Factors associated with age of onset and type of menopause in a cohort of UK women

History of infertility and anti-Müllerian hormone levels among participants in the Nurses' Health Study II

OBJECTIVES

To better understand whether history of infertility is associated with anti-Müllerian hormone (AMH) levels later in life, outside of reproduction.

METHODS

Among 1,758 premenopausal women in the Nurses' Health Study II with measured AMH, we used multivariable generalized linear models to compare log-transformed plasma AMH for women with a history of infertility compared with fertile women. We investigated AMH levels by cause of infertility and effect modification by menstrual cycle regularity. Lastly, we investigated AMH levels by history of primary and secondary infertility and age at reported infertility.

RESULTS

Mean age at blood collection was 40 years. We observed no association between overall history of infertility and AMH levels (% difference AMH: -8.1% [CI, -19.4 to 4.8]). The association between overall infertility and AMH was strongest among women who first reported infertility at >30 years (-17.7% [CI, -32.1 to -0.3]).

CONCLUSIONS

Overall, we observed no association between the history of infertility and AMH levels later in life. However, specific subgroups of women with a history of infertility may have lower AMH levels throughout life compared with fertile women. This association was observed among subgroups, such as those who first experienced infertility at >30 years. These findings have implications for mechanisms through which infertility may be associated with premature menopause and chronic disease risk.

Age at natural menopause and associated factors with early and late menopause among Chinese women in Zhejiang province: A cross-sectional study

OBJECTIVES

Menopause is a significant life transition for women, impacting their physical and psychological health. The age at natural menopause (ANM) and its associated factors have differed by race and region. This study aimed to investigate ANM and associated factors of early and late menopause among Chinese women in Zhejiang province.

METHODS

A cross-sectional study was conducted using a multi-stage stratified cluster sampling method to recruit 8,006 women aged 40-69 years who had resided in Zhejiang province for over 6 months between July 2019 and December 2021. Self-reported ANM and sociodemographics, lifestyle behaviors, reproductive history, and health-related factors were collected using questionnaires in face-to-face surveys. ANM were categorized into three groups: early menopause (<45 years), normal menopause (45-54 years), and late menopause (≥55 years). Kaplan-Meier survival analysis was utilized to calculate the median ANM. Multivariable multinomial logistic regression was employed to explore the associated factors of early menopause and late menopause.

RESULTS

A total of 6,047 women aged 40-69 years were included for survival analysis, with 3,176 of them for the regression analysis. The overall median ANM was 51 years (Inter-quartile range [IQR]: 51-52). Women who were smokers (odds ratio [OR]:4.54, 95% confidence interval [CI]:1.6-12.84), had irregular menstrual cycles (OR:1.78, 95% CI:1.12-2.83) and hypertension (OR:1.55, 95% CI:1.09-2.21) had a higher odds ratio of early menopause, while central obesity (OR:1.33, 95% CI:1.03-1.73) and hyperlipidemia (OR:1.51, 95% CI:1.04-2.18) were factors associated with late menopause.

CONCLUSIONS

This study revealed the associations between ANM and various factors among Chinese women. These factors included socio-demographic factors such as age; life behavior factors like current or prior smoking status; reproductive history factors such as irregular menstrual cycles, miscarriages, and breastfeeding; and health-related factors like central adiposity, hypertension, and hyperlipidemia. These findings provided a basis for understanding factors associated with ANM.

Laparoscopically confirmed endometriosis and anti-Müllerian hormone levels: Findings from the Nurses' Health Study II

OBJECTIVE

Anti-Müllerian hormone is a reliable measure of ovarian reserve associated with menopause timing and fertility. Previous studies have observed that individuals with endometriosis have lower anti-Müllerian hormone levels than those without. However, sample sizes have been small and information is limited regarding the long-term influence of endometriosis on anti-Müllerian hormone levels among the general population, which may have important implications for menopause timing and chronic disease risk.

METHODS

Among 1961 premenopausal women in the Nurses' Health Study II who provided a blood sample and had not been pregnant in the last 6 months, we used generalized linear models to determine the association between laparoscopically-confirmed endometriosis and log-transformed plasma anti-Müllerian hormone level, adjusted for age (continuous and squared) and other potential confounding variables.

RESULTS

Participants were on average 40 years old (interquartile range 37-42 years) at blood draw. Women with endometriosis diagnosed prior to blood draw (n = 119) had a lower mean anti-Müllerian hormone level (1.6 ng/mL [SD = 2.3]) than women without known endometriosis (n = 1842) (2.8 ng/mL [SD = 3.0]). In multivariable adjusted models, women with endometriosis had 29.6 % lower anti-Müllerian hormone levels (95 % CI: -45.4, -9.2 %) than women without. This association was greater among women with a body mass index of 25 kg/m2 or more (percent difference: -44.0 % (-63.7, -13.8)), compared to those with a body mass index of under 25 kg/m2 (percent difference: -19.8 % (-41.7, 10.4)), but did not vary by parity or infertility history.

CONCLUSIONS

Lower anti-Müllerian hormone levels in women with endometriosis may be one mechanism through which endometriosis influences risk of infertility, younger age at menopause, and cardiovascular disease.

An economic evaluation of eptinezumab for the preventive treatment of migraine in the UK, with consideration for natural history and work productivity

BACKGROUND

Migraine is a highly prevalent neurological disease with a substantial societal burden due to lost productivity. From a societal perspective, we assessed the cost-effectiveness of eptinezumab for the preventive treatment of migraine.

METHODS

An individual patient simulation of discrete competing events was developed to evaluate eptinezumab cost-effectiveness compared to best supportive care for adults in the United Kingdom with ≥ 4 migraine days per month and prior failure of ≥ 3 preventive migraine treatments. Individuals with sampled baseline characteristics were created to represent this population, which comprised dedicated episodic and chronic migraine subpopulations. Clinical efficacy, utility, and work productivity inputs were based on results from the DELIVER randomised controlled trial (NCT04418765). Timing of natural history events and treatment holidays-informed by the literature-were simulated to unmask any natural improvement of the disease unrelated to treatment. The primary outcomes were monthly migraine days, migraine-associated costs, quality-adjusted life years (QALYs), incremental cost-effectiveness ratio, and net monetary benefit, each evaluated over a 5-year time horizon from 2020. Secondary analyses explored a lifetime horizon and an alternative treatment stopping rule.

RESULTS

Treatment with eptinezumab resulted in an average of 0.231 QALYs gained at a saving of £4,894 over 5 years, making eptinezumab dominant over best supportive care (i.e., better health outcomes and less costly). This result was confirmed by the probabilistic analysis and all alternative assumption scenarios under the same societal perspective. Univariate testing of inputs showed net monetary benefit was most sensitive to the number of days of productivity loss, and monthly salary.

CONCLUSIONS

This economic evaluation shows that from a societal perspective, eptinezumab is a cost-effective treatment in patients with ≥ 4 migraine days per month and for whom ≥ 3 other preventive migraine treatments have failed.

TRIAL REGISTRATION

N/A.

Age at natural menopause and its determinants in female population of Kharameh cohort study: Comparison of regression, conditional tree and forests

BACKGROUND

Natural menopause is defined as the permanent cessation of menstruation that occurs after 12 consecutive months of amenorrhea without any obvious pathological or physiological cause. The age of this phenomenon has been reported to be associated with several health outcomes.

OBJECTIVES

This study aimed to estimate the Age at Natural Menopause (ANM) and to identify reproductive and demographic factors affecting ANM.

METHODS

This cross-sectional, population-based study was conducted on 2517 post-menopausal women aged 40-70 years participating in the first phase of the PERSIAN cohort study of Kharameh, Iran, during 2014-2017. To more accurately detect the determinants of ANM, we applied multiple linear regression beside some machine learning algorithms including conditional tree, conditional forest, and random forest. Then, the fitness of these methods was compared using Mean Squared Error (MSE) and Pearson correlation coefficient.

RESULTS

The mean±SD of ANM was 48.95±6.13. Both applied forests provided more accurate results and identified more predictors. However, according to the final comparison, the conditional forest was the most accurate method which recognized that more pregnancies, longer breastfeeding, Fars ethnicity, and urbanization have the greatest impact on later ANM.

CONCLUSIONS

This study found a wide range of reproductive and demographic factors affecting ANM. Considering our findings in decision-making can reduce the complications related to this phenomenon and, consequently, improve the quality of life of post-menopausal women.

Age at natural menopause and development of chronic diseases in the female population of Kharameh, Iran: A historical cohort study

Background and Aims

Declines in estradiol levels after menopause have been reported to be associated with several health outcomes. This study aimed to determine the effect of age at natural menopause (ANM) on some of the most common chronic diseases.

Methods

This historical cohort study was performed on 2636 postmenopausal women aged 40-70 years participating in phase one of the PERSIAN cohort study in Kharameh, Iran, during 2015-2017. The effect of early (<45 years), intermediate (45-53 years), and late menopause (>53 years) on chronic diseases such as hypertension, diabetes, ischemic heart diseases, stroke, thyroid diseases, and depression was assessed using classic logistic regression for diseases with an incidence rate of more than 10% and Firth's logistic regression for diseases with an incidence of less than this amount.

