Human studies on genetics of the age at natural menopause: a systematic review

Effects of menopause on temperature regulation

Changes in thermoregulation, notably the emergence of hot flashes, occur during the menopause transition in association with reproductive hormonal changes. Hot flashes constitute the most characteristic symptom of menopause (prevalence of 50-80%), and have a substantial negative effect on quality of life. Here, we review the endocrine changes associated with menopause and the thermoregulatory system and its sensitivity to female sex hormones. We then review current knowledge on the underlying neural mechanisms of hot flashes and how the reproductive and thermoregulatory systems interact in females. We consider the kisspeptin-neurokinin B-dynorphin (KNDy) neuron complex, which becomes hyperactive when estradiol levels decrease. KNDy neurons project from the arcuate nucleus to thermoregulatory areas within the hypothalamic preoptic area, where heat loss mechanisms are triggered, including cutaneous vasodilation and sweating - characteristics of the hot flash. We describe the physiology and measurement of hot flashes and discuss the mixed research findings about thresholds for sweating in symptomatic individuals. We consider the unique situation of hot flashes that arise during sleep, and discuss the relationships between the environment, exercise, and body mass index with hot flashes. We also discuss the unique situation of surgical menopause (with oophorectomy) and cancer therapy, conditions that are associated with frequent, severe, hot flashes. We then provide an overview of treatments of hot flashes, including hormone therapy and targeted neurokinin B-antagonists, recently developed to target the neural mechanism of hot flashes. Finally, we highlight gaps in knowledge about menopausal thermoregulation and hot flashes and suggest future directions for research.

DXA Android-to-Gynoid Ratio and Cardiovascular Risk Assessment in Age and BMI Propensity-Matched Early Postmenopausal Women

Background and Objectives: The literature suggests that physiological menopause (MP) seems linked with increased adiposity with a preference for intra-abdominal fat accumulation, greater than what can be attributed only by aging, which could magnify this period's increased cardiovascular risk. Materials and Methods: We retrospectively analyzed two age and body mass index (BMI) propensity-matched subgroups each formed of 90 clinically healthy, 40-60-year-old postmenopausal women, within the first 5 and 5-10 years of MP. The 10-year ASCVD risk was assessed using medical history, anthropometric data, and lipid profile blood tests. The android-to-gynoid (A/G) ratio was computed using Lunar osteodensitometry lumbar spine and hip scans. Results: The A/G ratio was significantly higher for the subgroup evaluated in years 5-10 of MP than in the first 5 years of MP, even after controlling for BMI (1.05 vs. 0.99, p = 0.005). While displaying a significant negative correlation with HDL cholesterol (r = 0.406), the A/G ratio also had positive correlations with systolic blood pressure (BP) values (r = 0.273), triglycerides (r = 0.367), and 10-year ASCVD risk (r = 0.277). After adjusting for smoking, hypertension treatment, and type 2 diabetes, the 10-year ASCVD risk became significantly different for women in the first 5 years (3.28%) compared to those in years 5-10 of MP (3.74%), p = 0.047. Conclusions: In women with similar age and BMI, the A/G ratio appears to vary based on the number of years since menopause onset and correlates with either independent cardiovascular risk parameters like BP, triglycerides, and HDL cholesterol or with composite scores, such as 10-year ASCVD risk.

Age at Natural Menopause and Influencing Factors in Women Attending the Gynecological Outpatient Clinic at a Tertiary Care Hospital

Background

Menopause is the irreversible cessation of menstruation that results from the lack of ovarian follicular function and is diagnosed after 12 consecutive months of amenorrhea without reasonable cause. This study aims to determine the average age at natural menopause and identify its associated factors among Somali women.

Methods

This is a cross-sectional study conducted at the Mogadishu Somalia Türkiye Recep Tayyip Erdogan research and training hospital's Obstetrics and Gynecology outpatient clinic between June 1 and July 1, 2023. Data was collected from subjects during the data collection period using face-to-face interviews with structured questionnaires consisting of sociodemographic, lifestyle, dietary, and reproductive characteristics. A multivariate logistic regression analysis was conducted to find the association between menopause age and target variables.

Results

Out of the 188 participants recruited for the study, the median age of menopause was 45.00 (95% CI = 44.50-45.62), and 48.9% had either premature or early menopause. The majority (53.7%) of the participants had a minimum of eight children. In Spearman's rank correlation analysis, we found a significantly positive correlation between menopausal age and age at first (p<0.01), last childbirth (p<0.01), number of parities (p<0.05), and age at marriage (p<0.05). In multivariate logistic regression, we found that the odds of developing premature or early menopause among unemployed women were 59% lower than those of employed women (AOR = 0.41, 95% CI = 0.18-0.93).

Conclusion

In this study, we established that the age of natural menopause was lower than the findings reported by previous authors. We also found that employment status, education, history of contraceptive use, BMI, age at first and last childbirth, and parity were associated with age at natural menopause, suggesting that social, lifestyle, and reproductive factors may have an impact on menopausal age.

Age at natural menopause in women with a history of chronic diseases-A population-based cohort study

OBJECTIVE

This study was carried out to determine whether chronic diseases can influence age at natural menopause (ANM).

STUDY DESIGN AND MAIN OUTCOME MEASURES

This population-based prospective study recruited all eligible women from participants in the Tehran Lipid and Glucose Study (TLGS). The Cox proportional-hazards model (unadjusted and adjusted) was used to assess associations of ANM with chronic diseases, including diabetes mellitus (DM), hypertension (HTN), dyslipidemia, metabolic syndrome (MetS), cardiovascular disease (CVD), chronic kidney disease (CKD), and thyroid disorders, which were not included simultaneously in the model because there were correlations between chronic diseases.

RESULTS

A total of 4662 women, aged 15-50 years, who had not reached menopause at initiation of the TLGS were included. Of these women, 1220 (26.2%) experienced menopause during the study follow-up. In the multivariable Cox regression model adjusted for potential confounders, women with DM [HR:1.75; 95%CI: (1.32, 2.32)], HTN [HR: 2.11; 95%CI: (1.64, 2.72)], MetS [HR: 2.01; 95%CI: (1.57, 2.58)], CVD [HR: 3.02; 95%CI: (1.93, 4.73)], CKD [HR: 2.64; 95%CI: (2.16, 3.22)], and thyroid disorders [HR: 1.41; 95%CI: (1.06, 1.88)] reached menopause earlier, while dyslipidemia was not associated with ANM.

CONCLUSION

This study demonstrates that women with a history of chronic diseases, such as metabolic disorders, cardiovascular events, and CKD, experience menopause earlier than their counterparts without such a history.

The relation of number of childbirths with age at natural menopause: a population study of 310 147 women in Norway

STUDY QUESTION

Does age at natural menopause increase with increasing of number of childbirths?

SUMMARY ANSWER

Age at menopause increased with increasing number of childbirths up to three childbirths; however, we found no further increase in age at menopause beyond three childbirths.

