Association between ACE (rs4646994), FABP2 (rs1799883), MTHFR (rs1801133), FTO (rs9939609) Genes Polymorphism and Type 2 Diabetes with Dyslipidemia

Genetic Risk Scores for the Determination of Type 2 Diabetes Mellitus (T2DM) in North India

BACKGROUND

Globally, type 2 diabetes mellitus (T2DM) is one of the fastest-growing noncommunicable multifactorial and polygenic diseases, which leads to many health complications and significant morbidity and mortality. South Asians have a high genetic predisposition to T2DM, with India being home to one in six diabetics. This study investigates the association of selected genetic polymorphisms with T2DM risk and develops a polygenic risk score (PRS).

METHODS

A case-control study recruited fully consented participants from a population of Jat Sikhs in north India. DNA samples were genotyped for a range of polymorphisms and odds ratios were calculated under several genetic association models. Receiver operating characteristic (ROC) curves were produced for combinations of the PRS and clinical parameters.

RESULTS

The GSTT1(rs17856199), GSTM1(rs366631), GSTP1(rs1695), KCNQ1(rs2237892), ACE(rs4646994), and TCF7L2(rs12255372; rs7903146; rs7901695) polymorphisms were associated with increased T2DM risk (p ≤ 0.05). No association was observed with IGF2BP2(rs4402960) or PPARG2(rs1801282). The weighted PRS was found to be significantly higher in patients (mean = 15.4, SD = 3.24) than controls (mean = 11.9, SD = 3.06), and t(454) = -12.2 (p < 0.001). The ROC curve analysis found the weighted PRS in combination with clinical variables to be the most effective predictor of T2DM (area under the curve = 0.844, 95%CI = 0.0.808-0.879).

CONCLUSIONS

Several polymorphisms were associated with T2DM risk. PRS based on even a limited number of loci improves the prediction of the disease. This may provide a useful method for determining T2DM susceptibility for clinical and public health applications.

Development of a genetic risk score for obesity predisposition evaluation

Obesity is a major public health issue resulting from an interaction between genetic and environmental factors. Genetic risk scores (GRSs) are useful to summarize the effects of many genetic variants on obesity risk. In this study, we aimed to assess the association of previously well-studied genetic variants with obesity and develop a genetic risk score to anticipate the risk of obesity development in the Iranian population. Among 968 participants, 599 (61.88%) were obese, and 369 (38.12%) were considered control samples. After genotyping, an initial screening of 16 variants associated with body mass index (BMI) was performed utilizing a general linear model (p < 0.25), and seven genetic variants were selected. The association of these variants with obesity was examined using a multivariate logistic regression model (p < 0.05), and finally, five variants were found to be significantly associated with obesity. Two gene score models (weighted and unweighted), including these five loci, were constructed. To compare the discriminative power of the models, the area under the curve was calculated using tenfold internal cross-validation. Among the studied variants, ADRB3 rs4994, FTO rs9939609, ADRB2 rs1042714, IL6 rs1800795, and MTHFR rs1801133 polymorphisms were significantly associated with obesity in the Iranian population. Both of the constructed models were significantly associated with BMI (p < 0.05) and the area under the mean curve of the weighted GRS and unweighted GRS were 70.22% ± 0.05 and 70.19% ± 0.05, respectively. Both GRSs proved to predict obesity and could potentially be utilized as genetic tools to assess the obesity predisposition in the Iranian population. Also, among the studied variants, ADRB3 rs4994 and FTO rs9939609 polymorphisms have the highest impacts on the risk of obesity.

Obesity, dyslipidaemia and candidate gene polymorphisms: a cross-sectional study among the Liangmai and Mizo tribes of Manipur, India

BACKGROUND

The prevalence of obesity and dyslipidaemia was observed to be increased among the tribal populations, due to globalization.

MATERIALS AND METHODS

In the present study, data on demographic, somatometric and blood samples were collected from 613 participants of both sex, age 18-60 years, further lipid profiling and genotyping was executed. Multifactor dimensionality reduction (MDR) software was used for gene-gene interactions analysis.

RESULTS

Significantly differences were observed with respect to the general characteristic and selected gene polymorphisms in both the tribes. Among the Liangmai tribe, MC4R gene was found to pose significant decreased risk for waist-height ratio (WHtR) (OR = 0.56; 95% confidence interval (CI)= 0.32-0.99; p value = .04) and HDL (OR = 0.58; 95% CI = 0.36-0.92; p value = .02). Similar trends of significant decreased risk (OR = 0.39; 95% CI = 0.20-0.76; p value=.006) for BMI were observed among the Mizo tribe. The gene-gene interaction revealed the combined model of FTO+MC4R genes shows an increased risk for BMI in both the tribes. The independent significant increased risk posed by FTO gene was moderated by interaction with MC4R gene.

