Visceral Fat Obesity Research Articles

Adipose tissue macrophages: their role in adipose tissue remodeling

The adipose tissue secretes a large number of bioactive substances, adipocytokines, which may be involved in a variety of physiologic and pathologic processes. Unbalanced production of pro- and anti-inflammatory adipocytokines seen in visceral fat obesity contributes critically to the development of the metabolic syndrome. Evidence has accumulated indicating that obesity is associated with a state of chronic, low-grade inflammation, suggesting that inflammation may be a potential mechanism, whereby obesity leads to insulin resistance. Indeed, obese adipose tissue is characterized by adipocyte hypertrophy, followed by increased angiogenesis, immune cell infiltration, extracellular matrix overproduction, and thus, increased production of proinflammatory adipocytokines during the progression of chronic inflammation. The dynamic change found in the adipose tissue can be referred to as "adipose tissue remodeling," in which stromal cells change dramatically in number and cell type during the course of obesity. Among stromal cells, infiltration of macrophages in the adipose tissue precedes the development of insulin resistance in animal models, suggesting that they are crucial for obesity-related adipose tissue inflammation. We have demonstrated that a paracrine loop involving saturated fatty acids and TNF-alpha derived from adipocytes and macrophages, respectively, aggravates obesity-induced adipose tissue inflammation. Notably, saturated fatty acids, which are released from hypertrophied adipocytes via the macrophage-induced lipolysis, serve as a naturally occurring ligand for TLR4 complex, thereby activating macrophages. Understanding the molecular mechanism underlying adipose tissue remodeling may lead to the identification of novel, therapeutic strategies to prevent or treat obesity-induced adipose tissue inflammation.

Comparison of Metabolic Syndrome Patients in Terms of BMI and Subcutaneous and Visceral Fat Obesity

Comparison of Metabolic Syndrome Patients in Terms of BMI and Subcutaneous and Visceral Fat Obesity

Establishment of a concept of visceral fat syndrome and discovery of adiponectin

Although obesity is a major background of life style-related diseases such as diabetes mellitus, lipid disorder, hypertension and cardiovascular disease, the extent of whole body fat accumulation does not necessarily the determinant for the occurrence of these diseases. We developed the method for body fat analysis using CT scan and established the concept of visceral fat obesity, in other word metabolic syndrome in which intra-abdominal visceral fat accumulation has an important role in the development of diabetes, lipid disorder, hypertension and atherosclerosis. In order to clarify the mechanism that visceral fat accumulation causes metabolic and cardiovascular diseases, we have analyzed gene expression profile in subcutaneous adipose tissue and visceral adipose tissue. From the analysis, we found that adipose tissue, especially visceral adipose tissue expressed abundantly the genes encoding bioactive substances such as cytokines, growth factors and complements. In addition to known bioactive substances, we found a novel collagen-like protein which we named adiponectin. Adiponectin is present in plasma at a very high concentration and is inversely associated with visceral fat accumulation. Adiponectin has anti-diabetic, anti-hypertensive and anti-atherogenic properties and recent studies revealed that this protein has an anti-inflammatory and anti-oncogenic function. Therefore hypoadiponectinemia induced by visceral fat accumulation should become a strong risk factor for metabolic and cardiovascular diseases and also some kinds of cancers.In this review article, I would like to discuss the mechanism of life style-related diseases by focusing on the dysregulation of adiponectin related to obesity, especially visceral obesity.

Relationship between C-reactive protein and visceral fat obesity and their impacts on target organ damage

Relationship between C-reactive protein and visceral fat obesity and their impacts on target organ damage

Amelioration of abdominal obesity by low-molecular-weight polyphenol (Oligonol) from lychee

The effect of low-molecular-weight polyphenols extracted from lychee (Oligonol) on metabolic syndrome characterized by abdominal obesity was examined. We performed a clinical trial for Oligonol conducted by randomized double-blind, placebo-controlled study. Eighteen (male, 14; female, 4) adult volunteers with abdominal circumference over 85 cm were enrolled and divided into two groups, Oligonol and placebo groups. All subjects took two capsules of Oligonol (50 mg/capsule) or placebo twice a day for 10 weeks. Physical and haematological examinations as well as a CT scan of the abdomen were carried out, before (control) and 10 weeks after Oligonol intake. Clinical parameters of body weight, abdominal circumference and visceral fat volume were significantly decreased in the Oligonol group compared to the control. Insulin resistance was improved by Oligonol in conjunction with elevation of serum adiponectin. These results suggest that Oligonol ameliorates metabolic syndrome by reducing visceral fat obesity.

