Association of abdominal fat depots and insulin resistance in patients with coronary artery disease and metabolic syndrome

Visceral Adipose Tissue Attacks Beyond the Liver: Esophagogastric Junction as a New Target

Aim Abdominal fat, especially visceral adipose tissue (VAT), is proven to relate with metabolic syndrome and coronary artery disease. Using FDG to estimate VAT and subcutaneous adipose tissue (SAT) glucose metabolism had been recently reported (J Am Coll Cardiol Img 2010;3:843-851). The analysis of SAT and VAT volume by applying imaging segmentation on attenuation low dose CT images from PET/CT and correlated with the mean standard uptake values (SUV) of liver, fat and muscle were studied. The formula was derived from BMI and waist circumference to estimate the volume of abdominal fat. Materials and Methods In a 4-year period, 100 negative FDG PET/CT findings subjects who had blood sugar, serum cholesterol and triglycerol tests within two weeks were recruited for the study. After reconstruction, the CT image was display in Philips Syntegrar software for CT segmentation by setting the binary Hounsfield unit (HU) between -30 and -190 for fat tissue. The SAT and VAT volume measurement was applied between L4 and L5 spine level for 2 cm thickness. Intra- and inter-observer measurements of the SAT and VAT from CT were tested. The means of FDG SUVs of the liver, spleen, psoas muscle, VAT and SAT were measured from PET imaging. The correlation between total abdominal fat, SAT, and VAT volume, mean FDG SUVs of above mentioned tissue, body mass index (BMI), waist circumference, and serum biochemical analysis were tested. Results The correlation between intra- and inter-observer measurements of the abdominal fat were all excellent (r = 0.99). The correlation between total abdominal fat (TAF), VAT, and SAT to BMI were (r = 0.79, 0.69, and 0.62), and those to the waist circumference were (r = 0.78, 0.76, and 0.57), respectively. The correlation between all the fat measurements to the blood biochemical tests and SUVs of above mentioned tissue were all low (r < 0.5). To estimate the abdominal fat from BMI, we could take the advantage of the formula y = 6.538x + 426.53. We could also estimate the abdominal fat from waist circumference through the formula y = 6.029x + 452.21. Conclusions The abdominal adipose tissue measurement was feasible and reproducible by using the attenuation CT imaging of the FDG PET/CT. The results of the measurements correlated well with the BMI and waist circumference but not with the blood biochemical tests and mean SUVs of liver, fat and muscle. The abdominal fat formula obtained from the BMI and waist circumference, it could provide for clinical to estimate the volume of fat.

Abdominal fat distribution and insulin resistance in Indian women with polycystic ovarian syndrome

Objective: To explore abdominal fat mass distribution and contents among obese children via magnetic resonance imaging (MRI), and analyze the correlations of abdominal adipose tissue with anthropometric and metabolic parameters. Methods: Cross-sectional study. There were 60 obese children admitted to the Children's Health Care Department and Endocrinology Department at Children's Hospital of Nanjing Medical University from July 2016 to December 2018. Children's gender, age, height, weight, body composition, waist circumference and blood pressure were recorded. The levels of fasting blood glucose, lipids, insulin were measured, and liver ultrasound was performed, and the body mass index Z score (BMI-Z), waist-to-height ratio (WHtR) and homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. In addition, contents of subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT) and total abdominal adipose tissue (TAAT) were calculated according to feedback of abdominal MRI scan images. The associations between the contents of abdominal adipose tissue, physical examination status and metabolic disorders among obese children were analyzed through correlation analysis and regression analysis. Receiver operating characteristic (ROC) curve was used to compare the accuracy of fat mass in different parts of the abdomen in predicting their metabolic disorders. Results: A total of 60 children were enrolled in the study, included 44 boys and 16 girls, with age of (9.2±1.4) years. The contents of SAT, VAT and TAAT among the 60 children were positively associated with BMI-Z (r=0.60, 0.46, 0.59), body fat percentage (r=0.64, 0.67, 0.68) and waist-to-height ratio (r=0.60, 0.57, 0.61) (all P<0.01). Meanwhile, contents of SAT and TAAT were also positively correlated with systolic blood pressure (r=0.47, 0.49), triglyceride (r=0.33, 0.35) and HOMA-IR (r=0.33, 0.28)(all P<0.05). In order to adjust the confounding effects among various variables, regression analysis was applied and the result showed that the body fat percentage (β=0.59, 0.66, 0.65) and waist-to-height ratio (β=0.53, 0.63, 0.59) were most related to abdominal fat contents (all P<0.01), including SAT, VAT and TAAT among obese children. According to ROC, SAT had outstanding evaluation performances for the diagnosis of insulin resistance and metabolic syndrome, while VAT had excellent evaluation performances for non-alcoholic fatty liver disease (area under curve=0.68, 0.69, 0.69, 95%CI 0.54-0.82, 0.55-0.84, 0.53-0.85, P=0.017, 0.014, 0.019). Conclusions: As one of the best indexes, body fat percentage and WHtR can be used to predict the contents of SAT, VAT and TAAT among obese children. With the increase of abdominal SAT or VAT, the risks for insulin resistance, metabolic syndrome and non-alcoholic fatty liver disease would increase. Assessment of abdominal fat and metabolic risks in obese children should combine BMI-Z with waist circumference and body composition analysis.

