Validity of age at menarche self-reported in adulthood

Adolescent Sport Participation and Age at Menarche in Relation to Midlife Body Composition, Bone Mineral Density, Fitness, and Physical Activity

This study aimed to investigate the associations of competitive sport participation in adolescence and age at menarche (AAM) with body composition, femoral neck bone mineral density (BMD), physical performance, and physical activity (PA) in middle-aged women. 1098 women aged 47–55 years formed the sample of this retrospective study. Participants self-reported their PA level at age 13–16 years and AAM. The protocol also included dual-energy X-ray absorptiometry, physical performance tests, and accelerometer-measured PA. Participants were divided into three groups according to their PA level at the age of 13–16 (no exercise, regular PA, and competitive sport) and according to their AAM (≤12, 13, and ≥14 years). After adjusting for potential confounding factors, participation in competitive sport at age 13–16 was associated with higher midlife lean mass and BMD, and better physical performance compared to groups with no exercise or regular PA. Individuals with AAM ≥ 14 years had lower midlife BMI and fat mass than participants in the other AAM groups and pre- and perimenopausal women with AAM ≥ 14 years had lower BMD than those with AAM ≤ 12. The findings indicate that participation in competitive sport in adolescence is associated with healthier body composition, higher BMD, and better physical performance in midlife, but BMD might be impaired if menarche occurs late.

Pubertal timing and breast cancer risk in the Sister Study cohort

Background

Earlier age at menarche is an established risk factor for breast cancer. While age at menarche has been fairly stable over the past half-century, age at breast development (thelarche) has continued to decrease. Recently, earlier age at thelarche and a longer time between thelarche and menarche (pubertal tempo) were shown to be associated with increased breast cancer risk. Our objective was to examine how breast cancer risk was associated with pubertal timing and tempo in a prospective US cohort.

Methods

Women ages 35–74 years without a history of breast cancer, but who had a sister previously diagnosed with breast cancer, were enrolled in the Sister Study from 2003 to 2009 (N = 50,884). At enrollment, participants reported their ages at thelarche and menarche. Pubertal tempo was age at menarche minus age at thelarche. We estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each pubertal milestone and risk of breast cancer (invasive or ductal carcinoma in situ) using Cox proportional hazards regression. We examined whether associations between age at thelarche and breast cancer risk were modified by birth cohort, race/ethnicity, weight at age 10, and extent of breast cancer family history, as characterized by a Bayesian score based on first-degree family structure.

Results

During follow-up (mean = 9.3 years), 3295 eligible women were diagnosed with breast cancer. Early ages at thelarche (HR = 1.23, 95% CI 1.03–1.46 for < 10 vs. 12–13 years) and menarche (HR = 1.10, 95% CI 1.01–1.20 for < 12 vs. 12–13 years) were positively associated with breast cancer risk. Pubertal tempo was not associated with breast cancer risk (HR = 0.99, 95% CI 0.97–1.02 per 1-year longer tempo). When considering early thelarche (< 10 years) and early menarche (< 12 years) jointly, women with both had a 30% greater risk of breast cancer compared with women with neither risk factor (95% CI 1.07–1.57). The association between age at thelarche and breast cancer risk did not significantly vary by birth cohort, race/ethnicity, childhood weight, or Bayesian family history score.

Conclusions

Earlier ages at thelarche and menarche may enhance susceptibility to breast carcinogenesis. Age at thelarche is an important risk factor to consider given secular trends towards earlier development.

Bone density and frame size in adult women: Effects of body size, habitual use, and life history

OBJECTIVE

Bone mineral density (BMD) and frame size are important predictors of future bone health, with smaller frame size and lower BMD associated with higher risk of later fragility fractures. We test the effects of body size, habitual use, and life history on frame size and cortical BMD of the radius and tibia in sample of healthy adult premenopausal women.

METHODS

We used anthropometry and life history data from 123 women (age 18-46) from rural Poland. Standard techniques were used to measure height, weight, and body fat. Life history factors were recorded using surveys. Grip strength was measured as a proxy for habitual activity, wrist breadth for skeletal frame size. Cortical BMD was measured at the one-third distal point of the radius and mid-point of the tibia using quantitative ultrasound (reported as speed of sound, SoS).

RESULTS

Radial SoS was high (mean t-score 3.2 ± 1.6), but tibia SoS was average (mean t-score 0.35 ± 1.17). SoS was not associated with age, although wrist breadth was positively associated with age after adjusting for height. Radius SoS was not associated with measures of body size, habitual use, or life history factors. Wrist breadth was associated with body size (p < .05 for all), lean mass, and grip strength. Tibia SoS was associated with height. Life history factors were not associated with frame size or cortical SoS.

CONCLUSIONS

Habitual use and overall body size are more strongly associated with frame size and cortical SoS than life history factors in this sample of healthy adult women.

Biological aging in childhood and adolescence following experiences of threat and deprivation: A systematic review and meta-analysis

Life history theory argues that exposure to early life adversity (ELA) accelerates development, although existing evidence for this varies. We present a meta-analysis and systematic review testing the hypothesis that ELA involving threat (e.g., violence exposure) will be associated with accelerated biological aging across multiple metrics, whereas exposure to deprivation (e.g., neglect, institutional rearing) and low-socioeconomic status (SES) will not. We meta-analyze 54 studies (n = 116,010) examining associations of ELA with pubertal timing and cellular aging (telomere length and DNA methylation age), systematically review 25 studies (n = 3,253) examining ELA and neural markers of accelerated development (cortical thickness and amygdala-prefrontal cortex functional connectivity) and evaluate whether associations of ELA with biological aging vary according to the nature of adversity experienced. ELA overall was associated with accelerated pubertal timing (d = -0.10) and cellular aging (d = -0.21), but these associations varied by adversity type. Moderator analysis revealed that ELA characterized by threat was associated with accelerated pubertal development (d = -0.26) and accelerated cellular aging (d = -0.43), but deprivation and SES were unrelated to accelerated development. Systematic review revealed associations between ELA and accelerated cortical thinning, with threat-related ELA consistently associated with thinning in ventromedial prefrontal cortex, and deprivation and SES associated with thinning in frontoparietal, default, and visual networks. There was no consistent association of ELA with amygdala-PFC connectivity. These findings suggest specificity in the types of early environmental experiences associated with accelerated biological aging and highlight the importance of evaluating how accelerated aging contributes to health disparities and whether this process can be mitigated through early intervention. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Early age at menarche and risk of postpartum hemorrhage: a retrospective study in Chinese women

Objective: The objective of this study is to investigate whether early age at menarche is associated with increased risk of postpartum hemorrhage among Chinese women.Materials and methods: Clinical data from 6,383 Chinese women who gave birth to live singleton infants at The First Affiliated Hospital of Chengdu Medical College between October 2016 and October 2019 were extracted from the electronic medical records system. Patients were categorized into four groups according to their age at menarche (≤12, 13, 14 and ≥15 years). Logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for postpartum hemorrhage for the different menarche age groups.Results: After controlling for potential confounders, women with menarche at an early age (≤12 years) had a significantly higher risk of developing postpartum hemorrhage than women with an age at menarche of 13 years, and the ORs (95% CIs) for postpartum hemorrhage across the menarche age categories (≤12, 13, 14 and ≥15 years) were 1.27 (1.02-1.81), 1.00 (reference), 0.95 (0.61-1.57), and 0.91 (0.51-1.58), respectively. Moreover, age at menarche was inversely associated with the risk of postpartum hemorrhage after adjustment for all relevant confounding factors, and the OR (95% CI) for postpartum hemorrhage per year of increasing in the age at menarche was 0.93 (0.74-0.99).Conclusion: Early age at menarche was associated with a significantly increased risk of postpartum hemorrhage after adjustment for known confounding factors. This finding could help obstetricians and midwives to identify pregnant women at higher risk of developing postpartum hemorrhage, and allow early preventative strategies to be implemented.

Measurement in the study of menstrual health and hygiene: A systematic review and audit

Background

The lack of established measurement tools in the study of menstrual health and hygiene has been a significant limitation of quantitative studies to date. However, there has been limited exploration of existing measurement to identify avenues for improvement.

Methods

We undertook two linked systematic reviews of (1) trials of menstrual health interventions and their nested studies in low- and middle-income countries, (2) studies developing or validating measures of menstrual experiences from any location. Systematic searching was undertaken in 12 databases, together with handsearching. We iteratively grouped and audited concepts measured across included studies and extracted and compared measures of each concept.

Results

A total of 23 trials, 9 nested studies and 22 measure development studies were included. Trials measured a range of outcomes including menstrual knowledge, attitudes, and practices, school absenteeism, and health. Most measure validation studies focused on assessing attitudes towards menstruation, while a group of five studies assessed the accuracy of women’s recall of their menstrual characteristics such as timing and cycle length. Measures of menstrual knowledge, attitudes, beliefs and restrictions were inconsistent and frequently overlapped. No two studies measured the same menstrual or hygiene practices, with 44 different practices assessed. This audit provides a summary of current measures and extant efforts to pilot or test their performance.

Conclusions

Inconsistencies in both the definition and operationalisation of concepts measured in menstrual health and hygiene research should be addressed. To improve measurement, authors should clearly define the constructs they aim to measure and outline how these were operationalised for measurement. Results of this audit indicate the need for the development and validation of new measures, and the evaluation of the performance of existing measures across contexts. In particular, the definition and measurement of menstrual practices, knowledge, attitudes, norms and restrictions should be addressed.

Review protocol registration

CRD42018089884.

Age at puberty and accelerometer-measured physical activity: Findings from two independent UK cohorts

BACKGROUND

It is unclear if puberty timing influences future physical activity (PA).

