Puberty is a pivotal biological process that completes sexual maturation to achieve full reproductive capability. It is a major transformational period of life, whose timing is strongly affected by genetic makeup of the individual, along with various internal and external factors. Although the exact mechanism for initiation of the cascade of molecular events that culminate in puberty is not yet known, the process of pubertal onset involves interaction of numerous complex signaling pathways of hypothalamo-pituitary-testicular (HPT) axis. We developed a classification of the mechanisms involved in male puberty that allowed placing many genes into physiological context. These include (i) hypothalamic development during embryogenesis, (ii) synaptogenesis where gonadotropin releasing hormone (GnRH) neurons form neuronal connections with suprahypothalamic neurons, (iii) maintenance of neuron homeostasis, (iv) regulation of synthesis and secretion of GnRH, (v) appropriate receptors/proteins on neurons governing GnRH production and release, (vi) signaling molecules activated by the receptors, (vii) the synthesis and release of GnRH, (viii) the production and release of gonadotropins, (ix) testicular development, (x) synthesis and release of steroid hormones from testes, and (xi)the action of steroid hormones in downstream effector tissues. Defects in components of this system during embryonic development, childhood/adolescence, or adulthood may disrupt/nullify puberty, leading to long-term male infertility and/or hypogonadism. This review provides a list of 598 genes involved in the development of HPT axis and classified according to this schema. Furthermore, this review identifies a subset of 75 genes for which genetic mutations are reported to delay or disrupt male puberty.
Adolescent ; Male ; Humans ; Adult ; Child ; Gonadotropin-Releasing Hormone ; Gonadotropins/metabolism* ; Hypogonadism ; Testis/metabolism* ; Puberty/physiology* ; Sexual Maturation

Pubertal development may be altered in boys with cryptorchidism and hypospadias, but existing knowledge is inconsistent. Therefore, we investigated the association between cryptorchidism and hypospadias and pubertal development in a large cohort study. Boys in the Puberty Cohort, a cohort nested within the Danish National Birth Cohort, were included in this study. Information on cryptorchidism and hypospadias was retrieved from the Danish National Patient Register. From 11 years until 18 years or full pubertal development, information on physical markers of pubertal development was provided biannually, including Tanner stages, axillary hair, acne, voice break, and first ejaculation. In multivariate regression models for interval censored data, the mean (95% confidence intervals [CIs]) differences in months in obtaining the pubertal markers between boys with and without the anomalies were estimated. Among 7698 boys, 196 (2.5%) had cryptorchidism and 60 (0.8%) had hypospadias. Boys with hypospadias experienced first ejaculation and voice break 7.7 (95% CI: 2.5-13.0) months and 4.5 (95% CI: 0.3-8.7) months later than boys without hypospadias. The age at attaining the Tanner stages for gonadal and pubic hair growth was also higher, though not statistically significant. Pubertal development seemed unaffected in boys with mild as well as severe cryptorchidism. In conclusion, hypospadias may be associated with delayed pubertal development, but pubertal development seems unaffected by cryptorchidism. The relation between hypospadias and later pubertal development may be due to the underlying shared in utero risk or genetic factors.
Adolescent ; Age Factors ; Child ; Cohort Studies ; Cryptorchidism/physiopathology* ; Denmark ; Humans ; Hypospadias/physiopathology* ; Male ; Puberty/physiology*

