Showing papers on "Menarche published in 2008"

Link Between Body Fat and the Timing of Puberty

Abstract: Several recent studies suggest that the timing of the onset of puberty in girls has become earlier over the past 30 years, and there is strong evidence that the increasing rates of obesity in children over the same time period is a major factor. This article reviews studies from the United States that examined the age of menarche and the age of onset of breast development and pubic hair as a function of body mass index, which is a good surrogate measure of body fat. These studies are nearly all cross-sectional, so many questions remain unanswered. However, at least several studies show that girls who have relatively higher body mass index are more likely to have earlier menses, as well as a relationship between body mass index and other measures of pubertal onset. The evidence published to date suggests that obesity may be causally related to earlier puberty in girls rather than that earlier puberty causes an increase in body fat. In contrast, few studies have found a link between body fat and earlier puberty in boys. A growing body of evidence from both rodent and human studies suggests that leptin may be the critical link between body fat and earlier puberty. Leptin-deficient mice and humans fail to enter puberty unless leptin is administered, and rodent studies indicate that very low levels of leptin stimulate gonadotropin secretion both at the hypothalamic and the pituitary level. Current evidence indicates that leptin appears to play a permissive role rather than act as the critical metabolic signal initiating puberty. The linkage between body fat and the reproductive axis in girls may have evolved in mammals as a mechanism for ensuring that pregnancy will not occur unless there are adequate fat stores to sustain both the mother and the growing fetus.

Examination of US Puberty-Timing Data from 1940 to 1994 for Secular Trends: Panel Findings

Abstract: Whether children, especially girls, are entering and progressing through puberty earlier today than in the mid-1900s has been debated. Secular trend analysis, based on available data, is limited by data comparability among studies in different populations, in different periods of time, and using different methods. As a result, conclusions from data comparisons have not been consistent. An expert panel was asked to evaluate the weight of evidence for whether the data, collected from 1940 to 1994, are sufficient to suggest or establish a secular trend in the timing of puberty markers in US boys or girls. A majority of the panelists agreed that data are sufficient to suggest a trend toward an earlier breast development onset and menarche in girls but not for other female pubertal markers. A minority of panelists concluded that the current data on girls' puberty timing for any marker are insufficient. Almost all panelists concluded, on the basis of few studies and reliability issues of some male puberty markers, that current data for boys are insufficient to evaluate secular trends in male pubertal development. The panel agreed that altered puberty timing should be considered an adverse effect, although the magnitude of change considered adverse was not assessed. The panel recommended (1) additional analyses of existing puberty-timing data to examine secular trends and trends in the temporal sequence of pubertal events; (2) the development of biomarkers for pubertal timing and methods to discriminate fat versus breast tissue, and (3) establishment of cohorts to examine pubertal markers longitudinally within the same individuals.

Menstrual Hygiene: How Hygienic is the Adolescent Girl?

Abstract: Background: Menstruation and menstrual practices are still clouded by taboos and socio-cultural restrictions resulting in adolescent girls remaining ignorant of the scientific facts and hygienic health practices, which sometimes result into adverse health outcomes. Objectives: (i) To elicit the beliefs, conception and source of information regarding menstruation among the study population and (ii) to find out the status of menstrual hygiene among adolescent girls. Materials and Methods: A descriptive, cross-sectional study was conducted among 160 adolescent girls of a secondary school situated in the field practice area of Rural Health Unit and Training Center, Singur, West Bengal, with the help of a pre-designed and pre-tested questionnaire. Data were analyzed statistically by simple proportions. Results: Out of 160 respondents, 108 (67.5%) girls were aware about menstruation prior to attainment of menarche. Mother was the first informant regarding menstruation in case of 60 (37.5%) girls. One hundred and thirty-eight (86.25%) girls believed it as a physiological process. Seventy-eight (48.75%) girls knew the use of sanitary pad during menstruation. Regarding practices, only 18 (11.25%) girls used sanitary pads during menstruation. For cleaning purpose, 156 (97.5%) girls used both soap and water. Regarding restrictions practiced, 136 (85%) girls practised different restrictions during menstruation. Conclusions: Menstrual hygiene, a very important risk factor for reproductive tract infections, is a vital aspect of health education for adolescent girls. Educational television programmes, trained school nurses/health personnel, motivated school teachers and knowledgeable parents can play a very important role in transmitting the vital message of correct menstrual hygiene to the adolescent girl of today.

