Visceral Adipose Tissue and Markers of the Insulin Resistance Syndrome in Obese Black and White Teenagers

Objective: To determine the relationships between visceral and general adiposity, cardiovascular fitness, and markers of the insulin resistance syndrome in obese black and white teenagers. Research Methods and Procedures: Cross‐sectional survey of 81 obese 13‐ to 16‐year‐old youths. Visceral adipose tissue was measured with magnetic resonance imaging, and percentage body fat was measured with dual‐energy X‐ray absorptiometry. Cardiovascular fitness was assessed with a submaximal treadmill test. Fasting blood samples were analyzed for lipids/lipoproteins and insulin. Resting blood pressure was obtained using an automated cuff. Results: Visceral adipose tissue was significantly correlated with unfavorable levels of: triacylglycerol (r = 0.27, p < 0.05), total cholesterol (r = 0.27, p < 0.05), high‐density lipoprotein cholesterol (r = ?0.26, p < 0.05), the ratio of total cholesterol/high‐density lipoprotein cholesterol (r = 0.42, p < 0.01), low‐density lipoprotein cholesterol (r = 0.27, p < 0.05), apolipoprotein B (r = 0.38, p < 0.01), and systolic blood pressure (r = 0.30, p < 0.01). Multiple regression analyses revealed that visceral adipose tissue was more powerful than percentage body fat for explaining variance in lipoproteins (e.g., for the ratio of total cholesterol/high‐density lipoprotein cholesterol, r² = 0.13, p < 0.01, and for systolic blood pressure, r² = 0.07, p < 0.05). Ethnicity was the most powerful of the demographic predictors for blood lipids (r² = 0.15 for triacylglycerol with lower levels in blacks; r² = 0.10 for high‐density lipoprotein cholesterol with higher levels in blacks; r² = 0.06 for the ratio of total cholesterol/high‐density lipoprotein cholesterol with lower levels in blacks). Cardiovascular fitness was not retained as a significant predictor of markers of the insulin resistance syndrome. Discussion: Some of the deleterious relationships between visceral adiposity and markers for the insulin resistance syndrome seen in adults were already present in these obese young people.     

Methods of Estimation of Visceral Fat: Advantages of Ultrasonography

Objective: To compare methods for the assessment of visceral fat with computed tomography (CT) and establish cutoffs to define visceral obesity based on such alternative methods. Research Methods and Procedures: One hundred women (50.4 ± 7.7 years; BMI 39.2 ± 5.4 kg/m²) underwent anthropometric evaluation, bioelectrical impedance, DXA, abdominal ultrasonography (US), and CT scan. Results: Waist circumference, waist‐to‐hip ratio (WHR), and US‐determined visceral fat values showed the best correlation coefficients with visceral fat determined by CT (r = 0.55, 0.54, and 0.71, respectively; p < 0.01). Fat mass determined by DXA was inversely correlated with visceral‐to‐subcutaneous‐fat ratio (r = ?0.47, p < 0.01). Bioimpedance‐determined fat mass and skinfolds were correlated with only subcutaneous abdominal fat quantified by CT. Linear regression indicated US visceral‐fat distance and WHR as the main predictors of CT‐determined visceral fat (adjusted r² = 0.51, p < 0.01). A waist measurement of 107 cm (82.7% specificity, 60.6% sensitivity) and WHR of 0.97 (78.8% specificity, 63.8% sensitivity) were chosen as discriminator values corresponding with visceral obesity diagnosed by CT. A value of 6.90 cm for visceral fat US‐determined diagnosed visceral obesity with a specificity of 82.8%, a sensitivity of 69.2%, and a diagnostic concordance of 74% with CT. Discussion: US seemed to be the best alternative method for the assessment of intra‐abdominal fat in obese women. Its diagnostic value could be optimized by an anthropometric measurement. Prospective studies are needed to establish CT and US cutoffs for defining visceral‐fat levels related to elevated cardiovascular risk.     

