Association between deposit of abdominal adipose tissues and metabolic abnormality in a Chinese population

BackgroundPrevious studies indicated that deposit of abdominal adipose tissue associated with the abnormalities of cardiometabolic components. However, the results were inconsistent on the effects of subcutaneous adipose tissue (SAT) and difference between men and women. The aim of this study was to examine the associations of VAT, SAT with metabolic status and the different effects between male and female. Methods1388 eligible subjects were recruited from the baseline investigation of metabolic syndrome investigation in China. Areas of abdominal VAT and SAT were determined by nuclear magnetic resonance imaging (MRI). Total triglycerides (TG), high-density lipoprotein cholesterol (HDL-C) were measured by biochemical auto-analyzer. Metabolic abnormality (MA) was defined more than one of abnormally metabolic components, which were based on the definition of metabolic syndrome (IDF 2005). Multiple logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (95%CI). The predictive values were assessed with area under the curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI), respectively. ResultsSubjects with MA had higher levels of VAT in both of men and women, and higher levels of SAT in men than those with metabolic normality (MN) (P< 0.05). Different associations of SAT in women depended of levels of BMI. Higher levels of VAT were significantly correlated with higher risks for MA (p for trend <0.05). Comparing with the subjects of the first quartile (Q1) of VAT, OR in fourth quartile (Q4) was 6.537 (95% CI= 3.394 -12.591) in men and 3.364 (95% CI=1.898-5.962) in women. However, no significance was found in SAT. In men, VAT improved the predictive value of MA with the AUC of 0.727 (95% CI= 0.687-0.767), and NRI of 0.139 (95%CI=0.070-0.208) and 0.106 (95%CI=0.038-0.173), IDI of 0.074 (95%CI = 0.053-0.095) and 0.046 (95%CI=0.026-0.066) comparing with BMI and WC, respectively. Similar results were found in women.Conclusions VAT and SAT linked increased risks for metabolic abnormality in men no matter in the BMI＜24kg/m2 or in BMI≥24kg/m2, but in women, SAT only increased the risk of MA in BMI≥24kg/m2.Deposit of abdominal adipose tissue associated with the metabolic abnormalities. VAT improved the predictive ability of MA.

Evaluation of Abdominal Computed Tomography Scans for Differentiating the Discrepancies in Abdominal Adipose Tissue Between Two Major Subtypes of Primary Aldosteronism

The aim of this study was to analyze the differences in the distribution of abdominal adipose tissue between the two subtypes of primary aldosteronism (PA) using abdominal computed tomography. We retrospectively analyzed patients diagnosed as having essential hypertension (EH) or PA from the prospectively collected Taiwan Primary Aldosteronism Investigation (TAIPAI) database. Patients with PA were divided into the subgroups of idiopathic hyperaldosteronism (IHA) and unilateral aldosterone-producing adenoma (APA). Patients’ basic clinicodemographic data were collected, and a self-developed CT-based software program was used to quantify the abdominal adiposity indexes, including visceral adipose tissue (VAT) area, VAT ratio, waist circumference (WC), subcutaneous adipose tissue (SAT) area, and SAT ratio. We included 190 patients with EH and 436 patients with PA (238 with IHA and 198 with APA). The APA group had significantly lower abdominal adiposity indexes than the other groups. We also found negative correlations of aldosterone-to-renin ratio (ARR) with VAT area, VAT ratio, WC, and body mass index (BMI) in the APA group. After propensity score matching (which left 184 patients each in the IHA and APA groups), patients in the APA group still had significantly lower WC, SAT area, SAT ratio, and VAT ratio than those in the IHA group. Furthermore, logistic regression analysis indicated that lower probability of abdominal obesity was significantly related to patients with APA. Our data revealed that the distribution of abdominal adipose tissue was similar in patients with IHA and those with EH, but the abdominal adiposity indexes were significantly lower in patients with APA than in those with IHA and EH.

