Considering sex and gender in Alzheimer disease and other dementias

Quality of life in early-stage Alzheimer's disease: the moderator role of family variables and coping strategies from the patients' perspective

AIM

This study assessed the effects of sociodemographic and psychological variables on quality of life (QOL), as well as the moderator role of family variables and coping strategies in the relationship between psychological morbidity and QOL, based on patients' perspective.

METHODS

This study used a cross-sectional design. A total of 158 patients with early Alzheimer's disease completed the Mini-Mental State Examination, the Montreal Cognitive Assessment, the Hospital Anxiety and Depression Scale, the Ways of Coping Questionnaire, the Spiritual and Religious Attitudes in Dealing with Illness, the Family Adaptability and Cohesion Evaluation Scales, the Family Satisfaction Scale, the Family Communication Scale, the Barthel Index, and the Quality of Life in Alzheimer's Disease Scale.

RESULTS

Being a man, having a higher education, and engaging in more exercise activity were associated with better QOL. Lower levels of cognitive impairment, psychological morbidity, and spirituality predicted better QOL. Also, lower levels of functionality, family communication, family satisfaction, and family functioning contributed to worse QOL. Gender, psychological morbidity, and functionality contributed significantly to QOL. Family satisfaction, family communication, and coping strategies moderated the relationship between psychological morbidity and QOL.

CONCLUSION

Intervention in early-stage Alzheimer's disease should focus on patients' coping strategies and family context, particularly family satisfaction and communication, to foster QOL.

Chronic Traumatic Encephalopathy: A Comparison with Alzheimer's Disease and Frontotemporal Dementia

The clinical diagnosis of chronic traumatic encephalopathy (CTE) is challenging due to heterogeneous clinical presentations and overlap with other neurodegenerative dementias. Depending on the clinical presentation, the differential diagnosis of CTE includes Alzheimer's disease (AD), behavioral variant frontotemporal dementia (bvFTD), Parkinson's disease, amyotrophic lateral sclerosis, primary mood disorders, posttraumatic stress disorder, and psychotic disorders. The aim of this article is to compare the clinical aspects, genetics, fluid biomarkers, imaging, treatment, and pathology of CTE to those of AD and bvFTD. A detailed clinical evaluation, neurocognitive assessment, and structural brain imaging can inform the differential diagnosis, while molecular biomarkers can help exclude underlying AD pathology. Prospective studies that include clinicopathological correlations are needed to establish tools that can more accurately determine the cause of neuropsychiatric decline in patients at risk for CTE.

The effect of scalp electroacupuncture combined with Memantine in patients with vascular dementia: A retrospective study

Currently there is no effective treatment for vascular dementia (VaD). Pharmacological treatment often lead to severe complications and require drug dosage adjustment. This study investigated the effect of scalp electroacupuncture combined with Memantine in VaD. The safety and antioxidative effect of scalp electroacupuncture were also explored.A retrospective study was conducted and data of inpatients of Linyi Central Hospital with VaD between June 2017 and May 2018 were collected and sorted. The patients were divided into scalp electroacupuncture-medication (A), scalp electroacupuncture (B) and medication (control) (C) groups, in which Memantine was prescribed as medication. Cognitive function, activities of daily living and quality of life assessed by Montreal Cognitive Assessment (MoCA), Barthel index and dementia quality of life questionnaire; the contents of superoxide dismutase, lipid peroxide and nitric oxide in blood samples; and adverse reaction were compared.Data from a total of 150 patients were collected (Group A, n = 55; Group B, n = 50; Group C, n = 45). The post-treatment/follow-up Montreal Cognitive Assessment, Barthel index and dementia quality of life questionnaire scores were significantly improved in all groups compared to pre-treatment (groups A and B, P<.01; group C, P<.05). The improvements were significant for groups A vs C, B vs C (P<0.01, both), and group A vs B (P<.05). The post-treatment/follow-up levels of lipid peroxide and nitric oxide decreased significantly while superoxide dismutase increased significantly in groups A and B compared to pre-treatment (P<.01, both). The differences were significant for groups A vs C, and B vs C (P < .01, both), but not significant between groups A and B (P > .05). There were no significant adverse events occurred during the study and follow-up.In combined treatment, scalp electroacupuncture works in parallel with Memantine and significantly increase the therapeutic effect in VaD with no significant adverse events. Scalp electroacupuncture may have the potential to serve as an option or alternative treatment for VaD. Scalp electroacupuncture may alleviate VaD symptoms through its antioxidative mechanism.

Sex differences in exercise efficacy: Is midlife a critical window for promoting healthy cognitive aging?

Dementia is one of the most pressing health care issues of this century. As no curative treatment for dementia exists, research efforts are growing to identify effective lifestyle interventions to prevent or delay onset. One such promising strategy that promotes cognitive and brain health is engaging in physical exercise. However, current exercise recommendations are imprecise. To advance the potential of exercise as a preventative and treatment strategy, important questions regarding moderators (ie, biological sex and age) are being addressed in the literature. Biological sex is recognized as an important variable to consider in exercise efficacy on brain health, with females showing greater cognitive gains. This may be related to sex differences in underlying mechanisms. Here, we argue to better understand the sex differences in exercise efficacy, the timing of exercise intervention should also be considered. Specifically, we present the hypothesis that midlife in females is a critical window for the implementation of exercise as an early intervention to promote brain health and prevent dementia. Further, we speculate that exercise interventions targeting midlife will be of critical importance for the female brain, as females exit this period of the lifespan at greater risk for cognitive impairment. Given the potential sex differences in dementia risk and prevalence, it is imperative to assess potential sex differences in exercise efficacy as an early intervention during midlife.

Nuances in Alzheimer's Genetic Risk Reveal Differential Predictions of Non-demented Memory Aging Trajectories: Selective Patterns by APOE Genotype and Sex

BACKGROUND

Apolipoprotein E (APOE) is a prominent genetic risk factor for Alzheimer's disease (AD) and a frequent target for associations with non-demented and cognitively impaired aging. APOE offers a unique opportunity to evaluate two dichotomous comparisons and selected gradations of APOE risk. Some evidence suggests that APOE effects may differ by sex and emerge especially in interaction with other AD-related biomarkers (e.g., vascular health).

METHODS

Longitudinal trajectories of non-demented adults (n = 632, 67% female, Mage = 68.9) populated a 40-year band of aging. Focusing on memory performance and individualized memory trajectories, a sequence of latent growth models was tested for predictions of (moderation between) APOE and pulse pressure (PP) as stratified by sex. The analyses (1) established robust benchmark PP effects on memory trajectories, (2) compared predictions of alternative dichotomous groupings (ε4- vs ε4+, ε2- vs ε2+), and (3) examined precision-based predictions by disaggregated APOE genotypes.

RESULTS

Healthier (lower) PP was associated with better memory performance and less decline. Therefore, all subsequent analyses were conducted in the interactive context of PP effects and sex stratification. The ε4-based dichotomization produced no differential genetic predictions. The ε2-based analyses showed sex differences, including selective protection for ε2-positive females. Exploratory follow-up disaggregated APOE genotype analyses suggested selective ε2 protection effects for both homozygotic and heterozygotic females.

CONCLUSION

Precision analyses of AD genetic risk will advance the understanding of underlying mechanisms and improve personalized implementation of interventions.

