The projected effect of risk factor reduction on Alzheimer's disease prevalence

The Peripheral Amyloid-β Nexus: Connecting Alzheimer's Disease with Atherosclerosis through Shared Pathophysiological Mechanisms

Alzheimer's disease (AD) and atherosclerosis (AS) are two chronic diseases with seemingly distinct pathologies. However, emerging research points to a bidirectional relationship driven by common mechanisms, such as inflammation, oxidative stress, and dysregulation of Amyloid-Beta (Aβ). This review focuses on the role of Aβ as a critical molecular link between AD and AS, emphasizing its contribution to neuronal impairment and vascular damage. Specifically, peripheral Aβ produced in the pancreas and skeletal muscle tissues exacerbates AS by promoting endothelial dysfunction and insulin resistance (IR). Furthermore, AS accelerates AD progression by impairing cerebral blood flow and inducing chronic hypoxia, causing Aβ accumulation. This review critically evaluates recent findings, highlighting inconsistencies in clinical studies and suggesting future research directions. Understanding the bidirectional influence of AD and AS could pave the way for novel therapeutic approaches targeting shared molecular pathways, particularly emphasizing Aβ clearance and inflammation.

Mindfulness-Based Interventions Targeting Modifiable Lifestyle Behaviors Associated With Brain Health: A Systematic Review and Meta-Analysis

A systematic review and meta-analysis investigated randomized clinical trials (RCTs) of mindfulness-based interventions (MBIs) targeting lifestyle behaviors commonly associated with brain health in adults. Data sources included Ovid Medline, Ovid PsycINFO, CINAHL [EBSCO], Embase, Cochrane Library [Ovid], Web of Science, and https://ClinicalTrials.gov. Studies were screened using Covidence 2.0. A total of 79 published RCTs of MBIs for adults (18+, patient and non-patient populations) targeting one or more lifestyle behavior (physical activity, sleep, diet, alcohol use, tobacco cessation, and social and mental activities) met eligibility criteria. MBIs were associated with reduced sleep disturbance (40/54 RCTs; 3537 participants; SMD = -.53; 95% CI = -.74 to -.32; I 2 = 78%), increased physical activity (9/17 RCTs analyzed; 685 participants; SMD = .72; 95% CI = .04 to 1.40; I 2 = 89%), improved tobacco cessation (8/12 RCTs; 1234 participants; OR = 2.11; 95% CI = 1.12 to 3.97; I 2 = 55%), and lowered alcohol use (4/6 RCTs; 261 participants; SMD = -.39; 95% CI = -.45 to -.32; I 2 = 0%). This review found moderate to high-quality evidence for MBIs targeting sleep, physical activity, alcohol use, and tobacco cessation. Heterogeneity for these outcomes and insufficient data to analyze diet, mental activities, and cognitive functioning limit our ability to draw definitive conclusions about the effects of MBIs on brain health.

WMH Contributions to Cognitive Impairment: Rationale and Design of the Diverse VCID Study

As awareness of dementia increases, more individuals with minor cognitive complaints are requesting clinical assessment. Neuroimaging studies frequently identify incidental white matter hyperintensities, raising patient concerns about their brain health and future risk for dementia. Moreover, current US demographics indicate that ≈50% of these individuals will be from diverse backgrounds by 2060. Racial and ethnic minority populations bear a disproportionate burden of vascular risk factors magnifying dementia risk. Despite established associations between white matter hyperintensities and cognitive impairment, including dementia, no study has comprehensively and prospectively examined the impact of individual and combined magnetic resonance imaging measures of white matter injury, their risk factors, and comorbidities on cognitive performance among a diverse, nondemented, stroke-free population with cognitive complaints over an extended period of observation. The Diverse VCID (Diverse Vascular Cognitive Impairment and Dementia) study is designed to fill this knowledge gap through 3 assessments of clinical, behavioral, and risk factors; neurocognitive and magnetic resonance imaging measures; fluid biomarkers of Alzheimer disease, vascular inflammation, angiogenesis, and endothelial dysfunction; and measures of genetic risk collected prospectively over a minimum of 3 years in a cohort of 2250 individuals evenly distributed among Americans of Black/African, Latino/Hispanic, and non-Hispanic White backgrounds. The goal of this study is to investigate the basic mechanisms of small vessel cerebrovascular injury, emphasizing clinically relevant assessment tools and developing a risk score that will accurately identify at-risk individuals for possible treatment or clinical therapeutic trials, particularly individuals of diverse backgrounds where vascular risk factors and disease are more prevalent.

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.

