Oophorectomy, menopause, estrogen treatment, and cognitive aging: clinical evidence for a window of opportunity

Epidemiological Evidence on the Associations of Metal Exposure with Alzheimer's Disease and Related Dementias Among Elderly Women

Background: Emerging evidence suggests a potential link between heavy metals and Alzheimer's disease and related dementias (AD/ADRD). This study compiled epidemiological evidence from research published over the past 11 years on the impact of metals on AD/ADRD in women. Women have unique risk factors for late onset of AD/ADRD, in addition to genetic factors, apolipoprotein E allele (APOE4), and longer life expectancy. Furthermore, women are twice likely as men to experience depression, which increases their risk of developing AD/ADRD. Our narrative review underscored the necessity of a sex-specific approach to address women's vulnerability to AD/ADRD. Methods: Electronic databases, including PubMed, Google Scholar, NIOSH Toxline, and Scopus, were thoroughly searched to identify primary epidemiological studies on older women exposed to metals and published between 2014 to 2024. Results: We identified 34 epidemiological studies that met the inclusion criteria. The findings revealed a complex interplay between environmental metals such as lead (Pb), cadmium (Cd), arsenic (As), manganese (Mn), selenium (Se), iron (Fe), zinc (Zn), copper (Cu), magnesium (Mg), and calcium (Ca) and the risk of AD/ADRD in women. Significant adverse effects were reported for Cu, Cd, As, Pb, and Mn while significant protective effects were found between Se, Fe, and Zn in blood and AD/ADRD among older women. However, some studies also reported no correlations. Conclusions: Overall, our review identified contrasting results regarding the effects of metals on AD/ADRD in women. Future studies should collect additional evidence to understanding the effects of heavy metals on AD/ADRD in women for developing preventive measures.

Prenatal immune origins of brain aging differ by sex

With an increasing aging population and Alzheimer's disease tsunami, it is critical to identify early antecedents of brain aging to target for intervention and prevention. Women and men develop and age differently, thus using a sex differences lens can contribute to identification of early risk biomarkers and resilience. There is growing evidence for fetal antecedents to adult memory impairments, potentially through disruption of maternal prenatal immune pathways. Here, we hypothesized that in utero exposure to maternal pro-inflammatory cytokines will have sex-dependent effects on specific brain circuitry regulating offspring's memory and immune function that will be retained across the lifespan. Using a unique prenatal cohort, we tested this in 204 adult offspring, equally divided by sex, who were exposed/unexposed to an adverse in utero maternal immune environment and followed into early midlife (~age 50). Functional magnetic resonance imaging results showed exposure to pro-inflammatory cytokines in utero (i.e., higher maternal IL-6 and TNF-α levels) was significantly associated with sex differences in brain activity and connectivity underlying memory circuitry and performance and with a hyperimmune state, 50 years later. In contrast, the anti-inflammatory cytokine, IL-10 alone, was not significantly associated with memory circuitry in midlife. Predictive validity of prenatal exposure was underscored by significant associations with age 7 academic achievement, also associated with age 50 memory performance. Results uniquely demonstrated that adverse levels of maternal in utero pro-inflammatory cytokines during a critical period of the sexual differentiation of the brain produced long-lasting effects on immune function and memory circuitry/function from childhood to midlife that were sex-dependent, brain region-specific, and, within women, reproductive stage-dependent.

Premenopausal and perimenopausal predictors of postmenopausal health and well-being: Testing a disposition-belief-motivation framework

The present study tested a Disposition-Belief-Motivation model of peri- and post-menopausal health and well-being using a 20-year prospective design from the Midlife in the United States (MIDUS) study. Screening algorithms based on World Health Organization guidelines produced a sample of women that was premenopausal at Time 1, perimenopausal at Time 2, and postmenopausal at Time 3 (N = 247). Prospective path modeling tested the direct and indirect effects of premenopausal factors on peri- and post-menopausal health and well-being. The results showed positive premenopausal attitudes toward aging were directly associated with greater postmenopausal well-being. Older baseline age was indirectly associated with greater postmenopausal well-being through perimenopausal well-being. Greater premenopausal functional ability was indirectly associated with greater self-rated postmenopausal health via greater perimenopausal self-rated health. Although premenopausal factors predicted perimenopausal optimism, coping, and symptoms, none was directly associated with postmenopausal health or well-being. Controlling for perimenopausal health and well-being, the results highlight the roles of greater premenopausal age, greater functional ability, and less concern about fertility, attractiveness, and illness in predicting perceptions of health and well-being across the menopause transition. The finding for aging attitudes, in particular, suggests the importance of reinforcing positive messaging and norms for women's aging and health, rather than medicalizing menopause and its symptoms.

The role of estrogen in Alzheimer's disease pathogenesis and therapeutic potential in women

Estrogens are pivotal regulators of brain function throughout the lifespan, exerting profound effects from early embryonic development to aging. Extensive experimental evidence underscores the multifaceted protective roles of estrogens on neurons and neurotransmitter systems, particularly in the context of Alzheimer's disease (AD) pathogenesis. Studies have consistently revealed a greater risk of AD development in women compared to men, with postmenopausal women exhibiting heightened susceptibility. This connection between sex factors and long-term estrogen deprivation highlights the significance of estrogen signaling in AD progression. Estrogen's influence extends to key processes implicated in AD, including amyloid precursor protein (APP) processing and neuronal health maintenance mediated by brain-derived neurotrophic factor (BDNF). Reduced BDNF expression, often observed in AD, underscores estrogen's role in preserving neuronal integrity. Notably, hormone replacement therapy (HRT) has emerged as a sex-specific and time-dependent strategy for primary cardiovascular disease (CVD) prevention, offering an excellent risk profile against aging-related disorders like AD. Evidence suggests that HRT may mitigate AD onset and progression in postmenopausal women, further emphasizing the importance of estrogen signaling in AD pathophysiology. This review comprehensively examines the physiological and pathological changes associated with estrogen in AD, elucidating the therapeutic potential of estrogen-based interventions such as HRT. By synthesizing current knowledge, it aims to provide insights into the intricate interplay between estrogen signaling and AD pathogenesis, thereby informing future research directions and therapeutic strategies for this debilitating neurodegenerative disorder.

Estrogens and human brain networks: A systematic review of structural and functional neuroimaging studies

Estrogen fluctuations during the menstrual cycle, puberty, postpartum, or in the menopausal transition are associated with cognitive, affective, and behavioral effects. Additionally, estrogens are essential in hormonal contraception, menopausal hormone therapy, or gender-affirming hormone therapy. This systematic review summarizes findings on the role of estrogens for structure, function, and connectivity of human brain networks. We searched PubMed, Web of Science, and ScienceDirect for neuroimaging articles assessing estrogens published since 2008. We included 54 studies (N = 2,494 participants) on endogenous estrogen, and 28 studies (N = 1,740 participants) on exogenous estrogen conditions. Estrogen-related changes were reported for emotion, reward, memory, and resting-state networks, and in regional white and gray matter, with a particular neural plasticity in the hippocampus and amygdala. By examining study designs, imaging measures, and analysis methods, this review highlights the role of neuroimaging in advancing neuroendocrine and neurocognitive research, particularly promoting brain health for women and individuals with ovaries.

A comprehensive proteomic analysis reveals novel inflammatory biomarkers in intracranial aneurysms

Inflammation is a complex factor in the pathogenesis of intracranial aneurysms (IA), but its specific cellular inflammatory factors remain uncertain. We collected two cohorts and measured the representation of vascular inflammation-related proteins using the Olink CVD II Vascular Inflammation Panel. We subsequently validated our findings using ELISA and RT-qPCR. Our proteomic analysis identified 11 vascular inflammation-related markers that were significantly differentially represented between the IA and control groups. These markers were implicated in leukocyte migration, immune response, triglyceride and lipoprotein metabolism, acute phase response, T cell regulation, and several key biological pathways, including PPAR, HIF-1, cytokine-cytokine interactions, and PI3K-AKT signaling. Further validation with ELISA and RT-qPCR confirmed the differential representation of IL6, PTX3, LPL, and OLR1 between the two groups. Notably, a combination marker incorporating these four factors demonstrated high diagnostic potential for the early detection of IA. Our study has identified a set of informative biomarkers (IL6, PTX3, LPL, and OLR1) that could be valuable for the early diagnosis of IA. Importantly, this is the first report of significantly elevated OLR1 representation in the plasma of IA patients. Further investigation into the role of OLR1 in the pathogenesis of IA is warranted. SIGNIFICANCE: This study significantly advances our understanding of the molecular mechanisms underlying intracranial aneurysm (IA) pathogenesis. By identifying a panel of novel biomarkers, including the previously unreported elevated expression of OLR1 in IA patients, we provide crucial insights into the inflammatory processes involved in aneurysm formation and development. These findings have important clinical implications, as the identified biomarkers could serve as valuable tools for early diagnosis and potentially targeted therapeutic interventions. Furthermore, the study highlights the complex interplay of inflammatory pathways in IA, suggesting that a multi-faceted approach may be necessary for effective management.

