Review of the Literature on Current Changes in the Timing of Pubertal Development and the Incomplete Forms of Early Puberty

Association between serum vitamin C and body mass index in adolescents aged 12-19 years

BACKGROUND

Evidence on the association between serum vitamin C (sVC) levels and obesity is limited. This study aimed to explore the relationship between sVC and body mass index (BMI) in adolescents aged 12 to 19 years.

METHODS

We analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2003-2006, with 3952 participants. sVC and BMI were independent variables and dependent variables, respectively. The associations of sVC with BMI were examined using multivariable linear regression models. Age, sex, and race/ethnicity were analyzed as subgroups. Then, we devised smooth curve fittings and saturation threshold analysis to address the nonlinear relationship.

RESULTS

sVC had a negative correlation with BMI after adjusting for all covariates (β: -1.020, 95% CI: -1.359, -0.680). In the subgroup analysis by age, sex, and race/ethnicity, there was still a negative correlation between sVC and BMI (p < 0.05). The analysis of saturation effects of sVC and BMI showed the relationship between sVC and BMI in female adolescents followed an N-shaped curve, whereas the relationship between sVC and BMI in adolescents aged 12-15 years and Mexican Americans followed a U-shaped curve.

CONCLUSION

Based on the results, proper vitamin C supplementation may be beneficial to weight loss. However, considering the threshold effect, large-scale and good-quality randomized controlled trials are required to obtain the optimal vitamin C level for weight control.

Developing body estimation in adolescence is associated with neural regions that support self-concept

Both self-concept, the evaluation of who you are, and the physical body undergo changes throughout adolescence. These two processes might affect the development of body image, a complex construct that comprises one's thoughts, feelings, and perception of one's body. This study aims to better understand the development of body image in relation to self-concept development and its neural correlates. Adolescents (aged 11-24) from the longitudinal Leiden Self-Concept study were followed for three consecutive years (NT1 = 160, NT2 = 151, and NT3 = 144). Their body image was measured using a figure rating scale and body dissatisfaction questionnaire. Body estimation was calculated based on figure ratings relative to their actual body mass index (BMI). Additionally, participants evaluated their physical appearance traits in an functional magnetic resonance imaging (fMRI) task. Results revealed that body estimation and body dissatisfaction increased with age. Heightened inferior parietal lobe (IPL) activation during physical self-evaluation was associated with lower body estimation, meaning that the neural network involved in thinking about one's physical traits is more active for individuals who perceive themselves as larger than they are. IPL activity showed continued development during adolescence, suggesting an interaction between neural development and body perception. These findings highlight the complex interplay between affective, perceptual, and biological factors in shaping body image.

A strike to the head: Parallels between the pediatric and adult human and the rodent in traumatic brain injury

Traumatic brain injury (TBI) is a condition that occurs commonly in children from infancy through adolescence and is a global health concern. Pediatric TBI presents with a bimodal age distribution, with very young children (0-4 years) and adolescents (15-19 years) more commonly injured. Because children's brains are still developing, there is increased vulnerability to the effects of head trauma, which results in entirely different patterns of injury than in adults. Pediatric TBI has a profound and lasting impact on a child's development and quality of life, resulting in long-lasting consequences to physical, cognitive, and emotional development. Chronic issues like learning disabilities, behavioral problems, and emotional disturbances can develop. Early intervention and ongoing support are critical for minimizing these long-term deficits. Many animal models of TBI exist, and each varies significantly, displaying different characteristics of clinical TBI. The neurodevelopment differs in the rodent from the human in timing and effect, so TBI outcomes in the juvenile rodent can thus vary from the human child. The current review compares findings from preclinical TBI work in juvenile and adult rodents to clinical TBI research in pediatric and adult humans. We focus on the four brain regions most affected by TBI: the prefrontal cortex, corpus callosum, hippocampus, and hypothalamus. Each has its unique developmental projections and thus is impacted by TBI differently. This review aims to compare the healthy neurodevelopment of these four brain regions in humans to the developmental processes in rodents.

Therapeutic effects of melatonin in female mice with central precocious puberty by regulating the hypothalamic Kiss-1/Kiss1R system

In recent years, central precocious puberty (CPP) in children is becoming more common, which seriously affects their physical and psychological health and requires finding a safe and effective treatment method. The aim of this study was to investigate the therapeutic effect of melatonin on CPP. A CPP model was established by subcutaneous injection of 300 micrograms of danazol into 5-day-old female mice, followed by treatment with melatonin and leuprolide. The vaginal opening was checked daily. Mice were weighed, gonads were weighed, gonadal index was calculated, and gonadal development was observed by hematoxylin and eosin (HE) staining. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) levels were measured by ELISA. By using RT-PCR and Western blotting, the mRNA and protein expression of the hypothalamus Kiss-1, Kiss-1 receptor (Kiss1R), gonadotropin-releasing hormone (GnRH), and pituitary GnRH receptor (GnRHR) were identified. The results showed that melatonin delayed vaginal opening time and reduced body weight, gonadal weight and indices in female CPP mice. Melatonin treatment prevents uterine wall thickening and ovarian luteinization in female CPP mice. Melatonin treatment reduces serum concentrations of FSH, LH, and E2 in female CPP mice. Melatonin suppressed the expressions of Kiss-1, Kiss1R and GnRH in the hypothalamus, and the expression of GnRHR in the pituitary of the female CPP mice. Our results suggest that melatonin can inhibit the hypothalamic-pituitary-gonadal (HPG) axis by down-regulating the Kiss-1/Kiss1R system, thereby treating CPP in female mice.

Not Only Metabolic Complications of Childhood Obesity

The increasing incidence of obesity in the pediatric population requires attention to its serious complications. It turns out that in addition to typical, well-known metabolic complications, obesity as a systemic disease carries the risk of equally serious, although less obvious, non-metabolic complications, such as cardiovascular diseases, polycystic ovary syndrome, chronic kidney disease, asthma, thyroid dysfunction, immunologic and dermatologic conditions, and mental health problems. They can affect almost all systems of the young body and also leave their mark in adulthood. In addition, obesity also contributes to the exacerbation of existing childhood diseases. As a result, children suffering from obesity may have a reduced quality of life, both physically and mentally, and their life expectancy may be shortened. It also turns out that, in the case of obese pregnant girls, the complications of obesity may also affect their unborn children. Therefore, it is extremely important to take all necessary actions to prevent the growing epidemic of obesity in the pediatric population, as well as to treat existing complications of obesity and detect them at an early stage. In summary, physicians treating a child with a systemic disease such as obesity must adopt a holistic approach to treatment.

Enduring sex-dependent implications of pubertal stress on the gut-brain axis and mental health

The gut-brain axis (GBA) is a network responsible for the bidirectional communication between the central nervous system and the gastrointestinal tract. This multifaceted system is comprised of a complex microbiota, which may be altered by both intrinsic and extrinsic factors. During critical periods of development, these intrinsic and extrinsic factors can cause long-lasting sex-dependent changes in the GBA, which can affect brain structure and function. However, there is limited understanding of how the GBA is altered by stress and how it may be linked to the onset of mental illness during puberty. This article reviews current literature on the relationships between the GBA, the effects of stress during puberty, and the implications for mental health.

