Adiponectin gene polymorphisms (T45G and G276T), adiponectin levels and risk for metabolic diseases in an Arab population

ADIPOQ gene (T45G and G276T) single nucleotide polymorphisms and their association with gestational diabetes mellitus in a Filipino population

Several studies have associated the presence of ADIPOQ gene polymorphisms with insulin resistance, adiponectin levels, and metabolic diseases such as diabetes, although with varying degrees of correlation depending on ethnicity. Here we aim to identify individual's susceptibility to gestational diabetes mellitus (GDM) in the presence of T45G and G276T single nucleotide polymorphisms (SNPs) within the ADIPOQ gene among Filipino pregnant women. A total of 285 pregnant women (95 GDM cases and 190 controls) were included in this study. Two ADIPOQ gene polymorphisms were genotyped using TaqMan assay. Results of SNP genotyping showed no significant differences in the frequencies of TT, TG and GG genotypes of T45G SNP between the GDM and control group [p = 1.0000, 0.6179, 0.5797; OR (95%CI) = 1.030 (0.582-1.874), 1.135 (0.683-1.828), 0.833 (0.481-1.420)]. Similarly, the frequencies of GG, GT, and TT genotypes of G276T SNP were comparable in both groups [p = 0.8002, 1.0000, 0.3466; OR (95%CI) = 1.090 (0.654-1.785), 1.022 (0.616-1.665), 0.433 (0.092-1.698)]. Moreover, although adiponectin levels were significantly decreased in GDM group (p = 0.0196) and have shown substantial negative correlations with FBS, 1-hour OGTT, 2-hour OGTT, and HOMA-IR (p < 0.05), they were not significantly different according to genotypes of T45G and G276T polymorphisms both in GDM and control group. Our results suggest that neither of the two ADIPOQ gene polymorphisms influence adiponectin levels and development of GDM in a Filipino population.

Dissecting the Molecular Role of ADIPOQ SNPs in Saudi Women Diagnosed with Gestational Diabetes Mellitus

The traditional definition of gestational diabetes mellitus (GDM) is the leading cause of carbohydrate intolerance in hyperglycemia of varying severity, with onset or initial detection during pregnancy. Previous studies have reported a relationship among obesity, adiponectin (ADIPOQ), and diabetes in Saudi Arabia. ADIPOQ is an adipokine that is produced and secreted by adipose tissue involved in the regulation of carbohydrate and fatty acid metabolism. This study investigated the molecular association between rs1501299, rs17846866, and rs2241766 single-nucleotide polymorphisms (SNPs) in ADIPOQ and GDM in Saudi Arabia. Patients with GDM and control patients were selected, and serum and molecular analyses were performed. Statistical analyses were performed on clinical data, Hardy Weinberg Equilibrium, genotype and allele frequencies, multiple logistic regression, ANOVA, haplotype, linkage disequilibrium, as well as MDR and GMDR analyses. The clinical data showed significant differences in various parameters between the GDM and non-GDM groups (p < 0.05). In GDM women with alleles, genotypes, and different genetic models, the rs1501299 and rs2241766 SNPs showed a strong association (p < 0.05). Multiple logistic regression analysis revealed a negative correlation (p > 0.05). This study concluded that rs1501299 and rs2241766 SNPs were strongly associated with GDM in women in Saudi Arabia.

Influence of Single Nucleotide Polymorphism of ENPP1 and ADIPOQ on Insulin Resistance and Obesity: A Case-Control Study in a Javanese Population

Single nucleotide polymorphisms (SNPs) in obesity-related genes, such as ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1) and adiponectin (ADIPOQ), potentially increase the risk of insulin resistance, the most common metabolic dysregulation related to obesity. We investigated the association of ENPP1 SNP K121Q (rs1044498) with insulin resistance and ADIPOQ SNP + 267G > T (rs1501299) with circulating adiponectin levels in a case–control study involving 55 obese and 55 lean Javanese people residing in Yogyakarta, Indonesia. Allele frequency was determined by a chi squared test or Fisher’s exact test with an expected value less than 0.05. Odds ratios and 95% confidence intervals were estimated by regression logistic analysis. The presence of the Q121 allele of ENPP1 resulted in significantly higher fasting glucose, fasting insulin levels, and HOMA-IR, as compared to homozygous K121 carriers. The risk of insulin resistance was elevated in obese individuals carrying Q121 instead of homozygous K121. Adiponectin level was significantly lower in the obese group as compared to the lean group. Obese individuals carrying homozygous protective alleles (TT) of ADIPOQ tended to have lower adiponectin levels as compared to GT and GG carriers, however, we did not find statistically significant effects of the +276G > T SNP of the ADIPOQ gene on the plasma adiponectin levels or on the development of obesity.

Meta-analysis of the association between adiponectin SNP 45, SNP 276, and type 2 diabetes mellitus

Objective

The present study aimed to determine whether the polymorphisms at rs2241766 and rs1501299 on the ADIPOQ gene were related to the susceptibility of type 2 diabetes mellitus (T2DM).

Methods

Eight databases, PubMed, GWAS, Embase, Lochrane, Ebsco, CNKI (Chinese National Knowledge Infrastructure), VIP (Viper Database) and ChinaInfo were searched, and a meta-analysis of susceptibility was conducted between SNP45, SNP276 polymorphisms and T2DM. Furthermore, HWE test was conducted to assess the genetic balance of the study, evaluate the quality of Newcastle–Ottawa quality assessment scale (NOS), and establishing allelic, dominant, recessive, heterozygous, and homozygous gene models.

Results

This meta-analysis included 53 articles, encompassing 9285 cases with rs2241766 and 14156 controls and 7747 cases with rs1501299 and 10607 controls. For the rs2241766 locus, a significant correlation was found in the three models by the subgroup analysis. Western Asians: dominant gene model (TT + TG vs. GG, P = 0.01); heterozygous gene model (TG vs. GG, P = 0.02); homozygous gene model (TT vs. GG, P = 0.01). South Asians: dominant gene model (TT + TG vs. GG, P = 0.004); heterozygous gene model (TG vs. GG, P = 0.009); homozygous gene model (TT vs. GG, P = 0.005). However, no statistically significant correlation was established among the five genetic models for rs1501299 locus.

