解偶联蛋白基因-3826多态性与其mRNA表达相关性的研究

为了探讨解偶联蛋白（ＵＣＰ）基因－３８２６多态性与ＵＣＰｍＲＮＡ表达水平之间可能存在的联系,应用ＲＴ－ＰＣＲ方法测定了ＵＣＰ基因－３８２６多态性野生型（ＡＡ）,杂合子（ＡＧ）和突变纯合子（ＧＧ）３组人群脂肪组织中ＵＣＰｍＲＮＡ的表达水平．定量结果指出：３种基因型（ＡＡ、ＡＧ和ＧＧ）携带者腹膜内脂肪的ＵＣＰｍＲＮＡ表达水平存在极显著差异（Ｐ＜０．０１）,并显示突变等位基因（Ｇ）的数量与ＵＣＰｍＲＮＡ表达水平呈负相关．此结果表明ＵＣＰ基因Ａ→Ｇ（－３８２６）变异与ＵＣＰｍＲＮＡ表达水平降低密切相关．但该变异导致ＵＣＰｍＲＮＡ表达水平降低的机制还有待进一步研究     

Human SMAD4 is phosphorylated at Thr9 and Ser138 by interacting with NLK

A polymorphism in the promoter region of uncoupling protein 2 gene ?866 G/A has been associated with its expression levels, the risk of obesity, and metabolic abnormalities. We aimed to investigate the associations of uncoupling protein (UCP)2 gene variants with obesity and related traits. A total of 440 subjects, 200 obese, and 240 non-obese individuals were included in this case–control study. Hormone and glucose levels were estimated using standard protocols. Genotyping of UCP-2 gene polymorphism for all subjects was performed by the PCR–RFLP polymerase chain reaction (PCR) method. Higher Systolic blood pressure, Diastolic blood pressure, Waist to hip ratio, Leptin, Insulin, and blood glucose levels were observed in obese than non-obese (P < 0.05). The distributions of genotype (0.001) and allele (0.003) were significantly different between the non-obese and the obese groups. In the obese group, subjects with the A allele showed significant high insulin levels (<0.001) in comparison with A allele non-carriers. In conclusion, our results suggest that the ?866 AA genotype and A allele of the UCP2 gene is associated with obesity and A allele associated with hyperinsulinemia in obese subjects.     

The common -866G/A polymorphism of the UCP2 gene in healthy Iranians compared with world populations

Uncoupling protein 2 (UCP2) is a member of the mitochondrial transporter superfamily. It is proposed as a candidate gene for obesity. A common G/A polymorphism in the promoter region of this gene is associated with enhanced adipose tissue mRNA expression in vivo. Using a PCR-RFLP method, we genotyped the UCP2 -866G/A polymorphism in 75 unrelated nonobese nondiabetic Iranians. The frequencies of the UCP2 -866G/A genotypes in 75 Iranian normal subjects were 7 (9.4%) for AA, 41 (54.6%) for GA, and 27 (36%) for GG. Significantly higher HDL cholesterol was detected in people with the GG genotype (p = 0.02) compared to individuals with the GA and AA genotypes. The frequency distribution results were compared with data from Japanese, Italians, Germans, Austrians, and Danes. Our allele frequencies were significantly different from the Japanese data from two different reports (P < 0.025) but not from the others. The Japanese data showed a higher frequency of the AA genotype, which is associated with a low prevalence of obesity, than the Caucasian individuals' data did. In conclusion, a single nucleotide polymorphism in the promoter region of the UCP2 gene has a significant association with HDL cholesterol level in Iranian nonobese nondiabetic subjects. Also, our allele-frequency distribution for this single nucleotide polymorphism is closer to European Caucasians than to Japanese in nonobese nondiabetic individuals.     

