Weight and age at menarche

Psychosocial and energetic factors on human female pubertal timing: a systematized review

Childhood psychosocial stressors have been proposed to favour fast life history strategies promoting earlier puberty in females. However, studies demonstrating this association often do not elucidate causal mechanisms, nor account for greater childhood energetic availability - also known to promote rapid growth and earlier puberty. To assess the extent to which such confounding has been considered, we conducted a systematized review to identify studies examining measures of both prepubertal growth (e.g. weight, height) and psychosocial stressors (e.g. adversity, father absence) in relation to female pubertal timing. A total of 1069 non-duplicated studies were identified across five databases. Twenty studies met selection criteria for critical review following independent screening of titles, abstracts and manuscripts. Within these studies, measures indicative of rapid childhood growth were more consistently associated with earlier pubertal timing than were measures of psychosocial stress. We discuss future research directions to investigate the impact of psychosocial stress on pubertal timing more robustly, including methodological and mechanistic considerations, and contextualization of findings by socioecological environments.

Impact of reproductive factors on breast cancer incidence: Pooled analysis of nine cohort studies in Japan

Prior studies reported the association of reproductive factors with breast cancer (BC), but the evidence is inconsistent. We conducted a pooled analysis of nine cohort studies in Japan to evaluate the impact of six reproductive factors (age at menarche/age at first birth/number of births/age at menopause/use of female hormones/breastfeeding) on BC incidence. We conducted analyses according to menopausal status at the baseline or at the diagnosis. Hazard ratio (HR) and 95% confidence interval (CI) were estimated by applying Cox proportional-hazards model in each study. These hazard ratios were integrated using a random-effects model. Among 187,999 women (premenopausal: 61,113, postmenopausal: 126,886), we observed 873 premenopausal and 1,456 postmenopausal cases. Among premenopausal women, use of female hormones significantly increased BC incidence (HR: 1.53 [1.04-2.25]). Although P value for trend was not significant for age at first birth and number of births (P for trend: 0.15 and 0.30, respectively), women giving first birth at ages ≥36 experienced significantly higher BC incidence than at ages 21-25 years, and women who had ≥2 births experienced significantly lower BC incidence than nulliparous women. Among postmenopausal women, more births significantly decreased BC incidence (P for trend: 0.03). Although P value for trend was not significant for age at first birth and age at menopause (P for trend: 0.30 and 0.37, respectively), women giving first birth at ages 26-35 years experienced significantly higher BC incidence than at ages 21-25 years, and women with age at menopause: ≥50 years experienced significantly higher BC incidence than age at menopause: ≤44 years. BC incidence was similar according to age at menarche or breastfeeding history among both premenopausal and postmenopausal women. In conclusion, among Japanese women, use of female hormones increased BC incidence in premenopausal women, and more births decreased BC incidence in postmenopausal women.

The Effect of Bisphenol A on Puberty: A Critical Review of the Medical Literature

Many scientific studies have revealed a trend towards an earlier onset of puberty and have disclosed an increasing number of children that display precocious puberty. As an explanation, some authors have considered the global socio-economic improvement across different populations, and other authors have considered the action of endocrine disrupting chemicals (EDCs). Among these, bisphenol A (BPA), an aromatic compound largely used worldwide as a precursor of some plastics and chemical additives, is well known for its molecular oestrogen-like and obesogenic actions. We reviewed the medical literature of the previous 20 years that examined associations between BPA exposure and the age of puberty in humans, considering only those referring to clinical or epidemiological data. Of 19 studies, only 7 showed a correlation between BPA and puberty. In particular, the possible disruptive role of BPA on puberty may be seen in those with central precocious puberty or isolated premature breast development aged 2 months to 4 years old, even if the mechanism is undefined. Some studies also found a close relationship between urinary BPA, body weight, and early puberty, which can be explained by the obesogenic effect of BPA itself. The currently available data do not allow establishment of a clear role for BPA in pubertal development because of the conflicting results among all clinical and epidemiological studies examined. Further research is needed to fully understand the potential role of exposure to EDCs and their adverse endocrine health outcomes.

The mystery of puberty initiation: genetics and epigenetics of idiopathic central precocious puberty (ICPP)

Puberty is a major developmental stage. Damaging mutations, considered as "mistakes of nature", have contributed to the unraveling of the networks implicated in the normal initiation of puberty. Genes involved in the abnormal hypothalamic-pituitary-gonadal (HPG) axis development, in the normosmic idiopathic hypogonadotropic hypogonadism (nIHH), in the X-linked or autosomal forms of Kallmann syndrome and in precocious puberty have been identified (GNRH1, GNRHR, KISS1, GPR54, FGFR1, FGF8, PROK2, PROKR2, TAC3, TACR3, KAL1, PROK2, PROKR2, CHD7, LEP, LEPR, PC1, DAX1, SF-1, HESX-1, LHX3, PROP-1). Most of them were found to play critical roles in HPG axis development and regulation, the embryonic GnRH neuronal migration and secretion, the regulation and action of the hypothalamic GnRH. However, the specific neural and molecular mechanisms triggering GnRH secretion remain one of the scientific enigmas. Although GnRH neurons are probably capable of autonomously generating oscillations, many gonadal steroid-dependent and -independent mechanisms have also been proposed. It is now well proven that the secretion of GnRH is regulated by kisspeptin as well as by permissive or opposing signals mediated by neurokinin B and dynorphin. These three supra-GnRH regulators compose the kisspeptin-neurokinin B-dynorphin neuronal (KNDy) system, a key player in pubertal onset and progression. Moreover, an ongoing increasing number of inhibitory, stimulatory and permissive networks acting upstream on GnRH neurons, such as GABA, NPY, LIN28B, MKRN3 and others integrate diverse hormonal and peripheral signals and have been proposed as the "gate-keepers" of puberty, while epigenetic modifications play also an important role in puberty initiation.

Timing of menarche in Norwegian girls: associations with body mass index, waist circumference and skinfold thickness

Background

Research studies show conflicting results regarding the association between menarche and body weight. The purpose of the present study was to investigate if anthropometric indicators of body composition, body mass index (BMI), waist circumference (WC), triceps (TSF) and subscapular skinfold (SSF) thicknesses, were differentially associated with age at menarche in Norwegian girls.

Methods

The association between menarche and BMI, WC, TSF and SSF was investigated in 1481 girls aged 8–15.5 years, and in a subgroup of 181 girls with menarche during the 12 months prior to examination. Anthropometric measures were categorized as low (< −1SDS), average (−1 ≤ SDS ≤ +1) or high (> 1SDS), and menarche according to this classification was analysed with Kaplan-Meier curves and unadjusted and adjusted Cox regression.

