Obesity is characterized by abnormal and excessive adipose tissue accumulated in the body. Compared with peripheral obesity (the accumulation of subcutaneous adipose tissue), abdominal obesity (the accumulation of visceral adipose tissue) is associated with increased risk of the metabolic syndrome, such as diabetes, hypertension, atherosclerosis, and dyslipidemia. Adipose tissue is a highly heterogeneous endocrine organ. Adipose tissue depots differ significantly in anatomy, cell biology, glucose and lipid metabolism as well as in endocrine regulation. Visceral adipose tissue has a stronger metabolic activity and secrets a larger amount of free fat acids, adipocytokines, hormones and inflammatory factors, which flux into the liver directly via the hepatic portal vein. These characteristics indicate that visceral adiposity may lead to the metabolic syndrome and thus visceral adipose tissue might be the clinical target for the prevention and treatment of obesity.
Adipose Tissue ; pathology ; Humans ; Intra-Abdominal Fat ; pathology ; Lipid Metabolism ; Metabolic Syndrome ; physiopathology ; Obesity ; physiopathology ; Obesity, Abdominal ; physiopathology ; Subcutaneous Fat ; pathology

Visceral fat has been reported to be associated with nonalcoholic fatty liver disease (NAFLD) and the metabolic syndrome (MetS). We assessed the prevalence of both NAFLD and the MetS, measured visceral fat thickness VFT), and estimated the physical activity indexes of 224 relatively healthy hospital workers. We also investigated the associations between both VFT and physical activity index and each of NAFLD and the MetS. The MetS was diagnosed according to the guidelines outlined by the Adult Treatment Panel III, and NAFLD was diagnosed by ultrasonography. Subjects with hepatitis B and C infections and those reporting moderate alcohol consumption were excluded from the study. The prevalence of the MetS was 11.6% and that of NAFLD was 41.5%. Many subjects with the MetS had NAFLD (73.1%), and some subjects with NAFLD (20.4%) also had several components of the MetS (p=0.001). VFT was significantly increased by both the addition of components of the MetS and the severity of NAFLD (p<0.001). In addition, VFT was independently associated with NAFLD (odds ratio [OR], 1.10; 95% confidence interval [CI], 1.02-1.19) in subjects with more than 2 components of the MetS. In contrast, habitual physical activity was reversely associated with NAFLD (OR, 0.29; 95% CI, 0.10-0.87). In conclusion, an increased visceral fat content and reduced physical activity could be not only biological markers but also therapeutic targets in the treatment of NAFLD and the MetS.
Adult ; Alcohol Drinking ; Blood Pressure ; Comorbidity ; Fatty Liver/*physiopathology ; Female ; Humans ; Hyperinsulinism/complications ; *Intra-Abdominal Fat ; Male ; Metabolic Syndrome X/*physiopathology ; Middle Aged ; Multivariate Analysis ; Odds Ratio

OBJECTIVECentral obesity is considered to be a central component of metabolic syndrome. Waist circumference (WC) has been widely used as a simple indicator of central obesity. This study is aimed to evaluate the sensitivity of WC cut-off values for predicting metabolic risk factors in middle-aged Chinese.

METHODSThe study involved 923 subjects aged 40-65 years. The metabolic risk factors were defined according to the Chinese Joint Committee for Developing Chinese Guidelines on Prevention and Treatment of Dyslipidemia in Adults. WC cut-off 85-90 cm and ⋝90 cm were used as cut-off values of central pre-obesity and central obesity in males, respectively, while WC 80-85 cm and ⋝85 cm were used as cut-off values of central pre-obesity and central obesity in females.

RESULTSFirst, WC values corresponding to body mass index (BMI) 24 kg/m2 and visceral fat area (VFA) 80 cm2 were 88.55 cm and 88.51 cm in males, and 81.46 cm and 82.51 cm in females respectively. Second, receiver operating characteristic curves showed that the optimal WC cut-off of value was 88.75 cm in males, higher than that in females (81.75 cm). Third, the subjects with higher WC values were more likely to have accumulating metabolic risk factors. The prevalence of metabolic risk factors increased linearly and significantly in relation to WC levels.

CONCLUSIONWC cut-off values of central pre-/central obesity are optimal to predict multiple metabolic risk factors.

