Physical activity is not related to risk of early menopause in a large prospective study

Age at natural menopause and its associated characteristics among Brazilian women: cross-sectional results from ELSI-Brazil

OBJECTIVES

This study aimed to determine the median age at natural menopause and analyze lifestyle, anthropometric, and dietary characteristics associated with the age at natural menopause among Brazilian women.

METHODS

This cross-sectional study involved 2,731 women 50 years and over, drawn from the baseline of the Brazilian Longitudinal Study of Aging (ELSI-Brazil, 2015/16). Nonparametric Kaplan-Meier cumulative survivorship estimates were used to assess the median timing of natural menopause. Cox proportional hazards regression models were employed to estimate the associations between age at natural menopause and exposure variables.

RESULTS

The overall median age at natural menopause was 50 years. In the adjusted Cox model, current smoking (hazard ratio [HR], 1.11; 95% CI, 1.01-1.23) and underweight (HR, 1.34; 95% CI, 1.12-1.61) were associated with earlier natural menopause. Conversely, performing recommended levels of physical activity in the last week (HR, 0.88; 95% CI, 0.80-0.97), being overweight (HR 0.86; 95% CI, 0.74-0.99), and adhering to two or three healthy eating markers (HR, 0.80; 95% CI, 0.66-0.97; HR, 0.76; 95% CI, 0.61-0.94, respectively) were associated with later age at natural menopause. Binge drinking and waist circumference were not associated with age at natural menopause.

CONCLUSIONS

Lifestyle, anthropometric, and dietary characteristics are significant factors that affect the age at natural menopause. Our findings can contribute to public policies targeted at Brazilian women's health.

Current Status and Future Prospects of Stem Cell Therapy for Infertile Patients with Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI), also known as premature menopause or premature ovarian failure, signifies the partial or complete loss of ovarian endocrine function and fertility before 40 years of age. This condition affects approximately 1% of women of childbearing age. Although 5-10% of patients may conceive naturally, conventional infertility treatments, including assisted reproductive technology, often prove ineffective for the majority. For infertile patients with POI, oocyte donation or adoption exist, although a prevalent desire persists among them to have biological children. Stem cells, which are characterized by their undifferentiated nature, self-renewal capability, and potential to differentiate into various cell types, have emerged as promising avenues for treating POI. Stem cell therapy can potentially reverse the diminished ovarian endocrine function and restore fertility. Beyond direct POI therapy, stem cells show promise in supplementary applications such as ovarian tissue cryopreservation and tissue engineering. However, technological and ethical challenges hinder the widespread clinical application of stem cells. This review examines the current landscape of stem cell therapy for POI, underscoring the importance of comprehensive assessments that acknowledge the diversity of cell types and functions. Additionally, this review scrutinizes the limitations and prospects associated with the clinical implementation of stem cell treatments for POI.

The Role of Lifestyle and Dietary Factors in the Development of Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a condition that arises from dysfunction or early depletion of the ovarian follicle pool accompanied by an earlier-than-normal loss of fertility in young women. Oxidative stress has been suggested as an important factor in the decline of fertility in women and POI. In this review, we discuss the mechanisms of oxidative stress implicated in ovarian ageing and dysfunction in relation to POI, in particular mitochondrial dysfunction, apoptosis and inflammation. Genetic defects, autoimmunity and chemotherapy, are some of the reviewed hallmarks of POI that can lead to increased oxidative stress. Additionally, we highlight lifestyle factors, including diet, low energy availability and BMI, that can increase the risk of POI. The final section of this review discusses dietary factors associated with POI, including consumption of oily fish, mitochondria nutrient therapy, melatonin, dairy and vitamins that can be targeted as potential interventions, especially for at-risk women and in combination with personalised nutrition. Understanding the impact of lifestyle and its implications for POI and oxidative stress holds great promise in reducing the burden of this condition.

Risk factors for natural menopause before the age of 45: evidence from two British population-based birth cohort studies

Background

Menopause that occurs before the age of 45 and is not medically induced (referred to here as ‘early natural menopause’) affects around one in 10 women and has serious health consequences. These consequences include increased risk of all-cause mortality, cardiovascular disease, osteoporosis, and type 2 diabetes.

Methods

We investigate risk factors for the onset of natural menopause before the age of 45 in two population-based prospective cohort studies in Britain: the 1958 cohort following 8959 women and the 1970 cohort following 8655 women. These studies follow women from birth to adulthood, and we use harmonized data on birth and early life characteristics, reproductive health, health behaviour, and socioeconomic characteristics for 6805 women who were pre-menopausal, peri-menopausal or had undergone natural menopause. Of these 6805 women, 3614 participated in the 1958 cohort (of which 368 had early menopause) and 3191 participated in the 1970 cohort (of which 206 had early menopause). Taking a life course approach, we focus on three distinct life stages - birth/early life, childhood, and early adulthood - to understand when risk factors are most harmful. Respecting the temporal sequence of exposures, we use a series of multivariable logistic regression models to estimate associations between early menopause and each potential risk factor adjusted for confounders.

