Association between early-life factors and pubertal timing in girls / 中国当代儿科杂志

OBJECTIVES@#To study the association between early-life factors (including birth weight, method of birth, gestational age, and history of gestational metabolic disorders) and pubertal timing in girls.@*METHODS@#The stratified cluster sampling method was used to select the girls in grades 2-3 and 7-8 from three primary schools and three middle schools in Guangzhou, China from March to December, 2019, and breast development was examined for all girls. A questionnaire survey was performed to collect the information on early-life factors. The multivariate logistic regression model was used to evaluate the association of gestational metabolic disorders, birth weight, method of birth, and gestational age with pubertal timing in girls. The Bootstrap method was used to assess the mediation effect of body mass index (BMI) (Z score) between high birth weight (≥4 000 g) and pubertal timing.@*RESULTS@#A total of 1 665 girls were enrolled, among whom 280 (16.82%) were judged to have early pubertal timing. The multivariate logistic regression analysis showed that high birth weight was associated with the increased risk of early pubertal timing (OR=2.12, 95%CI: 1.19-3.66, P=0.008). Nevertheless, no significant association was observed between other early-life factors and pubertal timing (P>0.05). The OR for the mediation effect of BMI (Z score) between high birth weight and early pubertal timing was 1.25 (95%CI: 1.09-1.47), accounting for 29.33% of the total effect of high birth weight on early pubertal timing.@*CONCLUSIONS@#High birth weight is associated with the increased risk of early pubertal timing in girls, and overweight/obesity may play a partial mediating role in the association between high birth weight and early pubertal timing in girls.

The association between sleep duration, bedtimes, and early pubertal timing among Chinese adolescents: a cross-sectional study

BACKGROUND AND OBJECTIVE@#Early pubertal timing is associated with sleep among Western adolescents, but little is known about this association in Chinese adolescents, especially with regard to the association between bedtimes and early pubertal timing. This paper aimed to identify the association between sleep duration, bedtimes, and early pubertal timing in Chinese adolescents.@*METHODS@#An anonymous cross-sectional survey was conducted among primary and junior middle students (grades 3 to 9) from QiJiang District, ChongQing, China. Participants were recruited by applying stratified cluster sampling. Pubertal timing, sleep duration, and bedtimes were assessed using the Pubertal Development Scale and a self-designed sleep questionnaire. We utilized multivariable logistic linear regression (MLLR) to test the association between sleep duration, bedtimes, and pubertal timing.@*RESULTS@#A total of 5461 adolescents were evaluated, with mean age and BMI values of 11.41 ± 2.05 and 18.03 ± 3.03, respectively, of whom 1257 (23.02%) were in early pubertal timing. In MLLR controlling for age, BMI, family economic status, and other covariates, sufficient sleep (b = - 0.214, P = 0.032, OR = 0.808, 95% CI 0.664-0.982) was negatively related to early pubertal timing, and later bedtime (b = 0.195, P < 0.001, OR = 1.215, 95% CI 1.104-1.338) was positively associated with early pubertal timing.@*CONCLUSION@#Students with early pubertal timing had less sleep duration and later bedtimes, which may be the result of increased stress caused by physical and psychological changes. Therefore, more attention should be paid to pubertal health education for adolescents during puberty. Further longitudinal studies are needed to confirm the causality between sleep and early pubertal timing in Chinese adolescents.

Influencing factors of early puberty / 国际儿科学杂志

Nearly half a century,an increasing number of studies have found that the puberty of human being is at early trends.Puberty is the process of physical changes involving reproductive system maturation and the acquisition of fertility,by the combination effects of nervous system,endocrine system and the environment.Pubertal timing is a relative concept and the process of pubertal development can be shown as early,timely or relatively late as compared with a reference group.This article mainly focuses on related influencing factors of pubertal timing including genetic factor,childhood obesity,growth pattern (intrauterine growth retardation,catchup growth,adiposity rebound),psychosocial stress (poor family emotional environment,father absence,international adoption),environmental endocrine disrupting chemicals with their mechanism and significance.The exploration of relevant risk factors of early puberty can provide scientific evidence for formulating relevant policies and targeted prevention.

