Premenopausal factors influencing premature ovarian failure and early menopause

Exposure to Polycyclic Aromatic Hydrocarbons and adverse reproductive outcomes in women: current status and future perspectives

OBJECTIVES

Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous, toxic environmental chemicals that can cause adverse reproductive health effects. The objectives of this mini-review are to highlight the adverse reproductive outcomes due to PAH exposure with the main focus on polycystic ovary syndrome (PCOS) and premature ovarian failure (POF) and to provide perspectives on future research needs.

CONTENT

We reviewed studies that have reported the adverse reproductive outcomes associated with PAHs exposures in women through a comprehensive search of bibliographic databases and gray literature sources. In addition, potentially modifiable sources of exposure to PAHs and associated reproductive outcomes were also investigated.

SUMMARY

A total of 232 papers were retrieved through a comprehensive search of bibliographic databases, out of which three studies met the eligibility criteria and were included in the review. Results showed that exposure to PAHs is associated with adverse reproductive outcomes defined as PCOS, POF, and reproductive hormone imbalance. Sources of PAH exposure associated with adverse reproductive outcomes include active and passive tobacco smoking, specific cooking methods, and pesticides.

OUTLOOK

Future studies are warranted to examine the mechanisms by which PAHs result in adverse reproductive endpoints in women. Further, environmental exposures that are potentially modifiable such as exposure to tobacco smoke, may contribute to PAH exposure, and these exposures should be targeted in future policies and interventions.

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.

Exploring the triggers of premature and early menopause in India: a comprehensive analysis based on National Family Health Survey, 2019-2021

Due to ovarian insufficiency, some women attain menopause at an early age due to lifestyle factors and hormonal imbalances. Menopause occurring before the age of 40 is premature and between 40 and 44 years age is early, since the natural age of menopause lies between 45 and 50. The study estimated the prevalence of both premature and early menopause, and examined the potential associated factors that could trigger its occurrence in India. The National Family Health Survey, conducted during 2019-2021, was used to fulfil the study objective. The study sample was divided into two parts, with age group 15-39 and 40-44 for estimating premature and early menopause, respectively. Cox-proportional hazard model was used for the multivariate analysis. The estimated prevalence of premature menopause is 2.2% and early menopause is 16.2%. Lower educational level, poor economic condition, smoking, fried food consumption, early age at menarche are some of the significant explanatory factors. In India, both the proportion and the absolute number of post-menopausal women are growing, therefore it is critical to revamp public reproductive healthcare facilities to include menopausal health segment in women's health as well. Future detailed micro-studies would help in better understanding of the premature or early menopausal cases.

Premature ovarian insufficiency: a review on the role of tobacco smoke, its clinical harm, and treatment

Premature ovarian insufficiency (POI) is a condition in which the quantity of follicles and the quality of oocytes gradually decrease. This results in an estrogen secretion disorder and abnormal follicle development, which can lead to related diseases, early onset of menopause, sexual dysfunction, and an increased risk of cardiovascular issues, osteoporosis, and depression, among others. This disease significantly impacts the physical and mental health and overall quality of life of affected women. Factors such as genetic abnormalities, oophorectomy, radiotherapy for malignancy, idiopathic conditions, and an unhealthy lifestyle, including smoking, can accelerate the depletion of the follicular pool and the onset of menopause. Extensive research has been conducted on the detrimental effects of tobacco smoke on the ovaries. This article aims to review the advancements in understanding the impact of tobacco smoke on POI, both in vivo and in vitro. Furthermore, we explore the potential adverse effects of common toxicants found in tobacco smoke, such as polycyclic aromatic hydrocarbons (PAHs), heavy metals like cadmium, alkaloids like nicotine and its major metabolite cotinine, benzo[a]pyrene, and aromatic amines. In addition to discussing the toxicants, this article also reviews the complications associated with POI and the current state of research and application of treatment methods. These findings will contribute to the development of more precise treatments for POI, offering theoretical support for enhancing the long-term quality of life for women affected by this condition.

The dose-response relationship of pre-menopausal alcohol consumption with age at menopause: a population study of 280 497 women in Norway

BACKGROUND

Previous research suggests that alcohol consumption is associated with high age at menopause. Yet, knowledge about the dose-response relationship is inconsistent. Thus, we studied the pattern of the association of pre-menopausal alcohol consumption with age at natural menopause.

METHODS

We performed a retrospective population-based study using self-reported data from 280 497 women aged 50-69 years attending the Norwegian breast cancer screening programme (BreastScreen Norway) during 2006-15. Associations of weekly alcohol consumption between the age of 20 and 49 years with age at menopause were estimated as hazard ratios (HRs) using Cox proportional hazard models with restricted cubic splines to allow for non-linear associations. We adjusted for year and place of birth, number of childbirths, educational level, body mass index and smoking habits.

RESULTS

Mean age at natural menopause was 51.20 years (interquartile range: 49-54 years). The adjusted HR of reaching menopause was highest for women with no alcohol consumption (reference) and the HR decreased by alcohol consumption up to 50 grams per week (adjusted HR 0.87; 95% CI: 0.86-0.88). Above 50 grams, there was no further decrease in the HR of reaching menopause (P for non-linearity of <0.001).

CONCLUSIONS

Women who did not consume alcohol were youngest at menopause. The lack of a dose-response association among alcohol consumers implies virtually no relation of alcohol consumption with age at menopause. Our findings may suggest that characteristics of the women who did not consume alcohol, not accounted for in the data analyses, explain their younger age at menopause.

Is there a link between infertility, miscarriage, stillbirth, and premature or early menopause? Results from pooled analyses of 9 cohort studies

BACKGROUND

Some reproductive factors (such as age at menarche and parity) have been shown to be associated with age at natural menopause, but there has been little quantitative analysis of the association between infertility, miscarriage, stillbirth, and premature (<40 years) or early menopause (40-44 years). In addition, it has been unknown whether the association differs between Asian and non-Asian women, although the age at natural menopause is younger among Asian women.