Sex difference in cardiometabolic risk profile and adiponectin expression in subjects with visceral fat obesity

This study investigates the sex difference of cardiometabolic risk profiles in subjects with visceral fat obesity (VFO) but normal waist circumference (WC). VFO, which is defined as visceral adipose tissue (VAT) area more than 100 cm(2) by computed tomography (CT), and cardiometabolic risk profiles were assessed in 437 subjects with normal WC (197 female subjects and 240 male subjects). The expression of adiponectin and its receptor in abdominal adipose tissue was measured in a subgroup of the subjects. Compared with the male subjects, female subjects had a larger abdominal subcutaneous adipose tissue (SAT) area (158+/-56 vs 116+/-38 cm(2), P<0.01), smaller VAT area (67+/-44 vs 78+/-33 cm(2); P<0.01), and lower prevalence of VFO (12.2 vs 24.2%, P<0.001). This finding was accompanied by upregulated expressions of adiponectin and its receptor in abdominal adipose tissue in female subjects. Without VFO, the risk profiles were not significantly different between male subjects and female subjects. Although risk factors were increased and intensified in both sexes in the presence of VFO, female subjects with VFO were associated with greater cardiometabolic risks than male subjects. A regression analysis indicates the ratio of VAT/SAT for female subjects, whereas VAT and age for male subjects were independently associated with clustering of multiple cardiometabolic risk factors. In conclusion, in subjects with normal WC, the prevalence of VFO is lower and the expression of adiponectin and its receptor is higher in female subjects compared with male subjects. Although VFO was associated with increased risk in both sexes, the risk profile in female subjects with VFO was more pronounced.

P-230 Gender Difference of Cardiometabolic Risk and Role of Adiponectin in Visceral Fat Obesity with Normal Waist Circumference

P-230 Gender Difference of Cardiometabolic Risk and Role of Adiponectin in Visceral Fat Obesity with Normal Waist Circumference

Getting Radical About Obesity

Visceral obesity has become the most frequent preventable condition accounting for diseases such as hypertension and diabetes, two of the major risk factors for coronary artery disease, stroke, and chronic renal failure.1–3 Despite the awareness aiming to reduce the prevalence of obesity, the number of obese patients continues to rise and now includes even developing countries, and increasingly children are affected.4,5 In fact, if this trend continues, 26 million children in Europe will be overweight or obese by the year 2010, rising by approximately 1.3 million per year.5,6 The annual health costs related to obesity have been estimated close to 100 billion USD in the United States,7,8 illustrating the enormous economic burden the disease obesity carries. See accompanying article in ATVB 2009;29:239–245. What are the mechanisms contributing to the high cardiovascular risk brought about by obesity? Obesity is a low-grade inflammatory condition9 and typically characterized by increase in visceral adipose tissue. Visceral fat is both a source and target of inflammatory cytokines and growth factors, which directly may affect preadipocyte differentiation via signaling cascades implicated in cell growth such as Ras-Raf-ERK-1/2.10 Adipose tissue also contains inflammatory cells, including cytokine-producing macrophages.9 In addition, adipocytes express a fully functional NADPH oxidase …