Subdivision of the Subcutaneous Adipose Tissue Compartment and Lipid‐Lipoprotein Levels in Women

Objective: The aim of this study was to compare the relative importance of computed tomography‐measured abdominal fat compartment areas, including adipose tissue located posterior to the subcutaneous Fascia, in predicting plasma lipid‐lipoprotein alterations. Research Methods and Procedures: Areas of visceral as well as subcutaneous deep and superficial abdominal adipose tissue were measured by computed tomography in a sample of 66 healthy women, ages 37 to 60 years, for whom a detailed lipid‐lipoprotein profile was available. Results: Strong significant associations were observed between visceral adipose tissue area and most variables of the lipid‐lipoprotein profile (r = ?0.25, p < 0.05 to 0.62, p < 0.0001). Measures of hepatic lipoprotein synthesis such as very‐low‐density lipoprotein‐triglyceride and cholesterol content as well as total and very‐low‐density lipoprotein‐apolipoprotein B levels were also strongly associated with visceral adipose tissue area (r = 0.57, 0.57, 0.61, and 0.62, respectively, p < 0.0001). Significant associations were found between these variables and the deep subcutaneous adipose tissue area or DXA‐measured total body fat mass. However, the correlation coefficients were of lower magnitude compared to those with visceral adipose tissue area. Multivariate regression analyses demonstrated that visceral adipose tissue area was the strongest predictor of lipid‐lipoprotein profile variables (7% to 48% explained variance, 0.02 ≥ p ≤ 0.0001). Discussion: Although previous studies have generated controversial data as to which abdominal adipose tissue compartment was more closely associated with insulin resistance, our results suggest that visceral adipose tissue area is a stronger correlate of other obesity‐related outcomes such as lipid‐lipoprotein alterations.     

Ultrasound evaluation of visceral fat and metabolic risk factors during early pregnancy

Objective: The objective was to study the relationships between ultrasound estimated visceral fat and metabolic risk factors during early pregnancy. Research Methods and Procedures: Thirty consecutive healthy pregnant women at 11 to 14 weeks of gestation were studied. Maximum subcutaneous fat thickness (SFT) and visceral fat thickness (VFT) were successfully measured by ultrasound. Fasting plasma glucose, insulin, triglycerides, total cholesterol, high‐density lipoprotein cholesterol (HDL‐C), and blood pressure were measured. Insulin resistance was calculated by using the homeostasis model assessment (HOMA). Results: VFT significantly correlated with diastolic blood pressure (r = 0.37, p = 0.04), glycemia (r = 0.37, p = 0.04), insulinemia (r = 0.59, p = 0.001) insulin sensitivity (HOMA; r = 0.59, p = 0.001), triglycerides (r = 0.58, p = 0.03), HDL‐C (r = ?0.39, p = 0.03), and total cholesterol/HDL‐C ratio (p = 0.002), whereas SFT was significantly correlated with only diastolic blood pressure (p = 0.03). VFT better significantly correlated with the metabolic risk factors than pre‐gestational BMI [r = 0.39, p = 0.03 for insulinemia, r = 0.42, p = 0.02 for insulin sensitivity (HOMA), and r = 0.49, p = 0.01 for triglycerides and not significant for the rest]. Discussion: Visceral fat thickness can be easily measured by ultrasound at early pregnancy and correlates better than BMI with metabolic risk factors.     

Both Subcutaneous and Visceral Adipose Tissue Correlate Highly with Insulin Resistance in African Americans

Objective: The contribution of visceral adipose tissue (VAT) to insulin resistance is well‐established; however, the role of subcutaneous abdominal adipose tissue (SAT) in insulin resistance remains controversial. Sex may determine which of these two components of abdominal obesity is more strongly related to insulin resistance and its consequences. The aim of this study was to determine whether both VAT and SAT contribute to insulin resistance in African Americans and to examine the effects of sex on this relationship. Research Methods and Procedures: This was a cross‐sectional study of 78 nondiabetic African‐American volunteers (44 men, 35 women; age 33.8 ± 7.3 years; BMI 30.9 ± 7.4 kg/m²). VAT and SAT volumes were measured using serial computerized tomography slices from the dome of the diaphragm to the iliac crest. The insulin sensitivity index (S_I) was determined from the minimal model using data obtained from the frequently sampled intravenous glucose tolerance test. Results: In men, both VAT and SAT were negatively correlated with S_I (r for both correlations = ?0.57; p < 0.01). In women, the correlation coefficient between VAT and S_I was ?0.50 (p < 0.01) and between SAT and S_I was ?0.67 (p < 0.01). In women, the correlation coefficient for S_I with SAT was significantly greater than the correlation coefficient with VAT (p = 0.02). Discussion: Both SAT and VAT are strongly correlated with insulin resistance in African Americans. For African‐American women, SAT may have a greater effect than VAT on insulin resistance.     

