Search

Context: Reliable estradiol (E2) reference intervals (RIs) are crucial in pediatric endocrinology., Objectives: This study aims to develop a sensitive ultra-performance liquid chromatographic tandem mass spectrometry (UPLC-MS/MS) method for E2 in serum, to establish graphically represented RI percentiles and annual RIs for both sexes, and to perform a systematic literature comparison., Methods: First, a UPLC-MS/MS method for E2 was developed. Second, graphically represented RI percentiles and annual RIs covering 0-18 years were computed (cohort of healthy children [1181 girls and 543 boys]). Subsequently, RIs were compared with published data by systematic searches., Results: Lower limit of quantification was 11 pmol/L, indicating high sensitivity. Estradiol first peaked during mini-puberty in both sexes (girls up to 192 pmol/L; boys up to 225 pmol/L). As could be expected, girls showed higher pubertal E2 (up to 638 pmol/L). However, boys' RIs (up to 259 pmol/L) overlapped considerably. We found 4 studies in the literature that also used LC-MS/MS to determine E2 and published RIs for the complete pediatric age range. Reference intervals varied considerably. Pre-pubertal and pubertal phases were present in all studies. Higher E2 during the time of mini-puberty in both sexes was documented in 3 studies including ours., Conclusions: Variability of RIs for E2 between studies illustrates the importance of laboratory-specific RIs despite using a LC-MS/MS reference method. In boys, the striking E2 peak during mini-puberty as well as high pubertal E2 without phenotypic estrogenization in regular male puberty indicates that the role of E2 in children and, especially in boys, requires better functional understanding., Competing Interests: Conflict of interest: The authors have nothing to declare., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Endocrinology.)

It is controversial whether obesity in children is associated with earlier onset of puberty and advanced appearance of distinct parameters of pubertal development. To investigate the impact of obesity on markers of the onset and parameters representing stages of puberty, we analyzed auxological parameters and secondary sex characteristics in three representative cohorts of Caucasian children. Body weight, height, peak height velocity and pubertal stages were evaluated in two recent German cohorts (CrescNet and Leipzig Schoolchildren), and a historical Swiss cohort. According to body mass index (BMI), children were classified into three weight groups of lean, overweight, or normal weight with limits defined below -1.28 and above +1.28 BMI SDS. Peak height velocity (PHV) occurred significantly later in lean compared to normal weight children in the CrescNet and Swiss cohort, while there was no difference between obese and normal weight children. There was a trend towards acceleration of parameters of puberty onset and progression in obese children in all three cohorts. Height SDS was significantly higher in obese children compared to normal weight peers, but after completion of pubertal development it was similar in adolescents. The impact of overweight on the acceleration of puberty seems to be slightly stronger in boys. Once girls have reached a critical weight for entering the process of maturation, further increase in body weight does not seem to advance the onset of puberty.

The initiation of mammalian puberty requires an increase in pulsatile release of GnRH from the hypothalamus. This increase is brought about by coordinated changes in transsynaptic and glial-neuronal communication. As the neuronal and glial excitatory inputs to the GnRH neuronal network increase, the transsynaptic inhibitory tone decreases, leading to the pubertal activation of GnRH secretion. The excitatory neuronal systems most prevalently involved in this process use glutamate and the peptide kisspeptin for neurotransmission/neuromodulation, whereas the most important inhibitory inputs are provided by gamma-aminobutyric acid (GABA)ergic and opiatergic neurons. Glial cells, on the other hand, facilitate GnRH secretion via growth factor-dependent cell-cell signaling. Coordination of this regulatory neuronal-glial network may require a hierarchical arrangement. One level of coordination appears to be provided by a host of unrelated genes encoding proteins required for cell-cell communication. A second, but overlapping, level might be provided by a second tier of genes engaged in specific cell functions required for productive cell-cell interaction. A third and higher level of control involves the transcriptional regulation of these subordinate genes by a handful of upper echelon genes that, operating within the different neuronal and glial subsets required for the initiation of the pubertal process, sustain the functional integration of the network. The existence of functionally connected genes controlling the pubertal process is consistent with the concept that puberty is under genetic control and that the genetic underpinnings of both normal and deranged puberty are polygenic rather than specified by a single gene. The availability of improved high-throughput techniques and computational methods for global analysis of mRNAs and proteins will allow us to not only initiate the systematic identification of the different components of this neuroendocrine network but also to define their functional interactions.

Sexual development and mature reproductive function are controlled by a handful of neurones that, located in the basal forebrain, produce the decapeptide luteinizing hormone releasing hormone (LHRH). LHRH is released into the portal system that connects the hypothalamus to the pituitary gland and act on the latter to stimulate the synthesis and release of gonadotrophin hormones. The pubertal activation of LHRH release requires coordinated changes in excitatory and inhibitory inputs to LHRH-secreting neurones. These inputs are provided by both transsynaptic and glia-to-neurone communication pathways. Using cellular and molecular approaches, in combination with transgenic animal models and high-throughput procedures for gene discovery, we are gaining new insight into the basic mechanisms underlying this dual control of LHRH secretion and, hence, the initiation of mammalian puberty. Our results suggest that the initiation of puberty requires reciprocal neurone-glia communication involving excitatory amino acids and growth factors, and the coordinated actions of a group of transcriptional regulators that appear to represent a higher level of control governing the pubertal process.

In this review, studies are described indicating that the increase in pulsatile release of gonadotropin releasing hormone that signals the initiation of puberty requires both changes in transsynaptic communication and the activation of glia-to-neuron signaling pathways. The major players in the transsynaptic control of puberty are neurons that utilize excitatory and inhibitory amino acids as transmitters. Glial cells employ a combination of trophic factors and small cell-cell signaling molecules to regulate neuronal function and thus promote sexual development. A neuron-to-glia signaling pathway mediated by excitatory amino acids serves to coordinate the simultaneous activation of transsynaptic and glia-to-neuron communication required for the advent of sexual maturity., (Copyright 2003 S. Karger AG, Basel)

The sine qua non event of puberty is an increase in pulsatile release of gonadotrophin hormone releasing hormone (GnRH). It is now clear that this increase and, therefore, the initiation of the pubertal process itself, require both changes in transsynaptic communication and the activation of glia-to-neuron signaling pathways. While neurons that utilize excitatory and inhibitory amino acids as transmitters represent major players in the transsynaptic control of puberty, glial cells utilize a combination of trophic factors and small cell-cell signaling molecules to regulate neuronal function and, thus, promote sexual development. A coordinated increase in glutamatergic transmission accompanied by a decrease in inhibitory GABAergic tone appears to initiate the transsynaptic cascade of events leading to the pubertal increase in GnRH release. Glial cells facilitate GnRH secretion via cell-cell signaling loops mainly initiated by members of the EGF and TGF- families of trophic factors, and brought about by either these factors themselves or by chemical messengers released in response to growth factor stimulation. In turn, a neuron-to-glia communication pathway mediated by excitatory amino acids serves to coordinate the simultaneous activation of transsynaptic and glia-to-neuron communication required for the advent of sexual maturity. A different--and perhaps higher--level of control may involve the transcriptional regulation of subordinate genes that, by contributing to neuroendocrine maturation, are required for the initiation of the pubertal process.

Background: Poor glycemic control in children with type 1 diabetes (T1D) may hinder sexual development and the associated growth spurt. This study aims to identify factors that may affect the timing of puberty, total pubertal growth (TPG), and final height (F-Ht) in boys with T1D., Methods: This was a retrospective longitudinal study of 68 boys diagnosed with T1D during 1996 to 2009, who were prepubertal at diagnosis and had completed puberty at the time of data collection. Data were accessed regarding anthropometric measurements, Tanner stage, and glycosylated hemoglobin (HbA1c) levels from diagnosis to F-Ht. F-Ht was compared to parental height and Israeli National Health Survey data., Results: The mean F-Ht standard deviation score (F-Ht-SDS) was lower than the mean Ht-SDS at diagnosis (P < .006) but similar to the mean target height SDS (P = .3) and to values from the national survey (P = .12). Mean HbA1c levels in the year preceding pubertal onset were associated with the age at onset of puberty (R = 0.33, P = .009) and inversely with TPG (R = -0.3, P = .03). Mean HbA1c levels during puberty were inversely associated with TPG (R = -0.26, P = .035) and F-Ht (R = -0.28, P = .02). Boys who presented with diabetic ketoacidosis at diagnosis were shorter than those who did not throughout the follow-up., Conclusions: We found associations of age of pubertal onset, pubertal growth spurt, and F-Ht with target height and glycemic control before and during puberty. Targeted interventions to achieve optimal metabolic control during these time periods are needed for normal, timely puberty and for achieving optimal adult height within the genetic target height., (© 2021 Ruijin Hospital, Shanghai JiaoTong University School of Medicine and John Wiley & Sons Australia, Ltd.)

