Genome-wide association studies of age at menarche and age at natural menopause

Chromosomal polymorphisms and susceptibility to menstrual disorders: a retrospective analysis of 24,578 women

PURPOSE

To evaluate the association between the polymorphic variants of chromosomes and menstrual disorders.

METHODS

The data from our previous retrospective, single-center cohort study were re-analyzed. Women with regular menstruation were included as controls. Women with menstrual cycle abnormalities were subgrouped according to reproductive causes. The frequency of chromosomal polymorphisms was compared between groups. Regression analysis was used to adjust for potential confounding variables.

RESULT

A total of 24,578 women composed of 8062 women with regular cycles as the control group and 16,516 women as the menstrual cycle irregularity group were included. When compared with the control group, the incidence of chromosomal polymorphisms in the total menstrual cycle irregularity group, Polycystic ovary syndrome group, and Primary ovarian insufficiency group were significantly higher (4.49% versus 5.34%, P = 0.004, 4.49% versus 5.35%, P = 0.018 and 4.49% versus 5.94%, P = 0.002, respectively). The incidences of inv(9) in the Primary ovarian insufficiency group were significantly higher than that in the control individuals (1.0% versus 1.6%, P = 0.024). Logistic regression analysis showed an effect of chromosomal polymorphisms on menstrual cycle irregularity (OR: 1.62, 95% CI: 1.234-2.187, P = 0.007; adjusted OR: 1.46, 95% CI: 1.153-1.819, P < 0.001). The result demonstrated an effect of chromosomal polymorphisms on the Primary ovarian insufficiency group (OR: 2.52, 95% CI: 1.307-5.177, P < 0.001; adjusted OR: 2.61, 95% CI: 1.371-4.605, P < 0.001).

CONCLUSION

The study suggests chromosomal polymorphisms adversely affect female menstrual cycle irregularity.

Assessment and quantification of ovarian reserve on the basis of machine learning models

BACKGROUND

Early detection of ovarian aging is of huge importance, although no ideal marker or acknowledged evaluation system exists. The purpose of this study was to develop a better prediction model to assess and quantify ovarian reserve using machine learning methods.

METHODS

This is a multicenter, nationwide population-based study including a total of 1,020 healthy women. For these healthy women, their ovarian reserve was quantified in the form of ovarian age, which was assumed equal to their chronological age, and least absolute shrinkage and selection operator (LASSO) regression was used to select features to construct models. Seven machine learning methods, namely artificial neural network (ANN), support vector machine (SVM), generalized linear model (GLM), K-nearest neighbors regression (KNN), gradient boosting decision tree (GBDT), extreme gradient boosting (XGBoost), and light gradient boosting machine (LightGBM) were applied to construct prediction models separately. Pearson's correlation coefficient (PCC), mean absolute error (MAE), and mean squared error (MSE) were used to compare the efficiency and stability of these models.

RESULTS

Anti-Müllerian hormone (AMH) and antral follicle count (AFC) were detected to have the highest absolute PCC values of 0.45 and 0.43 with age and held similar age distribution curves. The LightGBM model was thought to be the most suitable model for ovarian age after ranking analysis, combining PCC, MAE, and MSE values. The LightGBM model obtained PCC values of 0.82, 0.56, and 0.70 for the training set, the test set, and the entire dataset, respectively. The LightGBM method still held the lowest MAE and cross-validated MSE values. Further, in two different age groups (20-35 and >35 years), the LightGBM model also obtained the lowest MAE value of 2.88 for women between the ages of 20 and 35 years and the second lowest MAE value of 5.12 for women over the age of 35 years.

CONCLUSION

Machine learning methods combining multi-features were reliable in assessing and quantifying ovarian reserve, and the LightGBM method turned out to be the approach with the best result, especially in the child-bearing age group of 20 to 35 years.

BRCA 1, 2 mutation and earlier menopause. Could BRCA 1, 2 be used as predictor of menopause?

Many studies have shown that BRCA mutation is not only related to cancer but also to ovarian aging. Studies in both human and mice oocytes have shown that Double-strand breaks (DSBs) accumulate with age. Genome-wide association studies (GWAS) have found 44 genetic loci that are related to variations when a female is about to have menopause. BRCA1 is involved in these 44 loci that are associated with the age of menopause. This review has gathered all results of literature search about the association between BRCA genes and early menopause. The majority of the articles found that women with BRCA mutation have earlier menopause compared to non-carriers. In conclusion, in the near future BRCA1,2 genes could be used as predictive biomarkers of menopause.

Joint Associations of Actual Age and Genetically Determined Age at Menarche With Risk of Mortality

IMPORTANCE

Previous studies have shown an association between actual age at menarche and risk of all-cause mortality; however, the results are inconsistent, and no study has analyzed the joint associations between genetic susceptibility and actual age at menarche with the risk of mortality in prospective cohorts.

OBJECTIVES

To investigate joint associations of actual age and genetically determined age at menarche with risk of all-cause mortality.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was conducted using data from the UK Biobank population across the United Kingdom from March 13, 2006, to October 1, 2010. A total of 264 546 women aged between 39 and 71 years with actual menarcheal age were included in this study; 246 676 of these women had genetic data available. Actual age at menarche was obtained from the touchscreen questionnaire at recruitment from 2006 to 2010. Genetically determined age at menarche was assessed by a genetic risk score. Statistical analysis was performed from August 22 to December 12, 2019.

EXPOSURE

Age at menarche.

MAIN OUTCOMES AND MEASURES

A multivariable Cox proportional hazards regression model was used to assess associations of actual or genetically determined age at menarche with risk of all-cause mortality.

RESULTS

The mean (SD) age of the study population at baseline was 56.4 (8.0) years, and the mean (SD) age at menarche included in the analyses was 13.0 (1.6) years. During a median of 9.0 years (range, 8.3-9.7 years) of follow-up, 7761 deaths were documented among the women with actual age at menarche, and 7054 deaths were documented among the women with genetically determined age at menarche. Both the actual age at menarche and the genetically determined age at menarche showed a U-shaped association with the risk of all-cause mortality (lowest actual age [<12 years] vs reference age [15 years]: hazard ratio [HR], 1.16 [95% CI, 1.07-1.26]; highest actual age [≥16 years] vs reference age [15 years]: HR, 1.17 [95% CI, 1.05-1.31]; P < .001 for quadratic trend; genetic risk score [GRS] of 1 vs reference score [GRS of 4]: HR, 1.10 [95% CI, 1.01-1.19; GRS of 6 vs reference score [GRS of 4]: HR, 1.09 [95% CI, 1.00-1.18]; P = .03 for quadratic trend). Significant interactions were also found between actual age at menarche and genetically determined age at menarche with all-cause mortality (HR of mortality associated with age of menarche <12 year was 1.24 [95% CI, 1.10-1.40] in the GRS of 1 group and 1.44 [95% CI, 1.21-1.72] in the GRS of 6 group; P = .001 for interaction). Women with mismatch of actual age and genetically determined age at menarche had the highest mortality risks; participants with the lowest genetic risk score and the highest age at menarche had an HR of 2.12 (95% CI, 1.58-2.83), and participants with the highest GRS and the lowest age at menarche had an HR of 1.44 (95% CI, 1.21-1.72).

