Age at menarche and age of onset of pubertal characteristics in 6-14-year-old girls from the Province of L'Aquila (Abruzzo, Italy).

The present study is part of a research project on growth models of children in an area of central-southern Italy. It analyzes the phases of pubertal breast development (BD) in 397 girls, pubic hair development (PHD) in 399 girls, and menarche in 583 girls from 6-14 years old. The status quo method was used to evaluate the age at menarche. Probit analysis was used to analyze the data for all three variables. The onset of BD and PHD (Tanner stage 2) occurs at age 7 in 6.1% of girls. Passage to stage 3 of one or both secondary sexual characteristics occurs at age 10 in 8.5% of girls. Comparison with data from the United States shows higher percentages of American white girls in stage 2 (or greater) of both characteristics at any age. The mean (median) age of onset (Tanner stage 2) of BD or PHD or both of them is 9.96 years. The passage to stage 3 occurs at age 12.36 for BD (95% confidence interval: 1.36 years) and at age 12.10 for PHD (95% confidence interval: 0.51 years). The mean age at menarche is 12.55 years, in general agreement with other values found in Italy. Sexual maturation at any considered stage for both pubertal characteristics is generally in line with literature data concerning other Mediterranean and industrialized countries or countries in which the demographic transition is in an advanced phase. It does not show a significant earlier onset. The evidence emerging from the general project suggests that the secular trend is still in progress in this region of Italy.     

Sexual maturation in Turkish girls

Ages of attainment of successive puberty stages of the breast, public hair and axillary hair and of menarche were established in a cross-sectional study of 1468 Turkish school girls in Istanbul. The subjects were grouped into four socioeconomic classes. Onset of secondary sexual characteristics and of menarche in the highest socioeconomic class were early as compared to other population groups. Mean ages of attainment for the initial stage of breast, pubic hair and axillary hair development were 9.8, 10.4 and 10.8 years respectively in this group. Mean menarcheal age was 12.36 +/- 0.01 years. All stages of breast, pubic hair and axillary hair and also menarche consistently occurred later in the lower socioeconomic classes as compared with the higher. The time intervals from onset to completion of secondary sexual characteristics were comparable to those reported for European girls for pubic and axillary hair development, but relatively longer for the development of the breast. They differed little between the socioeconomic classes.     

Is puberty starting earlier in urban South Africa?

Age at the initation of pubertal development was estimated for 401 Black (212 boys) and 206 White (100 boys) urban South African adolescents born in Soweto‐Johannesburg in 1990. Average age at the initation of puberty, assessed by age at the transition from Tanner Stage 1 to Tanner Stage 2 for breast/genitalia or pubic hair development ranged between 9.8 and 10.5 years. There were no statistically significant differences in age at initiation between genders or ethnic groups. Age at the initation of pubertal development has remained stable over the last 10 to 15 years, with the exception of pubic hair in boys which has declined on average 1.3 years over a decade. There is evidence to suggest that the tempo of pubertal maturation is increasing in girls born in the Soweto‐Johannesburg area, however, the evidence is less clear for boys. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.     

Age of onset of pubertal characteristics in boys aged 6-14 years of the Province of L'Aquila (Abruzzo, Italy)

BACKGROUND: Previous results on growth patterns of children from central-southern Italy (Abruzzo region) showed an increasing tendency to obesity and suggested that the secular trend was still in progress in this region. However, data on pubertal development was lacking. OBJECTIVE: The objective of the study was to provide population data on pubertal development in a sample of 535 boys aged 6-14 years as a contribution to the ongoing debate on earlier onset of pubertal traits and on the slowing down of the secular trend. METHODS: A cross-sectional survey was used. Data for genital and pubic hair development (GD and PHD) were analysed by probit analysis. RESULTS: The boys start developing sexual characteristics at age 9: 13.3% had entered stage 2 of GD and 8.9% showed PHD. At 13 years of age, 5% and 7.4% were still in stage 1 of GD and PHD, respectively, whereas almost one-third had attained stage 5 for both sexual characteristics. The median age for attainment of stage 2 was 11.2 years for GD, 11.5 years for PHD and 11 years for one or both of them. CONCLUSIONS: These results are in line with those for several European and industrialized countries and do not show a significantly earlier onset of sexual maturation.     

