Association of four insulin resistance genes with type 2 diabetes mellitus and hypertension in the Chinese Han population

ECHDC3 Variant Regulates the Right Hippocampal Microstructural Integrity and Verbal Memory in Type 2 Diabetes Mellitus

ECHDC3 is a risk gene for white matter (WM) hyperintensity and is associated with insulin resistance. This study aimed to investigate whether ECHDC3 variants selectively regulate brain WM microstructures and episodic memory in patients with type 2 diabetes mellitus (T2DM). We enrolled 106 patients with T2DM and 111 healthy controls. A voxel-wise general linear model was employed to explore the interaction effect between ECHDC3 rs11257311 polymorphism and T2DM diagnosis on fractional anisotropy (FA). A linear modulated mediation analysis was conducted to examine the potential of FA value to mediate the influence of T2DM on episodic memory in an ECHDC3-dependent manner. We observed a noteworthy interaction between genotype and diagnosis on FA in the right inferior temporal WM, right anterior limb of the internal capsule, right frontal WM, and the right hippocampus. Modulated mediation analysis revealed a significant ECHDC3 modulation on the T2DM → right hippocampal FA → short-term memory pathway, with only rs11257311 G risk homozygote demonstrating significant mediation effect. Together, our findings provide evidence of ECHDC3 modulating the effect of T2DM on right hippocampal microstructural impairment and short-term memory decline, which might be a neuro-mechanism for T2DM related episodic memory impairment.

Genetic predisposition of LEPR (rs1137101) gene polymorphism related to type 2 diabetes mellitus - a meta-analysis

Background: Type 2 diabetes mellitus (T2DM) is a multifaceted disease appropriate to elevated blood glucose levels resulting from decreased insulin and beta-cell activity. Using a case-control methodology, researchers have examined the relationship between polymorphisms in LEPR and T2DM in a population from south India.Materials and Methods: We conducted a genetic analysis of 311 participants, and results were accomplished using a case-control study, a meta-analysis of previous studies on LEPR was conducted, and type 2 diabetes genotype distribution across various geographical regions Malaysians, Chinese Han, Kuwait, Iran, Mongolia, and Han Chinese, Greece, Saudi, India (North India, Punjabi), (South India, Tamilnadu). The study involved 254 prospective investigations, and nine association studies were preferred according to preset criteria. Studies were assessed for quality using the Hardy-Weinberg equilibrium (HWE) and the Newcastle-Ottawa Scale (NOS). An analysis of the genetic models was conducted to determine their relationship, statistical analysis was utilized to calculate odds ratios (ORs) and matching 95% confidence intervals (CIs).Results: The LEPR-rs1137101 polymorphism in the case-control study was associated with a significant increase in the risk of type 2 diabetes. A meta-analysis revealed a connection between LEPR gene polymorphism (rs1137101) and type 2 diabetes risk. Investigators might gain a more profound thought on the significance of the identified genetic variation and its impact on the chance of developing type 2 diabetes by verifying and strengthening previously reported findings. The model of fixed effects was chosen due to the low heterogeneity, and significant associations were observed in the allelic (OR = 0.79, 95% CI [0.70-0.87]), homozygote (OR = 0.58, 95% CI [0.46-0.72]), dominant (OR = 0.66, 95% CI [0.56-0.79]), and recessive (OR = 0.83, 95% CI [0.71-0.96]) genetic models. A Begg's funnel plot and Egger's test indicated no publication bias. These findings suggest that the rs1137101 variant in the LEPR gene has been linked to a higher risk of T2DM.Conclusions: A larger sample size, however, is required for further research, and consideration of potential confounding factors is needed to validate these associations. Understanding the implications of LEPR gene polymorphisms in T2DM susceptibility may contribute to personalized treatment strategies for patients with T2DM.

Association of genetic variants in Leptin, leptin receptor and adiponectin with hypertension risk and circulating Leptin/Adiponectin changes

BACKGROUNDS

Hypertension is inheritable, and some candidate genes such as leptin and adiponectin have drawn special concerns.

OBJECTIVES

We performed a meta-analysis on the association of 7 genetic variants in genes encoding leptin, leptin receptor and adiponectin with hypertension risk and circulating leptin/adiponectin changes.

METHODS

Literature search, report selection and data extraction were performed by two authors independently. Effect sizes are expressed as odds ratio (OR) or standard mean difference (SMD) with 95% confidence interval (CI).

RESULTS

Total 32 reports (7432 cases with hypertension and 9218 controls) were meta-analyzed. Overall analyses indicated that rs7799039 (dominant model: OR = 1.67; 95 % CI: 1.03 to 2.71; P = 0.038) and (TTTC)_n (allelic model: OR = 1.53; 95 % CI: 1.05 to 2.23; P = 0.028) were significantly associated with hypertension risk. Subgroup analyses indicated that hypertension type, race, diabetes, genotyping method and quality score might be potential causes for between-study heterogeneity. Besides rs2241766, no evidence of publication bias existed for the other variants. Carriers of rs7799039-AG genotype had significantly higher leptin concentrations than carriers of rs7799039-GG genotype (SMD = 1.98; 95 % CI: 0.07 to 3.89; P = 0.042). In Mendelian randomization analyses, an increment of leptin concentrations by 1 ng/mL was causally associated with a 25 % significantly increased risk of hypertension (95 % CI: 1.02 to 10+; P < 0.05).