OBJECTIVE

This study aimed to investigate the association of infertility, miscarriage, and stillbirth with age at natural menopause, and whether the association differed by race (Asian and non-Asian).

STUDY DESIGN

This was a pooled individual participant data analysis from 9 observational studies contributing to the InterLACE consortium. Naturally postmenopausal women with data on at least 1 of the reproductive factors (ie, infertility, miscarriage, and stillbirth), age at menopause, and confounders (ie, race, education level, age at menarche, body mass index, and smoking status) were included. A multinomial logistic regression model was used to estimate relative risk ratios and 95% confidence intervals for the association of infertility, miscarriage, and stillbirth with premature or early menopause, adjusting for confounders. Between-study difference and within-study correlation were taken into account by including study as a fixed effect and indicating study as a cluster variable. We also examined the association with number of miscarriages (0, 1, 2, ≥3) and stillbirths (0, 1, ≥2), and tested whether the strength of association differed between Asian and non-Asian women.

RESULTS

A total of 303,594 postmenopausal women were included. Their median age at natural menopause was 50.0 years (interquartile range, 47.0-52.0). The percentages of women with premature and early menopause were 2.1% and 8.4%, respectively. The relative risk ratios (95% confidence intervals) of premature and early menopause were 2.72 (1.77-4.17) and 1.42 (1.15-1.74) for women with infertility; 1.31 (1.08-1.59) and 1.37 (1.14-1.65) for women with recurrent miscarriages; and 1.54 (1.52-1.56) and 1.39 (1.35-1.43) for women with recurrent stillbirths. Asian women with infertility, recurrent miscarriages (≥3), or recurrent stillbirths (≥2) had higher risk of premature and early menopause compared with non-Asian women with the same reproductive history.

CONCLUSION

Histories of infertility and recurrent miscarriages and stillbirths were associated with higher risk of premature and early menopause, and the associations differed by race, with stronger associations for Asian women with such reproductive history.

Single-nucleus RNA Sequencing reveals the mechanism of cigarette smoke exposure on diminished ovarian reserve in mice

The systematic toxicological mechanism of cigarette smoke (CS) on ovarian reserve has not been extensively investigated. Female 8-week-old C57BL/6 mice at peak fertility were exposed to CS or indoor air only for 30 days (100 mice per group) and the effects of CS on ovarian reserve were assessed using Single-Nucleus RNA Sequencing (snRNA-seq). In addition, further biochemical experiments, including immunohistochemical staining, ELISA, immunofluorescence staining, transmission electron microscopy, cell counting kit-8 assay, flow cytometry analysis, senescence-associated β-galactosidase staining, and western blotting, were accomplished to confirm the snRNA-seq results. We identified nine main cell types in adult ovaries and the cell-type-specific differentially expressed genes (DEGs) induced by CS exposure. Western blot results verified that down-regulation of antioxidant genes (Gpx1 and Wnt10b) and the steroid biosynthesis gene (Fdx1) occurred in both ovarian tissue and human granulosa cell-like tumor cell line (KGN cells) after CS exposure. Five percent cigarette smoke extract (CSE) effectively stimulated the production of reactive oxygen species (ROS), DNA damage, cellular senescence and markedly inhibited KGN cell proliferation by inducing G1-phase cell cycle arrest. Moreover, down-regulation of Gja1, Lama1 and the Ferroptosis indicator (Gpx4) in granulosa cells plays a significant role in ultrastructural changes in the ovary induced by CS exposure. These observations suggest that CS exposure impaired ovarian follicle reserve might be caused by REDOX imbalance in granulosa cells. The current study systematically determined the damage caused by CS in mouse ovaries and provides a theoretical basis for early clinical prediction, diagnosis and intervention of CS exposure-associated primary ovarian insufficiency (POI), and is of great significance in improving female reproductive health.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Association of lifetime lactation and age at natural menopause: a prospective cohort study

OBJECTIVE

The aim of this study was to examine the association between duration of lifetime lactation and age at natural menopause.

METHODS

In this prospective cohort study, we analyzed parous premenopausal women in the multiethnic Study of Women's Health Across the Nation who were followed approximately annually for 10 years (1995-2008). Lifetime lactation was defined as the duration of breastfeeding across all births in months. Age at natural menopause was defined as age in years after 12 consecutive months of amenorrhea after the final menstrual period for no other reported cause. We used Cox proportional hazard models to analyze time to natural menopause with age as the underlying time scale. Multivariable models controlled for education, race/ethnicity, parity, smoking, body mass index, and oral contraceptive use.

RESULTS

Among 2,377 women, 52.6% experienced natural menopause during follow-up and reported a valid final menstrual period date. The small, crude association between lifetime lactation up to 24 months and later age at natural menopause attenuated to nonsignificance in adjusted models (6 months: adjusted hazard ratio [AHR], 0.96; 95% confidence interval (CI), 0.87-1.06; 12 months: AHR, 0.95; 95% CI, 0.82-1.11; 18 months: AHR, 0.96; 95% CI, 0.82-1.13; 24 months: AHR, 0.99; 95% CI, 0.84-1.16).

CONCLUSIONS

Duration of lifetime lactation was not associated with age at natural menopause after controlling for sociodemographic characteristics.

Does the Value of FSH Predict Severity of Metabolic Complications in Females with POI?