Conclusion

The findings of the present study indicated that the T allele of rs2241766 polymorphism is the susceptibility locus of T2DM in the West Asian population, but has a protective effect in the South Asian population, albeit further studies are needed in other populations. Also, no association was found between the ADIPOQ rs1501299 polymorphism and T2DM.

Correlation Between Adiponectin Gene rs1501299 Polymorphism and Nonalcoholic Fatty Liver Disease Susceptibility: A Systematic Review and Meta-Analysis

Background

Metabolic related nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver diseases around the world. A single nucleotide polymorphism (SNP) rs1501299 (+276G>T) in the adiponectin gene has been recently revealed to be responsible for susceptibility to NAFLD. This meta-analysis intended to assess the association risk of NAFLD and rs1501299 polymorphism.

Material/Methods

We conducted a literature search on PubMed, Embase, and Cochrane Library databases. All involved studies were selected based on our search criteria. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to quantify the strength of the association. Subgroup analysis considered the effects of ethnicity, subject scope, and source of control. Publication bias was assessed by Begg’s tests.

Results

Eight qualified case-control studies with 1639 patients and 1426 controls demonstrated a significant correlation between rs1501299 polymorphism in adiponectin and NAFLD under the dominant model (OR=1.18, 95% CI=1.02–1.36), allelic contrast (OR=1.21, 95% CI=1.09–1.36), homozygote comparison (OR=1.63, 95% CI=1.26–2.01) and the recessive allele model (OR=1.58, 95% CI=1.23–2.02) with evident heterogeneity. No association was observed between the risk of NAFLD and the genotypic variants in heterozygote comparison (OR=1.11, 95% CI=0.95–1.29) without heterogeneity. Subgroup analysis suggested that the sample size could be the potential source of heterogeneity. Source of control was not the reason for between-study heterogeneity and further sensitivity analysis and publication bias revealed good consistency and symmetry in the pooling studies.

Conclusions

Results from our current meta-analysis gave insight into the correlation between rs1501299 polymorphism and the risk of NAFLD, indicating the variant of rs1501299 might be related to increased NAFLD susceptibility.

Adiponectin Single Nucleotide Polymorphisms and Serum Levels Are Relevant to Prognosis of Patients With Aneurysmal Subarachnoid Hemorrhages

To investigate the association of adiponectin gene polymorphisms and its levels with aneurysmal subarachnoid hemorrhages (aSAHs) prognosis. This case-control study enrolled 138 patients with aSAH and 102 healthy controls as case group and control group, respectively. Prognosis of case group was evaluated using Glasgow Outcome Scale. Polymerase chain reaction-restriction fragment length polymorphism was used to examine the genotypes of 45T>G and -11377C>G. Enzyme-linked immunosorbent assay was used to detect adiponectin levels. Logistic regression analysis was applied to assess the association of adiponectin gene polymorphism with aSAH prognosis. Case group had increased GG genotype and G allele genotype frequencies of 45T>G and -11377C>G compared with control group (all P < 0.01). In case group, TT genotype had the highest adiponectin level compared with both TG and GC genotypes (both P < 0.05). As for -11377C>G, GG genotype had the lowest adiponectin levels, followed by CG genotype and CC genotype in both groups (P < 0.05). In general, case group had decreased adiponectin levels compared with control group (P < 0.05). Univariate analysis showed that hypertension, Hunt-Hess grade, aneurysm size, aneurysms multiplicity and -11377C>G were associated with aSAH prognosis, while multivariate logistic regression analysis confirmed that hypertension, Hunt-Hess grade, residual flow in aneurysms and aneurysm size were independent risk factors for aSAH prognosis. Decreased adiponectin levels may be a pathological index for aSAH, which may be explain by the G allele of -11377C>G in adiponectin. Moreover, hypertension, Hunt-Hess grade, residual flow in aneurysms and aneurysm size may be independent risk factors for aSAH prognosis.

Analysis of the correlation between adiponectin gene polymorphism and metabolic syndrome incidence and its relationship with the degree of atherosclerosis in patients

The aim of the present study was to determine the correlation between adiponectin (APN) gene polymorphism, metabolic syndrome incidence, and degree of atherosclerosis in patients with this disease. The study was conducted on 369 unrelated patients, diagnosed with metabolic abnormalities. The patients were divided into the metabolic syndrome group (MS group, n=182), the metabolic abnormality group (n=187) and the control group with metabolic normality (n=134), as per the degree of metabolic abnormality. The gene polymorphism of rs121917815 site of APN gene was detected by TaqMAN probe technique, and the OR values of different genotypes and alleles were calculated. The APN protein, C-reactive protein (CRP), IL-1 and high-density lipoprotein (HDL) 2a and 2b expression level changes were detected by immunoblotting. The atherosclerosis index (AI) of each allele in patients with MS was calculated. Compared with the control group, the expression levels of APN protein in the metabolic abnormality and MS groups were significantly decreased. However, there was no distinct difference in the comparison of gene polymorphism between the control and metabolic abnormality groups. The CC genotype frequency and C allele frequency of rs121917815 polymorphic site in the MS group were significantly increased, compared with the control group. The TT genotype frequency and T allele frequency were significantly decreased and the OR values of the CC genotype and C allele were increased. The results of immunoblotting showed that there was no obvious change of CRP, IL-1, HDL-2a and HDL-2b in the three groups, and there was no statistically significant difference in the comparison of AI between the MS and control groups as well as the metabolic abnormality group. The APN gene polymorphic site rs121917815 is associated with MS. The occurrence of CC genotype and C allele increased the incidence of MS, but it did not increase the degree of atherosclerosis in MS patients.

