Considering sex and gender in Alzheimer disease and other dementias

Are behavioral and psychological symptoms of dementia related to sensory processing?

Problems with sensory processing may have an impact on the behavioral and psychological symptoms that can be seen in Alzheimer's patients. Examining the relationship between the two factors may provide a new perspective for the management of behavioral and psychological symptoms of dementia. Mid-stage Alzheimer's patients completed the Neuropsychiatric Inventory and Adolescent/Adult Sensory Profile. The relationship between behavioral and psychological symptoms of dementia and sensory processing was investigated. Sixty individuals with a mean age of 75.35 (7.86) years and diagnosed with Alzheimer's Dementia 6.6 (2.92) years ago participated in the study. Individuals with severe behavioral and psychological symptoms had higher scores than individuals with moderate behavioral and psychological symptoms in low registration and sensory sensitivity quadrants . A relationship was found between sensory processing and behavioral and psychological symptoms of dementia in mid-stage Alzheimer's patients. This study highlighted the sensory processing differences in patients with Alzheimer's dementia. In future studies, interventions for sensory processing skills may play a role in improving the quality of life of individuals by contributing to the management of behavioral and psychological symptoms of dementia.

Racial/Ethnic Disparities in Use of Angiotensin II Receptor Type 2/4 Stimulatory Vs. Inhibitory Antihypertensive Among Hypertensive Adults in the USA

OBJECTIVES

Studies showed angiotensin II type 2 receptor/angiotensin II type 4 receptor (AT2R/AT4R) stimulatory antihypertensive was associated with a lower risk of dementia and cognitive impairment compared to the inhibitory one. This study aimed to identify the racial and ethnic differences in using these agents among the USA adults with hypertension.

METHODS

A cross-sectional study was conducted using data from the Medical Expenditure Panel Survey (MEPS, 2016-2019). Individuals with a diagnosis of hypertension or self-reported hypertension and without dementia or Alzheimer's disease diagnosis were included in the analysis. We applied two multivariable logistic regressions to compare racial/ethnic differences in AT2R/AT4R stimulatory antihypertensive use and AT2R/AT4R inhibitory antihypertensive use, adjusting for covariates.

RESULTS

Twenty-four thousand five hundred eighty-one individuals with hypertension and without dementia or Alzheimer's disease were identified. Among non-Hispanic Whites, 72.39% were using AT2R/AT4R inhibitory antihypertensive agents, vs. 66.97% using AT2R/AT4R stimulatory antihypertensive agents. In contrast, both non-Hispanic Black and Asian Americans were using more AT2R/AT4R stimulatory agents than inhibitory ones (16.40% vs. 12.16% and 4.79% vs. 3.43%, respectively). Compared to non-Hispanic White, non-Hispanic Black (OR 1.980, 95% CI 1.839-2.132) and non-Hispanic Asian Americans (OR 1.545, 95% CI 1.356-1.761) were significantly associated with higher odds of prescribing AT2R/AT4R stimulatory agents, while Hispanics (OR 0.744, 95% CI 0.685-0.808) were associated with lower odds of prescribing AT2R/AT4R inhibitory agents compared to non-Hispanic Whites.

CONCLUSIONS

The results showed that the high-dementia risk populations like non-Hispanic Black and Asian American races are proportionally prescribed with higher use of low-dementia risk antihypertensive agents, compared to non-Hispanic Whites.

Neurofibrillary tangles predict dementia in patients with carotid stenosis

OBJECTIVE

There is growing appreciation that extracranial carotid atherosclerotic disease (ECAD) is associated with increased dementia risk. Despite this, clinical management of ECAD does not involve evaluation for cognitive outcomes or risk stratification for dementia. One impediment to studying and improving clinical care for this cohort (roughly 10% of adults aged >60 years) is that factors to identify patients with ECAD at risk for dementia are not known.

METHODS

Our prospective clinicopathologic study, the Arizona Study of Aging and Neurodegenerative Disorders study, evaluated clinical and histopathologic factors for dementia in subjects with ECAD. The primary outcome (dementia) was defined as a composite of Alzheimer's disease and/or vascular dementia based on a clinical/neuropathologic diagnosis. Of 1234 subjects, those with dementia other than Alzheimer's disease and/or vascular dementia were excluded; there remained 111 subjects with ECAD to be evaluated. Logistic regression analysis was performed to examine the association of key risk factors for dementia including age, sex, cardiovascular risk factors, apolipoprotein E4 (APOE4) genetic status, and dementia biomarkers. A precision recall curve was also generated to evaluate the diagnostic accuracy of dementia prediction models.

RESULTS

Individuals with dementia compared with those without had significantly increased levels of stroke, APOE4 genotype, and dementia biomarkers, neurofibrillary tangles (NFTs), and amyloid plaques. Models of multiple combined risk factors were little or no better than NFTs alone, which showed a 96.9% positive predictive value at an NFT threshold of 10.

CONCLUSIONS

Although we hypothesized that a combination of clinical and histopathologic biomarkers would result in the strongest predictive model for dementia, we found that NFTs alone had the highest association and positive predictive value for dementia risk in patients with ECAD. As blood-based assays for NFT quantification become more clinically reliable and available, these data support the possibility that NFT quantification may help identify patients with ECAD at increased risk for dementia.

Sex and gender differences in access, quality of care, and effectiveness of treatment in dementia: a scoping review of studies up to 2024

BACKGROUND

Dementia represents one of the greatest global health challenges. Women have a greater lifetime risk of developing dementia compared to men. Both pharmacological and non-pharmacological interventions aimed at slowing cognitive decline show promising results. However, most studies do not examine whether there are sex and gender differences in access to treatment, quality of care or treatment effectiveness.

OBJECTIVES

To summarise evidence on sex and gender differences in access to treatment, management, and treatment effectiveness for people with dementia.

METHODS

This scoping review followed PRISMA guidelines and was conducted in PubMed/MEDLINE, EMBASE, Google Scholar, and ClinicalTrials.Gov databases in November 2023 and updated in January 2024. Systematic reviews and observational studies were included to explore sex and gender differences in access or management of dementia. Systematic reviews and clinical trials were included to investigate sex and gender differences in treatment effectiveness.

RESULTS

We included 16 studies in our review. Sex and gender differences were observed in the prescription and receipt of anti-dementia medications, as well as access to primary care, with variations by settings. Mixed results were found concerning polypharmacy and inappropriate medications, with women being prescribed antipsychotic and other psychotropic medications for longer periods compared to men. Studies of the impact of exercise on cognitive decline yielded mixed results, though limited disaggregated data by sex indicated a more pronounced impact in women than in men. Cognitive stimulation therapy interventions showed greater cognitive improvements for women. Clinical trials assessing the effectiveness of disease-modifying therapies (DMTs) suggest that women may be less responsive to DMTs than men.

CONCLUSIONS

There are important differences between men and women living with dementia in access to diagnosis, treatments, quality of care and effectiveness of treatments. Such differences can significantly impact health outcomes. Sex and gender inequalities should be considered when planning and implementing healthcare, social care, and associated strategies in dementia. To provide conclusive evidence, it is essential for clinical trials to have sufficient statistical power and report outcomes disaggregated by sex.

Sex differences in risk factors for Alzheimer dementia encephalopathy patients

Background

The objective is to identify risk factors that contribute to sex differences in Alzheimer dementia (AD) patients with encephalopathy (ADEN) and determine whether these factors are different between male and female ADEN patients. This is the first large-scale study comparing sex-specific ADEN risk profiles.

Methods

Our retrospective cohort study analyzed data collected from February 2016 to August 2020. It included a total of 128,769 AD patients, among whom 41,266 AD patients also presented with encephalopathy, compared to 87,503 AD patients that did not. The univariate analysis was used to determine differences in risk factors for male and female AD patients. Multivariate analysis predicted specific risk factors associated with male and female ADEN patients.

Result

In the adjusted analysis, males presented with hypertension (OR = 1.144, 95% CI, 1.094-1.197, p < 0.001), peripheral vascular disease (OR = 1.606, 95% CI, 1.485-1.737, p < 0.001), atrial fibrillation (OR = 1.555, 95% CI, 1.443-1.676, p < 0.001), hallucinations (OR = 1.406, 95% CI, 1.119-1.766, p = 0.003), and traumatic head injury (OR = 3.211, 95% CI, 2.346-4.395, p < 0.001). Females presented with osteoporosis (OR = 0.307, 95% CI, 0.278-0.340, p < 0.001), unspecified cancer (OR = 0.615, 95% CI, 0.512-0.740, p < 0.001), anxiety (OR = 0.609, 95% CI, 0.565-0.655, p < 0.001), urinary tract infections (UTI) (OR = 0.451, 95% CI, 0.423-0.481, p < 0.001), upper respiratory infections (URI) (OR = 0.531, 95% CI, 0.432-0.653, p < 0.001) and gastrointestinal ulceration (OR = 0.338, 95% CI, 0.269-0.424, p < 0.001).

Conclusion

Our analysis identified risk factors that contribute to sex differences in ADEN. This difference was fully mediated by peripheral vascular disease, atrial fibrillation, hallucinations, and traumatic head injury for males and unspecified cancer, anxiety, urinary tract infections, upper respiratory infections, and gastrointestinal ulceration for females. These findings provide valuable insights into the risk factors that can be managed to improve the care of male and female ADEN patients.

