Puberty in girls of the 21st century

Changes in the Bile Acid Pool and Timing of Female Puberty: Potential Novel Role of Hypothalamic TGR5

CONTEXT

The regulation of pubertal timing and reproductive axis maturation is influenced by a myriad of physiologic and environmental inputs yet remains incompletely understood.

OBJECTIVE

To contrast differences in bile acid isoform profiles across defined stages of reproductive maturity in humans and a rat model of puberty and to characterize the role of bile acid signaling via hypothalamic expression of bile acid receptor populations in the rodent model.

METHODS

Secondary analysis and pilot studies of clinical cohorts, rodent models, ex vivo analyses of rodent hypothalamic tissues. Bile acid concentrations is the main outcome measure.

RESULTS

Lower circulatory conjugated:deconjugated bile acid concentrations and higher total secondary bile acids were observed in postmenarcheal vs pre-/early pubertal adolescents, with similar shifts observed in infantile (postnatal day [PN]14) vs early juvenile (PN21) rats alongside increased tgr5 receptor mRNA expression within the mediobasal hypothalamus of female rats. 16S rRNA gene sequencing of the rodent gut microbiome across postnatal life revealed changes in the gut microbial composition predicted to have bile salt hydrolase activity, which was observed in parallel with the increased deconjugated and increased concentrations of secondary bile acids. We show that TGR5-stimulated GnRH release from hypothalamic explants is mediated through kisspeptin receptors and that early overexpression of human-TGR5 within the arcuate nucleus accelerates pubertal onset in female rats.

CONCLUSION

Bile acid isoform shifts along stages of reproductive maturation are conserved across rodents and humans, with preclinical models providing mechanistic insight for the neuroendocrine-hepatic-gut microbiome axis as a potential moderator of pubertal timing in females.

Building a Future for School-Based Menstruation Health and Hygiene (MHH): Evaluating Implementation of a Menstrual Hygiene Management (MHM) Policy in Chicago Public Schools

Menstrual health and hygiene (MHH) inequities disproportionately impact communities who are marginalized. In 2018, Illinois passed the Learn with Dignity Act (LWDA) requiring schools to provide menstrual products in bathrooms, yet little is known about its impacts. This evaluation examined LWDA implementation across Chicago Public Schools (CPS) and identified barriers, facilitators, and lessons to inform future MHH policy implementations. A qualitative study was conducted by thematically analyzing interviews with CPS staff (n = 36) from October 2020 - September 2021 in partnership with CPS Office of Student Health and Wellness (OSHW). Staff reported inadequate LWDA and MHH education and inconsistent menstrual product availability. Structural, systemic, and cultural implementation barriers hindered student access to products and created inequities based on age, gender, and income. Staff investment and student education were implementation facilitators. Staff awareness of policy implementation protocol, student MHH education, and addressing access inequities are key factors for consideration in future policy implementations. Through the WSCC model, these findings demonstrated the importance of strengthening MHH policies and policy implementation to promote student health, well-being, and educational opportunities.

Pubertal Timing Across Asian American, Native Hawaiian, and Pacific Islander Subgroups

Importance

Earlier puberty is associated with adverse health outcomes, such as mental health issues in adolescence and cardiometabolic diseases in adulthood. Despite rapid growth of the Asian American, Native Hawaiian, and Pacific Islander populations in the US, limited research exists on their pubertal timing, potentially masking health disparities.

Objective

To examine pubertal timing among Asian American, Native Hawaiian, and Pacific Islander children and adolescents by disaggregating ethnic subgroups.

Design, Setting, and Participants

This retrospective cohort study included Asian American, Native Hawaiian, and Pacific Islander youths aged 5 to 18 years assessed for pubertal development at Kaiser Permanente Northern California, a large, integrated health care delivery system. Follow-up occurred from March 2005, through December 31, 2019. Data were analyzed in October 2023.

Exposure

Race and ethnicity, categorized into 11 ethnic subgroups: Asian Indian, Chinese, Filipino, Japanese, Korean, Native Hawaiian and Pacific Islander, Other South Asian, Other Southeast Asian, Vietnamese, multiethnic, and multiracial.

Main Outcomes and Measures

Pubertal timing was determined using physician-assessed sexual maturity ratings (SMRs). Outcomes included the median age at transition from SMR 1 (prepubertal) to SMR 2 or higher (pubertal) for onset of genital development (gonadarche) in boys, breast development (thelarche) in girls, and pubic hair development (pubarche) in both boys and girls.

Results

In this cohort of 107 325 Asian American, Native Hawaiian, and Pacific Islander children and adolescents (54.61% boys; 12.96% Asian Indian, 22.24% Chinese, 26.46% Filipino, 1.80% Japanese, 1.66% Korean, 1.96% Native Hawaiian and Pacific Islander, 0.86% Other South Asian, 3.26% Other Southeast Asian, 5.99% Vietnamese, 0.74% multiethnic, and 22.05% multiracial), the overall median ages for girls' pubarche and thelarche were 10.98 years (95% CI, 10.96-11.01 years) and 10.13 years (95% CI, 10.11-10.15 years), respectively. For boys' pubarche and gonadarche, median ages were 12.08 years (95% CI, 12.06-12.10 years) and 11.54 years (95% CI, 11.52-11.56 years), respectively. Differences between subgroups with earliest and latest median age at onset were 14 months for girls' pubarche, 8 months for thelarche, 8 months for boys' pubarche, and 4 months for gonadarche. In general, Asian Indian, Native Hawaiian and Pacific Islander, and Other South Asian subgroups had the earliest ages at onset across pubertal markers, while East Asian youths exhibited the latest onset. Restricting to those with healthy body mass index did not substantially change the findings.

Conclusions and Relevance

In this cohort study of Asian American, Native Hawaiian, and Pacific Islander children and adolescents, pubertal timing varied considerably across ethnic subgroups. Further investigation is warranted to assess whether these differences contribute to observed health disparities in adulthood, such as type 2 diabetes and cardiovascular diseases.

Association of blood metal exposure with age at menarche in Korean women: KNHANES (2008-2017)

Humans are exposed to metals in their daily lives and this metal exposure is responsible for various adverse health effects. Delayed pubertal development has been suggested as an adverse outcome of metal exposure; however, evidence in nationally representative populations, especially in Asia, is limited. We evaluated the association of blood cadmium (Cd), lead (Pb), and mercury (Hg) levels with the age at menarche in Korean females whose blood heavy metals were measured as part of the Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2017. Among the females 16 years of age or older, all measured heavy metals in blood, i.e., Cd, Pb, and Hg, were positively associated with age at menarche. These associations remained significant in a model adjusted for age, survey year, income, education, body mass index, smoking history, and menopausal status as covariates (β: 0.10, 95% confidence interval (CI): 0.03-0.18 for Cd; β: 0.17, 95%CI: 0.06-0.27 for Pb; β: 0.12, 95%CI: 0.05-0.19 for Hg). When the population was separated by age group at the time of the survey, the significance between heavy metal levels and age at menarche became inconsistent, but the general trends were similar. Among those in their 20s and 40s, blood Cd showed a significant association, while Pb was significant among those in their 40s and 50s. A similar trend was observed in the sensitivity analysis in the girls aged 10-15 years at the time of the survey. Blood Cd levels were associated with decreased odds of precocious menarche (OR: 0.57, 95%CI: 0.31-1.03). Delayed menarche is a risk factor for cardiovascular and chronic kidney diseases in later life; hence, public health implication of heavy metal exposure warrants a public health attention.

Childhood physical activity and pubertal timing: findings from the LEGACY girls study

BACKGROUND

There is limited research on whether physical activity (PA) in early childhood is associated with the timing of pubertal events in girls.

METHODS

We used data collected over 2011-16 from the LEGACY Girls Study (n = 984; primarily aged 6-13 years at study enrolment), a multicentre North American cohort enriched for girls with a breast cancer family history (BCFH), to evaluate if PA is associated with age at thelarche, pubarche and menarche. Maternal-reported questionnaire data measured puberty outcomes, PA in early childhood (ages 3-5 years) and total metabolic equivalents of organized PA in middle childhood (ages 7-9 years). We used interval-censored Weibull parametric survival regression models with age as the time scale and adjusted for sociodemographic factors, and we tested for effect modification by BCFH. We used inverse odds weighting to test for mediation by body mass index-for-age z-score (BMIZ) measured at study enrolment.

