脂联素及其受体对糖尿病肾病大鼠的保护作用

目的 探讨脂联素（ADPN）及其受体（AdipoR）对糖尿病肾病的保护作用及其可能机制。 方法 （1）64只雌性SD大鼠被随机均分入对照组和实验组：实验组一次性空腹腹腔注射链脲菌素（STZ) 60 mg/kg,诱导糖尿病大鼠模型;对照组腹腔注射等体积的枸橼酸缓冲液。于糖尿病大鼠成模后第2、6、10、12周两组分别测体质量、肾质量、空腹血糖、24 h尿白蛋白排泄量;心内采血检测空腹血清胰岛素;ELISA法检测血、尿脂联素浓度;取肾脏常规制作PAS染色,免疫组化SP法检测肾脏脂联素受体1和2（AdipoR1和AdipoR2）的表达。（2）将NRK-52E细胞分别用含5 mmol/L葡萄糖（正常对照组）、30 mmol/L葡萄糖（高糖组）、30 mmol/L葡萄糖+不同浓度ADPN（终浓度分别为1 mg/L、5 mg/L、10 mg/L）培养,12 h后RT-PCR法检测单核细胞趋化蛋白1（MCP-1） mRNA表达。 结果 （1）造模成功后6、10、12周实验组血清和尿ADPN水平均高于对照组（P < 0.01）,并随着肾脏病变进展而逐渐升高。（2）实验组各时期AdipoR1和AdipoR2在肾脏的表达高于对照组,并随时间逐渐增强,其与血清脂联素水平呈正相关（r = 0.666,P < 0.01;r = 0.684,P < 0.01）。（3）MCP-1 mRNA在高糖组表达较高,加入脂联素以后MCP-1 mRNA表达显著减少（P < 0.05）。 结论 血和尿脂联素水平随糖尿病肾病病程进展而升高,与AdipoR1和AdipoR2的表达亦呈正相关,推测脂联素通过AdipoR直接作用于肾小管,通过减少MCP-1的表达对肾脏起保护作用。     

Pattern of Expression of Adiponectin Receptors in Human Liver and its Relation to Nonalcoholic Steatohepatitis

BACKGROUND: Adiponectin has antisteatosis-anti-inflammatory properties and its circulating levels are reduced in nonalcoholic steatohepatitis (NASH). METHODS: To assess the role of adiponectin in NASH, we measured expression of adiponectin gene (APM1) and receptors (AdipoR1/AdipoR2) in liver and subcutaneous and visceral fat in subjects with biopsy-proven NASH or pure steatosis (PS). In 103 subjects undergoing gastric bypass or elective abdominal surgery (17 with normal liver histology (C), 52 with PS, and 34 with NASH), RNA was extracted from tissue samples, and quantification of APM1, AdipoR1, and AdipoR2 was carried out by real-time polymerase chain reaction. RESULTS: In NASH vs C, circulating adiponectin levels (3.6[2.4] vs 5.3[4.3] mug/ml, median[interquartile range], p < 0.05) and adiponectin concentrations, APM1, AdipoR1, and AdipoR2 expression in visceral fat were all reduced (p 相似文献   

Response of adiponectin and its receptors to changes in metabolic state after gastric bypass surgery: dissociation between adipose tissue expression and circulating levels