Newer Therapeutic Approaches in Treating Alzheimer's Disease: A Comprehensive Review

Alzheimer's disease (AD) is an aging-related irreversible neurodegenerative disease affecting mostly the elderly population. The main pathological features of AD are the extracellular Aβ plaques generated by APP cleavage through the amyloidogenic pathway, the intracellular neurofibrillary tangles (NFT) resulting from the hyperphosphorylated tau proteins, and cholinergic neurodegeneration. However, the actual causes of AD are unknown, but several studies suggest hereditary mutations in PSEN1 and -2, APOE4, APP, and the TAU genes are the major perpetrators. In order to understand the etiology and pathogenesis of AD, various hypotheses are proposed. These include the following hypotheses: amyloid accumulation, tauopathy, inflammation, oxidative stress, mitochondrial dysfunction, glutamate/excitotoxicity, cholinergic deficiency, and gut dysbiosis. Currently approved therapeutic interventions are donepezil, galantamine, and rivastigmine, which are cholinesterase inhibitors (ChEIs), and memantine, which is an N-methyl-d-aspartate (NMDA) antagonist. These treatment strategies focus on only symptomatic management of AD by attenuating symptoms but not regeneration of neurons or clearance of Aβ plaques and hyperphosphorylated Tau. This review focuses on the pathophysiology, novel therapeutic targets, and disease-altering treatments such as α-secretase modulators, active immunotherapy, passive immunotherapy, natural antioxidant products, nanomaterials, antiamyloid therapy, tau aggregation inhibitors, transplantation of fecal microbiota or stem cells, and microtubule stabilizers that are in clinical trials or still under investigation.

Reduced levels of angiogenesis biomarkers predict increased symptom severity in Chinese Americans with Alzheimer's disease with demographic-specific effect

Alzheimer's disease (AD) symptomatology, while classically studied through the lens of amyloid-β and tau burden, is likely also influenced by multiple-interacting co-pathologies like vascular disease and dysmetabolism. These co-pathologies, especially vascular disease, occur disparately in the Chinese-American population and are often treatable via therapeutics and lifestyle modifications. Given this, we explored whether plasma biomarkers, including an array of vascular-related proteins, associate with cognition in a cohort of 34 Chinese Americans clinically diagnosed as cognitively normal, with mild cognitive impairment, or with AD. We found that a composite score of plasma angiogenesis biomarkers (MMP-1, bFGF, VEGF, and VEGF-C) were positively associated with total Mini Mental State Examination scores (p = 0.045) as well as memory performance (p = 0.006), and that this relationship was most pronounced in AD (biomarker composite score within AD vs MMSE & memory, both p < 0.001). To explore whether these findings were specific to the Chinese-American population, we repeated the above analyses in 73 demographically matched non-Hispanic White American participants and found no significant associations between angiogenesis biomarkers and MMSE or memory, highlighting the potential relevance of vascular dysregulation in Chinese Americans at risk for AD.

Cross-sectional association between plasma aldosterone concentration and cognitive performance by mini-mental state examination in community dwellers

Background

Aldosterone is the effector hormone in the renin angiotensin aldosterone system and existing data suggest aldosterone affect cognitive function. However, the relationship between plasma aldosterone concentration (PAC) and cognitive performance remains unexplored in community dwellers. Therefore, we aimed to explore whether PAC is associated with cognitive performance in this population.

Methods

We cross-sectionally enrolled adults using multistage random sampling from Emin, China in 2019. Participants underwent questionnaires and data collection. Cognitive status was assessed using mini-mental state examination (MMSE) questionnaire. Multi-variable linear and logistic regression were used to explore the association between log PAC and log MMSE score, and between tertiled PAC (the higher PAC as the exposure) and low cognitive performance, respectively, in total, apparently healthy and diseased participants. Subgroup analyses also were performed by age, gender, BMI, living region, ethnicity and education attainment status.

Results

27,707 subjects were included, of whom, 12,862 were apparently healthy and 14,845 had disease. Log-PAC was positively associated with log-MMSE score in the multivariable linear regression in the total (B = 0.01, 95%CI: 0-0.01, p < 0.001), apparently healthy (B = 0.01, 95%CI: 0-0.01, p = 0.007) participants, and the diseased without taking medicine (B = 0.01, 95%CI: 0.01-0.02, p = 0.004) participants. In logistic regression, the highest third tertile of PAC group showed significantly lower odds for the presence of low cognitive performance in total (OR = 0.83, 95%CI: 0.73-0.93, p = 0.002) and diseased without taking medicine participants (OR = 0.70, 95%CI: 0.57-0.86, p < 0.001). Various sub-group analysis showed largely consistent results with the main analysis.

Conclusion

There was a positive correlation between plasma aldosterone and cognitive functions in community dwellers, whereas further studies are need when considering the cross-sectional nature of the current study.

A bibliometric analysis of research on dementia comorbid with depression from 2005 to 2024

Introduction

With the global rise in life expectancy, the incidence of dementia is increasing, often accompanied by depressive symptoms. Understanding the interplay between dementia and depression is crucial, as depression may not only co-occur with but also potentially exacerbate the progression of dementia. This study employs bibliometric analysis to map the global research landscape, identify prevailing themes, and discern future research directions.

