Outcomes of pubertal development in girls as a function of pubertal onset age

Characteristics of Puberty in a Population-Based Sample of Danish Adolescents

PURPOSE

To describe the duration, timing, tempo, and synchronicity of puberty, as well as the correlation between timing and tempo of puberty.

METHODS

Overall, 15,819 of 22,439 invited children participated in the Puberty Cohort within the Danish National Birth Cohort. Participants completed a web-based questionnaire every 6 months through maturation with questions on current pubertal status. Girls reported current Tanner stage of breast and pubic hair development, and timing of menarche. Boys reported current Tanner stage of genital and pubic hair development, timing of first ejaculation, and vocal changes. While accounting for this interval-censored puberty information, we estimated the duration of puberty. Then, we used a nonlinear mixed effect growth model to estimate timing, tempo, synchronicity of puberty, and correlation between timing and tempo of puberty.

RESULTS

In girls, the average duration of breast development was longer, whereas the average tempo was slower than pubic hair development. The average timing of breast development was earlier than the average timing of pubic hair development. The majority of girls had asynchronous puberty. In boys, the average duration was longer and average tempo slower for genital than pubic hair development. The average timing of genital and pubic hair development were comparable; hence, the majority had synchronous pubertal development. Adolescents who had earlier timing also tended to have a faster tempo.

DISCUSSION

Being one of the largest puberty cohorts worldwide, these unique contemporary data can help physicians, parents, and children to understand and anticipate expected progression through pubertal development.

Pattern of linear growth and progression of bone maturation for girls with early-onset puberty: A mixed longitudinal study

Background and objective

With a worldwide trend to earlier age of onset of puberty, the prevalence of early-onset puberty (EP) among girls has increased. The impact of EP on the pattern of linear growth and bone maturation is unclear. Accordingly, the objective of our study was to describe this pattern for girls with EP in Shenzhen, China.

Methods

A total of 498 untreated girls diagnosed with EP at Shenzhen Children's Hospital, China, between January 2016 and December 2021. A total of 1,307 anthropometric measurements and 1,307 left-hand radiographs were available for analysis. Artificial intelligence (AI) was used to determine bone age (BA). Participants were classified into groups according to chronological age (CA) and BA. The pattern of linear growth (height) and progression of bone maturation was described between groups using the Lambda-Mu-Sigma (LMS) method. Published height-for-CA and height-for-BA norm references for a healthy Chinese population were used for age-appropriate comparisons.

Results

The mean CA of appearance of first pubertal signs (breast buds) was 8.1 ± 0.5 years. Compared to norm-referenced data, girls with EP were significantly taller at a CA of 7-10 years. This was followed by a slowing in linear growth after a CA of 10 years, with 71 girls with EP having already achieved their target adult height. From 7 to 10 years of BA, the linear growth was slower in the EP group compared to norm-reference values. This was followed by a period of catch-up growth at 11.2 years of BA, with growth curves approaching norm-referenced values. The BA progressed rapidly from 7 to 8 years of age in about half of the girls with EP (median ΔBA/ΔCA >1.9), slowing, thereafter, until the period of catch-up growth at 11.2 years of BA.

Conclusions

BA provides a more reliable reference than CA to assess growth parameters among girls with EP. Our limited data set does indicate that EP does not negatively impact final adult height. Therefore, the growth curves from our study are relevant, providing a reference for pediatricians in this clinical population and, thus, preventing over-treatment for EP.

Combined assisted bone age assessment and adult height prediction methods in Chinese girls with early puberty: analysis of three artificial intelligence systems

BACKGROUND

The applicability and accuracy of artificial intelligence (AI)-assisted bone age assessment and adult height prediction methods in girls with early puberty are unknown.

OBJECTIVE

To analyze the performance of AI-assisted bone age assessment methods by comparing the corresponding methods for predicted adult height with actual adult height.

MATERIALS AND METHODS

This retrospective review included 726 girls with early puberty, 87 of whom had reached adult height at last follow-up. Bone age was evaluated using the Greulich-Pyle (GP), Tanner-Whitehouse (TW3-RUS) and China 05 RUS-CHN (RUS-CHN) methods. Predicted adult height was calculated using the China 05 (CH05), TW3 and Bayley-Pinneau (BP) methods.

