The SNP276G>T polymorphism in the adiponectin (ACDC) gene is more strongly associated with insulin resistance and cardiovascular disease risk than SNP45T>G in nonobese/nondiabetic Korean men independent of abdominal adiposity and circulating plasma adiponectin

This study aimed to determine whether polymorphisms of the adiponectin (ACDC) gene independently contribute to insulin resistance (IR) and other cardiovascular disease (CVD) risk factors in nonobese, nondiabetic Korean men after adjusting for major environmental factors that influence IR. Among the 7 ACDC single-nucleotide polymorphisms (SNPs;C-11377G, T45G, G276T, H241P, Y111H, G90S, and R221S) prescreened in 48 subjects, we genotyped 333 subjects for SNP45 and SNP276, both of which showed an allele frequency of more than 2%. In Pearson correlation and multiple stepwise regression analyses, we found that waist circumference was the most important influencing factor (beta = .369, P < .001) in homeostasis model assessment (HOMA)-IR, whereas plasma adiponectin was the second most important (beta = -.217, P = .023). At position 276, T/T subjects showed significantly lower glucose concentrations (P = .043) and higher low-density lipoprotein particle sizes (P = .033) than the G/G and G/T subjects. The subjects also had lower serum triglycerides and HOMA-IR; however, these results were not statistically significant. After adjusting for waist circumference and plasma adiponectin, T/T subjects showed a significantly lower HOMA-IR than G/G or G/T subjects (P = .048). On the other hand, at position 45, only glucose concentrations were significantly lower in G carriers (P = .005). In the SNP45-SNP276 haplotype test, TT/TT subjects (having T/T at both SNP45 and SNP276) showed significantly lower IR before and after adjusting for waist circumference and adiponectin levels than did other carriers. In conclusion, we suggest that SNP276G>T, rather than SNP45T>G, is more strongly associated (both directly and indirectly) than with several components of metabolic syndrome and CVD risk, including IR, triglyceride concentration, and low-density lipoprotein particle size, in nonobese, nondiabetic men.     

Associations between two single nucleotide polymorphisms of adiponectin gene and coronary artery diseases

Adiponectin, an adipocyte-secreted protein, is known to have anti-atherogenic, anti-inflammatory and anti-diabetic properties and its serum levels are decreased in obesity, type 2 diabetes, and coronary artery disease. Several studies have been performed to investigate the association of genetic variations in the adiponectin with obesity, insulin resistance, and type 2 diabetes, but few studies were performed in association with coronary artery disease. Therefore we examined the associations between two single nucleotide polymorphisms (SNPs), +45T>G and +276G>T of the adiponectin gene, and coronary artery diseases (CAD). One hundred and fifty six subjects (mean age 57.4 yrs) were enrolled in which coronary angiograms were performed due to chest pain. Genotypings were done for two SNPs in the adiponectin gene by Taqman polymerase chain reaction (PCR) method. The presence of CAD was defined as a >50% reduction of coronary artery diameter. Among 156 subjects, the allele frequencies were 0.683 for G allele and 0.317 for T allele in SNP +276G>T and 0.705 for T allele and 0.295 for G allele in SNP +45T>G. Both genotypes were in compliance with Hardy-Weinberg equilibrium. No association with the presence of CAD was observed for adiponectin gene SNP276 and SNP45 (p = 0.954, p = 0.843). Also, no significant association was observed between the severity of CAD and either SNPs (p = 0.571, p = 0.955). Our study showed that SNP +276G>T and +45T>G in adiponectin gene were not associated with the presence of CAD. Further studies will be necessary to confirm the role of SNP 276G>T and 45T>G in the development of CAD.     

Associations between single-nucleotide polymorphisms (+45T>G, +276G>T, ?11377C>G, ?11391G>A) of adiponectin gene and type 2 diabetes mellitus: a systematic review and meta-analysis

Aims/hypothesis

The associations between adiponectin polymorphisms and type 2 diabetes have been studied widely; however, results are inconsistent.

Methods

We searched electronic literature databases and reference lists of relevant articles. A fixed or random effects model was used on the basis of heterogeneity. Sub-group and meta-regression analyses were conducted to explore the sources of heterogeneity.