Methods

We analyzed reviews and original research articles on dementia and depression extracted from the Web of Science Core Collection spanning from 2005 to 2024. Utilizing tools such as CiteSpace, VOSviewer, and an R-based bibliometric analysis package, we assessed trends in publication volume, citation frequency, contributing countries, leading institutions, predominant journals, influential authors, and emergent keywords.

Results

A total of 1972 publications were obtained, revealing a consistent increase in both the number of publications and their citation impact over the study period. The United States is the country with the most publications and the most extensive collaborations. The University of Toronto and the Journal of Alzheimer's Disease were identified as key contributors to this field. This research area is currently focused on cognitive impairments, the role of gut microbiota, and non-drug interventions. Future directions emphasize the importance of early detection and intervention, a deeper understanding of the gut-brain axis, and the integration of technology in treatment strategies. Additionally, there is a growing interest in the physiological and psychological interplays such as oxidative stress and its implications.

Conclusion

This study underscores pathogenesis, comorbid conditions, and non-drug interventions as primary research focal points, suggesting these areas as potential pathways for therapeutic innovation. These insights are intended to deepen our understanding, enhance diagnostics, and improve the management of dementia and depression, providing guidance for future research aimed at addressing these escalating global health challenges.

Cardiorespiratory fitness is associated with cognitive function in late adulthood: baseline findings from the IGNITE study

OBJECTIVES

To evaluate the association between cardiorespiratory fitness (CRF) and cognition in a large sample of older adults, and to examine clinical and demographic factors that might moderate these associations.

METHODS

CRF was measured with a graded exercise test performed on a motorised treadmill. A confirmatory factor analysis was conducted using data from a comprehensive neuropsychological battery to obtain latent factors reflecting core cognitive domains. Linear regression models evaluated the association between CRF and each of the cognitive composites, and potential moderators including demographic factors (age, sex, education), apolipoprotein E ε4 (APOE4) carriage, beta-blocker use and components of maximal effort criteria during CRF testing.

RESULTS

The sample consisted of 648 adults (mean (SD) age 69.88 (3.75)), including 461 women (71.1%). The highest oxygen consumption obtained during testing (VO2max) was mean (SD) = 21.68 (5.06) mL/kg/min. We derived a five-factor model composed of episodic memory, processing speed, working memory, executive function/attentional control and visuospatial function. Higher CRF was associated with better performance across all five cognitive domains after controlling for covariates. Age and APOE4 carriage did not moderate observed associations. The relationship between CRF and cognitive performance was greater in women, those with fewer years of education and those taking beta-blockers in the domains of processing speed (sex: β=-0.447; p=0.015; education: β=-0.863; p=0.018) and executive function/attentional control (sex: β=-0.417; p=0.022; education β=-0.759; p=0.034; beta-blocker use: β=0.305; p=0.047).

CONCLUSION

Higher CRF in older adulthood is associated with better cognitive performance across multiple domains susceptible to age-related cognitive decline. Sex, education and use of beta-blockers moderated observed associations within select cognitive domains.

mHealth Intervention for Dementia Prevention through lifestyle Optimisation (MIND-PRO) in a primary care setting: protocol for a randomised controlled trial in people with low SES and/or migration background

INTRODUCTION

The Mobile Health (mHealth) Intervention for Dementia Prevention through lifestyle Optimisation (MIND-PRO) study addresses the increasing prevalence of dementia among populations with lower socio-economic status (SES) and/or a migration background. The study aims to evaluate the effectiveness and implementation of an mHealth intervention designed for self-managing lifestyle modifications with remote coaching to reduce dementia risk factors.

METHODS AND ANALYSIS

This prospective randomised open-label blinded end point (PROBE) trial follows a type 2 hybrid effectiveness-implementation design with a 12-month intervention period. It aims to recruit 692 participants in Dutch primary care. Entry criteria include age 50-75 years, low SES and/or migration background, one or more dementia risk factors (hypertension, dyslipidaemia, diabetes mellitus, physical inactivity, smoking, depression and overweight) or manifest cardiovascular disease and possession of a smartphone. Participants are randomised to a coach-supported, interactive app facilitating self-management of dementia risk factors or to a control app with static health information. The primary effectiveness outcome is a composite score of systolic blood pressure, non-high-density lipoprotein cholesterol and body mass index. Implementation outcomes include coverage, adoption, acceptability, appropriateness, feasibility, fidelity, costs and sustainability of the intervention. Secondary outcomes include the Cardiovascular Risk Factors, Ageing and Dementia risk score and its individual risk factors, and disability, physical activity, depressive symptoms, cognitive functioning and daily distance moved.

ETHICS AND DISSEMINATION

The MIND-PRO trial is funded by the Netherlands Organisation for Health Research and Development (ZonMw, grant number 10510032120004) and approved by the Ethics Committee of Amsterdam UMC (reference: METC 2023.0770). Results are expected in 2026 and will be submitted for publication in a peer-reviewed journal, and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

ISRCTN92928122.