WHAT IS KNOWN ALREADY

Pregnancies interrupt ovulation, and a high number of pregnancies have therefore been assumed to delay menopause. Previous studies have had insufficient statistical power to study women with a high number of childbirths. Thus, the shape of the association of number of childbirths with age at menopause remains unknown.

STUDY DESIGN, SIZE, DURATION

A retrospective population study of 310 147 women in Norway who were 50-69 years old at data collection.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The data were obtained by two self-administered questionnaires completed by women attending BreastScreen Norway, a population-based screening program for breast cancer. The associations of number of childbirths with age at menopause were estimated as hazard ratios by applying Cox proportional hazard models, adjusting for the woman's year of birth, cigarette smoking, educational level, country of birth, oral contraceptive use and body mass index.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with three childbirths had the highest mean age at menopause (51.36 years; 95% CI: 51.33-51.40 years), and women with no childbirths had the lowest (50.55 years; 95% CI: 50.48-50.62 years). Thus, women with no childbirths had higher hazard ratio of reaching menopause compared to women with three childbirths (reference group) (adjusted hazard ratio, 1.24; 95% CI: 1.22-1.27). Beyond three childbirths, we estimated no further increase in age at menopause. These findings were confirmed in sub-analyses among (i) women who had never used hormonal intrauterine device and/or systemic menopausal hormonal therapy; (ii) women who were born before 1950 and (iii) women who were born in 1950 or after.

LIMITATIONS, REASONS FOR CAUTION

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

WIDER IMPLICATIONS OF THE FINDINGS

If pregnancies truly delay menopause, one would expect that women with the highest number of childbirths had the highest age at menopause. Our results question the assumption that interrupted ovulation during pregnancy delays menopause.

STUDY FUNDING/COMPETING INTEREST(S)

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

TRIAL REGISTRATION NUMBER

N/A.

The association between chronic diseases and the age at natural menopause: a systematic review

Despite several existing studies on the age at natural menopause (ANM) and its related factors, epidemiologic data on the associations between chronic diseases and ANM are scarce with conflicting and inconclusive results. The aim of this systematic review was to summarize the results of the studies investigating the association between chronic disease and ANM. PubMed, Scopus, and Web of Science were searched for retrieving and summarizing studies published up to October 2020 investigating the association between chronic medical conditions and ANM. All types of observational studies published in the English language were eligible to be included in the systematic review. Studies needed to report the effect of at least one chronic disease on ANM. Studies with other designs, studies with unreliable and incomplete results, and those that assessed none of the chronic diseases as outcomes of interest were excluded. Of the 6294 records retrieved by searching the databases, a total of 28 observational studies were included for this review. According to the Newcastle-Ottawa scale, nine studies were classified as high-quality, fifteen studies as moderate, and four as low-quality. Among the five studies investigating the association between polycystic ovary syndrome (PCOS) and ANM, three studies reported that PCOS was associated with a later ANM, whereas others found no such association. Eight studies showed that diabetes was associated with an earlier ANM, whereas eight other studies found no such association. While only one study showed a younger age at the onset of menopause in patients with a history of hypertension, five studies did not report such an effect. Only one study assessed the effect of dyslipidemia on ANM and showed no association between these variables. While three studies documented the effects of cardiovascular diseases (CVD) and heart disease on earlier ANM, one study found no association between these diseases and ANM. Most included studies showed the association of mood disorders with earlier ANM. There were no sufficient data for assessing the effects of thyroid, skin, and autoimmune diseases on ANM. Chronic diseases particularly cardio-metabolic disturbances, cardiovascular events, and psycho-emotional disorders are associated with earlier menopause, whereas other diseases such as PCOS may lead to later menopause. Accordingly, early diagnosis and managing chronic medical conditions in women can potentially prevent early or late menopause.

Identification of Key Genes and Potential New Biomarkers for Ovarian Aging: A Study Based on RNA-Sequencing Data

Ovarian aging leads to reproductive and endocrine dysfunction, causing the disorder of multiple organs in the body and even declined quality of offspring's health. However, few studies have investigated the changes in gene expression profile in the ovarian aging process. Here, we applied integrated bioinformatics to screen, identify, and validate the critical pathogenic genes involved in ovarian aging and uncover potential molecular mechanisms. The expression profiles of GSE84078 were downloaded from the Gene Expression Omnibus (GEO) database, which included the data from ovarian samples of 10 normal C57BL/6 mice, including old (21-22 months old, ovarian failure period) and young (5-6 months old, reproductive bloom period) ovaries. First, we filtered 931 differentially expressed genes (DEGs), including 876 upregulated and 55 downregulated genes through comparison between ovarian expression data from old and young mice. Functional enrichment analysis showed that biological functions of DEGs were primarily immune response regulation, cell-cell adhesion, and phagosome pathway. The most closely related genes among DEGs (Tyrobp, Rac2, Cd14, Zap70, Lcp2, Itgb2, H2-Ab1, and Fcer1g) were identified by constructing a protein-protein interaction (PPI) network and consequently verified using mRNA and protein quantitative detection. Finally, the immune cell infiltration in the ovarian aging process was also evaluated by applying CIBERSORT, and a correlation analysis between hub genes and immune cell type was also performed. The results suggested that plasma cells and naïve CD4+ T cells may participate in ovarian aging. The hub genes were positively correlated with memory B cells, plasma cells, M1 macrophages, Th17 cells, and immature dendritic cells. In conclusion, this study indicates that screening for DEGs and pathways in ovarian aging using bioinformatic analysis could provide potential clues for researchers to unveil the molecular mechanism underlying ovarian aging. These results could be of clinical significance and provide effective molecular targets for the treatment of ovarian aging.

Recovery of menses after functional hypothalamic amenorrhoea: if, when and why

BACKGROUND

Prolonged amenorrhoea occurs as a consequence of functional hypothalamic amenorrhoea (FHA) which is most often induced by weight loss, vigorous exercise or emotional stress. Unfortunately, removal of these triggers does not always result in the return of menses. The prevalence and conditions underlying the timing of return of menses vary strongly and some women report amenorrhoea several years after having achieved and maintained normal weight and/or energy balance. A better understanding of these factors would also allow improved counselling in the context of infertility. Although BMI, percentage body fat and hormonal parameters are known to be involved in the initiation of the menstrual cycle, their role in the physiology of return of menses is currently poorly understood. We summarise here the current knowledge on the epidemiology and physiology of return of menses.

OBJECTIVE AND RATIONALE

The aim of this review was to provide an overview of (i) factors determining the recovery of menses and its timing, (ii) how such factors may exert their physiological effects and (iii) whether there are useful therapeutic options to induce recovery.

SEARCH METHODS

We searched articles published in English, French or German language containing keywords related to return of menses after FHA published in PubMed between 1966 and February 2020. Manuscripts reporting data on either the epidemiology or the physiology of recovery of menses were included and bibliographies were reviewed for further relevant literature. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria served to assess quality of observational studies.

