Resistin gene 3'-untranslated region +62G-->A polymorphism is associated with hypertension but not diabetes mellitus type 2 in a German population

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.

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.

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.

Association of adiponectin and resistin gene polymorphisms in South Indian women with polycystic ovary syndrome

OBJECTIVES

To investigate whether genetic polymorphisms in the resistin and adiponectin genes cause a predisposition towards polycystic ovary syndrome (PCOS) in a South Indian women population.

STUDY DESIGN

This case controlled study included samples from 484 study subjects (282 diagnosed with PCOS and 200 normal controls). The clinical and biochemical parameters of the samples assayed included BMI, LH, FSH, testosterone, fasting glucose, adiponectin and resistin levels. Three single nucleotide polymorphisms of the resistin (RETN) gene 420(C→G) (rs1862513), 299(G→A) (rs3745367), and 62(G→A) (rs3745368), and two single nucleotide polymorphisms of the adiponectin (ADPIOQ) gene 45(T→G) (rs2241766), and 276(G→T) (rs1501299), were analyzed using a PCR-RFLP method. Statistical analysis was carried out to determine the association of the genotypic and allelic variations with the syndrome and also analyze the influence of genotypic variations on adipokine levels.

RESULTS

Serum levels of testosterone, LH, fasting glucose and resistin were found to be significantly increased in the PCOS patients when compared to controls, while adiponectin was found to be significantly lower (P<0.05). BMI was found to positively correlate with resistin levels and negatively correlate with adiponectin levels. A positive association was found between the RETN promoter 420 (C→G) SNP and the intron 2 299 (G→A) variant of the resistin gene, while no association was found between the ADPIOQ gene polymorphisms and PCOS. The 'GG' variant of the adiponectin 45 (T→G) variant showed a near-significant tendency towards a decreased concentration of adiponectin in PCOS patients.

CONCLUSIONS

Polymorphisms of the resistin gene could be assigned to play a role in increasing the risk of PCOS. However, the adiponectin gene does not seem to play a major role in PCOS susceptibility in a South Indian population. Serum adiponectin and resistin levels were more dependent on BMI rather than the presentation of PCOS. Obesity plays a major role in aggravating the hormonal disturbances found associated with PCOS.

Resistin: insulin resistance to malignancy

Adipose tissue is recognized as an endocrine organ that secretes bioactive substances known as adipokines. Excess adipose tissue and adipose tissue dysfunction lead to dysregulated adipokine production that can contribute to the development of obesity-related co-morbidities. Among the various adipokines, resistin, which was initially considered as a determinant of the emergence of insulin resistance in obesity, has appeared as an important link between obesity and inflammatory processes. Several experimental and clinical studies have suggested an association between increased resistin levels and severe conditions associated with obesity such as cardiovascular disease and malignancies. In this review, we present the growing body of evidence that human resistin is an inflammatory biomarker and potential mediator of obesity-associated diseases. A common pathway seems to involve the combined alteration of immune and inflammatory processes that favor metabolic disturbances, atherosclerosis and carcinogenesis. The mode of action and the signaling pathways utilized by resistin in its interactions with target cells could involve oxidative and nitrosative stress. Therefore, resistin could function as a key molecule in the complications of obesity development and could potentially be used as a diagnostic and prognostic marker.

Association between four resistin polymorphisms, obesity, and metabolic syndrome parameters in Tunisian volunteers

Resistin is an adipocyte-secreted cytokine recently discovered and has been proposed as a link between obesity and diabetes. Many resistin gene polymorphisms were described and their implication in obesity and metabolic syndrome (MetS) was controversial. Our aim was to study the relationship between four resistin polymorphisms (420C/G, 44G/A, 62G/A, and 394C/G), MetS parameters, and the risk of obesity in Tunisian volunteers. We recruited 169 nonobese (sex ratio=0.594; mean age=43.25±13.12 years; mean body mass index [BMI]=24.73±3.50 kg/m(2)) and 160 obese subjects (sex ratio=0.221; mean age=48.41±10.92 years; mean BMI=36.6±4.8 kg/m(2)). Genotyping was performed using polymerase chain reaction-restriction fragment length polymorphism. Anthropometric parameters, lipid levels, glycemia, and insulinemia were measured. BMI was calculated and insulin resistance was evaluated with the homeostasis model assessment insulin resistance (HOMA-IR). Statistical analyses were performed by SPSS 17.0. The 420C/G seems to contribute to obesity. In fact adjusted odds ratio (OR) of obesity associated to mutated genotypes was 2.17 and 95% confidence interval was 1.28-3.68 (p=0.004). Mutated genotypes at 420C/G were associated with higher waist circumference and BMI. In addition, 44G/A polymorphism was associated with increased total cholesterol and low-density lipoprotein-cholesterol levels. The other genotypes showed no association with MetS parameters. Concerning association between single-nucleotide polymorphisms and MetS risk, only mutated genotypes at 44G/A increase the risk of MetS after adjustment to confounding parameters (OR=1.93, p=0.023). In conclusion, resistin gene polymorphisms 420C/G and 44G/A were associated with obesity and MetS parameters in Tunisian volunteers.