Ambiente de desenvolvimento e início da vida reprodutiva em mulheres Brasileiras / Environment of development and the start of Brazilian women's reproductive life

Modelos teóricos inspirados na teoria da história de vida têm avaliado padrões de reprodução humanos em países desenvolvidos, com resultados ainda não conclusivos. Em vista das condições de vida na população brasileira, foram investigadas relações entre marcos da carreira reprodutiva feminina, condições ambientais e variáveis psicossociais relacionadas às condições de criação. Foram entrevistadas 606 mulheres em seis estados. Os resultados apóiam a teoria da história de vida, mostrando associações entre condições de vida na infância e início da vida sexual e da reprodução, mas não com a idade da menarca. Sugerimos que diferentes marcadores da vida reprodutiva podem estar sob controle de diferentes fenômenos e que a diversidade de condições da população brasileira oferece contextos alternativos para testar hipóteses.

Several models inspired by the life history theory have assessed the patterns of human reproduction in developed countries with promising but inconclusive results. Considering the diversity of life conditions in Brazil, we investigated the relationship between the time of main events in female reproductive life, environmental conditions and psychosocial variables related to child-rearing. We interviewed 606 women in six different states in Brazil. Results corroborate the life history theory, showing associations among the investigated factors, especially between life conditions during childhood and the beginning of sexual life and reproduction, but not to sexual maturity. We suggest that landmarks in reproductive life, although related, can be under the influence of several phenomena. Diversity of life conditions in Brazil offers alternative contexts to hypotheses testing.

A study of factors influencing advanced puberty / 소아과

PURPOSE: The purpose of this study was to evaluate the timing of puberty and the factors inducing advanced puberty in elemental school students of low grades. METHODS: The 1st, 2nd, and 3rd grade elemental students from the Goyang province were randomly selected, and their sexual maturation rate was assessed by physical examination. After obtaining an informed consent, a questionnaire was administered to the parents; eating habits, lifestyle, use of growth-inducing medication, and present illness of the students were evaluated to determine the factors that induced advanced puberty. The data were statistically analyzed. RESULTS: We selected 170 children and the girls:boys sex ratio was 1.2:1. Two 9-year-old boys were in genital stage 2. Two (14.3%) 6-year-old girls, 6 (19.4%) 7-year-old girls, 15 (39.6%) 8-year-old girls, and 4 (57.1%) 9-year-old girls were in breast stage 2. The average pubertal timing predicted for girls was 9.11+/-1.86 years. The main factors influencing pubertal timing were obesity scale, frequency of eating fast food, and the use of growth-inducing medication. A high rating on the obesity scale and high frequency of eating fast food indicated advanced stage of puberty. Growth-inducing medication induced puberty through obesity. CONCLUSION: We proposed that predictive average pubertal timing in girls was 9.11+/-1.86 years, which was consistent with the previously reported findings from abroad. The significant influencing factors in advanced puberty were obesity scale and frequency of fast food.

The timing of sexual maturation and secular trends of menarchial age in Korean adolescents / 소아과

PURPOSE: The purpose of this study was to evaluate the timing of sexual maturation and secular trends of menarchial age in Korean adolescents. METHODS: Nine hundred eighty two school students and 119 university female students were included. Tanner's pubertal assessment method was applied using a self-assessment sheet with pictures for their developmental stages. A medical checkup database from 1,156,022 women was also used to analyze the age of menarche from the year 1900 to 1980. RESULTS: Onset of puberty was at 11.3+/-1.3 years(y) in girls and 12.1+/-1.5 y in boys and total pubertal duration was 3.6 y in girls and 3.3 y in boys. Height at the onset of puberty was 146.1+/-7.9 cm in girls and 152.7+/-9.8 cm in boys. Weight at the onset of puberty was 39.3+/-6.9 kg in girls and 47.7+/-14.4 kg in boys. The mean age of menarche was 12.0+/-1.0 y and mean age at nocturnal emission was 12.3+/-1.8 y. By age ten, 3.0 percent of girls experienced menarche, which increased to 41.1 percent by age 12, and 98.0 percent by age over 15. By SMR 2 breast stage, 18.2 percent of girls experienced menarche, which increased to 66.1 percent and 91.7 percent by SMR stages 3 and 4, respectively. By SMR 2 pubic hair stage, 52.0 percent and by SMR 3, 93.8 percent of girls experienced menarche. While the menarchial age of women born around 1980 was 12.4+/-1.1 y, the menarchial age of women born around 1990 was 12.0+/-1.1 y. Age at menarche has been advanced approximately by 2 years between 1900 and 1980 birth cohorts. CONCLUSION: There was a downward secular trend in pubertal timing. Age at menarche has been advanced by 2 years during the last 80 years. Further large scale, prospective studies, including inspection by specialists, are needed to provide reference data for pubertal timing in Korean adolescents.