Patient- and Caregiver-Reported Impact of Symptoms in Alzheimer Disease, Mild Cognitive Impairment, and Dementia

Background and Objectives

In preparation for future clinical trials involving individuals with Alzheimer disease (AD), mild cognitive impairment (MCI), and dementia, it is important to ascertain the widespread impact of symptoms from the direct perspectives of patients and caregivers. In this study, we performed cross-sectional surveys using large-scale patient and caregiver data to identify the prevalence and average impact of symptoms and symptomatic themes experienced by adults with AD, MCI, and dementia. Subsequent analyses were used to determine which demographic and disease-specific factors are associated with more severe disease.

Methods

Fifteen adults with AD (6), MCI (8), and dementia (1) and 15 caregivers of adults with AD (7), MCI (6), and dementia (2) participated in qualitative interviews providing 1,166 and 1,097 unique quotes pertaining to symptom burden. Using open-ended questions from a comprehensive interview guide, participants were asked to identify the symptoms of AD that have the greatest effect on their lives or the lives of the individual for whom they provide care. A cross-sectional survey was then implemented inquiring about the potential symptoms of importance identified during preliminary qualitative interviews. Four-hundred thirty-three individuals (patients and caregivers) participated in the cross-sectional survey, providing more than 35,000 symptom rating responses. Subsequent analyses were conducted to determine how demographic and disease-specific characteristics correlate with symptomatic theme prevalence.

Results

The most frequent symptomatic themes reported by individuals with AD, MCI, and dementia in the cross-sectional survey were memory problems (99.0%), problems thinking (90.3%), and communication difficulties (80.4%). Patients identified decreased satisfaction in social situations (1.45), fatigue (1.45), and memory problems (1.41) as the most impactful symptomatic themes (range 0-4). Patient-reported symptomatic theme prevalence was strongly associated with the Modified Rankin Scale (mRS) for neurologic disability.

Discussion

Individuals with AD, MCI, and dementia experience a variety of symptoms that significantly affect their daily lives. These symptoms, many underrecognized, are of variable importance to individuals with these diseases and may inform potential targets for future therapeutic intervention as well as facilitate the development and validation of disease-specific outcome measures.

Association of a multiplex immune marker panel with incident cognitive impairment and dementia: The Northern Manhattan Study

Objective

To determine whether a panel of immune markers adds significant information to known correlates of risk of dementia and cognitive impairment.

Background

The impact of immune mechanisms on dementia risk is incompletely characterized.

Design/methods

A subsample of the Northern Manhattan Study, a prospective cohort study in the racially/ethnically diverse population of New York City, underwent comprehensive neuropsychological testing up to three times, at approximately 5-year intervals. Cognitive outcomes were adjudicated as no cognitive impairment, mild cognitive impairment (MCI), or dementia. Immune markers were assessed using a multiplex immunoassay on plasma samples collected at the time of the first neuropsychological test. Least absolute shrinkage and selection operator (LASSO) techniques were employed to yield a panel of immune markers linearly related to the outcome of dementia/MCI vs. no cognitive impairment. Nested logistic regression models were run to determine the independent association of the immune marker panel with dementia/MCI after adjusting for other predictors of risk.

Results

Among 1179 participants (mean age 70.0 ± 8.9 years, 60% women, 68% Hispanic), immune markers improved model fit above demographic and vascular risk factors (p-value for likelihood ratio test <0.0001) as correlates of MCI/dementia. Individual immune markers found to be associated with dementia/MCI were C-X-C Motif Chemokine Ligand 9 (CXCL9) and C-C Motif Chemokine Ligand 2 (CCL2). The effect of the immune markers was comparable to traditional risk factors, with CCL2 (per SD) having almost the same effect as 1 year of aging and CXCL9 (per SD) showing approximately twice this magnitude.

Conclusion

Immune markers are associated with cognitive decline and dementia outcomes in a multi-ethnic cohort. More work is needed to further characterize these associations and determine therapeutic strategies. (Funded by the National Institute of Health/National Institute of Neurological Disorders and Stroke; grant number R01 29993 (Sacco/Elkind)).

Potential molecular mechanisms of tobacco smoke exposure in Alzheimer's disease

BACKGROUND

Smoking is detrimental to health, with tobacco use being a critical factor in the development of various neurodegenerative diseases, including Alzheimer's disease (AD), which progressively impairs brain function and poses a significant threat to public health. This study aims to examine the potential genetic alterations induced by smoking that are associated with AD and to investigate the underlying regulatory mechanisms. The research will provide theoretical foundations for targeted prevention and treatment strategies for AD.