Associations between hormone therapy use and tau accumulation in brain regions vulnerable to Alzheimer's disease

Elucidating the downstream impact of exogenous hormones on the aging brain will have far-reaching consequences for understanding why Alzheimer's disease (AD) predominates in women almost twofold over men. We tested the extent to which menopausal hormone therapy (HT) use is associated with later-life amyloid-β (Aβ) and tau accumulation using PET on N = 146 baseline clinically normal women, aged 51 to 89 years. Women were scanned over a 4.5-year (SD, 2.1; range, 1.3 to 10.4) and 3.5-year (SD, 1.5; range, 1.2 to 8.1) period for Aβ and tau, respectively, ~14 years after the initiation of HT. In older women (aged >70 years), HT users exhibited faster regional tau accumulation relative to non-users, localized to the entorhinal cortex and the inferior temporal and fusiform gyri, with an indirect effect of HT on cognitive decline through regional tau accumulation. In younger women (aged <70 years), HT associations with tau accumulation were negligible. Findings are relevant for optimizing menopausal treatment guidelines.

Strategies for studying sex differences in brain aging

Studying sex effects and their underlying mechanisms is of major relevance to understanding brain health. Despite growing interests, experimentally studying sex differences, particularly in the context of aging, remains challenging. Since sex chromosomal content influences gonadal development, separating the effects of gonadal hormones and chromosomal factors requires specific model systems. Here, we highlight rodent and tractable models for examining sex dimorphism in brain and cognitive aging. In addition, we discuss multi-omic and bioinformatic approaches that yield biological insights from animal and human studies. This review provides a comprehensive overview of the diverse toolkit now available to advance our understanding of sex differences in brain aging.

Ovarian Aging: The Silent Catalyst of Age-Related Disorders in Female Body

Age-related diseases have emerged as a global concern as the population ages. Consequently, understanding the underlying causes of aging and exploring potential anti-aging interventions is imperative. In females, the ovaries serve as the principal organs responsible for ovulation and the production of female hormones. The aging ovaries are related to infertility, menopause, and associated menopausal syndromes, with menopause representing the culmination of ovarian aging. Current evidence indicates that ovarian aging may contribute to dysfunction across multiple organ systems, including, but not limited to, cognitive impairment, osteoporosis, and cardiovascular disease. Nevertheless, due to the widespread distribution of sex hormone receptors throughout the body, ovarian aging affects not only these specific organs but also influences a broader spectrum of age-related diseases in women. Despite this, the impact of ovarian aging on overall age-related diseases has been largely neglected. This review provides a thorough summary of the impact of ovarian aging on age-related diseases, encompassing the nervous, circulatory, locomotor, urinary, digestive, respiratory, and endocrine systems. Additionally, we have outlined prospective therapeutic approaches for addressing both ovarian aging and age-related diseases, with the aim of mitigating their impacts and preserving women's fertility, physical health, and psychological well-being.

Treating new-onset cognitive complaints after risk-reducing salpingo-oophorectomy: A randomized controlled crossover trial of lisdexamfetamine

OBJECTIVE

To determine whether the psychostimulant lisdexamfetamine improves subjective and objective measures of cognitive functioning among women genetically at-risk for cancer who have undergone risk-reducing salpingo-oophorectomy and report new-onset executive functioning difficulties.

METHODS

69 participants were assigned to a randomized controlled crossover trial with 6-week trials of active medication (lisdexamfetamine) and placebo, separated by a minimum 2-week washout in an intent-to-treat framework (clinical trial registration number: NCT03187353). At trial baseline, midpoint, and endpoint, participants completed a self-report measure of executive functioning (Brown Attention Deficit Disorder Scale). At study baseline and trial endpoint, participants completed sustained attention, attention/working memory, and verbal learning/memory cognitive tasks. Side effects were assessed at 2, 3, 4, and 6 weeks for each trial.

RESULTS

From trial baseline to trial endpoint, lisdexamfetamine - relative to placebo - significantly improved total scores on the self-report Brown Attention Deficit Disorder Scale (and scores on four of five subdomains) as well as attention and working memory performance. Significantly more participants endorsed side effects across the lisdexamfetamine trial versus placebo; however, trial completion rates were similar, indicating that lisdexamfetamine was nonetheless well-tolerated.

CONCLUSIONS

Lisdexamfetamine improved both subjective and objective measures of attention and working memory and could offer women experiencing cognitive difficulties post-risk-reducing salpingo-oophorectomy an alternative therapeutic option.

Leukocyte telomere length and memory circuitry and cognition in early aging: Impact of sex and menopausal status

Telomere length (TL) is an important cellular marker of biological aging impacting the brain and heart. However, how it is related to the brain (e.g., cognitive function and neuroanatomic architecture), and how these relationships may vary by sex and reproductive status, is not well established. Here we assessed the association between leukocyte TL and memory circuitry regional brain volumes and memory performance in early midlife, in relation to sex and reproductive status. Participants (N = 198; 95 females, 103 males; ages 45-55) underwent structural MRI and neuropsychological assessments of verbal, associative, and working memory. Overall, shorter TL was associated with smaller white matter volume in the parahippocampal gyrus and dorsolateral prefrontal cortex. In males, shorter TL was associated with worse working memory performance and corresponding smaller white matter volumes in the parahippocampal gyrus, anterior cingulate cortex, and dorsolateral prefrontal cortex. In females, the impact of cellular aging was revealed over the menopausal transition. In postmenopausal females, shorter TL was associated with poor associative memory performance and smaller grey matter volume in the right hippocampus. In contrast, TL was not related to memory performance or grey and white matter volumes in any memory circuitry region in pre/perimenopausal females. Results demonstrated that shorter TL is associated with worse memory function and smaller volume in memory circuitry regions in early midlife, an association that differs by sex and reproductive status. Taken together, TL may serve as an early indicator of sex-dependent brain abnormalities in early midlife.

Risks and benefits of hormone therapy after menopause for cognitive decline and dementia: A conceptual review

OBJECTIVE

The effects on the brain of hormone therapy after the onset of menopause remain uncertain. The effects may be beneficial, neutral, or harmful. We provide a conceptual review of the evidence.

METHODS

We 1) provide a brief history of the evidence, 2) discuss some of the interpretations of the evidence, 3) discuss the importance of age at menopause, type of menopause, and presence of vasomotor symptoms, and 4) provide some clinical recommendations.

RESULTS

The evidence and the beliefs about hormone therapy and dementia have changed over the last 30 years or more. Five recent observation studies suggested that hormone therapy is associated with an increased risk of dementia, and the association appears not to change with the timing of initiation of therapy. These harmful associations may be explained by a causal effect of hormone therapy on the brain or by several confounding mechanisms. We suggest that the use of hormone therapy should be customized for different subgroups of women. It may be important to subgroup women based on age at onset of menopause, type of menopause, and presence or absence of vasomotor symptoms. In addition, the effects may vary by type, dose, route, and duration of administration of estrogens and by the concurrent use of progestogens.

DISCUSSION

The relation of hormone therapy with the risk of dementia is complex. Hormone therapy may have beneficial, neutral, or harmful effects on the brain. Hormone therapy should be guided by the clinical characteristics of the women being treated.

Estradiol improves behavior in FAD transgenic mice that express APOE3 but not APOE4 after ovariectomy

Increasing evidence suggests that female individuals have a higher Alzheimer's disease (AD) risk associated with post-menopausal loss of circulating estradiol (E2). However, clinical data are conflicting on whether E2 lowers AD risk. One potential contributing factor is APOE. The greatest genetic risk factor for AD is APOE4, a factor that is pronounced in female individuals post-menopause. Clinical data suggests that APOE impacts the response of AD patients to E2 replacement therapy. However, whether APOE4 prevents, is neutral, or promotes any positive effects of E2 is unclear. Therefore, our goal was to determine whether APOE modulates the impact of E2 on behavior and AD pathology in vivo. To that end, mice that express human APOE3 (E3FAD) or APOE4 (E4FAD) and overproduce Aβ42 were ovariectomized at either 4 months (early) or 8 months (late) and treated with vehicle or E2 for 4 months. In E3FAD mice, we found that E2 mitigated the detrimental effect of ovariectomy on memory, with no effect on Aβ in the early paradigm and only improved learning in the late paradigm. Although E2 lowered Aβ in E4FAD mice in the early paradigm, there was no impact on learning or memory, possibly due to higher Aβ pathology compared to E3FAD mice. In the late paradigm, there was no effect on learning/memory and Aβ pathology in E4FAD mice. Collectively, these data support the idea that, in the presence of Aβ pathology, APOE impacts the response to E2 supplementation post-menopause.

