The pubertal transition in 179 healthy Danish children: associations between pubarche, adrenarche, gonadarche, and body composition

Prenatal phthalate exposure and pubertal development in 16-year-old daughters: reproductive hormones and number of ovarian follicles

STUDY QUESTION

Is there a possible association between prenatal phthalate exposure and late effects in teenage daughters with respect to reproductive hormone levels, uterine volume, and number of ovarian follicles?

SUMMARY ANSWER

Our study showed subtle associations between phthalate metabolite concentrations in maternal serum from pregnancy or cord blood and LH and insulin-like growth factor 1 (IGF-1) levels as well as uterine volume in their daughters 16 years later.

WHAT IS KNOWN ALREADY

Endocrine-disrupting environmental chemicals may adversely affect human reproductive health, and many societies have experienced a trend toward earlier puberty and an increasing prevalence of infertility in young couples. The scientific evidence of adverse effects of foetal exposure to a large range of chemicals, including phthalates, on male reproductive health is growing, but very few studies have explored effects on female reproduction.

STUDY DESIGN, SIZE, DURATION

This follow-up study included 317 teenage daughters who were part of the Copenhagen Mother-Child Cohort, a population-based longitudinal birth cohort of 1210 females born between 1997 and 2002.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 317 female participants (median age 16 years) were examined for weight, height, and menstrual pattern. A serum sample was analysed for concentrations of reproductive hormones, and trans-abdominal 3D ultrasonography was performed to obtain the number of ovarian follicles, ovarian and uterine size. Prenatal maternal serum samples were available for 115 females, and cord blood samples were available for 118 females. These were analysed for concentrations of 32 phthalate metabolites. Weighted quantile sum regression was used for modelling associations of combined prenatal phthalate exposure with the reproductive outcomes in post-menarcheal females.

MAIN RESULTS AND THE ROLE OF CHANCE

In bivariate correlation analyses, negative significant associations were found between several prenatal phthalate metabolite concentrations and serum hormone concentrations (testosterone, 17-OH-progesterone, and IGF-1) as well as number of ovarian follicles in puberty. Positive significant correlations were found between prenatal phthalate exposure and FSH and sex hormone-binding globulin concentrations. Combined analyses of phthalate exposure (weighted quantile sums) showed significant negative associations with IGF-1 concentration and uterine volume as well as a significant positive association with LH concentration.

LIMITATIONS, REASONS FOR CAUTION

Phthalate metabolites were measured in serum from single prenatal maternal blood samples and cord blood samples. Potential concomitant exposure to other endocrine-disrupting environmental chemicals before or after birth was not controlled for. The study population size was limited.

WIDER IMPLICATIONS OF THE FINDINGS

Our results support the need for further research into possible adverse effects of environmental chemicals during foetal development of the female reproductive system.

STUDY FUNDING/COMPETING INTEREST(S)

The work was supported by The Center on Endocrine Disruptors (CeHoS) under The Danish Environmental Protection Agency and The Ministry of Environment and Food (grant number: MST-621-00 065). No conflicts of interest are declared.

TRIAL REGISTRATION NUMBER

N/A.

Associations Among Birth Weight, Adrenarche, Brain Morphometry, and Cognitive Function in Preterm Children Ages 9 to 11 Years

BACKGROUND

Preterm infants with low birth weight are at heightened risk of developmental sequelae, including neurological and cognitive dysfunction that can persist into adolescence or adulthood. In addition, preterm birth and low birth weight can provoke changes in endocrine and metabolic processes that likely impact brain health throughout development. However, few studies have examined associations among birth weight, pubertal endocrine processes, and long-term neurological and cognitive development.

METHODS

We investigated the associations between birth weight and brain morphometry, cognitive function, and onset of adrenarche assessed 9 to 11 years later in 3571 preterm and full-term children using the ABCD (Adolescent Brain Cognitive Development) Study dataset.

RESULTS

The preterm children showed lower birth weight and early adrenarche, as expected. Birth weight was positively associated with cognitive function (all Cohen's d > 0.154, p < .005), global brain volumes (all Cohen's d > 0.170, p < .008), and regional volumes in frontal, temporal, and parietal cortices in preterm and full-term children (all Cohen's d > 0.170, p < .0007); cortical volume in the lateral orbitofrontal cortex partially mediated the effect of low birth weight on cognitive function in preterm children. In addition, adrenal score and cortical volume in the lateral orbitofrontal cortex mediated the associations between birth weight and cognitive function only in preterm children.

CONCLUSIONS

These findings highlight the impact of low birth weight on long-term brain structural and cognitive function development and show important associations with early onset of adrenarche during the puberty. This understanding may help with prevention and treatment.

Serum INSL3 measured by LC-MS/MS in pubertal girls and in girls with precocious puberty during GnRH agonist treatment

Introduction

The peptide hormone Insulin-like Factor 3 (INSL3) is a biomarker of testicular Leydig cells in the male but is also expressed by the theca cells of the ovaries. With the advent of sensitive assays INSL3 can be quantified in female circulation, and we suggest that circulating INSL3 is a novel biomarker for pubertal development in girls. The aim of the study is to quantify INSL3 by LC-MS/MS in sera from normal girls during pubertal transition, and during gonadal suppression by GnRH agonist therapy in girls with central precocious puberty (CPP).

Method

The sensitivity of an established LC-MS/MS-based method for serum INSL3 was improved by switching to a state-of-the-art triple quadruple mass spectrometer (Altis Plus, Thermo).

Results

The limit of detection of the improved LC-MS/MS method for serum INSL3 was 0.01 ug/L (1.5 pM) and the inter-assay CV was < 12%. Serum INSL3 increased during the pubertal transition in healthy girls and changes correlated with the concomitant rise in other measured hormones. In some girls, but not all, INSL3, FSH, inhibin B and estradiol serum concentrations increased prior to first clinical signs of puberty. Serum INSL3 concentrations were increased at baseline in girls with CPP compared to prepubertal controls and decreased during treatment with GnRH agonist followed by a steep rise and normalization after cessation of treatment.

Conclusion

The improved method allowed for quantification of INSL3 in longitudinally collected serum samples during pubertal transition in healthy girls as well as in girls with CPP before, during and after treatment with GnRH agonist. Future studies are needed to clarify if INSL3 in combination with other biomarkers enhances the predictive value of differentiating between premature thelarche and CPP.

Normative Data on Dehydroepiandrosterone Sulphate (DHEAS) and its Attributes in Healthy Indian Children and Adolescents

Dehydroepiandrosterone sulphate (DHEAS), the biochemical indicator of adrenarche and pubarche, is of paramount importance in the evaluation of puberty-related disorders. The reference range of DHEAS should be ethnicity, age, sex, pubarche and Tanner stage specific. Anthropometry, puberty assessment and hormonal parameters were estimated using electrochemiluminescence assay. Bone age was estimated using the BoneXpert software. Of 2191 healthy Indian children aged 5-18 y screened at Chandigarh, 1919 were included in the final analysis (994 boys). The median DHEAS levels at pubarche stage P2 were 82.10 (55.0-129.0) g/dl in girls and 132.50 (95.12-205.50) g/dl in boys. By ROC analysis, the level of DHEAS at pubarche was 63.7 g/dl (sensitivity 72.6%, specificity 64.4%) in girls and 82.2 g/dl (sensitivity 81.8%, specificity 68.8%) in boys. The median age at adrenarche was 9.5 y in both sexes. On multivariate regression analysis; bone age, body mass index (BMI), gonadal steroids, and insulin-like growth factor-1 (IGF-1) significantly correlated with serum DHEAS levels in either sex.

Rhythmic profile of memory T and B-cells along childhood and adolescence

Immunobiography describes the life-long effects of exogenous or endogenous stimuli on remodeling of immune cell biology, including the development of memory T and B-cells. The present study aimed at investigating the rhythms of changes in phenotypic features of memory T and B-cells along childhood and adolescence. A descriptive-observational investigation was conducted including 812 healthy volunteers, clustered into six consecutive age groups (9Mths-1Yr; 2Yrs; 3-4Yrs; 5-7Yrs; 8-10Yrs; 11-18Yrs). Immunophenotypic analysis of memory T-cell (CD4+ and CD8+) and B-cell subsets were performed by flow cytometry. The results pointed out that memory-related biomarkers of T and B-cells displayed a bimodal profile along healthy childhood and adolescence, regardless of sex. The first stage of changes occurs around 2Yrs, with predominance of naive cells, while the second and more prominent wave occurs around the age 8-10Yrs, with the prevalence of memory phenotypes. The neighborhood connectivity profile analysis demonstrated that the number of correlations reaches a peak at 11-18Yrs and lower values along the childhood. Males presented higher and conserved number of correlations when compared to females. Altogether, our results provide new insights into immunobiography and a better understanding of interactions among the cellular subsets studied here during childhood and adolescence.

Mini review shows that a testicular volume of 3 mL was the most reliable clinical sign of pubertal onset in males

AIM

We aimed to evaluate aspects of pubertal development to identify the most reliable clinical sign of pubertal onset in males.

METHODS

We performed a mini review of the literature.