Association Between Angiotensin-Converting Enzyme (ACE) Gene Insertion/Deletion (I/D) Polymorphism Genotypes With Brain Volume and Hypertension in Alzheimer's Disease-A Retrospective Study

This study investigates the role of the ACE I/D polymorphism in Alzheimer's disease (AD) patients, particularly in relation to hypertension and its influence on brain volume. Seventy-seven AD patients, diagnosed based on Aging and Alzheimer's Association criteria, were enrolled from the Kaohsiung Municipal Ta-Tung Hospital Dementia Cohort. ACE I/D genotypes were identified through polymerase chain reaction, and various factors such as age, sex, education, brain volume, and neuropsychological test scores were analyzed. The results indicated that ACE genotypes, presence of apolipoprotein epsilon 4 (APOEε4), and brain volume did not significantly differ between patients with and without hypertension. While age and sex were associated with gray matter volume, cerebrospinal fluid volume correlated with age, sex, and hypertension. Total cranial volume was linked to sex, and the cerebrospinal fluid-to-total intracranial volume ratio was influenced by sex and education. Overall, ACE I/D genotypes and APOEε4 did not have a significant impact on brain volume in AD patients, regardless of hypertension status. Instead, brain atrophy was associated with sex, age, education, and hypertension. These findings suggest that although ACE may not significantly influence brain volume in AD patients, further large-scale studies are needed to clarify its role in AD pathogenesis.

Sex Hormones and Risk of Incident Dementia in Men and Postmenopausal Women

BACKGROUND

Dementia poses a major global public health challenge, with its risk varying by sex. Women were nearly twice as likely to have Alzheimer's and other forms of dementia compared to men. Although testosterone levels are believed to influence cognitive function in older adults, existing studies have reported inconsistent findings, leaving the relationship between sex hormones and dementia unclear.

METHODS

We used data from UK Biobank. Serum total testosterone and sex hormone binding globulin (SHBG) were measured by immunoassay. Serum free testosterone was calculated using vermeulen method. The incident dementia and Alzheimer's disease (AD) was recorded from hospital inpatient data. Cox proportional hazards regression was conducted to assess the association between sex hormones and dementia, adjusted for age and other variables. Restricted cubic spline models were employed to quantify dose-response relationships.

RESULT

A total of 186,296 men (mean age: 56.68 years, SD: 8.18) and 126,109 postmenopausal women (mean age: 59.73 years, SD: 5.78) were included. After 12.0 (IQR: 11.0-13.0)-year follow-up, 3874 (2.08%) male participants and 2523 (2.00%) female participants developed dementia. Men in the highest quintile of free testosterone levels had a reduced risk of all-cause dementia (HR: 0.63, 95%CI: 0.56-0.71) and AD (0.49, 0.60-0.72) compared to those in the lowest quintile. Conversely, men in the highest quintile of SHBG levels had an increased risk of all-cause dementia (1.47, 1.32-1.64) and AD (1.32, 1.11-1.58) compared to those in the lowest quintile. Among postmenopausal women, those in the fourth quintile of free testosterone levels exhibited a lower risk of all-cause dementia (0.84, 0.78-0.95) and AD (0.76, 0.63-0.91). Higher SHBG was linked to an increased incidence of all-cause dementia (1.35, 1.28-1.55) and AD (1.52, 1.25-1.85) in menopausal women.

CONCLUSION

Our findings revealed that higher SHBG and lower free testosterone concentrations seem to be associated with higher incidence of all-cause dementia and AD and further studies must be done to determine causality.

The impact of unpaid caring on cognitive function: a rapid review

OBJECTIVES

Our review aimed to examine the role of unpaid care in influencing cognitive function independently or via risk factors for dementia.

METHOD

This rapid review, registered in PROSPERO and following PRISMA guidelines, searched EMBASE, MEDLINE, and APA PsycINFO databases for longitudinal studies comparing dementia, cognitive function and associated risk factors for dementia between carers and non-carers. Studies were assessed for quality. Data were synthesised narratively.

RESULTS

Five studies looked at cognitive function directly; others examined risk factors: depression, social isolation, physical activity, body-mass index, type 2 diabetes, high blood pressure, educational attainment, and alcohol consumption. Unpaid carers have increased risk of depression and social isolation, and younger carers have lower educational attainment. Studies evaluating the link between unpaid caring and cognitive decline suggest that caring at low and moderate intensities may act as a protective factor against cognitive decline, but not at higher intensities. Female gender and high-intensity caring significantly influence the strength of association between unpaid care and dementia risk factors.

CONCLUSION

The impact of unpaid caring on cognitive health is complex, influenced by factors like intensity of care and social and cultural context. Across all studies, high-intensity caring negatively impacts carers physical and mental health, which in turn affect their cognitive health.

Electroacupuncture ameliorates cognitive impairment and white matter injury in vascular dementia rats via activating HIF-1α/VEGF/VEGFR2 pathway

Vascular dementia (VaD) significantly impairs patients' quality of life and imposes a major social and economic burden. Electroacupuncture (EA), a contemporary modification of traditional acupuncture, has demonstrated potential in improving cognitive function in VaD, particularly when applied at the Shenting and Baihui. However, the underlying mechanisms remain inadequately understood. Elucidating how EA ameliorates cognitive deficits is critical for validating its clinical application and advancing non-pharmacological interventions for neurodegenerative disorders. This study aimed to investigate the neuroprotective mechanisms of electroacupuncture at these acupoints on cognitive function in VaD rats. VaD was induced in male Sprague-Dawley rats through bilateral common carotid artery occlusion (BCAO), with sham rats serving as controls. Rats were subsequently divided into three groups: BCAO, BCAO + EA and BCAO + EA + YC-1 (a HIF-1α inhibitor). Electroacupuncture was applied to the Shenting and Baihui. Cerebral blood flow (CBF) was measured using dynamic susceptibility contrast functional MRI, and cognitive recovery was evaluated through the Morris water maze. Immunohistochemical analysis quantified myelin repair and angiogenesis, while expression of HIF-1α, VEGF and VEGFR2 in white matter was quantified using PCR and Western blot. The results indicated that electroacupuncture improved learning and memory, increased CBF, enhanced myelin recovery and promoted angiogenesis in VaD rats. The expression of HIF-1α, VEGF and VEGFR2 in the white matter was significantly elevated in VaD rats. Electroacupuncture at Shenting and Baihui activates the HIF-1α/VEGF/VEGFR2 pathway, enhances angiogenesis, white matter perfusion and myelin repair, thereby restoring cognitive function in VaD rats.

Sex differences in cognitive trajectories and practice effects in a cohort of older Londoners: The role of risk factors

BackgroundSex differences in cognitive abilities have been reported; however, the underlying reasons remain unclear.ObjectiveTo (i) investigate sex differences in cognitive performance, (ii) evaluate the contributions of established dementia risk factors to these differences, and (iii) examine the role of non-modifiable risk factors on sex differences in cognitive performance.MethodsAmong 964 cognitively unimpaired participants (aged 60-85) of the UK CHARIOT-PRO Main Study, we assessed cross-sectional and longitudinal associations, over up to 3 years of follow-up, between sex and cognitive performance, using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).ResultsSex differences, mostly favoring women were observed at baseline across almost all RBANS indices including the total scale (Cohen's d = 0.3, adjusted mean difference in score = -5.4, p < 0.001). Sex differences were observed in Practice effects (PEs), with men showing less PE in almost all cognitive domains including the total scale (adjusted 1.3, p = 0.002). Greater sex differences in PEs, were documented among the 'older' participants in two out of five cognitive domains including the immediate memory index (mean difference: older (69-85 years) group = -3.2, p = 0.002); younger (60-68 years) group = -0.8, p = 0.4). Sex differences were more pronounced among 'Apolipoprotein-Ꜫ4 -carriers' in three out of five domains including the total scale (mean difference in carriers = -2.6, p = 0.002); non-carriers = -0.7, p = 0.3).ConclusionsSex differences in cognition and PE were observed after adjusting for risk factors associated with Alzheimer's disease. Future studies should also consider the effects of sex on non-modifiable risk factors and PEs to identify potential 'masked' neuropathology.

Lifetime posttraumatic stress disorder and longitudinal cognitive decline: A cognitive aging framework in the National Alzheimer's Coordinating Center Uniform Data Set

Posttraumatic stress disorder (PTSD) is associated with both cognitive deficits and an increased risk of dementia. Few studies, however, have examined the association between PTSD and cognitive decline in the context of parameters important to brain aging, including health conditions and genetics (e.g., APOE Ɛ4 status). National Alzheimer's Coordinating Center data were used to investigate the associations between lifetime PTSD status and working memory, immediate and delayed episodic memory, and executive functions over 7 years in 11,961 older adults with (n = 179) and without PTSD. Inverse probability weighting was used to mitigate confounding variables. Linear mixed-effects models were fit to weighted data. Sex, race, and APOE Ɛ4 status were examined as moderators. Lifetime PTSD was associated with an additional 0.031 standard deviations of decline in working memory annually, B = -0.031, 95% CI [-0.055, -0.007]. There was no significant PTSD x Time interaction for other cognitive domains. Sex moderated the associations between PTSD and working memory, B = 0.067, SE = 0.03, and delayed recall, B = 0.063, SE = 0.03, such that, among individuals with PTSD, men demonstrated faster decline than women. APOE Ɛ4 moderated the associations between PTSD and delayed recall, B = -0.106, SE = 0.03, and executive functions, B = 0.061, SE = 0.02; among individuals with PTSD, APOE Ɛ4 carriers showed faster and slower decline, respectively, than noncarriers. PTSD in older adults is associated with accelerated decline in working memory. Men and/or APOE Ɛ4 carriers may be important targets for early cognitive decline prevention.

Towards a better diagnosis and treatment of dementia: Identifying common and distinct neuropathological mechanisms in Alzheimer's and vascular dementia

Alzheimer's disease (AD) and vascular dementia (VaD) together contribute to almost 90 % of all dementia cases leading to major health challenges of our time with a substantial global socioeconomic burden. While in AD, the improved understanding of Amyloid beta (Aß) mismetabolism and tau hyperphosphorylation as pathophysiological hallmarks has led to significant clinical breakthroughs, similar advances in VaD are lacking. After comparing the clinical presentation, including risk factors, disease patterns, course of diseases and further diagnostic parameters for both forms of dementia, we highlight the importance of shared pathomechanisms found in AD and VaD: Endothelial damage, blood brain barrier (BBB) breakdown and hypoperfusion inducing oxidative stress and inflammation and thus trophic uncoupling in the neurovascular unit. A dysfunctional endothelium and BBB lead to the accumulation of neurotoxic molecules and Aß through impaired clearance, which in turn leads to neurodegeneration. In this context we discuss possible neuropathological parameters, which might serve as biomarkers and thus improve diagnostic accuracy or reveal targets for novel therapeutic strategies for both forms of dementia.

