ABSTRACT
Endocrine-disrupting chemicals ( EDCs ) are widely found in people's daily supplies or environments. The individuals in the world contact with these substances through different pathways. Adolescent-developed individuals are more sensitive to these substances. The integration of many environmental factors through epigenetic modification affects the starting age of puberty. Although there are various related studies, it is impossible for humans to contact only a single substance, and there is still much doubt about the additive effect of EDCs mixtures with similar mechanisms of action. Therefore, analytical scientists, molecular biologists, toxicologists, epidemiologists, endocrinologists, gynecologists, obstetricians, and oncologists are required to conduct multidisciplinary research to address and to discuss all the scientific results. It may have far-reaching implications for formulating the prevention strategies and individualized health plans.
ABSTRACT
Objective To describe the situation of insufficient sleep and the association between insufficient sleep and physical exercise,among Chinese Han students aged 9-18 years.Methods We selected 172 197 Chinese Han students aged 9-18 years from the project 2014 Chinese National Survey on Students Constitution and Health.The average sleep duration per day of less than 9 h for children aged 9-12 years and of less than 8 h for adolescents aged 13-18 years,were defined as insufficient sleep.We described the distribution of sleep duration and the prevalence rates of insufficient sleep for each subgroup.Logistic regression models were established to assess the association between insufficient sleep and physical exercise.Results In 2014,6.6％,30.8％,26.3％,20.8％,13.8％ and 1.8％ of the Chinese Han students self-reported sleep duration were ＜6,6-,7-,8-and ≥ 10 h,respectively.The overall prevalence rate of insufficient sleep was 77.2％,with 75.8％ for boys and 78.6％ for girls.No gender disparity was found at each 9-11 age groups.However,in the 12-18 age groups,the prevalence rates for girls were significantly higher than that for boys.The prevalence rates of insufficient sleep for primary school,middle school and high school students were 66.6％,74.1％ and 93.8％,respectively.Rates were increasing with age for children aged 9-12 years and adolescents aged 13-18 years respectively.The three provinces with the lowest prevalence rates of insufficient sleep were Zhejiang (68.8％),Jiangsu (66.7％) and Shaanxi (65.2％).Data from the logistic regression models revealed that,when comparing to those students with only exercise of ＜0.5 h per day,the exercise hours of 0.5-1 h (OR=0.72,95％ CI:0.69-0.74) or ≥1 h (OR=0.46,95％ CI:0.44-0.47) per day seemed as protective factors for insufficient sleep.When compared with physicalexercise frequency ＜2 times per week,the 2 times (OR=0.82,95％CI:0.78-0.86) or ＞2 times (OR=0.65,95％CI:0.62-0.68) frequencies also appeared as protective.Conclusions The prevalence rate of insufficient sleep prevailing among students aged 9-18 years was high,in China.Our data called for setting up effective measures to deal with this situation.
ABSTRACT
Objective To describe the situation of insufficient sleep and the association between insufficient sleep and physical exercise,among Chinese Han students aged 9-18 years.Methods We selected 172 197 Chinese Han students aged 9-18 years from the project 2014 Chinese National Survey on Students Constitution and Health.The average sleep duration per day of less than 9 h for children aged 9-12 years and of less than 8 h for adolescents aged 13-18 years,were defined as insufficient sleep.We described the distribution of sleep duration and the prevalence rates of insufficient sleep for each subgroup.Logistic regression models were established to assess the association between insufficient sleep and physical exercise.Results In 2014,6.6％,30.8％,26.3％,20.8％,13.8％ and 1.8％ of the Chinese Han students self-reported sleep duration were ＜6,6-,7-,8-and ≥ 10 h,respectively.The overall prevalence rate of insufficient sleep was 77.2％,with 75.8％ for boys and 78.6％ for girls.No gender disparity was found at each 9-11 age groups.However,in the 12-18 age groups,the prevalence rates for girls were significantly higher than that for boys.The prevalence rates of insufficient sleep for primary school,middle school and high school students were 66.6％,74.1％ and 93.8％,respectively.Rates were increasing with age for children aged 9-12 years and adolescents aged 13-18 years respectively.The three provinces with the lowest prevalence rates of insufficient sleep were Zhejiang (68.8％),Jiangsu (66.7％) and Shaanxi (65.2％).Data from the logistic regression models revealed that,when comparing to those students with only exercise of ＜0.5 h per day,the exercise hours of 0.5-1 h (OR=0.72,95％ CI:0.69-0.74) or ≥1 h (OR=0.46,95％ CI:0.44-0.47) per day seemed as protective factors for insufficient sleep.When compared with physicalexercise frequency ＜2 times per week,the 2 times (OR=0.82,95％CI:0.78-0.86) or ＞2 times (OR=0.65,95％CI:0.62-0.68) frequencies also appeared as protective.Conclusions The prevalence rate of insufficient sleep prevailing among students aged 9-18 years was high,in China.Our data called for setting up effective measures to deal with this situation.