BackgroundApelin, as an adipokine, plays an important role in the pathogenesis of insulin resistance and type 2 diabetes. This study aimed to determine whether the quality and quantity of dietary carbohydrates were associated with apelin gene expression in subcutaneous and visceral adipose tissues.MethodsIn this cross-sectional study, 102 adults who underwent minor abdominal surgery were selected. Approximately 100 mg of subcutaneous and visceral adipose tissues were collected during the surgery to measure apelin gene expression. Anthropometric measurment, blood samples, and dietary intakes were collected before surgery. The dietary carbohydrate intake, glycemic index (GI), and glycemic load (GL) were determined.ResultsThe average apelin concentration was 269.6 ± 98.5(pg/mL), and 16.3% of participants were insulin resistant. There was a correlation between insulin (p-value = 0.043), Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)(p-value = 0.045) and apelin gene expression in visceral adipose tissue. There was a positive association of apelin gene expression with dietary GI and GL after adjustment for age, sex, and waist circumference in visceral and subcutaneous adipose tissues(p < 0.05). Apelin gene expression in visceral(p = 0.002) and subcutaneous(p = 0.003) adipose tissues was directly associated with foods with a higher GI. There was no association between total carbohydrate intake and apelin gene expression in both visceral and subcutaneous adipose tissues.ConclusionsDietary GI and GL, not total carbohydrate intake, were positively associated with apelin gene expression in both visceral and subcutaneous adipose tissues. Future studies are warranted to illustrate the chronic and acute effect of carbohydrate quality on apelin homeostasis.

Apolipoprotein C-III (apoC-III) is a marker of triglyceride (TG)-rich lipoproteins, which are often increased in metabolic syndrome (MS). The T-455C polymorphism in the insulin-responsive element of the APOC3 gene influences TG and apoC-III levels. To evaluate the contribution of apoC-III levels and T-455C polymorphisms in the coronary artery disease (CAD) risk of MS patients, we studied 873 patients, 549 with CAD and 251 with normal coronary arteries. Patients were classified also as having or not having MS (MS, n = 270; MS-free, n = 603). Lipids, insulin, apolipoprotein levels, and APOC3 T-455C genotypes were evaluated. ApoC-III levels were significantly increased in MS patients, and the probability of having MS was correlated with increasing quartiles of apoC-III levels. MS patients with CAD had significantly higher apoC-III levels than did CAD-free MS patients. The carriership for the -455C variant multiplied the probability of CAD in MS in an allele-specific way and was associated with increased apoC-III and TG levels. Obesity was less frequent in MS carriers of the -455C allele than in MS noncarriers (21.6% vs. 34.8%, P < 0.05). In conclusion, apoC-III-rich lipoprotein metabolism and the APOC3 polymorphism have relevant impacts on the CAD risk of MS patents.