SCREENING OF RESISTANT TRIACYLGLYCEROLS TO THE PANCREATIC LIPASE AND THEIR POTENTIALITIES AS A DIGESTIVE RETARDANT

ABSTRACT A gradual retarding of lipid digestion and absorption might contribute to preventing the visceral fat accumulation and obesity in humans. The lipolysis rates of different triacylglycerols (TAGs) by pancreatic lipase in vitro were studied in order to find suitable components as a retardant for lipolysis. Several TAGs containing longer acyl chains than stearic acid or containing unsaturated fatty acids whose double bonds are located closely to the carboxyl group like petroserinic and γ‐linolenic acid showed significantly lower lipolysis rates as compared with triolein (OOO) control. Most of these resistant TAGs contributed to decelerating the lipolysis rate when replaced at 10% into the OOO control. Especially, 1‐behenoyl‐2,3‐dioleoyl‐rac‐glycerol (BOO) was comprehensively thought to be a suitable TAG as a digestive retardant among them. Each 10% replacement of edible oils by BOO gave 15% to 30% reduction of the lipolysis rate in vitro. Resistant TAGs that are able to melt or solubilize into liquid oil at body temperature have some potential as a digestive retardant for lipids.PRACTICAL APPLICATIONSVisceral fat accumulation and obesity in humans are thought to be correlated with the rate of lipid digestion and absorption. The entire rate of lipid absorption is controlled by their partial replacement with some digestive retardant. Resistant triacylglycerols may have some potential as a digestive retardant of lipids. Results of the present study propose a new fat system for foods with antiobesity effect.

1. Efficacy of Diet and Exercise Therapy for Diabetes Mellitus --visceral Fat Obesity and Intracellular Fat Obesity

2週間程度の食事・運動療法でもインスリン抵抗性は確実に改善する．これは肝臓と筋肉の細胞内脂肪量が減少するからである．肥満は脂肪組織の脂肪過剰のみでなく，肝臓と筋肉の細胞内肥満も含めた状態ととらえるべきである．生活習慣改善をさらに継続すると脂肪組織の脂肪量減少による効果が上乗せになる．僅かな減量をほめ，継続するように励ますこと，逆に僅かな増加を戒めることが生活指導上のポイントである．

Weight Loss and Blood Pressure Reduction in Obese Subjects in Response to Nutritional Guidance Using Information Communication Technology

The metabolic syndrome caused by visceral-fat obesity is a major risk factor for atherosclerosis. This study used a new information communication technology (ICT) to investigate body weight (BW) and blood pressure (BP) changes in response to nutritional guidance. Obese subjects with hypertension, hyperlipidemia, or impaired glucose tolerance received guidance with the ICT method (n = 13) or face-to-face according to conventional methods (n = 39). The effects of the methods were compared. After 12 weeks, significant weight loss and BP reduction were observed in the ICT group. Also, significant higher improvements were observed in total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and HbA1c in the ICT-group compared with those groups using the conventional method. The effectiveness of the ICT method in reducing BW, BP, total and LDL cholesterol, and HbA1c was demonstrated.

Evaluation of visceral adipose in abdominal obesity and its clinical application

To compare the values of measurements of obesity, including body mass index(BMI), waist circumference (WC), waist-to-hip ratio (WHR), bioelectrical impedance analyzer(BIA) (fat mass and FAT%), ultrasonography (US) (subcutaneous fat distance and intraabdominal fat distance), and computed tomography (CT) in predicting the quantification of visceral adipose in abdominal obesity, and to evaluate the best cut-off point, sensitivity and specificity of these methods. 4,301 inpatients with hypertension, 2,155 males and 2,146 females, aged (56.4 +/- 13.8) (11 - 89), all with at least 1 risk factor of cardiovascular diseases, underwent simple body fat measurement. 3458 received BIA, 2,553 received B mode ultrasonography, 1039 underwent CT examination, and 659 received all kinds of examination. Abdominal visceral adipose area (VA) measured with CT >or= 100 cm(2) was the diagnostic criteria of visceral fat obesity (VFO). Receiver operating characteristic (ROC) curve was used to analyze the body fat indexes to determine the best cut-off point. (1) It was accurate for WC, fat mass, BMI, intraabdominal fat distance, FAT%, and WHR were all accurate in diagnosis of VFO with the values of area under ROC of 0.730 - 0.867. WC was the most effective measurement. (2) The best cut-off points of these methods in predicting abdominal visceral obesity in males and females were as follows: WC: 89.5 cm and 85.5 cm for WC. 25 kg/m(2) and 26 kg/m(2) for BMI, 0.97 and 0.95 for WHR, 29% and 38% for fat composition, 18.6 kg, and 20.4 kg for fat mass, and 38.5 mm and 34.7 mm for intraabdominal fat distance. WC, fat mass, BMI, intraabdominal fat distance, simple fat parameters, and WHR all can predict visceral adipose in abdominal obesity, in which WC is the best. For a given WC, the type of obesity can be determined by BIA and US.