ABSTRACT
Objective To analyze the trend of secular growth among the minority girls in China from 1985 to 2005 in order to develop national and local intervention strategies and measures to improve their physical fitness and health.Methods A total of 19 Chinese minoritt girls,including Mongolian,Hui,Zhuang,Korean,Tibetan,Miao,Buyi,Dong,Yao,Bai,Tujia,Hani,Dai,Lisu,Wa,Nakhi,Tu,Qiang and Salar were sampled from the 1985 and 2005 Chinese national surveys to study the students' physical fitness and health.Probit analyses were used to calculate age at menarche (AAM),and the heights and weights of 17-years-old girls in various minority groups.Results From 1985 to 2005,the increments of adult heights and weights increased significantly in many minority groups.The average height of girls aged 17 years old in each minority group had an increase of 150 cm in 2005.Ethnic groups with height growth rates of more than 1 cm per decade in girls aged 17 years old were Korean ( 1.47 cm/decade),Tujia( 1.38 crn/decade),Qiang ( 1.32 cm/decade),Bai ( 1.25 cm/decade),Hui ( 1.13 cm/decade) and Buyi ( 1.07 cm/decade).And the mionority ethnics with weight growth rates of more than 1 kg per decade in girls aged 17 years old were Mongolian ( 1.79 kg/decade),Korean ( 1.69 kg/decade),Tibetan ( 1.66 kg/decade),Nakhi ( 1.39 kg/decade),Qiang ( 1.28 kg/decade) and Hui ( 1.10 kg/decade).The overall AAM showed a downward rate in all the 19 minority groups,but with different degrees.Tujia,Yao and Nakhi showed the largest reductions,with AAMs as 2.15,1.76 and 1.38 years earlier in 2005 than in 1985,respectively.Conclusion Our data suggested that the downward secular trend in AAMs and the increments of adult heights might reflect the secular growth change in the major minority groups during the past 20 years,but there was an obvious disequilibrium of puberty development and increments of heights in adults between the minority groups.
ABSTRACT
Objective To explore the effect of serum leptin on puberty development in schoolboys.Methods 170 health schoolboys were investigated on the first spermatorrhea time and detected the levels of serum leptin, testosterone,follicle stimulating hormone (FSH), luteinizing hormone (LH). Case-controlled study was carried by multivariable logistic regression in puberty development of schoolchildren with and without spermatorrhea. Meanwhile, follow-up studies on the independent influencing factors on the puberty development were applied to this investigation in continuous two years.Results The levels of serum leptin, testosterone,FSH and LH of schoolboys with spermatorrhea were significantly higher than those of schoolboys without spermatorrhea. Multiple logistic regression analysis demonstrated that the serum leptin,testosterone, FSH, and bodyweight were the independent influence factors in puberty of the schoolboy.The levels of serum leptin,testosterone of pre-spermatorrhea schoolboys were significantly higher than schoolboys without spermatorrhea.Conclusions Serum leptin,testosterone, FSH, and bodyweight were the independent influence factors in puberty of the schoolboy.The levels of serum leptin and testosterone had obviously changed before spermatorrhea.