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Indian Pediatrics Jun 2006
Topics: Adolescent; Age Factors; Child; Female; Global Health; Humans; Male; Puberty; Puberty, Precocious; Rural Population; Sexual Maturation; Time Factors
PubMed: 16820656
DOI: No ID Found -
Brain Research Dec 2010The initiation of mammalian puberty requires a sustained increase in pulsatile release of gonadotrophin releasing hormone (GnRH) from the hypothalamus. This increase is... (Review)
Review
The initiation of mammalian puberty requires a sustained increase in pulsatile release of gonadotrophin releasing hormone (GnRH) from the hypothalamus. This increase is brought about by coordinated changes in transsynaptic and glial-neuronal communication, consisting of an increase in neuronal and glial stimulatory inputs to the GnRH neuronal network and the loss of transsynaptic inhibitory influences. GnRH secretion is stimulated by transsynaptic inputs provided by excitatory amino acids (glutamate) and at least one peptide (kisspeptin), and by glial inputs provided by growth factors and small bioactive molecules. The inhibitory input to GnRH neurons is mostly transsynaptic and provided by GABAergic and opiatergic neurons; however, GABA has also been shown to directly excite GnRH neurons. There are many genes involved in the control of these cellular networks, and hence in the control of the pubertal process as a whole. Our laboratory has proposed the concept that these genes are arranged in overlapping networks internally organized in a hierarchical fashion. According to this concept, the highest level of intra-network control is provided by transcriptional regulators that, by directing expression of key subordinate genes, impose genetic coordination to the neuronal and glial subsets involved in initiating the pubertal process. More recently, we have begun to explore the concept that a more dynamic and encompassing level of integrative coordination is provided by epigenetic mechanisms.
Topics: Animals; Epigenomics; Female; Humans; Neurosecretory Systems; Puberty; Sexual Maturation; Transcription, Genetic
PubMed: 20851111
DOI: 10.1016/j.brainres.2010.09.039 -
Fertility and Sterility Nov 2022To study whether the timing of puberty in adolescents who reported gender incongruence (incongruence between birth-assigned sex and self-identified gender) was different...
OBJECTIVE
To study whether the timing of puberty in adolescents who reported gender incongruence (incongruence between birth-assigned sex and self-identified gender) was different from those adolescents who reported gender congruence.
DESIGN
Population-based cohort study using data from the Danish National Birth Cohort.
SETTING
Not applicable.
PATIENT(S)
Birth-assigned boys and girls born between 2000 and 2003, who self-reported gender incongruence at 11 years (N = 10,046) and their pubertal developmental stages from age 11 years to every 6 months throughout puberty were included.
INTERVENTION(S)
Not applicable.
MAIN OUTCOME MEASURE
Mean age differences in months at reaching Tanner stages 2-5 for breast or genital development and pubic hair, voice break, first ejaculation, menarche, axillary hair, acne, and the average difference at attaining all pubertal milestones (primary outcome).
RESULT(S)
In total, 549 (5.5% ) adolescents reported part or full gender incongruence at 11 years. Tendencies toward earlier timing of puberty were observed in adolescents who reported part gender incongruence (average difference, birth-assigned boys: -3.2 months [95% confidence interval {CI}: -6.7; 0.3]; birth-assigned girls: -2.0 months [95% CI: -3.9; -0.1]). Tendencies toward earlier timing of puberty were observed in adolescents who reported full gender incongruence (average difference, birth-assigned boys: -2.4 months [95% CI: -5.0; 0.4]; birth-assigned girls: -1.9 months [95% CI: -5.1; 1.2]).
CONCLUSIONS
The results from this study indicated that birth-assigned boys and girls who reported either part or full gender incongruence tended to reach puberty slightly earlier than those adolescents who reported gender congruence at 11 years of age. Knowledge on the timing of puberty among adolescents who experience gender incongruence is essential to inform mutual decision-making in clinical settings.
Topics: Adolescent; Male; Female; Humans; Child; Cohort Studies; Puberty; Menarche
PubMed: 36163086
DOI: 10.1016/j.fertnstert.2022.07.018 -
Tidsskrift For Den Norske Laegeforening... May 2008Onset of puberty in boys is more complex than in girls, and delayed onset is the most common puberty complication in boys. This article presents the physiology of normal... (Review)
Review
BACKGROUND
Onset of puberty in boys is more complex than in girls, and delayed onset is the most common puberty complication in boys. This article presents the physiology of normal development of male puberty and the background for commonly associated disturbances.
MATERIAL AND METHOD
The article builds on clinical experience and relevant publications within pediatric endocrinology.