Association of Mediterranean, high-quality, and anti-inflammatory diet with dementia in UK Biobank cohort

BACKGROUND

This study examined the relationship between adherence to the Mediterranean diet, MIND diet, Recommended Food Score (RFS), Alternative Healthy Eating Index (AHEI), and Energy-adjusted Dietary Inflammatory Index (EDII) and dementia risk in a large UK population cohort.

METHODS

We analyzed data from 131,209 participants in the UK Biobank, aged 40-69 years, with no prior diagnosis of dementia at baseline. Dietary intake was assessed using the validated Oxford WebQ tool, and adherence to each dietary pattern was calculated. Dementia incidence was identified using algorithmically defined outcomes based on ICD codes. Fine-Gray subdistribution hazard models adjusted for sociodemographic, genetic, and lifestyle factors were applied to examine the association between dietary indices and dementia risk. Subgroup analyses were conducted based on age, sex, obesity status, and ApoEε4 status.

RESULTS

Over a median follow-up of 13.5 years, 1453 dementia cases were identified. Higher adherence to the MEDAS, MIND diet, RFS, and AHEI was significantly associated with reduced dementia risk (HRs: 0.79, 0.73, 0.72, and 0.77, respectively). Conversely, higher EDII scores, indicating pro-inflammatory diets, were linked to an increased dementia risk (HR: 1.3). These associations were more pronounced in older adults (≥60 years), women, non-obese individuals, and ApoEε4 non-carriers. Subgroup analyses revealed differential impacts of dietary patterns based on demographic and health-related factors.

CONCLUSION

Greater adherence to Mediterranean, MIND, and high-quality diets is associated with a lower risk of dementia, while pro-inflammatory diets increase the risk. High-quality anti-inflammatory diets play a significant role in reducing the risk of dementia, with stronger effects observed in specific subgroups.

Alzheimer disease seen through the lens of sex and gender

Alzheimer disease (AD) is a life-limiting neurodegenerative disorder that disproportionately affects women. Indeed, sex and gender are emerging as crucial modifiers of diagnostic and therapeutic pathways in AD. This Review provides an overview of the interactions of sex and gender with important developments in AD and offers insights into priorities for future research to facilitate the development and implementation of personalized approaches in the shifting paradigm of AD care. In particular, this Review focuses on the influence of sex and gender on important advances in the treatment and diagnosis of AD, including disease-modifying therapies, fluid-based biomarkers, cognitive assessment tools and multidomain lifestyle interventional studies.

Genetic and Lifestyle Risks for Coronary Artery Disease and Long-Term Risk of Incident Dementia Subtypes

BACKGROUND

Shared genetic and lifestyle risk factors may underlie the development of both coronary artery disease (CAD) and dementia. We examined whether an increased genetic risk for CAD is associated with long-term risk of developing all-cause, Alzheimer's, or vascular dementia, and investigated whether differences in potentially modifiable lifestyle factors in the mid- to late-life period may attenuate this risk.

METHODS

A prospective cohort study of 365 782 participants free from dementia for at least 5 years after baseline assessment was conducted within the UK Biobank cohort. Genetic risk was assessed using a genomewide polygenic risk score (PRS) for CAD and lifestyle risk using a modified version of the American Heart Association's Life's Essential 8 Lifestyle Risk Score (LRS). Higher values for both scores were deemed to represent increased risk. Primary outcomes were incident all-cause, Alzheimer's, and vascular dementia diagnoses obtained from self-report and electronic health records. Secondary outcomes were neuroimaging phenotypes measured in 32 028 participants recalled for magnetic resonance imaging. Sensitivity analyses were conducted to test the extent by which biological and behavioral risk factors contributed to observed associations.

RESULTS

A total of 8870 cases of all-cause dementia were observed over a median 13.9-year follow-up. Both genetic (PRS) and lifestyle (LRS) risk scores for CAD were associated with a modestly elevated risk of all-cause dementia (subhazard ratio per SD increase, 1.10 [1.08, 1.12], P<0.001, for PRS and 1.04 [1.02, 1.06], P=0.006, for LRS). This risk appeared largely attributable to underlying vascular dementia diagnoses (subhazard ratio, 1.16 [1.11, 1.21], P<0.001 for PRS and 1.15 [1.09, 1.22], P<0.001, for LRS), because Alzheimer's disease was found to demonstrate moderate associations with PRS alone (subhazard ratio, 1.09 [1.06, 1.13]; P<0.001). LRS was found to have an additive rather than interactive effect with PRS, with individuals in the highest tertiles for both genetic and lifestyle risk for CAD ≈70% more likely to develop vascular dementia during follow-up compared with those in the lowest tertiles for both (subhazard ratio, 1.71 [1.39, 2.11]; P<0.001). This was substantially attenuated in those with a low LRS at baseline, however, regardless of underlying genetic risk (30% reduction for low versus high LRS tertile regardless of PRS tertile; P<0.001 for all). In a subset of individuals recalled for neuroimaging assessments, those in the highest tertiles for genetic and lifestyle risk for CAD demonstrated a ≈25% greater volume of white matter hyperintensities than those in the lowest risk tertiles, but showed little difference in gray matter or hippocampal volumes. Sensitivity analyses identified associations between both biological and behavioral risk scores with white matter hyperintensity burden and vascular dementia, whereas some Alzheimer's dementia associations showed seemingly paradoxical relationships.

CONCLUSIONS

Individuals who are genetically predisposed to developing CAD also face an increased risk of developing dementia in old age. This risk is reduced in those demonstrating healthy lifestyle profiles earlier in the lifespan, particularly in those who may be at an increased risk of developing dementia caused by an underlying vascular pathology.

Relationship Between Within-Session Digital Motor Skill Acquisition and Alzheimer Disease Risk Factors Among the MindCrowd Cohort: Cross-Sectional Descriptive Study

Background

Previous research has shown that in-lab motor skill acquisition (supervised by an experimenter) is sensitive to biomarkers of Alzheimer disease (AD). However, remote unsupervised screening of AD risk through a skill-based task via the web has the potential to sample a wider and more diverse pool of individuals at scale.

Objective

The purpose of this study was to examine a web-based motor skill game ("Super G") and its sensitivity to risk factors of AD (eg, age, sex, APOE ε4 carrier status, and verbal learning deficits).

Methods

Emails were sent to 662 previous MindCrowd participants who had agreed to be contacted for future research and have their APOE ε4 carrier status recorded and those who were at least 45 years of age or older. Participants who chose to participate were redirected to the Super G site where they completed the Super G task using their personal computer remotely and unsupervised. Once completed, different Super G variables were derived. Linear and logistic multivariable regression was used to examine the relationship between available AD risk factors (age, sex, APOE ε4 carrier status, and verbal learning) and distinct Super G performance metrics.

Results

Fifty-four participants (~8% response rate) from the MindCrowd web-based cohort (mean age of 62.39 years; 39 females; and 23 APOE ε4 carriers) completed 75 trials of Super G. Results show that Super G performance was significantly associated with each of the targeted risk factors. Specifically, slower Super G response time was associated with being an APOE ε4 carrier (odds ratio 0.12, 95% CI 0.02-0.44; P=.006), greater Super G time in target (TinT) was associated with being male (odds ratio 32.03, 95% CI 3.74-1192,61; P=.01), and lower Super G TinT was associated with greater age (β -3.97, 95% CI -6.64 to -1.30; P=.005). Furthermore, a sex-by-TinT interaction demonstrated a differential relationship between Super G TinT and verbal learning depending on sex (βmale:TinT 6.77, 95% CI 0.34-13.19; P=.04).

Conclusions

This experiment demonstrated that this web-based game, Super G, has the potential to be a skill-based digital biomarker for screening of AD risk on a large scale with relatively limited resources.

Patterns and trends in the burden of Alzheimer's disease and related dementias in China (1990-2021) and predictions to 2040

BackgroundThe epidemiology of Alzheimer's disease and related dementias (ADRD) in China is understudied as compared to global levels.ObjectiveThe aim of this study was to examine the trend of dementia epidemiology in China from 1990 to 2021 and provide predictions for the next two decades.MethodsThe Global Burden of Disease study (GBD) 2021 were used to analyze the prevalence, incidence, mortality, and disability-adjusted life years (DALYs) rates due to ADRD in China and globally. Joinpoint regression analysis was used to analyze the epidemiological trends from 1990 to 2021. A forecast of ADRD prevalence trends was conducted utilizing Autoregressive Integrated Moving Average (ARIMA) models.ResultsChina was experiencing a growing burden of ADRD. As of 2021, the number of people with dementia in China had risen to 56.85 million (95%CI: 49.38, 64.98), up from 21.80 (95%CI: 19.07, 24.84) million in 1990. The prevalence, incidence, mortality, and DALY rates all indicated a greater disease burden among the Chinese population compared to global levels, with a significantly higher burden in the female group. The projected prevalence rate was expected to increase by 60% compared to the current prevalence rate.ConclusionsAs the population in China continues to age, ADRD presents an undeniable challenge. To mitigate the growing burden of ADRD and improve the overall health of the population, it is essential to establish a comprehensive plan that focuses on increasing public awareness and enhancing the quality of life for all, with special attention given to women.

Insomnia and risk of all-cause dementia: A systematic review and meta-analysis

BACKGROUND

The evidence on the relationship between insomnia and risk of dementia, Alzheimer's disease (AD), and Vascular dementia (VD) is not consistent. We conducted this meta-analysis to examine the evidence for the risk of developing dementia, AD, or VD in patients with all subtypes of insomnia.