Sex-dimorphism in human serum endocannabinoid and n-acyl ethanolamine concentrations across the lifespan

The endocannabinoid (ECB) system has recently been considered a potential treatment target for various clinical disorders. However, research around age- and sex-related changes within the ECB system is relatively limited. To improve our understanding of these changes, the current study measured arachidonoyl ethanolamide (AEA), 2-arachidonoyl glycerol (2-AG), oleoylethanolamine (OEA), palmitoylethanolamine (PEA), arachidonic acid (AA), cortisol, and progesterone in pooled serum samples stratified by sex (male and female) and age groups (5-15; 15-30; 30-45; 45-60; 60-75; 85+), using liquid-chromatography tandem mass spectrometry. Serum progesterone levels significantly increased in females of the 15-30 and 30-45 age groups, before declining. Significantly higher cortisol, AEA, 2-AG, OEA, and PEA were found in males and in older age, while significantly higher AA was found in females. Our results indicate that ECBs and related hormones exhibit sexual dimorphism in the age ranges that correspond with female pregnancy, menopause, and post menopause. Male testosterone levels most likely influences male ECB changes throughout the lifespan. Future research could capitalise on these findings by performing repeated measurements in individuals in a longitudinal style, to further refine the temporal profile of age-specific changes to the ECB system identified here.

Pupils' Attitudes toward Inclusive Education

The presented research is a study of the attitudes of adolescents toward individuals with disabilities and a description of the level of knowledge about this issue among a selected group of adolescents. The study is focused on the school social environment, specifically on pupils without disabilities and their attitudes toward pupils with disabilities, which is one of the factors influencing their school success. The target group was 1806 pupils between the ages of 11 and 16 from the entire Czech Republic, approached by random selection. The research tool for the quantitative approach was a questionnaire developed by the authors of this article. The questionnaire section with open questions served for the qualitative part of the research. The results show that 70% of the respondents have basic knowledge about people with disabilities. Furthermore, it was shown that these adolescents have an overall positive attitude toward people with disabilities. This attitude is statistically significantly better among the girls than the boys, and the girls are also more open to discussing individuals with disabilities. At the same time, even if attitudes are positive, they still depend on the type of disability. The greatest uncertainty or discomfort is manifested when interacting with individuals with intellectual disabilities.

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

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

The Effects of Dairy Product Supplementation on Bone Health Indices in Children Aged 3 to 18 Years: A Meta-Analysis of Randomized Controlled Trials

Childhood and adolescence are critical periods for optimizing skeletal growth. Dairy products are valuable sources of bone-beneficial nutrients, particularly calcium and protein. A random-effects meta-analysis of published randomized controlled trials was performed to quantitatively assess the effects of dairy supplementation on bone health indices in children and adolescents. The PubMed and Web of Science databases were searched. Dairy supplementation increased whole-body bone mineral content (BMC) (+25.37 g) and areal bone mineral density (aBMD) (+0.016 g/cm2), total hip BMC (+0.49 g) and aBMD (+0.013 g/cm2), femoral neck BMC (+0.06 g) and aBMD (+0.030 g/cm2), lumbar spine BMC (+0.85 g) and aBMD (+0.019 g/cm2), and height (0.21 cm). When expressed as a percentage difference, whole-body BMC was increased by 3.0%, total hip BMC by 3.3%, femoral neck BMC by 4.0%, lumbar spine BMC by 4.1%, whole-body aBMD by 1.8%, total hip aBMD by 1.2%, femoral neck aBMD by 1.5%, and lumbar spine aBMD by 2.6%. Dairy supplementation increased serum insulin-like growth factor I concentrations (19.89 nmol/L) and reduced concentrations of urinary deoxypyridinoline (-1.78 nmol/mmol creatinine) and serum parathyroid hormone (-10.46 pg/mL) but did not significantly affect the serum concentrations of osteocalcin, bone alkaline phosphatase, and C-terminal telopeptide of type 1 collagen. Serum 25-hydroxyvitamin D concentrations (+4.98 ng/mL) increased with vitamin D-fortified dairy supplementation. The positive effects on bone mineral mass parameters and height were generally consistent across subgroups defined by sex, geographical region, baseline calcium intake, calcium from the supplementation, trial duration, and Tanner stages. In summary, dairy supplementation during growth leads to a small but significant increase in bone mineral mass parameters, and these findings are generally supported by the changes in several biochemical parameters related to bone health.

A complex systems model of breast cancer etiology: The Paradigm II Model

BACKGROUND

Complex systems models of breast cancer have previously focused on prediction of prognosis and clinical events for individual women. There is a need for understanding breast cancer at the population level for public health decision-making, for identifying gaps in epidemiologic knowledge and for the education of the public as to the complexity of this most common of cancers.

METHODS AND FINDINGS

We developed an agent-based model of breast cancer for the women of the state of California using data from the U.S. Census, the California Health Interview Survey, the California Cancer Registry, the National Health and Nutrition Examination Survey and the literature. The model was implemented in the Julia programming language and R computing environment. The Paradigm II model development followed a transdisciplinary process with expertise from multiple relevant disciplinary experts from genetics to epidemiology and sociology with the goal of exploring both upstream determinants at the population level and pathophysiologic etiologic factors at the biologic level. The resulting model reproduces in a reasonable manner the overall age-specific incidence curve for the years 2008-2012 and incidence and relative risks due to specific risk factors such as BRCA1, polygenic risk, alcohol consumption, hormone therapy, breastfeeding, oral contraceptive use and scenarios for environmental toxin exposures.

CONCLUSIONS

The Paradigm II model illustrates the role of multiple etiologic factors in breast cancer from domains of biology, behavior and the environment. The value of the model is in providing a virtual laboratory to evaluate a wide range of potential interventions into the social, environmental and behavioral determinants of breast cancer at the population level.

Reciprocal relationship between interpersonal communication and depressive symptoms and the mediating role of resilience across two years: Three-wave cross-lagged panel model

BACKGROUND

Depression among children has been a growing public health concern. It is generally recognized that individuals with depression are likely to have interpersonal malfunctioning. However, there remains a limited scientific understanding of the reciprocal relationship between interpersonal communication and depressive symptoms among rural Chinese children in a longitudinal approach.

METHODS

Therefore, guided by the interpersonal model of depression and the developmental cascade model, the present study conducted a cross-lagged panel analysis study to explore the bidirectional relationship between interpersonal communication and depressive symptoms across three waves among 2188 elementary school students in rural areas of one county of Gansu Province, China. We also examined the mediating effect of resilience and sex differences of the models.

RESULTS

Our results showed that depressive symptoms negatively predicted interpersonal communication from T1 to T2 and T2 to T3. Interpersonal communication negatively predicted depressive symptoms from T1 to T2, but not T2 to T3. Furthermore, resilience showed significant partial mediating effects in the reciprocal relationship between interpersonal communication and depressive symptoms. In terms of sex differences, the significant relationship between depressive symptoms at T1 and interpersonal communication at T2 was found to be significant among male students and marginally significant among female students. The full mediating effect of resilience at T1 was found only among male students, whereas resilience at T2 functioned as a full mediator between depressive symptoms at T2 and interpersonal communication at T3 only among female students.

LIMITATIONS

First, the present sample consisted of only third and fourth grade (i.e., in T1) students from one county in rural China. Second, the present study examined depressive symptoms instead of depression as a clinical diagnosis. Third, the third wave of the data was collected during COVID-19. The impact of the COVID-19 pandemic could unexpectedly pose on child mental health.

CONCLUSIONS

The finding underlined the importance of providing comprehensive depression prevention and intervention from fostering children's inner resilience and promoting their ability to navigate interpersonal resources.

Investigation of irisin's role in pubertal onset physiology in female rats

OBJECTIVE

The timing of pubertal development is closely related to metabolic status and energy reserves. It is thought that irisin, which is involved in the regulation of energy metabolism and is shown to be present in the hypothalamo-pituitary-gonadal (HPG) axis, may play a role in this process. In our study, we aimed to investigate the effect of irisin administration on pubertal development and HPG axis in rats.

DESIGN-METHODS

36 female rats were included in the study were divided into 3 groups: 100 ng/kg/day irisin treatment group (irisin-100), 50 ng/kg/day irisin treatment group (irisin-50), and control group. On the 38th day, serum samples were taken to determine levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH), estradiol and irisin. Brain hypothalamus samples were taken to determine levels of pulsatile gonadotropin-releasing hormone (GnRH), kisspeptin, neurokinin-B, dynorphin (Dyn), and makorin ring finger protein-3 (MKRN3).