Estradiol-mediated modulation of memory and of the underlying dendritic spine plasticity through the life span

The morphophysiology of the nervous system changes and adapts in response to external environmental inputs and the experiences of individuals throughout their lives. Other changes in the organisms internal environment can also contribute to nervous system restructuring in the form of plastic changes that underlie its capacity to adapt to emerging psychophysiological conditions. These adaptive processes lead to subtle modifications of the organisms internal homeostasis which is closely related with the activity of chemical messengers, such as neurotransmitters and hormones. Hormones reach the brain through the bloodstream, where they activate specific receptors through which certain biochemical, physiological, and morphological changes take place in numerous regions. Fetal development, infancy, puberty, and adulthood are all periods of substantial hormone-mediated brain remodeling in both males and females. Adulthood, specifically, is associated with a broad range of life events, including reproductive cycles in both sexes, and pregnancy and menopause in women. Events of this kind occur concomitantly with eventual modifications in behavioral performance and, especially, in cognitive abilities like learning and memory that underlie, at least in part, plastic changes in the dendritic spines of the neuronal cells in cerebral areas involved in processing cognitive information. Estrogens form a family that consists of three molecules [17β-estradiol (E2), estrone, estriol] which are deeply involved in regulating numerous bodily functions in different stages of the life-cycle, including the modulation of cognitive performance. This review addresses the effects of E2 on the dendritic spine-mediated synaptic organization of cognitive performance throughout the life span.

Association of bilateral oophorectomy with incidence of Parkinson's disease: A systematic review and meta-analysis

INTRODUCTION

Current evidence in the literature is inconclusive due to conflicting results with regards to an association between B/L (B/L) oophorectomy and Parkinson's disease (PD). We included large, powered studies to assess the association of PD in women who have undergone B/L oophorectomy.

METHODS

We conducted a comprehensive search across three databases from inception to October 2022 for observational studies including pre-menopausal or post-menopausal women undergoing B/L oophorectomy. Primary outcome of interest was incidence of PD or parkinsonism. The results for these associations were presented as Risk Ratios (RR) with 95% confidence intervals (CI), which were pooled using a generic invariance weighted random effects model using Review Manager (RevMan).

RESULTS

Data was included from a total of 4 studies. No significant association was found between B/L oophorectomy and PD (RR: 1.38; 95% CI: 0.76 to 2.49; I2:89 %) in contrast significant association was found with parkinsonism (RR: 1.80; 95% CI: 1.29 to 2.52). Age at surgery didn't significantly affect Parkinsonism incidence (RR: 0.88; 95% CI: 0.59 to 1.3). No significant association was found between ovarian indication and Parkinsonism (RR: 1.08; 95% CI: 0.69 to 1.68). B/L oophorectomy with hysterectomy was associated with higher Parkinson's risk compared to without hysterectomy (RR: 1.4; 95% CI: 1.13 to 1.74). Lastly, there was no significant association between Post Menopausal Hormonal (PMH) use and Parkinson's disease (RR: 1.07; 95% CI: 0.92 to 1.26).

CONCLUSION

Our findings suggest that B/L oophorectomy is significantly associated with the incidence of Parkinsonism. Further research is needed to understand the potential relationship between oophorectomy and Parkinson's disease.

Microglial immunometabolism endophenotypes contribute to sex difference in Alzheimer's disease

INTRODUCTION

The molecular mechanisms that contribute to sex differences, in particular female predominance, in Alzheimer's disease (AD) prevalence, symptomology, and pathology, are incompletely understood.

METHODS

To address this problem, we investigated cellular metabolism and immune responses ("immunometabolism endophenotype") across AD individuals as a function of sex with diverse clinical diagnosis of cognitive status at death (cogdx), Braak staging, and Consortium to Establish a Registry for AD (CERAD) scores using human cortex metabolomics and transcriptomics data from the Religious Orders Study / Memory and Aging Project (ROSMAP) cohort.

RESULTS

We identified sex-specific metabolites, immune and metabolic genes, and pathways associated with the AD diagnosis and progression. We identified female-specific elevation in glycerophosphorylcholine and N-acetylglutamate, which are AD inflammatory metabolites involved in interleukin (IL)-17 signaling, C-type lectin receptor, interferon signaling, and Toll-like receptor pathways. We pinpointed distinct microglia-specific immunometabolism endophenotypes (i.e., lipid- and amino acid-specific IL-10 and IL-17 signaling pathways) between female and male AD subjects. In addition, female AD subjects showed evidence of diminished excitatory neuron and microglia communications via glutamate-mediated immunometabolism.

DISCUSSION

Our results point to new understanding of the molecular basis for female predominance in AD, and warrant future independent validations with ethnically diverse patient cohorts to establish a likely causal relationship of microglial immunometabolism in the sex differences in AD.

HIGHLIGHTS

Sex-specific immune metabolites, gene networks and pathways, are associated with Alzheimer's disease pathogenesis and disease progression. Female AD subjects exhibit microglial immunometabolism endophenotypes characterized by decreased glutamate metabolism and elevated interleukin-10 pathway activity. Female AD subjects showed a shift in glutamate-mediated cell-cell communications between excitatory neurons to microglia and astrocyte.

Natural vs. Surgical Postmenopause and Psychological Symptoms Confound the Effect of Menopause on Executive Functioning Domains of Cognitive Experience

Objective

The menopause transition is associated with difficulties in executive function. However, it is unclear whether these difficulties persist past perimenopause. This study investigated whether potential confounders, including natural vs. surgical postmenopause and menopause-related psychological symptoms, influence whether executive dysfunction persists into postmenopause.

Study Design

A cross-sectional sample of women aged 35-65 years (N = 1971) in one of four groups, premenopause, perimenopause, natural postmenopause, and surgical postmenopause, were surveyed. Participants self-reported executive functioning with the Brown Attention Deficit Disorder Scale (BADDS), anxiety symptom severity with the Generalized Anxiety Disorder Questionnaire (GAD-7), and depression symptom severity with the Center for Epidemiologic Studies Depression Scale (CES-D).

Main Outcome Measures

We analyzed the association between group and BADDS scores using linear regression models - first, by controlling for age, education, and self-reported attention deficit hyperactivity disorder (ADHD) diagnosis (Model #1) and, second, by further controlling for current difficulty sleeping, anxiety, and depression (Model #2).

Results

In both models, BADDS scores were significantly elevated (indicating more difficulties in executive function) among women in the perimenopausal and surgical postmenopausal groups compared with those in the premenopausal group. Likewise, the perimenopausal and surgical postmenopausal groups had the highest proportions of participants who reported difficulty sleeping and clinical levels of anxiety and depression. BADDS scores were significantly higher in natural postmenopausal vs. premenopausal women without controlling for difficulty sleeping, anxiety, and depression (Model #1), but not when adjusting for these variables (Model #2).

Conclusions

The type of menopause and psychological symptoms are important confounders of the relationship between the menopause transition and executive dysfunction, and help explain whether executive dysfunction persists or recovers in postmenopause.Reprinted from Maturitas 2023; 170:64-73, with permission from Elsevier. Copyright © 2023.

Sex and Sleep Disruption as Contributing Factors in Alzheimer's Disease

Alzheimer's disease (AD) affects more women than men, with women throughout the menopausal transition potentially being the most under researched and at-risk group. Sleep disruptions, which are an established risk factor for AD, increase in prevalence with normal aging and are exacerbated in women during menopause. Sex differences showing more disrupted sleep patterns and increased AD pathology in women and female animal models have been established in literature, with much emphasis placed on loss of circulating gonadal hormones with age. Interestingly, increases in gonadotropins such as follicle stimulating hormone are emerging to be a major contributor to AD pathogenesis and may also play a role in sleep disruption, perhaps in combination with other lesser studied hormones. Several sleep influencing regions of the brain appear to be affected early in AD progression and some may exhibit sexual dimorphisms that may contribute to increased sleep disruptions in women with age. Additionally, some of the most common sleep disorders, as well as multiple health conditions that impair sleep quality, are more prevalent and more severe in women. These conditions are often comorbid with AD and have bi-directional relationships that contribute synergistically to cognitive decline and neuropathology. The association during aging of increased sleep disruption and sleep disorders, dramatic hormonal changes during and after menopause, and increased AD pathology may be interacting and contributing factors that lead to the increased number of women living with AD.

Association between cognitive function and dusty weather: a propensity score matching study

BACKGROUND

With a rapidly aging global population, the health of older adults is a national priority for countries across the world. Dusty weather has been demonstrated to be a potential risk factor of cognitive function among the elderly population. However, there is a paucity of studies exploring the associations between dusty weather and cognitive function among the older in China.

METHODS

Data on individual characteristics were obtained from the China Health and Retirement Longitudinal Survey (CHARLS) 2018, whereas data on air pollution were sourced from environmental monitoring stations in China. Cognitive function, including general cognitive function, episodic memory, and linguistic competence, was assessed by self- or informant-questionnaires. We used propensity score matching and linear regression to investigate the relationship between dusty weather and cognitive function. Sensitivity analyses were conducted to test the robustness of the results.

RESULTS

This study included 8,604 participants older than 60 years old. After controlling air pollutant weather, dusty weather was demonstrated to be positively associated with a decline in cognitive function (Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE), 4.0, 95% confidence interval (CI): 3.11, 4.89; Mini-Mental State Exam (MMSE), 0.63, 95% CI: 0.34, 0.92). Results of sensitivity analysis showed that our research findings are robust.

CONCLUSION

Older adults living in dusty weather regions suffered a higher level of cognitive impairment, and such adverse effects were more substantial among females compared with their male counterparts. Targeted health interventions to help older adults living in regions where dusty weather occurs frequently are suggested to be proposed.