Low-Dose Physiological Growth Hormone in Patients With HIV and Abdominal Fat Accumulation

Antiretroviral therapy can be associated with visceral adiposity and metabolic complications, increasing cardiovascular risk, and reduced growth hormone (GH) secretion may be a contributing factor. To investigate the effects of low-dose physiological GH administration on body composition, glucose, and cardiovascular parameters in patients with human immunodeficiency virus (HIV) having abdominal fat accumulation and relative GH deficiency. A randomized, double-blind, placebo-controlled trial of 56 patients with HIV, abdominal fat accumulation, and reduced GH secretion (peak GH <7.5 ng/mL) conducted at a US academic medical center between November 2003 and October 2007. Patients were randomly assigned to receive either subcutaneous GH or matching placebo titrated to the upper quartile of normal insulinlike growth factor 1 (IGF-1) range for 18 months. Starting dose was 2 microg/kg/d and increased to maximum dose of 6 microg/kg/d (average dose, 0.33 mg/d). Change in body composition assessed by computed tomographic scan and dual-energy x-ray absorptiometry. Secondary outcomes included glucose, IGF-1, blood pressure (BP), and lipids. Treatment effect was the difference in the change between GH and placebo groups, using all available data. Fifty-five patients (26 with GH and 29 with placebo) were included in the safety analyses and 52 patients (25 with GH and 27 with placebo) were included in the efficacy analyses. Visceral adipose tissue area (treatment effect [last-value-carried-forward analysis {n = 56}, -19 cm(2); 95% confidence interval {CI}, -37 to -0.3 cm(2)], -19 cm(2); 95% CI, -38 to -0.5 cm(2); P = .049); trunk fat (-0.8 kg; 95% CI, -1.5 to -0.04 kg; P = .04); diastolic BP (-7 mm Hg; 95% CI, -11 to -2 mm Hg; P = .006); and triglycerides (-7 mg/dL, P = .002) improved but 2-hour glucose levels on glucose tolerance testing increased in the GH group vs the placebo group (treatment effect, 22 mg/dL; 95% CI, 6-37 mg/dL; P = .009). The IGF-1 levels increased (treatment effect, 129 ng/mL; 95% CI, 95-164 ng/mL; P < .001). Adverse events were not increased for GH vs placebo (23%; 95% CI, 9%-44% vs 28%; 95% CI, 13%-47%; P = .70). In HIV-associated abdominal fat accumulation and relative GH deficiency, low-dose GH received for 18 months resulted in significantly reduced visceral fat and truncal obesity, triglycerides, and diastolic BP, but 2-hour glucose levels on glucose tolerance testing were increased. clinicaltrials.gov Identifier: NCT00100698.

Insulin Resistance in Patients with Stroke is Related to Visceral Fat Obesity and Adipocytokines

Insulin resistance is associated with hyperglycemia and dyslipidemia and promotes atherosclerosis. Although insulin resistance is associated with adipocytokines, little is known about the association in patients with stroke without diabetes mellitus. The aim of the current study was to examine the relationship among insulin resistance, visceral fat area, and adipocytokines in patients with stroke. This study design was cross-sectional in a university hospital. We studied 60 patients with stroke and no history of diabetes mellitus who had hyperglycemia or hypertriglyceridemia or reduced fasting plasma high-density lipoprotein cholesterol. We measured insulin resistance, the plasma level of tumor necrosis factor (TNF)-alpha, adiponectin, and the visceral fat area. Insulin resistance was defined by the homeostasis model assessment and the level of insulin at 120 minutes after consuming oral glucose. We classified two groups (insulin sensitive or insulin resistant). In all, 21 of 60 patients (35.0%) had insulin resistance and 35 (58.3%) had hyperinsulinemia. Compared with insulin-sensitive patients with stroke (n = 18), insulin-resistant patients with stroke (n = 21) had significantly wider visceral fat areas and a high level of plasma TNF-alpha. The plasma level of adiponectin in insulin-resistant patients with stroke was similar to that in insulin-sensitive patients. Insulin-resistant patients with stroke in this study had a large amount of visceral fat and increased levels of TNF-alpha. We recommend that obese patients with stroke should be examined for insulin resistance to reduce the risk of the development of atherosclerosis.

