Investigate The Relationship Between Childhood Obesity And Precocious Puberty

【Objectives】 To investigate the relationship between childhood obesity and precocious puberty from both dietary and genetic factors.【Methods】 1.A multistage,stratified cluster random sampling was conducted in a large population-based cross-sectional study.Physical examination and assessment of secondary sexual characteristics development was conducted by trained physicians.Obesity was defined according to the WHO Child Growth Standards.Central obesity was defined by sex-specific waist-to-height ratio(WHt R)cut-offs.Precocious puberty was identified by Tanner stage of breast,pubic hair and testicle.Probit analysis was used for estimating the median age at entry into Tanner stage 2 or greater for breast,pubic hair and testicle development.Exploratory factor analysis with a Varimax rotation was used to identify dietary patterns.Logistic regression analysis was applied to explore the relationship among childhood obesity,dietary patterns and precocious puberty.2.A hospital-based case-control study was conducted in Shanghai Children’s medical center.The subjects were divided into four groups: precocious group,obesity group,precocious and obesity combined group and normal control group.To screen for obesity and precocious puberty related SNP sites,we searched the relevant databases and related and reported literature.Blood samples were taken from the subjects and the genotypes of the selected SNP loci were determined.Logistic regression analysis was used to explore the association between gene polymorphism and the risk of childhood obesity and precocious puberty.【Results】 1.25.98% and 38.58% precocious boys were accompanied with obesity and central obesity separately,meanwhile,13.76% and 29.59% precocious girls with obesity and central obesity.The median age of boys’ pubic hair and testicle development showed an advance trend with BMI increased.The median age of pubic hair development in central obesity boys was higher than that in non-central obesity boys,but the median age of testicular development was lower in non-central obesity boys.The median age of girls’ breasts and pubic hair development decreased with BMI increased.The median age of the breasts and pubic hairs development was lower in girls with central obesity than non-central obesity.2.Among the 8-year-old boys,the unhealthy diet pattern was the risk factor for precocious puberty(OR = 1.24,95% CI = 1.02-1.51),but showed no statistical significance after adjusting for age and BMI.Among 7-year-old girls,unhealthy diet pattern was the risk factors for precocious puberty(OR = 1.24,95% CI = 1.04-1.49)after age and BMI adjustment,but showed no statistically significances after further adjusting for socioeconomic factors(P > 0.05).Neither traditional diet pattern nor protein diet pattern showed association with precocious puberty(P > 0.05).3.There was no significant difference in genotype and allele frequency distribution of BDNF gene rs6265 among precocious group,obesity group,precocious and obesity combined group and normal control group(P > 0.05).Also,there were no significant differences in homozygous model,heterozygous dominant model,dominant model,recessive model and allele model among the four groups(P > 0.05).After the further adjustment of age,all models still showed no statistically significance(P > 0.05).【Conclusions】 1.Earlier pubertal development was positively associated with obesity and central obesity in Chinese children.2.The unhealthy diet pattern was the risk factor for precocious puberty.The traditional diet and protein diet pattern didn’t show associated with precocious puberty.3.BDNF gene rs6265 locus gene polymorphism was not associated with childhood obesity and precocious puberty in Shanghai girls.【Objectives】 We aimed to investigate the relationship between precocious puberty and obesity as well as central obesity.【Methods】 A multistage,stratified cluster random sampling was conducted in a large population-based cross-sectional study.Physical examination and assessment of secondary sexual characteristics development was conducted by trained physicians.Obesity was defined according to the WHO Child Growth Standards.Central obesity was defined by sex-specific waist-to-height ratio(WHt R)cut-offs.Precocious puberty was identified by Tanner stage of breast,pubic hair and testicle.Probit analysis was used for estimating the median age at entry into Tanner stage 2 or greater for breast,pubic hair and testicle development.Odds ratios(ORs)with 95% confident interval(CI)were calculated to assess the association between precocious puberty and obesity as well as central obesity.