Early Marriage, Age of Menarche, and Female Schooling Attainment in Bangladesh

Abstract: Using data from rural Bangladesh, we explore the hypothesis that women attain less schooling as a result of social and financial pressure to marry young. We isolate the causal effect of marriage timing using age of menarche as an instrumental variable. Our results indicate that each additional year that marriage is delayed is associated with 0.22 additional year of schooling and 5.6 percent higher literacy. Delayed marriage is also associated with an increase in use of preventive health services. In the context of competitive marriage markets, we use the above results to obtain estimates of the change in equilibrium female education that would arise from introducing age of consent laws.

Public Health Implications of Altered Puberty Timing

Abstract: Changes in puberty timing have implications for the treatment of individual children, for the risk of later adult disease, and for chemical testing and risk assessment for the population. Children with early puberty are at a risk for accelerated skeletal maturation and short adult height, early sexual debut, potential sexual abuse, and psychosocial difficulties. Altered puberty timing is also of concern for the development of reproductive tract cancers later in life. For example, an early age of menarche is a risk factor for breast cancer. A low age at male puberty is associated with an increased risk for testicular cancer according to several, but not all, epidemiologic studies. Girls and, possibly, boys who exhibit premature adrenarche are at a higher risk for developing features of metabolic syndrome, including obesity, type 2 diabetes, and cardiovascular disease later in adulthood. Altered timing of puberty also has implications for behavioral disorders. For example, an early maturation is associated with a greater incidence of conduct and behavior disorders during adolescence. Finally, altered puberty timing is considered an adverse effect in reproductive toxicity risk assessment for chemicals. Recent US legislation has mandated improved chemical testing approaches for protecting children's health and screening for endocrine-disrupting agents, which has led to changes in the US Environmental Protection Agency's risk assessment and toxicity testing guidelines to include puberty-related assessments and to the validation of pubertal male and female rat assays for endocrine screening.

Adolescent Obesity and Puberty: The “Perfect Storm”

Abstract: Obesity is the most serious long-term health risk currently facing America's adolescents. Weight gain during adolescence carries a higher risk for adult obesity and the metabolic syndrome. This review highlights early adolescence as a particularly high-risk time for weight gain due to the synergy of naturally occurring metabolic changes along with increasing behavioral risk factors. One of the first potential health effects of abnormal weight gain during this period is earlier puberty, usually manifested as thelarche. The obesity epidemic is clearly implicated in the national trend toward earlier thelarche, although the data are not as strong in relation to menarche. Leptin activation of the hypothalamic-pituitary axis, combined with insulin resistance, and increased adiposity may result in the higher estrogen levels that are linked to breast development. Young adolescents also experience a sharp decline in their level of physical activity, worsening nutritional habits, and other important psychosocial and developmental risk factors that may contribute to obesity and estrogen-dependent disease in later life, including polycystic ovary syndrome and breast cancer. Unfortunately, the very psychosocial factors that contribute to abnormal weight gain during early adolescence make prevention and treatment in this population particularly challenging. Therefore, intervening prior to pubertal onset becomes even more important given the risk factors present once puberty begins.

Impact of fathers on daughters' age at menarche: a genetically and environmentally controlled sibling study.

Abstract: Girls growing up in homes without their biological fathers tend to go through puberty earlier than their peers. Whereas evolutionary theories of socialization propose that this relation is causal, it could arise from environmental or genetic confounds. To distinguish between these competing explanations, the authors used a genetically and environmentally controlled sibling comparison design to examine the effects of differential exposure to family disruption/father absence in a community sample of sister pairs. As specified by evolutionary causal theories, younger sisters had earlier menarche than their older sisters in biologically disrupted families (n = 68) but not biologically intact families (n = 93). This effect was superseded, however, by a large moderating effect of paternal dysfunction. Younger sisters from disrupted families who were exposed to serious paternal dysfunction in early childhood attained menarche 11 months earlier than either their older sisters or other younger sisters from disrupted families who were not exposed to such dysfunction. These data suggest that early exposure to disordered paternal behavior, followed by family disruption and residential separation from the father, can lead to substantially earlier menarche.

Risk Factors for the Incidence of Breast Cancer: Do They Affect Survival From the Disease?

