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 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.     

Longitudinal estimates of puberty timing in Senegalese adolescent girls.

This study aimed to assess the timing of sexual maturation (breast development and menarche occurrence) among sub-Saharan African adolescent girls from rural areas. In the framework of a longitudinal study of growth at puberty, the stages of pubertal development (Tanner classification) and menarche occurrence were recorded at intervals between 1995 and 2000 in a sample of 406 Senegalese adolescent girls from a rural area. Nutritional status was estimated during infancy, childhood, and adolescence within this sample, and body composition was estimated only during adolescence. At the beginning of the study (1995), the adolescent girls were 11.4 years old (SD = 0.6). At the end of the study, they were 16.5 years old (SD = 0.6). Median and quartile ages at entry into each maturity stage and its confidence limits were estimated by a lognormal parametric survival model. These adolescent girls were shorter and thinner than girls of the same age from developed countries. Median age at the onset of breast development was 12.6 years (95% CI = 12.5-12.8). Median age at the end of sexual maturation and median age at menarche were estimated respectively at 15.8 years (95% CI = 15.7-15.9) and 15.9 years (95% CI = 15.7-15.9). These adolescent girls were less mature than other adolescent girls of the same age from other developing countries. Their puberty was extremely delayed compared to that of adolescent girls of the same age from industrialized countries. Puberty in these Senegalese adolescent girls is delayed by about 3 years. This may be due to malnutrition, significant energy expenditure, and poor diet and living conditions, and possibly to genetic control.     

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.     

Inhibin A and B in adolescents and young adults with Turner's syndrome and no sign of spontaneous puberty

BACKGROUND: The aim of this study was to assess levels of inhibin A and B, FSH and LH in Turner's syndrome (TS) without signs of spontaneous ovarian activity. METHODS: Twenty-four girls with TS (median age, 14.7 years) without signs of spontaneous ovarian function were included in the study. Sixty prepubertal girls (PPG) (10.3 years) that had not yet experienced menarche (all Tanner stage 1), and 34 pubertal girls (PG) (13.8 years) (Tanner stage 3-4), who were regularly menstruating, served as controls. The levels of inhibin A and B, FSH, LH, and pubertal stage were determined. RESULTS: Inhibin A was not detected in females with TS, or in almost all PPG (59 of 60) (P = not significant), and inhibin B in TS females, while most PPG produced inhibin B (53 of 60, P < 0.0005). FSH and LH were elevated in TS, but with overlapping values. In follow-up samples in TS, three of twenty-four females showed detectable levels of inhibin A and/or B. In one of these, 6 serial samples were available. At 20 years this patient had a high level of LH and FSH, which declined, and concurrently inhibin A and inhibin B rose, only later to decrease, when FSH and LH started to rise again. In comparison with PG baseline levels of inhibin A and B were lower in TS, with inhibin A detectable in 23 of 34, and inhibin B detectable in 32 of 34 PG. Levels of FSH and LH were also different, although with overlapping values. CONCLUSION: The result raises the possibility that functional or partly functional ovaries are present in some females with TS, without apparent menstrual cycling.     

Age at menarche: Relationships to socioeconomic status,growth rate in stature and weight,and skeletal and sexual maturation

A sample of 114 girls from low-middle and highest socioeconomic levels of Istanbul were followed at 6-month intervals for 7–9 years during adolescence. Results pertaining to age of menarche and its relationship to growth and maturation are presented. No significant difference was found for the occurrence of menarche in relation to season. The age of menarche was 6.6 months earlier in daughters compared to their mothers, but the variation between mothers and daughters was great. In the lower socioeconimic class, age of menarche was significantly later, 12.5 years in the high and 13.4 years in the lower class. Later menarche in the lower class was related to lower rates of growth in stature and weight, and of skeletal and sexual maturation. There was no significant correlation between age at menarche and stature and weight attained at menarche. Those with a faster rate of growth reached menarche early and the height velocity continued to be faster. The median stages of secondary sexual characteristics at menarche were 4 for breast and pubic hair, and 3 for axillary hair. The stage of development at menarche did not differ significantly with age of menarche and social class. Menarche occurred 2.4 years after the appearance of pubic hair, 2.0 years after the appearance of the breast bud, and 1.4 years after the appearance of axillary hair, and the ages at which the secondary sexual characters appeared correlated significantly with the age of menarche. Skeletal age at menarche was 13.0 ± 0.69 years. Age of menarche correlated best with the age at which fusion of the second and first distal phalanges occurred. The percentage of adult height attained at menarche correlated significantly with the age of menarche. Regression equations and standard errors are presented to aid in the prediction of the age at menarche from other variables related to menarche.     