Results

The mean age of women was 53.48 ± 8.59. Respectively, early and intermediate menopause was associated with ischemic heart disease (odds ratio [OR = 1.61, 95% confidence interval [CI]: 1.08-2.42; p = 0.020), (OR = 1.57, 95% CI: 1.13-2.21; p = 0.008) and thyroid diseases (OR = 3.10, 95% CI: 1.64-6.24; p < 0.001), (OR = 1.83, 95% CI: 1.02-3.57; p = 0.042). furthermore, early menopause was a risk factor for diabetes (OR = 1.46, 95% CI: 1.07-2.00; p = 0.018), depression (OR = 4.79, 95% CI: 2.20-11.79; p = <0.001) and stroke (OR = 3.00, 95% CI: 1.08-9.32; p = 0.034).

Conclusions

In this study, women with diabetes, ischemic heart diseases, stroke, thyroid disorders, and depression had a younger ANM compared to their healthy counterparts. Therefore, applying appropriate strategies to postpone the age of menopause, can reduce the incidence of these types of chronic diseases.

Revealing the diagnostic value and immune infiltration of senescence-related genes in endometriosis: a combined single-cell and machine learning analysis

Introduction: Endometriosis is a prevalent and recurrent medical condition associated with symptoms such as pelvic discomfort, dysmenorrhea, and reproductive challenges. Furthermore, it has the potential to progress into a malignant state, significantly impacting the quality of life for affected individuals. Despite its significance, there is currently a lack of precise and non-invasive diagnostic techniques for this condition. Methods: In this study, we leveraged microarray datasets and employed a multifaceted approach. We conducted differential gene analysis, implemented weighted gene co-expression network analysis (WGCNA), and utilized machine learning algorithms, including random forest, support vector machine, and LASSO analysis, to comprehensively explore senescence-related genes (SRGs) associated with endometriosis. Discussion: Our comprehensive analysis, which also encompassed profiling of immune cell infiltration and single-cell analysis, highlights the therapeutic potential of this gene assemblage as promising targets for alleviating endometriosis. Furthermore, the integration of these biomarkers into diagnostic protocols promises to enhance diagnostic precision, offering a more effective diagnostic journey for future endometriosis patients in clinical settings. Results: Our meticulous investigation led to the identification of a cluster of genes, namely BAK1, LMNA, and FLT1, which emerged as potential discerning biomarkers for endometriosis. These biomarkers were subsequently utilized to construct an artificial neural network classifier model and were graphically represented in the form of a Nomogram.

Association of infertility with type and timing of menopause: a prospective cohort study

STUDY QUESTION

What is the association between past infertility and the type and timing of menopause in midlife women?

SUMMARY ANSWER

Women with a history of infertility were more likely to experience surgical menopause overall and had elevated risk of earlier surgical menopause until age 43 years but experienced no differences in the timing of natural menopause.

WHAT IS KNOWN ALREADY

Infertility is experienced by 12-25% of women and is thought to reveal a propensity for poor health outcomes, such as chronic illness, later in life. However, little is known about whether infertility is linked with characteristics of the menopausal transition as women age, despite possible shared underlying pathways involving ovarian function and gynecologic disease.

STUDY DESIGN, SIZE, DURATION

Secondary analysis of a prospective cohort study of 13 243 midlife females recruited in Phase 1 of the Alberta's Tomorrow Project (Alberta, Canada) and followed approximately every 4 years (2000-2022).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data were collected through standardized self-report questionnaires. History of infertility, defined as ever trying to become pregnant for more than 1 year without conceiving, was measured at baseline. Menopause characteristics were measured at each study follow-up. Menopause type was defined as premenopause, natural menopause, surgical menopause (bilateral oophorectomy), or indeterminate menopause (premenopausal hysterectomy with ovarian conservation). Timing of natural menopause was defined as the age at 1 full year after the final menstrual period, and timing of surgical and indeterminate menopause was defined as the age at the time of surgery. We used flexible parametric survival analysis for the outcome of menopause timing with age as the underlying time scale and multinomial logistic regression for the outcome of menopause type. Multivariable models controlled for race/ethnicity, education, parity, previous pregnancy loss, and smoking. Sensitivity analyses additionally accounted for birth history, menopausal hormone therapy, body mass index, chronic medical conditions, and age at baseline.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, 18.2% of women reported a history of infertility. Past infertility was associated with earlier timing of surgical menopause exclusively before age 43 years (age 35: adjusted hazard ratio 3.13, 95% CI 1.95-5.02; age 40: adjusted hazard ratio 1.83, 95% CI 1.40-2.40; age 45: adjusted hazard ratio 1.13, 95% CI 0.87-1.46) as well as greater odds of experiencing surgical menopause compared to natural menopause (adjusted odds ratio 1.40, 95% CI 1.18-1.66). Infertility was not associated with the timing of natural or indeterminate menopause.

LIMITATIONS, REASONS FOR CAUTION

Information on the underlying cause of infertility and related interventions was not collected, which precluded us from disentangling whether associations differed by infertility cause and treatment. Residual confounding is possible given that some covariates were measured at baseline and may not have temporally preceded infertility.

WIDER IMPLICATIONS OF THE FINDINGS

Women with a history of infertility were more likely to experience early surgical menopause and may therefore benefit from preemptive screening and treatment for gynecologic diseases to reduce bilateral oophorectomy, where clinically appropriate, and its associated health risks in midlife. Moreover, the lack of association between infertility and timing of natural menopause adds to the emerging knowledge that diminishing ovarian reserve does not appear to be a primary biological mechanism of infertility nor its downstream implications for women's health.

STUDY FUNDING/COMPETING INTEREST(S)

Alberta's Tomorrow Project is only possible due to the commitment of its research participants, its staff and its funders: Alberta Health, Alberta Cancer Foundation, Canadian Partnership Against Cancer and Health Canada, and substantial in-kind funding from Alberta Health Services. The views expressed herein represent the views of the author(s) and not of Alberta's Tomorrow Project or any of its funders. This secondary analysis is funded by Project Grant Priority Funding in Women's Health Research from the Canadian Institutes of Health Research (Grant no. 491439). N.V.S. is supported by a Banting Postdoctoral Fellowship from the Canadian Institutes of Health Research. H.K.B. is supported by the Canada Research Chairs Program. E.A.B. is supported by an Early Career Investigator Award in Maternal, Reproductive, Child and Youth Health from the Canadian Institutes of Health Research. A.K.S. has received honoraria from Pfizer, Lupin, Bio-Syent, and Eisai and has received grant funding from Pfizer. N.V.S., H.K.B., and E.A.B. have no conflicts of interest to report.

TRIAL REGISTRATION NUMBER

N/A.

Managing Early Onset Osteoporosis: The Impact of Premature Ovarian Insufficiency on Bone Health

Premature ovarian insufficiency is a reproductive endocrine disorder characterized by the cessation of ovarian function before the age of 40 years. Although the etiopathology of POI remains largely unknown, certain causative factors have been identified. Individuals affected by POI are at an increased risk of experiencing bone mineral density (BMD) loss. Hormonal replacement therapy (HRT) is recommended for patients with POI to mitigate the risk of decreased BMD, starting from the time of diagnosis until reaching the average age of natural menopause. Various studies have compared the dose-effect relationship of estradiol supplementation, as well as different HRT formulations on BMD. The impact of oral contraception on reduced BMD or the potential benefits of adding testosterone to estrogen replacement therapy are still subjects of ongoing discussion. This review provides an overview of the latest advancements in the diagnosis, evaluation, and treatment of POI as it relates to BMD loss.

The Association of Female Reproductive Factors with Glaucoma and Related Traits: A Systematic Review

TOPIC

This systematic review summarizes evidence for associations between female reproductive factors (age at menarche, parity, oral contraceptive [OC] use, age at menopause, and postmenopausal hormone [PMH] use) and intraocular pressure (IOP) or open-angle glaucoma (OAG).

CLINICAL RELEVANCE

Understanding the associations between female reproductive factors and glaucoma may shed light on the disease pathogenesis and aid clinical prediction and personalized treatment strategies. Importantly, some factors are modifiable, which may lead to new therapies.

METHODS

Two reviewers independently extracted articles in MEDLINE, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials databases to identify relevant studies. Eligibility criteria included studies with human subjects aged > 18 years; a measured outcome of either IOP or OAG; a cohort, case-control, cross-sectional, or randomized controlled trial design; a reported measure of association, such as the hazard ratio, relative risk, odds ratio, or mean difference, with an associated confidence interval; and a measured exposure of at least 1 of the following variables: age at menarche, parity, OC use, age at menopause, or PMH use.