Does hearing loss lead to dementia? A review of the literature

Recent studies have revealed a correlation between aging-related hearing loss and the likelihood of developing Alzheimer Disease. However, it is not yet known if the correlation simply reflects the fact that these two disorders share common risk factors or whether there is a causal link between them. The answer to this question carries therapeutic implications. Unfortunately, it is not possible to study the question of causality between aging-related hearing loss and dementia in human subjects. Here, we evaluate the research surrounding induced-hearing loss in animal models on non-auditory cognition to help infer if there is any causal evidence linking hearing loss and a more general dementia. We find ample evidence that induction of hearing loss in animals produces cognitive decline, particularly hippocampal dysfunction. The data suggest that noise-exposure produces a toxic milieu in the hippocampus consisting of a spike in glucocorticoid levels, elevations of mediators of oxidative stress and excitotoxicity, which as a consequence induce cessation of neurogenesis, synaptic loss and tau hyperphosphorylation. These data suggest that hearing loss can lead to pathological hallmarks similar to those seen in Alzheimer's Disease and other dementias. However, the rodent data do not establish that hearing loss on its own can induce a progressive degenerative dementing illness. Therefore, we conclude that an additional "hit", such as aging, APOE genotype, microvascular disease or others, may be necessary to trigger an ongoing degenerative process such as Alzheimer Disease.

Walking Speed is the Sole Determinant Criterion of Sarcopenia of Mild Cognitive Impairment in Japanese Elderly Patients with Type 2 Diabetes Mellitus

Diabetes mellitus is a risk factor for mild cognitive impairment (MCI) and dementia. However, how the clinical characteristics of MCI patients with type 2 diabetes mellitus are linked to sarcopenia and/or its criteria remain to be elucidated. Japanese patients with type 2 diabetes mellitus were categorized into the MCI group for MoCA-J (the Japanese version of the Montreal cognitive assessment) score <26, and into the non-MCI group for MoCA-J ≥26. Sarcopenia was defined by a low skeletal mass index along with low muscle strength (handgrip strength) or low physical performance (walking speed <1.0 m/s). Univariate and multivariate-adjusted odds ratio models were used to determine the independent contributors for MoCA-J <26. Among 438 participants, 221 (50.5%) and 217 (49.5%) comprised the non-MCI and MCI groups, respectively. In the MCI group, age (61 ± 12 vs. 71 ± 10 years, p < 0.01) and duration of diabetes mellitus (14 ± 9 vs. 17 ± 9 years, p < 0.01) were higher than those in the non-MCI group. Patients in the MCI group exhibited lower hand grip strength, walking speed, and skeletal mass index, but higher prevalence of sarcopenia. Only walking speed (rather than muscle loss or muscle weakness) was found to be an independent determinant of MCI after adjusting for multiple factors, such as age, gender, body mass index (BMI), duration of diabetes mellitus, hypertension, dyslipidemia, smoking, drinking, estimated glomerular filtration rate (eGFR), HbA1c, and history of coronary heart diseases and stroke. In subgroup analysis, a group consisting of male patients aged ≥65 years, with BMI <25, showed a significant OR for walking speed. This study showed that slow walking speed is a sole determinant criterion of sarcopenia of MCI in patients with type 2 diabetes mellitus. It was suggested that walking speed is an important factor in the prediction and prevention of MCI development in patients with diabetes mellitus.

Science Runs and the Debate Brakes: Somatic Gene-Editing as a New Tool for Gender-Specific Medicine in Alzheimer's Disease

Gender-specific medicine is a discipline that studies the influence of sex and gender on physiology, pathophysiology, and diseases. One example in light of how a genetic-based disease among other diseases, that impact on sex, can be represented by the risk of developing dementia or Alzheimer's disease. The question that comes into focus is whether gene-editing can represent a new line of investigation to be explored in the development of personalized, gender-specific medicine that guarantees gender equity in health policies. This article aims to discuss the relevance of adopting a gender-specific focus on gene-editing research, considered as a way of contributing to the advance of medicine's understanding, treatment, and prevention of dementia, particularly Alzheimer's disease. The development or improvement of cures could take advantage of the knowledge of the gender diversity in order to ascertain and develop differential interventions also at the genetic level between women and men, and this deserves special attention and deep ethical reflection.

TGF-β Signaling: A Therapeutic Target to Reinstate Regenerative Plasticity in Vascular Dementia?

Vascular dementia (VaD) is the second leading form of memory loss after Alzheimer's disease (AD). Currently, there is no cure available. The etiology, pathophysiology and clinical manifestations of VaD are extremely heterogeneous, but the impaired cerebral blood flow (CBF) represents a common denominator of VaD. The latter might be the result of atherosclerosis, amyloid angiopathy, microbleeding and micro-strokes, together causing blood-brain barrier (BBB) dysfunction and vessel leakage, collectively originating from the consequence of hypertension, one of the main risk factors for VaD. At the histopathological level, VaD displays abnormal vascular remodeling, endothelial cell death, string vessel formation, pericyte responses, fibrosis, astrogliosis, sclerosis, microglia activation, neuroinflammation, demyelination, white matter lesions, deprivation of synapses and neuronal loss. The transforming growth factor (TGF) β has been identified as one of the key molecular factors involved in the aforementioned various pathological aspects. Thus, targeting TGF-β signaling in the brain might be a promising therapeutic strategy to mitigate vascular pathology and improve cognitive functions in patients with VaD. This review revisits the recent understanding of the role of TGF-β in VaD and associated pathological hallmarks. It further explores the potential to modulate certain aspects of VaD pathology by targeting TGF-β signaling.

Early Onset of Sex-Dependent Mitochondrial Deficits in the Cortex of 3xTg Alzheimer's Mice

Alzheimer’s disease (AD) is a major public health concern worldwide. Advanced age and female sex are two of the most prominent risk factors for AD. AD is characterized by progressive neuronal loss, especially in the cortex and hippocampus, and mitochondrial dysfunction has been proposed to be an early event in the onset and progression of the disease. Our results showed early perturbations in mitochondrial function in 3xTg mouse brain, with the cortex being more susceptible to mitochondrial changes than the hippocampus. In the cortex of 3xTg females, decreased coupled and uncoupled respiration were evident early (at 2 months of age), while in males it appeared later at 6 months of age. We observed increased coupled respiration in the hippocampus of 2-month-old 3xTg females, but no changes were detected later in life. Changes in mitochondrial dynamics were indicated by decreased mitofusin (Mfn2) and increased dynamin related protein 1 (Drp1) (only in females) in the hippocampus and cortex of 3xTg mice. Our findings highlight the importance of controlling and accounting for sex, brain region, and age in studies examining brain bioenergetics using this common AD model in order to more accurately evaluate potential therapies and improve the sex-specific translatability of preclinical findings.

Improving translational research in sex-specific effects of comorbidities and risk factors in ischaemic heart disease and cardioprotection: position paper and recommendations of the ESC Working Group on Cellular Biology of the Heart

Ischaemic heart disease (IHD) is a complex disorder and a leading cause of death and morbidity in both men and women. Sex, however, affects several aspects of IHD, including pathophysiology, incidence, clinical presentation, diagnosis as well as treatment and outcome. Several diseases or risk factors frequently associated with IHD can modify cellular signalling cascades, thus affecting ischaemia/reperfusion injury as well as responses to cardioprotective interventions. Importantly, the prevalence and impact of risk factors and several comorbidities differ between males and females, and their effects on IHD development and prognosis might differ according to sex. The cellular and molecular mechanisms underlying these differences are still poorly understood, and their identification might have important translational implications in the prediction or prevention of risk of IHD in men and women. Despite this, most experimental studies on IHD are still undertaken in animal models in the absence of risk factors and comorbidities, and assessment of potential sex-specific differences are largely missing. This ESC WG Position Paper will discuss: (i) the importance of sex as a biological variable in cardiovascular research, (ii) major biological mechanisms underlying sex-related differences relevant to IHD risk factors and comorbidities, (iii) prospects and pitfalls of preclinical models to investigate these associations, and finally (iv) will provide recommendations to guide future research. Although gender differences also affect IHD risk in the clinical setting, they will not be discussed in detail here.