A mixed effects model to estimate timing and intensity of pubertal growth from height and secondary sexual characteristics

Aim: To estimate and compare pubertal growth timing and intensity in height, Tanner stage markers and testis volume.

Subjects and methods: Data on height, genital stage, breast stage and pubic hair stage, testis volume and menarche in 103 boys and 74 girls from the Edinburgh Longitudinal Growth Study were analysed. The SITAR model for height and a novel mixed effects logistic model for Tanner stage and testis volume provided estimates of peak velocity (PV, intensity) and age at peak velocity (APV, timing), both overall (from fixed effects) and for individuals (random effects).

Results: Based on the six markers, mean APV was 13.0–14.0 years in boys and 12.0–13.1 years in girls, with between-subject standard deviations of ～1 year. PV for height was 8–9?cm/year by sex and for testis volume 6?ml/year, while Tanner stage increased by 1.2–1.8 stages per year at its peak. The correlations across markers for APV were 0.6–0.8 for boys and 0.8–0.92 for girls, very significantly higher for girls (p?=?0.005). Correlations for PV were lower, ?0.2–0.6.

Conclusions: The mixed effects models perform well in estimating timing and intensity in individuals across several puberty markers. Age at peak velocity correlates highly across markers, but peak velocity less so.     

Sexual maturation and growth pattern in Egyptian boys

The mean ages of attainment of successive stages of puberty were estimated in a cross-sectional sample of 453 Egyptian schoolboys from a semi-urban area of Cairo, ranging in age from 9 to 17 years. The stages of puberty were as defined by Tanner (1962).

The mean age of onset of puberty (stage 2) was 11·1 years, assessed either by genitalia or by pubic hair. Stage 5 occurred at age 16·2 years, again both for genitalia and pubic hair. The time interval between these ages, 5·1 years, was 2 years longer than for British or Chinese boys.

There was a highly significant effect of social class on the mean ages of attainment, and the heights and weights of the boys were also related to social class, the class 1 boys being taller and heavier than Tanner's British boys.     

Catch‐up reproductive maturation in rural Tonga girls,Zambia?

To compare the timing of reproductive maturation among urban and rural Tonga girls in Zambia, anthropometric measures and Tanner stages of breast development were obtained. Subjects were 774 (282 rural, 492 urban) girls ages 6-18. Results indicate that rural girls are shorter and have smaller triceps and subscapular skinfolds than their urban counterparts. Median age at menarche for the entire sample, as estimated by probit analysis, was 14.8 years (95% CL = 14.34-15.40). Onset of breast development among urban girls was significantly younger than for the rural girls: 11.47 (95% CL 11.22-11.71) years vs. 13.15 (95% CL 12.40-14.15) years. In contrast, the two groups did not differ in timing of pubertal completion as assessed by median age for Tanner Breast Stage 5: 17.01 (95% CL 16.30-18.33) vs. 16.96 (95% CL 16.37-17.56) years. Predictors of pubertal onset, based on multivariate logistic regression, included dental maturation, height, and triceps skinfold. Triceps skinfold was the only significant predictor of pubertal completion. These results suggest that rural girls progress through puberty more rapidly than the urban girls despite their later start. This finding of maturational catch-up contrasts with earlier urban/rural comparisons of girls as well as previous results among Gwembe boys, for which later pubertal onset is associated with longer duration of pubertal maturation. While the mechanism remains unclear, biocultural explanations suggest preferential feeding during adolescence as a source for rural girl's maturational catch-up.     

Individual Differences in Puberty Onset in Girls: Bayesian Estimation of Heritabilities and Genetic Correlations

We report heritabilities for individual differences in female pubertal development at the age of 12. Tanner data on breast and pubic hair development in girls and data on menarche were obtained from a total of 184 pairs of monozygotic and dizygotic twins. Genetic correlations were estimated to determine to what extent the same genes are involved in different aspects of physical development in puberty. A Bayesian estimation approach was taken, using Markov-chain Monte Carlo simulation to estimate model parameters. All three phenotypes were to a significant extent heritable and showed high genetic correlations, suggesting that a common set of genes is involved in the timing of puberty in general. However, gonadarche (menarche and breast development) and adrenarche (pubic hair) are affected by different environmental factors, which does not support the three phenotypes to be regarded as indicators of a unitary physiological factor.     