BackgroundAdiponectin is an adipokine with anti-atherogenic and insulin-sensitizing properties. Specific adiponectin receptors, adiponectin receptors 1 (AdipoR1) and 2 (AdipoR2), are present in adipose tissue, indicating adiponectin might have autocrine/paracrine effects on its production or action. In addition, endoplasmic reticulum oxidoreductase 1-Lα might mediate regulation of its secretion. The study aim was to determine the subcutaneous adipose tissue (SAT) adiponectin gene and protein expression and their correlation to metabolic parameters during metabolically distinct times after gastric bypass surgery.MethodsA total of 12 morbidly obese male patients underwent SAT biopsy during gastric bypass surgery, active weight loss (negative energy state), and at weight stabilization (steady state energy). The SAT mRNA and protein content of adiponectin, AdipoR1 and AdipoR2, and endoplasmic reticulum oxidoreductase 1-Lα protein levels and the serum levels of adiponectin were assessed.ResultsSAT adiponectin, AdipoR1, and AdipoR2 gene expression increased significantly at the negative energy state, with no further change at steady state energy (P <.05, P <.05, and P = .04, respectively), without significant increases in protein at any stage. Changes in SAT adiponectin protein correlated with changes in AdipoR1 and AdipoR2 during steady state energy (P = .003 and P = .002, respectively). Changes in SAT adiponectin expression did not correlate with those in circulating levels. Changes in endoplasmic reticulum oxidoreductase 1-Lα did not correlate with either SAT or circulating levels of adiponectin.ConclusionOur data indicate distinct functions of adiponectin receptors, AdipoR1 and AdipoR2, mediate the autocrine/paracrine actions of adiponectin. The lack of correlation between changes in SAT adiponectin gene and protein expression and its circulating levels suggests that adipose tissue synthesis and release of adiponectin are highly regulated pathways.     

Opposing effects of adiponectin receptors 1 and 2 on energy metabolism

The adipocyte-derived hormone adiponectin regulates glucose and lipid metabolism and influences the risk for developing obesity, type 2 diabetes, and cardiovascular disease. Adiponectin binds to two different seven-transmembrane domain receptors termed AdipoR1 and AdipoR2. To study the physiological importance of these receptors, AdipoR1 gene knockout mice (AdipoR1(-/-)) and AdipoR2 gene knockout mice (AdipoR2(-/-)) were generated. AdipoR1(-/-) mice showed increased adiposity associated with decreased glucose tolerance, spontaneous locomotor activity, and energy expenditure. However, AdipoR2(-/-) mice were lean and resistant to high-fat diet-induced obesity associated with improved glucose tolerance and higher spontaneous locomotor activity and energy expenditure and reduced plasma cholesterol levels. Thus, AdipoR1 and AdipoR2 are clearly involved in energy metabolism but have opposing effects.     

Expression of adiponectin receptor mRNA in human skeletal muscle cells is related to in vivo parameters of glucose and lipid metabolism

The adiponectin receptors, AdipoR1 and AdipoR2, are thought to transmit the insulin-sensitizing, anti-inflammatory, and atheroprotective effects of adiponectin. In this study, we examined whether AdipoR mRNA expression in human myotubes correlates with in vivo measures of insulin sensitivity. Myotubes from 40 metabolically characterized donors expressed 1.8-fold more AdipoR1 than AdipoR2 mRNA (588 +/- 35 vs. 321 +/- 39 fg/microg total RNA). Moreover, the expression levels of both receptors correlated with each other (r = 0.45, P < 0.01). AdipoR1 mRNA expression was positively correlated with in vivo insulin and C-peptide concentrations, first-phase insulin secretion, and plasma triglyceride and cholesterol concentrations before and after adjustment for sex, age, waist-to-hip ratio, and body fat. Expression of AdipoR2 mRNA clearly associated only with plasma triglyceride concentrations. In multivariate linear regression models, mRNA expression of AdipoR1, but not AdipoR2, was a determinant of first-phase insulin secretion independent of insulin sensitivity and body fat. Finally, insulin did not directly modify myotube AdipoR1 mRNA expression in vitro. In conclusion, we provide evidence that myotube mRNA levels of both receptors are associated with distinct metabolic functions but not with insulin sensitivity. AdipoR1, but not AdipoR2, expression correlated with insulin secretion. The molecular nature of this link between muscle and beta-cells needs to be further clarified.     

