Effect of Reproductive History and Exogenous Hormone Use on Cognitive Function in Mid- and Late Life

Beyond Birth Control: The Neuroscience of Hormonal Contraceptives

Hormonal contraceptives (HCs) are one of the most highly prescribed classes of drugs in the world used for both contraceptive and noncontraceptive purposes. Despite their prevalent use, the impact of HCs on the brain remains inadequately explored. This review synthesizes recent findings on the neuroscience of HCs, with a focus on human structural neuroimaging as well as translational, nonhuman animal studies investigating the cellular, molecular, and behavioral effects of HCs. Additionally, we consider data linking HCs to mood disorders and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and stress response as a potential mediator. The review also addresses the unique sensitivity of the adolescent brain to HCs, noting significant changes in brain structure and function when HCs are used during this developmental period. Finally, we discuss potential effects of HCs in combination with smoking-derived nicotine on outcomes of ischemic brain damage. Methodological challenges, such as the variability in HC formulations and user-specific factors, are acknowledged, emphasizing the need for precise and individualized research approaches. Overall, this review underscores the necessity for continued interdisciplinary research to elucidate the neurobiological mechanisms of HCs, aiming to optimize their use and improve women's health.

Research Note: The Association Between Parity and Odds of Alzheimer's Disease and Dementias Status

While parity is a significant factor influencing parental health, its relationship with dementia remains underexplored. This research note advances the literature by conducting a well-powered analysis of associations between parity (i.e., number of children) and Alzheimer's disease and dementias (AD/D) status in large-scale population data. The data contain a large number of AD/D cases (37,228 women and 19,846 men), allowing a range (1-10) of parity associations to be estimated precisely. Using proxy (adult child's) reports of parental AD/D status, we find that both fathers and mothers with grand multiparity have decreased odds of AD/D status, and the effect sizes become larger as parity increases, with 30-40% reduction in AD/D status at parities above 7. The association is stronger for mothers than for fathers. This finding differs from much of the prior literature and likely suggests the impact of parity, as one of the important life course contexts, on people's cognitive function and risk of having AD/D. Finally, we include population projections that consider how large changes in parity distributions over time may contribute to small elevations in AD/D rates.

Do pregnancy and motherhood have an impact on cognitive functions in women

Pregnancy and motherhood are some of the most physically and mentally challenging periods in a woman's life. The aim of current study was to examine aspects of cognitive functions in pregnancy and motherhood that are controversial in the literature. The study included 30 healthy pregnant women aged between 18-40 years in their second and third trimesters, 30 healthy controls (nulliparous and non-pregnant women) and 30 healthy mothers matched with the pregnant women for age, handedness and education level. Edinburgh Postpartum Depression Scale, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Trail Making, Stroop, Digit Span, Verbal Fluency and Rey Auditory and Verbal Learning Tests (RAVLT) were applied to all participants. The pregnant group showed significantly lower performance in trail making, digit span, verbal fluency as well as RAVLT compared to other two groups suggesting deficiencies in cognitive areas such as attention, set-shifting, planning, learning, language functions, semantic memory, working memory, encoding memory and retrieval. A trend toward increased function in response inhibition was observed in the mothers. Regression analyses revealed that pregnancy significantly decreased performance in verbal fluency, trail making, and RAVLT. Our findings from rigorously selected participants may help comprehend alterations in cognitive functioning during pregnancy and motherhood, as well as shed light on the contradictory literature.

Alzheimer's disease as a women's health challenge: a call for action on integrative precision medicine approaches

Alzheimer's Disease (AD) is marked by pronounced sex differences in pathophysiology and progression. However, the field has yet to fully recognize AD as a women's health issue, delaying the development of targeted preventative strategies and treatments. This perspective explores the elements impacting AD in women, identifying sex specificity in risk factors, highlighting new diagnostic approaches with electronic health records, and reviewing key molecular studies to underscore the need for integrative precision medicine approaches. Established AD risk factors such as advancing age, the apolipoprotein E4 allele, and poorer cardiovascular health affect women differently. We also shed light on sociocultural risk factors, focusing on the gender disparities that may play a role in AD development. From a biological perspective, sex differences in AD are apparent in biomarkers and transcriptomics, further emphasizing the need for targeted diagnostics and treatments. The convergence of novel multiomics data and cutting-edge computational tools provides a unique opportunity to study the molecular underpinnings behind sex dimorphism in AD. Thus, precision medicine emerges as a promising framework for understanding AD pathogenesis through the integration of genetics, sex, environment, and lifestyle. By characterizing AD as a women's health challenge, we can catalyze a transformative shift in AD research and care, marked by improved diagnostic accuracy, targeted interventions, and ultimately, enhanced clinical outcomes.

Sex-associated microRNAs potentially implicated in sporadic Alzheimer's disease (sAD)

BACKGROUND

The onset and pathology of sporadic Alzheimer's disease (sAD) seem to be affected by both sex and genetic mechanisms. Evidence supports that the high prevalence of sAD in women, worldwide, may be attributed to an interplay among aging, sex, and lifestyle, influenced by genetics, metabolic changes, and hormones. Interestingly, epigenetic mechanisms such as microRNAs (miRNAs), known as master regulators of gene expression, may contribute to this observed sexual dimorphism in sAD.

OBJECTIVES

To investigate the potential impact of sex-associated miRNAs on processes manifesting sAD pathology, as described by the Tau-driven Adverse Outcome Pathway (AOP) leading to memory loss.

METHODS

Using publicly available human miRNA datasets, sex-biased miRNAs, defined as differentially expressed by sex in tissues possibly affected by sAD pathology, were collected. In addition, sex hormone-related miRNAs were also retrieved from the literature. The compiled sex-biased and sex hormone-related miRNAs were further plugged into the dysregulated processes of the Tau-driven AOP for memory loss.

RESULTS

Several miRNAs, previously identified as sex-associated, were implicated in dysregulated processes associated with the manifestation of sAD pathology. Importantly, the described pathology processes were not confined to a particular sex. A mechanistic-based approach utilizing miRNAs was adopted in order to elucidate the link between sex and biological processes potentially involved in the development of memory loss.

CONCLUSIONS

The identification of sex-associated miRNAs involved in the early processes manifesting memory loss may shed light to the complex molecular mechanisms underlying sAD pathogenesis in a sex-specific manner.

Connections between reproductive health and cognitive aging among women enrolled in the HCHS/SOL and SOL-INCA

INTRODUCTION

Reproductive health history may contribute to cognitive aging and risk for Alzheimer's disease, but this is understudied among Hispanic/Latina women.

METHODS

Participants included 2126 Hispanic/Latina postmenopausal women (44 to 75 years) from the Study of Latinos-Investigation of Neurocognitive Aging. Survey linear regressions separately modeled the associations between reproductive health measures (age at menarche, history of oral contraceptive use, number of pregnancies, number of live births, age at menopause, female hormone use at Visit 1, and reproductive span) with cognitive outcomes at Visit 2 (performance, 7-year change, and mild cognitive impairment [MCI] prevalence).

RESULTS

Younger age at menarche, oral contraceptive use, lower pregnancies, lower live births, and older age at menopause were associated with better cognitive performance. Older age at menarche was protective against cognitive change. Hormone use was linked to lower MCI prevalence.

DISCUSSION

Several aspects of reproductive health appear to impact cognitive aging among Hispanic/Latina women.

Associations of reproductive factors and exogenous estrogens with global and domain-specific cognition in later life

INTRODUCTION

Few studies have comprehensively examined the impact of reproductive factors (i.e., reproductive window, parity, hormonal contraception [HC], and menopausal hormone therapy [MHT]) on global and domain-specific cognition in later life.

METHODS

We studied a population-based sample of 2458 women (median age 74.2 years) residing in Olmsted County, Minnesota; participants underwent a clinical evaluation and comprehensive cognitive testing.