Association of the -112A>C polymorphism of the uncoupling protein 1 gene with insulin resistance in Japanese individuals with type 2 diabetes

The -112A>C polymorphism (rs10011540) of the gene for uncoupling protein 1 (UCP1) has been associated with type 2 diabetes mellitus in Japanese individuals. The aim of the present study was to investigate the effects of this polymorphism, as well as the well-known -3826A>G polymorphism (rs1800592), on clinical characteristics of type 2 diabetes. We determined the genotypes of the two polymorphisms in 93 Japanese patients with type 2 diabetes. Intramyocellular lipid content and hepatic lipid content (HLC) were measured by magnetic resonance spectroscopy. No significant differences in age, sex, BMI, or HbA1c level were detected between type 2 diabetic patients with the -112C allele and those without it. However, homeostasis model assessment for insulin resistance (p=0.0089) and HLC (p=0.012) was significantly greater in patients with the -112C allele. We did not detect an association of the -3826A>G polymorphism (rs1800592) of UCP1 gene with any measured parameters. These results suggest that insulin resistance caused by the -112C allele influences the susceptibility to type 2 diabetes.     

Ⅱ型糖尿病患者APOA5-1131T/C基因多态性与血脂代谢和胰岛素抵抗的关系研究

为了探讨载脂蛋白A5基因(APOA5)-1131T/C多态性在中国镇江地区的频率分布及其与血浆脂质代谢和Ⅱ型糖尿病患者胰岛素抵抗的关系, 采用聚合酶链反应-限制性片段长度多态性分析(PCR-RFLP)结合琼脂糖凝胶电泳技术检测152例健康人及71例Ⅱ型糖尿病患者APOA5 -1131T/C基因型及等位基因频率分布, 同时采用生化方法测定所有研究对象的血脂、血糖和胰岛素水平。结果显示: 糖尿病组APOA5 -1131C等位基因频率显著高于对照组(0.430 vs 0.296, P = 0.006)。CC纯合子患糖尿病的风险是TT纯合子的3.75倍(OR = 3.75, 95% CI: 1.57~8.92), 且经Logistic回归分析, 校正年龄、BMI和血浆HDL-c、LDL-c及ApoB水平等其他混杂因素影响后, 这种差异仍具有显著性意义(OR = 2.70, 95%CI: 1.24 ~ 5.86)。糖尿病组C等位基因携带者TG水平显著高于非C等位基因携带者(P < 0.01), TC水平和LDL-c水平亦明显升高(P < 0.05)。但是在两组中, 不同基因型患者 胰岛素抵抗相关指标均无显示差异。提示APOA5-1131T/C单核苷酸多态性对人群血浆TG水平有影响, -1131C等位基因与血浆TG、TC和LDL-c水平增高有关, 但是与糖尿病患者胰岛素相关指标无关; APOA5 -1131C等位基因可能与人群糖尿病的发生相关联。     

PPAR-gamma2 Pro12Ala polymorphism in the population of obese and non-obese men of the city of Wroclaw

INTRODUCTION: The aim of this study was to examine the association of Pro12Ala PPARgamma2 polymorphism with anthropometric and biochemical parameters defining the risk for the development of metabolic syndrome in a healthy population of men. MATERIAL AND METHODS: The study group consisted of 176 healthy men, aged 25-65 years (average 54.16 years). Polymorphisms of the PPAR-g gene (Pro12Ala, Ala12Ala, Pro12Pro) were explored using the PCR-RFLP method. Plasma glucose, insulin, total cholesterol, LDL, HDL and TG were measured using commercially available kits. RESULTS: The genotypic distribution of the Pro12Ala polymorphism was as follows: Pro/Ala 69.8% (n = 123), Ala/Ala 28.4% (n = 50) and Pro/Pro 1.8% (n = 3). The Pro12Ala and Ala12Ala subjects did not differ in any of the measured variables. The non-obese (BMI < 30 kg/m(2), n = 117) and obese subpopulations (BMI > 30 kg/m(2), n = 56) did not significantly differ in the distribution of the genotypes. In the nonobese subpopulation, the homozygous Ala12 carriers (n = 38, 32.4%) had higher systolic blood pressure, plasma triglycerides, insulin levels and HOMA-IR. CONCLUSIONS: We conclude that despite the high frequency of the Ala allele at the PPAR-gamma2 gene in our population of Polish men, the Ala12 allele does not appear to improve insulin sensitivity or have an influence on the occurrence of obesity. It remains to be explained by larger studies if this polymorphism carries any risk of the development of metabolic abnormalities in non-obese men.     