Results

There were no statistically significant associations between +45T>G (rs2241766), +276G>T (rs1501299), ?11391G>A (rs17300539) and type 2 diabetes risk. However, for ?11377C>G (rs266729), the pooled OR (95% CI) for G vs C allele was 1.07 (1.03?C1.11, p?=?0.001). Subgroup analysis by study design revealed that ?11377C>G (rs266729) dominant model (CG+GG vs CC, p?=?0.0008) and G vs C allele (p?=?0.0004) might be associated with type 2 diabetes risk in population-based case?Ccontrol studies. After stratification by ethnicity, we found that ?11377C>G (rs266729) dominant model (CG+GG vs CC, p?=?0.004) and G vs C allele (p?=?0.001) might be associated with type 2 diabetes risk in white individuals. In individuals with a family history of diabetes, the presence of ?11391G>A (rs17300539) dominant model (GA+AA vs GG) and A vs G allele might be associated with increased risk of type 2 diabetes.

Conclusions/interpretation

The presence of +45T>G (rs2241766), +276G>T (rs1501299) and ?11391G>A (rs17300539) do not appear to influence the development of type 2 diabetes. However, G vs C allele of ?11377C>G (rs266729) might be a risk factor for type 2 diabetes.     

Influence of adiponectin gene polymorphism SNP276 (G/T) on adiponectin in response to exercise training

Adiponectin is an adipocytokine that is involved in insulin sensitivity. The adiponectin gene contains a single nucleotide polymorphism (SNP) at position 276 (G/T). The GG genotype of SNP276 (G/T) is associated with lower plasma adiponectin levels and a higher insulin resistance index. Therefore, we examined the influence of SNP276 (G/T) on the plasma level of adiponectin in response to exercise training. Thirty healthy Japanese (M12/F18; 56 to 79 years old) performed both resistance and endurance training, 5 times a week for 6 months. The work rate per kg of weight at double-product break-point (DPBP) was measured. Blood samples were obtained before and after the experiment. Plasma concentrations of adiponectin, HbA1c, insulin, glucose, total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol, and triglyceride were measured. Genotypes of SNP276 were specified. Student's t-test for paired values and unpaired values was used. After the 6-month training period, the work rate per kg of weight at DPBP and the plasma HDL-cholesterol level were significantly improved (P<0.05), while no change was observed in the total plasma adiponectin level. However, the plasma adiponectin level in those with the GT + TT genotype had significantly increased (P<0.05). Additionally, the degree of the decrease in the HOMA-R level was significantly greater in the subjects with the GT + TT genotype than those with the GG genotype (p<0.05). Our results suggest that subjects with the genotype GT + TT at SNP276 (G/T) have a greater adiponectin-related response to exercise training than those with the GG genotype.     

Variation in the ADIPOQ gene promoter is associated with carotid intima media thickness independent of plasma adiponectin levels in healthy subjects.

AIMS: The ADIPOQ gene encodes the protein adiponectin, and decreased circulating adiponectin levels have been observed in cardiovascular disease. We investigated the role of the ADIPOQ gene single-nucleotide polymorphisms (SNPs) A-11426G, G-11391A, C-11377G, and T45G with plasma adiponectin levels and common carotid artery intima media thickness (IMT) in a cohort of healthy subjects participating in the RISC (Relationship between Insulin Sensitivity and Cardiovascular disease) study. METHODS AND RESULTS: Anthropometric and metabolic assessment and B-mode ultrasound of the carotid IMT were measured in 1306 subjects [589 men; 717 women, mean +/- SD age 43.8 +/- 8.3 years, BMI 25.5 +/- 4.0 kg/m(2)] recruited from 19 centres in 14 European countries. Carriers of the -11426G allele and homozygous carriers of the -11391G allele had significantly lower plasma adiponectin levels. These relationships remained significant after adjusting for age, sex, recruitment centre, and BMI. Carriers of SNP -11377G allele had significantly greater IMT values compared with C allele homozygotes [geometric mean (interquartile range) 601 (543-665) vs. 590 (537-647) mum, P = 0.021]. This relationship became stronger after correcting for key covariates, including plasma adiponectin levels (P = 0.011). CONCLUSION: Variation within the ADIPOQ gene promoter is directly associated with carotid IMT in healthy subjects and is independent of circulating adiponectin levels.     

