Life-course origins of the ages at menarche and menopause

Mother's age at menarche is associated with odds of preterm delivery: A case-control study

OBJECTIVE

There is a secular trend towards earlier age of menarche in the US and globally. Earlier age at menarche (AAM) has been associated with metabolic disorders that increase risk for preterm delivery (PTD), yet no studies in the US have investigated whether AAM influences risk of PTD. This study tested the hypothesis that AAM is associated with PTD.

DESIGN

A case-control study.

SETTING

The Boston Medical Center (BMC) in Boston, Massachusetts.

POPULATION OR SAMPLE

8264 mother-newborn dyads enrolled at birth at BMC between 1998 and 2019, of which 2242 mothers had PTD (cases) and 6022 did not have PTD (controls).

METHODS

Multivariable-adjusted logistic regression models and restricted cubic splines were used to examine the association between AAM and risk of PTD. The combined impact of AAM and age at delivery on the risk of PTD was also examined.

MAIN OUTCOME MEASURES

Preterm delivery and gestational age (GA) was defined by maternal last menstrual period and early ultrasound documented in medical records.

RESULTS

Maternal age at delivery was 28.1 ± 6.5 years and AAM was 12.85 ± 1.86 years. Multivariable-adjusted cubic spline suggested an inverse dose-response association of AAM with odds of PTD and, consistently, a positive association with GA. A 1-year earlier AAM was associated with 5% (95% CI 2%-8%) higher odds of PTD, after adjustment for maternal year of birth, parity, maternal place of birth, education, smoking status and Mediterranean-style diet score. The association between AAM and PTD was stronger among older mothers whose age at delivery was ≥35 years.

CONCLUSIONS

Earlier AAM is associated with higher odds for PTD, and this association is stronger among women at advanced reproductive age.

Causal associations between female reproductive behaviors and psychiatric disorders: a lifecourse Mendelian randomization study

BACKGROUND

The timings of reproductive life events have been examined to be associated with various psychiatric disorders. However, studies have not considered the causal pathways from reproductive behaviors to different psychiatric disorders. This study aimed to investigate the nature of the relationships between five reproductive behaviors and twelve psychiatric disorders.

METHODS

Firstly, we calculated genetic correlations between reproductive factors and psychiatric disorders. Then two-sample Mendelian randomization (MR) was conducted to estimate the causal associations among five reproductive behaviors, and these reproductive behaviors on twelve psychiatric disorders, using genome-wide association study (GWAS) summary data from genetic consortia. Multivariable MR was then applied to evaluate the direct effect of reproductive behaviors on these psychiatric disorders whilst accounting for other reproductive factors at different life periods.

RESULTS

Univariable MR analyses provide evidence that age at menarche, age at first sexual intercourse and age at first birth have effects on one (depression), seven (anxiety disorder, ADHD, bipolar disorder, bipolar disorder II, depression, PTSD and schizophrenia) and three psychiatric disorders (ADHD, depression and PTSD) (based on p<7.14×10-4), respectively. However, after performing multivariable MR, only age at first sexual intercourse has direct effects on five psychiatric disorders (Depression, Attention deficit or hyperactivity disorder, Bipolar disorder, Posttraumatic stress disorder and schizophrenia) when accounting for other reproductive behaviors with significant effects in univariable analyses.

CONCLUSION

Our findings suggest that reproductive behaviors predominantly exert their detrimental effects on psychiatric disorders and age at first sexual intercourse has direct effects on psychiatric disorders.

Secular trends in premature and early menopause in low-income and middle-income countries

BACKGROUND

While secular trends in high-income countries show an increase in the mean age at menopause, it is unclear if there is a similar pattern in low-income and middle-income countries (LMICs), where women's exposure to biological, environmental and lifestyle determinants of menopause may differ. Premature (before age 40 years) and early (ages 40-44 years) menopause could have negative repercussions on later life health outcomes which in ageing societies could mean further stress on low-resource health systems. An evaluation of such trends in LMICs has been hampered by the suitability, quality and comparability of data from these countries.

METHODS

Using 302 standardised household surveys from 1986 to 2019, we estimate trends and CIs using bootstrapping in the prevalence of premature and early menopause in 76 LMICs. We also developed a summary measure of age at menopause for women who experience menopause before the age of 50 years based on demographic estimation methods that can be used to measure menopausal status in surveys with truncated data.

RESULTS

Trends indicate an increasing prevalence of early and premature menopause in LMICs, in particular in sub-Saharan Africa and South/Southeast Asia. These regions also see a suggested decline of the mean age at menopause with greater variation across continents.

CONCLUSIONS

This study enables the analysis of menopause timing by exploiting data generally used for the study of fertility by methodologically allowing the use of truncated data. Findings show a clear increase in prevalence of premature and early menopause in the regions with the highest fertility with possible consequences for later life health. They also show a different trend compared with high-income regions, confirming a lack of generalisability and the importance of accounting for nutritional and health transitions at the local level. This study calls for further data and research on menopause on a global scale.

The risk of endometriosis by early menarche is recently increased: a meta-analysis of literature published from 2000 to 2020

PURPOSE

The relationship between menarche age and endometriosis has been studied extensively; however, the results were inconsistent due to differences in study dates, populations, and methodology. The goal of this meta-analysis was to see how different research populations, dates, and types affected the estimated risk of endometriosis in early menarche.

METHODS

The terms "endometriosis", "early menarche", and other pertinent terms were searched in PubMed, Medline, and Embase. This meta-analysis comprised 16 papers published between 2000 and 2020, with a start year ranging from 1989 to 2017. Random effects were used to examine endometriosis risks in these articles. Study start years, countries, types (case-control and cohort studies), and quality (Newcastle-Ottawa scale, NOS) were all taken into account in further stratified analysis and meta-regression analyses.

RESULTS

Early menarche (< 12 years) was associated with a significant pooled risk of endometriosis with high heterogeneity (OR = 1.34, 95% CI 1.16-1.54, I² = 72.0%). Stratified analysis showed that this risk was increased in studies started after 2000 (OR = 1.62, 95% CI 0.96-1.35, I² = 74.4%), compared to those before 2000 (OR = 1.13, 95% CI 1.16-1.54, I² = 40.7%); additionally, this risk was higher in low-income countries (OR = 2.11, 95% CI 1.55-2.87, I² = 0%) than in other countries (OR = 1.25, 95% CI 1.09-1.43, I² = 70.6%). These results were further confirmed by meta-regression analysis (both P values < 0.1). No significant differences were found between different study types and NOS scores.

CONCLUSION

Our results suggested an increasing risk of endometriosis with early menarche, which was more noticeable in low-income countries. Large-scale studies are warranted.

Discrete-time Survival Analysis of Risk Factors for Early Menarche in Korean Schoolgirls

OBJECTIVES

The aim of this study was to evaluate the effect of body weight status and sleep duration on the discrete-time hazard of menarche in Korean schoolgirls using multiple-point prospective panel data.

METHODS

The study included 914 girls in the 2010 Korean Children and Youth Panel Study who were in the elementary first-grader panel from 2010 until 2016. We used a Gompertz regression model to estimate the effects of weight status based on age-specific and sex-specific body mass index (BMI) percentile and sleep duration on an early schoolchild's conditional probability of menarche during a given time interval using general health condition and annual household income as covariates.

RESULTS

Gompertz regression of time to menarche data collected from the Korean Children and Youth Panel Study 2010 suggested that being overweight or sleeping less than the recommended duration was related to an increased hazard of menarche compared to being average weight and sleeping 9 hours to 11 hours, by 1.63 times and 1.38 times, respectively, while other covariates were fixed. In contrast, being underweight was associated with a 66% lower discrete-time hazard of menarche.

CONCLUSIONS

Weight status based on BMI percentiles and sleep duration in the early school years affect the hazard of menarche.

Life course reproductive dynamics associated with menopause in Ugandan women aged 40-49

BACKGROUND

Early menopausal onset can increase adverse health outcomes in later life; meanwhile, reproductive experiences before menopause may affect its timing. Framed by life course methodology, the study tested for independent and interdependent associations between reproductive history (contraception, age at first birth, parity, terminated pregnancy) and socioeconomic factors (education, wealth, rural-urban residence, cigarette use, marital status, age at first cohabitation) with the occurrence of early menopause.