Sex and APOE ε4 carrier effects on atrophy, amyloid PET, and tau PET burden in early-onset Alzheimer's disease

INTRODUCTION

We used sex and apolipoprotein E ε4 (APOE ε4) carrier status as predictors of pathologic burden in early-onset Alzheimer's disease (EOAD).

METHODS

We included baseline data from 77 cognitively normal (CN), 230 EOAD, and 70 EO non-Alzheimer's disease (EOnonAD) participants from the Longitudinal Early-Onset Alzheimer's Disease Study (LEADS). We stratified each diagnostic group by males and females, then further subdivided each sex by APOE ε4 carrier status and compared imaging biomarkers in each stratification. Voxel-wise multiple linear regressions yielded statistical brain maps of gray matter density, amyloid, and tau PET burden.

RESULTS

EOAD females had greater amyloid and tau PET burdens than males. EOAD female APOE ε4 non-carriers had greater amyloid PET burdens and greater gray matter atrophy than female ε4 carriers. EOnonAD female ε4 non-carriers also had greater gray matter atrophy than female ε4 carriers.

DISCUSSION

The effects of sex and APOE ε4 must be considered when studying these populations.

HIGHLIGHTS

Novel analysis examining the effects of biological sex and apolipoprotein E ε4 (APOE ε4) carrier status on neuroimaging biomarkers among early-onset Alzheimer's disease (EOAD), early-onset non-AD (EOnonAD), and cognitively normal (CN) participants. Female sex is associated with greater pathology burden in the EOAD cohort compared to male sex. The effect of APOE ε4 carrier status on pathology burden was the most impactful in females across all cohorts.

APOE genotype and sex modulate Alzheimer's disease pathology in aged EFAD transgenic mice

Increasing evidence supports that age, APOE and sex interact to modulate Alzheimer's disease (AD) risk, however the underlying pathways are unclear. One way that AD risk factors may modulate cognition is by impacting amyloid beta (Aβ) accumulation as plaques, and/or neuroinflammation Therefore, the goal of the present study was to evaluate the extent to which age, APOE and sex modulate Aβ pathology, neuroinflammation and behavior in vivo. To achieve this goal, we utilized the EFAD mice, which express human APOE3 or APOE4 and have five familial AD mutations (FAD) that result in Aβ42 overproduction. We assessed Aβ levels, reactive glia and Morris water maze performance in 6-, 10-, 14-, and 18-month-old EFAD mice. Female APOE4 mice had the highest Aβ deposition, fibrillar amyloid deposits and neuroinflammation as well as earlier behavior deficits. Interestingly, we found that female APOE3 mice and male APOE4 mice had similar levels of pathology. Collectively our data support that the combination of APOE4 and female sex is the most detrimental combination for AD, and that at older ages, female sex may be equivalent to APOE4 genotype.

A small-molecule TLR4 antagonist reduced neuroinflammation in female E4FAD mice

BACKGROUND

APOE genotype is the greatest genetic risk factor for sporadic Alzheimer's disease (AD). APOE4 increases AD risk up to 12-fold compared to APOE3, an effect that is greater in females. Evidence suggests that one-way APOE could modulate AD risk and progression through neuroinflammation. Indeed, APOE4 is associated with higher glial activation and cytokine levels in AD patients and mice. Therefore, identifying pathways that contribute to APOE4-associated neuroinflammation is an important approach for understanding and treating AD. Human and in vivo evidence suggests that TLR4, one of the key receptors involved in the innate immune system, could be involved in APOE-modulated neuroinflammation. Consistent with that idea, we previously demonstrated that the TLR4 antagonist IAXO-101 can reduce LPS- and Aβ-induced cytokine secretion in APOE4 glial cultures. Therefore, the goal of this study was to advance these findings and determine whether IAXO-101 can modulate neuroinflammation, Aβ pathology, and behavior in mice that express APOE4.

METHODS

We used mice that express five familial AD mutations and human APOE3 (E3FAD) or APOE4 (E4FAD). Female and male E4FAD mice and female E3FAD mice were treated with vehicle or IAXO-101 in two treatment paradigms: prevention from 4 to 6 months of age or reversal from 6 to 7 months of age. Learning and memory were assessed by modified Morris water maze. Aβ deposition, fibrillar amyloid deposition, astrogliosis, and microgliosis were assessed by immunohistochemistry. Soluble levels of Aβ and apoE, insoluble levels of apoE and Aβ, and IL-1β were measured by ELISA.

RESULTS

IAXO-101 treatment resulted in lower Iba-1 coverage, lower number of reactive microglia, and improved memory in female E4FAD mice in both prevention and reversal paradigms. IAXO-101-treated male E4FAD mice also had lower Iba-1 coverage and reactivity in the RVS paradigm, but there was no effect on behavior. There was also no effect of IAXO-101 treatment on neuroinflammation and behavior in female E3FAD mice.

CONCLUSION

Our data supports that TLR4 is a potential mechanistic therapeutic target for modulating neuroinflammation and cognition in APOE4 females.

Gynecological surgery in adulthood imparts cognitive and brain changes in rats: A focus on hysterectomy at short-, moderate-, and long-term intervals after surgery

Premenopausal hysterectomy is associated with a greater relative risk of dementia. We previously demonstrated cognitive impairments in adult rats six weeks after hysterectomy with ovarian conservation compared with intact sham-controls and other gynecological surgery variations. Here, we investigated whether hysterectomy-induced cognitive impairments are transient or persistent. Adult rats received sham-control, ovariectomy (Ovx), hysterectomy, or Ovx-hysterectomy surgery. Spatial working memory, reference memory, and anxiety-like behavior were tested either six-weeks post-surgery, in adulthood; seven-months post-surgery, in early middle-age; or twelve-months post-surgery, in late middle-age. Hysterectomy in adulthood yielded spatial working memory deficits at short-, moderate-, and long-term post-surgery intervals. Serum hormone levels did not differ between ovary-intact, but differed from Ovx, groups. Hysterectomy had no significant impact on healthy ovarian follicle or corpora lutea counts for any post-surgery timepoint compared with intact sham-controls. Frontal cortex, dorsal hippocampus, and entorhinal cortex were assessed for activity-dependent markers. In entorhinal cortex, there were alterations in FOSB and ΔFOSB expression during the early middle-age timepoint, and phosphorylated ERK1/2 levels at the adult timepoint. Collectively, results suggest a primary role for the uterus in regulating cognition, and that memory-related neural pathways may be modified following gynecological surgery. This is the first preclinical report of long-term effects of hysterectomy with and without ovarian conservation on cognition, endocrine, ovarian, and brain assessments, initiating a comprehensive framework of gynecological surgery effects. Translationally, findings underscore critical needs to decipher how gynecological surgeries, especially those involving the uterus, impact the brain and its functions, the ovaries, and overall aging from a systems perspective.

Repurposing of Tibolone in Alzheimer's Disease

Alzheimer's disease (AD) is a debilitating neurodegenerative disease characterised by the accumulation of amyloid-beta and tau in the brain, leading to the progressive loss of memory and cognition. The causes of its pathogenesis are still not fully understood, but some risk factors, such as age, genetics, and hormones, may play a crucial role. Studies show that postmenopausal women have a higher risk of developing AD, possibly due to the decrease in hormone levels, especially oestrogen, which may be directly related to a reduction in the activity of oestrogen receptors, especially beta (ERβ), which favours a more hostile cellular environment, leading to mitochondrial dysfunction, mainly affecting key processes related to transport, metabolism, and oxidative phosphorylation. Given the influence of hormones on biological processes at the mitochondrial level, hormone therapies are of clinical interest to reduce the risk or delay the onset of symptoms associated with AD. One drug with such potential is tibolone, which is used in clinics to treat menopause-related symptoms. It can reduce amyloid burden and have benefits on mitochondrial integrity and dynamics. Many of its protective effects are mediated through steroid receptors and may also be related to neuroglobin, whose elevated levels have been shown to protect against neurological diseases. Its importance has increased exponentially due to its implication in the pathogenesis of AD. In this review, we discuss recent advances in tibolone, focusing on its mitochondrial-protective effects, and highlight how valuable this compound could be as a therapeutic alternative to mitigate the molecular pathways characteristic of AD.