Premature ovarian insufficiency (POI) is defined as a cessation of ovarian function before the age of 40. Such early deprivation of estrogens in women may be associated with several adverse cardiovascular and metabolic consequences. The aim of this retrospective study was to investigate whether women with POI and a serum follicle-stimulating hormone (FSH) level of 25−40 I/U (Group A) have the same metabolic profile as women with POI and a serum FSH level of >40 I/U (Group B). One hundred twenty-three women were included in the study group (Group A; n = 41; Group B; n = 82). The control group comprised 77 healthy women with regular menstruation. In the age- and BMI-adjusted model, no differences were found between the groups with respect to total cholesterol, high-density lipoproteins, triglycerides, HOMA-IR, glucose, and insulin. The only significant difference was found in terms of low-density lipoprotein cholesterol (LDL-C). The highest serum concentration was found in Group B, the second highest was found in Group A, and the lowest was in the controls. In conclusion, changing the threshold of FSH required to establish a POI diagnosis may have an impact on the level of serum LDL-C.

miRNA-122-5p in POI ovarian-derived exosomes promotes granulosa cell apoptosis by regulating BCL9

This study is to explore the therapeutic effect and potential mechanisms of exosomal microRNAs (miRNAs) derived from the ovaries with primary ovarian insufficiency (POI). The POI mouse model was established by intraperitoneal injection of cyclophosphamide (CTX) and busulfan. The apoptosis of granulosa cells (GCs) incubated with exosomes extracted from ovarian tissues of control and POI groups was analyzed by flow cytometry. Then, high-throughput sequencing was performed to detect the difference of miRNAs profile in ovarian tissue-derived exosomes between the control and POI mice. The effect of differential miRNA on the apoptosis of CTX-induced ovarian GCs was analyzed by flow cytometry. The results showed that POI mouse model was successfully established. Exosomes extracted from ovarian of normal and POI group have different effects on apoptosis of GCs induced by CTX. miRNA-seq found that exosomal miR-122-5p in POI group increased significantly. miR-122-5p as the dominant miRNA targeting BCL9 was significantly upregulated in ovarian tissues of chemotherapy-induced POI group. Exosomes derived from the ovaries in the control group and miR-122-5p inhibitor group attenuated the apoptosis of primary cultured ovarian GCs. In conclusion, exosomal miR-122-5p promoted the apoptosis of ovarian GCs by targeting BCL9, suggested that miR-122-5p may function as a potential target to restore ovarian function.

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.

Is Alcohol Consumption Associated With Risk of Early Menopause?

Earlier age at menopause is associated with increased long-term health risks. Moderate alcohol intake has been suggested to delay menopause onset, but it is unknown whether alcohol subtypes are associated with early menopause onset at age 45 years. Therefore, we aimed to evaluate risk of early natural menopause among 107,817 members of the Nurses' Health Study II who were followed from 1989 to 2011. Alcohol consumption overall and by subtypes, including beer, red wine, white wine, and liquor, was assessed throughout follow-up. We estimated hazard ratios in multivariable models that were adjusted for age, body mass index, parity, smoking, and other potential confounders. Women who reported moderate current alcohol consumption had lower risks of early menopause than did nondrinkers. Those who reported consuming 10.0-14.9 g/day had a lower risk of early menopause than did nondrinkers (hazard ratio = 0.81, 95% confidence interval: 0.68, 0.97). Among specific beverages, evidence of lower early menopause risk was confined to consumption of white wine and potentially red wine and liquor, but not to beer. Data from this large prospective study suggest a weak association of moderate alcohol intake with lower risk of early menopause, which was most pronounced for consumption of white and red wine and liquor. High consumption was not related to lower risk of early menopause.

Factors related to age at natural menopause in China: results from the China Kadoorie Biobank

OBJECTIVES

The aim of this study was to investigate the potentially modifiable factors affecting age at natural menopause (ANM) in Chinese women.

METHODS

We used cross-sectional data from the China Kadoorie Biobank study which that recruited 0.5 million (0.3 million women) Chinese adults aged 30 to 79 from 2004 to 2008. Multinomial logistic regression models were used to examine the relationships between ANM and various factors recorded at baseline.

RESULTS

Among 87,349 postmenopausal women, the mean ANM (SD) was 48.7 (4.3) years. Older age, being a housewife, earlier menarche, and passive smoking were associated with both premature menopause (PM, ie, ANM <40 years) and early menopause (EM, ie, ANM between 40 and 44 years). A higher odds for EM was observed in women who were widowed (odds ratio: 1.10, 95% confidence interval: 1.04-1.16), had spontaneous abortions (1.33 [1.05-1.69]), current regular smoking (1.19 [1.07-1.37]), and frequent spicy food intake (1.11 [1.05-1.08]). Higher socioeconomic status; later first birth; more live births and induced abortions; longer breastfeeding; tea drinking, as well as intakes of meat, fruits, dairy, and soybean products; and increased body mass index gain were inversely associated with PM and/or EM. In contrast, women who had more pregnancies, occasional alcohol drinking, higher levels of physical activity or body mass index, vitamin intake, and hypertension were more likely to have a later age at menopause (LM, ie, ANM ≥53 years).

CONCLUSIONS

This large epidemiological study found a wide range of sociodemographic, lifestyle, dietary, and reproductive factors related to PM, EM, and LM in Chinese women.

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.

Prevalence and Risk Factors of Premature Ovarian Insufficiency/Early Menopause

Premature ovarian insufficiency (POI) and early menopause, defined as loss of ovarian activity prior to 40 years or menopause between the ages of 40 and 45 years, respectively, is associated with significant adverse health impacts. Recent data indicate that the prevalence of POI and early menopause is greater than was previously thought, affecting more than 10% of women. Biopsychosocial risk factors including genetic, autoimmune, reproductive, lifestyle, early-life, social/environmental, and iatrogenic have been associated with POI/early menopause or earlier age at menopause. However, establishing a causal role and the underlying mechanisms remains elusive. Understanding and clarification of these risk factors will facilitate prevention and risk minimization strategies to optimize women's health.

The Effects of Negative Elements in Environment and Cancer on Female Reproductive System

With the development of human society, factors that contribute to the impairment of female fertility is accumulating. Lifestyle-related risk factors, occupational risk factors, and iatrogenic factors, including cancer and anti-cancer treatments, have been recognized with their negative effects on the function of female reproductive system. However, the exact influences and their possible mechanism have not been elucidated yet. It is impossible to accurately estimate the indexes of female fertility, but many researchers have put forward that the general fertility has inclined through the past decades. Thus the demand for fertility preservation has increased more and more dramatically. Here we described some of the factors which may influence female reproductive system and methods for fertility preservation in response to female infertility.

Prospective study of cigarette smoking and fecundability

STUDY QUESTION

To what extent is cigarette smoking associated with reduced fecundability?

