The study was conducted in 2518 females of age from 9 to 75. The finding showed: during the pubertal stage, the heights and weights increased quickly. The heights of Hue students started increasing rapidly at the age of 10-12, especially at 11-12 years old: their heights increased 5.95 cm per year (P<0.001); The weights gradually increased at the ages of 9 to 11, quickly increased at the age of 12: their weights increased 3,79 kg per year (P<0.001). The first menstruation was at age of 13.581.10 during the 90s decade. The first menstruation began at the younger ages during the 90s decade when comparing with that of previous decades
Puberty ; Physiology ; pupil

Androgens have multiple actions on the skeleton throughout life. Androgens promote skeletal growth and accumulation of minerals during puberty and adolescence and stimulate osteoblast but suppress osteoclast function, activity and lifespan through complex mechanisms. Also androgens increase periosteal bone apposition, resulting in larger bone size and thicker cortical bone in men. There is convincing evidence to show that aromatization to estrogens was an important pathway for mediating the action of testosterone on bone physiology. Estrogen is probably the dominant sex steroid regulating bone resorption in men, but both testosterone and estrogen are important in maintaining bone formation.
Aging ; physiology ; Androgens ; metabolism ; physiology ; therapeutic use ; Bone Resorption ; etiology ; prevention & control ; Bone and Bones ; pathology ; physiology ; Estrogens ; physiology ; Humans ; Hypogonadism ; pathology ; Male ; Puberty ; physiology ; Testosterone ; physiology

OBJECTIVETo evaluate the impact of menarche age (MA) on obese status in late puberty (LP) and mid-life (ML) females.

METHODS2035 girls aged 16 to 18 years were selected from a Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study, which was performed from April to October in 2004, as the LP study population. 479 women aged 41 to 52 years were from the Fetal Origin of Adult Disease (FOAD) cohort, which established in 1995 to 2001, as the ML study population. Based on the 25 and 75 percentile of MA of each population, all subjects of LP and ML were divided into early, middle, and late matured groups, respectively. Overweight and obesity were defined by Chinese age-, gender-specific BMI criteria for LP girls, and Chinese BMI criteria for ML women while central obesity was defined by the waist-to-height ratio (WHtR) cutoff of 0.5. Multiple linear regression was used to explore the associations between MA and BMI, waist circumference (WC) and WHtR. The impact of early menarche on obese status in late life was estimated by odds ratio (OR) using logistic regression analyses.

RESULTSThe prevalence of overweight and obesity increased with the decrease of MA in both LP and ML population. When MA had a one-year advance, a 0.58 kg/m2 increase in BMI and a 1.1 cm increase in WC during LP, and a 0.35 kg/m2 increase in BMI and a 0.6 cm increase in WC during ML were observed. After adjustment for age, residence area and life style related variables, those who experienced earlier menarche were at higher risk of suffering from obesity in LP (OR :8.740, 95% CI: 3.653-20.911) and during ML (2.498, 1.145-5.453) when compared to those with later menarche. We also noticed that the risk increased for central obesity [LP: 14.280 (3.223-63. 267), ML: 15.604 (1.821-133.679)].

CONCLUSIONMenarche age appeared to be an independent predictor for obese status in LP and ML among women.

Adiposity ; physiology ; Adolescent ; Adult ; Female ; Humans ; Linear Models ; Menarche ; physiology ; Middle Aged ; Obesity ; epidemiology ; Prevalence ; Puberty ; physiology ; Risk Factors

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*

OBJECTIVETo compare the changes in body composition, including fat mass index (FMI) and fat free mass index (FFMI) during puberty development of obese and normal-weight children in China, and to explore the effect of age and gender on body composition.

METHODSA total of 356 children at the age of 7-15 years were enrolled in this study. Body composition of 10 normal-weight and obese children in each age group was measured by dual-energy x-ray absorptiometry (DEXA). FFMI and FMI were calculated according to the following formula: FFMI (kg x m(-2)) = FFM(kg) / height2 (m2) and FMI (kg x m(-2)) = FM (kg) / height2 (m2).

RESULTSThe fat mass and fat free mass of obese children were significantly higher than those of normal-weight children (P < 0.05). The FMI and FFMI of obese children increased significantly with age and were higher than those of the same sex, gender, and age normal-weight children (P < 0.05).

CONCLUSIONThe levels of fat mass, fat free mass, FMI, and FFMI are different in obese and normal-weight children, and gender effects are significant in boys having higher levels of these indicators than in girls. FFMI and FMI can be used as monitoring indexes in weight control of obese children.

Adolescent ; Body Composition ; physiology ; Body Mass Index ; Child ; China ; Female ; Humans ; Male ; Obesity ; metabolism ; Puberty ; physiology ; Sex Characteristics

OBJECTIVETo study the contribution of puberty maturation to smoking behavior in Chinese adolescents.