RESULTS AND INTERPRETATION
Mechanisms involved in pubertal development of gonads remain unclear despite intensive research. Height growth as well as the age for onset of puberty are influenced by environmental factors. Genetic factors are however more important determinants within a defined population and one usually inherits the probability for both early and delayed puberty. Gonadotropin releasing hormone (GnRH) neurons in the hypothalamus secrete GnRH in intermittent pulses to the pituitary glands that respond with pulsatile LH and FSH production. These neurons are thus decisive for testicle activity and therefore puberty development. GnRH-neurons are inactive during childhood because many types of hypothalamic neurons suppress them. Puberty starts when this suppression is reduced and kisspeptin-producing neurons stimulate GnRH neuron activity. At a testicle volume of 4 mL the Leydig cells' testosterone production has reached such a level that pubertal changes become apparent. Delayed or incomplete puberty sometimes occurs in certain syndromes, and complete lack of puberty can also be syndrome-related. Klinefelter's syndrome is associated with gonad dysgenesis expressed as gradual reduction of gonadal function starting after puberty. Cancer treatment during childhood; especially radiation therapy of the gonads, may cause hypogonadism and infertility. It is therefore essential to follow gonad function closely in these patients. In conclusion, each doctor treating children should be able to evaluate the degree of puberty development and when needed request adequate laboratory tests.
Topics: Adolescent; Adrenarche; Child; Disorders of Sex Development; Gonadotropin-Releasing Hormone; Growth Hormone; Humans; Hypogonadism; Male; Puberty; Sex Chromosome Disorders; Testis
PubMed: 18511972
DOI: No ID Found -
Pediatrics Feb 2008Several recent studies suggest that the timing of the onset of puberty in girls has become earlier over the past 30 years, and there is strong evidence that the... (Comparative Study)
Comparative Study Review
Several recent studies suggest that the timing of the onset of puberty in girls has become earlier over the past 30 years, and there is strong evidence that the increasing rates of obesity in children over the same time period is a major factor. This article reviews studies from the United States that examined the age of menarche and the age of onset of breast development and pubic hair as a function of body mass index, which is a good surrogate measure of body fat. These studies are nearly all cross-sectional, so many questions remain unanswered. However, at least several studies show that girls who have relatively higher body mass index are more likely to have earlier menses, as well as a relationship between body mass index and other measures of pubertal onset. The evidence published to date suggests that obesity may be causally related to earlier puberty in girls rather than that earlier puberty causes an increase in body fat. In contrast, few studies have found a link between body fat and earlier puberty in boys. A growing body of evidence from both rodent and human studies suggests that leptin may be the critical link between body fat and earlier puberty. Leptin-deficient mice and humans fail to enter puberty unless leptin is administered, and rodent studies indicate that very low levels of leptin stimulate gonadotropin secretion both at the hypothalamic and the pituitary level. Current evidence indicates that leptin appears to play a permissive role rather than act as the critical metabolic signal initiating puberty. The linkage between body fat and the reproductive axis in girls may have evolved in mammals as a mechanism for ensuring that pregnancy will not occur unless there are adequate fat stores to sustain both the mother and the growing fetus.
Topics: Adipose Tissue; Age Factors; Animals; Body Mass Index; Child; Female; Humans; Male; Menarche; Puberty; Skinfold Thickness
PubMed: 18245513
DOI: 10.1542/peds.2007-1813F -
Annals of the New York Academy of... Jun 2004This article introduces and summarizes the goals of the symposium. It also provides an overview of a conceptual framework for understanding adolescence, which emphasizes... (Review)
Review
This article introduces and summarizes the goals of the symposium. It also provides an overview of a conceptual framework for understanding adolescence, which emphasizes how the very nature of this developmental transition requires an interdisciplinary approach-one that focuses on brain/behavior/social-context interactions during this important maturational period. More specifically it describes a set of neurobehavioral changes that appear to be linked to pubertal development, which appear to have a significant effect on motivation and emotion, and considers these puberty-specific changes in affect in relation to a much larger set of developmental changes in adolescence. This framework is used to argue for the need for a transdisciplinary dialogue that brings together work in several areas of neuroscience (including animal models) and normal development with clinical and social policy research aimed at early intervention and prevention strategies.
Topics: Adolescent; Adolescent Development; Affect; Brain; Humans; Neurosciences; Psychology, Adolescent; Puberty; Social Behavior
PubMed: 15251869
DOI: 10.1196/annals.1308.001 -
Pediatrics Feb 2008Whether children, especially girls, are entering and progressing through puberty earlier today than in the mid-1900s has been debated. Secular trend analysis, based on... (Comparative Study)
Comparative Study
Whether children, especially girls, are entering and progressing through puberty earlier today than in the mid-1900s has been debated. Secular trend analysis, based on available data, is limited by data comparability among studies in different populations, in different periods of time, and using different methods. As a result, conclusions from data comparisons have not been consistent. An expert panel was asked to evaluate the weight of evidence for whether the data, collected from 1940 to 1994, are sufficient to suggest or establish a secular trend in the timing of puberty markers in US boys or girls. A majority of the panelists agreed that data are sufficient to suggest a trend toward an earlier breast development onset and menarche in girls but not for other female pubertal markers. A minority of panelists concluded that the current data on girls' puberty timing for any marker are insufficient. Almost all panelists concluded, on the basis of few studies and reliability issues of some male puberty markers, that current data for boys are insufficient to evaluate secular trends in male pubertal development. The panel agreed that altered puberty timing should be considered an adverse effect, although the magnitude of change considered adverse was not assessed. The panel recommended (1) additional analyses of existing puberty-timing data to examine secular trends and trends in the temporal sequence of pubertal events; (2) the development of biomarkers for pubertal timing and methods to discriminate fat versus breast tissue, and (3) establishment of cohorts to examine pubertal markers longitudinally within the same individuals.