RESULTS

In 1951 Reynolds and Wines categorised pubic hair growth and genital development in five stages by visual inspection. Today the Tanner scale is used to assess the five stages of pubertal development, The second genital stage, characterised by enlargement of the scrotum defines pubertal onset in males. Testicular volume may be evaluated by using a calliper or by ultrasound scan. The Prader orchidometer, described in 1966, offers a method for evaluating testicular growth by palpation. Pubertal onset is commonly defined as testicular volume >3 or ≥4 mL. The development of sensitive laboratory methods has enabled studies analysing hormonal activity in the hypothalamus-pituitary-gonadal axis. We review the relationships between physical and hormonal signs of puberty. We also discuss the results of studies assessing different aspects of pubertal development with a focus on identifying the most reliable clinical sign of pubertal onset in males.

CONCLUSION

A substantial amount of evidence supports testicular volume of 3 mL as the most reliable clinical sign of male pubertal onset.

AMH and other markers of ovarian function in patients with Turner syndrome - a single center experience of transition from pediatric to gynecological follow up

Turner syndrome (TS) is a chromosomal disorder that affects about 1 in 2500 female births and is characterized by the partial or complete absence of the second X chromosome. Depending on karyotype, TS is associated with primary ovarian insufficiency (POI). Approximately 50% of girls with a mosaic 45, X/46, XX karyotype may enter puberty spontaneously, but only 5-10% of women with TS achieve pregnancy without egg donation. In this review, we will evaluate the clinical use of markers of ovarian function in TS patients. Based on longitudinal studies of serum concentrations of reproductive hormones as well as ovarian morphology in healthy females and patients with TS, we will evaluate how they can be applied in a clinical setting. This is important when counseling patients and their families about future ovarian function essential for pubertal development and fertility. Furthermore, we will report on 20 years of experience of transition from pediatric to gynecological and adult endocrinological care in our center at Rigshospitalet, Copenhagen, Denmark.

The effects of puberty and sex on adolescent white matter development: A systematic review

Adolescence, the transition between childhood and adulthood, is characterized by rapid brain development in white matter (WM) that is attributed in part to rising levels in adrenal and gonadal hormones. The extent to which pubertal hormones and related neuroendocrine processes explain sex differences in WM during this period is unclear. In this systematic review, we sought to examine whether there are consistent associations between hormonal changes and morphological and microstructural properties of WM across species and whether these effects are sex-specific. We identified 90 (75 human, 15 non-human) studies that met inclusion criteria for our analyses. While studies in human adolescents show notable heterogeneity, results broadly demonstrate that increases in gonadal hormones across pubertal development are associated with macro- and microstructural changes in WM tracts that are consistent with the sex differences found in non-human animals, particularly in the corpus callosum. We discuss limitations of the current state of the science and recommend important future directions for investigators in the field to consider in order to advance our understanding of the neuroscience of puberty and to promote forward and backward translation across model organisms.

Modelling timing and tempo of adrenarche in a prospective cohort study

To better understand how health risk processes are linked to adrenarche, measures of adrenarcheal timing and tempo are needed. Our objective was to describe and classify adrenal trajectories, in terms of timing and tempo, in a population of children transitioning to adolescence with repeated measurements of salivary dehydroepiandrosterone (DHEA), DHEA-sulphate, and testosterone. We analysed data from the Childhood to Adolescence Transition Study (CATS), a longitudinal study of 1239 participants, recruited at 8-9 years old and followed up annually. Saliva samples were assayed for adrenal hormones. Linear mixed-effect models with subject-specific random intercepts and slopes were used to model longitudinal hormone trajectories by sex and derive measures of adrenarcheal timing and tempo. The median values for all hormones were higher at each consecutive study wave for both sexes, and higher for females than males. For all hormones, between-individual variation in hormone levels at age 9 (timing) was moderately large and similar for females and males. Between-individual variation in hormone progression over time (tempo) was of moderate magnitude compared with the population average age-slope, which itself was small compared with overall hormone level at each age. This suggests that between-individual variation in tempo was less important for modelling hormone trajectories. Between-individual variation in timing was more important for determining relative adrenal hormonal level in childhood than tempo. This finding suggests that adrenal hormonal levels at age 8-9 years can be used to predict relative levels in early adolescence (up to 13 years).

A multidimensional approach to understanding the emergence of sex differences in internalizing symptoms in adolescence

Women are more vulnerable to internalizing disorders (e.g., depression and anxiety). This study took an integrative developmental approach to investigate multidimensional factors associated with the emergence of sex differences in internalizing symptoms, using data from the Adolescent Brain Cognitive Development (ABCD) study. Indices of sex hormone levels (dehydroepiandrosterone, testosterone, and estradiol), physical pubertal development, task-based functional brain activity, family conflict, and internalizing symptoms were drawn from the ABCD study's baseline sample (9- to 10-year-old; N = 11,844). Principal component analysis served as a data-driven dimensionality reduction technique on the internalizing subscales to yield a single robust measure of internalizing symptoms. Moderated mediation analyses assessed whether associations between known risk factors and internalizing symptoms vary by sex. Results revealed direct and indirect effects of physical pubertal development on internalizing symptoms through family conflict across sexes. No effects were found of sex hormone levels or amygdala response to fearful faces on internalizing symptoms. Females did not report overall greater internalizing symptoms relative to males, suggesting that internalizing symptoms have not yet begun to increase in females at this age. Findings provide an essential baseline for future longitudinal research on the endocrine, neurocognitive, and psychosocial factors associated with sex differences in internalizing symptoms.

Considerations when treating male pubertal delay pharmacologically

INTRODUCTION

Delayed puberty, defined as the appearance of pubertal signs after the age of 14 years in males, usually affects psychosocial well-being. Patients and their parents show concern about genital development and stature. The condition is transient in most of the patients; nonetheless, the opportunity should not be missed to diagnose an underlying illness.

AREAS COVERED

The aetiologies of pubertal delay in males and their specific pharmacological therapies are discussed in this review.

EXPERT OPINION

High-quality evidence addressing the best pharmacological therapy approach for each aetiology of delayed puberty in males is scarce, and most of the current practice is based on small case series or unpublished experience. Male teenagers seeking attention for pubertal delay most probably benefit from medical treatment to avoid psychosocial distress. While watchful waiting is appropriate in 12- to 14-year-old boys when constitutional delay of growth and puberty (CGDP) is suspected, hormone replacement should not be delayed beyond the age of 14 years in order to avoid impairing height potential and peak bone mass. When primary or central hypogonadism is diagnosed, hormone replacement should be proposed by the age of 12 years provided that a functional central hypogonadism has been ruled out. Testosterone replacement regimens have been used for decades and are fairly standardised. Aromatase inhibitors have arisen as an interesting alternative for boy with CDGP and short stature. Gonadotrophin therapy seems more physiological in patients with central hypogonadism, but its relative efficacy and most adequate timing still need to be established.

Prepubertal BMI, pubertal growth patterns, and long-term BMI: Results from a longitudinal analysis in Chinese children and adolescents from 2005 to 2016

OBJECTIVE

To assess the effects of prepubertal BMI on pubertal growth patterns, and the influence of prepubertal BMI and pubertal growth patterns on long-term BMI among Chinese children and adolescents.

METHODS

A total of 9606 individuals aged between 7 and 18 years from longitudinal surveys in Zhongshan city of China from 2005 to 2016 were enrolled. Age at peak height velocity (APHV) and peak height velocity (PHV) were estimated using Super-Imposition by Translation and Rotation (SITAR) model. Associations between prepubertal BMI, APHV, PHV, and long-term overweight and obesity were assessed by linear regression and multinominal logistic regression. Scatter plots were elaborated to show the associations between prepubertal BMI and pubertal growth patterns according to prepubertal BMI categories.

RESULTS

Prepubertal BMI Z-Score was positively correlated with long-term BMI Z-Score, and negatively correlated with APHV in both sexes. In addition, there was a negative association between prepubertal BMI Z-Score and PHV in boys. With 1-year decrease in APHV, risk of long-term underweight decreased by 92%, while overweight increased by 33% in boys. Corresponding risk of long-term underweight and overweight for girls decreased by 42% and increased by 20%, respectively.

CONCLUSION

High prepubertal BMI levels were associated with earlier APHV and lower PHV, and the early onset of pubertal development could increase the risks of long-term overweight and obesity at 17-18 years of age both in boys and girls. Such evidence emphasized the importance of reducing prepubertal obesity risks combined with appropriate pubertal development timing, including later APHV and higher PHV, so as to prevent the obesity and related cardiovascular diseases in adulthood.

Risk factors on testicular function in adolescents

PURPOSE

Adolescence represents an important window for gonadal development. The aim of this review is to carry out a critical excursus of the most recent literature on endogenous and exogenous risk factors related to testicular function, focusing the research on adolescence period.

METHODS

A comprehensive literature search within PubMed was performed to provide a summary of currently available evidence regarding the impact on adolescence of varicocele, cryptorchidism, cancer, diabetes, lifestyle factors, endocrine disruptors, obesity and sexually transmitted diseases. We focused on human studies that evaluated a possible impact of these factors on puberty timing and their effects on andrological health.