METHODS

The study population was ever-married women aged 40-49 from the 2016 Demographic & Health Survey (N = 2748). Analytical methods involved probability- and age-adjusted multivariate logistic regression models and predictive margins.

RESULTS

Connections between reproductive and socioeconomic characteristics were key dynamics associated with menopause in ages 40-49. Contraception, parity, and ages at first birth and marriage were found to be independently associated with menopause in this age group. Evidence of interactions was found where no contraceptive use was associated with higher probabilities of menopause for first-time mothers aged 12-15 and for women with no education.

CONCLUSIONS

Studying Ugandan women's reproductive histories highlighted the importance of regional knowledge about menopause. Though we hypothesized that risks would correlate in a chain, the results pointed to risks clustering around contraception, suggesting that improving contraceptive use and education for women could increase menopausal age. Furthermore, the positive association between low parity and early menopause supports the biological mechanism of faster oocyte depletion; however, high-parity populations like Uganda tend to have a younger menopausal age than low-parity populations. Declining mortality in the demographic transition could explain these inverse associations.

Diabetes Mellitus Mediates Risk of Depression in Danish Women with Polycystic Ovary Syndrome—A National Cohort Study

Aim: To investigate the risk of depression in Danish women with PCOS compared to controls and possible mediators for depression in PCOS. National register-based study in Danish women with PCOS (PCOS Denmark, N = 25,203) and age-matched controls (N = 112,414). PCOS Odense University Hospital (PCOS OUH, N = 998) was a sub-cohort of women with PCOS with available clinical and biochemical results. The main study outcome was depression occurring after PCOS diagnosis. Depression was defined according to hospital ICD-10 diagnosis codes and/or inferred from filled medicine prescription of antidepressants. Diabetes, medical comorbidity, infertility, hormonal anti-contraception and low family income were entered as mediators in Cox regression analyses for depression. In PCOS OUH, PCOS characteristics (age, BMI, Ferriman-Gallwey score) were entered in Cox regression analyses. The median age at cohort entry was 28 (interquartile range (IQR) 23; 35) years. The median follow-up time to incident depression or censuring was 4.8 (IQR 2.2; 8.8) years in PCOS Denmark and 5.2 (IQR 2.4; 9.2) years in controls. Women with PCOS had a 40% increased risk of depression compared to controls (Hazard Ratio 1.42 (95% CI 1.38; 1.47). In regression analyses, diabetes, medical comorbidity, infertility, hormonal anticonception, and low family income were significant mediators of depression. Mediation analyses showed that the proportion of the association explained by diabetes was 12.5% (95% CI 10.4; 14.5). In PCOS OUH, BMI, waist and Ferriman-Gallwey score predicted development of depression. Conclusion: The risk of depression was increased in PCOS. Diabetes was an important mediator of depression in PCOS.

Maternal pre-pregnancy body mass index, gestational weight gain, and pubertal timing in daughters: A systematic review and meta-analysis of cohort studies

The timing of daughter's puberty onset is constantly earlier. It is still unclear about the maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) as important prenatal factors that may affect offspring's onset of puberty. Thus, we evaluated the association among maternal pre-pregnancy BMI, GWG, and daughters' early pubertal development based on the existing literature. Literature review was conducted in different databases, including Web of Science, Pubmed, Wiley, ScienceDirect, Web of Science, and Chinese National Knowledge Infrastructure databases up to June 2021. We selected random effects model or fixed effects model for meta-analysis according to the I² statistics value to obtain the summary measurement. A total of 12 cohort studies were included. Compared to maternal pre-pregnancy normal weight, maternal pre-pregnancy overall overweight/obesity (RR = 1.24; 95% CI 1.17 to 1.32), obesity (RR = 1.35; 95% CI 1.23 to 1.48), and overweight (RR = 1.17; 95% CI 1.09 to 1.26) were significantly associated with the increased risk of earlier timing of pubertal onset in daughters. Daughters born of mothers with pre-pregnancy overall overweight/obesity, obesity, and overweight had earlier pubertal onset compared to those born of mothers with normal weight ([mean difference = -3.03, 95% CI: -3.97 to -2.10], [mean difference = -3.50, 95% CI: -5.38 to -1.62], and [mean difference = -2.89, 95% CI: -4.07 to -1.71], respectively). The effects were also significant in the assessed three milestones (menarche, breast development, and pubic hair development). Maternal excessive GWG increased the risk of early pubertal timing in daughters (RR = 1.19; 95% CI 1.09 to 1.30).

The relationships between women's reproductive factors: a Mendelian randomisation analysis

BACKGROUND

Women's reproductive factors include their age at menarche and menopause, the age at which they start and stop having children and the number of children they have. Studies that have linked these factors with disease risk have largely investigated individual reproductive factors and have not considered the genetic correlation and total interplay that may occur between them. This study aimed to investigate the nature of the relationships between eight female reproductive factors.

METHODS

We used data from the UK Biobank and genetic consortia with data available for the following reproductive factors: age at menarche, age at menopause, age at first birth, age at last birth, number of births, being parous, age first had sexual intercourse and lifetime number of sexual partners. Linkage disequilibrium score regression (LDSC) was performed to investigate the genetic correlation between reproductive factors. We then applied Mendelian randomisation (MR) methods to estimate the causal relationships between these factors. Sensitivity analyses were used to investigate directionality of the effects, test for evidence of pleiotropy and account for sample overlap.

RESULTS

LDSC indicated that most reproductive factors are genetically correlated (rg range: |0.06-0.94|), though there was little evidence for genetic correlations between lifetime number of sexual partners and age at last birth, number of births and ever being parous (rg < 0.01). MR revealed potential causal relationships between many reproductive factors, including later age at menarche (1 SD increase) leading to a later age at first sexual intercourse (beta (B) = 0.09 SD, 95% confidence intervals (CI) = 0.06,0.11), age at first birth (B = 0.07 SD, CI = 0.04,0.10), age at last birth (B = 0.06 SD, CI = 0.04,0.09) and age at menopause (B = 0.06 SD, CI = 0.03,0.10). Later age at first birth was found to lead to a later age at menopause (B = 0.21 SD, CI = 0.13,0.29), age at last birth (B = 0.72 SD, CI = 0.67, 0.77) and a lower number of births (B = -0.38 SD, CI = -0.44, -0.32).

CONCLUSION

This study presents evidence that women's reproductive factors are genetically correlated and causally related. Future studies examining the health sequelae of reproductive factors should consider a woman's entire reproductive history, including the causal interplay between reproductive factors.

Residential green space and age at menarche in German and Australian adolescent girls: A longitudinal study

BACKGROUND

A large multicentre European study reported later onset of menopause among women residing in greener areas. This influence on the timing of a reproductive event like menopause, raises the question whether similar associations can be observed with timing of menarche. We investigated whether exposure to residential green space was related to the age at menarche in German and Australian adolescent girls.

METHODS

The analytic samples comprised of 1706 German and 1474 Australian adolescent girls. Percentage of green space was calculated in 1000 m buffers around a residential address or its surrogate at the previous follow-up. Mixed effects Cox proportional hazard models were used to explore the associations. The survival object was the occurrence of menarche at the time of follow-up (15-year follow-up of the German cohorts and the study wave at 14-15 years in the Australian cohort) and number of years since baseline (10-year follow-up in the German cohort and the study wave at 10-11 years in the Australian cohort). Participants who did not reach menarche were included as censored observations.

RESULTS

A greener residence was not associated with the age at menarche. Null findings were consistent in the general population and in analyses stratified by socioeconomic status or urbanicity in both countries. Urban residents were more likely to have earlier menarche, and this association was consistent across Germany and Australia.

CONCLUSION

The results of our analysis do not support the hypothesis that residing in places with more green space can influence timing of menarche. However, given the limitations of our study, researchers should not be discouraged to further explore environmental risk factors of early menarche.

