Pubertal development in Danish children: comparison of recent European and US data

Association between BMI and age at menarche or spermarche among both sexes: Findings from six successive national surveys in China

Background

To explore trends of the association between body mass index (BMI) and age at menarche or spermarche and its urban-rural disparities from 1995 to 2019.

Methods

A total of 912 753 children and adolescents - including 519 940 9-18 years old girls and 392 813 11-18 years old boys - were involved in six successive cross-sectional surveys conducted across 30 provinces in China from 1995 to 2019. Data on menarche and spermarche was collected using the status quo method, where same-gender physicians conducted face-to-face interviews to determine if children and adolescents had experienced their first menstrual cycle or ejaculation (yes/no). The median age at menarche or spermarche was estimated by probit analysis. Anthropometric measurements measured the height and weight of the study subjects. Children and adolescents were classified into thinness, normal range of weight, overweight, and obesity. t test was used to compare the differences in BMI between premenarchal and postmenarchal girls or prespermarcheal and postspermarcheal boys. Logistic regression was used to explore the associations between BMI/nutritional status and menarche or spermarche stratified by urban or rural residency status.

Results

From 1995 to 2019, BMI in all age groups growth over time, and the values of BMI among children and adolescents under 15 who had menarche or spermarche were more significant than those without menarche or spermarche. In 2019, for girls, thinness was associated with delayed menarche (odds ratio (OR) = 0.26; 95% confidence interval (CI) = 0.24-0.28), while overweight (OR = 1.99; 95% CI = 1.85-2.14) and obesity (OR = 2.20; 95% CI = 1.92-2.53) was associated with advanced menarche. For boys, thinness was associated with delayed spermarche (OR = 0.71; 95% CI = 0.65-0.78), overweight was associated with advanced spermarche (OR = 1.08; 95% CI = 1.01-1.15) while obesity had no association with spermarche. The OR between BMI and menarche in 1995 was 1.35 (95% CI = 1.33-1.37), which decreased to 1.19 (95% CI = 1.18-1.20) by 2019. The OR between BMI and spermarche in 1995 was 1.10 (95% CI = 1.09-1.11), which decreased to 1.02 (95% CI = 1.02-1.03) by 2019. The trends by urban-rural stratification were consistent with the total sample.

Conclusions

We have established a dose-response relationship between BMI and menarche in girls, whereas the association appears to be nonlinear in boys, and the associations were diminishing. Similar findings were observed in both urban and rural areas. Considering the dual adverse effects of obesity and early puberty on health, the results of this study suggest that sexual health education should be strengthened, especially among obese girls. Further research on the influencing factors and biological mechanisms of early puberty will be beneficial.

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.

Central precocious puberty in boys: secular trend and clinical features

OBJECTIVE

Recent studies suggest that boys enter puberty at a younger age, and the incidence of male central precocious puberty (CPP) is increasing. In this study, we explore the incidence of male CPP and identify key clinical and auxological indicators for organic CPP (OCPP).

DESIGN

A retrospective registry-based study.

METHODS

The medical records of 43 boys treated with CPP at the Helsinki University Hospital between 1985 and 2014 were reviewed. Clinical, auxological, and endocrine data of the CPP patients were included in the analyses.

RESULTS

Based on brain MRI, 26% of patients had OCPP. Between 2010 and 2014, the CPP incidence in boys was 0.34 per 10 000 (95% CI 0.20-0.60). Between 1990 and 2014, the male CPP incidence increased (incidence rate ratio [IRR] 1.10, P = .001). This increase was driven by rising idiopathic CPP (ICPP) incidence (IRR 1.11, 95% CI 1.05-1.19, P < .001), while OCPP incidence remained stable (P = .41). Compared with the patients with ICPP, the patients with OCPP were younger (P = .006), were shorter (P = .003), and had higher basal serum testosterone levels (P = .038). Combining 2 to 4 of these readily available clinical cues resulted in good to excellent (all, area under the curve 0.84-0.97, P < .001) overall performance, differentiating organic etiology from idiopathic.

CONCLUSIONS

The estimated incidence of CPP in boys was 0.34 per 10 000, with 26% of cases associated with intracranial pathology. The increase in CPP incidence was driven by rising ICPP rates. Patients with OCPP were characterized by shorter stature, younger age, and higher basal testosterone levels, providing valuable cues for differentiation in addition to brain MRI. Utilizing multiple cues could guide diagnostic decision-making.

Differentiation of Idiopathic Central Precocious Puberty From Premature Thelarche Using Principal Component Analysis

CONTEXT

Nonprogressive premature thelarche (PT) is a self-limiting variant of early puberty, while idiopathic central precocious puberty (ICPP) is a disorder that causes progressive development of secondary sexual characteristics and often requires treatment. The diagnostic differentiation between these conditions is important but can be challenging since they often both initially present clinically with isolated breast development.

OBJECTIVE

To describe relevant clinical variables in a large cohort of girls referred for early puberty, and to evaluate clinical and biochemical parameters to distinguish between girls with ICPP and PT.

METHODS

This retrospective study included 1361 girls referred with signs of early puberty to a single, tertiary center from 2009 to 2019. We evaluated clinical presentation, medical history, growth velocity, bone age, hormonal serum concentrations, and gonadotropin-releasing hormone (GnRH) test results.

RESULTS

Central precocious puberty was diagnosed in 11% (ICPP: n = 143, organic CPP: n = 11) girls, whereas 8% (n = 91 girls) presented with PT. Receiver operating characteristic (ROC) analysis showed several biochemical and anthropometric markers as potential parameters to differentiate between ICPP and PT; however, none were individually adequate. Principal component analysis (PCA)-derived clinical and hormone profiles could predict girls with ICPP from girls with PT with a specificity of 90% and sensitivity of 84%, outperforming any single marker.

CONCLUSION

Differentiation of girls with ICPP and PT can be supported by individual clinical and biochemical parameters. However, dimension reduction of clinical and hormonal profiles by PCA improved the diagnostic value, which in the future may support the diagnostic process as a supplement to the GnRH test in evaluation of pubertal disorders.

A Narrative Review of Flutamide in Juvenile Nasopharyngeal Angiofibroma

The detection of androgen receptors within Juvenile Nasopharyngeal Angiofibroma (JNA) has prompted investigation of the role of Flutamide. The aim of this review is to evaluate Flutamide as a possible neo-adjuvant treatment for JNA. Literature searches were conducted using MEDLINE, EMBASE and Web of Science. The Joanna Briggs Institute (JBI) checklist was used to assess risk of bias. The Oxford Centre of Evidence-Based Medicine (OCEBM) Levels of Evidence was used to stratify the evidence level. Literature searches were conducted using MEDLINE, EMBASE and Web of Science. Flutamide as neo-adjuvant treatment potentially causes a reduction in JNA tumor volume by ≥ 25%. Based on the current limited evidence, Flutamide has a limited role in JNA management and further research is required. Its utilization should only follow discussion with the patient, their families, and within the multidisciplinary team.

The influence of a permanent double-shift school start time on adolescent sleep and chronotype across different age groups

The main objective of this study was to explore the differences in sleep habits and chronotype across different age groups in Mexican adolescents attending a permanent double-shift school system. This cross-sectional study consisted of 1,969 (1,084 girls) students from public elementary, secondary, and high schools, as well as undergraduate university students from Mexico. Age range was 10-22 [15.33 ± 3.28 (mean ± SD)] years, 988 morning shift and 981 afternoon shift students. Questions regarding usual self-reported bedtime and rise time were collected, and from that, estimates for time in bed, midpoint of sleep, social jetlag, and chronotype were evaluated. Afternoon shift students reported later rise times, bedtimes, midpoint of sleep, and longer time in bed on school days than morning shift students, as well as less social jetlag. Overall, afternoon shift students reported a later chronotype than morning shift students. Peak lateness of chronotype in afternoon shift students was at age 15, with girls peaking at age 14 and boys at age 15. Meanwhile, morning shift students reported peak lateness of chronotype around age 20. In this study, adolescents from different age ranges attending an extremely delayed school start time reported adequate sleep compared with adolescents attending a fixed morning school start time. In addition, the analysis presented in this study seems to suggest that the peak of late chronotype may be influenced by school start times.

Safety and Efficacy of Pediatric Growth Hormone Therapy: Results From the Full KIGS Cohort

CONTEXT

The Kabi/Pfizer International Growth Database (KIGS) is a large, international database (1987-2012) of children treated with recombinant human growth hormone (rhGH) in real-world settings.

OBJECTIVE

This work aimed to evaluate the safety and efficacy of rhGH from the full KIGS cohort.

METHODS

Data were collected by investigators from children with growth disorders treated with rhGH (Genotropin [somatropin]; Pfizer). Safety was evaluated in all treated patients, and efficacy in those treated for 1 year or more. A subgroup included patients treated for 5 years or more (≥ 2 years prepubertal) who had reached near-adult height (NAH). Main outcomes included adverse events (AEs), serious AEs (SAEs), and height growth.