宁夏回族代谢综合征与脂联素水平及基因多态性的相关性研究

目的探讨脂联素水平及其单核苷酸多态性(SNP+45T/G和SNP+276G/T)2个位点与宁夏回族代谢综合征(MS)的关系。方法选择祖居宁夏、无亲缘关系、3代内无异族通婚史的回族个体共305例,分为MS组207例和对照组98例;应用ELISA及PCR-RFLP技术检测血浆脂联素水平及其2个位点的SNP。结果与对照组比较,MS组体重指数、腰臀比、收缩压、舒张压、空腹血糖、空腹胰岛素、TG、LDL-C、胰岛素抵抗指数明显升高,TC、HDL-C、脂联素水平明显降低,差异有统计学意义(P<0.05,P<0.01)。与对照组比较,MS组SNP+45位点TG+GG基因型和G等位基因频率明显升高,TT基因型及T等位基因频率明显降低,差异有统计学意义(P<0.01)。多因素逐步logistic回归分析显示,SNP+45T/G基因多态性是回族MS的危险因素。结论回族MS患者脂联素水平下降,回族人群中携带SNP+45G等位基因者患MS的风险增加。     

The glucose clamp reveals an association between adiponectin gene polymorphisms and insulin sensitivity in obese subjects

Results concerning the association of adiponectin gene polymorphisms (single-nucleotide polymorphisms, SNPs) with obesity, type 2 diabetes (T2DM), metabolic disorders and insulin resistance have not lead to definite conclusions. The aim of our study was to investigate a possible association between the -11391G>A and -11377C>G SNPs of adiponectin gene and measure of insulin sensitivity evaluated by the hyperinsulinemic-euglycemic clamp in a group of 'uncomplicated' obese subjects (with no associated comorbidities) (n=99, mean age 35 years) with a history of obesity lasting at least 10 years. The study of uncomplicated obese subjects, free of possible confounding factors that could interfere with insulin sensitivity, such as pharmacological treatment, provides a good model to assess insulin sensitivity per se. We observed that subjects homozygous for the G allele at locus -11391 had lower M (mg/kg min)/fat-free mass (FFM) index and adiponectin levels compared to subjects with GA+AA genotypes (P=0.002 and P=0.03, respectively) and subjects carrying the -11377G variant had lower M (mg/kg min)/FFM index and adiponectin levels compared to noncarriers (P=0.003 and P=0.03, respectively). Our results imply that the two promoter SNPs, -11391G>A and -11377C>G, of the adiponectin gene are associated with a reduced insulin sensitivity evaluated by hyperinsulinemic-euglycemic clamp in obese subjects.     

Genetic variation at the perilipin locus is associated with changes in serum free fatty acids and abdominal fat following mild weight loss