Global adiponectin suppress the high expression of monocyte chemotactic protein-1 induced by high glucose in NRK52E cells

Objective To investigate the effect of globular adiponectin on the high expression of monocyte chemotactic protein-1 (MCP-1) induced by high glucose in rat renal tubular epithelial cells(NRK52E), and its relationship with adiponectin receptors and p38MAPK. Methods NRK52E cells were cultured in vitro and divided into six groups: normal glucose group (NG, 5.6 mmol/L glucose), high glucose group(HG, 25 mmol/L glucose), gAd group1 (HG+gAd 2 mg/L), gAd group2 (HG+gAd 5 mg/L), gAd group3 (HG+gAd 10 mg/L), p38MAPK antagonist group：(SB, HG+SB203580 10 μmol/L). The protein expression of phosphorylated p38MAPK (p-p38MAPK), total p38MAPK (t-p38MAPK), MCP-1 and AdipoR1/AdipoR2 were examined by western blotting. The mRNA expression of MCP-1 and AdipoR1/AdipoR2 were detected by RT-PCR and real-time PCR respectively. Results Compared with NG group, the mRNA and protein expression of MCP-1 increased significantly in HG group (all P＜0.05). The phosphorylation of p38MAPK increased (P＜0.05) with no change in t-p38MAPK protein. The addition of gAd or SB203580 inhibited the unregulation of MCP-1 and p-p38MAPK induced by HG. Two kinds of adipoR,adipoR1 and adipoR2,were all detectable in NG group, and mRNA and protein expression of adipoR1 was higher than that of adipoR2 (P＜0.01). Compared with NG group, the expression of adipoR decreased in HG group, but the difference had no statistical significance(P＞0.05). Compared to HG group, the mRNA and protein expression of adipoR1 increased in gAd groups (all P＜0.01). Conclusion The gAd can dose-dependently attenuate the overexpression of MCP-1 induced by high glucose, and this protective effect may be mediated by adipoR1 and p38MAPK.     

Metabolic syndrome in severely obese patients

Background: The authors assessed the prevalence of diabetes, hypertension, dyslipidemia and metabolic syndrome in patients with a high degree of obesity. Methods: A retrospective investigation was planned in a cohort of obese patients with a wide range of body mass index (BMI) referred to a large University Hospital for weight loss. Results: An increase in prevalence of diabetes and hypertension with increase in the degree of obesity was observed, while the prevalence of dyslipidemia and metabolic syndrome appeared to be independent of the BMI values. Conclusion: In severely obese patients a still unknown factor which affects differently glucose and lipid metabolism cannot be excluded.     

Adiponectin Expression and Adipose Tissue Lipolytic Activity in Lean and Obese Women

Background: The authors evaluated whether adipose adiponectin expression is related to adipose tissue lipolytic activity and fatty acid oxidation rate in lean and obese women. Methods:The study consisted of 60 adult females distributed in a wide range of adiposity (BMI 24.0-53.4 kg/m² ). Body composition was estimated by bioelectrical impedance. Respiratory quotient was measured by open-circuit indirect calorimetry. RT-PCR assays were performed to measure TNFα and adiponectin expression in subcutaneous adipose tissue biopsies. Lipolysis studies were performed in fresh tissue samples obtained from subcutaneous abdominal depots during bariatric surgery in 19 morbidly obese females or by an incisional biopsy or during abdominal elective surgery in normal weight and obese females. Glycerol release was measured with a colorimetric endpoint method. Results: Patients with a higher degree of adiposity showed lower adipose tissue adiponectin expression and hormone-sensitive lipase (HSL) activity than women in the low range of adiposity. HSL activity was positively related to adiponectin expression. No relationship was observed between adiponectin and TNFα subcutaneous adipose tissue expression. The positive relationship between respiratory quotient and adiponectin expression was in the limit of statistical significance (P=0.05). Percentage of body fat and mRNA adiponectin explained 26% of the variance of the adipose tissue HSL activity. Conclusions: Low adipose tissue adiponectin expression observed in obese people may contribute to the progression of obesity and its co-morbidities by modulating hormone-sensitive lipase activity and fatty acid oxidation.     

