Cognitive complaints are associated with smaller right medial temporal gray-matter volume in younger postmenopausal women

Neurophysiological correlates of subjective cognitive decline in perimenopausal and postmenopausal midlife women at risk for Alzheimer's disease

OBJECTIVE

This study aimed to investigate neurophysiological correlates of subjective cognitive decline (SCD) among midlife women at risk for Alzheimer's disease (AD).

METHODS

We examined 156 cognitively normal perimenopausal and postmenopausal women aged 40 to 65 years, with an AD family history and/or apolipoprotein E epsilon 4 genotype, who were not on menopause hormone therapy. Participants underwent neuropsychological testing, health and menopausal symptom questionnaires, and brain volumetric magnetic resonance imaging, arterial spin labeling-magnetic resonance (MR) measuring cerebral blood flow, and 31 phosphorus magnetic resonance spectroscopy ( 31 P-MRS) measuring mitochondria high-energy phosphates (adenosine triphosphate [ATP], phosphocreatine [PCr], inorganic phosphate [Pi]). We used multivariable regressions to compare outcomes between participants with and without SCD and to identify the main correlates of SCD status.

RESULTS

The SCD group (n = 53) exhibited worse verbal memory and executive function test performance (multivariable adjusted P  = 0.029) compared to controls (n = 103). On brain imaging, the SCD group showed higher PCr/ATP in precuneus, posterior cingulate, and parietal regions compared to controls (multivariable adjusted P  < 0.05) and no overall differences in Pi/ATP, PCr/Pi, volume, or cerebral blood flow measures. Results were controlled for age, race, smoking status, hysterectomy status, presence of vasomotor symptoms, menopause symptom severity score, past menopause hormone therapy usage, history of depression, AD family history, and apolipoprotein E epsilon 4 status. The factors more strongly associated with SCD status were inferior parietal PCr/ATP, menopause symptom severity, and presence of vasomotor symptoms.

CONCLUSIONS

Among perimenopausal and postmenopausal midlife women, SCD was associated with altered brain mitochondria bioenergetics in some brain regions similarly affected by AD, warranting further investigation.

The psychometric properties and applicability of subjective cognitive measures used in menopause research: a systematic review

IMPORTANCE

Many midlife women report cognitive issues when they transition through menopause. These cognitive complaints affect women's mental health and quality of life. However, the current understanding of women's cognitive experiences during the menopause transition has been limited by the lack of validated self-reported cognitive measures.

OBJECTIVE

This systematic review aimed to identify existing self-reported, or subjective, cognitive measures used in menopause research and evaluate their psychometric properties and applicability.

EVIDENCE REVIEW

Three databases, Medline, Embase, and PsycINFO, were searched in March 2024 with no restriction on publication year. Studies investigating women transitioning into postmenopause and with cognitive experiences measured using validated subjective cognitive measures were selected. The assessment of psychometric properties and applicability of included measures was conducted based on their development process and their performance in the menopause studies selected.

FINDING

Twenty-eight menopause studies involving 15 measures were included. Included measures showed adequate content validity, internal consistency, and construct validity when they were developed, yet other psychometric properties were either poor or not reported. Hence, the overall performance of included measures was generally moderate to poor. Information relating to psychometric properties of included measures in menopause studies was also lacking, indicating doubtful applicability.

CONCLUSIONS AND RELEVANCE

Poor psychometric properties or the lack of psychometric assessment of existing subjective cognitive measures may indicate doubt or uncertainty regarding their applicability in women transitioning through menopause. This review recommends the use of subjective cognitive measures that assess more than one cognitive domain, as well as further assessment of the psychometric properties of these measures before their use in menopause research or clinical settings, particularly those measures initially developed for clinical practice. It also highlights the need for future development of a subjective cognitive measure for women transitioning through menopause to improve the current understanding of their cognitive challenges.

A fNIRS investigation of menopausal-related symptoms and brain cortical activity in menopause

BACKGROUND

This study aimed to delineate the association between menopausal-related symptoms and brain cortical hemodynamics in peri-postmenopause women.

METHODS

Cross-sectional data from a total of 358 Han-Chinese women who visited the Menopause Clinic in the Shanghai Sixth People's Hospital from August 2019 to August 2022. Menopausal-related symptoms were analyzed through Kupperman index (KMI) scale and PSQI scale, while cerebral blood flow was measured using a functional near-infrared spectroscopy (fNIRS). Multiple linear regression model was used to assess the risk factors for subregions of brain hemodynamic response.

RESULTS

After adjusting for confounding factors, we identified that menopausal symptom (B = -1.575, 95 % CI (-2.661, -0.488), p = 0.005) and duration of menopause (B = -14.583, 95 % CI (-26.753, -4.192), p = 0.007) were independently associated with the lower brain hemodynamic response in the prefrontal lobe, while in the temporal lobe, overweight (BMI ≥ 24 kg/m2) was negatively associated with the lower brain cortical activity (B = -36.882, 95 % CI (-72.708, -1.056), p = 0.044) after adjusting for other confounding variables.

CONCLUSIONS

Our findings proposed that menopausal symptom and overweight should be attached great importance to the postmenopausal women, which provides clinical evidence for the feasible early detection and effective prevention such as menopausal hormone therapy (MHT) of brain health in postmenopausal women.