Results

The median age at menarche in the total sample was 13.1 years. In the unadjusted models, low categories of all traits were associated with later menarche, and high categories with earlier menarche. When adjusted for other covariates, earlier menarche was only related with a high BMI (Hazard Ratio 1.41, 95% confidence interval (CI) 1.07, 1.85), and later menarche with a low BMI (HR 0.53, 95%CI 0.38, 0.75) and low SSF (HR 0.54, 95%CI 0.39, 0.75). In girls with recent menarche, early menarche was significantly associated with a high BMI in the final model (HR 1.79, 95%CI 1.23, 2.62).

Conclusions

The timing of menarche was associated with the BMI, WC, TSF and SSF, but more strongly so with the BMI. These associations may be related to a common tempo of growth, as the mean age at menarche has remained stable during the last decades during a time period while the prevalence of overweight and obesity has increased significantly.

The Long-Term Cognitive and Socioeconomic Consequences of Birth Intervals: A Within-Family Sibling Comparison Using Swedish Register Data

We examine the relationship between birth-to-birth intervals and a variety of mid- and long-term cognitive and socioeconomic outcomes, including high school GPA, cognitive ability, educational attainment, earnings, unemployment status, and receiving government welfare support. Using contemporary Swedish population register data and a within-family sibling comparison design, we find that neither the birth interval preceding the index person nor the birth interval following the index person are associated with any substantively meaningful changes in mid- or long-term outcomes. This is true even for individuals born before or after birth-to-birth intervals of less than 12 months. We conclude that in a contemporary high-income welfare state, there appears to be no relationship between unusually short or long birth intervals and adverse long-term outcomes.

Earlier age at menarche in girls with rapid early life growth: cohort and within sibling analyses

PURPOSE

The purpose of the article was to examine the association of early life growth with age at menarche.

METHODS

Using data from a prospective birth cohort (n = 1134 women, 290 sibling sets), we assessed the association between postnatal growth at 4 months, 1 year, and 4 years and age at menarche, using generalized estimating equations and generalized linear random effects models.

RESULTS

Overall, 18% of the cohort experienced early menarche (<12 years). After accounting for postnatal growth in length, faster postnatal change in weight (per 10-percentile increase) in all three periods was associated with an increase (range 9%-20%) in the likelihood of having an early menarche. In adjusted linear models, faster weight gains in infancy and childhood were associated with an average age at menarche that was 1.1-1.3 months earlier compared with stable growth. The overall results were consistent for percentile and conditional growth models. Girls who experienced rapid growth (defined as increasing across two major Centers for Disease Control and Prevention growth percentiles) in early infancy had an average age at menarche that was 4.6 months earlier than girls whose growth was stable.

CONCLUSIONS

Faster postnatal weight gains in infancy and early childhood before the age of 4 years are associated with earlier age at menarche.

Correlation of body mass index levels with menarche in adolescent girls in Shaanxi, China: a cross sectional study

Background

Menarche is a milestone for adolescent girls. The timing of menarche is influenced by genetics, social status and nutritional status (e.g., height, weight and body mass index [BMI]) and impacts future health (e.g., obesity and breast cancer). There have been many studies on trends in age at menarche among adolescent girls in China, but few have investigated associations between growth status and the timing of menarche. This study examined the association between age at menarche and growth status among adolescent girls in Western China.

Methods

The participants in this cross sectional study came from three geographical regions of Shaanxi Province. A total of 533 adolescent girls from urban and rural areas were randomly selected. Trained investigators administered a standard questionnaire to each participant during a face-to-face interview and carried out anthropometric measurements.

Results

The average age at menarche was 13.3 years. There were statistically significant differences in BMI z-scores between pre-menarcheal and post-menarcheal girls of the same age and these differences were related to socioeconomic factors. Girls who had reached menarche, in particular those aged 13–14 years, were significantly taller (P < 0.01) and had higher BMI (P < 0.01) than girls in the same age group who had not reached menarche.

Conclusions

BMI is associated with the timing of menarche but socioeconomic factors are also important.

A new childhood asthma phenotype: obese with early menarche

Three concomitant phenomena occur in the later years of childhood: increases in the incidence of asthma, obesity and early menarche. This article is an overview of the current epidemiologic, basic, genetic and epigenetic evidence about this relationship. As a consequence we propose that obese girls who have an early menarche (≤ 11 years of age) constitute a new asthma phenotype in childhood. Future studies need to be carried out in order to find the best control and treatment of this new asthma phenotype.

Long-term secular trends in the age at menarche in Israel: a systematic literature review and pooled analysis

BACKGROUND/AIMS

A worldwide decline in the age at menarche (AAM) has been reported in recent decades. This trend has been also clinically observed among Israeli women and was reported in our previous study.

METHODS

We reviewed the literature reporting the mean AAM in Israel during the past century. Studies were excluded if participants had been investigated due to illness or any condition which could affect sexual maturation. Mean AAM was analyzed using a simple linear regression weighted for number of participants in each birth cohort and stratified to birth cohorts before and after 1970, based on the outcome of our previous study.

RESULTS

AAM varied little among women born between 1875 and 1970, but there was a clear downwards trend from 13.4 in 1970 to 12.8 two decades later. In a stratified analysis we found a significant negative association between birth year and AAM in the birth cohort after 1970 (standardized β coefficient = -0.94 per year, R(2) = 0.87; p < 0.001).

CONCLUSION

These results suggest a significant decline in mean AAM in Israeli women born in 1970 or later.

Nongenetic determinants of age at menarche: a systematic review

BACKGROUND

The acceleration of pubertal development is an important medical and social problem, as it may result in increased morbidity and mortality in later life. This systematic review summarizes relevant data about nongenetic factors, which contribute to age at menarche (AAM), and suggests those which may be the most important.

METHODS

The available literature from 1980 till July 2013 was searched using PubMed and Google Scholar databases. Finally, 154 papers were selected for the analysis.

RESULTS

Environmental factors, which may affect AAM, vary in populations of different ethnicity. The prenatal, infancy, and early childhood periods are the most susceptible to these factors. Body weight, high animal protein intake, family stressors (e.g., single parenting), and physical activity seem to influence AAM in most populations.

CONCLUSIONS

The data about influence of nongenetic factors on AAM are still inconsistent. The factors affecting prenatal and early childhood growth seem to have a larger effect on further sexual maturation. Further studies are needed in order to validate the association between other environmental determinants and AAM in different ethnical groups.

Gonadal dysfunction in morbidly obese adolescent girls

OBJECTIVE

To describe gonadal dysfunction and evaluate polycystic ovary syndrome (PCOS) and its association with metabolic syndrome (MeS) among girls in a morbidly obese adolescent population.