Abstract: Purpose Risk factors that influence the incidence of breast cancer may also affect survival after diagnosis. Methods Data from 4,560 women with invasive breast cancer who had taken part in the population-based Studies of Epidemiology and Risk Factors in Cancer Heredity (SEARCH) breast cancer study were used to investigate the influence on survival of variables related to pregnancy, menarche and menopause, prior use of exogenous hormones, height, weight, body mass index (BMI), smoking history, and alcohol intake. Results In univariate analyses, there was no association between prognosis and age at menarche and menopause, menopausal status at diagnosis, smoking history, or prior use of the oral contraceptive pill. Women whose most recent pregnancy was more than 30 years ago had a 35% reduced risk of dying (95% CI, 8% to 54%) compared with women who had a full-term pregnancy in the past 15 years, and the use of hormone replacement therapy for more than 4 years was associated with a similar risk reduction. BM...

Role of Environmental Factors in the Timing of Puberty

Abstract: Puberty-timing measures have historically been used as indicators of adequate nutrition and growth. More recently, these measures have been examined in relation to exposure to estrogenic or antiandrogenic agents, as well as other environmental factors. The scientific community has debated whether puberty timing is occurring earlier today than in the mid-1900s in the United States and, if so, whether environmental factors play a role; however, no one has asked a multidisciplinary panel to resolve this question. Thus, a multidisciplinary expert panel jointly sponsored by the US Environmental Protection Agency, the National Institute of Environmental Health Sciences, and Serono Symposia International was convened to examine the evidence of a secular trend, identify potential environmental factors of concern, and identify research needs regarding environmental factors and puberty timing at "The Role of Environmental Factors on the Timing and Progression of Puberty" workshop. The majority of the panelists concluded that the girls' data are sufficient to suggest a secular trend toward earlier breast development onset and menarche from 1940 to 1994 but that the boys' data are insufficient to suggest a trend during this same period. The weight-of-the-evidence evaluation of human and animal studies suggest that endocrine-disrupting chemicals, particularly the estrogen mimics and antiandrogens, and body fat are important factors associated in altered puberty timing. A change in the timing of puberty markers was considered adverse from a public health perspective. The panel recommended research areas to further our understanding of the relationships among environmental factors, puberty-timing outcomes, and other reproductive and adult disease at the individual and population levels.

Association between age at menarche and risk of diabetes in adults: results from the EPIC-Norfolk cohort study

Abstract: Aims/hypothesis Earlier age at menarche is associated with increased BMI and obesity risk from early childhood through to adulthood. We hypothesised that earlier age at menarche would also predict subsequent diabetes risk.

Forty years trends in timing of pubertal growth spurt in 157,000 Danish school children.

Abstract: Background Entering puberty is an important milestone in reproductive life and secular changes in the timing of puberty may be an important indicator of the general reproductive health in a population Too early puberty is associated with several psychosocial and health problems The aim of our study was to determine if the age at onset of pubertal growth spurt (OGS) and at peak height velocity (PHV) during puberty show secular trends during four decades in a large cohort of school children Methods and Findings Annual measurements of height were available in all children born from 1930 to 1969 who attended primary school in the Copenhagen Municipality 135,223 girls and 21,612 boys fulfilled the criteria for determining age at OGS and age at PHV These physiological events were used as markers of pubertal development in our computerized method in order to evaluate any secular trends in pubertal maturation during the study period (year of birth 1930 to 1969) In this period, age at OGS declined statistically significantly by 02 and 04 years in girls and boys, respectively, whereas age at PHV declined statistically significantly by 05 and 03 years in girls and boys, respectively The decline was non-linear with a levelling off in the children born between 1940 and 1955 The duration of puberty, as defined by the difference between age at OGS and age at PHV, increased slightly in boys, whereas it decreased in girls Conclusion Our finding of declining age at OGS and at PHV indicates a secular trend towards earlier sexual maturation of Danish children born between 1930 and 1969 Only minor changes were observed in duration of puberty assessed by the difference in ages at OGS and PHV

Pregnancy and Lactation Hinder Growth and Nutritional Status of Adolescent Girls in Rural Bangladesh