RESULTS

Vaginal opening and estrus were seen firstly in the irisin-100 group. At the end of the study, the highest rate of vaginal patency was found in the irisin-100 group. Hypothalamic protein expression levels of GnRH, NKB and Kiss1 in homogenates; serum FSH, LH, and estradiol levels were the highest in the irisin-100 group, followed by the irisin-50 and control groups, respectively. Ovarian sizes were significantly greater in the irisin-100 group compared to the other groups. The hypothalamic protein expression levels of MKRN3 and Dyn were the lowest in the irisin-100 group.

CONCLUSIONS

In this experimental study, irisin triggered the onset of puberty in a dose-dependent manner. Irisin administration caused the excitatory system to dominate in the hypothalamic GnRH pulse generator.

Secondary oxidized di-2-ethylhexyl phthalate metabolites may be associated with progression from isolated premature thelarche to central precocious or early puberty

Phthalate esters (PAEs) may act as estrogen receptor agonists, and their relationship with precocious puberty is a global health concern. However, their role in isolated premature thelarche (IPT) progression remains unclear. We conducted a cohort study investigating the relationship between IPT progression and urinary PAE metabolites. Girls with IPT aged 6-8 years were regularly followed up every three months for one year. Clinical data and urine PAE metabolite levels were collected. Participants who progressed to central precocious puberty (CPP) or early puberty (EP) had significantly higher ovarian volume, breast Tanner stage, and levels of the creatinine-adjusted urinary secondary oxidized di-2-ethylhexyl phthalate (DEHP) metabolites (Σ₄DEHP). Breast Tanner stage (odds ratio [OR] = 7.041, p = 0.010), ovarian volume (OR = 3.603, p = 0.019), and Σ₄DEHP (OR = 1.020, p = 0.005) were independent risk factors for IPT progression. For each 10 µg/g/Cr increase in the urine level of Σ₄DEHP, the risk of progression from IPT to CPP/EP within one year increased by 20%. This study demonstrated that the breast Tanner stage, ovarian volume, and Σ₄DEHP in urine were independent risk factors for IPT progression, and Σ₄DEHP may be associated with the progression of IPT to CPP or EP.

Burden and contributing factors to overweight and obesity in young adolescents in Addis Ababa, Ethiopia

The prevalence of overweight/obesity in adolescents has increased globally, including in low- and middle-income countries. Early adolescence provides an opportunity to develop and encourage positive health and behavioural practices, yet it is an understudied age group with limited information to guide and inform appropriate interventions. This study aims to determine the prevalence of overweight/obesity in young adolescents, aged between 10 and 14 years attending public schools in Addis Ababa, Ethiopia, and to explore the contributing factors. A cross-sectional school-based study was conducted. Adolescents completed individual questionnaires. Weight (kg) and height (m) measurements were converted to BMI-for-age and gender z-scores. Multivariate regression analysis was conducted to determine the associated factors. The overall prevalence of overweight/obesity was 8% among adolescents aged 10-14 years and it was significantly higher in females (13%) than males (2%). The diet quality for the majority of the adolescents was inadequate, putting them at risk for poor health outcomes. The contributors to overweight/obesity were different between males and females. Age and no access to a flush toilet were negatively associated with overweight/obesity in males and access to a computer, laptop or tablet was positively associated. In females, menarche was positively associated with overweight/obesity. Living with only their mother or another female adult and an increase in physical activity were negatively associated with overweight/obesity. There is a need to improve the diet quality of young adolescents in Ethiopia and understand the reasons why females are less physically active to limit the risk of poor diet-related health outcomes.

Mixed exposure to phthalates and organic UV filters affects Children's pubertal development in a gender-specific manner

BACKGROUND

Previous studies showed phthalates and UV filters are endocrine-disruptive and associated with puberty. However, few studies have examined effects of mixed exposure.

METHODS

Six phthalate metabolites and 12 organic UV filters were detected among 223 school-age children. Puberty development was evaluated at baseline and after 18 months of follow-up. Ordered logistic regression models, least absolute shrinkage and selection operator (LASSO) regression and quantile-based g-computation (qgcomp) were used to evaluate relationships between phthalate metabolites or UV filters exposure and pubertal development.

RESULTS

Six phthalate metabolites and 5 UV filters were detectable in urine samples. In boys, BP-3 and 4'-MAP were negatively associated with genital (ORBP-3 = 0.52, (0.27, 0.93), OR4'-MAP = 0.45, (0.25, 0.74)) and pubic hair development (ORBP-3:0.24, (0.05, 0.76), OR4'-MAP:0.24, (0.05, 0.77)). In girls, MEP levels were associated with advanced breast development (OR: 1.29, (1.04, 1.64)). LASSO regression identified BP-3, 4'-MAP, and OD-PABA for inverse associations with pubertal development in boys. MEP was related to an increase in girls' breast development (OR: 1.64, (1.08, 2.63)). Overall mixture was related to a 70% reduction in boys' genital development stage, with a larger effect size than a single chemical in qgcomp. Mixed exposure was associated with girls' earlier puberty onset (OR: 2.61, (1.06, 6.42)).

CONCLUSIONS

Our results suggested higher levels of phthalate metabolites and UV filters were associated with delayed pubertal development in boys but with earlier puberty in girls. Higher effect size of joint exposure than single chemicals suggested phthalates and UV filters might have synergistic effects on puberty and distort adolescent endocrine function together.

Serum metabolomic analysis reveals key metabolites in drug treatment of central precocious puberty in female children

Precocious puberty (PP) is a common condition among children. According to the pathogenesis and clinical manifestations, PP can be divided into central precocious puberty (CPP, gonadotropin dependent), peripheral precocious puberty (PPP, gonadotropin independent), and incomplete precocious puberty (IPP). Identification of the variations in key metabolites involved in CPP and their underlying biological mechanisms has increased the understanding of the pathological processes of this condition. However, little is known about the role of metabolite variations in the drug treatment of CPP. Moreover, it remains unclear whether the understanding of the crucial metabolites and pathways can help predict disease progression after pharmacological therapy of CPP. In this study, systematic metabolomic analysis was used to examine three groups, namely, healthy control (group N, 30 healthy female children), CPP (group S, 31 female children with CPP), and treatment (group R, 29 female children) groups. A total of 14 pathways (the top two pathways were aminoacyl-tRNA biosynthesis and phenylalanine, tyrosine, and tryptophan biosynthesis) were significantly enriched in children with CPP. In addition, two short peptides (His-Arg-Lys-Glu and Lys-Met-His) were found to play a significant role in CPP. Various metabolites associated with different pathways including amino acids, PE [19:1(9Z)0:0], tumonoic acid I, palmitic amide, and linoleic acid-biotin were investigated in the serum of children in all groups. A total of 45 metabolites were found to interact with a chemical drug [a gonadotropin-releasing hormone (GnRH) analog] and a traditional Chinese medicinal formula (DBYW). This study helps to understand metabolic variations in CPP after drug therapy, and further investigation may help develop individualized treatment approaches for CPP in clinical practice.