Relationship of different types of abdominal obesity to risk of metabolic syndrome

To explore the relationship of different types of abdominal obesity to risk of metabolic syndrome (MS). Visceral fat area (VA) and substantial fat area (SA) were assessed by CT in 846 patients, 470 males and 376 females, aged 55 +/- 12, who suffered from at least one cardiometabolic risk factor and divided into 4 groups according to their VA and waist circumference (WC): non-obesity, masked visceral fat obesity (VFO), pseudo-VFO, and VFO groups. Blood pressure, fasting blood glucose, fasting serum insulin, and lipid profile were also measured. The MS risks of different types of abdominal obesity were compared. The prevalence rate of masked VFO of males was 10.9% (51/470), significantly higher than that of female (4.8%, 18/376). The prevalence rate of MS of the male patients with masked VFO was 43.1%, significantly higher than that of those in non-obesity group (25.0%), and lower than those of the males in the pseudo-VFO group (78.7%) and in the VFO group (88.6%), whereas the MS prevalence rate of the males in the pseudo-VFO group was significantly higher than those in the non-obesity and masked VFO groups. On the other hand, the MS prevalence rate of the female patients with masked VFO was 33.3%, not significantly different from that of the female patients in the non-obesity group (31.2%), but significantly lower than those of the pseudo-VFO and VFO groups (78.7% and 90.9% respectively). The MS prevalence rate of the female pseudo-VFO patients was also significantly higher than those in the non-obesity and masked VFO groups. Logistic regression analysis showed that WC and VA were independent risk factors for MS [OR (95% CI) = 1.13 (1.10-1.17), 1.01 (1.01-1.02), respectively, P < 0.01). Different types of abdominal obesity have important impacts on the risk of metabolic syndrome. Masked VFO, even though with normal WC, and pseudo-VFO have considerably higher cardiometabolic risks.

150 Visceral Fat Obesity and Abnormal Glucose Tolerance Correlate with Dysplastic Aberrant Crypt Foci in Colorectal Tumor Free Male

150 Visceral Fat Obesity and Abnormal Glucose Tolerance Correlate with Dysplastic Aberrant Crypt Foci in Colorectal Tumor Free Male

Anthropometric and Clinical Findings in Obese Japanese: The Saku Control Obesity Program (SCOP)

BACKGROUND: Japan has entered the epidemic of obesity. To clarify the contributing factors to the development of metabolic syndrome triggered by visceral fat obesity and to investigate the effectiveness of a weight-loss program, we launched a new intervention program for obese people. METHODS: Japanese subjects with high body mass index (BMI > 28.3 kg/m²) were selected for a weight-loss program from those who had undergone a medical checkup at the Saku Central Hospital. The baseline anthropometric and clinical findings of the participants were analyzed.RESULTS: At baseline, 235 subjects (116 men and 119 women) participated in this program. The mean weight, waist circumference, and visceral fat area were 86.4 ± 11.8 kg, 101.5 ± 8.7 cm, and 159.0 ± 54.1 cm² in men and 75.2 ± 9.5 kg, 103.7 ± 8.3 cm, and 129.8 ± 47.0 cm² in women, respectively. Using the Japanese diagnostic criteria, the prevalence of metabolic syndrome was 62.9% in men and 51.3% in women. Leptin, c-peptide, and insulin levels tended to increase with increasing numbers of metabolic risk factors in men. In women, c-peptide and free fatty acid levels tended to increase with increasing numbers of these factors, but adiponectin decreased dose-dependently with increasing numbers of factors. CONCLUSIONS: More than half the subjects were founded to meet the criteria for metabolic syndrome. Immediate intervention to lose weight and to improve other risk factors of metabolic syndrome is necessary in such seriously obese people.

Dietary regulation of nuclear receptors in obesity-related metabolic syndrome.