Background: Previous studies investigating the association between weight status and onset of puberty in boys have been equivocal. It is currently unclear to what extent weight class influences puberty onset and progression., Objectives: To explore the relationship between degree of sexual maturation and anthropometric measures in Norwegian boys., Methods: The following endpoints were collected in a Norwegian cross-sectional study of 324 healthy boys aged 9-16: ultrasound-determined testicular volume (USTV), total serum testosterone, Tanner pubic hair stage, height, weight, waist circumference (WC), subscapular skinfolds (SSF), and body fat percentage (%BF). Testicular volume-for-age z-scores were used to classify "early," "average," or "late" maturing boys. Ordinal logistic regression analyses with a proportional odds model were applied to analyze the association between anthropometric variables and age-adjusted degree of pubertal development, with results expressed as age-adjusted odds ratios (AOR). Cumulative incidence curves for reaching pubertal milestones were stratified by BMI., Results: Boys with a low BMI for age (BMI z  < -1) were less likely to have reached a pubertal testicular volume (USTV ≥ 2.7 mL) or a pubertal serum level of testosterone (≥0.5 nmol/L) compared to normal weight boys (AOR 0.3, p = 0.038, AOR 0.3, p = 0.026, respectively), and entered puberty on average with a delay of approximately eight months. Boys with high BMI for age (BMI z  > 1) exhibited a comparable timing as normal weight boys. The same was found for WC. Pubertal markers were not associated with SSF or %BF., Conclusion: By examining the association between puberty and weight status classified as low, average, or high, we found that a low BMI or WC for age were associated with a less advanced pubertal development and delayed timing of puberty in boys. No significant association was observed for a high BMI or WC. Moreover, no significant effects of SSF or %BF were observed. A low weight status should also be considered when assessing pubertal development in boys., (© 2021 The Authors. Andrology published by Wiley Periodicals LLC on behalf of American Society of Andrology and European Academy of Andrology.)

Objectives: The results of existing studies on bisphenol A (BPA) and puberty timing did not reach a consensus. Thereby we performed this meta-analytic study to explore the association between BPA exposure in urine and puberty timing., Methods: Meta-analysis of the pooled odds ratios (OR), prevalence ratios (PR) or hazards ratios (HR) with 95% confidence intervals (CI) were calculated and estimated using fixed-effects or random-effects models based on between-study heterogeneity., Results: A total of 10 studies involving 5621 subjects were finally included. The meta-analysis showed that BPA exposure was weakly associated with thelarche (PR: 0.96, 95% CI: 0.93-0.99), while no association was found between BPA exposure and menarche (HR: 0.99, 95% CI: 0.89-1.12; OR: 1.02, 95% CI: 0.73-1.43), and pubarche (OR: 1.00, 95% CI: 0.79-1.26; PR: 1.00, 95% CI: 0.95-1.05)., Conclusions: There was no strong correlation between BPA exposure and puberty timing. Further studies with large sample sizes are needed to verify the relationship between BPA and puberty timing., Competing Interests: Authors state no conflict of interest., (2020 Hui Meng et al., published by De Gruyter, Berlin/Boston.)

Minipuberty is the second phase of physiological activation of the reproductive axis, playing a role in the postnatal development of sexual organs. The course of female minipuberty was found to be affected by low maternal vitamin D status and hypothyroidism during pregnancy. The aim of the current study was to assess the hormonal profile and the size of sexual organs in daughters of mothers with gestational diabetes mellitus. The study included three matched groups of infant girls: daughters of healthy women without metabolic disorders during pregnancy (group 1), daughters of women with poorly controlled gestational diabetes mellitus (group 2), and daughters of women with gestational diabetes mellitus adequately controlled during pregnancy (group 3). Urinary levels of gonadotropins, salivary levels of estradiol, testosterone, DHEA-S and progesterone, ovarian volume, uterine length and breast diameter were measured from postnatal month 1 to postnatal month 18. Concentrations of FSH, LH and estradiol were higher, while concentration of progesterone was lower in group 2 than in the remaining groups. There were no between-group differences in concentrations of testosterone and DHEA-S. Levels of LH, FSH, estradiol and progesterone correlated with maternal whole-blood levels of glycated hemoglobin. Group 2 was also characterized by the longest detection periods for LH and estradiol. Ovarian volume, uterine length and breast diameter were greater in group 1 than in the remaining two groups. Over the entire observation period, there were no differences in hormone levels and sizes of the sexual organs between groups 1 and 3. The obtained results suggest that poorly controlled, but not well controlled, gestational diabetes mellitus affects the course of female minipuberty. [ABSTRACT FROM AUTHOR]

The editorial discusses the need for reclassification of male hypogonadism, a condition characterized by gonadal dysfunction and impaired spermatogenesis. It explores the various forms of hypogonadism, including functional and organic causes, and highlights the role of genetics in determining susceptibility to hypogonadism. The article also presents a study on fertile eunuch syndrome, emphasizing the importance of reclassifying hypogonadism to better understand its manifestations. Additionally, it addresses the debate on medical versus surgical treatment of cryptorchidism, suggesting that medical therapy may be a safer and less invasive option. [Extracted from the article]

Background: This study aimed to assess the anthropometric measures and pubertal growth of children and adolescents with Type 1 diabetes mellitus (T1DM) and to detect risk determinants affecting these measures and their link to glycemic control. Patients and methods: Two hundred children and adolescents were assessed using anthropometric measurements. Those with short stature were further evaluated using insulin-like growth factor 1 (IGF-1), bone age, and thyroid profile, while those with delayed puberty were evaluated using sex hormones and pituitary gonadotropins assay. Results: We found that 12.5% of our patients were short (height SDS < -2) and IGF-1 was less than -2 SD in 72% of them. Patients with short stature had earlier age of onset of diabetes, longer duration of diabetes, higher HbA1C and urinary albumin/creatinine ratio compared to those with normal stature (p < 0.05). Additionally, patients with delayed puberty had higher HbA1c and dyslipidemia compared to those with normal puberty (p < 0.05). The regression analysis revealed that factors associated with short stature were; age at diagnosis, HbA1C > 8.2, and albumin/creatinine ratio > 8 (p < 0.05). Conclusion: Children with uncontrolled T1DM are at risk of short stature and delayed puberty. Diabetes duration and control seem to be independent risk factors for short stature. [ABSTRACT FROM AUTHOR]

The gut microbiota has been implicated in the context of sexual maturation during puberty, with discernible differences in its composition before and after this critical developmental stage. Notably, there has been a global rise in the prevalence of precocious puberty in recent years, particularly among girls, where approximately 90% of central precocious puberty cases lack a clearly identifiable cause. While a link between precocious puberty and the gut microbiota has been observed, the precise causality and underlying mechanisms remain elusive. This narrative review aims to systematically elucidate the potential mechanisms that underlie the intricate relationship between the gut microbiota and precocious puberty. Potential avenues of exploration include investigating the impact of the gut microbiota on endocrine function, particularly in the regulation of hormones, such as gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH). Additionally, this review will delve into the intricate interplay between the gut microbiome, metabolism, and obesity, considering the known association between obesity and precocious puberty. This review will also explore how the microbiome's involvement in nutrient metabolism could impact precocious puberty. Finally, attention is given to the microbiota's ability to produce neurotransmitters and neuroactive compounds, potentially influencing the central nervous system components involved in regulating puberty. By exploring these mechanisms, this narrative review seeks to identify unexplored targets and emerging directions in understanding the role of the gut microbiome in relation to precocious puberty. The ultimate goal is to provide valuable insights for the development of non-invasive diagnostic methods and innovative therapeutic strategies for precocious puberty in the future, such as specific probiotic therapy. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to explore the impact of gonadotropin-releasing hormone agonists (GnRHa) on final adult height (FAH) in girls with early and fast puberty. Methods: A retrospective study was conducted by reviewing data from the medical records of the Pediatric Endocrinology Clinics between January 1, 2010, and December 31, 2020, at MacKay Children's Hospital. The treatment group included 109 patients who received 3.75 mg monthly for at least 1 year, whereas the control group consisted of 95 girls who received no treatment. Results: The treatment group was significantly older at the time of inclusion (chronological age (CA1), treatment vs. control, 8.7 vs. 8.4 years, p < 0.001), had a more advanced bone age (BA) (BA1, 11.5 vs. 10.8 years, p < 0.001), BA1-CA1 (2.7 vs. 2.2 years, p < 0.001), and shorter predicted adult height (PAH1) (153.3 vs. 157.1 cm, p = 0.005) that was significantly lower than their target height (Tht) (PAH1-Tht, -3.9 vs. -1.3 cm, p = 0.039). The FAHs of the GnRHa and the control group were similar (157.0 vs. 156.7 cm, p = 0.357) and were not significantly different from their Tht (FAH vs. Tht in the GnRHa group, 157.0 vs. 157.0 cm; control group, 156.7 vs. 157.0 cm). In the subgroup analysis, FAH was significantly higher after GnRHa treatment in those with PAH1 less than 153 cm and Tht (154.0 vs. 152.0 cm, p = 0.041), and those whose CA1 was between 8 and 9 years (158.0 vs. 155.4 cm, p = 0.004). We defined satisfactory FAH outcome as FAH- PAH1>5 cm and significant factors were GnRHa therapy, PAH1 shorter than their Tht, age younger than 9 years, and faster growth velocity during the first year. Discussion: GnRHa is effective in restoring the Tht in some early and fast pubertal girls, especially in those with poorly PAH (PAH lower than 153 cm and shorter than their target height). A younger age at initiation of treatment and a faster growth velocity during treatment are associated with a better height gain. [ABSTRACT FROM AUTHOR]