OBJECTIVE: Perilipin (PLIN) is a class of protein-coating lipid droplets in adipocytes. We aimed to examine the association between common single-nucleotide polymorphisms (SNPs) at PLIN locus with circulating free fatty acid (FFA) and abdominal fat distribution in response to weight loss. METHODS: Non-diabetic/overweight-obese Koreans (n=177) participated in a 12-week calorie restriction (-300kcal/day) program. Seven SNPs (6209T>C, 10076C>G, 10171A>T, 11482G>A, 13042A>G, 13048C>T and 14995A>T), abdominal fat areas (visceral/subcutaneous fat areas at 1st lumbar and 4th lumbar levels), serum lipids, glucose, insulin, FFA, oxidized low-density lipoprotein (LDL) and urinary 8-epi-prostaglandin F(2alpha) (PGF(2alpha)) were examined. RESULTS: Single-nucleotide polymorphisms 10076C>G/10171A>T showed the strongest positive linkage disequilibrium (LD) (D'=0.923, R (2)=0.839, P<0.001) and SNPs11482G>A/14995A>T showed moderate positive LD (D'=0.824, R (2)=0.578, P<0.001). Calorie restriction induced 4.6% weight loss with significant abdominal fat reduction. In response to weight loss, subjects with nCA/nCA haplotypes at SNPs 10076C>G/10171A>T showed greater reduction in FFA levels than those with CA/CA haplotype (CA/CA: C/C at SNP 10076 and A/A at SNP 10171, nCA: non-CA haplotype carrier). On the other hand, subjects with nGA/nGA haplotype at SNPs 11482G>A/14995A>T had increased FFA levels with a rapid loss in abdominal fat, whereas GA/GA haplotype carriers had reduction in FFA levels. These results still remained significant after adjusting for age, gender and BMI. Prostaglandin F(2alpha) and oxidized LDL were also more reduced in GA/GA haplotype carriers than in nGA haplotype carriers. This effect remained significant after adjusting for baseline level, age, gender and BMI. Paradoxically, nGA haplotype carriers had increased levels of urinary PGF(2alpha) after weight reduction. CONCLUSION: Fasting plasma FFA changes following a modest weight loss in overweight-obese subjects are influenced by the genetic variability at the PLIN locus. Furthermore, circulating FFA changes rather than body fat itself may determine changes in lipid peroxides such as urinary PGF(2alpha) and oxidized LDL.     

脂联素基因多态性和血清脂联素水平与非酒精性脂肪肝的相关性

目的:探讨脂联素基因单核苷酸多态性及血清脂联素水平与汉族人非酒精性脂肪肝(nonalcoholic fatty liver disease,NAFLD)的关系.方法:根据性别、年龄和体质量指数(body-mass index,BMI)配对入选NAFLD患者和对照组,各106例.测定基因多态性和血清脂联素水平,分析其与人体测量参数、生化、激素和代谢的关系.结果:在NAFLD和对照者中,SNP+45位点T/T、T/G和G/G基因型分别为64.2%、54.7%和23.6%、38.7%和12.2%、6.6%,NAFLD组G/G基因型频率比对照组高(2=6.47,P<0.05),但两组等位基因型频率(2=0.64,P>0.05)差异无显著性;S N P+276位点中G/G、T/G和T/T基因型分别为4.2%、47.2%和27.3%、36.8%和8.5%、16.0%,NAFLD组T/T基因型频率高于对照组(2=6.68,P<0.05),两组等位基因频率差异有显著性(2=7.86,P<0.05).NAFLD组的血清脂联素水平较对照组显著降低(3.75mg/L±3.94mg/Lvs6.18mg/L±4.12mg/L),而且有更高的胰岛素低抗(2.19±1.35vs1.33±0.93).Logistic回归分析显示:BMI、WHR、HOMA-IR、脂联素是NAFLD的主要危险因素.结论:SNP45G/G和SNP276T/T基因型可能是中国汉族人NAFLD的易感基因,高BMI、WHR、HOMA-IR、低脂联素血症是NAFLD的主要危险因素.     

Adiponectin gene polymorphism 45T>G is associated with carotid artery plaques in patients with type 2 diabetes mellitus

Adiponectin has been reported to have a wide range of antiatherogenic actions. Two common single nucleotide polymorphisms (SNPs) at the adiponectin locus (45T>G and 276G>T) have been reported to be associated with diabetes and cardiovascular diseases. The aim of this study was to examine the association between common polymorphisms of the adiponectin gene (ACDC) and carotid atherosclerosis in patients with type 2 diabetes mellitus. A total of 708 unrelated patients with type 2 diabetes mellitus were recruited. SNP45 and SNP276 ACDC were genotyped, and B-mode ultrasonography of the carotid arteries was performed to measure carotid intima-media thickness and assess the presence of carotid artery plaques (CAP). Although there was no significant difference in carotid intima-media thickness according to ACDC genotype, subjects carrying the SNP45 GG genotype had a significantly higher risk of having CAP (odds ratio, 2.468; P = .045) compared with carriers of the T allele after adjustment for possible confounding factors. This study suggests that the GG genotype at ACDC SNP45 is associated with the presence of CAP and may contribute to atherosclerosis in type 2 diabetes mellitus.     