RESULTS

The full KIGS cohort (N = 83 803 [58% male]) was treated for idiopathic GH deficiency (IGHD; 46.9%), organic GHD (10.0%), small for gestational age (SGA; 9.5%), Turner syndrome (TS; 9.2%), idiopathic short stature (ISS; 8.2%), and others (16.2%). Median rhGH treatment duration was 2.7 years and observation 3.1 years. SAEs occurred in 3.7% of patients and death in 0.4%. The most common SAEs were recurrence of craniopharyngioma (n = 151), neoplasm (n = 99), and cancer (n = 91); and scoliosis (n = 91). Median first-year delta height-SD score (SDS) (Prader) in prepubertal patients was 0.66 (IGHD), 0.55 (ISS), 0.58 (TS), and 0.71 (SGA). Median gains in NAH-SDS were 1.79 (IGHD), 1.37 (ISS), and 1.34 (SGA) for boys, and 2.07 (IGHD), 1.62 (ISS), 1.07 (TS), and 1.57 (SGA) for girls.

CONCLUSION

Data from KIGS, the largest and longest running international database of rhGH-treated children, show that rhGH is safe and increases short-term height gain and adult height across GHD and non-GHD conditions.

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.

The Interaction of Obesity and Reproductive Function in Adolescents

Obesity is increasing worldwide, including in pediatrics. Adequate nutrition is required for initiation of menses, and there is a clear secular trend toward earlier pubertal onset and menarche in females in countries around the globe. Similar findings of earlier pubertal start are suggested in males. However, as individuals and populations have crossed into over-nutritional states including overweight and obesity, the effect of excess weight on disrupting reproductive function has become apparent. Hypothalamic hypogonadism and polycystic ovary syndrome are two conditions where reproductive function appears to directly relate to excess weight. Clinical findings in individuals with certain polygenic and monogenic obesity syndromes, which also have reproductive disruptions, have helped elucidate neurologic pathways that are common to both. Clinical endocrinopathies such as hypothyroidism or panhypopituitarism also aide in the understanding of the role of the endocrine system in weight gain. Understanding the intersection of obesity and reproductive function may lead to future therapies which can treat both conditions.

Adolescence exposure to China's great famine period and the association of metabolic syndrome in adulthood: a retrospective study

BACKGROUND

Exposure to famine during early life is related to several adverse health outcomes in adulthood, but the effect of famine exposure during adolescence is unclear. This study aims to examine whether exposure to famine in adolescence is associated with metabolic syndrome (MetS) in adulthood.

METHODS

This study included 4130 Chinese adults (2059 males and 2071 females) aged 59-71 from the 2011 China Health and Retirement Longitudinal Study (CHARLS). All the selected participants were exposed to the three-year time period (1959-1961) of China's Great Famine. Participants were categorized into an adolescent-exposed group (born 01/01/1944-12/31/1948) and a non-adolescent-exposed group (born 01/01/1940-12/31/1941 and 01/01/1951-12/31/1952). Sex-stratified multiple logistic regression models were used to estimate the association between exposure to famine in adolescence and MetS.

RESULTS

Participants exposed to famine during adolescence were more likely to report MetS (aOR = 1.35; 95%CI 1.01-1.78) compared to the non-adolescent-exposed group. Further, males were 45% less likely to report MetS than females (aOR = 0.55; 95%CI 0.36-0.83). After stratification by sex, the effects of famine exposure during adolescence on MetS were detected among males only (aOR = 1.97; 95%CI 1.20-3.24). Additionally, males with a history of drinking were more likely to report MetS compared to those with no history of drinking (aOR = 2.63; 95%CI 1.41-4.90).

CONCLUSIONS

Our findings reveal that exposure to famine during adolescence is associated with higher odds of MetS in adulthood overall, and this association is only pronounced among males. This study emphasizes that undernutrition in early life, including adolescence, may have a long-term effect and be associated with adverse health events in middle-to-late life. Targeting those elderly people who suffered famine during adolescence may help prevent the development of MetS in later life.

Neonatal Anthropometrics and Obesity Treatment Response in Children and Adolescents

OBJECTIVE

To investigate the relationship between in utero growth conditions, as indicated by neonatal anthropometric measures, and childhood obesity treatment response, to examine the potential usefulness of neonatal anthropometrics as a potential childhood obesity treatment stratification tool.

STUDY DESIGN

The study included 2474 children and adolescents with obesity (mean age, 11.2 years; range, 5.0-18.9 years) treated at the Children's Obesity Clinic in Holbæk, Denmark. Treatment response was registered prospectively, and neonatal data were collected from national electronic registers.

RESULTS

Birth weight, birth length, birth weight for gestational age, and large for gestational age status were positively associated with the degree of obesity at treatment initiation. After a mean (SD) of 1.27 (0.69) years of enrollment in obesity treatment, the children exhibited a mean reduction of -0.32 (0.50) in body mass index SD score. No significant associations between neonatal anthropometric measures and childhood obesity treatment response were detected.

CONCLUSIONS

Neonatal anthropometric measures were positively associated with the degree of obesity at treatment initiation but not with response to multidisciplinary treatment of childhood obesity. Individualization of obesity treatment based on neonatal anthropometry does not seem warranted.

Body composition in sexual precocity

PURPOSE OF REVIEW

In this review, we have summarized the current data on the effect of sexual precocity and treatment with gonadotropin-releasing hormone analogues (GnRHa) on body composition.

RECENT FINDINGS

Higher body weight and weight gain in infancy and childhood may increase the risk of early puberty in girls. The relation between BMI and pubertal onset in boys is controversial. Current studies draw attention to the fact that a similar relationship may exist in boys too. Obesity prevalence is high among girls with central precocious puberty (CPP) and treatment with GnRHa has a different effect on BMI according to baseline body composition. Although BMI values of normal weight girls tend to increase under treatment, they return to normal following treatment. The few studies that have followed up body composition longitudinally in girls show a gradual increase in adiposity, decrease in muscle mass and bone mineral density during GnRHa treatment, whereas bone mass was preserved after treatment. Adequate data are not available in boys to determine the effect of GnRHa therapy on body composition.

SUMMARY

Body composition and fat distribution should be monitored longitudinally in patients with CPP treated with GnRHa to ascertain the long-term effects of therapy.

Characteristics of Growth in Children With Classic Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency During Adrenarche and Beyond

CONTEXT

Patients with classic congenital adrenal hyperplasia (CAH) often do not achieve their full growth potential. Adrenarche may accelerate bone maturation and thereby result in decreased growth in CAH.

OBJECTIVE

The study aimed to analyze the impact of growth during adrenarche on final height of adequately treated classic CAH patients.

METHODS

This retrospective, multicenter study (4 academic pediatric endocrinology centers) included 41 patients with classical CAH, born 1990-2012. We assessed skeletal maturation (bone age), growth velocity, and (projected) adult height outcomes, and analyzed potential influencing factors, such as sex, genotype, and glucocorticoid therapy.

RESULTS

Patients with classic CAH were shorter than peers (-0.4 SDS ± 0.8 SD) and their parents (corrected final height -0.6 SDS ± 1.0 SD). Analysis of growth during adrenarche revealed 2 different growth patterns: patients with accelerating bone age (49%), and patients with nonaccelerating bone age relative to chronological age (BA-CA). Patients with accelerating BA-CA were taller than the normal population during adrenarche years (P = 0.001) and were predicted to achieve lower adult height SDS (-0.9 SDS [95% CI, -1.3; -0.5]) than nonaccelerating patients when assessed during adrenarche (0.2 SDS [95% CI, -0.3; 0.8]). Final adult height was similarly reduced in both accelerating and nonaccelerating BA-CA groups (-0.4 SDS [95% CI, -0.9; 0.1] vs -0.3 SDS [95% CI, [-0.8; 0.1]).

CONCLUSION

Patients with and without significant bone age advancement, and thus differing height prediction during adrenarche, showed similar (predicted) final height when reassessed during pubertal years. Bone age alone should not be used during adrenarche as clinical marker for metabolic control in CAH treatment.

Pubertal Timing and Growth Dynamics in Children With Severe Primary IGF-1 Deficiency: Results From the European Increlex® Growth Forum Database Registry

BACKGROUND

Puberty is delayed in untreated children and adolescents with severe primary IGF-1 deficiency (SPIGFD); to date, it has not been reported whether recombinant human insulin-like growth factor-1 mecasermin (rhIGF-1) treatment affects this. Pubertal growth outcomes were extracted from the European Increlex^® Growth Forum Database (Eu-IGFD) Registry (NCT00903110).

METHODS

The Eu-IGFD Registry includes children and adolescents aged 2 to 18 years with growth failure associated with SPIGFD who are treated with rhIGF-1. Reported outcomes include: age at last registration of Tanner stage 1 and first registration of Tanner stage 2-5 (T2-T5; based on breast development for girls and genital development for boys, respectively); maximum height velocity during each Tanner stage; and pubertal peak height velocity (PPHV). Data cut-off was 13 May 2019.

RESULTS

This analysis included 213 patients (132 boys and 81 girls). Mean (SD) age at last registration of T1 and first registration of T5 was 13.0 (2.0) and 16.3 (1.6) years, respectively, in boys and 11.6 (1.8) and 14.7 (1.5) years, respectively, in girls. Among patients reaching the end of puberty (25 boys and 11 girls), mean (SD) height SDS increased from -3.7 (1.4) at baseline in the Eu-IGFD Registry to -2.6 (1.4) at T5 in boys and from -3.1 (1.1) to -2.3 (1.5) in girls. Maximum height velocity was observed during T2 in girls and T3 in boys. Median (range) PPHV was 8.0 (0.3-13.0) cm/year in boys and 6.8 (1.3-9.6) cm/year in girls and occurred most frequently during T2. Overall, the adverse events seen in this analysis were in line with the known safety profile of rhIGF-1.

