L2 or L5-S1 in males were most representative of VAT. WC is indicative of VAT. VAT should be measured at L2-L3 in female children and at either L1-L2 or L5-S1 in males. WC is a strong indicator of VAT in children.

Effects of Eicosapentaenoic Acid Treatment on Epicardial and Abdominal Visceral Adipose Tissue Volumes in Patients with Coronary Artery Disease

Epicardial adipose tissue (EAT) is a pathogenic fat depot that may be associated with coronary atherosclerosis and cardiovascular events. Because eicosapentaenoic acid (EPA) has been reported to exert cardiovascular protective effects, we aimed to assess the effects of EPA on the volume of visceral adipose tissue, including EAT and abdominal visceral adipose tissue (AVAT), using multislice computed tomography (CT). In 30 patients with coronary artery diseases (9 women; mean age, 67.2 ± 5.4 years), EAT and AVAT volumes were compared between the control group (n=15, conventional therapy) and the EPA group (n=15, conventional therapy plus purified EPA 1800 mg/day) during a six-month period. EAT was defined as any pixel that had CT attenuation of -150 to -30 Hounsfield units (HU) within the pericardial sac. After the six-month follow-up, the serum EPA level increased from 59.9 ± 18.8 to 177.2 ± 3.3 μg/mL in the EPA group (p<0.01), but no increase was noted in the control group. Similarly, the EPA/arachidonic acid (AA) ratio increased from 0.39 ± 0.12 to 1.22 ± 0.28 in the EPA group (p<0.01), with no significant increase in the control group. The AVAT and EAT volumes decreased in the EPA group but were unchanged in the control group (AVAT, -11.6 ± 17.0 vs. +8.8 ± 13.6 cm(2), p<0.01; EAT, -7.3 ± 8.3 vs. +8.7 ± 8.8 cm(3), p<0.01). Moreover, the change in the AVAT volume negatively correlated with the change in EPA (r=-0.58, p<0.01) and EPA/AA levels (r=-0.53, p<0.01). A similar negative correlation in these parameters was also observed for the EAT volume. Oral intake of purified EPA appears to be associated with reductions in EAT and AVAT volumes.

The effects of 3-month atorvastatin therapy on arterial inflammation, calcification, abdominal adipose tissue and circulating biomarkers

(18)F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT has the potential to track vascular inflammation and monitor therapeutic response. The purpose of this study was to determine the association between arterial inflammation, calcification and serological biomarkers in subjects with atherosclerosis, and to assess their therapeutic response to 12-week atorvastatin treatment. Forty-three statin-naïve subjects with atherosclerosis received atorvastatin (40 mg/day) for 12 weeks and underwent (18)F-FDG PET/CT, coronary calcification and abdominal adipose tissue volume measurements. A panel of serological biomarkers was analysed. Arterial inflammation was measured at seven arterial segments and normalized to venous FDG activity to produce target to background ratios (TBR). Thirty-four subjects without cardiovascular disease who repeated PET 1-4 years apart for routine health check-ups were retrospectively evaluated for comparison. The baseline mean TBR values in atherosclerotic patients were positively correlated with age (R = 0.36), body mass index (R = 0.54), abdominal visceral adipose tissue volume (R = 0.65), coronary calcification score (R = 0.40), levels of low-density lipoprotein cholesterol (R = 0.54), matrix metalloproteinase (MMP)-9 (R = 0.46) and fatty acid binding protein 4 (FABP4) (R = 0.67, all p < 0.05). The TBR as well as high-sensitivity C-reactive protein (hsCRP), E-selectin, MMP-9, monocyte chemotactic protein 1, FABP4 and follistatin values were reduced significantly after the 12-week atorvastatin treatment. The TBR reduction marginally correlated with changes in MMP-9 levels (R = 0.56, p = 0.05). The control group, whose median age was younger, by comparison had lower hsCRP and arterial TBR than the subjects with atherosclerosis (all p < 0.05), and moreover had a slight but insignificant increase in mean TBR at their 2.5±0.8 year follow-up. The medium dose of atorvastatin over a 12-week period resulted in a significant reduction of arterial inflammation as well as various circulating biomarkers.

