The adiponectin gene SNP+45 is associated with coronary artery disease in Type 2 (non-insulin-dependent) diabetes mellitus

Association of Adiponectin 45T/G Polymorphism with Diabetic Cardiovascular Complications in Korean Type 2 Diabetes

BACKGROUND

Adiponectin is an adipokine that regulates lipid and glucose metabolism and has been shown to have anti-inflammatory and anti-atherogenic effects. It also plays an important role in the development of cardiovascular disease (CVD).

METHODS

This study evaluated the association between adiponectin 45T/G polymorphism and cardiovascular complication in type 2 diabetes in Koreans.

RESULTS

The present study included 758 patients with type 2 diabetes. The distribution of the adiponectin 45T/G polymorphism was 3.56% (n = 27) for GG, 42.35% (n = 321) for TG, and 54.09% (n = 410) for TT in patients with type 2 diabetes. The prevalence of CVD was significantly higher in subjects with the GG + TG genotype compared to those with the TT genotype (17.5% vs. 9.8%, P = 0.002). The G allele was associated with a higher risk of CVD (P = 0.002).

CONCLUSION

Our findings suggest that the adiponectin 45T/G polymorphism is associated with diabetic cardiovascular complication in type 2 diabetes.

Contribution of adiponectin polymorphisms to the risk of coronary artery disease in a North-African Tunisian population

BACKGROUND

Adiponectin, an adipocyte-derived protein, is known to play a key role in the processes leading to atherosclerosis and coronary artery disease (CAD) through its anti-atherogenic, anti-inflammatory, antioxidative, and anti-apoptotic properties. In the current study, we have studied the association of two single nucleotide polymorphisms (SNPs) +45 T>G (rs2241766) and +276 G>T (rs1501299) of the adiponectin gene with coronary artery disease (CAD) on an Arab/North-African population from Tunisia.

METHODS

Subjects comprised 277 patients with angiographically demonstrated CAD and 269 age- and gender-matched control subjects. The adiponectin genotypes were performed by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP). The contribution of adiponectin variants to CAD was analyzed by haplotype and regression analysis.

RESULTS

Adiponectin +45T>G and +276G>T genotypic and allelic distributions did not show a significant difference between cases and controls. Similarly, no association with CAD was observed for the haplotype analysis. Assuming dominant model of transmission for both polymorphisms and after adjustment of a number of traditional risk factors for CAD, logistic regression analysis showed an association of SNP +45 T>G with increased risk of developing CAD [adjusted OR (95% CI) = 2.59 (1.17-5.70); P = .01]. However, SNP + 276 G>T is associated with decreased risk of developing CAD [adjusted OR (95% CI) = 0.47 (0.22-0.97); P = .04].

CONCLUSION

There is no allelic or genotypic association of +45 T>G and +276 G>T of the adiponectin gene with CAD in the Tunisian population.

Associations between two common single nucleotide polymorphisms (rs2241766 and rs1501299) of ADIPOQ gene and coronary artery disease in type 2 diabetic patients: a systematic review and meta-analysis

ADIPOQ gene polymorphisms were indicated to be associated with coronary artery disease (CAD) in diabetic patients, however, published studies reported inconsistent results. We performed this meta-analysis to reach a more accurate estimation of the relationship between two common ADIPOQ genetic polymorphisms (rs2241766 and rs1501299) and CAD risk in diabetic patients. Eligible studies were retrieved by searching PubMed, Embase, Wangfang, VIP database and China National Knowledge Infrastructure databases. Included and excluded criteria were formulated. The case group was diabetic patients with CAD, and the control group was diabetic subjects without CAD. Summary odds rations (ORs) and 95% confidence intervals (CIs) were used to evaluate ADIPOQ polymorphisms associations with CAD risk in diabetic group. Heterogeneity was evaluated by Q statistic and I² statistic. A total of twelve published articles, involving 3996 cases and 8876 controls were included in this meta-analysis. The pooled results from rs1501299 polymorphism showed decreased risk in homozygote model (TT VS GG: OR=0.67, 95%CI=0.54-0.83). Heterogeneity was detected in our study. Sensitivity analysis and subgroup analysis were conducted in the meta-analysis. For rs2241766 polymorphism, an increased risk was detected in Caucasian subgroup in heterozygote model (CT VS TT: OR=1.19, 95%CI=1.00-1.42). In genotyping method (PCR-RFLP) subgroup, an increased risk was found in recessive model (GG VS GT+TT: OR=2.05, 95%CI=1.23-3.39). In the sensitivity analysis of rs1501299, decreased risk was detected in allelic model (T VS G: OR=0.86, 95%CI=0.76-0.98) and recessive model (TT VS TG+GG: OR=0.47, 95%CI=0.33-0.67). Publication bias is not observed in our results. Our meta-analysis suggests that the rs1501299 polymorphism may play a protective role in CAD in diabetic patients. The rs2241766 polymorphism is found to be associated with a significant increase in CAD risk in Caucasian and genotyping method (PCR-RFLP) subgroups. Further studies are needed to confirm the prediagnostic effect of the two gene polymorphisms in CAD risk in diabetic patients.

Targeting endothelial metaflammation to counteract diabesity cardiovascular risk: Current and perspective therapeutic options

The association of obesity and diabetes, termed "diabesity", defines a combination of primarily metabolic disorders with insulin resistance as the underlying common pathophysiology. Cardiovascular disorders associated with diabesity represent the leading cause of morbidity and mortality in the Western world. This makes diabesity, with its rising impacts on both health and economics, one of the most challenging biomedical and social threats of present century. The emerging comprehension of the genes whose alteration confers inter-individual differences on risk factors for diabetes or obesity, together with the potential role of genetically determined variants on mechanisms controlling responsiveness, effectiveness and safety of anti-diabetic therapy underlines the need of additional knowledge on molecular mechanisms involved in the pathophysiology of diabesity. Endothelial cell dysfunction, resulting from the unbalanced production of endothelial-derived vascular mediators, is known to be present at the earliest stages of insulin resistance and obesity, and may precede the clinical diagnosis of diabetes by several years. Once considered as a mere consequence of metabolic abnormalities, it is now clear that endothelial dysfunctional activity may play a pivotal role in the progression of diabesity. In the vicious circle where vascular defects and metabolic disturbances worsen and reinforce each other, a low-grade, chronic, and 'cold' inflammation (metaflammation) has been suggested to serve as the pathophysiological link that binds endothelial and metabolic dysfunctions. In this paradigm, it is important to consider how traditional antidiabetic treatments (specifically addressing metabolic dysregulation) may directly impact on inflammatory processes or cardiovascular function. Indeed, not all drugs currently available to treat diabetes possess the same anti-inflammatory potential, or target endothelial cell function equally. Perspective strategies pointing at reducing metaflammation or directly addressing endothelial dysfunction may disclose beneficial consequences on metabolic regulation. This review focuses on existing and potential new approaches ameliorating endothelial dysfunction and vascular inflammation in the context of diabesity.