Role of adipokines in obesity-associated hypertension

It has been well documented that obesity is a major risk factor for the development of the hypertensive state. The correlation between body mass index and blood pressure level is well established. Nevertheless, the exact mechanisms which contribute to obesity-related hypertension remain poorly understood. In the last years, we have realized that the white adipose tissue is not just an inert organ for nutrient storage and isolation but rather depending on the body mass index the biggest endocrinological organ. Thus, the possible contribution of adipokines to the blood pressure elevation becomes an attractive hypothesis to explain the hypertensive state that often occurs in obesity. In this review, we consider direct and indirect effects of main adipokines on structural and functional changes in the cardiovascular system.

Plasma resistin concentration determined by common variants in the resistin gene and associated with metabolic traits in an aged Japanese population

AIMS/HYPOTHESIS

Resistin is a cytokine derived from adipose tissue and is implicated in obesity-related insulin resistance and type 2 diabetes mellitus. Polymorphisms of the resistin gene (RETN) have been shown to affect the plasma resistin concentration. The aims of this study were to identify polymorphisms of RETN that influence plasma resistin concentration and to clarify the relation between plasma resistin level and metabolic disorders in an aged Japanese cohort.

METHODS

The study participants comprised 3133 individuals recruited to a population-based prospective cohort study (KING study). Plasma resistin concentration, BMI, abdominal circumference, blood pressure, fasting plasma glucose and serum insulin concentrations, HbA(1c) content and serum lipid profile were measured in all participants. The HOMA index of insulin resistance (HOMA-IR) was also calculated. Eleven polymorphisms of RETN were genotyped.

RESULTS

A combination of ANOVA and multiple linear regression analysis in screening and large-scale subsets of the study population revealed that plasma resistin concentration was significantly associated with rs34861192 and rs3745368 polymorphisms of RETN. Multiple linear regression analysis with adjustment for age and sex also showed that the plasma resistin level was significantly associated with serum concentrations of HDL-cholesterol, triacylglycerol and insulin, as well as with BMI.

CONCLUSIONS/INTERPRETATION

Our results implicate the rs34861192 and rs3745368 polymorphisms of RETN as robust and independent determinants of plasma resistin concentration in the study population. In addition, plasma resistin level was associated with dyslipidaemia, serum insulin concentration and obesity.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00262691.

Dietary determinants of subclinical inflammation, dyslipidemia and components of the metabolic syndrome in overweight children: a review

OBJECTIVE

To review and summarize the dietary determinants of the metabolic syndrome, subclinical inflammation and dyslipidemia in overweight children.

DESIGN

Review of the current literature, focusing on pediatric studies.

PARTICIPANTS

Normal weight, overweight, or obese children and adolescents.

RESULTS

There is a growing literature on the metabolic effects of excess body fat during childhood. However, few pediatric studies have examined the dietary determinants of obesity-related metabolic disturbances. From the available data, it appears that dietary factors are not only important environmental determinants of adiposity, but also may affect components of the metabolic syndrome and modulate the actions of adipokines. Dietary total fat and saturated fat are associated with insulin resistance and high blood pressure, as well as obesity-related inflammation. In contrast to studies in adults, resistin and adiponectin do not appear to be closely linked to insulin resistance or dyslipidemia in childhood. However, circulating leptin and retinol-binding protein (RBP) 4 correlate well with obesity, central obesity and the metabolic syndrome in children. Intakes of antioxidant vitamins tend to be low in obese children and may be predictors of subclinical inflammation. Higher fructose intake from sweets and sweetened drinks in overweight children has been linked to decreased low-density lipoprotein (LDL) particle size.

CONCLUSIONS

Dietary interventions aimed at reducing intakes of total fat, saturated fat and free fructose, whereas increasing antioxidant vitamin intake may be beneficial in overweight children. More research on the relationships between dietary factors and the metabolic changes of pediatric obesity may help to identify the dietary changes to reduce health risks.

