ABSTRACT
Objective@#The purpose of this study was to describe the status quo and related factors on low vision (LV) among students of Beijing.@*Methods@#All the students in Beijing were included as the subjects of interest, based on the reference of the Chinese National Survey on Students’ Constitution and Health.@*Results@#The overall rate of LV among students in Beijing was 58.6% in 2017, with 61.6% in females, higher than 55.9% in males. LV also appeared higher in urban than in rural areas. The rates of LV appeared as 46.8%, 78.0%, 89.0%, 71.0%, in students from primary, middle, high or vocational high schools, respectively. Rates on light, moderate or severe LV were 8.4%, 17.8% and 32.5%, respectively.@*Conclusions@#The overall rate of LV among students in Beijing was considered high. Students in preschool, in 4-6 grades and the 2nd grade of middle schools, were at the key stages of developing vision-related problems. Factors as heavy load on homework, lack of outdoor activities and 'limit of vision space’ as well as incorrect reading behavior during puberty, need to be of concern.
ABSTRACT
Objective On whole-genome scale,we tried to explore the correlation between obesity-related traits and DNA methylation sites,based on discordant monozygotic twin pairs.Methods A total of 90 pairs of 6-17 year-old twins were recruited in Chaoyang district,Yanqing district and Fangshan district in Beijing in 2016.Information on twins was gathered through a self-designed questionnaire and results from physical examination,including height,weight and waist circumference of the subjects under study.DNA methylation detection was chosen on the Illumina Human Methylation EPIC BeadChip.R 3.3.1 language was used to read the DNA methylation signal under quality control on samples and probes.Ebayes function of empirical Bayes paired moderated t-test was used to identify the differential methylated CpG sites (DMCs).VarFit function of emp irical Bayes paired moderated Levene test was used to identify the differentially variables CpG sits (DVCs) in obese and normal groups.Results According to the obesity discordance criteria,we collected 23 pairs of twins (age range 7 to 16 years),including 12 male pairs.A total of 817 471 qualified CpG loci were included in the genome-wide correlation analysis.According to the significance level of FDR set as ＜0.05,no positive sites would meet this standard.When DMC CpG site cg05684382,with the smallest P value (1.26E-06) as on chromosome 12,the DVC CpG site cg26188191 with the smallest P value (6.44E-06) appeared in CMIP gene on chromosome 16.Conclusions In this study,we analyzed the genome-wide DNA methylation and its correlation with obesity traits.After multiple testing corrections,no positive sites were found to have associated with obesity.However,results from the correlation analysis demonstrated sites cg05684382 (chr:12) and cg26188191 (chr:16) might have played a role in the development of obesity.This study provides a methodologic reference for the studies on discordance twins related problems.
ABSTRACT
Objective On whole-genome scale,we tried to explore the correlation between obesity-related traits and DNA methylation sites,based on discordant monozygotic twin pairs.Methods A total of 90 pairs of 6-17 year-old twins were recruited in Chaoyang district,Yanqing district and Fangshan district in Beijing in 2016.Information on twins was gathered through a self-designed questionnaire and results from physical examination,including height,weight and waist circumference of the subjects under study.DNA methylation detection was chosen on the Illumina Human Methylation EPIC BeadChip.R 3.3.1 language was used to read the DNA methylation signal under quality control on samples and probes.Ebayes function of empirical Bayes paired moderated t-test was used to identify the differential methylated CpG sites (DMCs).VarFit function of emp irical Bayes paired moderated Levene test was used to identify the differentially variables CpG sits (DVCs) in obese and normal groups.Results According to the obesity discordance criteria,we collected 23 pairs of twins (age range 7 to 16 years),including 12 male pairs.A total of 817 471 qualified CpG loci were included in the genome-wide correlation analysis.According to the significance level of FDR set as ＜0.05,no positive sites would meet this standard.When DMC CpG site cg05684382,with the smallest P value (1.26E-06) as on chromosome 12,the DVC CpG site cg26188191 with the smallest P value (6.44E-06) appeared in CMIP gene on chromosome 16.Conclusions In this study,we analyzed the genome-wide DNA methylation and its correlation with obesity traits.After multiple testing corrections,no positive sites were found to have associated with obesity.However,results from the correlation analysis demonstrated sites cg05684382 (chr:12) and cg26188191 (chr:16) might have played a role in the development of obesity.This study provides a methodologic reference for the studies on discordance twins related problems.