CONCLUSIONS

Our findings indicated that leptin gene rs7799039 and (TTTC)_n were potential hypertension-candidacy loci, and importantly high circulating leptin concentrations causally precipitated the development of hypertension.

Association of rs1137101 with hypertension and type 2 diabetes mellitus of Mongolian and Han Chinese

BACKGROUND

Hypertension (HTN) and type 2 diabetes mellitus (T2DM) are often coincident, and each condition is considered a risk factor for the other. Both occur frequently in the Inner Mongolia region of China. The reasons for differences in risk between Han and Mongolian ethnic groups are not known. The LEPR gene and its polymorphism, rs1137101 (Gln223Arg), are both considered risk factors for HTN and T2DM, but any role of rs1137101 in the occurrence of HTN + T2DM remains unclear for Mongolian and Han populations in the Inner Mongolia region.

AIM

To investigate the relationship between rs1137101 and the occurrence of HTN with T2DM in Mongolian and Han populations in Inner Mongolia.

METHODS

A total of 2652 subjects of Han and Mongolian ethnic origins were enrolled in the current study, including 908 healthy controls, 1061 HTN patients and 683 HTN patients with T2DM.

RESULTS

The association between the rs1137101 polymorphism and HTN with T2DM was analyzed, and differences between Han and Mongolian individuals assessed. There was a significant correlation between rs1137101 and HTN (co-dominant, dominant, over-dominant and log-additive models) and HTN + T2DM (co-dominant, dominant, over-dominant and log-additive models) after adjustment for sex and age in individuals of Mongolian origin. rs1137101 was significantly associated with HTN (co-dominant, recessive and log-additive models) and HTN + T2DM (co-dominant, dominant, over-dominant and log-additive models) in the Han Chinese population.

CONCLUSION

Mongolian and Han subjects from Inner Mongolia with HTN who had rs1137101 were protected against the development of T2DM. Allele A has the opposite impact on the occurrence of HTN in Mongolian and Han Chinese populations.

Association of single nucleotide polymorphisms in ADIPOQ gene with risk of hypertension: a systematic review and meta-analysis

BACKGROUND

Hypertension has been continuing to be a major contributor to the global burden of disease and to the global mortality, leading to over 10 million deaths each year. The purpose of this study was to investigate the association between Adiponectin gene polymorphism with Essential hypertension (EH).

METHODS

PubMed, EMbase, the Cochrane Library, and China National Knowledge Infrastructure (CNKI) were searched independently by two investigators. Pooled odds ratios and 95% confidence intervals were calculated to estimate the associations of Adiponectin polymorphism with EH.

RESULTS

Thirteen studies with 3198 cases and 3076 controls for meta-analysis (MA) were included in present study. Pooled results showed that rs2241766 polymorphism is associated with the risk of EH in the allelic model (G vs. T: OR=1.10; 95% CI, 1.01-1.21). In the <40 years subgroup, rs2241766 polymorphism is associated with the risk of EH in allele model (G vs. T: OR=1.43; 95% CI, 1.06-1.94), recessive model (GG vs. GT + TT: OR=5.26, 95% CI=1.47-18.76), homozygous model of GG (GG vs.TT: OR=5.27, 95% CI=1.47-18.95), and rs266729 in recessive model (GG vs. GT + TT: OR=2.33, 95% CI=1.33-4.08).

CONCLUSIONS

Our meta-analysis results show that the rs2241766 polymorphism is associated with the risk of hypertension. There still need a larger sample with better design to verify.

Association of resistin (rs3745367) and urotensin II (rs228648 and rs2890565) gene polymorphisms with risk of type 2 diabetes mellitus in Indian population

Insulin resistance may become the most powerful predictor of future development of type 2 diabetes mellitus (T2DM) and a therapeutic target for the treatment of the same. Both Resistin, an adipose derived peptide hormone and Urotensin II a potent vasoconstrictor, are reported to be involved in the development of insulin resistance and T2DM but the results remain contradictory. Therefore, investigations were carried out to study the association of T2DM and single nucleotide polymorphism (SNP) in Resistin (RETN) gene at rs3745367 (+ 299 G > A) and Urotensin II (UTS2) gene at rs228648 (+ 143 G > A) and rs2890565 (+ 3836 C > T) in a North Indian population. Method: The present case-control study, conducted from August 2017 to July 2020, involved 168 T2DM patients and 102 healthy controls. SNPs rs3745367, rs228648 and rs2890565 were amplified from genomic DNA in the studied samples by polymerase chain reaction (PCR) using specific primers. The amplified products were genotyped by restriction fragment length polymorphism (RFLP) using particular restriction endonucleases. Clinical parameters viz. glycosylated haemoglobin (HbA1c), fasting blood glucose (FBG), high density lipoprotein cholesterol (HDL-C), triglycerides (TG), total cholesterol (CHL) and fasting insulin were determined by enzymatic methods. Result and conclusion: A statistically significant association between T2DM and RETN gene at SNP rs3745367 (p = 0.001) and UTS2 gene at SNP rs2890565 (p = 0.001) was observed. In RETN gene SNP rs3745367, insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were found to be higher in GA + AA combined genotype than in GG genotype for T2DM subjects. Regression analysis revealed that SNP rs2890565 and HOMA-IR were independently associated with the risk of development of T2DM when three SNPs were taken as independent variable adjusted for clinical variables. Among four haplotypes, A/T was found associated with increased risk of T2DM as determined for rs228648 and rs2890565 of UTS2 gene. It can be concluded from these results that polymorphism at rs3745367 of RETN gene and at rs2890565 of UTS2 gene are associated with risk of T2DM in North Indian population.