OBJECTIVES: Mothers who smoke during pregnancy or while their children are small were common in some populations. Epidemiological studies have tried to detect the effect of prenatal tobacco smoke (PTS), and childhood environmental tobacco smoke (ETS) on puberty timing have not shown a consensus results. We aimed to examine current evidence and estimate the associations between PTS or/and ETS and puberty timing. METHODS: Seven databases were searched from inception to May 2017. All the cohort studies examining the associations between PTS and/or ETS and puberty timing were identified. Two reviewers independently screened all studies, evaluated the quality of eligible studies, and extracted the data. The quality assessment of the eligible cohort studies was based on the Newcastle-Ottawa Scale. Risk ratio (RR), standard mean difference (SMD), and 95% confidence intervals (CIs) were calculated and pooled by CMA (Version 2.0, Biostat, Inc., USA). RESULTS: Compared with controls, girls with PTS and ETS exposure have an earlier age at menarche (SMD - 0.087, 95% CI 0.174 to - 0.000), and similar results were found in both PTS subgroup (SMD - 0.097, 95% CI - 0.192 to - 0.002) and prospective cohort subgroup (SMD - 0.171, 95% CI - 0.253 to - 0.090). And number of boys with early voice break in PTS group was significantly increasing than non-exposed boys (RR 1.34, 95% CI 1.29 to 1.40). CONCLUSIONS PTS exposure possibly decrease age of menarche of girls, and studies on boys were urgent needed. Appropriate and comprehensive outcome measures using unified criteria to classify puberty should be reported in future studies.
Aging ; physiology ; Environmental Exposure ; adverse effects ; Female ; Humans ; Menarche ; physiology ; Pregnancy ; Prenatal Exposure Delayed Effects ; etiology ; Puberty ; physiology ; Smoking ; adverse effects ; Tobacco Smoke Pollution ; adverse effects

OBJECTIVETo investigate the status of pubertal development in children born with assisted reproductive technology (ART).

METHODSA retrospective analysis was performed on the pubertal development data of children born with ART in Peking University Third Hospital from 1994 to 2003 (ART group). The data in the cross-sectional study "Reports on the Physical Fitness and Health Research of Chinese School Students in 2010" were used as a control. The age at menarche and the age at spermarche were compared between the two groups. The status of pubertal development in the overweight and obese children in the ART group was evaluated to investigate the correlation between pubertal development and body mass index (BMI).

RESULTSA total of 200 children born with ART were enrolled in this study, and 72 of them (41 males and 31 females) completed the survey (response rate=36.0%). In the ART group, the mean age at spermarche and the mean age at menarche were 13.9 years (95%CI: 13.7-14.3 years) and 12.2 years (95%CI: 11.8-12.6 years), respectively. There were no significant differences in the age at spermarche and the age at menarche between the ART and control groups (P>0.05). In the ART group, there were no significant differences in the age at spermarche and the age at menarche between the overweight and obese children and the normal weight children (P>0.05). There were also no significant differences in overweight rate and obesity rate between the children in the ART group and the adolescents in Beijing (P>0.05). In the ART group, there was no significant correlation between the age at spermarche or menarche and BMI (P>0.05).

CONCLUSIONSNo delayed or precocious puberty is observed in children born with ART. This is consistent with the normal control data. And there is no significant correlation between pubertal development and BMI in children born with ART.

Adolescent ; Body Mass Index ; Child ; Child Development ; Cross-Sectional Studies ; Female ; Humans ; Male ; Menarche ; Obesity ; physiopathology ; Overweight ; physiopathology ; Puberty ; physiology ; Reproductive Techniques, Assisted ; Retrospective Studies

OBJECTIVETo investigate the cardiac autonomic nerve function in girls with idiopathic central precocious puberty (ICPP).

METHODSA total of 66 girls with ICPP were enrolled, among whom 36 were obese and 30 were not obese. A total of 68 age-matched healthy girls (normal controls) and 51 girls with simple obesity were enrolled as controls. All the subjects underwent 24-hour ambulatory electrocardiography, and deceleration capacity of heart rate (DC), acceleration capacity of heart rate (AC), and heart rate variability (HRV), and body mass index (BMI) were compared between groups.

RESULTSCompared with the normal control group, the ICPP group had significantly lower DC, standard deviation of normal-to-normal R-R intervals (SDNN), standard deviation of the average normal-to-normal intervals (SDANN), root mean square of successive differences (RMSSD), and high-frequency power (HF) and significantly higher AC and BMI. The ICPP group had significantly lower RMSSD and BMI than the simple obesity group (P<0.05). Compared with the ICPP girls without obesity, those with obesity had significantly lower DC, RMSSD, and HF and significantly higher AC and BMI (P<0.05).

CONCLUSIONSCardiac autonomic dysfunction is seen in girls with ICPP, especially those with obesity, mainly presenting with reduced vagal tone.