Factors Affecting Menstrual Cycle Developmental Trajectory in Adolescents: A Narrative Review

CONTEXT

The time interval between the age at menarche and regulation of menstrual cycles (menstrual cycle developmental trajectory) is considered an indicator of the function of the reproductive system later in life. This study aimed to summarize the factors affecting this trajectory.

EVIDENCE ACQUISITION

A comprehensive literature search in PubMed, Scopus, Google Scholar, and Web of Science was performed to identify studies investigating factors influencing the regularity of the menstrual cycle in adolescents.

RESULTS

The interval between menarche and the onset of the regular menstrual cycle in adolescent girls may vary from several months to several years. Several factors, including genetic, race/ethnicity, intrauterine situation, social factors, geographical factors, lifestyle, and chronic diseases, are considered the predisposing factors for the trajectory.

CONCLUSIONS

Age at menarche and the onset of regular menstrual cycles are directly and indirectly influenced by several genetic, environmental, and lifestyle factors. Understanding these factors may improve our practice in managing irregular menstrual cycles that commonly happen in the first years after menarche.

Menstrual cycle impacts lung structure measures derived from quantitative computed tomography

OBJECTIVE

Quantitative computed tomography (qCT) is being increasingly incorporated in research studies and clinical trials aimed at understanding lung disease risk, progression, exacerbations, and intervention response. Menstrual cycle-based changes in lung function are recognized; however, the impact on qCT measures is currently unknown. We hypothesize that the menstrual cycle impacts qCT-derived measures of lung structure in healthy women and that the degree of measurement change may be mitigated in subjects on cyclic hormonal birth control.

METHODS

Thirty-one non-smoking, healthy women with regular menstrual cycles (16 of which were on cyclic hormonal birth control) underwent pulmonary function testing and qCT imaging at both menses and early luteal phase time points. Data were evaluated to identify lung measurements which changed significantly across the two key time points and to compare degree of change across metrics for the sub-cohort with versus without birth control.

RESULTS

The segmental airway measurements were larger and mean lung density was higher at menses compared to the early luteal phase. The sub-cohort with cyclic hormonal birth control did not have less evidence of measurement difference over the menstrual cycle compared to the sub-cohort without hormonal birth control.

CONCLUSIONS

This study provides evidence that qCT-derived measures from the lung are impacted by the female menstrual cycle. This indicates studies seeking to use qCT as a more sensitive measure of cross-sectional differences or longitudinal changes in these derived lung measurements should consider acquiring data at a consistent time in the menstrual cycle for pre-menopausal women and warrants further exploration.

KEY POINTS

• Lung measurements from chest computed tomography are used in multicenter studies exploring lung disease progression and treatment response. • The menstrual cycle impacts lung structure measurements. • Cyclic variability should be considered when evaluating longitudinal change with CT in menstruating women.

The Role of Pediatric Nutrition as a Modifiable Risk Factor for Precocious Puberty

Puberty is a critical phase of growth and development characterized by a complex process regulated by the neuroendocrine system. Precocious puberty (PP) is defined as the appearance of physical and hormonal signs of pubertal development at an earlier age than is considered normal. The timing of puberty has important public health, clinical, and social implications. In fact, it is crucial in psychological and physical development and can impact future health. Nutritional status is considered as one of the most important factors modulating pubertal development. This narrative review presents an overview on the role of nutritional factors as determinants of the timing of sexual maturation, focusing on early-life and childhood nutrition. As reported, breast milk seems to have an important protective role against early puberty onset, mainly due to its positive influence on infant growth rate and childhood overweight prevention. The energy imbalance, macro/micronutrient food content, and dietary patterns may modulate the premature activation of the hypothalamic-pituitary-gonadal axis, inducing precocious activation of puberty. An increase in knowledge on the mechanism whereby nutrients may influence puberty will be useful in providing adequate nutritional recommendations to prevent PP and related complications.

Shared Genetics Between Age at Menopause, Early Menopause, POI and Other Traits

Reproductive ageing leading to menopause is characterized by depletion of follicles and its regulating mechanisms are only partly understood. Early age at menopause and premature ovarian insufficiency (POI) are associated with several other traits such as cardiovascular disease, dyslipidemia, osteoporosis and diabetes. In large cohorts of Northern European women hundreds of Single Nucleotide Polymorphisms (SNPs) have been identified to be associated with age at menopause. These SNPs are located in genes enriched for immune and mitochondrial function as well as DNA repair and maintenance processes. Genetic predisposition to earlier menopause might also increase the risk of other associated traits. Increased risk for cardiovascular disease in women has been associated with age at menopause lowering SNPs. Pleiotropy between early age at menopause and increased mortality from coronary artery disease has been observed, implicating that genetic variants affecting age at menopause also affect the risk for coronary deaths. This review will discuss the shared genetics of age at menopause with other traits. Mendelian Randomization studies implicate causal genetic association between age at menopause and age at menarche, breast cancer, ovarian cancer, BMD and type 2 diabetes. Although the shared biological pathways remain to be determined, mechanisms that regulate duration of estrogen exposure remain an important focus.

A secular trend in age at menarche in Yunnan Province, China: a multiethnic population study of 1,275,000 women

Background

Age at menarche (AAM) has shown different trends in women from different ethnic and economic regions in recent decades. Data on AAM among multiethnic women living in developing areas are scarce.

Methods

Data on AAM from 1,275,000 women among 26 ethnicities in Yunnan Province, China, who were born from 1965 to 2001 were obtained from the National Free Preconception Health Examination Project from 2010 to 2018. The patterns of AAM trends were analysed according to ethnic group, area of residence, and socioeconomic status.

Results

The mean AAM was 13.7 ± 1.21 years (95% CI 13.697–13.701), with a decrease from 14.12 (±1.41) among women born before 1970 to 13.3 (±1.04) among those born after 2000. The decline was 0.36 years per 10-year birth cohort, and the plateau has not yet been reached in Yunnan. A secular trend of earlier AAM was observed in all 26 ethnic groups. The fastest rate of decline was observed for the Bai ethnicity (0.36 years per decade). Consistent declining trends in AAM appeared among extreme-, middling-, and nonpoverty economic patterns from 1965 to 2001, with reductions of 1.19, 1.44, and 1.5 years, respectively (P < 0.001). The peak reduction among middling poverty and extreme poverty occurred in the early 2000s (0.4 and 0.32 years). Multivariate analysis showed a significant difference in the declining trends in AAM along rural/urban lines (P < 0.001).

Conclusion

There was a secular trend towards a younger AAM during the twentieth century and early twenty-first century birth cohorts in the Yunnan population. Considering the difference in AAM trends due to ethnic and socioeconomic status in Yunnan, the health authority should utilize flexible adjusted health care strategies in different regions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11951-x.

Early age at menarche is associated with post-menarche back pain: An analysis of the Raine Study

INTRODUCTION

Back pain (BP) experienced by females during adolescent years appears to predispose them to an increased likelihood of its presence in adulthood. Understanding this phenomenon by identifying risk factors of those at risk potentially fosters preventative strategies and effective treatments.

OBJECTIVES

To investigate for associations between post-menarche BP and low back pain (LBP) and age at menarche (AAM) in Australian adolescents using the Western Australian pregnancy cohort (The Raine Study).

METHODS

This study used data from a longitudinal cohort study. BP data were collected retrospectively using a questionnaire. Menarche data was split into three established age classifications early (<12-years), normal (≥12 to >14-years) and late (≥14-years). Logistic regression models examined the effect of AAM on BP.

RESULTS

666 female participants provided valid menarche data with 183 (27.5%) early AAM, 429 (64.4%) normal AAM and 54 (8.1%) with late AAM. The mean AAM was 12.59 years. BP was disclosed by 27.5% in the 14-year follow-up and 31.5% in the 17-year follow-up. Participants who had early AAM had 79% higher odds of experiencing BP compared to participants who had normal AAM, after adjusting for confounders at the 14-year follow-up (adjOR 1.79, 95% CI 1.18-2.64).

CONCLUSION

There is evidence of an association, in this cohort, of early AAM with post-menarche BP. This result identifies an area for future exploration, including understanding this mechanism which may lead to the development of effective intervention measures.