CONCLUSIONS AND RELEVANCE

The results suggest that both actual age and genetically determined age at menarche exhibit U-shaped associations with all-cause mortality. Women with mismatch of actual age and genetically determined age at menarche may have the highest risk of all-cause mortality.

Associations of long-term exposure to environmental noise and outdoor light at night with age at natural menopause in a US women cohort

Previous studies have suggested noise, especially at night time, and light at night (LAN) could cause neuroendocrine disturbance and circadian disruption, which may lead to ovarian follicle atresia and earlier onset of menopause. However, no study to date has directly investigated the associations of exposure to these factors and menopausal age.

Methods

Premenopausal women from the Nurses' Health Study II (NHS II) were followed from age 40 through 2015. Median daytime and nighttime anthropogenic noise and outdoor LAN exposure were measured from a geospatial prediction model and satellite images, respectively, at residential addresses throughout the follow-up. Time-varying Cox proportional hazard models were used to calculate the hazard ratios and 95% confidence intervals, adjusting for individual lifestyle, reproductive history, and neighborhood socioeconomic factors. Possible effect modification by region, smoking status, body mass index, race/ethnicity, history of rotating shift work, and census tract population density and median income was examined.

Results

A total of 63,380 of 105,326 women self-reported natural menopause during 1,043,298 person-years of follow-up. No associations were found for noise (both daytime and nighttime) and outdoor LAN exposure with age at natural menopause (hazard ratios = 0.99-1.00) in the fully adjusted models. Sensitivity analyses showed similar null associations. No meaningful effect modification was found for region, smoking status, body mass index, race/ethnicity, history of rotating shift work, and census tract socioeconomic measures in stratified analyses.

Conclusion

No associations were found between environmental noise and outdoor LAN exposure in mid-adulthood and menopausal age in this cohort of US women.

Delayed age at menarche in chronic respiratory diseases

OBJECTIVE

Age at menarche (AAM) is an important indicator of physiological development in women, and delayed AAM has been associated with chronic illnesses. We investigated predictive factors at diagnosis that influence AAM in adolescents with chronic respiratory diseases.

STUDY DESIGN

AAM was assessed in 1207 northern Italian female aged 11-24 (1062 healthy, 98 with asthma and 47 with cystic fibrosis [CF]). AAM was defined by recall and status quo methods. We studied anthropometric data, metabolic status, diagnosis parameters, presence of irregular menses. Clinical data of subjects with chronic respiratory illness were compared with that of healthy adolescents.

RESULTS

Mean AAM for healthy adolescents was 12.49 ± 1.2 years. Mother's AAM was positively associated with that of their daughters (P < .001). BMI was negatively correlated with AAM (P < .001). 69% of healthy adolescents referred regular menses. AAM in the different groups was 12.79 ± 3.0 years for patients with asthma (P < .05 vs healthy) and 13.24 ± 1.44 years for adolescents with CF (P < .0001 vs healthy). In the asthmatic group, 57% of the patients referred regular menses, and no significant differences were found between AAM and control of the disease (ACT test). In the CF group, no correlation was found between the type of CFTR mutation or FEV1% and AAM. 53% of the patients with CF referred regular menses.

CONCLUSIONS

AAM in patients with CF and asthma was significantly higher than in healthy adolescents, and menses abnormalities were observed in the last two groups. Inflammation influences the reproductive function in chronic respiratory disease.

Relationship between age at menarche and risk of glucose metabolism disorder: a systematic review and dose-response meta-analysis

OBJECTIVE

Studies investigating the impact of age at menarche on glucose metabolism disorder have reached inconsistent conclusions, and a quantitative comprehensive assessment of the dose-response association between age at menarche and glucose metabolism disorder has not been reported. We performed a systematic review and meta-analysis of studies assessing the risk of glucose metabolism disorder by age at menarche.

METHODS

MEDLINE via PubMed and EMBASE databases were searched up to March 13, 2019. Restricted cubic splines were used to model the dose-response association.

RESULTS

Twenty-five publications (including 34 studies) were included in the meta-analysis. The summary risk ratios (RRs) and 95% confidence limit (CL) per 1-year increase in age at menarche were 0.98 (95% CL 0.98, 0.99) for type 2 diabetes mellitus (T2DM), 0.97 (95% CL 0.96, 0.99) for impaired fasting glucose (IFG), and 0.98 (95% CL 0.97, 0.99) for gestational diabetes mellitus (GDM). We identified linear negative correlations between age at menarche and T2DM (Pnonlinearity = 0.052) and IFG (Pnonlinearity = 0.145), a nonlinear dose-response between age at menarche and GDM (Pnonlinearity = 0.038).

CONCLUSIONS

Older age at menarche (range 8-18 years old) is associated with reduced risk of glucose metabolism disorder. The strongest reduction in risk of GDM is observed at menarche age of 14.5 years.

Genetics of Menopause and Primary Ovarian Insufficiency: Time for a Paradigm Shift?

This review summarizes the existing information concerning the genetic background of menopause and primary ovarian insufficiency (POI). There is overwhelming evidence that majority of genes are involved in double-strand break repair, mismatch repair, and base excision repair. The remaining loci were involved in cell energy metabolism and immune response. Gradual (or in case of rapid POI) accumulation of unrepaired DNA damage causes (premature) cell death and cellular senescence. This in turn leads to exhaustion of cell renewal capacity and cellular dysfunction in affected organs and eventually to aging of the entire soma. Similar erosion of the genome occurs within the germ cell line and the ovaries. Subsequently, the systemic "survival" response intentionally suppresses the sex-steroid hormonal output, which in turn may contribute to the onset of menopause. The latter occurs in particular when age-dependent DNA damage accumulation does not cease. Both effects are expected to synergize to promote (premature) ovarian silencing and install (early) menopause. Consequently, aging of the soma seems to be a primary driver for the loss of ovarian function in women. This challenges the current dogma which implies that loss of ovarian function initiates aging of the soma. It is time for a paradigm shift!

Premature and Early Menopause in Relation to Cardiovascular Disease

Postmenopausal women have an increased risk for cardiovascular diseases. It has been postulated that the loss of ovarian function and subsequent deficiency of endogenous estrogens after menopause contributes to this elevated risk of cardiovascular disease in postmenopausal women. Compared with woman entering menopause at the mean age of 51 years, in women with early menopause or premature ovarian insufficiency the risk for cardiovascular disease is even greater. These women lack the cardioprotective effect of endogenous estrogens for many more years than do women entering natural menopause. The majority of data assessing the risk of cardiovascular disease in relation to age at menopause and specifically premature menopause are derived from large epidemiological cohort studies. In addition, observations in women undergoing bilateral oophorectomy at an early age provide convincing evidence regarding association between early menopause or POI and the development of cardiovascular events and mortality. Moreover, genetic variants associated with earlier age at menopause have also been found to increase the risk of cardiovascular events in women. It has been substantiated that hormone replacement therapy (HRT) decreases the risk for ischemic heart disease and eliminates the increased cardiovascular disease mortality. It is therefore crucial to start HRT as soon as possible, particularly in women with premature ovarian insufficiency.