RESULTS

The length of a woman's reproductive window was not associated with cognition. Higher parity was associated with greater cognitive decline in all domains. Ever HC use was associated with less decline in all domains. Ever MHT use was associated with greater decline in global cognition and all domain-specific z-scores except visuospatial; results were driven by women who initiated MHT 5 or more years after menopause. Additional adjustments for APOE and vascular-related covariates did not attenuate the results.

DISCUSSION

Multiple reproductive risk factors are associated with cognitive decline in later life.

HIGHLIGHTS

The length of a woman's reproductive window was not associated with cognition longitudinally. Greater parity was associated with greater cognitive decline longitudinally. Ever HC use was associated with less decline in global cognition and all domain-specific z-scores longitudinally (all p < 0.01). Ever MHT use was associated with greater decline in global cognition and all domain-specific z-scores except visuospatial longitudinally (all p < 0.01). The greatest cognitive decline was among women who initiated MHT more than 5 years after menopause.

The role of sex hormones, oral contraceptive use, and its parameters on visuospatial abilities, verbal fluency, and verbal memory

Sex hormones can cross the blood-brain barrier and access brain regions underlying higher-order cognition. Containing synthetic sex hormones, oral contraceptives (OC) have been found to modulate visuospatial and verbal abilities, though inconsistencies have been found in the literature. Among possible explanations, certain OC use parameters (progestin androgenicity, synthetic hormone levels, duration of use) have not received consistent consideration. Thus, the objectives were to (1) examine group differences between men, combined OC users, and naturally cycling women (NC women; not using OC) in visuospatial abilities, verbal fluency, and verbal memory and (2) investigate the contribution of endogenous and exogenous sex hormones on these effects. We also aimed to (3) identify OC use parameters relevant to cognitive outcomes. In total, 70 combined OC users, 53 early follicular (EF) women, 43 pre-ovulatory (PO) women, and 47 men underwent cognitive tests. Performance was compared based on hormonal milieus (OC, EF, PO, men) and OC users' contraceptive androgenicity (anti, low, high). Correlations between performance, hormone levels and OC use duration were also conducted. OC use dampened the sex difference that typically favors men in 3D visuospatial abilities, whereas its duration of use positively predicted verbal fluency. Androgenicity and hormone levels did not predict performance in any task. These results highlight the importance of considering OC use duration. Results also did not support a role for androgenicity in cognition. Importantly, combined OC use (including prolonged use) does not impair visuospatial, verbal, and memory functions in a healthy young sample.

Sex steroids and the female brain across the lifespan: insights into risk of depression and Alzheimer's disease

Despite widespread sex differences in prevalence and presentation of numerous illnesses affecting the human brain, there has been little focus on the effect of endocrine ageing. Most preclinical studies have focused on males only, and clinical studies often analyse data by covarying for sex, ignoring relevant differences between the sexes. This sex- (and gender)-neutral approach is biased and contributes to the absence of targeted treatments and services for all sexes (and genders). Female health has been historically understudied, with grave consequences for their wellbeing and health equity. In this Review, we spotlight female brain health across the lifespan by informing on the role of sex steroids, particularly oestradiol, on the female brain and on risk for diseases more prevalent in females, such as depression and Alzheimer's disease.

The conceivable role of prolactin hormone in Parkinson disease: The same goal but with different ways

Parkinson disease (PD) is a progressive neurodegenerative disease (NDD) of the brain. It has been reported that prolactin (PRL) hormone plays a differential effect in PD, may be increasing, reduced or unaffected. PRL level is dysregulated in different neurodegenerative disorders including PD. Preclinical and clinical studies pointed out that PRL may has a neuroprotective against PD neuropathology . Though, the mechanistic role of PRL in PD is not fully elucidated. Therefore, the objective of the present review was to clarify the potential role and mechanistic pathway of PRL in PD neuropathology. The present review highlighted that PRL appears to have a neuroprotective effect against PD neuropathology by inhibiting the expression of pro-inflammatory signaling pathways, antioxidant effects and by inhibiting neuroinflammation. Thus, preclinical and clinical studies are warranted in this regard.

Number of children and cognitive function among Chinese menopausal women: The mediating role of depressive symptoms and social participation

OBJECTIVES

This study examined the association between number of children and cognitive function and its possible hormone and psychosocial pathways in Chinese menopausal women.

METHODS

We analyzed data from the China Health and Retirement Longitudinal Study (CHALRS), including 4803 menopausal women. Ordinary least squares (OLS) regression modeling and structural equation modeling (SEM) were applied to explore the association between number of children and cognitive function and the potential mechanisms.

RESULTS

Overall, the median number of biological children was three among participants. The cognitive function score decreased significantly with increasing numbers of children [β = -0.547, 95 % confidence interval (CI): -0.677, -0.416]. There was a significant interaction between number of children and residence (P = 0.003). Compared with older women with three or less children, women with more than three children had worse cognitive function (β = -0.798, 95 % CI: -1.081, -0.514). Mediation analysis verified that depressive symptoms and social participation partially mediate the associations between the number of children and cognitive function.

LIMITATIONS

First, because of the cross-sectional design, our study was unable to make causal inferences. Second, information about endogenous estrogen exposure was not collected in CHARLS. Third, recall bias may exist due to the use of self-reported data.

CONCLUSION

Our results indicated that a higher number of children is associated with an increased risk for cognitive impairment. We suggest paying special attention to mental and social health among women with multiple children (>3).

Possible cognition changes in women with polycystic ovary syndrome: a narrative review

Nowadays, polycystic ovary syndrome (PCOS) and cognitive dysfunction are major health problems among female. This narrative review aimed to investigate cognitive dysfunction in female with PCOS. English and Persian articles published in PubMed, Scopus, Web of Science, Google Scholar, PsycINFO, Scientific Information Database, and Cochrane Database of Systematic Reviews until May 2022 were searched. Sixteen studies involving 850 female with PCOS and 974 controls were assessed. In these studies, the association between biochemical factors and symptoms of PCOS and memory, attention, executive functioning, information processing speed, and visuospatial skills was evaluated. The literature review revealed the possible cognitive changes in female with PCOS. This study summarized the different aspects of cognitive function in female with PCOS due to medication, psychological problems (mood disorders caused by disease symptoms and complications), and biochemical markers, such as metabolic and sex hormone abnormalities. Considering the existing scientific gap regarding the possibility of cognitive complications in female with PCOS, further biological studies should be conducted to evaluate the potential mechanisms involved.

Reproductive period duration and cognitive function in postmenopausal Latina women in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

OBJECTIVES

A shorter reproductive period, a marker of estrogen exposure, has been related to cognitive impairment among older (>65 years) non-Hispanic White women. We explored whether reproductive period duration, age at menarche, and age at menopause are related to cognitive function among postmenopausal Hispanic/Latina women.

METHODS

This cross-sectional analysis used baseline (Visit 1: 2008-2011) data from 3630 postmenopausal women in the Hispanic Community Health Study/Study of Latinos. Reproductive period duration, age at menarche, and age at menopause were assessed by self-report. Cognitive function variables included global cognition, verbal learning, memory, verbal fluency, and processing speed. Associations between each reproductive event and cognitive function were examined using multivariable linear and logistic regression analyses accounting for the complex survey design of the study and adjusting for socio-demographics, parity, and cardiovascular risk factors. We assessed whether associations differed by type of menopause (natural versus surgical) and hormone therapy use.

RESULTS

The study population was on average aged 59 years, with a mean reproductive period duration of 35 years. Older age at menopause and a longer reproductive period were related to higher verbal learning (β = 0.04, SE = 0.02; p < 0.05) and processing speed (ß = 0.16, SE = 0.04; p < 0.001); associations were more pronounced for women with natural menopause. Older age at menarche was associated with lower scores on the digit symbol substitution test (ß = -0.62, SE = 0.15; p < 0.0001). There were no associations with global cognition.