Automated MRI-Based Deep Learning Model for Detection of Alzheimer’s Disease Process

In the context of neuro-pathological disorders, neuroimaging has been widely accepted as a clinical tool for diagnosing patients with Alzheimer’s disease (AD) and mild cognitive impairment (MCI). The advanced deep learning method, a novel brain imaging technique, was applied in this study to evaluate its contribution to improving the diagnostic accuracy of AD. Three-dimensional convolutional neural networks (3D-CNNs) were applied with magnetic resonance imaging (MRI) to execute binary and ternary disease classification models. The dataset from the Alzheimer’s disease neuroimaging initiative (ADNI) was used to compare the deep learning performances across 3D-CNN, 3D-CNN-support vector machine (SVM) and two-dimensional (2D)-CNN models. The outcomes of accuracy with ternary classification for 2D-CNN, 3D-CNN and 3D-CNN-SVM were [Formula: see text]%, [Formula: see text]% and [Formula: see text]% respectively. The 3D-CNN-SVM yielded a ternary classification accuracy of 93.71%, 96.82% and 96.73% for NC, MCI and AD diagnoses, respectively. Furthermore, 3D-CNN-SVM showed the best performance for binary classification. Our study indicated that ‘NC versus MCI’ showed accuracy, sensitivity and specificity of 98.90%, 98.90% and 98.80%; ‘NC versus AD’ showed accuracy, sensitivity and specificity of 99.10%, 99.80% and 98.40%; and ‘MCI versus AD’ showed accuracy, sensitivity and specificity of 89.40%, 86.70% and 84.00%, respectively. This study clearly demonstrates that 3D-CNN-SVM yields better performance with MRI compared to currently utilized deep learning methods. In addition, 3D-CNN-SVM proved to be efficient without having to manually perform any prior feature extraction and is totally independent of the variability of imaging protocols and scanners. This suggests that it can potentially be exploited by untrained operators and extended to virtual patient imaging data. Furthermore, owing to the safety, noninvasiveness and nonirradiative properties of the MRI modality, 3D-CNN-SMV may serve as an effective screening option for AD in the general population. This study holds value in distinguishing AD and MCI subjects from normal controls and to improve value-based care of patients in clinical practice.

Gender Differences in Cognitive Impairment among Rural Elderly in China

Elders in rural areas of developing countries are particularly vulnerable to cognitive impairment and gender disparities are notable. Yet, evidence related to gender differences in cognitive impairment in these settings is scarce. This study examined gender differences in cognitive impairment among elderly people aged 65 and above in rural China. A multi-site cross-sectional survey was conducted. In total, 550 males and 700 females were recruited. The Chinese version of the Mini-Mental Status Examination was applied for cognitive impairment screening. Demographic information, lifestyle factors, psychosocial factors, and health-related information were assessed. The prevalence of cognitive impairment was 40.0%in males and 45.1% in females, respectively. Females showed significant higher prevalence after age 75 (62.7% vs. 45.4%, p < 0.005). Older age, hearing impairment, and activities of daily living dependence were common factors associated with cognitive impairment in both females and males. For males, living in a neighborhood with poor social interactions and diabetes were risk factors, while tea consumption was a protective factor. For females, vision impairment and illiteracy were additional risk factors. Individualized interventions and standardized measurements of cognitive function should be developed to suit older populations living in rural and less-developed areas, through collective efforts involving all stakeholders and multidisciplinary teamwork.

Prevalence of Comorbidities in Individuals Diagnosed and Undiagnosed with Alzheimer's Disease in León, Spain and a Proposal for Contingency Procedures to Follow in the Case of Emergencies Involving People with Alzheimer's Disease

Background: Alzheimer's disease (AD) which is the most common type of dementia is characterized by mental or cognitive disorders. People suffering with this condition find it inherently difficult to communicate and describe symptoms. As a consequence, both detection and treatment of comorbidities associated with Alzheimer's disease are substantially impaired. Equally, action protocols in the case of emergencies must be clearly formulated and stated. Methods: We performed a bibliography search followed by an observational and cross-sectional study involving a thorough review of medical records. A group of AD patients was compared with a control group. Each group consisted of 100 people and were all León residents aged ≥65 years. Results: The following comorbidities were found to be associated with AD: cataracts, urinary incontinence, osteoarthritis, hearing loss, osteoporosis, and personality disorders. The most frequent comorbidities in the control group were the following: eye strain, stroke, vertigo, as well as circulatory and respiratory disorders. Comorbidities with a similar incidence in both groups included type 2 diabetes mellitus, glaucoma, depression, obesity, arthritis, and anxiety. We also reviewed emergency procedures employed in the case of an emergency involving an AD patient. Conclusions: Some comorbidities were present in both the AD and control groups, while others were found in the AD group and not in the control group, and vice versa.

Alzheimer's Disease and Cardiovascular Disease: A Particular Association

Methods

This review is based on the material obtained via MEDLINE (PubMed), EMBASE, and Clinical Trials databases, from January 1980 until May 2019. The search term used was "Alzheimer's disease," combined with "cardiovascular disease," "hypertension," "dyslipidaemia," "diabetes mellitus," "atrial fibrillation," "coronary artery disease," "heart valve disease," and "heart failure." Out of the 1,328 papers initially retrieved, 431 duplicates and 216 records in languages other than English were removed. Among the 681 remaining studies, 98 were included in our research material on the basis of the following inclusion criteria: (a) the community-based studies; (b) using standardized diagnostic criteria; (c) reporting raw prevalence data; (d) with separate reported data for sex and age classes.

Results

While AD and CVD alone may be considered deleterious to health, the study of their combination constitutes a clinical challenge. Further research will help to clarify the real impact of vascular factors on these diseases. It may be hypothesized that there are various mechanisms underlying the association between AD and CVD, the main ones being hypoperfusion and emboli, atherosclerosis, and the fact that, in both the heart and brain of AD patients, amyloid deposits may be present, thus causing damage to these organs.

Conclusions

AD and CVD are frequently associated. Further studies are needed in order to understand the effect of CVD and its risk factors on AD in order to better comprehend the effects of subclinical and clinical CVD on the brain. Finally, we need to clarify the impact of the underlying hypothesized mechanisms of this association and to investigate gender issues.

Anxiety and Risk of Vascular Dementia in an Elderly Community Sample: The Role of Sex

Background: To assess the association between anxiety and risk of vascular dementia (VaD), as well as potential sex differences, in a community-based cohort. Methods: A random sample of 4057 dementia-free community participants aged 55 or older, from the longitudinal, community-based Zaragoza Dementia and Depression Project (ZARADEMP) study were followed for 4.5 years. Geriatric Mental State B (GMS)-Automated Geriatric Examination for Computer Assisted Taxonomy (AGECAT) was used for the assessment and diagnosis of anxiety, and a panel of research psychiatrists diagnosed the incident cases of VaD according to DSM-IV (Diagnostic and Statistical Manual of mental disordes). Multivariate survival analysis with competing risk regression model was performed. Results: In men, the incidence rate of VaD was significantly higher among anxiety subjects compared with non-anxiety subjects (incidence rate ratio (IRR) (95% confidence interval (CI)): 3.24 (1.13-9.35); p = 0.029), and no difference was observed in women (IRR (95%CI): 0.68 (0.19-2.23); p = 0.168). In the multivariate model, for men, cases of anxiety had 2.6-fold higher risk of VaD (subdistribution hazard ratio (SHR): 2.61; 95%CI: 0.88-7.74) when all potential confounding factors were controlled, with no statistical significance (p = 0.084), but a clinically relevant effect (Cohen's d: 0.74). No association was found in women. Conclusions: In men, but not in women, risk of VaD was higher among individuals with anxiety, with a clinically relevant effect. Potential anxiety-related preventive interventions for VaD might be tailored to men and women separately.