Echocardiographic Abnormalities in Normotensive Obese Patients: Relationship with Visceral Fat

Objective: To evaluate the relationship of echocardiographic characteristics and visceral adipose tissue (VAT) distribution in normotensive obese patients. Research Methods and Procedures: Echocardiographic parameters were assessed in 28 normotensive obese patients [7 men, 21 women, mean age, 43.2 years; mean body mass index (BMI), 37.2 kg/m²; 10 with impaired glucose tolerance (IGT); 6 with type 2 diabetes] and 18 sex‐ and age‐matched healthy, normal‐weight controls (4 men, 14 women; mean age, 45.8 years; mean BMI, 22.4 kg/m²) by an M‐mode, color‐doppler videofluoroscope. VAT in the obese patients was assessed by computed tomography (at L4 level). Results: The obese patients had a significantly larger internal diastolic left ventricular (LV) diameter (p < 0.05), a thicker end‐diastolic septum (p < 0.001) and posterior wall (p < 0.001), a greater indexed (g/m^2.7) LV mass (p < 0.001), a higher atrial diastolic filling wave velocity (p < 0.001), a lower ratio between early and atrial diastolic filling wave velocities (p < 0.01), and a prolonged isovolumic relaxation time (p < 0.05). End‐diastolic septum and posterior wall thickness and the LV mass were significantly greater in patients with a VAT area >130 cm² than with <130 cm². In the multivariate regression analysis, only VAT (p < 0.0001), waist‐to‐hip ratio (p < 0.001), and sex (p < 0.001) were associated with the most important echocardiographic alterations. Discussion: The morphological and functional echocardiographic alterations usually found in normotensive obese patients closely correlate with the amount of intra‐abdominal fat deposition, even in the presence of diabetes or IGT.     

Preventing Overestimation of Pixels in Computed Tomography Assessment of Visceral Fat

Objective: Computed tomography (CT) is a common research procedure for measuring abdominal fat distribution, but little is written about the software used to analyze images. Our objective was to compare in‐house and commercially available software for quantitative measurement of abdominal fat distribution. In the process, we encountered some unexpected problems. Research Methods and Procedures: A total of 123 volunteers had single‐slice abdominal CT images taken that were used to evaluate various aspects of the commercial image analysis program. Results: The agreement between the commercial and in‐house programs was excellent (r = 0.996, p < 0.00, 001) for both total and intraabdominal fat, and we were able to reduce between‐observer variability in measured fat areas through the use of statistical handling of region of interest information. We also noted that intracolonic contents sometimes had the same Hounsfield units as adipose tissue. We analyzed single‐slice CT images from 50 volunteers to determine the potential impact of this effect on visceral fat area; the overestimate of visceral fat area was 19 ± 22% (maximum, 112% overestimate). The commercial program could prevent this error, whereas our in‐house program could not. Discussion: We concluded that a readily available commercial image analysis program compares well with a previously validated in‐house program and that it offers some advantages with respect to preventing overestimation of pixels as visceral fat.     

Two-dimensional predictive equation to classify visceral obesity in clinical practice

Objective: Visceral obesity assessment is not easy, and although computed tomography (CT) is an accurate tool, this technique is expensive and sometimes not suitable in clinical practice. We developed a new two‐dimensional elliptical anthropometric equation to classify visceral obesity and evaluated the validity and the reliability of the new equation compared with CT. Research Methods and Procedures: We collected anthropometric and CT data from overweight/obese subjects (n = 61, BMI = 32.4 ± 3.7 kg/m²). A validation group of 32 subjects was also selected. An equation for the assessment of visceral obesity was developed using multiple regression analysis. Once validated, the equation was compared with previous models. Tests for accuracy included mean differences, analysis of diagnostic, R², Snedecor's F‐test, and Bland‐Altman plot. Results: Multiple regression analysis revealed that the sagittal and coronal diameters and the triceps skinfold were significant contributors to the model. The final equation was: visceral area (VA)/subcutaneous area (SA)_predicted = 0.868 + 0.064 × sagittal diameter ?0.036 × coronal diameter ?0.022 × triceps skinfold. Patients with visceral‐subcutaneous area ratio (VA/SA) >0.42 were classified as having visceral obesity. The predictive equation was valid, showing a significant association with VA/SA assessed by CT (VA/SA_CT; r = 0.68; p < 0.0001). Paired Student's t test showed no significant differences with VA/SA_CT (p = 0.541). The reliability was high [F(24/60) = 2.12; p = 0.01]. Discussion: The new two‐dimensional and elliptical predictive equation is valid to assess visceral obesity and is more precise than previous models.     