Weight-loss diet alone or combined with resistance training induces different regional visceral fat changes in obese women

Quantification of abdominal fat and its regional distribution has become increasingly important in assessing the cardiovascular risk. To examine the effects of 16 weeks of a hypocaloric diet with a caloric restriction of 500 Kcal per day (WL) or the same dietary intervention plus resistance training (WL+RT) on regional variation of abdominal visceral (visceral adipose tissue (VAT)) and subcutaneous (subcutaneous adipose tissue (SAT)) fat loss. Second, to identify the single-image that best represents total magnetic resonance imaging measurements of total VAT and SAT volume before and after WL or WL+RT intervention. A total of 34 obese (body mass index: 30-40 kg m(-2)) women, aged 40-60 years, were randomized to three groups: a control group (C; n = 9), a diet group (WL; n = 12) and a diet plus resistance training group (WL+RT; n = 13) with the same caloric restriction as group WL and a 16-week supervised whole-body RT of two sessions per week. WL+RT programs lead to significant changes in the location of highest mean VAT area from L3-L4 to L2-L3 discal level from pre- to post- intervention, whereas after WL the greatest relative VAT losses were located at L5-S1. Similar decreases in the SAT areas at all discal levels were observed after WL and WL+RT. Different weight loss regimes may lead to different distribution of VAT. Sites located significantly above (cranial to) L4-L5 (that is, ∼ 5-6 cm above L4-L5 or at L2-L3 discal level) provided superior prediction of total abdominal VAT volume, whereas more caudal slices provide better prediction of subcutaneous fat, not only before but also after either WL or WL+RT.

Abdominal Visceral Adipose Tissue Volume Is Associated With Increased Risk of Erosive Esophagitis in Men and Women

Data on the association between erosive esophagitis and obesity are inconsistent because of variations in study populations and methods used to determine obesity. Participants in a prospective health-screening cohort underwent esophagogastroduodenoscopy and computed tomography. The association between erosive esophagitis and obesity (measured by body mass index [BMI], waist circumference, and abdominal visceral adipose tissue volume) was estimated with odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for confounding factors. We also analyzed the association between obesity and erosive esophagitis by sex. The prevalence of erosive esophagitis was 9.3% (495/5329). The OR for erosive esophagitis correlated with obesity measured by BMI, waist circumference, and abdominal visceral adipose tissue volume (P < .001 for each factor). The multivariate OR for erosive esophagitis was 1.97 (95% CI: 1.34-2.90) for a visceral adipose tissue volume of 500-999 cm(3), 2.27 (95% CI: 1.51-3.39) for 1000-1499 cm(3), and 2.94 (95% CI: 1.87-4.62) for ≥1500 cm(3), compared with participants who had visceral adipose tissue volumes less than 500 cm(3). When measures of obesity were analyzed simultaneously, abdominal visceral adipose tissue volume, but not BMI or waist circumference, was associated with erosive esophagitis. The 3 measures of obesity were significantly associated with erosive esophagitis in males, but only visceral adipose tissue volume was associated with erosive esophagitis in females (P = .002). In contrast to BMI or waist circumference, abdominal visceral adipose tissue volume is associated with an increased risk of erosive esophagitis in males and females.

Weight of Pericardial Fat on Coronaropathy

The regional distribution of adipose tissue (AT) is a major determinant of metabolic and cardiovascular diseases. The mass of fat in the visceral area associates independently of obesity with the development and progression of cardiovascular diseases in a series of clinical and epidemiological studies.1 This led to the concept of a pathophysiological link between abdominal obesity and metabolic syndrome. More recently, fat depots localized around the heart, highly variable among individuals, were proposed to contribute to the pathogenesis of coronaropathy independently of other visceral depots (ie, in the omental and mesenteric area).2,3 The study by Greif et al3a in this issue of Arteriosclerosis, Thrombosis, and Vascular Biology highlights the association between pericardial adipose tissue (PAT) and the number of atherosclerotic plaques evaluated concomitantly by Dual source CT scan. This measurement was qualitatively interpretable in 264 consecutive patients with a large range of age, a normal or moderately increased body mass index (BMI), and no a priori coronary disease. An estimated volume of pericardial fat more than 300 cm3 provided an incremental value for the presence of coronary atherosclerosis (odds ratio 4.1) independently of well known risk factors (hyperglycemia or diabetes, hypercholesterolemia, hypertension, and smoking). Ninety-five percent of patients with PAT volume >300 cm3 had one or more atherosclerotic plaques by ROC estimation. In univariate statistical analysis, PAT …

Approximation of total visceral adipose tissue with a single magnetic resonance image