Association analysis of polymorphisms in LEP (rs7799039 and rs2167270) and LEPR (rs1137101) gene towards the development of type 2 diabetes in North Indian Punjabi population

OBJECTIVES

Obesity is a major risk factor in aetiology of type 2 diabetes mellitus (T2DM). Leptin (LEP) is an anti-obesity hormone which regulates food intake, energy expenditure and glucose metabolism. The genetic variants in leptin and leptin receptor gene (LEPR) may play major role in the pathogenesis of T2DM and obesity. The current study aimed to investigate the association of polymorphisms in LEP (rs7799039, -2548G/A and rs2167270, 19G/A) and LEPR (rs1137101, 668A/G) gene with type 2 diabetes in North Indian Punjabi population.

METHODS

A total of 817 subjects were included for the present case-control study, consisting of 417 T2DM patients and 400 healthy controls. The anthropometric, physiometric and biochemical measurements were taken from all the subjects. The genotyping of LEP and LEPR gene variants were carried out by polymerase chain reaction based restriction fragment length polymorphism method (PCR-RFLP), followed by genotyping of 10% of the samples for each polymorphism by Sanger sequencing method for quality control measurement.

RESULTS

The risk genotype frequencies were found to be significantly higher in T2DM cases than control subjects (rs7799039, p = 0.001; rs2167270, p = 0.019 and rs1137101, p = 0.003). Under recessive genetic model LEPrs7799039 and LEPRrs1137101 polymorphism conferred 3.4 and 2.1 fold risk towards the development of T2DM after adjustment of various covariates (OR = 3.44, 95%CI: 1.768-6.681, p = 0.001 and OR: 2.12, 95%CI: 1.256-3.569, p = 0.005, respectively). In the stratified analysis of LEP variant rs7799039 by age, gender, BMI and alcohol use, a significantly increased risk of T2DM was found in female, BMI ≥ 23 and never drinking subgroups. However, in the LEPR variant rs1137101, significantly increased risk of T2DM was observed in age <50, male, BMI ≥ 23 and never drinking subgroup. The A-G haplotype combination of rs7799039A and rs2167270G conferred significant 2 fold risk towards T2DM (OR = 2.35, 95%CI: 1.34-4.12, p = 0.002). In control group, the genetic variants rs7799039 and rs1137101 were significantly associated with levels of random blood sugar and low density lipoprotein cholesterol levels.

CONCLUSION

The present study revealed the association of LEP rs7799039 and LEPR rs1137101 with type 2 diabetes mellitus, which suggest its predominant role in the estimation of type 2 diabetes mellitus in North Indian Punjabi population.

TRIB3 rs6037475 is a potential biomarker for predicting felodipine drug response in Chinese patients with hypertension

Background

Our previous studies have found that single nucleotide polymorphisms (SNPs) of tribbles homolog 3 (TRIB3) are related to the hypotensive effects of calcium-channel blockers (CCBs) and angiotensin-converting enzyme (ACE) inhibitors. In this study, we aimed at exploring and validating the effect of TRIB3 polymorphism on antihypertensive drugs responses.

Methods

A total of 830 hypertensive patients, who were administered with open-labeled hydrochlorothiazide (12.5 mg once daily) and randomly assigned to off-labeled felodipine (5 mg) or a matched placebo combination treatment (1:1), were selected from the Felodipine Event Reduction (FEVER) study. A strategy of screening 259 samples and validating the remaining 531 samples was implemented. Four functional SNPs were selected (rs2295490, rs11470129, rs4815567 and rs6037475 in TRIB3). A mixed linear model was performed to analyze the effects of TRIB3 SNPs on antihypertensive drugs responses.

Results

We found that TRIB3 rs6037475 CC genotype was associated with a reduction of diastolic blood pressure (DBP) (P=6.3×10⁻³) in the felodipine treatment group of screening set, and was also associated with a reduction of systolic blood pressure (SBP) (P=0.021), DBP (P=6.0×10⁻³) and mean arterial pressure (MAP) (P=0.021) in the felodipine treatment group of the validation set. As for the reductions influenced by the rs2295490, rs11470129 and rs4815567 genetic variations, however, the adjusted P-value did not reach statistical significance. Combined screening and validation set analysis found that patients with TRIB3 rs6037475 CC genotype had a significant higher mean SBP, DBP and MAP than those with TT genotype in the felodipine treatment group (CC vs. TT −10.2±0.74 vs. −17.8±0.21, P=7.8×10⁻³; −4.6±0.50 vs. −10.2±0.23, P=3.0×10⁻⁴; −6.5±0.54 vs. −12.7±0.14, P=3.0×10⁻⁴, respectively).