DESIGN

In a cross-sectional study of 174 girls, height, weight, waist circumference, Tanner stage, reproductive hormones, carbohydrate and lipid markers, drug use, and menstrual history were obtained at baseline. Exclusion criteria were menarcheal age <2 years, hormonal contraceptive or metformin use, Tanner stage <4, and incomplete data on PCOS or MeS classification.

SETTING

University medical center outpatient clinic.

PATIENT(S)

Ninety-eight girls ages 13-19.6 years, Tanner 5, average body mass index of 46.6 kg/m(2), menarche at 11.4 years, and average menarcheal age of 5 years.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Polycystic ovary syndrome and MeS.

RESULT(S)

Ninety-eight girls were divided into four groups: PCOS by National Institutes of Health criteria (PCOSN, n = 24), irregular menses only (n = 25), elevated T (≥55 ng/dL) only (n = 6), and obese controls (n = 43). Metabolic syndrome by modified Cook criteria affected 32 girls or 33% overall: 6 of 24 PCOSN, 7 of 25 irregular menses only, 4 of 6 elevated T only, and 15 of 43 obese controls. Polycystic ovary syndrome by National Institutes of Health criteria and its individual components were not associated with MeS after adjusting for body mass index.

CONCLUSION(S)

Unlike obese adults, PCOSN and its individual components were not associated with MeS in the untreated morbidly obese adolescent population.

Clinical review: Lifecycle of polycystic ovary syndrome (PCOS): from in utero to menopause

CONTEXT

Polycystic ovary syndrome (PCOS) is diagnosed during the reproductive years when women present with 2 of 3 of the following criteria: 1) irregular menstrual cycles or anovulation, 2) hyperandrogenism, and 3) PCO morphology. However, there is evidence that PCOS can be identified from early infancy to puberty based on predisposing environmental influences. There is also increasing information about the PCOS phenotype after menopause. The goal of this review is to summarize current knowledge about the appearance of PCOS at different life stages and the influence of reproductive maturation and senescence on the PCOS phenotype.

EVIDENCE

PubMed, the bibliography from the Evidence-Based PCOS Workshop, and the reference lists from identified manuscripts were reviewed.

EVIDENCE SYNTHESIS

The current data suggest that daughters of women with PCOS have a greater follicle complement and mild metabolic abnormalities from infancy. PCOS is often diagnosed in puberty with the onset of hyperandrogenism and may be preceded by premature pubarche. During the reproductive years, there is a gradual decrease in the severity of the cardinal features of PCOS. Menopausal data suggest that the majority of women who had PCOS during their reproductive years continue to manifest cardiovascular risk factors. However, the majority do not present an increased risk for cardiovascular morbidity and mortality, perhaps because women with no history of PCOS may catch up after menopause.

CONCLUSION

The current data provide a comprehensive starting point to understand the phenotype of PCOS across the lifespan. However, limitations such as a bias of ascertainment in childhood, age-based changes during reproductive life, and the small numbers studied during menopause point to the need for additional longitudinal studies to expand the current knowledge.

Environmental and genetic factors influence age at menarche in women with polycystic ovary syndrome

OBJECTIVE

We hypothesized that body mass index (BMI) and DNA variants would predict age at menarche in polycystic ovarian syndrome (PCOS).

SUBJECTS

Subjects aged 18-45 years with PCOS defined by the National Institutes of Health criteria (n=522) and controls with regular menstrual cycles and no hyperandrogenism (n=472) were studied.

METHODS

Age at menarche was compared between PCOS cases and controls and examined as a function of multiple parameters.

RESULTS

There was a strong inverse relationship between BMI and age at menarche in PCOS (r=-0.32, p=5 x lO(-11)). The chromosome 6 rs7759938-T variant was associated with earlier age at menarche in women with PCOS (12.60 +/- 0.09 vs. 13.41 +/- 0.23 years; genotype TT vs. CC; p = 0.006). Age at menarche was predicted by PCOS status (beta = 0.512, p < 0.001), reported weight group at 10-14 years (beta = -0.432, p < 0.001), current BMI (beta = -0.0202, p = 0.01), and genotype (beta = 0.169, p = 0.02).

CONCLUSIONS

Age at menarche in women with PCOS is influenced by BMI and genetic variants near LIN28B.

Growth status and menarcheal age among adolescent school girls in Wannune, Benue State, Nigeria

BACKGROUND

Menarcheal age is a sensitive indicator of environmental conditions during childhood. The aim of study is to determine the age at menarche and growth status in adolescents in a rural area of Tarka, Wannune, Nigeria.

METHODS

Data on 722 female students (aged 12-18 years) were collected in February 2009. Height and weight were measured. Body mass index (BMI; kg m-2) was used as an index of relative weight.

RESULTS

Mean and median menarcheal age calculated by probit analysis were 13.02 (SD 3.0) (95% CI: 13.02-13.07), and age 13.00 (SD 2.8) (95% CI: 12.98-13.04), respectively. Girls who reach menarche are significantly heavier and taller with higher BMIs than those of their pre-menarcheal peers.

CONCLUSION

The age of menarche is probably still declining in Nigeria. Although BMI is an important factor in the onset of menstruation, some other unmeasured environmental variables may be implicated in this population.

Growth, body composition, and the onset of puberty: longitudinal observations in Afro-Caribbean children

CONTEXT

Childhood growth and body composition may influence the onset of puberty.

OBJECTIVE

We examined the effects of birth size, growth rates throughout childhood, and body composition on the onset of puberty in Afro-Caribbean children.

DESIGN AND SETTING

This was a longitudinal birth cohort study (the Vulnerable Windows Cohort Study) in Jamaica.

SUBJECTS AND MEASUREMENTS

The anthropometry (weight, height, skinfold measurements, and waist circumference) of 259 children was measured at birth, at 6 wk, every 3 months to 2 yr, and then every 6 months. Tanner staging for puberty and orchidometry were performed every 6 months starting at approximately age 8 yr. Bioelectrical impedance was done at age 11 yr.

RESULTS

In the girls, thelarche, pubarche, and menarche occurred at median ages of 8.8, 9.9, and 12.0 yr, respectively. Pubarche in boys occurred at a median age of 11.3 yr when the median testicular volume was 2.8 ml. Faster weight gain during infancy (age 0-6 months) and childhood, but not birth size, was associated with more advanced puberty (P values <0.05). Fat mass at age 8 yr was associated with more advanced puberty (P values <0.001) in both sexes. At age 11 yr, lean mass, but not fat mass, was associated with more advanced puberty (P values <0.001).

CONCLUSION

These data support the hypothesis that faster growth throughout childhood, especially with fat mass accretion, is associated with more advanced puberty apart from menarche. With the onset of puberty, lean mass accretion significantly increases.