Integrating Clinical and Polygenic Factors to Predict Breast Cancer Risk in Women Undergoing Genetic Testing

PURPOSE

Screening and prevention decisions for women at increased risk of developing breast cancer depend on genetic and clinical factors to estimate risk and select appropriate interventions. Integration of polygenic risk into clinical breast cancer risk estimators can improve discrimination. However, correlated genetic effects must be incorporated carefully to avoid overestimation of risk.

MATERIALS AND METHODS

A novel Fixed-Stratified method was developed that accounts for confounding when adding a new factor to an established risk model. A combined risk score (CRS) of an 86-single-nucleotide polymorphism polygenic risk score and the Tyrer-Cuzick v7.02 clinical risk estimator was generated with attenuation for confounding by family history. Calibration and discriminatory accuracy of the CRS were evaluated in two independent validation cohorts of women of European ancestry (N = 1,615 and N = 518). Discrimination for remaining lifetime risk was examined by age-adjusted logistic regression. Risk stratification with a 20% risk threshold was compared between CRS and Tyrer-Cuzick in an independent clinical cohort (N = 32,576).

RESULTS

Simulation studies confirmed that the Fixed-Stratified method produced accurate risk estimation across patients with different family history. In both validation studies, CRS and Tyrer-Cuzick were significantly associated with breast cancer. In an analysis with both CRS and Tyrer-Cuzick as predictors of breast cancer, CRS added significant discrimination independent of that captured by Tyrer-Cuzick (P < 10-11 in validation 1; P < 10-7 in validation 2). In an independent cohort, 18% of women shifted breast cancer risk categories from their Tyrer-Cuzick-based risk compared with risk estimates by CRS.

CONCLUSION

Integrating clinical and polygenic factors into a risk model offers more effective risk stratification and supports a personalized genomic approach to breast cancer screening and prevention.

Long-term exposure to particulate matter and roadway proximity with age at natural menopause in the Nurses' Health Study II Cohort

Evidence has shown associations between air pollution and traffic-related exposure with accelerated aging, but no study to date has linked the exposure with age at natural menopause, an important indicator of reproductive aging. In this study, we sought to examine the associations of residential exposure to ambient particulate matter (PM) and distance to major roadways with age at natural menopause in the Nurses' Health Study II (NHS II), a large, prospective female cohort in US. A total of 105,996 premenopausal participants in NHS II were included at age 40 and followed through 2015. Time-varying residential exposures to PM10, PM2.5-10, and PM2.5 and distance to roads was estimated. We calculated hazard ratios (HR) and 95% confidence intervals (CIs) for natural menopause using Cox proportional hazard models adjusting for potential confounders and predictors of age at menopause. We also examined effect modification by region, smoking, body mass, physical activity, menstrual cycle length, and population density. There were 64,340 reports of natural menopause throughout 1,059,229 person-years of follow-up. In fully adjusted models, a 10 μg/m3 increase in the cumulative average exposure to PM10 (HR: 1.02, 95% CI: 1.00, 1.04), PM2.5-10 (HR: 1.03, 95% CI: 1.00, 1.05), and PM2.5 (HR: 1.03, 95% CI: 1.00, 1.06) and living within 50 m to a major road at age 40 (HR: 1.03, 95%CI: 1.00, 1.06) were associated with slightly earlier menopause. No statistically significant effect modification was found, although the associations of PM were slightly stronger for women who lived in the West and for never smokers. To conclude, we found exposure to ambient PM and traffic in midlife was associated with slightly earlier onset of natural menopause. Our results support previous evidence that exposure to air pollution and traffic may accelerate reproductive aging.

Age at menarche and risk of all-cause and cardiovascular mortality: a systematic review and dose-response meta-analysis

OBJECTIVE

The evidence between age at menarche and mortality risk is controversial. We aimed to quantify the dose-response association of age at menarche and risk of all-cause and cardiovascular disease (CVD) mortality based on cohort studies.

METHODS

PubMed, EMBASE, Web of Science, and Scopus databases were searched up to March 15, 2018 for relevant articles. Random-effects models and restricted cubic splines were used for this meta-analysis.

RESULTS

Twelve cohort studies, with 79,363 deaths and 2,341,769 participants, met the inclusion criteria. With each 1-year increase in menarche age, the relative risk (RR) was reduced for all-cause mortality (RR: 0.977, 95% confidence interval [CI]: 0.970-0.984), CVD mortality (RR: 0.993, 95% CI: 0.975-1.011), ischemic heart disease (IHD) mortality (RR: 0.969, 95% CI: 0.947-0.993), and stroke mortality (RR: 0.983, 95% CI: 0.954-1.012). We found a nonlinear dose-response association (Pnonlinearity = 0.001) between age at menarche and all-cause mortality, with the lowest risk observed at menarche age 15 years (RR: 0.849 95% CI: 0.800-0.901), but no evidence of a nonlinear association between menarche age and CVD mortality (Pnonlinearity = 0.543), IHD mortality (Pnonlinearity = 0.310), or stroke mortality (Pnonlinearity = 0.824).

CONCLUSIONS

Age at menarche is inversely associated with all-cause and IHD mortality.

Age at natural menopause in Koreans: secular trends and influences thereon

OBJECTIVES

Age at natural menopause (ANM) has become an important health issue in older women. We explored secular trends in ANM in Korea during the past decade, and defined factors predicting ANM.

METHODS

A total of 12,761 naturally menopausal women were selected from the 2001 to 2014 data of the Korea National Health and Nutrition Examination Survey, stages II to VI. The participants were divided into four groups based on 5-year ANM categories: <45, 45 to 49, 50 to 54, and ≥55 years. To identify factors associated with ANM, the regression analysis was used.

RESULTS

Both the mean (SE) and median (SE) ANM were 49.30 (0.07) years. The cumulative proportion of women experiencing menopause before the age of 40, 45, 50, and 55 years was 3.6%, 11.8%, 46.0%, and 90.3%, respectively. The mean (SE) ANM in women born in 1929 or earlier, and between 1930 to 1934, 1935 to 1939, 1940 to 1944, and 1945 to 1949, was 47.9 (0.3), 48.1 (0.2), 48.8 (0.2), 50.1 (0.2), and 50.5 (0.1) years, respectively (P < 0.001). Residence in a rural area (odds ratio [OR] 1.82), low weight status (OR 1.61), a history of or current smoking, a low educational level, being without a partner, and participating in at least moderate physical activity (OR 1.47, 1.33, 1.32, and 1.26, respectively) were more likely to result in an early ANM. Women with prior childbirth were less likely to experience early menopause (OR 0.34). In contrast, late menopause was associated with obesity and being overweight (OR 1.63 and 1.27).

CONCLUSIONS

We found that the mean ANM exhibited upward secular trends. Socioeconomic status and lifestyle factors were the principal independent factors affecting ANM.

Puberty and the Evolution of Developmental Science

In recent decades, theoretical and methodological advances have operated synergistically to advance understanding of puberty and prompt increasingly comprehensive models that engage with the temporal, psychosocial, and biological dimensions of this maturational milepost. This integrative overview discusses these theoretical and methodological advances and their implications for research and intervention to promote human development in the context of changing maturational schedules and massive ongoing social transformations.

