Study On The Relationship Between Environmental Factors And Estrogen Receptor Gene Polymorphisms And Precocious Puberty In Girls

ObjectivesPrecocious Puberty(PP)usually refers to the onset of secondary sexual characteristics before the age of 8 or the onset of menstruation before the age of 10.In recent years,the incidence of precocious puberty in children has been gradually increasing.With the increasing attention to children’s growth and development,parents have gradually deepened their understanding of precocious puberty,and more and more patients go to the hospital for treatment.However,there are many factors and complex mechanisms affecting precocious puberty,from society to family,from life to diet,from external causes to internal causes,from macro to micro,involving all aspects of children’s growth cycle.Therefore,in this study,a case-control method design was adopted to investigate the influence of the interaction between various environmental factors and their interaction on girls’ precocious puberty through epidemiological investigation,in order to improve the health level of children and protect their physical health.Methods1.Collected from female patients aged 6-10 years old in the Child Health Department of Shenyang Children’s Hospital.Case group: 80 girls with precocious puberty.Breast development,appearance of pubic hair,vaginal secretions,vaginal bleeding,menarche,height surge and/or B ultrasound examination results of normal or enlarged ovaries,uterus normal or little enlargement,that is,the diagnosis of precocious puberty.Control group: 71 healthy girls aged 6-10 years who sought medical advice during the same period due to "physical examination".Children were collected through questionnaires.2.Venous blood of the subjects was collected for FSH,LH,E2 and T hormone analysis;Subjects were examined for bone age.3.Oral mucosal cells of the study subjects were collected,genomic DNA of the cells was extracted,and generation sequencing was conducted,and gene polymorphisms analysis were conducted on the sequence.4.Excel 2010 was used for data entry,SPSS 20.0 software was used for statistical analysis of the data.T-test was used to analyze the measurement data conforming to normal distribution,Wilcoxon test was used to analyze the measurement data not conforming to normal distribution.Chi-square tests were performed on the counting data,and Fisher exact probabilities were used when there were multiple expected values <5.Then,the factors with P<0.05 were screened out,and the single Logistic regression analysis was carried out to obtain the protective factors and risk factors.All the risk factors were put into the multi-factor Logistic regression model to obtain the risk factors under the interaction.For the analysis of estrogen receptor gene polymorphisms,genotype frequency and allele frequency of the two groups were counted respectively.Chi-square test showed that genotype P<0.05,OR value and 95% CI were calculated.The interaction between genotypes and environmental risk factors was analyzed by fork analysis and Andersson tabulation.Results1.Relationship between environmental factors and precocious puberty in girls1)General data distributionCompared with the control group,there was no significant difference in general condition(age,birth height,weight,nationality,address)between the case group and the control group(P>0.05).There were statistical differences in the development of secondary sex characteristics,such as breast tenderness,vulva development,body hair and vaginal secretions between the two groups(P<0.05).There were no significant differences in other diseases,birth and rearing modes between the two groups(P>0.05).In terms of life and study,except sleeping with the light turned on,the two groups showed significant differences(P<0.05).Among the family environment factors,there were statistically significant differences in the father’s education level and the mother’s precocious puberty in the case group and the control group(P<0.05).In addition,the age of first spermatogenesis of the father and the age of first menarche of the mother were significantly different between the two groups(P<0.05).There were significant differences in height,weight,BMI,bone age and obesity ratio between the two groups(P<0.05).Weight,height and BMI values of the case group were higher than one standard deviation,while the control group’s height level was slightly lower than the average,but not more than one standard deviation.The bone age in the case group was more than 1 year earlier.2)Age composition and hormone levelsWhen the subjects were included in the study,the 8-10 year old patients with only secondary sex characteristics,such as simple breast development and simple growth acceleration,were excluded,and were not accompanied by early menarche.After the exclusion,the age composition ratio of the two groups at 6-8 years old and8-10 years old wasn’t affected.More children with peripheral precocious puberty(PPP)and incomplete precocious puberty(IPP),that is,non-central precocious puberty,visited the hospital than those with central precocious puberty(CPP).The difference in age between CPP group and non-central group and control group was statistically significant(P<0.05),but there was no statistically significant