Relationships of serum leptin to clinical and anthropometric findings in obese patients

Background: The authors evaluated the relationship between leptin and the clinical, anthropometric and metabolic variables connected to the metabolic syndrome in obese individuals. Methods: A large group of patients with different degrees of obesity was investigated: body mass index (BMI) values, serum leptin, fasting glucose and insulin, triglycerides and HDL-cholesterol concentrations, insulin resistance index and blood pressure were measured. Results: On multiple regression analysis, serum leptin levels appeared to be positively correlated to the BMI and to the serum HDL-cholesterol concentration. Principal component factor analysis revealed three factors, explaining 61.3% of the total variance of the sample. General features of these factors were: factor 1 - BMI values and serum leptin and fasting glucose concentration; factor 2 - systolic and diastolic blood pressure and serum triglycerides and HDL-cholesterol concentration; factor 3 - fasting serum insulin concentration and insulin resistance index. Conclusions: In obese subjects multiple factors underlie the metabolic syndrome and therefore more than one mechanism may account for the clustering characteristics. In obese patients leptin loads only one factor, and therefore leptin does not appear to be a key feature in the metabolic syndrome. On the contrary, multiple correlation and factor analysis data give rise to the hypothesis that in obese patients, leptin may play a protective role against cardiovascular risk.     

Omentin plasma levels and gene expression are decreased in obesity

Central obesity and the accumulation of visceral fat are risk factors for the development of type 2 diabetes and cardiovascular disease. Omentin is a protein expressed and secreted from visceral but not subcutaneous adipose tissue that increases insulin sensitivity in human adipocytes. To determine the impact of obesity-dependent insulin resistance on the regulation of two omentin isoforms, gene expression and plasma levels were measured in lean, overweight, and obese subjects. Omentin 1 was shown to be the major circulating isoform in human plasma. Lean subjects had significantly higher plasma omentin 1 levels than obese and overweight subjects. In addition, higher plasma omentin 1 levels were detected in women compared with men. Plasma omentin 1 levels were inversely correlated with BMI, waist circumference, leptin levels, and insulin resistance as measured by homeostasis model assessment and positively correlated with adiponectin and HDL levels. Both omentin 1 and omentin 2 gene expression were decreased with obesity and were highly correlated with each other in visceral adipose tissue. In summary, decreased omentin levels are associated with increasing obesity and insulin resistance. Therefore, omentin levels may be predictive of the metabolic consequences or co-morbidities associated with obesity.     

Gene Expression of Leptin, Resistin, and Adiponectin in the White Adipose Tissue of Obese Patients with Non-Alcoholic Fatty Liver Disease and Insulin Resistance

Background: Adipose tissue is an active endocrine organ that secretes a variety of metabolically important substances including adipokines. These factors affect insulin sensitivity and may represent a link between obesity, insulin resistance, type 2 diabetes (DM), and nonalcoholic fatty liver disease (NAFLD). This study uses real-time polymerase chain reaction (PCR) quantification of mRNAs encoding adiponectin, leptin, and resistin on snap-frozen samples of intra-abdominal adipose tissue of morbidly obese patients undergoing bariatric surgery. Methods: Morbidly obese patients undergoing bariatric surgery were studied. Patients were classified into two groups: Group A (with insulin resistance) (N=11; glucose 149.84 ± 40.56 mg/dL; serum insulin 8.28 ± 3.52 μU/mL), and Group B (without insulin resistance) (N=10; glucose 102.2 ± 8.43 mg/dL; serum insulin 3.431 ± 1.162 μU/mL). Results: Adiponectin mRNA in intra-abdominal adipose tissue and serum adiponectin levels were significantly lower in Group A compared to Group B patients (P<0.016 and P<0.03, respectively). Although serum resistin was higher in Group A than in Group B patients (P<0.005), resistin gene expression was not different between the two groups. Finally, for leptin, neither serum level nor gene expression was different between the two groups. Serum adiponectin level was the only predictor of nonalcoholic steatohepatitis (NASH) in this study (P=0.024). Conclusions: Obese patients with insulin resistance have decreased serum adiponectin and increased serum resistin. Additionally, adiponectin gene expression is also decreased in the adipose tissue of these patients. This low level of adiponectin expression may predispose patients to the progressive form of NAFLD or NASH.     