CONCLUSION

Among postmenopausal Hispanic/Latinas, a longer reproductive period was related to more favorable cognitive measures of verbal learning and processing speed. Our findings support the hypothesis that greater lifetime exposure to estrogens may be associated with higher cognitive performance.

Beyond sex differences: short- and long-term effects of pregnancy on the brain

Growing attention has been directed to the inclusion of females in neuroscience studies, and to the importance of studying sex as a biological variable. However, how female-specific factors such as menopause and pregnancy, affect the brain remains understudied. In this review, we use pregnancy as a case in point of a female-unique experience that can alter neuroplasticity, neuroinflammation, and cognition. We examine studies in both humans and rodents indicating that pregnancy can modify neural function in the short term, as well as alter the trajectory of brain aging. Furthermore, we discuss the influence of maternal age, fetal sex, number of pregnancies, and presence of pregnancy complications on brain health outcomes. We conclude by encouraging the scientific community to prioritize researching female health by recognizing and including factors such as pregnancy history in research.

Lactation attenuates pro-oxidant reactions in the maternal brain

Reactive oxygen species (ROS) are intimately linked to bioenergetics and redox biology, contributing to cellular functioning and physiological signaling, but also acting as toxic agents during oxidative stress. Hence, the balance between pro-oxidant reactions and the activity of antioxidant defenses sustains a basal oxidative status, controls the increase of redox signaling, and mediates potential pathological events during oxidative stress. Maternal experience, especially during nursing, requires high energetic demands and expenditure to ensure the well-being of the offspring. The mother must adapt from satisfying her own needs to additionally fulfilling those of her descendants. Oxidative stress has been proposed as one of the reproductive trade-off hallmarks. However, the oxidative shielding hypothesis has also been proposed in the context of reproduction. The reproductive experience induces a wide range of well-documented changes in the female brain, which potentially lead to protection against the enhanced oxidative activity. To date, the metabolic and cellular mechanisms that underlie lactation-induced neuroprotection against oxidants are unknown. The neuroendocrine changes in the brain of the lactating dam promote diminished propensity to excitotoxic brain injury and stress, as well as enhanced neuroprotection and plasticity. In addition to review studies on the oxidant balance due to motherhood, we included new data from our laboratory, addressing the importance of measuring pro-oxidant reactions in separated brain regions. The hippocampus of lactating rats exhibits lower levels of pro-oxidant reactions than that of virgin rats, supporting the oxidative shielding hypothesis in lactation.

Maternal age at birth of last child and cardiovascular disease mortality later in life among a national cohort of postmenopausal women from the United States

Maternal age at last birth of child is increasing in the United States, and it has been reported to influence future chronic diseases. In this study of nationally-representative sample of postmenopausal women, there was no conclusive association between maternal age at last birth of child and cardiovascular disease mortality later in life.

Objective

Maternal age at last birth (ALB) of child is increasing in the United States, and it has been reported to influence future chronic diseases. However, the relationship of ALB and cardiovascular disease (CVD) events later in life has not been widely studied. We evaluated the association of ALB with CVD mortality.

Methods

Data were from 7,971 parous postmenopausal women older than 45 years who participated in the US National Health and Nutritional Examination Survey from 1999 to 2018 and had mortality follow-up data through to December 31, 2019. ALB was self-reported, whereas CVD mortality was assessed using International Classification of Diseases codes. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI).

Results

The mean age of participants was 63 ± 9.8 years, with 9.5% being non-Hispanic Black, 9.7% being Hispanic women, and 21% reporting ALB ≥35 years. During a median follow-up of 8.1 years, 443 participants died from CVD. In age-adjusted models, CVD mortality was elevated for women with ALB of <25 years (HR, 1.68; 95% CI, 1.23-2.29) and ALB of ≥35 years (HR, 1.37; 95% CI, 1.00-1.88). However, after additional adjustment for race and ethnicity, foreign born, education, marital status, poverty income ratio, parity, smoking status, age at menarche, oral contraceptive pills use and family history of myocardial infarction, these estimates were attenuated resulting in no association between ALB and CVD mortality.

Conclusions

In this study of nationally representative sample of postmenopausal women, there was no conclusive association between maternal ALB and CVD mortality later in life.

Gender differences in the association between parity and cognitive function: Evidence from the UK biobank

While much previous work linking fertility history with late-life cognition has focused on a narrow set of cognitive measures and/or has used modest sample sizes in the analysis, our paper expands the size and scope of these linkages by analyzing cognitive function across five domains and precisely estimating gendered patterns between men and women. Results point to important gendered associations between parity and cognition: having children is likely associated with better cognitive function for fathers in all five domains. However, mothers show worse cognitive function in some domains (i.e., numeric memory, prospective memory, and fluid intelligence) than childless women. We explore the possibility of confounding in these associations and rule out the effects of genetic cognitive ability on fertility. We also find that adding controls for educational attainment differ by gender-strengthening associations between parity and cognition for men and largely eliminating them for women. The findings support previous work done on how life course contexts may link to the risk of dementia or cognitive impairment, highlighting parity as potential protective or risk factors to parents' cognitive health. The use of five cognitive domains yields variations in results, giving implications on measure selection of cognitive function and calling for replicated work covering more cognitive domains.

[Cognitive and psychoemotional changes in menopausal transition: The possibility of medical correction]

The increasing of older age group in the population determines studying of age related diseases and emergence of new investigations in this area. In Female body, entering the menopausal transition is the start of «aging» of reproductive function and linked with decreasing of sex hormons levels. A direct connection between changes of estrogen, progesterone, androgen ratios and cognitive function of women was revealed. The anatomical localization of sex hormone receptors, the mechanisms of interaction of hormones with these receptors determine the ways of implementing biological effects of steroids on the CNS. Modern theories of «healthy nerve cells» and «eu-estrogenemia» explains the role of additional criteria, such as the absence of neurological diseases history and the duration of hypoestrogenia, to the outcome of menopausal hormone therapy. Additional factors that can affect to MHT action include: the composition of hormone therapy, administration methods, regimens (cyclic, continuous), duration of treatment, history of endocrine diseases, diabetes mellitus, gynecological history (parity, menarche age, COC use), heredity. The sections present the effect of menopausal transition on the development of depression, mood changes, sleep disturbances and mental disabilities. The explanation of negative effects of menopausal hormone therapy to cognitive health is also described by modern point of view. The ambivalent opinions of researchers, the potential of new reading of the results of earlier studies, confirms the necessity of continuing study of this topic.

Mental rotation, episodic memory, and executive control: Possible effects of biological sex and oral contraceptive use

Oral contraceptives (OCs) are one of the most common forms of hormonal birth control. A small literature suggests that OC use may affect visuospatial ability, episodic memory, and executive control. However, previous studies have been criticized for small sample sizes and the use of different, single cognitive tests. We investigated the degree to which biological sex and OC use might affect individual mental rotation, episodic memory, and executive control in a large sample of healthy, young adults (N = 155, including 52 OC users, 53 naturally cycling females, and 50 males) tested individually over videoconference. To measure cognition, we used a set of neuropsychological tasks inspired by Glisky and colleagues' two-factor episodic memory and executive control battery, from which two composite scores (based on principal component analysis) were derived for each participant. Our pre-registered analysis revealed a clear female advantage in episodic memory, independent of OC use. In an exploratory analysis, gist memory was elevated in OC users. Interestingly, we found no significant sex-related differences nor effects of OC use on mental rotation or executive control. Duration of OC use was also not related to any of our cognitive measures. These results suggest that the use of combined, monophasic OCs does not lead to many significant changes in cognition in young adults, although young females overall may have better episodic memory than young males. Additional studies, including longitudinal designs and looking in more detail at the menstrual cycle and OC use history, will further clarify the effects of different types of OCs and their duration of use on different aspects of cognition.