RESULTS

Evidence collected seems to suggest that andrological health in adolescence may be impaired by several factors, as varicocele, cryptorchidism, and childhood cancer. Despite an early diagnosis and treatment, many adolescents might still have symptoms and sign of a testicular dysfunction in their adult life and at the current time it is not possible to predict which of them will experience andrological problems. Lifestyle factors might have a role in these discrepancies. Most studies point out towards a correlation between obesity, insulin resistance, alcohol, smoking, use of illegal drugs and testicular function in pubertal boys. Also, endocrine disruptors and sexually transmitted diseases might contribute to impair reproductive health, but more studies in adolescents are needed.

CONCLUSION

According to currently available evidence, there is an emerging global adverse trend of high-risk and unhealthy behaviors in male adolescents. A significant proportion of young men with unsuspected and undiagnosed andrological disorders engage in behaviors that could impair testicular development and function, with an increased risk for later male infertility and/or hypogonadism during the adult life. Therefore, adolescence should be considered a key time for intervention and prevention of later andrological diseases.

Variability of response to early puberty induction demonstrated by transverse uterine diameter measurement and a novel method of 3D breast imaging

OBJECTIVE

Induction of puberty with exogenous oestrogen results in considerable variability in final uterine and breast volumes. We set out to quantify the variability of these two outcome measures with a view to establishing monitoring methods that could be used to individualise treatment protocols.

DESIGN

A prospective observational study.

PARTICIPANTS

Sixteen participants with pubertal delay and primary amenorrhoea, due to hypogonadism were recruited from paediatric gynaecology and endocrinology clinics at University College London Hospital. A standardised protocol of transdermal 17β oestradiol (17βE) was used (Evorel™), with a starting dose of 12.5 mcg increasing to 25 mcg (patch changed twice weekly) after 4 months. Follow up was every 2 months for a total of 8 months.

MEASUREMENTS

Uterine dimensions using ultrasound, oestradiol concentrations and breast development assessed by both Tanner staging and 3D photographic imaging.

RESULTS

After 8 months of treatment, the changes in oestradiol concentrations (0-174 pmol), uterine volume growth (4.4-16.4 ml) and breast volume (1.76-140.1 ml) varied greatly between individuals. Of uterine parameters, transverse uterine diameter was most closely associated with serum oestradiol levels at 8 months (beta standardised coefficient = 0.80, p = .001). Change in breast volume was associated with age of treatment initiation (beta standardised coefficient 0.55 p = .04).

CONCLUSIONS

We demonstrate variation in response to exogenous oestrogen, emphasising the necessity for individualised dose titration. In the absence of sensitive oestradiol assays, uterine transverse measurements may be used as a surrogate marker of oestrogen sensitivity to guide early dose adjustment. 3D breast imaging may provide a quantitative assessment of breast development to complement Tanner breast staging.

Earlier Age at Menarche Is Associated with Body Fat and Negative Body Image in Adult Life

Earlier age at menarche is one of the well-documented antecedents of a range of adverse health effects in adulthood including obesity and psychopathological effects. Yet, few researchers have examined the potential association of menarcheal age with body fat distribution, self-perception, and body image. We retrospectively tested a sample (N = 392) of adult women (18-80 years) to examine the associations of age at menarche with body composition and body image indices. Analyses of covariance and multivariable logistic and linear regression were fitted adjusting for age, physical activity level, smoking, and alcohol consumption. Further adjustment was made for body mass index (BMI) and percentage of fat mass. Earlier age at menarche was associated with slightly increased odds of higher BMI and abdominal fat percentage; of note is the positive correlation with lower body composition indices including hip and calf circumferences/skinfolds. Additionally, earlier age at menarche was associated with higher scores in the negative body image scales, namely overweight preoccupation and self-classified weight, whereas lower risks were found for higher scores in the positive body image scales, namely appearance evaluation and body area satisfaction scales. These findings remained significant after correcting for body fat percentage. The present results showed positive associations for earlier age at menarche with gross indices of obesity with the associations mainly confined to distribution of body fat in the lower part of the body, whereas an increased risk of negative body image was also found. Future research could refine our understanding of the biological and psychological mechanisms underlying these associations.

Clinical assessment of blood pressure in 60 girls with Turner syndrome compared to 1888 healthy Danish girls

OBJECTIVE

Hypertension contributes to increased risk of cardiovascular disease in patients with Turner syndrome (TS). Our objective was to evaluate blood pressure (BP) in girls with TS followed longitudinally through childhood and adolescence compared to a newly established BP reference material.

DESIGN

Cohort study with data collected from 1991 to 2019 consisting of a population-based reference cohort and a group of girls with TS followed at a single tertiary centre.

PATIENTS/PARTICIPANTS

Reference population of 1888 healthy girls with 4890 BP recordings and 60 girls with TS with 365 BP recordings.

MEASUREMENTS

Difference in diastolic BP (DBP) and systolic BP (SBP), expressed in standard deviation scores (SDS), between girls with TS and the reference population, unadjusted and adjusted for BMI. Difference in BP (SDS) between TS subgroups (karyotype, oestrogen treatment, cardiac diagnosis).

RESULTS

The girls with TS had significantly higher DBP (mean ± SD, 0.72 SDS ± 0.95; p < .001) and SBP (0.53 SDS ± 1.11; p = .001) than the reference population. Adjusted for BMI, girls with TS had significantly higher DBP (mean ± SE, 0.71 SDS ± 0.12; p < .001) but not SBP (0.17 SDS ± 0.16; p = .29). There was no significant difference in DBP (median, IQR: 0.97 SDS, 0.30-1.58 vs. 0.76 SDS, 0.10-1.20; p = .31) or SBP (0.51 SDS, 0.15-1.30 vs. 0.57 SDS, -0.30 to 1.05; p = .67) between individuals with or without a cardiac diagnosis. In the TS population, 55% (31/56) had at least one BP recording above the hypertension threshold.

CONCLUSIONS

Our findings indicate that standardised longitudinal routine monitoring of BP in girls with TS already in childhood is of utmost importance.

Socioeconomic Status Is Related to Pubertal Development in a German Cohort

INTRODUCTION

Current health literature suggests that there has been a decline in the age of pubertal onset and that pubertal onset/duration of puberty may, besides weight status, be influenced by socioeconomic context.

OBJECTIVE

The goal of this study was to determine whether pubertal onset/duration and puberty-triggering hormones luteinizing hormone (LH) and follicle-stimulating hormone (FSH) vary according to socioeconomic status (SES). Moreover, we aimed to propose cutoff values of serum LH and FSH for predicting gonadarche in boys.

METHODS

2,657 apparently healthy children and adolescents between 5.5 and 18 years from the area of Leipzig were recruited from the LIFE Child study. Age at pubertal onset/end of puberty was given in 738/573 children, respectively. Anthropometric parameters of puberty, blood measurements of LH and FSH, and questionnaires assessing SES were evaluated.

RESULTS

Lower SES was associated with earlier thelarche and longer duration of puberty in overweight/obese girls, whereas age of menarche was not affected. In boys with low SES, a trend versus earlier puberty onset can be seen. Lower SES was significantly associated with boys' age at mutation. No significant differences in boys' and girls' serum levels of LH and FSH during puberty according to SES were observed. Serum LH levels of 0.56 IU/L and serum FSH levels of 1.74 IU/L showed the best prediction of gonadarche in boys.

CONCLUSION

Puberty onset/duration and boys' age at mutation is affected by SES. The proposed cutoff levels for serum LH and FSH could provide a serological tool to determine gonadarche in boys.

The Measurement of Female Early Adolescent Sexual Desire

We used the developmental systems model to deduce a definition of female early adolescent sexual desire. We evaluated a measure of this phenomenon with a secondary analysis of data from a randomized group sexual health intervention trial involving low-income, English-speaking, seventh grade Latinas enrolled in a Miami-Dade County public school (n = 542). As part of this study, girls completed a four-item early adolescent sexual desire (EASD) measure. Study findings supported internal consistency (Cronbach's alpha = .81 to .82) and stability over a 1-month period (r = .74). Developmental sensitivity was supported by a decline in stability over 12- (r = .66) and 24-month periods (r = .56). Validity was supported by correlations with puberty changes, sexual intentions, sexting, and sexual behavior, and hypothesized mean differences associated with dating and preference for shoes culturally associated with female sexual attractiveness (p < .01). Research implications include validation work with other ethnic/racial groups and using the EASD as a starting point for a measurement continuum tracking development of sexual desire across adolescence and into adulthood. Directions for future research also include measuring the development of sexual desire in boys and transgendered youth across adolescence and into adulthood.

Casual Associations and Shape Between Prepuberty Body Mass Index and Early Onset of Puberty: A Mendelian Randomization and Dose-Response Relationship Analysis

BACKGROUND

There is an ongoing controversial issue regarding whether onset of puberty is related to childhood BMI.

OBJECTIVES

This study aims at investigating the causal association and its shape between prepuberty BMI and early puberty onset.

METHODS

Breast development and testicular volume were assessed annually from a population-based prospective cohort of 997 children for consecutive years by professional endocrinologists. Seventeen puberty- and BMI-related SNPs were selected to calculate the polygenic risk score. The two-stage least square method was used to assess and confirm causal effects. A dose-response association between prepuberty BMI and early puberty onset was conducted by using restricted cubic spline Cox regression.