difference between non-central group and control group.Compared with the other two groups,FSH,LH,E2 and LH/FSH in CPP group were statistically significant(P<0.05).Compared with the control group,the non-central group only showed significant difference in FSH(P<0.05).T showed significant difference only between the central group and the non-central group.3)The influence of Explication of EEDs on premature Sexual development of girlsThe factors that children may be exposed to in their life,only "whether there is a family dish or garden",showed significant difference between the two groups(P<0.05).4)Influence of dietary habits on precocious puberty in girlsThere were statistically significant differences between the two groups in eating nuts,fried food,butter bread,biscuits,sugary drinks,milk tea and plastic products(P<0.05).5)Univariate Logistic regression analysisAll the above tested factors with P<0.05 were screened out,and single factor Logistic regression was performed one by one.The variable test standard 0.05 was used,the variable test level α=0.10 was eliminated,and the variables were screened by stepwise forward method.Among them,long sleep time,more physical exercise,more nuts,less fried food,high paternal education level were the protective factors for early puberty,while the more antibiotics use,more heavy school load,the presence of family gardens,gardens,bread,sugary drinks,milk tea,the use of plastic products in hot food were the risk factors for early puberty(P<0.05).6)Multivariate Logistic regression analysisThe risk factors after single factor regression analysis were put into the multiple Logistic regression model,the variable test standard was 0.05,the variable test levelα=0.10 was excluded,and the variables were screened by stepwise forward method.The results showed that schoolwork load(heavy),home vegetable garden,garden,sugary drinks(1-3 times/month)were risk factors,which was statistically significant(P<0.05).2.Analysis of estrogen receptor gene polymorphisms1)All the study populations conform to the law of Hardy-Weinberg Equilibruim genetic balance and are representative of the population.2)There were no significant differences in the distribution of ERα gene PvuⅡgenotype and P allele frequency between the two groups(P>0.05),but there were significant differences in Xba Ⅰ genotype and X allele frequency,suggesting that Xba Ⅰ gene may be related to precocious puberty.Xx(56.0%)had the highest constituent ratio,and this genotype may be a risk factor for precocious puberty,and the relative risk of precocious puberty with X allele was 2.172 times that of x(95% CI1.190-3.967).Compared with the control group,there was no difference in ERαgenotype.The proportion of Pp Xx and pp Xx genotypes in the case group was higher,which may be a risk factor for precocious puberty.However,the proportion of Ppxx and ppxx genotypes in the control group was higher.3)The Rsa Ⅰ genotype and R allele frequency of ERβ gene were statistically different between the two groups(P<0.05),but there was no significant difference between the AluⅠgenotype and A allele frequency,indicating that RsaⅠgene may be related to precocious puberty.Rr(50.0%)was the highest component ratio,which may be the risk factor of precocious puberty.The relative risk of precocious puberty with R allele was 1.857 times higher than that with r allele(95% CI 1.015-3.996).There was no difference in the combination of ERβ gene RsaⅠand AluⅠgenotypes between the two groups.Rr Aa and Rraa genotype accounted for a higher proportion in the case group,which may be a risk factor for precocious puberty.rr Aa and rraa genotype composition was higher in the control group.3.Interaction between genes and environmentAfter the cross analysis,only the OR values of Xx genotype and environmental factors(drinking sugar-sweetened beverages)were significant.After calculation,S<1,AP was 0.141,and RERI was 0.124.However,95% CI of RERI and AP contained 0,and 95% CI of S contained 1,suggesting the existence of negative additive interaction between the two,which was not statistically significant.Conclusion1.The levels of height,weight,BMI,bone age,FSH,LH,LH/FSH and E2 in precocious puberty girls were significantly higher than those of normal children.2.Heavy school load,access to family dishes,garden,and consumption of sugary drinks(1-3 times/month)may be risk factors for the onset of precocious puberty.3.The polymorphism of ERα gene XbaⅠwas associated with the incidence of precocious puberty in girls,among which Xx genotype had the highest risk,while PvuⅡgenotype polymorphism had no significant association with the incidence of precocious puberty in girls.In the analysis of ERα polymorphic loci,Pp Xx and pp Xx genotypes may be associated with the onset of precocious puberty.4.RsaⅠpolymorphism of ERβ gene was associated with precocious puberty,but AluⅠwas not.Alleles R are more likely to be associated with precocious puberty than r,and Rr genotype is the most susceptible.In the analysis of polymorphic loci of ERβgene,Rraa and Rr Aa genotype may be potential risk factors for precocious puberty.5.Xx genotype and sugar-sweetened beverage consumption(1-3 times/month)may have a negative additive interaction on the incidence of precocious puberty in girls,but there was no significant effect.