Association of ADIPOQ, leptin, LEPR, and resistin polymorphisms with obesity parameters in Hammam Sousse Sahloul Heart Study

BACKGROUND

Adipose tissue is an important endocrine organ that secretes a number of adipokines, such as adiponectin (ADIPOQ), leptin (LEP), leptin receptor (LEPR), and resistin (RETN) which may be implicated in obesity. Some adipokines' polymorphisms of genes might influence their concentrations and/or activities. Our aim was to study the relationship between seven SNPs in ADIPOQ (+45T<G (rs2241766); +276G<T (rs1501299); -4255C<T (rs822393); -395G<T (rs17366568)), LEP (2548G<A (rs7799039)), LEPR (223Q<R (rs1137101)), and RETN (-420C<G (rs1862513)) and obesity in Hammam Sousse Sahloul Heart Study (HSHS).

METHODS

The study, carried out between February and June 2009, is mainly focused on 1121 respondents in HSHS which is a population-based epidemiological study of type "community-based" on cardiovascular risk. Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum lipids and anthropometric parameters were measured. Statistic analysis was performed on SPSSv19.

RESULTS

The polymorphisms of ADIPOQ 4522C<T and 276G<T, LEP 2548G<A, and RETN 420C<G seem to contribute to obesity. In fact, adjusted odds ratios (ORs) of obesity associated with mutated genotypes of each polymorphism were respectively OR=1.38, P=.037; OR=0.608, P<.001; OR=2.23, P=.034; and OR=2.18, P<.001. The 276G<T, 4522C<T, and 420C<G were associated with increased BMI (P=.010, P=.028, and P<.001). A significant association was found between the 276G<T; 4522C<T, LEP 2548G<A and 420C<G, and the waist circumference and hip measurements.

CONCLUSION

ADIPOQ, LEP, and RETN gene polymorphisms were associated with obesity parameters in HSHS population.

Genetic and Non-Genetic Determinants of Circulating Levels of Adiponectin in a Cohort of Chilean Subjects

BACKGROUND

Low adiponectin levels have been associated with obesity, diabetes, coronary disease and polymorphisms. The aim of this study was to assess the clinical and genetic factors related to adiponectin levels in a Chilean adult population.

METHODS

Four groups of 27 individuals, stratified by gender and abdominal obesity, were included in this cross-sectional study. Physical activity level, cardiovascular risk factors and therapy were assessed. Anthropometric measurements, adiponectin, glucose, insulin, hs-CRP, rs1501299, rs2241766, rs266729 and rs17300539 single nucleotide polymorphisms of the adiponectin gene were determined.

RESULTS

Adiponectin levels were inversely correlated with waist circumference, waist-to-hip ratio, weight, body mass index, insulin levels, homeostasis model insulin resistance index (HOMA-IR) and physical activity. Mean adiponectin levels were lower in men (10.1 ± 3.6 vs 11.9 ± 2.9 μg/mL, p = 0.0051), obese (9.9 ± 3.2 vs 12.1 ± 3.3, p < 0.01), physically inactive (8.9 ± 3.2 vs 11.0 ± 2.8, p = 0.015) and insulin-resistant individuals (10.2 ± 3.1 vs 12.9 ± 3.9; p = 0.005). Adiponectin levels were lower in subjects with GG genotype (rs1501299) compared with those with TT or GT variants (6.9 ± 4.6 vs 12.2 ± 2.9 and 11.5 ± 3.4 μg/mL, p = 0.006) but were similar in the other polymorphisms studied.

CONCLUSION

Lower adiponectin levels were related to gender, abdominal obesity, physical activity and insulin resistance and were less influenced by the polymorphisms studied.

Insertion and deletion polymorphism in the alpha-2B adrenoceptor gene in pregnant women ripens gestational diabetes mellitus

There are no earlier studies that reported the association of the 12Glu9 polymorphism in the alpha-2B adrenoceptor (ADRA2B) gene with gestational diabetes mellitus (GDM). We examined the potential association between the ADRA2B gene insertion/deletion (I/D) polymorphism in the Saudi population with GDM. Pregnant women with GDM have been reported to exhibit the same susceptibility as that observed in type 2 diabetes mellitus (T2DM). We have selected I/D polymorphism of the ADRA2B gene located in chromosome 2q11.1 that has been extensively related to T2DM and cardiovascular diseases. This case–control study was conducted with 200 GDM and 300 non-GDM pregnant women. Genotyping of I/D polymorphism was performed by conventional PCR method. Biochemical analyses were found to be significantly different between GDM and non-GDM subjects (p < 0.05). Genotype (ID + DD vs II, p = 0.0002) and allele (D vs I, p = 0.0002) frequencies of the 12Glu9 polymorphism were found to be statistically significant. However, a significant difference was found between allele and genotypes of I/D polymorphism of the ADRA2B gene or the clinical characteristics of the subjects. Our results obtained in this study indicate the ADRA2B gene in the Saudi women was associated with the development of GDM.

Association of two Common Single Nucleotide Polymorphisms (+45T/G and +276G/T) of ADIPOQ Gene with Coronary Artery Disease in Type 2 Diabetic Patients

Background:

Adiponectin, an adipocyte-secreted hormone, is known to have anti-atherogenic, anti-inflammatory, and anti-diabetic properties. In the present study, the association between two common single nucleotide polymorphisms (SNPs) (+45T/G and +276G/T) of ADIOPQ gene and coronary artery disease (CAD) was assessed in the subjects with type 2 diabetes (T2DM).

Methods:

Genotypes of two SNPs were determined by polymerase chain reaction-restriction fragment length polymorphism in 200 subjects with T2DM (100 subjects with CAD and 100 without CAD).

Results:

The frequency of TT genotype of +276G/T was significantly elevated in CAD compared to controls (χ²=7.967, P=0.019). A similar difference was found in the allele frequency of +276G/T between two groups (χ²=3.895, P=0.048). The increased risk of CAD was associated with +276 TT genotype when compared to reference GG genotype (OR=5.158; 95% CI=1.016-26.182, P=0.048). However, no similar difference was found in genotype and allele frequencies of SNP +45T/G between two groups. There was a CAD protective haplotype combination of +276 wild-type and +45 mutant-type allele (276G-45G) (OR=0.37, 95% CI=0.16-0.86, P=0.022) in the subject population.

Conclusion:

Our findings indicated that T allele of SNP +276G/T is more associated with the increased risk of CAD in subjects with T2DM. Also, a haplotype combination of +45G/+276G of these two SNPs has a protective effect on the risk of CAD.