Results

We find that early menopause is influenced by circumstances at birth. Women born in lower social class families, whose mother smoked during the pregnancy or who were breastfed 1 month or less were more likely to undergo early menopause. Early menopause is also associated with poorer cognitive ability and smoking in childhood. Adult health behaviour also matters. Smoking is positively correlated with early menopause, while regular exercise and moderate frequency of alcohol drinking in women’s early thirties are associated with reduced risk of early menopause. The occurrence of gynaecological problems by women’s early thirties is also linked to early menopause.

Conclusions

We demonstrate that characteristics at different periods of life are associated with early menopause. Some of these associations relate to modifiable behaviours and thus the risks of early menopause and the adverse health outcomes associated with it may be preventable.

The Relationship Between Usual Daily Physical Activity With Serum Markers Related to Bone Metabolism and Demographic Characteristics in Postmenopausal Women Aged 50-65 Years

BACKGROUND

Bone turnover markers can predict subsequent changes in bone status. This study aimed to investigate the relationship between usual daily physical activity (PA) with bone markers.

METHODS

This cross-sectional study was conducted on 500 postmenopausal women aged 50-65 years in Tabriz-Iran in 2018. The women were recruited by a simple random method. The International Physical Activity Questionnaire was used to assess PA. The laboratory tests of 25-Hydroxyvitamin D3, alkaline phosphatase, calcium, and phosphorus were also used to examine bone function.

RESULTS

The education, income, employment status, sun exposure, and history of exercise were significantly correlated with PA. Among reproductive characteristics, only menopausal age showed a significant relationship with total PA levels (r = .285, P = .048). None of the anthropometric indices showed a statistically significant relationship with total PA. Serum calcium (r = -.242) and phosphorus (r = -.045) levels showed negative and inverse relationships with total PA. The intensity of this association was statistically significant only for the calcium (β = -0.108, 95% confidence interval, -0.117 to 0.098; P = .023). 25-Hydroxyvitamin D3 (r = .007) and alkaline phosphatase (r = .046) were directly and positively but nonsignificantly correlated to the intensity of total PA.

CONCLUSION

Usual daily physical activity with any levels has no effect on bone markers except for calcium. Despite of the beneficial effects of PA, our findings showed that usual daily physical activity without increasing total PA cannot affect bone health. For maximal effects of PA on bone health, it seems that a degree of intensity, continuity, and regularity of PA programs should be considered to stimulate bone formation.

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.

The Comparison of Physical Activity, Sedentary Behavior, and Mental Health between Early Menopausal Women and Age-Matched General Middle-Aged Women

The current study is to examine the differences in physical activity (PA), sedentary behavior (SB), and mental health (i.e., stress, depression, and suicidal behaviors) between early menopausal women and age-matched general middle-aged women. Among 1348 participants in South Korea, 674 participants who experienced menopause before the age of 45 were defined as the early menopausal group, and 674 women who experienced menopause from 45 years to 55 years were classified as the general group by matching age based on early menopausal women. PA, SB, and mental health were evaluated by using the Global Physical Activity Questionnaire (GPAQ). An independent t-test was used to compare the associations of PA, SB, and mental health between the two groups. To demonstrate the predictors of early menopause, variables in the study were analyzed by multinomial logistic regression. The main findings were that moderate-to-vigorous PA (MVPA) and light PA (LPA) had significant differences between the two groups, but SB had no significant differences. In mental health, only perceived stress had significant differences in this study. The moderate level of stress in the early menopausal group was twice as high as that of the general group, and the severe level of stress was even 2.6 times higher than the general group. PA plays an essential role in mitigating the causes of mortality and the risk of various chronic diseases and improving quality of life; thus, the main findings of this study could be important to provide insights on the corresponding impact between early menopausal women and PA to encourage their healthy lifestyle. Further longitudinal studies are needed to examine the mechanisms underlying the effects of PA, SB, and mental health on early menopausal women.

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.

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.

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.

Does night work affect age at which menopause occurs?

PURPOSE OF REVIEW

To delineate the current state of evidence on the impact of night shift work on age at natural menopause.

RECENT FINDINGS

The only direct evidence is from a single observational study, which indicates that women who work night shifts are at moderately higher risk for earlier menopause and that this risk is more pronounced among younger women. Underlying biological mechanisms have yet to be sufficiently substantiated. A long-held line of inquiry, most strongly propagated by the observed link between night shift work and female breast cancer, is the 'Light at Night' hypothesis, which suggests melatonin-mediated circadian disruption as a potential regulator of reproductive signaling in women. Supporting evidence is found from observations of changes in endogenous melatonin production among night working women or in response to light exposure, and corresponding changes in endogenous ovarian hormone levels and modulated menstrual patterns, among other indications of altered central ovulation-governing processes. Susceptibility to night shift work may be modified by chronotype.

SUMMARY

This review summarizes the literature related to night work and ovulatory regulation in humans, prioritizing population-based evidence to provide motivation for the study of circadian disruption and night shift work as a regulator of menopausal timing.