Associations Between Midlife Menopausal Hormone Therapy Use, Incident Diabetes, and Late Life Memory in the Wisconsin Longitudinal Study

BACKGROUND

Prior research suggests a link between menopausal hormone therapy (MHT) use, memory function, and diabetes risk. The menopausal transition is a modifiable period to enhance long-term health and cognitive outcomes, although studies have been limited by short follow-up periods precluding a solid understanding of the lasting effects of MHT use on cognition.

OBJECTIVE

We examined the effects of midlife MHT use on subsequent diabetes incidence and late life memory performance in a large, same-aged, population-based cohort. We hypothesized that the beneficial effects of MHT use on late life cognition would be partially mediated by reduced diabetes risk.

METHODS

1,792 women from the Wisconsin Longitudinal Study (WLS) were included in analysis. We employed hierarchical linear regression, Cox regression, and causal mediation models to test the associations between MHT history, diabetes incidence, and late life cognitive performance.

RESULTS

1,088/1,792 women (60.7%) reported a history of midlife MHT use and 220/1,792 (12.3%) reported a history of diabetes. MHT use history was associated with better late life immediate recall (but not delayed recall), as well as a reduced risk of diabetes with protracted time to onset. Causal mediation models suggest that the beneficial effect of midlife MHT use on late life immediate recall were at least partially mediated by diabetes risk.

CONCLUSION

Our data support a beneficial effect of MHT use on late life immediate recall (learning) that was partially mediated by protection against diabetes risk, supporting MHT use in midlife as protective against late life cognitive decline and adverse health outcomes.

Fertility History and Risk of Cognitive Impairment Among Older Parents in the United States

OBJECTIVES

I work from a gendered life-course perspective to examine the association between older parents' fertility history (i.e., timing and parity) and their risk of cognitive impairment in the United States.

METHODS

I analyze nationally representative data from 9 waves over 16 years of the Health and Retirement Study (2000-2016). The sample includes 14,543 respondents (6,108 men and 8,435 women) aged 50 and older at the baseline survey. I examine the relationship between parity, age at first birth, and age at last birth with risk of cognitive impairment using nonlinear discrete-time hazard models.

RESULTS

Adjusting for the effects of full covariates, there are U-shaped relationships between women's age at last birth and risk of cognitive impairment and between women's parity and risk of cognitive impairment. In the sensitivity tests, the relationships remain robust when sampling weights are applied, or mortality selection is corrected.

DISCUSSION

Fertility timing and parity are likely factors associated with the risk of cognitive impairment for older women. Understanding fertility history and its impact on cognition can help identify the most vulnerable subpopulations, so that more effective interventions can be made to improve cognitive functioning among older adults.

Cognitive Aging in Same- and Different-Sex Relationships: Comparing Age of Diagnosis and Rate of Cognitive Decline in the Health and Retirement Study

INTRODUCTION

The ongoing marginalization of lesbian, gay, and bisexual people has been hypothesized to produce poorer late-in-life cognitive outcomes, according to mechanisms posited by minority stress and allostatic load theories. Yet the existence of those outcomes remains understudied, and results of existing studies have been contradictory. Using a population-based longitudinal aging study, this paper will compare age at diagnosis of Alzheimer's disease (AD) or a related dementia and rates of cognitive decline between participants in same-sex relationships (SSRs) and different-sex relationships (DSRs).

METHODS

The study used longitudinal cognitive-health data from the Health and Retirement Study (HRS; 1998-2018; N = 26,344) to analyze the onset of cognitive impairment and AD/dementia and the rates of cognitive change between participants in SSRs and those in DSRs. We hypothesized that SSR participants would have worse overall cognitive functioning in old age and would experience earlier onset of cognitive impairment. Using multiple regression, we compared the ages at which participants in SSRs and DSRs first reported AD or dementia diagnoses and the ages at which they first scored below cutoffs for cognitive impairment, not dementia (CIND) and possible dementia as determined using the cognitive assessment. The study then compared rates of cognitive decline over time across the SSR and DSR groups, including stratified analyses by education, race/ethnicity, wealth, and sex/gender.

RESULTS

Participants in SSRs reported dementia diagnoses (β = -12.346; p = 0.001), crossed the threshold into CIND (β = -8.815; p < 0.001) and possible dementia (β = -13.388; p < 0.001) at a younger age than participants in DSRs. When adjusted for covariates, participants in SSRs also had lower cognition at baseline (β = 0.745; p = 0.003), though having slower rates of cognitive decline when SSR was interacted with time (β = 0.066; p = 0.003). In separate analyses, cognitive differences for SSR participants were only found in participants without undergraduate degrees, with below-median household incomes, and women.

CONCLUSION

Our findings support theories suggesting that marginalization and stigma cause premature cognitive impairment. Findings also suggest that higher education might mitigate the adverse effects of sexuality-minority status on cognitive aging. Results do not support these theories' claims of more rapid cognitive decline; the lower slopes of cognitive decline with time are compatible with the possibility of slower rates of decline for aging individuals in SSRs.

Hormonal contraceptive influences on cognition and psychopathology: Past methods, present inferences, and future directions

In the last decade, there has been a remarkable surge in research on the neural and behavioral correlates of hormonal contraceptive use, particularly oral contraceptive use. Questions have evolved swiftly and notably, with studies no longer revealing if hormonal contraceptives matter for the brain and behavior, but rather how, when, and for whom they matter most. Paralleling this shift, the goal of this review is to move beyond an average synthesis of hormonal contraceptive influences on human cognition and psychopathology (and their neural substrates) in order to consider the nature and specificity of effects. Accompanied by an evaluation of study methods and informed by findings from animal models, this consideration uncovers promising areas of research in the next ten years, including potential activational and organizational effects of hormonal contraceptive use, individual differences in effects that matter for the wellbeing of unique individuals, and correlates of intrauterine device use.

Fertility experiences and later-life cognitive function among older adults in China

OBJECTIVES

The relationship between fertility history and human health has long fascinated scholars; however, whether there is a link between number of children and cognitive function in older adults remains unclear. We investigated the associations between parity and the timing of first and last births with the cognitive function of older adults over 65.

METHODS

The mini-mental state examination (MMSE) was selected as a tool to measure cognitive function. We analyzed data on 5847 older adults in rural and urban communities in China from the 2018 Chinese Longitudinal Healthy Longevity Survey using ordinary least squares. To further explore the transmission mechanism, we also conducted a mediating effect analysis.

RESULTS

We found a negative association between number of children and cognitive function in older adults. Compared with older adults with four children, the MMSE scores of older adults with more than five children decreased significantly, and the score of older adults with zero to three children increased. Further, a late age at first birth (≥35) and a late age at last birth (≥35) were negatively associated with cognitive function. We also found that the associations between parity and cognition might be partly explained by variations in health.

CONCLUSION

Our analyses provided evidence from China to support the link between fertility history and cognitive function that has been observed in previous international studies: We suggest that high parity (≥5) is negatively associated with cognitive function.