RESULTS

We included a total of 27 studies. Substantial differences in study designs, exposure and treatment levels, treatment durations, and variable reporting precluded a meaningful quantitative synthesis of the identified studies. Overall, relatively consistent associations between PMH use and a lower IOP were identified. Estrogen-only PMH use may be associated with lower OAG risk, which may be modified by race. No significant associations were found with combined estrogen-and-progesterone PMH use. No strong associations between parity or age at menarche and glaucoma were found, but a younger age at menopause was associated with an increased glaucoma risk, and adverse associations were identified with a longer duration of OC use, though no overall association with OC use was found.

CONCLUSIONS

The association between PMH use and lower IOP or OAG risk is a potentially clinically relevant and modifiable risk factor and should be investigated further, although this needs to be interpreted in the context of a high risk of bias across included studies. Future research should examine associations with IOP specifically and how the relationship between genetic factors and OAG risks may be influenced by female reproductive factors.

Achieving proportional representation in a reproductive health survey through social media: process and recommendations

BACKGROUND

The narrative surrounding women's reproductive health has shifted from a medical model to an emphasis on reproductive well-being over different life-stages. We developed and piloted a tracker survey for monitoring women's reproductive health and well-being in England, recruiting respondents online. This paper reports on the success of the online recruitment strategies in achieving a sample proportionally representative of the England general population.

METHODS

Recruitment was through Facebook and Instagram advertisements and dissemination through Twitter and a blog. At the end week one, the sample was reviewed and compared to the 2011 Census England population. From week two, recruitment targeted under-represented groups. Key data were compared with prevalence estimates from the Third National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

RESULTS

Between 1 July-17 August 2021, 13,962 people initiated the online survey, with 11,578 completing it. Numbers were low initially, but peaked at 1700 survey initiations per day after increasing the daily advertisement budget on day seven. At the end of week one, minority ethnic groups and people without a degree or equivalent were under-represented. From week two, we altered the advertisement settings to show to people whose profile indicated they were a 'high school leaver' had 'up to some high school', worked in industries that do not typically require a degree or lived in local authorities with a high proportion of ethnic minority residents. This had a modest effect, with the final sample short of proportional representation in terms of ethnicity and education but close in terms of region and age. Compared to Natsal-3, we found consistency in the proportion of respondents reporting an abortion and a live birth in the last year, however, the proportion of our sample reporting ever having experienced infertility was significantly higher than in Natsal-3, as was the proportion of 'planned' pregnancies in the last year.

CONCLUSIONS

It is possible to recruit large numbers of respondents online, relatively quickly, to complete a reproductive health survey. This will be valuable to track reproductive health and well-being at a national level over time. More work is needed to understand reasons for non-response among under-represented groups.

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.

Association of weight, smoking, and alcohol consumption with age at natural menopause

In South Korea, rapid economic growth and modernization have led to changes in lifestyle factors that may affect age at natural menopause. Data from 4,793 women aged ≥55 years, who had a natural menopause, were analyzed from the Korea National Health and Nutrition Examination Survey (2013-2017). Multinomial logistic regression was used to examine the association between lifestyle factors and age at natural menopause after adjusting for birth cohort (Model 1) and sociodemographic and reproductive factors (Model 2). Overall, 3.1% of women experienced premature menopause (<40 years), 7.6% early menopause (40-44 years), and 12.8% late menopause (≥55 years). Women born in the 1940s or earlier among the birth cohorts had the highest prevalence of premature (70.0%), early (58.5%), and late (43.1%) menopause. In Model 2, current smoking (odds ratio = 3.99 and 95% confidence interval = 1.35-11.81) was associated with premature menopause. Low (<18.5 kg/m²) and high (≥25 kg/m²) body mass index were associated with early (odds ratio = 2.30 and 95% confidence interval = 1.01-5.22) and late (odds ratio = 1.38 and 95% confidence interval = 1.10-1.72) menopause respectively. Conversely, there was no association between age at natural menopause and alcohol consumption. The results suggest that healthy lifestyle factors, such as not smoking and proper weight maintenance, are significant factors affecting age at natural menopause. Our findings may help develop health policies and provide targeted care to improve women's health after midlife.

The Effects of Environmental Contaminant Exposure on Reproductive Aging and the Menopause Transition

PURPOSE OF REVIEW

Menopause marks the end of a woman's reproductive lifetime. On average, natural menopause occurs at 51 years of age. However, some women report an earlier age of menopause than the national average. This can be problematic for women who delay starting a family. Moreover, early onset of menopause is associated with increased risk of cardiovascular disease, depression, osteoporosis, and premature death. This review investigates associations between exposure to endocrine-disrupting chemicals (EDCs) and earlier onset of menopause.

RECENT FINDINGS

Recent data suggest exposure to certain EDCs may accelerate reproductive aging and contribute to earlier onset of menopause. Human and rodent-based studies identify positive associations between exposure to certain EDCs/environmental contaminants and reproductive aging, earlier onset of menopause, and occurrence of vasomotor symptoms. These findings increase our understanding of the detrimental effects of EDCs on female reproduction and will help lead to the development of strategies for the treatment/prevention of EDC-induced reproductive aging.

Association Between Laparoscopically Confirmed Endometriosis and Risk of Early Natural Menopause

IMPORTANCE

Early natural menopause (ENM) has been associated with reduced reproductive span, cardiovascular disease risk, and early mortality. The potential adverse implications of endometrioma surgery for ovarian reserve are known, yet the association of endometriosis with menopausal timing remains understudied.

OBJECTIVE

To investigate the association between endometriosis and risk for ENM.

DESIGN, SETTING, AND PARTICIPANTS

This large, population-based cohort study analyzed data from the Nurses' Health Study II cohort questionnaires from the 1989 to 2015 questionnaire cycles. The sample included premenopausal women aged 25 to 42 years at baseline or enrollment in 1989. Cumulative follow-up rate was greater than 90%, and participants continued follow-up until the onset of ENM, age 45 years, hysterectomy, oophorectomy, cancer diagnosis, death, loss to follow-up, or end of follow-up in May 2017, whichever occurred first. Data analyses were conducted from October 26, 2020, to April 27, 2021.

EXPOSURES

Endometriosis diagnosis status was queried in the biennial questionnaires, with participants reporting physician diagnosis and whether the diagnosis was laparoscopically confirmed.

MAIN OUTCOMES AND MEASURES

Natural menopause before age 45 years. Menopause status was assessed every 2 years.

RESULTS

The study included 106 633 premenopausal women with a mean (SD) age of 34.8 (4.3) years at baseline, of whom 3921 reported a laparoscopically confirmed endometriosis diagnosis. During 1 508 462 person-years of follow-up, 6640 participants reported being diagnosed with endometriosis, 99 993 never reported endometriosis, and 2542 reported experiencing ENM. In the age- and calendar time-adjusted model, laparoscopically confirmed endometriosis was associated with a 50% greater risk for ENM (hazard ratio [HR], 1.51; 95% CI, 1.30-1.74). A similar risk was observed after adjusting for race and ethnicity and time-varying anthropometric and behavioral factors (HR, 1.46; 95% CI, 1.26-1.69). With additional adjustment for reproductive factors, the HR of ENM was attenuated but significant (HR, 1.28; 95% CI, 1.10-1.48). A greater risk of ENM was observed among women who were nulliparous after stratifying by parity (nulliparous vs parous: HR, 1.46 [95% CI, 1.15-1.86] vs 1.14 [95% CI, 0.94-1.39]; P for heterogeneity = .05) or who never used oral contraceptives when stratifying by oral contraceptive use (never vs ever: HR, 2.03 [95% CI, 1.34-3.06] vs 1.20 [95% CI, 1.02-1.42]; P for heterogeneity = .02). No significant differences were observed in the association between endometriosis and ENM when stratifying by body mass index (calculated as weight in kilograms divided by height in meters squared; <25 vs ≥25: HR, 1.20 [95% CI, 0.99-1.45] vs 1.43 [95% CI, 1.11-1.83; P for heterogeneity = .34), cigarette smoking status (never vs ever: HR, 1.36 [95% CI, 1.13-1.65] vs 1.11 [95% CI, 0.87-1.42]; P for heterogeneity = .57), or history of infertility attributed to ovulatory disorder (no vs yes: HR, 1.28 [95% CI, 1.08-1.51] vs 1.28 [95% CI, 0.90-1.82]; P for heterogeneity = .86).

CONCLUSIONS AND RELEVANCE

This cohort study found a risk for ENM in women with laparoscopically confirmed endometriosis. These women compared with those without endometriosis may be at a higher risk for shortened reproductive duration, particularly those who were nulliparous or never used oral contraceptives.

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.

Effects of ovarian endometrioma aspiration on in vitro fertilization-intracytoplasmic sperm injection and embryo transfer outcomes: a systematic review and meta-analysis

PURPOSE

To evaluate the effect of ovarian endometrioma aspiration on IVF/ICSI outcomes.

METHODS

The PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure, and Wanfang databases were searched to identify studies related to the treatment of endometrioma up to October 1, 2020, and the data of 1207 patients from 10 studies were analyzed using STATA.