OUTCOMES

Few studies investigate return of menses and most of them have serious qualitative and methodological limitations. These include (i) the lack of precise definitions for FHA or resumption of menses, (ii) the use of short observation periods with unsatisfactory descriptions and (iii) the inclusion of poorly characterised small study groups. The comparison of studies is further hampered by very inhomogeneous study designs. Consequently, the exact prevalence of resumption of menses after FHA is unknown. Also, the timepoint of return of menses varies strongly and reliable prediction models are lacking. While weight, body fat and energy availability are associated with the return of menses, psychological factors also have a strong impact on the menstrual cycle and on behaviour known to increase the risk of FHA. Drug therapies with metreleptin or naltrexone might represent further opportunities to increase the chances of return of menses, but these require further evaluation.

WIDER IMPLICATIONS

Although knowledge on the physiology of return of menses is presently rudimentary, the available data indicate the importance of BMI/weight (gain), energy balance and mental health. The physiological processes and genetics underlying the impact of these factors on the return of menses require further research. Larger prospective studies are necessary to identify clinical parameters for accurate prediction of return of menses as well as reliable therapeutic options.

RANKL is a new Epigenetic Biomarker for the Vasomotor Symptom During Menopause

During menopausal transition, decreased level of estrogen brings a number of physiological problems and hormonal changes. In this study, promoter methylation of RANKL and FSHR genes were identified in 30 premenopausal and 35 postmenopausal women using methylation-specific high resolution melting (MS-HRM) analysis. The statistical analyses and their association with patient characteristics were performed by Pearson χ² and Fisher's exact test (p <0.05). The methylated RANKL gene was detected in 16 postmenopausal cases, and 12 (75.0%) of the RANKL methylated cases had hot flashes (p = 0.024). The methylated FSHR gene was detected in 18 postmenopausal cases, and 13 (75.0%) of the methylated cases had hot flashes (p = 0.028). In vitro studies demonstrated the association between RANKL expression, FSH level and hot flashes in the mouse. Although lack of epigenetic studies in this field proves our results crucial and therefore, our results showed magnitude of epigenetic profiles of Turkish Cypriot post-menopausal women. This was the first study which has investigated the RANKL and FSHR methylation and their relationship with hot flashes in postmenopausal women.

BRCA1/2 genes mutations, ovarian reserve and female reproductive outcomes: a systematic review of the literature

INTRODUCTION

BRCA1 and BRCA2 genes mutations seems to impact female fertility, in addition to increasing the risk of ovarian and breast cancer. Several studies had investigated this issue but data available are still controversial. In order to clarify the role of BRCA1 and BRCA2 mutations in female fertility and ovarian function we carried out a systematic review of the literature with the aim to establish a possible management's strategy of these patients.

EVIDENCE ACQUISITION

A review of current literature regarding BRCA mutation (BRCAm) and fertility was conducted using the PubMed tool to select remarkable articles with the keywords "BRCA1/2 gene," "BRCA1/2 mutation," "anti-Müllerian hormone," "female fertility," "ovarian reserve" and "premature ovarian failure."

EVIDENCE SYNTHESIS

In current literature there are controversial findings about the relation between BRCA genes mutations and lifespan of female reproductive age. Several studies showed an higher risk of premature ovarian insufficiency of BRCAs mutations carriers, according to lower serum AMH level, primordial follicle count, or fewer oocyte yield after ovarian stimulation; on the other hand more recent studies reported not significant differences in serum AMH level or in reproductive outcomes between mutated and non-mutated BRCA patients. For this reason, currently there is not a strict recommendation for routine evaluation of fertility in female carriers of BRCA mutations. Nevertheless, the strong advice to complete childbearing by age 40 and then to undergo a risk-reducing salpingo-oophorectomy and the increased risk of infertility as a result of anticancer treatment in breast cancer BRCAm patients, make the issue of fertility and pregnancy planning in these women worthy of consideration.

CONCLUSIONS

A dedicated counseling to discuss these issues, eventually associated with a personalized assessment of serum AMH or antral follicle count in order to have a panoramic view of ovarian reserve, may be useful in the management of these patients.

Rotating night shift work and menopausal age

STUDY QUESTION

How are rotating night shift schedules associated with age at menopause among a large, national cohort of shift working nurses?

SUMMARY ANSWER

Our findings suggest that working rotating night shifts with sufficient frequency may modestly accelerate reproductive senescence among women who may already be predisposed to earlier menopause.

WHAT IS KNOWN ALREADY

Younger age at menopause has been associated with increased risk of adverse health outcomes, particularly those linked to reproduction. Night work has been associated with reproductive dysfunction, including disruption of menstrual cycle patterns.

STUDY DESIGN, SIZE, DURATION

This cohort study was conducted among 80 840 women of the Nurses' Health Study 2 (NHS2), with prospective follow-up from 1991 through 2013. Loss-to-follow-up of the NHS2 is estimated to be <10%.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We assessed the association between cumulative and current rotating night shift work and age at natural menopause over 22 years of follow-up (1991-2013). Cox proportional hazards models were used to estimate hazard ratios (HR) for menopause, adjusted for age, smoking status, body mass index, physical activity, alcohol consumption, reproductive factors and exogenous hormone use.

MAIN RESULTS AND THE ROLE OF CHANCE

Over follow-up, 27 456 women (34%) reached natural menopause. Women who worked 20 or more months of rotating night shifts in the prior 2-year had an increased risk of earlier menopause (multivariable-adjusted (MV)-HR = 1.09, 95% CI: 1.02-1.16) compared to women without rotating night shift work. This risk was stronger among women undergoing menopause or otherwise censored under age 45 years (MV-HR = 1.25, 95% CI: 1.08-1.46), than it was for those continuing in the study when >45 years old (MV-HR = 1.05, 95% CI: 0.99-1.13). Working 10 or more years of cumulative rotating night work was also associated with higher risk of menopause among women reaching menopause under age 45 (MV-HR10-19 years = 1.22, 95% CI: 1.03-1.44; MV-HR≥20 years = 1.73, 95% CI: 0.90-3.35), though not over the age of 45 years (MV-HR10-19 years = 1.04, 95% CI: 0.99-1.10; MV-HR≥20 years = 1.01, 95% CI: 0.89-1.15).

LIMITATIONS, REASONS FOR CAUTION

The degree to which observed effects of rotating night shifts on age at natural menopause are due to circadian disruption, rather than fatigue and stress associated with working more demanding schedules, is uncertain due to potential residual confounding by these factors.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to assess the effects of night work on menopausal timing among a larger national cohort of shift working women. Women already prone to earlier menopause may further truncate their reproductive lifetime by working schedules comprising day as well as night shifts.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by Center for Disease Control and Prevention/The National Institute for Occupational Safety and Health Grant 5R01OH009803 (PI: Schernhammer E), as well as UM1 CA176726 from the National Institute of Health. The funding sources had no role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the article; and decision to submit the article for publication. The authors have no conflicts of interest.