Conclusions

These results suggest that TRIB3 rs6037475 genetic variation can be useful as a bio-marker for predicting felodipine drug response in Chinese patients with hypertension.

Variation of Resistin Gene Is Correlated with Insulin Resistance in Obese People of Indonesia

BACKGROUND

Obesity is considered associated with an increase of resistin levels that plays a role in the regulation of energy and maintaining fasting blood glucose. Polymorphism of resistin is thought to be correlated with the levels of resistin and insulin resistance.

AIM

This study aimed to examine the association of +299G > A and -420C > G resistin (RETN) gene with resistin level and insulin resistance in obese people of Indonesia.

METHODS

We examined 142 healthy unrelated subjects consisting of 71 obese and 71 controls. Fasting blood glucose was measured by the enzymatic method while the resistin and insulin levels were measured by Elisa method. Insulin resistance was calculated by HOMA-IR index. Polymorphisms of RETN genes were examined by the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method, and the data was tested. The data were correlated with Kruskal Wallis continue logistic regression and simple linear regression.

RESULTS

In the obese group, there was an increased level of insulin (17.74 vs 11.27 mU/L) and insulin resistance (HOMA-IR 3.9 vs 1.46) compared to the control group. Polymorphism of +299G > A was associated with insulin resistance (GA and GA + AA genotype significantly different compare GG genotype with P < 0.001). Resistin level was negatively correlated with insulin level (P = 0.017).

CONCLUSION

In this study, polymorphism of +299G > A was identified as a risk factor for insulin resistance, and there was a significant association of serum resistin level with insulin level in the population of Indonesia.

Interactions among moderate/severe periodontitis, ADIPOQ-rs1501299, and LEPR-rs1137100 polymorphisms on the risk of type 2 diabetes in a Chinese population

OBJECTIVE

Type 2 diabetes mellitus (T2DM) is a complex disease influenced by genes and the environment. Periodontitis a demonstrated risk factor of T2DM. Previous studies related to gene-environment interactions on the risk of T2DM mainly focused on gene-obesity interactions. However, the impact of gene-periodontitis interaction on the risk of T2DM has not yet been investigated. This study aimed to investigate gene-environment interactions among moderate/severe periodontitis, polymorphisms of adiponectin (ADIPOQ)-rs1501299, and leptin receptor (LEPR)-rs1137100 on T2DM risk in Chinese subjects.

DESIGN

A case-control study was conducted in 239 Chinese participants from Beijing Hypertension Association Institute (BHAL). After full-mouth periodontal examinations, the participants underwent bilateral buccal swabs for DNA testing. ADIPOQ-rs1501299 and LEPR-rs1137100 were used for genotyping. Generalised multifactor dimensionality reduction (GMDR) and logistic regression were used to examine the interactions among single nucleotide polymorphisms (SNPs) and moderate/severe periodontitis on the risk of T2DM.

RESULTS

The risk of T2DM was higher in moderate/severe periodontitis [adjusted odds ratio (AOR) = 3.67, 95% confidence interval (95%CI): 1.26-10.71] in ADIPOQ-rs1501299 GG genotype (AOR = 3.42, 95%CI: 1.81-6.46) and LEPR-rs1137100 GG genotype (AOR = 3.16, 95%CI: 1.56-6.39). The GMDR model indicated that there was a significant three-factor model (p = 0.001) involving rs1501299, rs1137100, and moderate/severe periodontitis, demonstrating a potential gene-environment interaction among periodontitis, polymorphisms of rs1501299, and rs1137100 influencing the risk of T2DM. Moderate/severe periodontitis patients with rs1501299-GG and rs1137100-GG have the highest T2DM risk after adjusting for age, gender, BMI, WHR, smoking status, alcohol consumption, economic status, and hypertension (AOR = 20.39, 95%CI: 2.64-157.26).

CONCLUSIONS

Interactions among moderate/severe periodontitis, rs1501299-GG, and rs1137100-GG were associated with an increased risk of T2DM. This study may provide a new insight into the effect of gene-environment interactions on T2DM.

Ocimum basilicum miRNOME revisited: A cross kingdom approach

O. basilicum is medicinally important herb having inevitable role in human health. However, the mechanism of action is largely unknown. Present study aims to understand the mechanism of regulation of key human target genes that could plausibly modulated by O. basilicum miRNAs in cross kingdom manner using computational and system biology approach. O. basilicum miRNA sequences were retrieved and their corresponding human target genes were identified using psRNA target and interaction analysis of hub nodes. Six O. basilicum derived miRNAs were found to modulate 26 human target genes which were associated `with PI3K-AKTand MAPK signaling pathways with PTPN11, EIF2S2, NOS1, IRS1 and USO1 as top 5 Hub nodes. O. basilicum miRNAs not only regulate key human target genes having a significance in various diseases but also paves the path for future studies that might explore potential of miRNA mediated cross-kingdom regulation, prevention and treatment of various human diseases including cancer.

A meta-analysis of associations of LEPR Q223R and K109R polymorphisms with Type 2 diabetes risk

Background

Leptin receptor (LEPR) plays a pivotal role in the control of body weight, energy metabolism, and insulin sensitivity. Various genetic association studies were performed to evaluate associations of LEPR genetic variants with type 2 diabetes (T2D) susceptibility.