Abstract: Adolescent pregnancy is associated with adverse birth outcomes. Less is known about its influence on maternal growth and nutritional status. We determined how pregnancy and lactation during adolescence affects postmenarcheal linear and ponderal growth and body composition of 12-19 y olds in rural Bangladesh. In a prospective cohort study, anthropometric measurements were taken among primigravidae (n = 229) in the early first trimester of pregnancy and at 6 mo postpartum. Randomly selected never-pregnant adolescents (n = 458) of the same age and time since menarche were measured within 1 wk of these assessments. Annual changes in anthropometric measurements were compared between the 2 groups adjusting for confounders using mixed effects regression models. The mean +/- SD age and age at menarche of adolescents were 16.3 +/- 1.6 y and 12.7 +/- 1.2 y, respectively. Unlike pregnant girls who did not grow in height (-0.09 +/- 0.08 cm/y), never-pregnant girls increased in stature by 0.35 +/- 0.05 cm/y. The adjusted mean difference between the 2 groups was 0.43 +/- 0.1cm (P or =24 mo since menarche (BMI, -1.40 +/- 0.18 vs. -0.60 +/- 0.11 kg/m(2); all interaction terms, P < 0.05). Pregnancy and lactation during adolescence ceased linear growth and resulted in weight loss and depletion of fat and lean body mass of young girls.

Prevalence and severity of dysmenorrhea: a problem related to menstruation, among first and second year female medical students.

Abstract: Dysmenorrhea is the most common of gynecologic complaints. It affects half of all female adolescents today and represents the leading cause of periodic college/school absenteeism among that population. To evaluate the menstrual problem specially dysmenorrhea and its severity in female medical students and its effect on their regular activities. This is a cross-sectional descriptive study; conducted on 107 female medical students, all participants were given a questionnaire to complete; questions were related to menstruation elucidating variations in menstrual patterns, history of dysmenorrhea and its severity, pre-menstrual symptom and absenteeism from college and /or class; to detect the severity of dysmenorrhea we used the verbal multi-dimensiona l scoring system, participants were given 20 minutes to complete the questionnaire. The mean age of subjects at menarche was 12.5 (±1.52) years, with a range of 10-15 years. The prevalence of dysmenorrhea was 73.83%; approximately 4.67%of dysmenorrhic subjects had severe dysmenorrhea. The average duration between two periods and the duration of menstrual flow were 28.34 (±7.54) days and 4.5 (±2.45) days respectively. Prevalence of other menstrual disorders like irregularity, prolonged menstrual bleeding, heavy menstrual bleeding and PCOD were 7.47%, 10.28%, 23.36% and 3.73% respectively. Among female medical students who reported dysmenorrhea; 31.67% and 8.68% were frequently missing college & classes respectively. Premenstrual symptom was the second most (60.50%) prevalent disorder and 67.08% reported social withdrawal. Dysmenorrhea and PMS is highly prevalent among female medical students, it is related to college/class absenteeism, limitations on social, academic, sports and daily activities. Maximum participants do not seek medical advice and self treat themselves with prostaglandin inhibitors; like Ibuprofen.

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

Abstract: 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 independentpredictorofbodymassindex(BMI)andawiderangeof cardiovascular risk factors in adolescence and adulthood. Design:WeexaminedtheassociationsofmenarchealagewithBMI (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:A1-ydecreaseinmenarchealagewasassociatedwith0.81 (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 associationbetweenageatmenarcheandadultBMIremained.However, this inverse association was lost after adjustment for premenarcheal BMI (: 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. Am J Clin Nutr 2008;87:1876–82.

Problems related to menstruation amongst adolescent girls

Abstract: To study the types and frequency of problems related to menstruation in adolescent girls and the effect of these problems on daily routine. Girls in the age group 13–19 years who had had menarche for at least one year at the time of study. 198 adolescent girls have been studied. Data was collected by personal interviews on a pre-tested, semi-structured questionnaire. The questions covered menstrual problems, regularity of menses in last three cycles of menstruation and the effect of these problems on the daily routine. Analysis was done using SPSS version 12. Percentages were calculated for drawing inferences. More than a third (35.9%) of the study subjects were in the age group 13–15 years followed by 17–19 years, 15–17 years respectively. Mean age of study participants was calculated to be 16.2 years. Dysmenorrhea (67.2%) was the commonest problem and (63.1%) had one or the other symptoms of Pre-menstrual syndrome (PMS). Other related problems were present in 55.1% of study subjects. Daily routine of 60% girls was affected due to prolonged bed rest, missed social activities/commitments, disturbed sleep and decreased appetite. 17.24% had to miss a class and 25% had to abstrain from work. Mothers and friends were the most common source of information on the issue. Screen adolescent girls for menstruation related problems and provide them with counseling services and relevant information on possible treatment options. Besides, there is a need to emphasize on designing menstrual health programmes for adolescents.