Age at menarche, abnormal glucose tolerance and type 2 diabetes mellitus: The Rancho Bernardo Study

OBJECTIVE

We examined the association of age at menarche with risk of abnormal glucose tolerance (AGT) and type 2 diabetes in postmenopausal women.

METHODS

Participants were 997 women aged 50-92 years who had a clinic visit in 1984-87, when reproductive and diabetes history were recorded, and an oral glucose tolerance test administered. Information on age at menarche was collected in 1989. Diabetes status was based on WHO 1999 criteria, and AGT on having impaired fasting glucose (IFG) or impaired glucose tolerance (IGT).

RESULTS

The average age was 69.5 years; 12.5% had diabetes and 29.8% had AGT. Menarche was < 12 years in 14.5%, 12-15 years in 78.9% and > or = 16 years in 6.6%. Age and body mass index (BMI) predicted AGT (p < 0.001, p = 0.003, respectively), while age, BMI and family history of diabetes predicted type 2 diabetes (p < 0.001, p < 0.001, p = 0.02, respectively). Polynomial logistic regression showed no association of menarche with AGT or type 2 diabetes risk. In linear regressions, however, older age at menarche was associated with lower fasting (p = 0.01) and post-challenge plasma glucose (p = 0.03). Covariates, especially BMI, weakened these associations, although women with menarche > or = 16 years still had lower post-challenge (0.86 mmol/l, p = 0.05) and fasting glucose (0.26 mmol/l, p = 0.11) than those with menarche < 12 years.

CONCLUSIONS

Age at menarche was not associated with AGT or type 2 diabetes risk. Late age at menarche was inversely associated with fasting and post-challenge glycemia. Obesity may mediate the observed associations.

Birth weight, postnatal growth, and age at menarche

Larger body size in childhood is correlated with earlier age at menarche; whether birth and infant body size changes are also associated with age at menarche is less clear. The authors contacted female participants enrolled in the New York site of the US National Collaborative Perinatal Project born between 1959 and 1963 (n = 262). This racially and ethnically diverse cohort (38% white, 40% African American, and 22% Puerto Rican) was used to investigate whether maternal (body size, pregnancy weight gain, age at menarche, smoking) and birth (birth weight, birth length, placental weight) variables and early infant body size changes were associated with age at menarche even after considering later childhood body size. Higher percentile change in weight from ages 4 months to 1 year was associated with earlier age at menarche even after adjustment for later childhood growth (beta = -0.15, 95% confidence interval: -0.27, -0.02 years per 10-percentile change in weight from ages 4 months to 1 year). The association was in the same direction for all 3 racial/ethnic groups but was largest for the white group. These New York Women's Birth Cohort Adult Follow-up data (2001-2006) suggest that infant weight gain, in addition to childhood weight gain, may be associated with earlier age at menarche.

Delayed menarche in young German women with type 1 diabetes mellitus: recent results from the DPV diabetes documentation and quality management system

BACKGROUND

Findings have been inconsistent regarding the effect of T1DM (type 1 diabetes) on age at menarche.

OBJECTIVE

The purpose was to investigate in young German women with T1DM menarcheal age and factors potentially affecting menarche, including glycemic control, BMI (body mass index), relative T1DM duration (proportion of life with diabetes), insulin dose, and insulin therapy intensity. Initiated in 1990, the DPV program is an ongoing, prospective long-term longitudinal follow-up study to benchmark the quality of care provided to pediatric and, more recently, adult diabetes patients. Two hundered two German diabetes centers participated in nationwide data collection. Based on ethnicity and the availability of menarche and T1DM onset data as the main inclusion criteria, 643 young German women were selected from 11,629 female T1DM patients aged <20 years, recruited by referral, clinic or hospital ascertainment, or self report. Mean age at menarche (+/-SD) was 13.22 +/- 1.31 years, representing a delay of 0.52 years (p < 0.001) relative to the general population. Significant delay (p < 0.05) was also found for relative T1DM duration, BMI SD score, insulin dose, and HbA1c level, with a 1% increase in HbA1c resulting in a delay in menarche by 0.07 years.

CONCLUSIONS

Age at menarche is delayed in type 1 diabetes mellitus. The delay increases with relative T1DM duration and poor quality of glycemic control.

Association of age at menarche with cardiovascular risk factors, vascular structure, and function in adulthood: the Cardiovascular Risk in Young Finns study

BACKGROUND

It is unclear whether age at menarche is an independent determinant of future cardiovascular risk.

OBJECTIVE

We aimed to determine whether menarcheal age is an independent predictor of body mass index (BMI) and a wide range of cardiovascular risk factors in adolescence and adulthood.

DESIGN

We examined the associations of menarcheal age with BMI (in kg/m(2)) and other cardiovascular risk factors in adolescence and adulthood in a population-based sample of 794 female adolescents aged 9-18 y at baseline. Their age at first menstruation was requested at baseline and again 3 and 6 y later. Cardiovascular risk factors were assessed at baseline and at age 30-39 y.

RESULTS

A 1-y decrease in menarcheal age was associated with 0.81 (95% CI: 0.53, 1.08) higher adult BMI as well as greater waist circumference and waist-to-hip ratio, elevated systolic blood pressure, higher insulin resistance, and greater risk of metabolic syndrome (P < 0.05 for all). In multivariable analysis in which these adult risk factors were mutually adjusted for, only the inverse association between age at menarche and adult BMI remained. However, this inverse association was lost after adjustment for premenarcheal BMI (beta: -0.16; 95% CI -0.55, 0.23; P = 0.42). Higher premenarcheal BMI predicted earlier menarche, and the strong association between premenarcheal BMI and adult BMI was robust to adjustment for age at menarche.

CONCLUSIONS

These findings suggest that early menarche is only a risk marker. Greater childhood BMI seems to contribute to earlier age at menarche and, because of tracking, greater adult BMI and associated cardiovascular risk. An independent effect of early menarche on adult adiposity cannot be excluded, but it is likely to be small at best.

Delayed pubertal onset and development in German children and adolescents with type 1 diabetes: cross-sectional analysis of recent data from the DPV diabetes documentation and quality management system

OBJECTIVE

To investigate the effect of type 1 diabetes on pubertal onset and development, and to identify factors potentially affecting puberty, including glycemic control, relative diabetes duration, body mass index standard delta score (BMI SDS), insulin dose, and intensity of insulin therapy.