Risk of Fracture After Bilateral Oophorectomy

Fragility fractures, resulting from low-energy trauma, occur in approximately 1 in 10 Danish women aged 50 years or older. Bilateral oophorectomy (surgical removal of both ovaries) may increase the risk of fragility fractures due to loss of ovarian sex steroids, particularly estrogen. We investigated the association between bilateral oophorectomy and risk of fragility fracture and whether this was conditional on age at time of bilateral oophorectomy, hormone therapy (HT) use, hysterectomy, physical activity level, body mass index (BMI), or smoking. We performed a cohort study of 25,853 female nurses (≥45 years) participating in the Danish Nurse Cohort. Nurses were followed from age 50 years or entry into the cohort, whichever came last, until date of first fragility fracture, death, emigration, or end of follow-up on December 31, 2018, whichever came first. Cox regression models with age as the underlying time scale were used to estimate the association between time-varying bilateral oophorectomy (all ages, <51/≥51 years) and incident fragility fracture (any and site-specific [forearm, hip, spine, and other]). Exposure and outcome were ascertained from nationwide patient registries. During 491,626 person-years of follow-up, 6600 nurses (25.5%) with incident fragility fractures were identified, and 1938 (7.5%) nurses had a bilateral oophorectomy. The frequency of fragility fractures was 24.1% in nurses who were <51 years at time of bilateral oophorectomy and 18.1% in nurses who were ≥51 years. No statistically significant associations were observed between bilateral oophorectomy at any age and fragility fractures at any site. Neither HT use, hysterectomy, physical activity level, BMI, nor smoking altered the results. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Long-Term Health Consequences After Ovarian Removal at Benign Hysterectomy : A Nationwide Cohort Study

BACKGROUND

More evidence is needed to substantiate current recommendations about removing ovaries during hysterectomy for benign conditions.

OBJECTIVE

To compare long-term outcomes in women with and without bilateral salpingo-oophorectomy (BSO) during hysterectomy for benign conditions.

DESIGN

Emulated target trial using data from a population-based cohort.

SETTING

Women in Denmark aged 20 years or older during 1977 to 2017.

PARTICIPANTS

142 985 women with hysterectomy for a benign condition, 22 974 with BSO and 120 011 without.

INTERVENTION

Benign hysterectomy with or without BSO.

MEASUREMENTS

The primary outcomes were overall hospitalization for cardiovascular disease (CVD), overall cancer incidence, and all-cause mortality through December 2018.

RESULTS

Compared with women without BSO, women with BSO who were younger than 45 years at surgery had a higher 10-year cumulative risk for hospitalization for CVD (risk difference [RD], 1.19 percentage points [95% CI, 0.09 to 2.43 percentage points]). Women with BSO had a higher 10-year cumulative risk for cancer for ages 45 to 54 years (RD, 0.73 percentage point [CI, 0.05 to 1.38 percentage points]), 55 to 64 years (RD, 1.92 percentage points [CI, 0.69 to 3.25 percentage points]), and 65 years or older (RD, 2.54 percentage points [CI, 0.91 to 4.25 percentage points]). Women with BSO had higher 10-year mortality in all age groups, although the differences were statistically significant only for ages 45 to 54 years (RD, 0.79 percentage point [CI, 0.27 to 1.30 percentage points]). The mortality at 20 years was inconsistent with that at 10 years in women aged 65 years or older.

LIMITATION

Age was a proxy for menopausal status.

CONCLUSION

The authors find that these results support current recommendations for conserving ovaries in premenopausal women without a high risk for ovarian cancer and suggest a cautious approach in postmenopausal women.

PRIMARY FUNDING SOURCE

The Danish Cancer Society's Scientific Committee and the Mermaid Project.

Natural vs. surgical postmenopause and psychological symptoms confound the effect of menopause on executive functioning domains of cognitive experience

OBJECTIVE

The menopause transition is associated with difficulties in executive function. However, it is unclear whether these difficulties persist past perimenopause. This study investigated whether potential confounders, including natural vs. surgical postmenopause and menopause-related psychological symptoms, influence whether executive dysfunction persists into postmenopause.

STUDY DESIGN

A cross-sectional sample of women aged 35-65 years (N = 1971) in one of four groups, premenopause, perimenopause, natural postmenopause, and surgical postmenopause, were surveyed. Participants self-reported executive functioning with the Brown Attention Deficit Disorder Scale (BADDS), anxiety symptom severity with the Generalized Anxiety Disorder Questionnaire (GAD-7), and depression symptom severity with the Center for Epidemiologic Studies Depression Scale (CESD).

MAIN OUTCOME MEASURES

We analyzed the association between group and BADDS scores using linear regression models - first, by controlling for age, education, and self-reported attention deficit hyperactivity disorder (ADHD) diagnosis (Model #1) and, second, by further controlling for current difficulty sleeping, anxiety, and depression (Model #2).

RESULTS

In both models, BADDS scores were significantly elevated (indicating more difficulties in executive function) among women in the perimenopausal and surgical postmenopausal groups compared with those in the premenopausal group. Likewise, the perimenopausal and surgical postmenopausal groups had the highest proportions of participants who reported difficulty sleeping and clinical levels of anxiety and depression. BADDS scores were significantly higher in natural postmenopausal vs. premenopausal women without controlling for difficulty sleeping, anxiety, and depression (Model #1), but not when adjusting for these variables (Model #2).

CONCLUSIONS

The type of menopause and psychological symptoms are important confounders of the relationship between the menopause transition and executive dysfunction, and help explain whether executive dysfunction persists or recovers in postmenopause.

Characteristics of reproductive history, use of exogenous hormones and walking speed among women: Data from the CONSTANCES French Cohort Study

OBJECTIVE

To investigate the cross-sectional associations of reproductive history and use of exogenous hormones with fast walking speed (WS) in women.

STUDY DESIGN

Between 2012 and 2020, 33,892 French women aged 45 years or more, recruited at health centers, underwent physical function tests and self-reported information on reproductive history and use of exogenous hormones. Linear mixed models with the center as random intercept were used to estimate the association of exposures with WS.

MAIN OUTCOME MEASURES

Fast WS.

RESULTS

Mean WS was 172.2 cm/s. WS increased with age at menarche (β_+1y = 0.23, 95 % confidence interval = 0.05 to 0.40), age at first birth (β_+1y = 0.20, 95 % CI = 0.13 to 0.27) and duration of breastfeeding (β_{for ≥10 vs ≤5months} = 1.38; 95 % CI = 0.39 to 2.36). In addition, parity was quadratically associated with WS, with women with 3 children having the highest WS (p for U-shaped relationship < 0.01). Menopausal status had no impact on WS but age at menopause was positively associated with WS (β_+5y = 0.52, 95 % CI = 0.17 to 0.87) and partly explained the deleterious impact of artificial menopause on WS. WS increased with reproductive lifetime duration (β_+5y = 0.49, 95 % CI = 0.16 to 0.83) and decreased with time since onset of menopause (β_+5y = -0.65, 95 % CI = -0.99 to -0.31). By contrast, there was no association of WS with oral contraception and postmenopausal hormone therapy.

CONCLUSION

Our findings suggest that reproductive life characteristics may be associated with WS and timing of exposure could play a role.

Frequency and type of premature or early menopause in a geographically defined American population

OBJECTIVE

There is limited information on the prevalence of premature and early menopause. Therefore, we studied the frequency and type of premature (age < 40 years) or early (age 40-44 years) menopause in a geographically-defined American population.

METHODS

We studied a random sample of women aged 18 to 50 years who resided in Olmsted County, MN between 1988 and 2007. Women were followed through December 2021, and age at cessation of menses was assessed via review of the medical records included in a medical records-linkage system. Menopause was defined as cessation of menses due to spontaneous or induced ovarian insufficiency.

RESULTS

1015 women (71.3 %) underwent spontaneous menopause, 138 (9.7 %) underwent bilateral oophorectomy, 17 (1.2 %) had antecedent chemotherapy or radiation therapy, and 254 (17.8 %) underwent hysterectomy or endometrial ablation. The median age at cessation of menses was 51.0 years (IQR, 49.0-52.0) for spontaneous menopause, 46.0 years (IQR, 41.0-49.0) for menopause induced by oophorectomy, chemotherapy, or radiation therapy, and 38.0 years (IQR, 33.0-44.0) for hysterectomy. Considering both spontaneous and induced menopause, the frequency was 3.1 % (95 % CI, 2.2-4.2) for premature and 6.2 % (95 % CI, 5.0-7.8) for early menopause. Considering only spontaneous menopause, the frequency reduced to 0.4 % (95 % CI, 0.2-1.0) for premature and 5.2 % (95 % CI, 4.0-6.8) for early menopause. However, considering all types of cessations of menses, the frequency was 12.2 % (95 % CI, 10.6-14.0) for premature and 9.7 % (95 % CI, 8.3-11.3) for early cessation of menses.

DISCUSSION

Approximately 3 % of women in the general population experienced either spontaneous or induced premature menopause. The most common cause of premature menopause was bilateral oophorectomy.

Sex difference in biological change and mechanism of Alzheimer’s disease: from macro- to micro-landscape

Alzheimer's disease (AD) is the most common form of dementia and numerous studies reported a higher prevalence and incidence of AD among women. Although women have longer lifetime, longevity does not wholly explain the higher frequency and lifetime risk in women. It is important to understand sex differences in AD pathophysiology and pathogenesis, which could provide foundation for future clinical AD research. Here, we reviewed the most recent and relevant literature on sex differences in biological change of AD from macroscopical neuroimaging to microscopical pathologic change (neuronal degeneration, synaptic dysfunction, amyloid-beta and tau accumulation). We also discussed sex differences in cellular mechanisms related to AD (neuroinflammation, mitochondria dysfunction, oxygen stress, apoptosis, autophagy, blood-brain-barrier dysfunction, gut microbiome alteration, bulk and single cell/nucleus omics) and possible causes underlying these differences including sex-chromosome, sex hormone and hypothalamic-pituitary- adrenal (HPA) axis effects.