Perinatal exposure to low doses of cypermethrin induce the puberty-related hormones and decrease the time to puberty in the female offspring

Pyrethroid insecticides are ubiquitously detected in environmental media, food, and urine samples. Our previous epidemiological study reported a correlation between increased pyrethroid exposure and delayed pubertal development in Chinese girls. In this study, we further investigated the effects of perinatal exposure to low doses of cypermethrin (CP) on pubertal onset and hypothalamic-pituitary-ovarian axis in the female mice offspring. The treatment of CP with 60 μg/kg/day from gestation day 6 (GD6) to postnatal day 21 (PND21) significantly decreased the time to puberty in the female offspring. Exposure of CP increased the serum levels of gonadotropin-releasing hormone (GnRH) and the expression of GnRH genes in a dose-dependent manner in the female offspring. CP also induced the serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), as well as the expression of gonadotropin subunit genes [LHβ, FSHβ, and chorionic gonadotropin α (Cgα)]. Furthermore, CP induced serum estradiol (E₂) levels and the expression of steroidogenesis-related genes [steroidogenic acute regulatory (StAR) and Cytochrome p 450, family 11, subfamily A, polypeptide 1 (CYP11A1)] in the ovary. In accordance with the in vivo tests, administration of CP (6.7, 20, and 60 μg/L) stimulated a dose-dependent increase in the synthesis and secretion of the puberty-related hormones in the explants of hypothalamus, pituitary, and ovary. The interference with calcium channels in the ovary may be responsible for CP-induced pubertal onset. Our study provided evidence that perinatal exposure to low doses of CP induced puberty-related hormones and decreased the time to puberty in the female offspring.

Diet and Nutrients Intakes during Infancy and Childhood in Relation to Early Puberty: A Systematic Review and Meta-Analysis

The onset of puberty has become earlier over the decades, and nutrients and diet are related to the timing of puberty onset. Hence, we aimed to investigate the association between diet or nutrients in infancy, childhood and early puberty. PubMed, Embase, and Cochrane library were searched systematically up to 15 April 2022. The pooled relative risks (RRs) or regression coefficients (beta) were estimated using the random-effect model or fixed-effect model according to the heterogeneity between studies. Twenty-two articles on diet or nutrients in childhood and six about breastfeeding in infancy were included. The prolonged breastfeeding duration in infancy could reduce the risk of early menarche (beta 0.31, 95% CI: 0.01, 0.60, p = 0.045). The high intake of yogurt was associated with a 35% reduction in the risk of earlier menarche (RR 0.65, 95% CI: 0.47, 0.89, p = 0.008). Girls with severe food insecurity experienced later menarche (RR 0.81, 95% CI: 0.67, 0.98, p = 0.027). Conversely, due to the high intake of protein, the risk of early menarche increased by 8% (RR 1.08, 95% CI: 1.01, 1.16, p = 0.016). High intake of yogurt, longer duration of breastfeeding, and food insecurity decreased the possibility of earlier menarche, while high intake of protein increased that risk. As a modifiable factor, diet and nutrients in infancy and childhood provide new insights into the future prevention of early puberty.

Maturation-dependent vulnerability of emotion regulation as a response to COVID-19 related stress in adolescents

BACKGROUND

The COVID-19 pandemic created unpredictable circumstances resulting in increased psychological strain. Here we investigate pandemic-related alterations in emotion regulation in adolescents assessed before and during the pandemic. We also take biological age into account in the response to the pandemic.

METHODS

Mann-Whitney U tests were conducted to compare baseline data on the Difficulties in Emotion Regulation Scale (DERS) total scores of a pre-pandemic adolescent cohort (n = 241) with those obtained during the second wave of the pandemic (n = 266). We estimated biological age based on an ultrasonic boneage assessment procedure in a subgroup of males, including grammar school and vocational school students in the 9th and 10th grades, and analyzed their data independently.

FINDINGS

There is a gender difference in the timing of vulnerability for pandemic-related stress in grammar school students: females are affected a year earlier than males. Vocational school male students mature faster than grammar school male students, and the timing of emotional vulnerability also precedes that of the grammar school students'.

DISCUSSION

We interpret our findings within a developmental model suggesting that there might be a window of highest vulnerability in adolescent emotion regulation. The timing of the window is determined by both chronological and biological age, and it is different for females and males.

APPLICATION TO PRACTICE

Defining the exact temporal windows of vulnerability for different adolescent cohorts allows for the timely integration of preventive actions into adolescent care to protect mental health during future chronic stressful situations.

Puberty disorders among ART-conceived singletons: a Nordic register study from the CoNARTaS group

STUDY QUESTION

Do ART-conceived children have an increased risk for puberty disorders?

SUMMARY ANSWER

Both ART-conceived boys and girls had a higher risk of puberty disorders; early puberty was more common among girls and late puberty among boys.

WHAT IS KNOWN ALREADY

Some physiological differences in growth and metabolism have been reported for ART-conceived children compared to non-ART-conceived children. Knowledge on pubertal development and disorders in ART-conceived children is limited.

STUDY DESIGN, SIZE, DURATION

A register-based cohort study was carried out including data from 1985 to 2015. The Committee of Nordic Assisted Reproductive Technology and Safety (CoNARTaS) study population consists of all live and stillborn children, as well as their mothers, registered in the Medical Birth Registers during the study period in Denmark, Sweden, Finland and Norway.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 122 321 ART-conceived singletons and 6 576 410 non-ART singletons born in Denmark (1994–2014), Finland (1990–2014), Norway (2002–2015) and Sweden (1985–2015) were included. Puberty disorders were defined using International Classification of Diseases and Related Health Problems (ICD)-9/ICD-10 codes and classified in the following groups: late puberty (6268/E30.0), early puberty (2591 and 2958/E30.1 and E30.8) and unspecified disorders (V212 and V579/E30.9 and Z00.3 as well as Z51.80 for Finland). The results in Cox regression were adjusted for maternal age, parity, smoking, gestational diabetes, chronic hypertension, hypertensive disorders during pregnancy and country, and further for either gestational age, birthweight, small for gestational age or large for gestational age.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 37 869 children with diagnoses related to puberty disorders, and 603 of them were born after ART. ART-conceived children had higher risks for early (adjusted hazard ratio (aHR) 1.45, 95% CI: 1.29–1.64) and late puberty (aHR 1.47, 95% CI: 1.21–1.77). Girls had more diagnoses related to early puberty (aHR 1.46, 95% CI: 1.29–1.66) and boys with late puberty (aHR 1.55, 95% CI: 1.24–1.95).

LIMITATIONS, REASONS FOR CAUTION

Using reported puberty disorders with ICD codes in health care registers might vary, which may affect the numbers of cases found in the registers. Register data may give an underestimation both among ART and non-ART-conceived children, especially among non-ART children, who may not be as carefully followed as ART-conceived children. Adjustment for causes and duration of infertility, mothers’ own puberty characteristics and BMI, as well as children’s BMI, was not possible because data were not available or data were missing for the early years. It was also not possible to compare ART to non-ART siblings or to study the pubertal disorders by cause of subfertility owing to a small number of discordant sibling pairs and a large proportion of missing data on cause of subfertility.

WIDER IMPLICATIONS OF THE FINDINGS

This large, register-based study suggests that ART-conceived children have a higher risk for puberty disorders. However, the mechanisms of infertility and pubertal onset are complex, and ART is a rapidly advancing field with various treatment options. Studying the pubertal disorders of ART-conceived offspring is a continuing challenge.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Nordic Trial Alliance: a pilot project jointly funded by the Nordic Council of Ministers and NordForsk (71450), the Central Norway Regional Health Authorities (46045000), the Nordic Federation of Obstetrics and Gynaecology (NF13041, NF15058, NF16026 and NF17043), the Interreg Öresund-Kattegat-Skagerrak European Regional Development Fund (ReproUnion project), the Research Council of Norway’s Centre of Excellence funding scheme (262700), the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (ALFGBG-70940) and FLUX Consortium ‘Family Formation in Flux—Causes, Consequences and Possible Futures’, funded by the Strategic Research Council, Academy of Finland (DEMOGRAPHY 345130). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Comparison of the Toxicological Effects of Pesticides in Non-Tumorigenic MCF-12A and Tumorigenic MCF-7 Human Breast Cells

Humans are exposed to residues of organophosphate and neonicotinoid pesticides, commonly used in agriculture. Children are particularly vulnerable and, among possible adverse outcomes, the increased incidence of premature mammary gland development (thelarche) has raised concern. We evaluated the toxicological effects of chlorpyrifos (CPF), imidacloprid (IMI) and glyphosate (GLY) at exposure concentrations occurring in children on the tumorigenic MCF-7 and non-tumorigenic MCF-12A breast cell lines, as representative of the target organ model, assessing cytotoxicity, apoptosis, necrosis, intracellular reactive oxygen species (ROS) and ATP levels, 17β-estradiol secretion and gene expression of nuclear receptors involved in mammary gland development. The pesticides decreased cell vitality in MCF-7 and cell proliferation in MCF-12A cells. ATP levels were decreased in MCF-7 cells by pesticides and apoptosis was increased in MCF-12A cells only by GLY (2.3 nM). ROS production was decreased by pesticides in both cell lines, except IMI (1.6 nM) in MCF-7 cells. Endocrine disrupting activity was highlighted by induction of 17β-estradiol secretion and modulation of the gene expression of estrogen alpha and beta, progesterone, androgen, and aryl hydrocarbon receptors in both cell lines. The use of MCF-7 and MCF-12A cells highlighted dissimilar modes of action of each pesticide at low human relevant concentrations.