Disorders of pubertal development are enlisted as associated conditions in children and adolescents with type-1 diabetes (T1D). We conducted this study with objective (1) To estimate the median age at onset of puberty and luteinizing hormone (LH) and sex-steroid concentrations in Indian adolescents with T1D and (2) To assess the impact of puberty on glycemic control and insulin resistance (IR). This cross-sectional study included 399 children and youth aged 6–23 years with T1D. Demographic, anthropometric, biochemical and pelvic ultrasound data were collected using standard protocols. IR was calculated using estimated glucose disposal rate and puberty was assessed using Tanner staging. Median age at onset of thelarche, pubarche and menarche were 11.3, 11.4 and 12.8 years in girls and that of gonadarche and pubarche were 10.6 and 12.7 years for boys. The mean LH and sex-steroid concentrations of subjects with T1D were similar to healthy subjects at each stage of puberty. The cut-offs of LH and sex-steroids derived from healthy Indian children yielded high sensitivity and specificity in determining pubertal onset. The prevalence of precocity, delayed puberty, ovarian cysts and polycystic ovaries was 0.9 , 5.1, 5.1 and 8.6 %, respectively. Glycaemic control and insulin sensitivity was poor in pubertal subjects. The age at onset of puberty, LH, and sex-steroid concentrations in subjects with T1D were like otherwise healthy Indian children with poor glycemic control and IR in pubertal subjects. Although most complications of T1D are associated with poor glycemic control, pubertal disorders were significantly low despite the less-than-optimal glycemic control. [ABSTRACT FROM AUTHOR]

Central precocious puberty (CPP) classically refers to premature activation of the hypothalamic–pituitary–gonadal axis with onset of sexual development before the age of 8 years in girls and 9 years in boys. A decrease in the age of thelarche has been reported over the past several decades; however, the tempo of pubertal progression can be slower and adult height may not be adversely affected in many of the girls who experience thelarche at 6-8 years. Outside of this secular trend in the development itself, the past several decades have also brought about advances in diagnosis and management. This includes the widespread use of an ultrasensitive luteinizing hormone assay, decreasing the need for stimulation testing and a better understanding of the genetics that govern the onset of puberty. Additionally, management of CPP using gonadotropin-releasing hormone analogs (GnRHas) has changed with the advent of new longer-acting formulations. Emerging long-term outcomes of GnRHa administration with regards to obesity, cardiovascular risk factors and fertility are reassuring. Despite these advancements, clinical care in CPP is hampered by the lack of well-designed controlled studies, and management decisions are frequently not supported by clear practice guidelines. Data in boys with CPP are limited and this article focuses on the diagnosis and management of CPP in girls, particularly, in those who present with thelarche at the age of 6-8 years. [ABSTRACT FROM AUTHOR]

Aim: In this study, it was aimed to examine the clinical and laboratory findings that can be used to predict central precocious puberty (CPP) in cases whose breast development started before the age of 8. Materials and Methods: The chronological age, anthropometric measurements, bone age (BA), hormone test results and pelvic ultrasonography findings of the cases were recorded. Those with a peak luteinizing hormone (LH) level of =5 IU/L in the gonadotropin-releasing hormone (GnRH) stimulation test were classified as CPP and those with a peak LH level of <5 IU/L were classified as prepubertal cases. A receiver operating characteristic (ROC) analysis was performed to determine the diagnostic accuracy of laboratory variables. Findings: A total of 297 female cases were included in the study. The age at the time of admission, height-standard deviation score (SDS), BA, the long axis of the uterus and the volumes of the right and left ovaries of the cases diagnosed with CPP were found to be significantly higher than those of the prepubertal group. The cut-off value providing the best sensitivity (99%) and specificity (99%) for the peak LH was found to be 4.55; the cut-off value providing the best sensitivity (94%) and specificity (85%) for the peak LH/follicle-stimulating hormone (FSH) ratio was found to be 0.32 and the cut-off value providing the best sensitivity (47%) and specificity (93%) for the basal LH was found to be 0.13. Conclusion: We believe that in female cases with early breast development, a peak LH level of =4.55 may possibly indicate CPP and a basal LH level of <0.13 can significantly rule out CPP. [ABSTRACT FROM AUTHOR]

Introduction: Estrogenic endocrine disrupting chemicals (EDCs) such as diethylstilbestrol (DES) are known to alter the timing of puberty onset and reproductive function in females. Accumulating evidence suggests that steroid synthesis inhibitors such as ketoconazole (KTZ) or phthalates may also affect female reproductive health, however their mode of action is poorly understood. Because hypothalamic activity is very sensitive to sex steroids, we aimed at determining whether and how EDCs with different mode of action can alter the hypothalamic transcriptome and GnRH release in female rats. Design: Female rats were exposed to KTZ or DES during perinatal (DES 3-6-12mg/kg.d; KTZ 3-6-12mg/kg.d), pubertal or adult periods (DES 3-12-48mg/kg.d; KTZ 3-12-48mg/kg.d). Results: Ex vivo study of GnRH pulsatility revealed that perinatal exposure to the highest doses of KTZ and DES delayed maturation of GnRH secretion before puberty, whereas pubertal or adult exposure had no effect on GnRH pulsatility. Hypothalamic transcriptome, studied by RNAsequencing in the preoptic area and in the mediobasal hypothalamus, was found to be very sensitive to perinatal exposure to all doses of KTZ before puberty with effects persisting until adulthood. Bioinformatic analysis with IngenuityPathwayAnalysis predicted "CrebsignalinginNeurons" and "IGF-1 signaling" among the most downregulated pathways by all doses of KTZ and DES before puberty, and "PPARg" as a common upstream regulator driving gene expression changes. Deeper screening of RNAseq datasets indicated that a highnumber of genes regulating the activity of the extrinsic GnRH pulse generator were consistently affected by all the doses of DES and KTZ before puberty. Several, including MKRN3, DNMT3 or Cbx7, showed similar alterations in expression at adulthood. Conclusion: nRH secretion and the hypothalamic transcriptome are highly sensitive to perinatal exposure to both DES and KTZ. The identified pathways should be exploredfurther to identify biomarkers for future testing strategies for EDC identification and when enhancing the current standard information requirements in regulation. [ABSTRACT FROM AUTHOR]

Pubertal children with significant growth retardation represent a considerable therapeutic challenge. In growth hormone (GH) deficiency, and in those without identifiable pathologies (idiopathic short stature), the impact of using GH is significantly hindered by the relentless tempo of bone age acceleration caused by sex steroids, limiting time available for growth. Estrogen principally modulates epiphyseal fusion in females and males. GH production rates and growth velocity more than double during puberty, and high-dose GH use has shown dose-dependent increases in linear growth, but also can raise insulin-like growth factor I concentrations supraphysiologically, and increase treatment costs. Gonadotropin-releasing hormone analogs (GnRHas) suppress physiologic puberty, and when used in combination with GH can meaningfully increase height potential in males and females while rendering adolescents temporarily hypogonadal at a critical time in development. Aromatase inhibitors (AIs) block androgen to estrogen conversion, slowing down growth plate fusion, while allowing normal virilization in males and stimulating longitudinal bone growth via androgen receptor effects on the growth plate. Here, we review the physiology of pubertal growth, estrogen and androgen action on the epiphyses, and the therapeutic impact of GH, alone and in combination with GnRHa and with AIs. The pharmacology of potent oral AIs, and pivotal work on their efficacy and safety in children is also reviewed. Time-limited use of AIs is a viable alternative to promote growth in pubertal males, particularly combined with GH. Use of targeted growth-promoting therapies in adolescence must consider the impact of sex steroids on growth plate fusion, and treatment should be individualized. [ABSTRACT FROM AUTHOR]