CONCLUSION

Children and adolescents treated with rhIGF-1 for SPIGFD with growth failure experienced an increase in height SDS in prepubertal years compared with baseline. Despite 1.5 years delay in pubertal start and a delayed and slightly lower PPHV, height SDS gain during puberty was maintained.

Genetics of pubertal timing

Puberty marks the end of childhood and is a period when individuals undergo physiological and psychological changes to achieve sexual maturation and fertility. The onset of puberty is first detected as an increase in pulsatile secretion of gonadotropin-releasing hormone (GnRH). Pubertal onset is regulated by genetic, nutritional, environmental, and socio-economic factors. Disturbances affecting pubertal timing result in adverse health conditions later in life. Human genetic studies show that around 50-80% of the variation in pubertal onset is genetically determined. The genetic control of pubertal timing has been a field of active investigation in attempt to better understand the neuroendocrine control of this relevant period of life. Large populational studies and patient cohort-based studies have provided insights into the genetic regulation of pubertal onset. In this review, we discuss these discoveries and discuss potential mechanisms for how implicated genes may affect pubertal timing.

Early and precocious puberty during the COVID-19 pandemic

During the year 2020, the COVID-19 pandemic rapidly became a severe health emergency worldwide. In order to contrast the spread of the novel SARS-CoV-2, many countries implemented extraordinary restrictive measures, such as a strict lockdown and school closures. The pandemic had a great impact on children and adolescents' daily life, leading to a much more sedentary lifestyle, to larger use of electronic devices and to an increase in stress-related symptoms. These conspicuous changes acted as disruptors of children's normal development. Since the beginning of the pandemic, many studies reported an increase in the number of precocious puberty cases as well as a faster progression rate of puberty itself, if compared to the pre-pandemic years. In this review, our aim was to evaluate the incidence of new cases of early and precocious puberty during the COVID-19 pandemic, analyzing variations in the timing of puberty and in pubertal progression rate, and to investigate the role of environmental and lifestyle factors during the pandemic in modulating the physiopathology of pubertal development. While a direct effect of SARS-CoV-2 infection remains, at the moment, a remote hypothesis, both physical and psychological factors related to the pandemic seem to have a role in triggering GnRH pulsatile secretion leading to earlier pubertal onset. It is indeed important to stress the need to clarify the exact role of COVID-19 in early pubertal onset comparing data from all over the world; long-term comprehensive studies are also pivotal to explain whether this phenomenon will continue while we resume pre-pandemic habits.

The impact of BMI on long-term anthropometric and metabolic outcomes in girls with idiopathic central precocious puberty treated with GnRHas

BACKGROUND

Gonadotropin-releasing hormone analogs (GnRHas) are effective in increasing the final height of children with idiopathic central precocious puberty (ICPP). However, in previous years, some transient metabolic complications have been described during this treatment, for which there are no long-term outcome data. Our study aimed to evaluate the efficacy of GnRHas and clarify if body mass index (BMI) at diagnosis of ICPP could influence long-term outcomes.

METHODS

This was an observational, retrospective study that recruited a cohort of girls with ICPP. Data for anthropometric measures, fasting lipid profile, and glucose metabolism were collected at baseline [when GnRHas treatment started (T1)], at the end of the treatment (T2), and near-final height (nFH) or final height (FH) (T3). Predicted adult height (PAH) was calculated at T1 following Bayley and Pinneau's method. Analysis was carried out using BMI standard deviation score (SDS) categories at T1 (group A, normal weight, vs. group B, overweight/obese).

RESULTS

Fifty-seven girls with ICPP who were treated with GnRHas were enrolled in the study (group A vs. group B: 33 vs. 24 patients, aged 7.86 ± 0.81 vs. 7.06 ± 1.61 years, respectively; p < 0.05). In the study population, nFH/FH was in line with the target height (TH) (p = 0.54), with a mean absolute height gain of 11.82 ± 5.35 cm compared with PAH. Even if the length of therapy was shorter (group A vs. group B: 1.84 ± 2.15 vs. 2.10 ± 0.81 years, respectively; p < 0.05) and the age at menarche was younger (group A vs. group B: 10.56 ± 1.01 vs. 11.44 ± 0.85 years, respectively; p < 0.05) in group B than in group A, the nFH/FH gain was still comparable between the two groups (p = 0.95). At nFH/FH, BMI SDS was still greater in group B than in group A (p = 0.012), despite the fact that BMI SDS significantly increased in group A only (p < 0.05). Glucose metabolism got worst during GnRHa with a complete restoring after it, independently from pre-treatment BMI. The ratio of low-density to high-density lipoprotein cholesterol transiently deteriorated during treatment with GnRHas in group A only (p = 0.030).

CONCLUSIONS

Our results confirm the effectiveness of treatment with GnRHas on growth and do not support the concern that being overweight and obese can impair the long-term outcomes of GnRHas therapy. However, the observed transient impairment of metabolic parameters during treatment suggests that clinicians should encourage ICPP girls treated with GnRHas to have a healthy lifestyle, regardless of their pretreatment BMI.

Timing of Puberty and Late Pubertal Height in Saudi Schoolboys: Riyadh Puberty Study II

OBJECTIVE

Puberty has a significant contribution to the final height. Therefore, it is crucial to understand the normal variations in the onset and tempo of puberty in a specific population. In this study, we aimed to provide normative data on the timing of puberty and late pubertal height (LPH) in Saudi schoolboys in Riyadh.

METHODS

This is a cross-sectional field study (2011-2013) including Saudi schoolboys (grades 1-12; aged 6 to 19 years). Schools were chosen to represent the population from urban and rural areas in the Riyadh region. Pubertal maturity staging for gonads was assessed by measuring testicular size using a Prader orchidometer and assessing the Tanner staging of pubic hair. The marginal mean age was calculated using regression analysis.

RESULTS

We recruited 1086 schoolboys. The estimated mean age of pubertal onset at G2 was 11.8 (95% CI 11.60-12.0) years, for gonadal development at G3 was 13.2 (95% CI 12.9-13.5), G4 = 15.0 (95% CI 14.7-15.2), and G5 = 16.1 (95% CI 15.9-16.3) years, and for pubic hair stage 2 (PH2) was 12.6 (95% CI 12.4-12.9) years. The estimated time from G2/PH2 to G5/PH5 was 4.3 and 3.9 years, respectively. At the onset of puberty, the mean height was 144.7 cm and it reached 167.8 cm at G5 with a pubertal height gain of 23.1 cm.

CONCLUSION

Our data present the norms of the timing of puberty and LPH in Saudi schoolboys. Saudi adolescent males are shorter than some European and American comparatives mainly due to shortness during childhood. However, they could have shorter LPH than Turkish, Greek, Thai, and Japanese due to a less pubertal height gain.

Population-based pediatric reference values for serum parathyroid hormone, vitamin D, calcium, and phosphate in Danish/North-European white children and adolescents

INTRODUCTION

Parathyroid hormone (PTH) and vitamin D are essential hormones in bone metabolism, especially during pediatric growth. Vitamin D insufficiency is often asymptomatic and is prevalent in high-latitude countries.

METHODS

In a Danish population-based cohort of 2211 6-18-year-olds, sex- and age-specific pediatric reference values for fasting concentrations of intact serum PTH, vitamin D (25-hydroxycholecalciferol, 25-OH-D), total calcium, and phosphate were generated in accordance with Clinical and Laboratory Standards Institute (CLSI) EP28-A3c guidelines. The effect of season on these biomarkers of bone metabolism was evaluated.

RESULTS

In boys, PTH concentrations increased with age, while the vitamin D and phosphate concentrations decreased (all p < .001). In girls, a peak in PTH concentrations and a nadir in vitamin D concentrations were observed in the 10-14-year-olds (both p < .001). Calcium and phosphate decreased with age for both sexes (girls: both p < .001; boys calcium: p < .05, boys phosphate: p < .001). Vitamin D was 20% lower in winter than summer for both sexes (both p < .001). Individuals with vitamin D sufficiency (25-OH-D > 50 nmol/L) exhibited a 5% lower level of PTH compared to the whole sample population (p < .001).

CONCLUSION

The concentrations of PTH, vitamin D, calcium, and phosphate vary during childhood and adolescence, and is dependent on sex and season. These factors should be considered when screening for and treating imbalances in bone metabolism.

Sex estimation through geometric morphometric analysis of the frontal bone: an assessment in pre-pubertal and post-pubertal modern Spanish population

Sex estimates is a key step of biological profile assessment in a forensic or anthropologic context. In this study, the sexual dimorphism of the frontal bone was analyzed to assess the accuracy of sex estimates using a geometric morphometric approach in a pre-pubertal and post-pubertal sample. The shape of the frontal bone was digitized on the lateral cephalograms of 87 pre-pubertal subjects (42 males, mean age 10.14, SD ± 1.48 years; 45 females mean age 10.02, SD ± 1.11 years) and 103 post-pubertal ones (53 males, mean age 29.33 SD ± 11.88 years; 50 females, mean age 26.77 SD ± 11.07 years). A generalized Procrustes analysis (GPA) was performed for shape analyses, filtering the effects of position, rotation, translation, and size. A principal component analysis (PCA) was performed on the GPA transformed variables, and a multiple logistic regression model was used to assess the accuracy of sex estimates. In both age groups, the average size of the centroid was significantly larger in males. The females presented shapes with a shorter distance between P2 (glabella) and P1 (supratoral) and a general narrowing of the structure on the sagittal plane. In the pre-pubertal group, the shape difference was not statistically significant. In the post-pubertal group, the mean shape was significantly different between the sexes. The method displayed a high accuracy for sex estimates (88.7% males, 90.3% females) also when applied in a validation sample (82.6% males and 94.1% females). The described morphometric analysis of the frontal bone is based on a limited number of landmarks, which allows sex estimates with high accuracy in post-pubertal subjects, while it is not applicable in pre-pubertal ones.