Aged ; China ; epidemiology ; Cross-Sectional Studies ; Female ; Humans ; Intra-Abdominal Fat ; physiopathology ; Male ; Metabolic Syndrome ; diagnosis ; epidemiology ; physiopathology ; Middle Aged ; Obesity ; diagnosis ; ROC Curve ; Waist Circumference

OBJECTIVETo study the changes of insulin sensitivity in individuals with impaired glucose tolerance and diabetes and the relationship between insulin sensitivity and over weight/obesity (OW/OB) .

METHODSFifty-two individuals were divided into 4 groups according to WHO diagnostic criteria of obesity (1998) and diabetes (1999): normal weight with normal glucose tolerance (NW-NGT) group, OW/OB with normal glucose tolerance (OW/OB-NGT) group, OW/OB with impaired glucose tolerance (OW/OBIGT) group and OW/OB with diabetes mellitus (OW/OB-DM) group. Individuals in OW/OB-NGT group were further classified into 3 subgroups: over weight subgroup, mild obesity subgroup, and mediate obesity subgroup. Abdominal fat area was measured with magnetic resonance imaging. Visceral obesity was defined as intra-abdominal fat area over 100 cm(2). All subjects with NGT were divided into visceral obesity (VA) group and non-visceral obesity ( Non-VA) group. Extended hyperinsulinemic euglycemic clamp was performed to assess the peripheral tissue insulin sensitivity in all subjects.

RESULTSThe rates of insulin mediated glucose disappearance (Rd) were (3. 25+/-0. 13) mg x kg (-1) min (-1) in OW/OB-NGT group, (3. 06+/-0. 26) mg x kg(-1) x min(-1) in OW/OB-IGT group, and (3.19+/-0.44) mg x kg(-1) x min (-1) in OW/OB-DM group, which were significantly lower than that in NW-NGT group [ (5. 86+/-0. 65) mg x kg (-1) min (-1) ] (P < 0. 05, P < 0.01). The Rd in over weight subgroup [(3.50+/-0. 19) mg kg(-1) x min(-1) ] , mild obesity subgroup [(3. 03+/-0. 13) mg x kg (-1) min(-1)] , and mediate obesity subgroup [(2. 75 +/-0. 24) mg x kg (-1) min(-1)] were significantly lower than that of NW-NGT group (P <0. 05, P <0. 01). The Rd [ (2. 97+/-0. 12) mg kg(-1) x min(-1) vs (4.55+/-0.43) mg x kg(-1) x min(-1)] and glucose oxidation [(1.47 +/-0. 19) mg x kg(-1) min(-1) vs (2.24 +/-0. 19) mg kg(-1) x min(-1) in VA group were significantly decreased than that in non-VA group (P < 0. 05, P < 0. 01). Body mass index, waist and hip ratio, waist circumference, and intra-abdominal fat area were negatively correlated with Rd, respectively (P < 0. 01). Multiple regression analysis showed that body mass index, intra-abdominal fat area and abdominal subcutaneous fat area were the main risk factors of insulin sensitivity.

CONCLUSIONSInsulin sensitivity decreased in OW/OB individuals with or without hyperglycemia. Insulin sensitivity is lower in subjects with visceral obesity. Total body fat and abdominal fat are the main risk factors of insulin sensitivity.

Adolescent ; Adult ; Body Mass Index ; Female ; Glucose Clamp Technique ; methods ; Glucose Intolerance ; etiology ; Humans ; Insulin Resistance ; Intra-Abdominal Fat ; metabolism ; Male ; Middle Aged ; Obesity ; complications ; physiopathology ; Subcutaneous Fat, Abdominal ; metabolism

PURPOSE: Visceral fat (VF) is closely associated with many metabolic risk factors and is also known to be a strong predictive factor for severe metabolic complications in adults. But there are only a few studies concerning the association of VF and risk factors for metabolic syndrome (MS) in children and adolescents. In our study, we emphasized the association of VF [measured by VF computed tomography (VFCT)] and risk factors for metabolic syndrome in children and adolescents. MATERIALS AND METHODS: The subjects were outpatients aged 6 to 18 years who underwent VFCT in the family medicine of The Catholic University of Korea from January 2005 to August 2009. There were 82 patients in total (42 children, 40 adolescents). Height, weight, blood pressure (BP), blood tests, body composition analysis and VF were measured. The three groups were also classified by metabolic score. RESULTS: In children, only high density lipoprotein cholesterol (HDL-C) showed a statistically significant difference, while in adolescents, triglyceride, HDL-C, BP, body mass index (BMI), waist circumference (WC) and VFA showed statistically significant differences. In terms of VFA, fasting glucose, BP, BMI, basal metabolic rate (BMR) and WC showed statistically significant differences. BMI showed a statistically significant difference in terms of BP, BMR, WC, VFA and HDL-C. CONCLUSION: There is a need to acknowledge the statistically significant associations of VF and risk factors for MS in children and adolescents. Screening tests for BP, cholesterol, fasting glucose and WC should be given in clinics for children and adolescents so that MS can be detected and its risk factors treated early.
Adolescent ; Body Mass Index ; Child ; Female ; Humans ; Intra-Abdominal Fat/*physiology ; Male ; Metabolic Syndrome X/*epidemiology/metabolism/physiopathology ; Risk Factors ; Waist Circumference/physiology