The pathophysiology of amenorrhea in the adolescent.

Abstract: Menstrual irregularity is a common occurrence during adolescence, especially within the first 2-3 years after menarche. Prolonged amenorrhea, however, is not normal and can be associated with significant medical morbidity, which differs depending on whether the adolescent is estrogen-deficient or estrogen-replete. Estrogen-deficient amenorrhea is associated with reduced bone mineral density and increased fracture risk, while estrogen-replete amenorrhea can lead to dysfunctional uterine bleeding in the short term and predispose to endometrial carcinoma in the long term. In both situations, appropriate intervention can reduce morbidity. Old paradigms of whom to evaluate for amenorrhea have been challenged by recent research that provides a better understanding of the normal menstrual cycle and its variability. Hypothalamic amenorrhea is the most prevalent cause of amenorrhea in the adolescent age group, followed by polycystic ovary syndrome. In anorexia nervosa, exercise-induced amenorrhea, and amenorrhea associated with chronic illness, an energy deficit results in suppression of hypothalamic secretion of GnRH, mediated in part by leptin. Administration of recombinant leptin to women with hypothalamic amenorrhea has been shown to restore LH pulsatility and ovulatory menstrual cycles. The use of recombinant leptin may improve our understanding of the pathophysiology of hypothalamic amenorrhea in adolescents and may also have therapeutic possibilities.

17-beta-estradiol in relation to age at menarche and adult obesity in premenopausal women.

Abstract: BACKGROUND: We hypothesize that premenopausal endogenous estradiol may be associated with age at menarche and adult overweight and obesity, potentially contributing to breast cancer risk. METHODS: We assessed age at menarche by questionnaire among 204 healthy Norwegian women, aged 25 – 35 years. Measures of body composition included body mass index (BMI, kg/m2), waist circumference (WC, cm), waist-to-hip ratio (WHR) and fat percentage dual energy X-ray absorptiometry, (DEXA). Daily salivary 17-b-estradiol (E2) concentrations were collected throughout one entire menstrual cycle and assessed by radioimmunoassay (RIA). Linear regression analyses and linear mixed models for repeated measures were used and potential confounding factors and effect modifiers were tested. RESULTS: Among women with an early age at menarche (12 years), the overall mean salivary E2 concentration increased by 3.7 pmol/l (95% confidence interval, 1.8 – 5.7 pmol/l) with each 9.8 cm (1 SD) increase in WC, which represents a 20.7% change in the mean for the total group. Among the same early maturers, a 1 SD (0.06) change in WHR was directly associated with a 24.0% change in mean E2 concentration for the total group. CONCLUSIONS: Our findings support the hypothesis that early age at menarche, together with adult overweight and obesity, result in high levels of 17-b-estradiol throughout the menstrual cycle.

Pubertal development and menarche.

Abstract: Puberty is the developmental process that culminates in reproductive capability and is the result of a complex series of molecular and physiological events. The release of gonadotropin-releasing hormone from specialized neurons of the hypothalamus begins the hormonal cascade that causes gonadal activation and the physical changes of puberty. Several factors have been proposed to influence the activation of the hypothalamus to trigger puberty, but the involved pathways have not been fully elucidated. The recent observations that the age of pubertal onset may be lowering in American girls calls attention to the lack of knowledge of modulating factors that affect the pubertal process. Genes necessary for puberty have been found by studying persons who do not achieve puberty; such studies have provided insights into the pathways necessary for pubertal development. A multidisciplinary focus is required to elucidate the complex mechanisms involved in the initiation and progression of puberty.