RESULTS

Being highly active vs inactive in early childhood was associated with later thelarche in girls with a BCFH [adjusted hazard ratio (aHR) = 0.39, 95% CI = 0.26-0.59), but not in girls without a BCFH. In all girls, irrespective of BCFH, being in the highest vs lowest quartile of organized PA in middle childhood was associated with later menarche (aHR = 0.70, 95% CI = 0.50-0.97). These associations remained after accounting for potential mediation by BMIZ.

CONCLUSION

This study provides new data that PA in early childhood may be associated with later thelarche in girls with a BCFH, also further supporting an overall association between PA in middle childhood and later menarche.

Epidemiologic investigation of pediatric distal humerus fractures: An American insurance claims database study

BACKGROUND

Distal humerus elbow fractures are one of the most common traumatic fractures seen in pediatric patients and present as three main types: Supracondylar (SC), lateral condyle (LC), and medial epicondyle (ME) fractures.

AIM

To evaluate the epidemiology of pediatric distal humerus fractures (SC, LC, and ME) from an American insurance claims database.

METHODS

A retrospective review was performed on patients 17 years and younger with the ICD 9 and 10 codes for SC, LC and ME fractures based on the IBM Truven MarketScan® Commercial and IBM Truven MarketScan Medicare Supplemental databases. Patients from 2015 to 2020 were queried for treatments, patient age, sex, length of hospitalization, and comorbidities.

RESULTS

A total of 1133 SC, 154 LC, and 124 ME fractures were identified. SC fractures had the highest percentage of operation at 83%, followed by LC (78%) and ME fractures (41%). Male patients were, on average, older than female patients for both SC and ME fractures.

CONCLUSION

In the insurance claims databases used, SC fractures were the most reported, followed by LC fractures, and finally ME fractures. Age was identified to be a factor for how a pediatric distal humerus fractures, with patients with SC and LC fractures being younger than those with ME fractures. The peak age per injury per sex was similar to reported historic central tendencies, despite reported trends for younger physiologic development.

Mean age at menarche and climate variables on a global scale

OBJECTIVES

Cross-population variation in age at menarche is related to many factors. The purpose of this study was to examine climate variables in relation to mean age at menarche among 87 modern human populations. We hypothesized a later age at menarche among populations living in areas with high precipitation variability, heavy seasonal rainfall, and high temperatures year-round due to water-borne diseases and periods of resource scarcity.

METHODS

Using a comparative dataset, we examined geospatial distribution and climate variables in relation to age at menarche for 87 modern human populations.

RESULTS

We found the strongest predictor of a later age at menarche was higher fertility followed by a later mean age at death. In addition, higher annual rainfall, higher precipitation seasonality, and lower annual mean temperature were moderate predictors of age at menarche.

CONCLUSIONS

We propose that later ages at menarche in countries with high fertility may be a life-history strategy developed in response to climatic conditions that have resulted in higher immunological load. In these conditions, females may prioritize growth rather than reproduction. Shifts in climate and global population growth may change the future biological landscape of age at menarche.

Testosterone and Prolactin Perturbations Possibly Associated with Reduced Levels of β-Arrestin1 in Mononuclear Leukocytes of Women with Premenstrual Dysphoric Disorder

Previously, we reported that a reduction in β-Arrestin1 protein levels in peripheral blood mononuclear leukocytes (PBMC) significantly correlated with the severity of depression symptoms in women with premenstrual dysphoric disorder (PMDD). This study aimed to determine whether the reduced premenstrual β-Arrestin1 protein levels were associated with changes in the regulator for late luteal phase progesterone secretion. The study participants (n = 25) were non-pregnant women between 18 and 42 years of age not taking any antidepressants or receiving therapy and experiencing the luteal phase of menstruation. ELISA determined the β-Arrestin1 protein in PBMC; testosterone and prolactin levels from the plasma were determined by radioimmunoassay. Reduced levels of β-Arrestin1 protein in women with Hamilton Rating Scale for Depression (HAM-D) scores above 19 were observed alongside significantly higher plasma testosterone and prolactin concentrations. Understanding the mechanism underlying the initiation of PMDD will allow for identification of a key perturbed metabolic enzyme that can serve as a target for drug development to ensure the alleviation of PMDD, which has been suggested earlier as a risk factor for developing major depressive disorders.

Interpersonal Violence Victimization Experiences of Middle School Youth: An Exploration by Gender and Sexual/Romantic Attraction

Sexual minority youth (SMY) are at increased risk for interpersonal violence victimization compared to heterosexual youth. The current study examined how self-reported victimization (i.e., bullying, sexual harassment and dating violence) among middle school youth varied as a function of sexual/romantic attraction as well as gender identity. Cross-sectional data were gathered from students at seven middle schools in New England (n = 2245). Mean comparisons with post-hoc Tukey tests determined differences in rates of past 6-month and lifetime interpersonal violence victimization by sexual/romantic attraction and the intersection of gender and attraction. As hypothesized, interpersonal violence victimization among middle school youth differed as a function of sexual/romantic attraction as well as gender. To date, most research has focused on older samples, particularly high-school youth and young adults. These data are consistent with these prior studies documenting increased risk for interpersonal violence victimization among youth who indicate same-gender attraction but add to the literature in demonstrating the expansive forms of peer victimization that same-gender-attracted youth already experience by early adolescence. Given that victimization is associated acutely and longitudinally with many deleterious outcomes, including poorer mental health and increased risk for subsequent victimization, greater structural supports are needed for early adolescent SMY.

Immigrant generation status and its association with pubertal timing and tempo among Hispanic girls and boys

PURPOSE

In the United States, Hispanic-Latino children reach puberty earlier on average than non-Hispanic white children. Yet among U.S. Hispanic/Latino children, pubertal timing comparisons between immigrant generations have not been made, hence we examined whether pubertal timing differs by immigrant generational status, independent of BMI and acculturation measures.

METHODS

Cross-sectional data on 724 boys and 735 girls, aged 10-15 years, from the Hispanic Community Children's Health Study/Study of Latino (SOL) Youth, were used to predict the median ages of thelarche, pubarche, and menarche in girls, and pubarche and voice change in boys, using Weibull survival models, while adjusting for SOL center, BMI, and acculturation.

RESULTS

In girls, the first generation began thelarche earlier than second and third generations (median age [years] [95% confidence interval]: 7.4 [6.1, 8.8] vs. 8.5 [7.3, 9.7] and 9.1 [7.6, 10.7], respectively), but began menarche later (12.9 [12.0,137] vs. 11.8 [11.0, 12.5] and 11.6 [10.6, 12.6], respectively). Pubertal timing and tempo for boys did not differ by generational status.

CONCLUSIONS

First-generation U.S. Hispanic/Latino girls had the earliest thelarche, latest menarche and longest pubertal tempo, compared to second and third generations. Factors beyond BMI and acculturation may account for the differences in pubertal timing by generational status of U.S. Hispanic/Latino girls.

Estimated Prevalence of Depressive Disorders in Children From 2004 to 2019: A Systematic Review and Meta-Analysis

Importance

Depression during childhood (ie, age <13 years) poses a major health burden. Recent changes in environmental and lifestyle factors may increase children's risk of mental health problems. This has been reported for anxiety disorders, but it is unclear whether this occurs for depressive disorders.

Objective

To provide prevalence estimates for the depressive disorders (ie, major depressive disorder [MDD], dysthymia, disruptive mood dysregulation disorder [DMDD], and overall) in children, and whether they have changed over time.

Data Sources

The MEDLINE, PsycINFO, Embase, Scopus, and Web of Science databases were searched using terms related to depressive disorders, children, and prevalence. This was supplemented by a systematic gray literature search.

Study Selection

Studies were required to provide population prevalence estimates of depressive disorder diagnoses (according to an established taxonomy and standardized interviews) for children younger than 13 years, information about participants' year of birth, and be published in English.