AIM

To investigate the association of puberty timing with PA across adolescence and adulthood.

SUBJECTS AND METHODS

Data were from two British cohorts. Participants from an adolescent birth cohort (females = 2349, males = 1720) prospectively reported age at menarche and voice break and had PA recorded by Actigraph accelerometers at ages 14 years and 16 years. A cohort of middle-aged and older adults (40-70 years; females = 48,282; males = 36,112) recalled their age at puberty and had PA (mean acceleration; mg) measured by AxivityAX3 accelerometers.

RESULTS

After adjustment for age, education, smoking and BMI, per 1-year older age at menarche was associated with higher mean counts/minute at age 14 years (0.07 SD counts/minute; 95% CI = 0.04-0.11) with associations attenuated at age 16 years (0.02; -0.03-0.07). Differences in mean acceleration per older year at menarche were close to the null in women aged 40-49 years (0.02 mg; 0.01-0.03), 50-59 years (0.01; 0.00-0.02) and 60-70 years (0.01; 0.00-0.01). Age at voice break and PA associations were close to the null in both cohorts.

CONCLUSION

We found a positive association between puberty timing and PA in females which weakened at older ages and limited evidence of an association at any age in males.

Early puberty and risk for type 2 diabetes in men

AIMS/HYPOTHESIS

The association between pubertal timing and type 2 diabetes, independent of prepubertal BMI, is not fully understood. The aim of the present study was to evaluate the association between pubertal timing and risk of adult type 2 diabetes, independent of prepubertal BMI, in Swedish men.

METHODS

We included 30,697 men who had data for BMI at age 8 and 20 years and age at Peak Height Velocity (PHV), an objective assessment of pubertal timing, available from the BMI Epidemiology Study Gothenburg (BEST Gothenburg), Sweden. Information on type 2 diabetes (n = 1851) was retrieved from the Swedish National Patient Register. HRs and 95% CIs were estimated by Cox regression analysis. We observed violations of the assumption of proportional hazards for the association between age at PHV and the risk of type 2 diabetes and therefore split the follow-up period at the median age of type 2 diabetes diagnosis (57.2 years of age) to define early (≤57.2 years) and late (>57.2 years) type 2 diabetes diagnosis.

RESULTS

Age at PHV was inversely associated with both early (HR 1.28 per year decrease in age at PHV, 95% CI 1.21, 1.36) and late (HR 1.13, 95% CI 1.06, 1.19) type 2 diabetes. After adjustment for childhood BMI, the associations between age at PHV and both early (HR 1.24, 95% CI 1.17, 1.31) and late (HR 1.11, 95% CI 1.05, 1.17) type 2 diabetes were similar. Moreover, early age at PHV predicted insulin treatment of type 2 diabetes (OR 1.25 per year decrease in age at PHV, 95% CI 1.17, 1.33). Assuming a higher risk among those with an age at PHV below the median, the population attributable factor indicates that 15% fewer of the diagnosed individuals would have developed type 2 diabetes had they not reached puberty early.

CONCLUSIONS/INTERPRETATION

These findings indicate that early puberty may be a novel independent risk factor for type 2 diabetes.

The levelling-off of the secular trend of age at menarche among Italian girls

OBJECTIVE

The main aim of this study was to verify whether the secular trend stopped in Italy by comparing the results of a 1990-2000 birth cohort versus a 1980-1990 birth cohort of Italian young women. The results were used to speculate about age at menarche as adaptive response to non-genetic factors.

METHODS

In 2016, a study was set on 413, 18-to-26 year-old women (1990-2000 birth cohort) attending two Italian Universities by web-based, self-reported questionnaires. Previously in 2000, a research including 3,783 high school female students (1980-1990 birth cohort) was led. The age at menarche distribution was performed by Kaplan-Meier analysis. The comparison between the findings of the two birth cohorts was performed by Wilcoxon sum-rank test. Mixed models analysis was applied to evaluate the effect of cohort and socio-economic status on age at menarche.

RESULTS

1990-2000 cohort's age at menarche median was 12.44y (95%CI 12.37; 12.59y). There was no significant difference with age at menarche of the previous cohort (p = 0.56). Consistently, the advance of age at menarche in comparison to the mothers' one was not significantly different between the two cohorts (-0.27y±0.10y vs -0.25y±0.03y, p = 0.33). The socio-economic level was not significantly associated with menarcheal age.

CONCLUSIONS

The findings of this study confirm that, like in other developed countries, the advance of age at menarche has stopped in Italy, consistently with the stop of the improvement of socio-economic conditions. Further studies are needed to explore the differential effect of each non-genetic factor to outline future scenarios of human sexual maturation.

TRIAL REGISTRATION

the Comitato Etico per la Sperimentazione Clinica (CESC) della Provincia di Padova of the Veneto Region (Italy), n°3993/U16/16.

Secular trends in age at menarche in 20th century Mexico: Differences by ethnicity, area of residency, and socioeconomic status

OBJECTIVES

This study aims to assess the secular trend in age at menarche (AAM) in Mexico over the 20th century, and compare the patterns according to area of residence (rural/urban), socioeconomic status (SES), and ethnicity (indigenous/nonindigenous).

METHODS

Data on AAM from 24 380 women aged ≥20 years born between 1906 and 1986 were obtained from the Mexican National Health and Nutrition Survey 2006. Birth cohorts were compared to test for a secular trend and differences in mean AAM by area of residence, SES, and ethnicity were evaluated using the Welch test for heterogeneous variances followed by Tamhane T² for post hoc comparisons.

RESULTS

Mean AAM declined from 13.3 years among Mexican women born before the 1940s to 12.56 years among those born in the 1980s. Across birth cohorts, urban women had significantly earlier AAM than their rural counterparts. Nonindigenous urban women reached menarche the earliest and rural indigenous women the latest of all groups. Nonindigenous urban residents experienced a comparatively earlier decline, while that for the indigenous rural women occurred last. High SES women reached menarche the earliest and low SES women the latest. The historical decline in AAM for high and medium SES groups occurred relatively early, whereas that for the low SES occurred last.

CONCLUSIONS

Mean AAM was associated with area of residence, ethnicity, and SES. Our findings indirectly suggest that advances in living conditions experienced in Mexico during the 20th century appear to have been insufficient to overcome the social and biological inequalities accumulated over centuries in some groups.

Association of puberty timing with type 2 diabetes: A systematic review and meta-analysis

BACKGROUND

Emerging studies have investigated the association between puberty timing, particularly age at menarche (AAM), and type 2 diabetes. However, whether this association is independent of adiposity is unclear. We aimed to systematically review published evidence on the association between puberty timing and type 2 diabetes (T2D) or impaired glucose tolerance (IGT), with and without adjustment for adiposity, and to estimate the potential contribution of puberty timing to the burden of T2D in the United Kingdom (UK).

METHODS AND FINDINGS

We searched PubMed, Medline, and Embase databases for publications until February 2019 on the timing of any secondary sexual characteristic in boys or girls in relation to T2D/IGT. Inverse-variance-weighted random-effects meta-analysis was used to pool reported estimates, and meta-regression was used to explore sources of heterogeneity. Twenty-eight observational studies were identified. All assessed AAM in women (combined N = 1,228,306); only 1 study additionally included men. In models without adjustment for adult adiposity, T2D/IGT risk was lower per year later AAM (relative risk [RR] = 0.91, 95% CI 0.89-0.93, p < 0.001, 11 estimates, n = 833,529, I2 = 85.4%) and higher for early versus later menarche (RR = 1.39, 95% CI 1.25-1.55, p < 0.001, 23 estimates, n = 1,185,444, I2 = 87.8%). Associations were weaker but still evident in models adjusted for adiposity (AAM: RR = 0.97 per year, 95% CI 0.95-0.98, p < 0.001, 12 estimates, n = 852,268, I2 = 51.8%; early menarche: RR = 1.19, 95% CI 1.11-1.28, p < 0.001, 21 estimates, n = 890,583, I2 = 68.1%). Associations were stronger among white than Asian women, and in populations with earlier average AAM. The estimated population attributable risk of T2D in white UK women due to early menarche unadjusted and adjusted for adiposity was 12.6% (95% CI 11.0-14.3) and 5.1% (95% CI 3.6-6.7), respectively. Findings in this study are limited by residual and unmeasured confounding, and self-reported AAM.

CONCLUSIONS

Earlier AAM is consistently associated with higher T2D/IGT risk, independent of adiposity. More importantly, this research has identified that a substantial proportion of T2D in women is related to early menarche, which would be expected to increase in light of global secular trends towards earlier puberty timing. These findings highlight the need to identify the underlying mechanisms linking early menarche to T2D/IGT risk.

Genomics of Reproductive Traits and Cardiometabolic Disease Risk in African American Women

BACKGROUND

Age at menarche and age at natural menopause occur significantly earlier in African American women than in other ethnic groups. African American women also have twice the prevalence of cardiometabolic disorders related to the timing of these reproductive traits.

OBJECTIVES

The objectives of this integrative review were to (a) summarize the genome-wide association studies of reproductive traits in African American women, (b) identify genes that overlap with reproductive traits and cardiometabolic risk factors in African American women, and (c) propose biological mechanisms explaining the link between reproductive traits and cardiometabolic risk factors.

METHODS

PubMed was searched for genome-wide association studies of genes associated with reproductive traits in African American women. After extracting and summarizing the primary genes, we examined whether any of the associations with reproductive traits had also been identified with cardiometabolic risk factors in African American women.

RESULTS

Seven studies met the inclusion criteria. Associations with both reproductive and cardiometabolic traits were reported in or near the following genes: FTO, SEC16B, TMEM18, APOE, PHACTR1, KCNQ1, LDLR, PIK3R1, and RORA. Biological pathways implicated include body weight regulation, vascular homeostasis, and lipid metabolism.