脂联素基因多态性与2型糖尿病大血管病变的关系

目的研究脂联素基因多态性与2型糖尿病（T2DM）大血管病变的关系。方法采用聚合酶链式反应-限制性片段长度多态性技术对198例T2DM患者和98例正常对照组进行脂联素基因多态性分析。结果对照组脂联素＋276TT基因型频率较患者组明显增多（P〈0．01）;T2DM组有无大血管病变患者无明显差异。结论脂联素＋276G〉T多态性与T2DM相关,携带TT基因型可能减少患T2DM的几率;其多态性与T2DM大血管病变无明显相关性。     

Genetic association study of adiponectin polymorphisms with risk of Type 2 diabetes mellitus in Korean population.

AIMS: To investigate any association between Type 2 diabetes mellitus and two single nucleotide polymorphisms (SNPs) in the adiponectin gene, T45G and G276T, in the Korean population. METHODS: We genotyped 427 non-diabetic controls and 493 Type 2 diabetic patients for SNPs T45G and G276T of adiponectin gene, measured plasma adiponectin concentrations, and examined clinical parameters in Koreans. RESULTS: There were no statistically significant differences in allele frequencies of SNPs 45 and 276 comparing control with Type 2 diabetic subjects (T frequency 68.3% vs. 71.6%, P=0.13 for SNP45, G frequency 72.2% vs. 68.9%, P=0.12 for SNP276). The genotype distributions of these SNPs had no association with the risk of Type 2 diabetes and metabolic parameters of insulin resistance. Plasma levels of adiponectin were not statistically different according to T45G and G276T either, in both control and Type 2 diabetic subjects. CONCLUSION: The T45G and G276T of the adiponectin gene may not be an important determinant of Type 2 diabetes or insulin resistance in Korean subjects.     

代谢综合征患者脂联素基因多态性分析

目的探讨脂联素基因单核苷酸多态性（SNP）45T→G和276G→T两个位点与代谢综合征（MS）的关系。方法收集MS患者183例（MS组）和健康对照人群144例（对照组）,采用TaqMan探针技术进行脂联素基因SNP45分析,直接测序法进行脂联素基因SNP276分析。结果SNP45在MS组与对照组比较差异有统计学意义（P〈0．05）,等位基因分布频率提示C等位基因在MS组高于对照组（P〈0.05）,MS组中携带TG＋GG型患者血清脂联素水平低于TT型患者（P〈0．05）;两组SNP276基因型分布及等位基因频率比较均无统计学差异。结论SNP45G／G基因型可能是中国汉族人群MS的易感基因。     

福建地区2型糖尿病患者脂联素基因启动子区多态性与颈动脉内膜中层厚度有关

目的 探讨脂联素基因启动子区-11377位点单核苷酸多态性与2型糖尿病患者颈动脉内膜中层厚度(CIMT)之间的关系.方法 采用PCR-限制性片段长度多态性(RFLP)技术在504例2型糖尿病患者(CIMT正常组254例,CIMT增厚组250例)中检测脂联素基因-11377位点多态性,同时检测血脂、空腹血糖、空腹胰岛素及血清脂联素水平.结果 脂联素基因-11377C→G基因型和等位基因频率在CIMT正常组与CIMT增厚组的分布有显著性差别(P相似文献   

脂联素基因单倍型与汉族人群2型糖尿病的相关性研究

目的探讨脂联素基因多态性及其单倍型与2型糖尿病（T2DM）的相关性。方法入选T2DM患者202例,糖尿病家族史阴性的非糖尿病个体（NDM）143例。采用聚合酶链反应限制性内切酶片段长度多态性（PCR—RFLP）方法对脂联素基因SNP-11391、SNP-11377、SNP-4522、SNP＋45和SNP＋331位点进行基因分型,并构建单倍型。评估以上5个多态性位点及构建的单倍型与T2DM的相关性。结果T2DM组和NDM组脂联素基因SNP-11391、SNP—11377、SNP～4522、SNP＋45和SNP＋331基因型和等位基因频率差异无统计学意义。T2DM组和NDM组SNP—11377C—SNP-4522T单倍型频率差异有统计学意义（P〈0．05）。结论脂联素基因SNP-11377C—SNP-4522T单倍型与T2DM相关,且可能增加患T2DM风险（OR=1．60,95％CI：1．09～2．35）。     