Puberty Induction in Adolescent Males: Current Practice

Puberty is a developmental stage characterized by the appearance of secondary sexual characteristics which leads to complete physical, psychosocial, and sexual maturation. The current practice of hormonal therapy to induce puberty in adolescent males is based on published consensus and expert opinion. Evidence-based guidelines on optimal timing and regimen in puberty induction in males are lacking, and this reflects some discrepancies in practice among endocrinologists. It is worth mentioning that the availability of various hormonal products in markets, their different routes of administration, and patients/parents’ preference also have an impact on clinical decisions. This review outlines the current clinical approach to delayed puberty in boys with an emphasis on puberty induction.

Assessment of Gonadotropin Concentrations Stimulated by Gonadotropin-Releasing Hormone Analog by Electrochemiluminescence in Girls with Precocious Puberty and Premature Thelarche

OBJECTIVE

The aim of this study is to determine the cutoff values of gonadotropin response to gonadotropin-releasing hormone analogs (GnRHas) corresponding to the activation of the hypothalamic-pituitary-gonadal axis that could differentiate central precocious puberty (CPP) from premature thelarche (PT) and using the electrochemiluminescence assay method.

METHODS

A total of 49 girls underwent the stimulation test with an intramuscular injection of 3.75 mg leuprolide acetate. Based on the clinical and laboratory characteristics, they were divided into two groups: CPP (n = 22) and PT (n = 27). Baseline estradiol, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were collected before GnRHa administration and LH and FSH at 60 and 120 min, respectively, after GnRHa administration.

RESULTS

The girls with CPP presented an increased height Z-score, advanced bone age, and higher baseline LH, FSH, estradiol, and LH/FSH ratio in relation to PT (p < 0.001). Stimulated LH differed significantly between the two groups, and the LH cutoff values were ≥4.29 IU/L (p < 0.001) and ≥3.95 IU/L at 60 and 120 min, respectively (p < 0.001). The LH peak was found at 60 min after stimulation.

CONCLUSIONS

The GnRHa test is effective in distinguishing CPP from PT, and a single sampling, at 60 min, with LH concentrations above 4.29 may be the parameter of choice with the advantage of greater convenience and practicality.

Retrospective longitudinal analysis of the effects of postnatal weight gain on the timing and tempo of puberty and menarche in a cohort of Italian girls

OBJECTIVE

over the last few decades there has been a progressive decline in the average age of onset of pubertal development stages in both sexes. The increase in the prevalence of childhood obesity seems to play an important role in this phenomenon.

DESIGN

we undertook a retrospective, longitudinal evaluation of the average age of thelarche and menarche to evaluate the relationship between BMI and weight change during the first years of life and the timing and tempo of puberty.

METHODS

we evaluated data for 577 Italian girls born between 1995 and 2003. We collected the main auxological and clinical parameters, including age at B2 and at menarche, BMI SDS at B2 and menarche, gestational age and birth weight and Z-score change from birth weight (BW) to BMI at B2 and menarche.

RESULTS

the mean age of B2 was 10.06 ± 1.03 years and the mean age of menarche was 12.08 ± 1.02 years. Age at B2 and menarche were inversely correlated with BMI SDS (p < 0.0001). Both age at menarche and at thelarche have an inverse relationship with the Z-score change from birth weight and BMI at menarche and thelarche respectively (p < 0.0001).

CONCLUSIONS

our data confirm a significant relationship between BMI and age of B2 and menarche. We observed a clear relationship among weight change during the first years of life, age at thelarche and menarche and the duration of puberty, demonstrating the importance of weight and weight gain in determining the timing and tempo of pubertal changes and growth.

Investigation of early puberty prevalence and time of addition thelarche to pubarche in girls with premature pubarche: two-year follow-up results

We aimed to determine the prevalence of early puberty in girls with premature pubarche and analyze the time interval between their pubarche and succeeding thelarche. This study included 60 female children with premature pubarche. We retrospectively collected clinical, laboratory, and radiological findings from all participants. We investigated the time interval between pubarche and thelarche in cases wherein premature pubarche was followed by thelarche. The mean age at onset of pubarche was 6.93 ± 0.79 yr old. Among the participants, 16.7% were preterm, 20% were small for gestational age (SGA), and 55% were overweight or obese. The mean time interval between pubarche and thelarche was 11.20 ± 7.41 mo. The mean serum DHEA-S level was higher in the preterm group (p = 0.016), and DHEA-S levels were generally higher in the SGA group (p = 0.004). This study documented the presence of being overweight or obese and having more advanced growth than their genetic potential in half of the patients who had premature pubarche. In addition to these identified risk factors, obesity-independent DHEA-S levels were observed to be higher in patients who had early puberty with the first six months of their follow-up considered to be the most critical time in predicting early puberty.

Precocious puberty and microbiota: The role of the sex hormone-gut microbiome axis

Puberty is a critical phase of life associated with physiological changes related to sexual maturation, and represents a complex process regulated by multiple endocrine and genetic controls. Puberty is driven by hormones, and it can impact the gut microbiome (GM). GM differences between sex emerge at puberty onset, confirming a relationship between microbiota and sex hormones. In this narrative review, we present an overview of precocious pubertal development and the changes in the GM in precocious puberty (PP) in order to consider the role of the sex hormone-gut microbiome axis from the perspective of pediatric endocrinology. Bidirectional interactions between the GM and sex hormones have been proposed in different studies. Although the evidence on the interaction between microbiota and sex hormones remains limited in pediatric patients, the evidence that GM alterations may occur in girls with central precocious puberty (CPP) represents an interesting finding for the prediction and prevention of PP. Deepening the understanding of the connection between the sex hormones and the role of microbiota changes can lead to the implementation of microbiota-targeted therapies in pubertal disorders by offering a pediatric endocrinology perspective.

Developmental cascades and educational attainment

Developmental cascades describe how systems of development interact and influence one another to shape human development across the lifespan. Despite its popularity, developmental cascades are commonly used to understand the developmental course of psychopathology, typically in the context of risk and resilience. Whether this framework can be useful for studying children's educational outcomes remains underexplored. Therefore, in this chapter, we provide an overview of how developmental cascades can be used to study children's academic development, with a particular focus on the biological, cognitive, and contextual pathways to educational attainment. We also provide a summary of contemporary statistical methods and highlight existing data sets that can be used to test developmental cascade models of educational attainment from birth through adulthood. We conclude the chapter by discussing the challenges of this research and explore important future directions of using developmental cascades to understand educational attainment.

Factors Affecting Menstrual Cycle Developmental Trajectory in Adolescents: A Narrative Review

CONTEXT

The time interval between the age at menarche and regulation of menstrual cycles (menstrual cycle developmental trajectory) is considered an indicator of the function of the reproductive system later in life. This study aimed to summarize the factors affecting this trajectory.