DISCUSSION

A better understanding of the genetic basis of reproductive traits in African American women may provide insight into the biological mechanisms linking variation in these traits with increased risk for cardiometabolic disorders in this population.

Dimorphism in axial and appendicular dimensions, cortical and trabecular microstructure and matrix mineral density in Chinese and Caucasian women

INTRODUCTION

Appendicular fractures are less common in Chinese than Caucasian women. Bone mineral density (BMD) is lower, not higher than in Caucasians because Chinese have smaller appendicular dimensions than Caucasians. However, smaller bones may offset the liability to fracture by being assembled with a more robust microstructure. We hypothesized that Chinese assemble an appendicular skeleton with a thicker, less porous and more mineralized cortex that is less deteriorated in advanced age than in Caucasians.

METHODS

We compared anthropometry in 477 Chinese and 278 Caucasian women and compared bone microstructure using high-resolution peripheral quantitative computed tomography in another cohort of 186 Chinese and 381 Caucasian women aged 18 to 86 years, all living in Melbourne, Australia. Trabecular plate (p) and rod (r) bone volume/total volume (BV/TV) were quantified using individual trabecula segmentation (ITS). Bone strength was estimated using micro-finite element analysis (μFEA).

RESULTS

Premenopausal Chinese were shorter than Caucasian women, mainly due to shorter leg length. Distal radial total cross sectional area (CSA) was 14.8% smaller (p < 0.001). After adjusting for age and total CSA, Chinese had similar cortical and medullary areas but 0.30 SD lower cortical porosity and 0.27 SD higher matrix mineral density (both p < 0.05). Trabecular plate-to-rod ratio was 0.55 SD higher due to a 0.41 SD higher pBV/TV and 0.36 SD lower rBV/TV (p ranging 0.001 to 0.023). Chinese also had 0.36 SD greater whole bone stiffness and 0.36 SD greater failure load than Caucasians (both p < 0.05). After adjusting for age and total CSA, postmenopausal Chinese had 3.3% smaller cortical area, medullary area was 2.1% larger, cortical porosity was no lower, matrix mineral density and pBV/TV were no higher compared with Caucasians at the distal radius. Whole bone stiffness was 0.39 SD lower and failure load was 0.40 SD lower in Chinese (both p < 0.05).

CONCLUSION

Chinese build a more robust skeleton than Caucasians during growth, an advantage not observed in advanced age due to greater bone loss or race-specific secular trends in bone morphology.

Early menarche is associated with an increased risk of type 2 diabetes in rural Chinese women and is partially mediated by BMI: the Henan Rural Cohort Study

OBJECTIVE

The aim of the study was to determine if early menarche is associated with an increased risk of type 2 diabetes mellitus (T2DM) in rural Chinese women and to estimate the proportion that can be attributed to adiposity.

METHODS

A total of 15,346 postmenopausal women were enrolled in this study. Logistic regression and restricted cubic spline analysis were performed to estimate the relationship between age at menarche and T2DM. Mediation analysis was used to investigate whether the association was mediated by body mass index (BMI).

RESULTS

After adjusting for multiple confounders, the early menarche group (≤14 y) had a higher risk of T2DM (odds ratio [OR] = 1.21; 95% CI = 1.06-1.38; P = 0.004) compared with the reference group (16-17 y), whereas the late onset group (≥19 y) had a lower risk of T2DM (OR = 0.78; 95% CI = 0.66-0.92; P = 0.003). BMI partially mediated the association between age at menarche and T2DM, and the proportion of the effect was 28%.

CONCLUSIONS

Early menarche increases the risk of T2DM, whereas later menarche decreases the risk. The association seems to be partially mediated by BMI.

Maternal age at menarche and offspring body mass index in childhood

Background

Earlier age of menarche has been associated with an increased risk of chronic diseases during adulthood, but whether early menarche has intergenerational effect is not clear.

Methods

In this population-based cross-sectional study, we recruited children from 26 primary schools using cluster random probability sampling in Shanghai, China, in 2014. We used multiple linear regression models to estimate the adjusted associations of maternal age of menarche (MAM) with offspring body mass index (BMI). We also used the mediation analysis to examine the contribution of maternal BMI and gestational diabetes to offspring BMI.

Results

A total of 17,571 children aged 6–13 years were enrolled, of whom 16,373 had their weight and height measured. Earlier MAM was associated with higher child BMI in boys (− 0.05 z-score per year older MAM, 95% CI − 0.08 to − 0.02) and in girls (− 0.05 z-score per year older MAM, 95% CI − 0.07 to − 0.02). Maternal BMI positively mediated the association of MAM with offspring BMI in both sexes, with mediation effects of 37.7 and 19.4% for boys and girls, respectively.

Conclusion

Early maternal menarche was associated with greater offspring BMI. This study provides evidence for the intergenerational effect in the development of BMI in offspring.

Electronic supplementary material

The online version of this article (10.1186/s12887-019-1659-4) contains supplementary material, which is available to authorized users.

The relationship between pubertal timing and markers of vascular and cardiac structure and function in men and women aged 60-64 years

Earlier age at menarche has been associated with higher risk of coronary heart disease, but the mechanisms underlying the association remain unclear. We assessed the relationship of pubertal timing, in both men (n = 672) and women (n = 713), with vascular (carotid intima-media thickness (cIMT), pulse wave velocity (PWV)) and cardiac (left ventricular (LV) structure and function) measures recorded at age 60–64 yrs in a British birth cohort study. Regression models found that earlier menarche was associated with higher (more adverse) LV mass, LV end diastolic volume and left atrial volume, but not with other cardiac measures, cIMT or PWV. Associations were attenuated after adjustment for either adult or childhood BMI (e.g. mean difference in LV mass per year later menarche: −4.2 g (95% CI:−7.0,−1.4) reducing to −2.2 g (95% CI:−4.7,0.4) after adjustment for adult BMI). There were no associations among men, despite those fully mature at 15 yrs having higher blood pressure than the least mature group by 10.21 mmHg (95% CI:19.45,0.98). Any effect of pubertal timing on vascular and cardiac structure and function is likely to be small and primarily confounded by pre-pubertal BMI and/or mediated through adult adiposity.

Age at menarche does not correlate with the endometriosis phenotype

Objective

To evaluate the association between the endometriosis phenotype and the age at menarche.

Design

An observational, cross-sectional study using prospectively collected data (Canadian Task Force classification II-2).

Setting

Single university tertiary referral center.

Patients

To be eligible, women had to have undergone their 1^st complete surgical exeresis of endometriotic lesions. For each patient, a standardized questionnaire was completed the month before the surgery. Endometriotic lesions were classified into 3 phenotypes: superficial peritoneal endometriosis (SUP), endometrioma (OMA), or deep infiltrating endometriosis (DIE). Patients were divided into 3 groups: early menarche (< 12 years), typical menarche (≥ 12 and ≤ 13 years) and late menarche (> 13 years). The groups were compared in terms of general characteristics, medical history, disease phenotype, and disease severity.

Interventions

Surgical management for a benign gynecologic condition.

Main Outcome Measure(s)

Correlation between the endometriosis phenotype and the age at menarche.

Measurements and main results

From January 2004 to December 2016, 789 women with histologically confirmed endometriosis were enrolled in the study. The mean age at menarche was 12.9 ± 1.6 years of age, (range 9 to 18). The mean age at menarche and the mean time interval between menarche and the 1^st surgery for endometriosis were not significantly different between the three phenotypes (SUP, OMA, DIE). When women with early menarche, typical menarche, or late menarche were compared, no differences were observed in terms of the endometriosis phenotype and the anatomical distribution of the endometriotic lesions.

Conclusion

For women operated for the first time for endometriosis, age at menarche is not associated with the disease phenotype.

Early Menstrual Factors Are Associated with Adulthood Cardio-Metabolic Health in a Survey of Mexican Teachers

Objectives To evaluate whether age at menarche and time to menstrual regularity were related to cardio-metabolic risk factors in Mexican women. Methods The study population comprised 54,921 women from the 2008-2010 wave of the Mexican Teacher's Cohort. A modified Poisson approach was used; exposures were age at menarche and time to menstrual regularity (< 1 year vs. ≥1 year), and outcomes were prevalent obesity, type 2 diabetes, high blood pressure, and high cholesterol. Results Mean (SD) age of women was 42.1 (7.6) years, and mean (SD) menarcheal age was 12.5 (1.5) years. Compared to women with menarche age 13 years, those with menarche < 9 years had a 65% (95% CI 43-90%); 27% (95% CI 4-55%); and 23% (95% CI 1-49%) higher prevalence of obesity, high blood pressure, and high cholesterol, respectively. For diabetes, there was a U-shaped association; compared to menarche age 13 years, those with menarche < 9 years had an 89% higher prevalence of diabetes (95% CI 39-156%), and those with menarche ≥ 17 years had a 65% higher prevalence (95% CI 16-134%). Among women with regular cycles (n = 43,113), a longer time to menstrual regularity was associated with diabetes (PR = 1.11 with 95% CI 1.02-1.22), high blood pressure (PR = 1.11 with 95% CI 1.06-1.17), and high cholesterol (PR = 1.09 with 95% CI 1.04-1.14). Conclusions for practice Mexican women with earlier and later ages at menarche and/or longer time to menstrual regularity may have higher risk of cardio-metabolic disease in adulthood.

Early menarche and premature natural menopause in Indonesia

BACKGROUND

An association has been suggested between early menarche and premature natural menopause. However, existing studies in developed countries show mixed findings.

