Study On Association Between NR3C1 Gene Polymorphism And Age-related Hearing Impairment

Objective:Age-related hearing impairment(ARHI)is a disease that seriously impacts the life quality of the elderly.In order to reveal the pathogenesis of ARHI and to provide scientific basis for the prevention of ARHI,this study investigated the effects of single nucleotide polymorphism(SNP)of glucocorticoid receptor(Nuclear Receptor Subfamily 3,Group C,Member 1,NR3C1)gene and NR3C1 gene score reflecting the overall level of the gene on ARHI,and studied the multiplicative interaction between NR3C1 gene score and environmental factors(such as smoking,drinking,diabetes,hypertension)on ARHI.The importance order of genetic factors and environmental factors on ARHI was explored by constructing neural network model.Methods:In this study,cluster sampling method was adopted to select 2communities in Chengyang district of Qingdao as the investigation site.Non-related individuals of the Han nationality aged 60 or above with hearing impairment in the community were selected as the case group,and the non-related individuals of the Han nationality with normal hearing in the same community and matched 1:1 with the gender and age of the case group were selected as the control group.Data were collected through questionnaire survey,pure tone hearing test,and blood sample collection.According to the classification standard of hearing level recommended by the World Health Organization,the pure tone average(PTA)of 0.5k Hz,1.0k Hz,2.0k Hz and 4.0k Hz of better hearing ear was used for judgment.In other words,the PTA of good hearing ear≤25d B HL was defined as normal hearing group;PTA>25d B HL was defined as the ARHI group.The nine sites for the rs6191,rs61757411,rs41400245,rs258751,rs6196,rs41423247,rs6877893,rs12655166 and rs33388 of the NR3C1 gene were selected as target SNP by referring to information of Hap Map database and 1000 Genomes database.To investigate the association between SNP of NR3C1 gene and ARHI,the genotypies and allele distributions of nine SNP were compared in the case group and the control group byx~2test.The matched logistic regression analysis method was used to calculate the odd ratio(OR)and 95%confidence interval(CI)of the nine SNP through five genetic models including codominance,additive,dominant,recessive and overdominant.Comparison of distribution differences on haplotype frequency between normal hearing group and ARHI group through linkage disequilibrium and haplotype analysis.The weighted gene score method was used to calculate gene score of NR3C1 to explore its relationship with ARHI at the overall level of the gene.The multiplicative interaction model based on the matched logistic regression method was used to study the influence of the interaction between NR3C1 gene and environmental factors on ARHI.The neural network model was used to investigate the order of importance of NR3C1 gene and environmental factors affecting the occurrence of ARHI.Results:A total of 404 objects were recruited in this survey.Among them,ARHI patients,namely 202 people with hearing impairment(case group),and 202 people with normal hearing(control group)matched 1:1 with the gender and age of the case group.1.Comparison of the basic information of objects Comparing the basic conditions,it was found that two groups of research objects in PTA(P<0.001),smoking(P<0.001),and drinking(P=0.009)had a difference.2.Hardy-Weinberg Equilibrium of SNP The Hardy-Weinberg Equilibrium of 9SNP in the case group and the control group showed that the genotypes of all SNP were compliance with it(P>0.05),respectively.3.Comparison of genotype and allele in case and control groups The genotype and allele distribution of nine SNP of NR3C1 gene showed no difference between the two groups(P>0.05).4.The relationship between nine SNP of NR3C1 gene and ARHI After adjusting for covariates of whether osteoporosis is understood,diabetes,hypertension,smoking,drinking,frequency of green tea,fruit intake frequency,and satiety,multivariate matched logistic regression analysis of the genetic model of rs6191 showed that the overdominant genetic model suggested that individuals with AC genotype had a higher risk of ARHI compared with those with AA genotype(OR=2.817,95%CI:1.015-7.815,P=0.047).Additive models suggested a statistically significant association between this SNP and ARHI(OR=2.817,95%CI:1.015-7.815,P=0.047).The recessive model suggested that individuals with AA genotype had a lower risk of ARHI than those with AC genotype(OR=0.355,95%CI:0.128-0.985,P=0.047).However,the other eight SNP had no statistical correlation with ARHI under the five genetic models of codominant,additive,dominant,recessive,and overdominant(P>0.05).5.Linkage disequilibrium and haplotype analysis A total of two haplotype block including rs6196,rs258751,rs33388,rs6877893,rs41423247,rs12655166,rs41400245were constructed,respectively.The No.1 haplotypes with a total frequency of≥5%include AGTAG、AGAGC、GAAGC and AGAGG,and the No.2 haplotypes with a total frequency of≥5%include TC,CT and CC.The frequencies of AGTAG,AGAGC,GAAGC and AGAGG haplotype were 0.329,0.190,0.053,0.013 in the normal hearing group,and 0.259,0.144,0.055,0.031 in the ARHI group,respectively.The frequency distribution of AGTAG、AGAGC、GAAGC and AGAGG haplotypes showed no statistically significant differences between the two group(P>0.05).The frequencies of TC,CT and CC haplotype were 0.147,0.111,0.026 in the normal hearing group,and0.130,0.111,0.015 in the ARHI group,respectively.The frequency distribution of TC,CT and CC haplotypes showed no statistically significant differences between the two group(P>0.05).6.Relationship between the NR3C1 gene score and ARHI The results of multivariate matched logistic regression analysis after adjusting the covariates showed that there was a statistically significant association between the weight gene score of NR3C1 gene and ARHI(OR=0.790,95%CI:0.626–0.997,P=0.047).7.Interaction between the NR3C1 gene score and environmental factors Under the premise of matched logistic regression model without adjusting covariates,the results showed that there may be no multiplicative interaction between NR3C1 gene score and hypertension(OR=1.353,95%CI:0.630-2.904,P=0.439).After adjusting covariates,multivariate matched logistic regression model showed a positive multiplicative interaction between NR3C1 gene score and hypertension(OR=3.099,95%CI:1.105-8.694,P=0.032).The interaction of low NR3C1 gene score and have hypertension may increase the risk of ARHI in individual.8.Neural networks model analysis The area under the ROC curve of the analysis model based on neural network was 0.749,which indicated that the model had better predictability.In the model,NR3C1 gene score,smoking,drinking,diabetes,hypertension,frequency of drinking green tea,degree of satiety,frequency of fruit intake,and understanding of osteoporosis were sorted in order of importance.The top three variables were NR3C1 gene score,smoking and drinking,respectively.Conclusion:1.The rs6191 polymorphism of NR3C1 gene can increase the susceptibility of individuals to ARHI,suggesting that the polymorphism of NR3C1 gene is associated with ARHI.2.NR3C1 gene score is related to the ARHI.A high NR3C1 weighted gene score is associated with a reduced risk of ARHI.3.There may be a positive multiplicative interaction between NR3C1 gene score and hypertension,suggesting that the interaction between low NR3C1 gene score and have hypertension will lead to the greater risk of ARHI.4.The top three important factors affecting the incidence of ARHI are NR3C1 gene score,smoking and drinking,respectively.