A Single mri Slice Does Not Accurately Predict Visceral and Subcutaneous Adipose Tissue Changes During Weight Loss

Earlier cross‐sectional studies found that a single magnetic resonance imaging (MRI) slice predicts total visceral and subcutaneous adipose tissue (VAT and SAT) volumes well. We sought to investigate the accuracy of trunk single slice imaging in estimating changes of total VAT and SAT volume in 123 overweight and obese subjects who were enrolled in a 24‐week CB‐1R inverse agonist clinical trial (weight change, ?7.7 ± 5.3 kg; SAT change, ?5.4 ± 4.9 l, VAT change, ?0.8 ± 1.0 l). VAT and SAT volumes at baseline and 24 weeks were derived from whole‐body MRI images. The VAT area 5–10 cm above L₄—L₅ (A_+5–10) (R² = 0.59–0.70, P < 0.001) best predicted changes in VAT volume but the strength of these correlations was significantly lower than those at baseline (R² = 0.85–0.90, P < 0.001). Furthermore, the L₄—L₅ slice poorly predicted VAT volume changes (R² = 0.24–0.29, P < 0.001). Studies will require 44–69% more subjects if (A_+5–10) is used and 243–320% more subjects if the L₄—L₅ slice is used for equivalent power of multislice total volume measurements of VAT changes. Similarly, single slice imaging predicts SAT loss less well than cross‐sectional SAT (R² = 0.31–0.49 vs. R² = 0.52–0.68, P < 0.05). Results were the same when examined in men and women separately. A single MRI slice 5–10 cm above L₄—L₅ is more powerful than the traditionally used L₄—L₅ slice in detecting VAT changes, but in general single slice imaging poorly predicts VAT and SAT changes during weight loss. For certain study designs, multislice imaging may be more cost‐effective than single slice imaging in detecting changes for VAT and SAT.     

Epicardial Fat from Echocardiography: A New Method for Visceral Adipose Tissue Prediction

Objective: To validate transthoracic echocardiography as an easy and reliable imaging method for visceral adipose tissue (VAT) prediction. VAT is recognized as an important indicator of high cardiovascular and metabolic risk. Several methods are applied to estimate VAT, with different results. Research Methods and Procedures: We selected 60 healthy subjects (29 women, 31 men, 49.5 ± 16.2 years) with a wide range of body mass indexes. Each subject underwent transthoracic echocardiogram and magnetic resonance imaging (MRI) to measure epicardial fat thickness on the right ventricle. Measurements of epicardial adipose tissue thickness were obtained from the same echocardiographic and MRI views and points. MRI was also used to measure VAT cross‐sectional areas at the level of L4 to L5. Anthropometric indexes were also measured. Results: Subjects with predominant visceral fat accumulation showed higher epicardial adipose tissue thickness than subjects with predominant peripheral fat distribution: 9.97 ± 2.88 vs. 4.34 ± 1.98 (p = 0.005) and 7.19 ± 2.74 vs. 3.43 ± 1.64 (p = 0.004) in men and women, respectively. Simple linear regression analysis showed an excellent correlation between epicardial adipose tissue and waist circumference (r = 0.895, p = 0.01) and MRI abdominal VAT (r = 0.864, p = 0.01). Multiple regression analysis showed that epicardial adipose tissue thickness (r² = 0.442, p = 0.02) was the strongest independent variable correlated to MRI VAT. Bland test confirmed the good agreement between the two methods. Discussion: Epicardial adipose tissue showed a strong correlation with anthropometric and imaging measurements of VAT. Hence, transthoracic echocardiography could be an easy and reliable imaging method for VAT prediction.     

