Relationship Between Adiponectin Gene Polymorphism And Type 2 Diabetes And Insulin Resistance

Objectives:The purpose of this study was to investigate the genotype distribution of adiponeetin gene SNP+45 and SNP+276 T/G polymorphisms in Cangzhou,Hebei Province,to analyse the relationship between adiponectin gene SNP+45,SNP+276 and diabetes mellitus type 2 or insulin resistance and provide a theoretical basis,valuable genetic guidance in therapy of T2 DM.Subjects and Methods:1 SubjectsAll subjects are Hans population of Hebei in middle and old ages(native inhabitants),with a roughly equal proportion of men and women.Using WHO(WHO,1999)diabetes mellitus diagnostic criteria,100 patients with type 2 diabetes mellitus,from October 2015 to October 2016,were randomly selected from the Department of Endocrinology,Cangzhou Central Hospital,Hebei Province,as the experimental group.65 control subjects were selected from our hospital matching with sex and age.2 Extraction of DNAThe DNA was extracted with the CWBIO Flex Gen Blood DNA Kit.3 SNP typing detectionPolymerase chain reaction restriction fragment length polymorphism(PCR-RFLP)was used to detect adiponectin gene SNP+45 and SNP+276.Gene-specific primers of adiponectin gene exon 2 and intron 2 for polymerase chain reaction was designed using Premier5 and Oligo7 software,and adiponectin DNA sequence recorded by NCBI online.The DNA fragment was amplified by PCR and was identifiedby agarose gel electrophoresis,then using the restriction endonuclease Sma l and Eco R I to determine the genotype of SNP+45 and SNP+276.Finally,some samples of PCR products were randomly selected sequencing by the company(Beijing Sunbiotech co.,Ltd)to ensure the reliability of the results.4 Assay of plasma adiponeetin concentrationDetermination of APN in plasma by ELISAResult:1 Clinical characteristics of the experimental group and control group.There was no statistical significance in gender,age and height between Two groups,the P value was >0.05.Compared with the control group,the values of weight,body mass index(BMI),wist circumference,hip circumference,wist-to-hip ratio(WHR),diastolic blood pressure(DBP),systolic blood pressure(SBP),fasting Blood glucose(FBG),triglycerides(TG),Cholesterol(TC),low density lipoprotein(LDL-C),insulin,insulin resistance index(HOMA-IR)were significantly higher in the experimental group,the difference was statistically significant.The values of HDL-C and plasma adiponeetin concentration(APN)were lower in experimental group(P <0.05),the difference was statistically significant.2 Plasma adiponectin levels2.1 The plasma level of APN in T2 DM group was significantly lower than that in control group.2.2 Partial correlation analysis of all samples with clinical and biochemical parametersExcluding other confounding factors,partial correlation analysis was performed to determine the correlation of all samples among the plasma adiponectin level the biochemical parameters.It was found that plasma APN was negatively correlated with waist circumference,SBP,TG,TC,LDL-C,and HOMA-IR.Among them,waist circumference and LDL-C had the strongest correlation,and the difference was statistically significant(P<0.05).3 Comparison of genotype frequency and allele frequency distribution between the experimental group and the control group3.1 SNP+276 site:The TT,GT and GG genotype frequencies of T2 DM group were 13 %,37 % and 50 % respectively;the frequencies in control group were10.77%,GT 20%,GG69.23%respectively.The frequency of GG genotype in T2 DM group was significantly lower,but TTgenotype frequency was significantly higher than that of control group.Statistical difference was found in genotypic frequency between the two groups(P<0.05).T and G allele frequencies were 31.5%,68.5%in T2 DM group and 20.77%,79.23% in control group respectively,there were significant difference between the two groups(P<0.05).3.2 SNP+45 site:The TT,TG and GG genotype frequencies were53%,36%,11% in T2 DM group,and TT 35.38%,TG 46.15 %,GG 18.47 % in control group respectively.There was statistical difference in genotypic frequency between these two groups(P<0.05).T and G allele frequencies were71 %,29 % in T2 DM group and 58.46,41.54% in control group respectively,there was significant difference between the two groups(P<0.05).4 Comparison of SNP+276 and SNP+45 between insulin resistance and plasma APN levels in adiponectin gene4.1 SNP+276 site:There were significant differences between BMI,FBG,TC,HDL-C,LDL-C,HOMA-IR,TG and APN(P<0.05)in genotypes of adiponectin gene SNP+276.Among them,the difference between TC,FBG,insulin and HOMA-IR was the most significant(P<0.05).LSD-t test was used to compare the genotypes separately,it found that the level of TC in GG genotype was significantly higher than that in TT genotype,the level of HOMA-IR in GG genotype was significantly higher than that in non-GG genotype,the level of insulin and FBG in GG genotype was significantly lower than that in TT genotype.4.2 SNP+45 site:There were significant differences between BMI,FBG,TC,HDL-C,LDL-C,HOMA-IR,TG and APN in genotypes of adiponectin gene SNP+45(P<0.05).Among them,APN,FBG and insulin were the mostsignificant(P<0.05).LSD-t test was used to compare the genotypes independently,the level of FBG and insulin in TT genotypewere higher than non-TT genotype,the level of APN in GG genotypewere higher than non-GG genotype(P<0.05).5 Multivariate Logistic regressionTaken the biochemical and clinical parameters of all samples as independent variables,the type 2 diabetes as the dependent variable,Logistic multivariate regression analysis was performed.It was found that TC was a risk factor of type 2 diabetes mellitus(P<0.05,OR>1),and HDL-C was a protective factor of type 2 diabetes mellitus(P<0.05,OR<1),The TT genotype of SNP+276 were independent risk factors of type 2 diabetes mellitus(P<0.05,OR>1).Conclusions:1 There were T/G polymorphisms of ap Ml gene+45 site and+276 site in Hebei population.2 Plasma adiponectin levels in type 2 diabetic patients were significantly lower than those in healthy controls.Plasma APN was negatively correlated with waist circumference,SBP,TG,TC,LDL-C,and HOMA-IR.Among them,waist circumference and LDL-C had the strongest correlation,and the difference was statistically significant(P<0.05).3 The SNP+45GG genotype of APN was higher than that of non GG genotype,but there was no difference in APN between the genotypes of SNP+276.4 Adiponectin SNP+45 276 genotype and TC were risk factors for type 2 diabetes mellitus;SNP+45 genotype was not associated with type 2 diabetes mellitus.