The +299(G>A) resistin gene polymorphism and susceptibility to type 2 diabetes in Thais

Relationship of resistin gene polymorphism (rs7139228) with resistin levels and metabolic syndrome risk in obese subjects

Introduction

Background: despite the relationship of resistin with metabolic syndrome (MS), the relationship of the 5'UTR intron C/T variant SNP rs7139228 of the RETN gene with the presence of MS has not been evaluated. Objective: the objective of this study is to evaluate the influence of SNP rs7139228 of the RETN gene on circulating resistin levels, as well as on MS in obese subjects. Material and Methods: a Caucasian population of 1003 obese subjects was enrolled. An anthropometric evaluation (weight, waist circumference, fat mass), evaluation of nutritional intake, biochemical study (glucose, insulin, C-reactive protein, lipid profile, insulin, HOMA-IR, resistin) and rs7139228 genotype was carried out. Results: genotype distribution was: 852 subjects with GG (84.9 %), 147 subjects with GA (14.7 %) and 4 subjects with AA (0.4 %). The allelic frequency was G (0.92) and A (0.08). Serum levels of resistin (delta: 1.7 ± 0.2 ng/ml; p = 0.01), insulin (delta: 4.2 ± 0.4 IU/L; p = 0.01) and HOMA-IR (delta: 1.9 ± 0.2 units; p = 0.03) were higher in patients carrying the A allele than in non-carriers. The overall prevalence of MS was 48.1 %. A logistic regression analysis showed a high percentage of hyperglycemia (OR = 1.60, 95 % CI = 1.08-2.96; p = 0.02) and metabolic syndrome (OR = 1.33, 95 % CI = 1.07-3.39, p = 0.02) in carriers of the A allele after adjusting for resistin levels, sex, BMI and age. Conclusions: the A allele of the genetic variant rs7139228 is associated with higher levels of resistin, basal insulin, insulin resistance, and prevalence of metabolic syndrome in obese subjects.

Genetic Markers of Insulin Resistance and Atherosclerosis in Type 2 Diabetes Mellitus Patients with Coronary Artery Disease

Type 2 diabetes mellitus (T2DM) is characterized by impaired insulin secretion on a background of insulin resistance (IR). IR and T2DM are associated with atherosclerotic coronary artery disease (CAD). The mechanisms of IR and atherosclerosis are known to share similar genetic and environmental roots. Endothelial dysfunction (ED) detected at the earliest stages of IR might be the origin of atherosclerosis progression. ED influences the secretion of pro-inflammatory cytokines and their encoding genes. The genes and their single nucleotide polymorphisms (SNPs) act as potential genetic markers of IR and atherosclerosis. This review focuses on the link between IR, T2DM, atherosclerosis, CAD, and the potential genetic markers CHI3L1, CD36, LEPR, RETN, IL-18, RBP-4, and RARRES2 genes.

Association between the RETN -420C/G polymorphism and type 2 diabetes mellitus susceptibility: A meta-analysis of 23 studies

BACKGROUND

The published findings on the link between the resistin (RETN) gene polymorphism and type 2 diabetes mellitus (T2DM) risk are still contradictory. Here, through a meta-analysis, we summarized a more precise evaluation of their connection by synthesizing existing research.

METHODS

PubMed, Google Scholar, and Web of Science were electronically searched, and all cited sources were manually searched. The heterogeneity of effects was tested and all statistical analyses were performed in Stata 12.0.