SUMMARY ANSWER

Current female smokers, particularly those who had smoked ≥10 cigarettes/day for ≥10 years, had lower fecundability than never smokers, but current male smoking and passive smoking in either partner showed little association with reduced fecundability.

WHAT IS KNOWN ALREADY

Female smoking has been identified as a cause of infertility, yet there has been limited characterization of the dose and duration at which an effect is observed. Results for male active smoking and passive smoking in both partners are less consistent.

STUDY DESIGN, SIZE, DURATION

We analyzed data from a North American internet-based preconception cohort study of 5473 female and 1411 male pregnancy planners, enrolled from 2013 to 2018. Participants had been attempting conception for ≤6 menstrual cycles at study entry.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We collected information on active and passive smoking history on baseline questionnaires. Pregnancy was reported on female bi-monthly follow-up questionnaires. We calculated fecundability ratios (FR) and 95% CI using proportional probabilities regression models, adjusted for demographic, behavioral, medical, reproductive and dietary variables.

MAIN RESULTS AND THE ROLE OF CHANCE

Female current regular smoking (FR = 0.90, 95% CI: 0.77, 1.07), current occasional smoking (FR = 0.88, 95% CI: 0.73, 1.06), and former smoking (FR = 0.89, 95% CI: 0.81, 0.98) were associated with small reductions in fecundability. Results were stronger among women who smoked ≥10 cigarettes/day for ≥10 years (FR = 0.77, 95% CI: 0.53, 1.10). Male current regular and former smoking, and current passive smoking in either partner were not meaningfully associated with reduced fecundability. In utero exposure to ≥10 cigarettes/day among females was associated with reduced fecundability (FR = 0.75, 95% CI: 0.52, 1.06).

LIMITATIONS, REASONS FOR CAUTION

Numbers of cigarette smokers, particularly within categories of intensity and duration, were small. Under-reporting of smoking may have resulted in non-differential misclassification, and smokers were more likely to be lost to follow-up.

WIDER IMPLICATIONS OF THE FINDINGS

Given the consistency of our findings with results from previous studies and our observation of a dose-response relation in intensity of smoking, this study supports an association between female cigarette smoking and lower fecundability.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the National Institute of Child Health and Human Development (R01-HD086742, R21-HD072326, R03-HD090315 and T32-HD052458). The authors declare no competing interests.

Association between age at menarche and age at menopause among women of an indigenous population of North Bengal, India

Menarche and menopause are two major components of a woman's reproductive life. Ages at menarche and menopause vary widely between and within populations and are influenced by various factors, both genetic and environmental. The present community-based cross-sectional investigation aimed to assess the association between ages at menarche and natural menopause among women belonging to the indigenous Rajbanshi population of North Bengal, India. The investigation was carried out from January 2015 to May 2015 among 510 Rajbanshi women aged between 45 and 55 years residing in the district of Darjeeling, West Bengal, India. A structured schedule was used to collect data on ages at menarche and natural menopause, marital status, parity, education, age of first and last pregnancies, duration of breastfeeding, nature of occupation, health status, smoking and monthly family income. Anthropometric measurements of height and weight were recorded and Body Mass Index (BMI) calculated. The statistical analyses, which included descriptive statistics and binary logistic regression (BLR), were done using SPSS. The women's mean age of menarche and median age of natural menopause were 12.52 years and 50 years, respectively. The BLR analysis indicated that education, age at first pregnancy had significant effects on the age at natural menopause among women who experienced menarche at <12 years of age (p<0.05). In the case of women who attained menarche at ≥12 years of age, marital status, age at last pregnancy, parity, education, duration of breastfeeding, smoking, occupation, monthly income and BMI had a greater influence on age at natural menopause. There appears to be an indirect association between age at menarche and age at natural menopause, along with different predictor variables, among the Rajbanshi women.

Exposure to polycyclic aromatic hydrocarbons and risk for premature ovarian failure and reproductive hormones imbalance

Polycyclic aromatic hydrocarbons (PAHs) are a typical class of persistent organic pollutants that is ubiquitous worldwide. Previous animal studies suggested that PAHs had adverse effects on female reproduction. However, the human data regarding relationship of PAHs exposure with women reproductive health, such as ovarian dysfunction, are scarce. In this case-control study, the associations of serum levels of PAHs with the risk of premature ovarian failure (POF) and reproductive hormones in Chinese women were investigated, with recruiting 157 POF patients and 217 healthy women. The serum levels of 12 types of PAHs, as well as reproductive hormones, including follicle-stimulating hormone, luteinizing hormone and anti-mullerian hormone, were determined. In the logistic regression models, most individual PAH congeners showed significantly positive correlations with the risk of POF (p < 0.05), except for fluorine and pyrene. Benzo(a)pyrene (BaP), as the most carcinogenic PAH congener, was observed to be significantly positively associated with the risk of POF. After adjustment for age, body mass index, educational levels and household income, per one-unit increase in the log-transformed BaP concentration was significantly correlated with 2.191-fold increased risk of POF (OR = 2.191, 95%CI: 1.634-2.938, p < 0.05). To the best of our knowledge, this is the first study to report an association between internal exposure levels of PAHs and the increased risk of POF in women.

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.

Smoke, alcohol and drug addiction and female fertility

BACKGROUND

Considerable interest has been gathered on the relevant impact of preventable factors, including incorrect lifestyle and unhealthy habits, on female fertility. Smoking, alcohol and addictive drugs consumption represent a major concern, given the broad range of diseases which might be favored or exacerbated by these dependable attitudes. Despite the well-characterized effects of prenatal exposure on pregnancy outcomes and fetus health, a substantial proportion of women of reproductive age is still concerned with these habits. At present, the impact of smoke, alcohol and addictive drugs on women fertility, and, particularly, the specific targets and underlying mechanisms, are still poorly understood or debated, mainly due to the scarcity of well-designed studies, and to numerous biases.