Uncoupling protein 2 promoter polymorphism -866G/A, central adiposity, and metabolic syndrome in Asians

A polymorphism in the promoter region of uncoupling protein 2 gene -866G/A has been associated with its expression levels in adipose tissue, the risk of obesity, and metabolic abnormalities. Our purpose was to examine the associations of -866G/A with body fat and the risk of metabolic syndrome in a random sample of 4018 Asians (1858 men and 2160 women) from three ethnic groups (Chinese, Malay, and Indian). The minor allele frequency of -866G/A polymorphism in South Asians was similar to that in whites. After adjustment for covariates including age, cigarette smoking, and physical activity, the -866A/A genotype was associated with higher waist-to-hip ratio as compared with the wild-type genotype in Chinese and Indian men (p = 0.018 and p = 0.046, respectively). Moreover, Indian men with -866A/A genotype had a significantly increased risk of metabolic syndrome as compared with those homozygous for the wild-type (odds ratio, 2.66; 95% confidence interval, 1.21 to 5.88; p = 0.015). Such a risk was mainly caused by the excess presence of hypertriglyceridemia and central obesity. Our findings indicate that the uncoupling protein 2 gene -866G/A polymorphism may increase the risks of central obesity and metabolic syndrome, with greater effects on Asian men.     

Meta-Analysis Reveals the Association of Common Variants in the Uncoupling Protein (UCP) 1–3 Genes with Body Mass Index Variability

Background

The relationship between uncoupling protein (UCP) 1–3 polymorphisms and susceptibility to obesity has been investigated in several genetic studies. However, the impact of these polymorphisms on obesity is still under debate, with contradictory results being reported. Until this date, no meta-analysis evaluated the association of UCP polymorphisms with body mass index (BMI) variability. Thus, this paper describe a meta-analysis conducted to evaluate if the -3826A/G (UCP1); -866G/A, Ala55Val and Ins/Del (UCP2) and -55C/T (UCP3) polymorphisms are associated with BMI changes.

Methods

A literature search was run to identify all studies that investigated associations between UCP1-3 polymorphisms and BMI. Weighted mean differences (WMD) were calculated for different inheritance models.

Results

Fifty-six studies were eligible for inclusion in the meta-analysis. Meta-analysis results showed that UCP2 55Val/Val genotype was associated with increased BMI in Europeans [Random Effect Model (REM) WMD 0.81, 95% CI 0.20, 1.41]. Moreover, the UCP2 Ins allele and UCP3-55T/T genotype were associated with increased BMI in Asians [REM WMD 0.46, 95% CI 0.09, 0.83 and Fixed Effect Model (FEM) WMD 1.63, 95% CI 0.25, 3.01]. However, a decreased BMI mean was observed for the UCP2-866 A allele in Europeans under a dominant model of inheritance (REM WMD −0.18, 95% CI −0.35, −0.01). There was no significant association of the UCP1-3826A/G polymorphism with BMI mean differences.

Conclusions

The meta-analysis detected a significant association between the UCP2-866G/A, Ins/Del, Ala55Val and UCP3-55C/T polymorphisms and BMI mean differences.     

Association of the TNF‐α−308 G/A Promoter Polymorphism with Insulin Resistance in Obesity

Objective: Obesity is a major risk factor for the development of type 2 diabetes. Tumor necrosis factor (TNF)‐α is a candidate gene for the development of both obesity and insulin resistance. We investigated whether a common polymorphism in the promoter region (?308 G/A) of the TNF‐α gene was associated with increased risk for the development of insulin resistance and cardiovascular disease in an obese Australian population. Research Methods and Procedures: Obese, non‐diabetic subjects (146 women and 34 men) were genotyped with polymerase chain reaction‐restriction fragment length polymorphism techniques, and anthropometric and biochemical measurements were analyzed. A homeostasis model assessment (HOMA) score was used to gauge the level of insulin resistance. Results: The frequencies of the G allele and the A allele were 0.759 and 0.241, respectively. Subjects homozygous for the A allele had higher fasting insulin levels (226 vs. 131 pM; p < 0.001), higher HOMA scores (10.2 vs. 5.3; p < 0.001), higher systolic blood pressure (143 vs. 129 mm Hg; p = 0.02), and lower high‐density lipoprotein (HDL) cholesterol (1.13 vs. 1.25 mM; p = 0.04) than did subjects homozygous for the G allele. Whereas an association between insulin resistance and body mass index or waist circumference was seen in all subjects, a highly significant negative correlation of HDL cholesterol to HOMA scores (r = ?0.710; p < 0.001) occurred in subjects with the A allele only. Discussion: The ?308 G/A TNF‐α gene variant conveys an increased risk for the development of insulin resistance in obese subjects. The presence of low HDL cholesterol levels further increases the risks associated with insulin resistance in carriers of the A allele.     