RESULTS

A total of 23 studies with 10,651 cases and 14,366 controls on RETN -420C/G polymorphism were included. The overall results showed that the association of RETN -420C/G polymorphism and T2DM susceptibility was not significant [for the allelic model: odds ratio (OR) = 0.98, 95% confidence interval (CI) = 0.87-1.10, p_{heterogeneity} <.001; I ² = 84.6%; for the dominant model: OR = 0.96, 95% CI = 0.80-1.15, p_{heterogeneity} <.001; I ² = 87.1%; and for the recessive model: OR = 0.96, 95% CI = 0.82-1.12, p_{heterogeneity} <.001; I ² = 56.9%] but with high heterogeneity across studies (p <.0001). Meta-regression found that the median age of T2DM participants (using age 50 as the cutoff) could be a factor in the observed variation. The RETN -420C/G polymorphism seems to be linked to an increased risk of T2DM in younger individuals [for dominant: OR = 0.84 (95% CI, 0.72-0.98; p_{heterogeneity} <.001; I ² = 80.9%)] and decreased risk in older people [for dominant: OR = 3.14 (95% CI, 2.35-4.19; p_{heterogeneity} = .98; I ² = 0.0%)].

CONCLUSIONS

Current results found no evidence that the RETN -420C/G variant was linked to T2DM susceptibility, but the patient's age appears to be a potential factor that contributed to high heterogeneity across studies. Additional high-quality and well-designed investigations are required to confirm these results.

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.

The Relevance of Single-nucleotide Polymorphism +62 G>A to the Expression of Resistin Gene Affecting Serum Resistin Levels in Metabolic Syndrome in the Egyptian Population

BACKGROUND

Metabolic Syndrome (MS) is a clinical condition consisting of risk factors associated with type two diabetes and developing cardiovascular disease. It has been suggested that resistin is a linkage between obesity, inflammation and type two diabetes. This study aims to investigate whether Resistin Gene (RETN) polymorphism (+62G>A) is linked to MS and resistin levels among the Egyptian population.

METHODS

This study was performed with 310 Egyptian volunteers: 160 MS subjects and 150 controls. Anthropometric parameters and biochemical variables were determined. The RETN +62G>A polymorphism was genotyped by PCR-RFLP technique.

RESULTS

The resistin levels of the MS group were significantly higher than those of the control group. Resistin levels were positively correlated with anthropometric parameters and liver biomarkers in the MS group. According to RETN +62G>A polymorphism, carriers with the A allele (GA/AA) had significantly increased resistin levels than subjects with the GG genotype, consequently, the RETN +62G >A polymorphism was found to be related to MS, biochemical parameters and anthropometric variables.

CONCLUSION

These findings propose that the RETN +62G>A polymorphism has a great impact on the circulating resistin concentrations, and that resistin levels are strongly related to MS. Therefore, this RETN polymorphism is related to the risk of the prevalence of MS in the Egyptians.

Role of resistin genetic variations in knee osteoarthritis pathogenesis, a cross sectional study

Osteoarthritis (OA) is a serious health concern globally and is recognized by degradation of articular cartilage, bone remodeling and synovial inflammation. Resistin is an adipokine that shown to be involved in inflammatory process associated with OA. Aim of the current study was to estimate the link of resistin gene polymorphisms (- 420 C>G, + 299 G>A) with genetic susceptibility of knee OA in a Pakistani population. 280 patients and 308 age and sex matched controls were recruited in this case-control study. Genotype and allele frequencies were evaluated by Polymerase chain reaction-Restriction Fragment Length Polymorphism. Resistin concentration was measured by immunoassay. A significant difference in allele and genotype frequency was observed for both study groups. Resistin - 420 mutant genotype was associated with an increased susceptibility to OA (p = 0.001). Similarly, resistin + 299 GA + AA genotypes showed a relation with an elevated risk of knee OA compared to GG genotype (p = 0.01). Moreover, the mutant alleles frequency was significantly high in patient group as compared to healthy individuals for both loci (p < 0.01). Resistin - 420/+ 299 alleles haplotype analysis demonstrated that mutant alleles were more prevalent in OA affected individuals compared to healthy subjects (p < 0.05). The serum resistin levels were not remarkably different in patient vs. control group (p = 0.9). Further, the circulating resistin level was not found to be influenced by - 420G and + 299A alleles and non significant differences were observed in resistin concentration in mutant vs. wild type genotypes for both SNPs (p > 0.05). Our data suggest an association between investigated resistin genetic variants and knee OA susceptibility in our population. This is the first report to show association between investigated single nucleotide polymorphisms and OA among any population.