AIM

This study examined whether early menarche (first menstrual period ≤11 years old) is a factor for premature natural menopause (final menstrual period <40 years old) in the context of a developing country.

SUBJECTS AND METHODS

Data came from the Indonesia Family Life Survey (IFLS) 2014, which consists of 1608 post-menopausal women.

RESULTS

Results of hierarchical logistic regression show that women who experienced early menarche (first menstrual period ≤11 years old) were found to be at higher risk of premature natural menopause (β = 0.94, p < 0.01, CI = 0.24-1.63). The results are robust against potential confounding factors including individual reproductive history, lifestyle and sociodemographic characteristics, as well as unobserved factors at the household and community levels.

CONCLUSION

The findings support early monitoring of women with early menarche, especially those who have no children, for preventive health interventions aimed at mitigating the risk of adverse health outcomes associated with premature natural menopause.

Age at Menarche and Blood Pressure in Pregnancy

Objectives

To investigate whether age at menarche is related to maternal blood pressure in pregnancy and, if so, whether obesity and insulin resistance can modify the associations.

Study Design

Analysis of data collected from 438 pregnant women from the longitudinal and prospective Cambridge Baby Growth Study.

Main Outcome

Testing associations between questionnaire-derived age at menarche and blood pressure measurements in pregnancy collected from hospital notes, and investigating whether any associations were altered by maternal pre-pregnancy body mass index (BMI) and insulin resistance.

Measures

Mean arterial blood pressure at four time points across pregnancy, age at menarche, (Homeostasis Model Assessment) insulin resistance around week 28 of pregnancy.

Results

For each increased year in age at menarche there was a drop in mean arterial blood pressure (mmHg) of 0.6 at 11.9 weeks, 0.9 at 31.4 and 37.0 weeks, and 0.4 at 38.8 weeks (a maximal difference of over 7 mmHg across extremes of AAM). Each association was attenuated by both maternal pre-pregnancy BMI and insulin resistance.

Conclusions

Age at menarche is negatively associated with future blood pressure in pregnancy, so those with the earliest age at menarche have the highest blood pressures. Either these associations may be mediated by links between age at menarche and obesity/insulin resistance, or there may be a confounder (e.g. systemic inflammation) that links age at menarche to each of them.

Effect of Interaction between Early Menarche and Genetic Polymorphisms on Triglyceride

Early menarche has been associated with increased risk of metabolic syndrome. Therefore, investigating the association of each component of metabolic syndrome with age at menarche, and interactions between them, might lead to a better understanding of metabolic syndrome pathogenesis. In this study, we evaluated age at menarche for risk of metabolic syndrome and associations with its components. As a result, the risk of MetS incidence was significantly increased only at ≤12 years of age at menarche (OR = 1.91, P < 0.05). Women with early menarche (≤12 years) had significantly higher levels of triglycerides (β coefficient = 37.83, P = 0.02). In addition, hypertriglyceridemia was significantly increased at early menarche with 1.99 (95% CI: 1.16–3.41, P < 0.01). With GWAS-based pathway analysis, we found the type 2 diabetes mellitus, stress-activated protein kinase signaling, and Jun amino-terminal kinase cascade pathways (all nominal P < 0.001, all FDR < 0.05) to be significantly involved with early menarche on triglyceride levels. These findings may help us understand the role of early menarche on triglyceride and interaction between gene and early menarche on triglyceride for the development of metabolic syndrome.

Timing of puberty in boys and girls: A population-based study

BACKGROUND

A secular trend towards earlier puberty has been observed in girls, while a similar trend has been more uncertain in boys. We estimated current ages at pubertal development in both boys and girls.

METHODS

In this population-based cohort study, 14 759 of 22 439 invited boys and girls born from 2000 to 2003 in the Danish National Birth Cohort gave half-yearly self-reported information on puberty from the age of 11.5 years and throughout puberty. This late start of follow-up limits the estimation of age at onset of puberty but not later pubertal milestones. We estimated mean age at attaining the following pubertal milestones in years with 95% confidence intervals (CI): age at menarche, voice break, first ejaculation of semen and Tanner stages for pubic hair development and breast development or genital development. Further, the difference in mean age at menarche between mothers and daughters was estimated.

RESULTS

In boys, voice break occurred at 13.1 (95% CI 13.0, 13.1) years, first ejaculation of semen occurred at 13.4 (95% CI 13.3, 13.4) years, and Tanner Genital Stage 5 occurred at 15.6 (95% CI 15.5, 15.6) years. In girls, age at menarche occurred at 13.0 (95% CI 13.0, 13.1) years and Tanner Breast Stage 5 occurred at 15.8 (95% CI 15.7, 15.9) years. Daughters had menarche 3.6 (95% CI 3.1, 4.2) months earlier than their mothers had.

CONCLUSION

These data indicate that age at menarche has declined and to some extent support a decline in age at attaining other markers of pubertal development among boys.

Association of blood leukocyte DNA methylation at LINE-1 and growth-related candidate genes with pubertal onset and progression

Puberty is a developmentally plastic phase. Variations in pubertal tempo have implications for the risk of later adult diseases. Influences on pubertal tempo have been widely discussed, but the underlying biological mechanisms remain unclear. Epigenetic modifications are known to regulate development processes; they could play an important role in affecting pubertal outcomes. We conducted a population-based analysis to investigate the association of peripubertal blood DNA methylation at LINE-1 and growth-related candidate genes with pubertal onset and progression in healthy adolescents. The analytic sample included 114 males and 129 females aged 10 to 18 years. DNA methylation at growth-related candidate loci IGF2, H19, HSD11B2, as well as LINE-1 repetitive elements were quantified. Cox survival and ordinal regression models were used to examine sex- and locus-specific associations of epigenetic markers with pubertal development using physician-assessed Tanner stages and self-reported menarche, adjusted for covariates. Among boys, DNA methylation at H19 was associated with later pubarche. HSD11B2 methylation was associated with earlier onset of pubic hair and genitalia development and slower pubertal progression. IGF2 was associated with later onset of genital development. Among girls, LINE-1 methylation was associated with later onset of breast development. For each percent increase of methylation at H19, there was 5% increased odds in the earlier onset of breast development. DNA methylation of IGF2 was associated with earlier onset of pubic hair. DNA methylation at genes known to influence early-life growth may also influence pubertal outcomes.

Association of Height Growth in Puberty with Lung Function. A Longitudinal Study

Rationale: Puberty may influence lung function, but the precise role of pubertal height growth in lung development is unclear.Objectives: To examine associations of timing of puberty and peak velocity of pubertal height growth with lung function in adolescence and early adulthood.Methods: Longitudinal analyses of repeat height measurements from age 5 to 20 years for a British birth cohort with 4,772 males and 4,849 females were conducted to characterize height growth trajectories and to derive pubertal age and peak height velocity using the validated SITAR (SuperImposition by Translation and Rotation) model. Association of these estimates with prebronchodilator and post-bronchodilator spirometry measures: FEV1; FVC; FEV1/FVC; FEF25-75% at age 15 and 24 years were investigated using multivariable regression models adjusted for lung function at age 8 years, height and age at time of outcome measurements, and potential confounders.Measurements and Main Results: Later pubertal age and greater peak velocity were associated with higher FEV1 and FVC at 24 years in both sexes. A 1-year increase in pubertal age was associated with a 263-ml higher FVC (95% confidence interval [CI], 167-360 ml) for males (n = 567) and 100-ml (95% CI, 50-150 ml) higher FVC for females (n = 990). A 1-cm/yr increase in peak velocity was associated with 145-ml (95% CI, 56-234 ml) and 50-ml (95% CI, 2-99 ml) increases in FVC for males and females, respectively. No associations were found with FEV1/FVC.Conclusions: Later onset and greater peak velocity of height growth in puberty are associated with increased FEV1 and FVC in young adults but there was no evidence of dysanapsis of pubertal lung growth.

Menstrual Cycle Characteristics in Adolescence and Early Adulthood Are Associated With Risk of Early Natural Menopause

CONTEXT

Early natural menopause (i.e., before age 45 years) is associated with increased risk of adverse outcomes. Associations of earlier menopause with younger age at menarche and short and/or regular cycle length are suggested, but study findings are inconsistent and few address early menopause risk.

OBJECTIVE

To evaluate the relationship between menstrual cycle characteristics in early life with incident early natural menopause.

DESIGN

The prospective Nurses' Health Study 2 (1989 to 2011).

SETTING AND PARTICIPANTS

Women ages 25 to 42 years and premenopausal in 1989 (N = 108,811).

MAIN OUTCOME MEASURE(S)

Risk of early natural menopause not due to surgery, radiation, or chemotherapy (n = 2794) was evaluated with Cox proportional hazards models. Anti-Müllerian hormone (AMH) levels were considered in a nested case-control sample (n = 820).

RESULTS

In adjusted models, risk was associated with earlier age at menarche (P for trend = 0.05), shorter (P for trend < 0.0001), and more-regular cycles (P for < 0.0001). The hazard ratio (HR) for women with age at menarche ≤9 (vs. 12) years was 1.28 (95% CI, 0.99 to 1.67). Women reporting usual menstrual cycle lengths <25 days at ages 18 to 22 years had substantially higher risk of early menopause (HR, 1.70; 95% CI, 1.47 to 1.96) than women with 26- to 31-day cycles, whereas women with ≥40 day cycles had lower risk (HR, 0.44; 95% CI, 0.34 to 0.58). Women with irregular cycle length had lower risk compared with women with regular cycles (HR, 0.51; 95% CI, 0.43 to 0.60). Associations with AMH concentrations among the nested case-control subset were consistent with these findings.