Methods

A comprehensive search was conducted to identify all eligible case-control studies for examining the associations of LEPR single nucleotide polymorphisms (SNPs) Q223R (rs1137101) and K109R (rs1137100) with T2D risk. Odds ratios (OR) and corresponding 95% confidence intervals (CIs) were used to measure the magnitudes of association.

Results

For Q223R, 13 studies (11 articles) consisting of a total of 4030 cases and 2844 controls, and for K109R 7 studies (7 articles) consisting of 3319 cases and 2465 controls were available. Under an allele model, Q223R was not significantly associated with T2D risk (OR = 1.09, 95% CI: 0.80–1.48, P-value = 0.5989), which was consistent with results obtained under four genotypic models (ranges: ORs 1.08–1.20, 95% CIs: 0.58–2.02 to 0.64–2.26; P-values, 0.3650–0.8177, which all exceeded multiplicity-adjusted α = 0.05/5 = 0.01). In addition, no significant association was found between K109R and T2D risk based on either an allele model (OR = 0.93, 95% CI: 0.85–1.03, P-value = 0.1868) or four genotypic models (ranges: ORs 0.81–0.99, 95% CIs: 0.67–0.86 to 0.97–1.26, P-values, 0.0207–0.8804 which all exceeded multiplicity-adjusted α of 0.01). The magnitudes of association for these two SNPs were not dramatically changed in subgroup analyses by ethnicity or sensitivity analyses. Funnel plot inspections as well as Begg and Mazumdar adjusted rank correlation test and Egger linear regression test did not reveal significant publication biases in main and subgroup analyses. Bioinformatics analysis predicted that both missense SNPs were functionally neutral and benign.

Conclusions

The present meta-analysis did not detect significant genetic associations between LEPR Q223R and K109R polymorphisms and T2D risk.

The association of two polymorphisms in adiponectin-encoding gene with hypertension risk and the changes of circulating adiponectin and blood pressure: A meta-analysis

Objectives

This meta-analysis was prepared to synthesize published data on the association of two polymorphisms (T45G and G276T) in adiponectin-encoding gene (ADIPOQ) with hypertension risk and the changes of circulating adiponectin and blood pressure.

Methodology and Major Findings

Data were collected and corrected by two authors, and were managed with Stata software. In total, 12 articles were synthesized, including 12 studies (3358 cases and 5121 controls) for the association of two study polymorphisms with hypertension risk and 11 studies (3053 subjects) for the between-genotype changes of adiponectin and/or blood pressure. Based on all qualified studies, the risk prediction for hypertension was nonsignificant for both polymorphisms, with significant heterogeneity for G276T polymorphism (I² = 53.8%). Overall changes in adiponectin and blood pressure were also nonsignificant for T45G, while contrastingly 276GT genotype was associated with significantly higher levels of adiponectin (weighted mean difference [WMD] = 0.72 μg/mL, 95% confidence interval [CI]: 0.04 to 1.41, P = 0.038), systolic (WMD = 5.15 mm Hg, 95% CI: 0.98 to 9.32, P = 0.016) and diastolic (WMD = 3.45 mm Hg, 95% CI: 0.37 to 6.53, P = 0.028) blood pressure with evident heterogeneity (I² = 72.0%, 78.3% and 80.0%, respectively), and these associations were more obvious in hypertensive patients. Publication bias was a low probability event for overall comparisons.

Conclusions

Our findings suggested that in spite of the nonsignificant association between ADIPOQ T45G or G276T polymorphism and hypertension, the heterozygous mutation of G276T was observed to account for increased levels of circulating adiponectin and blood pressure, especially in hypertensive patients.

LEPR gene Gln223Arg polymorphism and type 2 diabetes mellitus: a meta-analysis of 3,367 subjects

Background

The Leptin receptor (LEPR) Gln223Arg gene polymorphism has been associated with an increased susceptibility to Type 2 diabetes mellitus (T2DM). Results from various studies, however, are inconsistent.

Objective and methods

To better elucidate the association of LEPR Gln223Arg gene polymorphism with T2DM in the Chinese population, a meta-analysis of 3,367 subjects from seven independent studies was performed. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) were evaluated by the fixed-effects model.

Results

A significant relationship between LEPR Gln223Arg gene polymorphism and T2DM in the Chinese population was found under allele (OR: 1.432, 95% CI: 1.211-1.694, P=2.67×10^-5), dominant (OR: 1.466, 95% CI: 1.215-1.769, P=6.33×10^-5), recessive (OR: 0.539, 95% CI: 0.303-0.960, P=0.036), heterozygous (OR: 0.700, 95% CI: 0.577-0.849, P=3.06×10^-4), and homozygous (OR: 0.472, 95% CI: 0.265-0.839, P=0.011) genetic models.

Conclusions

LEPR Gln223Arg gene polymorphism was associated with an increased risk of T2DM in the Chinese population. Therefore, Chinese carriers of the G allele of LEPR Gln223Arg gene polymorphism may be more susceptible to T2DM than the general population.