The impact of FMR1 gene mutations on human reproduction and development: a systematic review

PURPOSE

This is a comprehensive review of the literature in this field attempting to put the FMR1 gene and its evaluation into context, both in general and for the reproductive health audience.

METHODS

Online database search of publications with systematic review of all papers relevant to ovarian reserve and assisted reproduction was done.

RESULTS

Relevant papers were identified and assessed, and an attempt was made to understand, rationalize and explain the divergent views in this field of study. Seminal and original illustrations were employed.

CONCLUSIONS

FMR1 is a highly conserved gene whose interpretation and effect on outcomes remains controversial in the reproductive health setting. Recent re-evaluations of the commonly accepted normal range have yielded interesting tools for possibly explaining unexpected outcomes in assisted reproduction. Fragile X investigations should perhaps become more routinely assessed in the reproductive health setting, particularly following a failed treatment cycle where oocyte quality is thought to be a contributing factor, or in the presence of a surprise finding of diminished ovarian reserve in a young patient.

Association between vascular health and ovarian ageing in type 1 diabetes mellitus

STUDY QUESTION

Is vascular health associated with ovarian reserve status using type 1 diabetes mellitus (DM-1) as a model for vascular compromise?

SUMMARY ANSWER

No conclusive evidence for an association between vascular health and ovarian ageing was found in women with DM-1.

WHAT IS KNOWN ALREADY

The mechanism behind advanced ovarian ageing has not yet been elucidated. We hypothesize that vascular impairment precedes ovarian ageing. DM-1 is hallmarked by premature vascular complications that may consequently play a role in the rate of primordial follicle decline.

STUDY DESIGN, SIZE, DURATION

A cross-sectional, patient-control study was performed in 150 premenopausal, regular cycling women with DM-1, as well as a reference population of 177 healthy, fertile women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In a single-study visit, an inventory of both ovarian reserve and vascular status was carried out in the DM-1 group. A transvaginal ultrasound to calculate the antral follicle count (AFC) and blood sampling for anti-Müllerian hormone (AMH), lipids, C-reactive protein and HbA1c measurements were performed. Furthermore, vascular screening including measurements of blood pressure, flow-mediated dilation, peripheral arterial tonometry, pulse wave velocity, pulse wave analysis and intima-media thickness was carried out. The relative decrease in serum AMH levels in women with DM-1 compared with healthy references was investigated.

MAIN RESULTS AND THE ROLE OF CHANCE

Systolic blood pressure was negatively correlated with both serum AMH (P= 0.006) and AFC (P= 0.004) in the DM-1 group. A non-linear relationship between HDL-cholesterol and serum AMH was found (P= 0.0001). No associations were detected between other vascular risk factors or vascular function tests and serum AMH or AFC in women with DM-1. With regard to the comparison of AMH levels between women with and without DM-1, mean AMH levels were 2.5 ± 1.9 ng/ml and 3.0 ± 2.8 ng/ml, respectively. After adjustment for confounders the difference in AMH levels between both groups appeared non-significant (fold change: 0.92, 95% confidence interval: 0.68-1.23).

LIMITATIONS, REASON FOR CAUTION

The use of different AMH assays and the cross-sectional design may limit the interpretation of this study.

WIDER IMPLICATIONS OF THE FINDINGS

The lack of evident association between vascular health and ovarian ageing may be the result of an insufficient vascular compromise in the relatively young, DM-1 group.

STUDY FUNDING/COMPETING INTERESTS

No external funding was received for conducting or publishing this study. F.Y., W.S., A.F., F.L.J.V., M.J.C.E. and H.W.d.V. have nothing to disclose. F.J.M.B. has received fees and grant support from the following companies: Ferring, Gedeon Richter, Merck Serono, Medical Specialties Distributors and Roche.

TRIAL REGISTRATION NUMBER

Not applicable.

Relationship between some indicators of reproductive history, body fatness and the menopausal transition in Hungarian women

BACKGROUND

This paper analyzed the relationship between some indicators of reproductive history and body fatness in relation to the timing of the menopause transition in Hungarian women using survival analysis after controlling for birth cohort.

METHODS

Data on menstruation and reproductive history were collected during the personal interviews in a sample of 1932 women (aged 35+ years). Menarcheal age, the length of menstrual cycles and menstrual bleedings, regularity of menstrual cycles, number of gestations, lactation, the ever use of contraceptives, menopausal status and age at menopause were used as indicators of reproductive history. The body fat fraction was estimated by bioelectrical impedance analysis. Body fatness was also estimated by dividing women into obese and non-obese categories (considering body mass index and waist-to-hip ratio). Survival analyses were used to analyze the relationship between the indicators of reproductive history and body fatness during the menopausal transition.

RESULTS

Only the menarcheal age among the investigated reproductive life characteristics showed secular changes in the studied decades in Hungary; the mean age at menarche decreased by approximately 2.5 months per decade from the 1920s until the 1970s. Ever use of hormonal contraceptives, a relatively long cycle length in the perimenopausal transition and higher parity were all related with lower risk of early menopause. Later menarcheal age, normal length of menstrual cycle or bleeding in the climacterium, irregular bleeding pattern and postmenopausal status were associated with a higher amount of body fatness, while never use of contraceptives, regular menstruation, postmenopausal status and relatively early menopause were associated with a higher risk of abdominal obesity.

CONCLUSION

This report confirms that age of menarche is not significantly predictive of age at menopause but prior use of oral contraceptives, longer mean cycle length and smaller number of gestations all are. In addition, age of menarche, irregular bleeding pattern before the climacterium, length of menstrual cycles and bleedings during the climacterium and postmenopausal status were associated with obesity during the climacterium.

Effects of Smoking on Menopausal Age: Results From the Korea National Health and Nutrition Examination Survey, 2007 to 2012

Objectives:

Decreased fertility and impaired health owing to early menopause are significant health issues. Smoking is a modifiable health-related behavior that influences menopausal age. We investigated the effects of smoking-associated characteristics on menopausal age in Korean women.

Methods:

This study used data from the Korea National Health and Nutrition Examination Survey from 2007 to 2012. Menopausal age in relation to smoking was analyzed as a Kaplan-Meier survival curve for 11 510 women (aged 30 to 65 years). The risk of entering menopause and experiencing early menopause (before age 48) related to smoking were assessed using a Cox proportional hazards model.

Results:

The menopausal age among smokers was 0.75 years lower than that among non-smokers (p<0.001). The results of the Cox proportional hazards model showed pre-correction and post-correction risk ratios for entering menopause related to smoking of 1.26 (95% confidence interval [CI], 1.09 to 1.46) and 1.27 (95% CI, 1.10 to 1.47), respectively, and pre-correction and post-correction risk ratios for experiencing early menopause related to smoking of 1.36 (95% CI, 1.03 to 1.80) and 1.40 (95% CI, 1.05 to 1.85), respectively.