Association of variants in RETN with plasma resistin levels and diabetes-related traits in the Framingham Offspring Study

OBJECTIVE

The RETN gene encodes the adipokine resistin. Associations of RETN with plasma resistin levels, type 2 diabetes, and related metabolic traits have been inconsistent. Using comprehensive linkage disequilibrium mapping, we genotyped tag single nucleotide polymorphisms (SNPs) in RETN and tested associations with plasma resistin levels, risk of diabetes, and glycemic traits.

RESEARCH DESIGN AND METHODS

We examined 2,531 Framingham Offspring Study participants for resistin levels, glycemic phenotypes, and incident diabetes over 28 years of follow-up. We genotyped 21 tag SNPs that capture common (minor allele frequency >0.05) or previously reported SNPs at r2 > 0.8 across RETN and its flanking regions. We used sex- and age-adjusted linear mixed-effects models (with/without BMI adjustment) to test additive associations of SNPs with traits, adjusted Cox proportional hazards models accounting for relatedness for incident diabetes, and generated empirical P values (Pe) to control for type 1 error.

RESULTS

Four tag SNPs (rs1477341, rs4804765, rs1423096, and rs10401670) on the 3' side of RETN were strongly associated with resistin levels (all minor alleles associated with higher levels, Pe<0.05 after multiple testing correction). rs10401670 was also associated with fasting plasma glucose (Pe = 0.02, BMI adjusted) and mean glucose over follow-up (Pe = 0.01; BMI adjusted). No significant association was observed for adiposity traits. On meta-analysis, the previously reported association of SNP -420C/G (rs1862513) with resistin levels remained significant (P = 0.0009) but with high heterogeneity across studies (P < 0.0001).

CONCLUSIONS

SNPs in the 3' region of RETN are associated with resistin levels, and one of them is also associated with glucose levels, although replication is needed.

Absence of evidence for an association between resistin gene variants and insulin resistance in an Asian population with low and high blood pressure

AIMS

Although the function of resistin in human biology is unclear, some evidence suggests resistin gene variants influence insulin resistance, and insulin resistance-related hypertension. We searched for associations between common resistin gene variants and factors related to insulin resistance in Asian individuals with high or low blood pressure (BP).

METHODS

Non-diabetic Chinese or Japanese sibling pairs were included if one had extreme hypertension and the other was either hypertensive or hypotensive. Four common, non-coding single nucleotide polymorphisms (SNPs) were identified by sequencing the resistin gene in 24 hypertensive probands. Generalized estimating equations (GEEs)-based regressions were then performed to test for SNP associations using the entire study population (n=1556).

RESULTS

Of 72 tests, only one was significant at the 0.05 level; 3.5 significant tests were expected by chance alone. High variability in insulin and triglyceride levels created wide confidence intervals, thus the negative results are not conclusive for these phenotypes. However, the large sample size resulted in narrow confidence intervals for BMI, fasting and 120min post-load glucose, and high and low density lipoprotein cholesterol (LDL-C).

CONCLUSION

Several factors associated with insulin resistance are not likely influenced by the resistin gene in non-diabetic Asian individuals with high and low blood pressure.

Resistin increases with obesity and atherosclerotic risk factors in patients with myocardial infarction

The objective of the study was to assess the relation of resistin to the anthropometric parameters, metabolic risk factors, and C-reactive protein (CRP) in men with myocardial infarction. Subjects were 40 obese (age, 53.6 +/- 7.39 years; body mass index, > or =30 kg/m2) and 40 lean (age, 54.4 +/- 6.62 years; body mass index, <25 kg/m2) men with first acute myocardial infarction. Waist and hip circumferences, CRP, uric acid, fasting glucose, lipid profile, and blood resistin concentration were measured. In obese patients, triglycerides, fasting glucose, and CRP were significantly higher whereas high-density lipoprotein cholesterol was lower than in lean patients. The range of blood resistin concentration was 6.0 to 70.5 ng/mL: 27.84 +/- 12.15 ng/mL in obese subjects and 17.35 +/- 11.08 ng/mL in lean subjects (P < .0001). Significant positive correlation was revealed between blood resistin concentration and each of the analyzed anthropometric parameter and with fasting glucose, low-density lipoprotein cholesterol, and CRP, whereas negative relation was observed between resistin and high-density lipoprotein cholesterol. As revealed by univariate logistic regression analysis, risk of blood resistin concentration being greater than the median value (19.75 ng/mL) was increased by obesity, high-density lipoprotein cholesterol <40 mg/dL, hypertension, and CRP. In multivariate model, independent variables associated with higher median of resistin were obesity and CRP. Obesity increased 5.5-fold the probability of blood resistin concentration being greater than 19.75 ng/mL, whereas each 1-mg/dL increase in CRP increased this probability by 13%. In patients with acute myocardial infarction, obesity is positively related to blood resistin concentration. Resistin is likely to play a major role in the atherogenesis and its complications, and this action seems to be mostly related to the inflammatory reaction.