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-CoV2, 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 SARSCoV-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. [ABSTRACT FROM AUTHOR]

Simple Summary: An increase in the pulsatile release of gonadotropin-releasing hormone (GnRH) is essential for the onset of puberty. However, the mechanisms controlling pubertal increases in GnRH release are still unclear. In primates the GnRH neurosecretory system is active during the neonatal period but subsequently enters a dormant state in the juvenile period. The present study examined developmental changes in the gonadotropin inhibitory hormone (GnIH) neuronal system, an inhibitory neuropeptidergic system upstream of GnRH neurons, and the relationship among changes that were observed in GnRH and kisspeptin (Kiss1) gene expression during puberty. A significant inverse age-related relationship between GnRH, Kiss1, and GnIH was observed, suggesting GnIH's potential role in reproductive suppression prior to puberty, with this theoretical 'brake' during the pubertal transition. These findings underscore the need for further research on the role that is played by GnIH in reproductive transition to aid in the development of potential GnIH-based drugs to treat pubertal disorders and adult fertility. Modulation of pulsatile gonadotropin-releasing hormone (GnRH) secretion across postnatal development in higher primates is not fully understood. While gonadotropin-inhibitory hormone (GnIH) is reported to suppress reproductive axis activity in birds and rodents, little is known about the developmental trajectory of GnIH expression in rhesus monkeys throughout the pubertal transition. This study was aimed at examining the variation in GnIH immunoreactivity (-ir) and associated changes among GnIH, GnRH, and Kiss1 mRNA expression in the hypothalamus of infant, juvenile, prepubertal, and adult male rhesus monkeys. The brains from rhesus macaques were collected from infancy until adulthood and were examined using immunofluorescence and RT-qPCR. The mean GnIH-ir was found to be significantly higher in prepubertal animals (p < 0.01) compared to infants, and significantly reduced in adults (p < 0.001). Significantly higher (p < 0.001) GnRH and Kiss1 mRNA expression was noted in adults while GnIH mRNA expression was the highest at the prepubertal stage (p < 0.001). Significant negative correlations were seen between GnIH-GnRH (p < 0.01) and GnIH-Kiss1 (p < 0.001) expression. Our findings suggest a role for GnIH in the prepubertal suppression of the reproductive axis, with disinhibition of the adult reproductive axis occurring through decreases in GnIH. This pattern of expression suggests that GnIH may be a viable target for the development of novel therapeutics and contraceptives for humans. [ABSTRACT FROM AUTHOR]

Age at menarche (AAM) is an effective marker of puberty timing but its onset could be influenced by several intrinsic and extrinsic factors. This study aimed to assess the AAM in a sample of Italian adolescents and to investigate its association with anthropometric variables. Considering the rise in overweight/obesity worldwide, special attention was paid to a possible decrease in AAM as adiposity indices increase. A longitudinal study was carried out on 117 middle school girls in Northern Italy. Data concerning menarche and anthropometric traits (standing and sitting height, weight, waist circumference, and skinfold thicknesses) were directly collected. Lower limb length and indices of adiposity and growth were calculated. The median AAM was 11.66 (95% IC: 11.31–11.68). Age-adjusted ANCOVA between mature and non-mature girls showed significant differences in growth-related traits and WHtR. No preponderance of overweight/obesity among mature participants was found. AAM was not significantly associated with weight or the growth velocity of adiposity indices in a subsample of maturers. Moreover, the median AAM of our sample was similar to that found in women born about 60 years ago in the same region. In conclusion, in addition to a stabilization of AAM since the 1960s, our results suggest that there is no significant correlation between increased adiposity and early AAM. [ABSTRACT FROM AUTHOR]

Copyright of Gynäkologische Endokrinologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The hypothalamus and the pituitary gland are directly involved in the complex systemic changes that drive the onset of puberty in cattle. Here, we applied integrated bioinformatics to elucidate the critical proteins underlying puberty and uncover potential molecular mechanisms from the hypothalamus and pituitary gland of prepubertal (n = 6) and postpubertal (n = 6) cattle. Proteomic analysis in the hypothalamus and pituitary gland revealed 275 and 186 differentially abundant (DA) proteins, respectively (adjusted p -value < 0.01). The proteome profiles found herein were integrated with previously acquired transcriptome profiles. These transcriptomic studies used the same tissues harvested from the same heifers at pre- and post-puberty. This comparison detected a small number of matched transcripts and protein changes at puberty in each tissue, suggesting the need for multiple omics analyses for interpreting complex biological systems. In the hypothalamus, upregulated DA proteins at post-puberty were enriched in pathways related to puberty, including GnRH, calcium and oxytocin signalling pathways , whereas downregulated proteins were observed in the estrogen signalling pathway, axon guidance and GABAergic synapse. Additionally, this study revealed that ribosomal pathway proteins in the pituitary were involved in the pubertal development of mammals. The reported molecules and derived protein-protein networks are a starting point for future experimental approaches that might dissect with more detail the role of each molecule to provide new insights into the mechanisms of puberty onset in cattle. [ABSTRACT FROM AUTHOR]

Background: According to the Developmental Origins of Health and Disease (DOHaD) hypothesis, environmental changes taking place during early maturational periods may alter normal development and predispose to the occurrence of diverse pathologies later in life. Indeed, adverse conditions during these critical developmental windows of high plasticity have been reported to alter the offspring developmental trajectory, causing permanent functional and structural perturbations that in the long term may enhance disease susceptibility. However, while solid evidence has documented that fluctuations in environmental factors, ranging from nutrient availability to chemicals, in early developmental stages (including the peri-conceptional period) have discernible programming effects that increase vulnerability to develop metabolic perturbations, the impact and eventual mechanisms involved, of such developmental alterations on the reproductive phenotype of offspring have received less attention.Objective and Rationale: This review will summarize recent advances in basic and clinical research that support the concept of DOHaD in the context of the impact of nutritional and hormonal perturbations, occurring during the periconceptional, fetal and early postnatal stages, on different aspects of reproductive function in both sexes. Special emphasis will be given to the effects of early nutritional stress on the timing of puberty and adult gonadotropic function, and to address the underlying neuroendocrine pathways, with particular attention to involvement of the Kiss1 system in these reproductive perturbations. The implications of such phenomena in terms of reproductive medicine will also be considered.Search Methods: A comprehensive MEDLINE search, using PubMed as main interface, of research articles and reviews, published mainly between 2006 and 2021, has been carried out. Search was implemented using multiple terms, focusing on clinical and preclinical data from DOHaD studies, addressing periconceptional, gestational and perinatal programming of reproduction. Selected studies addressing early programming of metabolic function have also been considered, when relevant.Outcomes: A solid body of evidence, from clinical and preclinical studies, has documented the impact of nutritional and hormonal fluctuations during the periconceptional, prenatal and early postnatal periods on pubertal maturation, as well as adult gonadotropic function and fertility. Furthermore, exposure to environmental chemicals, such as bisphenol A, and maternal stress has been shown to negatively influence pubertal development and gonadotropic function in adulthood. The underlying neuroendocrine pathways and mechanisms involved have been also addressed, mainly by preclinical studies, which have identified an, as yet incomplete, array of molecular and neurohormonal effectors. These include, prominently, epigenetic regulatory mechanisms and the hypothalamic Kiss1 system, which likely contribute to the generation of reproductive alterations in conditions of early nutritional and/or metabolic stress. In addition to the Kiss1 system, other major hypothalamic regulators of GnRH neurosecretion, such as γ-aminobutyric acid and glutamate, may be targets of developmental programming.Wider Implications: This review addresses an underdeveloped area of reproductive biology and medicine that may help to improve our understanding of human reproductive disorders and stresses the importance, and eventual pathogenic impact, of early determinants of puberty, adult reproductive function and fertility. [ABSTRACT FROM AUTHOR]