RESULTS

After adjusting for covariates, prepuberty BMI was positively associated with early thelarche among girls (coefficients = 0.18, 95% CI: 0.01, 0.29). A non-linear model suggested an inverted U-shaped relationship between prepuberty BMI and risk for early thelarche (χ² = 276.3, p < 0.001). The risk for early thelarche increased rapidly from prepuberty BMI at 15.70 kg/m² (P₂₅) to 20.75 kg/m² (P₈₅) and gradually decreased afterward. Compared with the P₂₅ of prepuberty BMI, the HRs (95% CI) for early thelarche were 5.08 (1.15, 8.55), 4.48 (1.02, 7.74), 10.15 (3.93, 17.50), and 8.43 (1.91, 13.71) for percentiles P₂₅-P₅₀, P₅₀-P₇₅, P₇₅-P₈₅, and ≥P₈₅ of BMI categories, respectively. In boys, compared with the P₂₅ of prepuberty BMI, boys with BMI between P₂₅ and P₅₀ showed an increased risk of early puberty (HR: 3.94, 95% CI: 1.44, 6.80).

CONCLUSIONS

Prepuberty BMI may serve the purpose of identifying the girls at higher risk of early thelarche, which could assist in the adaptation of prevention and intervention strategies targeting childhood obesity. The findings emphasize a non-linear correlation between prepuberty BMI and early puberty onset.

Pubarche and Gonadarche Onset and Progression Are Differently Associated With Birth Weight and Infancy Growth Patterns

Context

Controversy exists regarding associations between early-life growth patterns and timing of puberty.

Objective

This work aims to investigate associations between birth anthropometry, early growth patterns, and onset/progression of pubertal milestones in boys and girls.

Methods

Among children examined at birth (1997-2003) and at age 36 months in a mother-child cohort, pubertal Tanner stages (B1-5, PH1-5, G1-5) and testicular volume were examined by trained physicians at 1 to 5 follow-up examinations during childhood and adolescence (672 girls and 846 boys, 2006-2013).With parametric survival models we analyzed associations between birth weight, changes in SD scores (SDS) from birth to 36 months (ΔSDS 0-36 > 0.67 SD defining catch-up growth), and age at pubertal onset/attainment of late pubertal stages/menarche.

Results

A 1-kg higher birth weight was associated with earlier onset of B2+ (thelarche): -3.9 months (CI, -6.7 to -1.1 months), G2+ (gonadarche): -2.7 months (-5.3 to -0.1 months), Tvol3+ (testis size > 3 mL): -2.8 months (CI, -4.9 to -0.7 months), but with later G4+ and PH4+ in boys, and a slower progression from B2 to menarche (5.3 months [CI, 1.2 to 9.4 months]) in girls. Catch-up growth was associated with earlier PH2+ (pubarche) in girls (-4.1 months [CI, -7.6 to -0.6 months]), earlier PH2+ in boys (-3.4 months [CI, -6.6 to -0.2 months]), faster progression from B2 to menarche in girls (-9.1 months [CI, 14.6 to 3.5 months]), and earlier G4+ and PH4+ in boys.

Conclusion

Associations between birthweight and infancy catch-up growth differed for gonadarche and pubarche, and for early and late pubertal markers, with similar patterns in both sexes.

The LH/FSH ratio is not a sex-dimorphic marker after infancy: data from 6417 healthy individuals and 125 patients with Differences of Sex Development

STUDY QUESTION

What is the course of the LH/FSH ratio from infancy into adulthood in healthy individuals and in patients with Differences of Sex Development (DSD)?

SUMMARY ANSWER

The LH/FSH ratio had a marked overlap between the sexes after infancy and onwards throughout adulthood in healthy individuals and it was not a marker of hypogonadism in DSD patients.

WHAT IS KNOWN ALREADY

The LH/FSH ratio is a distinct marker of sex during minipuberty. No study has evaluated the LH/FSH ratio from infancy into adulthood.

STUDY DESIGN, SIZE, DURATION

This was a combined study of prospective longitudinal and cross-sectional cohorts of healthy individuals totaling 6417 males and females aged 0-80 years. Retrospective data from a single, tertiary center on 125 patients with DSD was also included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the healthy males (n = 3144) and females (n = 3273) aged 0-80 years, reference ranges for LH, FSH and the LH/FSH ratio were established from infancy (after minipuberty) and onwards. LH, FSH, and the LH/FSH ratio in 125 patients with DSD not undergoing treatment were compared to the reference ranges. Included DSD diagnoses were: Klinefelter syndrome including mosaic variants (males: n = 14), Turner syndrome including mosaic variants without Y-chromosome material (females: n = 48), 45,X/46,XY mosaicism (males: n = 24 and females: n = 6), partial androgen insensitivity syndrome (males: n = 11), complete androgen insensitivity syndrome (females: n = 13) and anorchia (males: n = 9).

MAIN RESULTS AND THE ROLE OF CHANCE

An overlap was observed in the LH/FSH ratio reference curves between males and females. However, when comparing the sexes at specific time points, the LH/FSH ratio was significantly higher in healthy males during childhood and adulthood and significantly higher in healthy females during puberty. When compared with healthy participants, male patients with anorchia and 45,X/46,XY mosaicism had significantly lower ratios, while patients with androgen insensitivity, regardless of sex, had significantly higher ratios.

LIMITATIONS, REASONS FOR CAUTION

The limitations of this study include that; (i) all healthy individuals were Caucasian, so conclusions may not apply to non-Caucasians; (ii) the calculated LH/FSH ratios were restricted to the specific analytical method used and may not be applicable to other laboratories; (iii) the samples from healthy individuals were stored for varying amounts of time up to 20 years which may affect the durability; and (iv) DSD diagnoses are heterogeneous thus making sturdy conclusions across diagnoses impossible.

WIDER IMPLICATIONS OF THE FINDINGS

In this study of combined cohorts of healthy participants, the largest normative ranges of LH, FSH, and the LH/FSH ratio to date were created. These reference ranges provide the opportunity for clinical as well as research use for all three markers. However, the previously rather undescribed LH/FSH ratio was not a distinct marker of sex after infancy nor a new marker of hypogonadism. Although there were significant differences between subgroups of DSD patients compared to healthy controls, the clinical significance of the LH/FSH ratio after infancy lacked. However, it can be speculated whether there are other areas of clinical application not investigated in this article, for example as a marker of fertility in select patient groups. As gonadotropin assays are readily available and gonadotropin measurements are part of regular workups, the LH/FSH ratio can easily be explored in further research without additional costs.

STUDY FUNDING/COMPETING INTEREST(S)

M.L.L. was funded by the Absalon Foundation. Cohort 1 was funded by the European Commission, through the Biomed 2 Program (BMH4-CT96-0314), Environmental Reproductive Health (QLK4-CT1999-01422) and EXPORED (QLK4-2001-00269), by the Danish Council for Independent Research (9700833 and 9700909), and by the Svend Andersens Foundation. Cohort 2 was funded by the Danish Environmental Research Program (96.01.015.16.05). Cohort 3 was funded by Kirsten and Freddy Johansens Foundation.

TRIAL REGISTRATION NUMBER

NA.

DATE OF FIRST PATIENT’S ENROLMENT

June 1990 (the launch of the department from which this project stems).

Obesity in childhood: how to improve male adolescence incoming

INTRODUCTION

Earlier or delayed puberty can be determined by numerous causes, but the exact mechanisms are not fully known. Anyway, those may be independent from the hypothalamicpituitary-gonadal axis involvement. Certainly, obesity is one of the main factors. In fact, obesity and infertility are strongly linked. For this reason, we want to analyse the relationship between puberty and obesity and give an updated state-of-the-art starting by discussing a 14-year-old obese boy's clinical case.

EVIDENCE ACQUISITION

Literature data are conflicting. Main criticisms are related to study design and evaluation criteria. Indeed, examined populations are not homogeneous by age, Tanner stage and BMI classification. The obesity epidemic is involved in earlier puberty, and puberty seems to be anticipated in all BMI groups. Very few studies evaluate the level of adiposity in the diagnosis of obesity. However, the role of the adipose tissue is crucial for hormone synthesis and regulation. Therefore, fat mass age-related and not simply BMI has to be considered by clinicians for appropriate diagnosis.

EVIDENCE SYNTHESIS

Regarding the clinical case, in three months our patient recovered delayed pubertal development following an anti-inflammatory and antioxidant Mediterranean Diet. Loss of weight, as in decrease of fat mass but saving of lean mass, increased testicular volume and testosterone levels occurred.

CONCLUSIONS

Puberty depends on several factors, including obesity. Further studies are needed to evaluate age groups, Tanner stage, diet and lifestyle, ethnicity and above all the fat/lean mass ratio. Lack of adequate tools could hinder a clinician's ability to recognize when or if therapeutic intervention is needed.

Correspondence Between Perceived Pubertal Development and Hormone Levels in 9-10 Year-Olds From the Adolescent Brain Cognitive Development Study

Aim

To examine individual variability between perceived physical features and hormones of pubertal maturation in 9-10-year-old children as a function of sociodemographic characteristics.