Ovarian steroid hormones: A long overlooked but critical contributor to brain aging and Alzheimer's disease

Ovarian hormones, particularly 17β-estradiol, are involved in numerous neurophysiological and neurochemical processes, including those subserving cognitive function. Estradiol plays a key role in the neurobiology of aging, in part due to extensive interconnectivity of the neural and endocrine system. This aspect of aging is fundamental for women's brains as all women experience a drop in circulating estradiol levels in midlife, after menopause. Given the importance of estradiol for brain function, it is not surprising that up to 80% of peri-menopausal and post-menopausal women report neurological symptoms including changes in thermoregulation (vasomotor symptoms), mood, sleep, and cognitive performance. Preclinical evidence for neuroprotective effects of 17β-estradiol also indicate associations between menopause, cognitive aging, and Alzheimer's disease (AD), the most common cause of dementia affecting nearly twice more women than men. Brain imaging studies demonstrated that middle-aged women exhibit increased indicators of AD endophenotype as compared to men of the same age, with onset in perimenopause. Herein, we take a translational approach to illustrate the contribution of ovarian hormones in maintaining cognition in women, with evidence implicating menopause-related declines in 17β-estradiol in cognitive aging and AD risk. We will review research focused on the role of endogenous and exogenous estrogen exposure as a key underlying mechanism to neuropathological aging in women, with a focus on whether brain structure, function and neurochemistry respond to hormone treatment. While still in development, this research area offers a new sex-based perspective on brain aging and risk of AD, while also highlighting an urgent need for better integration between neurology, psychiatry, and women's health practices.

Sex Differences in Cognition Across Aging

Sex and gender differences are seen in cognitive disturbances in a variety of neurological and psychiatry diseases. Men are more likely to have cognitive symptoms in schizophrenia whereas women are more likely to have more severe cognitive symptoms with major depressive disorder and Alzheimer's disease. Thus, it is important to understand sex and gender differences in underlying cognitive abilities with and without disease. Sex differences are noted in performance across various cognitive domains - with males typically outperforming females in spatial tasks and females typically outperforming males in verbal tasks. Furthermore, there are striking sex differences in brain networks that are activated during cognitive tasks and in learning strategies. Although rarely studied, there are also sex differences in the trajectory of cognitive aging. It is important to pay attention to these sex differences as they inform researchers of potential differences in resilience to age-related cognitive decline and underlying mechanisms for both healthy and pathological cognitive aging, depending on sex. We review literature on the progressive neurodegenerative disorder, Alzheimer's disease, as an example of pathological cognitive aging in which human females show greater lifetime risk, neuropathology, and cognitive impairment, compared to human males. Not surprisingly, the relationships between sex and cognition, cognitive aging, and Alzheimer's disease are nuanced and multifaceted. As such, this chapter will end with a discussion of lifestyle factors, like education and diet, as modifiable factors that can alter cognitive aging by sex. Understanding how cognition changes across age and contributing factors, like sex differences, will be essential to improving care for older adults.

Endogenous and Exogenous Estrogen Exposures: How Women's Reproductive Health Can Drive Brain Aging and Inform Alzheimer's Prevention

After advanced age, female sex is the major risk factor for late-onset Alzheimer's disease (AD), the most common cause of dementia affecting over 24 million people worldwide. The prevalence of AD is higher in women than in men, with postmenopausal women accounting for over 60% of all those affected. While most research has focused on gender-combined risk, emerging data indicate sex and gender differences in AD pathophysiology, onset, and progression, which may help account for the higher prevalence in women. Notably, AD-related brain changes develop during a 10-20 year prodromal phase originating in midlife, thus proximate with the hormonal transitions of endocrine aging characteristic of the menopause transition in women. Preclinical evidence for neuroprotective effects of gonadal sex steroid hormones, especially 17β-estradiol, strongly argue for associations between female fertility, reproductive history, and AD risk. The level of gonadal hormones to which the female brain is exposed changes considerably across the lifespan, with relevance to AD risk. However, the neurobiological consequences of hormonal fluctuations, as well as that of hormone therapies, are yet to be fully understood. Epidemiological studies have yielded contrasting results of protective, deleterious and null effects of estrogen exposure on dementia risk. In contrast, brain imaging studies provide encouraging evidence for positive associations between greater cumulative lifetime estrogen exposure and lower AD risk in women, whereas estrogen deprivation is associated with negative consequences on brain structure, function, and biochemistry. Herein, we review the existing literature and evaluate the strength of observed associations between female-specific reproductive health factors and AD risk in women, with a focus on the role of endogenous and exogenous estrogen exposures as a key underlying mechanism. Chief among these variables are reproductive lifespan, menopause status, type of menopause (spontaneous vs. induced), number of pregnancies, and exposure to hormonal therapy, including hormonal contraceptives, hormonal therapy for menopause, and anti-estrogen treatment. As aging is the greatest risk factor for AD followed by female sex, understanding sex-specific biological pathways through which reproductive history modulates brain aging is crucial to inform preventative and therapeutic strategies for AD.

Associations between reproductive history, hormone use, APOE ε4 genotype and cognition in middle- to older-aged women from the UK Biobank

Introduction

Relative to men, women are at a higher risk of developing age-related neurocognitive disorders including Alzheimer's disease. While women's health has historically been understudied, emerging evidence suggests that reproductive life events such as pregnancy and hormone use may influence women's cognition later in life.

Methods

We investigated the associations between reproductive history, exogenous hormone use, apolipoprotein (APOE) ε4 genotype and cognition in 221,124 middle- to older-aged (mean age 56.2 ± 8.0 years) women from the UK Biobank. Performance on six cognitive tasks was assessed, covering four cognitive domains: episodic visual memory, numeric working memory, processing speed, and executive function.

Results

A longer reproductive span, older age at menopause, older age at first and last birth, and use of hormonal contraceptives were positively associated with cognitive performance later in life. Number of live births, hysterectomy without oophorectomy and use of hormone therapy showed mixed findings, with task-specific positive and negative associations. Effect sizes were generally small (Cohen's d < 0.1). While APOE ε4 genotype was associated with reduced processing speed and executive functioning, in a dose-dependent manner, it did not influence the observed associations between female-specific factors and cognition.

Discussion

Our findings support previous evidence of associations between a broad range of female-specific factors and cognition. The positive association between a history of hormonal contraceptive use and cognition later in life showed the largest effect sizes (max. d = 0.1). More research targeting the long-term effects of female-specific factors on cognition and age-related neurocognitive disorders including Alzheimer's disease is crucial for a better understanding of women's brain health and to support women's health care.

Exploring the sex and gender correlates of cognitive sex differences

The correlates of cognitive sex differences are yet to be fully understood. Many biological and psychosocial factors modulate these cognitive abilities leading to mixed results in the scientific literature. The current study aims to explore the different parameters potentially influencing cognitive abilities acting in synergy. Sex and gender correlates of cognitive functioning were assessed in a sample of individuals ages 18 to 45 years (N = 87) from diverse sexual orientations. Sex hormones were assessed via saliva samples at four timepoints throughout the testing. Gender roles, sexual orientation and socio-demographics were measured via self-report questionnaires. Participants completed mental rotation and verbal fluency tasks. Men performed better than women at mental rotation, while no significant difference was found for verbal fluency. Significant positive associations were observed between estradiol and word fluency for the naturally cycling women compared to the women using oral contraception. While controlling for sex hormones, a significant interaction effect of sex by gender roles was identified for mental rotation among masculine women. These exploratory results suggest an effect principally driven by sex and sex hormones on cognitive performance that will need to be furthered with larger studies.

The relationship between fertility history and incident dementia in the US Health and Retirement Study

OBJECTIVES

An emerging literature suggests that fertility history, which includes measures of parity and birth timing, may influence cognitive health in older ages, especially among women given their differential exposure to pregnancy and sex hormones. Yet, few studies have examined associations between measures of fertility history and incident dementia in population-based samples.

METHODS

We examined the associations between parity, younger age at first birth, and older age at last birth with incident dementia over a 16-year period in a prospective sample of 15,361 men and women aged 51-100 years at baseline drawn from the Health and Retirement Study. We used Cox regression and the Fine and Gray model to obtain cause-specific (csHRs) and subdistribution hazard ratios (sdHRs) for incident dementia from gender-stratified models in which we accounted for the semi-competing risk of death.

RESULTS

During the follow-up period (median 13.0 years), the crude incidence rate for dementia was 16.6 and 19.9 per 1,000 person-years for men and women, respectively. In crude models estimating csHRs, higher parity (vs. parity 2) and younger age at first birth were associated with increased risk of dementia for both genders. These associations did not persist after full covariate adjustment. Across all models in which we estimated sdHRs, we observed a positive relationship between older age at last birth and incident dementia for women only.

