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Molecular and Cellular Endocrinology Aug 2010Secular trends in timing of puberty appear to continue although under-nutrition has not been any longer a limiting factor for pubertal development. Now obesity and other... (Review)
Review
Secular trends in timing of puberty appear to continue although under-nutrition has not been any longer a limiting factor for pubertal development. Now obesity and other environmental reasons have been suspected to cause this trend, and endocrine disrupting chemicals have become into focus as possible contributors. Epidemiological studies on endocrine disrupters are still scarce and show only weak associations between exposures and timing of puberty. Since genetic background explains 50-80% of variability in the timing of puberty, it is not surprising that the observed environmental effects are rather modest when individual exposures are assessed. Despite that, some exposures have been reported to be associated to early (e.g., polybrominated biphenyls) or delayed (e.g., lead) puberty. Here we shortly review the available data on recent trends in timing of puberty and the possible role of endocrine disrupters.
Topics: Endocrine Disruptors; Environment; Environmental Exposure; Geography; Humans; Puberty; Time Factors
PubMed: 20298746
DOI: 10.1016/j.mce.2010.03.011 -
Neuroendocrinology 2014All reproductively competent adults have gone through puberty. While key genes and signaling pathways that lead to the onset of sexual maturation are known, the... (Review)
Review
All reproductively competent adults have gone through puberty. While key genes and signaling pathways that lead to the onset of sexual maturation are known, the molecular mechanisms that determine when an individual enters puberty are only beginning to be understood. Both genetic and environmental factors determine the timing of puberty. New advances in understanding how environmentally sensitive, yet highly heritable developmental processes are regulated have come from the field of epigenetics. Of note, studies investigating the epigenetic control of the onset of puberty suggest that epigenetic repression of key inhibitory loci may play a fundamental role in the initiation of puberty. Current technologies that not only read out the DNA sequence, but also determine how the DNA is modified in response to the environment, promise new insight into how puberty is regulated, including the identification and understanding of gene regulatory networks that control the biological pathways affecting pubertal timing. Here we review the findings to date and discuss how epigenetic investigation can further our understanding of this fundamental aspect of human development.
Topics: Animals; Epigenesis, Genetic; Epigenomics; Humans; Puberty; Sexual Maturation
PubMed: 24718029
DOI: 10.1159/000362559 -
The Journal of Adolescent Health :... Nov 2006
Topics: Adolescent; Humans; Puberty; Research
PubMed: 17046496
DOI: 10.1016/j.jadohealth.2006.05.014 -
Journal of Research on Adolescence :... Mar 2019This special section is the product of a small-group meeting of those who study puberty and its relevance. Our aim was to gather information and write manuscripts to...
This special section is the product of a small-group meeting of those who study puberty and its relevance. Our aim was to gather information and write manuscripts to inform scientists of advances and continuing obstacles, as well as to stimulate interdisciplinary research on puberty relevant across the lifespan. The themes of the nine position or review papers (and commentary), range from cell to society. We hope this introduction will entice you to read all the papers and consider how they apply or expand your next steps in research or help you synthesize the literature on puberty. We anticipate the papers can embellish your adolescent courses, and, for junior scientists, we hope the many intriguing possibilities for future research on puberty will be apparent.
Topics: Adolescent; Adolescent Health; Biobehavioral Sciences; Congresses as Topic; Guidelines as Topic; Humans; Manuscripts as Topic; Puberty; Research; Sexual Maturation
PubMed: 30869840
DOI: 10.1111/jora.12449 -
Journal of Pediatric and Adolescent... Oct 2020Several strategies have been proposed to determine onset of puberty without examination by a trained professional. This study sought to evaluate a novel approach to...
STUDY OBJECTIVE
Several strategies have been proposed to determine onset of puberty without examination by a trained professional. This study sought to evaluate a novel approach to determine onset of puberty in girls.
DESIGN, SETTING, AND PARTICIPANTS
This study used the Cincinnati cohort of the Breast Cancer and the Environment Research Program. Girls were recruited at 6-7 years of age and followed every 6 months in the initial 6 years, and annually thereafter. Breast maturation and foot length were performed at each visit by health professionals certified in those methods. Mothers were asked to provide the age at which they believed that their daughter's shoe size had increased more rapidly.
RESULTS
These analyses include 252 participants. Age at increase in shoe size was correlated to age at onset of puberty (r = 0.21) and increase in foot length (r = 0.24). The difference of reported age of increased shoe size was 0.46 years before breast development.
CONCLUSION
Reported increase in shoe size occurred somewhat earlier and was significantly correlated to age of breast development. These preliminary results suggest that mother's report of increase in shoe size appear to be as accurate as reports of other indirect methods of determining onset of puberty, such as self- or maternal estimates of breast development.
Topics: Adolescent; Breast; Child; Female; Foot; Humans; Longitudinal Studies; Mothers; Puberty; Shoes
PubMed: 32485297
DOI: 10.1016/j.jpag.2020.05.007 -
Best Practice & Research. Clinical... Mar 2002Children born small for gestational age (SGA: birth weight or birth length more than 2 standard deviations below the mean score) are at a higher risk of perinatal... (Review)
Review
Children born small for gestational age (SGA: birth weight or birth length more than 2 standard deviations below the mean score) are at a higher risk of perinatal morbidity and mortality and of a number of chronic diseases in later life such as hypertension, decreased insulin sensitivity, diabetes mellitus type 2 and an increased risk of cardiovascular disease. The programming of the endocrine axes occurs during critical phases of fetal development and might thus be affected by intrauterine growth retardation. Studies in Northern Spanish adolescent girls have indicated associations between reduced fetal growth and the occurrence of precocious adrenarche, pubarche, hyperandrogenism, polycystic ovary syndrome (PCOS) and hyperinsulinism. These findings have attracted much attention because it might have serious consequences in later life. However, hyperandrogenism and precocious pubarche were not confirmed in a large Dutch study in short children born SGA. Two studies reported a lower number of follicles in the ovaries in girls born SGA, which might have an impact on fertility. Clearly, further studies are required before definite conclusions can be drawn. There are still only limited data concerning the timing of puberty in children born SGA. Most studies indicate that these children start their puberty at a normal age but relatively early within the normal range. Age at menarche seems comparable with controls. Data on duration of puberty, influence of puberty on attainment of adult height, peak height velocity during puberty and fertility are not yet known.