We use Mendelian randomization to estimate the causal effect of age at menarche on late pubertal height growth and total pubertal height growth. The instrument SNPs selected from the exposure genome-wide association study (GWAS) are validated in additional population-matched exposure GWASs. Based on the inverse variance weighting method, there is a positive causal relationship of age at menarche on late pubertal growth ( β ^ = 0.56 , 95% CI: (0.34, 0.78), p = 3.16 × 10 − 7 ) and on total pubertal growth ( β ^ = 0.36 , 95% CI: (0.14, 0.58), p = 1.30 × 10 − 3 ). If the instrument SNPs are not validated in additional exposure GWASs, the estimated effect on late pubertal height growth increases by 3.6% to β ^ = 0.58 (95% CI: (0.42, 0.73), p = 4.38 × 10 − 13 ) while the estimates on total pubertal height growth increases by 41.7% to β ^ = 0.51 (95% CI: (0.35, 0.67), p = 2.96 × 10 − 11 ). [ABSTRACT FROM AUTHOR]

The average age for pubertal onset in girls has declined over recent decades. Epidemiological studies in humans and experimental studies in animals suggest a causal role for endocrine disrupting chemicals (EDCs) that are present in our environment. Of concern, current testing and screening regimens are inadequate in identifying EDCs that may affect pubertal maturation, not least because they do not consider early-life exposure. Also, the causal relationship between EDC exposure and pubertal timing is still a matter of debate. To address this issue, we have used current knowledge to elaborate a network of putative adverse outcome pathways (pAOPs) to identify how chemicals can affect pubertal onset. By using the AOP framework, we highlight current gaps in mechanistic understanding that need to be addressed and simultaneously point towards events causative of pubertal disturbance that could be exploited for alternative test methods. We propose 6 pAOPs that could explain the disruption of pubertal timing by interfering with the central hypothalamic trigger of puberty, GnRH neurons, and by so doing highlight specific modes of action that could be targeted for alternative test method development. [ABSTRACT FROM AUTHOR]

Background: Early age at breast development (thelarche) has been associated with increased breast cancer risk. Average age at thelarche has declined over time, but there are few established risk factors for early thelarche. We examined associations between pre- and postnatal exposures and age at thelarche in a US cohort of women born between 1928 and 1974.Methods: Breast cancer-free women ages 35-74 years who had a sister diagnosed with breast cancer were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported information on early-life exposures and age at thelarche, which we categorized as early (≤ 10 years), average (11-13 years), and late (≥ 14 years). For each exposure, we estimated odds ratios (ORs) and 95% confidence intervals (CIs) for early and late thelarche using polytomous logistic regression, adjusted for birth cohort, race/ethnicity and family income level in childhood.Results: Early thelarche was associated with multiple prenatal exposures: gestational hypertensive disorder (OR = 1.25, 95% CI 1.09-1.43), diethylstilbestrol use (OR = 1.23, 95% CI 1.04-1.45), smoking during pregnancy (OR = 1.20, 95% CI 1.13-1.27), young maternal age (OR 1.30, 95% CI 1.16-1.47 for < 20 vs. 25-29 years), and being firstborn (OR = 1.25, 95% CI 1.17-1.33). Birthweight < 2500 g and soy formula use in infancy were positively associated with both early and late thelarche.Conclusions: Associations between pre- and postnatal exposures and age at thelarche suggest that the early-life environment influences breast development and therefore may also affect breast cancer risk by altering the timing of pubertal breast development. [ABSTRACT FROM AUTHOR]

Background: Diabetes and other chronic diseases can affect linear growth and pubertal development. Poor glucose control, long duration, and younger age at onset negatively affect growth and pubertal development. Objectives: This study was designed to describe height, body mass index, and sexual maturation of Iraqi type 1 diabetic adolescents, and their relation to the age at diagnosis, duration of disease, and insulin dose. Materials and Methods: Seventy type 1 diabetic patients were involved in this cross-sectional study. Their ages ranged between 10 and 18 years with diabetes for more than 2 years. Height, weight, body mass index, and pubertal stage were assessed. Then they were correlated with insulin dose, age at diagnosis, and duration of diabetes. Results: There was no significant difference between male and female mean height Z score, whereas the mean body mass index Z score was significantly higher for females than for males. Most of the patients had normal height and body mass index, and only 14.3% and 4.3% were short and underweight, respectively, and there was a significant inverse correlation between duration of diabetes and height SD. Twenty-seven females had menarche. Its age ranged from 10 to 16 years, with a mean of 13.5 ± 1.44 years. Three males and three females (8.6%) had delayed puberty, and no patient had precocious, with a significant positive correlation between pubertal development and height SD. Conclusion: Although there is an improvement in growth parameters for Iraqi diabetic children, they are still abnormal, especially with long diabetes duration. [ABSTRACT FROM AUTHOR]

BACKGROUND: The effects of endocrine-disrupting chemicals (EDCs) on fertility and reproductive development represent a rising concern in modern societies. Although the neuroendocrine control of sexual maturation is a major target of EDCs, little is known about the potential role of the hypothalamus in puberty and ovulation disruption transmitted across generations. OBJECTIVES: We hypothesized that developmental exposure to an environmentally relevant dose of EDC mixture could induce multi- and/or transgenerational alterations of sexual maturation and maternal care in female rats through epigenetic reprograming of the hypothalamus. We investigated the transmission of a disrupted reproductive phenotype via the maternal germline or via nongenomic mechanisms involving maternal care. METHODS: Adult female Wistar rats were exposed prior to and during gestation and until the end of lactation to a mixture of the following 13 EDCs: di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), vinclozolin, prochloraz, procymidone, linuron, epoxynaxole, dichlorodiphenyldichloroethylene, octyl methoxynimmate, 4-methylbenzylidene camphor (4-MBC), butylparaben, and acetaminophen. Perinatally exposed offspring (F1) were mated with unexposed males to generate germ cell (F2) and transgenerationally exposed (F3 and F4) females. Sexual maturation, maternal behavior, and hypothalamic targets of exposure were studied across generations. RESULTS: Germ cell (F2) and transgenerationally (F3) EDC-exposed females, but not F1, displayed delayed pubertal onset and altered folliculogenesis. We reported a transgenerational alteration of key hypothalamic genes controlling puberty and ovulation (Kiss1, Esr1, and Oxt), and we identified the hypothalamic polycomb group of epigenetic repressors as actors of this mechanism. Furthermore, we found a multigenerational reduction of maternal behavior (F1–F3) induced by a loss in hypothalamic dopaminergic signaling. Using a cross-fostering paradigm, we identified that the reduction in maternal phenotype was normalized in EDC-exposed pups raised by unexposed dams, but no reversal of the pubertal phenotype was achieved. DISCUSSION: Rats developmentally exposed to an EDC mixture exhibited multi- and transgenerational disruption of sexual maturation and maternal care via hypothalamic epigenetic reprogramming. These results raise concerns about the impact of EDC mixtures on future generations. [ABSTRACT FROM AUTHOR]

The age at first calving (AFC) has a huge impact on profitability in the dairy industry. It can be used as an indicator of fertility and productivity and it is also considered as an essential factor to ascertain the overall production performance of the animal. There are large variations in AFC in herd to herd, breed to breed and also country to country. This may be due to various factors that affect directly or indirectly on AFC; out of many factors, nutrition, body weight, environments, managements and genetics factors play a major role into attainment of puberty, sexual maturity and AFC. The current review covers various aspects of the seasonal influence of AFC on certain genetic variations and subsequent effect of these genetic variations in reproductive performances of the Murrah buffaloes. [ABSTRACT FROM AUTHOR]

Puberty is a developmental period characterized by a broad range of physiologic changes necessary for the acquisition of adult sexual and reproductive maturity. These changes mirror complex modifications within the central nervous system, including within the hypothalamus. These modifications result in the maturation of a fully active hypothalamic–pituitary–gonadal (HPG) axis, the neuroendocrine cascade ensuring gonadal activation, sex steroid secretion, and gametogenesis. A complex and finely regulated neural network overseeing the HPG axis, particularly the pubertal reactivation of gonadotropin-releasing hormone (GnRH) secretion, has been progressively unveiled in the last 3 decades. This network includes kisspeptin, neurokinin B, GABAergic, and glutamatergic neurons as well as glial cells. In addition to substantial modifications in the expression of key targets, several changes in neuronal morphology, neural connections, and synapse organization occur to establish mature and coordinated neurohormonal secretion, leading to puberty initiation. The aim of this review is to outline the current knowledge of the major changes that neurons secreting GnRH and their neuronal and glial partners undergo before and after puberty. Emerging mediators upstream of GnRH, uncovered in recent years, are also addressed herein. In addition, the effects of sex steroids, particularly estradiol, on changes in hypothalamic neurodevelopment and plasticity are discussed. [ABSTRACT FROM AUTHOR]