Conclusions:

Smokers reached menopause earlier than non-smokers, and their risk for experiencing early menopause was higher.

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.

Menopause

Menopause is an inevitable component of ageing and encompasses the loss of ovarian reproductive function, either occurring spontaneously or secondary to other conditions. It is not yet possible to accurately predict the onset of menopause, especially early menopause, to give women improved control of their fertility. The decline in ovarian oestrogen production at menopause can cause physical symptoms that may be debilitating, including hot flushes and night sweats, urogenital atrophy, sexual dysfunction, mood changes, bone loss, and metabolic changes that predispose to cardiovascular disease and diabetes. The individual experience of the menopause transition varies widely. Important influential factors include the age at which menopause occurs, personal health and wellbeing, and each woman's environment and culture. Management options range from lifestyle assessment and intervention through to hormonal and non-hormonal pharmacotherapy, each of which has specific benefits and risks. Decisions about therapy for perimenopausal and postmenopausal women depend on symptomatology, health status, immediate and long-term health risks, personal life expectations, and the availability and cost of therapies. More effective and safe therapies for the management of menopausal symptoms need to be developed, particularly for women who have absolute contraindications to hormone therapy. For an illustrated summary of this Primer, visit: http://go.nature.com/BjvJVX.

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.

Cytogenetic abnormalities in Tunisian women with premature ovarian failure

To identify the distribution of chromosome abnormalities among Tunisian women with premature ovarian failure (POF) referred to the department of Cytogenetic at the Pasteur Institute of Tunis (Tunisia), standard cytogenetic analysis was carried out in a total of 100 women younger than 40 affected with premature ovarian failure. We identified 18 chromosomal abnormalities, including seven X-numerical anomalies in mosaic and non-mosaic state (45,X; 47,XXX), four sex reversal, three X-structural abnormalities (terminal deletion and isochromosomes), one autosomal translocation and one supernumerary marker. The overall prevalence of chromosomal abnormalities was 18% in our cohort. X chromosome aneuploidy was the most frequent aberration. This finding confirms the essential role of X chromosome in ovarian function and underlies the importance of cytogenetic investigations in the routine management of POF.

Ecology drives intragenomic conflict over menopause

Menopause is the transition from reproductive to non-reproductive life well before natural death. Rather than involving a smooth, rapid change, it is normally preceded by a long period of erratic hormonal fluctuation that is accompanied by a plethora of unpleasant symptoms. Here, we (1) suggest that this turbulent period owes to conflict, between a woman's maternally inherited (MI) and paternally inherited (PI) genes, over the trade-off between reproduction and communal care; (2) perform a theoretical analysis to show that this conflict is resolved either through silencing or fluctuating expression of one of the genes; (3) highlight which of the symptoms preceding menopause may result from antagonistic co-evolution of MI and PI genes; (4) argue that ecological differences between ancestral human populations may explain the variability in menopause among different ethnic groups; (5) discuss how these insights may be used to inform family planning and cancer risk assessment based on a woman's ancestral background.

Serum AMH levels in women with a history of preeclampsia suggest a role for vascular factors in ovarian aging

CONTEXT

The association between early menopause and vascular disease as a possible causative factor has recently received attention. Preeclampsia (PE) is associated with future cardiovascular risk factors, and this premature vascular aging potentially modifies the ovarian aging process.

OBJECTIVE

The purpose of this study was to assess whether women with a history of PE have lower anti-Müllerian hormone (AMH) levels than women with normotensive pregnancies.

DESIGN

This was a retrospective cohort study.

SETTING

The study was conducted in a tertiary referral center.

PATIENTS

Clinical data and blood samples of participants in the Preeclampsia Risk EValuation in FEMales study were used (336 women with a history of PE and 329 women after a normotensive pregnancy).

INTERVENTIONS

There were no interventions.

MAIN OUTCOME MEASURES

The relative decrease in AMH levels was assessed after a median follow-up of 10.5 years.

RESULTS

The mean AMH level was 2.00 ± 1.87 μg/L in the PE group compared with 2.26 ± 2.56 μg/L in the reference group. Linear regression analysis with censoring for undetectable AMH levels, adjusted for age, smoking, and hormonal contraceptive use, showed a relative reduction in AMH levels of 20.9% at any age (fold change 0.79, 95% confidence interval, 0.67-0.94).

CONCLUSIONS

We demonstrate that women with a history of PE have significantly lower AMH levels than women with normotensive pregnancies. Calculations based on a reference population indicate advancement of reproductive age of approximately 1.5 years. Because PE is considered a manifestation of impaired vascular health, these results support the hypothesis that compromised vascular health could act as a causative mechanism in early ovarian aging.

Prenatal famine, birthweight, reproductive performance and age at menopause: the Dutch hunger winter families study

STUDY QUESTION

Is there an association between acute prenatal famine exposure or birthweight and subsequent reproductive performance and age at menopause?

SUMMARY ANSWER

No association was found between intrauterine famine exposure and reproductive performance, but survival analysis showed that women exposed in utero were 24% more likely to experience menopause at any age.

WHAT IS KNOWN ALREADY

Associations between prenatal famine and subsequent reproductive performance have been examined previously with inconsistent results. Evidence for the effects of famine exposure on age at natural menopause is limited to one study of post-natal exposure.

STUDY DESIGN, SIZE, DURATION

This cohort study included men and women born around the time of the Dutch famine of 1944-1945. The study participants (n = 1070) underwent standardized interviews on reproductive parameters at a mean age of 59 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The participants were grouped as men and women with prenatal famine exposure (n = 407), their same-sex siblings (family controls, n = 319) or other men and women born before or after the famine period (time controls, n = 344). Associations of famine exposure with reproductive performance and menopause were analysed using logistic regression and survival analysis with competing risk, after controlling for family clustering.

MAIN RESULTS AND THE ROLE OF CHANCE

Gestational famine exposure was not associated with nulliparity, age at birth of first child, difficulties conceiving or pregnancy outcome (all P> 0.05) in men or women. At any given age, women were more likely to experience menopause after gestational exposure to famine (hazard ratio 1.24; 95% CI 1.03, 1.51). The association was not attenuated with an additional control for a woman's birthweight. In this study, there was no association between birthweight and age at menopause after adjustment for gestational famine exposure.

LIMITATIONS, REASON FOR CAUTION

Age at menopause was self-reported and assessed retrospectively. The study power to examine associations with specific gestational periods of famine exposure and reproductive function was limited.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings support previous results that prenatal famine exposure is not related to reproductive performance in adult life. However, natural menopause occurs earlier after prenatal famine exposure, suggesting that early life events can affect organ function even at the ovarian level.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the NHLBI/NIH (R01 HL-067914).

TRIAL REGISTRATION NUMBER

Not applicable.

Shared genetic factors for age at natural menopause in Iranian and European women

STUDY QUESTION

Do differences in heritable genetic factors explain some of the difference in age at natural menopause (ANM) among populations?