Single nucleotide polymorphism rs3774261 in the AdipoQ gene is associated with the risk of coronary heart disease (CHD) in Northeast Han Chinese population: a case-control study

Background

Coronary Heart Disease (CHD) is one of the leading causes of death in the world with a projected global 82 million DALYs by 2020. Genetic and environmental factors contribute to CHD development. Here, the authors investigate the association between CHD risk and three Single Nucleotide Polymorphisms (SNPs) in the AdipoQ gene (rs3774261, rs1063537 and rs2082940); and the interaction of this association with environmental factors, in Northeast Han Chinese population.

Methods

Using a case–control study design, 1514 participants (754 cases and 760 controls) were investigated. Three variants in the AdipoQ gene (rs3774261, rs1063537 and rs2082940) were selected and genotyped. The online SNPstats program and SPSS 21.0 software were used for data analyses.

Results

The authors found that the rs3774261G allele is associated with the risk of CHD but that the rs2082940T allele protects against CHD. No significant association was found between rs1063537 and CHD risk. The study also found significant interactions between triglyceride levels and the SNPs studied (P < 0.0001 for rs3774261, P = 0.014 for rs1063537, and P = 0.031 for rs2082940).

Conclusions

Variations in AdipoQ gene can protect against CHD (as with rs2082940T) or associated with CHD risk (as with rs3774261G) in Northeast Han Chinese – findings that will help shed light on the reported conflicting roles of AdipoQ in cardiovascular diseases. Serum triglycerides levels also interact in the AdipoQ – CHD association, thus further highlighting the roles environmental factors play in the genetic aspect of diseases.

Genetic polymorphisms of cytokine genes in type 2 diabetes mellitus

Diabetes mellitus is a combined metabolic disorder which includes hyperglycemia, dyslipidemia, stroke and several other complications. Various groups all over the world are relentlessly working out the possible role of a vast number of genes associated with type 2 diabetes (T2DM). Inflammation is an important outcome of any kind of imbalance in the body and is therefore an indicator of several diseases, including T2DM. Various ethnic populations around the world show different levels of variations in single nucleotide polymorphisms (SNPs). The present review was undertaken to explore the association of cytokine gene polymorphisms with T2DM in populations of different ethnicities. This will lead to the understanding of the role of cytokine genes in T2DM risk and development. Association studies of genotypes of SNPs present in cytokine genes will help to identify risk haplotype(s) for disease susceptibility by developing prognostic markers and alter treatment strategies for T2DM and related complications. This will enable individuals at risk to take prior precautionary measures and avoid or delay the onset of the disease. Future challenges will be to understand the genotypic interactions between SNPs in one cytokine gene or several genes at different loci and study their association with T2DM.

Correlation study on adiponectin gene SNP45 and long-term oxidative stress in patients with diabetes and carotid atherosclerosis

The aim of the present study was to investigate the correlation between the adiponectin gene single nucleotide polymorphism (SNP)45 T/G and long-term oxidative stress in type II diabetes mellitus (T2DM) patients with carotid atherosclerosis. Patients with T2DM were divided into non-carotid atherosclerosis and carotid atherosclerosis groups, which were then subsequently divided into TT and TG + GG groups according to the adiponectin SNP45 T/G genotypes. Enzyme-linked immunosorbent assay, TaqMan probe quantitative polymerase chain reaction (PCR), PCR-TaqMan, color Doppler and other methods were used to determine the adiponectin levels, gene polymorphisms, acquired mitochondrial DNA (mtDNA) A3243G somatic cell mutation rates and the carotid intima-media thickness. The somatic cell mutation rate of acquired mtDNA A3243A/G in the T2DM carotid atherosclerosis group was significantly higher compared with the group without carotid atherosclerosis. In addition, the acquired mtDNA A3243A/G somatic cell mutation rate in the T2DM carotid atherosclerosis group with the adiponectin gene SNP45 TT genotype was significantly lower compared with the SNP45 TG/GG genotype group. T2DM combined with carotid atherosclerosis was associated with long-term oxidative stress. In addition, adiponectin gene SNP45 T/G was associated with increased mtDNA A3243A/G somatic mutation rates in T2DM patients with carotid atherosclerosis. Therefore, adiponectin gene polymorphisms may lead to diabetes atherosclerosis through oxidative stress.

Adiponectin: a manifold therapeutic target for metabolic syndrome, diabetes, and coronary disease?

Adiponectin is the most abundant peptide secreted by adipocytes, being a key component in the interrelationship between adiposity, insulin resistance and inflammation. Central obesity accompanied by insulin resistance is a key factor in the development of metabolic syndrome (MS) and future macrovascular complications. Moreover, the remarkable correlation between coronary artery disease (CAD) and alterations in glucose metabolism has raised the likelihood that atherosclerosis and type 2 diabetes mellitus (T2DM) may share a common biological background. We summarize here the current knowledge about the influence of adiponectin on insulin sensitivity and endothelial function, discussing its forthcoming prospects and potential role as a therapeutic target for MS, T2DM, and cardiovascular disease. Adiponectin is present in the circulation as a dimer, trimer or protein complex of high molecular weight hexamers, >400 kDa. AdipoR1 and AdipoR2 are its major receptors in vivo mediating the metabolic actions. Adiponectin stimulates phosphorylation and AMP (adenosin mono phosphate) kinase activation, exerting direct effects on vascular endothelium, diminishing the inflammatory response to mechanical injury and enhancing endothelium protection in cases of apolipoprotein E deficiency. Hypoadiponectinemia is consistently associated with obesity, MS, atherosclerosis, CAD, T2DM. Lifestyle correction helps to favorably modify plasma adiponectin levels. Low adiponectinemia in obese patients is raised via continued weight loss programs in both diabetic and nondiabetic individuals and is also accompanied by reductions in pro-inflammatory factors. Diet modifications, like intake of fish, omega-3 supplementation, adherence to a Mediterranean dietary pattern and coffee consumption also increase adiponectin levels. Antidiabetic and cardiovascular pharmacological agents, like glitazones, glimepiride, angiotensin converting enzyme inhibitors and angiotensin receptor blockers are also able to improve adiponectin concentration. Fibric acid derivatives, like bezafibrate and fenofibrate, have been reported to enhance adiponectin levels as well. T-cadherin, a membrane-associated adiponectin-binding protein lacking intracellular domain seems to be a main mediator of the antiatherogenic adiponectin actions. The finding of novel pharmacologic agents proficient to improve adiponectin plasma levels should be target of exhaustive research. Interesting future approaches could be the development of adiponectin-targeted drugs chemically designed to induce the activaton of its receptors and/or postreceptor signaling pathways, or the development of specific adiponectin agonists.

Adiponectin gene variants, adiponectin isoforms and cardiometabolic risk in type 2 diabetic patients

AIMS/INTRODUCTION

The aim of the present study was to examine the associations of rs2241766 (+45T>G), rs1501299 (+276G>T), rs17300539 (-11391G>A) and rs182052 (-10069G>A) in the adiponectin (Ad) gene with adiponectin concentrations, and concomitantly the association of these variants with cardiometabolic risk in type 2 diabetic patients of African ancestry.

MATERIALS AND METHODS

A cross-sectional study of 200 patients was carried out. Concentrations of total, high (HMW), middle (MMW) and low (LMW) molecular weight adiponectin isoforms were measured. The four polymorphisms were genotyped.

