Postmenopausal hormone treatment alters neural pathways but does not improve verbal cognitive function

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

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

The mediating and moderating effects of depression on the relationship between cognitive function and difficulty in activities of daily living among postmenopausal women

OBJECTIVE

Cognitive function and depression impact critically the daily functioning of menopausal women. This study aimed to explore the mediating and moderating effects of depressive symptoms on the association between cognitive function and activities of daily living (ADL) difficulty in postmenopausal women.

METHODS

A total of 2,596 postmenopausal women from the China Health and Retirement Longitudinal Study completed the Chinese version of the Mini-Mental State Examination, basic ADL (BADL) and instrumental ADL (IADL) scales, and 10-item Short-Form Center for Epidemiological Studies Depression. We constructed structural equation modeling to examine the association between cognitive function, depressive symptoms, and BADL/IADL difficulty.

RESULTS

The prevalence of BADL/IADL difficulty in postmenopausal women was 22.5% and 31.5%, respectively. After adjustments for demographic and health-related covariates, cognitive decline (contributed by four cognitive dimensions with different weights) was significantly associated with BADL/IADL difficulty (contributed by six-item daily activities with different weights). Depressive symptoms mediated and explained 28.8% and 23.2% of cognitive function associations with BADL and IADL difficulty, respectively. The Johnson-Neyman technique identified a threshold of eight and four for depressive symptoms, beyond which the protective effect of cognitive function on BADL and IADL emerged.

CONCLUSIONS

Depressive symptoms mediated and moderated the association between cognition and BADL/IADL difficulty in postmenopausal women. Compared with BADL, IADL may be more sensitive to changes in cognitive function. More strength should be put on developing comprehensive intervention techniques focusing on simultaneous intervention of multidimensional cognitive function and depression to maintain and improve the quality of life of postmenopausal women.

A review of the impact of hormone therapy on prefrontal structure and function at menopause

The menopause transition arises mainly from a decline in ovarian function characterized by a decrease in levels of ovarian estrogens (estradiol) and progesterone in women. Menopausal hormone therapy (MHT) has been used to counteract menopause-associated symptoms in postmenopausal women. With the development of advanced brain imaging methods, understanding MHT-related effects on brain structures and functions could help advance our understanding of the biological consequence of MHT-related effects on behavior, thereby contributing to developing new strategies for optimizing brain health during the menopause transition. This review focuses on the human research related to the impact of MHT on structural and functional organization of the prefrontal cortex in postmenopausal women. Although such MHT-related effects on brain structures and functions have only begun to be understood, it may be useful to examine present findings to identify areas for future research.

Association of objectively measured physical fitness with health-related quality of life of mid-life women: the FLAMENCO project

OBJECTIVES

This study aimed to explore the association of physical fitness with health-related quality of life (HRQoL) in mid-life women and to examine the potential independent association of physical fitness components with the physical and mental components from the 36-Item Short-Form Health Survey (SF-36) in this population.

METHODS

This cross-sectional study comprised 183 mid-life women from southern Spain who participated in the FLAMENCO project. Body composition was measured through an impedanciometer, a stadiometer, and dual-energy X-ray absorptiometry. Physical fitness was objectively measured with the Senior Fitness Test battery (cardiorespiratory fitness, flexibility, and dynamic balance/agility) plus handgrip strength (muscle strength). The SF-36 questionnaire was used to assess HRQoL of the participants.

RESULTS

All the physical fitness components were associated with the SF-36 physical function (all p < 0.05) except for lower-body flexibility. The rest of the physical fitness components showed associations with most of the SF-36 dimensions (all p < 0.05). Dynamic balance/agility and upper-body flexibility were independently associated with the SF-36 physical component scale, explaining 15% and 17% of the SF-36 physical component scale, respectively. Any physical fitness component showed independent associations with the SF-36 mental component scale.

CONCLUSIONS

Greater physical fitness levels are associated with better HRQoL of mid-life women. Dynamic balance/agility and upper-body flexibility were the strongest independent physical fitness components associated with the SF-36 physical component scale.