METHODS

This study analyzed datasets from the Gene Expression Omnibus (GEO) and the Comparative Toxicogenomics Database (CTD) to identify genes affected by tobacco smoke exposure and those altered in patients with AD relative to normal controls. We conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses using OmicShare tools to screen for key pathways. Key genes were identified by constructing protein-protein interaction networks (PPI) in the STRING database with the aid of CytoHubba. Additionally, the binding activity of the proteins encoded by these key genes to nicotine, the main component of tobacco, was analyzed using molecular docking techniques. Finally, the analytical results were verified using Quantitative Real-Time Polymerase Chain Reaction.

RESULTS

The CTD identified 12,164 CE-related genes affected by tobacco smoke exposure. A comparison of these datasets yielded 94 common genes that were both influenced by tobacco and differentially expressed across all brain regions. The GO and KEGG pathway enrichment analyses showed that these common differentially expressed genes (DEGs) were predominantly enriched in the Wnt/β-catenin and PI3K-AKT signaling pathways. The DEGs' PPI network, constructed using the STRING database, highlighted key genes such as HSP90AB1, SOS2, MAGI1, and YWHAZ. Molecular docking studies demonstrated that nicotine binds effectively to the protein structures of these key genes, primarily through amino acid residues such as Ser and Glu. Experimental validation showed that HSP90AB1 and YWHAZ exhibited notable expression discrepancies under varying concentrations of cigarette smoke extract (CSE) treatments, particularly demonstrating a pronounced down-regulation trend at elevated concentrations.

CONCLUSION

The study indicates that tobacco may impact the function of transmembrane transporter proteins and contribute to the development of AD by affecting key genes such as HSP90AB1 and YWHAZ, as well as signaling pathways like PI3K-AKT.

Role of NLRP3 Inflammasome in Chronic Pain and Alzheimer's Disease-A Review

The coexistence of Alzheimer's disease (AD) and chronic pain (CP) in the elderly population has been extensively documented, and a growing body of evidence supports the potential interconnections between these two conditions. This comprehensive review explores the mechanisms by which CP may contribute to the development and progression of AD, with a particular focus on neuroinflammatory pathways and the role of microglia, as well as the activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome. The review proposes that prolonged pain processing in critical brain regions can dysregulate the activity of the NLRP3 inflammasome within microglia, leading to the overproduction of pro-inflammatory cytokines and excessive oxidative stress in these regions. This aberrant microglial response also results in localized neuroinflammation in brain areas crucial for cognitive function. Additionally, CP as a persistent physiological and psychological stressor may be associated with hypothalamic-pituitary-adrenal (HPA) axis dysfunction, systemic inflammation, disruption of the blood-brain barrier (BBB), and neuroinflammation. These pathophysiological changes can cause morphological and functional impairments in brain regions responsible for cognition, memory, and neurotransmitter production, potentially contributing to the development and progression of CP-associated AD. Resultant neuroinflammation can further promote amyloid-beta (Aβ) plaque deposition, a hallmark of AD pathology. Potential therapeutic interventions targeting these neuroinflammatory pathways, particularly through the regulation of microglial NLRP3 activation, hold promise for improving outcomes in individuals with comorbid CP and AD. However, further research is required to fully elucidate the complex interplay between these conditions and develop effective treatment strategies.

The U.S. POINTER neurovascular ancillary study: Study design and methods

INTRODUCTION

POINTER Neurovascular (POINTER-NV) is an ancillary study that leverages the rich infrastructure and design of the U.S. Study to Protect Brain Health through Lifestyle Intervention to Reduce Risk (U.S. POINTER) to investigate neurovascular mechanisms that may underlie intervention effects on key brain outcomes.

METHODS

A comprehensive neurovascular assessment is conducted at baseline, Month 12, and Month 24 using a variety of complementary non-invasive techniques including transcranial Doppler ultrasound, carotid ultrasound, echocardiography, tonometry, and continuous blood pressure and heart rate monitoring. Measurements are acquired at rest and during orthostatic challenges, hyperventilation, and carbon dioxide inhalation.

RESULTS

The primary outcomes are baroreflex sensitivity and cerebral autoregulation. Secondary outcomes include aortic, carotid, and cerebral hemodynamics and various measures of autonomic function and vascular structure and function.

DISCUSSION

POINTER-NV will provide critical insight into neurovascular mechanisms that may change with intensive lifestyle modification and promote improvements in cognition and overall brain health.

HIGHLIGHTS

This study takes advantage of U.S. Study to Protect Brain Health through Lifestyle Intervention to Reduce Risk (U.S. POINTER) to address key gaps in the field. POINTER Neurovascular (POINTER-NV) will provide insight into neurovascular mechanisms underlying dementia. POINTER-NV may help shed light on modifiable vascular contributions to dementia.

Multi-domain Online Therapeutic Investigation Of Neurocognition (MOTION) - A randomized comparative-effectiveness study of two remotely delivered mind-body interventions for older adults with cognitive decline

BACKGROUND

Research suggest that mind-body movement programs have beneficial effects on cognitive outcomes for older adults with cognitive decline. However, few studies have directly compared specific approaches to mind-body movement or studied the impact of remote program delivery.