SIGNIFICANCE

Age at menarche is related to a range of health issues. This study sought to investigate if it was a risk factor for spinal pain. We used an existing Australian data base to explore this possibility and found an association with early age onset and post-menarche back pain. This result identifies an area for future exploration, including understanding this mechanism which may lead to the development of effective intervention measures.

Maternal investment, life-history trajectory of the off-spring and cardiovascular disease risk in Emirati females in the United Arab Emirates

Background

Variations in cardiovascular disease risk (CVD) are suggested to be partly influenced by factors that affect prenatal growth patterns and outcomes, namely degree of maternal investment (proxied by birth weight and gestational age). Using the life history trajectory model, this study investigates whether maternal investment in early prenatal life associates with menarcheal age and whether maternal investment affects CVD risk in adulthood and predicts adult size and adiposity levels.

Methods

A cross-sectional study was conducted among 94 healthy Emirati females. Birth weight, gestational age and menarcheal age were obtained. Anthropometrical measurements, body composition analysis, and blood pressure values were collected. Regression analyses were conducted to establish associations.

Results

There was no association between birth weight standard deviation score (SDS) and age at menarche. When investigating the associations of birth weight SDS and age at menarche with growth indices, it was found that only birth weight was positively and significantly associated with both height (β = 1.342 cm, 95% CI (0.12, 2.57), p = 0.032) and leg length (β = 0.968 cm, 95% CI (0.08, 1.86), p = 0.034). Menarcheal age was significantly and inversely associated with fat mass index (FMI) (β = − 0.080 cm, 95% CI (− 0.13, − 0.03), p = 0.002), but not with waist circumference and fat free mass index (FFMI) (p > 0.05). Birth weight SDS was positively and significantly associated with waist circumference (β = 0.035 cm, 95% CI (0.01, 0.06), p = 0.009), FMI (β = 0.087 cm, 95% CI (0.01, 0.16), p = 0.027), and FFMI (β = 0.485 cm, 95% CI (0.17, 0.80), p = 0.003). Birth weight SDS was not significantly associated with either systolic blood pressure (SBP) or diastolic blood pressure (DBP) (p > 0.05). However, FMI, waist circumference, and FFMI were positively and significantly associated with SBP. Regarding DBP, the relationship was negatively and significantly associated with only FFMI (β = − 1.6111 kg/m2, 95% CI (− 2.63, − 0.60), p = 0.002).

Conclusion

Although the results do not fully support that Emirati females fast-life history is associated with increased chronic disease risk, the data does suggest a link between restricted fetal growth in response to low maternal investment and metabolic and reproductive health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11182-0.

Examining developmental plasticity in the skeletal system through a sensitive developmental windows framework

Developmental plasticity facilitates energetically costly but potentially fitness-enhancing adjustments to phenotypic trajectories in response to environmental stressors, and thus may significantly impact patterns of growth, morbidity, and mortality over the life course. Ongoing research into epigenetics and developmental biology indicate that the timing of stress exposures is a key factor when assessing their impact on developmental processes. Specifically, stress experienced within sensitive developmental windows (SDWs), discrete developmental periods characterized by heightened energy requirements and rapid growth, may alter the pace and tempo of growth in ways that significantly influence phenotypic development over both the short and long term. In human skeletal biology, efforts to assess how developmental environments shape health outcomes over the life course could be enhanced by incorporating the SDW concept into existing methodological approaches. The goal of this article is to outline an interpretive framework for identifying and interpreting evidence of developmental stress in the skeletal system using the SDW concept. This framework provides guidance for the identification of elements most likely to capture evidence of stress most relevant to a study's core research questions, the interpretation of developmental stress exhibited by those elements, and the relationship of skeletal indicators of stress to the demographic patterning of morbidity and mortality. Use of the SDW concept in skeletal biology has the potential to enrich traditional approaches to addressing developmental origins of health and disease hypotheses, by targeting periods in which individuals are most susceptible to stress and thus most likely to exhibit plasticity in response.

Temporal trends in age at menarche and age at menopause: a population study of 312 656 women in Norway

STUDY QUESTION

Have mean age at menarche or mean age at natural menopause changed from the 1939 birth cohort to the 1964 birth cohort?

SUMMARY ANSWER

We estimated a minor decrease in mean age at menarche and an increase by nearly 3 years in mean age at natural menopause.

WHAT IS KNOWN ALREADY

In the Western world, age at menarche decreased across birth cohorts from the early 1800s until the 1950s. Whether mean age at menarche has continued to decrease in birth cohorts after the 1950s remains uncertain. It is also uncertain whether mean age at natural menopause has changed across birth cohorts.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective population study of 312 656 women who were born in Norway during the years 1936–1964.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The data were obtained by two self-administered questionnaires from women who participated in the Norwegian breast cancer screening program (BreastScreen Norway) during the years 2006–2014. We used flexible parametric survival models with restricted cubic splines to estimate mean age at menarche, mean age at menopause and mean number of years between menarche and menopause according to the women’s year of birth. The women who were still having menstrual periods contributed with follow-up time until the time of data collection, and the women who had reported surgical removal of the uterus and/or both ovaries prior to natural menopause contributed with follow-up time until the time of surgery.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean age at menarche was 13.42 years (95% CI: 13.40–13.44 years) among women born during 1936–1939, and it was 13.24 years (95% CI: 13.22–13.25 years) among women born during 1960–1964. The mean age at natural menopause increased from 50.31 years (95% CI: 50.25–50.37 years) among women born during 1936–1939 to 52.73 years (95% CI: 52.64–52.82 years) among women born during 1960–1964. The mean number of years between menarche and menopause increased from 36.83 years (95% CI: 36.77–36.89 years) to 40.22 years (95% CI: 40.11–40.34 years).

LIMITATIONS, REASONS FOR CAUTION

Information about age at menarche and age at menopause was based on self-reports.

WIDER IMPLICATIONS OF THE FINDINGS

Late menopause is associated with increased risk of breast cancer but also with increased life expectancy. Thus, higher mean age at menopause may partly explain the increase in breast cancer incidence after menopause and the increase in life expectancy in recent time. Also, a longer interval between menarche and menopause could suggest that the number of years of female fecundity has increased.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the South-Eastern Norway Regional Health Authority [grant number 2016112 to M.S.G.] and by the Norwegian Cancer Society [grant number 6863294-2015 to E.K.B.]. The authors declare no conflicts of interest.

Factors influencing age at natural menopause

AIM

Women who experience menopause before 45 years, have an increased risk for morbidity and mortality. We aimed to identify the factors influencing the age at natural menopause and to investigate whether tubal ligation alter age at natural menopause.

METHODS

This cross-sectional study was conducted on total 1660 women with natural menopause. The participants were divided into two groups as the ones having menopause before age of 45 years and after 45 years old.

RESULTS

Positive family history, smoking and use of oral contraceptive were found to increase the risk of early menopause by 3.68, 1.34 and 1.04 times, respectively. First pregnancy at older age reduced the risk of early menopause by 0.97 and obesity reduced this risk by 0.65 (95% CI 0.47-0.90). There was no significant difference between menopausal age of patients who underwent BTL (47.46 ± 4.67 years old) and those who did not (47.68 ± 5.18 years old) (P:0.320; P > 0.05). The mean age at menopause of patients who had tubal ligation with laparoscopic cauterization and Pomeroy technique was 46.91 ± 4.07 and 47.55 ± 4.76 years old, respectively (P:0.503; P > 0.05). Besides, there was no significant difference between patients having tubal ligation at the time of cesarean section and those who did not regarding menopausal age (P:0.314; P > 0.05).

CONCLUSION

We recommend identifying modifiable factors and informing women at risk of early menopause. Tubal ligation, when performed correctly, should not compromise ovarian function. If tubal ligation interferes with vascular supply to the ovaries, it may not be substantial enough to result in an earlier onset of menopause.