Methods

Cross-sectional metrics of puberty were utilized from the baseline assessment of the Adolescent Brain Cognitive Development (ABCD) Study-a multi-site sample of 9-10 year-olds (n = 11,875)-and included perceived physical features via the pubertal development scale (PDS) and child salivary hormone levels (dehydroepiandrosterone and testosterone in all, and estradiol in females). Multi-level models examined the relationships among sociodemographic measures, physical features, and hormone levels. A group factor analysis (GFA) was implemented to extract latent variables of pubertal maturation that integrated both measures of perceived physical features and hormone levels.

Results

PDS summary scores indicated more males (70%) than females (31%) were prepubertal. Perceived physical features and hormone levels were significantly associated with child's weight status and income, such that more mature scores were observed among children that were overweight/obese or from households with low-income. Results from the GFA identified two latent factors that described individual differences in pubertal maturation among both females and males, with factor 1 driven by higher hormone levels, and factor 2 driven by perceived physical maturation. The correspondence between latent factor 1 scores (hormones) and latent factor 2 scores (perceived physical maturation) revealed synchronous and asynchronous relationships between hormones and concomitant physical features in this large young adolescent sample.

Conclusions

Sociodemographic measures were associated with both objective hormone and self-report physical measures of pubertal maturation in a large, diverse sample of 9-10 year-olds. The latent variables of pubertal maturation described a complex interplay between perceived physical changes and hormone levels that hallmark sexual maturation, which future studies can examine in relation to trajectories of brain maturation, risk/resilience to substance use, and other mental health outcomes.

In utero and peripubertal metals exposure in relation to reproductive hormones and sexual maturation and progression among boys in Mexico City

BACKGROUND

Endocrine disrupting chemicals (EDCs) such as metals have been reported to alter circulating reproductive hormone concentrations and pubertal development in animals. However, the relationship has rarely been investigated among humans, with the exception of heavy metals, such as Pb and Cd. Our aim was to investigate measures of in utero and peripubertal metal exposure in relation to reproductive hormone concentrations and sexual maturation and progression among boys from the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) cohorts.

METHODS

Our analysis included 118 pregnant women and their male children from the ELEMENT study. Essential and non-essential metals were measured in urine collected from the mothers during the third trimester of pregnancy and their male children at 8-14 years. Reproductive hormone concentrations [serum testosterone, estradiol, dehydroepiandrosterone sulfate (DHEA-S), inhibin B, and sex hormone-binding globulin (SHBG)] were measured in blood samples from the children at 8-14 years. We also assessed Tanner stages for sexual maturation (genital, pubic hair development, and testicular volume), at two time points (8-14, 10-18 years). We used linear regression to independently examine urinary metal concentrations in relation to each peripubertal reproductive hormones adjusting for child age and BMI. Generalized estimation equations (GEEs) were used to evaluate the association of in utero and peripubertal metal exposures with sexual maturation and progression during follow-up based on Tanner staging and testicular volume.

RESULTS

In utero and prepubertal concentrations of some urinary metals were associated with increased concentrations of peripubertal reproductive hormones, especially non-essential metal(loid)s As and Cd (in utero), and Ba (peripubertal) as well as essential metal Mo (in utero) in association with testosterone. More advanced pubic hair developmental stage and higher testicular volume at the early teen visit was observed for boys with higher non-essential metal concentrations, including in utero Al and peripubertal Ba, and essential metal Zn concentration (peripubertal). These metals were also associated with slower pubertal progression between the two visits.

CONCLUSION

These findings suggest that male reproductive development may be associated with both essential and non-essential metal exposure during in utero and peripubertal windows.

Pubertal Synchrony and Depressive Symptoms: Differences by Race and Sex

Individual differences in the timing and tempo of pubertal development have been shown to be related to depressive symptoms during adolescence, particularly among girls. Another measure of variability in pubertal development is pubertal synchrony, the degree to which the development of pubertal indicators (e.g., breast growth and ancillary hair growth) are synchronized within the individual. Pubertal synchrony also has been hypothesized to be related to depressive symptoms, but, to date, only one study has tested this hypothesis. However, it remains unclear whether pubertal synchrony confers risk for depressive symptoms more proximally in time or differentially among boys or non-White youth. The current study examined the relation between pubertal synchrony and depressive symptoms concurrently and six months later as a function of race and sex in a community sample of 215 youth (53% female, 44.7% African American; mean age = 12.90 years (SD = 0.86)). Girls with asynchronous development at Time 1 reported significantly higher depressive symptoms at Time 2 than girls with synchronous development and boys with asynchronous development. In addition, boys with asynchronous development at Time 1 had lower depressive symptoms at Time 2 than boys with synchronous development. Race did not moderate pubertal synchrony-depression relations. These results suggest that pubertal asynchrony is a risk factor for girls, but a protective factor for boys, and lend support for pubertal synchrony as a potential contributor to the gender gap in depression that emerges during adolescence.

Longitudinal Increases in Serum Insulin-like Factor 3 and Testosterone Determined by LC-MS/MS in Pubertal Danish Boys

BACKGROUND

Serum concentrations of the peptide hormone insulin-like factor 3 (INSL3) is a candidate marker for improved distinction between constitutional delay of growth and puberty (CDGP) and permanent hypogonadotropic hypogonadism (HH) in boys.

AIM

To assess the possible diagnostic role of LC-MS/MS-based INSL3 measurements as a marker of imminent puberty by comparison with testosterone (T) and luteinizing hormone (LH) levels in serum longitudinally collected from 18 healthy boys throughout puberty.

RESULTS

The first increase in serum LH was detected on average 4 months earlier, as compared with the first observed increases in INSL3 and T. When comparing the 2 testicular hormones only, we found that in 22% (4 of 18) of the boys the first increase in serum INSL3 was observed prior to the first observed increase in T, whereas in 44% (8 of 18) the first increase in T was observed before the first observed increase in INSL3. In the remaining 6 boys, the 2 testicular hormones showed the first increase at the same examination.

CONCLUSION

In some boys with delayed puberty, the first indication of testicular maturation may be detectable by observing serum INSL3. Further studies of LC-MS/MS determination of serum INSL3 in patients with CDGP and HH are warranted.

Changes in Adrenal Androgens and Steroidogenic Enzyme Activities From Ages 2, 4, to 6 Years: A Prospective Cohort Study

CONTEXT

The levels of adrenal androgens are increased through the action of steroidogenic enzymes with morphological changes in the adrenal zona reticularis.

OBJECTIVE

We investigated longitudinal changes in androgen levels and steroidogenic enzyme activities during early childhood.

DESIGN AND PARTICIPANTS

From a prospective children's cohort, the Environment and Development of Children cohort, 114 boys and 86 girls with available blood samples from ages 2, 4, and 6 years were included.

OUTCOME MEASUREMENTS

Serum concentrations of adrenal androgens using liquid chromatography-tandem mass spectrometry and steroidogenic enzyme activity calculated by the precursor/product ratio.

RESULTS

During ages 2 to 4 years, 17,20-lyase and dehydroepiandrosterone (DHEA) sulfotransferase activities increased (P < 0.01 for both in boys). During ages 4 to 6 years, 17,20-lyase activity persistently increased, but 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD activities decreased (P < 0.01 for all). Serum DHEA sulfate (DHEA-S) levels persistently increased from 2, 4, to 6 years, and DHEA, 17-hydroxyprogesterone, and androstenedione levels increased during ages 4 to 6 years (P < 0.01 for all). Serum DHEA-S levels during early childhood were associated with body mass index z-scores (P = 0.001 in only boys).

CONCLUSION

This study supports in vivo human evidence of increased 17,20-lyase and DHEA sulfotransferase activities and decreased 3β-HSD activity during early childhood.

PUBERTY IN A SAMPLE OF BRAZILIAN SCHOOLBOYS: ONSET AND ANTHROPOMETRIC CHARACTERISTICS

Objective:

To determine the age of puberty onset in boys and collect anthropometric data of participants at different puberty stages.

Methods:

This is a cross-sectional study that assessed 430 boys in a random sample representing 48,390 students from public and private schools from the city of Uberaba, Southeast Brazil. The inclusion criteria were males, aged between 5 and 18 years, and absence of previous diseases. Participants and their guardians filled a semistructured questionnaire with questions relevant to their and their parents’ puberty. We set the significance at p<0.05 and calculated the 95% confidence intervals.

Results:

The mean age found in the puberty stage G2 was 11.2±1.8 (95% of participants in stage G2 were 9.2-13.4 years old). Pubarche data showed a mean of age of 11.0±1.6 years (95% of the participants experienced pubarche when they were 8.0-14.0 years old). When compared to the confidence intervals of two classical studies on the subject, our results showed a trend toward earlier pubarche. In addition, the mean age of this event in the children’s parents was of 12.1±1.4 years, which was significantly higher than the age of the children’s pubarche (p<0.001).

Conclusions:

These results indicate a secular decreasing trend in pubarche age and an earlier puberty onset. Considering these parameters, is important to design public policies aimed at preventing these early events.