Topics: Age Factors; Child; Female; Gonadal Steroid Hormones; Humans; Longitudinal Studies; Male; Menarche; Puberty; Puberty, Precocious; Sexual Maturation; United States
PubMed: 18245511
DOI: 10.1542/peds.2007-1813D -
Hormones and Behavior Jul 2013This article is part of a Special Issue "Puberty and Adolescence". Historical records reveal a secular trend toward earlier onset of puberty in both males and females,... (Review)
Review
This article is part of a Special Issue "Puberty and Adolescence". Historical records reveal a secular trend toward earlier onset of puberty in both males and females, often attributed to improvements in nutrition and health status. The trend stabilized during the mid 20th century in many countries, but recent studies describe a recurrence of a decrease in age of pubertal onset. There appears to be an associated change in pubertal tempo in girls, such that girls who enter puberty earlier have a longer duration of puberty. Puberty is influenced by genetic factors but since these effects cannot change dramatically over the past century, environmental effects, including endocrine disrupting chemicals (EDCs), and perinatal conditions offer alternative etiologies. Observations that the secular trends in puberty in girls parallel the obesity epidemic provide another plausible explanation. Early puberty has implications for poor behavioral and psychosocial outcomes as well as health later in life. Irrespective of the underlying cause of the ongoing trend toward early puberty, experts in the field have debated whether these trends should lead clinicians to reconsider a lower age of normal puberty, or whether such a new definition will mask a pathologic etiology.
Topics: Adolescent; Adolescent Development; Female; Humans; Male; Pregnancy; Prenatal Exposure Delayed Effects; Psychology, Adolescent; Puberty; Sexual Maturation; Time Factors
PubMed: 23998669
DOI: 10.1016/j.yhbeh.2013.03.014 -
Molecular and Cellular Endocrinology Jul 2006The mechanisms that control the onset of puberty remain within the purview of the neurobiologists who first recognised the concept of removal of a restraint factor to... (Review)
Review
The mechanisms that control the onset of puberty remain within the purview of the neurobiologists who first recognised the concept of removal of a restraint factor to permit reawakening of puberty. The discovery of a ligand-activated G protein receptor-signalling pathway upstream of the GnRH pulse generator adds further weight to the role of the hypothalamus in the central regulation of puberty. The physical pointers to puberty are the mainstay of assessing timing and tempo in a clinical setting but non-invasive and indirect methods of assessment only are appropriate for population studies in normal children. That puberty can be regarded as a sensor recognises the observation of secular changes in pubertal timing and perhaps qualitative aspects of tempo. The influences on the sensor include marked changes in nutrition and an environmental exposure to low-dose chemical mixtures interacting with a polygenic background.
Topics: Breast; Female; Genitalia; Humans; Male; Menarche; Puberty; Receptors, G-Protein-Coupled; Receptors, Kisspeptin-1
PubMed: 16824680
DOI: 10.1016/j.mce.2006.04.014 -
Journal of Pediatric Endocrinology &... Apr 2018The objective of this study was to assess the current use of patient-centered psychosocial assessments for the evaluation of children with central precocious puberty... (Review)
Review
The objective of this study was to assess the current use of patient-centered psychosocial assessments for the evaluation of children with central precocious puberty (CPP). Studies evaluating the psychosocial impact of CPP were identified through searches of the PubMed and Cochrane Library databases, ClinicalTrials.gov, a drug prescribing information database, and regulatory websites. Studies were screened using prespecified inclusion and exclusion criteria. Potentially relevant patient-centered outcome assessments (including patient-, parent- or observer-reported measures) used in the identified studies were evaluated in detail for their relevance in CPP. Of the 467 studies identified, 15 met the inclusion criteria. Frequently assessed concepts included depression and anxiety, behavior and behavioral problems, body image and self-esteem and personality type/characteristics. Among the assessments used in the identified studies, the Child Behavior Checklist, Pediatric Quality of Life Inventory (PedsQL), SF-10 for Children and Child Health Questionnaire were comprehensively evaluated. The PedsQL showed promise as a patient-centered outcome measure in CPP. Although there is a lack of validated tools measuring psychosocial health and health-related quality of life in patients with CPP, the PedsQL captures issues seen in this patient population and is relatively easy to administer. Further studies using this and other tools in children with CPP are needed.
Topics: Child; Humans; Patient-Centered Care; Program Evaluation; Psychology; Psychometrics; Puberty; Puberty, Precocious
PubMed: 29649000
DOI: 10.1515/jpem-2017-0465