Genetics of pubertal timing

PURPOSE OF REVIEW

To summarize advances in the genetics underlying variation in normal pubertal timing, precocious puberty, and delayed puberty, and to discuss mechanisms by which genes may regulate pubertal timing.

RECENT FINDINGS

Genome-wide association studies have identified hundreds of loci that affect pubertal timing in the general population in both sexes and across ethnic groups. Single genes have been implicated in both precocious and delayed puberty. Potential mechanisms for how these genetic loci influence pubertal timing may include effects on the development and function of the GnRH neuronal network and the responsiveness of end-organs.

SUMMARY

There has been significant progress in identifying genetic loci that affect normal pubertal timing, and the first single-gene causes of precocious and delayed puberty are being described. How these genes influence pubertal timing remains to be determined.

Japanese GWAS identifies variants for bust-size, dysmenorrhea, and menstrual fever that are eQTLs for relevant protein-coding or long non-coding RNAs

Traits related to primary and secondary sexual characteristics greatly impact females during puberty and day-to-day adult life. Therefore, we performed a GWAS analysis of 11,348 Japanese female volunteers and 22 gynecology-related phenotypic variables, and identified significant associations for bust-size, menstrual pain (dysmenorrhea) severity, and menstrual fever. Bust-size analysis identified significant association signals in CCDC170-ESR1 (rs6557160; P = 1.7 × 10-16) and KCNU1-ZNF703 (rs146992477; P = 6.2 × 10-9) and found that one-third of known European-ancestry associations were also present in Japanese. eQTL data points to CCDC170 and ZNF703 as those signals' functional targets. For menstrual fever, we identified a novel association in OPRM1 (rs17181171; P = 2.0 × 10-8), for which top variants were eQTLs in multiple tissues. A known dysmenorrhea signal near NGF replicated in our data (rs12030576; P = 1.1 × 10-19) and was associated with RP4-663N10.1 expression, a putative lncRNA enhancer of NGF, while a novel dysmenorrhea signal in the IL1 locus (rs80111889; P = 1.9 × 10-16) contained SNPs previously associated with endometriosis, and GWAS SNPs were most significantly associated with IL1A expression. By combining regional imputation with colocalization analysis of GWAS/eQTL signals along with integrated annotation with epigenomic data, this study further refines the sets of candidate causal variants and target genes for these known and novel gynecology-related trait loci.

Genetic variations, reproductive aging, and breast cancer risk in African American and European American women: The Women's Circle of Health Study

Reproductive aging phenotypes, including age at menarche (AM) and age at natural menopause (ANM), are well-established risk factors for breast cancer. In recent years, many genetic variants have been identified in association with AM and ANM in genome-wide association studies among European populations. Using data from the Women’s Circle of Health Study (WCHS) of 1,307 European-American (EA) and 1,365 African-American (AA) breast cancer cases and controls, we aimed to replicate 53 earlier GWAS variants for AM and ANM in AA and EA groups and to perform analyses on total and net reproductive lifespan (TRLS; NRLS). Breast cancer risk was also examined in relation to a polygenic risk score (PRS) for each of the reproductive aging phenotypes. We replicated a number of variants in EA women, including rs7759938 in LIN28B for AM and rs16991615 in MCM8 for ANM; whereas in the AA group, only one SNP (rs2947411 in TMEM18) for AM was directionally consistent and nominally significant. In analysis of TRLS and NRLS, several SNPs were significant, including rs466639 in RXRG that was associated with both phenotypes in both AA and EA groups. None of the PRS was associated with breast cancer risk. Given the paucity of data available among AA populations, our study contributes to the literature of genetics of reproductive aging in AA women and highlights the importance of cross population replication of GWAS variants.

Identifying genetic variants that affect viability in large cohorts

A number of open questions in human evolutionary genetics would become tractable if we were able to directly measure evolutionary fitness. As a step towards this goal, we developed a method to examine whether individual genetic variants, or sets of genetic variants, currently influence viability. The approach consists in testing whether the frequency of an allele varies across ages, accounting for variation in ancestry. We applied it to the Genetic Epidemiology Research on Adult Health and Aging (GERA) cohort and to the parents of participants in the UK Biobank. Across the genome, we found only a few common variants with large effects on age-specific mortality: tagging the APOE ε4 allele and near CHRNA3. These results suggest that when large, even late-onset effects are kept at low frequency by purifying selection. Testing viability effects of sets of genetic variants that jointly influence 1 of 42 traits, we detected a number of strong signals. In participants of the UK Biobank of British ancestry, we found that variants that delay puberty timing are associated with a longer parental life span (P~6.2 × 10⁻⁶ for fathers and P~2.0 × 10⁻³ for mothers), consistent with epidemiological studies. Similarly, variants associated with later age at first birth are associated with a longer maternal life span (P~1.4 × 10⁻³). Signals are also observed for variants influencing cholesterol levels, risk of coronary artery disease (CAD), body mass index, as well as risk of asthma. These signals exhibit consistent effects in the GERA cohort and among participants of the UK Biobank of non-British ancestry. We also found marked differences between males and females, most notably at the CHRNA3 locus, and variants associated with risk of CAD and cholesterol levels. Beyond our findings, the analysis serves as a proof of principle for how upcoming biomedical data sets can be used to learn about selection effects in contemporary humans.

Our global understanding of adaptation in humans is limited to indirect statistical inferences from patterns of genetic variation, which are sensitive to past selection pressures. We introduced a method that allowed us to directly observe ongoing selection in humans by identifying genetic variants that affect survival to a given age (i.e., viability selection). We applied our approach to the GERA cohort and parents of the UK Biobank participants. We found viability effects of variants near the APOE and CHRNA3 genes, which are associated with the risk of Alzheimer disease and smoking behavior, respectively. We also tested for the joint effect of sets of genetic variants that influence quantitative traits. We uncovered an association between longer life span and genetic variants that delay puberty timing and age at first birth. We also detected detrimental effects of higher genetically predicted cholesterol levels, body mass index, risk of coronary artery disease (CAD), and risk of asthma on survival. Some of the observed effects differ between males and females, most notably those at the CHRNA3 gene and variants associated with risk of CAD and cholesterol levels. Beyond this application, our analysis shows how large biomedical data sets can be used to study natural selection in humans.

ASSOCIATION OF AGE AT MENOPAUSE WITH POST-MENOPAUSAL SYMPTOMS, MENARCHE AGE AND OTHER REPRODUCTIVE FACTORS AMONG RURAL FEMALES IN SHIMLA, HIMACHAL PRADESH

This study analysed the association between menopause, menarche and number of live births using cross-sectional primary data for 75 post-menopausal rural women from Shimla in the Indian state of Himachal Pradesh. The mean/median ages at menarche of the 75 women were 14.23/14 years, and those at menopause 45.35/45 years. There were no significant differences in these values between women in the age groups 40–55 and 56–65 years. Age at menopause was found to be significantly associated with age at menarche and maternal age at birth of the first and last child, but not with menopausal symptom severity score. The majority of the 75 post-menopausal women (70.7%) had very mild or no menopausal symptoms. Three principal components were identified that explained 72.43% of the underlying variation in menopausal symptoms.