METHODS

In a 3-arm randomized controlled trial (RCT) for older adults with cognitive impairment, we are comparing a multidomain mind-body program that emphasizes movement, body awareness, personal meaningfulness, and social connection, and a traditional Chinese mind-body exercise (Tai Chi) to a health and wellness education control condition. All 3 interventions are delivered remotely two times per week (onehour per session) for 12 weeks. The two active interventions are live-streamed. Outcomes are assessed prior to, after, and 6-months after the interventions. The co-primary outcomes are changes on the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-cog) and brain functional connectivity in the Default Mode Network (DMN). Secondary outcomes include measures of specific cognitive domains (e.g., executive function, attention), mobility, and self-report measures of general well-being, quality of life, social engagement, self- and attention-regulation.

CONCLUSION

This RCT will directly compare the effects of two mind-body movement programs versus an education control delivered remotely over 12 weeks on cognitive, neuroimaging, and participant-reported outcomes. If successful, these programs may provide scalable strategies for slowing cognitive decline, which could potentially delay dementia onset in some individuals.

TRIAL REGISTRATION ID

NCT05217849.

Relationship Between Cognitive Abilities and Lower-Limb Movements: Can Analyzing Gait Parameters and Movements Help Detect Dementia? A Systematic Review

Identifying and diagnosing cognitive impairment remains challenging. Some diagnostic procedures are invasive, expensive, and not always accurate. Meanwhile, evidence suggests that cognitive impairment is associated with changes in gait parameters. Certain gait parameters manifesting differences between people with and without cognitive impairment are more pronounced when adding a secondary task (dual-task scenario). In this systematic review, the capability of gait analysis to identify cognitive impairment is investigated. Twenty-three studies published between 2014 and 2024 met the inclusion criteria. A significantly lower gait speed and cadence as well as higher gait variability were found in people with mild cognitive impairment (MCI) and/or dementia, compared with the group with no cognitive impairment. While dual tasks appeared to amplify the differences between the two populations, the type of secondary tasks (e.g., calculations and recalling phone numbers) had an effect on gait changes. The activity and volume of different brain regions were also different between the two populations during walking. In conclusion, while this systematic review supported the potential of using gait analysis to identify cognitive impairment, there are a number of parameters researchers need to consider such as gait variables to be studied, types of dual tasks, and analysis of brain changes while performing the movement tasks.

Ultrasensitive SERS nanoprobe-based multiplexed digital sensing platform for the simultaneous quantification of Alzheimer's disease biomarkers

Alzheimer's disease (AD) is a severe neurodegenerative disease that requires early diagnosis to manage its progression. Although the simultaneous detection of multiple AD biomarkers is expected to facilitate early assessment of AD risk, the lack of multiplexed sensing platforms for accurately quantifying multiple AD biomarkers remains a challenge. Here, we present a multiplexed digital sensing platform based on bumpy core-shell (BCS) surface-enhanced Raman spectroscopy (SERS) nanoprobes for ultrasensitive, quantitative, and simultaneous detection of Aβ42 and Aβ40 as AD biomarkers, enabling the accurate determination of the Aβ42/Aβ40 ratio. We synthesized BCS SERS nanoprobes with distinct Raman reporters to generate unique, intense, and reproducible SERS signals, offering single-nanoparticle sensitivity and quantification capabilities. These nanoprobes were subsequently employed in SERS-based immunoassays combined with digital SERS analysis for multiplexed quantification. The proposed platform accurately and quantitatively detected Aβ42 and Aβ40 across a range of five orders of magnitude, with a limit of detection of 8.7× 10-17 g/mL (1.9 × 10-17 M) for Aβ42 and 1.0 × 10-15 g/mL (2.3 × 10-16 M) for Aβ40, surpassing the performance of conventional enzyme-linked immunosorbent assays. Based on the exclusive detection of Aβ42 and Aβ40 using distinct SERS nanoprobes, the proposed sensing platform can also accurately quantify Aβ42 and Aβ40 at clinically relevant levels in both cerebrospinal fluid and blood plasma. Therefore, this sensing platform can be used to accurately and reliably determine the Aβ42/Aβ40 ratio, thus serving as an effective tool for the early diagnosis of AD.