ADIPOQ single nucleotide polymorphism: Association with adiponectin and lipoproteins levels restricted to men

Adiponectin is an adipokine inversely correlated with obesity, which has beneficial effect on insulin resistance and lipid metabolism. Considering its potential as a therapeutic target in the metabolic disorder contexts, and in order to add knowledge in the area, our study evaluated the ADIPOQ 276G > T polymorphism effect on adiponectin levels, and on lipoproteins of clinical interest in a population sample composed of 211 healthy individuals. Significant effects were observed only among men: the carriers of heterozygous genotype (GT) showed high levels of adiponectin (p = 0.018), while the rare homozygous genotype (TT) gave its carriers a negative phenotype, represented by higher levels of low density lipoprotein cholesterol (LDL-C) (p = 0.004 and p = 0.005) and total cholesterol (TC) (p = 0.010 and p = 0.005) compared to carriers of other genotypes (GG and GT respectively), the independent effect of SNP on LDL-C and TC levels was confirmed by multiple regression analysis (p = 0.008 and p = 0.044). We found no evidence of correlation between circulating adiponectin levels and biochemical markers, which suggests, therefore, an SNP 276G > T independent effect on adiponectin levels and on lipoprotein metabolism in men enrolled in this study.

Association of JAZF1 and TSPAN8/LGR5 variants in relation to type 2 diabetes mellitus in a Saudi population

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a chronic and multifactorial disease with a rapidly rising incidence in Saudi Arabia. Various genes including zinc finger protein 1 (JAZF1) and tetraspanin 8/leucine-rich repeat-containing G protein-coupled receptor (TSPAN8/LGR5) have been previously described to be associated with T2DM. This study investigated the association of JAZF1 (rs864745) and TSPAN8 (rs7961581) with T2DM in a Saudi population.

METHODS

Genomic DNA samples from 400 Saudi T2DM patients and 400 healthy controls were genotyped and analyzed using a polymerase chain reaction-restriction fragment length polymorphism method. The difference between the genotype frequencies were carried out with Chi-square test. Odds ratio, 95 % confidence intervals and p values were calculated using multinomial logistic regression. Dominant and recessive models were implemented to show the statistical significances. Analysis of variance was used to compare differences between genotypes for the various parameters.

RESULTS

Distribution frequencies of the AA, AG, and GG genotypes of JAZF1 (rs864745) differed significantly among T2DM patients and healthy controls (p < 0.05). The AG and GG genotypes were independently and significantly associated with a T2DM risk after adjusting for factors such as age, sex, and body mass index [odds ratio (OR) 2.1 (95 % confidence interval (CI) 1.3-3.4); p = 0.002] and [OR 1.9 (95 % CI 1.2-3.1); p = 0.005], respectively. A genotype-based stratification of anthropometric and biochemical data revealed that the AG + GG genotype is associated with waist circumference (p = 0.04) and fasting blood glucose (p = 0.01) and high-density lipoprotein cholesterol levels (p = 0.02). None of the allele or genotype showed the significant association between the T2DM cases and control subjects in rs7961581 polymorphism in TSPAN8/LGR5 gene.

CONCLUSION

The rs864745 variant in JAZF1 gene may act as genetic risk factors for the development of T2DM in a Saudi population.

ADIPOQ and IL6 variants are associated with a pro-inflammatory status in obeses with cardiometabolic dysfunction

BACKGROUND

Polymorphisms in genes encoding adiponectin (ADIPOQ) and interleukin-6 (IL6) have been associated with adiposity and obese-related phenotypes. This study investigated the relationship of ADIPOQ and IL6 gene polymorphisms with pro-inflammatory and cardiometabolic markers in obese patients.

METHODS

Anthropometric and body composition parameters were measured in 249 Brazilian subjects (30 to 68 yr). Metabolic and inflammatory markers and adipokines were analyzed in blood samples. ADIPOQ rs2241766 (45 T > G) and IL6 rs1800795 (-174G > C) polymorphisms were analyzed by real-time PCR and PCR-RFLP, respectively.

RESULTS

Type 2 diabetes, hypertension, dyslipidemia and increased values of waist circumference, body fat, leptin, fibrinogen, IL-1β, hsCRP and TNFα were related to obesity (p < 0.05). Multiple linear regression analysis showed a positive correlation between BMI and waist circumference, body fat, leptin, fibrinogen, PAI-1, IL-1β, hsCRP and TNFα values (p < 0.001) but not with adiponectin. Obese group had altered metabolic status, resistance to leptin and insulin, and atherogenic and pro-inflammatory profiles. ADIPOQ and IL6 variants were not directely related to obesity, leptin resistance or alterations in cardiometabolic markers. Individuals carrying ADIPOQ 45G allele (TG + GG genotype) had higher IL-6, IL-1β and TNFα levels than TT genotype carriers (p < 0.05). IL6 -174GG genotype was associated with increased IL-1β levels (p = 0.033).

CONCLUSION

Obesity is associated with leptin resistance, cardiometabolic alterations and a pro-inflammatory status. Our results are suggestive that ADIPOQ and IL6 polymorphisms contribute to cardiometabolic risk in obese individuals.

Association between ADIPOQ +45T>G polymorphism and type 2 diabetes: a systematic review and meta-analysis

Recently, a number of studies have reported the association between the single nucleotide polymorphisms (SNPs) +45T>G polymorphism in the adiponectin (ADIPOQ) gene and type 2 diabetes mellitus (T2DM) risk, though the results are inconsistent. In order to obtain a more precise estimation of the relationship, a meta-analysis was performed. In this current study, the Medline, Embase, Pubmed, ISI Web of Knowledge, Ovid, Science Citation Index Expanded Database, Wanfang Database, and China National Knowledge Infrastructure were searched for eligible studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the strength of association. Forty-five publications were included in the final meta-analysis with 9986 T2DM patients and 16,222 controls for ADIPOQ +45T>G polymorphism according to our inclusion and exclusion criteria. The +45T>G polymorphism was associated with an overall significantly increased risk of T2DM (G vs. T: OR = 1.18, 95% CI = 1.06–1.32; The dominant model: OR = 1.18, 95% CI = 1.03–1.33; The recessive model: OR = 1.47, 95% CI = 1.20–1.78; The homozygous model: OR = 1.62, 95% CI = 1.25–2.09; Except the heterozygous model: OR = 1.11, 95% CI = 0.98–1.24). Subgroup analysis revealed a significant association between the +45T>G polymorphism and T2D in an Asian population. Thus, this meta-analysis indicates that the G allele of the ADIPOQ +45T>G polymorphisms associated with a significantly increased risk of T2DM in the Asian population.