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.

Effects of nutraceuticals on quality of life and sexual function of perimenopausal women

PURPOSE

The aim of the study was to evaluate the effects of nutraceuticals containing Equol, Resveratrol, Quecitine and Passiflora (Zemiar^®, Avantgarde, Pomezia, Rome, Italy) on quality of life (QoL) and sexual function in perimenopausal women.

METHODS

Sixty perimenopausal women having vasomotor symptoms and being in the -1, +1a of the STRAW system (amenorrhea for longer than 60 days and FSH < 20 UI/L) were enrolled. The modified Kupperman Index (KI) was used to evaluate menopause symptoms. The Short Form-36 (SF-36), Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale (FSDS) were used to assess QoL, sexual function and sexual distress, respectively. The study had two follow-ups at 3 and 6 months.

RESULTS

The women reported an improvement in the KI total score from the baseline (35 ± 4) to the 1st (21 ± 3, p < 0.05) and the 2nd (18 ± 2, p < 0.01) follow-ups. At the 1st follow-up, the women reported QoL improvements in some functions (p < 0.05); at the 2nd follow-up, they reported improvements in all categories (p < 0.001). At baseline, the total FSFI score was 23.1 ± 1.2 and the FSDS score was 18.1 ± 1.4, both indicating sexual dysfunction with sexual distress. FSFI and FSDS total scores did not change at the 1st follow-up (p = NS). On the contrary, at the 2nd follow-up, the FSFI score had risen to (27.6 ± 1.5) (p < 0.001) and the FSDS score had dropped to (11.3 ± 1.2) (p < 0.001).

CONCLUSIONS

Nutraceuticals can be effective in modulating the perimenopausal symptoms in women. The progressive reduction of the vasomotor symptoms reported by women over the nutraceutical usage could contribute to improve their QoL and sexual life.

UGT2B4 previously implicated in the risk of breast cancer is associated with menarche timing in Ukrainian females

Age at menarche (AAM) is a multifactorial trait that is regulated by dozens environmental and genetic factors. Recent meta-analysis of GWAS showed significant association of 106 loci with AAM. These polymorphisms need replicating in different ethnic populations in order to confirm their association with menarche timing. This study was aimed to replicate 53 polymorphisms that were previously associated with AAM. DNA samples were collected from 416 Ukrainian young females for further genotyping. After data quality control 47 polymorphisms remained for the association analysis using the linear regression model. SNP rs13111134 located in UGT2B4 showed the most significant association with AAM (0.431years per allele A, padj=0.044 after the Bonferroni correction). Polymorphisms rs7589318 in POMC, rs11724758 in FABP2, rs7753051 in IGF2R, rs2288696 in FGFR1 and rs12444979 in GPRC5B may also contribute to menarche timing. However, none of these associations remained significant after the Bonferroni correction for multiple testing. The obtained results provide evidence that UGT2B4, which was previously associated with predisposition to breast cancer, may play a role in the onset of menarche.

Recent advances in the understanding and management of delayed puberty

Delayed puberty, especially in boys, is a common presentation in paediatrics. Recent advances have improved our understanding of the neuroendocrine, genetic and environmental factors controlling pubertal development, and hence inform the pathophysiology of delayed puberty. The discovery of kisspeptin signalling through its receptor identified neuroendocrine mechanisms controlling the gonadotrophin-releasing hormone (GnRH) pulse generator at the onset of puberty. Genetic mechanisms from single gene mutations to single nucleotide polymorphism associated with delayed puberty are being identified. Environmental factors, including nutritional factors and endocrine disruptors, have also been implicated in changes in secular trends and abnormal timing of puberty. Despite these advances, the key clinical question is to distinguish delayed puberty associated with an underlying pathology or hypogonadism from constitutional delay in growth and puberty, which remains challenging as biochemical tests are not always discriminatory. The diagnostic accuracies of newer investigations, including 36-hour luteinising hormone releasing hormone (LHRH) tests, GnRH-agonist tests, antimullerian hormone and inhibin-B, require further evaluation. Sex hormone replacement remains the main available treatment for delayed puberty, the choice of which is largely dictated by clinical practice and availability of the various sex steroid preparations. Spontaneous reversal of hypogonadism has been reported in boys with idiopathic hypogonadotrophic hypogonadism after a period of sex steroid treatment, highlighting the importance of reassessment at the end of pubertal induction. Novel therapies with a more physiological basis such as gonadotrophins or kisspeptin-agonist are being investigated for the management of hypogonadotrophic hypogonadism. Careful clinical assessment and appreciation of the normal physiology remain the key approach to patients with delayed puberty.

Events in Early Life are Associated with Female Reproductive Ageing: A UK Biobank Study

The available oocyte pool is determined before birth, with the majority of oocytes lost before puberty. We hypothesised that events occurring before birth, in childhood or in adolescence (‘early-life risk factors’) could influence the size of the oocyte pool and thus the timing of menopause. We included cross-sectional data from 273,474 women from the UK Biobank, recruited in 2006–2010 from across the UK. We analysed the association of early menopause with events occurring before adulthood in 11,781 cases (menopause aged under 45) and 173,641 controls (menopause/pre-menopausal at ≥45 years), in models controlling for potential confounding variables. Being part of a multiple birth was strongly associated with early menopause (odds ratio = 1.42, confidence interval: 1.11, 1.82, P = 8.0 × 10⁻⁹, fully-adjusted model). Earlier age at menarche (odds ratio = 1.03, confidence interval: 1.01, 1.06, P = 2.5 × 10⁻⁶) and earlier year of birth were also associated with EM (odds ratio = 1.02, confidence interval: 1.00, 1.04, P = 8.0 × 10⁻⁶). We also confirmed previously reported associations with smoking, drinking alcohol, educational level and number of births. We identified an association between multiple births and early menopause, which connects events pre-birth, when the oocyte pool is formed, with reproductive ageing in later life.

The genetics of premature ovarian failure: current perspectives

Premature ovarian failure (POF) is a common cause of infertility in women, characterized by amenorrhea, hypoestrogenism, and elevated gonadotropin levels in women under the age of 40. Many genes have been identified over the past few years that contribute to the development of POF. However, few genes have been identified that can explain a substantial proportion of cases of POF. The unbiased approaches of genome-wide association studies and next-generation sequencing technologies have identified several novel genes implicated in POF. As only a small proportion of genes influencing idiopathic POF have been identified thus far, it remains to be determined how many genes and molecular pathways may influence idiopathic POF development. However, owing to POF’s diverse etiology and genetic heterogeneity, we expect to see the contribution of several new and novel molecular pathways that will greatly enhance our understanding of the regulation of ovarian function. Future genetic studies in large cohorts of well-defined, unrelated, idiopathic POF patients will provide a great opportunity to identify the missing heritability of idiopathic POF. The identification of several causative genes may allow for early detection and would provide better opportunity for early intervention, and furthermore, the identification of specific gene defects will help direct potential targets for future treatment.

Association of maternal menarcheal age with anthropometric dimensions and blood pressure in children from Greater Bilbao

BACKGROUND

Earlier menarche has been related to shorter height and greater obesity-related anthropometric dimensions and blood pressure in women. Boys and girls with earlier maternal menarcheal age (MMA) have shown greater height and body mass index (BMI) in childhood.