Prenatal exposure to maternal stressful life events and earlier age at menarche: the Raine Study

STUDY QUESTION

Is there an association between prenatal exposure to stressful life events and age at menarche, and does childhood BMI mediate this association?

SUMMARY ANSWER

Girls exposed to prenatal stress had a slightly earlier age at menarche, but this association did not show a dose-response effect and was not mediated by childhood offspring BMI.

WHAT IS ALREADY KNOWN

Prenatal stress may impact on reproductive function in females including age at menarche, but human data are very limited. High childhood BMI is known to be associated with earlier age at menarche. Only one small study has measured the association between maternal stress and age at menarche and reported that childhood BMI mediated the association between maternal stress and earlier age at menarche. However, neither maternal stress nor age at menarche was prospectively recorded and the study was limited to 31 mother-daughter pairs.

STUDY DESIGN, SIZE, DURATION

The Raine Study is a large prospective population-based pregnancy cohort study (n = 1414 mother-daughter pairs) continuously followed from prenatal life through to adolescence. In the present study, we examined the association between exposure to maternal stressful life events during early, late and total gestation and age at menarche in offspring using 753 mother-daughter pairs with complete case information.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Mothers prospectively reported stressful life events during pregnancy at 18 and 34 weeks using a standardized 10-point questionnaire. Exact date of menarche was assessed using a purpose-designed questionnaire at 8, 10, 14 and 17 years of age. Complete information on exposure, outcome and confounding variables was obtained from 753 mothers-daughter pairs. Multivariate linear regression complete case analysis was used to examine associations between maternal stressful life event exposure and age at menarche. Potential selection bias was evaluated using multiple imputations (50 datasets). The mediating effects of offspring childhood BMI (ages 5, 8, or 10 years) on these associations were measured in separate sub-analyses.

MAIN RESULTS AND ROLE OF CHANCE

Most (580/753, 77%) daughters were exposed to at least one prenatal stressful life event. Exposure to maternal stressful life events during the entire pregnancy was associated with a non-linear earlier age at menarche. Exposure to one event and two or more psychological stressful events was associated with a 3.5 and 1.7-month earlier onset of puberty, respectively when compared to the reference group with no exposure maternal stressful life events. The estimates from multiple imputation with 50 datasets were comparable with complete case analysis confirming the existence of an underlying effect. No separate significant effects were observed for exposure during early or late gestation. The association between prenatal stressful events and age at menarche was not mediated by childhood BMI in the offspring.

LIMITATIONS, REASONS FOR CAUTION

Stressful life events may have affected pregnant women in different ways and self-perceived maternal stress severity may have provided a more precise estimate of gestational psychological stress. The observed non-linear U-shape of the association between maternal psychological stress and age at menarche did not reflect a dose-response. This suggests that the first exposure to prenatal stress exerts a greater effect on fetal reproductive development. A potential mechanism is via dramatic initial activation of the hypothalamic-pituitary-adrenal (HPA) axis following the first stressful life event which is greater than that observed following subsequent exposure to two or more maternal stressful life events. Whilst we adjusted for a priori chosen confounders, we cannot exclude residual confounding or confounding by factors we did not include. Maternal age at menarche was not available so the effects of familial history/genetics could not be assessed. There was a large loss due to the number of girls with no information on date of menarche and missing confounder information implying risk of selection bias and multiple imputation analyses did not fully exclude this risk (similar direction but slightly weaker estimate magnitude).

WIDER IMPLICATIONS OF THE FINDINGS

Menarche is a sentinel reproductive event and earlier age at menarche carries implications for psychological, social and reproductive health and for long-term risk of common non-communicable diseases. Understanding the factors regulating age at menarche has extensive health implications. This is the first population-based cohort study in humans to demonstrate that prenatal psychological stress might directly modify age at menarche.

STUDY FUNDING/COMPETING INTEREST(S)

Dr. Bräuner and Trine Koch's salaries were supported by Doctor Sofus Carl Emil Friis and spouse Olga Doris Friis foundation, The Danish Cancer Society (Kræftens Bekæmpelse, RP15468, R204-A12636, Denmark) and The Danish Health Foundation (Helsefonden, F-22181-23, Denmark). Martha Hickey was funded by NHMRC Practitioner Fellowships. The funding bodies played no role in the design, collection, analysis, or interpretation of data; in the writing of the manuscript; or in the decision to submit the manuscript for publication. Dr. Hart has received personal fees in his function as the Medical Director of Fertility Specialists of Western Australia and received educational sponsorship grants from MSD, Merck-Serono and from Ferring Pharmaceuticals. Dr Hart has also received personal fees from Shareholders in Western IVF outside the submitted work.

TRIAL REGISTRATION NUMBER

NA.

Characterization of pubertal development of girls in rural Bangladesh

This study aimed to describe the timing and patterns of pubertal maturation of girls living in rural Bangladesh. Starting in September 2015, a total of 15,320 girls from a birth cohort, aged 9 to 15 years at initial encounter, were visited twice at about a one year interval, typically in their birth month. Participants were asked to self-report extent of pubertal maturation, including breast development, pubic hair growth and age at menarche, if applicable. Pubertal stage (abbreviated as B2 and B3-4 for breast development and PH2 and PH3-4 for pubic hair growth) was assigned. Data from both visits were pooled, yielding a total of 29,377 age-related observations per pubertal characteristic. Probit regression models were used to estimate distributions of age at which each stage of pubertal development was attained. Before age 8, <3% of the study population initiated pubertal maturation as indicated by onset of breast development (B2). The median (95% confidence interval) age of B2 and B3-4 was 11.02 (11.00–11.04) and 12.82 (12.80–12.83) years, respectively; and 12.93 (12.91–12.94) and 14.29 (14.27–14.31) years for the onset (PH2) and advanced stage (PH3-4) of pubic hair growth, respectively. Median age at menarche was 13.17 (13.15–13.19) years, with 2.15 years of timespan from B2 to menarche. Girls in rural Bangladesh progressed through puberty following a well-documented sequence of sexual maturation stages. The age at which each pubertal milestone took place was somewhat later, but the tempo from breast development to menarche was comparable to that observed elsewhere. Our findings present a current norm of pubertal maturation in a typical, rural adolescent population in South Asia, which could help inform future studies and interventions to preserve or improve early adolescent health and development.

Growth and Maturity Status of Female Soccer Players: A Narrative Review

Reported mean ages, heights and weights of female soccer players aged <19 years in 161 studies spanning the years 1992-2020 were extracted from the literature or calculated from data available to the authors; 35 studies spanning the years 1981-2020 also included an indicator of biological maturation. Heights and weights were plotted relative to U.S. reference data. Preece-Baines Model 1 was fitted to moving averages to estimate ages at peak velocity. Maturity indicators included skeletal age, pubertal status, age at menarche, percentage of predicted adult height and predicted maturity offset. Heights and weights showed negligible secular variation across the time interval. Heights were slightly above or approximated the reference medians through 14 years old and then varied between the medians and 75th percentiles through 18 years old. Weights were above the reference medians from 9 to 18 years old. Mean ages at menarche ranged from 12.7 to 13.0 years. The trend in heights and weights suggested the persistence and/or selection of taller and heavier players during adolescence, while estimated age at peak height velocity (PHV) and ages at menarche were within the range of mean ages in European and North American samples. Data for skeletal and sexual maturity status were limited; predicted maturity offset increased linearly with mean ages and heights at prediction.

The association between in utero exposure to maternal psychological stress and female reproductive function in adolescence: A prospective cohort study

Background

Method

Results

Conclusion

•

Animal studies suggest reproductive function is influenced by maternal stress.

•

Human evidence is sparse and inconsistent.

•

We used a population-based pregnancy cohort of 228 mother female offspring.

•

Exposure to maternal psychological stress in late gestation affects uterine volume and ovarian AFC.

Nonhuman primate model in mammary gland biology and neoplasia research

Research on breast cancer pathogenesis, prevention and drug development remains an important field as this disease is still one of the leading causes of cancer death worldwide. Nonhuman primates, particularly macaque species, may serve as a highly translational animal model in breast cancer studies due to their similarity with humans in genetics, anatomy, reproductive and endocrine physiology including mammary gland development profile. The use of nonhuman primates in biomedical research, however, requires high ethical standards and an increasing expectation to improve strategies to replace, reduce and refine their use. Here, we discuss some key features of nonhuman primate mammary gland biology relevant to their strengths and limitations as models in studies of breast development and cancer risk.