RESULTS

Decreased values were noted for total Ad in overweight, dyslipidemia and coronary artery disease (CAD), for HMW in overweight and dyslipidemia, for MMW in CAD, for LMW in dyslipidemia and CAD, for the percentage HMW/total in overweight, and for MMW:HMW ratio in patients without hypertriglyceridemic waist (HTGW). Significant associations were noted between total Ad, HMW, and HMW/total Ad and rs182052 under a dominant model (P = 0.04, P = 0.03 and P = 0.04, respectively), and between MMW and rs17300539 (P = 0.006). No significant difference in adiponectin concentrations was noted according to rs2241766 and rs1501299 genotypes. Patients carrying the rs2241766 G allele (TG+GG) had an increased risk of HTGW (odds ratio [OR] 3.1; P = 0.04) and of CAD (OR 3.3; P = 0.01). The odds of having low total adiponectin concentrations (<25th percentile: 3.49 ng/mL) for carrying the rs182052A allele (AA+GA) was: OR 0.40; P = 0.009. The single-nucleotide polymorphism associated with adiponectin levels was not concomitantly associated with cardiometabolic risk factors.

CONCLUSIONS

Adiponectin concentrations and ADIPOQ variants are implicated in the pathophysiological process leading to cardiovascular diseases, but the genetic effects seem to be independent of adiponectin concentrations in our Afro-Caribbean diabetic patients.

The role of adiponectin gene variants in glycemic control in patients with Type 2 diabetes

The aim of this study was to investigate the association between glycemic control in Type 2 diabetes mellitus patients and common genetic variants of ADIPQO gene. A total of 427 Type 2 diabetes patients were recruited in the study and divided into two groups: 172 patients with good glycemic control and 249 with poor glycemic control. Genotyping of C11377G, G276T and T45G ADIPQO SNPs were carried out using restriction fragment length polymorphisms-polymerase chain reaction. The results showed that C11377G ADIPQO SNP is strongly associated with glycemic control in Type 2 diabetes patients. Patients with the GG genotype at adiponectin C11377G had better glycemic control than those with CC or CG genotypes. However, other examined SNPs were not correlated with glycemic control in Type 2 diabetes patients. Other parameters that impacted glycemic control include duration of the disease (p < 0.01), use of insulin therapy (p < 0.01) and presence of neuropathy complications (p < 0.01). However, no contribution was observed for gender, statin use, lipid profile and other oral medications to glycemic control (p > 0.05). Glycemic control among Type 2 diabetes patients might be affected by variants in ADIPQO gene.

Association of atherosclerotic peripheral arterial disease with adiponectin genes SNP+45 and SNP+276: a case-control study

Objectives. We hypothesized that adiponectin gene SNP+45 (rs2241766) and SNP+276 (rs1501299) would be associated with atherosclerotic peripheral arterial disease (PAD). Furthermore, the association between circulating adiponectin levels, fetuin-A, and tumoral necrosis factor-alpha (TNF-α) in patients with atherosclerotic peripheral arterial disease was investigated. Method. Several blood parameters (such as adiponectin, fetuin-A, and TNF-α) were measured in 346 patients, 226 with atherosclerotic peripheral arterial disease (PAD) and 120 without symptomatic PAD (non-PAD). Two common SNPs of the ADIPOQ gene represented by +45T/G 2 and +276G/T were also investigated. Results. Adiponectin concentrations showed lower circulating levels in the PAD patients compared to non-PAD patients (P < 0.001). Decreasing adiponectin concentration was associated with increasing serum levels of fetuin-A in the PAD patients. None of the investigated adiponectin SNPs proved to be associated with the subjects' susceptibility to PAD (P > 0.05). Conclusion. The results of our study demonstrated that neither adiponectin SNP+45 nor SNP+276 is associated with the risk of PAD.

Variants of the adiponectin gene and diabetic microvascular complications in patients with type 2 diabetes

OBJECTIVE

The aim of this study was to examine the association between common polymorphisms of the adiponectin gene (ADIPOQ) and microvascular complications in patients with type 2 diabetes mellitus (T2DM).

RESEARCH DESIGN AND METHODS

Rs2241766 and rs1501299 of ADIPOQ were genotyped in 708 patients with T2DM. Fundus photography, nerve conducting velocity, and urine analysis were performed to check for the presence of microvascular complications including diabetic nephropathy, retinopathy and neuropathy.

RESULTS

The prevalence of diabetic nephropathy tended to be different according to rs2241766 genotype (p=0.057) and the GG genotype of rs2241766 was associated with diabetic nephropathy [urine albumin/creatinine ratio (UACR) greater than 30 mg/g] after adjusting for age, sex, body mass index, duration of diabetes, HDL-cholesterol, smoking status, and blood pressure (odds ratio=1.96; 95% confidence interval=1.01-3.82, p=0.049). Also, the G allele of rs2241766 demonstrated a trend to be associated with an increase in UACR (p=0.087). Rs2241766 genotype was not associated with diabetic retinopathy (p=0.955) and neuropathy (p=0.104) or any diabetic microvascular complications (p=0.104). There was no significant association between the rs1501299 genotype of ADIPOQ and the prevalence of diabetic retinopathy and neuropathy or any diabetic microvascular complications even after adjustment.

CONCLUSION

These data suggest that the GG genotype at rs2241766 is implicated in the pathogenesis of risk for diabetic nephropathy defined as UACR greater than 30 mg/day in patients with T2DM.

The shared allelic architecture of adiponectin levels and coronary artery disease

OBJECTIVE

A large body of epidemiologic data strongly suggests an association between excess adiposity and coronary artery disease (CAD). Low adiponectin levels, a hormone secreted only from adipocytes, have been associated with an increased risk of CAD in observational studies. However, these associations cannot clarify whether this relationship is causal or due to a shared set of causal factors or even confounding. Genome-wide association studies have identified common variants that influence adiponectin levels, providing valuable tools to examine the genetic relationship between adiponectin and CAD.

METHODS

Using 145 genome wide significant SNPs for adiponectin from the ADIPOGen consortium (n = 49,891), we tested whether adiponectin-decreasing alleles influenced risk of CAD in the CARDIoGRAM consortium (n = 85,274).

RESULTS

In single-SNP analysis, 5 variants among 145 SNPs were associated with increased risk of CAD after correcting for multiple testing (P < 4.4 × 10(-4)). Using a multi-SNP genotypic risk score to test whether adiponectin levels and CAD have a shared genetic etiology, we found that adiponectin-decreasing alleles increased risk of CAD (P = 5.4 × 10(-7)).

CONCLUSION

These findings demonstrate that adiponectin levels and CAD have a shared allelic architecture and provide rationale to undertake a Mendelian randomization studies to understand if this relationship is causal.

Common variants in adiponectin gene are associated with coronary artery disease and angiographical severity of coronary atherosclerosis in type 2 diabetes

BACKGROUND

Adiponectin, an adipokine facilitating insulin action, has antiatherogenic effects. This study investigated whether common single nucleotide polymorphisms (SNPs) in the adiponectin gene influenced plasma adiponectin level and whether they were associated with the risk of coronary artery disease (CAD) and its angiographical severity in type 2 diabetes in Chinese population.