METHODS

A comprehensive search of PubMed, Embase, and the Cochrane Library was conducted using the following search strings: 'Insomnia OR Sleep initiation and Maintenance disorders OR Early morning awakening' AND 'Dementia OR Alzheimer's Disease OR Vascular Dementia' AND 'Risk'. Data extraction was done independently by two researchers. Pooled odds ratio (OR) accompanied by 95% confidence interval (CI) were calculated using either a random-effects model or a fixed-effects model. Sensitivity analyses were performed to assess the robustness of the findings. The potential for publication bias was evaluated through Egger's test and Begg's test.

RESULTS

This meta-analysis included 16 studies with a combined sample size of over 9 million individuals. Pooled analyses revealed a significant association between insomnia and dementia risk (OR = 1.36; 95% CI: 1.01-1.84), with increased risks for AD (OR = 1.52; 95% CI: 1.19-1.93) and VD (OR = 2.10; 95% CI = 2.06-2.14). Subgroup analyses showed no evidence of associations between initial insomnia (OR = 1.01; 95% CI = 0.71-1.31), sleep-maintenance insomnia (OR = 0.88; 95% CI = 0.66-1.17), and early morning awakening (OR = 0.94; 95% CI = 0.83-1.07) with dementia risk. Insomnia patients from Europe (OR = 1.24; 95% CI = 1.14-1.35), Asia (OR = 2.19; 95% CI = 2.06-2.32), and the Americas (OR = 1.05; 95% CI =  1.04-1.07) had varying risks of dementia. Subgroups with less than five years of follow-up (OR = 2.16; 95% CI = 1.81-2.60) exhibited higher dementia risks in insomnia patients, while those with more than five years of follow-up (OR = 1.17; 95% CI = 1.03-1.33) showed a lower risk.

CONCLUSION

Our meta-analysis reveals that insomnia is linked to the risk of dementia, AD, and VD. These findings suggest that insomnia may significantly contribute to the risk of all-cause dementia, highlighting the importance of early intervention and management of insomnia. Despite our efforts to minimize and explore the sources of heterogeneity, it still remained, and therefore our results should be interpreted with caution.

Association of allostatic load with all-cause and cause-specific dementia: A prospective cohort study

INTRODUCTION

Allostatic load (AL) serves as a valuable tool for objectively assessing the biological impact of chronic stress and has been implicated in dementia risk. This study aims to investigate the association between AL and all-cause dementia, Alzheimer's disease (AD), vascular dementia (VaD), and non-Alzheimer non-vascular dementia (NAVD).

METHODS

This prospective study included 361,920 adults from the UK Biobank, with an observation period extending from March 13, 2006, to October 31, 2022, excluding participants with prior dementia diagnoses. AL was estimated through 10 biomarkers related to the dysregulation of metabolic, cardiovascular, and inflammatory systems. Diagnoses were based on the International Classification of Diseases, 10th Revision (ICD-10). We performed Cox proportional hazards models to assess the relationship between AL and dementia. Additionally, we conducted subgroup analyses for sex, Townsend Deprivation Index (TDI), and smoking, along with sensitivity analyses.

RESULTS

The median follow-up period was 12.88 years. Over the follow-up period, 6155 (1.70%) participants developed all-cause dementia, 2762 (0.76%) developed AD, 1316 (0.36%) developed VaD, and 3790 (1.05%) developed NAVD. In the fully adjusted model, high AL was associated with an increased risk of all-cause dementia (hazard ratio [HR]: 1.269, 95% confidence interval [CI]: 1.159-1.390), VaD (HR: 1.934, 95% CI: 1.569-2.384), and NAVD (HR: 1.253, 95% CI: 1.116-1.408). Women and non-smoking individuals with high AL were vulnerable to VaD, and the associations between AL and all-cause dementia were stronger in people with high TDI.

DISCUSSION

AL is positively associated with an elevated risk of dementia, underscoring its effect as a risk factor in the neurodegenerative process that provokes dementia.

Highlights

This study estimated allostatic load (AL) index through 10 biomarkers.The associations between AL and all-cause and cause-specific dementia were evaluated.Elevated AL is a risk factor for all-cause dementia and vascular dementia.

Perceived risk of Alzheimer's disease: Insights into the Black and African American male perspective

BackgroundNon-Hispanic Black and African American men are more likely to have Alzheimer's disease (AD) than non-Hispanic White peers. Despite this, little is known about how Black and African American men perceive dementia risk, which is foundational to prevention.ObjectiveAcknowledging that personal vantage point influences behavior, our study examined Black and African American male perceptions about their anticipated risk for AD.MethodsWe conducted a secondary analysis of Black and African American adult male responses to the Recruitment Innovations for Diversity Enhancement electronic survey study. We examined associations between perceived risk of AD and age, education, employment status, household income adequacy, marital status, living status, prior experience with AD, and subjective memory performance using generalized linear models.ResultsRespondents (n = 112) were age 18 to 79 years (M = 51.05, SD = 13.44), and 35% reported prior experience with AD through a friend or family member. Respondents' perceived risk of developing AD ranged from 0 to 100% (M = 33.46, SD = 28.29). Spearman rho correlations revealed modest but significant correlations between perceived risk and age (r = 21, p = 0.03) and marital status (r = -0.22 p = 0.02). The best fitting generalized linear model revealed low perceived risk for AD was associated with younger age, income adequacy and being married or living as married (χ2 = 8.76, p = 0.03).ConclusionSelected social determinants of health were associated with perceived risk. Future studies should examine additional social determinants of health (e.g., social and physical environment) and measures of cognitive and physical health to further explore relationships with perceived risk of AD in Black and African American males.

Longitudinal excitation-inhibition balance altered by sex and APOE-ε4

Neuronal hyperexcitation affects memory and neural processing across the Alzheimer's disease (AD) cognitive continuum. Levetiracetam, an antiepileptic, shows promise in improving cognitive impairment by restoring the neural excitation/inhibition balance in AD patients. We previously identified a hyper-excitable phenotype in cognitively unimpaired female APOE-ε4 carriers relative to male counterparts cross-sectionally. This sex difference lacks longitudinal validation; however, clarifying the vulnerability of female ε4-carriers could better inform antiepileptic treatment efficacy. Here, we investigated this sex-by-ε4 interaction using a longitudinal design. We used resting-state fMRI and diffusion tensor imaging collected longitudinally from 106 participants who were cognitively unimpaired for at least one scan event but may have been assessed to have clinical dementia ratings corresponding to early mild cognitive impairment over time. By including scan events where participants transitioned to mild cognitive impairment, we modeled the trajectory of the whole-brain excitation-inhibition ratio throughout the preclinical cognitively healthy continuum and extended to early impairment. A linear mixed model revealed a significant three-way interaction among sex, ε4-status, and time, with female ε4-carriers showing a significant hyper-excitable trajectory. These findings suggest a possible pathway for preventative therapy targeting preclinical hyperexcitation in female ε4-carriers.

Application of mini-mental state examination and Montreal Cognitive Assessment in the diagnosis of dementia with Lewy bodies and Alzheimer's disease

BACKGROUND

Dementia with Lewy Bodies (DLB) and Alzheimer's disease (AD) are two types of dementia with a relatively high incidence, and their clinical manifestations are easily confused. However, the cognitive impairment characteristics of the two diseases are different, and the results of cognitive assessment can help the diagnosis of the disease.

OBJECTIVE

To explore the different characteristics of Mini-mental State Examination (MMSE) and Montreal Cognitive Assessment Scale (MoCA) in DLB and AD patients, and to explore potential markers to distinguish AD and DLB.

METHODS

This study included 66 patients with DLB, 81 with AD, and 58 cognitively normal subjects. All of them completed MMSE, MoCA, and Clinical Dementia Rating (CDR).

RESULTS

Compared with NC, both DLB and AD participants demonstrated statistically lower scores in the total and subitem domains of MMSE and MoCA (p < 0.05). When CDR was less than 2, DLB patients had better performance than AD in two subtests including memory and orientation (p < 0.05), demonstrated worse performance in most subtest including executive function, writing, visuospatial abilities, and attention (p < 0.05). Nonetheless, no notable distinction in scores existed for the DLB and AD groups with a CDR score of 2 (p > 0.05).

CONCLUSION

We observed distinct cognitive performances in subjects from both the DLB and AD groups across different stages of dementia. Our study confirms the high value of MMSE and MoCA in distinguishing patients with DLB and AD in the early stages of the disease, and they can improve the differential diagnosis of DLB and AD.

Sildenafil and risk of Alzheimer disease: a systematic review and meta-analysis

BACKGROUND

Alzheimer Disease (AD) affects more than 50 million people worldwide, with 10 million new diagnosis each year. The link between Sildenafil, a Phosphodiesterase-5 (PDE5) inhibitor, and risk of AD has been debated. We conducted the first meta-analysis on the association between Sildenafil use and risk of AD.

METHODS

We searched MEDLINE and Embase from inception to March 11, 2024 to identify cohort, case-control studies comparing the frequency of AD in patients taking Sildenafil with those without. We computed risk ratios (RR) and hazard ratios (HR) with accompanying 95% Confidence Intervals (CIs) for each study, and pooled the results using a random-effects meta-analysis.

RESULTS

Out of 415 studies that were screened initially, 5 studies comprising 885,380 patients were included for analysis. Sildenafil use was associated with a reduced risk of developing AD by two-fold compared to non-use (HR: 0.47, 95% CI: 0.27-0.82, p<0.001). There was a similar association in risk reduction of AD in patients on PDE5 inhibitors compared to non-use (RR: 0.55, 95% CI: 0.38-0.80, p=0.002).