CSF biomarkers are differentially linked to brain areas high and low in noradrenaline, dopamine and serotonin across the Alzheimer's disease spectrum

Neurotransmitter systems of noradrenaline, dopamine, serotonin and acetylcholine are implicated in cognitive functions such as memory, learning and attention and are known to be altered in neurodegenerative diseases like Alzheimer's disease. Specific brain structures involved in these systems, e.g. the locus coeruleus, the main source of noradrenaline in the cortex, are in fact affected earliest by Alzheimer's disease tau pathology. Preserved volumetric neurotransmitter specific brain areas could therefore be an important neural resource for cognitive reserve in aging. The aim of this study was to determine whether volumes of brain areas known to be high in neurotransmitter receptors are relatively preserved in individuals with lower levels of Alzheimer's disease pathology. Based on the Human Protein Atlas for neurotransmitter receptor distribution, we distinguished between 'areas high and low' in noradrenaline, dopamine, serotonin and acetylcholine and assessed associations of atrophy in those areas with CSF amyloid-ß 42/40, CSF phosphorylated tau protein and cognitive function across healthy controls (n = 122), individuals with subjective cognitive decline (n = 156), mild cognitive impairment or mild Alzheimer's disease dementia (n = 126) using structural equation modelling. CSF pathology markers were inversely correlated and showed a stronger association with disease severity, suggesting distinguishable interrelatedness of these biomarkers depending on the stage of Alzheimer's disease dementia. Across groups, amyloid pathology was linked to atrophy in areas high as well as low in neurotransmitter receptor densities, while tau pathology did not show any significant link to brain area volumes for any of the neurotransmitters. Within disease severity groups, individuals with more amyloid pathology showed more atrophy only in 'areas high in noradrenaline', whereas for dopamine tau pathology was linked to higher volumes in areas low in receptor density possibly indicating compensatory mechanisms. Furthermore, individuals with more tau pathology showed a selective decrease in memory function while amyloid pathology was related to a decline in executive function and language capacity as well as memory function. In summary, our analyses highlight the benefits of investigating disease-relevant factors in Alzheimer's disease using a multivariate multigroup approach. Assessing multivariate dependencies in different disease stages and across individuals revealed selective links of pathologies, cognitive decline and atrophy in particular for areas modulated by noradrenaline, dopamine and serotonin.

Proof-of-concept for integrating multimodal digital health assessments into lifestyle interventions for older adults with dementia risk factors

Multimodal digital health assessments overcome the limitations of patient-reported outcomes by allowing for continuous and passive monitoring but remain underutilized in older adult lifestyle interventions for brain health. Therefore, we aim to (1) report ecological momentary assessment (EMA) and ActiGraph adherence among older adults during a lifestyle intervention; and (2) use dynamic data collected via EMA and ActiGraph to examine person-specific patterns of mindfulness, steps, and sleep throughout the intervention. We analyzed EMA and ActiGraph data from a pilot study of the 8-week My Healthy Brain program (N = 10) lifestyle group for older adults (60+) with subjective cognitive decline. EMA adherence metrics included proportion of EMA completed and the proportion of days with at least 10 mindfulness minutes. ActiGraph GT9X adherence metrics included the number of valid wear days (≥ 7 h) and the number of days participants achieved their step goal. We used linear mixed-effects models to examine person-specific patterns of step count, sleep efficiency, and mindfulness practice. On average, participants completed 39 of the 49 possible EMAs (80%) during the program. ActiGraph adherence was slightly higher than EMA (M = 61.40 days, 87.71%). Participants achieved the daily mindfulness goal (10 min/day) and step goal on 46.32% and 55.10% of days, respectively. Dynamic data revealed that on average, participant step counts increased by approximately 16.5 steps per day (b = 16.495, p = 0.002). However, some participants exhibited no changes while improvements made by other participants returned to baseline levels of activity. There was substantial heterogeneity in trajectories of mindfulness practice and sleep efficiency. EMA and ActiGraph are feasible for older adults enrolled in dementia risk reduction lifestyle interventions. Future studies are needed to better understand how mechanisms of lifestyle behaviors captured by EMA and ActiGraph are related to cognitive outcomes in older adults.

Association between air pollution and lifestyle with the risk of developing mild cognitive impairment and dementia in individuals with cardiometabolic diseases

Lifestyle factors and ambient air pollution are linked to dementia and CMDs, yet few studies have investigated their impact on dementia risk in CMDs patients at the same time. The Cox proportional hazards model was used to evaluate the influence of lifestyle and ambient air pollution on the dementia risk of the CMDs population among 438,681 participants in the UK Biobank. It is found that the risk of developing mild cognitive impairment and dementia in the population seems to increase with the increase in the number of CMDs. There appears to be a statistically significant association between high levels of ambient air pollution, unhealthy lifestyles, and a higher risk of developing mild cognitive impairment and dementia in the CMDs population. It is found that a healthy lifestyle may have an effect modifier role in the association between ambient air pollution and the risk of mild cognitive impairment and the development of dementia in patients with CMDs. Therefore, maybe people with CMDs can lessen the impact of ambient air pollution on their risk of developing mild cognitive impairment and dementia by improving their lifestyle.

Depression and dementia: interrogating the causality of the relationship

BACKGROUND

Depression is often cited as a major modifiable risk factor for dementia, though the relative contributions of a true causal relationship, reverse causality and confounding factors remain unclear. This study applied a subset of the Bradford Hill criteria for causation to depression and dementia including strength of effect, specificity, temporality, biological gradient and coherence.