Data Extraction and Synthesis

Data extraction was compliant with the Meta-Analysis of Observational Studies in Epidemiology guidelines. A total of 12 985 nonduplicate records were retrieved, and 154 full texts were reviewed. Data were analyzed from 2004 (the upper limit of a previous review) to May 27, 2023. Multiple proportional random-effects meta-analytic and mixed-effects meta-regression models were fit.

Main Outcomes and Measures

Pooled prevalence rates of depressive disorders, prevalence rate differences between males vs females and high-income countries (HICs) vs low-and middle-income countries (LMICs), and moderating effects of time or birth cohort.

Results

A total of 41 studies were found to meet the inclusion criteria. Pooled prevalence estimates were obtained for 1.07% (95% CI, 0.62%-1.63%) for depressive disorders overall, 0.71% (95% CI, 0.48%-0.99%) for MDD, 0.30% (95% CI, 0.08%-0.62%) for dysthymia, and 1.60% (95% CI, 0.28%-3.90%) for DMDD. The meta-regressions found no significant evidence of an association with birth cohort, and prevalence rates did not differ significantly between males and females or between HICs and LMICs. There was a low risk of bias overall, except for DMDD, which was hindered by a lack of studies.

Conclusions and Relevance

In this systematic review and meta-analysis, depression in children was uncommon and did not increase substantially between 2004 and 2019. Future epidemiologic studies using standardized interviews will be necessary to determine whether this trend will continue into and beyond the COVID-19 pandemic.

Establishing the relationships between adiposity and reproductive factors: a multivariable Mendelian randomization analysis

BACKGROUND

Few studies have investigated associations between adiposity and reproductive factors using causal methods, both of which have a number of consequences on women's health. Here we assess whether adiposity at different points in the lifecourse affects reproductive factors differently and independently, and the plausibility of the impact of reproductive factors on adiposity.

METHODS

We used genetic data from UK Biobank (273,238 women) and other consortia (EGG, GIANT, ReproGen and SSGAC) for eight reproductive factors: age at menarche, age at menopause, age at first birth, age at last birth, number of births, being parous, age first had sexual intercourse and lifetime number of sexual partners, and two adiposity traits: childhood and adulthood body size. We applied multivariable Mendelian randomization to account for genetic correlation and to estimate the causal effects of childhood and adulthood adiposity, independently of each other, on reproductive factors. Additionally, we estimated the effects of reproductive factors, independently of other relevant reproductive factors, on adulthood adiposity.

RESULTS

We found a higher childhood body size leads to an earlier age at menarche, and an earlier age at menarche leads to a higher adulthood body size. Furthermore, we find contrasting and independent effects of childhood and adulthood body size on age at first birth (beta 0.22 SD (95% confidence interval: 0.14, 0.31) vs - 2.49 (- 2.93, - 2.06) per 1 SD increase), age at last birth (0.13 (0.06,0.21) vs - 1.86 (- 2.23, - 1.48) per 1 SD increase), age at menopause (0.17 (0.09, 0.25) vs - 0.99 (- 1.39, - 0.59) per 1 SD increase), and likelihood of having children (Odds ratio 0.97 (0.95, 1.00) vs 1.20 (1.06, 1.37) per 1 SD increase).

CONCLUSIONS

Our findings demonstrate the importance of considering a lifecourse approach when investigating the inter-relationships between adiposity measures and reproductive events, as well as the use of 'age specific' genetic instruments when evaluating lifecourse hypotheses in a Mendelian randomization framework.

Sexually dimorphic impact of preconceptional and gestational exposure to a real-life environmental chemical mixture (biosolids) on offspring growth dynamics and puberty in sheep

Humans are ubiquitously exposed to complex mixtures of environmental chemicals (ECs). This study characterised changes in post-natal and peripubertal growth, and the activation of the reproductive axis, in male and female offspring of sheep exposed to a translationally relevant EC mixture (in biosolids), during pregnancy. Birthweight in both sexes was unaffected by gestational biosolids exposure. In contrast to females (unaffected), bodyweight in biosolids males was significantly lower than controls across the peripubertal period, however, they exhibited catch-up growth eventually surpassing controls. Despite weighing less, testosterone concentrations were elevated earlier, indicative of early puberty in the biosolids males. This contrasted with females in which the mean date of puberty (first progesterone cycle) was delayed. These results demonstrate that developmental EC-mixture exposure has sexually dimorphic effects on growth, puberty and the relationship between body size and puberty. Such programmed metabolic/reproductive effects could have significant impacts on human health and wellbeing.

Association of adipocytokines and adipocytokine ratios with cardiovascular risk factors in Japanese preadolescents

OBJECTIVES

Asians are particularly susceptible to obesity-associated disorders and rapid progression of obesity from childhood to adulthood. Data on the association between adipocytokine parameters, particularly adipocytokine ratios, and cardiovascular risk factors in childhood remain limited. Herein, we assessed the association of resistin, adiponectin, and leptin levels and leptin/adiponectin and resistin/adiponectin ratios with selected cardiovascular risk factors and the influence of unhealthy weight on such associations in children aged 9-10 years.

METHODS

We included 380 children aged 9-10 years from three public elementary schools in Japan.

RESULTS

The body mass index (BMI) was significantly higher in male preadolescents than in female adolescents (median 16.5 kg/m² vs. 16.2 kg/m², p=0.032). No differences in height, weight, waist circumference (WC), waist/height ratio (W/Hr), total cholesterol and high-density lipoprotein cholesterol levels, or atherosclerosis index (AI) were observed between the sexes. Of the adipocytokine levels and ratios analyzed, only the leptin level and leptin/adiponectin ratio (L/Ar) were strongly and significantly positively correlated with the cardiovascular risk factors WC, W/Hr, and BMI (all p<0.05). The AI was not strongly correlated with any adipocytokine levels or ratios. Apart from the strong positive correlation between the L/Ar and W/Hr, no other significant associations were observed between any of the adipocytokine levels or ratios and the selected cardiovascular risk factors.

CONCLUSIONS

Our findings confirmed the value of adipocytokine ratios in risk assessment in pediatric populations, with leptin levels and leptin/adiponectin ratios strongly correlating with risk factors in children aged 9-10 years.

When it doesn't run in the blood(vessels) - events involved in vascular disorders

In the current issue of the Biomedical Journal the underlying pathology of hemodynamic compromise in acute small subcortical infarction are elucidated. A follow-up study in patients with childhood Kawasaki disease is presented, as well as an insight into the gradually decreasing antigen expression in cases of acute myeloid leukemia. Furthermore this issue provides an exciting update concerning COVID-19 and the use of CRISPR-Cas, a review about computational approaches in the research of kidney stone formation, factors connected to central precocious puberty, and why a rock star of paleogenetics recently received a Nobel Prize. Additionally, this issue contains an article proposing the repurposing of the lung cancer drug Capmatinib, a study of how the gut microbiome develops in neonates, an impulse about the role of the transmembrane protein TMED3 in esophageal carcinoma, and the revelation about how competing endogenous RNA influences ischemic stroke. Lastly, genetic reasons for male infertility are discussed, as well as the relation between non-alcoholic fatty liver disease and chronic kidney disease.

Fossil fuel is the common denominator between climate change and petrochemical exposures, and effects on women and children's health

Fossil fuels contribute to climate change and petrochemicals, both of which increase maternal and child disease. Reducing fossil fuels can reap a double benefit for climate change and improved health.

Pathologic acne in pre-pubertal children: A case series and review on when to refer to pediatric endocrinology

Acne vulgaris is an extremely common chronic disease of the pilosebaceous unit. Despite its ubiquity, acne in the childhood years of approximately ages 1-6 years is exceedingly rare. Physicians should be suspicious of underlying systemic disease processes in patients of this age who present with onset of acne lesions, as pre-pubertal acne in childhood has a distinctly different pathology than that of other age groups. Through a case series, we highlight the importance of a thorough work-up and provide a review on when to refer to pediatric endocrinology to rule out precocious puberty and tumors as the cause of pre-pubertal acne.