METHODS

11 tagging SNPs were genotyped in 1110 subjects with or without CAD in type 2 diabetes. Variants of adiponectin gene were determined by Taqman polymerase chain reaction method. The plasma adiponectin concentrations were measured by sandwich enzyme-linked immunosorbent assay. The severity and extent of coronary atherosclerosis were assessed using the angiographic Gensini score and Sullivan Extent score.

RESULTS

Among the 11 SNPs, the minor G allele of SNP rs266729 was significantly associated with higher odds of CAD (odds ratio (95% CI) = 1.49 (1.10 - 2.16), P = 0.022) after adjusting for covariates. In stepwise multivariate logistic regression, SNP rs266729 was a significant independent factor of CAD. Multivariate linear regression analysis revealed that rs266729 (β = -0.101, P < 0.0001), rs182052 (β = -0.044, P = 0.0035), and rs1501299 (β = 0.073, P < 0.0001) were significantly associated with adiponectin level, and also indicated that the minor G allele of SNP rs266729 had higher Gensini score (β = 0.139, P < 0.001) and Sullivan Extent score (β = 0.107, P < 0.001). Haplotypes analysis revealed different haplotype distributions in case and control subjects (P = 0.0003), with two common haplotypes GGG and GAG of the rs266729, rs182052, and rs1501299 being associated in heterozygotes with a greater than threefold increase in cardiovascular risk (odds ratio (95% CI)=3.39 (1.83 - 6.30), P = 0.0001).

CONCLUSIONS

In our population, genetic variants in the adiponectin gene influence plasma adiponectin levels, and one of them is a strong determinant of CAD susceptibility and its angiographical severity in type 2 diabetes. This study has provided further evidence for a role of adiponectin in the development of CAD.

The Human Obesity Gene Map: The 2004 Update

This paper presents the eleventh update of the human obesity gene map, which incorporates published results up to the end of October 2004. Evidence from single-gene mutation obesity cases, Mendelian disorders exhibiting obesity as a clinical feature, transgenic and knockout murine models relevant to obesity, quantitative trait loci (QTLs) from animal cross-breeding experiments, association studies with candidate genes, and linkages from genome scans is reviewed. As of October 2004, 173 human obesity cases due to single-gene mutations in 10 different genes have been reported, and 49 loci related to Mendelian syndromes relevant to human obesity have been mapped to a genomic region, and causal genes or strong candidates have been identified for most of these syndromes. There are 166 genes which, when mutated or expressed as transgenes in the mouse, result in phenotypes that affect body weight and adiposity. The number of QTLs reported from animal models currently reaches 221. The number of human obesity QTLs derived from genome scans continues to grow, and we have now 204 QTLs for obesity-related phenotypes from 50 genome-wide scans. A total of 38 genomic regions harbor QTLs replicated among two to four studies. The number of studies reporting associations between DNA sequence variation in specific genes and obesity phenotypes has also increased considerably with 358 findings of positive associations with 113 candidate genes. Among them, 18 genes are supported by at least five positive studies. The obesity gene map shows putative loci on all chromosomes except Y. Overall, >600 genes, markers, and chromosomal regions have been associated or linked with human obesity phenotypes. The electronic version of the map with links to useful publications and genomic and other relevant sites can be found at http://obesitygene.pbrc.edu.

Association of adiponectin gene polymorphism (+T45G) with acute coronary syndrome and circulating adiponectin levels

We investigated the association of adiponectin gene polymorphisms (+T45G and +G276T) and adiponectin levels with acute coronary syndrome (ACS) among Arabs in Qatar. A case-control study was performed in 142 Arab patients with ACS and 122 controls. Genotypes were determined using TaqMan real-time polymerase chain reaction assay. The TT, TG, and GG genotype frequencies of the T45G variant were significantly different among cases and controls (P = .023) but not significant for G276T genotypic frequencies. It was found that only the +45G allele was significantly associated with 3-fold increased risk of ACS (odds ratio = 2.77; 1.03-6.96; P = .043) among patients, using the genetic recessive model. Carriers of GG alleles had significantly lower adiponectin levels compared to TT/TG carriers of T45G in patients with ACS. The present study suggests that only T45G single-nucleotide polymorphism in the adiponectin gene is associated with higher odds for ACS events and has an effect on serum adiponectin levels among Arab populations.

Association between polymorphisms in the adiponectin gene and cardiovascular disease: a meta-analysis

Background

Previous studies have examined the associations between polymorphisms of adiponectin gene (ADIPOQ) and cardiovascular disease (CVD), but those studies have been inconclusive. The aim of this study was to access the relationship between three single nucleotide polymorphisms (SNPs), +45 T > G (rs2241766), +276 G > T (rs1501299) and -11377 C > G (rs266729) in ADIPOQ and CVD.

Methods

A comprehensive search was conducted to identify all studies on the association of ADIPOQ gene polymorphisms with CVD risk. The fixed and random effect pooled measures (i.e. odds ratio (OR) and 95% confidence interval (CI)) were calculated in the meta-analysis. Heterogeneity among studies was evaluated using Q test and the I². Publication bias was estimated using modified Egger’s linear regression test.

Results

Thirty-seven studies concerning the associations between the three polymorphisms of ADIPOQ gene and CVD risk were enrolled in this meta-analysis, including 6,398 cases and 10,829 controls for rs2241766, 8,392 cases and 18,730 controls for rs1501299 and 7,835 cases and 14,023 controls for rs266729. The three SNPs were significantly associated with CVD, yielding pooled ORs of 1.22 (95%CI: 1.07, 1.39; P = 0.004), 0.90 (95%CI: 0.83, 0.97; P = 0.007) and 1.09(95%CI: 1.01, 1.17; P = 0.032) for rs2241766, rs1501299 and rs266729, respectively. Rs2241766 and rs1501299 were significantly associated with coronary heart disease (CHD), yielding pooled ORs of 1.29 (95%CI: 1.09, 1.52; P = 0.004) and 0.89 (95%CI: 0.81, 0.99; P = 0.025), respectively. The pooled OR for rs266729 and CHD was 1.09 (95%CI: 0.99, 1.19; P = 0.090). Significant between-study heterogeneity was found in our meta-analysis. Evidence of publication bias was observed in the meta-analysis.

Conclusions

The present meta-analysis showed that the associations between rs2241766, rs1501299 and rs266729 in the ADIPOQ and CVD were significant but weak. High quality studies are still needed to confirm the associations, especially for rs2241766.

Genetic and environmental factors associated with type 2 diabetes and diabetic vascular complications

Faced with a global epidemic of type 2 diabetes (T2D), it is critical that researchers improve our understanding of the pathogenesis of T2D and related vascular complications. These findings may ultimately lead to novel treatment options for disease prevention or delaying progression. Two major paradigms jointly underlie the development of T2D and related coronary artery disease, diabetic nephropathy, and diabetic retinopathy. These paradigms include the genetic risk variants and behavioral/environmental factors. This article systematically reviews the literature supporting genetic determinants in the pathogenesis of T2D and diabetic vasculopathy, and the functional implications of these gene variants on the regulation of beta-cell function and glucose homeostasis. We update the discovery of diabetes and diabetic vasculopathy risk variants, and describe the genetic technologies that have uncovered them. Also, genomic linkage between obesity and T2D is discussed. There is a complementary role for behavioral and environmental factors modulating the genetic susceptibility and diabetes risk. Epidemiological and clinical data demonstrating the effects of behavioral and novel environmental exposures on disease expression are reviewed. Finally, a succinct overview of recent landmark clinical trials addressing glycemic control and its impact on rates of vascular complications is presented. It is expected that novel strategies to exploit the gene- and exposure-related underpinnings of T2D will soon result.