Visceral adipose tissue (VAT) imaged by computed tomography (CT) or magnetic resonance imaging (MRI) is associated with the metabolic syndrome features, being morphologically and functionally different from subcutaneous adipose tissue (SAT). Insulin effect is lower and catecholamine effect higher in visceral adipose tissue, with its metabolites and its secretions draining through portal system, partially at least, to the liver. Thus, visceral cells transfer and release fatty acids more extensively, have increased glucocorticoid and reduced thiazolidinedione responses, produce more angiotensinogen, interleukin-6 and plasminogen activator inhibitor-1, and secrete less leptin and adiponectin than SAT. Furthermore, there are regional differences in the intrinsic characteristics of the preadipocytes, with those of SAT presenting greater differentiation and fat cell gene expression but less apoptosis than that of VAT. All features contribute to the morbidity associated with increased VAT. To evaluate the relationship between VAT and components of the metabolic syndrome, 55 non-diabetic women, 11 lean (VAT < 68 cm 2) and 44 obese were studied. The obese with VAT within the normal range (VAT < or = 68 cm 2) had higher BMI, WHR, BP and resistance to FFA suppression during oGTT in comparison to the lean controls. The obese with VAT > 68 cm 2 compared to those with VAT < or = 68 cm 2 had similar body mass index (BMI) but significantly higher in vivo homeostasis model assessment for insulin resistance (HOMA IR ) results and triglycerides. By pooling all data, correlation analysis indicated that VAT contributes more to insulin resistance (HOMA IR ) than SAT does, but not when insulin-suppressed plasma free fatty acids during oral glucose tolerance test as an index of insulin resistance are taken into consideration.

FABP4 plasma levels are increased in familial combined hyperlipidemia

Correlation of adipose tissue with liver histology in Asian Indian patients with nonalcoholic fatty liver disease (NAFLD)

The aim of the present study was to examine whether the association of waist girth to visceral adipose tissue (AT) accumulation was altered by weight loss in abdominally obese men. We studied 45 dyslipidemic abdominally obese men (45.4 +/- 6.2 years of age; body mass index [BMI], 31.3 +/- 3.0 kg/m(2); waist circumference, 103.4 +/- 7.6 cm; total cholesterol, <6.72 mM; triglycerides, > or =1.7 mM but < or =5.65 mM; high density lipoprotein cholesterol, < or =1.2 mM). Each of them followed nutritional recommendations combined with a prescription of gemfibrozil (1200 mg/d) or a placebo for 1 year. After 6 months, a training exercise program was added at a frequency of four sessions of 60 minutes per week at 50% of maximal oxygen uptake. In response to the 1-year intervention program, men showed significant reductions in body weight, BMI, waist circumference, and in the partial volume of visceral and abdominal subcutaneous AT measured from two abdominal computed tomography scans performed at lumbar vertebra (L)2 to L3 and L4 to L5 levels. No change in waist-to-hip ratio was observed. Changes in visceral AT were strongly correlated with changes in body weight, BMI, and waist circumference (0.83 < r < 0.85; p < 0.001). However, a weak association was noted between waist-to-hip ratio and changes in visceral AT (r = 0.40; p < 0.05). There was no change in slopes or in intercepts before and after treatment in the relationships between volume or area of abdominal AT and anthropometric markers. Despite a greater level of the partial volume of subcutaneous AT than of the partial volume of visceral AT at baseline (p < 0.001), the greater relative reduction in the visceral AT volume in comparison with the subcutaneous AT volume suggested a preferential mobilization of visceral AT with weight loss in these abdominally obese men. The close relationship between changes in the partial volume of visceral AT and changes in cross-sectional areas of visceral AT measured at L2 to L3 (r = 0.94; p < 0.001) or L4 to L5 (r = 0.88; p < 0.001) suggests that a single computed tomography scan performed at L2 to L3 or L4 to L5 could predict changes in the partial volume of visceral AT secondary to weight loss.

Effect of Central Obesity on Prostate Specific Antigen Measured by Computerized Tomography: Related Markers and Prostate Volume