RESULTS

The 10 studies in our analysis included 7 comparing aspiration and surgery and 6 comparing aspiration with no intervention. In the aspiration versus surgery groups, live birth rate [OR 0.97 (95% CI 0.51, 1.85), P = 0.925] and clinical pregnancy rate [OR 1.30 (95% CI 0.95, 1.80), P = 0.105] showed no significant difference between the two groups. Abortion rate [OR 4.26 (95% CI 1.38, 13.08), P = 0.011], the number of oocytes retrieved [mean difference 1.95 (95% CI 0.10, 3.81), P = 0.039], and the estradiol peak on hCG day [mean difference 392.16 (95% CI 230.14, 554.18), P < 0.001] were significantly higher in the aspiration group compared to the surgical group. In the aspiration versus the no intervention group, live birth rate [OR 0.84 (95% CI 0.45, 1.59), P = 0.602] and clinical pregnancy rate [OR 1.25 (95% CI 0.88, 1.77), P = 0.206] were not significantly different between the two groups. The abortion rate [OR 0.31 (95% CI 0.11, 0.88), P = 0.028] and the number of gonadotropin ampoules [mean difference - 3.13 ampoules (95% CI - 4.90, - 1.37), P < 0.001] were significantly lower in the aspiration group compared to the no intervention group.

CONCLUSION

Compared with surgical treatment or no intervention treatment, aspiration has less effect on ovarian response, ovarian reserve, and pregnancy outcomes.

Prevalence of disordered eating, eating disorders and risk of low energy availability in professional, competitive and recreational female athletes based in the United Kingdom

Eating disorders (ED), disordered eating (DE) and low energy availability (LEA) can be detrimental to health and performance. Previous studies have independently investigated the prevalence of ED, DE or LEA; however, few combined methods have identified risk within female athletes. The aim of this study was to identify the prevalence of ED, DE and LEA in UK-based female athletes and investigate whether associations exist between age, competition level and primary sport. The Female Athlete Screening Tool (FAST) and Low Energy Availability in Females Questionnaire (LEAF-Q) were used in a cross-sectional study design. A total of 112 responses eligible for analysis were received. A total of 16%, 44% and 53% of female athletes were at risk of ED (FAST: >94), DE and LEA, respectively. Competition level (recreational, competitive or professional athletes; fishers, p ≤ 0.05) influenced and was a predictor of FAST (R²= 0.076, F_(1,110) = 10.067, p ≤ 0.05, variance inflation value; VIF = 1.0) whereas age influenced (age: H₍₂₎ = 13.128, p ≤ 0.05), and was a predictor (R² = 0.144, F_(2,109) =  9.170, p ≤ 0.05, VIF = 1.0) of LEAF-Q. A positive correlation was observed between FAST and LEAF-Q scores (R = 0.496, p ≤ 0.05). Age and competition level may be predicting risk factors of ED/DE and LEA within female athletes; however, further research is required to support the findings of this present study.

Association of oral contraceptives and tubal ligation with risk of early natural menopause

STUDY QUESTION

What is the association of oral contraceptives (OCs) and tubal ligation (TL) with early natural menopause?

SUMMARY ANSWER

We did not observe an association of OC use with risk of early natural menopause; however, TL was associated with a modestly higher risk.

WHAT IS KNOWN ALREADY

OCs manipulate hormone levels, prevent ovulation, and may modify the rate of follicular atresia, while TL may disrupt the blood supply to the ovaries. These mechanisms may be associated with risk of early menopause, a condition associated with increased risk of cardiovascular disease and other adverse health outcomes.

STUDY DESIGN, SIZE, DURATION

We examined the association of OC use and TL with natural menopause before the age of 45 years in a population-based study within the prospective Nurses' Health Study II (NHSII) cohort. Participants were followed from 1989 to 2017 and response rates were 85-90% for each cycle.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants included 106 633 NHSII members who were premenopausal and aged 25-42 years at baseline. Use, duration and type of OC, and TL were measured at baseline and every 2 years. Menopause status and age were assessed every 2 years. Follow-up continued until early menopause, age 45 years, hysterectomy, oophorectomy, death, cancer diagnosis, or loss to follow-up. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% CIs adjusted for lifestyle, dietary, and reproductive factors.

MAIN RESULTS AND THE ROLE OF CHANCE

Over 1.6 million person-years, 2579 members of the analytic cohort experienced early natural menopause. In multivariable models, the duration, timing, and type of OC use were not associated with risk of early menopause. For example, compared with women who never used OCs, those reporting 120+ months of OC use had an HR for early menopause of 1.01 (95% CI, 0.87-1.17; P for trend=0.71). TL was associated with increased risk of early menopause (HR = 1.17, 95% CI, 1.06-1.28).

LIMITATIONS, REASONS FOR CAUTION

Our study population is homogenous with respect to race and ethnicity. Additional evaluation of these relations in more diverse populations is important.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the largest study examining the association of OC use and TL with early natural menopause to date. While TL was associated with a modest higher risk of early menopause, our findings do not support any material hazard or benefit for the use of OCs.

STUDY FUNDING/COMPETING INTEREST(S)

The study was sponsored by UO1CA176726 and R01HD078517 from the National Institutes of Health and Department of Health and Human Services. The work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The authors have no competing interests to report.

TRIAL REGISTRATION NUMBER

N/A.

Endometriosis and polycystic ovary syndrome are diametric disorders

Evolutionary and comparative approaches can yield novel insights into human adaptation and disease. Endometriosis and polycystic ovary syndrome (PCOS) each affect up to 10% of women and significantly reduce the health, fertility, and quality of life of those affected. PCOS and endometriosis have yet to be considered as related to one another, although both conditions involve alterations to prenatal testosterone levels and atypical functioning of the hypothalamic-pituitary-gonadal (HPG) axis. Here, we propose and evaluate the novel hypothesis that endometriosis and PCOS represent extreme and diametric (opposite) outcomes of variation in HPG axis development and activity, with endometriosis mediated in notable part by low prenatal and postnatal testosterone, while PCOS is mediated by high prenatal testosterone. This diametric disorder hypothesis predicts that, for characteristics shaped by the HPG axis, including hormonal profiles, reproductive physiology, life-history traits, and body morphology, women with PCOS and women with endometriosis will manifest opposite phenotypes. To evaluate these predictions, we review and synthesize existing evidence from developmental biology, endocrinology, physiology, life history, and epidemiology. The hypothesis of diametric phenotypes between endometriosis and PCOS is strongly supported across these diverse fields of research. Furthermore, the contrasts between endometriosis and PCOS in humans parallel differences among nonhuman animals in effects of low versus high prenatal testosterone on female reproductive traits. These findings suggest that PCOS and endometriosis represent maladaptive extremes of both female life-history variation and expression of sexually dimorphic female reproductive traits. The diametric disorder hypothesis for endometriosis and PCOS provides novel, unifying, proximate, and evolutionary explanations for endometriosis risk, synthesizes diverse lines of research concerning the two most common female reproductive disorders, and generates future avenues of research for improving the quality of life and health of women.

Effects of Environment and Lifestyle Factors on Premature Ovarian Failure

Premature ovarian insufficiency (POI) or primary ovarian failure is defined as a cessation of the menstrual cycle in women younger than 40 years old. It is strictly defined as more than 4 months of oligomenorrhea or amenorrhea in a woman <40 years old, associated with at least two follicle-stimulating hormone (FSH) levels >25 U/L in the menopausal range, detected more than 4 weeks apart. It is estimated that POI was affected 1 and 2% of women. Although 80% of POI cases are of unknown etiology, it is suggested that genetic disorder, autoimmune origin, toxins, and environmental factors, as well as personal lifestyles, may be risk factors of developing POI. In this section, we will discuss the influences of environmental and lifestyle factors on POI. Moreover updated basic research findings regarding how these environmental factors affect female ovarian function via epigenetic regulations will also be discussed.

Menopause Transition and Cardiovascular Disease Risk: Implications for Timing of Early Prevention: A Scientific Statement From the American Heart Association

Cardiovascular disease (CVD) is the leading cause of death in women, who have a notable increase in the risk for this disease after menopause and typically develop coronary heart disease several years later than men. This observation led to the hypothesis that the menopause transition (MT) contributes to the increase in coronary heart disease risk. Over the past 20 years, longitudinal studies of women traversing menopause have contributed significantly to our understanding of the relationship between the MT and CVD risk. By following women over this period, researchers have been able to disentangle chronological and ovarian aging with respect to CVD risk. These studies have documented distinct patterns of sex hormone changes, as well as adverse alterations in body composition, lipids and lipoproteins, and measures of vascular health over the MT, which can increase a woman's risk of developing CVD postmenopausally. The reported findings underline the significance of the MT as a time of accelerating CVD risk, thereby emphasizing the importance of monitoring women's health during midlife, a critical window for implementing early intervention strategies to reduce CVD risk. Notably, the 2011 American Heart Association guidelines for CVD prevention in women (the latest sex-specific guidelines to date) did not include information now available about the contribution of the MT to increased CVD in women. Therefore, there is a crucial need to discuss the contemporary literature on menopause and CVD risk with the intent of increasing awareness of the significant adverse cardiometabolic health-related changes accompanying midlife and the MT. This scientific statement provides an up-to-date synthesis of the existing data on the MT and how it relates to CVD.