Meta-analysis of the association of ADIPOQ G276T polymorphism with insulin resistance and blood glucose

Insulin resistance (IR) is a major risk for the development of type 2 diabetes (T2D). Numerous studies have been conducted to determine the relationship of ADIPOQ G276T with IR and blood glucose, but the results are conflicting. We conducted a meta-analysis in this work to further investigate such an association. Published works were retrieved from PubMed and Embase databases. A pooled standardized mean difference (SMD) with 95 % confidence interval (CI) was calculated under a dominant model using a random effect model. Twenty-five studies involving 7,480 subjects were included in the meta-analysis. A significant association of G276T polymorphism with homeostasis model assessment insulin resistance index (HOMA-IR) was observed after excluding studies with obvious heterogeneity by performing influence analysis (SMD = -0. 08, 95 % CI -0.15 to -0.01, p = 0.019) and Galbraith plot analysis (SMD = -0.08, 95 % CI -0.14 to -0.02, p = 0.005). In the subgroup analysis, Asians with TG/TT genotypes were found to have a significantly decreased degree of HOMA-IR (SMD = -0.13, 95 % CI -0.20 to -0.07, p < 0.001). The association of G276T with IR or blood glucose for the subgroups (obese, male, and T2D) was also significant. However, the results may not be reliable for small sample sizes. The current meta-analysis suggested that the G276T polymorphism may genetically affect IR using HOMA-IR as an index, and the effect of this polymorphism on IR particularly exists in Asians.

AdipoQ T45 G and G276 T Polymorphisms and Susceptibility to Nonalcoholic Fatty Liver Disease Among Asian Populations: A Meta-Analysis and Meta-Regression

BACKGROUND

Adiponectin (AdipoQ) is an adipose-derived plasma protein that plays an important role in hepatic lipoprotein-lipid metabolism. Emerging evidence have shown that two common polymorphisms (T45 G and G276 T) in the AdipoQ gene may contribute to increasing susceptibility to nonalcoholic fatty liver disease (NAFLD); however individually published studies show inconclusive results. This meta-analysis aimed to derive a more precise estimation of the association of AdipoQ T45 G (rs2241766 T>G) and G276 T (rs1501299 G>T) polymorphisms with NAFLD risk.

METHOD

Potential relevant studies were identified covering the following databases: PubMed, Embase, Web of Science, the Cochrane Library, Chinese National Knowledge Infrastructure (CNKI), Chinese Bio-medicine Database (CBM), and Chinese Sci-tech Journals databases. Statistical analyses were calculated using the version 12.0 STATA software (Stata Corp, College Station, TX, USA). Odds ratios (ORs) and its corresponding 95% confidence interval (CI) were calculated.

RESULT

Ten case-control studies were included with a total of 2,672 subjects, of these 1,117 being NAFLD patients and 1,555 being healthy controls. Our meta-analysis results revealed that the T variant of AdipoQ rs2241766 T>G polymorphism may be associated with an increased risk of NAFLD. There was also a significant association between the G variant of AdipoQ rs1501299 G>T polymorphism and an increased risk of NAFLD. Country-stratified analysis indicated that a higher AdipoQ rs2241766 T>G polymorphism was closely related with an increased risk of NAFLD in Chinese and Indian populations (all Ps < 0.05); a similar result was observed in Chinese populations between AdipoQ rs2241766 T>G polymorphism and an increased risk of NAFLD (P < 0.05).

CONCLUSION

In conclusion, the current meta-analysis indicates that AdipoQ rs2241766 T>G and rs1501299 G>T polymorphisms may contribute to an increasing susceptibility to NAFLD. Moreover, this meta-analysis also suggests for future larger studies with stratified case-control population, and greater focus on the gene-environment interactions regarding NAFLD susceptibility for valid studies.

Association of the genetic variants of insulin receptor substrate 1 (IRS-1) with type 2 diabetes mellitus in a Saudi population

Type 2 diabetes mellitus (T2DM) is a chronic degenerative disease, phenotypically and genetically heterogeneous, characterized by high levels of glucose and metabolic complications. Insulin receptor substrate 1 (IRS-1) plays a key role in the insulin-stimulated signal transduction pathway. A glycine-to-arginine substitution at codon 972 (G972R) (rs1801278) in the IRS-1 gene has been associated with impaired insulin action. Another SNP rs2943641 in the IRS-1 gene has been found to be associated with T2DM and insulin resistance in genome-wide association studies. The aim of the present study was to evaluate whether rs1801278 and rs2943641 are associated with increased risk of T2DM in the Saudi population. The study included 376 T2DM cases and 380 healthy controls. Genomic DNA was isolated using a commercially available kit supplied by Norgen Biotech Corp. Genotyping was performed by PCR and RFLP analysis. There was a significant difference in the genotypic distribution as well as allelic frequency between the T2DM cases and controls in case of both the polymorphisms for rs1801278 (1.752, 95 % CI 1.002-3.121; p = 0.04), and for rs2943641 (OR = 1.482, 95 % CI 1.176-1.867; p = 0.001). In conclusion, both the (rs1801278 and rs2943641) polymorphisms are associated with T2DM in the Saudi population.

Association of adiponectin (ADIPOQ) rs2241766 polymorphism and dyslipidemia in HIV/HCV-coinfected patients

BACKGROUND

The adiponectin (ADIPOQ) rs2241766 polymorphism is related to metabolic abnormalities. The aim of this study was to evaluate the association of the ADIPOQ rs2241766 polymorphism with serum dyslipidemia and insulin resistance (IR) in human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected patients.