EVIDENCE ACQUISITION

A comprehensive literature search in PubMed, Scopus, Google Scholar, and Web of Science was performed to identify studies investigating factors influencing the regularity of the menstrual cycle in adolescents.

RESULTS

The interval between menarche and the onset of the regular menstrual cycle in adolescent girls may vary from several months to several years. Several factors, including genetic, race/ethnicity, intrauterine situation, social factors, geographical factors, lifestyle, and chronic diseases, are considered the predisposing factors for the trajectory.

CONCLUSIONS

Age at menarche and the onset of regular menstrual cycles are directly and indirectly influenced by several genetic, environmental, and lifestyle factors. Understanding these factors may improve our practice in managing irregular menstrual cycles that commonly happen in the first years after menarche.

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.

Kisspeptin Levels in Girls with Precocious Puberty: A Systematic Review and Meta-Analysis

BACKGROUND/AIMS

Kisspeptin (KP) is a key player in the regulation of the release of gonadotropin-releasing hormone (GnRH), which increases the secretion of gonadotropin during puberty to establish reproductive function and regulate the hypothalamic-pituitary-gonadal axis. Premature activation of GnRH secretion leads to idiopathic/central gonadotropin-dependent precocious puberty (CPP). We aimed to compare the blood KP concentrations in girls with CPP and healthy controls.

METHODS

A systematic review and meta-analysis was performed. We searched MEDLINE, EMBASE, The Cochrane Library, and SciELO. Random-effects model and standardized mean difference (SMD) were used. Heterogeneity was assessed through I2. Meta-regression considered patient age, KP fraction, and analytical method for KP measurement.

RESULTS

The 11 studies included comprised 316 CPP patients and 251 controls. Higher KP levels in the CPP group were found (SMD 1.53; CI 95% = 0.56-2.51). Subgroup analysis revealed association with patient age (p = 0.048), indicating a positive correlation between elevation in KP concentration and age in CPP group. A group of patients with precocious thelarche (PT) from 5 of the included studies comprising 121 patients showed higher levels of KP (1.10; -0.25-2.45: CI 95%) and high heterogeneity (I2 = 91%). The CPP/PT ratio for KP level indicates KP 36% higher on CPP than PT patients.

CONCLUSIONS

A consistent difference in KP levels between girls with CPP and controls was identified. While there are important limitations in KP assays which argue against its use as a diagnostic tool, the KP levels in CPP versus control and PT children are consistent with the predicted mechanisms and pathophysiology of CPP.

The Role of Pediatric Nutrition as a Modifiable Risk Factor for Precocious Puberty

Puberty is a critical phase of growth and development characterized by a complex process regulated by the neuroendocrine system. Precocious puberty (PP) is defined as the appearance of physical and hormonal signs of pubertal development at an earlier age than is considered normal. The timing of puberty has important public health, clinical, and social implications. In fact, it is crucial in psychological and physical development and can impact future health. Nutritional status is considered as one of the most important factors modulating pubertal development. This narrative review presents an overview on the role of nutritional factors as determinants of the timing of sexual maturation, focusing on early-life and childhood nutrition. As reported, breast milk seems to have an important protective role against early puberty onset, mainly due to its positive influence on infant growth rate and childhood overweight prevention. The energy imbalance, macro/micronutrient food content, and dietary patterns may modulate the premature activation of the hypothalamic-pituitary-gonadal axis, inducing precocious activation of puberty. An increase in knowledge on the mechanism whereby nutrients may influence puberty will be useful in providing adequate nutritional recommendations to prevent PP and related complications.

The effect of GnRH stimulation on AMH regulation in central precocious puberty and isolated premature thelarche

OBJECTIVES

There is a complex interaction between the anti-müllerian hormone (AMH) and hypothalamic-pituitary-gonadal axis. However, the effect of gonadotropin-releasing hormone (GnRH) stimulation on AMH levels is not clearly known. In the study, we aimed to evaluate the effect of GnRH stimulation on AMH levels in central precocious puberty (CPP) and isolated premature thelarche (PT) groups.

METHODS

Sixty-three girls with breast development before the age of 8 were enrolled in the study. GnRH test was performed on all subjects. Blood samples for follicle-stimulating hormone (FSH), luteinizing hormone (LH), and AMH levels were taken at basal, 40th, and 90th minute of GnRH test. Subjects were grouped as CPP and PT group.

RESULTS

After GnRH stimulation, AMH levels increased significantly at the 40th minute and the stimulating effect of GnRH on AMH continued till the 90th minute (p: 0.0001). There was a positive correlation between basal and 90th-minute AMH levels (r: 479, p: 0.0001). The highest FSH, LH, and AMH times were significantly different after the GnRH stimulation (p: 0.001, p: 0.001, and p: 0.007). Although the CPP group had a lower basal AMH level than the PT group's basal AMH level; AMH response to GnRH stimulation was not different (p>0.05).

CONCLUSIONS

In our study, which examined the effect of GnRH stimulation on AMH levels in early pubertal development disorders for the first time, GnRH stimulated AMH secretion rapidly, correlated with basal AMH. Basal AMH levels were lower in patients with CPP than in those with PT; however, the effect of GnRH stimulation on AMH levels was similar in both groups.

Diet-Induced Hypothalamic Inflammation, Phoenixin, and Subsequent Precocious Puberty

Recent studies have shown a rise in precocious puberty, especially in girls. At the same time, childhood obesity due to overnutrition and energy imbalance is rising too. Nutrition and fertility are currently facing major challenges in our societies, and are interconnected. Studies have shown that high-fat and/or high-glycaemic-index diet can cause hypothalamic inflammation and microglial activation. Molecular and animal studies reveal that microglial activation seems to produce and activate prostaglandins, neurotrophic factors activating GnRH (gonadotropin-releasing hormone expressing neurons), thus initiating precocious puberty. GnRH neurons’ mechanisms of excitability are not well understood. In this review, we study the phenomenon of the rise of precocious puberty, we examine the physiology of GnRH neurons, and we review the recent literature regarding the pathophysiological mechanisms that connect diet-induced hypothalamic inflammation and diet-induced phoenixin regulation with precocious puberty.

Disorders of Puberty in Girls

Puberty is the process through which reproductive competence is achieved and comprises gonadarche and adrenarche. Breast development is the initial physical finding of pubertal onset in girls and typically occurs between 8 and 13 years. Menarche normally occurs 2 to 3 years after the onset of breast development. Pubertal onset is controlled by the gonadotropin-releasing hormone pulse generator in the hypothalamus; however, environmental factors such as alterations in energy balance and exposure to endocrine-disrupting chemicals can alter the timing of pubertal onset. Improvement in nutritional and socioeconomic conditions over the past two centuries has been associated with a secular trend in earlier pubertal onset. Precocious puberty is defined as onset of breast development prior to 8 years and can be central or peripheral. Delayed puberty can be hypogonadotropic or hypergonadotropic and is defined as lack of breast development by 13 years or lack of menarche by 16 years. Both precocious and delayed puberty may have negative effects on self-esteem, potentially leading to psychosocial stress. Patients who present with pubertal differences require a comprehensive assessment to determine the underlying etiology and to devise an effective treatment plan.

Assessment of the median ages at sexual maturation stages of Brazilian schoolchildren according to overweight status and type of school over a 5-year period: 2007-2012/2013

OBJECTIVES

A secular trend of earlier puberty has been observed in girls, and, although more uncertain in boys, is associated with an increasing trend in the prevalence of overweight and obesity. We aimed to compare the median ages of sexual maturation stages in schoolchildren from a city in southern Brazil over a 5-year period, according to weight status and type of school.