Awareness Regarding Sex Hormone Disruptors in Everyday Products Among Females of Reproductive Age in Al-Jouf, the Kingdom of Saudi Arabia

Background and objective Endocrine-disrupting chemicals (EDCs) are natural or synthetic molecules that can alter and affect the operations of the hormonal system of an organism. These compounds include plastic consumer products and food containers such as phytoestrogen, which is also naturally present in food. EDCs can be found in the cord blood and maternal blood of pregnant women, as well as colostrum. Hence, they may affect not only the mother but also the offspring. In this study, we aimed to evaluate the awareness among females of reproductive age regarding the nature, source, as well as physiological and psychological burden associated with sex hormones disruptors. Methods A descriptive cross-sectional study was conducted among females between the age of 15-45 years in the Al-Jouf region, Saudi Arabia. A self-administrated questionnaire was used as the data collection tool; it consisted of multiple-choice questions to obtain information on the awareness among the females. In this study, females were classified into those with good knowledge and those with poor knowledge based on their level of knowledge by using a scoring system with a total score of 12. IBM SPSS Statistics version 24 (IBM Corp., Armonk, NY) was used to analyze the collected data. Results The study included 491 females; 6.6% of them had been using soya-containing products for a long time, and 32.5% reported using oatmeal for a long time. The majority (86.2%) did not use any other hormonal therapy. There were significant differences in the knowledge about sex hormone disruptors among the participants, and women with poorer knowledge about sex hormone disruptors were significantly less likely to report the long-time usage of soya-containing food when compared to women with greater knowledge (2.2% vs. 4.2%, p<0.001). The results showed that women with poorer knowledge were also significantly less likely to report the usage of hormonal therapies when compared to women with greater knowledge (6.7% vs. 7.2%, p<0.001), indicating that the usage of these chemicals is higher in women with greater knowledge although they are aware of their effects. Conclusion The study showed that females had good knowledge about the nature and usage of EDCs but poor knowledge about their impact. The knowledge of females was associated with their behavior regarding the usage of such products.

Discrete-time Survival Analysis of Risk Factors for Early Menarche in Korean Schoolgirls

OBJECTIVES

The aim of this study was to evaluate the effect of body weight status and sleep duration on the discrete-time hazard of menarche in Korean schoolgirls using multiple-point prospective panel data.

METHODS

The study included 914 girls in the 2010 Korean Children and Youth Panel Study who were in the elementary first-grader panel from 2010 until 2016. We used a Gompertz regression model to estimate the effects of weight status based on age-specific and sex-specific body mass index (BMI) percentile and sleep duration on an early schoolchild's conditional probability of menarche during a given time interval using general health condition and annual household income as covariates.

RESULTS

Gompertz regression of time to menarche data collected from the Korean Children and Youth Panel Study 2010 suggested that being overweight or sleeping less than the recommended duration was related to an increased hazard of menarche compared to being average weight and sleeping 9 hours to 11 hours, by 1.63 times and 1.38 times, respectively, while other covariates were fixed. In contrast, being underweight was associated with a 66% lower discrete-time hazard of menarche.

CONCLUSIONS

Weight status based on BMI percentiles and sleep duration in the early school years affect the hazard of menarche.

Gender differences in family meal frequency and their association with substance use and mental health among middle and high school students

Background

Family meals are associated with adolescent health outcomes. Studies have reported that girls are less likely than boys to have dinner with their families.

Purpose

This study examined gender differences in family meal frequency and the relationship between meal frequency and other health measures, using a large and representative sample of California middle and high school students.

Methods

This study analyzed data from the 2019-2020 California Student Tobacco Survey (159,904 students in grades 8, 10, and 12). Dinner with the family 5-7 times per week was defined as high frequency. Students reported substance use (of tobacco, marijuana, and alcohol) and rated their mental health and happiness in their home life. All analyses were weighted to reflect the California student population.

Results

Fewer than half (44.7%) of students reported a high frequency of family meals, with boys more likely than girls and those who identified their gender in another way the least likely to do so (48.3%, 42.2%, 34.0%, respectively). Gender differences persisted across demographics and the quality of family relationships, and were evident as early as eighth grade. Less frequent family meals were associated with poorer mental health (OR = 1.34, 95% CI: 1.29-1.40) and substance use (OR = 1.27, 95% CI: 1.21-1.32), controlling for the effects of demographics and family dynamics.

Conclusion

Gender differences in family meal frequency emerge early in adolescence and persist across demographics and family relationships. Given that family meals play a protective role in an adolescent's life, these gender differences are concerning.

Associations Between Childhood Obesity and Pubertal Timing Stratified by Sex and Race/Ethnicity

Earlier puberty has been associated with numerous adverse mental, emotional, and physical health outcomes. Obesity is a known risk factor for earlier puberty in girls, but research with boys has yielded inconsistent findings. We examined sex- and race/ethnicity-specific associations between childhood obesity and puberty in a multiethnic cohort of 129,824 adolescents born at a Kaiser Permanente Northern California medical facility between 2003 and 2011. We used Weibull regression models to explore associations between childhood obesity and breast development onset (thelarche) in girls, testicular enlargement onset (gonadarche) in boys, and pubic hair development onset (pubarche) in both sexes, adjusting for important confounders. Clear dose-response relationships were observed. Boys with severe obesity had the greatest risk for earlier gonadarche (hazard ratio = 1.23, 95% confidence limit: 1.15, 1.32) and pubarche (hazard ratio = 1.44, 95% confidence limit: 1.34, 1.55), while underweight boys had delayed puberty compared with peers with normal body mass index. A similar dose-response relationship was observed in girls. There were significant interactions between childhood body mass index and race/ethnicity. Childhood obesity is associated with earlier puberty in both boys and girls, and the magnitude of the associations may vary by race/ethnicity. Prevention of childhood obesity may delay pubertal timing and mitigate health risks associated with both conditions.

Urinary Biomarkers of Polycyclic Aromatic Hydrocarbons and Timing of Pubertal Development: The California PAH Study

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are endocrine-disrupting chemicals. Few studies have evaluated the association between pubertal development in girls and PAH exposures quantified by urinary biomarkers.

METHODS

We examined associations of urinary PAH metabolites with pubertal development in 358 girls 6-16 years of age from the San Francisco Bay Area enrolled in a prospective cohort from 2011 to 2013 and followed until 2020. Using baseline data, we assessed associations of urinary PAH metabolites with pubertal development stage. In prospective analyses limited to girls who at baseline had not yet started breast (N = 176) or pubic hair (N = 179) development or menstruation (N = 267), we used multivariable Cox proportional hazards regression to assess associations of urinary PAH metabolites with the onset of breast and pubic hair development, menstruation, and pubertal tempo (interval between the onset of breast development and menstruation).

RESULTS

We detected PAH metabolites in >98% of girls. In cross-sectional analyses using baseline data, PAH metabolites were not associated with the pubertal development stage. In prospective analyses, higher concentrations (≥ median) of some PAH metabolites were associated with two-fold higher odds of earlier breast development (2-hydroxy naphthalene, 1-hydroxy phenanthrene, summed hydroxy phenanthrenes) or pubic hair development (1-hydroxy naphthalene) among girls overweight at baseline (body mass index-for-age percentile ≥85) compared with nonoverweight girls with lower metabolites concentrations. PAH metabolites were not associated with age at menarche or pubertal tempo.

CONCLUSIONS

PAH exposures were widespread in our sample. Our results support the hypothesis that, in overweight girls, PAHs impact the timing of pubertal development, an important risk factor for breast cancer.

The Special Role of Middle Childhood in Self-Control Development: Longitudinal and Genetic Evidence

Despite the importance of self-control for well-being and adjustment, its development from early childhood to early adolescence has been relatively understudied. We addressed the development of mother-reported self-control in what is likely the largest and longest longitudinal twin study of the topic to this day (N = 1,889 individual children with data from at least one of 5 waves: ages 3, 5, 6.5, 8-9 and 11 years). We examined rank-order change in self-control from early childhood to early adolescence, genetic and environmental contributions to variance in the trait and differential developmental trajectories. The relative contribution of genetic and environmental factors to change and stability was also examined. Results point at middle childhood as a period of potential transition and change. During this period the rank-order stability of self-control increases, heritability rates substantially rise, and a cross-over occurs in two of the self-control trajectories. Non-additive genetic effects contribute to both stability and change in self-control while the non-shared environment contributes mostly to change, with no effect for the shared environment. Our findings suggest that new genetic factors, that emerge around age 6.5 and whose effect on self-control is carried on along development, may partially account for changes in self-control around late middle childhood, and explain the growing stability in the trait approaching early adolescence. We discuss the implications of the special role of middle childhood for self-control development. This article is protected by copyright. All rights reserved.