Testosterone Therapy and Its Monitoring in Adolescent Boys with Hypogonadism: Results of an International Survey from the I-DSD Registry

It is unclear whether testosterone replacement therapy (TRT) in adolescent boys, affected by a range of endocrine diseases that may be associated with hypogonadism, is particularly common. The aim of this study was to assess the contemporary practice of TRT in boys included in the I-DSD Registry. All participating centres in the I-DSD Registry that had boys between 10 and 18 years of age and with a condition that could be associated with hypogonadism were invited to provide further information in 2019. Information on 162 boys was collected from 15 centres that had a median (range) number of 6 boys per centre (1.35). Of these, 30 (19%) from 9 centres were receiving TRT and the median (range) age at the start was 12.6 years (10.8-16.2), with 6 boys (20%) starting at <12 years. Median (range) age of boys not on TRT was 11.7 years (10.7-17.7), and 69 out of 132 (52%) were <12 years. TRT had been initiated in 20 of 71 (28%) boys with a disorder of gonadal development, 3 of 14 (21%) with a disorder of androgen synthesis, and all 7 (100%) boys with hypogonadotropic hypogonadism. The remainder who did not have TRT included 15 boys with partial androgen insensitivity, 52 with non-specific XY DSD, and 3 with persistent Müllerian duct syndrome. Before starting TRT, liver function and blood count were checked in 19 (68%) and 18 boys (64%), respectively, a bone age assessment was performed in 23 (82%) and bone mineral density assessment in 12 boys (43%). This snapshot of contemporary practice reveals that TRT in boys included in the I-DSD Registry is not very common, whilst the variation in starting and monitoring therapy is quite marked. Standardisation of practice may lead to more effective assessment of treatment outcomes.

Secular trend of the skeletal maturation in relation to peak height velocity-a comparison between two groups of children born 1969-1973 and 1996-2000

BACKGROUND/OBJECTIVES

The aims were to study the presence of a secular trend in (a) age at peak height velocity (PHV), (b) velocity at PHV, and (c) duration of skeletal maturation in relation to PHV.

MATERIAL/METHOD

Two groups of children: 100 children (63 boys, 37 girls) born between 1969-1973 and 71 children (49 boys, 22 girls) born between 1996 and 2000, were compared. Age and velocity at PHV were measured on individual growth velocity curves. Skeletal maturation stages were assessed on hand-wrist radiographs, and duration from the skeletal maturation stages to PHV was determined.

RESULTS

Age at PHV occurred significantly earlier (0.47 years, CI 95% 0.19-0.76, P < 0.001), and velocity at PHV was significantly higher (0.68 cm/year, CI 95% 1.47-2.06, P < 0.003) in children born 1996-2000 compared to 1969-1973. No significant difference in duration of skeletal maturation was seen between the groups. Skeletal maturation stages occurred significantly in the following order before PHV for both genders: PP2= 2.18 years (P = 0.002), MP3= 1.60 year (P = 0.008), S 1.07 year (P = 0.003), and MP3cap 0.38 year (P = 0.037).

LIMITATIONS

Most radiographs were taken before PHV, the duration thus mainly reflects the early event of pubertal growth spurt.

CONCLUSION

A secular trend was evident: significantly decreased age at PHV and significantly increased velocity at PHV. No evidence of a secular trend regarding duration of the skeletal maturation in relation to PHV was found. Due to the declining age at PHV, the skeletal maturation stages occurred earlier in relation to chronological age.

Clinical charts for surveillance of growth and body proportion development in achondroplasia and examples of their use

Clinical surveillance of infants and children with achondroplasia necessitates syndrome-specific charts due to extreme short stature with deviating body proportions. Height, arm span and leg length develop far below normal population ranges. We present growth and body proportion charts for ages 0-20 years, constructed from semi-longitudinal standardized measurements of about 450 children, along with some examples of achondroplasia typical and atypical growth pattern. We combine head circumference, height and weight for 0-4 years into one (infancy) page and height and weight for 4-20 years in another (childhood-adolescence) using nonlinear axes to account for the rapidly decreasing growth velocity. Similarly, weight and BMI are based on nonlinear axes to balance wide SD-channels at higher and narrow SD-channels at lower levels of weight/BMI. Charts for following sitting height, sitting height/height ratio, arm span, leg and foot length are also presented. Clinical examples illustrating the applicability of the charts include cases of extreme prematurity, extreme head circumference development before and after shunting, achondroplasia complicated by chromosomal or additional genetic abnormality and by growth hormone deficiency as well as of evaluating growth promoting therapy.

Increased incidence of precocious and accelerated puberty in females during and after the Italian lockdown for the coronavirus 2019 (COVID-19) pandemic

Background

The timing of puberty in girls is occurring at an increasingly early age. While a positive family history is recognised as a predisposing factor for early or precocious puberty, the role of environmental factors is not fully understood.

Aims of the study

To make a retrospective evaluation of the incidence of newly diagnosed central precocious puberty (CPP) and the rate of pubertal progression in previously diagnosed patients during and after the Italian lockdown for COVID-19, comparing data with corresponding data from the previous 5 years. To determine whether body mass index (BMI) and the use of electronic devices increased during lockdown in these patients.

Patients and methods

The study included 49 females with CPP. We divided the patients into two groups: group 1, patients presenting a newly diagnosed CPP and group 2, patients with previously diagnosed slow progression CPP whose pubertal progression accelerated during or after lockdown. We collected auxological, clinical, endocrinological and radiological data which were compared with data from two corresponding control groups (patients followed by our Unit, March to July 2015–2019). Patients’ families completed a questionnaire to assess differences in the use of electronic devices before and during lockdown.

Results

Thirty-seven patients presented newly diagnosed CPP (group 1) and 12, with previously diagnosed but untreated slow progression CPP presented an acceleration in the rate of pubertal progression (group 2). The number of new CPP diagnoses was significantly higher than the mean for the same period of the previous 5 years (p < 0.0005). There were no significant differences between patients in group 1 and control group 1 regarding time between appearance of B2 and CPP diagnosis, although group 1 patients had a significantly earlier chronological age at B2, a more advanced Tanner stage at diagnosis (p < 0.005), higher basal LH and E2 levels, higher LH peak after LHRH test (p < 0.05) and increased uterine length (p < 0.005) and ovarian volume (p < 0.0005). The number of patients with previously diagnosed CPP whose pubertal development accelerated was also statistically higher compared to controls (p < 0.0005). In this group, patients’ basal LH (p < 0.05) and E2 levels (p < 0.0005) became more markedly elevated as did the LH peak after LHRH test (p < 0.05). These patients also showed a significantly accelerated progression rate as measured by the Tanner scale (p < 0.0005), uterine length (p < 0.005), and ovarian volume (p < 0.0005). In both group 1 and group 2, BMI increased significantly (p < 0.05) and patients’ families reported an increased use of electronic devices (p < 0.0005).

Conclusion

Our data show an increased incidence of newly diagnosed CPP and a faster rate of pubertal progression in patients with a previous diagnosis, during and after lockdown compared to previous years. We hypothesize that triggering environmental factors, such as the BMI and the use of electronic devices, were enhanced during lockdown, stressing their possible role in triggering/influencing puberty and its progression. However, more studies are needed to determine which factors were involved and how they interacted.

Age and sex specific incidence for depression from early childhood to adolescence: A 13-year longitudinal analysis of German health insurance data

BACKGROUND

Epidemiological studies indicate a disproportionate increase of depression incidence among adolescent girls, compared with boys. Since results regarding the age of onset of this sex difference are heterogeneous, this study aimed to investigate this difference on a large and representative sample. A second investigation sought to clarify whether there is a relevant sex difference in prepubertal onset of depression regarding the further course.

METHODS

Health insurance data of 6-18-year-old Barmer insured patients, representing a 7.9% sample of the German population born in 1999 (N = 61.199), were analyzed. The incidence of depression episodes (ICD-10 F32.x) was evaluated. Subsequently, the absolute and relative risk of a depression diagnosis (F32.x/F33.x) in early/late adolescence was analyzed based on the diagnosis of depression in primary school age in unstratified and stratified univariate analyses performed in SAS.

RESULTS

From 13 years of age, we found a significantly higher incidence of depressive disorders in girls than in boys. More than a fifth of the children with a depression diagnoses in primary school age had a depression relapse in early or late adolescence (early: 23.2%; 95% CI 19.6-26.9/late: 22.9%; 95% CI 19.3-26.5). Boys with depression in primary school age have a significantly higher relative risk for a depression relapse in late adolescence than girls (boys RR 4.2, 95% CI 3.3-5.2, girls RR: 2.1, 95% CI 1.7-2.7).

LIMITATIONS

The analysis is based on administrative data. Low sensitivity for depression in primary care setting and low service utilization leads to an underestimation of the incidence.

CONCLUSIONS

During puberty the risk for a first depressive episode increases more steeply in girls than in boys. Childhood depression has a high risk of relapse for both sexes, but is much more pronounced for boys.

Trends in the Incidence of Central Precocious Puberty and Normal Variant Puberty Among Children in Denmark, 1998 to 2017

IMPORTANCE

There has been a worldwide secular trend toward earlier onset of puberty in the general population. However, it remains uncertain if these changes are paralleled with increased incidence of central precocious puberty (CPP) and normal variant puberty (ie, premature thelarche [PT] and premature adrenarche [PA]) because epidemiological evidence on the time trends in the incidence of these puberty disorders is scarce.