Mood, hormone levels, metabolic and sleep across the menopausal transition in VCD-induced ICR mice

AIMS

Menopausal transition is the transitional period before menopause in women, often accompanied by abnormal fluctuations in hormone levels that increase the risk of aging-related diseases. 4-vinylcyclohexene dioxide (VCD) is a chemical agent that induces gradual depletion of ovarian follicles, which can mimic the natural human process of transition from menopausal transition to post-menopause. Previous studies have shown that the onset of menopausal transition or menopause in VCD-injected mice is associated with a specific strain, even in inbred animals. Institute of Cancer Research (ICR) mice constitute general purpose outbred population, which has not been well-characterized in the VCD-induced model. Thus, the current study aimed to explore the characteristic features, including sleep, mood, and metabolism, of the model by examining the effect of timing of VCD injection in ICR mice to extend the applications of this model.

MATERIALS AND METHODS

ICR mice were randomly divided into six groups: 20d VCD and 20d Control, 35d VCD and 35d Control, 52d VCD and 52d Control. VCD mice were intraperitoneally injected with VCD (160 mg/kg), while Control mice were injected intraperitoneally with sesame oil for 4 consecutive weeks, five times a week daily. A vaginal smear was used to observe the estrous cycle of the mice. On the 20th, 35th, and 52nd day after VCD or sesame oil injection, the ovarian morphology, the number of atretic cells, hormone levels, anxiety, depression-like behaviors, sleep phase, and energy metabolism were observed.

KEY FINDINGS

The menopausal transition model was successfully replicated by injecting VCD into ICR mice. On the specific days after VCD treatment, the number of atretic follicles increased, the level of E2 decreased and FSH increased, the depressive- and anxiety-like behavior increased, the time of REM and NREM sleep time decreased, and energy metabolism was reduced.

SIGNIFICANCE

These results suggested that the ICR mice model has human-like characteristics during the menopause transition. Moreover, the ICR model has a long menopausal transition duration.

Is Hormone Replacement Therapy a Risk Factor or a Therapeutic Option for Alzheimer's Disease?

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that accounts for more than half of all dementia cases in the elderly. Interestingly, the clinical manifestations of AD disproportionately affect women, comprising two thirds of all AD cases. Although the underlying mechanisms for these sex differences are not fully elucidated, evidence suggests a link between menopause and a higher risk of developing AD, highlighting the critical role of decreased estrogen levels in AD pathogenesis. The focus of this review is to evaluate clinical and observational studies in women, which have investigated the impact of estrogens on cognition or attempted to answer the prevailing question regarding the use of hormone replacement therapy (HRT) as a preventive or therapeutic option for AD. The articles were retrieved through a systematic review of the databases: OVID, SCOPUS, and PubMed (keywords "memory", "dementia," "cognition," "Alzheimer's disease", "estrogen", "estradiol", "hormone therapy" and "hormone replacement therapy" and by searching reference sections from identified studies and review articles). This review presents the relevant literature available on the topic and discusses the mechanisms, effects, and hypotheses that contribute to the conflicting findings of HRT in the prevention and treatment of age-related cognitive deficits and AD. The literature suggests that estrogens have a clear role in modulating dementia risk, with reliable evidence showing that HRT can have both a beneficial and a deleterious effect. Importantly, recommendation for the use of HRT should consider the age of initiation and baseline characteristics, such as genotype and cardiovascular health, as well as the dosage, formulation, and duration of treatment until the risk factors that modulate the effects of HRT can be more thoroughly investigated or progress in the development of alternative treatments can be made.

Role of estrogen in women's Alzheimer's disease risk as modified by APOE

Alzheimer's disease (AD) is characterized by numerous sexual dimorphisms that impact the development, progression, and probably the strategies to prevent and treat the most common form of dementia. In this review, we consider this topic from a female perspective with a specific focus on how women's vulnerability to the disease is affected by the individual and interactive effects of estrogens and apolipoprotein E (APOE) genotype. Importantly, APOE appears to modulate systemic and neural outcomes of both menopause and estrogen-based hormone therapy. In the brain, dementia risk is greater in APOE4 carriers, and the impacts of hormone therapy on cognitive decline and dementia risk vary according to both outcome measure and APOE genotype. Beyond the CNS, estrogen and APOE genotype affect vulnerability to menopause-associated bone loss, dyslipidemia and cardiovascular disease risk. An emerging concept that may link these relationships is the possibility that the effects of APOE in women interact with estrogen status by mechanisms that may include modulation of estrogen responsiveness. This review highlights the need to consider the key AD risk factors of advancing age in a sex-specific manner to optimize development of therapeutic approaches for AD, a view aligned with the principle of personalized medicine.

Neuropsychiatric symptoms influence differently cognitive decline in older women and men

OBJECTIVE

The potential impact of sex on cognitive performance in normal aging and participants with Alzheimer's disease (AD) has been outlined previously. Nevertheless, differences in neuropsychiatric symptoms (NPS) have been also outlined. We aimed to study a potential association between NPS and cognitive performances according to sex, in older individuals with and without cognitive impairment.

METHODS

Demographic, neuropsychiatric and neuropsychological data from the ADNI and NACC databases were merged into a dataset of 506 participants with healthy cognitive performance, 467 patients with mild cognitive impairment, and 238 patients with AD. Cognitive performance in each group was evaluated according to sex and the presence of NPS.

RESULTS

Based on sex, cognitive performance differed according to clinical stage: in the healthy controls and AD groups, women had better fluency performance, while in the mild cognitive impairment group, women had better working memory and men better oral naming. Regardless of sex, depression showed a negative effect on processing speed in AD. Finally, there was an interaction between sex and NPS in mild cognitive impairment, where women with apathy had better working memory performance, and in AD, women with depression had better fluency performance. The opposite pattern being was observed in men, where men with depression have worse focused attention.

CONCLUSION

Cognitive performance is influenced by sex, yet this influence has different manifestations at normal cognition, MCI or AD. Furthermore, apathy and depression seem to influence differently women and men at different types of cognitive decline.

Therapeutic roles of plants for 15 hypothesised causal bases of Alzheimer's disease

Alzheimer's disease (AD) is progressive and ultimately fatal, with current drugs failing to reverse and cure it. This study aimed to find plant species which may provide therapeutic bioactivities targeted to causal agents proposed to be driving AD. A novel toolkit methodology was employed, whereby clinical symptoms were translated into categories recognized in ethnomedicine. These categories were applied to find plant species with therapeutic effects, mined from ethnomedical surveys. Survey locations were mapped to assess how this data is at risk. Bioactivities were found of therapeutic relevance to 15 hypothesised causal bases for AD. 107 species with an ethnological report of memory improvement demonstrated therapeutic activity for all these 15 causal bases. The majority of the surveys were found to reside within biodiversity hotspots (centres of high biodiversity under threat), with loss of traditional knowledge the most common threat. Our findings suggest that the documented plants provide a large resource of AD therapeutic potential. In demonstrating bioactivities targeted to these causal bases, such plants may have the capacity to reduce or reverse AD, with promise as drug leads to target multiple AD hallmarks. However, there is a need to preserve ethnomedical knowledge, and the habitats on which this knowledge depends.

Sex and gender differences in movement disorders: Parkinson's disease, essential tremor, dystonia and chorea

Sex and gender-based differences in epidemiology, clinical features and therapeutical responses are emerging in several movement disorders, even though they are still not widely recognized. In this chapter, we summarize the most relevant evidence concerning these differences in Parkinson's disease, essential tremor, dystonia and chorea. Indeed, both sex-related biological (hormonal levels fluctuations) and gender-related variables (socio-cultural and environmental factors) may differently impact symptoms manifestation and severity, phenotype and disease progression of movement disorders on men and women. Moreover, sex differences in treatment responses should be taken into account in any therapeutical planning. Physicians need to be aware of these major differences between men and women that will eventually have a major impact on better tailoring prevention, treatment, or even delaying progression of the most common movement disorders.

Sex Hormones, Sleep, and Memory: Interrelationships Across the Adult Female Lifespan

As the population of older adults grows, so will the prevalence of aging-related conditions, including memory impairments and sleep disturbances, both of which are more common among women. Compared to older men, older women are up to twice as likely to experience sleep disturbances and are at a higher risk of cognitive decline and Alzheimer's disease and related dementias (ADRD). These sex differences may be attributed in part to fluctuations in levels of female sex hormones (i.e., estrogen and progesterone) that occur across the adult female lifespan. Though women tend to experience the most significant sleep and memory problems during the peri-menopausal period, changes in memory and sleep have also been observed across the menstrual cycle and during pregnancy. Here, we review current knowledge on the interrelationships among female sex hormones, sleep, and memory across the female lifespan, propose possible mediating and moderating mechanisms linking these variables and describe implications for ADRD risk in later life.