AIM

To analyse associations of menarcheal age with their own and their children's anthropometric dimensions and blood pressure.

SUBJECTS AND METHODS

The sample consisted of 493 women and their children (aged 2-19 years) from Greater Bilbao (Basque Country, Spain). For both generations there is information on 19 anthropometric dimensions, blood pressure and socio-demographic characteristics. Linear regressions adjusted for different covariates were used to analyse the associations.

RESULTS

Menarcheal age in women showed the greatest positive associations with iliospinal height and ectomorphy and negative associations with BMI, sum of six skin-folds, endomorphy and mesomorphy. Boys with earlier MMA had greater body heights and breadths, particularly iliospinal height and biacromial breadth (0.10 z-score/year; p < 0.05). In girls, earlier MMA predicted greater sitting height, biepicondylar humerus breadth, weight and sum of four circumferences (0.07-0.09 z-score/year; p < 0.05). However, there was some evidence that MMA was positively associated with body heights, ectomorphy and blood pressure in girls aged ≥12.

CONCLUSION

Children with earlier MMA tend to have greater anthropometric dimensions. Adolescent growth spurt might affect these relationships, at least in girls.

Menopause prediction and potential implications

Reproductive ageing in women is characterized by a decline in both the quantity and quality of oocytes. Menopause is reached upon exhaustion of the resting primordial follicle pool, occurring on average at 51 years of age (range 40-60 years). The mean global age at natural menopause (ANM) appears robust, suggesting a distinct genetic control. Accordingly, a strong correlation in ANM is observed between mothers and daughters. Few specific genetic determinants of ANM have been identified. Substantial efforts have been made to predict ANM by using anti-Müllerian hormone (AMH) levels. AMH serum concentrations at reproductive age predict ANM, but precision is currently limited. Early ANM is associated with early preceding fertility loss, whereas late menopause is associated with reduced morbidity and mortality later in life. Menopause affects various women's health aspects, including bone density, breast, the cardiovascular system, mood/cognitive function and sexual well-being. If the current trend of increasing human life expectancy persists, women will soon spend half their life postmenopause. Unfortunately, increased longevity does not coincide with an equal increase in years spend in good health. Future research should focus on determinants of long term health effects of ANM, and efforts to improve women's postmenopausal health and quality of life.

Natural fertility and longevity

Much empirical work suggests an association between fertility patterns and longevity. I review this association, focusing on natural fertility populations and emphasizing the role of both the timing and the intensity of fertility. Overall, it appears that although age at last reproduction routinely correlates with post-reproductive longevity, suggesting a slower rate of senescence among late fertile women, the same is not true for age at first reproduction and parity. I discuss some of the conceptual and methodologic issues, as well as the sources of the biases, that have been a persistent feature of this body of research. I conclude by suggesting avenues of research that could be initiated or pursued in the area.

Extended fertility and longevity: the genetic and epigenetic link

Many women now choose to develop their careers before having children. Thus, it is becoming increasingly important to assess a woman's potential for extended fertility and to understand the health consequences of having children at a late age. In particular, there is a striking positive correlation between extended fertility and longevity in women, which poses important implications for medicine, biology, and evolution. In this article we review the diverse epidemiologic evidence for the link between fertility potential, age of menopause, and women's lifespan. Then we discuss the recent advances using genomic technology to better understand biological mechanisms driving this association. At the genetic level, there are polymorphisms that may be driving both extended fertility and longevity. At the cellular and molecular levels, changes in the genome (both nuclear and mitochondrial), epigenome, and transcriptome during oocyte aging have important implications for fertility. By synthesizing results from diverse domains, we hope to provide a genomic-era conceptual framework in which this important connection can be investigated and understood.

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.

Genetic variation at CYP3A is associated with age at menarche and breast cancer risk: a case-control study

INTRODUCTION

We have previously shown that a tag single nucleotide polymorphism (rs10235235), which maps to the CYP3A locus (7q22.1), was associated with a reduction in premenopausal urinary estrone glucuronide levels and a modest reduction in risk of breast cancer in women age ≤50 years.

METHODS

We further investigated the association of rs10235235 with breast cancer risk in a large case control study of 47,346 cases and 47,570 controls from 52 studies participating in the Breast Cancer Association Consortium. Genotyping of rs10235235 was conducted using a custom Illumina Infinium array. Stratified analyses were conducted to determine whether this association was modified by age at diagnosis, ethnicity, age at menarche or tumor characteristics.

RESULTS

We confirmed the association of rs10235235 with breast cancer risk for women of European ancestry but found no evidence that this association differed with age at diagnosis. Heterozygote and homozygote odds ratios (ORs) were OR = 0.98 (95% CI 0.94, 1.01; P = 0.2) and OR = 0.80 (95% CI 0.69, 0.93; P = 0.004), respectively (P(trend) = 0.02). There was no evidence of effect modification by tumor characteristics. rs10235235 was, however, associated with age at menarche in controls (P(trend) = 0.005) but not cases (P(trend) = 0.97). Consequently the association between rs10235235 and breast cancer risk differed according to age at menarche (P(het) = 0.02); the rare allele of rs10235235 was associated with a reduction in breast cancer risk for women who had their menarche age ≥15 years (OR(het) = 0.84, 95% CI 0.75, 0.94; OR(hom) = 0.81, 95% CI 0.51, 1.30; P(trend) = 0.002) but not for those who had their menarche age ≤11 years (OR(het) = 1.06, 95% CI 0.95, 1.19, OR(hom) = 1.07, 95% CI 0.67, 1.72; P(trend) = 0.29).

CONCLUSIONS

To our knowledge rs10235235 is the first single nucleotide polymorphism to be associated with both breast cancer risk and age at menarche consistent with the well-documented association between later age at menarche and a reduction in breast cancer risk. These associations are likely mediated via an effect on circulating hormone levels.

The future for genetic studies in reproduction

Genetic factors contribute to risk of many common diseases affecting reproduction and fertility. In recent years, methods for genome-wide association studies (GWAS) have revolutionized gene discovery for common traits and diseases. Results of GWAS are documented in the Catalog of Published Genome-Wide Association Studies at the National Human Genome Research Institute and report over 70 publications for 32 traits and diseases associated with reproduction. These include endometriosis, uterine fibroids, age at menarche and age at menopause. Results that pass appropriate stringent levels of significance are generally well replicated in independent studies. Examples of genetic variation affecting twinning rate, infertility, endometriosis and age at menarche demonstrate that the spectrum of disease-related variants for reproductive traits is similar to most other common diseases. GWAS 'hits' provide novel insights into biological pathways and the translational value of these studies lies in discovery of novel gene targets for biomarkers, drug development and greater understanding of environmental factors contributing to disease risk. Results also show that genetic data can help define sub-types of disease and co-morbidity with other traits and diseases. To date, many studies on reproductive traits have used relatively small samples. Future genetic marker studies in large samples with detailed phenotypic and clinical information will yield new insights into disease risk, disease classification and co-morbidity for many diseases associated with reproduction and infertility.