OBJECTIVE

The current review will provide a comprehensive overview of clinical and experimental studies in humans and animals addressing the impact of smoke, alcohol and addictive drugs on female fertility, by also embracing effects on ovary, oviduct, and uterus, with particular reference to primary endpoints such as ovarian reserve, steroidogenesis, ovulation and menstrual cycle, oviduct function and uterus receptivity and implantation. A brief focus on polycystic ovary syndrome and endometriosis will be also included.

METHODS

A Pubmed literature search was performed with selected keywords; articles were individually retrieved by each author. No limitation was set for publication date. Articles in languages other than English were excluded. Additional articles were retrieved from references list of selected manuscripts.

RESULTS AND CONCLUSIONS

Currently, the most consistent evidences of a detrimental effect of smoke, alcohol and addictive drugs on specific domains of the female reproductive function are provided by experimental studies in animals. Overall, clinical studies suggest that smoking is associated to decreased fertility, although causal inference should be further demonstrated. Studies addressing the effect of alcohol consumption on female fertility provide conflicting results, although the majority reported lack of a correlation. Extremely scarce studies investigated the effects of addictive drugs on female fertility, and the specific actions of selected drugs have been difficult to address, due to multidrug consumption.

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.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Metabolic Profile of Patients with Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is hypogonadism associated with amenorrhea, increased levels of gonadotropins, and hypoestrogenism. Deficiency of estrogens may contribute to higher risk of cardiovascular diseases and death. POI patients present several risk factors for the development of cardiovascular diseases (CVD): endothelial dysfunction, abnormal lipid profile, insulin resistance, and insulin action disturbances. Therefore, patients present a higher risk of developing metabolic syndrome. Materials and methods: Follicle stimulating hormone (FSH), luteinizing hormone (LH), 17β-estradiol (E2), prolactin (PRL), testosterone (T), dehydroepiandrosterone sulfate (DHEA-S), thyroid stimulating hormone (TSH), thyroxine (fT4), fasting serum glucose and insulin concentrations, homeostatic model for insulin resistance (HOMA-IR), and lipid profiles were assessed in 56 women (mean age: 30.7 ± 6.9) suffering from POI diagnosed according to European Society of Human Reproduction and Embryology (ESHRE) criteria and 68 healthy age-and-weight matched women (mean age: 27.3 ± 4.5). Results: After regression analysis with BMI and age correction, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) serum concentrations were found to be significantly higher in the POI group, when compared to healthy subjects, whilst triglycerides, glucose, insulin serum concentrations, HOMA-IR, as well as systolic (SBP) and diastolic blood pressure (DBP) did not differ significantly between both groups. A significant positive correlation was identified between TC and LDL-C levels, regardless of BMI and age, whilst SBP correlated only with serum glucose concentration. Additionally, FSH correlated positively with fasting serum glucose concentration after BMI and age correction. Conclusions: Certain metabolic parameters appeared to correlate with POI and these correlations persisted after correction for BMI and age. More research is required to determine the influence of absent ovulatory function on metabolic profiles in POI women. This information may additionally help in early identification of CVD risk factors in those patients.

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

CONTEXT

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

OBJECTIVE

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

DESIGN

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

SETTING AND PARTICIPANTS

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

MAIN OUTCOME MEASURE(S)

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

RESULTS

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

CONCLUSION

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

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.

Testing ovarian reserve in pre-menopausal women: why, whom and how?

Numerous social and environmental factors (environmental hazards, social factors such as education and career, higher economic status desired before the decision is made to have children) influence a women's decision to postpone pregnancy until late reproductive age. In turn, age is related to a fall in ovarian reserve. The main goal of testing ovarian reserve is the identification of women with so-called diminished ovarian reserve (DOR). Additionally, it provides assistance in the counselling of women who are planning to use assisted reproductive techniques (ART). This review examines current methods of testing ovarian reserve and their application. The most useful methods of assessing ovarian reserve are ultrasonographic count of ovarian antral follicles (AFC) and serum tests of both the anti-Müllerian hormone (AMH) level and the third-day level of follicle stimulating hormone (FSH). However, there are limitations to the currently used methods of testing ovarian reserve, especially in relation to their specificity and sensitivity. It is also difficult to predict egg quality based on these tests. The value of screening programmes of ovarian reserve is yet to be determined.

Environmental pollutants, a possible etiology for premature ovarian insufficiency: a narrative review of animal and human data

BACKGROUND

Because only 25% of cases of premature ovarian insufficiency (POI) have a known etiology, the aim of this review was to summarize the associations and mechanisms of the impact of the environment on this pathology. Eligible studies were selected from an electronic literature search from the PUBMED database from January 2000 to February 2016 and associated references in published studies. Search terms included ovary, follicle, oocyte, endocrine disruptor, environmental exposure, occupational exposure, environmental contaminant, pesticide, polyaromatic hydrocarbon, polychlorinated biphenyl PCB, phenol, bisphenol, flame retardant, phthalate, dioxin, phytoestrogen, tobacco, smoke, cigarette, cosmetic, xenobiotic. The literature search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We have included the human and animal studies corresponding to the terms and published in English. We have excluded articles that included results that did not concern ovarian pathology and those focused on ovarian cancer, polycystic ovary syndrome, endometriosis or precocious puberty. We have also excluded genetic, auto-immune or iatrogenic causes from our analysis. Finally, we have excluded animal data that does not concern mammals and studies based on results from in vitro culture. Data have been grouped according to the studied pollutants in order to synthetize their impact on follicular development and follicular atresia and the molecular pathways involved. Ninety-seven studies appeared to be eligible and were included in the present study, even though few directly address POI. Phthalates, bisphenol A, pesticides and tobacco were the most reported substances having a negative impact on ovarian function with an increased follicular depletion leading to an earlier age of menopause onset. These effects were found when exposure occured at different times throughout the lifetime from the prenatal to the adult period, possibly due to different mechanisms. The main mechanism seemed to be an increase in atresia of pre-antral follicles.

CONCLUSION

Environmental pollutants are probably a cause of POI. Health officials and the general public must be aware of this environmental effect in order to implement individual and global preventive actions.