Early life exposure to famine and reproductive aging among Chinese women

OBJECTIVE

To assess the effect of early life exposure to famine, as endured during 1959 to 1961 in China, on reproductive aging in adult women.

METHODS

Between 2011 and 2012, 2,868 women born around the Chinese famine period (1956-1964) were enrolled in this study from three communities in China. Age at natural menopause was obtained retrospectively from a structured questionnaire. The associations of early life famine exposure with reproductive aging during adulthood were estimated, with adjustment of socioeconomic status, lifestyle factors, and body mass index.

RESULTS

Women exposed to prenatal famine had a higher risk of early menopause (ie, natural menopause <45 years, odds ratio: 1.59, 95% confidence interval [CI]: 1.07, 2.36), and a nonsignificant trend of higher risk of premature ovarian failure (ie, natural menopause <40 y, odds ratio: 1.94, 95% CI: 0.93, 4.00), compared to unexposed women. Exposure to famine during childhood was not significantly associated with reproductive aging. In a secondary analysis focusing on the fetal exposure, prenatal famine exposure was associated with a higher risk of premature ovarian failure (odds ratio: 2.07, 95% CI: 1.08, 3.87), and a nonsignificant trend of higher risk of early menopause (odds ratio: 1.37, 95% CI: 0.98, 1.91), compared to those unexposed to prenatal famine.

CONCLUSIONS

Our study showed that fetal exposure to famine was associated with an increased risk of early menopause. Such findings provided evidence in favor of the thrifty phenotype theory in reproductive aging and helped better understand the etiology of early menopause.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Management of endometriosis-related infertility: Considerations and treatment options

Endometriosis is a common inflammatory disease in women of reproductive age and is one of the major causes of infertility. Endometriosis causes a sustained reduction of ovarian reserve through both physical mechanisms and inflammatory reactions, which result in the production of reactive oxygen species and tissue fibrosis. The severity of endometriosis is related to ovarian reserve. With regard to infertility treatment, medical therapy as a neoadjuvant or adjuvant to surgical therapy has no definite beneficial effect. Surgical treatment of endometriosis can lead to ovarian injury during the resection of endometriotic tissue, which leads to the deterioration of ovarian reserve. To overcome this disadvantage, a multistep technique has been proposed to minimize the reduction of ovarian reserve. When considering surgical treatment of endometriosis in patients experiencing infertility, it should be kept in mind that ovarian reserve can be reduced both due to endometriosis itself and by the process of removing endometriosis. In cases of mild- to moderate-stage endometriosis, intrauterine insemination with ovarian stimulation after surgical treatment may increase the likelihood of pregnancy. In cases of severe endometriosis, the characteristics of the patient should be considered in a multidisciplinary manner to determine the prioritization of treatment modalities, including surgical treatment and assisted reproduction methods such as in vitro fertilization. The risk of cancer, complications after pregnancy, and infection during oocyte retrieval should also be considered when making treatment decisions.

Relationship between BRSK1 rs12611091 variant and age at natural menopause based on physical activity

Objectives:

The rs12611091 variant in the BR serine/threonine kinase 1 gene is one of the variants previously associated with age at natural menopause. So far, this variant has not been replicated in Taiwanese women. The purpose of this study was to determine the association between rs12611091 and age at natural menopause based on physical activity.

Methods:

A total of 1,758 women were eligible for analysis whose information about menopause was collected from the Taiwan Biobank. Multiple linear regression analysis was used for analysis.

Results:

The mean age (standard deviation) at natural menopause was 50.82 (3.59) years. Of the eligible participants, 56.94% were rs12611091 CC carriers, 36.69% were TC carriers, and 6.37% were TT carriers. Compared to CC carriers, TC and TT carriers were associated with early menopause (β = −0.42, P = 0.02 and −0.87, P = 0.01, respectively). There was a significant interaction between rs12611091 and physical activity (P for interaction = 0.02). Compared to rs12611091 CC carriers, TC and TT carriers who were physically inactive were significantly associated with earlier menopause (β = −0.88, P < 0.01 and −1.25, P = 0.02, respectively).

Conclusion:

We demonstrated that rs12611091 variant was associated with age at natural menopause especially among inactive women in Taiwan. That is, women with TC and TT genotypes who were physically inactive were significantly associated with earlier natural menopause compared to those with CC genotype.

Association of Parity and Breastfeeding With Risk of Early Natural Menopause

IMPORTANCE

Pregnancy and breastfeeding prevent ovulation and may slow the depletion of the ovarian follicle pool. These factors may lower the risk of early menopause, a condition associated with increased risk of cardiovascular disease and other adverse health outcomes.

OBJECTIVE

To examine the association of parity and breastfeeding with the risk of early menopause.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study within the Nurses' Health Study II cohort (1989-2015) included premenopausal participants who were aged 25 to 42 years at baseline. Response rates were 85% to 90% for each cycle, and follow-up continued until menopause, age 45 years, hysterectomy, oophorectomy, death, cancer diagnosis, loss to follow-up, or end of follow-up in May 2015. Hypotheses were formulated after data collection. Data analysis took place from February to July 2019.

EXPOSURES

Parity (ie, number of pregnancies lasting ≥6 months) was measured at baseline and every 2 years. History and duration of total and exclusive breastfeeding were assessed 3 times during follow-up. Menopause status and age were assessed every 2 years.

MAIN OUTCOMES AND MEASURES

Risk of natural menopause before age 45 years.

RESULTS

At baseline, 108 887 premenopausal women aged 25 to 42 years (mean [SD] age, 34.1 [4.6] years; 102 246 [93.9%] non-Hispanic white) were included in the study. In multivariable models, higher parity was associated with lower risk of early menopause. Hazard ratios were attenuated with adjustment for breastfeeding but remained significant. Compared with nulliparous women, those reporting 1, 2, 3, and 4 or more pregnancies lasting at least 6 months had hazard ratios for early menopause of 0.92 (95% CI, 0.79-1.06), 0.84 (95% CI, 0.73-0.96), 0.78 (95% CI, 0.67-0.92), and 0.81 (95% CI, 0.66-1.01), respectively (P for trend = .006). In multivariable models also adjusted for parity, hazard ratios for duration of exclusive breastfeeding of 1 to 6, 7 to 12, 13 to 18, and 19 or more months were 0.95 (95% CI, 0.85-1.07), 0.72 (95% CI, 0.62-0.83), 0.80 (95% CI, 0.66-0.97), and 0.89 (95% CI, 0.69-1.16), respectively, compared with less than 1 month of exclusive breastfeeding (P for trend = .001). Despite the significant test for trend, estimates were not observed to be lower as duration of exclusive breastfeeding increased. In a stratified analysis of parous women, risk of early menopause was lowest among those reporting exclusive breastfeeding for 7 to 12 months in each level of parity (women with 2 pregnancies and 7-12 months of breastfeeding: HR, 0.79; 95% CI, 0.66-0.96; ≥3 pregnancies and 7-12 months of breastfeeding: HR, 0.68; 95% CI, 0.52-0.88; 2 pregnancies and ≥13 months of breastfeeding: HR, 0.87; 95% CI, 0.66-1.15; ≥3 pregnancies and 13-18 months of breastfeeding: HR, 0.86; 95% CI, 0.66-1.13; and ≥3 pregnancies and ≥19 months of breastfeeding: HR, 0.98; 95% CI, 0.72-1.32).

CONCLUSIONS AND RELEVANCE

In this study, an inverse association of parity with risk of early menopause was observed. Breastfeeding was associated with significantly lower risk, even after accounting for parity. Breastfeeding at levels consistent with current recommendations may confer an additional benefit of lower risk of early menopause.

Effect of aging, menopause, and age at natural menopause on the trend in body mass index: a 15-year population-based cohort

OBJECTIVE

To observe the effects of menopause, age at natural menopause (ANM), and aging on the trend in body mass index (BMI).

DESIGN

Prospective cohort with a 15-year follow-up of 929 women. Data obtained from the Tehran Lipid and Glucose Study.

SETTING

Not applicable.

INTERVENTION(S)

none.

PARTICIPANT(S)

Of women participating in the Tehran Lipid and Glucose Study, 929 who were reproductive during the study and menopaused at the last follow-up were included. Anthropometric data were measured repeatedly every 3 years, and the trend in BMI, associated with menopause and ANM, was tested using the generalized estimating equation.

MAIN OUTCOME MEASURE(S)

Body mass index in each follow-up session.