Development of a data-mining algorithm to identify ages at reproductive milestones in electronic medical records

Electronic medical records (EMRs) are becoming more widely implemented following directives from the federal government and incentives for supplemental reimbursements for Medicare and Medicaid claims. Replete with rich phenotypic data, EMRs offer a unique opportunity for clinicians and researchers to identify potential research cohorts and perform epidemiologic studies. Notable limitations to the traditional epidemiologic study include cost, time to complete the study, and limited ancestral diversity; EMR-based epidemiologic studies offer an alternative. The Epidemiologic Architecture for Genes Linked to Environment (EAGLE) Study, as part of the Population Architecture using Genomics and Epidemiology (PAGE) I Study, has genotyped more than 15,000 patients of diverse ancestry in BioVU, the Vanderbilt University Medical Center's biorepository linked to the EMR (EAGLE BioVU). We report here the development and performance of data-mining techniques used to identify the age at menarche (AM) and age at menopause (AAM), important milestones in the reproductive lifespan, in women from EAGLE BioVU for genetic association studies. In addition, we demonstrate the ability to discriminate age at naturally-occurring menopause (ANM) from medically-induced menopause. Unusual timing of these events may indicate underlying pathologies and increased risk for some complex diseases and cancer; however, they are not consistently recorded in the EMR. Our algorithm offers a mechanism by which to extract these data for clinical and research goals.

Preliminary Hormonal Correlations in Female Patients as a Function of Somatic and Neurological Symptom Clusters: An Exploratory Development of a Multi-Hormonal Map for Bio-Identical Replacement Therapy (MHRT)

Females develop multiple hormonal alterations and certain genes may be involved in the intensity of subsequent symptoms including both mood and drug seeking. Seventy Four (74) females were included (mean age=60.23, SD=9.21, [43-87]). A medical evaluation was completed with hormone screening using a number of statistical analyses such as Pearson product moment; one way ANOVA and Regression analysis along with a Bonferroni significance correction p<.004. Of 120 correlations performed, significant hormone/domain correlations were as follows: DHEA/Genitourinary (r=.30, p<.05); FSH/Pulmonary (r=−.29, p<.05); Pregnenolone/Genitourinary (r=.40, p<.006) /Immunological (r=.38, p<.008); Testosterone/total endorsed symptoms (r=−0.34, p<.016); TSH/Pulmonary (r=−.33, p<.03) /Gynecological (r=.30, p<.05). Estrone/Musculoskeletal (r=−0.43, p<.012). After a Bonferroni correction (experiment-wise p<.00045) for statistical significance, no hormones remained significance. In the follow–up phase FSH/Neuropsychiatric (r=.56, p<.05) and Musculoskeletal (r=.67, p<.013); DHEA/Immunological (r=.64, p<.04); LH/ Musculoskeletal (r=.59, p<.34); Free Testosterone/Neuropsychiatric (r=.64, p<.019), Musculoskeletal (r=.68, p<.01), and Dermatologic (r=.57, p<.04); Total Testosterone/Immunological (r=.63, p<.028); TSH/Endocrinological (r=−.62, p<.031). Factor analysis of the MQ yielded two factors with eigenvalues > 1.0 (high loadings: first: Pulmonary, GI, Cardiovascular, and Immunological; second: Musculoskeletal, Gynecological, and the three Neurological domains). Both factors had significant correlations: first/pregnenolone (r=.37, p<.019); second/TSH (r=.33, p<.034). An additional factor analysis of hormone level clusters showed significant correlations with various domains. This study highlights the need to test the core biological endocrine hormones associated with females. Future research will focus on the relationship of for example Leptin and the electrophysiology of the brain. We are cautiously proposing a new paradigm shift whereby we replace the old nomenclature of HRT to MHRT.

Genomic markers of ovarian reserve

Ovarian reserve and its utilization, over a reproductive life span, are determined by genetic, epigenetic, and environmental factors. The establishment of the primordial follicle pool and the rate of primordial follicle activation have been under intense study to determine genetic factors that affect reproductive lifespan. Much has been learned from transgenic animal models about the developmental origins of the primordial follicle pool and mechanisms that lead to primordial follicle activation, folliculogenesis, and the maturation of a single oocyte with each menstrual cycle. Recent genome-wide association studies on the age of human menopause have identified approximately 20 loci, and shown the importance of factors involved in double-strand break repair and immunology. Studies to date from animal models and humans show that many genes determine ovarian aging, and that there is no single dominant allele yet responsible for depletion of the ovarian reserve. Personalized genomic approaches will need to take into account the high degree of genetic heterogeneity, family pedigree, and functional data of the genes critical at various stages of ovarian development to predict women's reproductive life span.

Identifying opportunities for cancer prevention during preadolescence and adolescence: puberty as a window of susceptibility

PURPOSE

Early life exposures during times of rapid growth and development are recognized increasingly to impact later life. Epidemiologic studies document an association between exposures at critical windows of susceptibility with outcomes as diverse as childhood and adult obesity, timing of menarche, and risk for hypertension or breast cancer.

METHODS

This article briefly reviews the concept of windows of susceptibility for providers who care for adolescent patients.

RESULTS

The theoretical bases for windows of susceptibility is examined, evaluating the relationship between pubertal change and breast cancer as a paradigm, and reviewing the underlying mechanisms, such as epigenetic modification.

CONCLUSIONS

The long-term sequela of responses to early exposures may impact other adult morbidities; addressing these exposures represents an important challenge for contemporary medicine.

Replication of genetic loci for ages at menarche and menopause in the multi-ethnic Population Architecture using Genomics and Epidemiology (PAGE) study

STUDY QUESTION

Do genetic associations identified in genome-wide association studies (GWAS) of age at menarche (AM) and age at natural menopause (ANM) replicate in women of diverse race/ancestry from the Population Architecture using Genomics and Epidemiology (PAGE) Study?

SUMMARY ANSWER

We replicated GWAS reproductive trait single nucleotide polymorphisms (SNPs) in our European descent population and found that many SNPs were also associated with AM and ANM in populations of diverse ancestry.

WHAT IS KNOWN ALREADY

Menarche and menopause mark the reproductive lifespan in women and are important risk factors for chronic diseases including obesity, cardiovascular disease and cancer. Both events are believed to be influenced by environmental and genetic factors, and vary in populations differing by genetic ancestry and geography. Most genetic variants associated with these traits have been identified in GWAS of European-descent populations.

STUDY DESIGN, SIZE, DURATION

A total of 42 251 women of diverse ancestry from PAGE were included in cross-sectional analyses of AM and ANM.