Genetic association of adiponectin gene polymorphisms (+45T/G and +10211T/G) with type 2 diabetes in North Indians

Adiponectin (ADIPOQ) is an abundant protein hormone which belongs to a family of so-called adipokines. It is expressed mostly by adipocytes and is an important regulator of lipid and glucose metabolism. It was shown that decreased serum adiponectin concentration indicated insulin resistance and type 2 diabetes (T2DM) with the risk of cardiovascular complications. The fact that adiponectin is an insulin-sensitizing hormone with anti-diabetic, anti-inflammatory and anti-atherogenic properties, we proposed to study the association of ADIPOQ gene polymorphisms in subjects with T2DM. DNA was isolated from venous blood samples, quantified and subjected to Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) using suitable primers and restriction endonucleases. Adiponectin levels were measured in serum using ELISA. The genotypic, allelic and carriage rate frequencies distribution in patients and controls were analyzed by PSAW software (ver. 17.0). Odd ratios (OR) with 95% confidence interval (CI) were determined to describe the strength of association by logistic regression model. Out of the two polymorphisms studied, +10211T/G showed significant association (P=0.042), the 'G' allele association being highly significant (P=0.022). Further analysis showed that individuals with 'GG' haplotype were at increased risk of T2DM up to 15.5 times [P=0.015, OR (95% CI); 15.558 (1.690-143.174)]. The present study showed that the 'G' allele of ADIPOQ gene (+10211T/G) plays a prominent role with respect to T2DM susceptibility in North-Indian population.

Association of ADIPOQ gene polymorphisms and coronary artery disease risk: a meta-analysis based on 12 465 subjects

INTRODUCTION

Coronary artery disease (CAD) is one of the most common cardiovascular diseases and is a major cause of morbidity and mortality worldwide. Various researchers have investigated the role of ADIPOQ gene in the risk of CAD, yet their results have been inconsistent.

METHODS

To evaluate the association between ADIPOQ genetic polymorphisms and CAD risk, relevant studies published before October 2011 were identified by searching PubMed and EMBASE. Studies were selected using previously defined criteria. The strength of the relationship between the four single nucleotide polymorphisms (SNPs) of the ADIPOQ gene and CAD risk was assessed using odds ratios (ORs).

RESULTS

A total of 12 465 subjects from 17 case-control studies were identified in the present study. Based on the relevant studies, it was determined that the risk of CAD was not associated with rs2241766 in any genetic model. Increased risk of CAD was associated with rs266729 in allele contrast (1.11, [1.03, 1.20]) and dominant genetic model (1.15, 95%CI: [1.05, 1.27]); increased risk of CAD was also associated with rs822395 in additive (1.63, 95%CI: [1.19, 2.22]) and recessive genetic model (1.71, 95%CI: [1.27, 2.30]). It was further determined that the rs1501299 polymorphism reduced the risk of CAD in the additive (0.80, 95%CI: [0.67, 0.94]) and recessive genetic model (0.81, 95%CI: [0.68, 0.95]). In the stratified analysis, significant associations were found in Asian subjects for rs266729 and in Caucasian subjects for rs1501299.

CONCLUSION

There is an association between ADIPOQ gene polymorphisms and CAD risk. Different SNPs of the ADIPOQ gene have different associations with CAD risk, and appear to increase risk in individuals of Asian ethnicity while decrease the CAD risk in Caucasians. However, the overall strength of association was mild to moderate.

Association of ADIPOQ variants, total and high molecular weight adiponectin levels with coronary artery disease in diabetic and non-diabetic Brazilian subjects

OBJECTIVE

To investigate the association of ADIPOQ variants, total and high molecular weight adiponectin (HMW) adiponectin levels with the prevalence of diabetes mellitus and coronary artery disease (CAD) diagnosed by coronary angiography in Brazilian subjects with high cardiovascular risk.

METHODS

603 subjects undergoing coronary angiography were studied in regard to their glycemic status and presence of CAD (lesions >0%). We evaluated baseline concentrations of total and HMW adiponectin and three ADIPOQ variants: -11391G>A (rs17300539), +45T>G (rs2241766) and+276G>T (rs1501299).

RESULTS

The G-allele of rs2241766 was associated with higher levels of total and HMW adiponectin, and the A-allele of rs17300539 was associated with higher levels of HMW adiponectin. Lower levels of total and HMW adiponectin were independently associated with CAD. The G-allele of rs2241766 (OR 2.45, 95% C.I. 1.05-6.04, p=0.04) and the G-allele of rs1501299 (OR 1.89, 95% C.I. 1.04-3.45, p=0.03) were associated with CAD, and these associations were independent of circulating levels of adiponectin.

CONCLUSIONS

In Brazilian subjects with high cardiovascular risk, CAD was associated with lower total and HMW adiponectin levels. The rs2241766 and rs1501299 polymorphisms were associated with CAD. The rs2241766 variant was associated with total and HMW adiponectin levels, while rs17300539 was associated with HMW adiponectin levels.

Recessive protective effect of ADIPOQ rs1501299 on cardiovascular diseases with type 2 diabetes: a meta-analysis

The association between a common variant of the ADIPOQ gene rs1501299 (+276G>T) and cardiovascular diseases (CVDs) outcomes has been reported with many studies. However, the evidence is insufficient for strong conclusions regarding CVDs and ADIPOQ rs15011299 (+276G>T). We performed a meta-analysis about the association between ADIPOQ rs1501299 (+276G>T) and CVDs risk using a predefined protocol, including 15 published studies with 5868 cases and 10,744 controls. The pooled data suggested a recessive protective effect of ADIPOQ rs1501299 (+276G>T) on CVDs for type 2 diabetes (T2D) population: the TT homozygote individuals had a reduced risk of developing CVDs compared to the carriers of G allele (OR=0.74, 95% confidence interval (CI): 0.58, 0.94; p=0.013). But there is still not enough evidence to indicate the association of the ADIPOQ rs1501299 (+276G>T) and the development of cardiovascular diseases (CVDs) outcomes in general population. In conclusion, our meta-analysis suggested that the ADIPOQ rs1501299 (+276G>T) polymorphism is a low-risk factor for the development of CVDs with T2D, but the association of this polymorphism with the susceptibility to CVDs in other populations remains unknown. It could be presumed that the ADIPOQ rs1501299 (+276G>T) be a potential cause of susceptibility to CVDs in persons with T2D, and it gives a new opportunity to investigate the mechanisms of CVDs susceptibility in T2D patients.

Association between adiponectin gene polymorphisms and coronary artery disease across different populations

OBJECTIVE

Many studies have suggested that adiponectin gene might be involved in the development of coronary artery disease (CAD). However, the results have been inconsistent. In this study, the authors performed a meta-analysis to assess the associations of +45T/G, +276G/T and -11377C/G polymorphisms in adiponectin gene with CAD susceptibility.