Association of maternal and fetal LEPR common variants with maternal glycemic traits during pregnancy

Recent studies suggested that maternal and placental leptin receptor (LEPR) may be involved in maternal glucose metabolism in pregnancy. To identify maternal and fetal LEPR common variants influencing gestational glycemic traits, we performed association study of 24-28-week maternal fasting glucose, glucose 1 hour after the consumption of a 50-g oral glucose load, fasting insulin and indices of beta-cell function (HOMA-β) and insulin resistance (HOMA-IR) in 1,112 unrelated women and their children. Follow-up of 36 LEPR loci identified 3 maternal loci (rs10889567, rs1137101 and rs3762274) associated with fasting glucose, these 3 fetal loci associated with fasting insulin and HOMA1-IR, as well as these 3 maternal-fetal loci combinations associated with HOMA2-β. We also demonstrated association of maternal locus rs7554485 with HOMA2-β and HOMA2-IR, maternal locus rs10749754 with fasting glucose, fetal locus rs10749754 with HOMA2-IR. However, these associations were no longer statistically significant after Bonferroni correction. In conclusion, our results first revealed multiple associations between maternal and fetal LEPR common variants and gestational glycemic traits. These associations did not survive Bonferroni correction. These corrections are overly conservative for association studies. We therefore believe the influence of these nominally significant variants on gestational glycometabolism will be confirmed by additional studies.

KCNQ1 variants associate with hypertension in type 2 diabetes and affect smooth muscle contractility in vitro

KCNQ1 encodes a potassium voltage-gated channel and represents a susceptibility locus for type 2 diabetes mellitus (T2DM). Here, we explored the association between KCNQ1 polymorphisms and hypertension risk in individuals with T2DM, as well as the role of KCNQ1 in vascular smooth muscle cell contraction in vitro. To investigate the relationship between KCNQ1 and the risk of developing hypertension in patients with T2DM, we divided the T2DM cohort into hypertension (n = 452) and non-hypertension (n = 541) groups. The Mann-Whitney U test, chi-square test, and multivariate regression analyses were used to assess the clinical characteristics and genotypic frequencies. In vitro studies utilized the rat aortic smooth muscle A10 cell line. Patients in the hypertension group were significantly older at the time of enrollment and had higher levels of body mass index, waist-to-hip ratio, and triglyceride than those in the non-hypertension group. The KCNQ1 rs3864884 and rs12576239 genetic variants were associated with hypertension in T2DM. KCNQ1 expression was lower in the individuals with the CC versus the CT and TT genotypes. Smooth muscle cell contractility was inhibited by treatment with a KCNQ1 inhibitor. These results suggest that KCNQ1 might be associated with hypertension in individuals with T2DM.

Associations between polymorphisms of the ADIPOQ gene and hypertension risk: a systematic and meta-analysis

ADIPOQ gene polymorphisms have been indicated to be associated with hypertension; however, published studies have reported inconsistent results. Eligible studies were retrieved by searching the PubMed, Embase and China National Knowledge Infrastructure databases. The case group consisted of patients with hypertension, and the control group consisted of subjects with normal blood pressure. Based on eleven published articles, involving 4837 cases and 5618 controls, the pooled results from rs2241766 polymorphism showed increased risk in the allelic model (G VS T: OR = 1.16, 95%CI = 1.06–1.27), recessive model (GG VS GT + TT: OR = 1.34, 95%CI = 1.10–1.63), dominant model (GG + GT VS TT: OR = 1.15, 95%CI = 1.02–1.30) and homozygote model (GG VS TT: OR = 1.38, 95%CI = 1.21–1.69). In addition, rs266729 polymorphism showed increased risk for hypertension in the recessive model (GG VS GC + CC: OR = 1.43, 95%CI = 1.02–2.01). In the Caucasian subgroup, rs1501299 polymorphism showed decreased risk of hypertension in the allelic model (T VS G: OR = 0.75, 95%CI = 0.58–0.97), dominant model (TT + TG VS GG: OR = 0.83, 95%CI = 0.71–0.98) and heterozygote model (TG VS GG: OR = 0.82, 95%CI = 0.68–0.99). The rs2241766 polymorphism was associated with a significant increase in hypertension risk based on our analysis. Moreover, an increased risk of rs266729 in hypertension patients was also detected. Our meta-analysis suggests that the rs1501299 polymorphism may play a protective role in hypertension in Caucasian subgroup; however, this finding requires further study.

The association between leptin receptor gene polymorphisms and type 2 diabetes mellitus: A systematic review and meta-analysis

BACKGROUND

Several case-control studies have demonstrated a relationship between leptin receptor (LEPR) gene polymorphism and type 2 diabetes mellitus (T2DM) risk, though the results have not always been consistent among diverse populations. This meta-analysis was designed to assess a more accurate association between LEPR polymorphism and T2DM.

METHODS

Eight electronic databases were consulted and researchers searched for Chinese and English peer-reviewed articles, published between 2000 and 2015, that referred to the association between LEPR polymorphism and T2DM. Pooled odds ratios (OR) with a 95% confidence interval (CI) were calculated in allele contrast, recessive, dominant and additive genetic models to assess this association.