Autonomic Nervous System ; physiopathology ; Body Mass Index ; Child ; Child, Preschool ; Female ; Heart ; innervation ; Heart Rate ; physiology ; Humans ; Obesity ; physiopathology ; Puberty, Precocious ; physiopathology

OBJECTIVETo study the relationship between the suppression of the hypothalamic-pituitary-gonadal axis (HPGA) and the predicted adult height (PAH) in girls with central precocious puberty (CPP) during the treatment with gonadotropin-releasing hormone analogue (GnRHa), in order to provide guidance for individualized GnRHa dose adjustment in clinical practice.

METHODSThe clinical data of 75 CPP girls were collected, and then height, bone age (BA), uterine and ovarian volumes, and peak luteinizing hormone (LH), peak follicle-stimulating hormone (FSH), and estradiol (E2) levels were recorded at different time points of GnRHa treatment. PAH at each time point was calculated. PAH improvement (ΔPAH=PAH-target height) and its relationship with the degree of HPGA suppression were analyzed. Threshold effect analysis was applied to determine the best HPGA suppression range forΔPAH.

RESULTSAfter GnRHa treatment, PAHs were improved markedly compared with the data in the early stage of treatment. ΔPAH showed a negative correlation with ΔBA. At 24 months of treatment, ΔPAH was also negatively correlated with LH. Uterine volume controlled between 2.3 and 3.0 mL, LH level controlled below 0.8 IU/L, and FSH controlled below 2.4 IU/L could slow down the growth of BA and improve PAH.

CONCLUSIONSGnRHa treatment can improve the PAH of CPP girls. Selection of an appropriate therapeutic dose for GnRHa to control uterine volume, LH and FSH levels within certain ranges can slow down the growth of BA and improve PAH.

Adult ; Body Height ; Child ; Female ; Follicle Stimulating Hormone ; blood ; Gonadotropin-Releasing Hormone ; analogs & derivatives ; Humans ; Hypothalamo-Hypophyseal System ; physiology ; Luteinizing Hormone ; blood ; Ovary ; physiology ; Puberty, Precocious ; blood ; drug therapy ; physiopathology ; Retrospective Studies

OBJECTIVETo assess and compare the predictive effects of hypertension before puberty and during puberty on adult hypertension.

METHODSA total of 412 adults from the "Beijing children and adolescents blood pressure (BP) study" cohort were followed up in a clinical examination in 2005. Systolic and diastolic BP, height, and weight in childhood were measured at a baseline survey in 1987. The participants were divided into pre-puberty and puberty sub-cohorts according to their pubertal development stage at baseline. Information on adult BP, anthropometric indices and life style were collected through questionnaire and physical examination. BP changes and the predictive effect on adult hypertension were compared between the two sub-cohorts. Correlation of BP levels between 1987 and 2005 was examined through linear regression models.

RESULTSFrom childhood to adulthood, the regression coefficients of systolic BP were similar in the two sub-cohorts (both β=0.34, P<0.001), while the coefficient of diastolic BP was larger in the pubertal cohort (β=0.31, P<0.001) compared with the pre-pubertal cohort (β=0.12, P=0.017). Fifty percent of children with pubertal hypertension became hypertensive adults, while pre-pubertal hypertension resulted in 34.3%. After adjustment for sex, age, family history of hypertension, obesity in childhood, and adulthood, pubertal hypertension predicted a higher risk of adult hypertension than pre-pubertal hypertension, with odds ratios (95% confidence intervals) of 10.00 (3.03-33.07) and 2.71 (0.83-8.85), respectively.

CONCLUSIONOur results suggest that hypertension during puberty is likely to result in adult hypertension.