Topics: Animals; Embryonic and Fetal Development; Female; Humans; Male; Pregnancy; Puberty
PubMed: 11987899
DOI: 10.1053/beem.2002.0181 -
Orvosi Hetilap Jul 2018Puberty is the stage of development in human life, when the hypothalamus-hypophysis-gonad axis is re-activated after quiescence. Humanity has long been concerned with... (Review)
Review
Puberty is the stage of development in human life, when the hypothalamus-hypophysis-gonad axis is re-activated after quiescence. Humanity has long been concerned with the idea of exogenous and endogenous factors and mechanisms that influence the temporal course of puberty neuroendocrine events. Recent discoveries have helped to understand the functioning of the neuroendocrine system. It has been clarified that kisspeptin plays a key role in puberty and regulation of fertility. However, in the function of the gonadotropin-releasing hormone (GnRH) pulse secretion, besides kisspeptin, neurokinin B, dynorphin neurons other positive and negative signals are involved, guiding the release of hormones of hypophysis gonadotropin. The knowledge of these nerves further enhanced the understanding of GnRH pulsation modulation by endocrine, metabolic and environmental impacts. The authors point out the risk of endocrine disruptors in the physiological course of puberty. The aim of the review is to provide a comprehensive picture of the research results of the physiology of kisspeptin, as the manipulation of kisspeptin signaling has the potential for novel therapies in patients with pathologically low or high luteinizing hormone (LH) pulsatility. Orv Hetil. 2018; 159(29): 1175-1182.
Topics: Female; Gonadotropin-Releasing Hormone; Humans; Male; Neurosecretory Systems; Puberty; Reproduction; Sexual Maturation
PubMed: 30008234
DOI: 10.1556/650.2018.31125 -
Biology of Reproduction Jan 2019Acquisition of reproductive maturity involves one of the most important series of developmental events in an organism's life. The beginning of adolescence is marked by... (Review)
Review
Acquisition of reproductive maturity involves one of the most important series of developmental events in an organism's life. The beginning of adolescence is marked by the onset of puberty. Puberty is the continuum of physical changes through which an infantile body matures into an adult capable of reproduction. This is a period of increased brain plasticity, where processes of re-wiring, neuronal proliferation, and pruning are enhanced. The initiation of mammalian puberty requires an increased pulsatile release of gonadotropin-releasing hormone from the hypothalamus. Puberty is regulated by neuroendocrine, genetic, and epigenetic factors. The maturation and function of the reproductive axis are highly sensitive to the energy status of the organism and sophisticated mechanisms exist to inhibit the axis in unfavorable energetic or metabolic conditions.In this review, we will focus on the impact of alcohol and obesity on reproductive outcomes, with emphasis on their effects on the timing of puberty. In the case of obesity, conflictive data are found, and while in females the association of overnutrition with advanced onset of puberty is consistent, in males, discrepant results have been reported. Concerning alcohol exposure, compelling evidence has documented a delay in the onset of puberty. We will present here data from both clinical studies and research involving preclinical models, which do not only delineate the impact of these conditions on the timing of puberty and potential underlying mechanisms, but that may help to define better strategies for the rational management of puberty disorders, especially of metabolic origin.
Topics: Adolescent; Adult; Age of Onset; Alcohol Drinking; Animals; Ethanol; Female; Humans; Male; Pediatric Obesity; Puberty; Sexual Maturation; Time Factors
PubMed: 30052777
DOI: 10.1093/biolre/ioy168 -
Endocrine Development 2010The initiation of mammalian puberty requires an increased pulsatile release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. This increase is brought... (Review)
Review
The initiation of mammalian puberty requires an increased pulsatile release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. This increase is brought about by changes in transsynaptic and glial-neuronal communication. Coordination of these cellular interactions likely requires the participation of sets of genes hierarchically arranged within functionally connected networks. Using high throughput, genetic, molecular and bioinformatics strategies, in combination with a systems biology approach, three transcriptional regulators of the pubertal process have been identified, and the structure of at least one hypothalamic gene network has been proposed. A genomewide analysis of hypothalamic DNA methylation revealed profound changes in methylation patterns associated with the onset of female puberty. Pharmacological disruption of two epigenetic marks associated with gene silencing (DNA methylation and histone deacetylation) resulted in pubertal failure, instead of advancing the onset of puberty, suggesting that disruption of these two silencing mechanisms leads to activation of repressor genes whose expression would normally decrease at puberty. These observations suggest that the genetic underpinnings of puberty are polygenic rather than specified by a single gene, and that epigenetic mechanisms may provide coordination and transcriptional plasticity to this genetic network.
Topics: Epigenomics; Female; Gene Expression Regulation; Gonadotropin-Releasing Hormone; Humans; Hypothalamus; Male; Puberty
PubMed: 19955755
DOI: 10.1159/000262527 -
Adolescent Medicine (Philadelphia, Pa.) Oct 2003
Review
Topics: Adaptation, Psychological; Adolescent; Adolescent Behavior; Genital Diseases, Male; Humans; Male; Men; Psychology, Adolescent; Puberty; Risk-Taking
PubMed: 15122159
DOI: 10.1016/S1041349903500433