RESEARCH DESIGN AND METHODS

Initiated in 1990, the Diabetes-Patienten-Verlaufsdaten (DPV) is an ongoing, prospective longitudinal follow-up program to benchmark the quality of diabetes care provided to, predominantly, pediatric patients. Data collection for this non-interventional audit was carried out at 202 German diabetes treatment centers. Patient recruitment was done by referral, clinic/hospital ascertainment, or self-report. Data were analyzed for subcohorts of 1218-2409 boys and 579-2640 girls from a cohort of 24 385 pediatric type 1 diabetic patients. Selection was based on ethnicity and availability of data on Tanner stage 2, or higher, of genital and pubic hair development (boys) or breast and pubic hair development, and menarche (girls).

RESULTS

Boys showed significant (P<0.05) delay (years) in mean ages at onset of genital development (12.0 (+/-0.9) years) and pubarche (12.2 (+/-0.4) years). In girls, mean ages at thelarche (11.4 (+/-0.5) years), pubarche (11.5 (+/-0.1) years), and menarche (13.2 (+/-0.5) years) were significantly delayed compared with the general population. Sexual maturity (Tanner stage 5) was not delayed in either sex. Elevated glycohemoglobin and decreased BMI SDS were associated with significantly delayed pubertal onset, whereas relative diabetes duration and insulin dose were not.

CONCLUSIONS

Pubertal onset, but not sexual maturity, is delayed in children with type 1 diabetes. Delay increases with higher glycohemoglobin and lower BMI SDS.

Menarche is related to fat distribution

The energy demands of pregnancy and lactation together with the accumulation of stored fat in human females during development suggest that a critical level of fat may be required for menarche; but multivariate analyses have supported the alternative view that skeletal growth is the main factor. However, significant differences between upper- and lower-body (gluteofemoral) fat suggest that fat distribution may be more relevant than total fat. Using cross-sectional data from the third National Health and Nutrition Examination Survey (NHANES III) for females aged 10-14, we show that menarche is more closely related to fat distribution than to skeletal maturity. Unit increases in hip circumference are associated with 24% higher odds of menarche while increases in waist circumference and triceps skinfold lower the odds by 7 and 9%, respectively. Those with menarche despite low levels of total body fat have relatively more fat stored in gluteofemoral depots than those without menarche or those with menarche and greater total amounts of fat. In young women with completed growth, age at menarche is negatively related to hip and thigh circumference and positively related to waist circumference, stature, and biiliac breadth; and blood leptin levels are much more strongly related to gluteofemoral than upper-body fat, suggesting that leptin may convey information about fat distribution to the hypothalamus during puberty. Fat distribution may be relevant because gluteofemoral fat may provide neurodevelopmentally important fatty acid reserves.

Opposing influences of prenatal and postnatal growth on the timing of menarche

CONTEXT AND OBJECTIVE

Menarche is a milestone of reproductive development, and its timing may be differentially influenced by the growth conditions before birth and those between birth and puberty. The present study explored the relationships among menarcheal timing and markers of prenatal and midchildhood growth in healthy Australian girls.

SETTING, DESIGN, AND PATIENTS

A total of 156 girls aged 8 yr from a birth cohort of full-term babies had height, weight, and waist circumference measured. One hundred three girls had dual x-ray absorptiometry performed and blood analyzed for insulin, leptin, IGF-I, estradiol, and dehydroepiandrosterone sulfate levels. Girls were followed up at age 15 yr and their age of menarche was recorded.

MAIN OUTCOME MEASURES

Measures included age of menarche; birth weight and birth length; height, weight, waist circumference, and body composition by dual x-ray absorptiometry; and plasma insulin, leptin, IGF-I, estradiol, and dehydroepiandrosterone sulfate at age 8 yr.

RESULTS

Girls with earlier menarche were light and long at birth and had higher total and central adiposity and IGF-I and estradiol levels in midchildhood, compared with those with later menarche. Age of menarche was best predicted by combining size at birth and body mass index z score at age 8 yr (r2 = 0.12; P < 0.001).

CONCLUSIONS

The timing of menarche appears to be influenced in opposing directions by pre- and postnatal growth. Menarche was found to occur earlier in girls who were long and light at birth and who had a higher fat mass and circulating IGF-I in childhood. These findings may partly explain ethnic differences and secular trends in the age of menarche.

Current wheezing, puberty, and obesity among mexican adolescent females and young women

BACKGROUND

Studies suggest an association between obesity and asthma. This may be modified by the physiological changes of puberty. We aim to explore the relation between overweight and current asthma among Mexican adolescent females and young women and evaluate how puberty may modify this association.

METHODS

Adolescent females (n=6944) and young women aged 11-24 years provided data. Current asthma was defined as wheezing in the last 12 months and obesity by body mass index (BMI). Puberty was defined by age at menarche. The association of obesity and current wheezing was evaluated by using logistic regression adjusting for confounders. The impact of puberty was studied by using stratified analysis by age at menarche.

RESULTS

The prevalence of current wheezing was 16.2% (95% CI 15-17). Compared with girls of normal weight (BMI 15 to >or=85 percentile), obese girls (BMI>or=95 percentile) had an increased risk of current wheezing of 19% (OR=1.19; 95% CI 0.97-1.46). After stratifying by age at menarche, we observed that this increased risk was only present in girls with menarche at 11 years old or younger (1.31%; 95% CI 1.01-1.73).

CONCLUSIONS

The association between obesity and asthma seems to be greater among girls with early puberty, suggesting the role of female hormones.

Early onset of puberty: tracking genetic and environmental factors

Under physiological conditions, factors affecting the genetic control of hypothalamic functions are predominant in determining the individual variations in timing of pubertal onset. In pathological conditions, however, these variations can involve different genetic susceptibility and the interaction of environmental factors. The high incidence of precocious puberty in foreign children migrating to Belgium and the detection in their plasma of a long-lasting 1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane (DDT) residue suggest the potential role of environmental endocrine disrupting chemicals in the early onset of puberty. This hypothesis was confirmed by experimental data showing that temporary exposure of immature female rats to DDT in vivo results in early onset of puberty. We compared the gene expression profile of hypothalamic hamartoma associated or not with precocious puberty in order to identify gene networks responsible for both hamartoma-dependent sexual precocity and the onset of normal human puberty. In conclusion, pathological variations in the timing of puberty may provide unique information about the interactions of either environmental conditions or genetic susceptibility with the hypothalamic mechanism controlling the onset of sexual maturation, as shown by examples of precocious puberty following exposure to endocrine disrupters or due to hypothalamic hamartoma.

Endocrine and metabolic consequences of intrauterine growth retardation

Size at birth and early infancy growth rates have been linked to long-term risks for diseases, such as type 2 diabetes and cardiovascular disease. These associations could be explained by permanent programming of metabolic responses and selective survival of those genetically predisposed to such adaptations. These epidemiologic associations may also affect long-term disease risk in short small-for-gestational age children, who are often treated with growth hormone. Study of the mechanisms and genetic factors involved in the association between small size at birth, rapid postnatal weight gain, and adult disease may promote the early identification of subjects with the highest disease risk and new opportunities to develop targeted early interventions.