Premature Ovarian Failure: An Association with Autoimmune Diseases

INTRODUCTION

Premature Ovarian Failure (POF) is the cessation of ovarian function before the age of 40 years. POF is reported to be associated with autoimmune diseases in 20-30% of cases.

AIM

Patients presenting with idiopathic POF were screened for the presence of autoimmune disorders.

MATERIALS AND METHODS

Twenty patients with idiopathic POF were included in the study. Baseline investigation in all subjects included fasting serum FSH, LH, E2, progesterone, free T3, free T4, Thyroid-Stimulating Hormone (TSH) and Anti-Thyroperoxidase (anti-TPO) antibodies, testosterone and Dehydroepiandrosterone (DHEAS) levels. Fasting and post-glucose (2 hours after 75g of oral glucose) serum calcium and phosphate were estimated using appropriate assays in biochemistry laboratory.

RESULTS

Seven patients (35%), who presented with secondary amenorrhea, had thyroid disorders and were already on thyroxine replacement therapy. One patient also had vitiligo. There was no history of adrenal disorder. Anti-TPO levels were elevated in two (10%) patients of secondary amenorrhea group. The levels of serum testosterone were low in three patients. Serum DHEAS levels were low in 13 patients. Blood sugar levels (fasting and 2 hour post 75g glucose load) and fasting insulin levels were normal. Serum calcium and phosphate levels were normal in all the patients.

CONCLUSION

Thyroid autoimmunity is the most common autoimmune disease associated with POF. The finding of low DHEAS in a large percentage of patients (65%), suggests possibility of adrenal dysfunction. This requires further testing for adrenal reserve and adrenal autoantibodies.

Premature ovarian insufficiency: the context of long-term effects

PURPOSE

Premature ovarian insufficiency (POI) is defined as the cessation of the ovarian function before the age of 40 years. POI aetiology may be related to iatrogenic or endogenous factors and in many cases remains unclear. The aim of this review was to characterize the long-term consequences of POI.

METHODS

The available literature regarding the long-term consequences of POI from MEDLINE has been reviewed.

RESULTS

Lack of ovarian steroids synthesis has serious consequences for women's health. The short-term effects are similar to spontaneous menopause and refer mainly to the climacteric syndrome. In a longer perspective, POI affects a variety of aspects. It obviously and drastically reduces the chances for spontaneous pregnancies. Oestrogen loss leads also to urogenital atrophy. The most common urogenital symptoms include vaginal dryness, vaginal irritation and itching. The urogenital atrophy and hypoestrogenism interferes also with sexual functioning. Patients with POI are threatened by a decrease in bone mineral density (BMD). POI women also experience psychological distress and some studies have shown an increased risk of neurodegenerating diseases. Overall, POI women have a shortened life expectancy, mainly due to cardiovascular disease. Some studies have reported a reduced risk of breast cancer in this group of patients.

CONCLUSIONS

In conclusion there are several well-characterized health risks in POI women. With every patient, an individualized approach is required to properly recognize and prevent these risks.

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.

Chronic inflammatory systemic diseases: An evolutionary trade-off between acutely beneficial but chronically harmful programs

It has been recognized that during chronic inflammatory systemic diseases (CIDs) maladaptations of the immune, nervous, endocrine and reproductive system occur. Maladaptation leads to disease sequelae in CIDs. The ultimate reason of disease sequelae in CIDs remained unclear because clinicians do not consider bodily energy trade-offs and evolutionary medicine. We review the evolution of physiological supersystems, fitness consequences of genes involved in CIDs during different life-history stages, environmental factors of CIDs, energy trade-offs during inflammatory episodes and the non-specificity of CIDs. Incorporating bodily energy regulation into evolutionary medicine builds a framework to better understand pathophysiology of CIDs by considering that genes and networks used are positively selected if they serve acute, highly energy-consuming inflammation. It is predicted that genes that protect energy stores are positively selected (as immune memory). This could explain why energy-demanding inflammatory episodes like infectious diseases must be terminated within 3–8 weeks to be adaptive, and otherwise become maladaptive. Considering energy regulation as an evolved adaptive trait explains why many known sequelae of different CIDs must be uniform. These are, e.g. sickness behavior/fatigue/depressive symptoms, sleep disturbance, anorexia, malnutrition, muscle wasting—cachexia, cachectic obesity, insulin resistance with hyperinsulinemia, dyslipidemia, alterations of steroid hormone axes, disturbances of the hypothalamic-pituitary-gonadal (HPG) axis, hypertension, bone loss and hypercoagulability. Considering evolved energy trade-offs helps us to understand how an energy imbalance can lead to the disease sequelae of CIDs. In the future, clinicians must translate this knowledge into early diagnosis and symptomatic treatment in CIDs.

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.

Risk of depressive disorders in women undergoing hysterectomy: A population-based follow-up study

OBJECTIVE

The objective of this study was to assess the risk of depressive disorders in women who underwent hysterectomy in Taiwan.

METHODS

A retrospective study was conducted in a matched cohort of cases using the National Health Insurance Research Database of Taiwan. Database records from 1689 women who underwent hysterectomy between 2001 and 2005 were included in this study. A control group matched for age and physical comorbidity was selected from the same database (n = 6752). For all cases, medical records were tracked until the end of 2009 to identify whether a depressive disorder was diagnosed during the follow-up period. The hazard ratio (HR) for depression during the observation period was analyzed using multivariable Cox proportional-hazards models, adjusted for age, physical comorbidities, and other socioeconomic factors.

RESULTS

The HR for depression was 1.78 times higher for the group that underwent hysterectomy than for the control group (adjusted HR = 1.78; 95% CI = 1.46-2.18, p < 0.001). In addition, HR for major depressive disorder in women who underwent hysterectomy was significantly higher (1.84 times) than for the control group (adjusted HR = 1.84; 95% CI = 1.23-2.74, p < 0.01).

CONCLUSIONS

Our study revealed that, in Taiwan, women who underwent hysterectomy had an increased risk of developing depression. Longitudinal studies to follow-up the psychological outcomes in Taiwanese women who underwent hysterectomy will be necessary to confirm our findings.