RESULTS

Four repeatedly reviewed polymorphisms, taken from 22 studies on Arg109Lys, Asn656Lys, Gln223Arg and Pro1019Pro with 31,260 controls and 25,560 cases, were included in the meta-analysis model. The meta-result demonstrated that only the Pro1019Pro polymorphism was substantially associated with T2DM risk-G vs. A: OR with 95% CI 0.58 (0.43-0.79), Z=3.51, p=0.0005; GG vs. AG+AA: 0.57 (0.42-0.77), Z=3.66, p=0.0002; GG+AG vs. AA: 0.55 (0.37-0.81), Z=3.01, p=0.003; GG vs. AA: 0.51 (0.37-0.69), Z=4.24, p<0.001.

CONCLUSIONS

Our meta-analysis suggested a significant association between the LEPR Pro1019Pro polymorphism and T2DM risk. Thus, targeted healthcare should be strengthened with regard to this gene carrier in order to prevent T2DM.

Relevance Study on Cerebral Infarction and Resistin Gene Polymorphism in Chinese Han Population

Recent research on genome-wide associations has implicated that the serum resistin level and its gene polymorphism are associated with cerebral infarction (CI) morbidity and prognosis, and could thereby regulate CI. This study aimed to investigate the association between the resistin single nucleotide polymorphism (SNP) and the susceptibility to CI in the Chinese Han population. A total of 550 CI patients and 313 healthy controls were genotyped. Nine SNPs of the resistin gene previously shown were sequenced and assessed for an association with CI. The numbers of GG genotype carriers of rs3219175 and rs3486119 in the CI group were significantly higher than those in the control group among the middle-aged group (aged 45-65), at 76% vs 67.9% (P=0.025) and 75.5% vs 67.9% (P=0.031). rs3219175 and rs34861192 were associated with CI in the dominant and superdominant models according to the genetic model analysis (P<0.05). Meanwhile, there was strong linkage disequilibrium among the rs34124816, rs3219175, rs34861192, rs1862513, rs3745367, 180C/G and rs3745369 sites. In a haplotype analysis, the occurrence rate of the haplotype AGGCAGC was 1.97 times (P<0.05) higher in the patient group than in the control group. In addition, the numbers of GG genotype carriers of rs3219175 and rs3486119 in the middle-aged male CI patients and the middle-aged small artery occlusion (SAO) CI patients were higher than those in the control group (P<0.05). In the Chinese Han middle-aged population, the GG gene type carriers of the resistin gene sites rs3219175 and rs34861192 had a high risk for CI onset, especially in middle-aged male patients and SAO CI in all middle-aged patients.

Association of ADIPOQ variants with type 2 diabetes mellitus susceptibility in ethnic Han Chinese from northeast China

AIMS/INTRODUCTION

To investigate the association between two single nucleotide polymorphisms (SNPs; rs3774261 and rs822393) in the ADIPOQ gene and type 2 diabetes mellitus in Han Chinese from northeast China.

MATERIALS AND METHODS

The present study comprised 993 type 2 diabetes mellitus patients and 966 unrelated controls from northeastern China. Two SNPs were sequenced using SNPscan. The distribution of genotype frequencies of the two SNPs in ADIPOQ between cases and controls, and in subgroups stratified based on body mass index, were compared using logistic regression analysis. Linear regression was used to analyze the association between each SNP and clinical indicators.

RESULTS

The GG genotype of rs3774261 increased the risk of type 2 diabetes mellitus compared with the AA genotype in participants with a body mass index <24 (P = 0.021; odds ratio 1.636, 95% CI 1.708-2.484). Rs822393 was correlated with glycosylated hemoglobin (P = 0.043) in controls. Rs3774261 had an association with diastolic blood pressure (P = 0.017) in controls, and in controls with a body mass index <24; rs3774261 also had an association with both systolic blood pressure (P = 0.025) and diastolic blood pressure (P = 0.043).

CONCLUSIONS

The present results confirm the association between ADIPOQ variants and type 2 diabetes mellitus in northeastern China. However, additional larger replication studies are required to validate these findings.

Genome-wide placental DNA methylation analysis of severely growth-discordant monochorionic twins reveals novel epigenetic targets for intrauterine growth restriction

BACKGROUND

Intrauterine growth restriction (IUGR), which refers to reduced fetal growth in the context of placental insufficiency, is etiologically heterogeneous. IUGR is associated not only with perinatal morbidity and mortality but also with adult-onset disorders, such as cardiovascular disease and diabetes, posing a major health burden. Placental epigenetic dysregulation has been proposed as one mechanism that causes IUGR; however, the spectrum of epigenetic pathophysiological mechanisms leading to IUGR remains to be elucidated. Monozygotic monochorionic twins are particularly affected by IUGR, in the setting of severe discordant growth. Because monozygotic twins have the same genotype at conception and a shared maternal environment, they provide an ideal model system for studying epigenetic dysregulation of the placenta.