The effect of thiazolidinediones on plasma adiponectin levels in normal,obese, and type 2 diabetic subjects

The insulin-sensitizing effects of thiazolidinediones are thought to be mediated through peroxisome proliferator-activated receptor-gamma, a nuclear receptor that is highly abundant in adipose tissue. It has been reported that adipocytes secrete a variety of proteins, including tumor necrosis factor-alpha, resistin, plasminogen activator inhibitor-1, and adiponectin. Adiponectin is a fat cell-secreted protein that has been reported to increase fat oxidation and improve insulin sensitivity. Our aim was to study the effects of troglitazone on adiponectin levels in lean, obese, and diabetic subjects. Ten diabetic and 17 nondiabetic subjects (8 lean, BMI <27 kg/m(2) and 9 obese, BMI >27 kg/m(2)) participated in the study. All subjects underwent an 80 mU. m(-2). min(-1) hyperinsulinemic-euglycemic glucose clamp before and after 3 months' treatment with the thiazolidinedione (TZD) troglitazone (600 mg/day). Fasting plasma glucose significantly decreased in the diabetic group after 12 weeks of treatment compared with baseline (9.1 +/- 0.9 vs. 11.1 +/- 0.9 mmol/l, P < 0.005) but was unchanged in the lean and obese subjects. Fasting insulin for the entire group was significantly lower than baseline (P = 0.02) after treatment. At baseline, glucose disposal rate (R(d)) was lower in the diabetic subjects (3.4 +/- 0.5 mg. kg(-1). min(-1)) than in the lean (12.3 +/- 0.4) or obese subjects (6.7 +/- 0.7) (P < 0.001 for both) and was significantly improved in the diabetic and obese groups (P < 0.05) after treatment, and it remained unchanged in the lean subjects. Baseline adiponectin levels were significantly lower in the diabetic than the lean subjects (9.0 +/- 1.7 vs. 16.7 +/- 2.7 micro g/ml, P = 0.03) and rose uniformly in all subjects (12.2 +/- 2.3 vs. 25.7 +/- 2.6 micro g/ml, P < 10(-4)) after treatment, with no significant difference detected among the three groups. During the glucose clamps, adiponectin levels were suppressed below basal levels in all groups (10.2 +/- 2.3 vs. 12.2 +/- 2.3 micro g/ml, P < 0.01). Adiponectin levels correlated with R(d) (r = 0.46, P = 0.016) and HDL cholesterol levels (r = 0.59, P < 0.001) and negatively correlated with fasting insulin (r = -0.39, P = 0.042) and plasma triglyceride (r = -0.61, P < 0.001). Our findings show that TZD treatment increased adiponectin levels in all subjects, including normal subjects in which no other effects of TZDs are observed. Insulin also appears to suppress adiponectin levels. We have confirmed these results in normal rats. These findings suggest that adiponectin can be regulated by obesity, diabetes, TZDs, and insulin, and it may play a physiologic role in enhancing insulin sensitivity.     

Mild obesity reduces survival and adiponectin sensitivity in endotoxemic rats

Background

Recent meta-analyses have reported that critically ill patients with morbid obesity (body mass index >40 kg/m²) have poor outcomes, but the effects and mechanisms of action of mild obesity are still unclear. The purpose of this study was to evaluate the effect of mild obesity using a lard-based, high-fat diet (HFD) on pathologic conditions and the mechanisms of adiponectin action in endotoxemic rats.

Materials and methods

Male Wistar rats underwent HFD feeding for 4 wk and were killed at 0, 1.5, and 6 h after lipopolysaccharide (LPS) injection. Plasma levels of adiponectin, nitric oxide, and interleukin 6; messenger RNA expression of adiponectin receptors (AdipoR1 and AdipoR2) in the liver and the skeletal muscle; blood biochemical test results; and histology of the liver were analyzed.