Effect of the Interleukin‐6 (−174) G/C Promoter Polymorphism on Adiponectin and Insulin Sensitivity

We investigated the relation among the interleukin (IL)‐6 (?174) G/C promoter polymorphism, adipose tissue gene expression of IL6, circulating adiponectin, and systemic insulin sensitivity. Eighty‐five Swedish male subjects who had participated in our previous prediabetic phenotype characterization study were genotyped for the IL6 (?174) G/C polymorphism. Subcutaneous adipose tissue gene expression of IL6 and adiponectin was measured in 44 subjects. The IL6 (?174) G allele carriers had higher fasting plasma insulin levels (C/C, 7.8 ± 1.1; G/C, 9.0 ± 0.6; G/G, 10.5 ± 1.0 mU/L) and higher homeostasis model assessment for insulin resistance (C/C, 1.6 ± 0.2; G/C, 1.9 ± 0.1; G/G, 2.2 ± 0.2) compared with subjects with the C/C genotype. The circulating adiponectin levels were lower in the G allele carriers (C/C, 7.93 ± 0.45; G/C, 7.05 ± 0.44; G/G, 7.02 ± 0.46 μg/mL), whereas the IL‐6 levels did not differ among the three genotypes. Adipose tissue IL6 gene expression was significantly higher in the G allele carriers compared with the subjects homozygous for the C allele (C/C, 0.29 ± 0.15; G/C, 0.84 ± 0.29; G/G, 0.62 ± 0.35). Our results suggest that IL6 (?174) G/C polymorphism is associated with insulin resistance and increased adipose tissue IL6 gene expression, which can impair adiponectin production.     

PAI-1 Gene 4G/5G polymorphism and risk of type 2 diabetes in a population-based sample

Elevated plasma levels of plasminogen activator inhibitor-1 (PAI-1) increase risk for type 2 diabetes. The PAI-1 4G/5G polymorphism is a major genetic determinant of plasma PAI-1 levels, with 4G/4G homozygotes having elevated PAI-1 levels relative to 5G allele carriers. These observations suggest the hypothesis that the PAI-1 4G/5G polymorphism could be a genetic risk factor for diabetes. We tested this hypothesis among 2169 participants of the Framingham Offspring Study followed for seven examinations over 26 years for 216 cases of type 2 diabetes. PAI-1 4G/4G homozygotes (genotype frequency, 27.4%) were not at significantly (p > 0.05) increased risk of incident diabetes compared with 5G allele carriers and did not have elevated levels of diabetes-related quantitative traits including BMI, fasting plasma glucose, or fasting insulin. In proportional hazards regression models accounting for correlation among siblings, with the 5G/5G genotype as the referent, the hazard ratio for incident diabetes for 4G/5G carriers was 0.93 (95% confidence interval, 0.68 to 1.28) and for 4G/4G carriers was 1.20 (95% confidence interval, 0.83 to 1.92). Results were not altered by further adjustment for sex or levels of BMI, triglycerides, or PAI-1. We conclude that the PAI-1 4G/5G polymorphism is not an important genetic risk factor for type 2 diabetes in this community-based sample. Elevated PAI-1 levels may be associated with an increased risk for diabetes as a marker for underlying endothelial dysfunction rather than by a direct effect of genetically mediated elevated levels.     

Association of Two CETP Polymorphisms With HDL Levels in the Chinese Obese Population

The association of two cholesterol ester transfer protein (CETP) polymorphisms, D442G and TAQIB (B1→B2), with high‐density lipoprotein (HDL) levels in 932 Chinese obese individuals (BMI ≥ 27) was investigated in comparison with normal controls (BMI ≤ 24). Independent association was demonstrated for TAQIB minor allele B2 and CETP442 minor allele G with elevated HDL levels. The CETP D442G polymorphism was associated with a much greater increase in HDL levels in subjects with BMI exceeding 27 kg/m² (+5.42 mg/dl, P = 0.0007) compared to normal controls (+1.97 mg/dl, P = 0.275), and the increase in HDL reached the highest level among subjects with BMI exceeding 30 kg/m² (+6.80 mg/dl, P = 0.016). TAQIB showed significant association with HDL levels only in normal BMI subgroup (P = 0.0017). TAQIB significantly interacted with serum triglyceride (TG) on modulating HDL levels (P = 0.027). The TAQIB–TG interaction effect remained marginally significant after controlling for BMI (P = 0.057). We conclude that D442G polymorphism is associated with more HDL elevation in obesity. TAQIB interacts with serum TG on modulating HDL levels, and the interaction is partly independent of BMI.     

