Timing of spermarche and menarche among urban students in Guangzhou, China: trends from 2005 to 2012 and association with Obesity

Sleep deprivation alters pubertal timing in humans and rats: the role of the gut microbiome

STUDY OBJECTIVES

Evidence implied that sleeping duration is associated with the timing of puberty and that sleep deprivation triggers early pubertal onset in adolescents. Sleep deprivation can affect metabolic changes and gut microbiota composition. This study investigated the effects of sleep deprivation on pubertal onset and gut microbiota composition in animal models and a human cohort.

METHODS

This study comprised 459 boys and 959 girls from the Taiwan Pubertal Longitudinal Study. Sleep duration was evaluated using the self-report Pittsburgh Sleep Quality Index questionnaire. Early sexual maturation was defined by pediatric endocrinologist assessments. Mediation analyses were done to examine the association between sleep parameters, obesity, and early sexual maturation. Besides, Sprague Dawley juvenile rats were exposed to 4 weeks of chronic sleep deprivation. Vaginal opening (VO) and preputial separation (PS) were observed every morning to determine pubertal onset in female and male rats.

RESULTS

The sleep-deprived juvenile rats in the sleep-deprived-female (SDF) and sleep-deprived-male (SDM) groups experienced delayed VO (mean VO days: 33 days in control; 35 days in SDF; p-value < 0.05) and PS (mean PS days: 42 days in control; 45 days in SDM; p-value < 0.05), respectively. Relative to their non-sleep-deprived counterparts, the sleep-deprived juvenile rats exhibited lower body weight and body fat percentage. Significant differences in relative bacterial abundance at genus levels and decreased fecal short-chain-fatty-acid levels were identified in both the SDF and SDM groups. In the human cohort, insufficient sleep increased the risk of early sexual maturation, particularly in girls (OR, 1.44; 95% CI: 1.09 to 1.89; p-value < 0.01). Insufficient sleep also indirectly affected early sexual maturation in girls, with obesity serving as the mediator.

CONCLUSIONS

Overall, sleep deprivation altered the timing of puberty in both animal and human models but in different directions. In the rat model, sleep deprivation delayed the pubertal onset in juvenile rats through gut dysbiosis and metabolic changes, leading to a low body weight and body fat percentage. In the human model, sleep deprivation led to fat accumulation, causing obesity in girls, which increased the risk of early puberty.

Secular trends and urban-rural disparities in the median age at menarche among Chinese han girls from 1985 to 2019

BACKGROUND

Menarche is a substantial milestone of female puberty. Timing of age at menarche is considered the key to understanding the potential linkages with women's health outcomes later in life. This study aimed to explore the secular trends and urban‒rural disparities in the median age at menarche among Chinese Han girls from 1985 to 2019.

METHODS

Data were extracted from the 1985, 1995, 2005, 2014, and 2019 Chinese National Surveys on Students' Constitution and Health, which were nationally representative cross-sectional studies, and a total of 173,535 Han girls aged 9-18 years were examined. Girls were asked whether menarche had occurred. The median age at menarche was estimated by probit analysis. Z tests were used to compare the differences between survey years and between urban and rural areas.

RESULTS

The median age at menarche among Chinese Han girls decreased from 13.37 years in 1985 to 12.00 years in 2019, and the overall decrease was more significant in rural areas (1.77 years) than in urban areas (0.99 years). The average five-year change in the decrease in the median age at menarche showed an accelerating and then slowing pace; and it was observed similarly in both urban and rural areas. The urban‒rural disparities shrank from 0.64 years in 1985 to 0.44 years in 1995, then to 0.27 years in 2005, 0.24 years in 2014, and finally to - 0.14 years in 2019.

CONCLUSIONS

The median age at menarche among Chinese Han girls continued to decline from 1985 to 2019 but at a slowing pace in the last five years. Urban‒rural disparities gradually narrowed. Sexual and reproductive health education and interventions to prevent the decline in the age of menarche are needed, especially in rural areas.

Changes in Kidney Function Among Malaysian Adolescents and Its Determinants

Introduction

The health and wellbeing of adolescents are often neglected, including the knowledge of chronic kidney disease (CKD), especially in its early stages.