Age of onset of pubertal characteristics in boys aged 6–14 years of the Province of L’Aquila (Abruzzo,Italy)

Background:?Previous results on growth patterns of children from central-southern Italy (Abruzzo region) showed an increasing tendency to obesity and suggested that the secular trend was still in progress in this region. However, data on pubertal development was lacking.

Objective:?The objective of the study was to provide population data on pubertal development in a sample of 535 boys aged 6–14 years as a contribution to the ongoing debate on earlier onset of pubertal traits and on the slowing down of the secular trend.

Methods:?A cross-sectional survey was used. Data for genital and pubic hair development (GD and PHD) were analysed by probit analysis.

Results:?The boys start developing sexual characteristics at age 9: 13.3% had entered stage 2 of GD and 8.9% showed PHD. At 13 years of age, 5% and 7.4% were still in stage 1 of GD and PHD, respectively, whereas almost one-third had attained stage 5 for both sexual characteristics. The median age for attainment of stage 2 was 11.2 years for GD, 11.5 years for PHD and 11 years for one or both of them.

Conclusions:?These results are in line with those for several European and industrialized countries and do not show a significantly earlier onset of sexual maturation.     

Age of puberty in Iranian girls living in Tehran

The aim of this study was to determine the age of appearance of secondary sexual characteristics in Iranian girls living in Tehran. A cross-sectional study was conducted between 2003 and 2004 on 1420 6-17-year-old females in different parts of Tehran. Data were collected on the basis of a multistage probability sampling. Secondary sexual characteristics were evaluated by inspection and palpation, and were recorded according to Tanner staging. The subjects were asked about the occurrence of menarche and the age of its onset. Generalized additive logistic modelling was used for the analysis of data. The median age (percentile 10-percentile 90) of Tanner 2 of breast development (B2) and Tanner 2 of pubic hair growth (P2) among 1136 girls was 9.74 years (8.23-11.94) and 10.49 years (8.86-12.17), respectively. The ages of the 2.5 percentile for B2 and P2 were 7.42 and 7.03 years, respectively, so the onset of puberty at < 7 years and 5 months is considered precocious in this population. The median age of menarche in 399 girls was 12.68 years (11.27-15.96).     

Age of puberty in Iranian girls living in Tehran

The aim of this study was to determine the age of appearance of secondary sexual characteristics in Iranian girls living in Tehran. A cross-sectional study was conducted between 2003 and 2004 on 1420 6–17-year-old females in different parts of Tehran. Data were collected on the basis of a multistage probability sampling. Secondary sexual characteristics were evaluated by inspection and palpation, and were recorded according to Tanner staging. The subjects were asked about the occurrence of menarche and the age of its onset. Generalized additive logistic modelling was used for the analysis of data. The median age (percentile 10–percentile 90) of Tanner 2 of breast development (B2) and Tanner 2 of pubic hair growth (P2) among 1136 girls was 9.74 years (8.23–11.94) and 10.49 years (8.86–12.17), respectively. The ages of the 2.5 percentile for B2 and P2 were 7.42 and 7.03 years, respectively, so the onset of puberty at <7 years and 5 months is considered precocious in this population. The median age of menarche in 399 girls was 12.68 years (11.27–15.96).     

Secular trends of growth and pubertal maturation of school children in Southern Thailand

Background: In Thailand, studies of growth date back to 1975, but there have been no studies examining any trends in increasing/decreasing growth.

Aim: To determine if there have been any secular trends of increasing/decreasing growth and/or ages at puberty in Thai children.

Methods: In 2012, a cross-sectional study of growth was conducted in 3460 children. The median heights and weights and the ages of pubertal maturation were compared with previous studies. Correlations between the secular trends and the health statistics indicators were calculated.

Results: From 1975–2012, the median final height of boys and girls had increased by 1.32 and 0.86?cm/decade and weight by 2.49 and 1.76?kg/decade, respectively. In girls, the age at thelarche and menarche had declined by 0.39 and 0.12 years/decade, respectively. In boys, the age at testicular enlargement Tanner II had declined by 0.15 years/decade. Increased physical growth was positively correlated to life expectancy, per capita income and prevalence of overweight/obesity was negatively correlated to prevalence of malnutrition and under-five mortality rate.