The evolutionary ecology of age at natural menopause: implications for public health

Evolutionary perspectives on menopause have focused on explaining why early reproductive cessation in females has emerged and why it is rare throughout the animal kingdom, but less attention has been given to exploring patterns of diversity in age at natural menopause. In this paper, we aim to generate new hypotheses for understanding human patterns of diversity in this trait, defined as age at final menstrual period. To do so, we develop a multilevel, interdisciplinary framework, combining proximate, physiological understandings of ovarian ageing with ultimate, evolutionary perspectives on ageing. We begin by reviewing known patterns of diversity in age at natural menopause in humans, and highlight issues in how menopause is currently defined and measured. Second, we consider together ultimate explanations of menopause timing and proximate understandings of ovarian ageing. We find that ovarian ageing is highly constrained by ageing of the follicle - the somatic structure containing the oocyte - suggesting that menopause timing might be best understood as a by-product of ageing rather than a facultative adaptation. Third, we investigate whether the determinants of somatic senescence also underpin menopause timing. We show that diversity in age at menopause can be, at least partly, explained by the genetic, ecological and life-history determinants of somatic ageing. The public health implications of rethinking menopause as the by-product rather than the catalyst of biological ageing are discussed.

A pragmatic approach to tackle the rising burden of breast cancer through prevention & early detection in countries 'in transition'

Among the emerging economies Brazil, Russia, India, China and South Africa (together known as the BRICS countries) share collectively approximately 40 per cent of the global population and contribute to 25 per cent of the world gross domestic products. All these countries are facing the formidable challenge of rising incidence of breast cancer and significant number of premature deaths from the disease. A multidimensional approach involving prevention, early detection and improved treatment is required to counteract the growing burden of breast cancer. A growing trend in the prevalence of major preventable risk factors of breast cancer such as obesity, western dietary habits, lack of physical activity, consumption of alcohol and smoking is contributing significantly to the rising burden of the disease in BRICS nations. Specific interventions are needed at the individual and population levels to mitigate these risk factors, preferably within the broader framework of non-communicable disease control programme. Population-based quality assured mammography-based screening of the 50-69 yr old women can reduce breast cancer mortality at least by 20 per cent. However, none of the BRICS countries have been able to implement population-based organized screening programme. Large scale opportunistic screening with mammography targeting predominantly the younger women is causing harms to the women and wasting precious healthcare resources. There are recent national recommendations to screen women with mammography in Brazil and Russia and with clinical breast examination in China (along with ultrasound) and India. Given the challenges of implementing systematic screening of the population, the BRICS countries should prioritize the early diagnosis approach and invest in educating the women about the breast cancer symptoms, training the frontline health providers to clinically detect breast cancers and appropriately refer for diagnostic confirmation, and creating improved access to good quality diagnostic and treatment facilities for breast cancer. The early diagnosis approach has been proved to achieve downstaging and improve survival at a fraction of the resources needed for population screening. The countries also need to focus on improving the services and capacity for multidisciplinary treatment of breast cancer, histopathology and immunohistochemistry, safe administration of chemotherapy and palliative care.

The effects of age at menarche and first sexual intercourse on reproductive and behavioural outcomes: A Mendelian randomization study

There is substantial variation in the timing of significant reproductive life events such as menarche and first sexual intercourse. Life history theory explains this variation as an adaptive response to an individual's environment and it is important to examine how traits within life history strategies affect each other. Here we applied Mendelian randomization (MR) methods to investigate whether there is a causal effect of variation in age at menarche and age at first sexual intercourse (markers or results of exposure to early life adversity) on outcomes related to reproduction, education and risky behaviour in UK Biobank (N = 114 883-181 255). Our results suggest that earlier age at menarche affects some traits that characterize life history strategies including earlier age at first and last birth, decreased educational attainment, and decreased age at leaving education (for example, we found evidence for a 0.26 year decrease in age at first birth per year decrease in age at menarche, 95% confidence interval: -0.34 to -0.17; p < 0.001). We find no clear evidence of effects of age at menarche on other outcomes, such as risk taking behaviour. Age at first sexual intercourse was also related to many life history outcomes, although there was evidence of horizontal pleiotropy which violates an assumption of MR and we therefore cannot infer causality from this analysis. Taken together, these results highlight how MR can be applied to test predictions of life history theory and to better understand determinants of health and social behaviour.

Effects of Physical Exercise on Sexual Function and Quality of Sexual Life Related to Menopausal Symptoms in Peri- and Postmenopausal Women: A Systematic Review

During the menopausal period, sexual dysfunction is associated with the development or worsening of psychological conditions, causing deterioration in women’s mental health and quality of life. This systematic review aims to investigate the effects of different exercise programs on sexual function and quality of sexual life related to menopausal symptoms. With this purpose, a systematic literature search was conducted in PubMed, CINAHL, Scopus, Web of Science, and Cochrane Plus. A total of 1787 articles were identified in the initial search and 11 prospective studies (including 8 randomized controlled trials) were finally included. The most commonly recommended training programs are based on exercising pelvic floor muscles, as they seem to have the largest impact on sexual function. Mind–body disciplines also helped in managing menopausal symptoms. However, as far as the most traditional programs were concerned, aerobic exercises showed inconsistent results and resistance training did not seem to convey any benefits. Although positive effects have been found, evidence supporting physical exercise as a strategy to improve sexual function and quality of sexual life related to menopausal symptoms is limited, and further studies on this topic are needed.

Trends of Premature and Early Menopause: a Comparative Study of the US National Health and Nutrition Examination Survey and the Korea National Health and Nutrition Examination Survey

BACKGROUND

While evidence shows a tendency toward delays in menopause worldwide, whether prevalence of premature (< 40 years) or early menopause (40-44 years) is also reduced in different ethnic groups is uncertain. The aim of this study was to explore birth cohort effect in the prevalence of premature and early menopause in United States (US) and Korea.

METHODS

This is a retrospective study using the National Health and Nutrition Examination Survey (NHANES, 1999-2014) and the Korea NHANES (KNHANES, 2007-2012). We analyzed prevalence of premature and early menopause in three ethnic groups of US and Korea. We restricted our analysis to women aged ≥ 45 years at the time of the survey born between 1920 and 1969. The data of both eligible 9,209 US women and 9,828 Korean was included in final analysis. We calculated odds ratios (OR) for each outcome adjusting for biological and socioeconomic factors, respectively.

RESULTS

Prevalence of premature menopause was 1.7% in US, 2.8% in Korean women. Early menopause occurred in 3.4% and 7.2% of US and Korean, respectively. In US women, prevalence of premature and early menopause did not change and did not differ across three ethnicities. Korean women showed highest and consistently decreasing prevalence (P < 0.001). When we adjusted for covariates, birth lower risk for premature menopause was evident in US Non-Hispanic black born in 1950s and in Korean born between 1940s and 1960s compared to those born in 1920s. In the analysis of early menopause, excluding premature menopause patients, lower risk of more recent generation (born in 1940s and later) was evident in Korean women.

CONCLUSION

The trend and birth cohort effect in occurrence of premature and early menopause among the US and Korea women are different. Prevalences of premature and early menopause decrease only in Korean.

Mid-life predictors of late-life depressive symptoms; determining risk factors spanning two decades in the Women's Heathy Ageing Project

Background

Data available from longitudinal studies of adequate duration to explore midlife risk factors for late life higher depressive symptom scores in women is lacking. This study examines midlife (mean ages 50 years and 60 years) predictors of late life (mean age 70 years) depressive symptom scores to enrich our understanding of the role of changing risk factors across the lifespan.

Methods

This investigation was an assessment of the long-term impact of lifestyle and health variables on depressive symptoms. Data were drawn from an epidemiological prospective study of women's healthy ageing spanning two decades. Variables included assessment of mood, demographics, physical health, smoking status, attitudes towards ageing and menopause, alcohol consumption and employment. Analysis was conducted to determine the set of strongest predictors assessed in 1992 (mean age 50 years) and in 2002 (mean age 60 years) in relation to higher CESD-SF scores measured in 2012 (mean aged 70 years (n = 249)). A cross-sectional analysis determining concurrent associations at mean age 70 years was also conducted.