METHODS

We carried out a cross-sectional study on 262 patients. ADIPOQ rs2241766 polymorphisms were genotyped by GoldenGate® assay. Generalized linear models (GLMs) were used to compare continuous outcome variables (total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C and homeostatic model assessment (HOMA)) and categorical outcome variables (TC≥200 mg/dL, TG≥170 mg/dL, LDL-C≥100 mg/dL, HDL-C≤35 mg/dL, non-HDL-C≥120 mg/dL and HOMA≥3·8) according to ADIPOQ genotype under a dominant inheritance model.

RESULTS

Patients with the rs2241766 GG/GT genotype had significantly lower serum TC levels (P=0·038) and percentages of TC≥200 mg/dL (P=0·022) than rs2241766 TT carriers. When adjusted GLM was performed, rs2241766 GG/GT was associated with low serum TC levels (arithmetic mean ratio (AMR)=0·92 [(95% CI=0·85; 0·99) P=0·024]) and low likelihood of TC≥200 mg/dL (odds ratio (OR)=0·32 [(95% CI=0·11; 0·88) P=0·027]. When stratifying by steatosis, no significant values were found for patients without steatosis. However, for patients with steatosis, rs2241766 GG/GT genotypes were related to low TC serum values of TC (AMR=0·89; P=0·027), LDL-C (AMR=0·85; P=0·039) and non-HDL-C (AMR=0·86; P=0·015). No significant associations were found between rs2241766 and HOMA values.

CONCLUSIONS

The presence of the ADIPOQ rs2241766 G allele (GG/GT genotype) was associated with a protective effect against dyslipidemia, primarily in HIV/HCV-coinfected patients with steatosis.

Comprehensive analysis of circulating adipokines and hsCRP association with cardiovascular disease risk factors and metabolic syndrome in Arabs

Background

Cardiovascular diseases (CVD) are a leading cause of death worldwide including the Middle East. This is caused in part by the dysregulation of adipose tissue leading to increased production of pro-inflammatory adipokines and reduction in cardio-protective adipokines such as adiponectin. Ethnicity has been recognized as a major factor in the association between CVD risk factors and the different circulating adipokines. In this study, for the first time, the relationship between traditional cardiovascular risk factors, Metabolic Syndrome (MetS) and circulating level of adipokines in Arab ethnicity was investigated.

Methods

We conducted a population-based cross-sectional survey on 379 adult Arab participants living in Kuwait. Traditional cardiovascular risk factors such as blood pressure (BP), low density lipoprotein (LDL) and triglyceride (TG) were measured. Plasma levels of circulating Leptin, Plasminogen Activator Inhibitor (PAI-1) visfatin, adiponectin, resistin and adipsin were assessed using the multiplexing immunobead-based assay.

Results

Circulating levels of High sensitivity C-Reactive Protein (hsCRP), Leptin, PAI-1 and adiponectin were significantly higher in Arab women than men (p < 0.0001). In multi-variate analysis, the homeostasis model assessment-insulin resistance (HOMA-IR) and body mass index (BMI) showed strong association with most of the biomarkers (p < 0.05). HsCRP showed significant association with all risk factors (p < 0.05). Leptin, PAI-1 and adipsin showed significant positive correlation with BMI, unlike adiponectin which showed inverse correlation (p < 0.05). Subjects in the highest tertile of leptin, PAI-1 and hsCRP had higher odds of having Metabolic Syndrome (MetS) (odd ratio [OR] = 3.02, 95% confidence interval [CI] = 1.47 – 6.19) and (OR = 2.52, 95% CI = 1.45 – 4.35), (OR = 4.26, 95% CI = 2.39 – 7.59) respectively. On the other hand subjects with highest tertile of adiponectin had lower odds of having MetS (OR = 0.22, 95% CI = 0.12 – 0.40). Leptin, PAI-1 and hsCRP showed significant positive association with increased MetS components (P-trend <0.05), while adiponectin was negatively associated with increased MetS components (P-trend <0.0001).

Conclusion

Our results show positive association between hsCRP, leptin, PAI-1 with increased MetS components and increase the odds of having MetS. Adiponectin on the other hand showed inverse correlation with MetS components and associated with reduction in MetS. Overall, our data highlights the significant clinical value these markers have in MetS especially hsCRP which can be used as good marker of low grade inflammation in Arabs.

Association between the g.14461A>G genetic polymorphism of the TLR4 gene and type 2 diabetes mellitus risk in a Chinese population

OBJECTIVE

Toll-like receptor 4 (TLR4) is an important candidate gene for mediating the susceptibility to type 2 diabetes mellitus (T2DM). The purpose of this study was to investigate the association between the TLR4 gene polymorphisms and T2DM susceptibility.

METHODS

A total of 671 T2DM patients and 677 healthy controls were recruited in this study. The created restriction site-polymerase chain reaction and DNA sequencing methods have been used to analyze the TLR4 gene polymorphisms.

RESULTS

One novel genetic polymorphism (g.14461A>G) was found. Our data indicated that the g.14461A>G genetic polymorphism was significantly associated with the increased susceptibility to T2DM in a homozygote comparison (GG vs. AA: odds ratio [OR]=2.09, 95% confidence interval [CI] 1.44-3.04, p<0.001), dominant model (GG/AG vs. AA: OR=1.27, 95% CI 1.03-1.57, p=0.028), recessive model (GG vs.

AG/AA

OR=1.98, 95% CI 1.39-2.83, p<0.001), and allele contrast (G vs. A: OR=1.33, 95% CI 1.13-1.57, p=0.001). The allele-G might be the risk allele for enhancing the susceptibility to T2DM.

CONCLUSION

These preliminary findings suggest that the g.14461A>G genetic polymorphism of the TLR4 gene is potentially related to the susceptibility to T2DM in the studied population.