METHODS

Two cross-sectional studies were performed in 2007 and 2012/2013, including 2215 and 1614 schoolchildren, respectively. Body mass index z-scores were calculated and categorized as either nonoverweight or overweight (including obesity). The type of school was categorized as either public or private. Sexual maturation was self-assessed according to the Tanner stages. Mann-Whitney and Kruskal-Wallis tests were performed to compare the median ages of sexual maturation stages.

RESULTS

The median age decreased for almost all stages over the 5-year period in both sexes. In boys, the decrease ranged from 0.3 to 1.0 years (stages 2, 3, 4, and 5 for genitalia, and stages 2 and 4 for pubic hair), and from 0.3 to 0.7 years (stages 2, 3, and 4 for breast, and stages 3, 4, and 5 for pubic hair). In 2012, overweight students had lower median ages for most stages compared to those in 2007, especially in girls. Differences by type of school were balanced across years.

CONCLUSIONS

The median age of Tanner's stages after 5 years was reduced in both sexes. In overweight girls, the reduction was more pronounced. The results by type of school were inconsistent.

The relationship between body weight and dietary habits with respect to the timing of puberty among saudi children and adolescents

Objective

The objective is to investigate the timing of pubertal onset as determined by the development of secondary sexual characteristics in relation to body weight and dietary patterns among Saudi females.

Methods

Children/adolescents visiting general and endocrinology pediatric clinics in King AbdulAziz University Hospital were invited to participate in this study. Female subjects between the ages of 5 and 20 years were included in this study, and those with syndromic disease, chronic comorbidities, endocrinopathies, organic causes of precocious puberty, positive family history of early pubertal onset, and under chronic medication were excluded from the study. Data were collected through clinical interviews with the consent of the legal guardians, and physical examinations were conducted.

Results

A.

total of 164 females were investigated. The mean age of thelarche, adrenarche, and menarche was 10, 11.3, and 12.2 years, respectively. We found a significant correlation between higher weight standard deviation and an earlier age of both thelarche and adrenarche. In addition, daily consumption of fast foods was significantly associated with an earlier menarchal age. Consumption of nonorganic poultry was linked to early thelarche.

Conclusion

Efforts should be directed to increase public and community awareness that fast food consumption, inorganic poultry, and higher body weight are important modifiable factors that lead to an earlier onset of female puberty across different parameters: breast development, adrenarche, and menstruation.

Urinary and salivary endocrine measurements to complement Tanner staging in studies of pubertal development

Background

Many studies investigating pubertal development use Tanner staging to assess maturation. Endocrine markers in urine and saliva may provide an objective, sensitive, and non-invasive method for assessing development.

Objective

Our objective was to examine whether changes in endocrine levels can indicate the onset of pubertal development prior to changes in self-rated Tanner stage.

Methods

Thirty-five girls and 42 boys aged 7 to 15 years were enrolled in the Growth and Puberty (GAP) study, a longitudinal pilot study conducted from 2007–2009 involving children of women enrolled in the Agricultural Health Study (AHS) in Iowa. We collected saliva and urine samples and assessed pubertal development by self-rated Tanner staging (pubic hair, breast development (girls), genital development (boys)) at three visits over six months. We measured dehydroepiandrosterone (DHEA) in saliva and creatinine-adjusted luteinizing hormone (LH), testosterone, follicle stimulating hormone (FSH), estrone 3-glucuronide (E₁3G) and pregnanediol 3-glucuronide (Pd3G) concentrations in first morning urine. We evaluated the relationships over time between Tanner stage and each biomarker using repeated measures analysis.

Results

Among girls still reporting Tanner breast stage 1 at the final visit, FSH levels increased over the 6-month follow-up period and were no longer lower than higher stage girls at the end of follow-up. We observed a similar pattern for testosterone in boys. By visit 3, boys still reporting Tanner genital stage 1 or pubic hair stage 1 had attained DHEA levels that were comparable to those among boys reporting Tanner stages 2 or 3.

Conclusions

Increasing concentrations of FSH in girls and DHEA and testosterone in boys over a 6-month period revealed the start of the pubertal process prior to changes in self-rated Tanner stage. Repeated, non-invasive endocrine measures may complement the more subjective assessment of physical markers in studies determining pubertal onset.

A comparison of the growth status, level of blood glucose, and lipid metabolism in small for gestational age and appropriate for gestational age girls with central precocious puberty: a retrospective study

BACKGROUND

To compare the physical development status, level of blood glucose and lipid metabolism in small for gestational age (SGA) and appropriate for gestational age (AGA) groups with central precocious puberty (CPP).

METHODS

This was a retrospective study. Three hundred and twenty-two girls with CPP were divided into the AGA group (304 cases) and the SGA group (18 cases). Physical index such as height, weight, and body mass index (BMI), as well as sex hormones, adrenal androgens, blood lipid levels, fasting blood glucose, insulin levels, and homeostasis model assessment of insulin resistance (HOMA-IR) were compared between the two groups.

RESULTS

Height, weight, and BMI in the SGA group were lower than those in the AGA group (P<0.05). The level of LH/FSH, estradiol, testosterone, DHEA and androstenedione had no significant difference between the SGA group and AGA group (P>0.05). The fasting blood glucose, insulin level, HOMA-IR, high-density lipoprotein (HDL) and the average level of triglycerides were similar between these two groups (P>0.05). There was a statistically significant difference in total cholesterol and low-density lipoprotein (LDL) between the two groups (P<0.05). However, the blood lipids and blood glucose in both groups were within the normal range.

CONCLUSIONS

The height, weight, BMI, serum cholesterol and LDL of girls in SGA with CPP were significantly lower than that of those girls born AGA.

Once-daily Dapsone 7.5% Gel for the Treatment of Acne Vulgaris in Preadolescent Patients: A Phase IV, Open-label, 12-week Study

CLINICAL TRIALS ID: NCT02959970 BACKGROUND: Acne vulgaris in patients aged younger than 12 years is increasingly common and primarily noninflammatory (i.e., comedonal). Dapsone 7.5% gel is indicated for the topical treatment of acne vulgaris in patients nine years of age or older. OBJECTIVE: We sought to evaluate efficacy, safety, tolerability, and pharmacokinetics (PK) of once-daily topical dapsone 7.5% gel. METHODS: This was a Phase IV, multicenter, open-label study in patients with acne aged 9 to 11 years. Patients applied dapsone 7.5% gel once daily to the face and acne-affected areas on the upper chest, upper back, and shoulders for 12 weeks. Patients in the PK cohort applied dapsone 7.5% gel under maximal-use conditions for eight days and a thin layer for the remaining 11 weeks. Lesion counts and proportions of patients with an Investigator's Global Assessment score of zero points (clear) or one point (almost clear) were assessed. Plasma concentrations of dapsone and metabolites were evaluated after one week in the PK cohort. Safety and dermal tolerability were evaluated. RESULTS: After 12 weeks, facial acne was clear or almost clear in about 47 percent of patients. Inflammatory, noninflammatory, and total lesions decreased from baseline, with a greater reduction apparent in noninflammatory lesions. Systemic exposure to dapsone in PK patients was low. The overall rate of adverse events was low, and dermal tolerability scores indicated no or mild stinging/burning, dryness, scaling, and erythema. CONCLUSION: Once-daily topical dapsone 7.5% gel used for 12 weeks was safe, effective, and well tolerated in preadolescent patients with acne.

Obesity in childhood: how to improve male adolescence incoming

INTRODUCTION

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

Association between melanoma and exposure to sex hormones in puberty: A possible window of susceptibility (Review)

The risk factors for melanoma in adolescents are similar to those in adults; however, it remains unclear whether these risk factors are also associated with melanoma in children. Epidemiological studies in the literature have reported a logarithmic increase in melanoma incidence after the age of 10 years. This may, in part, reflect the acute and chronic exposure to solar ultraviolet (UV) radiation during childhood. However, it appears unlikely that the cumulative exposure to UV radiation alone could explain such a sharp increase in melanoma incidence at the beginning of adolescence. It has been suggested that circulating sex hormones, the levels of which increase during puberty, may play a role in melanoma initiation and progression in predisposed individuals through binding to specific sex steroid receptors. The association between a longer cumulative exposure to sex hormones and the risk of melanoma may be supported by the reported epidemiological association between melanoma and several other sex hormone-related types of cancer, such as breast and prostate cancer, in which the enhanced exposure to androgens and estrogens was found to be directly associated with pubertal onset. Therefore, determining the association between pubertal onset and melanoma development may improve the current understanding of melanoma pathophysiology.