PurposeAdipose tissue dysfunction is at the center of metabolic dysfunctions associated with obesity. Through studies in isolated adipocytes and mouse models, ATP-binding cassette transporter A1 (ABCA1) expression in the adipose tissue has been shown to regulate high-density lipoprotein (HDL) cholesterol levels in the circulation and insulin sensitivity at both adipose tissue and whole-body levels. We aimed to explore the possible link between ABCA1 expression in the adipose tissue and metabolic derangements associated with obesity in humans.Patients and methodsThis exploratory study among individuals who were lean (body mass index [BMI]: 22.3±0.34 kg/m2, n=28) and obese (BMI: 44.48±5.3 kg/m2, n=34) compared the expression of ABCA1, adiponectin and GLUT4 (SLC2A4) in visceral and subcutaneous adipose tissue using quantitative real-time PCR and immunohistochemistry. Homeostatic model assessment for insulin resistance (HOMA-IR) and adipose tissue insulin resistance (adipo-IR) were used as insulin resistance markers.ResultsVisceral adipose tissue from individuals who were obese had significantly lower ABCA1 (P=0.04 for mRNA and protein) and adiponectin (P=0.001 for mRNA) expression compared to that from lean individuals. Subcutaneous adipose tissue did not show any significant difference in the expression. When individuals were divided into insulin-sensitive (IS) and insulin-resistant (IR) groups based on HOMA-IR, IR individuals had lower ABCA1 (P=0.0001 for mRNA and P=0.009 for protein) expression compared to IS individuals in visceral adipose tissue, but not in subcutaneous adipose tissue. The difference was significant after adjusting for age, gender and BMI. ABCA1 mRNA expression in visceral adipose tissue correlated negatively with both HOMA-IR (r=−0.44, P=0.0003) and adipo-IR (r=−0.35, P=0.005) after adjusting for age, gender and BMI. ABCA1 expression in either visceral or subcutaneous adipose tissue did not have any significant correlation with HDL cholesterol levels or mean adipocyte area.ConclusionObesity and insulin resistance are associated with lower expression of ABCA1 in visceral adipose tissue in humans.

Background Waist circumference (WC) is the most convenient anthropometric measure of obesity. Recently, abdominal fat distribution (AFD) has been identified as a more important risk factor for coronary artery disease (CAD) than the absolute amount of adipose tissue. However, studies examining the impact of body composition indicators (BCIs) on CAD severity are lacking. The computed tomography (CT)-derived SYNTAX score (CT-SXscore) is a feasible method for grading CAD severity based on coronary CT angiography (CTA) findings. Purpose This study was aimed to evaluate the association between BCI and CAD severity using the CT-SXscore. Methods We enrolled consecutive patients with suspected CAD who underwent CTA using a 320-row multidetector CT scanner between October 2014 and March 2020. Plain abdominal CT was also performed at the umbilical level to measure the visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) areas. The total adipose tissue (TAT) area was calculated as the sum of VAT and SAT. To assess the AFD, the VAT/SAT (V/S) ratios were also calculated as the VAT area divided by the SAT area in each case. WC was measured by tracing the body contour at the umbilical level in CT images. The severity of coronary artery stenosis was assessed using CTA. Significant stenosis was defined as a stenosis diameter of ≥50%. The CT-SXscore was calculated in patients with more than one significant stenoses. Each stenotic lesion was evaluated to calculate the CT-SXscore in the same manner as the invasive coronary angiography assessment. We assessed the effects of BCI [i.e., WC, body mass index (BMI), each adipose tissue area, and V/S ratios] on the CT-SXscores. Results 308 eligible patients (mean age, 70.9 ± 10.6 years; 69.5% males) were evaluated. The median values of WC, BMI, TAT, SAT, VAT, and V/S ratio were 84.8 cm, 23.6 kg/m2, 198.2 cm2, 111.8 cm2, 81.0 cm2, and 0.67, respectively. Although WC showed a significant correlation with BMI, TAT, SAT, and VAT area, no correlation was observed between WC and V/S ratio (Figure1). The CT-SXscore showed no association with WC, BMI, and TAT area; however, it exhibited a weak negative correlation with the SAT area and a weak positive correlation with the VAT area. Additionally, a strong correlation was observed between the CT-SXscore and V/S ratio. In the multivariate regression analysis, WC, BMI, TAT, SAT, and VAT were no longer associated with the CT-SXscore after adjusting for traditional coronary risk factors, whereas the V/S ratio remained as the only independent predictor of CAD severity based on the CT-SXscore (Figure2). Conclusions WC was strongly correlated with other BCIs, except for the V/S ratio; however, it could not be identified as a predictive factor of CAD severity. Among the BCIs, only the V/S ratio was an independent predictor of CAD severity, indicating that the AFD revealed by the V/S ratio may be a more important risk factor for progression of CAD than other BCIs.Figure1Figure2