Methods

A total of 607 adolescents were recruited from the Malaysian Health and Adolescents Longitudinal Research Team (MyHeART) study, a prospective cohort study conducted from March 2012 to May 2016 that explored the noncommunicable diseases (NCDs) risk factors among 13 to 17 years old students in 3 states of Peninsular Malaysia. Students who participated in all 3 data collection periods in 2012, 2014, and 2016 with kidney function assessment across all 3-time points were included in the current study. The students' estimated glomerular filtration rate (eGFR) was calculated from isotope-dilution mass spectrometry-traceable Schwartz's equation and categorized based on Kidney Disease: Improving Global Outcomes (KDIGO) classification. Changes in kidney function were examined, and the longitudinal relationship between eGFR and multiple NCD risk factors was analyzed using the generalized estimating equation (GEE).

Results

The prevalence of decreased eGFR (60-89 ml/min per 1.73 m2) among the students increased from 6.1% (2012) to 30.0% (2014) and 40.2% (2016). Based on the GEE, the student's eGFR decreased over time, with a steeper decline during early to midadolescence. Males and rural students had lower eGFR compared to their counterparts. Students who are morbidly obese had lower eGFR than those with normal body mass index (BMI). Protein consumption also has a potential moderating effect on eGFR in adolescents.

Conclusion

Kidney function changes can be detected as early as adolescence and are likely attributable to multiple NCD risk factors. Therefore, more comprehensive prevention efforts from various stakeholders are needed to identify health issues like CKD.

Association between precocious puberty and obesity risk in children: a systematic review and meta-analysis

Objectives

The aim of this study was to evaluate the potential association between early onset puberty and the risk of different forms of obesity in children.

Methods

The databases PubMed, EMBASE, Web of Science and Cochrane Library were systematically searched for relevant studies. The odds ratio (OR) and 95% confidence interval (CI) of obesity in precocious puberty were calculated using Stata software 14.0. A fixed-effects model was used if P > 0.1 and I2 ≤ 50%. Otherwise, a random-effects model was used. Publication bias was assessed using funnel plots and Egger's test.

Result

The pooling analysis showed that precocious puberty in girls was associated with a higher risk of obesity (OR = 1.98; 95% CI: 1.76-2.24; I2 = 0.00%, P < 0.001). Girls with a history of precocious puberty were found to have an increased risk of general obesity (OR = 2.03; 95% CI: 1.62-2.55; I2 = 22.2%, P < 0.001), central obesity (OR = 1.96; 95% CI: 1.70-2.26; I2 = 0.00%, P < 0.001), and overweight (OR = 2.03; 95% CI: 1.68-2.46; I2 = 5.1%, P < 0.001). The pooled analysis showed that precocious puberty in boys was not associated with an increased risk of obesity (OR = 1.14; 95% CI: 0.86-1.51; I2 = 50.6%, P = 0.369). In boys, the occurrence of precocious puberty was not associated with an elevated risk of general obesity (OR = 0.96; 95% CI: 0.40-2.27; I2 = 79.6%, P = 0.922), central obesity (OR = 1.17; 95% CI: 0.96-1.43; I2 = 0.00%, P = 0.125), or overweight (OR = 1.03; 95% CI: 0.56-1.88; I2 = 74.4%, P = 0.930).

Conclusion

This meta-analysis suggests that the onset of puberty at an early age in girls is associated with an increased risk of obesity, however precocious puberty in boy was not associated with an increased risk of obesity. These findings highlight that precocious puberty should be considered an independent risk factor for obesity in girls.

Systematic Review Registration

CRD42023404479.

Secular trend and urban-rural disparity for age at spermarche among Chinese Han boys from 1995 to 2019

AIM

To examine the secular trend and the urban-rural disparity of spermarche among Chinese Han boys from 1995 to 2019.

METHODS

A total of 392 775 boys of Han ethnicity aged 11-18 years were extracted from the 1995, 2000, 2005, 2010, 2014 and 2019 Chinese National Surveys on Students' Constitution and Health. The median age at spermarche was estimated using the status quo data and probit analysis. The chi-square, ANOVA and LSD tests were used to compare the differences between the year-subgroups. U-test was used to compare the difference between urban and rural areas at each year.

RESULTS

The median age at spermarche in Chinese Han boys decreased from 14.6 years in 1995 to 13.9 years in 2019 (p < 0.001). The rural boys showed a faster decreasing pace with a 1-year advance of age at spermarche while the urban boys had only a 0.5-year decrement, and there was still a statistically significant difference between urban-rural areas in 2019 (p < 0.001). Similar to urban-rural disparity, the age gap at spermarche between areas with different urbanisation rates became smaller over time.