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

Aim

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

Methods

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

Results

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

Conclusions

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

The Role of Fetal, Infant, and Childhood Nutrition in the Timing of Sexual Maturation

Puberty is a crucial developmental stage in the life span, necessary to achieve reproductive and somatic maturity. Timing of puberty is modulated by and responds to central neurotransmitters, hormones, and environmental factors leading to hypothalamic-pituitary-gonadal axis maturation. The connection between hormones and nutrition during critical periods of growth, like fetal life or infancy, is fundamental for metabolic adaptation response and pubertal development control and prediction. Since birth weight is an important indicator of growth estimation during fetal life, restricted prenatal growth, such as intrauterine growth restriction (IUGR) and small for gestational age (SGA), may impact endocrine system, affecting pubertal development. Successively, lactation along with early life optimal nutrition during infancy and childhood may be important in order to set up timing of sexual maturation and provide successful reproduction at a later time. Sexual maturation and healthy growth are also influenced by nutrition requirements and diet composition. Early nutritional surveillance and monitoring of pubertal development is recommended in all children, particularly in those at risk, such as the ones born SGA and/or IUGR, as well as in the case of sudden weight gain during infancy. Adequate macro and micronutrient intake is essential for healthy growth and sexual maturity.

Longitudinal 15-year follow-up of women with former early puberty: abnormal metabolic profiles not associated with earlier age at onset of puberty, but associated with obesity

BACKGROUND

In 2011, we described 104 girls who were diagnosed as early puberty (EP) during 2003-2005. In 2019-2020, the former EP women had been followed up 14 years after attaining their final height.

OBJECTIVE

To determine the reproductive function and metabolic profiles of former EP women.

STUDY DESIGN

Fifty-seven former EP women were evaluated for reproductive function and examined for health status. Blood samples were obtained for metabolic profiles of glucose, lipids and insulin, and testosterone levels.

RESULTS

In 2020, the average age of the study women was 22.9 ± 1.7 years. The average height was 156.7 ± 5.6 cm. The average weight had increased from 52.5 ± 7.8 kg in 2011 to 58.5 ± 11.1 kg in 2020 and average body mass index (BMI) from 21.4 ± 2.9 to 23.8 ± 4.0 kg/m². Obesity (BMI>25 kg/m²) was found in 8.8% (five participants) in 2011 and had increased to 22.8% (13 participants) in 2020. Most participants (79%) had regular menstrual cycle. Of the 17 married women, 4 (23.5%) had 1-2 children. Dividing the participants into obese and nonobese groups, the average fasting plasma glucose, lipid profiles, and testosterone levels were similar in both groups. However, the average systolic blood pressure and the serum insulin levels and HOMA-IR assessments were significantly higher in the obese group than in the nonobese group.

CONCLUSION

The former EP women had normal menstruation and reproductive function. The former EP women with average BMI at the follow-up had normal metabolic profiles while those who later became obese had significantly higher systolic blood pressure, serum insulin, and HOMA-IR assessments.

Neurobiology of puberty and its disorders

Puberty, which in humans is considered to include both gonadarche and adrenarche, is the period of becoming capable of reproducing sexually and is recognized by maturation of the gonads and development of secondary sex characteristics. Gonadarche referring to growth and maturation of the gonads is fundamental to puberty since it encompasses increased gonadal steroid secretion and initiation of gametogenesis resulting from enhanced pituitary gonadotropin secretion, triggered in turn by robust pulsatile GnRH release from the hypothalamus. This chapter reviews the development of GnRH pulsatility from before birth until the onset of puberty. In humans, GnRH pulse generation is restrained during childhood and juvenile development. This prepubertal hiatus in hypothalamic activity is considered to result from a neurobiological brake imposed upon the GnRH pulse generator resident in the infundibular nucleus. Reactivation of the GnRH pulse generator initiates pubertal development. Current understanding of the genetics and physiology of the brake will be discussed, as will hypotheses proposed to account for timing the resurgence in pulsatile GnRH and initiation of puberty. The chapter ends with a discussion of disorders associated with precocious or delayed puberty with a focus on those with etiologies attributed to aberrant GnRH neuron anatomy or function. A pediatric approach to patients with pubertal disorders is provided and contemporary treatments for both precocious and delayed puberty outlined.

Serum Irisin Levels in Central Precocious Puberty and Its Variants

AIM

The exact mechanisms that trigger the onset of puberty are not well known. Adipomyokines are postulated to stimulate the central neural network. In the present study, we investigated irisin levels in girls with central precocious puberty (CPP), slowly progressing precocious puberty (SPPP), or premature thelarche (PT); we also studied prepubertal girls and to determine if this adipomyokine could be used as a marker in this context.

METHODS

A total of 94 girls including 33 with CPP, 31 with precocious puberty (PP) variants (SPPP or PT), and 30 healthy controls were enrolled to the study. The mean irisin levels were compared between groups. The bivariate correlations of irisin levels with clinical and laboratory parameters were assessed. Multivariate linear regression analysis was performed to determine independent predictive factors of irisin levels.

RESULTS

Irisin levels were higher in the CPP group compared with the other groups (CPP group: 723.25 ± 62.35 ng/mL; PP variants group: 529.60 ± 39.66 ng/mL; and control group: 325.03 ± 27.53 ng/mL) (P < 0.001). Irisin levels were positively correlated with body mass index standard deviation scores (BMI-SDS), height-SDS, weight-SDS, bone age, uterus long axis, ovary size, baseline FSH and LH, and peak LH levels. Multivariate linear regression analysis revealed that irisin levels had the strongest correlation with peak LH. The other independent predictive factor of irisin levels was BMI-SDS.

CONCLUSIONS

The mean irisin levels were higher in patients with CPP compared with other groups. The results of this study imply that increased irisin levels may be used as a marker of CPP provided that these findings are confirmed in larger prospective studies.

Association Between Paternal Separation During Early Childhood and Pubertal Timing Among Girls Using Longitudinal Birth Cohort in Japan

INTRODUCTION

Previous studies have shown that paternal absence leads to earlier pubertal timing among girls in high-income countries. Despite the low divorce rate in Japan, paternal separation is commonly seen due to a unique corporation system, tanshin funin, where employees relocate with their spouses and children. We examined paternal separation, including paternal absence (due to divorce or paternal death) and paternal tanshin funin, during early childhood as a predictor of earlier girl's pubertal development, assessed as age at peak height velocity (PHV).

METHODS

This study examined 15 214 girls from a longitudinal survey conducted in Japan from 2001 to 2016 by the Ministry of Health, Labor and Welfare. Paternal separation was determined by the occurrence through annual surveys conducted at ages 0.5 to 4.5 years. Outcome was defined as age at PHV between ages 6 to 15 years. We conducted linear regression, adjusted for potential confounders and other covariates.

RESULTS

Continuous father cohabitation was seen in 88.7% of households, while paternal separation was experienced 1-2, 3-4 and 5 times (always) among 7.4%, 2.8% and 1.1% of households, respectively. Girls who confronted continuous paternal separation (5 times) experienced 0.42 years earlier [95% confidence interval (CI): -0.75, -0.10] age at PHV compared to their peers who always lived with their fathers.

CONCLUSION

Girls who experienced paternal separation throughout ages 0.5 to 4.5 years experienced PHV earlier.