CONCLUSION

Results from this large prospective study of early menopause suggest an influence of accelerated oocyte depletion on risk and may help clarify the etiology of early menopause.

Influence of puberty timing on adiposity and cardiometabolic traits: A Mendelian randomisation study

BACKGROUND

Earlier puberty is widely linked with future obesity and cardiometabolic disease. We examined whether age at puberty onset likely influences adiposity and cardiometabolic traits independent of childhood adiposity.

METHODS AND FINDINGS

One-sample Mendelian randomisation (MR) analyses were conducted on up to 3,611 white-European female and male offspring from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort recruited at birth via mothers between 1 April 1991 and 31 December 1992. Time-sensitive exposures were age at menarche and age at voice breaking. Outcomes measured at age 18 y were body mass index (BMI), dual-energy X-ray absorptiometry-based fat and lean mass indices, blood pressure, and 230 cardiometabolic traits derived from targeted metabolomics (150 concentrations plus 80 ratios from nuclear magnetic resonance [NMR] spectroscopy covering lipoprotein subclasses of cholesterol and triglycerides, amino acids, inflammatory glycoproteins, and others). Adjustment was made for pre-pubertal BMI measured at age 8 y. For negative control MR analyses, BMI and cardiometabolic trait measures taken at age 8 y (before puberty, and which therefore cannot be an outcome of puberty itself) were used. For replication analyses, 2-sample MR was conducted using summary genome-wide association study data on up to 322,154 adults for post-pubertal BMI, 24,925 adults for post-pubertal NMR cardiometabolic traits, and 13,848 children for pre-pubertal obesity (negative control). Like observational estimates, 1-sample MR estimates in ALSPAC using 351 polymorphisms for age at menarche (explaining 10.6% of variance) among 2,053 females suggested that later age at menarche (per year) was associated with -1.38 kg/m2 of BMI at age 18 y (or -0.34 SD units, 95% CI -0.46, -0.23; P = 9.77 × 10-09). This coefficient attenuated 10-fold upon adjustment for BMI at age 8 y, to -0.12 kg/m2 (or -0.03 SDs, 95% CI -0.13, 0.07; P = 0.55). Associations with blood pressure were similar, but associations across other traits were small and inconsistent. In negative control MR analyses, later age at menarche was associated with -0.77 kg/m2 of pre-pubertal BMI measured at age 8 y (or -0.39 SDs, 95% CI -0.50, -0.29; P = 6.28 × 10-13), indicating that variants influencing menarche also influence BMI before menarche. Cardiometabolic trait associations were weaker and less consistent among males and both sexes combined. Higher BMI at age 8 y (per 1 kg/m2 using 95 polymorphisms for BMI explaining 3.4% of variance) was associated with earlier menarche among 2,648 females (by -0.26 y, 95% CI -0.37, -0.16; P = 1.16 × 10-06), likewise among males and both sexes combined. In 2-sample MR analyses using 234 polymorphisms and inverse variance weighted (IVW) regression, each year later age at menarche was associated with -0.81 kg/m2 of adult BMI (or -0.17 SD units, 95% CI -0.21, -0.12; P = 4.00 × 10-15). Associations were weaker with cardiometabolic traits. Using 202 polymorphisms, later menarche was associated with lower odds of childhood obesity (IVW-based odds ratio = 0.52 per year later, 95% CI 0.48, 0.57; P = 6.64 × 10-15). Study limitations include modest sample sizes for 1-sample MR, lack of inference to non-white-European populations, potential selection bias through modest completion rates of puberty questionnaires, and likely disproportionate measurement error of exposures by sex. The cardiometabolic traits examined were heavily lipid-focused and did not include hormone-related traits such as insulin and insulin-like growth factors.

CONCLUSIONS

Our results suggest that puberty timing has a small influence on adiposity and cardiometabolic traits and that preventive interventions should instead focus on reducing childhood adiposity.

Prenatal lead exposure in relation to age at menarche: results from a longitudinal study in Mexico City

Animal and cross-sectional epidemiological studies suggest that prenatal lead exposure is related to delayed menarche, but this has not been confirmed in longitudinal studies. We analyzed this association among 200 girls from Mexico City who were followed since the first trimester of gestation. Maternal blood lead levels were analyzed once during each trimester of pregnancy, and daughters were asked about their first menstrual cycle at a visit between the ages of 9.8 and 18.1 years. We estimated hazard ratios (HRs) and 95% confidence intervals (CI) for probability of menarche over the follow-up period using interval-censored Cox models, comparing those with prenatal blood lead level ⩾5 µg/dl to those with prenatal blood lead <5 µg/dl. We also estimated HRs and 95% CI with conventional Cox regression models, which utilized the self-reported age at menarche. In adjusted analyses, we accounted for maternal age, maternal parity, maternal education, and prenatal calcium treatment status. Across trimesters, 36-47% of mothers had blood lead levels ⩾5 µg/dl. Using interval-censored models, we found that during the second trimester only, girls with ⩾5 µg/dl prenatal blood lead had a later age at menarche compared with girls with prenatal blood lead levels <5 µg/dl (confounder-adjusted HR=0.59, 95% CI 0.28-0.90; P=0.05). Associations were in a similar direction, although not statistically significant, in the conventional Cox regression models, potentially indicating measurement error in the self-recalled age at menarche. In summary, higher prenatal lead exposure during the second trimester could be related to later onset of sexual maturation.

The association between age at menarche and later risk of gestational diabetes is mediated by insulin resistance

AIMS

Associations have been reported between age at menarche and the later risk of gestational diabetes. However, it is not known whether these associations reflect differences in insulin sensitivity and/or pancreatic β-cell function in pregnancy.

METHODS

We examined this question in women enrolled in the prospective Cambridge Baby Growth Study who recalled their age at menarche in questionnaires during pregnancy. Polynomial logistic and linear regression models were used to relate menarche timing to the risk of gestational diabetes, both unadjusted and adjusted for the Homeostasis Model Assessments of insulin resistance (HOMA IR) and pancreatic β-cell function (HOMA B) at week 28 of pregnancy.

RESULTS

Age at menarche showed a U-shaped association with gestational diabetes risk (linear term: p = 9.5 × 10^-4; quadratic term: p = 1.0 × 10^-3; n = 889; overall model p = 8.1 × 10^-3). Age at menarche showed a negative linear association with insulin resistance (HOMA IR: β = -0.13, p = 5.2 × 10^-4, n = 771), which explained the relationship between age at menarche and gestational diabetes risk (adjusted linear term going from p = 0.03-0.08; adjusted quadratic term going from p = 0.04-0.08; n = 771). Age at menarche also showed a negative linear association with β-cell function (HOMA B: β = -0.11, p = 2.8 × 10^-3, n = 771) but this did not attenuate the relationship between age at menarche and gestational diabetes (adjusted linear term p = 0.02; adjusted quadratic term p = 0.03, n = 771).

CONCLUSIONS

These results suggest that the associations between age at menarche and risk of gestational diabetes and raised pregnancy glucose concentrations may be mediated by insulin resistance.

The relation of age at menarche with age at natural menopause: a population study of 336 788 women in Norway

STUDY QUESTION

Is age at menarche associated with age at menopause or with duration of the reproductive period (interval between menarche and menopause)?

SUMMARY ANSWER

The association of age at menarche with age at menopause was weak and non-linear, and the duration of the reproductive period decreased by increasing age at menarche.

WHAT IS KNOWN ALREADY

It remains uncertain whether age at menarche is associated with age at menopause. Some studies report that women with early menarche also have early menopause. Other studies report that women with early menarche have late menopause, or they report no association. The duration of the reproductive period may be an indicator of the cumulative endogenous exposure to estrogens and progestogens during life course and is associated with risk of breast cancer and endometrial cancer.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study of 336 788 women, aged 48-71 years, in the BreastScreen Norway during the years 2006-2014 was performed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Information about age at menarche and menopausal status was obtained by self-administered questionnaires. We used time to event approaches to estimate the associations.

MAIN RESULTS AND THE ROLE OF CHANCE

Median age at menopause was 51 years in most menarche groups. Women with menarche at age 16 years or age ≥ 17 years had menopause 1 year later [median: 52 years, interquartile range (IQR): 49-54 years] than women with menarche at age 13 years (median: 51 years, IQR: 49-54 years, reference) (crude hazard ratio (HR) = 0.95; 95% CI: 0.93-0.97 and 0.95; 95% CI: 0.92-0.99, Pnon-linearity < 0.001). The reproductive period decreased with increasing age at menarche (Pnon-linearity < 0.001), and women with menarche at age ≤ 9 years had 9 years longer median reproductive period than women with menarche at age ≥ 17 years (median: 43 versus 34 years). Adjustment for year of birth did not change the HR estimates notably.

LARGE SCALE DATA

Not applicable.

LIMITATIONS, REASONS FOR CAUTION

Information about age at menarche and age at menopause was based on self-reports. Particularly for age at menarche, the long time interval between the event and data collection may have caused imprecise reporting.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that age at menarche is a strong indicator for the duration of women's reproductive period. Our findings should encourage studies of the independent role of duration of the reproductive period on the risk of breast cancer and endometrial cancer, since these cancers have been associated with exposure to estrogens and progestogens.

STUDY FUNDING/COMPETING INTEREST(S)

The present study was funded by the Norwegian Cancer Society [Grant number 6863294-2015]. The authors declare no conflicts of interest.

Is age at menarche associated with total mortality? The Tromsø Study

Purpose

Early age at menarche (AAM) has been associated with increased mortality and morbidity, including premature death from all causes, breast cancer and cardiovascular diseases. The aim of this study was to examine the association between AAM and all-cause mortality.