CONCLUSIONS

In general, spermarche in Chinese Han boys showed a decreasing trend, but the pace was slowing down. The urban-rural disparity in puberty development still existed but was gradually narrowing.

Associations between body mass index and pubertal development based on the outcomes of girls with early breast development

Objective

To investigate the associations between physical and pubertal development based on the breast development outcomes in girls.

Methods

This was a retrospective study. A total of 452 girls aged 6~8 years were included. Based on their breast development outcomes, the patients were divided into an idiopathic central precocious puberty (ICPP) group and a premature thelarche (PT) group. Anthropometry included measurements of height, weight, and BMI. ICPP was diagnosed when five diagnostic criteria from the current guidelines were met.

Results

The girls with breast development at initial evaluation had a median age of 6.9 years. In total, 31.4% of patients were diagnosed with ICPP, and ICPP was rare in girls <7 years old (19%). Patients who presented with recurrence of breast development in the PT group accounted for 38.4%. At initial evaluation, the height, weight, BMI and bone age (BA) of the girls in the PT group corresponded to those of a normally developing girl at ages 7.8 years, 8.2 years, 8.6 years and 7.6 years, respectively. The girls in the ICPP group had a mean age of 7.3 years, and their mean height, weight, and BMI were 129.6 cm, 28.4 kg, and 17.0 kg/m2, which corresponded to the mean of a normally developing girl at ages 8.5 years, 9.1 years, and 10.5 years, respectively; these patients had BA of 9.2 years. Additionally, based on receiver operating characteristic (ROC) curve analysis, when the basal luteinizing hormone (LH) level was 0.32 IU/L and BMI reached 16.4 kg/m2, CPP was diagnosed in patients meeting all five diagnostic criteria for CPP, and the specificity and sensitivity were 71.9% and 88.2%, respectively.

Conclusions

Girls with breast development before 8 years old had a high proportion of recurrence of breast development. The physical development of these girls at the time of breast development preceded that of normally developing girls by 1-2 years. BMI is an independent risk factor for early pubertal development, and is a simple and clear predictor of ICPP. In addition to the five classic diagnostic criteria, CPP is diagnosed when physical development corresponds to the mean for a 10.5 years old girl.

Association of body composition with pubertal timing in children and adolescents from Guangzhou, China

Objective

An ongoing debate surrounds the relationship between body composition and pubertal timing, in particular for boys. This cross-sectional study aimed to investigate the association of body composition with pubertal timing among children and adolescents.

Methods

A total of 1,493 boys and 1,261 girls who entered puberty were enrolled in Guangzhou, China. Tanner stages were evaluated by examination of breast development for girls and testicular volume for boys. Fat mass (FM) and fat-free mass (FFM) were determined by bioelectrical impedance analysis. Parameters for body composition were transformed into age-and gender-specific Z-scores. The association of body composition with pubertal timing was examined using multinomial logistic regression with inverse probability weighting (IPW) based on the propensity score.

Results

For boys, IPW analysis showed Z-scores of body fat percentage (BF%) and FM index (FMI) were negatively associated with early puberty (OR = 0.75, 95% CI = 0.64-0.87; OR = 0.74, 95% CI = 0.63-0.88). As for girls, in contrast to boys, positive associations were seen between BF% and FMI with early puberty (OR = 1.39, 95% CI = 1.19-1.64; OR = 1.59, 95% CI = 1.33-1.90). With respect to appendicular skeletal muscle mass index (ASMI), there was a positive association with early puberty and a negative one with late puberty in boys (OR = 1.26, 95% CI = 1.07-1.49; OR = 0.82, 95% CI = 0.69-0.99).

Conclusion

There is a positive association of FM with early puberty for girls while negative for boys. FFM yields a positive association with early puberty and a negative one with late puberty in boys, but not in girls. Our findings highlight the gender differences in the connection between body composition and pubertal onset.

The Influence of Modifiable Factors on Breast and Prostate Cancer Risk and Disease Progression

Breast and prostate cancers are among the most commonly diagnosed cancers worldwide, and together represented almost 20% of all new cancer diagnoses in 2020. For both cancers, the primary treatment options are surgical resection and sex hormone deprivation therapy, highlighting the initial dependence of these malignancies on the activity of both endogenous and exogenous hormones. Cancer cell phenotype and patient prognosis is not only determined by the collection of specific gene mutations, but through the interaction and influence of a wide range of different local and systemic components. While genetic risk factors that contribute to the development of these cancers are well understood, increasing epidemiological evidence link modifiable lifestyle factors such as physical exercise, diet and weight management, to drivers of disease progression such as inflammation, transcriptional activity, and altered biochemical signaling pathways. As a result of this significant impact, it is estimated that up to 50% of cancer cases in developed countries could be prevented with changes to lifestyle and environmental factors. While epidemiological studies of modifiable risk factors and research of the biological mechanisms exist mostly independently, this review will discuss how advances in our understanding of the metabolic, protein and transcriptional pathways altered by modifiable lifestyle factors impact cancer cell physiology to influence breast and prostate cancer risk and prognosis.