Results

HFD-fed rats had a lower survival rate (12.8% versus 85.2%) and lower plasma adiponectin levels after LPS injection (P < 0.01). Messenger RNA expression of adiponectin receptors in the liver, but not the skeletal muscle, also decreased in HFD-fed rats (P < 0.05). Tissue injury and oxidative stress in the liver and plasma inflammatory mediator levels increased, and worsened lipid metabolism abnormalities were noted. The findings indicated that HFD decreased the sensitivity of adiponectin and was associated with an increase in oxidative stress and inflammation, which finally resulted in worsened liver injury and poor survival rate after LPS injection.

Conclusions

Short-term, HFD-induced, mild obesity is harmful to the septic host, reduces adiponectin sensitivity, and could be the cause of worsening pathologic conditions.     

miR-320 mediates diabetes amelioration after duodenal-jejunal bypass via targeting adipoR1

Background

Duodenal–jejunal bypass (DJB) surgery can improve type 2 diabetes (T2D) dramatically. Accumulating evidence implicates deficiency of hepatic adiponectin signaling as a contributor to gluconeogenesis disorders, and some microRNAs (miRNAs) regulate adiponectin receptors (AdipoR1, AdipoR2). We investigated the effects of DJB on hepatic gluconeogenesis, lipid metabolism, and inflammation as well as the effects of miRNA-320 (AdipoR1-targeting miRNA) on DJB-induced T2D amelioration.

Effect of free fatty acids on insulin receptor binding and tyrosine kinase activity in hepatocytes isolated from lean and obese rats.

We demonstrated previously that high physiological concentrations of free fatty acids (FFA) rapidly decrease insulin binding, degradation, and action in isolated rat hepatocytes. In this study, hepatocytes from lean and obese Sprague-Dawley rats (Alab, Stockholm) were preincubated with or without 0.4 mM oleic acid, and the effect on insulin binding and tyrosine kinase activity was measured. In the absence of exogenous FFA, insulin binding was reduced in hepatocytes from obese compared with lean rats (mean +/- SE reduction 44 +/- 7%, n = 8, P less than 0.01). Furthermore, the inhibitory effect of oleic acid added to hepatocytes from lean rats (n = 8; 40 +/- 9%, P less than 0.01) was not seen in cells from obese rats. Treating obese rats with Etomoxir, a carnitine palmitoyl transferase I inhibitor, increased insulin binding to isolated hepatocytes by 41 +/- 13% (n = 5, P less than 0.05). There was no difference in total binding to partially purified insulin receptors from solubilized hepatocytes from lean and obese rats, whether cells were or were not preincubated with oleic acid. Tyrosine kinase activity of partially purified receptors from basal or insulin-stimulated cells was not affected by either obesity, treatment with Etomoxir, or preincubating the cells with oleic acid. Thus, both obesity and elevated ambient FFA levels are associated with impaired insulin cell surface binding to isolated hepatocytes, possibly through an effect of lipid oxidation on the internalization/recycling of the insulin-receptor complex without any perturbation of the receptor tyrosine kinase activity. The data suggest that the reduced insulin binding to hepatocytes from obese rats is due to elevated ambient FFA levels.     

Adiponectin expression from human adipose tissue: relation to obesity,insulin resistance,and tumor necrosis factor-alpha expression