CONCLUSIONS

Our meta-analysis showed that the use of Sildenafil is associated with a reduced risk of developing AD by two-fold. Further randomized control trials to ascertain the effect of Sildenafil on AD pathology would be useful.

Beyond expectations: investigating nilotinib's potential in attenuating neurodegeneration in alzheimer's disease

Neurodegenerative diseases, such as Alzheimer's disease (AD), pose a formidable global challenge. While therapeutic options are available, their limitations are significant, necessitating the development of innovative treatment approaches. Here, we highlight the importance of repurposing drugs and discuss the future of drug treatments for AD. We review the potential of tyrosine kinase inhibitors (TKI) for mitigating AD pathology and symptoms, as well as neurodegenerative processes more broadly. We focus on nilotinib, a selective BCR-ABL tyrosine kinase inhibitor, which has unique mechanisms of action involving the modulation of cell responses and removal of toxic proteins associated with AD pathogenesis. Encouraging studies have demonstrated its efficacy, calling for further investigation through clinical trials to assess its potential in various neurodegenerative conditions. However, despite these promising preclinical findings, no clinical studies have yet conclusively demonstrated its efficacy in treating AD. Considering the future directions in AD research, personalized medicine approaches hold promise by incorporating patient-specific factors, including sex and gender differences, to tailor nilotinib treatment for improved efficacy and safety profiles.

Global, regional, and national burden of tobacco-related neurological disorders from 1990 to 2021: Trends and future projections

INTRODUCTION

Tobacco use is as a major public health concern around the world, adversely impacting quality of life. Our study aims to analyze the trends in the burden of tobacco-related neurological disorders (ND) at global, regional, and national levels from 1990 to 2021, as well as potential future trends.

METHODS

We performed a secondary dataset analysis for the assessment of mortality and disability-adjusted life years (DALYs) using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021, to explore the burden of tobacco-related ND. We also analyzed the associations between the burden of ND and factors such as age, gender, and the Sociodemographic Index (SDI).

RESULTS

In 2021, the age-standardized mortality rate (ASMR) and age-standardized DALYs rate (ASDR) for neurological disorders were 0.50 per 100000 persons (95% UI: -0.15-1.98) and 11.25 per 100000 persons (95% UI: 1.36-34.36), respectively. Alzheimer's disease and other dementias (ADOD) had a particularly significant impact on the burden of ND. However, the ASDR for Parkinson's disease was -8.38 per 100000 persons (95% UI: -10.72 - -6.20). The burden of disease was greater in men and older people, with substantial regional variation. While aging and population growth might contribute to the increase in DALYs for tobacco-related ND, epidemiological changes have the potential to reduce the burden. From 2022 to 2050, the BAPC model predicted a decline in the age-standardized rate (ASR) of DALYs and mortality for tobacco-related ND, globally.

CONCLUSIONS

Tobacco use increased the burden of ND such as ADOD and multiple sclerosis (MS), while reducing the burden of Parkinson's disease (PD). The burden of disease was disproportionately higher among older individuals and males, with significant disparities across nations and regions. Over the past 32 years, the burden of these diseases has gradually decreased, and this trend is expected to continue from 2022 to 2050.

Androgen effects on mesoprefrontal dopamine systems in the adult male brain

Epidemiological data show that males are more often and/or more severely affected by symptoms of prefrontal cortical dysfunction in schizophrenia, Parkinson's disease and other disorders in which dopamine circuits associated with the prefrontal cortex are dysregulated. This review focuses on research showing that these dopamine circuits are powerfully regulated by androgens. It begins with a brief overview of the sex differences that distinguish prefrontal function in health and prefrontal dysfunction or decline in aging and/or neuropsychiatric disease. This review article then spotlights data from human subjects and animal models that specifically identify androgens as potent modulators of prefrontal cortical operations and of closely related, functionally critical measures of prefrontal dopamine level or tone. Candidate mechanisms by which androgens dynamically control mesoprefrontal dopamine systems and impact prefrontal states of hypo- and hyper-dopaminergia in aging and disease are then considered. This is followed by discussion of a working model that identifies a key locus for androgen modulation of mesoprefrontal dopamine systems as residing within the prefrontal cortex itself. The last sections of this review critically consider the ways in which the organization and regulation of mesoprefrontal dopamine circuits differ in the adult male and female brain, and highlights gaps where more research is needed.

Sex Differences in Healthcare Utilization in Persons Living with Dementia Between 2000 and 2017: A Population-Based Study in Quebec, Canada

Objectives: Describe sex differences in healthcare utilization and mortality in persons with new dementia in Quebec, Canada. Methods: We conducted a repeated cohort study from 2000 to 2017 using health administrative databases. Community-dwelling persons aged 65+ with a new diagnosis of dementia were included. We measured 23 indicators of healthcare use across five care settings: ambulatory care, pharmacological care, acute hospital care, long-term care, and mortality. Clinically meaningful sex differences in age-standardized rates were determined graphically through expert consultations. Results: Women with dementia had higher rates of ambulatory care and pharmacological care, while men with dementia had higher acute hospital care, admission to long-term care, and mortality. There was no meaningful difference in visits to cognition specialists, antipsychotic prescriptions, and hospital death. Discussion: Men and women with dementia demonstrate differences in healthcare utilization and mortality. Addressing these differences will inform decision-makers, care providers and researchers and guide more equitable policy and interventions in dementia care.

Economic Implications of Off-Road Cycle Lanes to Increase Physical Activity and Reduce Sex and Gender Differences in the Risk of Dementia

BACKGROUND

Dementia represents one of the greatest global health challenges. There are known risk factors that might prevent or delay nearly 50% of the different types of dementia. There are substantial differences in risk factors and progression of dementia between women and men, including engagement in regular physical activity. The study aimed to quantify the impact of increasing women's participation in physical activity with off-road cycles and its effect on dementia incidence, relative to men and the associated health and social care costs.

METHODS

Our study employed a population model with secondary data analysis approach to investigate the potential economic effect of implementing off-cycle lanes in the UK. Data were drawn from published evidence on lifetime risk of dementia relative to physical activity in men and women for the UK population, levels of physical activity in the UK, evidence on the effectiveness of off-road cycle lanes in increasing the level of physical activity in men and women, lifetime costs of dementia in the UK. Two scenarios were compared, assuming an increase from the baseline levels of cycling of 40.3% and 114% for women and by 36.4% and 77% for men, respectively. Sensitivity analysis was conducted to account for variations in key variables.

RESULTS

Current dementia related lifetime costs were estimated at £1090.1 billion, and total lifetime costs £3326.1 billion. Under Scenario 1, dementia related lifetime costs decreased by £4.7 billion, and total lifetime costs by £0.11 billion. In Scenario 2, dementia related lifetime costs decreased by £7.0 billion, and total lifetime costs by £1.9 billion.

CONCLUSION

Off-road cycle lanes, especially for women, this type of structural and lifestyle intervention has the potential to bring health and economic benefits. Increased physical activity not only provides numerous health benefits, but also contributes to preventing the onset and lifetime costs of dementia.

Effect of 3D-MOT training on the execution of manual dexterity skills in a population of older adults with mild cognitive impairment and mild dementia

Computerized cognitive training tools are an alternative to preventive treatments related to cognitive impairment and aging. In this study, the transfer of 3D multiple object tracking (3D-MOT) training on manual dexterity concerning fine and gross motor skills in 38 elderly participants, half of them with mild cognitive impairment (MCI) and the other half with mild dementia (MD) was explored. A total of 36 sessions of the 3D-MOT training program were administered to the subjects. The Montreal Cognitive Assessment (MoCA) test was used to assess the baseline cognitive status of the participants. Two batteries of manual motor skills (GPT and MMDT) were applied before and after the 3D-MOT training program. The results showed an interaction effect of training and improvement in manual dexterity tests, from the first training session until the fifteenth session, and after this range of sessions, the interaction effect was lost. However, the training effect continued to the end of the thirty-six-session program. The experimental results show the effect of cognitive training on the improvement of motor skills in older adults. This type of intervention could have a broad impact on the aging population in terms of their attention, executive functions, and therefore, their quality of life.

Ligature-induced periodontitis in a transgenic mouse model of Alzheimer's disease dysregulates neuroinflammation, exacerbates cognitive impairment, and accelerates amyloid pathology

A growing body of literature has identified periodontal disease among the modifiable risk factors for Alzheimer's disease (AD), but the mechanisms underlying this relationship is unknown. This study investigated this relationship using a ligature-induced preclinical periodontitis (Pd) model in non-transgenic (non-Tg) and 3xTg-AD mice. We found that ligature placement caused significant alveolar bone loss, with 3xTg-AD mice exhibiting exacerbated bone loss, suggesting AD-related genetic risk may amplify disease progression. Pd induced robust local inflammatory gene expression in both genotypes, but 3xTg-AD mice indicated a dysregulated immune response. Cognitive deficits were observed only in Pd-afflicted 3xTg-AD mice, specifically in hippocampus-mediated spatial memory and perirhinal cortex-mediated object recognition memory, while non-Tg mice remained unaffected. Neuroinflammatory responses varied by brain region, with the hippocampus and prefrontal cortex (PFC) showing the most pronounced changes. In these regions, 3xTg-AD mice exhibited significantly altered cytokine gene expression compared to non-Tg mice, particularly at later time points. Synaptic markers revealed vulnerabilities in 3xTg-AD mice, including reduced baseline Syp expression and dysregulated Synpo post-ligature. Pd transiently reduced glutamate receptor gene expression in both genotypes, with non-Tg mice showing persistent changes, potentially linked to preserved memory. Pd also accelerated amyloid-β (Aβ) deposition and sustained neurodegeneration in 3xTg-AD mice. Overall, this study shows that combining Pd and AD-related genetic risk exacerbates inflammation, cognitive impairment, synaptic dysfunction, Aβ pathology, and neurodegeneration. Neither insult alone was sufficient to produce these effects, highlighting the synergistic impact. These findings emphasize the need to explore anti-inflammatory interventions and downstream mechanisms to mitigate the confluence of these diseases.