METHODSA cross-sectional survey was carried out. One thousand four hundred and fifty-three senior middle school students aged from 15 - 18 years were recruited in Shanghai in 2000. A standardized self-administrated questionnaire was designed to obtain information on smoking, age at first nocturnal ejaculation in boys, age at menarche in girls and variables that might be associated with smoking in adolescents.

RESULTSIn boys, the prevalence of experimental smoking was highest among later maturers (28.6%), followed by the earlier (21.3%) and the average (21.7%), and the prevalence of current smoking was highest among earlier maturers (16.4%), followed by the later (7.1%) and then the average (4.8%). In girls, the prevalence of ever smoked among earlier, average and later maturers were as follows: 24.2%, 12.0%, 6.3% respectively. When psychosocial variables which might be associated with smoking were under control, early maturation was a significant risk factor for current smoking in boys (OR = 3.68, 95% CI: 1.23 - 10.99), and might be a risk factor for ever smoked in girls (OR = 2.23, 95% CI: 0.89 - 5.60). Whereas late maturation might have been a risk factor for boys to experiment smoking (OR = 1.48, 95% CI: 0.72 - 3.06), while in girls it might be protective (OR = 0.64, 95% CI: 0.22 - 1.86).

CONCLUSIONEarlier or later matured boys and earlier matured girls were at higher risk of smoking. Pubertal changes and timing need to be considered in smoking prevention.

Adolescent ; Adolescent Behavior ; Female ; Humans ; Male ; Puberty ; physiology ; psychology ; Risk Factors ; Sexual Maturation ; physiology ; Smoking ; epidemiology ; psychology ; Statistics as Topic

OBJECTIVESTo study the roles of leptin in the development during puberty in girls and the its relationship with insulin (INS), growth hormone (GH), estradiol (E(2)) and testosterone (T).

METHODSOne hundred and fifty girls with simple obese aged 7 to 17 years, and 150 normal healthy girls and 150 girls with malnutrition matched for age (+/- 3 months) and height (+/- 2 cm) were selected. Serum levels of leptin, INS, GH, E(2) and T were measured for them.

RESULTSTheir serum level of leptin positively correlated with body mass index (BMI) and age. Serum level of leptin in girls increased steadily from Tanner stage B(1) to stage B(5). At Tanner stage B(2), serum level of leptin in the normal groups (7.72 microg/L) was not significantly different from that in those with malnutrition (7.36 microg/L), but significantly lower than that in the obese groups (12.85 microg/L). At other Tanner stages, there was significant difference in serum level of leptin among obese, normal and malnutrition groups. Serum level of leptin correlated negatively with serum GH and positively with serum INS, but not correlated with E(2) and T.

CONCLUSIONSLeptin may play a role in triggering development during puberty in girls. Serum level of leptin at Tanner stage B(2) may be the threshold dose to trigger the onset of puberty in girls. Quickly increasing level of leptin at Tanner stage B(5) may inhibit the increase of GH, which ushered the end of puberty in girls.

Adolescent ; Body Height ; physiology ; Body Mass Index ; Body Weight ; physiology ; Child ; Female ; Growth Hormone ; metabolism ; Humans ; Leptin ; blood ; physiology ; Puberty ; physiology ; Testosterone ; metabolism

OBJECTIVESTo study the role of leptin in the development boys during their puberty and its relationship with insulin (INS), growth hormone (GH), estradiol (E2) and testosterone (T).

METHODSOne hundred and fifty boys with simple obese aged 7 to 17 years, 150 normal healthy boys and 150 boys with malnutrition matched for age (+/- 3 months) and height (+/- 2 cm) were selected. Serum levels of leptin, INS, GH, E2 and T were measured for them.

RESULTSSerum level of leptin in obese group was significantly higher than that in normal group, and that in normal group was significantly higher than that in malnourished group. In the all three groups, serum level of leptin increased with age first until peak value, then began to decrease, with peak value of 6.96 microg/L at ages of 10-11 y in obese group, 10.25 microg/L at ages of 11-12 y in normal group and 5.08 microg/L at ages of 11-12 y in malnourished group. Serum level of leptin increased steadily from Tanner stages G1 to G2, then began to decrease steadily in G2 to G4. Serum level of leptin increased again in stage G5. Serum level of INS in boys increased steadily with age from 7 to 17 years old. Serum levels of GH, T and E2 in boys began to increase since 10-11 years old. Serum level of leptin positively correlated with serum level of INS and negatively correlated with serum levels of GH and T, but not correlated with serum level of E2.

CONCLUSIONSLeptin may promote pubertal development of boys, but not the determinant factor in triggering and maintaining their pubertal development. Re-increase in level of leptin during stage G5 could inhibit secretion of GH, and signalize the end of puberty in boys.

Adolescent ; Body Height ; physiology ; Body Mass Index ; Body Weight ; physiology ; Child ; Estradiol ; metabolism ; Growth Hormone ; metabolism ; Humans ; Leptin ; blood ; physiology ; Male ; Puberty ; physiology ; Testosterone ; metabolism

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 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