OBJECTIVE

To provide valid epidemiological data on the 20-year secular trend in the incidence rates of CPP and normal variant puberty.

DESIGN, SETTING, AND PARTICIPANTS

This population-based, 20-year cohort study used national registry data for all youth in Denmark registered with an incident diagnosis of CPP, PT, or PA in the Danish National Patient Registry from 1998 to 2017 (N = 8596) using the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10). We applied the maximum diagnostic age limit for precocious puberty (ie, onset of puberty before age 8 years for girls and age 9 years for boys) with and without a 12-month lag to address time from first contact to final registration in the Danish National Patient Registry. Data analysis was conducted in 2019.

EXPOSURES

Diagnosis of CPP, PT, or PA.

MAIN OUTCOMES AND MEASURES

The age-specific and sex-specific incidence rates of first-time diagnosis of CPP, PT, and PA were estimated using data from the Danish National Patient Registry from 1998 to 2017, and information about the total number of children at risk within the same age groups and sex from Statistics Denmark. Incidences were stratified according to immigration group (Danish origin, first-generation immigrant, second-generation immigrant).

RESULTS

Overall a total 8596 children (7770 [90.4%] girls; median [interquartile] age at diagnosis for boys, 8.0 [7.1-9.0] years; for girls, 8.0 [7.6-8.5] years) were registered with an incident diagnosis of CPP, PT, or PA, of whom 7391 (86.0%) had Danish origin (6671 [90.3%] girls), corresponding to 370 new cases in children with Danish origin per year. The 20-year mean annual incidence rates of CPP, PT, PA, and all 3 conditions per 10 000 girls with Danish origin were 9.2 (95% CI, 8.0 to 10.3), 1.1 (95% CI, 0.7 to 1.5), 1.3 (95% CI, 0.9 to 1.7), and 11.5 (95% CI, 10.3 to 12.8), respectively. For boys with Danish origin, the 20-year mean annual incidence rates per 10 000 boys were lower: 0.9 (95% CI, 0.6 to 1.2), 0.2 (95% CI, 0.1 to 0.4), and 1.1 (95% CI, 0.7 to 1.4) for CPP, PA, and the sum, respectively. There was a 6-fold increase in incidence for girls with Danish origin (from 2.6 per 10 000 to 14.6 per 10 000) and a 15-fold increase for boys with Danish origin (from 0.1 per 10 000 to 2.1 per 10 000). The 20-year mean incidence of CPP and PA among girls in the first-generation and second-generation immigrant groups were greater than that of girls with Danish origin. The incidence rate for CPP per 10 000 girls in the first-generation and second-generation groups were 13.7 (95% CI, 9.3 to 18.2) and 14.2 (95% CI, 4.6 to 23.9), respectively; the incidence rate for PA per 10 000 girls in the first-generation and second-generation groups were 2.0 (95% CI, 0.3 to 3.6) and 1.5 (95% CI, -1.6 to 4.7), respectively. No differences associated with immigration status were observed among boys.

CONCLUSIONS AND RELEVANCE

Our findings suggest that the annual incidence of CPP and normal variant puberty has substantially increased in Denmark during the last 20 years. These findings have implications for short-term and long-term health and potentially for the international classification of the reference age of puberty.

The impact of gender, puberty, and pregnancy in patients with POLG disease

Objective

To study the impact of gender, puberty, and pregnancy on the expression of POLG disease, one of the most common mitochondrial diseases known.

Methods

Clinical, laboratory, and genetic data were collected retrospectively from 155 patients with genetically confirmed POLG disease recruited from seven European countries. We used the available data to study the impact of gender, puberty, and pregnancy on disease onset and deterioration.

Results

We found that disease onset early in life was common in both sexes but there was also a second peak in females around the time of puberty. Further, pregnancy had a negative impact with 10 of 14 women (71%) experiencing disease onset or deterioration during pregnancy.

Interpretation

Gender clearly influences the expression of POLG disease. While onset very early in life was common in both males and females, puberty in females appeared associated both with disease onset and increased disease activity. Further, both disease onset and deterioration, including seizure aggravation and status epilepticus, appeared to be associated with pregnancy. Thus, whereas disease activity appears maximal early in life with no subsequent peaks in males, both menarche and pregnancy appear associated with disease onset or worsening in females. This suggests that hormonal changes may be a modulating factor.

Reproductive hormones during pubertal transition in girls with transient Thelarche

CONTEXT

Transient thelarche (TT), that is, the appearance, regression and subsequent reappearance of breast buds, is a frequent phenomenon, but little is known about pubertal transition in these girls.

OBJECTIVE

To describe pubertal progression, growth, genotypes, reproductive hormones and growth factors in girls with TT compared to those who do not present TT (non-TT).

DESIGN

Retrospective analysis of a longitudinal population-based study.

PATIENTS OR OTHER PARTICIPANTS

Girls (n = 508) of the Chilean Growth and Obesity cohort.

MEASUREMENTS

Pubertal progression, reproductive hormones, follicle stimulating hormone (FSH) beta subunit/FSH receptor gene single nucleotide polymorphisms and growth.

RESULTS

Thirty-seven girls (7.3%) were presented TT. These girls entered puberty by pubarche more frequently (51%) than girls with normal progression (non-TT; n = 471; 23%, P = .005). Girls with TT who were under 8 years old had lower androgens, anti-Müllerian hormone (AMH), luteinizing hormone (LH) and oestradiol (all P < .05) than older girls with TT. At the time of Tanner breast stage 2 (B2), girls with TT had higher androgens, LH, FSH, IGF1, LH, insulin and oestradiol (P < .01) than at the time of TT. TT girls were older at B2 (10.3 ± 1.1 vs. 9.2 ± 1.2 years, P < .001) and menarche (12.3 ± 0.8 vs. 12.0 ± 1.0 years, P = .040) than their counterparts (non-TT). No differences in anthropometric variables or FSHB/FSHR genotypes were detected.

CONCLUSION

Transient thelarche is a frequent phenomenon that does not appear to be mediated by hypothalamic-pituitary-gonadal axis activation or by adiposity. Hormonal differences between earlier TT and later TT suggest that their mechanisms are different.

Menstrual Pattern, Reproductive Hormones, and Transabdominal 3D Ultrasound in 317 Adolescent Girls

CONTEXT

The knowledge of normal variation of reproductive hormones, internal genitalia imaging, and the prevalence of gynecological disorders in adolescent girls is limited.

OBJECTIVE

The study aimed to describe reproductive parameters in postmenarchal girls from the general population including the frequency of oligomenorrhea, polycystic ovary syndrome, and use of hormonal contraception.

DESIGN

The Copenhagen Mother-Child Cohort is a population-based longitudinal birth cohort of 1210 girls born between 1997 and 2002.

SETTING

University hospital.

PARTICIPANTS

A total of 317 girls were included, with a median age of 16.1 years and time since menarche of 2.9 years.

MAIN OUTCOME MEASURE(S)

Tanner stage, height, weight, age at menarche, menstrual cycle length and regularity, ovarian/uterine volume, and number of follicles were recorded. Serum concentrations of FSH, LH, anti-Müllerian hormone (AMH), inhibin B, estradiol, testosterone, SHBG, androstenedione, dehydroepiandrosterone sulfate, 17-OH-progesterone, and IGF-1 were measured.

RESULTS

Twenty girls (6.3%) had oligomenorrhea and differed significantly in serum androgens and AMH, age at and time since menarche from girls with regular cycles. Twenty-seven girls were classified with PCOS (8.5%) and had significantly higher 17-OH-progesterone, estradiol, AMH, LH, and age at menarche than the reference group. Girls on oral contraception had significantly higher serum SHBG concentrations and lower serum concentrations of all hormones except AMH and IGF-1. Ovarian follicles 2 to 29.9 mm correlated positively with serum AMH (P < 0.0001).

CONCLUSIONS

Most 16-year-old girls had regular menstrual cycles, normal reproductive hormones, and uterine and ovarian ultrasound. Serum AMH reflected ovarian follicle count and may be a useful biomarker of ovarian reserve.

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.

Testicular Ultrasound to Stratify Hormone References in a Cross-Sectional Norwegian Study of Male Puberty

CONTEXT

Testicular growth represents the best clinical variable to evaluate male puberty, but current pediatric hormone references are based on chronological age and subjective assessments of discrete puberty development stages. Determination of testicular volume (TV) by ultrasound provides a novel approach to assess puberty progression and stratify hormone reference intervals.

OBJECTIVE

The objective of this article is to establish references for serum testosterone and key hormones of the male pituitary-gonadal signaling pathway in relation to TV determined by ultrasound.

DESIGN, SETTING, AND PARTICIPANTS

Blood samples from 414 healthy Norwegian boys between ages 6 and 16 years were included from the cross-sectional "Bergen Growth Study 2." Participants underwent testicular ultrasound and clinical assessments, and serum samples were analyzed by liquid chromatography tandem-mass spectrometry and immunoassays.

MAIN OUTCOME MEASURES

We present references for circulating levels of total testosterone, luteinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin in relation to TV, chronological age, and Tanner pubic hair stages.

RESULTS

In pubertal boys, TV accounted for more variance in serum testosterone levels than chronological age (Spearman r = 0.753, P < .001 vs r = 0.692, P < .001, respectively). Continuous centile references demonstrate the association between TV and hormone levels during puberty. Hormone reference intervals were stratified by TV during the pubertal transition.