Decrease in Serum Adiponectin Level Due to Obesity and Visceral Fat Accumulation in Children

Objective: To determine whether serum adiponectin is decreased in obesity and is restored toward normal level after treatment in children. Research Methods and Procedures: Subjects were 53 Japanese obese children, 33 boys and 20 girls (6 to 14 years old), and 30 age‐matched nonobese controls for measuring adiponectin (16 boys and 14 girls). Blood was drawn after an overnight fast, and the obese children were subjected to anthropometric measurements including waist and hip circumferences and skinfold thicknesses. Paired samples were obtained from 21 obese children who underwent psychoeducational therapy. Visceral adipose tissue area was measured by computed tomography. Adiponectin was assayed by an enzyme‐linked immunosorbent assay. Results: The serum levels of alanine aminotransferase, uric acid, triglyceride, total cholesterol, low‐density lipoprotein‐cholesterol, total cholesterol/high‐density lipoprotein‐cholesterol, apo B, apo B/apo A₁, and insulin in obese children were higher than the reference values. Serum adiponectin level was lower in the obese children than in the controls (6.4 ± 0.6 vs. 10.2 ± 0.8 mg/L, means ± SEM, p < 0.001). In 21 obese children whose percent overweight declined during therapy, the adiponectin level increased (p = 0.002). The adiponectin level was correlated inversely with visceral adipose tissue area in obese children (r = ?0.531, p < 0.001). The inverse correlations of adiponectin with alanine aminotransferase, uric acid, and insulin were significant after being adjusted for percentage overweight, percentage body fat, or sex. Discussion: Serum adiponectin level is decreased in obese children depending on the accumulation of visceral fat and is restored toward normal level by slimming.     

Acute modulation of adipose tissue lipolysis by intravenous estrogens

Objective: The aim of this study was to determine whether intravenous (IV) conjugated estrogens (EST) acutely enhance the suppression of whole‐body or regional subcutaneous adipose tissue (SAT) lipolysis by insulin in postmenopausal women. Research Methods and Procedures: We assessed whole‐body lipolysis by [²H₅]glycerol rate of appearance (Glyc_RA) and abdominal and femoral SAT lipolysis (interstitial glycerol; Glyc_IS) by subcutaneous microdialysis. Postmenopausal women (n = 12) were studied on two occasions, with IV EST or saline control (CON), under basal conditions and during a 3‐stage (4, 8, and 40 mU/m²/min) hyperinsulinemic, euglycemic clamp. Ethanol outflow/inflow ratio and recovery of [¹³C]glycerol during microdialysis were used to assess blood flow changes and interstitial glycerol concentrations, respectively. Results: Compared with CON, EST did not affect systemic basal or insulin‐mediated suppression of lipolysis (Glyc_RA) or SAT nutritive blood flow. Basal Glyc_IS in SAT was reduced on the EST day. However, insulin‐mediated suppression of lipolysis in SAT was not significantly influenced by EST. Discussion: These findings suggest that estrogens acutely reduce basal lipolysis in SAT through an unknown mechanism but do not alter whole‐body or SAT suppression of lipolysis by insulin.     

Expression of Clock Genes in Human Subcutaneous and Visceral Adipose Tissues

Disrupted circadian rhythms are associated with obesity and metabolic alterations, but little is known about the participation of peripheral circadian clock machinery in these processes. The aim of the present study was to analyze RNA expression of clock genes in subcutaneous (SAT) and visceral (VAT) adipose tissues of male and female subjects in AM (morning) and PM (afternoon) periods, and its interactions with body mass index (BMI). Ninety-one subjects (41?±?11 yrs of age) presenting a wide range of BMI (21.4 to 48.6?kg/m²) were included. SAT and VAT biopsies were obtained from patients undergoing abdominal surgeries. Clock genes expressions were evaluated by qRT-PCR. The only clock gene that showed higher expression (p?<?.0001) in SAT in comparison to VAT was PER1 of female (372%) and male (326%) subjects. Different patterns of expression between the AM and PM periods were observed, in particular REV-ERBα, which was reduced (p?<?.05) at the PM period in SAT and VAT of both women and men (women: ～53% lower; men: ～78% lower), whereas CLOCK expression was not altered. Relationships between clock genes were different in SAT vs. VAT. BMI was negatively correlated with SATPER1 (r?=??.549; p?=?.001) and SATPER2 (r?=??.613; p?=?.0001) and positively with VATCLOCK (r?=?.541; p?=?.001) and VATBMAL1 (r?=?.468; p?=?.007) only in women. These data suggest that the circadian clock machinery of adipose tissue depots differs between female and male subjects, with a sex-specific effect observed for some genes. BMI correlated with clock genes, but at this moment it is not possible to establish the cause-effect relationship. (Author correspondence: mzanquetta@gmail.com)     