Function of Chick Subcutaneous Adipose Tissue During the Embryonic and Posthatch Period

Since excess abdominal fat is one of the main problems in the broiler industry for the development of modern broiler and layer industry, the importance of subcutaneous adipose tissue has been neglected. However, chick subcutaneous adipose tissue appeared earlier than abdominal adipose tissue and more than abdominal adipose tissue. Despite a wealth of data, detailed information is lacking about the development and function of chick subcutaneous adipose tissue during the embryonic and posthatch period. Therefore, the objective of the current study was to determine the developmental changes of adipocyte differentiation, lipid synthesis, lipolysis, fatty acid β-oxidation, and lipid contents from E12 to D9.5. The results showed that subcutaneous adipose tissue was another important energy supply tissue during the posthatch period. In this stage, the mitochondrial copy number and fatty acid β-oxidation level significantly increased. It revealed that chick subcutaneous adipose tissue not only has the function of energy supply by lipidolysis but also performs the same function as brown adipose tissue to some extent, despite that the brown adipose tissue does not exist in birds. In addition, this finding improved the theory of energy supply in the embryonic and posthatch period and might provide theoretical basis on physiological characteristics of lipid metabolism in chicks.

Brown adipose tissue, adiposity and metabolic profile in preschool children

Context An inverse relationship between brown adipose tissue (BAT) and obesity has previously been reported in older children and adults, but unknown in young children. Objective We investigated the influence of BAT in thermoneutral condition on adiposity and metabolic profile in Asian preschool children. Design, Setting and Participants A total of 198 children aged 4.5 years from a prospective birth cohort study, Growing Up in Singapore Towards healthy Outcomes (GUSTO) were successfully studied with water-fat magnetic resonance imaging of the supraclavicular-axillary fat depot (FDSA). Regions within FDSA with fat-signal-fraction between 20% and 80% were considered BAT, and percentage BAT (%BAT), (100*BAT volume/ FDSA volume) was calculated. Main outcome measures Abdominal adipose tissue compartment volumes, ectopic fat in the soleus muscle and liver, fatty liver index, metabolic syndrome scores and markers of insulin sensitivity. Results A one percent unit increase in %BAT was associated with lower body mass index, difference (95%CI), -0.08 (-0.10, -0.06) kg/m 2 and smaller abdominal adipose tissue compartment volumes. Ethnicity and sex modified these associations. In addition, each unit increase in %BAT was associated with lower ectopic fat at 4.5 years in the liver, -0.008 (-0.013, -0.003) %, soleus muscle, -0.003 (-0.006, -0.001) % of water-content and lower fatty liver index at 6 years. Conclusions Higher %BAT is associated with a more favorable metabolic profile. BAT may thus play a role in the pathophysiology of obesity and related metabolic disorders. The observed ethnic and sex differences imply that the protective effect of BAT may vary among different groups.

STUDY OF SPECIFIC ANTIDIABETIC EFFECT OF PERSPECTIVE SIRTUIN-1 ACTIVATOR PYRABENTIN ON THE MODEL OF METABOLIC MEMORY IN RATS

Pharmacological activation of sirtuin-1 (SIRT1), which can mimic calorie restriction, reduce fat deposition along with stimulating its utilization, and possibly erase "metabolic memory", is a promising goal for the prevention and treatment of obesity and type 2 diabetes. The aim of the study was to evaluate the specific antidiabetic effect of the original heterocyclic compound with the proprietary name pyrabentin with in situ proven ability to activate human sirtuin-1 on the experimental model of "metabolic memory" in rats. The study was conducted on adult male Wistar rats (n=24), which were kept on a high-fat diet (HFD) for 5 months, control sex- and age-matched animals (n=6) were received standard diet (StD). At the end of the 5-mo HFD-period, the animals were randomized for the study over the next two months into 4 groups as follows: HFD/HFD+placebo, HFD/StD+placebo, HFD/StD+pyrabentin (PB), HFD/StD+metformin (MF). PB was administered orally at 50 mg/kg body weight as an aqueous suspension with Tween-80 daily, the reference drug metformin was administered in a similar way at 100 mg/kg body weight, the control group received a placebo. Glucose tolerance test and short insulin test were performed, body weight, abdominal adipose tissue weight by fraction and blood pressure were assessed. Shapiro-Wilk test, paired and unpaired Student’s t-test, and Mann-Whitney U-test were used. It was found that 60-day administration of pyrabentin to rats with a model of "metabolic memory", insulin resistance and obesity, was realized in a statistically significant decrease in basal glycemia, glucose intolerance, body weight and weight of abdominal adipose tissue fractions with comparable efficacy to the reference drug. This was accompanied by improved insulin sensitivity and blood pressure.