Association of the UCP polymorphisms with susceptibility to obesity: case–control study and meta-analysis

This paper describes a case–control study and a meta-analysis performed to evaluate if the following polymorphisms are associated with presence of obesity: ?3826A/G (UCP1); ?866G/A, Ala55Val and Ins/Del (UCP2) and ?55C/T (UCP3). The case–control study enrolled 282 obese and 483 non-obese patients with type 2 diabetes. A literature search was made to identify all studies that evaluated associations between UCP1–3 polymorphisms and obesity. In the case–control study the distributions of the UCP variants did not differ between obese and non-obese groups (P > 0.05). Forty-seven studies were eligible for the meta-analysis and the results showed that the UCP2 ?866G/A and UCP3 ?55C/T polymorphisms were associated with protection to obesity in Europeans (OR = 0.89, 95 % CI 0.82–0.97 and OR = 0.88, 95 % CI 0.80–0.97, respectively). The UCP2 Ala55 val polymorphism was associated with obesity in Asians (OR = 1.61, 95 % CI 1.13–2.30). The UCP2 Ins/Del polymorphism was associated with obesity mainly in Europeans (OR = 1.19, 95 % CI 1.00–1.42). There was no significant association of the UCP1 ?3826A/G polymorphism with obesity. In our case–control study we were not able to demonstrate any association between UCP polymorphisms and obesity in T2DM patients; however, in the meta-analysis we detected a significant association of UCP2 ?866G/A, Ins/Del, Ala55Val and UCP3 ?55C/T polymorphisms with obesity.     

The promoter region of the adiponectin gene is a determinant in modulating insulin sensitivity in childhood obesity

We investigated the association of the -11,391G>A, -11,377G>C, +45T>G, and +276G>T adiponectin single-nucleotide polymorphisms (SNPs) and expected haplotypes with the insulin resistance (IR) state in overweight/obese children; by using the haplotype background analysis, we also assessed the effect of each SNP independently. GG genotype at the -11,391 locus was associated with higher fasting insulin levels and homeostasis model assessment-IR index and lower adiponectin levels compared with GA + AA genotypes (p = 0.01, 0.002, and 0.03, respectively). Those heterozygous and homozygous for G allele at the -11,377 locus showed higher fasting glucose (p = 0.001 for both), fasting insulin (p = 0.001 for both), homeostasis model assessment-IR index (p < 0.001 for both), and triglyceride levels (p = 0.02 and 0.03, respectively) and lower adiponectin levels (p = 0.002 and 0.02, respectively) compared with C homozygotes. The +45G carriers showed higher fasting and 2-hour glucose levels (p = 0.01 for both) and lower adiponectin levels (p = 0.02) compared with non-carriers. Haplotype analysis suggested that, considering the same haplotypic background, each of the three polymorphisms exerted an independent effect on investigated parameters. The -11,391G>A, -11,377C>G, and +45T>G SNPs are associated with IR syndrome in overweight/obese children; they independently influence the investigated variables. The effect of +45T>G SNP seems to be marginal compared with the promoter SNPs. The GGT haplotype is associated with the highest degree of IR.     