Puberty onset in Northern Italy: a random sample of 3597 Italian children

Entering puberty is one of the most important milestones in life. Studies from around the world have shown that age of pubertal changes onset can vary with race and ethnicity, environmental conditions, geographical location and nutrition. In the last century, the onset of puberty progressively shifted back towards younger ages in several European countries, with a levelling off in the last decades. The aim of our study was to describe the prevalence of secondary sexual characteristics in a group of children living in Northern Italy comparing them with the percentile values published by Tanner in 1976. We enrolled 3496 children drawn from public schools and evaluated height, weight and pubertal stages. The analysis of our data evidenced that the 50th percentile age of puberty onset in both sexes decreased by about 1 yr compared to data published by Tanner. Mean body mass index (BMI) z-score was significantly higher (p = 0.01) in pubertal than in pre-pubertal girls, on the contrary it was higher (p = 0.005) in pre-pubertal than in pubertal boys. In conclusion, our study found that girls and boys of our region are beginning pubertal development about 1 yr earlier than Tanner's British population. Taking into consideration the 3rd percentile age for Tanner's breast stage 2 in girls and testicular volume (TV) of 4 ml in boys, the current internationally used cut-off age for precocious puberty, i.e. 8 yr for girls and 9 yr for boys, can be maintained in our population.

Effects of different socioeconomic conditions on menarche in Turkish female students

PURPOSE

The aim of this study was to determine the age at menarche, the menarcheal features, and the association between menarcheal age and socioeconomic status in an urban area in Turkey. In addition, we tried to assess whether there is a relationship between age at menarche and body composition.

METHODS

We asked some questions about menarche of 1017 female adolescent students in the high schools of Manisa region. Height and weight were measured. The body mass index (BMI; kg/m2) was used as an index of relative weight. Adolescent girls were grouped into three socioeconomic status according to the educational and occupational levels of their parents. The age at menarche and the menarcheal pattern were evaluated according to the socioeconomic status.

RESULTS

The ages of girls involved in the study ranged between 14 and 18 years, with a mean of 15.7+/-1.1 years. Although the menarcheal age was found to be lower in girls with higher socioeconomic status, there was no significant difference between the three different socioeconomic status. In all of the three groups, menarche was more common in summer and fall than in spring and winter. Although the mother was an important source of knowledge in all groups, it was significantly more important in the group with high socioeconomic status. Adolescent girls with low socioeconomic status had fewer premenstrual complaints. However, there was no significant difference between the groups. We found an inverse correlation between menarcheal age and postmenarcheal weight and the BMI (r=-0.14, p=0.000). However, there was no correlation between menarcheal age and postmenarcheal height.

CONCLUSION

These results indicate that as the social status differences decrease, the difference observed in menarcheal age and pattern disappears in urban areas of developing countries. Menarcheal age may be an indicator of socioeconomic development. It does not influence postmenarcheal height; however, as menarcheal age decreases, BMI increases.

The timing of normal puberty and the age limits of sexual precocity: variations around the world, secular trends, and changes after migration

During the past decade, possible advancement in timing of puberty has been reported in the United States. In addition, early pubertal development and an increased incidence of sexual precocity have been noticed in children, primarily girls, migrating for foreign adoption in several Western European countries. These observations are raising the issues of current differences and secular trends in timing of puberty in relation to ethnic, geographical, and socioeconomic background. None of these factors provide an unequivocal explanation for the earlier onset of puberty seen in the United States. In the formerly deprived migrating children, refeeding and catch-up growth may prime maturation. However, precocious puberty is seen also in some nondeprived migrating children. Attention has been paid to the changing milieu after migration, and recently, the possible role of endocrine- disrupting chemicals from the environment has been considered. These observations urge further study of the onset of puberty as a possible sensitive and early marker of the interactions between environmental conditions and genetic susceptibility that can influence physiological and pathological processes.

Critical periods in human growth and their relationship to diseases of aging

It has long been recognized that there are "critical periods" during mammalian development when exposure to specific environmental stimuli are required in order to elicit the normal development of particular anatomical structures or their normal functioning. The responses of the organism to these stimuli depend on a specific level of anatomical maturation and a state of rapid anatomical and/or functional change. This discussion of critical periods in growth is not confined to the classic definition of a narrow time frame of development during which a particular environmental threshold or limit must exist for normal growth and function to ensue. Using both auxological and epidemiological approaches, we suggest a lifespan perspective which encompasses accumulating and interacting risks that are manifest from prenatal life onward. By understanding the process of growth development, and by scrutinizing the growth process, early variations that lead to later disease can be identified. Here we review a significant amount of the evidence that links exposure during growth to later morbidity and mortality. The fetus appears to respond to insults during the prenatal period through the process of "programming," which has short-term survival advantages but may have a long-term disadvantage in that it is associated with cardiovascular disease, hypertension, type II diabetes, and later obesity. Low birth weight combined with rapid postnatal growth during infancy also appears to be associated, for instance, with later childhood and adult sequelae in terms of glucose tolerance and obesity. Independent of birth weight, the timing of adiposity rebound during mid-childhood also predicts later obesity. The timing, magnitude, and duration of adolescent growth and maturationare associated with critical body composition changes, including the normal acquisition of body fat and bone mineralization. In particular, the acquisition of appropriate peak bone mass is critical in determining the later risk of osteoporosis. A putative causal mechanism linking early growth variation to later chronic disease risk through telomeric attrition is discussed. The obligatory loss of telomeric DNA with each cell division serves as a mitotic clock and marks the rate of growth and repair processes in the cell. Although much more work is required, existing studies support the notion that telomere shortening is not only a clock of cellular division, but also marks relative growth rate, as well as contributing to common degenerative processes of aging through its impact on cellular senescence.

The relationship of rapid weight gain in infancy to obesity and skeletal maturity in childhood

OBJECTIVE

Children with birth weight appropriate for gestational age (AGA) who also demonstrate rapid weight gain in infancy have a greater risk of being overweight or obese during childhood. A concurrent advancement in skeletal maturity would account for their greater size and would, therefore, not necessarily pose a threat of greater risk during adolescence and early adulthood. This study aims to determine whether children with rapid weight gain during infancy have advanced skeletal maturity during childhood.