SUMMARY ANSWER

One single nucleotide polymorphism (SNP)-ANM association (rs16991615) detected in European women was replicated in Iranian women.

WHAT IS KNOWN ALREADY

Genetics plays an important role in ANM, and well-powered genome-wide association studies (GWAS) of ANM performed in European women have discovered many statistically significant SNP-ANM associations. Average ANM varies by ethnicity, and population-specific differences in ANM-associated alleles may in part explain these differences.

STUDY DESIGN, SIZE, DURATION

After quality control procedures, 97 SNPs were analyzed in genotype data of 828 Iranian women who experienced natural menopause. SNP genotyping data were used to perform linear regression analyses with ANM as a quantitative trait. Study participants were drawn from the population-based Tehran Lipid and Glucose Study based in Tehran, Iran. This study was performed between February 2009 and March 2012.

PARTICIPANTS/MATERIALS, SETTING AND METHODS

Based on an ANM-GWAS literature review, eight SNPs at four loci previously associated with ANM in European women were tested for replication in Iranian women. Linear regression analyses were performed including (n = 828) and excluding (n = 783) women who experience premature ovarian failure (ANM before 40 years of age). In addition, to search for novel population-specific ANM risk alleles, a pool-based GWAS was performed using this collection of Iranian women. Two DNA pools were constructed and compared: an 'early' ANM pool (lower 20(th) percentile of menopause ages, 40-45 years, n = 165) and a 'late' ANM pool (upper 20(th) percentile of menopause ages, 54-65 years, n = 187). Each DNA pool was assayed on four Illumina Human1M-Duo arrays, and allele-based tests of association were used to rank SNPs. One hundred and two highly ranked SNPs were chosen for individual genotyping by Sequenom MassARRAY and association analysis in the Iranian women.

MAIN RESULTS AND THE ROLE OF CHANCE

One SNP-ANM association previously detected in European women was replicated in Iranian women (rs16991615; β = 1.07, standard error (SE): 0.49, P = 0.02). SNPs at the previously reported 19q13.42 and 6p24.2 loci also approached statistical significance and had consistent SNP effects (magnitude and direction) in Iranian women (rs1172822; β = -0.39, SE: 0.22, P = 0.08; and rs2153157, β = 0.41, SE: 0.21, P = 0.05). We found little evidence for novel SNP-ANM associations in Iranian women; no SNP selected based on the pool-based GWAS achieved genome-wide significance.

LIMITATIONS, REASONS FOR CAUTION

Due to small sample size this study was powered to reliably detect only moderate-to-large SNP effect sizes. This limited our ability to replicate many of the previously reported SNP-ANM risk alleles and to discover novel SNP-ANM associations' specific to the Iranian population. In performing our pool-based GWAS, a reduction in power was introduced relative to a conventional GWAS.

WIDER IMPLICATIONS OF THE FINDINGS

Our results imply that European and Iranian women share ANM-associated genetic variants. Our study was underpowered but for all SNPs tested the direction of the effect was consistent with data from the European study. Therefore, we anticipate that many (if not all) of the ANM-associated SNPs discovered in European women will replicate in Iranian women upon genotyping a sufficient number of women. Our data do not support the hypothesis that population-specific SNP-ANM associations explain population-specific differences in the mean ANM.

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.

Comparison of age at natural menopause in BRCA1/2 mutation carriers with a non-clinic-based sample of women in northern California

BACKGROUND

Germline mutations in BRCA1 and BRCA2 (BRCA1/2) are related to an increased lifetime risk of developing breast and ovarian cancer. Although risk-reducing salpingo-oophorectomy reduces the risk of both cancers, loss of fertility is a major concern. A recent study suggested an association between BRCA1 mutation and occult primary ovarian insufficiency. The objective of the current study was to determine whether BRCA1/2 mutation carriers have an earlier onset of natural menopause compared with unaffected women.

METHODS

White carriers of the BRCA1/2 gene (n = 382) were identified within the Breast Cancer Risk Program Registry at the University of California at San Francisco and compared with non-clinic-based white women in northern California (n = 765). The 2 groups were compared with regard to median age at the time of natural menopause before and after adjustment for known risk factors, and the role of smoking within each group was examined using the Kaplan-Meier approach for unadjusted analyses and Cox proportional hazards regression analyses for adjusted analyses.

RESULTS

The median age at the time of natural menopause in the BRCA1/2 carriers was significantly younger than among the unaffected sample (50 years vs 53 years; P < .001). The unadjusted hazard ratio for natural menopause when comparing BRCA1/2 carriers with unaffected women was 4.06 (95% confidence interval, 3.03-5.45) and was 3.98 (95% confidence interval, 2.87-5.53) after adjusting for smoking, parity, and oral contraceptive use. For BRCA1/2 carriers who were current heavy smokers (smoking ≥ 20 cigarettes/day), the median age at natural menopause was 46 years versus 49 years for nonsmokers (P = .027).

CONCLUSIONS

The BRCA1/2 mutation was associated with a significantly earlier age at natural menopause, and heavy smoking compounded this risk. Because the relationship between menopause and the end of natural fertility is considered to be fixed, these findings suggest the risk of earlier infertility among BRCA1/2 carriers.

Genetic links between post-reproductive lifespan and family size in Framingham

BACKGROUND AND OBJECTIVES

Is there a trade-off between children ever born (CEB) and post-reproductive lifespan in humans? Here, we report a comprehensive analysis of reproductive trade-offs in the Framingham Heart Study (FHS) dataset using phenotypic and genotypic correlations and a genome-wide association study (GWAS) to look for single-nucleotide polymorphisms (SNPs) that are related to the association between CEB and lifespan.

METHODOLOGY

We calculated the phenotypic and genetic correlations of lifespan with CEB for men and women in the Framingham dataset, and then performed a GWAS to search for SNPs that might affect the relationship between post-reproductive lifespan and CEB.

RESULTS

We found significant negative phenotypic correlations between CEB and lifespan in both women (rP = -0.133, P < 0.001) and men (rP = -0. 079, P = 0.036). The genetic correlation was large, highly significant and strongly negative in women (rG = -0.877, P = 0.009) in a model without covariates, but not in men (P = 0.777). The GWAS identified five SNPs associated with the relationship between CEB and post-reproductive lifespan in women; some are near genes that have been linked to cancer. None were identified in men.

CONCLUSIONS AND IMPLICATIONS

We identified several SNPs for which the relationship between CEB and post-reproductive lifespan differs by genotype in women in the FHS who were born between 1889 and 1958. That result was not robust to changes in the sample. Further studies on larger samples are needed to validate the antagonistic pleiotropy of these genes.

A chromosome 19 locus positively influences the number of retrieved oocytes during stimulated cycles in Brazilian women

PURPOSE

To evaluate if several genetic loci that are associated with variation in normal menopause age and early menopause can account for a poor response to controlled ovarian stimulation.