DISCUSSION

In this population-based, multi-ethnic cohort, we observed limited evidence for an association between measures of fertility history and incident dementia among men and women after adjusting for potential confounders.

Age at last birth and risk of developing breast cancer: a meta-analysis

OBJECTIVES

Results from epidemiologic studies on age at last birth (ALB) and the risk of developing breast cancer were inconsistent. Therefore, we conducted this meta-analysis to evaluate the association between ALB and the risk of developing breast cancer quantitatively.

METHODS

Relevant articles published up to May 2019 were identified by searching systematically in PubMed, Web of Science, China National Knowledge Infrastructure, and Wan Fang Med Online. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Dose-response relationship was assessed by restricted cubic spline model.

RESULTS

Fourteen studies with 132 133 cases and 1 314 005 participants were eligible for this meta-analysis. The pooled RR (95% CI) of breast cancer for the highest vs. the lowest stratification of ALB was 1.22 (1.04-1.42). In the subgroup analysis, significant positive associations were also found in studies conducted in Europe (RR: 1.21, 95% CI: 1.06-1.38), studies with results adjusted for parity (RR: 1.26, 95% CI: 1.04-1.54), and studies with results adjusted for age at first birth (RR: 1.37, 95% CI: 1.08-1.74). The results of the dose-response analysis indicated that the departure from linearity was NS between ALB and the risk of breast cancer (Pnonlinearity = 0.711), but the linear associations were NS.

CONCLUSION

This meta-analysis suggested that ALB was positively associated with the risk of breast cancer. The risk of developing breast cancer increased gradually with the ALB for women. Our findings may have implications for family planning.

A Lifecourse Perspective on Female Sex-Specific Risk Factors for Later Life Cognition

PURPOSE OF REVIEW

The prevalence of Alzheimer's disease and related dementias is greater in women compared to men. We provide a review of female sex-specific risk factors across the lifecourse for cognition in older adulthood, highlighting areas that need further study.

RECENT FINDINGS

Pregnancy may affect late-life cognition, with adverse pregnancy outcomes associated with an increased risk of cognitive decline but parity providing a protective effect. Cumulative estrogen exposure, influenced by age of menarche, menopause, and exogenous estrogen use, may modify a woman's risk for dementia. Menopause transition-associated symptoms may impact cognitive health at the time of the symptoms, but long-term effects remain unknown. As compared to natural menopause, surgical menopause seems to increase the risk for cognitive impairment. Studies that have assessed the association between women's reproductive health and cognition have produced conflicting results. Future studies that address these inconsistencies among diverse populations are needed to better care for women throughout their lives.

Late Menarche, Not Reproductive Period, Is Associated with Poor Cognitive Function in Postmenopausal Women in Taiwan

Female sex hormones such as estrogen and progesterone play an important role in the regulation of a woman's body, including cognition and neurogenesis. However, the effects of age at menarche and reproductive period on cognitive function are still controversial. The aim of this study was to investigate the relationships between age at menarche and reproductive period with cognitive impairment. Data were obtained from the Taiwan Biobank. Cognitive function was assessed using the Mini Mental State Examination (MMSE) and its five subdomains. Multivariable linear regression analysis revealed that an old age at menarche (per one year; coefficient β, -0.189; p = 0.020) was significantly associated with a low total MMSE score, whereas reproductive period (p = 0.733) was not significantly associated with total MMSE score. Furthermore, an old age at menarche was significantly associated with low MMSE G2 (registration) (per one year; coefficient β, -0.022; p = 0.035) and G5 (language, construction and obey) scores (per one year; coefficient β, -0.054; p = 0.047). However, age at menarche was not significantly associated with MMSE G1 (orientation), G3 (attention and calculation) and G4 (recall) scores. In addition, reproductive period was not significantly associated with any MMSE subscores. Late menarche was associated with poor cognitive function, including low total MMSE score and low MMSE G2 and G5 scores. However, reproductive period was not associated with cognitive function in postmenopausal women.

Reproductive status impact on tau phosphorylation induced by chronic stress

Sex and exposure to chronic stress have been identified as risk factors for developing Alzheimer's disease (AD). Although AD has been demonstrated to be more prevalent in females, sex is often overlooked in research studies, likely due to the complexity of the hormonal status. In female rats, the reproductive status can modulate the well-known increase in tau phosphorylation (pTau) caused by the exposure to acute physical and psychological stressors. To test the hypothesis that reproductive status can impact hippocampal pTau induced by chronic stress, cohorts of virgin, lactating (4–5 days pp), and post-maternal (1-month post-weaned) rats were subjected to a daily 30-min episode of restraint stress for 14 days and were sacrificed either 20 min or 24 h after their last stress/handling episode. Western blot analysis of two well-characterized AD-relevant pTau epitopes (AT8 and PHF-1) and upstream pTau mechanisms (e.g. GSK3β) analysis, showed that stressed post-maternal rats have increased pTau in comparison to stressed lactating rats 20 min after their last stress episode. Furthermore, an increase in pTau was also seen 24 h after the last stress episode in stressed post-maternal rats in comparison to their non-stressed controls in the detergent-soluble fraction. GSK3 analysis showed an increase in total levels of GSK3β in virgin rats and an increase of inactive levels of GSK3β in post-maternal rats, which suggests a different stress response in pTau after the rat has gone through the maternal experience. Interestingly, post-maternal rats also presented the more variability in their estrous cycles in response to stress. Besides no differences in pTau, non-stressed lactating rats showed an increase in inactive GSK3β 24 h after the last handling episode. Immunohistochemical detection of the PHF-1 epitope revealed increased pTau in the CA4/hilar subfield of the hippocampus of virgin and post-maternal rats exposed to chronic stress shortly after their last stress episode. Overall, lactating rats remained unresponsive to chronic restraint stress. These results suggest increased sensitivity of the virgin and post-maternal rats to hippocampal stress-induced pTau with chronic restraint stress compared to lactating rats. Because no differences were detected in response to stress by lactating rats and an exaggerated response was observed in post-maternal rats, current results support the hypothesis that lactation affects tau processing in the brain of the female.

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pTau increases in the hippocampus of stressed virgin and especially post-maternal rats but not in that of lactating dams.

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The hippocampal area CA4 of virgin and post-maternal rats is most affected by the chronic restraint stress.

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GSK3β overall levels and activity are modified by the reproductive condition and stress.

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Reproductive experience modifies pTau induced by chronic stress.

Reproductive and hormonal factors and risk of cognitive impairment among Singapore Chinese women

BACKGROUND

Epidemiologic studies suggest that declining estrogen levels in menopause may play an important role in the pathogenesis of dementia and contribute to increased risk of cognitive impairment in women. Most previous studies have been conducted in Western populations to investigate the relationship of the length of reproductive periods and use of hormone-replacement therapy with risk of cognitive function and dementia, but the findings are inconclusive. Relevant evidence among Asian populations is limited.

OBJECTIVES

To evaluate the association between reproductive and hormonal factors and the risk of cognitive impairment in Chinese women with natural menopause.

STUDY DESIGN

The Singapore Chinese Health Study is a population-based study that recruited participants aged 45-74 years between 1993 and 1998, and the current study included 8222 women from this cohort who had natural menopause, complete data on reproductive factors and hormonal therapies at baseline (1993-1998), follow-up 1 (1999-2004) and follow-up 2 interviews (2006-2010), and cognitive function evaluated at ages 61-96 years using the Singapore Modified Mini-Mental State Examination during the follow-up 3 visits (2014-2016). Multivariable logistic regression models were used to estimate odds ratios and 95% confidence intervals for the risk of cognitive impairment.