METHODS

Published literature from PubMed and EMBASE databases were searched. Pooled odds ratio (OR) and corresponding 95% confidence interval (CI) were calculated using fixed- or random-effects model.

RESULTS

Sixteen studies (4394 cases / 8187 controls) for +45T/G polymorphism, fifteen studies (3569 cases / 7463 controls) for +276G/T polymorphism, and thirteen studies (3531 cases / 7072 controls) for -11377C/G polymorphism were included in the meta-analysis. The overall results showed that there was a statistically significant association between -11377C/G polymorphism and CAD (G vs. C: OR=1.15, 95%CI 1.07-1.24).Similar results were observed among European (G vs. C: OR=1.11, 95%CI 1.02-1.20) and East Asian populations (G vs. C: OR=1.27, 95%CI 1.11-1.45). However, no significant association was found for +45T/G or +276G/T polymorphism with CAD susceptibility.

CONCLUSIONS

The meta-analysis indicated the significant association of -11377C/G polymorphism, but not +45T/G or +276G/T polymorphism, with CAD susceptibility. However, large-scale studies with the consideration of gene-gene and gene-environment interactions should be conducted to investigate the associations in future.

Single-nucleotide polymorphisms at the adiponectin locus and risk of coronary artery disease in Tunisian coronaries

OBJECTIVE

Adiponectin is an adipocyte-derived hormone and an essential modulator of insulin sensitivity. Several studies suggest an important role of adiponectin in the process leading to atherosclerosis, thus indicating the adiponectin gene as a potential candidate for coronary artery disease. Two single-nucleotide polymorphisms (SNPs) at the adiponectin locus (+45T/G and +276G/T) have been associated with low circulating adiponectin levels, insulin resistance and type 2 diabetes. The objective was to examine the association of two SNPs (45T/G and 276G/T) with coronary artery disease in a Tunisian population.

METHODS

We have recruited 316 Tunisian patients, documented by coronary angiography. Significant coronary stenosis (SCS) was defined as a luminal narrowing of at least 50% in at least one major coronary artery. Genotyping was performed by polymerase chain reaction restriction fragment length polymorphism. Lipids and apolipoproteins were measured.

RESULTS

After adjustments for confounder parameters, odds ratio (OR) of SCS associated with 276G/T mutated genotypes was 0.472 [95% confidence interval (CI) 0.195-0.842, P=0.046]. The mutated genotypes at the +45T/G polymorphism were significantly associated with increased SCS only in obese patients (OR 3.31, 95% CI 0.996-11.05, P=0.049 versus OR 1.71, 95% CI 0.467-6.269, P=0.418 in non-obese individuals). A potential protective effect was also observed for the haplogenotype TT/TT (OR 0.548, 0.306-0.982, P=0.043) in all the studied population.

CONCLUSION

Mutated genotypes at +45T/G (GG + TG) were associated with an increase in SCS only in the obese group. Mutated genotypes at +276G/T (TT + GT) seem to reduce the risk of SCS in the studied population. When the two SNPs were combined, the TT/TT haplogenotype (normal genotype at 45T/G and mutated genotype at 276G/T) was associated with a protective effect.

ADIPOQ and adiponectin: the common ground of hyperglycemia and coronary artery disease?

Plasma adiponectin and the coding gene for adiponectin, ADIPOQ, are thought to explain part of the interaction between obesity, insulin resistance, type 2 diabetes (T2DM) and coronary artery disease (CAD). Here, we illustrate the role that adiponectin and ADIPOQ variants might play in the modulation of CAD, especially in the occurrence of hyperglycemia. Recent evidence suggests that total and high molecular weight (HMW) adiponectin levels are apparent markers of better cardiovascular prognosis in patients with low risk of CAD. However, in subjects with established or high risk of CAD, these levels are associated with poorer prognosis. We also provide recent evidences relating to the genetic control of total and HMW adiponectin levels, especially evidence regarding ADIPOQ. Accumulated data suggest that both adiponectin levels and polymorphisms in the ADIPOQ gene are linked to the risk of CAD in patients with hyperglycemia, and that these associations seem to be independent from each other, even if adiponectin levels are partly dependent on ADIPOQ.

Association of +45(T/G) and +276(G/T) polymorphisms in the adiponectin gene with coronary artery disease in a population of Iranian patients with type 2 diabetes

The relation of Two single nucleotide polymorphisms (SNPs) at the adiponectin locus (+45T/G and +276G/T) with coronary artery disease (CAD) is controversial. The aim of the present study was to evaluate the genetic influence of the adiponectin gene polymorphisms in the development of CAD among patients with Type 2 diabetes (T2D). The adiponectin genotypes were detected by polymerase chain reaction and restriction analysis (PCR-RFLP) in our patients. Two adiponectin gene (ADIPOQ) SNPs (i.e. SNPs +45T>G and +276G>T) were genotyped in 114 Type 2 diabetic subjects with CAD, and 127 Type 2 diabetic patients without CAD. Demographic and anthropometric data along with plasma biochemistry including lipids, glycemic indices, and adiponectin were collected. There was a significant difference in the distribution of genotypes of +45T/G and +276G/T between CAD and non-CAD individuals (P < 0.05). Based on our results SNP+276G>T is associated with decreased risk of CAD after adjustment for potential confounding factors [adjusted OR = 0.39 (95%CI: 0.22-0.68); P = 0.001]. Similar findings were not observed for the +45T>G SNP. Two haplotypes 45T-276T and 45G-276T were associated with a decreased risk of CAD [adjusted OR = 0.47 (95% CI: 0.32-0.94); P = 0.03 and adjusted OR = 0.33 (95% CI: 0.13-0.83); P = 0.02 respectively]. No significant difference was observed between HOMA-IR, BMI, waist circumference, history of hypertension, HbA1C, and lipid concentrations regarding the two SNPs. In conclusion, these findings suggest that T allele of +276G>T SNP is significantly associated with decreased risk of CAD in T2D Patients. Also Haplotype analysis showed that two haplotypes 45T-276T and 45G-276T were associated with a decreased risk of CAD.

Variations in Adipokine Genes AdipoQ, Lep, and LepR are Associated with Risk for Obesity-Related Metabolic Disease: The Modulatory Role of Gene-Nutrient Interactions

Obesity rates are rapidly increasing worldwide and facilitate the development of many related disease states, such as cardiovascular disease, the metabolic syndrome, type 2 diabetes mellitus, and various types of cancer. Variation in metabolically important genes can have a great impact on a population's susceptibility to becoming obese and/or developing related complications. The adipokines adiponectin and leptin, as well as the leptin receptor, are major players in the regulation of body energy homeostasis and fat storage. This paper summarizes the findings of single nucleotide polymorphisms in these three genes and their effect on obesity and metabolic disease risk. Additionally, studies of gene-nutrient interactions involving adiponectin, leptin, and the leptin receptor are highlighted to emphasize the critical role of diet in susceptible populations.