RESULTS

We compared genome-wide placental DNA methylation patterns of severely growth-discordant twins to identify novel candidate genes for IUGR. Snap-frozen placental samples for eight severely growth-discordant monozygotic monochorionic twin pairs were obtained at delivery from each twin. A high-resolution DNA methylation array platform was used to identify methylation differences between IUGR and normal twins. Our analysis revealed differentially methylated regions in the promoters of eight genes: DECR1, ZNF300, DNAJA4, CCL28, LEPR, HSPA1A/L, GSTO1, and GNE. The largest methylation differences between the two groups were in the promoters of DECR1 and ZNF300. The significance of these group differences was independently validated by bisulfite pyrosequencing, implicating aberrations in fatty acid beta oxidation and transcriptional regulation, respectively. Further analysis of the array data identified methylation changes most prominently affecting the Wnt and cadherin pathways in the IUGR cohort.

CONCLUSIONS

Our results suggest that IUGR in monozygotic twins is associated with impairments in lipid metabolism and transcriptional regulation as well as cadherin and Wnt signaling. We show that monozygotic monochorionic twins discordant for growth provide a useful model to study one type of the epigenetic placental dysregulation that drives IUGR.

Variations in the Obesity Gene "LEPR" Contribute to Risk of Type 2 Diabetes Mellitus: Evidence from a Meta-Analysis

Leptin is a hormone protein regulating food intake and energy expenditure. A number of studies have evaluated the genetic effect of leptin (LEP) and leptin receptor (LEPR) genes on T2DM. This study aimed to investigate the association between these gene polymorphisms and T2DM by a systematic review and meta-analysis. Published studies were identified through extensive search in PubMed and EMBASE. A total of 5143 T2DM cases and 5021 controls from 14 articles were included in this study. Five functional variants in LEPR were well evaluated. Meta-analysis showed that rs1137101 (p.R223Q) was significantly associated with T2DM in all genetic models: allele model (OR = 1.27, 95% confidence interval (CI) = 1.13-1.42), dominant model (OR = 1.19, 95% CI = 1.05-1.35), homozygote model (OR = 1.82, 95% CI = 1.38-2.39), and recessive model (OR = 1.75, 95% CI = 1.35-2.28), with minimal heterogeneity and no indication of publication bias. Similar associations with T2DM were also found for rs62589000 (p.P1019P) and 3'UTR ins/del, although the data was obtained from a small number of studies. For the other two polymorphisms rs1137100 (p.R109K) and rs8179183 (p.K656N), they were not significantly associated with T2DM. Our results provide robust evidences for the genetic association of rs1137101 (p.R223Q) in LEPR with T2DM susceptibility.

Haplotypes and Sequence Variation in the Ovine Adiponectin Gene (ADIPOQ)

The adiponectin gene (ADIPOQ) plays an important role in energy homeostasis. In this study five separate regions (regions 1 to 5) of ovine ADIPOQ were analysed using PCR-SSCP. Four different PCR-SSCP patterns (A₁-D₁, A₂-D₂) were detected in region-1 and region-2, respectively, with seven and six SNPs being revealed. In region-3, three different patterns (A₃-C₃) and three SNPs were observed. Two patterns (A₄-B₄, A₅-B₅) and two and one SNPs were observed in region-4 and region-5, respectively. In total, nineteen SNPs were detected, with five of them in the coding region and two (c.46T/C and c.515G/A) putatively resulting in amino acid changes (p.Tyr16His and p.Lys172Arg). In region-1, -2 and -3 of 316 sheep from eight New Zealand breeds, variants A₁, A₂ and A₃ were the most common, although variant frequencies differed in the eight breeds. Across region-1 and region-3, nine haplotypes were identified and haplotypes A₁-A₃, A₁-C₃, B₁-A₃ and B₁-C₃ were most common. These results indicate that the ADIPOQ gene is polymorphic and suggest that further analysis is required to see if the variation in the gene is associated with animal production traits.

Prevalence of Insulin Resistance in Subjects with Nonalcoholic Fatty Liver Disease and Its Predictors in a Chinese Population

OBJECTIVE

Insulin resistance (IR) is a key factor involved in the development and progression of nonalcoholic fatty liver disease (NAFLD). However, the prevalence of IR in NAFLD patients and its risk factors have been rarely reported, especially in China. This prospective study was undertaken to clarify these issues in the Chinese population.

METHODS

A total of 600 NAFLD patients and 300 age- and sex-matched healthy controls were recruited between January 1, 2011, and December 31, 2013. Demographic information and clinical characteristics were collected, and the presence of IR was evaluated using the homeostasis model. Uni- and multivariate analyses were conducted, and receiver operating characteristic (ROC) curves were generated to identify IR predictors.

RESULTS

NAFLD patients had a much higher prevalence of IR than healthy controls (37.8 vs. 2.3 %, P < 0.001). The rates of elevated alanine transferase (ALT) and aspartate transferase (AST) levels were much higher in NAFLD patients with IR than those without (53.7 vs. 41.6 % and 28.6 vs. 18.2 %, respectively, P < 0.001). Uni- and multivariate analyses revealed that female sex, general obesity, abdominal obesity, and hypertension were independent predictors for IR. The area under the ROC curve for fasting plasma insulin (FPI) detecting IR was 0.93 (P < 0.001), and the optimal cutoff was 11.3 μU/ml (sensitivity = 0.86, specificity = 0.92).

CONCLUSION

Chinese NAFLD patients are susceptible to IR. Female sex, general and abdominal obesity, and hypertension were independent predictors for IR in NAFLD patients. FPI is an optimal predictor for IR.