Conclusion: The positive secular trend towards an increase in growth and a decline in the age at onset of puberty of Thai children is correlated with improvements in overall living conditions in Thailand.     

Interrelationships of skeletal maturation, sexual development and somatic growth in man

Data on the age of attainment of various stages of puberty in some 70 girls and 100 boys of the longitudinal Harpenden Growth Study have been used to study the relation between skeletal age and sexual maturation.The variation in the skeletal ages of girls when they attained breast stages 2 and 5, pubic hair stage 3, the peak of adolescent growth spurt and 95% of their adult height was compared with the corresponding variation in their chronological ages. Only at menarche, 95% mature height and pubic hair stage 3 was skeletal age significantly less variable than chronological age.In boys at 95% of their mature height, skeletal age was significantly less variable than chronological age but no significant differences were found at genital stages 2 or 5, pubic hair stage 3, or the peak of the adolescent growth spurt.There was a positive correlation between skeletal and chronological age on reaching each stage of puberty in both sexes.The data suggest that the ossification of the skeleton in prepubertal children is independent of those maturational processes which lead to the development of the secondary sex characters.The role of skeletal age in predicting adult height is apparently not dependent upon a relationship between skeletal age and the attainment of peak height velocity but upon a more direct relationship with the percentage of growth which has been completed.     

National estimates of pubertal milestones among urban and rural Chinese boys

Aim: To provide up-to-date pubertal characteristics in a representative population of boys from both urban and rural areas of China.

Subjects and methods: The China Puberty Research Collaboration enrolled 15 011 boys of Chinese Han ethnicity aged 6.0–18.9 years in eight regions including both urban and rural areas. Stages of genital and pubic hair development were assessed by trained physicians according to the Tanner method. Testicular volume was evaluated with a Prader orchidometer.

Results: Median age for onset of testicular volume of 4 mL or greater was 11.02 years. Median age for onset of genital (G2), pubic hair development (PH2) and spermarche was 11.24 years, 12.67 years and 14.32 years, respectively. Boys with BMI ≥ 85th percentile reached the onset of TV ≥ 4 ml (11.09 years), G2 (11.34 years) and G3 (13.01 years) later than boys with a normal BMI (10.95 years, 11.1 years and 12.88 years, respectively). Urban boys achieved pubertal milestones at an earlier age than rural peers except for G5 (13.4 vs 13.76 years) and PH5 (12.86 years vs 13.14 years).

Conclusions: There is an asynchronous pattern in the onset of puberty among Chinese boys. Higher BMI is related to early pubertal onset but fast pubertal progression. Urban boys achieved onset of puberty earlier than rural boys in China.     

Pubertal development in Caracas upper-middle-class boys and girls in a longitudinal context

Changes between pubertal stages (PS) are best analyzed in a longitudinal context. A sample of 67 boys and 48 girls from the Caracas Longitudinal Study who presented data for the full range of pubertal development: genitalia (G2–G5), breast (B2–B5), pubic hair (PH2–PH5), axillary hair (AH2–AH3), and age at menarche (AM) during follow-up, were assessed at clinical examination. Medians and standard errors for ages at each stage were estimated with the logit method. For length of intervals between stages of genitalia, breast, pubic hair and axillary hair, intervals B2–M and PH2–M, survival analysis was used according to life tables and Cox regression analysis. In boys, G2 occurred at 11.61 years; in girls, B2 occurred at 10.35 years and AM at 12.55 years of age. In both sexes, length of the intervals PS 2–3 and 3–4 were approximately 1 year, while PS 4–5 was 1.5 years. Duration of puberty reached 3.7 years in boys (G2–G5) and 3.3 years in girls (B2–B5); corresponding intervals for PH2–PH5 were 3.1 and 3.0 years in boys and girls, respectively. B2–AM was 1.8 years (with a range of 0.3–3.6 years) and PH2–AM was 1.5 years (with a range 0.3–3.5 years). These results are useful for screening and monitoring: identifying abnormal pubertal patterns in subjects who are advanced or delayed with respect to their peers, together with other pubertal events such as age at peak height and weight velocity and skeletal age. Am. J. Hum. Biol. 12:88–96, 2000. © 2000 Wiley-Liss, Inc.     