Association between type 2 diabetes mellitus-related SNP variants and obesity traits in a Saudi population

Obesity, commonly measured as body mass index (BMI), has been on a rapid rise around the world and is an underlying cause of several chronic non-communicable diseases, including type 2 diabetes mellitus (T2DM). In addition to the environmental factors, genetic factors may also contribute to the ongoing obesity epidemic in Saudi Arabia. This study investigated the association between variants of 36 previously established T2DM SNPs and obesity phenotypes in a population of Saudi subjects. Study subjects consisted of 975 obese (BMI: ≥30), 825 overweight (25-30) and 423 lean controls (18-25) and of these 927 had a history of T2DM. Subjects were genotyped for 36 SNPs, which have been previously proved to be T2DM linked, using the KASPar method and the means of BMI and waist circumference (WC) corresponding to each of the genotypes were compared by additive, recessive and dominant genetic models. Five and seven of 36 T2DM-related SNPs were significantly associated with the BMI and WC, respectively. Variants of SNPs rs7903146, rs1552224 and rs11642841 in the control group and rs7903146 in T2DM group showed significant association with both BMI and WC. Variant of SNP rs10440833 was significantly associated with BMI in T2DM group of both males [OR = 1.8 (1.0, 3.3); P = 0.04] and females [OR = 2.0 (1.0, 3.9); P = 0.04]. Genetic risk scores explained 19 and 14% of WC and hip size variance in this population. Variants of a number of established T2DM related SNPs were associated with obesity phenotypes and may be significant hereditary factors in the pathogenesis of T2DM.

Association of the ADIPOQ T45G polymorphism with insulin resistance and blood glucose: a meta-analysis

Results of published studies on the association of the ADIPOQ T45G polymorphism with insulin resistance (IR) and blood glucose are conflicting. In this study, we performed a meta-analysis to further investigate such an association. Articles that evaluate the effect of the T45G polymorphism on IR and blood glucose were identified from the PubMed and Embase databases. Five indices, including fasting blood glucose (FBG), fasting insulin (F-insulin), 2-h blood glucose (2-h BG), 2-h insulin, and homeostasis model assessment insulin resistance index (HOMA-IR), were used to assess the effects of the T45G polymorphism on IR and blood glucose under a dominant model. 24 articles involving 7630 subjects were included. Twenty-two studies on FBG, 17 on F-insulin, 20 on HOMA-IR, and 3 on 2-h BG were included. No study on 2-h insulin was found. This meta-analysis revealed no significant association between the ADIPOQ T45G polymorphism and IR and blood glucose in the overall population and subgroup subjects under a dominant model, regardless of whether FBG, F-insulin, 2-h BG, or HOMA-IR was used. The present meta-analysis indicated that the mutation allele may have no function in IR development. The ADIPOQ T45G polymorphism is not associated with IR and blood glucose.

Associations between two single nucleotide polymorphisms of the adiponectin gene, its circulating concentrations and cardiometabolic risk factors in prepubertal children with and without abdominal obesity

BACKGROUND

The adiponectin gene has been identified as a susceptibility locus for metabolic syndrome, diabetes and cardiovascular disease.

AIM

To examine the influence of two single nucleotide polymorphisms (SNPs) of this gene (+276G>T and +45T>G) on circulating adiponectin concentrations, and to evaluate their relationship with adiposity and cardiometabolic risk factors in prepubertal children with and without abdominal obesity.

MATERIAL AND METHODS

168 children (78M, 6-10 yr) were examined, divided into three groups based on waist circumference (WC). Auxological and biochemical parameters were measured by standard procedures. Adiponectin SNPs were genotyped using TaqMan allelic discrimination assays.

RESULTS

Adiponectin concentration correlated inversely with measures of adiposity (rBMIz-score=-0.211, pBMIz-score=0.007; rwc=-0.210, pwc=0.008; rwc/height=-0.215, pwc/height=0.006), and was significantly influenced by blood glucose, insulin and systolic blood pressure (SBP). The +276T-allele carriers had higher SBP and diastolic BP compared to GG-homozygotes (p<0.05), and expressed higher obesity-related measures and lower adiponectin concentrations. As to the +45T>G SNP, the GGsubject had higher total cholesterol and LDL-C concentrations compared to the T-allele carriers (p<0.05), showing worse obesity measures, higher triglyceride, glucose and insulin and lower serum adiponectin values.

CONCLUSION

Genetic variants of the adiponectin gene had an impact on adiposity, adiponectin concentrations and some cardiometabolic variables among prepubertal children.

T45G and G276T Adiponectin Gene Polymorphisms in Primary Aldosteronism and Healthy Controls in an East Slovak Population

Metabolic complications are frequent in primary aldosteronism (PA) and adiponectin gene polymorphisms seem to confer a genetic risk for metabolic alterations. Aim of the study was to evaluate the prevalence of metabolic symptoms in patients with PA compared to controls and the prevalence of two single nucleotide polymorphisms (SNPs), T45G and G276T, in the adiponectin gene and their relationship to metabolic syndrome (MS). The study involved 47 patients with PA and 90 controls selected from general population. Body mass index (BMI), and selected biochemical parametres were examined, and the mentioned SNPs were genotyped in all subjects. PA patients had a significantly higher BMI (p0.0001), blood glucose level (p0.01), and triglycerides (p0.0005) compared to controls. There were no significant differences in the prevalence of the studied genotypes of adiponectin gene polymorphisms. The 276GT genotype was linked with lower levels of triglycerides (p≤0.05), while 276GG was related to higher levels of triglycerides (p=0.01). A similar but non-significant tendency was observed in relation to cholesterol levels. We can conclude that PA patients with the 276GT genotype have lower triglycerides levels, but there are not significant differences in the distribution of genotypes and alleles among PA patients and controls in an East Slovak population.