Introduction: Current health literature suggests that there has been a decline in the age of pubertal onset and that pubertal onset/duration of puberty may, besides weight status, be influenced by socioeconomic context. Objective: The goal of this study was to determine whether pubertal onset/duration and puberty-triggering hormones luteinizing hormone (LH) and follicle-stimulating hormone (FSH) vary according to socioeconomic status (SES). Moreover, we aimed to propose cutoff values of serum LH and FSH for predicting gonadarche in boys. Methods: 2,657 apparently healthy children and adolescents between 5.5 and 18 years from the area of Leipzig were recruited from the LIFE Child study. Age at pubertal onset/end of puberty was given in 738/573 children, respectively. Anthropometric parameters of puberty, blood measurements of LH and FSH, and questionnaires assessing SES were evaluated. Results: Lower SES was associated with earlier thelarche and longer duration of puberty in overweight/obese girls, whereas age of menarche was not affected. In boys with low SES, a trend versus earlier puberty onset can be seen. Lower SES was significantly associated with boys' age at mutation. No significant differences in boys' and girls' serum levels of LH and FSH during puberty according to SES were observed. Serum LH levels of 0.56 IU/L and serum FSH levels of 1.74 IU/L showed the best prediction of gonadarche in boys. Conclusion: Puberty onset/duration and boys' age at mutation is affected by SES. The proposed cutoff levels for serum LH and FSH could provide a serological tool to determine gonadarche in boys. [ABSTRACT FROM AUTHOR]

Objective: This analysis of previously published reports was performed to examine the effects of gonadotropin‐releasing hormone (GnRH) agonist treatment on adult height and the factors associated with adult height outcomes. Context: GnRH agonists are first‐line agents in the treatment of precocious puberty. However, studies regarding the treatment effect on subjects with early puberty have reported inconsistent results. Design: A total of 14 studies identified from a search of electronic databases (AMED, EMBASE, MEDLINE and RISS) were included. Controlled studies with girls who developed puberty before 10 years of age and measurements of the adult heights of the subjects were selected. Studies using only long‐acting GnRH agonists to suppress puberty were included. Adult height, duration of the treatment, age at the start of treatment and bone age advancement were analysed. Results: The mean age of the subjects ranged from 6.3 to 9.0 years. The meta‐analysis showed a pooled mean difference in adult height of 3.2 cm and a 95% confidence interval of 1.3‐5.1 cm. The height difference between the treated subjects and controls was significantly associated with the duration of treatment (P =.005) rather than the age at the start of treatment (P =.084) or the difference between bone age and chronological age (P =.427). Conclusions: Administration of GnRH agonists in girls who develop early puberty and demonstrate advanced bone age may be effective for increasing adult height, especially if a sufficiently long treatment duration can be achieved. [ABSTRACT FROM AUTHOR]

Expression of particular genes in hypothami of ewes was measured across the natural pubertal transition by in situ hybridization. The ewes were allocated to three groups (n = 4); prepubertal, postpubertal and postpubertally gonadectomized (GDX). Prepubertal sheep were euthanized at 20 weeks of age and postpubertal animals at 32 weeks. GDX sheep were also euthanized at 32 weeks, 1 week after surgery. Expression of KISS1, TAC3,PDYN in the arcuate nucleus (ARC), RFRP in the dorsomedial hypothalamus and GNRH1 in the preoptic area was quantified on a cellular basis. KISS1R expression by GNRH1 cells was quantified by double‐label in situ hybridization. Across puberty, detectable KISS1 cell number increased in the caudal ARC and whilst PDYN cell numbers were low, numbers increased in the rostral ARC. TAC3 expression did not change but RFRP expression/cell was reduced across puberty. There was no change across puberty in the number of GNRH1 cells that expressed the kisspeptin receptor (KISS1R). GDX shortly after puberty did not increase expression of any of the genes of interest. We conclude that KISS1 expression in the ARC increases during puberty in ewes and this may be a causative factor in the pubertal activation of the reproductive axis. A reduction in expression of RFRP may be a factor in the onset of puberty, removing negative tone on GNRH1 cells. The lack of changes in expression of genes following GDX suggest that the effects of gonadal hormones may differ in young and mature animals. [ABSTRACT FROM AUTHOR]

Objective: Doses of gonadotropin releasing hormone (GnRH) analogues used to treat idiopathic central precocious puberty (iCPP) vary among clinicians. Study aims were to evaluate the efficacy of a monthly 3.75 mg dose of leuprolide acetate (LA) to suppress the hypothalamo-pituitary-gonadal (HPG) axis in girls with iCPP and to determine factors that may have an impact on the supressing dose. Methods: Study subjects were 220 girls receiving LA for iCPP. LA was started at a dose of 3.75 mg/28 days. Suppression was assessed using the GnRH test at the third month. To assess clinical suppression signs and symptoms of puberty were also evaluated. The dose of LA was increased to 7.5 mg/28 days in those who had a peak luteinising hormone (LH) ≥2 IU/L and in whom adequate clinical suppression of puberty was absent. Receiver operating characteristic curves were used to determine thresholds for clinical and hormonal factors affecting the suppressing dose of LA. Logistic regression analyses were used to investigate thresholds which might differentiate between those requiring high dose for suppression and those in whom lower dose LA was adequate. Results: Peak stimulated LH <2 IU/L was achieved in 88.6% with a dose of LA of 3.75 mg (0.11±0.03 mg/kg). Significant variables for differentiating the two doses were body weight (Wt) of 36.2 kg and/or body mass index (BMI)-standard deviation scores (SDS) of 1.64 (p<0.001). Multiple logistic regressions showed that Wt and BMI-SDS values above thresholds indicated requirement of LA at a dose of 7.5 mg/28 days (p<0.001). Conclusion: Monthly injections of 3.75 mg LA is an effective treatment in the majority of girls with iCPP. However, a higher initial dose may be preferred in patients with a Wt ≥36 kg or BMI-SDS ≥1.6 for effective suppression of the HPG axis. [ABSTRACT FROM AUTHOR]

The mechanisms underlying the initiation of puberty, one of the cornerstones of human evolution, have not been fully elucidated as yet. However, recently, an accumulating body of evidence has helped unravel several critical aspects of the process. It is clear that a change in the pattern of pituitary gonadotropin secretion serves as a hormonal trigger for puberty induction. This change is directly guided by the hypothalamic GnRH pulse generation, a phenomenon regulated by the Kisspeptin-Neurokinin-Dynorphin (KNDy) system also in the hypothalamus. This represents the kisspeptin molecule, which is crucial in augmenting GnRH secretion at puberty, whose secretion is fine-tuned by the opposing signals neurokinin B and dynorphin. Recently, the novel kisspeptin inhibitory signal MKRN3 was described, whose role in puberty initiation provided further insight into the mechanistic aspects of pubertal onset. Furthermore, the description of higher inhibitory and stimulatory signals acting upstream of the KNDy neurons suggested that the trigger point of puberty is located upstream of the KNDy system and the GnRH pulse generator. However, the mechanism of pubertal onset should not be considered as an isolated closed loop system. On the contrary, it is influenced by such factors as adipose tissue, gastrointestinal function, adrenal androgen production, energy sensing, and physical and psychosocial stress. Also, fetal and early life stressful events, as well as exposure to endocrine disruptors, may play important roles in pubertal initiation, the latter primarily through epigenetic modifications. Here we present the available data in the field and attempt to provide an integrated view of this unique and crucial phenomenon. [ABSTRACT FROM AUTHOR]

Mkrn3, the maternally imprinted gene encoding the makorin RING-finger protein-3, has recently emerged as putative pubertal repressor, as evidenced by central precocity caused by MKRN3 mutations in humans; yet, the molecular underpinnings of this key regulatory action remain largely unexplored. We report herein that the microRNA, miR-30, with three binding sites in a highly conserved region of its 3′ UTR, operates as repressor of Mkrn3 to control pubertal onset. Hypothalamic miR-30b expression increased, while Mkrn3 mRNA and protein content decreased, during rat postnatal maturation. Neonatal estrogen exposure, causing pubertal alterations, enhanced hypothalamic Mkrn3 and suppressed miR-30b expression in female rats. Functional in vitro analyses demonstrated a strong repressive action of miR-30b on Mkrn3 3′ UTR. Moreover, central infusion during the juvenile period of target site blockers, tailored to prevent miR-30 binding to Mkrn3 3′ UTR, reversed the prepubertal down-regulation of hypothalamic Mkrn3 protein and delayed female puberty. Collectively, our data unveil a novel hypothalamic miRNA pathway, involving miR-30, with a prominent role in the control of puberty via Mkrn3 repression. These findings expand our current understanding of the molecular basis of puberty and its disease states. The microRNA miR-30 suppresses the expression of Mkrn3 (a known repressor of puberty) in the hypothalamus by binding to a highly conserved region of its 3' untranslated region, representing a novel mechanism for finely modulating the tempo of puberty. [ABSTRACT FROM AUTHOR]