RESULT(S)

The adjusted model of the generalized estimating equation illustrates that BMI increases by age (β = 0.16) and menopausal status (β = 1.11). It also shows that women with higher ANM experienced a decreasing BMI (β = -0.03) compared with women with lower ANM. The interaction term of menopause and time (menopause × time) has a negative effect on BMI; that is, the usual increase in BMI after menopause is attenuated by time. (β = -0.4, 95% confidence interval -0.6, -0.3).

CONCLUSION(S)

Menopause and aging are independently correlated with increasing BMI. The trend in BMI, however, depends on the ANM of study participants: women with higher ANM than mean ANM of our population (i.e., 49 years) face a decreasing BMI compared with those with lower ANM.

Link between Endometriosis, Atherosclerotic Cardiovascular Disease, and the Health of Women Midlife

Endometriosis and atherosclerotic cardiovascular disease (ASCVD) are both essentially diseases of inflammation. It is well established that inflammation is the leading mechanism in the initiation and maintenance of vascular injury and in the development and progression of atherosclerosis. Thus, if women with endometriosis do indeed have increased general inflammation, they are at increased risk of developing microvascular dysfunction and atherosclerosis. Currently available evidence suggests that young female patients with proven endometriosis may be at a higher lifetime risk of developing cardiovascular disease; this may be unrecognized due to the relatively young age of women found to have endometriosis. Other mechanisms proposed to explain the link between endometriosis and ASCVD include similarities in the genetic underpinnings of each condition, including microRNA dysfunction and the association between endometriosis and early menopause, a risk for developing ASCVD. Although physicians today primarily focus on traditional risk factors when evaluating an individual female patient's risk of developing ASCVD, we believe that a history of endometriosis should be included as a possible risk factor and needs further exploration. A better understanding of the mechanisms linking endometriosis with ASCVD will hopefully guide the implementation of new therapies to mitigate the increased cardiovascular disease burden that patients with endometriosis might face.

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.

A pilot study of preoperative heart rate variability predicting pain during local anesthetic varicose vein surgery

OBJECTIVE

Local anesthetic endovenous procedures were shown to reduce recovery time, to decrease postoperative pain, and to more quickly return the patient to baseline activities. However, a substantial number of patients experience pain during these procedures. The autonomic nervous system modulates pain perception, and its influence on stress response can be noninvasively quantified using heart rate variability (HRV) indices. The aim of our study was to evaluate whether preoperative baseline HRV can predict intraoperative pain during local anesthetic varicose vein surgery.

METHODS

Patients scheduled for radiofrequency ablation were included in the study. They had their electrocardiograms recorded from a single channel of a custom-made amplifier. Each patient preoperatively filled in forms Y-1 and Y-2 of Spielberger's State and Trait Anxiety Inventory, completed the Aberdeen Varicose Vein Questionnaire, and rated anxiety level on a numeric scale. Postoperatively, patients filled in the pain they felt during the procedure on the numeric pain intensity scale. MATLAB software (MathWorks, Natick, Mass) was used to extract R waves and to generate HRV signals, and a mathematical model was created to predict the pain score for each patient.

RESULTS

In multivariable analysis, we looked into correlation between reported patient's pain score (rPPS) and Aberdeen Varicose Vein Questionnaire score, preoperative forms Y-1 and Y-2, preoperative anxiety level, and predicted patient's pain (pPPS) score. Multivariable analysis found association only between rPPS and pPPS. The pPPS was significantly correlated with rPPS (R = 0.807; P < .001) with accuracy of prediction of 65.2%, which was calculated from R² on a linear regression model.

CONCLUSIONS

This preliminary study shows that preoperative HRV can accurately predict patients' pain, allowing patients with higher predicted score to have the procedure under general anesthesia.

Association between premature ovarian insufficiency, early menopause, socioeconomic status in a nationally representative sample from Korea

OBJECTIVE

We investigated whether, in the Korean population, the risk of premature ovarian insufficiency (POI) and early menopause varies with a woman's socioeconomic status, evaluated in relation to income, education, and occupation.

METHODS

This cross-sectional, population-based study involved 31,508 women aged >19 years registered in the Korea National Health and Nutrition Examination Survey (KNHANES) (2007-2016). Menopausal status and socioeconomic status were obtained from self-reported KNHANES data. A logistic regression model was applied to test whether POI and early menopause varied with socioeconomic status.

RESULTS

The prevalence of POI was 2.41% and of early menopause was 5.89%. The annual incidence of POI during the investigation period plateaued, while that of early menopause showed a linear trend. The risk of POI was significantly higher among participants with lower household incomes (odds ratio [OR], 95% confidence interval [CI]; 1.44, 1.16-1.78) and lower levels of education (OR, 95% CI: 1.75, 1.16-2.65) after adjustment for age.

CONCLUSION

The prevalence of POI in the Korean population was almost twice that reported in a previous study. Lower socioeconomic status was associated with an increased risk of POI and early menopause. Further studies are warranted to investigate this association.

Dietary intake and age at natural menopause: results from the UK Women's Cohort Study

BACKGROUND

Age at natural menopause is a matter of concern for women of reproductive age as both an early or late menopause may have implications for health outcomes.

METHODS

Study participants were women aged 40-65 years who had experienced a natural menopause from the UK Women's Cohort Study between baseline and first follow-up. Natural menopause was defined as the permanent cessation of menstrual periods for at least 12 consecutive months. A food frequency questionnaire was used to estimate diet at baseline. Reproductive history of participants was also recorded. Regression modelling, adjusting for confounders, was used to assess associations between diet and age at natural menopause.

RESULTS

During the 4-year follow-up period, 914 women experienced a natural menopause. A high intake of oily fish and fresh legumes were associated with delayed onset of natural menopause by 3.3 years per portion/day (99% CI 0.8 to 5.8) and 0.9 years per portion/day (99% CI 0.0 to 1.8), respectively. Refined pasta and rice was associated with earlier menopause (per portion/day: -1.5 years, 99% CI -2.8 to -0.2). A higher intake of vitamin B6 (per mg/day: 0.6 years, 99% CI 0.1 to 1.2) and zinc (per mg/day: 0.3 years, 99% CI -0.0 to 0.6) was also associated with later age at menopause. Stratification by age at baseline led to attenuated results.

CONCLUSION

Our results suggest that some food groups (oily fish, fresh legumes, refined pasta and rice) and specific nutrients are individually predictive of age at natural menopause.

Tibial Fracture Nonunion and Time to Healing After Reamed Intramedullary Nailing: Risk Factors Based on a Single-Center Review of 1003 Patients

OBJECTIVE

To determine factors associated with nonunion of adult tibial fractures.

DESIGN

Retrospective review with data collection for logistic regression and survival analysis.

SETTING

Scottish Level I trauma center, 1985-2007.

PATIENTS

During this period, 1590 adult tibial fractures were treated by reamed nailing and 1003 fractures met all inclusion criteria for the chosen analysis.

INTERVENTION

Reamed intramedullary nailing.

MAIN OUTCOME MEASURES

Record of nonunion diagnosis and final union time with characteristics, including age, gender, closed or open injury, OTA/AO classification, Gustilo classification, fasciotomy, infection, polytrauma, smoking, and injury severity score.

RESULTS

The overall nonunion rate was 12%, and median time to healing was 18 weeks. Age significantly influenced nonunion, with middle-aged patients at highest risk. Both fracture type (closed/open) and morphology (OTA/AO classification) significantly influenced nonunion risk and time to union. Among closed injuries, the highest nonunion rate was for OTA/AO type B fractures (15%). Among open injuries, the highest nonunion rate was for OTA/AO type C (61%). Both compartment syndrome and smoking did not significantly influence nonunion risk but did significantly extend time to union.

CONCLUSIONS

Injury characteristics including fracture morphology and severity of soft tissue injury were strong predictors of compromised fracture healing. Age also influenced nonunion risk in an unexpected way, with highest rates in the middle decades of adulthood. Future studies should consider the possibility of similar age-related effects and clinical studies should seek to identify explanations for why this may arise, including both physiological and socio-behavioral factors.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Endometrioma-related reduction in ovarian reserve (ERROR): a prospective longitudinal study

OBJECTIVE

To evaluate whether endometrioma is associated with a progressive decline in ovarian reserve, and to compare the rate of decline with natural decline in ovarian reserve.

DESIGN

Prospective, observational study.

SETTING

Tertiary university hospital, endometriosis clinic.

PATIENT(S)

Forty women with endometrioma and 40 age-matched healthy controls.

INTERVENTION(S)

Women with endometriomas who did not need hormonal/surgical treatment at the time of recruitment and were expectantly managed. Controls were age-matched, healthy women. All participants underwent serum antimüllerian hormone (AMH) testing twice, 6 months apart. Sexually active patients with endometrioma also underwent antral follicle count.

MAIN OUTCOME MEASURE(S)

Change in serum AMH levels.

RESULT(S)

Median (25th-75th percentile) serum AMH level at recruitment was 2.83 (0.70-4.96) ng/mL in the endometrioma group and 4.42 (2.26-5.57) ng/mL in the control group. The median percent decline in serum AMH level was 26.4% (11.36%-55.41%) in the endometrioma group and 7.4% (-11.98%, 29.33%) in the control groups. Twenty-two women with endometrioma who had antral follicle count (AFC) had median AFC of 10 (8-12) at recruitment and 8 (6.3-10) at 6 months.