Adiponectin gene polymorphisms may not be associated with idiopathic premature ovarian failure

Premature ovarian failure (POF) is a syndrome characterized by loss of ovarian function before the age of 40 years. Adiponectin, a protein secreted by adipose tissue, exerts beneficial effects on glucose and lipid metabolism. Transcription of adiponectin and its receptor gene is correlated with follicular development. POF, as a type of pathological ovarian aging, is associated with an increase in fat mass and body weight, in which adiponectin may be involved. The present study aimed to investigate the relationship between adiponectin gene polymorphisms and idiopathic POF in Chinese women. We examined DNA samples of the variant SmaI (rs2241766) and BsmI (rs1501299) loci of the adiponectin gene in 120 POF patients and 104 controls. Polymerase chain reaction and restriction fragment length polymorphism were used to assess these genotype variants. Our results showed that the genotype distributions of the SmaI and BsmI polymorphisms did not significantly differ between the patients with idiopathic POF and the controls. Moreover, no significant difference was found between the controls and POF patients in the haplotype analysis. This suggests that the SmaI and BsmI polymorphisms of adiponectin gene might not be responsible for idiopathic POF, at least, in the Chinese population. More researches are required to determine whether these findings can be extrapolated to other populations.

Prevalence of vitamin d insufficiency in qatar: a systematic review

Qatar has a high burden of chronic diseases including obesity, cardiovascular disease and type 2 diabetes mellitus. Low serum vitamin D levels have been implicated in the development and progression of a range of these chronic conditions. The prevalence of vitamin D insufficiency or deficiency in the general population of Qatar has still not been investigated. The aim of this study was to carry out a systematic review of published studies documenting the prevalence of vitamin D insufficiency or deficiency in the Qatari population. A search strategy was developed for online databases (PubMed, Ovid MEDLINE, Embase and Embase Classic) between 1980 to the last week of August 2012, and bibliographies of the included studies were further searched for additional reports. Search terms used were QATAR and VITAMIN D. Studies reporting the serum levels of vitamin D in several Qatari sub-populations were identified. Weighted-average vitamin D serum levels and prevalence of low vitamin D status (<75 nmol/L) were calculated. Subgroup analysis was carried out by age. The quality of each study was evaluated according to four criteria: national representativeness, representation of males and females, the sample size, and the sampling protocol. A total of 16 relevant publications were identified, and 8 of these (reporting from 7 unique studies) met our inclusion and exclusion criteria with a total number of 1,699 Qatari subjects. The pooled sample size weighted-average vitamin D concentration (±SD) was 45.3±14.3 nmol/L (95% CI: 44.6-46.0; range 29.2-66.9 nmol/L). The weighted-average prevalence of low vitamin D status was 90.4% (95% CI: 90.1-91.0; range 83%-91%). Age was inversely correlated with vitamin D levels and directly with its insufficiency/deficiency prevalence. There have only been a few studies on the prevalence of low vitamin D in Qatar a very high prevalence of vitamin D insufficiency/deficiency in Qatar that increases with age has been suggested. The present report underlines the need to develop a nationally representative study to further evaluate vitamin D status in Qatar. Given the growing evidence of the role of vitamin D in chronic disease, this study could help develop public health strategies for disease prevention in Qatar.

Amerindians show association to obesity with adiponectin gene SNP45 and SNP276: population genetics of a food intake control and "thrifty" gene

Adiponectin gene polymorphisms SNP45 and SNP276 have been related to metabolic syndrome (MS) and related pathologies, including obesity. However results of associations are contradictory depending on which population is studied. In the present study, these adiponectin SNPs are for the first time studied in Amerindians. Allele frequencies are obtained and comparison with obesity and other MS related parameters are performed. Amerindians were also defined by characteristic HLA genes. Our main results are: (1) SNP276 T is associated to low diastolic blood pressure in Amerindians, (2) SNP45 G allele is correlated with obesity in female but not in male Amerindians, (3) SNP45/SNP276 T/G haplotype in total obese/non-obese subjects tends to show a linkage with non-obese Amerindians, (4) SNP45/SNP276 T/T haplotype is linked to obese Amerindian males. Also, a world population study is carried out finding that SNP45 T and SNP276 T alleles are the most frequent in African Blacks and are found significantly in lower frequencies in Europeans and Asians. This together with the fact that there is a linkage of this haplotype to obese Amerindian males suggest that evolutionary forces related to famine (or population density in relation with available food) may have shaped world population adiponectin polymorphism frequencies.

Genetic association of adiponectin with type 2 diabetes in Jordanian Arab population

Adiponectin, a protein exclusively secreted by adipose tissue and present at low levels in obese individuals, is now widely recognized as a key determinant of insulin sensitivity and protection against obesity-associated metabolic syndrome. In Jordan, prevalence of diabetes (17.1%) is twice that of the United States (7.8%). In this study, we examined the contribution of the promoter variant rs266729 (-11377C>G) of the ADIPOQ gene as a risk factor for diabetic patients in Jordan. DNA was extracted from blood samples for patients and controls .Polymerase chain reaction and restriction fragment length polymorphism were used to genotype this variant. A total of 420 type 2 diabetic patients and 230 controls were successfully genotyped. The results showed a significant genotypic (p=0.00001) and allelic (p=0.01) association with variant in the diabetic patients as compared to controls. This suggests that the ADIPOQ gene plays a major role in increasing the risk of diabetes, at least in the Jordanian Arab population.

Association of the adiponectin gene rs1501299 G>T variant, serum adiponectin levels, and the risk of coronary artery disease in a Chinese population

BACKGROUND

The present study aimed to investigate whether the single nucleotide polymorphism (SNP) 276G>T (rs1501299) of the adiponectin (ADIPOQ) gene was associated with the risk of coronary artery disease (CAD) and serum adiponectin levels in a Chinese population.

METHODS

The rs1501299 polymorphism of the ADIPOQ gene was genotyped in 438 subjects with angiographically diagnosed CAD and 443 controls. Levels of serum adiponectin were determined in 152 CAD subjects and 155 controls.

RESULTS

The CAD subjects had GT and TT genotypes more frequently, and had GG genotype less frequently than the controls. The OR increased and was significant after adjustment for known CAD risk factors. Significant difference was also observed with T allele being more frequent among the CAD subjects. The T allele at the rs1501299 polymorphism was associated with a higher risk of CAD. The mean adiponectin levels of CAD patients were lower than control subjects. No significant correlation was seen of different genotypes with serum adiponectin levels.

CONCLUSIONS

The adiponectin rs1501299 G>T variant was positively related with an increased risk of CAD, and the CAD patients had lower adiponectin levels which were not affected by the different genotypes of rs1501299 in the present study.