CONCLUSIONS

The observed differences can possibly attribute to both their respective ancestries resulting in different gene pools and the physical environment. The results of the study highlight the importance of gene-gene and gene-environment interactions in adverse phenotype groups.KEY MESSAGEAmong the tribal population, the prevalence of obesity and dyslipidaemia has been increased.Differential distribution and associations of selected markers hint towards differential genetic architecture in these populations.MC4R rs17782313 polymorphism was found to show a significantly decreased risk for WHtR and low HDL among the Liangmai tribe and BMI among the Mizo tribe.Significant increased risk posed by FTO rs9939609 gene polymorphism was moderated by the interaction with MC4R rs17782313.

Association Between Retinoid X Receptor Gene Variants and Dyslipidemia Risk in an Iranian Population

Background

Dyslipidemia is a complex trait that is influenced by various genetic and environmental factors. While the exact cause of dyslipidemia is still unknown, some studies have shown that genetic factors such as single nucleotide polymorphisms (SNPs) have been primarily associated with dyslipidemia. Based on the available data, it appears that retinoid X receptor (RXR) genes are jointly or separately associated with lipid homeostasis and that SNPs may affect RXR gene functions in lipid metabolism.

Methods

To study the possible role of the RXR genes in genetic susceptibility of dyslipidemia, three selected polymorphisms, rs3132294 located in RXRA (RXR-alpha) gene and rs2651860 and rs1128977 located in RXRG (RXR-gamma) gene, were investigated in 391 individuals with the use of tetra-primer amplification refractory mutation system polymerase chain reaction (T-ARMS PCR) method.

Results

For the rs3132294 SNP, the genotype frequencies in the case group were GG 58.5%, GA 33.2%, and AA 8.3%, and in the control group, they were GG 51.8%, GA 36.3%, and AA 11.9%. The genotype distribution of rs2651860 SNP in the case group were TT 43.2%, TG 52.1%, and GG 4.7%, and in the control group, they were TT 50.8%, TG 46.2%, and GG 3%. Genotype frequencies for the rs1128977 SNP in the case group were CC 34.7%, CT 47.6% and TT 17.7%, compared with CC 37.8%, CT 44.3%, and TT 17.9% in the control group. When the clinical characteristics of the case and control groups were stratified by allele carrier status for each SNP, the rs1128977 SNP was associated with increased levels of HDL-cholesterol, body mass index, waist circumference, and diastolic blood pressure (P< 0.05). In contrast, the alleles of the rs2651860 and rs3132294 SNP were not associated with an increased prevalence of dyslipidemia or clinical characteristics in the case group compared to the control group.

Conclusion

The present study suggests that rs1128977 SNP in the RXRG gene may affect the clinical characteristics in cases. However, further genetics association studies on large samples are required to validate our findings.

Association of Polymorphisms of Metabolism-Related Genes with Psoriasis Vulgaris in Han Chinese

Aim

Psoriasis is a chronic inflammatory disease with a complex etiology, and psoriasis vulgaris (PsV) is the most common type of psoriasis. Recent studies suggest the relationship between psoriasis and metabolic syndrome in different ethnicities. This study is aimed at evaluating the association of metabolism-related gene variants with the risk of PsV in Chinese Han population. Material and Methods. PsV patients (1030) and healthy controls (965) were enrolled in this study. Eighteen single-nucleotide polymorphisms (SNPs) previously reported to be significantly associated with metabolic syndrome were selected. SNPs were detected by next-generation sequencing.

Results

Seven SNPs were significantly associated with PsV: rs805303 (P = 0.012, OR = 0.85), rs3177928 (P = 1.37 × 10⁻¹⁵, OR = 2.51), and rs2247056 (P = 3.73 × 10⁻⁴, OR = 0.67) located in the HLA gene region; rs1047781 (P = 0.012, OR = 1.18), rs281379 (P = 0.014, OR = 1.71), and rs492602 (P = 0.005, OR = 1.86) located in the FUT2 region; and rs2303138 (P = 0.014, OR = 1.18) located in the LNPEP region. After stratified analysis, rs805303 (P = 0.017, OR = 0.74) and rs2303138 (P = 0.041, OR = 1.30) were associated with PsVs when HLA-C^∗06 : 02 was positive, and rs805303 (P = 5.62 × 10⁻⁵, OR = 0.68), rs3177928 (P = 0.003, OR = 1.75), rs281379 (P = 0.034, OR = 1.96), and rs492602 (P = 0.025, OR = 2.04) were associated with PsVs when HLA-C^∗06 : 02 was negative.

Conclusion

PsV and metabolic syndrome may have overlapped susceptible genes in Chinese Han population.