CONCLUSION(S)

Women with endometrioma experience a progressive decline in serum AMH levels, which is faster than that in healthy women.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02438735.

Age at natural menopause and associated factors in adult women: Findings from the China Kadoorie Biobank study in Zhejiang rural area

Objectives

To investigate the factors associated with age at natural menopause in a large population of Chinese adult women.

Methods

This cross-sectional study was part of the baseline survey of China Kadoorie Biobank in Zhejiang Province. A total of 17,076 postmenopausal women were included in the present study. Relevant data of socio-demographic, lifestyle, dietary and reproductive characteristics were collected. Multinomial logistic regression models were used to examine the associated factors of age at natural menopause with adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were reported.

Results

The mean age at natural menopause was 48.94 years, with 3.40% of the women experienced premature menopause and 6.75% early menopause. Younger age, higher education, consumption of meat (1–3 days per week) and increased parity were associated with late menopause. Current smoking, underweight, higher physical activity, consumption of sea food (1–3 days per week), fresh eggs (≥4 days per week), fresh fruits (≥1 day per week), taking vitamins, experiencing severe food shortage, earlier age at menarche and older age at first birth were associated with earlier age at natural menopause.

Conclusions

These results suggest that certain factors involved with socio-demographic, lifestyle, dietary and reproductive characteristics are related to the age at natural menopause in Chinese women.

Cigarette Smoking and Risk of Early Natural Menopause

Menopause before 45 years of age affects roughly 5%-10% of women and is associated with a higher risk of adverse health conditions. Although smoking may increase the risk of early menopause, evidence is inconsistent, and data regarding smoking amount, duration, cessation, associated risks, and patterns over time are scant. We analyzed data of 116,429 nurses from the Nurses' Health Study II from 1989 through 2011 and used Cox proportional hazards models to estimate hazard ratios adjusted for confounders. Compared with never-smokers, current smokers (hazard ratio (HR) = 1.90, 95% confidence interval (CI): 1.71, 2.11) and former smokers (HR = 1.10, 95% CI: 1.00, 1.21) showed an increased risk of early menopause. Increased risks were observed among women who reported current smoking for 11-15 pack-years (HR = 1.72, 95% CI: 1.36, 2.18), 16-20 pack-years (HR = 1.72, 95% CI: 1.38, 2.14), and more than 20 pack-years (HR = 2.42, 95% CI: 2.11, 2.77). Elevated risk was observed in former smokers who reported 11-15 pack-years (HR = 1.29, 95% CI: 1.07, 1.55), 16-20 pack-years (HR = 1.42, 95% CI: 1.13, 1.79), or more than 20 pack-years (HR = 1.54, 95% CI: 1.23, 1.93). Women who smoked 10 or fewer cigarettes/day but quit by age 25 had comparable risk to never-smokers (HR = 1.03, 95% CI: 0.91, 1.17). A dose-response relationship between smoking and early natural menopause risk, as well as reduced risk among quitters, may provide insights into the mechanisms of cigarette smoking in reproductive health.

A combined connectivity mapping and pharmacoepidemiology approach to identify existing medications with breast cancer causing or preventing properties

PURPOSE

We applied a novel combined connectivity mapping and pharmacoepidemiological approach to identify medications that alter breast cancer risk.

METHODS

The connectivity mapping process identified 6 potentially cancer-causing (meloxicam, azithromycin, rizatriptan, citalopram, rosiglitazone, and verapamil) and 4 potentially cancer-preventing (bendroflumethiazide, sertraline, fluvastatin, and budesonide) medications that were suitable for pharmacoepidemiological investigation. Within the UK Clinical Practice Research Datalink, we matched 45,147 breast cancer cases to 45,147 controls based on age, year, and general practice. Medication use was determined from electronic prescribing records. We used conditional logistic regression to calculate odds ratios (ORs) for the association between medication use and cancer risk after adjustment for comorbidities, lifestyle factors, deprivation, and other medication use.

RESULTS

Bendroflumethiazide was associated with increased breast cancer risk (OR: 1.11; 95% CI: 1.06, 1.15); however the connectivity mapping exercise predicted that this medication would reduce risk. There were no statistically significant associations for any of the other candidate medications, with ever use ORs ranging from 0.93 (95% CI: 0.78, 1.11) for azithromycin to 1.16 (95% CI: 0.99, 1.37) for verapamil.

CONCLUSIONS

In this instance, our combined connectivity mapping and pharmacoepidemiological approach did not identify any additional medications that were substantially associated with breast cancer risk. This could be due to limitations in the connectivity mapping, such as implausible dosage requirements, or the pharmacoepidemiology, such as residual confounding.

Pain Prediction From ECG in Vascular Surgery

Varicose vein surgeries are routine outpatient procedures, which are often performed under local anaesthesia. The use of local anaesthesia both minimises the risk to patients and is cost effective, however, a number of patients still experience pain during surgery. Surgical teams must therefore decide to administer either a general or local anaesthetic based on their subjective qualitative assessment of patient anxiety and sensitivity to pain, without any means to objectively validate their decision. To this end, we develop a 3-D polynomial surface fit, of physiological metrics and numerical pain ratings from patients, in order to model the link between the modulation of cardiovascular responses and pain in varicose vein surgeries. Spectral and structural complexity features found in heart rate variability signals, recorded immediately prior to 17 varicose vein surgeries, are used as pain metrics. The so obtained pain prediction model is validated through a leave-one-out validation, and achieved a Kappa coefficient of 0.72 (substantial agreement) and an area below a receiver operating characteristic curve of 0.97 (almost perfect accuracy). This proof-of-concept study conclusively demonstrates the feasibility of the accurate classification of pain sensitivity, and introduces a mathematical model to aid clinicians in the objective administration of the safest and most cost-effective anaesthetic to individual patients.

Hormone replacement therapy in pre-menopausal women undergoing bilateral salpingo-oophorectomy for benign disease: A review of practice

Introduction The National Institute for Health and Care Excellence (NICE) guideline on the diagnosis and management of the menopause states that women who are likely to go through the menopause as a result of surgical treatment should be offered information about the menopause and the importance of starting hormonal replacement therapy before they have their treatment. Objectives To determine compliance with NICE guidelines at the Royal Derby Hospital. Study design We undertook a retrospective review of all pre-menopausal women undergoing bilateral salpingo-oophorectomy for benign pathology between 1 January 2016 and 30 June 2016. Results Thirty-six cases were reviewed. Women were aged between 32.5 and 49.8 years old (median 45.13, inter-quartile range 42.6-47.6). The commonest indications for bilateral salpingo-oophorectomy were dysfunctional uterine bleeding (36.1%), chronic pelvic pain (30.5%), complex cyst (13.9%), and pre-menstrual syndrome (13.9%). Fifteen women (41.7%) did not have hormonal replacement therapy discussed. Only two (5.6%) had hormonal replacement therapy discussed pre-operatively. The remaining 19 had hormonal replacement therapy discussed post-operatively, either on the ward prior to discharge (n = 3) or, more commonly, in clinic six to eight weeks later. Although hormonal replacement therapy was only contraindicated in one woman (3%), it was only prescribed to five (24%). Results were slightly better for women under 40 but still only 28.6% had hormonal replacement therapy discussed with them pre-operatively. Conclusion This audit has demonstrated that compliance with the NICE guidelines is poor. We suspect similar results might be found in other gynaecology departments nationally. A hospital guideline to aid clinicians and a patient information sheet to educate women has been devised. A re-audit is planned six months after ratification of these documents.

Association of alcohol consumption with the onset of natural menopause: a systematic review and meta-analysis

BACKGROUND

Early onset of menopause is associated with long-term health risks, including cardiovascular disease and premature death. Although alcohol intake has been suggested to affect the age at which natural menopause occurs, results from observational studies are not consistent.

OBJECTIVE AND RATIONALE

In the view of the differing risks to the health of early menopause and the increasing trends in alcohol consumption in women, in this systematic review, we aimed to quantify the association between all levels of alcohol consumption and menopause onset.

SEARCH METHODS

Six electronic databases (Medline, Embase, Cochrane, PubMed, Google Scholar and Web of Science) were systematically searched until 4 November 2015 to identify relevant studies assessing the association between alcohol consumption and onset of menopause. Two independent reviewers screened the titles and abstracts of all initially identified studies according to the selection criteria. Studies were sought if they (i) were observational cross-sectional, prospective and interventional studies, (ii) had reported on natural onset of menopause, (iii) had reported on alcohol consumption, (iv) had assessed the association between alcohol consumption and menopause onset, (v) were conducted in humans and (vi) were not conducted in patients with cancer. Data were extracted by two independent reviewers using a predesigned data-collection form. The primary exposure variable was the presence of active alcohol drinking at baseline compared with a reference group of non-drinkers. Pooled relative risks (RRs) were calculated.