Subjects and methods

A total of 12,409 women aged 25–94 years who took part in the fourth Tromsø Study in Norway during 1994–1995 were included in this prospective population-based study with a mean 18.7 years of follow-up. Multivariate Cox proportional hazard analysis was used to investigate the association between AAM and all-cause mortality with adjustment for known confounders (age, body mass index, physical activity, level of education and smoking history).

Results

During the 18.7 years of follow-up, a total of 2,203 women died. There was no association between AAM and all-cause mortality before or after adjusting for possible confounding factors.

Conclusion

This prospective study of 12,409 women did not find any association between AAM and all-cause mortality

Relationship between growth, maturation and musculoskeletal conditions in adolescents: a systematic review

Objective

To determine whether there is a relationship between physical growth and development, as determined by markers of biological maturation, and musculoskeletal conditions in adolescents.

Design

Systematic review.

Data sources

Electronic databases (PubMed, EMBASE and the Cumulative Index to Nursing and Allied Health Literature) were searched up to 6 September 2017.

Eligibility criteria for selecting studies

Studies that evaluated the association between biological maturation or growth and musculoskeletal conditions in adolescents (chronological age 10–19 years).

Results

From 20 361 titles identified by the searches, 511 full-text articles were retrieved and assessed for eligibility; 56 studies, all at high risk of bias, evaluating the relationship between maturation and/or growth and musculoskeletal conditions were included. A total of 208 estimates of association were identified across the included studies, which generally indicated no association or an unclear association between maturation, growth and musculoskeletal conditions.

Summary/Conclusions

While the relationship between maturation, growth and musculoskeletal conditions remains plausible, the available evidence is not supportive. The current body of knowledge is at high risk of bias, which impedes our ability to establish whether biological maturity and growth are independent risk factors for musculoskeletal conditions.

AGE AT MENARCHE AND SEXUAL DEBUT AMONG YOUNG FILIPINO WOMEN

There has been a secular decline in age at menarche since the 19th century. Early-maturing women are more likely to have their sexual debut at a younger age, which in turn gives rise to a host of reproductive health and social problems. This study used data from five waves of National Demographic and Health Surveys conducted in the Philippines between 1993 and 2013 to examine the trends and socioeconomic differentials in age at menarche and sexual debut. The changing trend in age at menarche and sexual debut was examined across birth cohorts, and logistic regressions were used to identify the determinants of early sexual debut. In the Philippines, the mean and median ages at menarche declined from 13.2 years and 12.6 years, respectively, among young women born in 1973-1977, to 12.9 years and 12.3 years, respectively, among those born in 1993-1997. The proportion who had their sexual debut by age 20 increased from 41.2% for the 1968-1972 birth cohort to 53.4% for the 1988-1992 birth cohort. Filipino women with low education, from poor families and living in rural areas were more likely to have earlier sexual debut despite attaining menarche at a later age as compared with their higher educated counterparts, and those from wealthier families and urban areas. Logistic regression analysis showed that, besides marital status, women's education and age at menarche were important determinants of early sexual debut. However, ethnicity, place of residence and family wealth had no significant effects on age at menarche. An increasing proportion of young women were found to be having unprotected sexual debut and at a younger age, with health and social ramifications. Hence, apart from increasing the enrolment of girls in schools and discouraging teenage marriage, there is a need for social and health agencies to implement appropriate adolescent sexual and reproductive health programmes such as counselling and educational campaigns, as well as support services, to address sexual problems among the youth.

Hair product use, age at menarche and mammographic breast density in multiethnic urban women

BACKGROUND

Select hair products contain endocrine disrupting chemicals (EDCs) that may affect breast cancer risk. We hypothesize that, if EDCs are related to breast cancer risk, then they may also affect two important breast cancer risk factors: age at menarche and mammographic breast density.

METHODS

In two urban female cohorts (N = 248): 1) the New York site of the National Collaborative Perinatal Project and 2) the New York City Multiethnic Breast Cancer Project, we measured childhood and adult use of hair oils, lotions, leave-in conditioners, root stimulators, perms/relaxers, and hair dyes using the same validated questionnaire. We used multivariable relative risk regression models to examine the association between childhood hair product use and early age at menarche (defined as <11 years of age) and multivariable linear regression models to examine the association between childhood and adult hair product use and adult mammographic breast density.

RESULTS

Early menarche was associated with ever use of childhood hair products (RR 2.3, 95% CI 1.1, 4.8) and hair oil use (RR 2.5, 95% CI 1.2, 5.2); however, additional adjustment for race/ethnicity, attenuated associations (hair products RR 1.8, 95% CI 0.8, 4.1; hair oil use RR 2.3, 95% CI 1.0, 5.5). Breast density was not associated with adult or childhood hair product or hair oil use.

CONCLUSIONS

If confirmed in larger prospective studies, these data suggest that exposure to EDCs through hair products in early life may affect breast cancer risk by altering timing of menarche, and may operate through a mechanism distinct from breast density.

Childhood psychosocial adversity and female reproductive timing: a cohort study of the ALSPAC mothers

BACKGROUND

Previous studies of childhood psychosocial adversity and age at menarche mostly evaluated single or a few measures of adversity, and therefore could not quantify total psychosocial adversity. Limited knowledge is currently available regarding childhood psychosocial adversity in relation to age at menopause and reproductive lifespan.

METHODS

We examined the associations of total and specific components of childhood psychosocial adversity with age at menarche (n=8984), age at menopause (n=945), and length of reproductive lifespan (n=841), in mothers participating in the Avon Longitudinal Study of Parents and Children. We used confirmatory factor analysis to characterise lack of care, maladaptive family functioning, non-sexual abuse, overprotective parenting, parental mental illness and sexual abuse. These specific components of childhood psychosocial adversity were combined into a total psychosocial adversity score using a second-order factor analysis. We used structural equation models to simultaneously conduct the factor analysis and estimate the association with the continuous outcomes of interest.

RESULTS

Total childhood psychosocial adversity was not associated with age at menarche, age at menopause or length of reproductive lifespan. When we examined the separate psychosocial adversity constructs, sexual abuse was inversely associated with age at menarche, with a mean difference of -0.17 (95% CI -0.23 to -0.12) years per SD higher factor score, and with age at menopause, with a mean difference of -0.17 (95% CI -0.52 to 0.18) per SD higher factor score.

CONCLUSION

Childhood sexual abuse was associated with lower age at menarche and menopause, but the latter needs to be confirmed in larger samples.

Differential Impact of Genetic Loci on Age at Thelarche and Menarche in Healthy Girls

CONTEXT

Recent genetic studies have identified genetic variants associated with age at pubertal onset. Whereas genome-wide association studies reported associations of several hundred genetic variants with timing of self-reported age at menarche, a recent clinical study focused on genetic variation affecting follicle-stimulating hormone action and clinically determined age at thelarche. The observations appear to be incongruent, as effect sizes varied substantially among the studies. Alternatively, this may point to a differential impact of specific genetic loci on distinct pubertal events.

OBJECTIVE

To investigate whether top-candidate genetic variants exhibit a different impact on timing of thelarche vs menarche, respectively.

DESIGN

Cross-sectional and longitudinal study of healthy girls.

SETTING

Population-based study in the Copenhagen area.

PATIENTS OR OTHER PARTICIPANTS

Girls (1478) were followed through puberty and genotyped for FSHB c.-211G>T (rs10835638), FSHR c.-29G>A (rs1394205), FSHR c.2039A>G (rs6116), LIN28B (rs7759938), INHA (rs4141153), MKRN3 (rs12148769), TMEM38B (rs10453225), and ZNF483 (rs10980921).

MAIN OUTCOME MEASURES

Clinical pubertal staging and anthropometric data.

RESULTS

We observed an association of LIN28B (rs7759938) with age at thelarche (P < 0.001, effect size: 0.27 year, 95% confidence interval: 0.12 to 0.42) and age at menarche (P = 0.005, 0.17 year, 0.05 to 0.29). FSHB c.-211G>T (rs10835638) and FSHR c.-29G>A (rs1394205) minor allele count was associated with age at thelarche (P = 0.004, 0.19 year, 0.06 to 0.31) but not with age at menarche (P = 0.97; all adjusted for body mass index z scores).

CONCLUSION

Our results indicate a differential impact of specific genetic loci on age at thelarche and menarche in healthy girls.

Markers of pubertal timing and leisure-time physical activity from ages 36 to 68 years: findings from a British birth cohort

OBJECTIVES

We aimed to examine associations between markers of pubertal timing and leisure-time physical activity (LTPA) from ages 36 to 68 years in men and women from the Medical Research Council National Survey of Health and Development.

STUDY DESIGN

Pubertal timing was ascertained by physicians at age 14-15 years. Boys were grouped, based on their secondary sexual characteristics, as prepubescent, in early-stage puberty, advanced stage puberty or fully mature at age 14-15 years. Girls were grouped as reaching menarche ≤11, 12, 13 or ≥14 years. LTPA was reported at ages 36, 43, 53, 60-64 and 68 years and classified as active or inactive at each age. Associations were examined using standard and mixed-effects logistic regression models.

RESULTS

Of 5362 singleton births recruited, 1499 men and 1409 women had at least one measure of LTPA and data on pubertal timing and selected covariates. When compared with men that were fully mature at age 14-15 years, those that were in advanced stage and early-stage puberty, but not the prepubescent stage, had lower likelihood of LTPA at younger but not older adult ages (p=0.06 for pubertal status-by-age at LTPA interaction in mixed-effects model). For example, fully adjusted ORs of LTPA (vs no LTPA) at ages 36 and 68 years, respectively, for advanced puberty versus fully mature were 0.69 (95% CIs 0.50 to 0.96) and 1.03 (0.72 to 1.47). Age at menarche was not associated with LTPA at any age (p_interaction with age at LTPA=0.9). For example, OR (from mixed-effects model) of LTPA between 36 and 68 years was 1.23 (0.93, 1.63) for menarche at 13 vs ≤11 years.