Altered Spontaneous Brain Activity in Women During Menopause Transition and Its Association With Cognitive Function and Serum Estradiol Level

OBJECTIVE

Serum hormone deficiencies during menopause transition may affect spontaneous brain activity and global cognition. The purpose of this study was to explore the differences in spontaneous brain activity between premenopausal and perimenopausal women, and to investigate the associations between spontaneous brain activity, serum hormone levels and global cognition.

METHODS

Thirty-two premenopausal women (47.75 ± 1.55 years) and twenty-five perimenopausal women (51.60 ± 1.63 years) underwent resting-state functional MRI (fMRI) scan. Clinical information including Mini-Mental State Examination (MMSE), levels of estradiol (E2), free testosterone, progesterone, prolactin, follicle-stimulating hormone and luteinizing hormone were measured. Regional homogeneity (ReHo) was used to evaluate spontaneous brain activity alterations between perimenopausal and premenopausal women. Correlation analysis was used to investigate the associations between brain functional alterations and clinical measures in perimenopausal group.

RESULTS

The results demonstrated increased ReHo value in the right lingual gyrus (LG) and decreased ReHo value in the right superior frontal gyrus (SFG) in perimenopausal women compared with premenopausal women. In perimenopausal group, ReHo of the right LG showed a negative correlation with level of E2 (r = -0.586, p = 0.002), ReHo of the right SFG showed a positive correlation with level of E2 (r = 0.470, p = 0.018) and MMSE (r = 0.614, p = 0.001).

CONCLUSIONS

The results demonstrated that women approaching menopause suffered from altered functions in brain regions related to cognitive function, working memory, the results also revealed a direct association between levels of E2 and brain functions in perimenopausal women.

The peri-menopause in a woman's life: a systemic inflammatory phase that enables later neurodegenerative disease

The peri-menopause or menopausal transition—the time period that surrounds the final years of a woman’s reproductive life—is associated with profound reproductive and hormonal changes in a woman’s body and exponentially increases a woman’s risk of cerebral ischemia and Alzheimer’s disease. Although our understanding of the exact timeline or definition of peri-menopause is limited, it is clear that there are two stages to the peri-menopause. These are the early menopausal transition, where menstrual cycles are mostly regular, with relatively few interruptions, and the late transition, where amenorrhea becomes more prolonged and lasts for at least 60 days, up to the final menstrual period. Emerging evidence is showing that peri-menopause is pro-inflammatory and disrupts estrogen-regulated neurological systems. Estrogen is a master regulator that functions through a network of estrogen receptors subtypes alpha (ER-α) and beta (ER-β). Estrogen receptor-beta has been shown to regulate a key component of the innate immune response known as the inflammasome, and it also is involved in regulation of neuronal mitochondrial function. This review will present an overview of the menopausal transition as an inflammatory event, with associated systemic and central nervous system inflammation, plus regulation of the innate immune response by ER-β-mediated mechanisms.

Examining the Relationship Between Neurosteroids, Cognition, and Menopause With Neuroimaging Methods

PURPOSE OF REVIEW

Previous literature has shown inconsistent findings regarding the effects of neurosteroids on the brain in postmenopausal women. The goal of this paper is to examine how and whether advances in neuroimaging have helped elucidate the relationship between the withdrawal of and/or treatment with neurosteroids and cognition at menopause.

RECENT FINDINGS

Neuroimaging techniques such as structural and functional MRI have been used in recent studies to examine the relationship between neurosteroids and brain structure and functioning. However, the recent literature shows that different formulations of postmenopausal hormones given at different times, through different routes of administration, and in different combinations with progestins result in a variety of relationships with the brain outcomes. We suggest that still further research is needed to understand how the structural changes resulting from estrogen withdrawal or therapy at menopause can influence cognitive functioning. However, imaging studies are time-, resource-, and expertise-intensive. We believe that this information will help uncover the mechanisms and relationships that can aid in the explanation of the individual differences in the effects of menopause on the brain as well as how this menopause-related hormone change influences risk for pathological aging.