Biosocial correlates of adolescent’s knowledge on pubertal changes in rural Bangladesh: A structural equation model

Background

The present study aimed to identify factors that are associated with puberty knowledge among school-going rural adolescents in Bangladesh.

Methods

This cross-sectional study was conducted on 2724 school-going (grades VI-IX) adolescents who were aged between 10–24 years. The adolescents resided only in rural areas of Bangladesh. In this study, relationship between socio-demographic factors and controlling behaviour was assessed considering Bronfenbrenner’s bioecological model. Considering the complex nature of Bronfenbrenner’s bioecological model the structural equation model to explore factors related to the Adolescents’ knowledge of pubertal changes.

Results

The structural equation model result showed a significant association among gender, education, age, and parental limit setting on daily activities with student’s knowledge on pubertal changes. peer connection, and peer regulation were associated with adolescent knowledge on puberty directly as well as through the mediator variables year of schooling, academic performance and, parental behavioural control.

Conclusion

Adolescents Age, years of schooling, and teachers concerns are positively associated with adolescents’ knowledge on puberty. Whereas, parents’ and peers’ controlling behaviors are negatively associated with adolescents’ understanding of pubertal changes. Therefore, there is needed an effective plan to raise the attention of parents and teachers on adolescents’ pubertal issues to ensure adolescents’ informed pubertal period.

Does adjusting for biological maturity when calculating child weight status improve the accuracy of predicting future health risk?

BACKGROUND

The aim of this study was to assess whether adjusting the weight categorisation of children for their biological maturity status could improve the accuracy of predicting weight status and cardiometabolic risk at age 17.

METHODS

Data from 1525 participants (787 female) from the ALSPAC study were analysed. Participants' weight status at age 11 was estimated using first standard chronological age and sex adjusted BMI cut-offs, and again using maturity adjusted BMI cut-offs. Each BMI category at age 11 was regressed against cardiometabolic risk score and BMI category at age 17, controlling for sex, ethnicity and socio-economic status.

RESULTS

At age 11 years, 22% of boys and 46% of girls who were categorised as overweight or having obesity based on chronological age were re-categorised into a lower BMI category after adjusting for biological maturity. Biologically adjusted BMI categories better predicted BMI category at age 17 compared with non-adjusted BMI categories (∆BIC = - 21.69); the odds of having obesity at age 17 were 18.28 times greater with each increase in BMI category at age 11. Adjusted and non-adjusted BMI status at 11 years showed equivalent accuracy in predicting cardiometabolic risk at age 17; the odds ratio of high cardiometabolic risk was 1.85, with heightened risk in boys, particularly early maturers.

CONCLUSION

The traditional method of categorising adolescents into a BMI category may over-predict overweight and obesity, particularly in girls. Adjusting for biological maturity when estimating weight status through calculating adolescents' BMI classification was equivalent to standard approaches in predicting other cardiovascular risk at age 17.

A comparative study of the effect of two educational methods of motivational interviewing and peers on self-efficacy of female high school students in relation to puberty health

BACKGROUND

Adolescents experience many physical and psychological changes during adolescence. Not paying attention to the issue of girls' puberty may have a negative impact on their mental health and self-efficacy in future. The aim of this study was to compare the two methods of motivational interviews and peers on puberty health of female high school students.

MATERIALS AND METHODS

This study was performed semi-experimental intervention on 334 high school students in 2019 through multi-stage randomization. Data using two demographic questionnaires and Scherrer self-efficacy questionnaire in three stages (pre-test, immediately after the test and one month after the test). It was collected that in the motivational interview group, 5 training sessions were presented, and in the peer group, only one training session was taught to the peers and the control group was not trained in any intervention.

RESULTS

Immediately after, and 1 month after the intervention, the two intervention groups had significantly better scores in self-efficacy compared to the control group (P = 0.001). The mean score of self-efficacy in the control group in the three time periods before, immediately, and one month after the intervention, respectively (50.75 ± 5.322, 50.45 ± 5.34, 50.45 ± 5.37), in the motivational interview group (50.56 ± 5.95, 53.63 ± 5.83, 56.03 ± 6.49) and in the peer group (50.10 ± 5.62, 54.40 ± 4.28, 59.19 ± 4.43) was. Moreover, there were significant differences in self-efficacy scores within and between the groups by time (P < 0.001) in intervention groups.

CONCLUSION

This study showed that puberty health education increases students' self-efficacy, that correct information should be conveyed by peers and motivational interview, and motivational interview is more effective.

The Onset of Menstruation and Social Networking Site Use in Adolescent Girls: The Mediating Role of Body Mass Index

Evidence suggests that girls spend much time on social networking sites (SNS), often more than boys do. It has been proposed that this may have to do with sex-based differences in the need and approaches for socialization. We posit that adolescent girls are also unique in that they are developing physiologically and start menstruating. Based on prior research, we hypothesize that the onset of menstruation can drive physiological changes (increased body mass index (BMI)), which together with common behavioral-psychological (social and emotional) responses to menstruation can contribute to an increase in SNS use. We therefore aim to test whether BMI partially mediates the relationship between menstruation and SNS use in adolescent girls. Results based on a large nationally representative sample in the United Kingdom suggest that the age of menarche was negatively associated with daily hours of SNS use, and that BMI elevation partially mediated this association. These results extend the negative effects of the early onset of menstruation and imply that BMI control strategies may help to reduce the use of SNS in girls who experience menarche at an earlier age.

Linear growth and puberty in childhood obesity: what is new?

Pediatric obesity is a growing and alarming global health problem and represents an important determinant of morbidity. Since nutrition plays an important role in regulating growth and development, the excess weight gain related to overnutrition can affect growth patterns, bone maturation and pubertal development. The purpose of this review is to summarize the current knowledge about the effect of primary obesity on linear growth and pubertal development in children and adolescents. Evidences about regulatory hormones and adipokines that may be involved in the physiology of childhood growth in the context of obesity were also discussed. The most recent literature confirms previous studies indicating that linear growth is accelerated (mainly due to longer trunks rather than longer legs) and bone age is advanced in prepubertal children with obesity, while there is a reduction of pubertal height gain and attainment of normal adult height. Conflicting results are reported on the timing of puberty, specifically in boys. Indeed, previous studies suggested earlier onset of puberty in obese girls and overweight boys, and a delayed puberty in obese boys. Conversely, the most recent studies show more consistently an earlier onset and completion of pubertal development also in boys with obesity. Considering the false belief of health associated with transient taller stature in children and the adverse outcomes related to early puberty, interventions on diet and physical activity are urgently needed to tackle the epidemics of childhood obesity in public health and clinical setting.

Sexual maturity assessment in Indian children-a study from western India

OBJECTIVES

Pubertal assessment is crucial as puberty is the transition from childhood to adulthood. Pubertal assessment, growth, and secular trend in puberty need to be explored further in India. The objectives were to assess Sexual Maturity Rating (SMR) among children and establish normative data of puberty from western India. We also compared age of attainment of various stages of puberty with BMI and secular trend in menarche.

METHODS

A cross-sectional observational study was undertaken at a tertiary care pediatric center. The study population were healthy girls and boys between 6 and 18 years. Demographic data was noted. Anthropometry and SMR assessment (Tanner staging) were performed. The age of menarche was noted among the girls and their mothers. Data were analyzed using SPSS 21.

RESULTS

In girls, median age of thelarche, pubarche, and menarche was 9.37 (8.5-10.2), 10.18 (9.87-10.49), and 12.55 years (12.41-12.75) respectively. There was an early appearance of thelarche but menarche was delayed in overweight-obese girls (statistically not significant). Age of menarche showed a shift to left in girls as compared to their mothers (p=0.036). In boys, median age of testicular stage 2 and pubarche was 10.7 (9.9-11.8) and 11.6 years (11.1-12.1) respectively. In overweight-obese boys the pubertal milestones were achieved earlier (statistically not significant).