Association of Obesity and Body Fat Percentage with Pubertal State in Six- to Nine-Year-Old Chinese Females

Background: An early trend in the mean age of pubertal onset appears in adolescents, but the association between body fat percentage (BF%) of children and precocious puberty is unclear. The aim of the study was to analyze the association of sexual development with BF% in girls. Methods: A total of 407 females were included in this cross-sectional study. BF% was measured by Inbody S10, International Obesity Task Force was used to judge overweight or obesity, and early puberty was defined as a younger age than the median age in each of the pubertal Tanner stages. Logistic regression analysis was used to test relationships between pubertal states and independent variables, including age, weight, waist circumference (WC), type of school, and residency. Results: Females with early puberty exhibited higher anthropometry data (such as weight, BMI, BF%) than females with normal maturation (p < 0.001). Weight, BMI, WC, BF% residency, and school type were related to pubertal state (p < 0.001). Females with higher BF% were more likely to exhibit early puberty (odds ratio = 1.138, 95% confidence interval = 1.046-1.237). The students who lived in urban areas and studied in public schools had a lower risk of early puberty. Moreover, BF% continuously increased with age in 6- to 9-year-old girls. Conclusions: Females with higher BF% may be more likely to exhibit early puberty. In future studies, more research is needed to analyze this mechanism of how BF% influences puberty development.

The mean age of menarche among Chinese schoolgirls declined by 6 months from 2005 to 2014

AIM

This study assessed the trends in the age at menarche in Chinese schoolgirls from the majority Han group and 21 ethnic minorities from 2005 to 2014. We also compared the group differences during the study period.

METHODS

A total of 344 230 girls aged 9-18 years were extracted from the 2005, 2010 and 2014 Chinese National Survey on Students' Constitution and Health. The age at menarche for each subgroup was estimated by probit analysis. The chi-square test and Z-test were used to compare the differences between the groups.

RESULTS

The overall average age at menarche in Chinese schoolgirls decreased from 12.8 years in 2005 to 12.3 years in 2014. The Han girls and girls from 17 ethnic minorities showed decreasing trends in the age at menarche, while four ethnic minorities demonstrated fluctuating increasing trends over time. The gaps in age at menarche between the Han group and 14 of the ethnic minorities became smaller over the study period and were similar by 2014.

CONCLUSION

The overall findings were a decrease in the age at menarche in China and smaller gaps between the majority Han group and ethnic minority groups. Ethnic-specific public health policies are urgently needed on issues such as contraception.

Serum uric acid and blood pressure among adolescents: data from the Nutrition and Health Survey in Taiwan (NAHSIT) 2010-2011

PURPOSE

Elevated serum uric acid (UA) is frequently observed in adults with high blood pressure (BP); however, data from adolescents are limited. We examined the association between serum UA and BP in a nationally representative sample of Taiwan adolescents.

MATERIAL AND METHODS

Some 1384 participants, aged 14-19 years, from the Nutrition and Health Survey in Taiwan 2010-2011 were included for the study. Elevated BP was defined as systolic or diastolic BP ≥120/80 mmHg. The analyses examined the relationship between serum UA and BP using linear regression and odds ratios of having an elevated BP using logistic regression.

RESULTS

In this study population, the mean age was 16.0 years, mean serum UA was 5.8 mg/dL, 22.5% were obese (body mass index ≥24 kg/m²) and 9.8% had an elevated BP. Compared to girls, boys are more likely to be obese and to have higher serum UA and BP. After full adjustments, systolic BP, diastolic BP and mean arterial pressure increased 0.45, 0.48 and 0.47 mmHg, respectively, for each 1-mg/dL increase in UA (p = 0.07, 0.03 and 0.02, respectively). The odds of having an elevated BP were 3.4 times higher in subjects of the upper tertile of serum UA than those of the lower tertile (p = 0.02).