Delayed pubertal onset has many etiologies, but on average two-thirds of patients presenting with late puberty have self-limited (or constitutional) delayed puberty. Self-limited delayed puberty often has a strong familial basis. Segregation analyses from previous studies show complex models of inheritance, most commonly autosomal dominant, but also including autosomal recessive, bilineal, and X-linked. Sporadic cases are also observed. Despite this, the neuroendocrine mechanisms and genetic regulation remain unclear in the majority of patients with self-limited delayed puberty. Only rarely have mutations in genes known to cause aberrations of the hypothalamic-pituitary-gonadal axis been identified in cases of delayed puberty, and the majority of these are in relatives of patients with congenital hypogonadotropic hypogonadism (CHH), for example in the FGFR1 and GNRHR genes. Using next generation sequencing in a large family with isolated self-limited delayed puberty, a pathogenic mutation in the CHH gene HS6ST1 was found as the likely cause for this phenotype. Additionally, a study comparing the frequency of mutations in genes that cause GnRH deficiency between probands with CHH and probands with isolated self-limited delayed puberty identified that a significantly higher proportion of mutations with a greater degree of oligogenicity were seen in the CHH group. Mutations in the gene IGSF10 have been implicated in the pathogenesis of familial late puberty in a large Finnish cohort. IGSF10 disruption represents a fetal origin of delayed puberty, with dysregulation of GnRH neuronal migration during embryonic development presenting for the first time in adolescence as late puberty. Some patients with self-limited delayed puberty have distinct constitutional features of growth and puberty. Deleterious variants in FTO have been found in families with delayed puberty with extremely low BMI and maturational delay in growth in early childhood. Recent exciting evidence highlights the importance of epigenetic up-regulation of GnRH transcription by a network of miRNAs and transcription factors, including EAP1 , during puberty. Whilst a fascinating heterogeneity of genetic defects have been shown to result in delayed and disordered puberty, and many are yet to be discovered, genetic testing may become a realistic diagnostic tool for the differentiation of conditions of delayed puberty. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the outcomes of gonadotropin-releasing hormone agonist (GnRHa) therapy with or without growth hormone (GH) therapy for girls with idiopathic central precocious puberty (CPP). Methods: The medical records of 166 girls diagnosed with CPP from 2002 to 2017 were retrospectively reviewed. All included patients were treated with GnRHa for =36 months. Changes in height standard deviation score (SDS) for bone age, chronological age (CA), and predicted adult height (PAH) were assessed for the first three years of treatment. The final height gain SDS was calculated as the difference between the initial PAH SDS and adult height (AH) SDS; these were then compared between the GnRHa group (group A, n=135) and the combined GnRHa/GH group (group B, n=31). Results: The initial mean CA was 7.89 years. The mean menarcheal age was 13.12 years (group A, 13.1±0.99; group B, 13.18±0.58 years; P=0.755). PAH SDS at the start of GnRHa treatment and AH SDS were significantly lower in group B than in group A (PAH SDS: -2.20±0.83 vs. -3.19±0.84, P<0.001; AH SDS: 0.18±084 vs. -0.30±0.66, P=0.021). The increase in PAH SDS was higher in group B than in group A for the first three years of GnRHa treatment (1.66±0.66 vs. 2.35±0.93, P<0.001). The height gain SDS was significantly higher in group B than in group A (2.5±0.75 vs. 2.93±1.02, P=0.048). Younger age, higher PAH at the start of treatment, and a greater increase in PAH SDS during the first year of GnRHa treatment positively affected AH. Conclusion: The combined GH group had more additional height gain than the GnRHa-alone group. [ABSTRACT FROM AUTHOR]

Insulin resistance and obesity are associated with reduced gonadotropin-releasing hormone (GnRH) release and infertility. Mice that lack insulin receptors (IRs) throughout development in both neuronal and non-neuronal brain cells are known to exhibit subfertility due to hypogonadotropic hypogonadism. However, attempts to recapitulate this phenotype by targeting specific neurons have failed. To determine whether astrocytic insulin sensing plays a role in the regulation of fertility, we generated mice lacking IRs in astrocytes (astrocyte-specific insulin receptor deletion [IRKOGFAP] mice). IRKOGFAP males and females showed a delay in balanopreputial separation or vaginal opening and first estrous, respectively. In adulthood, IRKOGFAP female mice also exhibited longer, irregular estrus cycles, decreased pregnancy rates, and reduced litter sizes. IRKOGFAP mice show normal sexual behavior but hypothalamic-pituitary-gonadotropin (HPG) axis dysregulation, likely explaining their low fecundity. Histological examination of testes and ovaries showed impaired spermatogenesis and ovarian follicle maturation. Finally, reduced prostaglandin E synthase 2 (PGES2) levels were found in astrocytes isolated from these mice, suggesting a mechanism for low GnRH/luteinizing hormone (LH) secretion. These findings demonstrate that insulin sensing by astrocytes is indispensable for the function of the reproductive axis. Additional work is needed to elucidate the role of astrocytes in the maturation of hypothalamic reproductive circuits. [ABSTRACT FROM AUTHOR]

Insulin resistance and obesity are associated with reduced gonadotropin-releasing hormone (GnRH) release and infertility. Mice that lack insulin receptors (IRs) throughout development in both neuronal and non-neuronal brain cells are known to exhibit subfertility due to hypogonadotropic hypogonadism. However, attempts to recapitulate this phenotype by targeting specific neurons have failed. To determine whether astrocytic insulin sensing plays a role in the regulation of fertility, we generated mice lacking IRs in astrocytes (astrocyte-specific insulin receptor deletion [IRKOGFAP] mice). IRKOGFAP males and females showed a delay in balanopreputial separation or vaginal opening and first estrous, respectively. In adulthood, IRKOGFAP female mice also exhibited longer, irregular estrus cycles, decreased pregnancy rates, and reduced litter sizes. IRKOGFAP mice show normal sexual behavior but hypothalamic-pituitary-gonadotropin (HPG) axis dysregulation, likely explaining their low fecundity. Histological examination of testes and ovaries showed impaired spermatogenesis and ovarian follicle maturation. Finally, reduced prostaglandin E synthase 2 (PGES2) levels were found in astrocytes isolated from these mice, suggesting a mechanism for low GnRH/luteinizing hormone (LH) secretion. These findings demonstrate that insulin sensing by astrocytes is indispensable for the function of the reproductive axis. Additional work is needed to elucidate the role of astrocytes in the maturation of hypothalamic reproductive circuits. Ablation of insulin receptors in astrocytes reveals that insulin promotes pubertal development and fertility in mice by acting on astrocytes rather than directly affecting neuronal reproductive circuits. Author summary: Astrocytes are a major cell type in the central nervous system, yet their impact on the neuroendocrine circuits that control fertility is under appreciated. Here, we show in mice that ablation of insulin signaling in astrocytes leads to delayed puberty, hypothalamic-pituitary-gonadotropin (HPG) axis dysfunction, and reduced fertility. These findings are the first demonstration that astrocytes and a metabolic signal collaborate to permit the maturation of the reproductive axis and adult fertility. [ABSTRACT FROM AUTHOR]

Heavy cannabis consumption among adolescents is associated with significant and lasting neurobiological, psychological and health consequences that depend on the age of first use. Chronic exposure to cannabinoid agonists during the perinatal period or adolescence alters social behavior and prefrontal cortex (PFC) activity in adult rats. However, sex differences on social behavior as well as PFC synaptic plasticity after acute cannabinoid activation remain poorly explored. Here, we determined that the consequences of a single in vivo exposure to the synthetic cannabimimetic WIN55,212-2 differently affected PFC neuronal and synaptic functions after 24 h in male and female rats during the pubertal and adulthood periods. During puberty, single cannabinoid exposure (SCE) reduced play behavior in females but not males. In contrast, the same treatment impaired sociability in both sexes at adulthood. General exploration and memory recognition remained normal at both ages and both sexes. At the synaptic level, SCE ablated endocannabinoid-mediated synaptic plasticity in the PFC of females of both ages and heightened excitability of PFC pyramidal neurons at adulthood, while males were spared. In contrast, cannabinoid exposure was associated with impaired long-term potentiation (LTP) specifically in adult males. Together, these data indicate behavioral and synaptic sex differences in response to a single in vivo exposure to cannabinoid at puberty and adulthood. [ABSTRACT FROM AUTHOR]