CONCLUSIONS

Normative data on pubertal assessment from western India is presented. Age of menarche shows a shift to left in girls as compared to their mothers. Pubertal milestones were observed at a younger age in overweight obese children which was not significant.

Early menarche is associated with insulin-resistance and non-alcoholic fatty liver disease in adolescents with obesity

OBJECTIVES

Recent evidence linked early menarche to a higher risk of insulin-resistance (IR) and nonalcoholic fatty liver disease (NAFLD) in adulthood. We aimed to evaluate the impact of early menarche on glucose derangements and NAFLD in a sample of Italian adolescents with obesity.

METHODS

Anthropometric and biochemical evaluations were conducted in all the enrolled 318 obese patients (mean age 12.31 ± 2.95 years). NAFLD was defined by the presence of ultrasound detected liver steatosis and/or alanine transaminase (ALT) levels >40 IU/L.

RESULTS

Patients with early menarche showed both higher homeostasis model assessment of insulin-resistance (HOMA-IR) (p=0.008) and ALT (p=0.02) values, an increased prevalence of NAFLD (p=0.001), and lower Matsuda and Insulinogenic Index (IGI) values than the other obese patients. The association between early menarche and both ALT and Matsuda Index remained significant in General Linear Models (GLMs) in which respectively body mass index standard deviation score (BMI-SDS) and Matsuda Index, and BMI-SDS were included as covariates. Patients with early menarche also showed a higher risk of both HOMA-IR>3 (OR 1.69, CI 1.05-2.70, p=0.02) and NAFLD (OR 1.10, CI 1.01-1.21, p=0.03).

CONCLUSIONS

Girls with obesity presenting early menarche showed higher HOMA-IR levels, lower Matsuda Index and IGI values, and higher risk of NAFLD compared to girls without early menarche.

Prenatal exposure to mixtures of persistent endocrine disrupting chemicals and early menarche in a population-based cohort of British girls

Exposure to endocrine disrupting chemicals (EDCs) is ubiquitous. EDC exposure, especially during critical periods of development like the prenatal window, may interfere with the body's endocrine system, which can affect growth and developmental outcomes such as puberty. Most studies have examined one EDC at a time in relation to disease; however, humans are exposed to many EDCs. By studying mixtures, the human experience can be more closely replicated. We investigated the association of prenatal exposure to persistent EDCs (poly- and perfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs)) as mixtures with early menarche among female offspring in a nested case-control study within the Avon Longitudinal Study of Parents and Children (ALSPAC) recruited in the United Kingdom in 1991-1992. Concentrations of 52 EDCs were quantified in maternal serum samples collected during pregnancy. Daughter's age at menarche was ascertained through mailed questionnaires sent annually. We used repeated holdout weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) to examine the association between prenatal exposure to multiple EDCs and early menarche (<11.5 (n = 218) vs. ≥11.5 years (n = 230)) for each chemical class separately (PFAS, PCBs, and OCPs) and for all three classes combined. Models adjusted for maternal age at menarche, maternal education, parity, pre-pregnancy body mass index, maternal age, prenatal smoking, and gestational week at sample collection. Mixture models showed null associations between prenatal exposure to EDC mixtures and early menarche. Using WQS regression, the odds ratio for early menarche for a one-decile increase in chemical concentrations for all three classes combined was 0.89 (95% CI: 0.76, 1.05); using BKMR, the odds ratio when all exposures were at the 60th percentile compared to the median was 0.98 (95% CI: 0.91, 1.05). Results suggest the overall effect of prenatal exposure to persistent EDC mixtures is not associated with early menarche.

Adiposity, reproductive and metabolic health, and activity levels in zoo Asian elephant (Elephas maximus)

Many captive Asian elephant populations are not self-sustaining, possibly due in part to obesity-related health and reproductive issues. This study investigated relationships between estimated body composition and metabolic function, inflammatory markers, ovarian activity (females only) and physical activity levels in 44 Asian elephants (n=35 females, n=9 males). Deuterium dilution was used to measure total body water from which fat mass (FM) and fat-free mass (FFM) could be derived to estimate body composition. Serum was analyzed for progestagens and estradiol (females only), deuterium, glucose, insulin and amyloid A. Physical activity was assessed by an accelerometer placed on the elephant's front leg for at least 2 days. Relative fat mass (RFM) - the amount of fat relative to body mass - was calculated to take differences in body size between elephants into consideration. Body fat percentage ranged from 2.01% to 24.59%. Male elephants were heavier (P=0.043), with more FFM (P=0.049), but not FM (P>0.999), than females. For all elephants, estimated RFM (r=0.45, P=0.004) was positively correlated with insulin. Distance walked was negatively correlated with age (r=-0.46, P=0.007). When adjusted for FFM and age (P<0.001), non-cycling females had less fat compared with cycling females, such that for every 100 kg increase in FM, the odds of cycling were 3 times higher (P<0.001). More work is needed to determine what an unhealthy amount of fat is for elephants; however, our results suggest higher adiposity may contribute to metabolic perturbations.

Timing and determinants of age at menarche in low-income and middle-income countries

INTRODUCTION

Understanding the timing and determinants of age at menarche is key to determining potential linkages between onset of puberty and health outcomes from a life-course perspective. Yet, we have little information in low-income and middle-income countries (LMICs) mainly due to lack of data. The aim of this study was to analyse trends in the timing and the determinants of menarche in LMICs.

METHODS

Using 16 World Fertility Survey and 28 Demographic and Health Surveys (DHS) from 27 countries, we analysed cohort trends and used fixed-effects models for DHS surveys to investigate sociodemographic and regional effects in the timing of age at menarche.

RESULTS

Trends of the mean age at menarche across time within and between countries show a declining or stalling path. Results of the determinant modelling show the relationship with wealth changes over time although not consistently across countries. We see a shift from poorer women having earlier menarche in earlier surveys to richer women having earlier menarche in later surveys in Indonesia, the Philippines and Yemen, while in Egypt, the reverse pattern is evident.

CONCLUSIONS

There is a considerable gap in both literature and data on menarche. We see a trend which is declining rapidly (from 14.66 to 12.86 years for the 1932 and 2002 cohorts, respectively), possibly at a faster pace than high-income countries and with a strong link to socioeconomic status. This study calls for menarche questions to be included in more nationally representative surveys and greater use of existing data because of its impact on life-course health in fast-ageing settings. Further studies will need to investigate further the use of the age at menarche as an indicator of global health.

Contrasting impact of androgens on male and female adiposity, fat distribution and insulin resistance in childhood and adolescence (EarlyBird 75)

OBJECTIVES

To investigate associations between androgens (testosterone, dehydroepiandrosterone sulphate [DHEAS] and androstenedione), adiposity, fat distribution and insulin resistance (IR) during childhood and adolescence.

METHODS

Three hundred and seven children (170 [55.4%] boys; 137 [44.6%] girls) recruited at age 5 and studied annually until age 16: androgens (liquid chromatography tandem-mass spectrometry), anthropometry, body composition (dual-energy x-ray absorptiometry) and IR (homeostasis model assessment).

RESULTS

Early adiposity was associated with earlier detection of androstenedione in both sexes, and DHEAS in boys. At puberty, higher androgen levels were associated with favourable metabolic changes in boys, but adverse metabolic effects in girls. In boys, higher free testosterone (FT) was associated with lower body fat and android/gynoid fat ratio (AGR) (both P < .001), but in girls higher total testosterone was associated with higher AGR. In girls only, higher androstenedione (P = .02) and FT (P = .01) was associated with higher IR during puberty.

CONCLUSIONS

In pre-pubertal children, adiposity is associated with higher secretion of androgen precursors. After pubertal onset, higher testosterone is associated with lower adiposity and AGR in boys, but higher AGR and IR in girls. Therefore, androgens have modest sex-specific associations with children's total body fat, fat distribution and IR.