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.     

Age of puberty: data from the United States of America

In an attempt to determine whether the secular trend toward an earlier onset of puberty has continued over recent decades in the United States of America, published reports concerning the age of attainment of pubertal events have been reviewed. Such reports are very limited and vary in both design and inclusive ages of study subjects. Among females, two recent large cross-sectional studies indicate that fifty percent of females in the United States attain Tanner breast stage 2 at 9.5 to 9.7 years of age. This is younger than previously thought, although adequate earlier studies of girls in the United States are not available for comparison. These two studies also indicate that about 14% of girls attain Tanner stage 2 while 8 years of age; one study extends earlier reporting that about 6% exhibit onset of breast development while 7 years of age. There is no evidence that the age of menarche or the attainment of adult (Tanner 5) breast development has decreased over the past 30 years. The data also suggest an earlier onset of Tanner stage 2 pubic hair but no change in attainment of stage 5. Among males, pubic hair may be appearing at younger ages, but data are inadequate or too inconsistent to allow firm interpretation. The lack of standardization of genital criteria of pubertal onset in the male makes any conclusions regarding secular trends impossible. In summary, earlier secular trends over recent decades related to better health, improved nutrition or socio-economic status, or any putative influence by endocrine disrupters cannot be verified.     

Age at menarche in Peruvian girls at sea level and at high altitude: Effect of ethnic background and socioeconomic status

The objective of the present study was to determine median age at menarche using the status quo method and the independent effects of ethnic background and socioeconomic status on the age at menarche in Peruvian girls from two distinct levels at altitude: Lima (150 m) and Cerro de Pasco (4,340 m). The sample included 503 girls from Lima and 625 girls from Cerro de Pasco, ages 10–18 years. Ethnic background was determined by four parental surnames. Subjects were classified as Quechua when one or more surnames were from Quechua origin and Spanish when four surnames were from Spanish origin. Socioeconomic status was determined using a socioeconomic index score and subjects were classified as belonging to the middle-low, low, or very low class. Median age at menarche was calculated by survival analysis using the Life Table Method with a 95% Confidence Interval (CI). Among Quechua and Spanish girls, age at menarche occurred later at high altitude than at sea level. Median ages at menarche for the overall groups were 13.08 (12.91–13.25, 95% CI) years in Lima and 14.33 (14.17–14.48, 95% CI) years in Cerro de Pasco (P < 0.0001). Socioeconomic status had no significant effect on menarcheal age (P > 0.05). Controlling socioeconomic status in the design, median age at menarche was still higher at high altitude than at sea level (P < 0.05). After logistic regression analysis, an effect on age at menarche of chronological age and place of residence was observed, but not by ethnic background, socioeconomic status and not by interactions of age and place of residence, age and socioeconomic status, place of residence and socioeconomic status, place of residence and ethnic background, or socioeconomic status and ethnic background. Thus later age at menarche observed in girls at high altitude is not due the differences in ethnicity or socioeconomic status. © 1996 Wiley-Liss, Inc.     