Relationship of Anterior and Posterior Subcutaneous Abdominal Fat to Insulin Sensitivity in Nondiabetic Men

Recent studies from our group reveal that adipose tissue (AT) in the subcutaneous abdominal region is the most important determinant of peripheral and hepatic insulin sensitivity. Because of different anatomic and physiologic characteristics of anterior and posterior subcutaneous abdominal AT, we investigated the relationship of the masses of each compartment, as determined by magnetic resonance imaging, to insulin sensitivity (using euglycemic hyperinsulinemic glucose clamp technique), and other anthropometric variables. Thirty-four healthy men with varying ranges of obesity were recruited for the study. The mass of posterior subcutaneous abdominal AT was ～1.6 times more than that of the anterior compartment, and these masses accounted for 12.9% and 8.2% of the total body fat mass, respectively. All anthropometric variables, including body mass index (BMI), waist-to-hip circumference ratio (WHR), skinfold thicknesses, and intraperitoneal AT mass were more significantly related to the posterior than the anterior subcutaneous abdominal AT mass. Compared to the anterior compartment mass, the posterior compartment mass displayed stronger relationship with insulin-mediated glucose disposal (Rd) (r=-0.44, p=0.009, and r=-0.76, p=0.0001, respectively) as well as with residual hepatic glucose output during the 40 mU.^?2.min-¹ insulin infusion (r=0.39, p=0.02, and r=0.53, p=0.001, respectively). After adjusting for total body fat, the Rd values showed a significant partial correlation with the posterior subcutaneous abdominal AT mass (r=-0.52, p=0.002). To conclude, posterior subcutaneous abdominal AT mass is a more important determinant of peripheral and hepatic insulin sensitivity than the anterior subcutaneous abdominal AT.     

Ethnic Differences in Visceral Adipose Tissue and Type 2 Diabetes: Filipino,African‐American,and White Women

Objective: To compare ethnic differences in visceral adipose tissue (VAT), assessed by computed tomography, and type 2 diabetes risk among 55‐ to 80‐year‐old Filipino, African‐American, and white women without known cardiovascular disease. Research Methods and Procedures: Subjects were participants in the Rancho Bernardo Study (n = 196), the Filipino Women's Health Study (n = 181), and the Health Assessment Study of African‐American Women (n = 193). Glucose and anthropometric measurements were assessed between 1995 and 2002. Results: African‐American women had significantly higher age‐adjusted BMI (29.7 kg/m²) and waist girth (88.1 cm) compared with Filipino (BMI, 25.5 kg/m²; waist girth, 81.9 cm) or white (BMI: 26.0 kg/m²; waist girth: 80.7 cm) women. However, VAT was significantly higher among Filipino (69.1 cm³) compared with white (62.3 cm³; p = 0.037) or African‐American (57.5 cm³, p < 0.001) women. VAT correlated better with BMI (r = 0.69) and waist (r = 0.77) in whites, compared with Filipino (r = 0.42; r = 0.59) or African‐American (r = 0.50; r = 0.56) women. Age‐adjusted type 2 diabetes prevalence was significantly higher in Filipinas (32.1%) than in white (5.8%) or African‐American (12.1%) women. Filipinas had higher type 2 diabetes risk compared with African Americans [adjusted odds ratio, 2.30; 95% confidence interval (CI), 1.09 to 4.86] or whites (adjusted odds ratio, 7.51; 95% CI, 2.51 to 22.5) after adjusting for age, VAT, exercise, education, and alcohol intake. Discussion: VAT was highest among Filipinas despite similar BMI and waist circumference as whites. BMI and waist circumference were weaker estimates of VAT in Filipino and African‐American women than in whites. Type 2 diabetes prevalence was highest among Filipino women at every level of VAT, but VAT did not explain their elevated type 2 diabetes risk.     