CONCLUSION

Adolescents with factors as male, obesity, and UA ≥5.5 mg/dL were prone to have an elevated BP, regardless of age and family history of hypertension. The present study found that serum UA levels are significantly correlated to BP in Taiwanese adolescents.

Body mass index growth trajectories, early pubertal maturation, and short stature

BACKGROUND

Childhood body mass index (BMI) trajectory classes are rarely linked to early puberty risk, particularly among Chinese children. We estimated early puberty risk across BMI trajectory classes, investigated factors contributing to pubertal development, and examined differences in final adult height between children exhibiting early and nonearly pubertal maturation across the classes.

METHODS

The Taiwan Children Health Study recruited 10-year-old children in 2010 from 14 Taiwanese communities and resurveyed them at age 11, 12, and 18 years. The study comprised 3109 children (50.4% boys) with available data for BMI (age 6-11 years) and pubertal stages (age 11, 12, and 18 years).

RESULTS

Classes 1-4 were persistently healthy weight, rapid BMI growth, chronically overweight/obese, and early transient overweight/obese. Children in class 3 exhibited the highest risk of early pubertal maturation. Puberty genetic score, low sleep quality, and high fat-free mass collectively explained 15% of the variance in Tanner stages among class 3 children. Early pubertal maturation was considered to cause short and tall stature in boys and girls, respectively.

CONCLUSIONS

Modifying sleep quality and fat-free mass may reduce early puberty risk in children with chronic overweight/obesity. Vigorous physical activity may reduce adiposity and increase the final adult height in the children.

Association of Early Menarche with Adolescent Health in the Setting of Rapidly Decreasing Age at Menarche

STUDY OBJECTIVE

This study aimed to investigate the association between age at menarche (AAM) and adverse health indicators in adolescent girls.

DESIGN

A retrospective cohort study.

SETTING

Population-based survey data.

PARTICIPANTS

A total of 319,437 female participants aged 12-18 years from the Korea Youth Risk Behaviour Web-based Survey.

INTERVENTIONS AND MAIN OUTCOME MEASURES

We assessed associations between AAM (categorized as ≤10, 11, and ≥12) and health indicators (poor self-rated health, high psychological stress, unhappiness, sexual initiation, and pregnancy). Covariates were individual-level (bodyweight, living with family, parent's education, household wealth, and presence of parents and siblings) and community-level factors (year of birth, single-sex education and level of school, urbanization level of school area, year of survey, and regional deprivation). Odds ratios (ORs) for each adverse health indicator were examined by each AAM group using multivariable regression analyses. For pregnancy, we calculated relative risks (RRs) using a log-binomial regression model.

RESULTS

Age at menarche was <12 in 42% of our study population. Nearly one-half of the girls born in the early 2000s went through menarche before the age of 12 years, whereas only one-third of girls born in the early 1990s went through menarche before the age of 12 years. Girls who experienced menarche at age ≤10 or age 11 years were more likely to show self-rated poor health (AAM ≤ 10: OR, 1.28; 95% confidence intervals [CI], 1.22-1.34; AAM = 11: OR, 1.16; 95% CI, 1.12-1.21), high stress (OR, 1.19; 95% CI, 1.14-1.23, and OR, 1.10; 95% CI, 1.06-1.14), and sexual initiation (OR, 2.21; 95% CI, 2.05-2.38, and OR, 1.32; 95% CI, 1.23-1.41) compared to those with AAM ≥12 years when data were adjusted for all covariates. AAM ≤10 years was associated with consistently higher odds for poor health than AAM ≥12 years. The ORs of sexual initiation increased with earlier AAM. Risk of pregnancy was similar across AAM groups when individual- and community-level covariates were controlled for.

CONCLUSION

Early menarche, defined as <12 years, can be still a useful indicator in adolescent health interventions to identify high-risk groups in the setting of declining AAM.

Adipokines: A gear shift in puberty

In this review, we discuss the role of adipokines in the onset of puberty in children with obesity during adrenarche and gonadarche and provide a clear and detailed overview of the biological processes of two major players, leptin and adiponectin. Adipokines, especially leptin and adiponectin, seem to induce an early onset of puberty in girls and boys with obesity by affecting the hypothalamic-pituitary-gonadal (HPG) axis. Moreover, adipokines and their receptors are expressed in the gonads, suggesting a role in sexual maturation and reproduction. All in all, adipokines may be a clue in understanding mechanisms underlying the onset of puberty in childhood obesity and puberty onset variability.