RESULTS

We analyzed 1,663 left-hand radiographs, including 155 from girls who had reached adult height. In the 6-8- and 9-11-years age groups, bone age differences were smaller than those in the 12-14-years group; however, the differences between predicted adult height and actual adult height were larger than those in the 12-14-years group. TW3 overestimated adult height by 0.4±2.8 cm, while CH05 and BP significantly underestimated adult height by 2.9±3.6 cm and 1.3±3.8 cm, respectively. TW3 yielded the highest proportion of predicted adult height within ±5 cm of actual adult height (92.9%), with the highest correlation between predicted and actual adult heights.

CONCLUSION

The differences in measured bone ages increased with increasing bone age. However, the corresponding method for predicting adult height was more accurate when the bone age was older. TW3 might be more suitable than CH05 and BP for predicting adult height in girls with early puberty. Methods for predicting adult height should be optimized for populations of the same ethnicity and disease.

Higher Prepubertal IGF-1 Concentrations Associate to Earlier Pubertal Tempo in Both Sexes

INTRODUCTION

Pubertal onset is triggered by multiple neuroendocrine interactions. The role of prepubertal IGF-1 in this process has not been explored in both sexes. Our objective was to analyze the association of prepubertal IGF-1 concentration with age at thelarche (B2) and menarche (M) in girls and age at gonadarche (G2) in boys.

METHODS

This is a longitudinal study (n = 1,196 boys and girls) within the Growth and Obesity Chilean Cohort Study (GOCS). At age ≈ 6.7 years, blood sample was taken for IGF-1. Subjects were divided into 4 groups according to the onset age of the pubertal event.

RESULTS

Higher prepubertal IGF-1 levels were observed at earlier ages of B2 (p = 0.003) and M onset (p = 0.041). A taller prepubertal height was observed at younger ages of B2 and M (p=<0.001 and 0.002, respectively). The hazard proportional regression models (HR) showed that with an increase of 1 SD in IGF-1, the HR of presenting B2 at younger ages was 1.25, and this association was maintained when adjusted for confounding variables. Similarly, the HR of presenting M at earlier ages was 1.21. This association was maintained only when adjusting for body mass index but not using further confounders. In boys, prepubertal IGF-1 showed a tendency to be significantly higher in children with earlier G2 and taller height (both p < 0.001). The HR of presenting G2 at younger ages was 1.22, and this association was maintained after adjusting for confounders.

CONCLUSIONS

Higher IGF-1 levels in mid-childhood are associated with earlier puberty onset. The role of IGF-1 in the onset of puberty requires further investigation.

Prospective associations of mid-childhood plasma per- and polyfluoroalkyl substances and pubertal timing

BACKGROUND

Exposure to per- and polyfluoroalkyl substances (PFAS) may disrupt pubertal timing. Higher PFAS plasma concentrations have been associated with later pubertal timing in girls, but cross-sectional findings may be explained by reverse causation.

OBJECTIVES

To assess prospective associations between PFAS plasma concentrations in mid-childhood and markers of pubertal timing in male and female adolescents.

METHODS

We studied 640 children in Project Viva, a Boston-area prospective cohort. We examined associations of plasma concentrations of 6 PFAS measured at mean 7.9 (SD 0.8) years (2007-2010) with markers of pubertal timing. Parents reported a 5-item pubertal development score at early adolescence (mean 13.1 (SD 0.8) years) and reported age at menarche annually. We calculated age at peak height velocity using research and clinical measures of height. We used sex-specific linear and Cox proportional hazards regression to estimate associations of single PFAS with outcomes, and we used Bayesian Kernel Machine Regression (BKMR) to estimate associations of the PFAS mixture with outcomes.