Variants of the adiponectin gene and type 2 diabetes in a Polish population

Several association studies of type 2 diabetes mellitus (T2DM) and adiponectin gene polymorphisms have been reported with conflicting results. Our aim was to search for the association of three polymorphisms (−11.391G>A, +45T>G, and +276G>T) in the adiponectin gene with T2DM and prediabetic quantitative traits in Polish Caucasians. The study groups comprised 495 unrelated T2DM cases and 435 controls. We compared the distribution of genotypes between study groups. In addition, genotype-quantitative trait analyses were also done in the controls. The study subjects were genotyped using the restriction fragment length polymorphism technique. The frequencies of the minor alleles were as follows: 10.6 versus 8.2% for −11.391G>A (p = 0.0722), 7.0 versus 8.0% for +45T>G (p = 0.48), and 15.5% in T2DM versus 19.8% in controls (p = 0.0145) for +276G>T, respectively. The difference for genotype distribution between the groups was statistically significant (p = 0.0247) for the +276G>T variant: 71.31 versus 62.99%, 26.46 versus 34.48% and 2.22 versus 2.53%, respectively, for GG, GT and TT. In quantitative traits analysis, the T allele of +276G>T was associated (p < 0.05) with lower insulin resistance (HOMA-IR, fasting insulin) among controls. Additionally, the A allele at position −11.391 was associated (p < 0.05) with higher insulin resistance (HOMA-IR, fasting insulin). In multiple regression analysis, all identified association remained significant after the inclusion in the model of gender, BMI and age. In addition, in this model, −11.391G>A and +276G>T were independently associated with T2DM. Finally, we conclude that the adiponectin gene polymorphisms are associated with T2DM and prediabetic quantitative traits in Polish Caucasians.     

Heritability of plasma adiponectin levels and body mass index in twins

CONTEXT: Adiponectin is suspected to exert antiatherogenic, antiinflammatory, and insulin-sensitizing effects. However, the relative importance of the genetic and environmental factors in influencing plasma adiponectin levels (ADPN) remains unclear. OBJECTIVE: The aim of the study was to investigate whether ADPN and body mass index (BMI) are genetically determined. DESIGN, SETTING, PARTICIPANTS, AND MAIN OUTCOME MEASURES: In a series of 60 pairs of healthy twins, we estimated genetic variance and heritability of ADPN and BMI using both ANOVA and path analysis methods. Twins were genotyped at two biallelic single nucleotide polymorphisms (SNPs) at the gene encoding adiponectin: the +45 T/G (on exon 2) and the -11377 G/C (on the promoter). RESULTS: A total of 30 pairs of twins were Monozygotic (MZ), and 30 were dizygotic (DZ). The mean ADPN (+/-SD) was 10.6 +/- 5.7 in MZ and 11.1 +/- 4.5 in DZ twins (nonsignificant). Three tests of heritability (within pair = 1.13, P < 0.0001; among components = 1.62, P = 0.005; and intraclass correlation 1.34, P < 0.0001) consistently showed ADPN heritability. The preferred model of a likelihood-based analysis included an additive genetic influence and an individually unique environmental influence for ADPN, accounting for 88% and 12% of ADPN variance, respectively. We found a significantly higher within-pair difference of ADPN in DZ than in MZ pairs, and in +45 T/G SNP discordant compared with concordant DZ twins, indicating a significant effect of this adiponectin gene SNP on ADPN. CONCLUSIONS: ADPN shows significant genetic variance and heritability, which is independent of BMI and partly accounted for by the +45 T/G, but not the -11377 G/C adiponectin gene SNP.     