Reproductive traits following a parent–child separation trauma during childhood: A natural experiment during World War II

Abstract: Given the ethical limitations of exposing children to experimentally manipulated adverse experiences, evidence of the effects of childhood traumas on subsequent life history are based mostly on women's retrospective reports and animal studies. Only a few prospective studies have assessed the life-long consequences of childhood trauma. We asked whether a traumatic separation from both parents during childhood is associated with reproductive and marital traits later in life, measured by age of onset of menarche, timing of menopause, period of fertile years, age at first childbirth, birth spacing, number of children, and history of divorce. We studied members of the 1934–1944 Helsinki Birth Cohort, including 396 former war evacuees from varying socioeconomic backgrounds, who were sent unaccompanied by their parents to temporary foster families in Sweden and Denmark, and 503 participants who had no separation experiences. Data on separation experiences, number of children, and divorces experienced came from national registers, and the remaining data from a survey among the participants aged 61.6 years (SD = 2.9). Former evacuees had earlier menarche, earlier first childbirth (men), more children by late adulthood (women), and shorter interbirth intervals (men), than the non-separated. A traumatic experience in childhood is associated with significant alterations in reproductive and marital traits, which characterize both women and men. The implications are relevant to the 9.2 million child refugees living throughout the world today. Am. J. Hum. Biol., 2008. © 2008 Wiley-Liss, Inc.

Cultural perceptions and practices around menarche and adolescent menstruation in the United States.

Abstract: This overview details the persistence of negative characterizations of the menstrual cycle as a feature of the current cultural context in which girls begin menstrual life in the United States. In addition, research on girls' current menstrual attitudes and experiences within this context are reviewed. Current research suggests that girls are not very knowledgeable about menstruation, and that menstrual education continues to provide girls with mixed messages, such as: menstruation is a normal, natural event, but it should be hidden. Girls' attitudes and expectations about menstruation are negatively biased and have been found to contribute to self-objectification, body shame, and lack of agency in sexual decision-making. Although preparation has been found to be associated with more positive menarcheal and menstrual experiences, specificity about what constitutes "good" preparation has not been well articulated. Implications for promoting the menstrual cycle among young girls as a vital sign in service of monitoring their health are discussed.

Association of blood lead levels with onset of puberty in Russian boys.

Abstract: Puberty, the period of transition from childhood to attainment of mature reproductive function, is characterized by accelerated growth, development of secondary sexual characteristics, and psychological changes. Activation of the hypothalamic–pituitary–gonadal axis, manifest as increasing pulsatile secretion of gonadotropin-releasing hormone (GnRH), initiates puberty. Although the precise mechanisms responsible for pubertal onset are not fully understood, body mass and nutritional status (Vizmanos and Marti-Henneberg 2000), psychosocial health, genetic factors, and neuroendocrine inputs to the hypothalamus are all important determinants (Nathan and Palmert 2005). Epidemiologic studies suggest a temporal trend of earlier pubertal onset in girls (Anderson et al. 2003; Herman-Giddens et al. 1997), with less consistent evidence in boys (Herman-Giddens et al. 2001; Karpati et al. 2002). Despite the earlier onset, the age of attainment of sexual maturity has not changed. These temporal shifts have raised concerns regarding the potential impact of environmental factors on pubertal development. In girls, the Third National Health and Nutrition Examination Survey (NHANES III), 1988–1994, showed cross-sectional associations of blood lead levels with delayed breast and pubic hair development and menarche (Selevan et al. 2003; Wu et al. 2003). In boys, several studies report a relationship between lead exposure and diminished early childhood growth (Ballew et al. 1999; Kafourou et al. 1997; Schwartz et al. 1986; Vivoli et al. 1993), but we are not aware of published data on its impact on puberty. The present study was conducted among boys from Chapaevsk, a town of 72,000 residents, in central Russia. Several large industries in Chapaevsk previously manufactured chemical warfare agents but presently produce industrial and agricultural chemicals (Revich et al. 2001). These processes have caused environmental contamination with dioxins and metals, including lead. Additional potential sources of lead exposure are leaded gasoline (Rubin et al. 2002) and lead solder in plumbing. We designed a longitudinal cohort study to explore the impact of environmental contaminants on growth and sexual maturation among Russian boys in Chapaevsk. Boys 8–9 years of age were recruited as subjects of the study to examine the impact of environmental toxicants on both pubertal onset and progression. In this article we present the results of the cross-sectional analysis of the baseline data at 8–9 years of age.