Association between factors related to the pregnancy, neonatal period, and later complications (especially asthma) and menarcheal age in a sample of Lebanese girls

BACKGROUND

Studies about the majority of the factors that may potentially influence the pubertal timing and menarche were controversial. The objective was to evaluate the association between factors related to the pregnancy, neonatal period, and the complications that may happen later in life and the menarcheal age in a sample of Lebanese girls admitted or not to the NICU at birth. Our secondary objective was to try to find, for the first time in literature, a correlation between respiratory distress at birth and the need of oxygen therapy with the age of the first menses in these girls.

METHODS

It is a cross-sectional retrospective study, conducted between January and March 2019. Our sample included all the 2474 girls born in Notre-Dame-de-Secours hospital, between 2000 and 2005; the sample consisted of 297 girls (97 girls admitted to the NICU and 200 randomly chosen to participate in our study with a ratio of 1:2 (1 girl admitted to the NICU vs 2 girls born in the nursery).

RESULTS

Asthma later in life was significantly associated with lower age at menarche in girls, whereas a higher mother's age at menarche and a higher gestational age were significantly associated with higher age at menarche in girls. When taking each cause of NICU admission as an independent variable, showed that a higher mother's age at menarche was significantly associated with higher age at menarche in girls, whereas a higher number of days of phototherapy, a preeclampsia in the mother during pregnancy and asthma later in life in the girl were significantly associated with a lower age at menarche in girls.

CONCLUSION

The timing of menarche seems to be associated with many factors in Lebanese girls that should not be disregarded by physicians.

Association between indicators of systemic inflammation biomarkers during puberty with breast density and onset of menarche

Background

Systemic inflammation may play a role in shaping breast composition, one of the strongest risk factors for breast cancer. Pubertal development presents a critical window of breast tissue susceptibility to exogenous and endogenous factors, including pro-inflammatory markers. However, little is known about the role of systemic inflammation on adolescent breast composition and pubertal development among girls.

Methods

We investigated associations between circulating levels of inflammatory markers (e.g., interleukin-6 (IL-6), tumor necrosis factor receptor 2 (TNFR2), and C-reactive protein (CRP)) at Tanner stages 2 and 4 and breast composition at Tanner stage 4 in a cohort of 397 adolescent girls in Santiago, Chile (Growth and Obesity Cohort Study, 2006–2018). Multivariable linear models were used to examine the association between breast composition and each inflammatory marker, stratifying by Tanner stage at inflammatory marker measurement. Accelerated failure time models were used to evaluate the association between inflammatory markers concentrations at each Tanner stage and time to menarche.

Results

In age-adjusted linear regression models, a doubling of TNFR2 at Tanner 2 was associated with a 26% (95% CI 7–48%) increase in total breast volume at Tanner 4 and a 22% (95% CI 10–32%) decrease of fibroglandular volume at Tanner 4. In multivariable models further adjusted for body fatness and other covariates, these associations were attenuated to the null. The time to menarche was 3% (95% CI 1–5%) shorter among those in the highest quartile of IL-6 at Tanner 2 relative to those in the lowest quartile in fully adjusted models. Compared to those in the lowest quartile of CRP at Tanner 4, those in the highest quartile experienced 2% (95% CI 0–3%) longer time to menarche in multivariable models.

Conclusions

Systemic inflammation during puberty was not associated with breast volume or breast density at the conclusion of breast development among pubertal girls after adjusting for body fatness; however, these circulating inflammation biomarkers, specifically CRP and IL-6, may affect the timing of menarche onset.

Body dissatisfaction and its association with domains of physical activity and of sedentary behavior in a sample of 15,632 adolescents

Objectives Body image is widely related to behavioral factors in adolescents and negative levels has been associated to poor physical and mental health. This study analyzed the association of physical activity and sedentary behavior with body dissatisfaction in adolescents. Methods Data from 15,632 adolescents between 11 and 17 years from the Brazilian National Scholar Health Survey - PeNSE 2015 were analyzed. Body dissatisfaction was self-reported. Sedentary behavior was assessed by hours in television (TV) viewing and in overall sitting behaviors. Physical activity was assessed by amount of time in domains of active commuting, physical education classes at school, and physical activities outside the school. Analyses were adjusted by age, ethnicity, body mass index, and scholarity of mother. Results Body dissatisfaction prevalence was 18.5%, being higher in girls than boys (24.2 vs. 12.7%, p < 0.001). Female gender (OR = 2.35), higher age-group (OR = 1.64), high scholarity of mother (OR = 1.43), and had overweight/obesity (OR = 2.38/4.81) were positively related to body dissatisfaction. Higher sedentary time was associated with body dissatisfaction in adolescents when compared to less than 2 h/day of sedentary time (OR varying from 1.45 to 2.14). Physical activity was negatively associated with adolescent body dissatisfaction in all assessed domains, with odds ratio varying from 0.66 to 0.89. Conclusions Body dissatisfaction showed an independent association of with total sedentary behavior (positively) and with different domains of physical activity (negatively) in a large scholar sample of Brazilian adolescents.

Influence of pubertal development on urinary oxidative stress biomarkers in adolescent girls in the New York LEGACY cohort

Puberty is a time of intense growth and differentiation of breast tissue and a window of susceptibility (WOS) for breast cancer. Although oxidative stress markers have been associated with breast cancer risk, it is unclear whether oxidative stress levels are different during the pubertal WOS, and if so, whether these differences are related to breast cancer susceptibility. We measured urinary biomarkers of whole body oxidative stress (urinary F2-Isoprostanes and 8-oxodeoxyguanosine (8-oxodG)) in 158 girls (ages 6-13 years), 71 with and 87 without a breast cancer family history (BCFH) from a cohort of adolescent girls from the New York site of the LEGACY cohort (Lessons in Epidemiology and Genetics in Adults Cancer from Youth). We compared levels of urinary oxidative stress biomarkers (F2-Isoprostanes and 8-oxodG) across the pubertal window, defined by Tanner Stage (TS) of breast development, both cross-sectionally and longitudinally within girls over an 18-month follow up period. Urinary oxidative stress biomarkers were unrelated to pubertal stages in cross-sectional analyses after considering adjustments for body mass index (BMI) and BCFH. In our longitudinal analysis, we found that urinary 8-oxodG levels, but not F2-Isoprostane levels, increased with age in BCFH + girls (β = 6.12, 95% CI = 0.08-12.16) compared to BCFH-girls. Higher BMI was associated with higher level of F2-Isoprostane in both cross-sectional (β = 0.02, 95% CI = 0.0004-0.05) and longitudinal analysis (β = 0.02, 95% CI = 0.0002-0.05). These findings support that higher BMI increases oxidative stress biomarkers over the pubertal window and that there are changes in 8-oxodG oxidative stress biomarkers in girls with a BCFH compared to girls without a BCFH.

Worldwide Secular Trends in Age at Pubertal Onset Assessed by Breast Development Among Girls: A Systematic Review and Meta-analysis

IMPORTANCE

The initial clinical sign of pubertal onset in girls is breast gland development (thelarche). Although numerous studies have used recalled age at menarche (first menstruation) to assess secular trends of pubertal timing, no systematic review has been conducted of secular trends of thelarche.

OBJECTIVES

To systematically evaluate published data on pubertal timing based on age at thelarche and evaluate the change in pubertal onset in healthy girls around the world.

DATA SOURCES

A systematic literature search was performed in PubMed and Embase of all original peer-reviewed articles published in English before June 20, 2019.

STUDY SELECTION

Included studies used clinical assessment of breast development in healthy girls and used adequate statistical methods, including the reporting of SEs or CIs. The quality of the articles was evaluated by assessing study design, potential sources of bias, main characteristics of the study population, and methods of statistical analysis.

DATA EXTRACTION AND SYNTHESIS

In accordance with PRISMA guidelines, all articles were assessed for eligibility independently by 2 authors. Weighted regression analysis was performed using a random-effects model.

MAIN OUTCOMES AND MEASURES

Studies examining age at thelarche (development of Tanner breast stage 2) in healthy girls.

RESULTS

The literature search resulted in a total of 3602 studies, of which 30 studies fulfilled the eligibility criteria. There was a secular trend in ages at thelarche according to race/ethnicity and geography. Overall, the age at thelarche decreased 0.24 years (95% CI, -0.44 to -0.04) (almost 3 months) per decade from 1977 to 2013 (P = .02).