Understanding Local Consultation Patterns of Inpatient Geriatric Medicine Teams: a Cross-Sectional Study

Background

Geriatric consultation for Comprehensive Geriatric Assessment (CGA) improves outcomes of older adults living with frailty who are hospitalized, but consultation patterns and utilization of inpatient geriatric consultation teams by other hospital-based services are poorly understood.

Methods

We conducted a cross-sectional study using linked health administrative data to describe characteristics of older adults (≥ 65 years) who received a CGA while hospitalized between January 1, and December 31, 2019. We identified hospital-based services requesting CGA and the frequency and reasons for referral. We used multivariable logistic regression to estimate the association between patient-level characteristics and receiving a CGA.

Results

A total of 29,090 older adults were admitted to hospital; 38.7% were classified as frail and 5.4% (1,563 patients) received at least one CGA. The top three reasons for requesting a CGA were to assess the need for care on an inpatient geriatric rehabilitation unit (43%), and for assessment and management of delirium (27%) and dementia (24%). Referrals were most frequently received from Hospitalists (48%). Frailty was associated with increased odds of receiving a CGA (adjusted odds ratio [aOR] 12.02; 95% confidence interval [CI] 9.67-14.82). A diagnosis of cancer was associated with lower odds of receiving a CGA (aOR 0.75; 95% CI 0.60-0.93).

Conclusions

Inpatient geriatric consultation teams support 5.4% of hospitalized older adults. With the rapidly growing aging population, future efforts are needed to explore the optimal delivery of inpatient geriatric services to support its sustainable provision.

Locus coeruleus vulnerability to tau hyperphosphorylation in a rat model

Post-mortem investigations indicate that the locus coeruleus (LC) is the initial site of hyperphosphorylated pretangle tau, a precursor to neurofibrillary tangles (NFTs) found in Alzheimer's disease (AD). The presence of pretangle tau and NFTs correlates with AD progression and symptomatology. LC neuron integrity and quantity are linked to cognitive performance, with degeneration strongly associated with AD. Despite their importance, the mechanisms of pretangle tau-induced LC degeneration are unclear. This study examined the transcriptomic and mitochondrial profiles of LC noradrenergic neurons after transduction with pseudophosphorylated human tau. Tau hyperphosphorylation increased the somatic expression of the L-type calcium channel (LTCC), impaired mitochondrial health, and led to deficits in spatial and olfactory learning. Sex-dependent alterations in gene expression were observed in rats transduced with pretangle tau. Chronic LTCC blockade prevented behavioral deficits and altered mitochondrial mRNA expression, suggesting a potential link between LTCC hyperactivity and mitochondrial dysfunction. Our research provides insights into the consequences of tau pathology in the originating structure of AD.

Sex differences in the central and peripheral omega 3 oxylipin response to acute systemic inflammation

High-density lipoprotein (HDL) oxylipins regulate inflammation, and acute systemic inflammation can precipitate cognitive impairment. Females have more HDL and stronger immune responses than males, yet higher dementia risk. Little is known about sex differences in oxylipin responses to inflammatory stimuli and potential crosstalk between acute systemic inflammation and central oxylipin signaling in either sex. In this targeted lipidomics study, we used liquid chromatography with tandem mass spectrometry (LC/MS/MS) to characterize oxylipin profiles in plasma HDL and cerebrospinal fluid (CSF) of male and female rats following an intraperitoneal interleukin-1β (IL-1β)-induced inflammatory challenge to determine whether and how peripheral and central oxylipins respond to acute systemic inflammation in both sexes. We hypothesized that females mount a greater oxylipin response to IL-1β than males and that acute activation of peripheral inflammatory pathways changes central oxylipin concentrations. We found that IL-1β altered the abundance of omega (ω)6 and ω3 oxylipins in plasma HDL and CSF of both sexes. However, IL-1β reduced global concentrations of peripheral and central oxylipins in plasma HDL and CSF, respectively, in female rats only. Reduced oxylipin concentrations in IL-1β-treated females were driven by a loss of anti-inflammatory ω3 eicosapentaenoic acid (EPA)-derived dihydroxyeicosatetraenoic acids (DiHETEs) in plasma HDL and CSF. Interestingly, plasma HDL and CSF concentrations of EPA-derived DiHETEs were only correlated in IL-1β-treated rats, suggesting increased periphery-brain crosstalk during acute systemic inflammation. Overall, the sexually dimorphic responses of peripheral and central oxylipins to acute systemic inflammation provide molecular insight into sex differences in both innate immunity and neuroinflammatory responses.NEW & NOTEWORTHY This study examines previously unexplored sex differences in oxylipin signaling cascade activation in the central nervous system and periphery during the acute phase response. This is the first study to assess and correlate oxylipins in plasma HDL and CSF in males and females following an acute systemic inflammatory challenge. This work showing reduced concentrations of anti-inflammatory ω3 EPA-derived DiHETEs in acutely inflamed females provides molecular insight into sex differences in immunity and inflammation-induced neurological changes.

Sex-Based Bias in Artificial Intelligence-Based Segmentation Models in Clinical Oncology

Artificial intelligence (AI) advancements have accelerated applications of imaging in clinical oncology, especially in revolutionizing the safe and accurate delivery of state-of-the-art imaging-guided radiotherapy techniques. However, concerns are growing over the potential for sex-related bias and the omission of female-specific data in multi-organ segmentation algorithm development pipelines. Opportunities exist for addressing sex-specific data as a source of bias, and improving sex inclusion to adequately inform the development of AI-based technologies to ensure their fairness, generalizability and equitable distribution. The goal of this review is to discuss the importance of biological sex for AI-based multi-organ image segmentation in routine clinical and radiation oncology; sources of sex-based bias in data generation, model building and implementation and recommendations to ensure AI equity in this rapidly evolving domain.

Estropausal gut microbiota transplant improves measures of ovarian function in adult mice

Decline in ovarian function with age not only affects fertility but is also linked to a higher risk of age-related diseases in women (e.g. osteoporosis, dementia). Intriguingly, earlier menopause is linked to shorter lifespan; however, the underlying molecular mechanisms of ovarian aging are not well understood. Recent evidence suggests the gut microbiota may influence ovarian health. In this study, we characterized ovarian aging associated microbial profiles in mice and investigated the effect of the gut microbiome from young and estropausal female mice on ovarian health through fecal microbiota transplantation. We demonstrate that the ovarian transcriptome can be broadly remodeled after heterochronic microbiota transplantation, with a reduction in inflammation-related gene expression and trends consistent with transcriptional rejuvenation. Consistently, these mice exhibited enhanced ovarian health and increased fertility. Using metagenomics-based causal mediation analyses and serum untargeted metabolomics, we identified candidate microbial species and metabolites that may contribute to the observed effects of fecal microbiota transplantation. Our findings reveal a direct link between the gut microbiota and ovarian health.

Long-Term Insomnia Treatment with Benzodiazepines and Alzheimer's Disease: A Systematic Review

Alzheimer's disease is the most common form of dementia. Benzodiazepines are the most widely used pharmacological class in the treatment of insomnia and other sleep disorders. Some literature suggests that the chronic use of benzodiazepines is associated with the development of cognitive decline. This review aims to evaluate the use of benzodiazepines and its association with the development of Alzheimer's disease. A systematic review of the literature was carried out using the MEDLINE and Embase databases. Protocols followed the PRISMA-P 2020 methodology, and, after the analysis of the included studies, a narrative synthesis of the results was carried out. Only two cohort studies were identified that met defined eligibility criteria. In the retrospective study, a significant risk of developing Alzheimer's disease after treatment with benzodiazepines was found. In the prospective study, the prevalence of Alzheimer's disease was not associated with treatment with benzodiazepines. Results suggest that only the largest study presented a significant risk of developing Alzheimer's disease. Given the scarce scientific evidence found, it is concluded that further research on this topic is necessary.

Unveiling the link between APOE ε4, environmental factors, and Alzheimer's disease in North Lebanon: A case-control study

BACKGROUND

Alzheimer's disease (AD) is a multifactorial and progressive neurodegenerative disorder influenced by a variety of genetic and environmental factors. The apolipoprotein E (APOE) gene is known to have a pivotal impact on disease onset, yet clinical studies on its impact on AD remain scarce in Lebanon.

OBJECTIVE

This study investigates the interplay between environmental risk factors, the APOE gene, and AD in North Lebanon.

METHODS

A case-control study was conducted with 136 individuals, including 57 AD patients and 79 normal individuals, among which 55 individuals were verified to be cognitively normal via the Mini-Mental State Examination (MMSE). A comprehensive survey was used to collect data on lifestyle factors, medical history, and other possible diseases and deficiencies. Blood samples were collected from all participants, then their DNA was isolated and stored. Real-time PCR was adopted for genotyping.

RESULTS

The total APOE ε4 allele prevalence was reduced from 19.1% to 16.1% after MMSE adjustment. Based on the univariate analysis, factors like age, illiteracy, vitamin and iron deficiencies, blood pressure, and chronic diseases were identified as prominent risk factors, while the allele showed no significant correlation with AD. However, in the multivariable analysis, this allele emerged as a key risk factor (p = 0.04). Factors like age ≥ 65, vitamin deficiency, iron deficiency, blood pressure, and other chronic diseases were consistently significant.

CONCLUSIONS

Our results provide significant evidence that the influence of APOE ε4 on AD is governed by several environmental factors such as age, vitamin and iron deficiencies, high blood pressure, and chronic diseases.

Gender differences in cognitive impairment among the elderly in rural West Texas counties

BACKGROUND

The prevalence of Alzheimer's disease or dementia in the elderly population has been increasing both nationally and globally. Males and females are impacted differently when it comes to cognitive health, and this can be influenced by various risk factors.