RESULTS

Compared with women with menopause at 50-54 years of age, the odds ratios (95% confidence interval) were 1.67 (1.32-2.11), 1.24 (1.08-1.44), and 1.06 (0.87- 1.29) for women who experienced menopause before 45 years, at 45-49 years of age, and after 54 years, respectively. Compared with women with 35-39 reproductive years from menarche to menopause, the odds ratios (95% confidence interval) were 1.28 (1.11-1.48) for women with <35 reproductive years. Furthermore, compared with women who had 1-2 children, the odds ratios (95% confidence interval) were 1.27 (1.04-1.55) for women who had more than 5 children, and the risk increased significantly by 5% per child birth (odds ratio, 1.05; 95% confidence interval, 1.01-1.09). Compared with those who had never used oral contraceptives, women with short-term use (≤5 years) of oral contraceptives had 26% lower odds of having cognitive impairment (odds ratio, 0.74; 95% confidence interval, 0.63-0.87), whereas the association was not statistically significant for those used for more than 5 years (odds ratio, 0.87; 95% confidence interval, 0.68-1.13). Women who used hormone-replacement therapy had a 39% lower odd of getting cognitive impairment compared with nonusers (odds ratio, 0.61; 95% confidence interval, 0.46-0.80).

CONCLUSION

Our data suggest that shorter reproductive years and greater parity were associated with a greater risk of cognitive impairment in late life, whereas the use of oral contraceptives and hormone-replacement therapy was associated with decreased risk. As the population ages, understanding how these factors affect late-life cognitive function in women may help health professionals develop preventive measures targeting lifetime estrogen exposure from endogenous or exogenous sources.

The many menopauses: searching the cognitive research literature for menopause types

Objective:

Recent evidence suggests that early or induced menopause increases the risk for cognitive impairment and dementia. Given the potential for different cognitive outcomes due to menopause types, it is important that present research on menopause and cognition distinguishes between types. The aim of this project was to determine to what extent research looking at cognition in postmenopausal women published in one year, 2016, accounted for menopausal type.

Methods:

We searched MEDLINE, EMBASE, and PsychINFO using keywords and MeSH terms for menopause and cognition. We included any research paper reporting a cognitive outcome measure in a menopausal human population. Differentiation between the types of menopause was defined by four categories: undifferentiated, demographic differentiation (menopause type reported but not analyzed), partial differentiation (some but not all types analyzed), and full differentiation (menopause types factored into analysis, or recruitment of only one type).

Results:

Fifty research articles were found and analyzed. Differentiation was distributed as follows: undifferentiated, 38% (19 articles); demographic differentiation, 16% (8); partial differentiation, 28% (14); and full differentiation, 18% (9).

Conclusions:

This review revealed that although some clinical studies differentiated between the many menopauses, most did not. This may limit their relevance to clinical practice. We found that when menopause types are distinguished, the differing cognitive outcomes of each type are clarified, yielding the strongest evidence, which in turn will be able to inform best clinical practice for treating all women.

Does Gender Influence the Relationship Between High Blood Pressure and Dementia? Highlighting Areas for Further Investigation

BACKGROUND

Gender differences have been noted in studies linking blood pressure to all-cause dementia, and the two most common forms of dementia: Alzheimer's disease (AD) and vascular dementia (VaD). However, how gender modifies the relationship between blood pressure and dementia remains unclear.

OBJECTIVE

To review evidence for a gender modifying effect on the link between blood pressure and all-cause dementia.

METHODS

A systematic review was conducted according to PRISMA guidelines. Sixteen out of 256 reviewed articles met inclusion criteria.

RESULTS

For women, higher midlife systolic blood pressure (SBP) and hypertension were both associated with greater risk of all-cause dementia, AD, and VaD, in six out of seven studies. Two of these studies reported higher midlife SBP/hypertension were associated with greater risk for all-cause dementia in women, but not men. One study reported higher midlife SBP associated with greater AD risk in women, but not men. However, another study reported that midlife hypertension associated with AD risk in men, but not women. No clear gender differences were reported in the relationship between late-life high blood pressure/hypertension with all-cause dementia or AD.

CONCLUSION

Studies rarely, and inconsistently, analyzed or reported gender effects. Therefore, interpretation of available evidence regarding the role of gender in blood pressure associated dementia was difficult. Several studies indicated higher midlife SBP was associated with greater risk of all-cause dementia for women, compared to men. Future studies should evaluate women-specific aging processes that occur in midlife when considering the association between blood pressure and dementia risk.

Female reproductive factors and risk of external causes of death among women: The Japan Public Health Center-based Prospective Study (JPHC Study)

Although empirical data suggest a possible link between female reproductive events and risk of nonfatal accidents and suicidal behaviors, evidence to determine these effects on mortality is scarce. This study investigated the association between female reproductive factors and the risk of external causes of death among middle-aged Japanese women. We used a population-based cohort study consisting of 71 698 women residing in 11 public health center areas across Japan between 1990 and 1994. Multivariable-adjusted Cox proportional hazard regression models were used to estimate hazard ratios (HRs) of the risk of all external causes, suicide, and accidents according to female reproductive factors at the baseline survey. During 1 028 583 person-years of follow-up for 49 279 eligible subjects (average 20.9 years), we identified 328 deaths by all injuries. Among parous women, ever versus never breastfeeding [0.67 (95% CI: 0.49–0.92)] was associated with a decreased risk of all injuries. Risk of suicide was inversely associated with ever versus never parity [0.53 (95% CI: 0.32–0.88)]. A lower risk of death by accidents was seen in ever breastfeeding [0.63 (95% CI: 0.40–0.97)] compared to never breastfeeding. This study suggests that parity and breastfeeding are associated with reduced risk of death by all external causes, suicide and/or accidents among Japanese women.

Newborn Health Indicators Associated with Maternal Age during First Pregnancy

Delaying motherhood is becoming increasingly common, raising questions of the possible influence that maternal age may have on newborn health. Therefore, the objective of this study was to determine the association between maternal age and different newborn health parameters. An observational study was conducted in Spain on primiparous women and their infants. Data were collected on newborn health variables, breastfeeding, and different clinical practices that are beneficial for child health and development. Crude and adjusted mean differences were calculated along with the standard error of the mean. A total of 373 women and their children participated. In terms of early commencement skin-to-skin contact, the mean age of women that did skin-to-skin contact was 29.95 ± 0.31 years compared to 31.49 ± 0.66 years in those that did not (p = 0.042). In terms of other newborn parameters, such as preterm birth, health problems or complications, or the need for hospital admission, these were more frequent in the oldest group of mothers, but the differences found were not significant (p > 0.05). Hence, indicators of newborn morbidity were not found to be significantly associated with maternal age; however, beneficial practices such as early commencement skin-to-skin contact were found to be significantly associated with maternal age.

Age at last birth and risk of developing epithelial ovarian cancer: a meta-analysis

Background: Many epidemiologic studies have explored the association between age at last birth (ALB) and the risk of epithelial ovarian cancer, but the results remain controversial. Methods: A literature search was performed in PubMed, Web of Science, China National Knowledge Infrastructure (CNKI) and WanFang Med Online for relevant articles published up to April 2019. Pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated using a random-effect model. Dose-response relationship was assessed by restricted cubic spline model. Results: Thirteen articles with 19,959 cases and 2,451,071 participants were included in our meta-analysis, and we found that ALB was negatively associated with epithelial ovarian cancer. The pooled RR (95% CI) of epithelial ovarian cancer for the highest versus the lowest stratification of ALB was 0.77 (0.65-0.91). Furthermore, significantly negative associations were shown in case-control studies (RR: 0.73; 95% CI: 0.60-0.88), studies conducted in North America (RR: 0.71; 95% CI: 0.60-0.84), studies with adjustment for parity (RR: 0.76; 95%CI: 0.63-0.93), studies with adjustment for tubal ligation (RR: 0.74; 95% CI: 0.58-0.94), in the subgroup analysis. In dose-response analysis, the risk of epithelial ovarian cancer decreased nonlinearly with the increase of ALB, and the negative results become significant when ALB was 22.5 years old. Conclusion: This meta-analysis suggested that ALB was negatively associated with the risk of epithelial ovarian cancer. The risk of epithelial ovarian cancer decreased gradually with the ALB for women.