Adolescent ; Adult ; Age Factors ; Blood Pressure ; Body Mass Index ; Child ; China ; epidemiology ; Cohort Studies ; Female ; Humans ; Hypertension ; epidemiology ; physiopathology ; Male ; Overweight ; epidemiology ; physiopathology ; Puberty ; physiology ; Risk Factors

Retinol binding protein 4 (RBP4) has been postulated to provide a new link between obesity and insulin resistance. We aimed to assess the relationship between serum RBP4 and insulin resistance by investigating serum RBP4 levels in children and adolescents according to degree of obesity and pubertal stage. A total of 103 (30 lean, 39 overweight, 34 obese) were evaluated for serum RBP4, adiponectin, insulin, glucose and lipid profiles. RBP4 levels of obese and overweight groups were higher than those of lean group. RBP4 level was higher in pubertal group than in prepubertal group. RBP4 was positively correlated with age, height, weight, body mass index (BMI), abdominal circumference, systolic blood pressure, fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), total cholesterol and triglyceride, and inversely with adiponectin. In the multiple linear regression analysis, RBP4 was found to be independently associated with pubertal stage, BMI and triglyceride but not with HOMA-IR. In conclusion, serum RBP4 level is related with degree of adiposity and pubertal development. The association of RBP4 with insulin resistance is supposed to be secondary to the relation between RBP4 and adipose tissue in children and adolescents.
Adiponectin/blood ; *Adiposity ; Adolescent ; Age Factors ; Blood Glucose/analysis ; Blood Pressure ; Body Mass Index ; Child ; Cholesterol/blood ; Female ; Humans ; Insulin/blood ; Insulin Resistance ; Male ; Obesity/*blood/metabolism/physiopathology ; Puberty/*blood/metabolism/physiology ; Republic of Korea ; Retinol-Binding Proteins, Plasma/*metabolism ; Sex Factors ; Triglycerides/blood ; Waist Circumference

OBJECTIVETo investigate the possible effects and roles of bodyweight on the puberty onset in adolescent girls.

METHODSTotally 288 Chinese female children and adolescent girls aged 5 to 16 were followed up yearly for four consecutive years. The height, bodyweight, fat percentage, sexual characteristics, and the serum levels of leptin and insulin-like growth factor-1 (IGF-1) were studied to analyze the influential factors of puberty onset and age of menarche.

RESULTSThe serum level of leptin elevated significantly from age 13 [(9.23 +/- 1.25) microg/L] and reached peak at age 16 [(13.19 +/- 1.45) microg/L]. IGF-1 significantly correlated with the timing of puberty onset (r = 0.292, P = 0.016). BMI and fat percentage had no significant effects on the onset of puberty, but were negatively correlated with the age of menarche (r = -0.323, P = 0.037, r = -0.298, P = 0.038 respectively).

CONCLUSIONBodyweight may have effect on puberty onset in female adolescents.

Adolescent ; Adolescent Development ; Body Weight ; Child ; Child, Preschool ; Cross-Sectional Studies ; Female ; Follow-Up Studies ; Humans ; Puberty ; physiology ; Young Adult

OBJECTIVETo investigate the association of estrogen receptor alpha (ER-alpha) PvuII polymorphisms with the effect of calcium supplementation on bone development in Chinese pubertal girls, and to study the importance of calcium supplementation by maximizing the peak bone mass at their pubertal stage for bone development and osteoporosis prevention and the role of estrogen in regulating bone mass.

METHODSNinety-four pubertal girls were recruited in the study and divided into two groups and three sub-groups according to the ER-alpha PvuII polymorphisms. One year before and after calcium supplementation, bone mineral density (BMD) was measured by DEXA, while BGP, BAP, TRACP5b, and 25-OH-VitD(3), as well as estrogen were detected by ELISA. Analysis of covariance was used to examine the effect of ER-alpha polymorphisms on bone development.

RESULTSThe absolute increase and percentage change of BGP were significantly higher in the supplemented group than in the control group (P<0.05). In the intervened group, The increase and percentage change of the total body and radio distal 1/3 BMD were higher in PP than in PP genotype (P<0.05), and the increase of BAP in Pp was also higher than PP in the same group (P<0.05).

CONCLUSIONPP genotype shows a better response to calcium supplementation than the other PvuII polymorphisms.

Adolescent ; Asian Continental Ancestry Group ; Biomarkers ; Bone Density ; drug effects ; Calcium ; administration & dosage ; pharmacology ; Dietary Supplements ; Estrogen Receptor alpha ; genetics ; Female ; Humans ; Polymorphism, Genetic ; Puberty ; physiology