Diagnostic significance of serum lncRNA HOTAIR and its predictive value for the development of chronic complications in patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) affects the social economy and quality of life, and has become a major threat to human health. This observation aimed to study the possibility of serum HOTAIR as a diagnostic index in patients with T2DM and to explore the prognostic potential of HOTAIR in the development of T2DM.

METHODS

The expression of HOTAIR in serum of 96 patients with T2DM and 82 healthy controls was detected by the qRT-PCR technique. The related biochemical indexes of all participants were determined, such as total cholesterol (TC) and fasting blood glucose (FBG). The value of serum HOTAIR in the diagnosis of T2DM in the two groups was analyzed by the ROC curve. Moreover, the prognostic value of HOTAIR on T2DM was examined by the K-M curve and COX multivariate analysis.

RESULTS

The results of the qRT-PCR analysis showed that the serum level of HOTAIR in patients with T2DM was significantly higher than that in healthy controls. ROC analysis showed that HOTAIR in serum was a diagnostic factor of T2DM. Further multivariate analysis showed that HOTAIR could be an independent biomarker in the prediction of chronic complications for T2DM patients, such as diabetic retinopathy and diabetic nephropathy.

CONCLUSIONS

We found the augment of HOTAIR expression was a character of T2DM. The high expression of serum HOTAIR was a potential non-invasive diagnostic marker and independent prognostic factor in patients with T2DM.

Association of MTHFR C677T polymorphism and type 2 diabetes mellitus (T2DM) susceptibility

Introduction

Methylenetetrahydrofolate reductase (MTHFR) is essential in mediating folate metabolism, and thus plays an important role in diabetes and diabetic complications. MTHFR C677T (rs1801133 C>T) polymorphism has been proposed to be linked with type 2 diabetes mellitus (T2DM) susceptibility. However, the conclusions are inconsistent. Therefore, we rechecked their linkage aiming to obtain a more reliable estimation by performing an updated meta‐analysis.

Methods

We searched electronic databases PubMed, EMBASE, CNKI, and Wanfang to obtain studies updated to October 2019.

Results

After carefully screening, we finally incorporated 68 studies with 10,812 cases and 8,745 controls. The genotype frequency of C677T polymorphism was analyzed pooled to generate odds ratios (ORs) and 95% confidence intervals (CIs). Pooled results presented that MTHFR C677T polymorphism was significantly associated with T2DM under homozygous (OR = 1.64, 95% CI = 1.39–1.94), heterozygous (OR = 1.38, 95% CI = 1.20–1.59), recessive (OR = 1.41, 95% CI = 1.23–1.61), dominant (OR = 1.47, 95% CI = 1.27–1.70), and allele (OR = 1.37, 95% CI = 1.23–1.52) genetic models. Stratified analysis demonstrated that C677T genotype was associated with T2DM in Asian populations, but not Caucasian and African populations.

Conclusion

Our results indicated that MTHFR C677T polymorphism confers to T2DM, especially in Asian populations. Much more large‐scale case–control studies are needed to strengthen such conclusion in the future.

Association of Two Methylenetetrahydrofolate Reductase Polymorphisms (rs1801133, rs1801131) with the Risk of Type 2 Diabetes in South-East of Iran

BACKGROUND

DNA methylation has been linked to the development and progression of multiple disorders including T2D. One significant enzyme involved in DNA methylation is methylene tetrahydrofolate reductase (MTHFR). This study was designed to evaluate the association between rs1801133 and rs1801131 polymorphisms, located in the MTHFR, and T2D in an Iranian population.

METHODS

Blood samples from 151 patients with T2D and 136 healthy individuals were collected and DNA was extracted using the salting out method. Variants were genotyped using amplification tetrarefractory mutation system-polymerase chain reaction analysis. The data were analyzed via independent sample t-test and x2 tests.

RESULTS

The rs1801131 A/C polymorphism significantly increased the risk of T2D in codominant heterozygous AC (P=0.008), homozygous CC (P=0.01), and recessive CC (P=0.001) genotypes. Significant correlations were found regarding rs1801133 T/C gene polymorphism and the risk of T2D in codominant heterozygous TC (P=0.001), homozygote CC (P=0.001), and recessive CC (P=0.0001) models. The presence of the C allele is a potential risk factor for T2D for rs1801133 T/C (P=0.001) and rs1801131 A/C (P=0.04) polymorphisms.

CONCLUSION

Both the rs1801133 T/C and rs1801131 A/C MTHFR polymorphisms significantly increased the risk of T2D in our population. Further studies in other ethnicities are necessary to verify our findings.