Sex-specific associations with cerebrospinal fluid biomarkers in dementia with Lewy bodies

Background

Dementia with Lewy bodies (DLB) is more prevalent in men than in women. In addition, post-mortem studies found sex differences in underlying pathology. It remains unclear whether these differences are also present antemortem in in vivo biomarkers, and whether sex differences translate to variability in clinical manifestation. The objective of this study was to evaluate sex differences in cerebrospinal fluid (CSF) biomarker concentrations (i.e., alpha-synuclein (α-syn), amyloid β1-42 (Aβ42), total tau (Tau), phosphorylated tau at threonine 181 (pTau)) and clinical characteristics in DLB.

Methods

We included 223 DLB patients from the Amsterdam Dementia Cohort, of which 39 were women (17%, age 70 ± 6, MMSE 21 ± 6) and 184 men (83%, age 68 ± 7, MMSE 23 ± 4). Sex differences in CSF biomarker concentrations (i.e., α-syn, Aβ42, Tau, and pTau) were evaluated using age-corrected general linear models (GLM). In addition, we analyzed sex differences in core clinical features (i.e., visual hallucinations, parkinsonism, cognitive fluctuations, and REM sleep behavior disorder (RBD) and cognitive test scores using age- and education-adjusted GLM.

Results

Women had lower CSF α-syn levels (F 1429 ± 164 vs M 1831 ± 60, p = 0.02) and CSF Aβ42 levels (F 712 ± 39 vs M 821 ± 18, p = 0.01) compared to men. There were no sex differences for (p) Tau concentrations (p > 0.05). Clinically, women were older, had a shorter duration of complaints (F 2 ± 1 vs M 4 ± 3, p < 0.001), more frequent hallucinations (58% vs 38%, p = 0.02), and scored lower on MMSE and a fluency task (MMSE, p = 0.02; animal fluency, p = 0.006). Men and women did not differ on fluctuations, RBD, parkinsonism, or other cognitive tests.

Conclusions

Women had lower Aβ42 and α-syn levels than men, alongside a shorter duration of complaints. Moreover, at the time of diagnosis, women had lower cognitive test scores and more frequent hallucinations. Based on our findings, one could hypothesize that women have a more aggressive disease course in DLB compared to men. Future research should investigate whether women and men with DLB might benefit from sex-specific treatment strategies.

Clinical Advances in Sex- and Gender-Informed Medicine to Improve the Health of All: A Review

IMPORTANCE

Biological sex and sociocultural gender represent major sources of diversity among patients, and recent research has shown the association of sex and gender with health. A growing body of literature describes widespread associations of sex and gender with cells, organs, and the manner in which individual patients interact with health care systems. Sex- and gender-informed medicine is a young paradigm of clinical practice and medical research founded on this literature that considers the association of sex and gender with each element of the disease process from risk, to presentation, to response to therapy.

OBSERVATIONS

Characteristics that underlie sex and gender involve both endogenous and exogenous factors that change throughout the life course. This review details clinical examples with broad applicability that highlight sex and gender differences in the key domains of genetics, epigenomic modifiers, hormonal milieu, immune function, neurocognitive aging process, vascular health, response to therapeutics, and interaction with health care systems. These domains interact with one another in multidimensional associations, contributing to the diversity of the sex and gender spectra. Novel research has identified differences of clinical relevance with the potential to improve care for all patients.

CONCLUSIONS AND RELEVANCE

Clinicians should consider incorporating sex and gender in their decision-making to practice precision medicine that integrates fundamental components of patient individuality. Recognizing the biological and environmental factors that affect the disease course is imperative to optimizing care for each patient. Research highlights the myriad ways sex and gender play a role in health and disease. However, these clinically relevant insights have yet to be systematically incorporated into care. The framework described in this review serves as a guide to help clinicians consider sex and gender as they practice precision medicine.

Identification of Novel Alzheimer's Disease Loci Using Sex-Specific Family-Based Association Analysis of Whole-Genome Sequence Data

With the advent of whole genome-sequencing (WGS) studies, family-based designs enable sex-specific analysis approaches that can be applied to only affected individuals; tests using family-based designs are attractive because they are completely robust against the effects of population substructure. These advantages make family-based association tests (FBATs) that use siblings as well as parents especially suited for the analysis of late-onset diseases such as Alzheimer's Disease (AD). However, the application of FBATs to assess sex-specific effects can require additional filtering steps, as sensitivity to sequencing errors is amplified in this type of analysis. Here, we illustrate the implementation of robust analysis approaches and additional filtering steps that can minimize the chances of false positive-findings due to sex-specific sequencing errors. We apply this approach to two family-based AD datasets and identify four novel loci (GRID1, RIOK3, MCPH1, ZBTB7C) showing sex-specific association with AD risk. Following stringent quality control filtering, the strongest candidate is ZBTB7C (Pinter = 1.83 × 10-7), in which the minor allele of rs1944572 confers increased risk for AD in females and protection in males. ZBTB7C encodes the Zinc Finger and BTB Domain Containing 7C, a transcriptional repressor of membrane metalloproteases (MMP). Members of this MMP family were implicated in AD neuropathology.

Functional Connectivity in Neurodegenerative Disorders: Alzheimer's Disease and Frontotemporal Dementia

Neurodegenerative disorders are a growing cause of morbidity and mortality worldwide. Onset is typically insidious and clinical symptoms of behavioral change, memory loss, or cognitive dysfunction may not be evident early in the disease process. Efforts have been made to discover biomarkers that allow for earlier diagnosis of neurodegenerative disorders, to initiate treatment that may slow the course of clinical deterioration. Neuronal dysfunction occurs earlier than clinical symptoms manifest. Thus, assessment of neuronal function using functional brain imaging has been examined as a potential biomarker. While most early studies used task-functional magnetic resonance imaging (fMRI), with the more recent technique of resting-state fMRI, "intrinsic" relationships between brain regions or brain networks have been studied in greater detail in neurodegenerative disorders. In Alzheimer's disease, the most common neurodegenerative disorder, and frontotemporal dementia, another of the common dementias, specific brain networks may be particularly susceptible to dysfunction. In this review, we highlight the major findings of functional connectivity assessed by resting state fMRI in Alzheimer's disease and frontotemporal dementia.

Psoriasis is not a risk factor for dementia: a 12-year nationwide population-based cohort study

Studies investigating the risk for dementia in psoriatic patients remain inconclusive. There are a limited number of population-based studies on the association between psoriasis and dementia. This study aims to investigate the risk for dementia in psoriatic patients. This nationwide population-based cohort study was based on data obtained from the Taiwan National Health Insurance Research Database between 2000 and 2012. A total of 111,825 patients with psoriasis and 111,825 age-, sex-, and index date-matched controls were recruited. The hazard ratio (HR) for subsequent dementia in patients with psoriasis was analyzed using a Cox model and a Fine-Gray competing risk model. During 1,358,774 person-years of follow-up, 2688 patients developed dementia in the psoriatic cohort, and 2062 developed dementia in the control cohort. In the multivariate adjusted Cox model, the hazard ratio (HR) of psoriatic patients for dementia was 1.02 [95% confidence interval (CI) 0.96-1.09] relative to the controls. Psoriasis did not increase the risk for dementia (both vascular dementia and degenerative dementia). In the competing risk model, the HR of dementia was 0.96 (95% CI 0.90-1.02) for psoriatic patients. Compared to psoriatic patients who had not received phototherapy or systemic treatment, those psoriatic patients receiving phototherapy or systemic treatment had a lower risk for dementia. However, this phenomenon was not observed in psoriatic patients who were observed for longer than 6 years. Psoriasis was not found to be a risk factor for dementia. Phototherapy and systemic treatment might not have a protective effect against dementia in psoriatic patients.