CONCLUSIONS AND RELEVANCE

The age at thelarche has decreased a mean of almost 3 months per decade from 1977 to 2013. A younger age at pubertal onset may change current diagnostic decision-making. The medical community needs current and relevant data to redefine "precocious puberty," because the traditional definition may be outdated, at least in some regions of the world.

Timing of puberty in boys and girls: Implications for population health

Puberty is marked by substantial increases and emerging sex differences in psychological disorders and risky behaviors. However, few studies have examined these effects beyond adolescence, and the previous literature has been dominated by samples of White girls. The current study examines the broadest known set of health sequelae related to traditional pubertal markers and peer-relative pubertal timing in a representative sample of 14,545 U.S. youth from the National Longitudinal Study of Adolescent to Adult Health.

Maturational timing was assessed by age at menarche for girls and physical development for boys (e.g., facial hair, voice change), and then categorized as early (1 SD below mean), on-time, or late (1 SD above mean) within-sex. Early and late peer-relative timing was assessed by a self-report of looking “much older” or “much younger” than one's peers. We examined psychological (depressive symptoms, antisocial behavior), behavioral (number of sex partners, drug use, physical activity, screen time, sleep hours), and physical health (self-reported health, BMI) outcomes during adolescence and young adulthood in a series of sex-stratified regression analyses using survey weights and a comprehensive set of sociodemographic covariates.

Results indicated that, overall, earlier pubertal timing (i.e., maturational timing and peer-relative timing) put both girls and boys at risk during adolescence, while later timing was protective. However, longitudinal models revealed mixed results. For instance, early maturational timing was associated with higher young adult BMI (girls: β = 0.139, p < .01; boys: β = 0.107, p < .01), but later timing for boys was associated with both risky (e.g., more screen time; β = 0.125, p < .05) and health promoting (e.g., more sleep; β = .296, p < .01) behaviors. Analysis of this holistic set of outcomes with sex differences in mind allows for more careful evidence-based recommendations for adolescent health promotion.

•

Early or late puberty predicts health, but there is little longitudinal research.

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Perceived pubertal development relative to peers also predicts health outcomes.

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Links between pubertal timing and long-term health were more pervasive for girls.

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Adolescent psychological symptoms and health behaviors explain long-term links.

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Results point to the need for high-quality puberty education early in life.

Diurnal variation of body height in children with idiopathic scoliosis

BACKGROUND

Body height (BH) measurement is an important part of the clinical evaluation of children with idiopathic scoliosis (IS) as its progression is defined based on the observation of a growth spurt.

OBJECTIVE

The aim of the study is to assess diurnal variation of BH in children with IS.

METHODS

BH was measured in 98 children with IS (Cobb angle: 10∘-52∘, mean 21.2∘± 9.9∘) both in standing and sitting position. The measurements were performed 4 times a day - between: (1) 7:00 and 8:00; (2) 11:00 and 12:00; (3) 15:00 and 16:00 and (4) 19:00 and 20:00.

RESULTS

A significant decrease in BH during the day was observed in both standing and sitting positions (p< 0.001). The highest decrease in height was observed between the measurements performed between 7:00 and 8:00 and measurements carried out in the evening (19:00-20:00). For standing, the mean loss of height was 0.7 cm (± 0.7), i.e. 0.43% of initial standing height, for sitting the mean decrease in height was 0.7 cm (± 0.7), i.e. 0.79% of initial sitting height.

CONCLUSIONS

BH decreases in children with IS during daytime. Due to diurnal BH variation, the time of the day should be recorded when measuring patients with IS.

Age, maturation and serum lipid parameters: findings from the German Health Survey for Children and Adolescents

BACKGROUND

Recommendations on preventive lipid screening among children and adolescents remain controversial. The aim of the study was to assess age and puberty-related changes in serum lipids, including total cholesterol (TC), and high-density (HDL-C) and non-high-density lipoprotein cholesterol (Non-HDL-C).

METHODS

Using cross-sectional data from the National Health Interview and Examination Survey for Children and Adolescents in Germany (KiGGS 2003-2006; N = 13,676; 1-17 years), changes in distributions of serum lipids were visualized according to sex, age and maturation. Youth aged 10-17 years were classified as prepubescent, early/mid-puberty, and mature/advanced puberty. Multiple linear regressions were used to quantify the impact of pubertal stage on serum lipid levels, adjusted for potential confounding factors.

RESULTS

Among children 1-9 years mean serum lipid measures increased with age, with higher mean TC and Non-HDL-C among girls than boys. Among children 10-17 years, advanced pubertal stage was independently related to lower lipid measures. Adjusted mean TC, HDL-C and Non-HDL-C was 19.4, 5.9 and 13.6 mg/dL lower among mature/advanced puberty compared to prepubescent boys and 11.0, 4.0 and 7.0 mg/dL lower in mature/advanced puberty compared to prepubescent girls.

CONCLUSIONS

Lipid concentrations undergo considerable and sex-specific changes during physical growth and sexual maturation and significantly differ between pubertal stages. Screening recommendations need to consider the fluctuations of serum lipids during growth and sexual maturation.

Early maturity, shortened stature, and hardship: Can life-history trade-offs indicate social stratification and income inequality in the United States?

OBJECTIVE

Life-history strategies promote reproductive fitness and survival. Limited energy availability and competing energetic demands between life-history decisions may result in organismal trade-offs leading to selection for "optimal" traits that facilitate fitness and survival in present environmental conditions. Few life-history analyses have been conducted in food abundant/high resource human populations. Here, we use a life-history theory framework integrated with a biocultural approach to assess whether trade-offs between growth (height) and the onset of reproductive maturation (ages at menarche) were observed in a sample of adult women living in the United States.

METHODS

Adult women (18 years and older) from the National Health and Nutrition Examination Survey (NHANES) 2005 to 2006 were analyzed using complex survey regression to evaluate associations between ages at menarche, height, and biological, socio-economic, demographic, and anthropometric variables. Associations between stature, ages at menarche, and socio-economic status (household income and education level) suggest life-history trade-offs in this populations may be mitigated by access to resources and marginalization.

CONCLUSIONS

These study results have applied public health implications. We demonstrate that females who experience early menarche in the US population achieve short stature. Our study also demonstrates the need for implementing life-history analyses in Western affluent populations, where marginalization may result in life-history trade-offs.

Normative values for ultrasound measurements of the female pelvic organs throughout childhood and adolescence

BACKGROUND

Normative data from pelvic ultrasonography (US) of the pediatric female reproductive organs are outdated and limited by sample size.

OBJECTIVE

The purpose of this study was to report normal uterine and ovarian volumes and endometrial stripe thickness in children and young adults and throughout the menstrual cycle in post-menarchal adolescents.

MATERIALS AND METHODS

Females ages 0 through 20 years who underwent pelvic US between January 2010 and May 2014 were identified. After excluding patients with pelvic and/or endocrine pathology, nomograms of uterine and ovarian volumes and endometrial thickness by age year were created. Data for patients ages 12 years and older with a recorded day of last menstrual period were used to create additional nomograms of volumes/thickness throughout the menstrual cycle. Student's t-tests and linear regression were performed to assess differences in measurements between groups and association of volumes/thickness with age.

RESULTS

During our study period, 5,647 patients underwent 6,953 pelvic US examinations. After further review, 907 examinations from 889 patients were included (mean age: 11.3±6.0 years). Mean pelvic US volumes (cm³) per organ were 25.5±27.0 (uterus), 4.5±4.7 (right ovary) and 4.0±4.1 (left ovary). Mean endometrial thickness was 4.5±3.7 mm. Right ovarian volume was significantly larger than the left (P=0.0126). Uterine volume, ovarian volume and endometrial thickness were significantly associated with age (P-values<0.0001). Plots of mean organ measurements with respect to week of menses are provided.

CONCLUSION

We report normal volumes of the uterus and ovaries and endometrial stripe thickness measured by pelvic US throughout childhood and adolescence with reference to the menstrual cycle. These values are significantly associated with age and vary visually by menstrual cycle week.