OUTCOMES

Of the 1193 references (all in English language) reviewed for eligibility, 22 articles based on 20 unique studies were included in the final analysis. A total of 41 339 and 63 868 non-overlapping women were included in the meta-analysis of cross-sectional and observational cohort studies, respectively. In cross-sectional studies, the pooled RR for earlier onset of menopause was 0.86 (95% confidence interval (CI): 0.78-0.96) between drinkers versus non-drinkers. Analysis of the levels of alcohol consumed showed that low and moderate alcohol consumption (more than one drink per week (RR = 0.60; 95% CI: 0.49-0.75) and three or fewer drinks per week (RR = 0.75; 95% CI: 0.60-0.94)) were associated with later menopause onset, compared to non-drinkers. In prospective studies, RR for earlier menopause onset was 0.95 (95% CI: 0.91-0.98) when comparing women who reported drinking alcohol versus women who did not. Analysis of the dose of alcohol consumed showed that low-to-moderate alcohol intake (0-8 g/day (RR = 0.95; 95% CI: 0.93-0.98), and 16 g/day (RR = 0.89, 95%CI: 0.86-0.92)) was associated with later menopause onset, compared to non-drinking.

WIDER IMPLICATIONS

The findings of this review indicate that alcohol consumption, particularly low and moderate alcohol intake, might be associated with later onset of menopause although the magnitude of the association is low. Further studies are needed to corroborate these findings, clarify the level of alcohol intake at which menopause is delayed and identify the potential mechanisms behind this association.

Genetic evidence that lower circulating FSH levels lengthen menstrual cycle, increase age at menopause and impact female reproductive health

STUDY QUESTION

How does a genetic variant in the FSHB promoter, known to alter FSH levels, impact female reproductive health?

SUMMARY ANSWER

The T allele of the FSHB promoter polymorphism (rs10835638; c.-211G>T) results in longer menstrual cycles and later menopause and, while having detrimental effects on fertility, is protective against endometriosis.

WHAT IS KNOWN ALREADY

The FSHB promoter polymorphism (rs10835638; c.-211G>T) affects levels of FSHB transcription and, as a result, circulating levels of FSH. FSH is required for normal fertility and genetic variants at the FSHB locus are associated with age at menopause and polycystic ovary syndrome (PCOS).

STUDY DESIGN, SIZE, DURATION

We used cross-sectional data from the UK Biobank to look at associations between the FSHB promoter polymorphism and reproductive traits, and performed a genome-wide association study (GWAS) for length of menstrual cycle.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included white British individuals aged 40-69 years in 2006-2010, in the May 2015 release of genetic data from UK Biobank. We tested the FSH-lowering T allele of the FSHB promoter polymorphism (rs10835638; c.-211G>T) for associations with 29, mainly female, reproductive phenotypes in up to 63 350 women and 56 608 men. We conducted a GWAS in 9534 individuals to identify genetic variants associated with length of menstrual cycle.

MAIN RESULTS AND THE ROLE OF CHANCE

The FSH-lowering T allele of the FSHB promoter polymorphism (rs10835638; MAF 0.16) was associated with longer menstrual cycles [0.16 SD (c. 1 day) per minor allele; 95% confidence interval (CI) 0.12-0.20; P = 6 × 10(-16)], later age at menopause (0.13 years per minor allele; 95% CI 0.04-0.22; P = 5.7 × 10(-3)), greater female nulliparity [odds ratio (OR) = 1.06; 95% CI 1.02-1.11; P = 4.8 × 10(-3)] and lower risk of endometriosis (OR = 0.79; 95% CI 0.69-0.90; P = 4.1 × 10(-4)). The FSH-lowering T allele was not associated with other female reproductive illnesses or conditions in our study and we did not replicate associations with male infertility or PCOS. In the GWAS for menstrual cycle length, only variants near the FSHB gene reached genome-wide significance (P < 5 × 10(-9)).

LIMITATIONS, REASONS FOR CAUTION

The data included might be affected by recall bias. Cycle length was not available for 25% of women still cycling (1% did not answer, 6% did not know and for 18% cycle length was recorded as 'irregular'). Women with a cycle length recorded were aged over 40 and were approaching menopause; however, we did not find evidence that this affected the results. Many of the groups with illnesses had relatively small sample sizes and so the study may have been under-powered to detect an effect.

WIDER IMPLICATIONS OF THE FINDINGS

We found a strong novel association between a genetic variant that lowers FSH levels and longer menstrual cycles, at a locus previously robustly associated with age at menopause. The variant was also associated with nulliparity and endometriosis risk. These findings should now be verified in a second independent group of patients. We conclude that lifetime differences in circulating levels of FSH between individuals can influence menstrual cycle length and a range of reproductive outcomes, including menopause timing, infertility, endometriosis and PCOS.

STUDY FUNDING/COMPETING INTERESTS

None.

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.

Sulfur dioxide exposure and other factors affecting age at natural menopause in the Jinchuan cohort

OBJECTIVE

To describe the associations between occupational exposures and age at natural menopause in the Jinchuan cohort.

METHODS

The Jinchuan cohort consists of all current or retired workers of the Jinchuan Nonferrous Metals Corporation (JNMC) in Jinchang, Gansu, China. Our final study population consisted of 3167 postmenopausal women. The data used for this study were derived from the epidemiological survey and were self-reported. Age at natural menopause (ANM) was defined as the age at the last period prior to 12 months of amenorrhea in women who experienced natural menopause. ANM was related to five commonly reported occupational exposures using bivariate and multivariate Cox proportional hazards regressions.

RESULTS

Blue-collar workers have significantly earlier mean ANM (49.0 years) than white-collar workers (49.5 years). Sulfur dioxide exposure was found to be associated with earlier mean ANM in blue-collar workers. After stratifying both blue-collar workers and white-collar workers further by exposure time for each of the exposures, blue-collar workers exposed to sulfur dioxide for 21-25 years had the earliest mean ANM (47.8 years) of any level of any exposure in this study.

CONCLUSION

This paper is significant because it is the first report of an association between sulfur dioxide and menopause, and one of few papers to look at the determinants of ANM in an occupational cohort. Blue-collar workers had earlier mean ANM than white-collar workers. Blue-collar workers are more exposed to sulfur dioxide and other occupational exposures than white-collar workers, and blue-collar workers who are more exposed to sulfur dioxide have earlier menopause. Sulfur dioxide may be part of the reason that blue-collar workers experience earlier menopause than white-collar workers.

Healthy lifestyle and risk of breast cancer for indigenous and non-indigenous women in New Zealand: a case control study

BACKGROUND

The reasons for the increasing breast cancer incidence in indigenous Māori compared to non-Māori New Zealand women are unknown. The aim of this study was to assess the association of an index of combined healthy lifestyle behaviours with the risk of breast cancer in Māori and non-Māori women.

METHODS

A population-based case-control study was conducted, including breast cancer cases registered in New Zealand from 2005-2007. Controls were matched by ethnicity and 5-year age bands. A healthy lifestyle index score (HLIS) was generated for 1093 cases and 2118 controls, based on public health and cancer prevention recommendations. The HLIS was constructed from eleven factors (limiting red meat, cream, and cheese; consuming more white meat, fish, fruit and vegetables; lower alcohol consumption; not smoking; higher exercise levels; lower body mass index; and longer cumulative duration of breastfeeding). Equal weight was given to each factor. Logistic regression was used to estimate the associations between breast cancer and the HLIS for each ethnic group stratified by menopausal status.

RESULTS

Among Māori, the mean HLIS was 5.00 (range 1-9); among non-Māori the mean was 5.43 (range 1.5-10.5). There was little evidence of an association between the HLIS and breast cancer for non-Māori women. Among postmenopausal Māori, those in the top HLIS tertile had a significantly lower odds of breast cancer (Odds Ratio 0.47, 95% confidence interval 0.23-0.94) compared to those in the bottom tertile.

CONCLUSION

These findings suggest that healthy lifestyle recommendations could be important for reducing breast cancer risk in postmenopausal Māori women.

Tubal ligation in relation to menopausal symptoms and breast cancer risk

Background:

Local inflammation after tubal ligation may affect ovarian function and breast cancer risk.

Methods:

We analysed tubal ligation, menopausal characteristics, and breast cancer risk in the Sister Study cohort (N=50 884 women).

Results:

Tubal ligation was associated with hot flashes (hazard ratio (HR) 1.09; 95% confidence interval (CI): 1.06–1.12) but not menopausal age (HR 0.99; 95% CI: 0.96–1.02). Tubal ligation did not have an impact on breast cancer overall (HR 0.95; 95% CI: 0.85–1.06), but had a suggested inverse relation with oestrogen receptor+/progesterone receptor+ invasive tumours (HR 0.84; 95% CI: 0.70–1.01), possibly because of subsequent hysterectomy/bilateral oophorectomy.

Conclusion:

Tubal ligation does not influence overall breast cancer risk.