C-reactive protein genetics is associated with carotid artery compliance in men in The Cardiovascular Risk in Young Finns Study

Although C-reactive protein (CRP) is known to predict cardiovascular events, its status as a causal risk factor is still controversial. CRP gene single nucleotide polymorphisms (SNPs) have been shown to associate with CRP concentration, but no direct independent effect on early atherosclerotic changes has been demonstrated. We aimed to determine if CRP gene polymorphisms or haplotypes are associated with CRP concentration or carotid artery compliance (CAC), an indicator of subclinical atherosclerosis. We genotyped CRP gene polymorphisms -717A>G, -286C>T>A, +1059G>C, +1444C>T and +1846G>A and measured CRP concentration and CAC in 2283 young adults participating in The Cardiovascular Risk in Young Finns Study. A strong association was found between CRP genotypes and CRP concentration, which was also seen at the haplotype level. Linear regression analysis showed an independent effect of each SNP on CRP concentration after adjustment for risk factors, except for +1444 in males. Moreover, -286C>T>A, +1444C>T and +1846G>A were associated with CAC in males, but not in females. Men carrying the SNP -286 allele C had increased CAC after adjusting for risk factors. These data suggest that the presence of high producer CRP genotype is deleterious to carotid elasticity in men.     

Associations between glucose tolerance,insulin sensitivity and insulin secretion phenotypes and polymorphisms in adiponectin and adiponectin receptor genes in the Quebec Family Study

Aims Studies suggest that adiponectin (APM1) and its receptors 1 and 2 (AdipoR1 and AdipoR2) play an important role in the development of insulin resistance (IR). Our objective was to examine associations between APM1 (+45T>G, +276G>T and –3971A>G), AdipoR1 (−100G>T and −3882T>C) and AdipoR2 (−35361A>G and –1352G>A) genes single-nucleotide polymorphisms (SNPs) and adiponectin plasma levels, indicators of glucose tolerance, insulin sensitivity (IS) and insulin secretion. Methods Six hundred and twenty-two non-diabetic subjects from the Quebec Family Study (QFS) underwent a 75-g oral glucose tolerance test (OGTT), with measurement of fasting adiponectin, glucose, insulin and C-peptide levels. Indices of glucose tolerance, IS and insulin secretion were derived from fasting and OGTT measurements. Results Significant evidence of association was found between indices of IS and APM1 and AdipoR1 SNPs. The APM1 –3971G/G homozygotes exhibited a reduced area under the curve of insulin during the OGTT (P = 0.007) and higher Cederholm index (P = 0.01) compared to the A/A homozygotes. The APM1+45T>G variant was also associated with fasting (P = 0.002) and 2-h (P = 0.007) glucose values as well as with higher Cederholm index (P = 0.04) and disposition index (P = 0.02). Finally, the AdipoR1−3882T>C SNP was associated with fasting glucose (P = 0.03), the homeostasis model assessment for insulin resistance (P = 0.04) and an index of insulin secretion (P30/G30, P = 0.02). No evidence of association was found with plasma adiponectin levels. Conclusions These results provide evidence for an influence of common SNPs in the APM1 and AdipoR1 genes on different phenotypes of glucose and insulin metabolism associated with increased risk of type 2 diabetes.     

The relationship between adiponectin, an adiponectin gene polymorphism, and high-density lipoprotein particle size: from the Mima study

This study examined the association among serum adiponectin levels, a single nucleotide polymorphism (SNP) of the adiponectin gene, and the size of serum high-density lipoprotein (HDL) particles in a general population. A total of 275 subjects were examined as part of the community-based Mima study. Serum adiponectin levels were measured with an enzyme-linked immunosorbent assay. Serum small-sized HDL was measured with the electrophoretic separation of lipoproteins using the Lipoprint system. Single nucleotide polymorphism G276T (rs1501299, SNP276) of the adiponectin gene was determined with a fluorescent allele-specific DNA primer assay system. Age- and sex-adjusted correlation test revealed a significant inverse relationship between small-sized HDL and adiponectin levels (r = -0.236, P < .001). More percentages of small-sized HDL were observed in the subjects with the SNP276 G/G and G/T genotypes than in those with the T/T genotype (5.5% ± 5.0% vs 3.0% ± 2.9%, P = .016). In a multiple regression analysis, small-sized HDL was significantly and independently correlated with triglycerides levels (β = 0.133, P = .030), adiponectin levels (β = -0.242, P < .001), and the SNP276 G allele (β = -0.142, P = .014). Our findings indicated that adiponectin and SNP276 of the adiponectin gene may modify the size of HDL particles.