METHODS

A total of 71 patients age ≤35 years old who were undergoing intracytoplasmic sperm injection were genotyped for four genetic variants that are associated with normal variation in menopausal age and early menopause. The patients were divided into two groups based upon treatment response: a poor responder group (PR group, n = 21) and a normal responder group (NR group, n = 50). The genetic variants rs244715, rs9379896, rs4806660 and rs16991615 were analyzed.

RESULTS

There was no significant difference in the incidence of the genetic variants between the NR and PR group. The risk allele for the chromosome 19 variant (rs4806660) demonstrated a protective effect for a poor ovarian response. The presence of a risk allele was associated with an increased response to COS, which resulted in an elevated number of follicles (Coef: 2.54, P = 0.041) and retrieved oocytes (Coef: 1.41, P = 0.041).

CONCLUSIONS

The genetic variants rs244715, rs9379896, rs4806660 and rs16991615 are not risk factors for poor ovarian response in Brazilian women. In contrast, rs4806660 is associated with higher number of follicles and retrieved oocytes. rs4806660 may be associated with an increased response to gonadotrophin stimulation in this population.

Genetics of age at menarche: a systematic review

BACKGROUND

Menarche is the first menstrual period of a girl at puberty. The timing of menarche is important for health in later life. Age at menarche is a complex trait and has a strong genetic component. This review summarizes the results of the genetic studies of age at menarche conducted to date, highlights existing problems in this area and outlines prospects of future studies on genetic factors for the trait.

METHODS

PubMed and Google Scholar were searched until May 2011 using the keywords: 'menarche', 'puberty' and 'age at menarche' in combination with the keywords 'polymorphism', 'candidate gene', 'genome-wide association study' and 'linkage'.

RESULTS

Our search yielded 170 papers, 35 of which were selected for further analysis. Several large-scale genome-wide association studies along with a powerful meta-analysis of their aggregated data identified about 50 candidate genes for the trait. Some genes were replicated in different studies of Caucasians (e.g. LIN28B, TMEM38B) or in different ethnicities (e.g. SPOCK, RANK and RANKL). However, despite the large volume of results obtained, there is a huge gap in relevant data on ethnic groups other than Caucasians.

CONCLUSIONS

The reviewed studies laid a solid basis for future research on genetics of age at menarche. However, as yet specific genes for this trait have not been identified consistently in all ethnicities and types of studies. We suggest expanding the research to different ethnicities and propose several methodologies to increase the efficiency of studies in this area, including a systems approach, which combines existing high-throughput methods in a single pipeline.

Ovarian aging: latest thoughts on assessment and management

PURPOSE OF REVIEW

In the past few decades, women have been intentionally delaying pregnancy and ovarian aging has become one of the most detrimental factors of pregnancy achievement. This review will discuss contemporary methods of ovarian aging assessment and present an overview of current management strategies.

RECENT FINDINGS

Antimullerian hormone (AMH) and antral follicle count (AFC) seem to be the most reliable predictors of ovarian aging appraisal. Nevertheless, they have not been shown to predict pregnancy achievement in assisted reproduction. Heritability has a high impact on ovarian aging. Employing several genetic approaches, it is now being widely investigated, but the task is far from being accomplished. Although multivariate models have not been proven to be superior to AFC, new data support the notion that chronological age and genetic markers inclusion may increase their reliability. Several strategies have been suggested to treat ovarian aging in assisted reproductive technology (ART) settings. None of the stimulation protocol manipulations have been found to be advantageous and individualization of treatment is still recommended. Ovarian priming by different androgen preparations has been shown to be promising but more randomized controlled trials are needed to support these findings. Except for oocyte donation other ART strategies have not shown a convincing benefit for ovarian aging. The new development of oocyte vitrification may well introduce opportunities for fertility preservation to women at risk of ovarian aging.

SUMMARY

Proper assessment and detection of ovarian aging, employing current or developing predictors of ovarian reserve, especially genetic tests, may enable health providers to recommend, at appropriate biological time, early pregnancy achievement or fertility preservation in women at risk.

Familial concordance for age at natural menopause: results from the Breakthrough Generations Study

OBJECTIVE

Existing estimates of the heritability of menopause age have a wide range. Furthermore, few studies have analyzed to what extent familial similarities might reflect shared environment, rather than shared genes. We therefore analyzed familial concordance for age at natural menopause and the effects of shared genetic and environmental factors on this concordance.

METHODS

Participants were 2,060 individuals comprising first-degree relatives, aged 31 to 90 years, and participating in the UK Breakthrough Generations Study. Menopause data were collected using a self-administered questionnaire and analyzed using logistic regression and variance-components models.

RESULTS

Women were at an increased risk of early menopause (≤45 y) if their mother (odds ratio, 6.2; P < 0.001) or non-twin sister (odds ratio, 5.5; P < 0.001) had had an early menopause. Likewise, women had an increased risk of late menopause (≥54 y) if their relative had had a late menopause (mother: odds ratio, 6.1; P < 0.01; non-twin sister: odds ratio, 2.3; P < 0.001). Estimated heritability was 41.6% (P < 0.01), with an additional 13.6% (P = 0.02) of the variation in menopause age attributed to environmental factors shared by sisters.

CONCLUSIONS

We confirm that early menopause aggregates within families and show, for the first time, that there is also strong familial concordance for late menopause. Both genes and shared environment were the source of variation in menopause age. Past heritability estimates have not accounted for shared environment, and thus, the effect of genetic variants on menopause age may previously have been overestimated.

Factors affecting gynaecologists' decision to perform prophylactic oophorectomy concomitantly with hysterectomy: a Belgian survey

BACKGROUND

The recommendation to perform an elective bilateral salpingo-oophorectomy (BSO) at the time of a hysterectomy for a benign condition is complex.

AIM

This survey evaluated the effect of three factors on BSO: the patient's age, her menopausal status, and the presence of a family history of breast cancer.

MATERIALS AND METHOD

We conducted an anonymous written survey, sent to 1513 gynaecologists, evaluating their attitude towards performing a prophylactic BSO concomitantly with a hysterectomy. We used a clinical vignette of a patient presenting a large and painful fibroid. We modified three factors: her age (either 44 or 49 years old), menopausal status (pre-menopausal or peri-menopausal), the absence or presence of a breast cancer family history. We randomly sent one case to each gynaecologist, who was asked whether he/she would perform a BSO.

RESULTS

The recommendation to perform a BSO varied between 2% and 81%, in relation to the different cases (χ(2): 151; p<0.001). On average, a five year difference in the patients' age (44 years vs 49 years) was associated with a 40% increase in proceeding a BSO. Being peri-menopausal vs being pre-menopausal, was associated with a 20% increase in suggesting a BSO. Having had a mother, diagnosed with breast cancer, was associated with a 10% increase of BSO.

CONCLUSION

The physicians' recommendation to perform an elective bilateral salpingo-oophorectomy at the time of a hysterectomy, is strongly influenced by the patients' age, and to a lesser extent by her menopausal status, or a family history of breast cancer.