Background:A single axial image measured between the 4th and 5th lumbar vertebrae (L4-L5) is most frequently chosen to approximate total abdominal visceral adipose tissue (VAT) volume, but growing evidence suggests that this measurement site is not ideal.Objective:The objective was to determine the single magnetic resonance (MR) image that best approximates the total VAT volume in a biracial sample of healthy subjects.Design:We used contiguous abdominal MR images to measure VAT area and summed them to determine total VAT volume. The sample included 820 healthy men and women (n= 692 whites, 128 blacks) aged 18–88 y.Results:A range of MR images had equally high correlations with total VAT in each race and sex group. The image 6 cm above L4-L5 (L4-L5 + 6) was within the best equivalent range for all race and sex groups. The L4-L5 + 6 image crossed the L3 vertebra in 85% of subjects and crossed the L2-L3 intervertebral space or the L2 vertebra for 15% of subjects. Linear regression models indicated that the L4-L5 + 6 image explained 97% of the variance in total abdominal VAT volume, and additional covariates did not increase the R2value significantly. The L4-L5 image explained 83% of the variance in VAT volume, and the covariates accounted for an additional 7% of the variance. Rank-order values for VAT can change if total VAT volume is approximated by a single image area. Whereas 25% of subjects changed rank by ≥10% with the L4-L5 image, only 3% changed rank to that degree with the L4-L5 + 6 image.Conclusions:A single MR image located approximately at the L3 vertebra can accurately estimate total VAT volume in blacks and whites of both sexes.

Aerobic fitness and visceral adipose tissue in children

To determine the relationship between aerobic fitness (peak VO2) and the volume of visceral adipose tissue (VAT) in children. Participants were 30 males (13.7+/-0.5 y) and 22 females (13.5+/-0.5 y). Peak VO2 was determined using a continuous, incremental treadmill protocol to exhaustion. Abdominal VAT volume was measured by magnetic resonance imaging using multiple slices from vertebral levels L1-L5. Subcutaneous body fat measure was calculated as the sum of seven skinfolds (sigma7SKF). Females had significantly (p < or = 0.05) more VAT than males (1035+/-717.3 vs 678.6+/-361.5 cm3); however, male peak VO2 was higher (215+/-34 vs 182+/-20 ml/kg(0.61)/min). VAT was significantly (p < or = 0.05) negatively correlated with peak VO2 in both males (r = - 0.43) and females (r = - 0.45). Subcutaneous body fatness was significantly correlated with VAT in both males (r = 0.74) and females (r = 0.72), and was the single strongest determinant of VAT. Aerobic fitness is significantly inversely related to VAT, but subcutaneous body fatness is the single strongest determinant of VAT in children aged 13-14 y.

Visceral fat loss evaluated by total body magnetic resonance imaging in obese women operated with laparascopic adjustable silicone gastric banding.

To investigate the changes of visceral fat, as compared with total and subcutaneous adipose tissue (AT) in obese patients operated with laparascopic adjustable silicone gastric banding (LAP-BAND). Six premenopausal morbid obese (body mass index range: 41.4-44.2 kg/m2) women, aged 38-42 y, operated with LAP-BAND, evaluated before, 8 weeks after, and 24 weeks after surgery. Fat distribution was analysed by total body multi-slices MRI. Total AT, gluteo-femoral subcutaneous AT, abdominal subcutaneous AT, and abdominal visceral AT volumes were measured. FM was calculated from MRI-determined total AT volume and AT density. A weight loss of 9.9+/-3.8 kg was observed in the first 8 weeks after LAP-BAND (0-8 weeks), and a further weight loss of 7.1+/-4.9 kg in the subsequent 16 weeks (8-24 weeks). Total AT showed a statistically significant reduction of 6.2+/-4.0 l in 0-8 weeks and a further significant reduction of 7.7+/-3.9 l in 8-24 weeks (P<0.01 from baseline). A similar trend was observed for both abdominal and gluteo-femoral subcutaneous AT. Visceral AT showed a statistically significant reduction of 1.0+/-0.9 l in the 0-8 weeks (P<0.05) and a further non-significant reduction of 0.6+/-0.7 l in 8-24 weeks (P<0.05 from baseline). In 0-8 weeks, the relative reduction of visceral AT was higher than the relative reduction of both total AT and gluteo-femoral subcutaneous AT. A highly significant correlation was observed between the reduction of total AT and the reduction of both abdominal and gluteo-femoral subcutaneous AT. By contrast, in 0-8 weeks, the reduction of total AT and the reduction of visceral AT were not correlated. In a subsequent analysis, both observations collected in the first 8 weeks after LAP-BAND and observations collected in the last 16 weeks are simultaneously considered, leading to a total of 12 time periods (two time periods for each individual patient). In order to identify factors associated with preferential visceral fat reduction, we calculated for each of the 12 time periods the difference between the percentage changes of visceral AT and the percentage changes of total AT. The relationship between this difference and several other variables were investigated by simple correlation analysis. The only variables found to be associated were the initial visceral AT volume, the absolute level of weight loss (kg) per week of observation, and the relative level of weight loss (%) per week of observation. In the phase of rapid weight loss following LAP-BAND, a preferential mobilization of visceral fat, as compared with total and subcutaneous AT, can occur. However, this preferential visceral fat reduction occurs only in those patients presenting higher levels of visceral fat deposition at baseline and higher levels of weight loss. International Journal of Obesity (2000)24, 60-69