The impact of lifestyle modifications, diet, and vitamin supplementation on natural fertility

BACKGROUND

Infertility is a relatively common condition. When patients are confronted with this diagnosis, there are medical, psychological, and financial sequelae. Patients often wonder if there is anything they can do to optimize their natural fertility or increase the effectiveness of infertility treatments.

FINDINGS

If there is a clear impact on fertility, such as with smoking and alcohol, cessation should be advised. Similarly, weight loss should be recommended if the BMI is in the overweight and obese category, and weight gain should be recommended for an underweight BMI. The evidence surrounding other lifestyle modifications is less clear. There are conflicting data regarding an optimal fertility diet and consumption of vitamins and supplements. Antioxidants seem to improve semen parameters in men, but the effect on female fertility is less clear. If conflicting evidence exists, such as with caffeine consumption or exercise, moderation should be emphasized. Finally, the diagnosis of infertility and subsequent fertility treatments are stressful for both partners. The psychological aspects should not be ignored and methods such as yoga and cognitive behavioral therapy may be beneficial.

CONCLUSION

Continued research will determine the optimal lifestyle modifications to achieve pregnancy.

Epistasis between polymorphisms in PCSK1 and DBH is associated with premature ovarian failure

OBJECTIVE

This study examined whether epistasis between single nucleotide polymorphisms (SNPs) within proprotein convertase subtilisin/kexin type 1 (PCSK1) and dopamine β-hydroxylase (DBH) genes is associated with premature ovarian failure (POF).

METHODS

One hundred twenty women with POF and 222 female controls were recruited for this study. To genotype SNPs within PCSK1 and DBH, we used a GoldenGate assay with VeraCode technology, which uses an allele-specific primer extension method.

RESULTS

Two SNPs (rs155979 and rs3762986) within PCSK1 and one SNP (rs1611114) within DBH, which were located in the 5' flanking region, were involved in synergistic interactions. The C allele in the rs155979 SNP showed an increased risk of POF in a dominant model when AA genotype in the rs1611114 SNP was present (odds ratio, 3.60; 95% CI, 1.82-7.14; P = 0.00024), whereas the G allele in the rs1611114 SNP showed a reduced risk of POF in a dominant model when at least one C allele at the rs155979 SNP was present (odds ratio, 0.24; 95% CI, 0.11-0.51; P = 0.00018) or one G allele at the rs3762986 SNP was present (odds ratio, 0.33; 95% CI, 0.19-0.60; P = 0.00023).

CONCLUSIONS

Epistases between SNPs within PCSK1 and DBH genes are significantly associated with susceptibility or resistance to POF.

Aerobic physical training increases contractile response and reduces cardiac fibrosis in rats subjected to early ovarian hormone deprivation

We investigated the effects of early ovarian hormone deprivation on the heart and the role of physical training in this condition using different approaches: cardiac autonomic tone, contractility, morphology and function, and cardiac fibrosis. Female Wistar rats ( n = 48) were assigned into two groups: ovariectomized (Ovx; 10-wk-old) and control rats (Sham; 10-wk-old). Each group was further divided into two subgroups, sedentary and trained (aerobic training by swimming for 10 wk). The sedentary groups showed similar cardiac autonomic tone values; however, only the Sham group had an increase in vagal participation for the determination of the basal heart rate after physical training. The contractile responses to cardiac β-agonists of the sedentary groups were similar, including an increased response to a β1-agonist (dobutamine) observed after physical training. The Ovx sedentary group presented changes in cardiac morphology, which resulted in decreases in the ejection fraction, fractional shortening, and cardiac index compared with the Sham sedentary group. Physical training did little to alter these findings. Moreover, histology analysis showed a significant increase in cardiac fibrosis in the sedentary Ovx group, which was not observed in the trained Ovx group. We conclude that early ovarian hormone deprivation in rats impairs autonomic control, cardiac morphology, and cardiac function and increases cardiac fibrosis; however, it does not affect the contractility induced by dobutamine and salbutamol. Furthermore, this model of physical training prevented an increase in fibrosis and promoted an increase in the cardiac contractile response but had little effect on cardiac autonomic control or morphological and functional parameters.

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.

Factors that discriminate age at menopause: A study of Bengali Hindu women of West Bengal

OBJECTIVE

This study aims to investigate the factors that discriminate different menopausal age groups.

METHODS

We selected 715 postmenopausal Bengali-speaking Hindu women from the State of West Bengal, India, who were married and had at least one child. We divided the participants into three groups based on the age at which they attained menopause: Group 1 (30-39 years), Group 2 (40-49 years), and Group 3 (50-55 years). A well-tested questionnaire was used to collect information on reproductive variables.

RESULTS

We applied discriminant function analysis to identify the factors associated with different ages at menopause. Results show that factors like age at menarche, duration of breastfeeding of the last child, and age at first pregnancy discriminate the different menopausal age groups.

CONCLUSION

We concluded that reproductive factors discriminate the three different menopausal age groups for this study population.

Current Concepts in Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a life-changing diagnosis, with profound physical and psychological consequences. Unfortunately, there are many deficiencies in our understanding of the condition as the underlying etiology and optimum management strategies are poorly understood. Improved awareness of POI and its long-term implications has led to increased research interest in recent years. Current research has allowed a greater understanding of the changing epidemiology in POI, genetic factors in its etiology and randomized controlled trials of hormone therapy are underway to provide evidence for treatment. This article reviews the latest literature on POI to summarize current understanding and future directions.

Polymorphisms within the FANCA gene associate with premature ovarian failure in Korean women

OBJECTIVE

This study investigated whether polymorphisms within the Fanconi anemia complementation group A (FANCA) gene contribute to the increased risk of premature ovarian failure (POF) in Korean women.

METHODS

Ninety-eight women with POF and 218 controls participated in this study. Genomic DNA from peripheral blood was isolated, and GoldenGate genotyping assay was used to identify single nucleotide polymorphisms (SNPs) within the FANCA gene.