Contemporary genetic technologies and female reproduction

BACKGROUND

The Fifth Evian Annual Reproduction (EVAR) Workshop Meeting discussed knowledge regarding contemporary genetics in female reproduction.

METHODS

Specialist reproductive medicine clinicians and geneticists delivered presentations based on published literature and current research. The content of this report is based on the expert presentations and subsequent group discussions that took place during this Workshop.

RESULTS

Numerous ovarian genes with a role in infertility have been identified. Future challenges for genetic screening of patients, such as those with polycystic ovary syndrome, primary ovarian insufficiency or endometriosis, include the identification of high-throughput strategies and how to apply these findings to infertile patients. The identification of high-quality embryos in IVF using objective technologies remains a high priority in order to facilitate single-embryo transfer. Gene expression profiling of cumulus cells surrounding the oocyte, and proteomic and metabolomic approaches in embryo culture media may significantly improve non-invasive embryo quality assessment.

CONCLUSIONS

The way forward in advancing the knowledge of genes involved in reproduction was considered to be through genome-wide association studies involving large numbers of patients. Establishing international collaboration is required to enable the application of such technologies in sufficient numbers of patients.

The molecular clock in terms of quantum information processing of coherent states, entanglement and replication of evolutionarily selected decohered isomers

Evolutionary pressures have selected quantum uncertainty limits -ΔxΔp ( x ) ≥ 1/2ħ-to operate on metastable amino DNA protons. This introduces a probability of molecular clock arrangement, keto-amino → enol-imine, where product protons are entangled and participate in coupled quantum oscillation at frequencies of ∼ 10(13) s(-1). The ket "seen by" the transcriptase, reading a coherent enol-imine G'-state, is |φ >= α| + + > +β|+- > +γ|-+ > +δ|-->. The transcriptase implements its measurement and generates an output qubit of observable genetic specificity information in an interval Δt ≪ 10(-13) s. These quantum measurements can specify the relative distribution of coherent G'-C' states at time of measurement. The ensuing quantum entanglement between coherent protons and transcriptase units is utilized as a resource to generate proper decoherence and introduce selected time-dependent substitutions, ts, and deletions, td. Topal-Fresco ts are G'202 → T, G'002 → C, *G020(0) → A and *C202(2) → T, whereas td are exhibited at coherent *A-*T sites. Variation in clock 'tic-rate' is a consequence of clock introduction of initiation codons - UUG, CUG, AUG, GUG - and stop codons, UAA, UAG, UGA. Using approximate quantum methods for times t < ∼ 100 y, the probability, P(t), of keto-amino → enolimine arrangement is P ( ρ )(t) = 1/2(γ ( ρ )/ħ)(2) t (2) where γ ( ρ ) is the energy shift. This introduces a quantum Darwinian evolution model which provides insight into biological consequences of coherent states populating human genes, including inherited (CAG)( n ) repeat tracts.

Age at menarche and menopause is not associated with two common genetic variants in the methylenetetrahydrofolate reductase (MTHFR) gene

OBJECTIVES

The study aimed at investigating the independent and the combined effects of the two common genetic variants in the methylenetetrahydrofolate reductase (MTHFR) gene, 677C > T and 1298A > C, and their interaction with lifestyle factors on timing of menarche and natural menopause.

METHODS

Postmenopausal women (N = 792) were assessed for the association of the two genetic variants with age at menarche (AM). A subsample of 578 of them who had a natural menopause were further investigated for the association of the two genetic variants with age at natural menopause (ANM). Genotyping was done by means of the TaqMan(®) allelic discrimination method. The effect of genetic variants and of lifestyle factors on AM and ANM were calculated by linear regression models.

RESULTS

The study revealed no association between the individual or combined effects of the two genetic variants and AM or ANM. The genetic variant 677C > T showed a significant interaction effect with duration of breastfeeding on ANM (p = 0.047).

CONCLUSION

We were unable to replicate previous findings suggesting that the MTHFR gene influences the onset of menarche and natural menopause. The interaction effect between the 677C >T genetic variant and duration of breastfeeding on the timing of natural menopause requires further investigation.

Genes involved in initial follicle recruitment may be associated with age at menopause

CONTEXT

Timing of menopause is largely influenced by genetic factors. Because menopause occurs when the follicle pool in the ovaries has become exhausted, genes involved in primordial follicle recruitment can be considered as candidate genes for timing of menopause.

OBJECTIVE

The aim was to study the association of 23 tagging single nucleotide polymorphisms in five genes [Anti-Müllerian hormone (AMH), AMH type II receptor (AMHR2), bone morphogenetic protein 15 (BMP15), forkhead transcription factor L2 (FOXL2), and growth differentiation factor-9 (GDF9)] involved in recruitment of the primary follicle pool, including the AMHR2 gene, which has recently been associated with age at menopause.

DESIGN

We conducted a cross-sectional association study.

SETTING AND PARTICIPANTS

We studied a population-based sample of 3616 Dutch women with natural menopause.

MAIN OUTCOME MEASURE

We measured age at natural menopause.

RESULTS

Both studied AMHR2 tagging single nucleotide polymorphisms (rs2002555 and rs11170547) in the AMHR2 gene were associated with age at natural menopause in interaction with parity. Parous rs2002555 G/G carriers had menopause 1 yr later compared with A/A carriers (P = 0.01). For rs11170547, each minor allele (T) was associated with a 0.41-yr later onset of menopause in parous women (P = 0.01). Additionally, rs6521896 in BMP15 was associated with later menopause (β = 0.41; P = 0.007). Variants in the AMH, FOXL2, and GDF9 genes were not associated with timing of menopause.

CONCLUSIONS

The present study confirms an earlier finding that variation in the AMHR2 gene modifies the relation between parity and age at natural menopause. In combination with the association of BMP15 with menopausal age, we find that there is evidence that genes involved in primary follicle recruitment influence timing of menopause.

[Age of menopause in patients with differentiated thyroid cancer treated with radioiodine]

INTRODUCTION

Differentiated thyroid cancer (DTC) is an increasingly frequent endocrinological disease. Radioiodine is a key component of treatment.

OBJECTIVE

To analyze the effects of I(131) therapy on ovarian and reproductive function.

MATERIAL AND METHODS

We retrospectively analyzed data from 202 women treated with radioiodine for DTC in our service from 1985-2008. Data on age at menopause in patients and their mothers and sisters, menstrual history, fertility and neonatal abnormalities were collected.

RESULTS

Menopause occurred in 34 patients at follow-up. The mean age at menopause in patients was 49.94+/-3.45 while that in their mothers and sisters was 49.20+/-5.37 and 48.73+/-3.74 years, respectively. Three patients had transient amenorrhea. No infertility or neonatal alterations were found.

CONCLUSIONS

In our series, menopause did not occur earlier in patients than in their first degree relatives. No significant alterations in neonatal health, fertility or menstruation were found.