Background: Recent studies have suggested that there is an earlier age of onset of puberty in healthy boys. However, no study has determined the age of pubertal development in boys with type 1 diabetes (T1D) and compared the results with a simultaneously recruited group of healthy children. Objective: The aim of this study was to evaluate the age of pubertal events in boys with TD1 and determine whether the duration of diabetes, metabolic control or insulin dose are associated with the age of puberty in boys with T1D. Methods: Boys aged 7 to 19 years with T1D (n = 148, age 12.9 ± 3.0 years) and healthy boys recruited from schools (n = 388 controls, age 12.8 ± 2.2 years) were studied. A pediatric endocrinologist evaluated pubertal development. Results: Boys at genital Tanner stage 2 and the final stages of puberty (genital Tanner 4 and 5) were younger than the control group (P = 0.005, P = 0.003, and P = 0.015, respectively). Both groups of boys had a similar age of pubic Tanner stage development. There were no cases of pubertal delay observed in the T1D cohort. There was no association observed between metabolic control with pubertal timing. T1D adolescents had lower height‐SDS than the C group at the final stages of puberty. Conclusions: Boys with T1D who are treated with modern insulin therapy appear to have an earlier age of onset and an earlier age of final pubertal events than a simultaneously studied group of healthy children. These data suggest that pubertal delay is not a frequent problem for male T1D patients. [ABSTRACT FROM AUTHOR]

The aim of treatment for idiopathic central precocious puberty (ICPP) is to increase final adult stature, for which gonadotropinreleasing hormone agonist (GnRHa) is the gold standard. Early puberty is frequently similar to ICPP, with pubertal onset only slightly advanced. Short stature may result from early pubertal onset. Some studies have suggested that recombinant human growth hormone (rhGH) should be combined with a GnRHa to improve adult height, while others have not. Here, the aim was to compare the efficacy of combined GnRHa and rhGH treatment with GnRHa or rhGH treatment alone, or no therapy, for the improvement of the final height of girls with ICPP or early puberty. Electronic databases of randomized and quasi-randomized controlled trials, in which the efficacy of GnRHa preparations was compared with that of rhGH for the treatment of children with precocious or early puberty, were searched and a meta-analysis conducted. Five studies of early puberty and four studies of ICPP were identified. There were no statistically significant differences between final adult height standard deviation score and initial height standard deviation score in the treatment of early puberty (GnRHa and rhGH versus rhGH alone or no treatment). The overall analysis of the data failed to indicate any benefit of combined therapy, while individual reports suggested that in specific instances combined therapy may be beneficial in preserving or reclaiming growth potential and improving adult height. [ABSTRACT FROM AUTHOR]

Objective: To compare the serum inhibin B, anti-Müllerian hormone (AMH) and leptin concentrations in girls with idiopathic central precocious puberty (CPP) to their concomitant characteristics and evaluate the capacity of each of these hormones to predict the age at first menstruation in those who were untreated and who completed their puberty. Methods: This single-center study included 94 girls selected from a cohort of 493 girls seen between 1981 and 2012 and diagnosed with idiopathic CPP for whom a remaining serum sample collected at the initial evaluation was available. Of these 25 were untreated and completed their puberty. Results- correlations at initial evaluation: In the whole cohort the inhibin B concentration displayed significant positive correlations with the age at the onset of puberty and at initial evaluation; bone age; breast Tanner stage; serum basal estradiol, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and AMH concentrations, LH peak and LH/FSH peak ratio. The AMH concentration displayed a significant positive correlation with serum estradiol and a negative correlation with basal FSH concentration. The leptin concentration displayed significant positive correlations with the age at initial evaluation, bone age, and body mass index and a negative correlation with the FSH peak. Results- prediction of age at first menstruation: In 25 untreated girls, the inhibin B concentration was negatively correlated with the age at first menstruation (r = -0.61, p = 0.001) and the time between the onset of puberty and first menstruation (r = -0.59, p = 0.002). Inhibin B concentrations <30 pg/mL were associated with a time between the onset of puberty and first menstruation ≥3 years in 14/15 patients with a sensitivity of 0.67 and a specificity of 0.75. The age at first menstruation was estimated using a formula: min (11.15–0.510 LH/FSH peak ratio, 11.57–0.025 inhibin B)available at: . Conclusion: We established formulas based on the serum inhibin B concentrations and LH/FSH peak ratio at the initial evaluation, alone or in combination, to predict the age at first menstruation in girls with CPP. These formulas can assist with determining the indications for treatment in CPP. [ABSTRACT FROM AUTHOR]

Background: The relationship between pubertal onset and tempo and pubertal growth is controversial. We hypothesized that the age at onset of girls' puberty predicts pubertal tempo and the rate of pubertal progression. Methods: We analyzed the data of 380 girls from the prospective Study of Early Child Care and Youth Development (SECCYD) who were recruited in the USA from 1991 to 2006 and followed from birth to age 15.5 years. We used the following indicators: thelarche age (Tanner stage B2), pubarche age (P2), menarche age (M), the age when breast (B5) and pubic hair (P5) became fully mature, pubertal growth, pubertal duration (time from B2 to B5) and pubertal progression (time from B2 to M). We clustered the girls according to B2 age into early onset (EO; <9.4 years), intermediate (IO; 9.4-10.5 years), late onset (LO; >10.5 years). Results: All indicators of pubertal onset and conclusion occurred earlier in the EOs than in the LOs; yet, the differences in the age at main pubertal milestones lessened as puberty progressed: 2 years for B2; -1.4 years for M; -1 year for B5. In EOs, puberty was 1 year (average) longer than in LOs. Although EOs grew 7 cm (average) more than LOs, their heights at B5 were comparable. There was a significant relationship between the thelarche age and puberty tempo (r = 0.23, P < 0.0001). Conclusions: The study highlights the predictive nature of variation in the onset age of puberty on its progression and duration. These results are reassuring in this context and will add to clinicians' and parental understanding of the expected milestones of puberty. [ABSTRACT FROM AUTHOR]

Background: A previous single-center study established a mathematical model for predicting the adult height (AH) in girls with idiopathic central precocious puberty (CPP). Objective: To perform internal and external validations by comparing the actual AH to the calculated AH established by this model and to update it. Methods: The original formula, calculated AH (cm) = 2.21 (height at initial evaluation, SD) + 2.32 (target height, SD) - 1.83 (luteinizing hormone/follicle-stimulating hormone peaks ratio) + 159.68, was established in a sample of 134 girls (group 4) and was applied to additional girls with CPP seen in the same center (group 1, n = 35), in Germany (group 2, n = 43) and in the Netherlands (group 3, n = 72). This formula has been updated based on these extended data, and both versions are available at the following location: . Results: Despite the differences among the 4 groups in terms of their characteristics at the initial evaluation and the percentages of patients treated with the gonadotropin-releasing hormone analogue, they have similar calculated and actual AHs. The actual AHs are 162.2±7.0, 163.0±7.6, 162.4±7.7 and 162.1±5.6 cm in groups 1 to 4, respectively. They are highly correlated with the AHs calculated by the formula established in the original group (group 4), with R at 0.84, 0.67 and 0.69 in groups 1 to 3, respectively. When the actual AHs and the AHs predicted by the Bayley and Pinneau method are compared, the R is 0.76, 0.51 and 0.64 in groups 1 to 3, respectively. The absolute differences between actual AHs and the calculated AHs are greater than 1 SD (5.6 cm) in 15%, 35% and 28% of the patients in groups 1 to 3, respectively. Conclusion: This study validates and updates the previously established formula for predicting AH in girls with CPP. This updated formula can help clinicians to make treatment decisions. [ABSTRACT FROM AUTHOR]

The timing of pubertal onset is occurring at younger ages. This phenomenon is associated with many environmental factors such as sufficient nutrition, stress, many kinds of endocrine-disrupting chemicals, and genetic background. The loss of transcriptional repression induces kisspeptin release, resulting in pulsatile gonadotropin-releasing hormone secretion, which trigger pubertal onset. According to many reports, gonadotropin-releasing hormone agonists therapy for patients with rapidly progressive central precocious puberty is effective for improving final adult height. However, those results were obtained from the treatment of relatively young patients at earlier stages of puberty. A large cohort study investigating the environmental causes of precocious puberty as well as genetic factors is needed. [ABSTRACT FROM AUTHOR]