Changes in menarcheal age in girls exposed to war conditions

The purpose of this study was to assess changes in mean menarcheal age of girls in the city of Šibenik in the period from mid-1980s to the mid-1990s. Šibenik is a Dalmatian town which was exposed to hard war conditions in 1991–1995. Menarcheal status of Šibenik girls was surveyed three times, in 1981, 1985, and 1996, and included 720, 1,207, and 1,680 girls, respectively, ages 9.5–16.5 years. Mean menarcheal age was estimated by the status quo method and application of probit analysis. Results show a slight decrease in menarcheal age from 1981 to 1985 (from 12.97 ± 0.06 years to 12.87 ± 0.05), and then a significant increase from 12.87 ± 0.05 years in 1985 to 13.13 ± 0.10 years in 1996. The increase in mean menarcheal age occurred in all socioeconomic groups based on parental occupation and number of siblings. In the group of girls whose homes were damaged during war, menarche occurred at an average of 13.53 ± 0.14 years, while those who lost a family member experienced menarche at an older mean age, 13.76 ± 0.27 years. However, when the girls who experienced personal tragedies were excluded the onset of menarche was still later than in girls surveyed in the earlier periods. The results suggest that the general reversal in the secular trend of menarcheal age in Šibenik girls can be attributed to persistent psychological pressures and uncertainties associated with conditions of war. Am. J. Hum. Biol. 12:503–508, 2000. © 2000 Wiley-Liss, Inc.     

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.     

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.     

Growth status and menarche in urban and rural China

OBJECTIVE: To examine the relationship between current age at menarche and growth status in an urban and rural area of Eastern China. Study design: Cross-sectional survey: self-completion questionnaire and anthropometry in 12 schools in urban Hangzhou and rural Chunan in Zhejiang Province. RESULTS: The median menarcheal age calculated by probit analysis was significantly different in the two areas: 12.8 years (SD 0.9) in the urban area and 13.2 (SD 1.0) in the rural area (p < 0.001). Girls who reach menarche are significantly heavier and taller with higher BMIs than those of the same age who are pre-menarche. After adjustment for BMI and other possible confounders, urban girls were still menstruating significantly earlier than girls in rural areas (OR 3.3, 2.1-5.2). CONCLUSIONS: The age of menarche is probably still declining in China. Although BMI is an important factor in the onset of menstruation, some other unmeasured environmental variable may be implicated in this population.     

Growth status and menarche in urban and rural China

Objective : To examine the relationship between current age at menarche and growth status in an urban and rural area of Eastern China. Study design : Cross-sectional survey: self-completion questionnaire and anthropometry in 12 schools in urban Hangzhou and rural Chunan in Zhejiang Province. Results : The median menarcheal age calculated by probit analysis was significantly different in the two areas: 12.8 years (SD 0.9) in the urban area and 13.2 (SD 1.0) in the rural area ( p < 0.001). Girls who reach menarche are significantly heavier and taller with higher BMIs than those of the same age who are pre-menarche. After adjustment for BMI and other possible confounders, urban girls were still menstruating significantly earlier than girls in rural areas (OR 3.3, 2.1-5.2). Conclusions : The age of menarche is probably still declining in China. Although BMI is an important factor in the onset of menstruation, some other unmeasured environmental variable may be implicated in this population.     

Age at menarche of schoolgirls in Maputo,Mozambique

Age at menarche was analysed in 753 Mozambican schoolgirls taking part in across-sectional anthropometric study in Maputo, Mozambique, in 2000. The probit analysis of the status quo data yielded an median age at menarche of 13.20 +/- 1.18 years. The retrospective method was applied only to recall data of the 396 post-menarcheal girls and it yielded an average of 13.91 +/- 1.29 years. Mean age at menarche in girls living in the urban centre of Maputo was 13.35 and 12.96 years, for recall age and probit analysis, respectively, and 14.51 and 13.68 years for girls living in the slums surrounding the centre. The differences in age at menarche, calculated by recall method, between girls from central Maputo and girls from the slums were statistically significant (p = 0.000). Parent's educational level also revealed a significant effect on age at menarche. Girls whose parents had a lower educational level showed a later age at menarche. For the size of the family, girls who were later borne had a higher age at menarche. In the 1960s, the age at menarche was 13.55 and 13.83 years in urban and rural girls, respectively. In this study, we found a lack of decrease in the mean age at menarche (13.9 years), which could be due to the poor living conditions in Mozambique between 1960 and 2000 as a result of the civil war from 1976 to 1990. Despite the economic growth of the country in the last decade, Mozambique is still in the group of the poorest countries in the world; in spite of this fact, the mean menarcheal age in these girls are amongst the lowest values presented for African countries.     

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.     