Type 2 diabetes mellitus risk and exercise: is resistin involved?

Obesity and associated disorders such as type 2 diabetes mellitus (T2DM) pose an increasing risk to the health of both individuals and society. Adipose tissue is an active endocrine organ, secreting many hormones, known as adipokines. Evidence suggests that one suggest adipokine, resistin, may be elevated in the plasma of individuals with T2DM, and early reports indicated that this may contribute to the impaired glucose tolerance and insulin resistance observed in T2DM, hence its name, resistin, however subsequent evidence suggests it may have a proinflammatory role. Performing regular exercise and dietary interventions improve insulin sensitivity and glucose tolerance in the majority of individuals with T2DM, and we hypothesized that plasma resistin levels may drop in individuals following a long term aerobic and/or resistance exercise intervention program. Articles analyzing the effects of exercise on serum resistin levels were therefore analyzed. Articles were selected and analyzed based on a minimum aerobic and/or resistance training program of 2 sessions per week for 12 weeks. Plasma resistin levels decreased following either endurance aerobic exercise and/or resistance training plans in individuals with obesity and/or insulin resistance, although this was not related to BMI change. Exercise intervention programs generally showed potentially beneficial changes in plasma resistin concentrations. It is possible these effects are mediated through exercise-induced decreases in inflammation via anti-inflammatory cytokine release rather than alterations in glucose metabolism and reductions in BMI per se. A possible link between resistin, exercise and T2DM is discussed.

Resistin polymorphims, plasma resistin levels and obesity in Tunisian volunteers

BACKGROUND

Adipose tissue is an important endocrine organ that secretes a number of adipokines, like Resistin (RETN); it's an adipocytes-secreted cytokine and has been proposed as a link between obesity and diabetes. Many resistin gene polymorphisms were described and their implication in obesity was controversial. This study was to investigate the prevalence of single nucleotide polymorphisms (SNPs) in RETN gene 420C/G; 44G/A; 62G/A; 394C/G and 299 G/A and their association with Resistin level and obesity in Tunisian volunteers.

METHODS

We recruited 169 nonobese (mean age=42.16-14.26 years; mean body mass index [BMI]=24.51-3.69 kg/m² ) and 160 obese (mean age=47.86-11.17 years; mean BMI=36-4.78 kg/m² ). Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. Anthropometric parameters, lipid levels, Glycemia and insulinemia were measured, BMI was calculated and insulinresistance was evaluated with the homeostasis model assessment insulin resistance (HOMA-IR) and resistin level was measured by ELISA. Statistical analyses were performed by SPSS19.0.

RESULTS

After adjustment for confounding parameters; the Odds Ratio (OR) of obesity associated with mutated genotypes at 420C/G compared with normal genotype was as: OR=2.17; 95% CI [1.28-3.68], P=.004. The serum Resistin levels present no significant association with all RETN polymorphisms and it was significantly associated with BMI (P=.047). In our haplotype analysis, one haplotype seems to be protective and one other seems to be the highest risk to obesity.

CONCLUSION

The 420 C/G Polymorphism were associated with obesity and Leptin concentration in our population.

Association of +62 G>A Polymorphism in the Resistin Gene with Type 2 Diabetes Mellitus among Thais: Case-Control Study

INTRODUCTION

Resistin gene (RETN) polymorphisms in humans may have a role in the pathogenesis of Type 2 Diabetes Mellitus (T2DM) and insulin resistance. There is still lack of evidence on association between +62 G>A polymorphism in the RETN and T2DM among Thais.

AIM

To determine the effect of polymorphisms at +62 G>A of RETN on Thai T2DM.

MATERIALS AND METHODS

This matched case control study was conducted with a total of 360 samples from all regions of Thailand (180 Thai new T2DM cases and 180 non-T2DM Thais for control) were enrolled. The RETN +62G>A polymorphism were detected using the Polymerase Chain Reaction (PCR) method. Conditional logistic regression was performed to test the association between +62 G>A polymorphism and T2DM.