Widespread sex dimorphism in aging and age-related diseases

Although aging is a conserved phenomenon across evolutionary distant species, aspects of the aging process have been found to differ between males and females of the same species. Indeed, observations across mammalian studies have revealed the existence of longevity and health disparities between sexes, including in humans (i.e. with a female or male advantage). However, the underlying mechanisms for these sex differences in health and lifespan remain poorly understood, and it is unclear which aspects of this dimorphism stem from hormonal differences (i.e. predominance of estrogens vs. androgens) or from karyotypic differences (i.e. XX vs. XY sex chromosome complement). In this review, we discuss the state of the knowledge in terms of sex dimorphism in various aspects of aging and in human age-related diseases. Where the interplay between sex differences and age-related differences has not been explored fully, we present the state of the field to highlight important future research directions. We also discuss various dietary, drug or genetic interventions that were shown to improve longevity in a sex-dimorphic fashion. Finally, emerging tools and models that can be leveraged to decipher the mechanisms underlying sex differences in aging are also briefly discussed.

Risk- and protective factors for memory plasticity in aging

Risk and protective factors for cognitive function in aging may affect how much individuals benefit from their environment or life experiences by preserving or improving cognitive abilities. We investigated the relations between such factors and outcome from episodic-memory training in 136 healthy young and older adults. Tested risk factors included carrying the ɛ4 variant of the apolipoprotein E allele (APOE), age, body mass index, blood pressure, and cholesterol. Protective factors included higher levels of education, intelligence quotient (IQ), physical activity, fatty acids, and vitamin D. Average increases in memory performance were seen after training, with ample variation between individuals. Being young, female, and having higher IQ were positive predictors of memory improvement. No other relationships were observed. Similar benefit was observed across APOE allelic variation. This indicates that beyond IQ, age, and sex, known risk -and protective factors of cognitive function in aging were not significantly related to memory plasticity.

Breath-based non-invasive diagnosis of Alzheimer's disease: a pilot study

Early detection of Alzheimer's disease (AD) will help researchers to better understand the disease and develop improved treatments. Recent developments have thus focused on identifying biomarkers for mild cognitive impairment due to AD (MCI) and AD during the preclinical phase. The aim of this pilot study is to determine whether exhaled volatile organic compounds (VOCs) can be used as a non-invasive method to distinguish controls from MCI, controls from AD and to determine whether there are differences between MCI and AD. The study used gas chromatography-ion mobility spectrometry (GC-IMS) techniques. Confounding factors, such as age, smoking habits, gender and alcohol consumption are investigated to demonstrate the efficacy of results. One hundred subjects were recruited including 50 controls, 25 AD and 25 MCI patients. The subject cohort was age- and gender-matched to minimise bias. Breath samples were analysed using a commercial GC-IMS instrument (G.A.S. BreathSpec, Dortmund, Germany). Data analysis indicates that the GC-IMS signal was consistently able to separate between diagnostic groups [AUC ± 95%, sensitivity, specificity], controls versus MCI: [0.77 (0.64-0.90), 0.68, 0.80], controls versus AD: [0.83 (0.72-0.94), 0.60, 0.96], and MCI versus AD: [0.70 (0.55-0.85), 0.60, 0.84]. VOC analysis indicates that six compounds play a crucial role in distinguishing between diagnostic groups. Analysis of possible confounding factors indicate that gender, age, smoking habits and alcohol consumption have insignificant influence on breath content. This pilot study confirms the utility of exhaled breath analysis to distinguish between AD, MCI and control subjects. Thus, GC-IMS offers great potential as a non-invasive, high-throughput, diagnostic technique for diagnosing and potentially monitoring AD in a clinical setting.

Association Between Adverse Childhood Experiences and Dementia in Older Japanese Adults

IMPORTANCE

The prevalence of dementia in Japan has been increasing. Childhood poverty has been associated with increased risk of cognitive impairment, possibly mediated by individuals' educational paths. However, the associations between dementia and adverse childhood experiences other than poverty and education have not been well documented.

OBJECTIVE

To examine the association between adverse childhood experiences and dementia onset among Japanese individuals born before 1948 who grew up during and after World War II.

DESIGN, SETTING, AND PARTICIPANTS

A 3-year (2013-2016) follow-up was performed of 17 412 participants in the Japan Gerontological Evaluation Study, a population-based cohort study of adults aged 65 years or older. Data were analyzed in December 2019.

MAIN OUTCOMES AND MEASURES

Dementia onset was assessed through the public long-term care insurance system. Adverse childhood experiences before the age of 18 years were assessed by survey at baseline. Seven adverse childhood experiences were assessed: parental death, parental divorce, parental mental illness, family violence, physical abuse, psychological neglect, and psychological abuse. Participants were classified according to whether they had 0, 1, 2, or 3 or more adverse childhood experiences. Cox regression models were used to estimate hazard ratios for the risk of dementia.

RESULTS

Among 17 412 participants (9281 women [53.3%]; mean [SD] age, 73.5 [6.0] years), dementia occurred in 703 participants (312 men and 391 women) during a mean follow-up of 3.2 years (range, 2.4-3.3 years). Among all participants, 6804 (39.1%) were older than 75 years; 10 968 (63.0%) reported 0 adverse childhood experiences, 5129 (29.5%) reported 1 adverse childhood experience, 964 (5.5%) reported 2 adverse childhood experiences, and 351 (2.0%) reported 3 or more adverse childhood experiences. Participants who experienced 3 or more adverse childhood experiences had a greater risk of developing dementia compared with those who grew up without adverse childhood experiences, after adjustment for age, sex, childhood economic hardship, nutritional environment, and education (hazard ratio, 2.18; 95% CI, 1.42-3.35). After successive adjustment for adult sociodemographic characteristics, social relationships, health behavior, and health status, this hazard ratio was attenuated but remained statistically significant (1.78; 95% CI, 1.15-2.75; P = .009).

CONCLUSIONS AND RELEVANCE

This study found that having 3 or more adverse childhood experiences was associated with increased dementia risk among older Japanese adults.

Integrating Convolutional Neural Networks and Multi-Task Dictionary Learning for Cognitive Decline Prediction with Longitudinal Images

BACKGROUND

Disease progression prediction based on neuroimaging biomarkers is vital in Alzheimer's disease (AD) research. Convolutional neural networks (CNN) have been proved to be powerful for various computer vision research by refining reliable and high-level feature maps from image patches.

OBJECTIVE

A key challenge in applying CNN to neuroimaging research is the limited labeled samples with high dimensional features. Another challenge is how to improve the prediction accuracy by joint analysis of multiple data sources (i.e., multiple time points or multiple biomarkers). To address these two challenges, we propose a novel multi-task learning framework based on CNN.

METHODS

First, we pre-trained CNN on the ImageNet dataset and transferred the knowledge from the pre-trained model to neuroimaging representation. We used this deep model as feature extractor to generate high-level feature maps of different tasks. Then a novel unsupervised learning method, termed Multi-task Stochastic Coordinate Coding (MSCC), was proposed for learning sparse features of multi-task feature maps by using shared and individual dictionaries. Finally, Lasso regression was performed on these multi-task sparse features to predict AD progression measured by the Mini-Mental State Examination (MMSE) and the Alzheimer's Disease Assessment Scale cognitive subscale (ADAS-Cog).