RESEARCH METHODS AND PROCEDURES

One hundred and ninety-three African children (boys = 108; girls = 85) of normal birth weight and gestational age were assessed from birth to 9 years. Body composition was assessed at 9 years of age by whole-body DXA, and skeletal maturity was assessed using the Tanner-Whitehouse II technique. Rapid weight gain in infancy was defined as a +0.67 change in weight-for-age Z-score between birth and 2 years.

RESULTS

Rapid weight gain was experienced by over 20% of the sample. Children with rapid weight gain were significantly lighter at birth and significantly taller, heavier, and fatter throughout childhood. Chronological age and Tanner-Whitehouse II technique skeletal ages at 9 years were not significantly different between groups or between sexes within groups.

DISCUSSION

Because AGA children with rapid weight gain have a greater risk of overweight and obesity but are not advanced in skeletal maturity, later adolescent adjustments toward average weight and fatness values are unlikely. The identification and monitoring of such children is of importance in reducing their risk of morbidity.

Body mass index and age at menarche in an adolescent clinic population

Body fatness as a determinant of menarche has been studied extensively, but limited to underweight females. Adolescent female patients were measured and interviewed. Subjects were divided into three groups based on body mass index (BMI) standard deviation score (SDS). Average age at menarche was 11.87 +/- 1.1 years in the obese group, 12.14 +/- 0.9 years in the overweight group, and 12.20 +/- 1.3 years in the normal weight group. Pearson correlation factor between BMI SDS and age at menarche was -0.24 (p < 0.01). These findings suggest an important role of increased body fatness on menarche that extends beyond underweight girls.

Effect of low versus normal birthweight on menarche in 14-year-old Polish girls

OBJECTIVE

The relationship between intrauterine growth retardation and sexual maturation has not been completely established. The aim of the present study was to compare menarche in 14-year-old Polish girls of low and normal birthweight, along with an evaluation of the impact of socio-economic status and body mass index (BMI).

METHODS

We studied 1060 girls (177 pre- and 883 post-menarche) aged 13.5-14.5 years. These girls attended the 7th grade of randomly selected primary schools in Wroclaw, Poland. The BMI was used as a measurement of general adiposity. The cut-off value of the 10th percentile of birthweight for gestational age was used to differentiate between girls born small for gestational age (SGA) and girls with a birthweight appropriate to gestational age (AGA). Parental education level and other measures were used to assess socio-economic status (SES).

RESULTS

Birthweight (OR = 2.54; 95% CI 1.22-5.28) and BMI at the age of 14 years (OR = 7.93; 95%CI 4.67-13.48) were factors affecting the onset of menarche among the 14-year-old girls.

CONCLUSION

Polish girls born small for gestational age are more likely to have experienced menarche by the age of 14 years, compared with their peers of normal weight at birth. These findings seem to be consistent with the hypothesis that the age of menarche is, to some extent, set by patterns of gonadotropin release, established prior to birth. Additionally, the age of menarche varies depending on levels of fat accumulation during childhood and adolescence.

Putative effects of endocrine disrupters on pubertal development in the human

Pubertal development is regulated by gonadotrophins and sex hormones. There has been a clear secular trend in the timing of puberty during the last century, puberty becoming earlier. Although improved nutrition is assumed to be the cause, this could partly be associated with exposure to so-called endocrine disrupters. Precocious puberty has been described in several case reports of accidental exposure to oestrogenic compounds in cosmetic products, food and pharmaceuticals. Local epidemics of premature thelarche have also been suggested to be linked to endocrine disrupters. Children adopted from developing countries to industrialized countries often develop precocious puberty. Not only precocious puberty, but also delayed puberty can, theoretically, be associated with exposure to endocrine disrupters. While it is very plausible that endocrine disrupters may disturb pubertal development, there is very little research on this and, therefore, we do not yet have any clear cause-effect relationships in humans.

Increased incidence of asthmalike symptoms in girls who become overweight or obese during the school years

The possibility of a causal relationship is suggested by recent concomitant increases in the prevalence of obesity and asthma. In a general population sample, prevalence and incidence of asthma symptoms, skin tests, and body mass index (BMI) were ascertained at mean ages of 6.3 (n = 688) and 10.9 (n = 600) yr. Lung function, bronchodilator responsiveness, and daily peak flow variability were measured at 11 yr of age. There was no association between BMI at age 6 and wheezing prevalence at any age. Females, but not males, who were overweight or obese at 11 yr of age were more likely to have current wheezing at ages 11 and 13 but not at ages 6 or 8. This effect was strongest among females beginning puberty before the age of 11. Females who became overweight or obese between 6 and 11 yr of age were 7 times more likely to develop new asthma symptoms at age 11 or 13 (p = 0.0002); at age 11 their peak flow variability and bronchodilator responsiveness were significantly more likely to be increased. In females, becoming overweight or obese between 6 and 11 yr of age increases the risk of developing new asthma symptoms and increased bronchial responsiveness during the early adolescent period.

Body fat mass, leptin and puberty

Leptin, the ob gene product, provides a molecular basis for the lipostatic theory of the regulation of energy balance. Leptin circulates as a monomeric 16 kDa protein in rodent and human plasma and is also bound to leptin binding proteins that may form large high molecular weight complexes. Initial models of leptin action included leptin-deficient ob/ob mice and leptin-insensitive db/db mice. Peripheral or central administration of leptin reduced body weight, adiposity, and food intake in ob/ob mice but not in db/db mice. In ob/ob mice leptin treatment restored fertility. Leptin interacts with many messenger molecules in the brain. For example, leptin suppresses neuropeptide Y (NPY) expression in the arcuate nucleus. Increased NPY activity has an inhibitory effect on the gonadotropin axis and represents a direct mechanism for inhibiting sexual maturation and reproductive function in conditions of food restriction and/or energy expenditure. By modulating the hypothalamo-pituitary-gonadal axis both directly and indirectly, leptin may thus serve as the signal from fat to the brain about the adequacy of fat stores for pubertal development and reproduction. Normal leptin secretion is necessary for normal reproductive function to proceed and leptin may be a signal allowing for the point of initiation of and progression toward puberty.

Deprivation and childhood obesity: a cross sectional study of 20,973 children in Plymouth, United Kingdom

OBJECTIVE

To study the association between socioeconomic deprivation and childhood obesity.

DESIGN

Cross sectional study.

SETTING

All state primary schools in Plymouth. Plymouth is a relatively deprived city in the United Kingdom, ranking 338th of 366 local authorities on the Department of the Environment Index of Local Conditions.

SUBJECTS

20 973 children between the ages of 5 and 14 years, 1994-96.

MAIN OUTCOME MEASURE

Numbers of obese children (body mass index (BMI) above the 98th centile) by quarters of Townsend score.