RESULTS

Among 360 samples that were enrolled, only 350 samples completed molecular analysis. It was found that GA+AA genotype frequencies in T2DM cases was higher than control by 16% (95% CI: 6.0%, 27.0%, p-value=0.002). After adjustments for possible confounders, multivariable analyses by conditional logistic regression showed that the RETN+62 G>A polymorphism was statistically associated with Thai T2DM (OR_adjusted =1.84, 95% CI: 1.03, 3.31, p-value=0.04). Other factors such as; low educational attainment (OR_adjusted=3.87, 95%CI: 1.60, 9.36), hypertension (OR_adjusted=3.07, 95%CI: 1.56, 6.04), had both obese father and mother (OR_adjusted=1.94, 95%CI: 1.06, 3.56) and triglyceride≥150 (OR_adjusted=2.18, 95% CI: 1.18, 4.02) were statistically associated with Thai T2DM (p-value<0.05). While regular consumption of glutinous rice was found to be a protective factor (OR_adjusted=0.29, 95%CI: 0.13, 0.64).

CONCLUSION

These findings suggest that RETN polymorphism at position +62 G>A may increase the susceptibility to T2DM in Thais.

Visfatin -948G/T and resistin -420C/G polymorphisms in Egyptian type 2 diabetic patients with and without cardiovascular diseases

Diabetes mellitus is one of the main threats to human health in the 21st century. Visfatin/Nampt and resistin are novel adipokines that have been implicated in the pathogenesis of type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) complication. Several genetic studies have shown inconsistent results regarding association of visfatin/Nampt gene (NAMPT) and resistin gene (RETN) polymorphisms with T2DM and CVD complications. Here, we investigate whether NAMPT -948G/T and RETN -420C/G polymorphisms are associated with T2DM, its CVD complications, and serum adipokines levels in 90 Egyptian diabetic patients (44 without CVD and 46 with CVD) along with 60 healthy control subjects. Higher frequencies of NAMPT -948G/G and RETN -420G/G were observed among T2DM patients compared with controls. Furthermore, the frequencies of these genotypes were significantly higher in T2DM patients with CVD than those without CVD. Both NAMPT -948G/G and RETN -420G/G genotypes and G alleles were significantly associated with T2DM and CVD in Egyptian diabetic patients. Moreover, serum visfatin/Nampt and resistin levels were markedly elevated in T2DM patients, with the highest values observed in G/G genotypes among T2DM patients with CVD. In addition, positive correlations were observed between plasma adipokines levels and CVD risk factors. In conclusion, our data suggests that genetic variations in NAMPT -948G/T and RETN -420C/G may contribute to the disposition for T2DM and its CVD complications in Egyptian patients. However, further studies with greater sample size should be performed to verify these results.

Adipokine profile in celiac patients: differences in comparison with patients suffering from diarrhea-predominant IBS and healthy subjects

OBJECTIVE. The role of adipokines such as resistin, leptin, and adiponectin could be pivotal in the molecular crosstalk between the inflamed intestine and the surrounding mesenteric adipose tissue. Our aims were to a) evaluate their circulating concentrations in patients with active celiac disease (ACD) and compare them to those in patients with diarrhea-predominant irritable bowel syndrome (IBS-d) and healthy subjects; b) establish the impact of genetic variability in resistin; and c) evaluate whether a 1-year gluten-free diet (GFD) modifies circulating concentrations of resistin, leptin, and adiponectin in celiac patients. MATERIAL AND METHODS. The study included 34 ACD patients, 29 IBS-d patients, and 27 healthy controls. Circulating concentrations of resistin, leptin, adiponectin, IL-6, and IL-8 were evaluated at the time of enrollment. Resistin +299 G/A polymorphism was also analysed. In CD patients, biochemical measurements were repeated after a 1-year GFD. RESULTS. Along with higher IL-6 and IL-8 plasma levels, higher resistin and adiponectin concentrations were found in ACD and IBS-d patients compared with controls (p: 0.0351 and p: 0.0020, respectively). Resistin values proved to be predictable from a linear combination of IL-8 and +299 polymorphism. GFD affected resistin (p: 0.0009), but not leptin and adiponectin concentrations. CONCLUSIONS. Our data suggest that these adipokines are involved in modulating inflammatory processes in both CD and IBS-d patients. Alterations in the adipokine profile as well as the higher prevalence of the resistin +299 G/A SNP A allele compared to controls support the hypothesis that, at least in well-defined cases of IBS, a genetic component may also be supposed.