CONCLUSIONS

Objective ultrasound assessments of TV and stratification of hormone references increase the diagnostic value of traditional references based on chronological age or subjective staging of male puberty.

Perceptual Measures of Boychoir Voices During the Phases of Pubertal Voice Mutation

BACKGROUND/OBJECTIVES

Vocal changes in the male singing voice associated with puberty are variable and often unpredictable resulting in challenges for the singer and the choral director. Limited knowledge regarding the physiologic changes in the vocal mechanism as they correlate to perceptual variations observed in the male adolescent singer exists in the literature. The purpose of this study was to examine pitch breaks and perceptual characteristics of vocal quality during singing tasks for boys in various stages of the male changing voice.

STUDY DESIGN

Prospective Study.

METHODS

Twenty-eight boys were initially evaluated at Cooksey Stage 0 (Pubertal Unchanged; n = 15) or Cooksey Stage 1 (Mid-Voice; n = 13). Range of age was 8-13 years old. Participants performed vocal slide intervals (1-3-1, 1-5-1, 1-8-1) with discrete starting frequencies on G3, C4, F4, and A4 and sang the "Star-Spangled Banner" in the key of Ab. Pitch breaks and perceptual qualities were evaluated on the recorded tasks by expert raters. Seven boys were evaluated again when they progressed to Cooksey Stage 4 (Baritone) performing the same singing tasks.

RESULTS

For the participants evaluated at Cooksey Stage 0/1, pitch breaks were observed more in the higher frequencies and increased interval spacing regardless of starting frequency. Participants at Cooksey Stage 0 had more pitch breaks than Stage 1. At Cooksey Stage 4, an increase in the number of pitch breaks was observed in comparison to their tasks performed at Stage 0/1 and the perceptual quality of breathiness was significantly greater.

CONCLUSIONS

Pitch breaks are a characteristic perceptual change that indicates a young man may be transitioning through puberty. Findings from the present study demonstrate that in addition to perceived pitch breaks, breathiness was noted to significantly increase as the male progressed through puberty. Breathiness was noted to be more significant than vocal timbre and overall vocal quality. This research provides acoustic evidence to enhance the perceptual characteristics of voice change for those who teach and train male voices through puberty.

References for Ultrasound Staging of Breast Maturation, Tanner Breast Staging, Pubic Hair, and Menarche in Norwegian Girls

CONTEXT

Discriminating adipose and glandular tissue is challenging when clinically assessing breast development. Ultrasound facilitates staging of pubertal breast maturation (US B), but has not been systematically compared to Tanner breast (Tanner B) staging, and no normative data have been reported.

OBJECTIVE

To present normative references for US B along with references for Tanner B, pubic hair (PH), and menarche.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional sample of 703 healthy girls aged 6 to 16 years were examined.

MAIN OUTCOME MEASURES

Breast development was determined with US B and Tanner B staging. Tanner PH and menarcheal status were recorded. The age distributions of entry in US B, Tanner B, and PH stages and menarche were estimated with generalized linear and generalized additive models with a probit link. Method agreement was tested with weighted Cohen's kappa.

RESULTS

The median (±2SD) ages for thelarche, US B2 and Tanner B2, were 10.2 (7.7, 12.8) and 10.4 (8.0, 12.7) years. The median (±2SD) ages at Tanner PH2 and menarche were 10.9 (8.5, 13.3) and 12.7 (11.0, 16.2) years. Cohen's kappa of agreement (95% confidence interval) between US B and Tanner B was 0.87 (0.85-0.88). When the methods disagreed, US B was usually more advanced.

CONCLUSION

Thelarche occurred at a slightly younger age when assessed with ultrasound compared to clinical Tanner staging, although the 2 methods had a very good agreement when determining pubertal breast maturation. A significant decrease of 2.8 months in age at menarche was observed during the past decade in Norwegian girls.

Sex differences in the longitudinal associations between body composition and bone stiffness index in European children and adolescents

Fat mass (FM) and fat free mass (FFM) may influence bone health differentially. However, existing evidences on associations between FM, FFM and bone health are inconsistent and vary according to sex and maturity. The present study aims to evaluate longitudinal associations between FM, FFM and bone stiffness index (SI) among European children and adolescents with 6 years follow-up. A sample of 2468 children from the IDEFICS/I.Family was included, with repeated measurements of SI using calcaneal quantitative ultrasound, body composition using skinfold thickness, sedentary behaviors and physical activity using self-administrated questionnaires. Regression coefficients (β) and 99%-confidence intervals (99% CI) were calculated by sex-specified generalized linear mixed effects models to analyze the longitudinal associations between FM and FFM z-scores (zFM and zFFM) and SI percentiles, and to explore the possible interactions between zFM, zFFM and maturity. Baseline zFFM was observed to predict the change in SI percentiles in both boys (β = 4.57, 99% CI: 1.36, 7.78) and girls (β = 3.42, 99% CI: 0.05, 6.79) after 2 years. Moreover, baseline zFFM (β = 8.72, 99% CI: 3.18, 14.27 in boys and β = 5.89, 99% CI: 0.34, 11.44 in girls) and the change in zFFM (β = 6.58, 99% CI: 0.83, 12.34 in boys and β = 4.81, 99% CI: -0.41, 10.02 in girls) were positively associated with the change in SI percentiles after 6 years. In contrast, a negative association was observed between the change in zFM and SI percentiles in boys after 6 years (β = -3.70, 99% CI: -6.99, -0.42). Besides, an interaction was observed between the change in zFM and menarche on the change in SI percentiles in girls at 6 years follow-up (p = .009), suggesting a negative association before menarche while a positive association after menarche. Our findings support the existing evidences for a positive relationship between FFM and SI during growth. Furthermore, long-term FM gain was inversely associated with SI in boys, whereas opposing associations were observed across menarche in girls.

Age at Pubertal Development in a Hispanic-Latina Female Population: Should the Definitions Be Revisited?

STUDY OBJECTIVE

To assess pubertal events in a Hispanic female population and to create normograms of puberty.

DESIGN

Longitudinal.

SETTING

University facility.

PARTICIPANTS

Five hundred forty-nine girls from the Growth and Obesity Chilean Cohort study.

INTERVENTIONS

Follow-up twice a year beginning at age 6 years.

MAIN OUTCOME MEASURES

Breast development, pubic hair development, and age. Breast development (B2, B3, and B4) and pubarche (P2) were determined. Age at menarche was obtained from the adolescents and their mothers. Age and growth velocity at peak height velocity were calculated.

RESULTS

In girls, B2, B3, and B4 occur at median ages of 9.2, 10.2, and 10.9 years, respectively. The median age at P2 was 9.7 years. The mean age at peak height velocity and the growth velocity were 10.6 years (SD = 1.1) and 8 cm/y, respectively. The mean age at menarche was 11.9 years (SD = 1.1); only 2.8% (15 /530) of girls experienced menarche after 14 years and 1.9% before 10 years. The mean interval time between B2 and menarche was 2.5 ± 1.0 years. Transient thelarche occurred in 8.6% of girls.

CONCLUSION

This longitudinal cohort shows that thelarche occurred 1.2 months later than previously reported in cross-sectional studies. Conversely, we found that pubic hair appeared 12 months earlier and menarche occurred 9 months earlier than previously reported. These findings are important in setting normalcy data and avoiding unnecessary clinical consultations.

Prevalence of Endocrine Disorders in Childhood Brain Tumor Survivors in South Korea

BACKGROUND/AIM

This longitudinal study aimed to analyze the prevalence of endocrine disorders in childhood brain tumor survivors in South Korea using claims data.

PATIENTS AND METHODS

We identified in 1,058 patients from a nationwide cohort of patients diagnosed with brain tumors between January 1st 2009 to March 29th 2016. Multivariable logistic regression was used to evaluate associations between clinical factors and endocrine disorders.

RESULTS

After a median follow-up of 60.0 months, 393 (37.1%) patients had at least 1 endocrine disorder. The commonest endocrine disorders were hypopituitarism (17.4%) and hypothyroidism (6.1%). Female gender (odds ratio(OR)=1.45, p=0.005) and age <10 years (OR=1.65, p=0.001) conferred a higher risk. Patients who received radiotherapy were more likely to have endocrine disorders compared to those who did not (OR=1.79, p<0.001).

CONCLUSION

Regular assessment of endocrine function and timely interventions are necessary for childhood brain tumor survivors with a risk of endocrine disorders.

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.

Glucose metabolism in children and adolescents: Population-based reference values and comparisons to children and adolescents enrolled in obesity treatment

BACKGROUND

Alterations in glucose metabolism that lead to the development of metabolic and cardiovascular disease may begin already in childhood.

OBJECTIVE

This study aims to generate pediatric age and sex-specific reference values for fasting concentrations of glucose, hemoglobin A1c (HbA1c), insulin, C-peptide, and homeostasis model assessment: insulin resistance (HOMA-IR) in Danish/North-European white children and adolescents from a population-based cohort and to compare values from children and adolescents with overweight/obesity with this reference.

METHODS

The population- and obesity clinic-based cohorts consisted of 2451 and 1935 children and adolescents between 6 and 18 years of age. Anthropometric measurements and blood samples were obtained and percentile curves were calculated.