Impacts of Visceral Adipose Tissue and Subcutaneous Adipose Tissue on Metabolic Risk Factors in Middle‐aged Japanese

Regional fat distribution rather than overall fat volume has been considered to be important to understanding the link between obesity and metabolic disorders. We aimed to evaluate the independent associations of visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) with metabolic risk factors in apparently healthy middle‐aged Japanese. Participants were 1,119 men and 854 women aged 38–60 years who were not taking medications for diabetes, hypertension, or dyslipidemia. VAT and SAT were measured by use of computed tomography (CT) scanning. VAT and SAT were significantly and positively correlated with each other in men (r = 0.531, P < 0.001) and women (r = 0.589, P < 0.001). In multiple regression analyses, either measure of abdominal adiposity (VAT or SAT) was positively associated with blood pressure, fasting plasma glucose, and log triglyceride (P < 0.001) and inversely with high‐density lipoprotein (HDL)‐cholesterol (P < 0.001). When VAT and SAT were simultaneously included in the model, the association of VAT with triglycerides was maintained (P < 0.001) but that of SAT was lost. The same was true for HDL‐cholesterol in women. For fasting plasma glucose, the association with VAT was strong (P < 0.001) and the borderline association with SAT was maintained (P = 0.060 in men and P = 0.020 in women). Both VAT and SAT were independently associated with blood pressure (P < 0.001). Further adjustment for anthropometric indices resulted in the independent association only with VAT for all risk factors. In conclusion, impacts of VAT and SAT differed among risk factors. VAT showed dominant impacts on triglyceride concentrations in both genders and on HDL‐cholesterol in women, while SAT also had an independent association with blood pressure.     

Comparison of methods for assessing abdominal adipose tissue from magnetic resonance images

Objective: To compare the inter‐rater and intra‐rater reliability and analysis time of two methods for quantifying visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) volumes from magnetic resonance (MR) images. Research Methods and Procedures: Ten subjects (BMI, 27.0 ± 2.1 kg/m²; 56 years of age ± 4 years) underwent MR imaging of the abdomen. Ten transverse T1‐weighted images were selected from each scan and analyzed using two software packages that differ in principle. The first method, ANALYZE version 5.0, represents the manual threshold method, and the second, HIPPO version 1.3, is based on the fuzzy clustering approach. Inter‐rater reliability for each method was assessed by comparing the intra‐class correlation coefficients (ICCs) for VAT and SAT results from two evaluators, and intra‐rater reliability for each method was assessed by comparing ICCs for VAT and SAT analyses performed 1 week apart by the same evaluator. The total time for analysis also was compared between methods. Results: The inter‐rater reliability for VAT was greater with HIPPO than with ANALYZE (ICC = 0.996 vs. 0.828), whereas inter‐rater reliability for SAT did not differ between methods (ICC = 0.975 and 0.987). The intra‐rater reliability was equally high with HIPPO and ANALYZE for both VAT (ICC = 0.998 vs. 0.992) and SAT (ICC = 0.996 vs. 0.992). HIPPO required less than one‐half as much analysis time as ANALYZE (15.9 ± 4.4 vs. 36.5 ± 8.2 minutes, p < 0.0001). Discussion: HIPPO software appears advantageous for the quantification of VAT from multislice MR images because inter‐rater results are more reliable, and it is more time‐efficient than less automated methods.     

Depressive Mood and Abdominal Fat Distribution in Overweight Premenopausal Women

Objective: There is increasing evidence that depressive mood is associated with central obesity, but little is known about the association between depression and abdominal fat distribution. This study investigated this relationship in premenopausal women. Research Methods and Procedures: We recruited 101 overweight premenopausal women who had no eating disorders as defined using the DSM IV criteria. Depressive mood was assessed using Zung's Self‐Rating Depression Scale (SDS). Areas of visceral (VAT) and subcutaneous (SAT) adipose tissue at the level of vertebral body L₄–L₅ were measured using computed tomography. Associations of VAT, SAT, and the ratio of VAT to SAT with natural logarithmic transformation [(ln)]SDS were evaluated using linear regression. Anthropometric indices and physical fitness were also measured. Information on socioeconomic status, education level, and alcohol and smoking habits was obtained using self‐administered questionnaires. A hospital nutritionist assessed nutritional status. All of these factors were adjusted for as possible confounding factors in the analyses. Results: The (ln)SDS score showed a positive association with the area of VAT, even after adjusting for the confounders mentioned above (p < 0.01). BMI, waist circumference, maximal oxygen uptake, and age were also associated with the area of VAT (all p < 0.05). In contrast, the (ln)SDS score was not associated with SAT (p > 0.10). Discussion: We showed that depressive mood is associated with VAT, not with SAT, in overweight premenopausal women. These findings may explain some of the association between depression and coronary heart disease. More studies are needed to elucidate the causal relationship.