RESULTS

Plymouth had a rate of childhood obesity two and half times that expected nationally (5% v 2%). The obesity prevalence increased with age, being almost double in the oldest age quarter (boys 6.2%; girls 7.0%), compared with the youngest age quarter. Within Plymouth, there was a significant trend for higher rates of obesity related to increasing deprivation in both boys (p=0. 017) and girls (p=0.018). The odds ratio (OR) for childhood obesity (highest-lowest quarter of Townsend scores) had borderline significance in boys (OR 1.29, 95% confidence intervals (CI) 1.00 to 1.65, p=0.049) but was larger and more significant in the girls (OR 1.39, 95% CI 1.08 to 1.80, p=0.011). Unlike boys, the association between obesity in girls and Townsend scores became stronger with age such that in the oldest age quarter (over 11.7 years), girls in the highest quarter of Townsend scores were nearly twice as likely be obese, as compared with the lowest quarter (OR 1.95, 95% CI 1.23 to 3.08, p=0.005). State of pubertal development could not be accounted for as this information was not available.

CONCLUSIONS

This study provides evidence for an association between deprivation and childhood obesity in this English population. The health of children from deprived households is affected by a number of adverse influences. The high prevalence of obesity in these children is yet another factor that could predispose to greater morbidity in adult life.

The role of leptin in human growth and puberty

Experimental animal studies demonstrate the effects of leptin on appetite, weight gain and metabolism. The biological effects of leptin in human adults are still to be determined, but recent reports show that congenital leptin deficiency leads to hyperphagia and excessive weight gain from early infancy as well as failure of pubertal onset in adolescence. Our recently reported data from two longitudinal cohorts suggest a role for leptin in the normal regulation of childhood weight gain, maturation and the development of secondary sexual features and body composition. Low leptin levels in cord blood closely reflected decreased adiposity at birth and strongly predicted high rates of weight gain in infancy and catch-up growth. In adolescents, leptin levels rose gradually with age prior to puberty, suggesting that a threshold effect may trigger puberty. In girls, low leptin levels at the start of puberty predicted large gains in the percentage of fat mass, perhaps suggesting a role in the preparation for childbearing.

Longitudinal study of leptin concentrations during puberty: sex differences and relationship to changes in body composition

Leptin may have a role in the initiation of puberty and the regulation of subsequent weight gain, but this hypothesis has not been tested by longitudinal study. We report data from 40 normal children (20 boys and 20 girls) followed from 8-16 yr of age with hormone measurements and auxology every 6 months. Before the onset of puberty, leptin levels were similar in boys and girls: G1, mean (95% confidence interval), 2.63 (2.17-3.20) ng/mL; B1, 2.47 (2.08-2.94) ng/mL (P = 0.64) and increased with age in both sexes (B, 0.107 +/- 0.042; P = 0.02). With the onset of puberty, leptin levels increased in girls (B2-B5, P < 0.0005), but decreased in boys (G2-G5, P < 0.0005). Similar positive independent relationships were seen between leptin and fat mass in girls (B, 0.106 +/- 0.022; P < 0.0005) and boys (B, 0.121 +/- 0.020; P < 0.0005), and negative relationships were found with fat-free mass [girls: B, -1.104 +/- 0.381 (P < 0.005); boys: B, -1.288 +/- 0.217 (P < 0.0005)]. Girls gained more fat mass than boys, whereas boys gained more fat-free mass, and this explained the sex difference in leptin levels. Leptin levels correlated significantly with a large number of other hormones, but none was independent of changes in body composition. In girls, but not in boys, low leptin levels during prepuberty (B1) predicted subsequent gains in the percent body fat during puberty (r = -0.75; P = 0.005). The sexual dimorphism in leptin levels during puberty reflects differential changes in body composition. Prepubertal leptin levels in girls also predict gains in the percent body fat.

Impact of the age at menarche on adult body composition in healthy pre- and postmenopausal women

The present study focuses on the impact of age at menarche on body composition development during adulthood. With 459 healthy middle-class women between 18 and 67 years (x = 41.5) the association between age at menarche and body composition was tested. Body composition, described by absolute and relative amount of fat mass, lean body mass, and bone mass, was estimated by means of dual energy x-ray absorptiometry. In order to exclude the influence of the menopausal transition on body composition, pre- and postmenopausal females were examined separately. The absolute amount of body fat was significantly lower within the group of women whose menarche occurred later. However, postmenopausal females exhibit less significant relations between the two trait systems than premenopausal women. This may be due to the impact of menopausal transition which affected the hormone levels and body composition development independently from the adolescent hormonal transition. While in both proband groups the quantitative amount of body fat was significantly related to menarcheal age, a significant relation between menarcheal age and adult body fat distribution could not be verified.

Growth pattern and age at menarche of obese girls in a transitional society

Childhood obesity is an increasing problem in a transitional society such as Thailand. To study physical growth and puberty in obese children, a cross-sectional survey of growth and age at menarche was carried out in schoolgirls aged between 8 and 16 years old. The 3,120 girls were divided into two groups based on weight-for-height criteria. Girls with weight-for-height between 80 and 120% were classified as normal stature (2,625; 84.1%) and those more than 120% were obese (495; 15.9%). Using probit analysis, age at menarche in obese girls was 0.9 year earlier than normal stature girls (11.5 years vs 12.4 years). At age 12, obese girls were reaching menarche 2.8 times more when compared with the normal stature girls. In terms of growth pattern, obese girls were taller and grew faster during the prepubertal period, and then reached their final height earlier than the normal stature girls (13 years vs 15 years). The final height in obese girls was significantly shorter (153.0 cm and 155.0 cm, p = 0.01). We conclude that: 1) obese girls grow faster, have earlier menarche and then stop growing earlier, and 2) obese girls tend to be shorter as adults, compared with normal stature girls.

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.

A review of child health in the 1958 birth cohort: National Child Development Study

In the week 3-9 March 1958, 98% of all births in England, Scotland and Wales (approximately 17,000) were studied in the Perinatal Mortality Survey. The follow-up of surviving children, known as the National Child Development Study, comprises four major sweeps at ages 7, 11, 16 and 23. Medical examinations were conducted at each age, except at 23 when health was self-reported. Details of the child's family background and socio-economic circumstances were recorded, together with assessments of their social development and educational attainment. Seventy-six per cent of the target population were interviewed at age 23. The health of subjects in the 1958 cohort has been described in over 200 publications but there is no comprehensive account of findings from birth to age 23. This overview attempts to redress this. As new data are gathered from the study subjects at age 33, opportunities will exist to investigate associations between childhood factors and health in midlife. Data on their partners and children will be included, allowing studies of inter-generational and family health. Further indications of changing illness patterns will be possible from comparisons with data collected on earlier and later born cohorts.