BACKGROUND/AIMS: Obstructive sleep apnea (OSA) is associated with an increased risk of obesity and non-alcoholic fatty liver disease (NAFLD), but it remains unclear whether the risk of NAFLD is independently related to OSA regardless of visceral obesity. Thus, the aim of the present study was to examine whether OSA alone or in combination with excessive daytime sleepiness (EDS) or short sleep duration was associated with NAFLD independent of visceral fat in Korean adults. METHODS: A total of 621 participants were selected from the Korean Genome and Epidemiology Study (KoGES). The abdominal visceral fat area (VFA) and hepatic fat components of the participants were assessed using computed tomography scans and they were then categorized into four groups depending on the presence of OSA and EDS. RESULTS: The proportions of NAFLD were 21.1%, 18.5%, 32.4%, and 46.7% in participants without OSA/EDS, with only EDS, with only OSA, and with both OSA and EDS, respectively. A combination of OSA and EDS increased the odds ratio (OR) for developing NAFLD (OR, 2.75; 95% confidence interval [CI], 1.21 to 6.28) compared to those without OSA/EDS, and this association remained significant (OR, 2.38; 95% CI, 1.01 to 5.59) even after adjusting for VFA. In short sleepers (< 5 hours) with OSA, the adjusted OR for NAFLD was 2.50 (95% CI, 1.08 to 5.75) compared to those sleeping longer than 5 hours without OSA. CONCLUSIONS: In the present study, OSA was closely associated with NAFLD in Korean adults. This association was particularly strong in those with EDS or short sleep duration regardless of VFA.
*Adiposity ; Aged ; Asian Continental Ancestry Group ; Chi-Square Distribution ; Disorders of Excessive Somnolence/diagnosis/*epidemiology/physiopathology ; Female ; Humans ; Intra-Abdominal Fat/*physiopathology ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; Non-alcoholic Fatty Liver Disease/diagnosis/*epidemiology/physiopathology ; Obesity, Abdominal/diagnosis/*epidemiology/physiopathology ; Odds Ratio ; Republic of Korea/epidemiology ; Risk Factors ; *Sleep ; Sleep Apnea, Obstructive/diagnosis/*epidemiology/physiopathology

OBJECTIVETo explore the effects of soy isoflavone (SIF) on low-grade inflammation in rats with high-fat diet-induced insulin resistance (IR) and explore the mechanisms of SIF in improving insulin sensitivity.

METHODSThe rats with high-fat diet-induced IR were randomly divided into one model control group and 3 SIF groups gavaged with SIF water solutions at the doses of 50, 150, and 450 mg/kg, respectively. One month after the treatment, fasting blood glucose (FBG), fasting insulin (FINS), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), C-reactive protein (CRP), resistin and adiponectin in the serum were detected by enzymatic method, radioimmunoassay, or enzyme-linked immunosorbent assay.

RESULTSIn the 150 and 450 mg/kg SIF groups, fasting body-weights, visceral adipose tissue deposition, FINS, resistin, TNF-alpha in serum, and IR index were lowered in comparison with the model control group, and in 450 mg/kg SIF group, serum IL-6 level was obviously lowered, and adiponectin increased. No differences were found in serum C-reactive protein levels between the 3 SIF groups.

CONCLUSIONSoy isoflavone may ameliorate insulin sensitivity by decreasing visceral adipose deposition and adjusting low-grade inflammatory molecules derived from white adipose tissue.

Adiponectin ; blood ; Animals ; Body Weight ; drug effects ; C-Reactive Protein ; metabolism ; Inflammation ; blood ; physiopathology ; Insulin ; blood ; Insulin Resistance ; Interleukin-6 ; blood ; Intra-Abdominal Fat ; drug effects ; metabolism ; Isoflavones ; pharmacology ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Resistin ; blood ; Soybeans ; chemistry ; Tumor Necrosis Factor-alpha ; blood