RESULTS

We applied this novel CNN-MSCC system on the Alzheimer's Disease Neuroimaging Initiative dataset to predict future MMSE/ADAS-Cog scales. We found our method achieved superior performances compared with seven other methods.

CONCLUSION

Our work may add new insights into data augmentation and multi-task deep model research and facilitate the adoption of deep models in neuroimaging research.

Subjective Cognitive Decline Among Sexual and Gender Minorities: Results from a U.S. Population-Based Sample

The risk of dementia and mild cognitive impairment between older adults in same-sex relationships and those in opposite-sex relationships have been found to be statistically not different. However, studies examining subjective cognitive decline (SCD) among sexual and gender minority populations (SGM) are lacking. The primary objective was to determine if SGM report greater SCD compared to non-SGM populations in a U.S. population-based sample of non-institutionalized adults aged 45 and older. The secondary objective was to assess the association between gender and SCD. Cross-sectional data were obtained from the 2016 Behavioral Risk Factor Surveillance System (n = 36,734). There were 1,094 SGM adults in the sample. Descriptive statistics examined sociodemographic characteristics and their distribution by SCD and SGM status. Crude and multivariable logistic regression models were used to determine the association between SGM status, gender, and SCD. Adjusted models controlled for age, race/ethnicity, income, education, employment, marital status, depression, and diabetes. Statistically significant differences in SGM status and SCD existed by age, race/ethnicity, education, employment, marital status, and depression. Differences in SCD also existed by income and diabetes status. There was no statistically significant association between SGM status and SCD (OR: 0.88; 95% CI: 0.63-1.24). However, men had 64% higher odds (OR: 1.64; 95% CI: 1.44-1.88) of reporting SCD compared to women. Future studies examining the potential reasons for this null association, including resilience and/or premature aging are warranted. Future research assessing potential reasons for gender differences in SCD, whether physiological or environmental, is also needed.

Sex-specific hippocampal metabolic signatures at the onset of systemic inflammation with lipopolysaccharide in the APPswe/PS1dE9 mouse model of Alzheimer's disease

Systemic inflammation enhances the risk and progression of Alzheimer's disease (AD). Lipopolysaccharide (LPS), a potent pro-inflammatory endotoxin produced by the gut, is found in excess levels in AD where it associates with neurological hallmarks of pathology. Sex differences in susceptibility to inflammation and AD progression have been reported, but how this impacts on LPS responses remains under investigated. We previously reported in an APP/PS1 model of AD that systemic LPS administration rapidly altered hippocampal metabolism in males. Here, we used untargeted metabolomics to comprehensively identify hippocampal metabolic processes occurring at onset of systemic inflammation with LPS (100 µg/kg, i.v.) in APP/PS1 mice, at an early pathological stage, and investigated the sexual dimorphism in this response. Four hours after LPS administration, pathways regulating energy metabolism, immune and oxidative stress responses were simultaneously recruited in the hippocampi of 4.5-month-old mice with a more protective response in females despite their pro-inflammatory and pro-oxidant metabolic signature in the absence of immune stimulation. LPS induced comparable behavioural sickness responses in male and female wild-type and APP/PS1 mice and comparable activation of both the serotonin and nicotinamide pathways of tryptophan metabolism in their hippocampi. Elevations in N-methyl-2-pyridone-5-carboxamide, a major toxic metabolite of nicotinamide, correlated with behavioural sickness regardless of sex, as well as with the LPS-induced hypothermia seen in males. Males also exhibited a pro-inflammatory-like downregulation of pyruvate metabolism, exacerbated in APP/PS1 males, and methionine metabolism whereas females showed a greater cytokine response and anti-inflammatory-like downregulation of hippocampal methylglyoxal and methionine metabolism. Metabolic changes were not associated with morphological markers of immune cell activation suggesting that they constitute an early event in the development of LPS-induced neuroinflammation and AD exacerbation. These data suggest that the female hippocampus is more tolerant to acute systemic inflammation.

The association of depression with subsequent dementia diagnosis: A Swedish nationwide cohort study from 1964 to 2016

BACKGROUND

Depression is associated with an increased risk of dementia. However, short follow-up times and lack of adjustment for familial factors in previous studies could influence this association. The purpose of the present study was to investigate the association between depression and subsequent dementia, while controlling for familial factors and with a follow-up of over 35 years.

METHODS AND FINDINGS

Two cohorts were formed from all individuals aged 50 years or older living in Sweden as of 31 December 2005 (n = 3,341,010). The Swedish National Patient Register was searched from 1964 through 2016 to identify diagnosis of depression and dementia. In the first cohort, individuals diagnosed with depression (n = 119,386) were matched 1:1 with controls without depression diagnosis. The second cohort was a sibling cohort (n = 50,644) consisting of same-sex full sibling pairs with discordant depression status. In the population matched cohort study, a total of 9,802 individuals were diagnosed with dementia during a mean follow-up time of 10.41 (range 0-35) years (5.5% of those diagnosed with depression and 2.6% of those without depression diagnosis (adjusted odds ratio [aOR] 2.47, 95% CI 2.35-2.58; p < 0.001), with a stronger association for vascular dementia (aOR 2.68, 95% CI 2.44-2.95; p < 0.001) than for Alzheimer disease (aOR 1.79, 95% CI 1.68-1.92; p < 0.001). The association with dementia diagnosis was strongest in the first 6 months after depression diagnosis (aOR 15.20, 95% CI 11.85-19.50; p < 0.001), then decreased rapidly but persisted over follow-up of more than 20 years (aOR 1.58, 95% CI 1.27-1.98; p < 0.001). Also in the sibling cohort, the association was strongest in the first 6 months (aOR 20.85, 95% CI 9.63-45.12; p < 0.001), then decreased rapidly but persisted over follow-up of more than 20 years (aOR 2.33, 95% CI 1.32-4.11; p < 0.001). The adjusted models included sex, age at baseline, citizenship, civil status, household income, and diagnoses at baseline. The main limitation of the study methodology is the use of observational data; hence, the associations found are not proof of causal effects.

CONCLUSIONS

Depression is associated with increased odds of dementia, even more than 20 years after diagnosis of depression, and the association remains after adjustment for familial factors. Further research is needed to investigate whether successful prevention and treatment of depression decrease the risk of dementia.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Locus of Control and Cognition in Older Adults With Type 1 Diabetes: Evidence For Sex Differences From the Study of Longevity in Diabetes (SOLID)

OBJECTIVE

Life expectancy for individuals with type 1 diabetes mellitus (T1DM) has increased recently; however, it is unknown how diabetes care attitudes affect late-life brain health.

RESEARCH DESIGN AND METHODS

The Study of Longevity in Diabetes (SOLID) consists of 734 older adults with T1DM, reporting diabetes locus of control (dLOC), age of diabetes diagnosis and other demographics, history of hypoglycemic episodes, and depressive symptoms. Global and domain-specific (language, executive function, episodic memory, simple attention) cognitive functioning was assessed at in-person interviews. Cross-sectional associations between dLOC and cognition were estimated using covariate-adjusted linear regression models in pooled and sex-stratified models.

RESULTS

In pooled analyses, a 1-point increase in dLOC (more internal) was positively associated with global cognition [β=0.05, 95% confidence interval (CI): 0.02, 0.07], language (β=0.04, 95% CI: 0.01, 0.07), and executive function (β=0.04, 95% CI: 0.01, 0.07), but not episodic memory or simple attention. However, in sex-stratified analyses, this effect was seen only in males and not females.

CONCLUSIONS

In elderly individuals with T1DM, we found associations between dLOC and cognition overall and in men but not women. Underlying sex differences should be considered in future research or interventions on psychosocial characteristics for cognition.