Secondary sexual development of 'Cape Coloured' girls following kwashiorkor

This report describes the secondary sexual development of 45 'Cape Coloured' female ex-kwashiorkor patients and 43 female controls. All patients were originally seen between five months and four years four months of age, treated and then followed up for 15 years after discharge. Age at menarche was available on 42 ex-patients and 33 controls, and age at peak height velocity (PHV) was available for 30 ex-patients and 15 controls. Maximum likelihood estimates of the mean age at entry to each pubertal stage were made, age at menarche was obtained directly from the subject records and age at PHV was obtained by fitting a non-linear growth function to the data for each subject. All subjects passed through the sequence of pubertal events in the normal order, i.e., no reversals were observed. Ex-patients were generally delayed in relation to controls but there were no significant differences for ages at entry to any of the pubertal stages. The subjects were combined for comparison to equivalent data on British girls. The South African girls were significantly delayed in the development of pubic hair and menarche but showed no significant differences for age at entry or duration of breast development and PHV. It is suggested that lack of delay in breast development may have selective advantages to females living in situations of chronic malnutrition.     

Human puberty: salivary melatonin profiles in constant conditions

This analysis examined the relative contributions of sex, age, body mass index (BMI), and puberty (Tanner) stage on salivary melatonin amplitude. Sixty-nine children and adolescents (30 females; 9.6-17.8 years) were examined for Tanner stage. Serial salivary melatonin samples were collected in controlled conditions, from which these melatonin amplitude measures were derived: area under the curve (AUC) and maximum value (MAX). AUC declined with advancing Tanner stage. This melatonin decline was similar between boys and girls, but girls secreted more melatonin compared to boys. Tanner stage and sex explained AUC variability, but age and BMI did not; similar results emerged for MAX. These results indicate that puberty stage may either mediate the decline of melatonin, or the decrease in melatonin amplitude may be an indicator of pubertal progression. These findings also indicate that the melatonin decline during puberty is not entirely accounted for by body mass or by age.     

Serum dehydroepiandrosterone sulphate and pubertal development in Chinese girls

Serum dehydroepiandrosterone sulphate (DHEAS), estradiol (E2), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by radioimmunoassay in 170 healthy school girls from 7–16 years old. Blood samples from postmenarcheal girls were taken on days 6–10 of the menstrual cycle. Bone age, height, weight, breast and pubic hair development were also investigated. Of the four hormones measured, serum DHEAS displayed the earliest elevation, at 7 years and upwards. A significant DHEAS increment at chronological age 13 years was observed. Girls with earlier menarche had higher DHEAS level than girls having later menarche. Serum DHEAS levels also correlated with bone age, height, weight, subcutaneous fat and pubertal stages. The results suggest that adrenal androgen might be involved in the initiation of puberty and female maturation.     

Serum dehydroepiandrosterone sulphate and pubertal development in Chinese girls

Serum dehydroepiandrosterone sulphate (DHEAS), estradiol (E2), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by radioimmunoassay in 170 healthy school girls from 7-16 years old. Blood samples from postmenarcheal girls were taken on days 6-10 of the menstrual cycle. Bone age, height, weight, breast and pubic hair development were also investigated. Of the four hormones measured, serum DHEAS displayed the earliest elevation, at 7 years and upwards. A significant DHEAS increment at chronological age 13 years was observed. Girls with earlier menarche had higher DHEAS level than girls having later menarche. Serum DHEAS levels also correlated with bone age, height, weight, subcutaneous fat and pubertal stages. The results suggest that adrenal androgen might be involved in the initiation of puberty and female maturation.     

Trends in pubertal development in Europe

The secular changes in growth and maturation can be seen as indicators of socio-economic and health status. In most European countries the age of onset of puberty and of menarcheal age has been decreasing during the past few decades. The duration of puberty seems also to decrease, though few studies provide sufficient data to support this postulation. The four Dutch nationwide growth surveys are useful examples assessing the secular trend in pubertal development over the past 45 years. Genetic and environmental factors contribute to the secular changes. Environmental factors seem to be the most important. Recently, attention has been given to substances with oestrogen-like actions that are present in nutrients. The possible role of these substances in growth and maturation is discussed.