Association between resistin gene -420 C/G polymorphism and the risk of type 2 diabetes mellitus: a meta-analysis

Epidemiological studies on the association between the single nucleotide polymorphism (SNP) at -420 C/G (rs1862513) in the human resistin gene (RETN) and the risk of type 2 diabetes mellitus (T2DM) are conflicting. In order to derive a more precise estimation of the association, a meta-analysis was conducted. Twelve studies with 5,935 cases and 5,959 controls were enrolled by searching the databases of Medline, EMBASE, and Cochrane. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. The heterogeneity and publication bias were investigated. The main analysis indicated no significant association [for allelic model: OR = 0.97 (0.92-1.03); for additive model: OR = 0.95 (0.83-1.09); for recessive model: OR = 0.98 (0.86-1.12); for dominant model: OR = 0.95 (0.88-1.04)]. Overall, no significant heterogeneity was found. Subgroup analysis by race and source of controls indicated no significant association. In conclusion, the current meta-analysis did not observe any association between the polymorphism of RETN -420 C/G and the risk of T2DM. The study may help us further understand the genetics of T2DM. However, larger and prospective studies are warranted to confirm this finding.

Association of resistin gene polymorphisms with insulin resistance in Egyptian obese patients

BACKGROUND

Obesity associated insulin resistance is a major risk factor for type 2 diabetes mellitus. Resistin is recently reported to provide a link between obesity, insulin resistance and type 2 diabetes mellitus. We aimed to investigate the possible associations of resistin gene (RETN) polymorphisms with obesity, and to detect whether these polymorphisms are associated with glucose intolerance and type 2 diabetes mellitus in obese patients.

METHODS

One hundred and forty-five Egyptian obese patients with or without glucose intolerance and 155 unrelated healthy controls were enrolled in this study. Polymorphisms of RETN +299G>A and RETN -420 C>G gene were detected by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP). Serum resistin was measured by ELISA.

RESULTS

RETN +299 AA and RETN -420 GG genotypes were significantly associated with obesity in Egyptian population. Moreover, the mutant alleles or genotypes of both examined polymorphisms were associated with impaired glucose tolerance and diabetes mellitus compared to normal glucose tolerant obese patients. Furthermore, our results revealed elevated waist/hip ratio, BMI, blood pressure, fasting blood glucose level, HOMA-IR, triglycerides, total cholesterol, resistin level, and decreased HDL cholesterol level in homozygote mutant genotypes carriers of both RETN polymorphisms among obese patients.

CONCLUSION

Resistin gene polymorphisms may play an important role in pathogenesis and susceptibility to obesity, impaired glucose tolerance, and type 2 diabetes mellitus in Egyptian population.

In vivo Studies on Antidiabetic Plants Used in South African Herbal Medicine

Diabetes is one of the most common metabolic disorders worldwide. It is a major health problem with its frequency increasing every day in most countries. The disease is generally believed to be incurable; and the few orthodox drugs available to manage the disease are not readily affordable to the poor. Based on the historical success of natural products as antidiabetic agents and the ever increasing need for new antidiabetics, a number of South African medicinal plants have been evaluated for their antidiabetic properties. In this article, we review the major studies conducted based on ethnobotanical surveys carried out between 2005 and 2008 in South Africa on plants that are traditionally used for the treatment of diabetes. Overall, the results of the studies conducted confirmed the potential of South African medicinal plants in antidiabetic drug discovery and identified a number of promising taxa for further in vivo investigation as plant-based antidiabetic agents.