RESULTS

In the population-based cohort, glucose, insulin, and HOMA-IR values increased before the expected onset of puberty (P < .05). Thereafter, all variables decreased in girls (P < .05) and HbA1c decreased in boys (P < .05). Concentrations of all measured markers of glucose metabolism were higher in the obesity clinic-based cohort than the population-based cohort (both sexes P < .001). Specifically, insulin and HOMA-IR continued to increase to 18 years in the clinic-based cohort, particularly among boys.

CONCLUSIONS

Fasting glucose, insulin, and HOMA-IR change during childhood, making pediatric reference values essential for timely identification of derangements in glucose metabolism. Children and adolescents with obesity exhibit increased concentrations of these biomarkers.

Pubertal abnormalities in adolescents with chronic disease

Pubertal disorders in the context of chronic disease especially in those with chronic inflammatory disorders or those requiring prolonged periods of treatment with glucocorticoid are common reasons for referral to the paediatric endocrine clinic. Disorders of puberty are also common in adolescents with disability requiring management by paediatric endocrinologists. In these adolescents, impaired skeletal development is also observed and this can be associated with fragility fractures. Chronic inflammation, glucocorticoid and sub-optimal nutrition all impact on the hypothalamic-pituitary gonadal axis, and can also impact on skeletal development locally by their effects on the growth plate and bone. Addressing pubertal disorders is important to ensure adolescents with chronic disease are matched with their peers, promote adequate bone mass accrual and linear growth. Careful discussion with primary clinicians, the young person and the family is needed when instituting endocrine therapies to address puberty and manage bone health.

Endocrine disrupters and possible contribution to pubertal changes

The onset of puberty strongly depends on organizational processes taking place during the fetal and early postnatal life. Therefore, exposure to environmental pollutants such as Endocrine disrupting chemicals (EDCs) during critical periods of development can result in delayed/advanced puberty and long-term reproductive consequences. Human evidence of altered pubertal timing after exposure to endocrine disrupting chemicals is equivocal. However, the age distribution of pubertal signs points to a skewed distribution towards earliness for initial pubertal stages and towards lateness for final pubertal stages. Such distortion of distribution is a recent phenomenon and suggests environmental influences including the possible role of nutrition, stress and endocrine disruptors. Rodent and ovine studies indicate a role of fetal and neonatal exposure to EDCs, along the concept of early origin of health and disease. Such effects involve neuroendocrine mechanisms at the level of the hypothalamus where homeostasis of reproduction is programmed and regulated but also peripheral effects at the level of the gonads or the mammary gland.

Incidence and Prevalence of Central Precocious Puberty in Korea: An Epidemiologic Study Based on a National Database

OBJECTIVES

To investigate the prevalence and incidence of central precocious puberty in Korea using claims data provided by the Health Insurance Review and Assessment Service in Korea as the population-based epidemiologic study.

STUDY DESIGN

In this national registry-based, longitudinal, epidemiologic study, patients who were registered with an International Classifications of Diseases, Tenth Revision diagnosis of central precocious puberty (E22.8 according to International Classifications of Diseases, Tenth Revision) and treated with gonadotropin-releasing hormone agonist were included. We assessed the age- and sex-specific prevalence and incidence rates of central precocious puberty in Korea from 2008 to 2014.

RESULTS

A total of 37 890 girls and 1220 boys were newly registered with a diagnosis of central precocious puberty from 2008 to 2014. The overall incidence of central precocious puberty during the study period was 122.8 per 100 000 persons (girls, 262.8; boys, 7.0). The overall prevalence of central precocious puberty during the study period was 193.2 per 100 000 persons (girls, 410.6; boys, 10.9). The incidence and prevalence of central precocious puberty steeply increased during the study period in both girls and boys.

CONCLUSIONS

This epidemiologic study, based on a national registry that included Korean children, demonstrated that the incidence and prevalence rates of central precocious puberty were high and increased steeply during the study period. Further investigations to determine the underlying causes for this rapid increase in central precocious puberty are needed.

Variations in reproductive events across life: a pooled analysis of data from 505 147 women across 10 countries

STUDY QUESTION

How has the timing of women's reproductive events (including ages at menarche, first birth, and natural menopause, and the number of children) changed across birth years, racial/ethnic groups and educational levels?

SUMMARY ANSWER

Women who were born in recent generations (1970-84 vs before 1930) or those who with higher education levels had menarche a year earlier, experienced a higher prevalence of nulliparity and had their first child at a later age.

WHAT IS KNOWN ALREADY

The timing of key reproductive events, such as menarche and menopause, is not only indicative of current health status but is linked to the risk of adverse hormone-related health outcomes in later life. Variations of reproductive indices across different birth years, race/ethnicity and socioeconomic positions have not been described comprehensively.

STUDY DESIGN, SIZE, DURATION

Individual-level data from 23 observational studies that contributed to the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE) consortium were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Altogether 505 147 women were included. Overall estimates for reproductive indices were obtained using a two-stage process: individual-level data from each study were analysed separately using generalised linear models. These estimates were then combined using random-effects meta-analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean ages were 12.9 years at menarche, 25.7 years at first birth, and 50.5 years at natural menopause, with significant between-study heterogeneity (I2 > 99%). A linear trend was observed across birth year for mean age at menarche, with women born from 1970 to 1984 having menarche one year earlier (12.6 years) than women born before 1930 (13.5 years) (P for trend = 0.0014). The prevalence of nulliparity rose progressively from 14% of women born from 1940-49 to 22% of women born 1970-84 (P = 0.003); similarly, the mean age at first birth rose from 24.8 to 27.3 years (P = 0.0016). Women with higher education levels had fewer children, later first birth, and later menopause than women with lower education levels. After adjusting for birth year and education level, substantial variation was present for all reproductive events across racial/ethnic/regional groups (all P values < 0.005).

LIMITATIONS, REASONS FOR CAUTION

Variations of study design, data collection methods, and sample selection across studies, as well as retrospectively reported age at menarche, age at first birth may cause some bias.

WIDER IMPLICATIONS OF THE FINDINGS

This global consortium study found robust evidence on variations in reproductive indices for women born in the 20th century that appear to have both biological and social origins.

STUDY FUNDING/COMPETING INTEREST(S)

InterLACE project is funded by the Australian National Health and Medical Research Council project grant (APP1027196). GDM is supported by the Australian National Health and Medical Research Council Principal Research Fellowship (APP1121844).

Exposure to Vitamin D Fortification Policy in Prenatal Life and the Risk of Childhood Asthma: Results From the D-Tect Study

Prenatal vitamin D insufficiency may be associated with an increased risk of developing childhood asthma. Results from epidemiological studies are conflicting and limited by short follow-up and small sample sizes. The objective of this study was to examine if children born to women exposed to the margarine fortification policy with a small dose of extra vitamin D during pregnancy had a reduced risk of developing asthma until age 9 years, compared to children born to unexposed women. The termination of a Danish mandatory vitamin D fortification policy constituted the basis for the study design. We compared the risk of inpatient asthma diagnoses in all Danish children born two years before (n = 106,347, exposed) and two years after (n = 115,900, unexposed) the termination of the policy. The children were followed in the register from 0–9 years of age. Data were analyzed using Cox proportional hazards regression. The Hazard Ratio for the first inpatient asthma admission among exposed versus unexposed children was 0.96 (95%CI: 0.90–1.04). When stratifying by sex and age, 0–3 years old boys exposed to vitamin D fortification showed a lower asthma risk compared to unexposed boys (HR 0.78, 95%CI: 0.67–0.92). Prenatal exposure to margarine fortification policy with extra vitamin D did not affect the overall risk of developing asthma among children aged 0–9 years but seemed to reduce the risk among 0–3 years old boys. Taking aside study design limitations, this could be explained by different sensitivity to vitamin D from different sex-related asthma phenotypes in children with early onset, and sex differences in lung development or immune responses.

EAP1 regulation of GnRH promoter activity is important for human pubertal timing

The initiation of puberty is orchestrated by an augmentation of gonadotropin-releasing hormone (GnRH) secretion from a few thousand hypothalamic neurons. Recent findings have indicated that the neuroendocrine control of puberty may be regulated by a hierarchically organized network of transcriptional factors acting upstream of GnRH. These include enhanced at puberty 1 (EAP1), which contributes to the initiation of female puberty through transactivation of the GnRH promoter. However, no EAP1 mutations have been found in humans with disorders of pubertal timing. We performed whole-exome sequencing in 67 probands and 93 relatives from a large cohort of familial self-limited delayed puberty (DP). Variants were analyzed for rare, potentially pathogenic variants enriched in case versus controls and relevant to the biological control of puberty. We identified one in-frame deletion (Ala221del) and one rare missense variant (Asn770His) in EAP1 in two unrelated families; these variants were highly conserved and potentially pathogenic. Expression studies revealed Eap1 mRNA abundance in peri-pubertal mouse hypothalamus. EAP1 binding to the GnRH1 promoter increased in monkey hypothalamus at the onset of puberty as determined by chromatin immunoprecipitation. Using a luciferase reporter assay, EAP1 mutants showed a reduced ability to trans-activate the GnRH promoter compared to wild-type EAP1, due to reduced protein levels caused by the Ala221del mutation and subcellular mislocation caused by the Asn770His mutation, as revealed by western blot and immunofluorescence, respectively. In conclusion, we have identified the first EAP1 mutations leading to reduced GnRH transcriptional activity resulting in a phenotype of self-limited DP.