Brain volumetric changes in menopausal women and its association with cognitive function: a structured review

The menopausal transition has been proposed to put women at risk for undesirable neurological symptoms, including cognitive decline. Previous studies suggest that alterations in the hormonal milieu modulate brain structures associated with cognitive function. This structured review provides an overview of the relevant studies that have utilized MRI to report volumetric differences in the brain following menopause, and its correlations with the evaluated cognitive functions. We performed an electronic literature search using Medline (Ovid) and Scopus to identify studies that assessed the influence of menopause on brain structure with MRI. Fourteen studies met the inclusion criteria. Brain volumetric differences have been reported most frequently in the frontal and temporal cortices as well as the hippocampus. These regions are important for higher cognitive tasks and memory. Additionally, the deficit in verbal and visuospatial memory in postmenopausal women has been associated with smaller regional brain volumes. Nevertheless, the limited number of eligible studies and cross-sectional study designs warrant further research to draw more robust conclusions.

Estradiol treatment in young postmenopausal women with self-reported cognitive complaints: Effects on cholinergic-mediated cognitive performance

OBJECTIVE

Older women are at increased risk of developing Alzheimer's disease compared to men. One proposed reason is that following menopause there is a decline in estrogens. Estrogens are important for cholinergic functioning and attenuate the impact of cholinergic antagonists on cognitive performance in postmenopausal women. Self-reported or subjective cognitive complaints in middle or older age may represent a harbinger of cognitive decline and those who endorse cognitive complaints appear more likely to develop future cognitive impairment. However, the response of individuals with cognitive complaints after menopause to estrogen and the relationship to cholinergic functioning has not been investigated. This study investigated the effect of estrogen treatment using 17β-estradiol on cognitive performance following anticholinergic blockade in postmenopausal women and the relationship of this interaction with the level of self-reported (subjective) postmenopausal cognitive complaints.

METHODS

Forty postmenopausal women (aged 50-60 years) completed a 3-month treatment regimen of either 1 mg oral estradiol or placebo. Participants then completed four challenge days in which they completed cognitive and behavioral tasks after one of four cholinergic antagonist drug conditions (oral mecamylamine (MECA), intravenous scopolamine, combined MECA and scopolamine, or PLC).

RESULTS

Compared to PLC, the estradiol treated group performed worse on attention tasks under cholinergic challenge including the choice reaction time task and the critical flicker fusion task. In addition, participants who endorsed greater cognitive complaints showed reduced performance on the N-back working memory task, regardless of whether they received estradiol treatment.

CONCLUSIONS

The findings of this study indicate that estradiol treatment was unable to mitigate anticholinergic blockade in postmenopausal women with subjective cognitive complaints, and worsened performance on attention tasks. Moreover, the present study suggests that greater levels of cognitive complaints following menopause may be associated with an underlying decline in cholinergic function that may manifest as an inability to compensate during working memory tasks.

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.

A research primer for studies of cognitive changes across the menopause transition

There has been a proliferation of studies demonstrating important sex differences in cognitive aging and dementia, and with this an increased interest in the role of menopause and sex steroid hormones in women's brain health. Foundational longitudinal studies of cognitive changes from the premenopause to perimenopause stage have shown reliable declines in verbal memory, with variable findings in processing speed, attention/working memory and verbal fluency. Continued research is needed to advance understanding of the range of cognitive domains affected, the duration of cognitive changes, the generalizability of these changes across cultures, the factors that account for such changes and the factors that can improve cognition at this time. In this article, we briefly review and draw on findings from large longitudinal studies of cognitive changes across the menopause transition to inform the design of future studies on this topic. We focus on key issues such as objective versus subjective cognitive measures; cognitive domains and tests; staging menopause; study design; mediators of cognitive effects (including hormones and menopause symptoms); and consideration of key covariates. We suggest that a more uniform and evidence-based approach to the investigation of these issues can advance the quality of the science in menopause and cognition.

Menopause and cognitive complaints: are ovarian hormones linked with subjective cognitive decline?

Subjective cognitive decline (SCD) and the loss of ovarian hormones after menopause have been independently linked to later-life Alzheimer's disease (AD). The objective of this review was to determine whether menopause and the loss of ovarian hormones contribute to cognitive complaints and SCD in women. This would suggest that SCD at the menopausal transition might be an important marker of eventual cognitive decline and AD. We conducted a literature search using PubMed, PsycINFO and Web of Science in July 2020. All English-language studies assessing SCD and cognitive complaints with respect to menopause and ovarian hormones were included. A total of 19 studies were included. Studies found that cognitive complaints increased across the menopause transition and were associated with reductions in attention, verbal and working memory, and medial temporal lobe volume. Women taking estrogen-decreasing treatments also had increased cognitive complaints and reduced working memory and executive function. The current literature provides impetus for further research on whether menopause and the loss of ovarian hormones are associated with cognitive complaints and SCD. Clinicians may take particular note of cognitive complaints after menopause or ovarian hormone loss, as they might presage future cognitive decline.

Genetics of Menopause and Primary Ovarian Insufficiency: Time for a Paradigm Shift?

This review summarizes the existing information concerning the genetic background of menopause and primary ovarian insufficiency (POI). There is overwhelming evidence that majority of genes are involved in double-strand break repair, mismatch repair, and base excision repair. The remaining loci were involved in cell energy metabolism and immune response. Gradual (or in case of rapid POI) accumulation of unrepaired DNA damage causes (premature) cell death and cellular senescence. This in turn leads to exhaustion of cell renewal capacity and cellular dysfunction in affected organs and eventually to aging of the entire soma. Similar erosion of the genome occurs within the germ cell line and the ovaries. Subsequently, the systemic "survival" response intentionally suppresses the sex-steroid hormonal output, which in turn may contribute to the onset of menopause. The latter occurs in particular when age-dependent DNA damage accumulation does not cease. Both effects are expected to synergize to promote (premature) ovarian silencing and install (early) menopause. Consequently, aging of the soma seems to be a primary driver for the loss of ovarian function in women. This challenges the current dogma which implies that loss of ovarian function initiates aging of the soma. It is time for a paradigm shift!