Age at menarche in deaf girls

Using the status quo and retrospective methods, age at menarche was estimated for a sample of 212 deaf girls 7 through 20 years of age. Median age at menarche via probit analysis was 11·91 ± 0·25 years, while the mean based on recalled age in older girls (≥ 15·5 years) was 12·56 ± 0·16 years. These two estimates thus differ by approximately 0·6 years. The probit estimate of median age at menarche in deaf girls is similar to mean ages reported for blind girls. However, the retrospective age is later. Thus, the present data are inconclusive as to whether the sensory deprivation imposed by deafness has an accelerating effect on menarche similar to that hypothesized for light deprivation in blind girls.     

Age of menarche and nutritional status of indigenous and non-indigenous adolescents in the Araucanía Region of Chile

Abstract

Background: Early onset of menarche has been linked to prevalence of obesity; however, this may differ for indigenous females.

Objective: To analyse the relationship between age of menarche and nutritional status among indigenous and non-indigenous girls.

Method: The design of this study was cross-sectional. Date of menarche was determined through interviews, and all responses were confirmed by the girls' mothers. A total of 8504 adolescents were screened for recent menarche. One hundred and thirty-one girls of Mapuche (indigenous) and 143 girls of Chilean–Spanish background were identified and evaluated by anthropometric measurements.

Results: Median age of menarche was 150 months, interquartile range (IR) 143–157 in indigenous, and 145.5 months, IR 139–153 in non-indigenous girls (p = 0.04). The indigenous females showed a higher prevalence of overweight (36.4% vs 23.1%), although the frequency of obesity was similar (16.8% vs 16.3%). For indigenous girls, age of menarche was delayed by 2.69 months (confidence intervals (CI) –0.38 to 5.77). It was observed that girls with overweight experienced age of menarche 7.59 months earlier than those with normal weight, CI –10.78 to –4.41. In the analysis of obesity, the effect on age of menarche was similar, with onset 7.53 months earlier than for the normal weight, CI –11.34 to –3.72.

Conclusion: Age of menarche is younger than has been previously reported and occurs earlier in girls with overweight and obesity, while being indigenous was not related.     

Combined estrogen receptor alpha and estrogen receptor beta genotypes influence the age of menarche

BACKGROUND: Age at menarche has a strong genetic influence. We reported recently an association between the XbaI (351A-->C)and PvuII (397T-->C) polymorphisms of the estrogen receptor (ER)alpha gene with the age of menarche in Greek adolescents. In the present study, we examined whether ERbeta genotypes alone, or in combination with ERalpha genotypes, may also influence onset of menarche. METHODS: We performed genotyping for the single nucleotide polymorphisms 1730A-->G and 1082G-->A of the ERbeta gene and examined their association with the age of menarche in the same cohort of 145 Greek girls. We then looked for a possible effect of combined ERalpha and beta genotypes on the age of menarche. RESULTS: Menarche occurred 7 months later in girls with the AA genotype of the 1730A-->G polymorphism than in girls with the AG genotype (mean +/- SD: 13.23 +/- 1.24 versus 12.66 +/- 1.26 years, respectively; P = 0.005). The 1082G-->A polymorphism was not detected in any of the girls examined. A significant effect of combined ERalpha and beta genotypes was also apparent. Menarche occurred 11 months later in girls bearing the AA/TT,AA (ERalpha, ERbeta) genotypes compared with girls with the CC/CC,AG genotype (13.30 +/- 1.27 nersus 12.41 +/- 1.28 years; P = 0.042). The difference remained significant after adjusting for body mass index (P = 0.034). CONCLUSION: Combined ERalpha and ERbeta polymorphisms may influence the age of menarche.     

Height, weight and menarcheal age of adolescent girls in Oman

A cross-sectional survey was carried out on 683 school girls aged 11.5-18.5 years in Oman, in order to assess their physical growth. Height, weight and age at menarche were measured. Results showed that median height and weight of Omani girls fluctuates between 25th and 5th percentiles and 25th and 10th percentiles of the North American reference standard (NCHS), respectively. The mean age at menarche was 13.3 +/- 0.09 years. In general Omani girls are shorter and lighter than girls of similar age in other Arabian Gulf countries (Bahrain and Kuwait).