The genetics of vascular complications in diabetes mellitus

Prospective identification of which individuals with diabetes mellitus (DM) are at greatest risk for developing cardiovascular disease (CVD) complications would have considerable public health importance by allowing the allocation of limited resources to be focused on those individuals who would most benefit from aggressive intervention. Over the past 20 years genetic disease association studies have demonstrated that polymorphisms at specific genetic loci may identify those individuals at greatest risk for developing CVD in the setting of DM. This article reviews the evidence accumulated to date on four polymorphic loci with the aim of explaining how these polymorphisms modify the risk for CVD in DM by modifying the functional activity of a specific gene. Use of the knowledge of these genetic differences among individuals in targeting drug therapy (pharmacogenomics) is also discussed.

Interaction of ADIPOQ genetic polymorphism with blood pressure and plasma cholesterol level on the risk of coronary artery disease

BACKGROUND

The protective effect of +45T >G polymorphism in the adiponectin gene (ADIPOQ) on coronary artery disease (CAD) has been demonstrated in European populations, so this study investigated the effect of +45T >G polymorphism on the risk of CAD and its interactions with other metabolic risk factors in a Chinese population.

METHODS AND RESULTS

The +45T >G polymorphism (rs2241766) of ADIPOQ was genotyped in 600 patients with angiographically diagnosed CAD and in 718 controls. The G allele at the +45T >G polymorphism was associated with a lower risk of CAD (odds ratio (OR), 0.76; 95% confidence interval (CI), 0.64-0.89; P=0.001). The protective effect of the G allele at +45T >G polymorphism was magnified at blood pressure <140/90 mmHg (OR, 0.65; 95%CI, 0.51-0.82; P=0.0004), but disappeared at blood pressure >or=140/90 mmHg (OR, 0.98; 95%CI, 0.76-1.28; P=0.93), indicating an interaction between +45T >G polymorphism and blood pressure on CAD risk (P=0.02 for interaction). A similar interaction was also observed between plasma cholesterol level and the +45T >G polymorphism.

CONCLUSIONS

An association of ADIPOQ genetic polymorphism with CAD risk is modified by traditional risk factors, such as blood pressure and plasma cholesterol level.

Interaction between poor glycemic control and 9p21 locus on risk of coronary artery disease in type 2 diabetes

CONTEXT

A common allele on chromosome 9p21 has been repeatedly associated with increased risk of coronary artery disease (CAD) in the general population. However, the magnitude of this effect in the population with diabetes has not been well characterized.

OBJECTIVE

To examine the association of the 9p21 variant with CAD in individuals with type 2 diabetes and evaluate its interaction with poor glycemic control.

DESIGN, SETTING, AND PARTICIPANTS

(1) Case-control study of 734 type 2 diabetes patients (322 with angiographically diagnosed CAD and 412 with no evidence of CAD) who were recruited between 2001 and 2006 at the Joslin Clinic, Beth Israel Deaconess Medical Center; and (2) independent cohort study of 475 type 2 diabetes patients from the Joslin Clinic whose survival status was monitored from their recruitment between 1993 and 1996 until December 31, 2004. Participants for both studies were genotyped for a representative single-nucleotide polymorphism at 9p21 (rs2383206) and characterized for their long-term glycemic control by averaging multiple hemoglobin A(1c) (HbA(1c)) measurements taken in the years before study entry.

MAIN OUTCOME MEASURES

For the case-control study, association between single-nucleotide polymorphism rs2383206 and CAD defined as angiographically documented stenosis greater than 50% in a major coronary artery or a main branch thereof was assessed and for the cohort study, cumulative 10-year mortality was documented.

RESULTS

Individuals who were homozygous for the risk allele were significantly more frequent among case than control participants (42.3% vs 28.9P = .0002). This association was unaffected by adjustment for cardiovascular risk factors, but the effect of the risk genotype was significantly magnified (adjusted P for interaction = .048) in the presence of poor glycemic control (worst tertile of the distribution of HbA(1c) at examination). Relative to the CAD risk for patients with neither a 9p21 risk allele nor poor glycemic control, the CAD odds for participants having 2 risk alleles but not poor glycemic control were increased 2-fold (odds ratio [OR], 1.99; 95% confidence interval [CI], 1.17-3.41), whereas the odds for study participants with the same genotype and with poor glycemic control were increased 4-fold (OR, 4.27; 95% CI, 2.26-8.01). The interaction was stronger (adjusted P = .005) when a measure of long-term glycemic control (7-year average rather than most recent HbA(1c)) was used with ORs of 7.83 (95% CI, 3.49-17.6) for participants having 2 risk alleles and a history of poor glycemia and 1.54 (95% CI, 0.72-3.30) for participants with the same genotype but without this exposure. A similar interaction between 9p21 variant and poor glycemic control was observed with respect to cumulative 10-year mortality in the cohort study (43.6% in patients with 2 risk alleles and poor glycemic control, 23.1% in individuals with only the 2 risk alleles, 30.0% in individuals with only poor glycemic control, and 31.6% in individuals with neither factor, P for interaction, = .036).

CONCLUSION

In this study population, the CAD risk associated with the 9p21 variant was increased in the presence of poor glycemic control in type 2 diabetes.

Physiological significance of heme oxygenase in hypertension

The last decade has witnessed an explosion in the elucidation of the role that the heme oxygenase system plays in human physiology. This system encompasses not only the heme degradative pathway, including heme oxygenase and biliverdin reductase, but also the products of heme degradation, carbon monoxide, iron, and biliverdin/bilirubin. Their role in diabetes, inflammation, heart disease, hypertension, transplantation, and pulmonary disease are areas of burgeoning research. The research has focused not only on heme itself but also on its metabolic products as well as endogenous compounds involved in a vast number of genetic and metabolic processes that are affected when heme metabolism is perturbed. It should be noted, however, that although the use of carbon monoxide and biliverdin/bilirubin as therapeutic agents has been successful, these agents can be toxic at high levels in tissue, e.g., kernicterus. Care must be used to ensure that when these compounds are used as therapeutic agents their deleterious effects are minimized or avoided. On balance, however, the strategies to target heme oxygenase-1 as described in this review offer promising therapeutic approaches to clinicians for the effective management of hypertension and renal function. The approaches detailed may prove to be seminal in the development of a new therapeutic strategy to treat hypertension.

Adiponectin gene and cardiovascular risk in type 2 diabetic patients: a review of evidences

Diabetic patients have a 3-fold higher risk of developing atherosclerosis and its clinical complications as compared to non-diabetic individuals. Part of the cardiovascular risk associated with diabetes is probably due to genetic determinants influencing both glucose homeostasis and the development of atherosclerosis. However, type 2 diabetes frequently coexists with other cardiovascular risk factors like arterial hypertension, central obesity and dyslipidemia. Genetic variability affecting many areas such as lipid and energy metabolisms, hypertension and haemodynamic mechanisms, blood clotting homeostasis, inflammation, and matrix turnover in the vascular wall will have an impact on the development of macrovascular complications in diabetic patients. Adiponectin is abundantly secreted by adipocytes. It plays important roles in lipid and glucose metabolisms and has direct anti-inflammatory and anti-atherogenic effects. In this review, we summarize recent data from the literature suggesting an implication of allelic variations of the adiponectin gene (ADIPOQ) in the genetic determinants of cardiovascular disease in diabetic subjects.