Analysis of genetic variations in the resistin gene shows no associations with obesity in women

Resistin is thought to be involved in the development of obesity and insulin resistance. Polymorphisms in the gene encoding resistin could contribute to this link, but different studies have yielded contradictory results. In this study, we investigated whether polymorphisms in resistin are involved in the development of obesity in a Belgian female population. We selected three single-nucleotide polymorphisms (SNPs; rs1862513, rs3745367, and rs3745369) and compared their genotype and allele frequencies between female obese patients (N = 541) and control individuals (N = 235). This analysis showed association with neither obesity for any of the variants nor with the haplotypes of these SNPs. Furthermore, we also investigated whether these variants have an influence on BMI. After Kruskal-Wallis analysis, we found that there was no difference in BMI between the genotypes for all variants. Together, these results suggest that these variants in resistin are not associated with obesity in the female population.

Study of Resistin gene expression in peripheral blood mononuclear cell and its gene polymorphism in a small range population

OBJECTIVE

To observe the expression of Resistin mRNA in peripheral blood mononuclear cells and its gene polymorphism in coding region in a small range population in Zhejiang Province of China.

METHODS

Eighty-three cases of type 2 diabetes mellitus and 53 healthy people were included. The expression of Resistin mRNA in peripheral blood mononuclear cells was detected by RT-PCR and semi-quantitative PCR assay. The sequencing work was done in Resistin cDNA and gene polymorphism was analyzed.

RESULTS

At the same condition, in 83 diabetes patients, Resistin mRNA was detected in 23 cases (11 males and 12 females). There was no Resistin mRNA expression in 53 healthy people. The ratio of PCR products between Resistin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was from 0.564 to 1.238, averaging 0.804+/-0.436. The sequence of Resistin cDNA is almost identical with each other and with that in GenBank with no single nucleotide polymorphism being found.

CONCLUSION

Resistin mRNA is expressed in human peripheral blood mononuclear cells in some type 2 diabetes mellitus, but its expression is at a low level. Among the experiment population we did not find polymorphism phenomenon in Resistin coding region. The different individual's Resistin coding region is highly coincident.

Resistin gene polymorphisms and progression of glycaemia in southern Chinese: a 5-year prospective study

OBJECTIVE

Human resistin gene (RETN) polymorphisms have been found to be associated with type 2 diabetes (T2DM), insulin resistance and/or obesity. We evaluated, in a 5-year prospective study, whether RETN polymorphisms could predict the progression of glycaemia in southern Chinese.

DESIGN AND PATIENTS

We conducted a systematic search for variants in RETN in 70 southern Chinese subjects. This was followed by the genotyping in 624 unrelated nondiabetic subjects of two polymorphisms, -420C-->G and +62G-->A, previously reported in cross-sectional studies to be associated with T2DM in Asians, to examine their relationship with the progression of glycaemia in this cohort.

RESULTS

We identified 15 polymorphisms, including 2 novel but rare polymorphisms (-319G-->A and +63G-->C). Compared to subjects with the CC genotype, -420GG subjects had higher 2-h glucose (7.7 +/- 1.8 vs. 7.2 +/- 2.0 mmol/l, P = 0.011) and insulin (101.6 +/- 69.5 vs. 79.8 +/- 59.5 mU/l, P = 0.021) during an oral glucose tolerance test. Carriers of the +62A allele had higher body mass indices (25.3 +/- 4.0 vs. 24.5 +/- 3.6 kg/m(2) in GG, P = 0.02). The presence of the allele -420G (OR 2.15, 95% CI 1.28-3.60, P = 0.004) or +62A (OR1.86, 95% CI 1.08-3.21, P = 0.025) predicted the progression of glycaemia at Year 5, after adjustment for sex, age or body mass index. The haplotype G-A also conferred a higher risk of progression in glycaemia (P = 0.002).

CONCLUSION

Our study would support the role of the resistin gene in obesity, insulin resistance and progression of glycaemia in southern Chinese.