Results

An increase in positive mood at 50 and 60 years was associated with a 0.3 (95% CI 0.1-0.5) and 0.4 (95%CI 0.1-0.8) point reduction in CESD score at 70 years respectively. An increase in Hassles score at age 50 was associated with a 0.18-point increase in CESD (95% CI 0.01-0.05) 20 years later. However, no relationship was observed between Hassles score at 60 and CESD 10 years later. Analysis of concurrent risk factors demonstrated that bothersome symptom frequency and higher anxiety were associated with higher depressive symptom scores when women were 70 years.

Conclusion

Low levels of positive mood were consistently associated with depressive symptoms scores 10 and 20 years later, suggesting clinical interventions aimed at improving positive affect may be particularly useful across the midlife.

Parental Obesity and Offspring Pubertal Development: Project Viva

OBJECTIVE

To investigate the association of preconception parental obesity (body mass index [BMI] ≥30 kg/m²) with offspring pubertal development.

STUDY DESIGN

Among 1377 children from a prospective prebirth cohort in Boston, we examined markers of puberty (age at peak height velocity [PHV], age at menarche, self-reported pubertal development score), and adrenarche (pictograph Tanner pubic hair staging). We used multivariable regression models to examine associations of maternal and paternal obesity with offspring pubertal indices, and applied marginal structural models to estimate the controlled direct effect not mediated by offspring prepubertal BMI.

RESULTS

The prevalence of paternal obesity alone, maternal obesity alone, and biparental obesity were 10.5%, 10.1%, and 5%, respectively. After adjusting for demographic and socioeconomic factors, parental heights and maternal age at menarche, maternal obesity alone (vs neither parent with obesity) was associated with earlier age at PHV (β -0.30 years; 95% CI -0.57, -0.03) and higher early adolescent pubertal score (0.29 units; 0.10, 0.48) in boys, but not with pubertal or adrenarchal outcomes in girls. Paternal obesity alone was not associated with any outcomes in either boys or girls. Biparental obesity was associated with earlier age at PHV in boys and earlier menarche in girls. Using marginal structural models with stabilized inverse probability weighting, maternal obesity alone had significant controlled direct effects on age at PHV (-0.31 years; -0.62, 0.00) and on pubertal score (0.22 units; 0.00, 0.44) in boys, independent of prepubertal BMI.

CONCLUSION

Maternal, but not paternal, obesity is associated with earlier pubertal development in boys, and such association is independent of prepubertal BMI.

Variations in reproductive events across life: a pooled analysis of data from 505 147 women across 10 countries

STUDY QUESTION

How has the timing of women's reproductive events (including ages at menarche, first birth, and natural menopause, and the number of children) changed across birth years, racial/ethnic groups and educational levels?

SUMMARY ANSWER

Women who were born in recent generations (1970-84 vs before 1930) or those who with higher education levels had menarche a year earlier, experienced a higher prevalence of nulliparity and had their first child at a later age.

WHAT IS KNOWN ALREADY

The timing of key reproductive events, such as menarche and menopause, is not only indicative of current health status but is linked to the risk of adverse hormone-related health outcomes in later life. Variations of reproductive indices across different birth years, race/ethnicity and socioeconomic positions have not been described comprehensively.

STUDY DESIGN, SIZE, DURATION

Individual-level data from 23 observational studies that contributed to the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE) consortium were included.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Altogether 505 147 women were included. Overall estimates for reproductive indices were obtained using a two-stage process: individual-level data from each study were analysed separately using generalised linear models. These estimates were then combined using random-effects meta-analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

Mean ages were 12.9 years at menarche, 25.7 years at first birth, and 50.5 years at natural menopause, with significant between-study heterogeneity (I2 > 99%). A linear trend was observed across birth year for mean age at menarche, with women born from 1970 to 1984 having menarche one year earlier (12.6 years) than women born before 1930 (13.5 years) (P for trend = 0.0014). The prevalence of nulliparity rose progressively from 14% of women born from 1940-49 to 22% of women born 1970-84 (P = 0.003); similarly, the mean age at first birth rose from 24.8 to 27.3 years (P = 0.0016). Women with higher education levels had fewer children, later first birth, and later menopause than women with lower education levels. After adjusting for birth year and education level, substantial variation was present for all reproductive events across racial/ethnic/regional groups (all P values < 0.005).

LIMITATIONS, REASONS FOR CAUTION

Variations of study design, data collection methods, and sample selection across studies, as well as retrospectively reported age at menarche, age at first birth may cause some bias.

WIDER IMPLICATIONS OF THE FINDINGS

This global consortium study found robust evidence on variations in reproductive indices for women born in the 20th century that appear to have both biological and social origins.

STUDY FUNDING/COMPETING INTEREST(S)

InterLACE project is funded by the Australian National Health and Medical Research Council project grant (APP1027196). GDM is supported by the Australian National Health and Medical Research Council Principal Research Fellowship (APP1121844).

Complex genetics of female fertility

Variation in reproductive lifespan and female fertility have implications for health, population size and ageing. Fertility declines well before general signs of menopause and is also adversely affected by common reproductive diseases, including polycystic ovarian syndrome (PCOS) and endometriosis. Understanding the factors that regulate the timing of puberty and menopause, and the relationships with fertility are important for individuals and for policy. Substantial genetic variation exists for common traits associated with reproductive lifespan and for common diseases influencing female fertility. Genetic studies have identified mutations in genes contributing to disorders of reproduction, and in the last ten years, genome-wide association studies (GWAS) have transformed our understanding of common genetic contributions to these complex traits and diseases. These studies have made great progress towards understanding the genetic factors contributing to variation in traits and diseases influencing female fertility. The data emerging from GWAS demonstrate the utility of genetics to explain epidemiological observations, revealing shared biological pathways linking puberty timing, fertility, reproductive ageing and health outcomes. Many variants implicate DNA damage/repair genes in variation in the age at menopause with implications for follicle health and ageing. In addition to the discovery of individual genes and pathways, the increasingly powerful studies on common genetic risk factors help interpret the underlying relationships and direction of causation in the regulation of reproductive lifespan, fertility and related traits.

Female reproductive history and risk of type 2 diabetes: A prospective analysis of 126 721 women

AIM

To examine the prospective associations between aspects of a woman's reproductive history and incident diabetes.

METHODS

We pooled individual data from 126 721 middle-aged women from eight cohort studies contributing to the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE). Associations between age at menarche, age at first birth, parity and menopausal status with incident diabetes were examined using generalized linear mixed models, with binomial distribution and robust variance. We stratified by body mass index (BMI) when there was evidence of a statistical interaction with BMI.

RESULTS

Over a median follow-up of 9 years, 4073 cases of diabetes were reported. Non-linear associations with diabetes were observed for age at menarche, parity and age at first birth. Compared with menarche at age 13 years, menarche at ≤10 years was associated with an 18% increased risk of diabetes (relative risk [RR] 1.18, 95% confidence interval [CI] 1.02-1.37) after adjusting for BMI. After stratifying by BMI, the increased risk was only observed in women with a BMI ≥25 kg/m² . A U-shaped relationship was observed between parity and risk of diabetes. Compared with pre-/peri-menopausal women, women with a hysterectomy/oophorectomy had an increased risk of diabetes (RR 1.17, 95% CI 1.07-1.29).

CONCLUSIONS

Several markers of a woman's reproductive history appear to be modestly associated with future risk of diabetes. Maintaining a normal weight in adult life may ameliorate any increase in risk conferred by early onset of menarche.