Applying a Women's Health Lens to the Study of the Aging Brain

A major challenge in neuroscience is to understand what happens to a brain as it ages. Such insights could make it possible to distinguish between individuals who will undergo typical aging and those at risk for neurodegenerative disease. Over the last quarter century, thousands of human brain imaging studies have probed the neural basis of age-related cognitive decline. "Aging" studies generally enroll adults over the age of 65, a historical precedent rooted in the average age of retirement. A consequence of this research tradition is that it overlooks one of the most significant neuroendocrine changes in a woman's life: the transition to menopause. The menopausal transition is marked by an overall decline in ovarian sex steroid production-up to 90% in the case of estradiol-a dramatic endocrine change that impacts multiple biological systems, including the brain. Despite sex differences in the risk for dementia, the influence that biological sex and sex hormones have on the aging brain is historically understudied, leaving a critical gap in our understanding of the aging process. In this Perspective article, we highlight the influence that endocrine factors have on the aging brain. We devote particular attention to the neural and cognitive changes that unfold in the middle decade of life, as a function of reproductive aging. We then consider emerging evidence from animal and human studies that other endocrine factors occurring earlier in life (e.g., pregnancy, hormonal birth control use) also shape the aging process. Applying a women's health lens to the study of the aging brain will advance knowledge of the neuroendocrine basis of cognitive aging and ensure that men and women get the full benefit of our research efforts.

Maternal Age and Pregnancy, Childbirth and the Puerperium: Obstetric Results

Delaying maternity is becoming more common, resulting in questions regarding the influence age may have on obstetric results. Therefore, we proposed the objective to determine the association between maternal age and different health variables during pregnancy, childbirth and the puerperium. We conducted an observational study in Spain with primiparous women in which data was collected on sociodemographic, health and obstetric variables. Crude and adjusted mean differences were calculated with their corresponding 95% confidence intervals. The study included a final sample of 373 women. The mean age of women presenting with hypertension during pregnancy was 34.54 years (95% CI: 31.80–37.27) compared with a mean of 30.11 (95% CI: 29.56–30.66) in women that did not (p = 0.002). Women who had a eutocic delivery were also younger: 29.17 years (95% CI: 28.48–29.86) compared with 31.90 years (95% CI: 31.05–32.74; p < 0.001) for those that had a dystocic delivery. The duration of dilatation was longer in those ≥35 years (p = 0.001). In conclusion, an advanced maternal age is associated with a higher incidence of pathology during pregnancy and dystocic labor.

Oral Contraceptives and Cigarette Smoking: A Review of the Literature and Future Directions

INTRODUCTION

Evidence continues to mount indicating that endogenous sex hormones (eg, progesterone and estradiol) play a significant role in smoking-related outcomes. Although approximately one out of four premenopausal smokers use oral contraceptives (OCs), which significantly alter progesterone and estradiol levels, relatively little is known about how OCs may influence smoking-related outcomes. Thus, the goal of this review article is to describe the state of the literature and offer recommendations for future directions.

METHODS

In March 2017, we searched seven databases, with a restriction to articles written in English, using the following keywords: nicotine, smoker(s), smoking, tobacco, cigarettes, abstinence, withdrawal, and craving(s). We did not restrict on the publication date, type, or study design.

RESULTS

A total of 13 studies were identified. Three studies indicated faster nicotine metabolism in OC users compared to nonusers. Five of six laboratory studies that examined physiological stress response noted heightened response in OC users compared to nonusers. Three studies examined cessation-related symptomatology (eg, craving) with mixed results. One cross-sectional study observed greater odds of current smoking among OC users, and no studies have explored the relationship between OC use and cessation outcomes.

CONCLUSIONS

Relatively few studies were identified on the role of OCs in smoking-related outcomes. Future work could explore the relationship between OC use and mood, stress, weight gain, and brain function/connectivity, as well as cessation outcomes. Understanding the role of OC use in these areas may lead to the development of novel smoking cessation interventions for premenopausal women.

IMPLICATIONS

This is the first review of the relationship between oral contraceptives (OCs) and smoking-related outcomes. The existing literature suggests that the use of OCs is related to increased nicotine metabolism and physiological stress response. However, the relationship between OC use and smoking-related symptoms (eg, craving) is mixed. Further, no published data were available on OC use and smoking cessation outcomes. Therefore, we recommend additional research be conducted to characterize the relationship between OC use and smoking cessation outcomes, perhaps as a function of the effect of OC use on mood, stress, weight gain, and brain function/connectivity.

The long and short term effects of motherhood on the brain

Becoming a mother is associated with dramatic changes in physiology, endocrinology, immune function, and behaviour that begins during pregnancy and persists into the postpartum. Evidence also suggests that motherhood is accompanied by long-term changes in brain function. In this review, we summarize the short (pregnancy and postpartum) and long-term (beyond the postpartum and into middle age) effects of pregnancy and motherhood on cognition, neuroplasticity, and neuroimmune signalling. We also discuss the effects of previous history of pregnancy and motherhood (parity) on brain health and disease (neurodegenerative diseases and stroke outcomes) and on efficacy of hormone and antidepressant treatments. Finally, we argue that pregnancy and motherhood are unique female experiences that need to be taken into account to better understand female brain function and aging.

Cognitive Changes with Reproductive Aging, Perimenopause, and Menopause

This article reviews the role of endogenous estrogen in neural and cognitive processing, followed by an examination of longitudinal cognitive data captured in various stages of the menopausal transition. The remaining text reviews the contradictory results from major hormone therapy trials to date, evidence for the "timing hypothesis," and closes with recommendations for future research and for practicing clinicians.

Does the use of hormonal contraceptives affect the mental rotation performance?

Oral contraceptive pill (OC) is one of the most popular form of contraception. Despite both behavioral and neuroimaging evidence of its significant impact on female brain and cognitive functions, much remains to be discovered regarding OCs targets in the brain and mechanisms of action. In the present study mental rotation performance was compared between women using anti-androgenic oral contraceptives (n = 35), naturally cycling (NC) women (n = 33) and men (n = 29). On average, OC users were less accurate than NC women and men. Men performed the task more accurately than NC women, but the difference reached significance only in the highest angular disparity condition (150 deg). The response time was positively related with progesterone level while accuracy was negatively related with 17ß-estradiol level, in NC, but not OC women. The comparison of slope and intercept values (parameters relating response time to angular disparity) revealed the main result of present study: OC users exhibited significantly lower slope compared to men and NC women, but there were no differences in intercept between groups. These results suggest that OC users instead of using rotation in mind strategy implemented some alternative method(s). We conclude that lower performance accuracy of OC users could be related to a less efficient performance strategy.

Tau Phosphorylation in Female Neurodegeneration: Role of Estrogens, Progesterone, and Prolactin

Sex differences are important to consider when studying different psychiatric, neurodevelopmental, and neurodegenerative disorders, including Alzheimer's disease (AD). These disorders can be affected by dimorphic changes in the central nervous system and be influenced by sex-specific hormones and neuroactive steroids. In fact, AD is more prevalent in women than in men. One of the main characteristics of AD is the formation of neurofibrillary tangles, composed of the phosphoprotein Tau, and neuronal loss in specific brain regions. The scope of this work is to review the existing evidence on how a set of hormones (estrogen, progesterone, and prolactin) affect tau phosphorylation in the brain of females under both physiological and pathological conditions.