Adiponectin is a 29-kDa adipocyte protein that has been linked to the insulin resistance of obesity and lipodystrophy. To better understand the regulation of adiponectin expression, we measured plasma adiponectin and adipose tissue adiponectin mRNA levels in nondiabetic subjects with varying degrees of obesity and insulin resistance. Plasma adiponectin and adiponectin mRNA levels were highly correlated with each other (r = 0.80, P < 0.001), and obese subjects expressed significantly lower levels of adiponectin. However, a significant sex difference in adiponectin expression was observed, especially in relatively lean subjects. When men and women with a BMI <30 kg/m(2) were compared, women had a twofold higher percent body fat, yet their plasma adiponectin levels were 65% higher (8.6 +/- 1.1 and 14.2 +/- 1.6 micro g/ml in men and women, respectively; P < 0.02). Plasma adiponectin had a strong association with insulin sensitivity index (S(I)) (r = 0.67, P < 0.0001, n = 51) that was not affected by sex, but no relation with insulin secretion. To separate the effects of obesity (BMI) from S(I), subjects who were discordant for S(I) were matched for BMI, age, and sex. Using this approach, insulin-sensitive subjects demonstrated a twofold higher plasma level of adiponectin (5.6 +/- 0.6 and 11.2 +/- 1.1 micro g/ml in insulin-resistant and insulin-sensitive subjects, respectively; P < 0.0005). Adiponectin expression was not related to plasma levels of leptin or interleukin-6. However, there was a significant inverse correlation between plasma adiponectin and tumor necrosis factor (TNF)-alpha mRNA expression (r = -0.47, P < 0.005), and subjects with the highest levels of adiponectin mRNA expression secreted the lowest levels of TNF-alpha from their adipose tissue in vitro. Thus, adiponectin expression from adipose tissue is higher in lean subjects and women, and is associated with higher degrees of insulin sensitivity and lower TNF-alpha expression.     

Weight loss after Swedish Adjustable Gastric Banding: relationships to insulin resistance and metabolic syndrome

Background:The metabolic syndrome is a cluster of cardiovascular risk factors (central obesity, hypertension,dyslipidemia, disturbance in glucose metabolism) associated with insulin-resistance. The cluster of risk factors defining the metabolic syndrome increases cardiovascular risk more than each single component. The aim of the present longitudinal study was to evaluate the relationship between weight loss and changes in insulin-resistance and in the prevalence of the metabolic syndrome 1-year after SAGB implantation. Methods: 51 premenopausal severely obese women (mean age 35.2±8.8 years, BMI 43.3±6.9) were enrolled. As a control group, 51 premenopausal nonobese women (BMI<30) were enrolled. All obese subjects underwent successful implantation of the SAGB via videolaparoscopy. In all subjects insulinresistance was estimated by HOMA index and metabolic syndrome was defined according to the criteria of the European Group for the Study of Insulin Resistance. Results: HOMA (4.2±2.0 vs 1.9±0.8, P<0.001) and the prevalence of the metabolic syndrome (58.8% vs 7.8%, P<0.001) were significantly higher in obese than non-obese women. 1 year after SAGB, BMI significantly decreased from 43.3±6.9 to 34.5±7.4 (P<0.001). HOMA index showed a significant dramatic breakdown (4.2±2.0 vs 2.4±1.0, P<0.001). The prevalence of the metabolic syndrome declined significantly (58.8% vs 21.6%, P<0.001). Conclusion: Our study shows that in severely obese women, insulin-resistance and the prevalence of the metabolic syndrome significantly decrease 1 year after SAGB. Our findings indicate that SAGB could be a useful tool to reduce the global cardiovascular risk in severely obese people and to improve their long-term prognosis.     

Common Polymorphisms in the Adiponectin Gene ACDC Are Not Associated With Diabetes in Pima Indians

Adiponectin is an abundant adipose tissue-derived protein with important metabolic effects. Plasma adiponectin levels are decreased in obese individuals, and low adiponectin levels predict insulin resistance and type 2 diabetes. Two variants in the adiponectin gene ACDC have been previously associated with plasma adiponectin levels, obesity, insulin resistance, and type 2 diabetes. To determine the role of genetic variation in ACDC in susceptibility to obesity and type 2 diabetes in Pima Indians, we screened the promoter, exons, and exon-intron boundaries of the gene to identify allelic variants. We identified 17 informative polymorphisms that comprised four common (minor allele frequency >15%) linkage disequilibrium clusters consisting of 1-4 variants each. We genotyped one representative polymorphism from each cluster in 1,338 individuals and assessed genotypic association with type 2 diabetes, BMI, serum lipid levels, serum adiponectin levels, and measures of insulin sensitivity and secretion. None of the ACDC variants were associated with type 2 diabetes, BMI, or measures of insulin sensitivity or secretion. One variant, single nucleotide polymorphism (SNP)-12823, was associated with serum adiponectin levels (P = 0.002), but this association explained only 2% of the variance of serum adiponectin levels. Our findings suggest that these common ACDC polymorphisms do not play a major role in susceptibility to obesity or type 2 diabetes in this population.     