"Bridging the Gap" Everything that Could Have Been Avoided If We Had Applied Gender Medicine, Pharmacogenetics and Personalized Medicine in the Gender-Omics and Sex-Omics Era

Gender medicine is the first step of personalized medicine and patient-centred care, an essential development to achieve the standard goal of a holistic approach to patients and diseases. By addressing the interrelation and integration of biological markers (i.e., sex) with indicators of psychological/cultural behaviour (i.e., gender), gender medicine represents the crucial assumption for achieving the personalized health-care required in the third millennium. However, ‘sex’ and ‘gender’ are often misused as synonyms, leading to frequent misunderstandings in those who are not deeply involved in the field. Overall, we have to face the evidence that biological, genetic, epigenetic, psycho-social, cultural, and environmental factors mutually interact in defining sex/gender differences, and at the same time in establishing potential unwanted sex/gender disparities. Prioritizing the role of sex/gender in physiological and pathological processes is crucial in terms of efficient prevention, clinical signs’ identification, prognosis definition, and therapy optimization. In this regard, the omics-approach has become a powerful tool to identify sex/gender-specific disease markers, with potential benefits also in terms of socio-psychological wellbeing for each individual, and cost-effectiveness for National Healthcare systems. “Being a male or being a female” is indeed important from a health point of view and it is no longer possible to avoid “sex and gender lens” when approaching patients. Accordingly, personalized healthcare must be based on evidence from targeted research studies aimed at understanding how sex and gender influence health across the entire life span. The rapid development of genetic tools in the molecular medicine approaches and their impact in healthcare is an example of highly specialized applications that have moved from specialists to primary care providers (e.g., pharmacogenetic and pharmacogenomic applications in routine medical practice). Gender medicine needs to follow the same path and become an established medical approach. To face the genetic, molecular and pharmacological bases of the existing sex/gender gap by means of omics approaches will pave the way to the discovery and identification of novel drug-targets/therapeutic protocols, personalized laboratory tests and diagnostic procedures (sex/gender-omics). In this scenario, the aim of the present review is not to simply resume the state-of-the-art in the field, rather an opportunity to gain insights into gender medicine, spanning from molecular up to social and psychological stances. The description and critical discussion of some key selected multidisciplinary topics considered as paradigmatic of sex/gender differences and sex/gender inequalities will allow to draft and design strategies useful to fill the existing gap and move forward.

High occurrence of transportation and logistics occupations among vascular dementia patients: an observational study

Background

Growing evidence suggests a role of occupation in the emergence and manifestation of dementia. Occupations are often defined by complexity level, although working environments and activities differ in several other important ways. We aimed to capture the multi-faceted nature of occupation through its measurement as a qualitative (instead of a quantitative) variable and explored its relationship with different types of dementia.

Methods

We collected occupational information of 2121 dementia patients with various suspected etiologies from the Amsterdam Dementia Cohort (age 67 ± 8, 57% male; MMSE 21 ± 5). Our final sample included individuals with Alzheimer’s disease (AD) dementia (n = 1467), frontotemporal dementia (n = 281), vascular dementia (n = 98), Lewy body disease (n = 174), and progressive supranuclear palsy/corticobasal degeneration (n = 101). Within the AD group, we used neuropsychological data to further characterize patients by clinical phenotypes. All participants were categorized into 1 of 11 occupational classes, across which we evaluated the distribution of dementia (sub)types with χ² analyses. We gained further insight into occupation-dementia relationships through post hoc logistic regressions that included various demographic and health characteristics as explanatory variables.

Results

There were significant differences in the distribution of dementia types across occupation groups (χ² = 85.87, p < .001). Vascular dementia was relatively common in the Transportation/Logistics sector, and higher vascular risk factors partly explained this relationship. AD occurred less in Transportation/Logistics and more in Health Care/Welfare occupations, which related to a higher/lower percentage of males. We found no relationships between occupational classes and clinical phenotypes of AD (χ² = 53.65, n.s.).

Conclusions

Relationships between occupation and dementia seem to exist beyond the complexity level, which offers new opportunities for disease prevention and improvement of occupational health policy.

Biological Sex: A Potential Moderator of Physical Activity Efficacy on Brain Health

The number of older people worldwide living with cognitive impairment and neurodegenerative diseases is growing at an unprecedented rate. Despite accumulating evidence that engaging in physical activity is a promising primary behavioral strategy to delay or avert the deleterious effects of aging on brain health, a large degree of variation exists in study findings. Thus, before physical activity and exercise can be prescribed as “medicine” for promoting brain health, it is imperative to understand how different biological factors can attenuate or amplify the effects of physical activity on cognition at the individual level. In this review article, we briefly discuss the current state of the literature, examining the relationship between physical activity and brain health in older adults and we present the argument that biological sex is a potent moderator of this relationship. Additionally, we highlight some of the potential neurobiological mechanisms underlying this sex difference for this relatively new and rapidly expanding line of research.

Cognition at age 70: Life course predictors and associations with brain pathologies

OBJECTIVE

To investigate predictors of performance on a range of cognitive measures including the Preclinical Alzheimer Cognitive Composite (PACC) and test for associations between cognition and dementia biomarkers in Insight 46, a substudy of the Medical Research Council National Survey of Health and Development.

METHODS

A total of 502 individuals born in the same week in 1946 underwent cognitive assessment at age 69-71 years, including an adapted version of the PACC and a test of nonverbal reasoning. Performance was characterized with respect to sex, childhood cognitive ability, education, and socioeconomic position (SEP). In a subsample of 406 cognitively normal participants, associations were investigated between cognition and β-amyloid (Aβ) positivity (determined from Aβ-PET imaging), whole brain volumes, white matter hyperintensity volumes (WMHV), and APOE ε4.

RESULTS

Childhood cognitive ability was strongly associated with cognitive scores including the PACC more than 60 years later, and there were independent effects of education and SEP. Sex differences were observed on every PACC subtest. In cognitively normal participants, Aβ positivity and WMHV were independently associated with lower PACC scores, and Aβ positivity was associated with poorer nonverbal reasoning. Aβ positivity and WMHV were not associated with sex, childhood cognitive ability, education, or SEP. Normative data for 339 cognitively normal Aβ-negative participants are provided.

CONCLUSIONS

This study adds to emerging evidence that subtle cognitive differences associated with Aβ deposition are detectable in older adults, at an age when dementia prevalence is very low. The independent associations of childhood cognitive ability, education, and SEP with cognitive performance at age 70 have implications for interpretation of cognitive data in later life.

Lifetime surgical exposure, episodic memory, and forniceal microstructure in older adults

Introduction: Aging is associated with heterogeneous cognitive trajectories. There is considerable interest in identifying risk factors for pathological aging, with recent studies demonstrating a link between surgical procedures and proximal cognitive decline; however, the role of lifetime exposure to surgical procedures and cognitive function has been relatively unexplored. This pilot study aimed to evaluate the association between total lifetime surgical procedures and memory function in older adults. Methods: A cohort of 62 older adults underwent a neuropsychological evaluation and health history assessment. Self-reported lifetime surgical history was categorized as "cardiac" or "non-cardiac." General linear models were fit with demographics as nuisance covariates, and the total number of non-cardiac surgeries as our predictor of interest. Total scores on measures of episodic memory, language, working memory, fluency, and visuospatial function were separate outcome variables. In a secondary analysis, vascular risk factors were included as covariates. Diffusion tensor imaging was obtained for exploratory analyses of selected regions of interest. Results: The mean age of participants was 70, and 0-13 lifetime non-cardiac surgical procedures were reported. Higher numbers of lifetime non-cardiac surgical procedures were associated with worse verbal learning and memory (p = .04). The negative association between lifetime non-cardiac procedures and cognition was specific to memory. Exploratory analyses showed that higher number of lifetime non-cardiac procedures was related to lower FA in the fornix body (p = .02). Conclusions: These results of this pilot study suggest that greater lifetime exposure to surgery may be associated with worse verbal learning and memory in healthy older adults. These findings add to a growing body of literature suggesting that cumulative medical events may be risk factors for negative cognitive outcomes.