Adiponectin gene polymorphisms modulate acute adiponectin response to dietary fat: Possible pathogenetic role in NASH

Factors underlying the independent association of nonalcoholic steatohepatitis (NASH) with increased cardiovascular risk are unknown. Adiponectin polymorphisms predict cardiometabolic risk in the general population. This association is not always mediated by low fasting adiponectin levels, adipose tissue accumulation, or traditional risk factors. Adiponectin modulates lipid metabolism and liver injury in nonalcoholic fatty liver disease (NAFLD) even in the absence of obesity, dyslipidemia, and diabetes. We hypothesized adiponectin polymorphisms may predispose to NAFLD and may increase cardiovascular risk by modulating circulating lipoprotein and adiponectin response postprandially. The prevalence of adiponectin single-nucleotide polymorphisms (SNPs) 45GT and 276GT was assessed in 70 nonobese, nondiabetic, normolipidemic NAFLD patients and 70 healthy matched controls; the impact of the adiponectin SNPs was subsequently correlated to liver histology and postprandial adiponectin and lipoprotein responses to oral fat load in a subgroup of 30 biopsy-proven patients with NASH and 30 controls. The 45TT and 276GT/TT genotypes were more prevalent in NAFLD patients than in controls and independently predicted the severity of liver disease in NASH. In both patients and controls, these genotypes exhibited a blunted postprandial adiponectin response and higher postprandial triglycerides (Tg), free fatty acids (FFA), oxidized LDL (oxLDL), and VLDL levels than their counterparts, despite comparable fasting adipokines, lipids, dietary habits, adiposity, and insulin resistance. They were also independently associated, together with dietary polyunsaturated fatty acid intake, with postprandial adiponectin response. IAUC adiponectin independently predicted postprandial Tg, FFA, oxLDL, and intestinal and hepatic VLDL subfraction responses in NASH.

CONCLUSION

The at-risk adiponectin SNPs 45TT and 276GT are significantly more prevalent in NAFLD than in the general population; they are associated with severity of liver disease, with blunted postprandial adiponectin response, and with an atherogenic postprandial lipoprotein profile in NASH independently of fasting adipokine and lipid levels.

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.

Adiponectin gene SNP 276G --> T, nutrient intakes, and cardiovascular disease risk in Korean type 2 DM patients

Single nucleotide polymorphism (SNP) in adiponectin gene has been associated with insulin resistance, diabetes, and cardiovascular disease (CVD). This study was performed to investigate the association of SNP 276G-->T at adiponectin gene with CVD risk factors in Korean type 2 diabetes mellitus (DM) patients. The subjects were 351 type 2 DM patients visited a DM clinic in Seoul, and the patients with known CVD were excluded. The adiponectin SNP 276G-->T was analyzed and dietary intakes were assessed by a Food Frequency Questionnaire. The prevalence of G/G, G/T, and T/T genotype was 47.6%, 43.3%, and 9.1%, respectively. Male subjects with T/T genotype showed significantly lower level of adiponectin and HDL-cholesterol and significantly higher C-reactive protein (CRP) level compared to G/G and G/T genotypes. In G/G genotype, protein intake was negatively correlated to body weight, BMI, and waist circumference, and there were positive correlation between carbohydrate intake and BMI, waist-hip ratio, and ApoB/apoA-1 ratio in G/T genotype. However, in T/T genotype, there was no significant association between macronutrient intakes and anthropometric and hematological values. In conclusion, CVD risk would be high in type 2 DM patients with T/T genotype, and the association of macronutrient intakes with anthropometric and hematologic factors was different among the three adiponectin genotypes. These results may imply the need for different dietary management regime according to adiponectin genotype to lower CVD complications in Korean type 2 DM patients.

Adiponectin, obesity and atherosclerosis

The circulating protein adiponectin has been the subject of immense interest ever since it was first discovered in the mid-1990s. The protein is uniquely produced and secreted by mature adipocytes and is believed to have important anti-inflammatory and anti-diabetic effects; low levels have been shown to be predictive of future type 2 diabetes and cardiovascular disease. This review discusses adiponectin in relation to obesity, inflammation, insulin resistance and atherosclerosis.

Single nucleotide polymorphisms at the adiponectin locus and risk of coronary heart disease in men and women

OBJECTIVE

The objective was to examine the association of 5 common single nucleotide polymorphisms (SNPs) at the adiponectin locus with risk of coronary heart disease (CHD) in men and women.

METHODS AND PROCEDURES

We genotyped five common SNPs in the adiponectin gene (rs266729, -11365C>G; rs822395, -4034A>C; rs822396, -3964A>G; rs2241766, +45T>G; and rs1501299, +276G>T) in men (Health Professionals Follow-up Study) and women (Nurses' Health Study) in a nested case control setting. Among participants free of cardiovascular disease at baseline, 266 men and 249 women developed non-fatal myocardial infarction or fatal CHD during 6 and 8 years of follow-up, respectively. In addition, 564 men had coronary artery bypass graft surgery or percutaneous transluminal coronary angioplasty. Using risk set sampling, controls were selected 2:1 matched on age, smoking, and date of blood draw.

RESULTS

The -4034CC genotype was related to an increased risk of non-fatal myocardial infarction or fatal CHD compared with the AA genotype [relative risk (RR), men, 1.69; 95% confidence interval (CI), 0.99 to 2.89; women, 2.04; 95% CI, 1.20 to 3.49); however, this genotype was not related to risk of coronary artery bypass graft surgery or percutaneous transluminal coronary angioplasty or to plasma adiponectin levels. Other SNPs or haplotypes defined by the 5 SNPs were not consistently related to risk of CHD in men and women or to plasma adiponectin levels.

DISCUSSION

Our study does not support the hypothesis that these 5 common SNPs in the adiponectin gene play an important role in the development of CHD among men and women, although we cannot exclude an association between the -4034CC genotype and risk of CHD.

Association of genetic variation of the adiponectin gene with body fat distribution and carotid atherosclerosis in Japanese obese subjects

AIM

The aim of this study was to investigate the effect of SNP45 of the adiponectin gene on body fat distribution and carotid atherosclerosis in Japanese obese subjects.

METHODS

A total of 64 obese subjects were investigated. Genotypes of SNP45 were assayed by polymerase chain reaction-restriction fragment length polymorphism. Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured using computed tomography. The progression of atherosclerosis was evaluated by plaque score (PS) of carotid artery using B-mode ultrasonography.

RESULTS

Men carrying the G allele of SNP45 showed higher VFA (172.8+/-50.8 vs. 147.1+/-58.7, p=0.005), lower SFA (209.9+/-101.8 vs. 273.4+/-142.2, p=0.007), higher VFA/SFA (V/S) ratio (1.00+/-0.46 vs. 0.60+/-0.26, p <0.001) and higher PS (9.5+/-3.7 vs. 6.8+/-4.2, p=0.012) than those with TT genotype. Multivariate analysis showed that SNP45 was an independent determinant of V/S ratio and PS in men. In subgroup analysis, PS tended to be associated with V/S ratio only in the carrier of 45G allele.

CONCLUSION

These results suggest that the G allele could be a risk factor of metabolic syndrome and the development of atherosclerosis in Japanese obese subjects.