Reference data for testicular volume measured with ultrasound and pubic hair in Norwegian boys are comparable with Northern European populations

AIM

To estimate references for testicular volume measured with ultrasound and Tanner stages of pubic hair in Norwegian boys, and to compare the timing of puberty with data from similar populations.

METHODS

Testicular volume was derived from ultrasound measurements of testicular volume in a cross-sectional study of 514 healthy boys. A continuous testicular volume for age reference curve was estimated with the LMS method. Tanner stages for pubic hair were clinically assessed in 452 boys. Age references for pubertal milestones were estimated with probit regression.

RESULTS

Puberty onset, defined by an ultrasound testicular volume of 2.7 mL, equivalent to an orchidometer volume of 4 mL, occurred at a mean (SD) age of 11.7 (1.1) years. The reference range was 9.7 (3rd) to 13.7 years (97th percentile). Pubic hair (Tanner stage 2) appeared on average at 11.8 (1.2) years with a corresponding reference range of 9.5-14.1 years.

CONCLUSION

The references for testicular volume measured with ultrasound are continuous in age and allow for the quantification of pubertal development. The age distribution of reaching pubertal milestones was comparable with data from other Northern European countries.

Pubertal development and reproductive hormone levels of singleton ICSI offspring in adolescence: results of a prospective controlled study

STUDY QUESTION

Are there any differences in the pubertal development and reproductive hormone status during adolescence between singletons following ICSI therapy or spontaneous conception (SC)?

SUMMARY ANSWER

Pubertal development and reproductive hormone levels are largely similar between ICSI and SC adolescents, except for a tendency towards lower inhibin B levels as well as significantly higher estradiol levels and a lower testosterone-to-estradiol-ratio in male adolescents.

WHAT IS KNOWN ALREADY

Previous data are scarce and partly inconclusive regarding pubertal development in female ICSI adolescents as well as demonstrating a tendency towards lower inhibin B serum levels in male ICSI offspring.

STUDY DESIGN, SIZE, DURATION

Prospective controlled study including 274 singleton ICSI-conceived adolescents (141 girls, 133 boys) followed up for the third time, and 273 SC controls (142 girls, 131 boys) from seven German registration offices (Aachen, Eichstätt, Erfurt, Lübeck, Hamburg, Heidelberg and Schwerin).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Pubertal development assessed by Tanner staging (breast, genital and pubic hair development), age at menarche and reproductive hormone levels were analyzed in ICSI and SC adolescents at the mean age of 16.5 years. Differences were analyzed by multinomial regression (Tanner stages) or t test and linear regression for hormonal assessments.

MAIN RESULTS AND THE ROLE OF CHANCE

Both female and male ICSI and SC adolescents showed adequate pubertal maturation according to their age, and the mean age at menarche (at 12.7 versus 12.8 years) was similar. Tanner stages as well did not display any relevant or significant differences between the groups. Reproductive hormone levels in female adolescents not using hormonal contraception were largely similar before and after adjustment for several factors such as preterm birth, Tanner stages, BMI or physical activity. In male ICSI adolescents, a tendency towards lower inhibin B (−14.8 pg/ml, 95% CI: −34.2 to 4.6 pg/ml), significantly higher estradiol (2.6 ng/l, 95% CI: 0.0 to 5.2 ng/l) and a significantly lower testosterone-to estradiol ratio (−0.047, 95% CI: −0.089 to −0.004) was found.

LIMITATIONS, REASONS FOR CAUTION

The all-over response rate and the willingness to participate in the blood test and medical examination were very low in the control group. Participating control families may have greater health awareness, and selection bias cannot be ruled out. Hormonal data in the females were measured irrespective of the cycle day and restricted to those not using hormonal contraception. Some parameters from the questionnaire data such as usage of hormonal contraception might suffer from reporting bias. As this is an observational study, we can draw only limited causal conclusions from the findings.

WIDER IMPLICATIONS OF THE FINDINGS

Differences in male reproductive hormones may indicate altered testicular function. However, at this time possible consequences for later reproductive success are unknown.

STUDY FUNDING/COMPETING INTEREST(S)

DFG research grant KA 1643/4-1. The authors declare no conflict of interest.

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.

Onset and tempo of sexual maturation is differentially associated with gestational phthalate exposure between boys and girls in a Mexico City birth cohort

Phthalates are endocrine disrupting compounds commonly found in consumer products, exposure to which may influence reproductive maturation. Effects from exposure in utero on the onset and progression of sexual development are understudied. We examined longitudinal associations between gestational phthalate exposure and sexual maturation at two points in adolescence (8-14, 9-18 years). Gestational exposure was quantified using the geometric mean of 3 trimester-specific urinary phthalate metabolite measurements. Sexual maturation was assessed using Tanner stages and menarche onset for girls and Tanner stages and testicular volume for boys. Generalized estimating equations for correlated ordinal multinomial responses were used to model relationships between phthalates and odds of transitioning to the next Tanner stage, while generalized additive (GA) mixed models were used to assess the odds of menarche. All models were adjusted for child age (centered around the mean), BMI z-score, change in BMI between visits, time (years) between visits (ΔT), and interactions between ΔT and mean-centered child age and the natural log of exposure metabolite concentration. Among girls, a doubling of gestational MBzP concentrations was associated with increased odds of being at a higher Tanner stage for breast development at 8-14 years (OR = 4.62; 95% CI: 1.38, 15.5), but with slower progression of breast development over the follow-up period (OR = 0.65 per year; 95% CI: 0.46, 0.92) after adjustment for child age and BMI z-score. Similar results were found for ∑DEHP levels and breast development. In boys, a doubling of gestational MBP concentrations was associated with lower odds of being at a higher Tanner stage for pubic hair growth at 8-14 years (OR = 0.37; 95% CI: 0.14, 0.95) but with faster progression (OR: 1.28; 95% CI: 0.97, 1.69). These results indicate that gestational phthalate exposures may impact the onset and progression of sexual development, and that these relationships differ between boys and girls.

Bumpy and Smoother Pathways of Puberty Hormone Change: A Novel Way to Define Gonadal Hormone Trajectories in Adolescents

CONTEXT

The study of gonadal hormone effects on adolescent wellbeing has been limited by logistical challenges. Urine hormone profiling offers new opportunities to understand the health and behavioral implications of puberty hormones.

OBJECTIVE

To characterize pubertal change in urinary testosterone and estradiol among male and female adolescents, respectively.

DESIGN

Three-year prospective cohort study.

SETTING

Australian regional community.

PARTICIPANTS

282 (163 male) normally developing adolescents aged 11.8 ± 1.0 years at baseline.

MAIN OUTCOME MEASURE

Quarterly urine measurements of testosterone and estradiol (mass spectrometry); annual anthropometric assessment and Tanner stage (TS) self-report.

RESULTS

Two-class sigmoidal and quadratic growth mixture models (centered on age at TS3) were identified as best-fit for describing testosterone (male) and estradiol (female) change. Classes 1 (male: 63%; female: 82%) and 2 (male: 37%; female: 18%) were respectively named the "stable" and "unstable" trajectories, characterized by different standard deviation of quarterly hormone change and magnitude of hormone peaks and troughs (all P < 0.001). Compared with class 1 (stable), class 2 males were taller at baseline (154 vs 151 cm), reported earlier and faster TS progression (P < 0.01), and showed higher serum testosterone levels at baseline and 3 years (P ≤ 0.01). Class 2 females exhibited smaller height and weight gains over the 3 years and had higher baseline serum estradiol (249 vs 98 pmol/L; P = 0.002) than class 1.

CONCLUSIONS

Adolescents showed 2 distinct urinary gonadal hormone trajectories, characterized by stability of change over time, which were not associated with consistent anthropometric differences. Results provide a methodology for studying gonadal hormone impacts on other aspects of biopsychosocial wellbeing. Identification of potential "at-risk" hormone groups would be important for planning supportive interventions.

Family composition and age at menarche: Findings from the international Health Behaviour in School-aged Children study

Background

Early menarche has been associated with father absence, stepfather presence and adverse health consequences in later life. This article assesses the association of different family compositions with the age at menarche. Pathways are explored which may explain any association between family characteristics and pubertal timing.

Methods

Cross-sectional, international data on the age at menarche, family structure and covariates (age, psychosomatic complaints, media consumption, physical activity) were collected from the 2009–2010 Health Behaviour in School-aged Children (HBSC) survey. The sample focuses on 15-year old girls comprising 36,175 individuals across 40 countries in Europe and North America (N = 21,075 for age at menarche). The study examined the association of different family characteristics with age at menarche. Regression and path analyses were applied incorporating multilevel techniques to adjust for the nested nature of data within countries.

Results

Living with mother (Cohen’s d = .12), father (d = .08), brothers (d = .04) and sisters (d = .06) are independently associated with later age at menarche. Living in a foster home (d = −.16), with ‘someone else’ (d = −.11), stepmother (d = −.10) or stepfather (d = −.06) was associated with earlier menarche. Path models show that up to 89% of these effects can be explained through lifestyle and psychological variables.