RESULTS

Two significant SNPs (rs1006547 and rs2239359; P < 0.05) were identified by logistic regression analysis, but results were insignificant after Bonferroni correction. Six SNPs formed a linkage disequilibrium block, and three main haplotypes were found. Two of three haplotypes (AAAGAA and GGGAGG) distributed highly in the POF group, whereas the remaining haplotype (GGAAGG) distributed highly in the control group by logistic regression analysis (highest odds ratio, 2.515; 95% CI, 1.515-4.175; P = 0.00036).

CONCLUSIONS

Our observations suggest that genetic variations in the FANCA gene may increase the risk for POF in Korean women.

Interaction between thyroglobulin and ADAMTS16 in premature ovarian failure

Objective

The aim of the present study was to examine whether interactions between polymorphisms in the thyroglobulin and ADAM metallopeptidase with thrombospondin type 1 motif, 16 (ADAMTS16) genes are associated with the development of premature ovarian failure (POF).

Methods

A total of 75 patients with POF and 196 controls were involved in this study. We used a GoldenGate assay to genotype single nucleotide polymorphisms (SNPs). Logistic regression analysis was performed to identify POF-associated polymorphisms and synergistic interactions between polymorphisms in the thyroglobulin and ADAMTS16 genes.

Results

Single gene analyses using logistic regression analysis showed no significant association between polymorphisms in the two genes and POF. In the results from interaction analyses, we found seven synergistic interactions between the polymorphisms in thyroglobulin and ADAMTS16, although there was no combination showing p-values lower than the significant threshold using the Bonferroni correction. When the AG genotype was present at the rs853326 missense SNP, the A and G alleles at the tagging SNPs rs16875268 and rs13168665 showed significant interactions (odds ratios=5.318 and 16.2 respectively; 95% confidence intervals, 1.64-17.28 and 2.08-126.4; p=0.0054 and 0.0079).

Conclusion

Synergistic interactions between polymorphisms in the thyroglobulin and ADAMTS16 genes were associated with an increased risk of POF development in Korean women.

The significance of fragile X mental retardation gene 1 CGG repeat sizes in the normal and intermediate range in women with primary ovarian insufficiency

STUDY QUESTION

Are fragile X mental retardation gene 1 (FMR1) CGG repeats in the normal and intermediate range (up to 55 repeats) associated with primary ovarian insufficiency (POI) in a large case-control study?

SUMMARY ANSWER

No association was found between CGG repeats of intermediate size and POI compared with controls.

WHAT IS KNOWN ALREADY

CGG repeats in the FMR1 gene in the premutation range (55-200 repeats) have consistenly associated with POI. Intermediate range CGG repeats have been considered for a potential association with POI.

STUDY DESIGN, SIZE

A case-control study in 375 well-phenotyped Dutch women diagnosed with POI and 3368 controls with natural menopause ≥40 years of age.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The FMR1 CGG repeat number was determined by PCR amplification in women diagnosed with POI and women with a known age at natural menopause ≥40 years. The prevalence of intermediate sized CGG repeats (45-54 repeats) was compared between POI cases and controls using Fisher's exact test. Differences in mean CGG repeat lengths on allele 1 and allele 2 between POI cases and controls were tested using analysis of variance.

MAIN RESULTS AND THE ROLE OF CHANCE

The frequency of intermediate sized CGG repeats on the allele with the longest triple repeat number was not statistically significantly different between POI cases and controls (2.7 and 3.8%, respectively, odds ratio 0.72, 95% confidence interval: 0.38-1.39, P = 0.38). In women with POI, linear regression analysis for age at POI diagnosis and CGG repeat size also failed to show any association (β = -0.018, P = 0.74).

LIMITATIONS, REASONS FOR CAUTION

FMR1 CGG repeat lengths in POI cases and controls were genotyped in two different laboratories. The distributions of CGG repeats may vary among the different ethnic populations in our study. Also, in our study women with primary amenorrhea (N = 17) were included in the POI group.

WIDER IMPLICATIONS OF THE FINDINGS

We found no association between intermediate sized CGG repeats and POI compared with controls. Therefore, a role for FMR1 CGG repeat sizes up to 55 repeats in the ovarian ageing process may be questioned. Moreover, there seems limited value in the evaluation of normal- and intermediate FMR1 repeat size in the diagnostic work-up of women affected by POI, or for prognostic purposes in women at risk of developing POI.

STUDY FUNDING/COMPETING INTERESTS

The Prospect-EPIC study was funded by 'Europe Against Cancer' Program of the European Commission (SANCO); the Dutch Ministry of Health; the Dutch Cancer Society; ZonMW the Netherlands Organization for Health Research and Development; World Cancer Research Fund (WCRF) and the Dutch Heart Association.

Autonomic Cardiovascular Damage during Post-menopause: the Role of Physical Training

Menopause is part of the aging process and is characterized by the natural cessation of menstruation; during this time, the production of ovarian hormones, especially estrogen, is sharply reduced. This reduction can cause symptoms and disorders that affect most women and can interfere with their quality of life. Women are also more susceptible to cardiovascular diseases during this period, considering that these ovarian hormones would be associated with a protective effect on the cardiovascular system, by acting at various levels, contributing to the body homeostasis. Among several effects on the cardiovascular system, the ovarian hormones seem to play an important role in the autonomic control of heart rate and blood pressure. A reduction in ovarian hormones causes an autonomic imbalance and increases the risk of cardiovascular diseases. In fact, this increased risk is justified by the key role the autonomic nervous system plays in all cardiac regulatory mechanisms, exerting a tonic and reflexive influence on the main variables of the cardiovascular system. The autonomic system controls various cardiovascular parameters, such as the modulation of heart rate and blood pressure, myocardial contractility and venous capacitance, directly participating in the regulation of cardiac output. Over the years, the standard treatment for menopause symptoms and disorders has been hormone replacement therapy (HRT). However, many studies have indicated the risks of HRT, which justify the need for new non-pharmacological therapies. To this end, physical training, mainly aerobic, has been applied with excellent results on the cardiovascular autonomic nervous system, as it reduces the risk of cardiac diseases and improves the survival rate with direct beneficial effects on the quality of life of these women during the aging process.