Genetic variation in the cannabinoid receptor gene (CNR1) (G1359A polymorphism) and their influence on anthropometric parameters and metabolic parameters under a high monounsaturated vs. high polyunsaturated fat hypocaloric diets

An intragenic polymorphism (1359 G/A) of the cannabinoid receptor 1 (CNR1) gene was reported as a common polymorphism in Caucasian populations (rs1049353). Intervention studies with this polymorphism have yield contradictories results. We decide to investigate the role of polymorphism (G1359A) of (CNR1) gene on metabolic parameters and weight loss secondary to a high monounsaturated fat and high polyunsaturated fat hypocaloric diets in obese subjects. A population of 258 obese subjects was analyzed in a randomized trial. A nutritional evaluation was performed at the beginning and at the end of a 3-month period in which subjects received 1 of 2 diets (diet M: high monounsaturated fat diet vs diet P: high polyunsaturated fat diet). One hundred and sixty five patients (63.9%) had the genotype G1359G and 93 (36.1%) patients (A allele carriers) had G1359A (78 patients,30.3%) or A1359A (15 patients,5.8%) genotypes. In subjects with both genotypes, body mass index, weight, fat mass, waist circumference and systolic blood pressures decreased with both diets. With the diet-type M and in both genotype groups, biochemical parameters remained unchanged. After the diet type P and in subjects with both genotypes, glucose, total cholesterol, low-density lipoprotein (LDL) cholesterol, insulin and homeostasis model assessment for insulin resistance (HOMA-IR) levels decreased. In G1359G genotype subjects after both diets, leptin levels decreased. The finding of this study is the association of the A allele with a lack of improvement on leptin levels. Subjects with both genotypes and after a high polyunsaturated fat hypocaloric diet showed a significant improvement of LDL cholesterol, total cholesterol, HOMA-IR and insulin levels.     

The common adiponutrin variant p.I148M does not confer gallstone risk but affects fasting glucose and triglyceride levels

Recently the common adiponutrin (PNPLA3) polymorphism p.I148M has been identified as a genetic determinant of severe forms of non-alcoholic fatty liver disease and alcoholic liver disease. Additionally, insulin resistance - linked to the development of non-alcoholic steatohepatitis - increases the risk of developing gallstones. Here we assessed whether the PNPLA3 p.I148M (c.444 C-G) polymorphism affects glucose and lipid levels and increases gallstone risk. We analysed 229 individuals with gallstones from 108 families (age 24-80 years, BMI 17-55 kg/m(2)) and 258 gallstone-free controls (age 20-70 years, BMI 14-43 kg/m(2)). Fasting glucose, triglyceride and cholesterol serum levels were determined. The p.I148M polymorphism was genotyped using a PCR-based assay with 5'-nuclease and fluorescence detection. Case-control association tests and nonparametric linkage (NPL) analysis in sib-pairs were performed. Individuals carrying the [GG] genotype had significantly (P<0.0001) higher median fasting glucose levels as compared to [GC] and [CC] carriers. After adjustment for multiple testing, we detected a trend for an association between triglyceride levels and variant adiponutrin in gallstone patients (P=0.032), and gallstone cases carrying the genotype [CC] presented with significantly higher triglyceride levels than the corresponding controls (P<0.003). No significant effects on cholesterol metabolism were detected. Neither genotype distributions nor NPL scores provided evidence for association or linkage between the PNPLA3 variant and gallstones. In conclusion, homozygous carriers of the PNPLA3 risk allele display higher fasting glucose. Although this adiponutrin variant may affect triglyceride homeostasis, it does not increase the risk of cholelithiasis.     

G allele of the −930A>G polymorphism of the CYBA gene is associated with insulin resistance in obese subjects

It has been shown that NADPH oxidase plays a role in oxidative stress which has been involved in the development of metabolic syndrome. The ?930A/G polymorphism of the CYBA gene (that codes p22phox, a major component of the NADPH oxidase) has been associated with human hypertension and with a reduction in NADPH oxidase activity. In this work, we have examined the influence of the ?930A/G polymorphism on obesity risk and insulin resistance in a case-control study of Spanish subjects (n=313). In the obese group (n=159), there was a statistically significant association between the GG genotype of the ?930A/G polymorphism of the CYBA gene and fasting insulin levels and HOMA index. This outcome agrees with previous findings concerning functional analyses of this polymorphism and reinforces the hypothesis that insulin resistance is associated with oxidative stress. In conclusion, a protective effect in carriers of the ?930A/G, polymorphism of the p22phox gene against insulin resistance in a population of Spanish obese adults has been found.     