OBJECTIVE

This study highlights the sociodemographic, chronic disease, and genetic biomarker risk factors associated with gender differences and cognitive impairments in the elderly population living in Cochran, Parmer, and Bailey counties of rural West Texas.

METHODS

Cross tabulation, Pearson's chi-squared, two sample proportions, binary logistic regression, and multinomial logistic regression were utilized to analyze data. SPSS software was used to detect significant risk factors.

RESULTS

Using a bivariate logistic regression, the age group 70 and above of males and females for the Cochran and Parmer counties was found significantly associated with cognitive impairment. Anxiety, depression, diabetes, and cardiovascular disease were found to be significantly associated with an increased risk of cognitive impairment in females in Parmer County. Gender differences were observed in Cochran County for smoking but females in Bailey County were found to be more tobacco-dependent compared to other counties. However, in Cochran County the prevalence of cognitive impairment with rates of 66% for males and 70% for females was observed to be significantly lower in hypertensive group who consumed modified diet.

CONCLUSIONS

Gender-based disparities in cognitive impairment are essential for gaining more insights into Alzheimer's disease or dementia prevention and advancement of healthcare and medical approaches in the underserved rural communities of West Texas.

Mapping the Numbers of Dementia in Brazil: A Delphi Consensus Study

OBJECTIVES

As the global dementia crisis intensifies, especially in low-and middle-income countries (LMICs), there is a pressing need for comprehensive prevalence data across diverse regions, including Brazil, where studies have been predominantly limited to affluent urban centers. This study aimed to conduct an expert consensus to determine the prevalence of all-cause dementia in Brazil, considering various age groups, sexes, and geographical areas.

METHODS

A Delphi consensus process with clinical and academic experts from across Brazil was conducted to provide dementia prevalence estimates in people aged ≥ 60 years living throughout Brazil for 2019. Each round consisted of answering structured questionnaires that incorporated information from the literature. A priori criteria were used to ascertain the point in which consensus was achieved for > 70% of the 15 prevalence estimates-for (1) total, (2) women and men, and (3) the five Brazilian macro-regions. The current and projected dementia cases in Brazil were calculated based on age and sex population distributions.

RESULTS

Fifteen experts, with a mean professional experience of 25 ± 10 years, reached a consensus in the fourth round. Experts agreed with a mean all-cause dementia prevalence of 8.5% among Brazilians aged ≥ 60 years, which comprised 2.46 million people in 2019 in this age. They reported higher dementia rates in women (9.1%) than men (7.7%); the highest total prevalence was in those over 80 where it exceeds 20%. Regional variations were also noted, with lower prevalence in the South (7.3%) and higher in the North (8.9%) and Northeast (10.1%). Projections estimate that considering Brazil's rapidly aging population, dementia cases will rise to 8.89 million by 2060.

CONCLUSIONS

This Delphi study estimated that dementia already affects roughly 1 in 12 older Brazilians aged 60 and above, with slightly higher prevalence in women and significant geographical variations. These results underscore the urgency for targeted public health strategies in Brazil and offer a framework for similar challenges in other LMICs, especially given that dementia cases are projected to increase by approximately 3.6 times in 4 decades.

The ABC transporter A7 modulates neuroinflammation via NLRP3 inflammasome in Alzheimer's disease mice

BACKGROUND

Specific genetic variants in the ATP-binding cassette transporter A7 locus (ABCA7) are associated with an increased risk of Alzheimer's disease (AD). ABCA7 transports lipids from/across cell membranes, regulates Aβ peptide processing and clearance, and modulates microglial and T-cell functions to maintain immune homeostasis in the brain. During AD pathogenesis, neuroinflammation is one of the key mechanisms involved. Therefore, we wanted to investigate the specific role of ABCA7 in microglial activation via the NLRP3 inflammasome.

METHODS

We developed the first humanized, Cre-inducible ABCA7flx knock-in mouse model, crossbred it with the APPPS1-21 β-amyloidosis model, and generated constitutive ABCA7ko and microglia Cx3cr1-specific conditional ABCA7ko AD mice. The role of ABCA7 was analyzed using histological, biochemical, molecular and mass spectrometry methods.

RESULTS

Constitutive knockout of the Abca7 gene in APPPS1 mice increased the levels of Aβ42 and the number of IBA1+ (microglia) and GFAP+ (astrocytes) cells. Changes in the levels of astrocytes and microglia are associated with the activation of the NLRP3 inflammasome and increased levels of proinflammatory cytokines, such as IL1β and TNFα. Interestingly, microglia-specific ABCA7ko restored Aβ42 peptide levels and IBA1+ and GFAP+ and NLRP3-related gene expression to the original APPPS1 mouse levels. In primary glial cell cultures of APPPS1-hA7ko microglia and APPPS1 astrocytes from newborn pups, we observed that conditioned media from LPS-stimulated microglia was able to induce NLRP3 inflammasome expression and proinflammatory cytokine release in astrocytes.

CONCLUSIONS

Our data suggest that ABCA7 transporters regulate the communication between microglia and astrocytes through the NLRP3 inflammasome and the release of proinflammatory cytokines. This regulation implicates ABCA7 as a key driver ultimately involved in the persistence of the inflammatory response observed in AD.

Targeting early tau pathology: probiotic diet enhances cognitive function and reduces inflammation in a preclinical Alzheimer's model

BACKGROUND

Alzheimer's disease (AD) remains incurable, yet its long prodromal phase offers a crucial window for early intervention. Pretangle tau, a precursor to neurofibrillary tangles, plays a key role in early AD pathogenesis. Intervening in pretangle tau pathology could significantly delay the progression of AD. The gut-brain axis, increasingly recognized as a contributor to AD, represents a promising therapeutic target due to its role in regulating neuroinflammation and neurodegeneration. While probiotics have shown cognitive benefits in amyloid-centered AD models, their effect on pretangle tau pathology remains elusive.

METHODS

This study evaluates the effects of probiotics in a rat model of preclinical AD, specifically targeting hyperphosphorylated pretangle tau in the locus coeruleus. TH-CRE rats (N = 47; 24 females and 23 males) received either AAV carrying pseudophosphorylated human tau (htauE14) or a control virus at 3 months of age. Probiotic or control diets were administered at 9-12 months, with blood and fecal samples collected for ELISA and 16S rRNA gene sequencing. Behavioral assessments were conducted at 13-14 months, followed by analysis of brain inflammation, blood-brain barrier integrity, and GSK-3β activation.

RESULTS

Rats expressing pseudophosphorylated tau displayed impairment in spatial Y-maze (F1,39 = 4.228, p = 0.046), spontaneous object location (F1,39 = 6.240, p = 0.017), and olfactory discrimination (F1,39 = 7.521, p = 0.009) tests. Phosphorylation of tau at S262 (t3 = -4.834) and S356 (t3 = -3.258) in the locus coeruleus was parallelled by GSK-3β activation in the hippocampus (F1,24 = 10.530, p = 0.003). Probiotic supplementation increased gut microbiome diversity (F1,31 = 8.065, p = 0.007) and improved bacterial composition (F1,31 = 3.4867, p = 0.001). The enhancement in gut microbiomes was associated with enhanced spatial learning (p < 0.05), reduced inflammation indexed by Iba-1 (F1,25 = 5.284, p = 0.030) and CD-68 (F1,26 = 8.441, p = 0.007) expression, and inhibited GSK-3β in female rats (p < 0.01 compared to control females).

CONCLUSIONS

This study underscores the potential of probiotics to modulate the gut-brain axis and mitigate pretangle tau-related pathology in preclinical AD. Probiotic supplementation could offer a novel early intervention strategy for AD, highlighting the pivotal role of gut health in neurodegeneration.

Impact of Anticholinergic Burden and Clinical-Demographic Characteristics on Incident Dementia in Parkinson Disease

PURPOSE

Anticholinergic medication use measured via the Anticholinergic Cognitive Burden (ACB) scale has been associated with an increased dementia incidence in older adults but has not been explored specifically for Parkinson disease dementia (PDD). We used adjusted Cox models to estimate the risk of incident PDD associated with demographic factors, clinical characteristics, and time-varying total ACB in a longitudinal, deeply-phenotyped prospective PD cohort.

MAJOR FINDINGS

56.5% of study participants were taking ACB-scale drugs at enrollment. Increasing age, motor symptom burden and psychosis were associated with PDD risk. Female sex and educational achievement were protective against PDD. ACB categories were not associated with PDD overall, but depression and impulse control disorder were strongly associated with PDD in a subsample with high baseline ACB.

CONCLUSIONS

Patient and clinical factors modify PDD risk. PD drug safety and drug-disease interaction studies may require considering multiple mechanisms and including dose-based, prospectively acquired medication exposure measures.

Evaluating Quinolines: Molecular Dynamics Approach to Assess Their Potential as Acetylcholinesterase Inhibitors for Alzheimer's Disease

Quinoline represents a promising scaffold for developing potential drugs because of the wide range of biological and pharmacological activities that it exhibits. In the present study, quinoline derivatives obtained from CADMA-Chem docking protocol were investigated in the mean of molecular dynamics simulations as potential inhibitors of acetylcholinesterase enzyme. The examined species can be partitioned between neutral, dq815 (2,3 dihydroxyl-quinoline-4-carbaldehyde), dq829 (2,3 dihydroxyl-quinoline-8-carboxylic acid methane ester), dq1356 (3,4 dihydroxyl-quinoline-6-carbaldehyde), dq1368 (3,4 dihydroxyl-quinoline-8-carboxylic acid methane ester) and dq2357 (5,6 dihydroxyl-quinoline-8-carboxylic acid methane ester), and deprotonated, dq815_dep, dq829_dep, dq1356_dep and dq2357_dep. Twelve molecular dynamics simulations were performed including those of natural acetylcholine, of the well-known donepezil inhibitor and of the founder quinoline chosen as reference. Key intermolecular interactions were detected and discussed to describe the different dynamic behavior of all the considered species. Binding energies calculation from MMPBSA well accounts for the dynamic behavior observed in the simulation time proposing dq1368 as promising candidate for the inhibition of acetylcholinesterase. Retrosynthetic route for the production of the investigated compounds is also proposed.