MATERIALS, SETTING, METHODS

SNPs previously associated with ANM (n = 5 SNPs) and AM (n = 3 SNPs) in GWAS were genotyped in American Indians, African Americans, Asians, European Americans, Hispanics and Native Hawaiians. To test SNP associations with ANM or AM, we used linear regression models stratified by race/ethnicity and PAGE sub-study. Results were then combined in race-specific fixed effect meta-analyses for each outcome. For replication and generalization analyses, significance was defined at P < 0.01 for ANM analyses and P < 0.017 for AM analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

We replicated findings for AM SNPs in the LIN28B locus and an intergenic region on 9q31 in European Americans. The LIN28B SNPs (rs314277 and rs314280) were also significantly associated with AM in Asians, but not in other race/ethnicity groups. Linkage disequilibrium (LD) patterns at this locus varied widely among the ancestral groups. With the exception of an intergenic SNP at 13q34, all ANM SNPs replicated in European Americans. Three were significantly associated with ANM in other race/ethnicity populations: rs2153157 (6p24.2/SYCP2L), rs365132 (5q35/UIMC1) and rs16991615 (20p12.3/MCM8). While rs1172822 (19q13/BRSK1) was not significant in the populations of non-European descent, effect sizes showed similar trends.

LIMITATIONS, REASONS FOR CAUTION

Lack of association for the GWAS SNPs in the non-European American groups may be due to differences in locus LD patterns between these groups and the European-descent populations included in the GWAS discovery studies; and in some cases, lower power may also contribute to non-significant findings.

WIDER IMPLICATIONS OF THE FINDINGS

The discovery of genetic variants associated with the reproductive traits provides an important opportunity to elucidate the biological mechanisms involved with normal variation and disorders of menarche and menopause. In this study we replicated most, but not all reported SNPs in European descent populations and examined the epidemiologic architecture of these early reported variants, describing their generalizability and effect size across differing ancestral populations. Such data will be increasingly important for prioritizing GWAS SNPs for follow-up in fine-mapping and resequencing studies, as well as in translational research.

Life-course origins of the ages at menarche and menopause

A woman's age at menarche (first menstrual period) and her age at menopause are the alpha and omega of her reproductive years. The timing of these milestones is critical for a woman's health trajectory over her lifespan, as they are indicators of ovarian function and aging. Both early and late timing of either event are associated with risk for adverse health and psychosocial outcomes. Thus, the search for a relationship between age at menarche and menopause has consequences for chronic disease prevention and implications for public health. This article is a review of evidence from the fields of developmental biology, epidemiology, nutrition, demography, sociology, and psychology that examine the menarche-menopause connection. Trends in ages at menarche and menopause worldwide and in subpopulations are presented; however, challenges exist in constructing trends. Among 36 studies that examine the association between the two sentinel events, ten reported a significant direct association, two an inverse association, and the remainder had null findings. Multiple factors, including hormonal and environmental exposures, socioeconomic status, and stress throughout the life course are hypothesized to influence the tempo of growth, including body size and height, development, menarche, menopause, and the aging process in women. The complexity of these factors and the pathways related to their effects on each sentinel event complicate evaluation of the relationship between menarche and menopause. Limitations of past investigations are discussed, including lack of comparability of socioeconomic status indicators and biomarker use across studies, while minority group differences have received scant attention. Suggestions for future directions are proposed. As research across endocrinology, epidemiology, and the social sciences becomes more integrated, the confluence of perspectives will yield a richer understanding of the influences on the tempo of a woman's reproductive life cycle as well as accelerate progress toward more sophisticated preventive strategies for chronic disease.

Paternal age at birth is associated with offspring leukocyte telomere length in the nurses' health study

STUDY QUESTION

Is the association between paternal age at birth and offspring leukocyte telomere length (LTL) an artifact of early life socioeconomic status (SES)?

SUMMARY ANSWER

Indicators of early life SES did not alter the relationship between paternal age at birth and offspring LTL among a population of white female nurses.

WHAT IS KNOWN ALREADY

Telomere length is considered a highly heritable trait. Recent studies report a positive correlation between paternal age at birth and offspring LTL. Maternal age at birth has also been positively associated with offspring LTL, but may stem from the strong correlation with paternal age at birth.

STUDY DESIGN, SIZE AND DURATION

The Nurses' Health Study (NHS) is an ongoing prospective cohort study of 121 700 female registered nurses who were enrolled in 1976. Great effort goes into maintaining a high degree of follow-up among our cohort participants (>95% of potential person-years). In 1989-1990, a subset of 32 826 women provided blood samples from which we selected participants for several nested case-control studies of telomere length and incident chronic disease. We used existing LTL data on a total of 4250 disease-free women who also reported maternal and paternal age at birth for this study.

PARTICIPANTS/MATERIALS, SETTING AND METHODS

Nested case-control studies of stroke, myocardial infarction, cancers of the breast, endometrium, skin, pancreas and colon, as well as colon adenoma, were conducted within the blood sub-cohort. Each study used the following study design: for each case of a disease diagnosed after blood collection, a risk-set sampling scheme was used to select from one to three controls from the remaining participants in the blood sub-cohort who were free of that disease when the case was diagnosed. Controls were matched to cases by age at blood collection (± 1 year), date of blood collection (± 3 months), menopausal status, recent postmenopausal hormone use at blood collection (within 3 months, except for the myocardial infarction case-control study), as well as other factors carefully chosen for each individual study. The current analysis was limited to healthy controls. We also included existing LTL data from a small random sample of women participating in a cognitive sub-study. LTL was measured using the quantitative PCR-based method. Exposure and covariate information are extracted from biennial questionnaires completed by the participants.

MAIN RESULTS AND THE ROLE OF CHANCE

We found a strong association between paternal age at birth and participant LTL (P = 1.6 × 10(-5)) that remained robust after controlling for indicators of early life SES. Maternal age at birth showed a weak inverse association with participant LTL after adjusting for age at blood collection and paternal age at birth (P = 0.01). We also noted a stronger association between paternal age at birth and participant LTL among premenopausal than among postmenopausal women (P(interaction) = 0.045). However, this observation may be due to chance as premenopausal women represented only 12.6% (N = 535) of the study population and LTL was not correlated with age at menopause, total or estrogen-only hormone therapy (HT) use suggesting that changes in in vivo estrogen exposure do not influence telomere length regulation.

LIMITATIONS AND REASONS FOR CAUTION

The women in our study are not representative of the general US female population, with an underrepresentation of non-white and low social class groups. Although the interaction was not significant, we noted that the paternal age at birth association with offspring LTL appeared weaker among women whose parents did not own their home at the time of the participant's birth. As telomere dynamics may differ among individuals who are most socioeconomically deprived, SES indicators may have more of an influence on the relationship between paternal age at birth and offspring LTL in such populations.

WIDER IMPLICATIONS OF THE FINDINGS

As of yet, our and prior studies have not identified childhood or adult characteristics that confound the paternal age at birth association with offspring LTL, supporting the hypothesis that offspring may inherit the longer telomeres found in sperm of older men. The biological implications of the paternal age effect are unknown. A recent theory proposed that the inheritance of longer telomere from older men may be an adaptive signal of reproductive lifespan, while another theory links telomere length attrition to female reproductive senescence. However, we are unaware of any data to substantiate a relationship between paternal age at birth and daughter's fertility. Generalizability of our study results to other white female populations is supported by prior reports of paternal age at birth and offspring telomere length. Furthermore, a confounding relationship between paternal or maternal age at birth and SES was not observed in a study of SES and telomere length.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Institutes of Health (grants numbers: CA87969, CA49449, CA065725, CA132190, CA139586, HL088521, CA140790, CA133914, CA132175, ES01664 to M.D.); and by the American Health Association Foundation. We have no competing interests to declare.