The impact of maternal age on foetal growth patterns and newborn size

The association patterns between maternal age and foetal growth parameters as well as newborn size were analysed using a dataset of 4737 singleton term births taking place at the Viennese Danube hospital. Foetal growth patterns were reconstructed by the results of three ultrasound examinations carried out at the 11th/12th, 20th/21th and 32th/33thweek of gestation. In detail, crown-rump length, biparietal diameter, fronto-occipital diameter, head circumference, abdominal transverse diameter, abdominal anterior-posterior diameter, abdominal circumference, and femur length were determined. Birth weight, birth length and head circumference were measured immediately after birth. Young teenage mothers (≤15 years), older adolescent mothers (16-19 years), mothers of optimal age range (20-35 years) and mothers of advanced age (>35 years) differed significantly in body height, pre-pregnancy weight status and gestational weight gain. Surprisingly, the foetuses of young adolescent mothers were the largest ones during first trimester. During the second and third trimester however, the foetuses of mothers of optimal age range (20-35 years) and mothers older than 35 years showed larger biometric dimensions than adolescent mothers. According to multiple regression analyses, maternal age was significantly related to Foetal head size (ß =-0.04; 95% CI = -0,08 – 0.01; p=0.034) and abdominal dimensions (ß= 0.03; 95% CI = 0.01-0.05; p=0,011) during the second trimester and to birthweight (ß= -0.03; 95% CI= -4.40 – 0.04; p=0.050). The associations however, are quite weak and the statistical significance is maybe due to the large sample size. At the time of birth, offspring of mothers of optimal age range (20 to 35 years) is significantly larger than that of adolescent mothers and mothers of advanced age. Mothers of advanced age showed the significantly highest (p=<0.0001) prevalence (5.6%) of SGA newborns (<2500g). The small size of newborn among young adolescent mothers may be due to a competition over nutrients between the still growing mothers and the foetuses during the third trimester, while placental ageing may be responsible for smaller size of offspring among mothers of advanced age.

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.

Associations Between Maternal Prepregnancy Body Mass Index and Gestational Weight Gain and Daughter's Age at Menarche: The Avon Longitudinal Study of Parents and Children

Earlier puberty and menarche are associated with adverse health outcomes. Reported associations of maternal adiposity with daughter’s age at menarche are inconsistent. We examined associations between maternal prepregnancy body mass index (BMI; weight (kg)/height (m)²) and gestational weight gain (GWG) and daughter’s ages at menarche (n = 3,935 mother-offspring pairs), pubarche (Tanner stage 2 for pubic hair) (n = 2,942 pairs), and thelarche (Tanner stage 2 for breast development) (n = 2,942 pairs) in the Avon Longitudinal Study of Parents and Children, a prospective United Kingdom pregnancy cohort study (baseline 1991–1992). During a follow-up period of up to 17 years (1991–2008), mean menarcheal age was 12.6 (standard deviation, 1.2) years. Both maternal prepregnancy BMI and GWG were inversely associated with daughter’s age at menarche after adjustment for maternal age, parity, socioeconomic status, smoking, maternal menarcheal age, and ethnicity (mean differences were −0.34 months (95% confidence interval: −0.45, −0.22) per BMI unit and −0.17 months (95% confidence interval: −0.26, −0.07) per kg, respectively). Associations remained unchanged after adjustment for birth weight and gestational age but were attenuated to the null when results were adjusted for daughter’s prepubertal BMI. Similar results were found for ages at pubarche and thelarche. These findings indicate that greater prepregnancy BMI and GWG are associated with earlier puberty in daughters and that these associations are mediated by daughters’ prepubertal BMIs.

Referral gynecological ambulatory clinic: principal diagnosis and distribution in health services

BACKGROUND

The association between gynecological diagnoses and their distribution in the health sectors provides benefits in the field of women's health promotion and in medical and interdisciplinary education, along with rationalization according to level of care complexity. Thus, the objective is analyze the clinical-demographic characteristics, main diagnoses in gynecological ambulatory care, and their distribution in health services.

METHOD

This is a research project of retrospective audit study design with a chart review of data from 428 women treated at University Ambulatory Clinic of Women's Health, the facility in gynecology and training for Family and Community Medical Residents, São Paulo, Brazil, from 2012 to 2014. Clinical and demographic information, gynecological diagnoses (International Classification of Diseases), and distribution of health services (primary, secondary, and tertiary) were described.

RESULTS

The female patients present non-inflammatory disorders of the female genital tract (81.07%, n = 347) and diseases of the urinary system (22.66%, n = 97) among the gynecological diagnoses. The chances of having benign breast disease and non-inflammatory disorders of the female genital tract during the reproductive period corresponds to being 3.61 (CI 1.00-16.29) and 2.56 times (CI 1.58-4.16) higher, respectively, than during the non-reproductive period. The non-inflammatory disorders of the female genital tract (93.33%, n = 28) are most related to the tertiary sector. The distribution in health services was the following: 71.30% (n = 305) in the primary sector, 21.70% (n = 93) in the secondary sector and 7% (n = 30) in the tertiary sector.

CONCLUSION

The studied women presented non-inflammatory disorders of the female genital tract and diseases of the urinary system as determined by gynecological diagnoses. Low-assistance complexity followed in most cases.

Childhood Socioeconomic Position and Pubertal Onset in a Cohort of Multiethnic Girls: Implications for Breast Cancer

Background: Higher socioeconomic position (SEP) has been associated with increased risk of breast cancer. Its relationship with earlier age of pubertal onset, a risk factor for breast cancer, is less clear.Methods: We studied the relationship of SEP to pubertal onset in a multiethnic cohort of 1,237 girls ages 6 to 8 years at baseline. Girls in three U.S. cities were followed for 5 to 8 years with annual clinical examinations from 2004 to 2012. SEP measures were examined for associations with pubertal onset, assessed by breast budding (thelarche) and pubic hair development (adrenarche). Analyses were conducted with accelerated failure time models using a Weibull distribution, with left, right, and interval censoring.Results: Higher body mass index percentage at entry to the study and black or Hispanic race/ethnicity were the strongest predictors of age at pubertal onset. An SEP index comprising household family income, mother's education, and home ownership was an independent predictor of thelarche in adjusted models for all girls together and for white and Latina, separately, but not black girls, and the relationship varied by study site. The SEP index was not related to adrenarche in adjusted models. Overall, girls from the lowest quintile of SEP entered puberty on average 6% earlier than girls from the highest quintile (time ratio = 0.94; 95% confidence interval 0.91-0.97) in adjusted models.Conclusions: Our results suggest that early-life SEP may influence the timing of pubertal development.Impact: Factors related to lower SEP in childhood can adversely affect early development in ways that may increase the risk of breast cancer. Cancer Epidemiol Biomarkers Prev; 26(12); 1714-21. ©2017 AACR.

Estrogen Effects on the Mammary Gland in Early and Late Life and Breast Cancer Risk

A woman has an increased risk of breast cancer if her lifelong estrogen exposure is increased due to an early menarche, a late menopause, and/or an absence of childbearing. For decades, it was presumed that the number of years of exposure drove the increased risk, however, recent epidemiological data have shown that early life exposure (young menarche) has a more significant effect on cancer risk than late menopause. Thus, rather than the overall exposure it seems that the timing of hormone exposure plays a major role in defining breast cancer risk. In support of this, it is also known that aberrant hormonal exposure prior to puberty can also increase breast cancer risk, yet the elevated estrogen levels during pregnancy decrease breast cancer risk. This suggests that the effects of estrogen on the mammary gland/breast are age-dependent. In this review article, we will discuss the existing epidemiological data linking hormone exposure and estrogen receptor-positive breast cancer risk including menarche, menopause, parity, and aberrant environmental hormone exposure. We will discuss the predominantly rodent generated experimental data that confirm the association with hormone exposure and breast cancer risk, confirming its use as a model system. We will review the work that has been done attempting to define the direct effects of estrogen on the breast, which are beginning to reveal the mechanism of increased cancer risk. We will then conclude with our views on the most pertinent questions to be addressed experimentally in order to explore the relationship between age, estrogen exposure, and breast cancer risk.

Invited Commentary: An Ingenious Approach to Examining the Relationship Between Maternal Stress and Offspring Health?

The potentially deleterious effects on offspring health of excess maternal stress in pregnancy are important to understand-both whether observed associations are causal and through what mechanisms their effects may exert an influence. In this issue of the Journal, Räikkönen et al. (Am J Epidemiol. 2012;000(0):000-000) provide an ingenious test of a potential pathway through which maternal stress may influence offspring development. Licorice consumption is known to disrupt the ability of the placental enzyme 11β-hydroxysteroid dehydrogenase type 2 to inactivate cortisol before it reaches the fetus, leading to higher levels of cortisol exposure. Higher levels of cortisol exposure are also hypothesized to underlie the mechanism through which maternal stress may disrupt fetal development. Thus licorice consumption may serve, in some ways, to mimic maternal stress. The authors report associations between heavy licorice consumption during pregnancy and a wide range of offspring outcomes, including changes in pubertal timing, intelligence quotient, and mental health. In our view, these results should be considered preliminary; more work needs to be completed to determine the relationship of prenatal licorice consumption to these outcomes. Nonetheless, these intriguing and suggestive results demonstrate that this line of work should be given high priority, and they set the stage for additional research moving forward.