Risk factors of male and female Alzheimer's disease patients with neuropsychiatric symptoms

BACKGROUND

This study investigates risk factors in the population of Alzheimer disease (AD) patients with NPS (ADNPS).

METHOD

Baseline risk factors associated with male and female ADNPS were examined using data from a regional AD care center. Univariate analysis was used to determine factors in male and female patients, while logistic regression models were developed to generate odds ratios (OR) to predict risk factors that are associated with male or female ADNPS.

RESULTS

In the adjusted analysis, dyslipidemia (OR = 0.630, 95 % CI, 0.431-0.992, P = 0.017), thyroid dysfunction (OR = 0.549, 95 % CI, 0.377-0.798, P = 0.002), and cerebral infarction (OR = 0.684, 95 % CI, 0.472-0.991, P = 0.0085) were associated with male ADNPS patients, whereas chronic heart failure (OR = 1.408, 95 % CI, 0.953-2.079, P = 0.0085) was associated with female ADNPS patients.

CONCLUSIONS

Our results reveal that female ADNPS patients were associated with heart failure, whereas male patients were associated with dyslipidemia and cerebral infarction.

Machine learning uncovers novel sex-specific dementia biomarkers linked to autism and eye diseases

Background

Recently, microRNAs (miRNAs) have attracted significant interest as predictive biomarkers for various types of dementia, including Alzheimer's disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB), normal pressure hydrocephalus (NPH), and mild cognitive impairment (MCI). Machine learning (ML) methods enable the integration of miRNAs into highly accurate predictive models of dementia.

Objective

To investigate the differential expression of miRNAs across dementia subtypes compared to normal controls (NC) and analyze their enriched biological and disease pathways. Additionally, to evaluate the use of these miRNAs in binary and multiclass ML models for dementia prediction in both overall and sex-specific datasets.

Methods

Using data comprising 1685 Japanese individuals (GSE120584 and GSE167559), we performed differential expression analysis to identify miRNAs associated with five dementia groups in both overall and sex-specific datasets. Pathway enrichment analyses were conducted to further analyze these miRNAs. ML classifiers were used to create predictive models of dementia.

Results

We identified novel differentially expressed miRNA biomarkers distinguishing NC from five dementia subtypes. Incorporating these miRNAs into ML classifiers resulted in up to a 27% improvement in dementia risk prediction. Pathway analysis highlighted neuronal and eye disease pathways associated with dementia risk. Sex-specific analyses revealed unique biomarkers for males and females, with miR-128-1-5 as a protective factor for males in AD, VaD, and DLB, and miR-4488 as a risk factor for female AD, highlighting distinct pathways and potential therapeutic targets for each sex.

Conclusions

Our findings support existing dementia etiology research and introduce new potential and sex-specific miRNA biomarkers.

Connecting the Dots: Gender, Sexuality, and Societal Influences on Cognitive Aging and Alzheimer's Disease

Alzheimer's disease (AD) has many etiologies and the impact of gender on AD changes throughout time. As a consequence of advancements in precision medical procedures and methodology, Alzheimer's disease is now better understood and treated. Several risk factors may be addressed to lower one's chances of developing Alzheimer's disease or associated dementia (ADRD). The presence of amyloid-α protein senile plaques, intracellular tau protein neurofibrillary tangles (NfTs), neurodegeneration, and neuropsychiatric symptoms (NPS) characterizes Alzheimer's disease. NPS is common in persons with Alzheimer's disease dementia, although its presentation varies widely. Gender differences might explain this clinical variability. The fundamental goal of this review is to 1) emphasize the function of old age, sex, and gender in the development of Alzheimer's disease, dementia, and ADRD, and 2) explain the importance of sexual hormones, education, and APOE (Apolipoprotein E) status. This is a narrative summary of new ideas and concepts on the differences in the chance of developing dementia or Alzheimer's disease between men and women. A more thorough examination of risk and protective variables in both men and women might hasten research into the epidemiology of neurological illnesses such as dementia and Alzheimer's disease. Similarly, future preventive efforts should target men and women separately.

Ginkgo biloba extract EGb 761® ameliorates cognitive impairment and alleviates TNFα response in 5xFAD Alzheimer's disease model mice

BACKGROUND

Ginkgo biloba leaf extract EGb 761® has shown clinical efficacy in patients with mild cognitive impairment and dementia. However, the pharmacological action of EGb 761® in Alzheimer's disease (AD) remains unclear and molecular mechanisms targeted in the brain are not completely understood.

HYPOTHESIS/PURPOSE

We aimed to investigate 1) the potential sex-dependent effects of oral administration of EGb 761® in 5xFAD mice, an AD mouse model, and 2) the underlying microglial subtype responsible for the observed anti-inflammatory effects in the brain.

METHODS

Eight-week old 5xFAD and wild type mice received EGb 761®-supplemented diet or control diet for eight weeks. The study investigated changes in cognitive function as well as amyloid plaque load, expression of AD-related genes, and anti-inflammatory effects. Moreover, we used organotypic brain slices for confirmation and assessment of concentration-dependency of the observed EGb 761® effects and performed single cell RNA sequencing on the prefrontal cortex of male mice with focus on microglia.

RESULTS

We demonstrate that EGb 761® treatment improves cognitive function in 5xFAD mice in several behavioral tests. Analysis of the brain tissue from these animals indicated a reduction in amyloid plaque load in the prefrontal cortex (PFC). This brain area was further investigated to assess the molecular changes that occurred following EGb 761® intake. Alterations in the expression of genes related to AD were highly sex-specific with effects on the cholinergic system, the γ-secretase complex, and neuroinflammation. Anti-inflammatory effects of EGb 761® with a particularly pronounced reduction of the TNFα-response could be shown for the PFC but also peripherally in the serum of 5xFAD mice of both sexes. Single-cell RNA sequencing revealed that EGb761® mainly affected disease-associated microglia stage 2 (DAM2), which are thought to have a detrimental role in AD.

CONCLUSIONS

EGb 761® shows efficacy in the treatment of cognitive deficits in the 5xFAD mouse model via multimodal activity, including sex-specific and sex-unrelated mechanisms including the normalization of neuroinflammatory parameters.

Linking metabolic syndrome, cerebral small vessel disease, and cognitive health: insights from a subclinical population study using TriNetX

Metabolic syndrome (MetS) has been linked to accelerated cognitive decline and Alzheimer's disease and related dementias (ADRDs) via cerebral small vessel disease (CSVD); however, this relation in MetS without overt cardiometabolic disease comorbidities is unknown and may represent a population amenable to preventative strategies. Our study aimed to determine risk profiles for neurocognitive decline and ADRDs in early-stage MetS with evidence of CSVD using the TriNetX electronic health records (EHR) research network. Patients aged 50 to 80 years old meeting MetS criteria were identified utilizing TriNetX data from 76 healthcare organizations. Propensity score matching controlled for demographic and confounding factors. Cohorts included MetS-only, non-MetS, and a MetS subset with evidence of CSVD (MetS-CSVD) created by clustering relevant ICD-codes for diagnoses, imaging, and lab work. Contingency analyses determined odds of developing neurocognitive decline, ADRDs, and CSVD in MetS vs non-MetS and MetS-CSVD vs. MetS-only, using odd ratios with 95% confidence intervals (p-value < 0.05). After propensity score matching, there were 57,347 men and 52,259 women in each of the MetS and non-MetS cohorts and 2,810 men and 2,862 women in each of the MetS-CSVD and MetS-only cohorts. Compared to non-MetS, the MetS cohort exhibited higher odds of developing neurocognitive decline (men: RR = 1.82, p < 0.001; women: RR = 1.34, p = 0.015) and CSVD (men: RR = 2.83, p < 0.001; women: RR = 2.14, p < 0.001), but only women exhibited significantly higher odds of developing ADRDs (men: RR = 1.13, p = 0.38; women: RR = 1.52, p < 0.001). Compared to MetS-only, the MetS-CSVD showed elevated odds in developing neurocognitive decline (men: RR = 1.81, p = 0.040; women: RR = 1.87, p = 0.018) and ADRDs (men: RR = 2.39, p = 0.009; women: RR = 1.65, p = 0.041). A large, predominantly US, sample of subclinical MetS demonstrated heightened odds for developing neurocognitive decline and ADRDs, with even higher odds when evidence of CSVD was also present. TriNetX facilitated a robust exploration of these associations, and our findings warrant further investigation of interventions that target this subclinical at-risk population.

The impact of sex on memory during aging and Alzheimer's disease progression: Epigenetic mechanisms

Alzheimer's disease (AD) is a leading cause of dementia, disability, and death in the elderly. While the etiology of AD is unknown, there are several established risk factors for the disease including, aging, female sex, and genetics. However, specific genetic mutations only account for a small percentage (1-5%) of AD cases and the much more common sporadic form of the disease has no causative genetic basis, although certain risk factor genes have been identified. While the genetic code remains static throughout the lifetime, the activation and expression levels of genes change dynamically over time via epigenetics. Recent evidence has emerged linking changes in epigenetics to the pathogenesis of AD, and epigenetic alterations also modulate cognitive changes during physiological aging. Aging is the greatest risk factor for the development of AD and two-thirds of all AD patients are women, who experience an increased rate of symptom progression compared to men of the same age. In humans and other mammalian species, males and females experience aging differently, raising the important question of whether sex differences in epigenetic regulation during aging could provide an explanation for sex differences in neurodegenerative diseases such as AD. This review explores distinct epigenetic changes that impact memory function during aging and AD, with a specific focus on sexually divergent epigenetic alterations (in particular, histone modifications) as a potential mechanistic explanation for sex differences in AD.