In Western culture, excess visceral fat accumulation or obesity has reached epidemic proportions, resulting in metabolic syndrome. However, more than 10 years of research has shown that adipocytes also function as endocrine cells that release various bioactive substances, so called "adipocytokines or adipokines", that play a major role in the regulation of food intake, insulin sensitivity, energy metabolism, and the vascular microenvironment. Adiponectin, an adipocytokine, is considered to improve insulin sensitivity. Recently, monocyte chemoattractant protein (MCP)-1 has been reported to be a novel adipocytokine involved in the development of obesity-associated insulin resistance and atherosclerosis. Nuclear receptors, especially peroxisome proliferator-activated receptor-alpha (PPAR alpha) and PPAR gamma are ligand-activated transcription factors that regulate the metabolism of glucose and lipids. PPAR gamma is strongly expressed in adipocytes and plays a significant role in the transcriptional activation of adipocytokines including adiponectin. PPAR alpha, another PPAR isoform, is involved in the control of lipid metabolism in the liver and skeletal muscle. PPAR alpha activation causes lipid clearance via beta-oxidation enhancement. We showed that various dietary terpenoids and other natural ingredients regulate the transcription of PPAR target genes, induces the expression and secretion of adiponectin, and inhibits those of MCP-1 in adipocytes and beta-oxidation in liver. These findings indicate that dietary factor acts as an agonist of PPARs and is a valuable medical and food component for the gradual improvement of metabolic syndrome.

Obstructive Sleep Apnea Syndrome Is Associated With Some Components of Metabolic Syndrome

Obesity, hypertension, dyslipidemia, and hyperglycemia are prevalent in obstructive sleep apnea syndrome (OSAS). Metabolic syndrome, however, is defined by visceral fat obesity plus at least two of these factors. However, whether OSAS contributes to the development of metabolic syndrome has not been defined. We investigated whether the components of metabolic syndrome were associated with OSAS in nonobese patients. We investigated the occurrence of hypertension, dyslipidemia, and hyperglycemia in 42 men with OSAS and 52 men without OSAS matched for age, body mass index (BMI), and visceral fat accumulation. Although serum levels of triglycerides, high-density lipoprotein cholesterol, and diastolic BP did not differ significantly between the two groups, fasting blood glucose (111 +/- 6 mg/dL vs 93 +/- 3 mg/dL) [mean +/- SE] and the percentage of hypertensive patients (45% vs 15%) were significantly higher in the group with OSAS. In addition, a significantly higher percentage of patients with OSAS (19% vs 4%) had at least two of the following: hypertension, hyperglycemia, and dyslipidemia. Logistic regression analysis showed that the apnea-hypopnea index value was the predictor of number of metabolic syndrome parameters such as hypertension, hyperglycemia, and dyslipidemia, while BMI and lowest arterial oxygen saturation during sleep did not. Independent of visceral fat obesity, OSAS was associated with hypertension, dyslipidemia, and hyperglycemia. It is possible that OSAS may predispose even nonobese patients to the development of metabolic syndrome.

Effects of telmisartan on fat distribution in individuals with the metabolic syndrome

Visceral fat obesity plays an essential role in the clustering of atherosclerotic multiple risk factors in the metabolic syndrome. Telmisartan, an angiotensin II type 1 receptor blocker, has partial agonistic properties for peroxisome proliferator-activated receptor gamma, which is a key regulator of adipocyte differentiation and function. This study aimed to clarify the impact of telmisartan on fat distribution and insulin sensitivity in the metabolic syndrome. In this open-label, prospective, randomized study, patients with the metabolic syndrome (waist circumference: men >or= 85 cm, women >or= 90 cm) were treated either with amlodipine (n = 26) or with telmisartan (n = 27) for 24 weeks, and fat distribution and insulin sensitivity were determined. Systolic and diastolic blood pressure were decreased in both groups to a comparable level. However, insulin and glucose levels during an oral 75 g glucose loading were decreased only in the telmisartan group. The visceral fat area, determined by abdominal computed tomography scan, was reduced in the telmisartan group after 24 weeks' treatment, but the subcutaneous fat area did not change in either group. The results imply that telmisartan could treat both the hemodynamic and metabolic aberrations seen in patients with the metabolic syndrome, improving insulin resistance and glucose intolerance at least partly through visceral fat remodeling.