RESULTS

Plasma concentrations were highest for perfluorooctane sulfonate (PFOS) [median (IQR) 6.4(5.6) ng/mL], followed by perfluorooctanoate (PFOA) [4.4(3.0) ng/mL]. In early adolescence, girls were further along in puberty than boys [pubertal development score mean (SD) 2.9 (0.7) for girls and 2.2(0.7) for boys; age at peak height velocity mean (SD) 11.2y (1.0) for girls and 13.1y (1.0) for boys]. PFAS was associated with later markers of pubertal timing in girls only. For example, each doubling of PFOA was associated with lower pubertal development score (-0.18 units; 95% CI: -0.30, -0.06) and older age at peak height velocity (0.23 years; 95% CI: 0.06, 0.40)]. We observed similar associations for PFOS, perfluorodecanoate (PFDA), and the PFAS mixture. PFAS plasma concentrations were not associated with age at menarche or markers of pubertal timing in boys.

DISCUSSION

Higher PFAS plasma concentrations in mid-childhood were associated with later onset of puberty in girls.

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.

A new type of pubertal height reference based on growth aligned for onset of pubertal growth

Objectives Growth references of today traditionally describe growth in relation to chronological age. Despite the broad variation in age of pubertal maturation, references related to biological age are lacking. To fill this knowledge gap, we aimed to develop a new type of pubertal height reference for improved growth evaluation during puberty, considering individual variation in pubertal timing. Methods Longitudinal length/height measures were obtained from birth to adult height in 1,572 healthy Swedish children (763 girls) born at term ∼1990 to nonsmoking mothers and Nordic parents, a subgroup of GrowUp1990Gothenburg cohort. A total height reference was constructed from Quadratic-Exponential-Puberty-Stop (QEPS)-function-estimated heights from individual height curves that had been aligned for time/age at onset of pubertal growth (5% of P-function growth). References that separated growth into specific pubertal heightSDS (P-function growth) and basic heightSDS (QES-function growth) were also generated. Results References (cm and SDS) are presented for total height, and height subdivided into that specific to puberty and to basic growth arising independently of puberty. The usefulness of the new pubertal growth reference was explored by identifying differences in the underlying growth functions that translate into differences in pubertal height gain for children of varying body mass, height, and with different pubertal timings. Conclusions A new type of height reference allowing alignment of individual growth curves, based on the timing of the pubertal growth spurt was developed using QEPS-model functions. This represents a paradigm shift in pubertal growth research and growth monitoring during the adolescent period.

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.

Near Adult Height in Girls with Turner Syndrome Treated with Growth Hormone Following Either Induced or Spontaneous Puberty

OBJECTIVE

To understand whether spontaneous vs induced puberty and the type and route of estrogen influence the height of girls with Turner syndrome on growth hormone (GH).

STUDY DESIGN

Search of an international database of children treated with GH revealed 772 girls with Turner syndrome followed from GH initiation to near adult height. Data from girls with sustained spontaneous puberty (n = 145) were compared with those requiring estrogens for induction or maintenance of puberty (n = 627).

RESULTS

At GH start, mean age (7.5 vs 7.9 years), weight (-1.7 vs -1.7 SDS), and body mass index (0.2 SDS vs 0.1 SDS) were similar for girls with spontaneous puberty and with induced puberty. Although those girls with spontaneous puberty were shorter than those with induced puberty, when midparental height was taken into consideration, starting heights in both groups averaged -2.8 SDS. Both groups received approximately 0.3 mg/kg/week of GH. Girls with spontaneous puberty initiated puberty and reached near adult height earlier than girls with induced puberty (12.6 ± 1.8 years vs 13.4 ± 1.4 years and 16.0 ± 1.3 years vs 16.9 ± 1.4 years, respectively). Although girls with spontaneous puberty grew more in the first year of GH therapy and between the onset of puberty and near adult height (11.0 cm vs 9.3 cm), height SDS at near adult height and the length of time in puberty before reaching near adult height were comparable. A 45,X karyotype was detected in 22.1% of girls with spontaneous puberty and in 58.4% of girls with induced puberty. Patients receiving transdermal estrogens did not grow better than those on oral estrogens. Adverse event reporting was comparable between groups.

CONCLUSIONS

Girls with Turner syndrome with spontaneous puberty tended to grow better in response to GH than girls with induced puberty, but not enough to produce a difference in height SDS at near adult height.