Menarche and father absence in a national probability sample

Abstract: The relation between women's timing of menarche and father absence was examined in a national probability sample of Great Britain (NATSAL 2000; N>5000). Current body mass index (as a proxy for childhood weight) was examined as a potential mediator of this relationship, along with the potential moderating role that siblings (e.g. number of older brothers) had on this relationship. As in a number of previous studies, an absent father (but not an absent mother) during childhood predicted an earlier age of puberty (i.e. an early menarche). There was no evidence that weight mediated this relationship or that siblings moderated it. Both a lower body mass index and more siblings (e.g. more younger sisters and brothers) were independent predictors of a later timing of puberty. The results confirm that certain psychosocial factors (i.e. father absence; presence of siblings) may affect the timing of sexual maturation in adolescent girls.

Menstrual and reproductive factors in relation to mammographic density : the Study of Women's Health Across the Nation (SWAN)

Abstract: Menstrual and reproductive factors may increase breast cancer risk through a pathway that includes increased mammographic density We assessed whether known or suspected menstrual and reproductive breast cancer risk factors were cross-sectionally associated with mammographic density, by measuring area of radiographic density and total breast area on mammograms from 801 participants in the Study of Women’s Health Across the Nation (SWAN), a multi-ethnic cohort of pre- and early perimenopausal women From multivariable linear regression, the following menstrual or reproductive factors were independently associated with percent mammographic density (area of dense breast/breast area): older age at menarche (β = 103, P 13 vs <12 years), premenstrual cravings and bloating (β = −336, P = 002), younger age at first full-term birth (β = −812, P < 001 for ≤23 years versus no births), greater number of births (β = −680, P < 001 for ≥3 births versus no births), and premenopausal status (β = 378, P < 001 versus early perimenopausal) Only number of births remained associated with percent density after adjustment for age, race/ethnicity, study site, body mass index (BMI), and smoking In addition, stratified analyses revealed that the association with number of births was confined to women within the lowest BMI tertile (β = −122, P < 001 for ≥3 births versus no births) Our data support a mechanism for parity and breast cancer that involves mammographic density among pre- and early perimenopausal women that may be modified by body size

Predictors of age at menarche in the newcastle thousand families study.

Abstract: Several studies have found relationships between early life factors (birth weight, length of gestation, height, weight, duration of breast-feeding, maternal age, social class, periods of infection, presence of adverse life events, and quality of housing conditions in childhood) and age at menarche but none has considered all of these factors in the same study. The follow-up study of the Newcastle Thousand Families birth cohort, established in 1947, provided age at menarche data collected retrospectively at age 50 from 276 women who returned self-completion questionnaires in 1997. Three main independent associations were observed: girls who experienced a shorter gestation, girls whose mothers were younger when they were born, and girls who were heavier at age 9 had earlier menarche. Birth weight, standardized for gestational age, was found to have different relationships with age at menarche depending upon how heavy or light a girl was at age 9. The results of this study support the hypotheses that conditions in fetal and early life are associated with the timing of menarche and that greater childhood growth is associated with earlier menarche. It is suggested that future work should focus on illuminating the mechanisms underlying these statistical relationships.

Update on the etiology, diagnosis and therapeutic management of sexual precocity

Abstract: Precocious puberty is defined as the development of secondary sexual characteristics before the age of 8 years in girls and 9 years in boys. Gonadotropin-dependent precocious puberty (GDPP) results from the premature activation of the hypothalamic-pituitary-gonadal axis and mimics the physiological pubertal development, although at an inadequate chronological age. Hormonal evaluation, mainly through basal and GnRH-stimulated LH levels shows activation of the gonadotropic axis. Gonadotropin-independent precocious puberty (GIPP) is the result of the secretion of sex steroids, independently from the activation of the gonadotropic axis. Several genetic causes, including constitutive activating mutations in the human LH-receptor gene and activating mutations in the Gs protein a-subunit gene are described as the etiology of testotoxicosis and McCune-Albright syndrome, respectively. The differential diagnosis between GDPP and GIPP has direct implications on the therapeutic option. Long-acting gonadotropin-releasing hormone (GnRH) analogs are the treatment of choice in GDPP. The treatment monitoring is carried out by clinical examination, hormonal evaluation measurements and image studies. For treatment of GIPP, drugs that act by blocking the action of sex steroids on their specific receptors (cyproterone, tamoxifen) or through their synthesis (ketoconazole, medroxyprogesterone, aromatase inhibitors) are used. In addition, variants of the normal pubertal development include isolated forms of precocious thelarche, precocious pubarche and precocious menarche. Here, we provide an update on the etiology, diagnosis and management of sexual precocity.