Effect of Yakae-Prajamduen-Jamod Traditional Thai Remedy on Cognitive Impairment in an Ovariectomized Mouse Model and Its Mechanism of Action

Cognitive impairment is a neurological symptom caused by reduced estrogen levels in menopausal women. The Thai traditional medicine, Yakae-Prajamduen-Jamod (YPJ), is a formula consisting of 23 medicinal herbs and has long been used to treat menopausal symptoms in Thailand. In the present study, we investigated the effects of YPJ on cognitive deficits and its underlying mechanisms of action in ovariectomized (OVX) mice, an animal model of menopause. OVX mice showed cognitive deficits in the Y-maze, the novel object recognition test, and the Morris water maze. The serum corticosterone (CORT) level was significantly increased in OVX mice. Superoxide dismutase and catalase activities were reduced, while the mRNA expression of IL-1β, IL-6, and TNF-α inflammatory cytokines were up-regulated in the frontal cortex and hippocampus of OVX mice. These alterations were attenuated by daily treatment with either YPJ or 17β-estradiol. HPLC analysis revealed that YPJ contained antioxidant and phytoestrogen constituents including gallic acid, myricetin, quercetin, luteolin, genistein, and coumestrol. These results suggest that YPJ exerts its ameliorative effects on OVX-induced cognitive deficits in part by mitigating HPA axis overactivation, neuroinflammation, and oxidative brain damage. Therefore, YPJ may be a novel alternative therapeutic medicine suitable for the treatment of cognitive deficits during the menopausal transition.

Menopause Status Moderates Sex Differences in Tau Burden: A Framingham PET Study

OBJECTIVE

Women have a higher lifetime risk of Alzheimer's disease (AD) than men. Among cognitively normal (CN) older adults, women exhibit elevated tau positron emission tomography (PET) signal compared with men. We explored whether menopause exacerbates sex differences in tau deposition in middle-aged adults.

METHODS

328 CN participants from the Framingham Study (mean age = 57 years (±10 years), 161 women, of whom, 104 were post-menopausal) underwent tau and β-amyloid (Aβ)-PET neuroimaging. We examined global Aβ-PET, and tau-PET signal in 5 regions identified a priori as demonstrating significant sex differences in older adults (in temporal, inferior parietal, middle frontal, and lateral occipital regions). We examined sex and menopause status-related differences in each region-of-interest, using linear regressions, as well as interactions with Aβ and APOEε4 genotype.

RESULTS

Women exhibited higher tau-PET signal (p < 0.002), and global Aβ-PET (p = 0.010), than men in inferior parietal, rostral middle frontal, and lateral occipital regions. Compared with age-matched men, post-menopausal women showed significantly higher tau-PET signal in parieto-occipital regions (p < 0.0001). By contrast, no differences in tau-PET signal existed between pre-menopausal women and men. Aβ-PET was not associated with menopausal status or age. Neither Aβ-PET nor APOEε4 status moderated sex or menopause associations with tau-PET.

INTERPRETATION

Clear divergence in tauopathy between the sexes are apparent approximately 20 years earlier than previously reported. Menopause status moderated sex differences in Aβ and tau-PET burden, with tau first appearing post-menopause. Sex and menopause differences consistently appeared in middle frontal and parieto-occipital regions but were not moderated by Aβ burden or APOEε4, suggesting that menopause-related tau vulnerability may be independent of AD-related pathways. ANN NEUROL 2022;92:11-22.

Bilateral oophorectomy and rate of colorectal cancer: A prospective cohort study

Worldwide, colorectal cancer is the second most common cancer and third cause of cancer death in women. Estrogen exposure has been inversely associated with colorectal cancer. Oophorectomy reduces circulating estrogen, but the effect on colorectal cancer remains uncertain. The aim of this study was to examine the association between unilateral and bilateral oophorectomy and subsequent risk of colorectal cancer, and whether this association varied by menopausal status at time of oophorectomy, use of hormone replacement therapy (HRT) at baseline, hysterectomy and baseline body mass index (BMI). The study included 25 698 female nurses (aged ≥45 years) participating in the Danish Nurse Cohort. Nurses were followed from baseline until date of colorectal cancer, death, emigration or end of follow-up at December 31, 2018, whichever came first. We examined the association between oophorectomy and colorectal cancer (all ages and stratified by menopausal status). The potential modifying effects of hysterectomy, HRT use at baseline and BMI were investigated. During 542 140 person-years of follow-up, 863 (3.4%) nurses were diagnosed with colorectal cancer. Bilateral oophorectomy was associated with a 79% increased colorectal cancer rate, adjusted rate ratio (aRR) (95% confidence interval [CI]): 1.79 (1.33-2.42). Effect estimates following unilateral oophorectomy also showed higher rate of colorectal cancer, although less pronounced and nonstatistically significant (aRR) (95% CI): 1.25 (0.86-1.82). Similar results were seen when stratifying by menopausal status. The association was not modified by baseline HRT use, hysterectomy or BMI. Oophorectomy was associated with increased rate of colorectal cancer, with highest rates among women with bilateral oophorectomy.

Sex and Gender Differences in Environmental Influences on Dementia Incidence in Germany, 2014-2019: An Observational Cohort Study Based on Health Claims Data

BACKGROUND

There is an ongoing debate about whether environmental characteristics influence dementia risk like individual traits do, and whether these differ by sex and gender.

OBJECTIVE

This study examines the influence of regional characteristics on the incidence of dementia and explores sex and gender differences using individual-level health information and regional characteristics.

METHODS

Using a random sample of 250,000 people aged 70 + insured through Germany's largest German public health agency, we analyzed quarterly data about diagnoses and place of residence from 2014 to 2019. Using five-digit postal codes, we added data on various dimensions of regional characteristics offered by the INKAR database and the 2011 Census database. We used multilevel survival regressions to tease out regional incidence differences while accounting for spatial clustering.

RESULTS

After adjusting for multi-morbidity and relocation-related selection bias, we saw that people living in regions with the highest tertile of income (HR = 0.87, p < 0.001), and who had the highest tertile of remaining life expectancy at age 60 (HR = 0.93, p = 0.012) had lower dementia risks. There was no gender difference in the regional income effect, but the effect of education (HR = 0.91, p = 0.015) was significant only for men and remaining life-expectancy was significant only for women (HR = 0.93, p = 0.026).

CONCLUSION

Environmental characteristics related to wealth and health resources of a region influence the risk of dementia among the elderly in Germany. This effect is independent of the health profiles of the individuals and differs between the two genders. Health policies need to acknowledge these modifiable risk factors and consider how they affect men and women differently.

Gene expression analyses on multi-target mode of action of black cohosh in menopausal complaints - a pilot study in rodents

PURPOSE

This study aimed at assessing gene expression profiles in hippocampus and hypothalamus of ovariectomized (OVX) rats with or without treatment with an isopropanolic extract of Cimicifuga racemosa rhizomes (iCR) in comparison to intact rats.

METHODS

Exploration of hippocampal (Hi) and hypothalamic (Hy) tissue from Sprague Dawley rats: without OVX (NHi = NHy = 4), tissues 3 months after OVX (NHi = 4, NHy = 3), or tissues of rats after their treatment with iCR for 3 months after OVX (NHi = NHy = 2). Gene expression profiles in these tissues were investigated by RNA-microarray-analysis and subsequent verification by qPCR.

RESULTS

4812 genes were differentially regulated when comparing the three groups in hippocampus and hypothalamus. iCR compensated the effects of OVX in 518 genes. This compensatory effect was most prominent in hippocampal signalling pathways, thereof genes (GAL, CALCA, HCRT, AVPR1A, PNOC, etc.) involved in thermoregulation, regulation of sleep and arousal, blood pressure regulation, metabolism, nociception, hormonal regulation, homeostasis, learning and cognition, mood regulation, neuroendocrine modulation, etc.. In the hypothalamus, iCR compensated OVX-effects at TAC3 and OPRM1 but not at KISS1. These genes are involved in the pathophysiology of hot flashes.

CONCLUSIONS

Our pilot study findings support a multifaceted mode of action of iCR in menopausal complaints on a tissue-specific brain gene expression level.

Association of bilateral salpingo-oophorectomy with all cause and cause specific mortality: population based cohort study

OBJECTIVES

To determine if bilateral salpingo-oophorectomy, compared with ovarian conservation, is associated with all cause or cause specific death in women undergoing hysterectomy for non-malignant disease, and to determine how this association varies with age at surgery.

DESIGN

Population based cohort study.

SETTING

Ontario, Canada from 1 January 1996 to 31 December 2015, and follow-up to 31 December 2017.

PARTICIPANTS

200 549 women (aged 30-70 years) undergoing non-malignant hysterectomy, stratified into premenopausal (<45 years), menopausal transition (45-49 years), early menopausal (50-54 years), and late menopausal (≥55 years) groups according to age at surgery; median follow-up was 12 years (interquartile range 7-17).

EXPOSURES

Bilateral salpingo-oophorectomy versus ovarian conservation.

MAIN OUTCOMES MEASURES

The primary outcome was all cause death. Secondary outcomes were non-cancer and cancer death. Within each age group, overlap propensity score weighted survival models were used to examine the association between bilateral salpingo-oophorectomy and mortality outcomes, while adjusting for demographic characteristics, gynaecological conditions, and comorbidities. To account for comparisons in four age groups, P<0.0125 was considered statistically significant.