Sex and Gender Driven Modifiers of Alzheimer's: The Role for Estrogenic Control Across Age, Race, Medical, and Lifestyle Risks

Research indicates that after advanced age, the major risk factor for late-onset Alzheimer’s disease (AD) is female sex. Out of every three AD patients, two are females with postmenopausal women contributing to over 60% of all those affected. Sex- and gender-related differences in AD have been widely researched and several emerging lines of evidence point to different vulnerabilities that contribute to dementia risk. Among those being considered, it is becoming widely accepted that gonadal steroids contribute to the gender disparity in AD, as evidenced by the “estrogen hypothesis.” This posits that sex hormones, 17β-estradiol in particular, exert a neuroprotective effect by shielding females’ brains from disease development. This theory is further supported by recent findings that the onset of menopause is associated with the emergence of AD-related brain changes in women in contrast to men of the same age. In this review, we discuss genetic, medical, societal, and lifestyle risk factors known to increase AD risk differently between the genders, with a focus on the role of hormonal changes, particularly declines in 17β-estradiol during the menopause transition (MT) as key underlying mechanisms.

Aβ oligomers induce sex-selective differences in mGluR5 pharmacology and pathophysiological signaling in Alzheimer mice.. [DOI: 10.1101/803262]

Sex is a key modifier of the prevalence and progression of Alzheimer’s disease (AD). β- Amyloid (Aβ) deposition is a pathological hallmark of AD and aberrant activation of metabotropic glutamate receptor 5 (mGluR5) by Aβ has been linked to AD progression. We find that mGluR5 exhibits distinct sex-dependent pharmacological profiles. Specifically, endogenous mGluR5 from male mouse cortex and hippocampus binds with high-affinity to Aβ oligomers whereas, female mGluR5 exhibits no affinity to Aβ oligomers. The binding affinity of mGluR5 to Aβ oligomer is dependent on its interaction with cellular prion protein (PrPC) as mGluR5 co-immunoprecipitates with PrPCfrom male, but not female, mouse brain. Aβ oligomers also bind with high-affinity to human mGluR5 in male, but not female, cortex. The mGluR5/Aβ oligomer/PrPCternary complex is essential to elicit mGluR5-dependent pathological signaling and as a consequence mGluR5-regulated GSK3β/ZBTB16 autophagic signaling is dysregulated in male, but not female, primary neuronal cultures. These sex-specific differences in mGluR5 signaling translate into in vivo differences in mGluR5-dependent pathological signaling between male and female AD mice. We show that the chronic inhibition of mGluR5 using a mGluR5-selective negative allosteric modulator reactivates GSK3β/ZBTB16-regulated autophagy, mitigates Aβ pathology and reverses cognitive decline in male, but not female, APPswe/PS1ΔE9 mice. Thus, it is evident that, unlike male brain, mGluR5 does not contribute to Aβ pathology in female AD mice. This study highlights the complexity of mGluR5 pharmacology and Aβ oligomer-activated pathological signaling and emphasizes the need for clinical trials redesign and analysis of sex-tailored treatment for AD.

Sex Differences in Neuropsychological Test Performance in Alzheimer's Disease and the Influence of the ApoE Genotype

BACKGROUND

Only few studies exist reporting sex differences in the Alzheimer disease (AD) patients regarding cognitive profile, brain damage, and risk factors. The present study investigated the influence of sex in combination with the Alzheimer risk allele, ε4-allele of apolipoprotein E, on cognitive performance.

MATERIALS AND METHODS

We examined the effect of sex and ApoE genotype on a range of neuropsychological markers from the German version of the Consortium to Establish a Registry in Alzheimer's Disease Neuropsychological Battery in a monocentric study of 399 AD patients.

RESULTS

Male patients had significantly more years of school and occupational education compared with women. Male AD patients outperformed female patients in tasks of object naming, constructional praxis, and constructional praxis recall. There was no statistically significant interaction effect between sex and ε4-allele of apolipoprotein E for any of the examined variables.

CONCLUSIONS

The superiority of healthy men compared with women in tasks of object naming, constructional praxis, and visual memory seems to remain stable when people develop AD, indicating larger cognitive reserves in men. In contrast, findings that cognitively healthy women outperform men in tests of verbal memory and verbal fluency are not stable in AD. Further studies are needed to gain insight in the reasons for sex differences.

Sex Differences in Vulnerability and Resilience to Stress Across the Life Span

Susceptibility and resilience to stress depend on 1) the timing of the exposure with respect to development, 2) the time across the life span at which effects are measured, and 3) the behavioral or biological phenotype under consideration. This translational review examines preclinical stress models that provide clues to causal mechanisms and their relationship to the more complex phenomenon of stress-related psychiatric and cognitive disorders in humans. We examine how genetic sex and epigenetic regulation of hormones contribute to the proximal and distal effects of stress at different epochs of life. Stress during the prenatal period and early postnatal life puts male offspring at risk of developing diseases involving socialization, such as autism spectrum disorder, and attention and cognition, such as attention-deficit/hyperactivity disorder. While female offspring show resilience to some of the proximal effects of prenatal and early postnatal stress, there is evidence that risk associated with developmental insults is unmasked in female offspring following periods of hormonal activation and flux, including puberty, pregnancy, and perimenopause. Likewise, stress exposures during puberty have stronger proximal effects on girls, including an increased risk of developing mood-related and stress-related illnesses, such as depression, anxiety, and posttraumatic stress disorder. Hormonal changes during menopause and andropause impact the processes of memory and emotion in women and men, though women are preferentially at risk for dementia, and childhood adversity further impacts estradiol effects on neural function. We propose that studies to determine mechanisms for stress risk and resilience across the life span must consider the nature and timing of stress exposures as well as the sex of the organism under investigation.

Dementia in China: epidemiology, clinical management, and research advances

China has the largest population of patients with dementia in the world, imposing a heavy burden on the public and health care systems. More than 100 epidemiological studies on dementia have been done in China, but the estimates of the prevalence and incidence remain inconsistent because of the use of different sampling methods. Despite improved access to health services, inadequate diagnosis and management for dementia is still common, particularly in rural areas. The Chinese Government issued a new policy to increase care facilities for citizens older than 65 years, but most patients with dementia still receive care at home. Western medicines for dementia symptoms are widely used in China, but many patients choose Chinese medicines even though they have little evidence supporting efficacy. The number of clinical trials of Chinese and western medicines has substantially increased as a result of progress in research on new antidementia drugs but international multicentre studies are few in number. Efforts are needed to establish a national system of dementia care enhance training in dementia for health professionals, and develop global collaborations to prevent and cure this disease.

A Dynamic Memory Systems Framework for Sex Differences in Fear Memory

Emerging research demonstrates that a pattern of overlapping but distinct molecular and circuit mechanisms are engaged by males and females during memory tasks. Importantly, sex differences in neural mechanisms and behavioral strategies are evident even when performance on a memory task is similar between females and males. We propose that sex differences in memory may be best understood within a dynamic memory systems framework. Specifically, sex differences in hormonal influences and neural circuit development result in biases in the circuits engaged and the information preferentially stored or retrieved in males and females. By using animal models to understand the neural networks and molecular mechanisms required for memory in both sexes, we can gain crucial insights into sex and gender biases in disorders including post-traumatic stress disorder (PTSD) in humans.