Association of Omentin rs2274907 and FTO rs9939609 gene polymorphisms with insulin resistance in Iranian individuals with newly diagnosed type 2 diabetes

Background

Insulin resistance (IR) and fat accumulation in visceral adipose tissue are key players in developing type 2 diabetes (T2D). Several adipose tissue derived-gene polymorphisms are related to higher body mass index (BMI), insulin resistance and T2D. The association of omentin rs2274907 (Val109Asp) and fat-mass and obesity-associated (FTO) rs9939609 gene polymorphisms with overweight/obesity and T2D is controversial. The aim of this study was to determine the association between omentin Val109Asp and FTO rs9939609 polymorphisms and insulin resistance in newly-diagnosed T2D patients.

Methods

The case-control study included 83 newly-diagnosed T2D patients and 85 healthy matched controls, aged 20–80 years. Fasting blood glucose and insulin levels were measured by the enzymatic method and enzyme-linked-immunosorbent assay, respectively. Insulin resistance was calculated using the homeostasis model assessment (HOMA) index. Genotyping was examined using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

Results

There are significant differences between both omentin Val109Asp and FTO rs9939609 polymorphisms and studied individuals (P = 0.011 and P = 0.0001, respectively). Both genetic polymorphisms of omentin Val109Asp and FTO rs9939609 (T/A) are significantly related to higher HOMA index (P = 0.030 and P = 0.046, respectively). However, omentin Val109Asp polymorphism was only related to individuals who were overweight/obese. Additionally, both omentin Val109Asp and FTO rs9939609 polymorphisms were significantly positively correlated to familial history of diabetes (P = 0.046 and P = 0.024, respectively).

Conclusions

Omentin V109D and FTO rs9939609 genetic variations may change insulin metabolism and have key roles in developing T2D through insulin resistance. Thus, the evaluation of these polymorphic regions may be helpful for predicting type 2 diabetes.

Common FTO rs9939609 variant and risk of type 2 diabetes in Palestine

BACKGROUND

Genetic and environmental factors play a crucial role in the development of type 2 diabetes mellitus (T2DM) and obesity. This study aimed to investigate the association of the fat-mass and obesity-associated gene (FTO) rs9939609 variant with T2DM and body mass index (BMI) among Palestinian population.

METHODS

A total of 399 subjects were recruited, of whom 281 were type 2 diabetic patients and 118 normoglycemic subjects. All of them were unrelated, aged > 40 years and recruited within the period 2016-2017. The A allele of FTO rs9939609 was identified by PCR-RFLP.

RESULTS

Significant association of the minor allele A of FTO rs9939609 and T2DM risk was observed with an allelic odd ratio of 1.92 (95% CI [1.09-3.29], p = 0.02) adjusted for age and gender, this association partly attenuated when adjusted for BMI with OR of 1.84, (95%CI [1.04-3.05], p = 0.03). Stratified data by glycemic status across FTO genotypes showed that A allele was marginally associated with increased BMI among diabetic group (p = 0.057) but not in control group (p = 0.7). Moreover, no significant association was observed between FTO genotypes and covariates of age, gender, T2DM complications or any tested metabolic trait in both diabetic and nondiabetic individuals (p > 0.05).

CONCLUSIONS

The variant rs9939609 of the FTO gene was associated with T2DM in Palestine. This is the first study conducted on this gene in the Palestinian population and provides valuable information for comparison with other ethnic groups. Further analysis with larger sample size is required to elucidate the role of this variant on the predisposition to increased BMI in Palestinians.

Type 2 diabetes mellitus: distribution of genetic markers in Kazakh population

Background

Ethnic differences exist in the frequencies of genetic variations that contribute to the risk of common disease. This study aimed to analyse the distribution of several genes, previously associated with susceptibility to type 2 diabetes and obesity-related phenotypes, in a Kazakh population.

Methods

A total of 966 individuals belonging to the Kazakh ethnicity were recruited from an outpatient clinic. We genotyped 41 common single nucleotide polymorphisms (SNPs) previously associated with type 2 diabetes in other ethnic groups and 31 of these were in Hardy–Weinberg equilibrium. The obtained allele frequencies were further compared to publicly available data from other ethnic populations. Allele frequencies for other (compared) populations were pooled from the haplotype map (HapMap) database. Principal component analysis (PCA), cluster analysis, and multidimensional scaling (MDS) were used for the analysis of genetic relationship between the populations.

Results

Comparative analysis of allele frequencies of the studied SNPs showed significant differentiation among the studied populations. The Kazakh population was grouped with Asian populations according to the cluster analysis and with the Caucasian populations according to PCA. According to MDS, results of the current study show that the Kazakh population holds an intermediate position between Caucasian and Asian populations.

Conclusion

A high percentage of population differentiation was observed between Kazakh and world populations. The Kazakh population was clustered with Caucasian populations, and this result may indicate a significant Caucasian component in the Kazakh gene pool.