Early Detrimental Metabolic Outcomes of rs17300539‐A Allele of ADIPOQ Gene Despite Higher Adiponectinemia

Minor allele A of single‐nucleotide polymorphism (SNP) 11391 G/A of ADIPOQ gene (rs17300539) has been consistently associated with higher adiponectin levels in adults and children. The aim of this study was to investigate the metabolic role of this variant in a large cohort of children of European origin. A total of 1,852 children from two general populations in Verona and in Fleurbaix–Laventie and from the Lille childhood obesity cohort, were genotyped and pooled together after checking for the absence of genetic heterogeneity for rs17300539 between Italian and French children. The genotype of rs17300539 was studied in relation to circulating adiponectin levels, BMI, fasting plasma glucose, fasting serum insulin (FSI), insulin resistance index (homeostasis model assessment of insulin resistance (HOMA_IR)), high‐density lipoprotein cholesterol, and triglycerides. After adjustment for known confounders, rs17300539 GA+AA carriers had 1.6 µg/ml higher adiponectin levels (P = 6 × 10^?8) than GG carriers. They also showed higher BMI (B = 0.97, P = 0.015) and higher prevalence of obesity (OR = 1.35 (1.06–1.85), P = 0.015) than GG carriers. Before adjusting for obesity status, GA+AA carriers had higher FSI (B = 1.10, P = 0.040) and higher HOMA_IR (B = 0.31, P = 0.020) than GG carriers. After adjustment for obesity status, they did not differ from GG carriers for any metabolic parameter, either among obese or nonobese children. The rs17300539‐A variant, though consistently associated with higher adiponectin levels, does not exert any appreciable protective metabolic effect in children, either in the presence or absence of obesity. In contrast, this SNP may increase the risk for childhood obesity and related insulin resistance.     

Association of ARHGEF11 R1467H polymorphism with risk for type 2 diabetes mellitus and insulin resistance in Chinese population

The human Rho guanine nucleotide exchange factor 11 (ARHGEF11), located on chromosome 1q21, is an activator of Rho GTPases involved in G protein signaling pathway known to regulate insulin secretion and action. The aim of our study was to evaluate the relationship between the previously reported R1467H G/A variant in ARHGEF11 and risk of type 2 diabetes mellitus (T2DM) and insulin resistance as well as metabolic traits in a Chinese population. We genotyped R1467H G/A polymorphism in 311 patients with T2DM and 328 control subjects in a Chinese population, using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocol and DNA sequencing methods. The genotype and allele distributions of the R1467H G/A polymorphism were significantly different between the T2DM group and the normal control group (P = 0.024, 0.018, respectively) and we also found that the A allele carriers (GA + AA genotype) had markedly higher risk of T2DM as compared with the wild-type GG genotype after adjustment for gender, age, and BMI (OR = 1.578, 95% CI 1.126–2.212, P = 0.008). Moreover, in the T2DM group the A allele carriers had higher FPG, FINS, and HOMA-IR than that of the GG homozygote (P = 0.015, 0.029, and 0.007, respectively). FPG and HOMA-IR levels were also significantly increased from A allele carriers to GG homozygote in the control group (P = 0.017, 0.012, respectively). Our investigation suggests that the R1467H polymorphism of ARHGEF11 gene may contribute to susceptibility to T2DM and insulin resistance in a Chinese population.     

Lack of association of glutamate decarboxylase 2 gene polymorphisms with severe obesity in utah

Three polymorphisms of the glutamate decarboxylase 2 gene, which encodes the glutamic acid decarboxylase enzyme, have been associated with severe obesity in a large French cohort. One of these polymorphisms was shown to have functional consequences on promoter expression. Another polymorphism was associated with insulin levels and secretion. These associations were examined in 855 severely obese Utah subjects (mean BMI = 48 kg/m(2)) and a normal-weight and normoglycemic subset (N = 130, mean BMI = 22 kg/m(2)) of a random sample of the Utah population (N = 462). Comparisons of the normal-weight random group with the severely obese group did not result in significant genotype or allele frequency differences for any of the three polymorphisms, C61450A, T83897A, or A-243G (all p > or = 0.18). Haplotypes were also not related to severe obesity (p = 0.10). None of the polymorphisms was significantly related to fasting glucose, insulin levels, or homeostasis model assessment insulin resistance or secretion indices. This study of normal-weight and severely obese subjects from Utah does not provide evidence for involvement of the three genotyped polymorphisms in the glutamate decarboxylase 2 gene with obesity or with insulin- and glucose-related measures associated with obesity.