Objective To investigate the association of abdominal fat distribution with glycolipid metabolism and diabetic complications in patients with T2DM. Methods Totally 357 inpatients with T2DM were collected from the Endocrinology Department of our hospital. All patients received quantitative computed tomography to measure the visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), and were divided into three groups depending on the tertile of VAT value: T1 group (VAT<162.0 cm2), T2 group (162.0≤VAT<221.1 cm2), T3 group (VAT≥221.1 cm2). The incidences of diabetic kidney disease, diabetic retinopathy, diabetic peripheral neuropathy, peripheral atherosclerosis, and cardia-cerebrovascular disease were examined in all patients. Results HbA1C level in T1 group was higher than that in T3 group(P<0.05). High density lipoprotein-cholesterol (HDL-C) and estimated glomerular filtration rate (eGFR) in T1 group were higher compared with those in T2 and T3 groups (P<0.05). Male proportion, age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), 24h urinary albumin, diabetic kidney disease and peripheral atherosclerosis in T2 and T3 groups were higher than those in T1 group (P<0.05). Fasting C- peptide (FCP) and modified homeostasis model assessment for insulin resistance (HOMA-IR) in T3 group were higher than those in T1 and T2 group (P<0.01). VAT and SAT were positively correlated with BMI, FCP, and HOMA-IR (p<0.01). VAT was positively correlated with age, SBP, DBP, TG, 24h urinary albumin, diabetic kidney disease, peripheral atherosclerosis, and cardia-cerebrovascular disease (P<0.05), while inversely correlated with HbA1C, HDL-C, and eGFR (P<0.05). SAT was positively correlated with total cholesterol and low density lipoprotein-cholesterol (P<0.01), while negatively correlated with peripheral atherosclerosis (P<0.01). Multivariate logistic regression analysis showed that VAT was still a risk factor for diabetic kidney disease after adjusted by age, BMI, SBP and fasting plasma glucose(P=0.013). Conclusion VAT and SAT are associated with blood lipids and insulin resistance, while VAT seems to be a risk factor for diabetic kidney disease. Key words: Abdominal fat area; Diabetes mellitus, type 2; Diabetic complications; Quantitative computed tomography

Aim MRI-quantification of the visceral and subcutaneous adipose tissue (AT) and investigation of its interconnections with anthropometric parameters of obesity, carbohydrate metabolism and condition of abdominal aorta in patients with chronic coronary artery disease (CAD). Methods The study included 55 patients (mean age 61.2±7.2 y.o.) with chronic CAD. All patients underwent MRI of the abdominal AT and abdominal aorta segment on a 1.5 T MRI in standard modes. Calculation of the area and volume of abdominal subcutaneous (SAT) and visceral adipose tissue (VAT) was conducted at L4-L5 level; the total volumes of abdominal SAT and VAT were calculated. Parameters of lipid and carbohydrate metabolism as well adipokines' profile were measured in blood serum. Results To eliminate gender bias the data in the total group was corrected for the sex, height and body weight. In the course of the multiple linear regression analysis, we detected the independent determinants, which described 95% of the total VAT volume variability and were represented by waist circumference and serum levels of HDL cholesterol and adiponectin. The model was characterized by the significance level p&amp;lt;0,ehab724.116501, the residues of the model were normal. The evaluation of the coefficients in the model was as following: 1,39 for waist circumference, −0.26 for HDL cholesterol and −0,19 for adiponectin. We detected direct correlation between the aorta diameter and total SAT volume (rs=0.30), which was independent from sex; and reverse correlations between the aorta diameter and HbA1c level (rs=−0.40) and postprandial glycemia (rs=−0.40). Patients with dilated aorta when compared to the patients with normal aorta diameter did not differ in the AT accumulation, but demonstrated decreased levels of HbA1c and postprandial glycaemia, which was dependent upon the lower numbers of patients with diabetes mellitus type 2. Conclusion We have identified the independent determinants of the total volume of the abdominal visceral AT increase, which appeared to be increment of the waist circumference and decrease of the serum adiponectin and HDL cholesterol. Results of the study indicate the presence of the interconnection between the processes of the abdominal aorta remodeling, accumulation of subcutaneous adipose tissue and carbohydrate metabolism impairments. Funding Acknowledgement Type of funding sources: None. MRI of the abdominal tissueMRI of the abdominal aorta