Histological Changes in the Liver of Morbidly Obese Patients: Correlation with Metabolic Parameters

Background: Obesity is a major risk factor for fatty liver disease. The purpose of this study was: 1) to determine the degree of steatosis, inflammation and fibrosis in liver biopsies of morbidly obese patients in relation to their body fat distribution and metabolic status, and 2) to examine the course of liver enzyme changes with surgically-induced weight loss. Methods: The study population included 179 morbidly obese bariatric surgical patients (82% female, 18% male, mean age 39±0.7 (SEM) years, BMI 52±0.6 kg/m², excess body weight 80±1.8 kg). All patients tested negative for hepatitis and HIV. Liver biopsies were taken intra-operatively. Hepatic enzyme activities were measured along with lipid parameters, fasting glucose, insulin and leptin. Results: Liver biopsies showed that 47% of morbidly obese females and 85% of males had >30% of hepatocytes filled with fat droplets. Clinically significant hepatic steatosis was associated (P<0.01) with: a) metabolic aberrations, i.e.hyperlipidemia, hyperglycemia, b) male gender, c) abdominal adiposity, and d) elevated hepatic aminotransferase activities. Hepatic inflammation was found in 47% of females and 55% of males, and 'moderate' fibrosis occurred in 12% of males and 6% of females. Postoperatively, the activity of hepatic aminotransferases declined after an initial increase in response to weight loss, with normalization of values occurring at an excess weight loss of 50% (P<0.0001). Conclusion: The majority of morbidly obese patients have >30% steatosis of the liver. The incidence of steatosis is higher for males than females, possibly due to their visceral obesity and associated metabolic aberrations.     

Serum Hepatocyte Growth Factor Concentration in Obese Women Decreases after Vertical Banded Gastroplasty

Background: Human obesity is associated with increased serum hepatocyte growth factor (HGF) concentration. This study examines whether reduced body fat mass after vertical banded gastroplasty (VBG) is associated with a decrease in serum HGF concentration. Methods: Serum HGF concentration and body weight, BMI, body fat mass, blood pressure, serum leptin, insulin, triacylglycerol, and cholesterol concentrations were studied in 10 obese women before and 1 year after VBG. 10 lean, healthy women were used as controls. Results: Obese women showed significantly higher serum HGF concentration than control (lean, healthy) subjects. The mean serum HGF concentration decreased significantly 1 year after VBG, but did not reach the value observed in lean women. After VBG, BMI, body fat mass and serum HGF had similar patterns of decrease. Moreover, serum HGF concentration was positively correlated with both BMI (r=0.6, P<0.01) and body fat mass (r=0.6, P<0.01). Before surgery in obese women, elevated blood pressure was observed, which decreased after VBG. Linear regression analysis between blood pressure and serum HGF concentration using all subjects, showed no correlation between either systolic blood pressure and serum HGF concentration (r=.15, P=NS) or between diastolic blood pressure and serum HGF concentration (r=0.1, P=NS). Insulin resistance index (HOMA score), serum leptin, insulin and triacylglycerol concentrations decreased 1 year after VBG. However, serum cholesterol concentration did not change significantly. Conclusions: These results indicate that VBG results in a reduction in circulating HGF concentration. The reduced body fat mass may contribute in part to the decrease of serum HGF concentration after VBG. Because elevated serum HGF concentration may contribute to the progression of atherosclerosis, the decrease in serum HGF concentration after VBG may be beneficial for obese subjects.