CONCLUSIONS

In a nationally representative study, there was little evidence to suggest that pubertal timing was an important correlate of LTPA between ages 36 and 68 years. Maturity-related variations in adolescents' LTPA may be transitory and lose importance over time.

Age at menarche and prevalence of preterm birth: Results from the Healthy Baby Cohort study

Little is known about the impact of age at menarche on preterm birth. The aim of this study was to examine the association between age at menarche and preterm birth. A total of 11,016 Chinese women who gave birth to live singleton infants were recruited from the Healthy Baby Cohort between 2012 and 2014 in the province of Hubei, China. Age at menarche was reported via face-to-face interviews and was categorized into five groups (≤11, 12, 13, 14 and ≥15 years). Gestational age was estimated using maternal last menstrual period. Preterm birth was defined as delivering a live singleton infant at <37 weeks' gestational age. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Earlier menarche (≤11 years) was associated with an increased prevalence of preterm birth (OR: 1.67, 95% CI: 1.18, 2.36) compared with menarche age at 13 years after controlling for the potential confounders. The findings of our study suggested that a history of earlier menarche might be useful for identifying women at higher risk of preterm birth.

The reproducibility of self-reported age at menarche: The Tromsø Study

BACKGROUND

Previous studies of the reproducibility of self-reported age at menarche have been limited because of small study samples, short follow-up and the limited age span of the women included.

METHODS

The present study assessed the reproducibility of age at menarche in 6731 women with a wide variation of age when giving the information about age at menarche. The women reported age at menarche in a self-administered questionnaire, both in 1986-1987 and 1994-1995. They were all residents of Tromsø, Norway, and aged 25-73 in 1994-1995. In order to investigate the agreement between self-reported age at menarche at the two points in time, Pearson's correlation coefficient was applied to assess the linear correlation between the reported menarcheal age at the two occasions. Analyses were stratified for age. A Bland-Altman plot was produced and limits of agreement computed.

RESULTS

We found a high correlation and a strong agreement between self-reported age at menarche in 1986-1987 and 1994-1995. The overall Pearson's correlation coefficient was 0.84 and was not attenuated by increasing age of the women. The Bland-Altman plot showed a strong agreement in self-reported age at menarche. The mean difference between self-reported age at menarche was 0.01 years with limits of agreement -1.52 to 1.54.

CONCLUSION

We found high reproducibility of self-reported age at menarche. The mean menarcheal age in the two surveys was identical (13.2 years) with 95% of the women reporting the same age at menarche or with a difference of 1 year. Only 0.7% of the women reported age at menarche with a difference of more than 2 years in 1986-1987 and 1994-1995.

Association between age at menarche and cardiovascular disease: A systematic review on risk and potential mechanisms

Age at menarche (AAM) has been reported to be associated with the risk of cardiovascular disease (CVD), but the shape of and the mechanisms behind this association remain unclear. We reviewed the data on the association between AAM and different subtypes of CVD, and used shared genetic loci to identify possible mechanisms underlying this association using shared genetic association. We searched the databases of PubMed, Web of Science and Embase through to April 2017. We included articles with any clinically manifest CVD endpoint and for any ethnicity. We identified single nucleotide polymorphisms (SNPs) for AAM in genome-wide association studies (GWAS) in Caucasians through PubMed and HuGE Navigator, and searched whether these SNPs or any of their proxies were associated with any CVD-related trait. Eight studies in Caucasian populations reported an inverse linear relation between AAM and CVD risk, whereas one large study reported a significant U-shaped relation between them. Data from Asian populations were contradictory and inconclusive. In total, 122 AAM SNPs were identified at a genome-wide significance level (p<5×10^-8). Of those, 18 were also associated with various CVD-related traits, primarily body mass index (BMI), obesity, and height. In conclusion, early AAM and possibly also late AAM increase the risk of CVD in Caucasian populations. Weight and height may be part of the mechanism underlying the relation between AAM and CVD risk in Caucasians. Data on other ethnicities are too limited for meaningful analysis and conclusions.

Is age of menarche among school girls related to academic performance?

Background There is strong evidence that the mean age of menarche has declined over the last few decades in developed and developing countries. This is of a major concern because of its enormous public health implications. This study aimed to estimate the age of menarche in Kuwait and investigate the association between menarcheal age and academic performance among high school girls in Kuwait. Methods A cross-sectional study was conducted on randomly selected female high school students from private and public high schools in all governorates in Kuwait. Data on the age of menarche were collected by self-administered questionnaire from the students, while data on academic performance were extracted from the students' academic records. Results Of the 907 students we selected, 800 (88.2%) responded. The mean age of menarche was 12.33 [95% confidence interval (CI) 12.18-12.49] years. There was no evidence for significant association between age of menarche and students' academic performance before or after adjusting for potential confounders. Conclusion The calculated age of menarche among contemporary girls in Kuwait is similar to that of the girls in industrialized countries. Early menarcheal age is unlikely to lead to adverse behavior that may affect academic performance in our setting.

Exposure to phytoestrogens in utero and age at menarche in a contemporary British cohort

Phytoestrogens are estrogenic compounds that occur naturally in plants. Phytoestrogens can cross the placenta, and animal studies have found associations between in utero exposure to phytoestrogens and markers of early puberty. We investigated the association between in utero exposure to phytoestrogens and early menarche (defined as <11.5 years of age at onset) using data from a nested case-control study within the Avon Longitudinal Study of Parents and Children, a longitudinal study involving families living in the South West of England. Concentrations of six phytoestrogens were measured in maternal urine samples collected during pregnancy. Logistic regression was used to explore associations between tertiles of phytoestrogen concentrations and menarche status, with adjustment for maternal age at menarche, maternal education, pre-pregnancy body mass index (BMI), child birth order, duration of breastfeeding, and gestational age at sample collection. Among 367 mother-daughter dyads, maternal median (interquartile range) creatinine-corrected concentrations (in µg/g creatinine) were: genistein 62.1 (27.1-160.9), daidzein 184.8 (88.8-383.7), equol 4.3 (2.8-9.0), O-desmethylangolensin (O-DMA) 13.0 (4.4-34.5), enterodiol 76.1 (39.1-135.8), and enterolactone 911.7 (448.1-1558.0). In analyses comparing those in the highest tertile relative to those in the lowest tertile of in utero phytoestrogen exposure, higher enterodiol levels were inversely associated with early menarche (odds ratio (OR)=0.47; 95% confidence interval (CI): 0.26-0.83), while higher O-DMA levels were associated with early menarche (OR=1.89; 95% CI: 1.04-3.42). These findings suggest that in utero exposure to phytoestrogens may be associated with earlier age at menarche, though the direction of association differs across phytoestrogens.

Changing trends in reproductive/lifestyle factors in UK women: descriptive study within the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS)

OBJECTIVE

There has been considerable interest in the impact of reproductive factors on health but there are little data on how these have varied over time. We explore trends in reproductive/lifestyle factors of postmenopausal British women by analysing self-reported data from participants of the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS).

DESIGN

Prospective birth cohort analysis.

SETTING

Population cohort invited between 2001 and 2005 from age-sex registers of 27 Primary Care Trusts in England, Wales and Northern Ireland and recruited through 13 National Health Service Trusts.

PARTICIPANTS

202 638 postmenopausal women aged 50-74 years at randomisation to UKCTOCS between April 2001 and October 2005.

INTERVENTIONS

Women were stratified into the following six birth cohorts (1925-1929, 1930-1934, 1935-1939, 1940-1944, 1945-1949, 1950-1955) based on year of birth. Self-reported data on reproductive factors provided at recruitment were explored using tabular and graphical summaries to examine for differences between the birth cohorts.

OUTCOME MEASURES

Trends in mean age at menarche and menopause, use of oral contraceptives, change in family size, infertility treatments, tubal ligation and hysterectomy rates.

RESULTS

Women born between 1935 and 1955 made up 86% of the cohort. Median age at menarche decreased from 13.4 for women born between 1925 and 1929 to 12.8 for women born between 1950 and 1955. Increased use of the oral contraceptives, infertility treatments and smaller family size was observed in the younger birth cohorts. Tubal ligation rates increased for those born between 1925 and 1945, but this increase did not persist in subsequent cohorts. Hysterectomy rates (17-20%) did not change over time.

CONCLUSIONS

The trends seen in this large cohort are likely to reflect the reproductive history of the UK female postmenopausal population of similar age. Since these are risk factors for hormone-related cancers, these trends are important in understanding the changing incidence of these cancers.

TRIAL REGISTRATION NUMBER

International Standard Randomised Controlled Trial Number: 22488978.

Early menarche, nulliparity and the risk for premature and early natural menopause

STUDY QUESTION

Are parity and the timing of menarche associated with premature and early natural menopause?

SUMMARY ANSWER

Early menarche (≤11 years) is a risk factor for both premature menopause (final menstrual period, FMP <40 years) and early menopause (FMP 40-44 years), a risk that is amplified for nulliparous women.

WHAT IS KNOWN ALREADY

Women with either premature or early menopause face an increased risk of chronic conditions in later life and of early death. Findings from some studies suggest that early menarche and nulliparity are associated with early menopause, however overall the evidence is mixed. Much of the evidence for a direct relationship is hampered by a lack of comparability across studies, failure to adjust for confounding factors and inadequate statistical power.