【Results】 A total of 15,937 children aged range from 6 to 12 years constituted the final sample.25.98% and 38.58% precocious boys were accompanied with obesity and central obesity separately,meanwhile,13.76% and 29.59% precocious girls with obesity and central obesity.Both obesity(Boys:OR = 2.15,95%CI = 1.31-3.50;Girls:OR=8.63,95%CI = 3.61-13.28)and central obesity(Boys:OR = 2.10,95%CI = 1.46-3.03;Girls:OR = 5.44,95%CI = 4.11-7.21)are the risk factors for precocious puberty.The median age of boys’ pubic hair development was lowest in the severe thinness group which was13.56 years old,and highest in thinness group which was 14.5 years old.Then the median ages were gradually decreased to 13.66 years in the obesity group with BMI increased.The median age of testicle development showed an advance trend with BMI increased.The median age of pubic hair development in central obesity boys was higher than that in non-central obesity boys,but the median age of testicular development was lower in non-central obesity boys.The median age of girls’ breasts and pubic hair development decreased with BMI increased.The median age of the breasts and pubic hairs development was lower in girls with central obesity than noncentral obesity.【Conclusions】 Earlier pubertal development was positively associated with obesity and central obesity in Chinese children.【Objectives】 To investigate the association between dietary patterns and precocious puberty among Shanghai children.【Methods】 A cross-sectional study was conducted among Shanghai children by multistage stratified cluster random sampling.Dietary was assessed by a simplified food frequency questionnaire(FFQ).Tanner stages of breast,pubic hair and testicular volume were strictly measured by professional physicians.Exploratory factor analysis with a Varimax rotation was used to identify dietary patterns and logistic regression analysis was applied to explore the association between dietary patterns and precocious puberty.【Results】 A total of 6254 children including 4221 boys aged 6 to 9 years and 2033 girls aged 6 to 8 years capable to determine whether precocious or not constituted the sample of this study.The three dietary patterns were identified by exploratory factor analysis and termed as ‘traditional diet’,‘unhealthy diet’ and ‘protein diet’ pattern separately.Among the 8-year-old boys,‘unhealthy diet’ pattern was the risk factor for precocious puberty(OR = 1.24,95% CI = 1.02-1.51),but showed no statistical significance after adjusting for age and BMI(P > 0.05).Among 7-year-old girls,‘unhealthy diet’ pattern was the risk factors for precocious puberty(OR = 1.24,95% CI = 1.04-1.49)after age and BMI adjustment,but showed no statistically significances after further adjusting for socioeconomic factors.Neither traditional diet pattern nor protein diet pattern showed association with precocious puberty(P > 0.05).【Conclusions】 Three dietary patterns,‘traditional diet’,‘unhealthy diet’ and ‘protein diet’ pattern,were extracted from Shanghai children.The ‘unhealthy diet’ pattern was the risk factor for precocious puberty.The ‘traditional diet’and ‘protein diet’ pattern didn’t show associated with precocious puberty.【Objectives】 To investigate the relationship between gene polymorphism and the risk of precocious puberty and obesity in Shanghai children.【Methods】 A hospital-based case-control study was conducted in Shanghai Children’s medical center.The subjects were divided into four groups: precocious group,obesity group,precocious and obesity combined group and normal control group.To screen for obesity and precocious puberty related SNP sites,we searched the relevant databases and related and reported literature.Blood samples were taken from the subjects and the genotypes of the selected SNP loci were determined.SNa Pshot typing was used to obtain the genotypes of SNP loci.Logistic regression analysis was used to explore the association between gene polymorphism and the risk of childhood obesity and precocious puberty.【Results】 23 SNPs of nine genes associated with obesity and sexual development were retrieved by searching the database and the rs6265 locus on the exon region of BDNF gene was screened.A total of 395 girls were included in this study,including 94 cases of children combined with precocious puberty and obesity,193 cases of precocious puberty,39 cases of obese girls and 69 healthy control.There was no significant difference in genotype and allele frequency distribution of BDNF gene rs6265 among the four groups(P > 0.05).Also,there were no significant differences in homozygous model,heterozygous dominant model,dominant model,recessive model and allele model among the four groups(P > 0.05).After the further adjustment of age,5 models still showed no statistically significance(P > 0.05).【Conclusions】 BDNF gene rs6265 locus gene polymorphism was not associated with precocious puberty,childhood obesity,precocious puberty combined with childhood obesity in Shanghai girls.