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.

Lack of any Association between the Hogg1 Ser326Cys Polymorphism and Breast Cancer Risk: a Systematic Review And Meta-Analysis Of 18 Studies

Background:

The human 8-oxoguanine DNA glycosylase (hOGG1) gene may be linked with cancer susceptibility. The aim of this study was to quantitatively summarize any association between the hOGG1 Ser326Cys polymorphism and breast cancer (BC) risk.

Materials and Methods:

A comprehensive search of the PubMed, Embase, and ISI web of knowledge databases for papers published before 1 October 2016 was conducted. Summary odds ratios (ORs) with corresponding 95 % confidence intervals (95 %CIs) were estimated, with fixed-effects or random-effects models when appropriate, to assess any association.

Results:

A total of 9,434 cases and 10,497 controls from 18 studies were included in this meta-analysis. When the eligible studies were pooled, there was no evidence found for a significant association between the hOGG1 Ser326Cys polymorphism and BC in in all genetic contrast models G vs. C (OR=1.19, 95% CI 0.92– 1.53), CG vs. CC (OR = 0.97, 95% CI 0.91-1.04, p = 0.46), GG vs. CC (OR = 1.11, 95% CI 0.91-1.35, p = 0.30), GG + CG vs. CC (OR = 0.98, 95% CI 0.92-1.05, p = 0.67), and GG vs. CG + CC (OR = 1.22, 95% CI 0.98-1.52, p = 0.07). According to subgroup analysis, we also did not find a significant association between the hOGG1 Ser326Cys polymorphism and BC risk in Asians and Caucasians considered separately.

Conclusions:

The current meta-analysis suggests that the hOGG1 Ser326Cys polymorphism is not significantly associated with BC risk.

Does Inflammation Mediate Relationships Between Racial Identity and Onset of Menopause Among US Adults?

We assess how well differences in ethnoracial background may predict timing of menopause among females in the USA and whether or not inflammatory biomarker levels appear to mediate these overall associations. We use data from the National Social Life, Health, and Aging Project (NSHAP) to model apparent net effects from race on menopausal onset, as well as possible mediating influences from the inflammatory biomarker C-reactive protein (CRP). Using continuous time event history analysis, we assess and frame overall relationships between race and menopausal age. We use structural equation modeling to assess potential mediating effects from CRP and to estimate direct and indirect components of these apparent effects. Our findings suggest that on average, black females experience menopause earlier than their peers of other racial backgrounds, and have higher inflammatory biomarker levels. Both black race and higher CRP have negative and significant direct associations with menopausal age. CRP appears to partially mediate the overall association between black race and earlier menopause. This apparent mediation persists with statistical controls for income, education, and body mass index. Our study concludes with recommendations for future research on racial identity, inflammation, and menopausal onset. We focus our recommendations on intersectional forms of inequality that may affect black females in later life.

Puberty timing associated with diabetes, cardiovascular disease and also diverse health outcomes in men and women: the UK Biobank study

Early puberty timing is associated with higher risks for type 2 diabetes (T2D) and cardiovascular disease in women and therefore represents a potential target for early preventive interventions. We characterised the range of diseases and other adverse health outcomes associated with early or late puberty timing in men and women in the very large UK Biobank study. Recalled puberty timing and past/current diseases were self-reported by questionnaire. We limited analyses to individuals of White ethnicity (250,037 women; 197,714 men) and to disease outcomes with at least 500 cases (~0·2% prevalence) and we applied stringent correction for multiple testing (corrected threshold P < 7.48 × 10^–5). In models adjusted for socioeconomic position and adiposity/body composition variables, both in women and men separately, earlier puberty timing was associated with higher risks for angina, hypertension and T2D. Furthermore, compared to the median/average group, earlier or later puberty timing in women or men was associated with higher risks for 48 adverse outcomes, across a range of cancers, cardio-metabolic, gynaecological/obstetric, gastrointestinal, musculoskeletal, and neuro-cognitive categories. Notably, both early and late menarche were associated with higher risks for early natural menopause in women. Puberty timing in both men and women appears to have a profound impact on later health.

Puberty and perimenopause: reproductive transitions and their implications for women's health

This scoping review synthesizes existing research on two major transitions in females' lives: puberty and perimenopause. These two periods of vast physiological change demarcate the beginning and the end of the reproductive life cycle and are associated with major neuroendocrine reorganization across two key systems, the hypothalamic-pituitary-gonadal (HPG) axis the hypothalamus-pituitary-adrenal (HPA) axis. Despite growing evidence suggesting that the timing and experience of puberty and perimenopause are related to various physical and mental health outcomes (e.g., mood disorders, metabolism, cardiovascular health, autoimmune conditions, and cancer), these two processes are rarely examined together. In this paper, we bridge these disparate literatures to highlight similarities, isolate inconsistencies, and identify important areas for future research in women's health.

A microsatellite polymorphism in IGF1 gene promoter and timing of natural menopause in Caucasian women

BACKGROUND

Genes involved in the IGF-1 aging pathways in the human ovary can be considered strong candidates for predictors of the natural menopause timing. This study evaluates the association between a cytosine-adenine (CA) microsatellite polymorphism in the IGF1 gene promoter P1 and age at natural menopause.

METHODS

Genomic DNA was extracted from the peripheral blood, PCR was performed using primers designed to amplify the polymorphic (CA) n repeat of the human IGF1 gene, an allele dose effect for the most common (CA)19 repeats allele, Cox proportional hazard regression models and the Kaplan-Meier cumulative survivorship method with the log-rank test were used to determine statistical significance of studied associations in a sample of 257 Polish women aged 40-58 years.

RESULTS

Crude Cox proportional hazard regression analysis confirmed the association between the IGF1 gene polymorphism and the menopause timing (p=0.038). This relationship remained statistically significant after controlling for other menopause confounders in multivariate modelling. Out of the input variables, the (CA)n polymorphism in the IGF1 gene promoter, age at menarche and smoking status were independent covariates of the natural menopause timing (χ2=12.845; df=3; p=0.034). The onset of menopause at a younger age was likely associated with the IGF1 genotype variant not carrying the (CA)19 repeats allele, menarche before the age of 12 and a current cigarette smoker status (HR=1.6).

CONCLUSION

This study provides evidence that a common cytosine-adenine (CA) microsatellite repeat polymorphism in the P1 promoter region of the IGF1 gene is an independent predictive factor for age at natural menopause in Caucasian women also after adjusting for other menopause covariates.

Socioeconomic status and age at menarche: an examination of multiple indicators in an ethnically diverse cohort

PURPOSE

Ethnic disparities exist in US girls' ages at menarche. Overweight and low socioeconomic status (SES) may contribute to these disparities but past research has been equivocal. We sought to determine which SES indicators were associated uniquely with menarche, for which ethnic groups, and whether associations operated through overweight.

METHODS

Using National Longitudinal Study of Youth data, we examined associations between SES indicators and age at menarche. Participants were 4851 girls and their mothers. We used survival analyses to examine whether SES, at various time points, was associated with menarche, whether body mass index mediated associations, and whether race/ethnicity modified associations.

RESULTS

Black and Hispanic girls experienced menarche earlier than whites. After adjusting for SES, there was a 50% reduction in the effect estimate for "being Hispanic" and 40% reduction for "being black" versus "being white" on menarche. SES indicators were associated uniquely with earlier menarche, including mother's unmarried status and lower family income. Associations varied by race/ethnicity. Body mass index did not mediate associations.

CONCLUSIONS

Racial differences in menarche may in large part be due to SES differences. Future experimental or quasiexperimental studies should examine whether intervening on SES factors could have benefits for delaying menarche among blacks and Hispanics.