STUDY DESIGN, SIZE, DURATION

This pooled study comprises 51 450 postmenopausal women from nine observational studies in the UK, Scandinavia, Australia and Japan that contribute to the International collaboration for a Life course Approach to reproductive health and Chronic disease Events (InterLACE).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Age at menarche (categorized as ≤11, 12, 13, 14 and 15 or more years) and parity (categorized as no children, one child and two or more children) were exposures of interest. Age at FMP was confirmed by at least 12 months of cessation of menses where this was not the result of an intervention (such as surgical menopause due to bilateral oophorectomy or hysterectomy) and categorized as premature menopause (FMP before age 40), early menopause (FMP 40-44 years), 45-49 years, 50-51 years, 52-53 years and 54 or more years. We used multivariate multinomial logistic regression models to estimate relative risk ratio (RRR) and 95% CI for associations between menarche, parity and age at FMP adjusting for within-study correlation.

MAIN RESULTS AND THE ROLE OF CHANCE

The median age at FMP was 50 years (interquartile range 48-53 years), with 2% of the women experiencing premature menopause and 7.6% early menopause. Women with early menarche (≤11 years, compared with 12-13 years) were at higher risk of premature menopause (RRR 1.80, 95% CI 1.53-2.12) and early menopause (1.31, 1.19-1.44). Nulliparity was associated with increased risk of premature menopause (2.26, 1.84-2.77) and early menopause (1.32, 1.09-1.59). Women having early menarche and nulliparity were at over 5-fold increased risk of premature menopause (5.64, 4.04-7.87) and 2-fold increased risk of early menopause (2.16, 1.48-3.15) compared with women who had menarche at ≥12 years and two or more children.

LIMITATIONS, REASONS FOR CAUTION

Most of the studies (except the birth cohorts) relied on retrospectively reported age at menarche, which may have led to some degree of recall bias.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings support early monitoring of women with early menarche, especially those who have no children, for preventive health interventions aimed at mitigating the risk of adverse health outcomes associated with early menopause.

STUDY FUNDING/COMPETING INTEREST(S)

InterLACE project is funded by the Australian National Health and Medical Research Council project grant (APP1027196). G.D.M. is supported by Australian Research Council Future Fellowship (FT120100812). There are no competing interests.

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.

Using Super-Imposition by Translation And Rotation (SITAR) to relate pubertal growth to bone health in later life: the Medical Research Council (MRC) National Survey of Health and Development

Background: To explore associations between pubertal growth and later bone health in a cohort with infrequent measurements, using another cohort with more frequent measurements to support the modelling, data from the Medical Research Council (MRC) National Survey of Health and Development (2–26 years, 4901/30 004 subjects/measurements) and the Avon Longitudinal Study of Parents And Children (ALSPAC) (5–20 years) (10 896/74 120) were related to National Survey of Health and Development (NSHD) bone health outcomes at 60–64 years.

Methods: NSHD data were analysed using Super-Imposition by Translation And Rotation (SITAR) growth curve analysis, either alone or jointly with ALSPAC data. Improved estimation of pubertal growth parameters of size, tempo and velocity was assessed by changes in model fit and correlations with contemporary measures of pubertal timing. Bone outcomes of radius [trabecular volumetric bone mineral density (vBMD) and diaphysis cross-sectional area (CSA)] were regressed on the SITAR parameters, adjusted for current body size.

Results: The NSHD SITAR parameters were better estimated in conjunction with ALSPAC, i.e. more strongly correlated with pubertal timing. Trabecular vBMD was associated with early height tempo, whereas diaphysis CSA was related to weight size, early tempo and slow velocity, the bone outcomes being around 15% higher for the better vs worse growth pattern.

Conclusions: By pooling NSHD and ALSPAC data, SITAR more accurately summarized pubertal growth and weight gain in NSHD, and in turn demonstrated notable associations between pubertal timing and later bone outcomes. These associations give insight into the importance of the pubertal period for future skeletal health and osteoporosis risk.

Pubertal timing and bone phenotype in early old age: findings from a British birth cohort study

Objectives: To investigate the effect of pubertal timing, assessed in adolescence, on bone size, strength and density in men and women in early old age.

Design: A British birth cohort study with prospective indicators of pubertal timing based on age at menarche, clinical assessment of pubertal stage, and growth tempo from serial height measures, and bone measures derived from peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA) at 60-64 years of age among 866 women and 792 men.

Methods: A first set of regression models investigated the relationships between pubertal timing and bone size, strength and density, adjusting for current height and weight, smoking and adult socioeconomic position. To make an equivalent comparison between men and women, the percentage difference in bone outcomes was calculated for a 5-year difference in age at menarche, and in men a comparison between those who were fully mature or pre-adolescent at 14.5 years. A second set of models investigated the percentage difference in bone outcomes for a 5-year difference in timing of peak height velocity (height tempo) derived from longitudinal growth modelling (Superimposition by Translation and Rotation model; SITAR).

Results: After adjustment for current height and weight, a 5-year increase in age at menarche was associated with an 8% [95% confidence interval (CI) -17%, 0.5%, P = 0.07) lower trabecular volumetric bone mineral density (vBMD); men who were pre-adolescent at 14.5 years had a 9%, (95% CI -14%, -4%; P = 0.001) lower trabecular vBMD compared with those who had been fully mature. Other confounders did not attenuate these estimates further. Patterns of association were similar but somewhat weaker for lumbar spine and total hip areal BMD. Age at peak height velocity was associated with even larger differences in BMD in men and women, and was negatively associated with bone size and strength.

Conclusions: The association between later puberty and lower BMD persists into early old age. The 9-10% lower trabecular vBMD in later compared with earlier maturers could be clinically important given a rate of bone loss from midlife of 1-2% a year and the negative association between BMD and fracture.

Reproductive factors related to childbearing and mammographic breast density

We investigated the associations of reproductive factors related to childbearing with percent breast density, absolute dense and nondense areas, by menopausal status. This study included 4110 cancer-free women within the Nurses' Health Study and Nurses' Health Study II cohorts. Percent breast density, absolute dense and nondense areas were measured from digitized mammography film images with computerized techniques. All density measures were square root-transformed in all the analyses to improve normality. The data on reproductive variables and other breast cancer risk factors were obtained from biennial questionnaires, at the time of the mammogram date. As compared to nulliparous women, parous postmenopausal women had lower percent density (β = -0.60, 95 % CI -0.84; -0.37), smaller absolute dense area (β = -0.66, 95 % CI -1.03; -0.29), and greater nondense area (β = 0.72, 95 % CI 0.27; 1.16). Among parous women, number of children was inversely associated with percent density in pre- (β per one child = -0.12, 95 % CI -0.20; -0.05) and postmenopausal women (β per one child = -0.07, 95 % CI -0.12; -0.02). The positive associations of breastfeeding with absolute dense and nondense areas were limited to premenopausal women, while the positive association of the age at first child's birth with percent density and the inverse association with nondense area were limited to postmenopausal women. Women with greater number of children and younger age at first child's birth have more favorable breast density patterns that could explain subsequent breast cancer risk reduction.

Menstrual cycle characteristics and fecundability in a North American preconception cohort

PURPOSE

The aim of this study was to evaluate the association between menstrual cycle characteristics in early life and adulthood and fecundability.

METHODS

Pregnancy Study Online (PRESTO) is an Internet-based preconception cohort study of pregnancy planners from the United States and Canada. During the preconception period, we enrolled 2189 female pregnancy planners aged 21-45 years who had been attempting conception for ≤6 cycles. Women self-reported menstrual cycle characteristics via an online baseline questionnaire, and pregnancy status was ascertained through bimonthly follow-up questionnaires. Proportional probabilities models were used to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs), adjusting for potential confounders.

RESULTS

Compared with usual menstrual cycle lengths of 27-29 days, cycle lengths of <25 (FR = 0.81, 95% CI: 0.54-1.22) and 25-26 days (FR = 0.92, 95% CI: 0.75-1.14) were associated with reduced fecundability. Compared with women who reached menarche at the age of 12-13 years, those who reached menarche at <12 years had reduced fecundability (FR = 0.87, 95% CI: 0.76-0.99). Women whose cycles never regularized after menarche (FR = 0.93, 95% CI: 0.81-1.06) had slightly reduced fecundability compared with women whose cycles regularized within 2 years of menarche. Bleed length and heaviness of bleeding were not appreciably associated with fecundability.

CONCLUSIONS

Menstrual cycle characteristics, specifically cycle length and age at menarche, may act as markers of fertility potential among pregnancy planners.

Pubertal maturation and affective symptoms in adolescence and adulthood: Evidence from a prospective birth cohort

The higher prevalence of affective symptoms among women compared to men emerges in adolescence, and it has been associated with pubertal maturation. However, it remains unclear whether pubertal timing has long-term influences on affective symptoms. Using data from the British 1946 birth cohort, we investigated whether pubertal timing was associated with affective symptoms over the life course, distinguishing those with symptoms in adolescence only, symptoms in adulthood only, and symptoms in both adolescence and adulthood. In females, there was no evidence that early pubertal maturation was a risk factor for affective symptoms. However, those with particularly late menarche (≥15 years) showed a lower risk of adult-onset affective symptoms (odds ratio = 0.54, 95% confidence interval = 0.31, 0.95). This effect of late pubertal timing was not explained by a range of sociobehavioral factors. In contrast, in males, late pubertal timing was associated with increased risk of adolescent-onset affective symptoms that tracked into adulthood (odds ratio = 2.10, 95% confidence interval = 1.44, 3.06). This effect was partly explained by low prepubertal body mass index. Sex-specific effects of pubertal timing on the long-term risk of affective symptoms might be due to different effects of gonadal hormonal on the central nervous system, as well as different social experiences during puberty.