Conclusions

Earlier menarche is reported amongst those with living conditions other than a family consisting of two biological parents. This can partly be explained by girls’ higher Body Mass Index in these families which is a biological determinant of early menarche. Lower physical activity and elevated psychosomatic complaints were also more often found in girls in these family environments.

Correspondence of Pubertal Neuroendocrine and Tanner Stage Changes in Boys and Associations With Substance Use

This study examined correspondence between timing (onset) and tempo (rate) of sexual maturation prospectively (average ages 11-16 years) measured by gonadal hormones and secondary sex characteristics (Tanner stage) using dual-process models, and associations of these measures with substance use (SU) involvement in boys at age 16 years (N = 534, 77.5% White/22.5% Non-White). All measures of timing were highly associated. Early Tanner stage timing often predicted slower increases in gonadal steroids, but not the reverse; patterns varied by ethnicity. Hormone and Tanner stage measures were similar earlier in development but diverged later in development. In White boys only, early timing of the pubertal rise in testosterone was associated with increased SU involvement, suggesting a physiological rather than psychosocial mechanism of association.

Adolescence as a Biocultural Life History Transition

While the categories of adolescence and puberty are often treated as one, the existence of two distinct terms points to different kinds of maturation in humans. Puberty refers to a period of coordinated somatic growth and reproductive maturation that shifts individuals from nonreproductive juvenility to reproductive maturity. Adolescence includes the behavioral and social assumption of adult roles. Life history theory offers powerful tools for understanding why puberty occurs later in humans than in other primates, including the benefits of delayed reproduction as part of a cooperation-intensive life history strategy. It also sheds light on the ways that pubertal timing responds to environmental variation. I review the mechanisms of maturation in humans and propose biocultural approaches to integrate life historical understandings of puberty with a broader definition of environment to encompass the concept of adolescence.

Delayed Puberty-Phenotypic Diversity, Molecular Genetic Mechanisms, and Recent Discoveries

This review presents a comprehensive discussion of the clinical condition of delayed puberty, a common presentation to the pediatric endocrinologist, which may present both diagnostic and prognostic challenges. Our understanding of the genetic control of pubertal timing has advanced thanks to active investigation in this field over the last two decades, but it remains in large part a fascinating and mysterious conundrum. The phenotype of delayed puberty is associated with adult health risks and common etiologies, and there is evidence for polygenic control of pubertal timing in the general population, sex-specificity, and epigenetic modulation. Moreover, much has been learned from comprehension of monogenic and digenic etiologies of pubertal delay and associated disorders and, in recent years, knowledge of oligogenic inheritance in conditions of GnRH deficiency. Recently there have been several novel discoveries in the field of self-limited delayed puberty, encompassing exciting developments linking this condition to both GnRH neuronal biology and metabolism and body mass. These data together highlight the fascinating heterogeneity of disorders underlying this phenotype and point to areas of future research where impactful developments can be made.

Calorie Restriction Modulates Reproductive Development and Energy Balance in Pre-Pubertal Male Rats

The objective was to determine effects of feed restriction and refeeding on reproductive development and energy balance in pre-pubertal male rats. Sprague Dawley rats (n = 32, 24 days old, ~65 g), were randomly allocated into four treatments (n = 8/treatment): (1) Control (CON, ad libitum feed; (2) Mild Restriction (MR, rats fed 75% of CON consumption); (3) Profound Restriction (PR, 50% of CON consumption); or (4) Refeeding (RF, 50% restriction for 14 days, and then ad libitum for 7 days). Feed restriction delayed reproductive development and decreased energy balance and tissue accretion, with degree of reproductive and metabolic dysfunctions related to restriction severity. In RF rats, refeeding largely restored testis weight, sperm production (per gram and total), plasma IGF-1, leptin and insulin concentrations and energy expenditure, although body composition did not completely recover. On Day 50, more CON and RF rats than PR rats were pubertal (5/6, 4/5 and 1/6, respectively; plasma testosterone >1 ng/mL) with the MR group (4/6) not different. Our hypothesis was supported: nutrient restriction of pre-pubertal rats delayed reproductive development, induced negative energy balance and decreased metabolic hormone concentrations (commensurate with restriction), whereas short-term refeeding after profound restriction largely restored reproductive end points and plasma hormone concentrations, but not body composition.

Paediatric and adult-onset male hypogonadism

The hypothalamic-pituitary-gonadal axis is of relevance in many processes related to the development, maturation and ageing of the male. Through this axis, a cascade of coordinated activities is carried out leading to sustained testicular endocrine function, with gonadal testosterone production, as well as exocrine function, with spermatogenesis. Conditions impairing the hypothalamic-pituitary-gonadal axis during paediatric or pubertal life may result in delayed puberty. Late-onset hypogonadism is a clinical condition in the ageing male combining low concentrations of circulating testosterone and specific symptoms associated with impaired hormone production. Testosterone therapy for congenital forms of hypogonadism must be lifelong, whereas testosterone treatment of late-onset hypogonadism remains a matter of debate because of unclear indications for replacement, uncertain efficacy and potential risks. This Primer focuses on a reappraisal of the physiological role of testosterone, with emphasis on the critical interpretation of the hypogonadal conditions throughout the lifespan of the male individual, with the exception of hypogonadal states resulting from congenital disorders of sex development.

Precocious pubertal events in Chilean children: ethnic disparities

PURPOSE

Puberty onset exhibits remarkable inter-individual and ethnic differences. 5% of Chileans are indigenous but puberty ethnic disparities have not been studied. We aim for evaluating precocious puberty prevalence in children with Mapuche ancestry vs non-indigenous Chilean children (according to their surnames).

METHODS

Longitudinal cohort study: 1003 children (50.2% girls) participating in the Growth and Obesity Chilean Cohort Study (GOCS) were studied. Annual anthropometry was measured since 4-7 years. Subsequently, Tanner staging and anthropometry were measured every 6 months. In girls, Tanner stage was assessed by breast palpation and in boys by testicular volume measurements. The cohort was stratified in three groups depending on Mapuche surname numbers as follows: (A) no indigenous surnames (n = 811), (B) one to two indigenous surnames (n = 147), and (C) three or more indigenous surnames (n = 45). We evaluated the prevalence of precocious thelarche, pubarche, menarche and gonadarche (testicular volume ≥ 4 ml-G2), using a cutoff age of 8 years in girls and 9 years in boys while controlling for socioeconomic status, body mass index, waist circumference, IGF-1 and DHEAS at 7 years.

RESULTS

In girls, no significant differences were observed. On the contrary, in boys, precocious gonadarche prevalence was higher in group C (29.2%) vs group A (6.0%) and vs group B (10.5%) (p =0.001, p = 0.004, respectively). Increased precocious gonadarche and pubarche risks in group C were observed even after adjustment [OR 7.31; 95% IC (2.32-23.51); p = 0.001] and [OR 6.17, 95% CI (1.62-23.49); p = 0.008], respectively.

CONCLUSION

Indigenous origin in Chile is an independent risk factor for precocious gonadarche and pubarche in boys but not in girls.

The Wonder Years: What Can Primary School Children Teach Us About Immunity to Mycobacterium tuberculosis?

In high burden settings, the risk of infection with Mycobacterium tuberculosis increases throughout childhood due to cumulative exposure. However, the risk of progressing from tuberculosis (TB) infection to disease varies by age. Young children (<5 years) have high risk of disease progression following infection. The risk falls in primary school children (5 to <10 years), but rises again during puberty. TB disease phenotype also varies by age: generally, young children have intrathoracic lymph node disease or disseminated disease, while adolescents (10 to <20 years) have adult-type pulmonary disease. TB risk also exhibits a gender difference: compared to adolescent boys, adolescent girls have an earlier rise in disease progression risk and higher TB incidence until early adulthood. Understanding why primary school children, during what we term the "Wonder Years," have low TB risk has implications for vaccine development, therapeutic interventions, and diagnostics. To understand why this group is at low risk, we need a better comprehension of why younger children and adolescents have higher risks, and why risk varies by gender. Immunological response to M. tuberculosis is central to these issues. Host response at key stages in the immunopathological interaction with M. tuberculosis influences risk and disease phenotype. Cell numbers and function change dramatically with age and sexual maturation. Young children have poorly functioning innate cells and a Th2 skew. During the "Wonder Years," there is a lymphocyte predominance and a Th1 skew. During puberty, neutrophils become more central to host response, and CD4+ T cells increase in number. Sex hormones (dehydroepiandrosterone, adiponectin, leptin, oestradiol, progesterone, and testosterone) profoundly affect immunity. Compared to girls, boys have a stronger Th1 profile and increased numbers of CD8+ T cells and NK cells. Girls are more Th2-skewed and elicit more enhanced inflammatory responses. Non-immunological factors (including exposure intensity, behavior, and co-infections) may impact disease. However, given the consistent patterns seen across time and geography, these factors likely are less central. Strategies to protect children and adolescents from TB may need to differ by age and sex. Further work is required to better understand the contribution of age and sex to M. tuberculosis immunity.

Association of prepubertal obesity with pubertal development in Chinese girls and boys: A longitudinal study

OBJECTIVES

The purpose of this study was to examine the association of prepubertal body mass index (BMI) and weight status with pubertal development in boys and girls in Chongqing, China.