RESULTS

Bilateral salpingo-oophorectomy was performed in 19%, 41%, 69%, and 81% of women aged <45, 45-49, 50-54, and ≥55 years, respectively. The procedure was associated with increased rates of all cause death in women aged <45 years (hazard ratio 1.31, 95% confidence interval 1.18 to 1.45, P<0.001; number needed to harm 71 at 20 years) and 45-49 years (1.16, 1.04 to 1.30, P=0.007; 152 at 20 years), but not in women aged 50-54 years (0.83, 0.72 to 0.97, P=0.018) or ≥55 years (0.92, 0.82 to 1.03, P=0.16). Findings in women aged <50 years were driven largely by increased non-cancer death. In secondary analyses identifying a possible change in the association between bilateral salpingo-oophorectomy and all cause death with advancing age at surgery, the hazard ratio gradually decreased during the menopausal transition and remained around 1 at all ages thereafter.

CONCLUSION

In this observational study, bilateral salpingo-oophorectomy at non-malignant hysterectomy appeared to be associated with increased all cause mortality in women aged <50 years, but not in those aged ≥50 years. While caution is warranted when considering bilateral salpingo-oophorectomy in premenopausal women without indication, this strategy for ovarian cancer risk reduction does not appear to be detrimental to survival in postmenopausal women.

Association of Premenopausal Bilateral Oophorectomy With Cognitive Performance and Risk of Mild Cognitive Impairment

IMPORTANCE

The associations of bilateral oophorectomy among premenopausal women, age at oophorectomy, and use of estrogen therapy after oophorectomy with cognitive performance later in life remain controversial.

OBJECTIVE

To investigate whether women who underwent premenopausal bilateral oophorectomy were at increased risk of mild cognitive impairment (MCI) and experienced decreased global or domain-specific cognitive performance.

DESIGN, SETTING, AND PARTICIPANTS

This case-control study and cross-sectional study were made possible by combining data from the Mayo Clinic Study of Aging (MCSA) and the Rochester Epidemiology Project (REP) medical record-linkage system. The studies were conducted among a population-based sample in Olmsted County, Minnesota, consisting of 2732 women aged 50 to 89 years who participated in the MCSA study from 2004 to 2019 and underwent a clinical evaluation and comprehensive cognitive testing. Data were analyzed from January to May 2021.

EXPOSURES

Medical record documentation of bilateral oophorectomy abstracted from a medical record-linkage system (ie, REP).

MAIN OUTCOMES AND MEASURES

Odds of MCI and global or domain-specific z scores on cognitive tests were measured at the first MCSA visit. The median (IQR) lag time between bilateral oophorectomy performed before menopause and before age 50 years and cognitive evaluation was 30 (22-38) years.

RESULTS

Among 2732 women aged 50 to 89 years (median [IQR] age at evaluation, 74 [66-81] years) who participated in the MCSA, the case-control study included 283 women with MCI (10.4%) and 2449 women without cognitive impairment (89.6%). Bilateral oophorectomy before menopause and before age 46 years was associated with clinically diagnosed MCI (adjusted odds ratio [aOR], 2.21; 95% CI, 1.41-3.45; P < .001) compared with no bilateral oophorectomy. The presence of an association with MCI varied by surgical indication, with an association among 259 women with bilateral oophorectomy before menopause and before age 50 years for the indication of benign ovarian condition (aOR, 2.43; 95% CI, 1.36-4.33; P = .003) but not for cancer or no ovarian condition. The presence of an association did not vary by estrogen therapy after bilateral oophorectomy, with associations among women aged less than 46 years with estrogen therapy (aOR, 2.56; 95% CI, 1.24-5.31; P = .01) and without estrogen therapy (aOR, 2.05; 95% CI, 1.18-3.52; P = .01). The cross-sectional study included 625 women with a history of bilateral oophorectomy (median [IQR] age, 75 [70-82] years) and 2107 women without a history of bilateral oophorectomy (median [IQR] age, 73 [65-80] years). Premenopausal bilateral oophorectomy was performed before age 46 years among 161 women and was associated with decreased global cognition z score (β, -0.17; 95% CI, -0.32 to -0.03; P = .02), attention and executive domain z score (β, -0.21; 95% CI, -0.36 to -0.05; P = .009), and Short Test of Mental Status score (β, -0.51; 95% CI, -0.95 to -0.08; P = .02) compared with no bilateral oophorectomy.

CONCLUSIONS AND RELEVANCE

This study found that women who underwent bilateral oophorectomy before menopause had increased odds of MCI and poorer performance on cognitive tests approximately 30 years later compared with women who did not undergo bilateral oophorectomy.

Premature or early bilateral oophorectomy: a 2021 update

In this invited review, we discuss some unresolved and controversial issues concerning premature (<40 years) or early (40-45 years) bilateral oophorectomy. First, we clarify the terminology. Second, we summarize the long-term harmful consequences of bilateral oophorectomy. Third, we discuss the restrictive indications for bilateral oophorectomy in premenopausal women to prevent ovarian cancer that are justified by the current scientific evidence. Fourth, we explain the importance of estrogen replacement therapy when bilateral oophorectomy is performed. Hormone replacement therapy is indicated after bilateral oophorectomy until the age of expected natural menopause like in premature or early primary ovarian insufficiency. Fifth, we discuss the relationship between adverse childhood experiences, adverse adult experiences, mental health, gynecologic symptoms and bilateral oophorectomy. The acceptance and popularity of bilateral oophorectomy over several decades, and its persistence even in the absence of supporting scientific evidence, suggest that non-medical factors related to sex, gender, reproduction, cultural beliefs and socioeconomic structure are involved. We discuss some of these non-medical factors and the need for more research in this area.

Absolute Quantification of Phosphorylated ERβ Amino Acids in the Hippocampus of Women and in A Rat Model of Menopause

The rapid decline of circulating 17β-estradiol (E2) at menopause leads to negative neurological consequences, although hormone therapy paradoxically has both harmful and positive effects depending on the age at which it is delivered. The inconsistent response to E2 suggests unappreciated regulatory mechanisms for estrogen receptors (ERs), and we predicted it could be due to age-related differences in ERβ phosphorylation. We assessed ERβ phosphorylation using a sensitive mass spectrometry approach that provides absolute quantification (AQUA-MS) of individually phosphorylated residues. Specifically, we quantified phosphorylated ERβ in the hippocampus of women (aged 21-83 years) and in a rat model of menopause at 4 residues with conserved sequence homology between the 2 species: S105, S176, S200, and Y488. Phosphorylation at these sites, which spanned all domains of ERβ, were remarkably consistent between the 2 species, showing high levels of S105 phosphorylation (80%-100%) and low levels of S200 (20%-40%). Further, S200 phosphorylation decreased with aging in humans and loss of E2 in rats. Surprisingly, Y488 phosphorylation, which has been linked to ERβ ligand-independent actions, exhibited approximately 70% phosphorylation, unaltered by species, age, or E2, suggesting ERβ's primary mode of action may not require E2 binding. We further show phosphorylation at 2 sites directly altered ERβ DNA-binding efficiency, and thus could affect its transcription factor activity. These findings provide the first absolute quantification of ERβ phosphorylation in the human and rat brain, novel insights into ERβ regulation, and a critical foundation for providing more targeted therapeutic options for menopause in the future.

Examination of CA1 Hippocampal DNA Methylation as a Mechanism for Closing of Estrogen's Critical Window

There is a critical window for estrogen replacement therapy, beyond which estradiol (E2) fails to enhance cognition and N-methyl-D-aspartate (NMDA) receptor function, and E2-responsive transcription decreases. Much less attention has been given to the mechanism for closing of the critical window, which is thought to involve the decline in estrogen signaling cascades, possibly involving epigenetic mechanisms, including DNA methylation. This study investigated changes in DNA methylation in region CA1 of the hippocampus of ovariectomized female rats over the course of brain aging and in response to E2-treatment, using whole genome bisulfite sequencing. Differential methylation of CpG and non-CpG (CHG and CHH) sites and associated genes were characterized in aged controls (AC), middle-age controls (MC), and young controls (YC) and differential methylation in response to E2-treatment (T) was examined in each age group (AT-AC, MT-MC, and YT-YC). Possible candidate genes for the closing of the critical window were defined as those that were hypomethylated by E2-treatment in younger animals, but were unresponsive in aged animals. Gene ontology categories for possible critical window genes were linked to response to hormones (Adcyap1, Agtr2, Apob, Ahr, Andpro, Calm2, Cyp4a2, Htr1b, Nr3c2, Pitx2, Pth, Pdk4, Slc2a2, Tnc, and Wnt5a), including G-protein receptor signaling (Gpr22 and Rgs4). Other possible critical window genes were linked to glutamate synapses (Nedd4, Grm1, Grm7, and Grin3a). These results suggest that decreased E2 signaling with advanced age, and/or prolonged E2 deprivation, results in methylation of E2-responsive genes, including those involved in rapid E2 signaling, which may limit subsequent transcription.