METHODS

In a longitudinal study, 1237 students (695 boys and 542 girls) were recruited from Chongqing, China, and examined at baseline, then followed every 6 months for three and a half years. Height, weight, testicular volume, and breast development were measured at every examination. Age of first spermatorrhea and menarche were obtained from self-report. Subjects were divided into normal weight, overweight, and obese groups according to baseline BMI. Multivariable Cox regression analysis was used to examine the association of BMI and weight status with pubertal development.

RESULTS

In girls, higher prepubertal BMI increased the chance of earlier menarche (hazards ratio (HR): 1.205, 95% confidence interval (95% CI): 1.151-2.261) and breast development (HR: 1.092, 95% CI: 1.045-1.142). Girls in the overweight (HR: 2.605, 95% CI: 1.716-3.956) and obese (HR: 2.565, 95% CI: 1.603-4.103) groups had an increased risk of early menarche compared with those in the normal weight group, while only overweight was associated with an increased risk for earlier breast development (HR: 1.469, 95% CI: 1.024-2.108). In boys, higher prepubertal BMI was significantly associated with the timing of first spermatorrhea (HR: 1.054, 95% CI: 1.004-1.106) and testicular development (HR: 1.098, 95% CI: 1.063-1.135). Overweight (HR: 1.672, 95% CI: 1.204-2.322) and obesity (HR: 1.598, 95% CI: 1.135-2.249) increased the hazard of earlier testicular development compared with the normal weight group, while no significant differences were detected among the three weight groups in terms of time to first spermatorrhea.

CONCLUSIONS

Higher prepubertal BMI was associated with earlier puberty in both Chinese boys and girls.

Anogenital distance and reproductive outcomes in 9- to 11-year-old boys: the INMA-Granada cohort study

BACKGROUND

Studies examining the association of anogenital distance (AGD), a biomarker of prenatal androgen exposure, with sexual development in children are lacking.

OBJECTIVE

To assess the association between AGD measures and reproductive outcomes, including puberty onset, testicular volume, reproductive hormone levels, and urogenital malformations in boys aged 9-11 years.

MATERIALS AND METHODS

A cross-sectional study was conducted among children belonging to the Spanish Environment and Childhood (INMA) Project, a population-based birth cohort study. The present sample included 279 boys for whom data were available on AGD, pubertal stage, testicular volume, and relevant covariates. Out of the boys with AGD data, 187 provided a blood sample for hormone analysis. AGD was measured from the center of the anus to the base of the scrotum. Pubertal development was assessed according to Tanner stage of genital development (G1-G5), and testicular volume was measured with an orchidometer.

RESULTS

After adjusting for potential confounders, logistic regression analysis showed that AGD was positively associated with testicular volume but not with Tanner stage (>G1 vs. G1), serum hormone levels, or undescended testis. Regardless of their age, body mass index, and Tanner stage (G1 or >G1), boys with longer AGD showed increased odds of a testicular volume >3 mL (OR = 1.06, 95%CI = 1.00-1.19 per 10% increment in AGD; and OR = 3.14, 95%CI = 0.99-9.94 for AGD >42 mm vs. <33 mm).

DISCUSSION

Longer AGD was associated with testicular growth, an indicator of gonadarche, but not with other reproductive outcomes.

CONCLUSIONS

Although AGD was positively associated with testicular volume, it remains unclear whether AGD predicts testis size at puberty or is related to puberty onset.

Parental hospital-treated somatic illnesses during offspring's childhood associated with later offspring use of psychotropic medication during childhood to young adult - The 1987 Finnish Birth Cohort study

This study aimed to systematically examine whether parental hospital-treated somatic illnesses, diagnosed during an offspring's childhood (1987-1995), are associated with later use of psychotropic medication (1996-2012) by the offspring. If so, which parental somatic illnesses, in particular, increase the likelihood for later use of psychotropic medication among the offspring. The 1987 Finnish Birth Cohort study yields longitudinal nationwide follow-up data that include a complete census of children born in a single year. A total 58,551 offspring are included in this study and, of these 57,752 had a known father. Offspring who had used psychotropic medication between the ages of 9 and 24 years, more often had parents who had experienced a greater number of somatic illnesses when their child was aged under 9, compared to offspring without any use of psychotropic medication. The specific parental somatic illnesses early in life, for example disorders of female tract (OR 1.12, 95%CI 1.01-1.23), pregnancy with abortive outcome (1.18, 1.09-1.28), paternal acute infections (1.20, 1.05-1.38), and paternal symptoms, signs, and ill-defined conditions (1.21, 1.03-1.42), were found to be associated with psychotropic medication treatment using parental-related determinants; death, education, receipt of social assistance and psychiatric inpatient care as covariates. This suggests that these specific parental somatic illnesses can affect psychological well-being of the offspring. Preventive actions and support for the child, should be provided in situations where a parent with a somatic illness has limited ability to care for and rear their child.

Deletion in the uridine diphosphate glucuronyltransferase 2B17 gene is associated with delayed pubarche in healthy boys

OBJECTIVE

Only a few genetic loci are known to be associated with male pubertal events. The ability of excreting testosterone (T) and other steroids in the urine depends on sulfation and glucuronidation. One of several essential glucuronidases is encoded by the UGT2B17 gene. In a preliminary report, we found that homozygous deletion of UGT2B17 in boys was associated with lower urinary excretion of T. We hypothesized that boys with a lower glucuronidation capacity may have altered androgen action and excretion affecting pubarche, as this represents a T-dependent event.

DESIGN, PARTICIPANTS AND MEASURES

668 healthy boys (cross-sectional) aged 6.1-21.9 years (COPENHAGEN puberty study conducted from 2005 to 2006) were included. 65 of the boys where followed longitudinally every 6 months. Participants were genotyped for UGT2B17 copy number variation (CNV). Clinical pubertal staging including orchidometry, anthropometry and serum reproductive hormone levels.

RESULTS

59 of the 668 boys (8.8%) presented with a homozygous deletion of UGT2B17 (del/del). These boys experienced pubarche at a mean age of 12.73 years (12.00-13.46) vs 12.40 years (12.11-12.68) in boys heterozygous for deletion of UGT2B17 (del/ins) vs 12.06 years (11.79-12.33) in boys with the wild-type genotype (ins/ins) (P = 0.029, corrected for BMI z-score). The effect accounted for 0.34 years delay per allele (95% CI: 0.03-0.64). A comparable trend was observed for onset of testicular enlargement >3 mL but did not reach significance.

CONCLUSION

CNV of UGT2B17 is a factor contributing to the timing of male pubarche.

Faster ticking rate of the epigenetic clock is associated with faster pubertal development in girls

Epigenetic age is an indicator of biological aging, capturing the impact of environmental and behavioral influences across time on cellular function. Deviance between epigenetic age and chronological age (AgeAccel) is a predictor of health. Pubertal timing has similarly been associated with cancer risk and mortality rate among females. We examined the association between AgeAccel and pubertal timing and adolescent breast composition in the longitudinal Growth and Obesity Cohort Study. AgeAccel was estimated in whole blood using the Horvath method at breast Tanner 2 (B2) and 4 (B4). Total breast volume, absolute fibro-glandular volume (FGV), and %FGV were evaluated at B4 using dual X-ray absorptiometry. The impact of AgeAccel (mean: 0; SD: 3.78) across puberty on the time to breast development (thelarche), menarche, and pubertal tempo (thelarche to menarche) was estimated using accelerated failure time models; generalized estimating equations were used to evaluate associations with breast density. A five-year increase in average adolescent AgeAccel was associated with a significant decrease in time to menarche [hazard ratio (HR): 1.37; 95% confidence interval (CI): 1.04, 1.80] adjusting for birth weight, maternal pre-pregnancy body mass index, maternal height, maternal education, B2 height, fat percentage, and cell composition. AgeAccel displayed a stronger inverse association with pubertal tempo (HR: 1.48; 95% CI: 1.10, 1.99). A five-year increase in AgeAccel was associated with 5% greater %FGV, adjusting for B4 percent body fat, and maternal traits (95% CI: 1.01, 1.10). Our study provides unique insight into the influence of AgeAccel on pubertal development in girls, which may have implications for adult health.

Is age at puberty associated with semen quality and reproductive hormones in young adult life?

The evidence is scarce on the association between age at puberty and semen quality. A cohort of 320 Danish men aged 18-21 years enrolled in the "Healthy Habits for Two" birth cohort provided self-reported data on pubertal indicators and delivered semen and blood samples. The results indicated an association between older age at pubertal development and lower semen quality and altered reproductive hormones concentrations as measured in young adult life. Men who had their first nocturnal emission, start of pubic hair growth and first voice break episode when older than 15 years had 37.0%, 45.0% and 32.7% lower sperm concentration; 37.8%, 44.2% and 29.1% lower total sperm count; 7.4%, 13.4% and 15.3% lower testosterone concentration; and 21.3%, 1.5% and 3.7% lower inhibin B concentration, respectively, compared with the men who were younger than 13 years at their first pubertal indicators. Only few of the results were statistically significant, but similar tendencies were seen in several of the reproductive parameters suggesting an association between the timing of pubertal development and reproductive health later in life.