METHODS

A total of 491 557 participants in UK Biobank aged between 40 and 69 at enrolment and followed up for a mean duration of 12.4 years were studied. Diagnoses of depression and dementia were ascertained from linked health records, self-reports and death certificate registration. Depressive symptoms were measured at enrolment using a combination of questions based on the Patient Health Questionnaire-9 depression screening questionnaire. Regional grey matter volumes were measured using T1-weighted MRI in 41 929 participants.

RESULTS

Depression was a strong risk factor for incident dementia with an OR of 1.76 (95% CI 1.63 to 1.90), a relationship which was found to be specific to depression rather than commonly proposed confounders. Depressive symptoms increased rapidly in the 10 years prior to dementia diagnosis. The severity of depressive symptoms showed a dose-response relationship with dementia risk. Depression at older ages correlated with reduced grey matter volume in an Alzheimer's pattern whereas younger onset depression was associated with reduced grey matter volume in the frontal lobes and cerebellum.

CONCLUSIONS

This study provides evidence that the link between depression and dementia is due to reverse causation with a smaller component of causation with clear evidence of both mechanisms driving the association.

Global Burden of Gallbladder Cancer Attributable to Modifiable Risk Factors

Gallbladder cancer (GBC) is a highly lethal and often overlooked malignancy increasingly affecting young adults. This study quantified the global proportion of GBC cases attributable to 10 key modifiable risk factors, employing Monte Carlo simulations and estimates from field-wide systematic review and meta-analysis. Approximately three-quarters of global GBC cases are attributable to key modifiable factors (74.6%; 95% uncertainty interval, 63.7-83.7), with a slightly higher share observed in females. Central obesity (29.7%; 8.7-49.5), gallstones (27.9%; 16.8-40.7), and physical inactivity (20.5%; 7.4-34.1) were identified as the leading contributors. Most GBC cases are preventable, with a large share linked to metabolic health conditions.

Tobacco cigarette smoking induces cerebrovascular dysfunction followed by oxidative neuronal injury with the onset of cognitive impairment

While chronic smoking triggers cardiovascular disease, controversy remains regarding its effects on the brain and cognition. We investigated the effects of long-term cigarette smoke (CS) exposure (CSE) on cerebrovascular function, neuronal injury, and cognition in a novel mouse exposure model. Longitudinal studies were performed in CS or air-exposed mice, 2 hours/day, for up to 60 weeks. Hypertension and carotid vascular endothelial dysfunction (VED) occurred by 16 weeks of CSE, followed by reduced carotid artery blood flow, with oxidative stress detected in the carotid artery, and subsequently in the brain of CS-exposed mice with generation of reactive oxygen species (ROS) and secondary protein and DNA oxidation, microglial activation and astrocytosis. Brain small vessels exhibited decreased levels of endothelial NO synthase (eNOS), enlarged perivascular spaces with blood brain barrier (BBB) leak and decreased levels of tight-junction proteins. In the brain, amyloid-β deposition and phosphorylated-tau were detected with increases out to 60 weeks, at which time mice exhibited impaired spatial learning and memory. Thus, long-term CSE initiates a cascade of ROS generation and oxidative damage, eNOS dysfunction with cerebral hypoperfusion, as well as cerebrovascular and BBB damage with intracerebral inflammation, and neuronal degeneration, followed by the onset of impaired cognition and memory.

Modifiable risk factors and symptom progression in dementia over up to 8 years-Results of the DelpHi-MV trial

INTRODUCTION

This study investigated the association between modifiable factors and symptom progression in dementia over up to 8 years.

METHODS

Multilevel growth curve models assessed the role of modifiable risk factors (low education, hearing impairment and its treatment, depression, physical inactivity, diabetes and its treatment, smoking, hypertension and its treatment, obesity, alcohol consumption, social isolation, and visual impairment) on cognitive and functional trajectories in 353 people with dementia.

RESULTS

Higher education was associated with higher initial cognitive status but faster decline. Antidiabetic medication was associated with slower cognitive decline, whereas depression and visual impairment were linked to low baseline functioning and faster cognitive decline.

DISCUSSION

Several modifiable risk factors influenced symptom progression. Education initially had a protective effect, whereas depressive symptoms were linked to worse symptom progression. Treatment of comorbidities (diabetes, visual impairment) could have a positive impact on dementia symptoms. Modifiable risk factors are promising targets for tertiary prevention.

Highlights

Modifiable risk factors were associated with symptom progression in dementia over up to 8 years.More education was associated with higher initial cognitive status but faster decline.Depressive symptoms were linked to less favorable symptom progression.Treatment of comorbidities (diabetes, visual impairment) may positively impact the course of symptoms.Modifiable risk factors are promising targets for tertiary prevention.

Nanomedicine: A New Frontier in Alzheimer's Disease Drug Targeting

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder affecting elderly individuals, characterized by progressive cognitive decline leading to dementia. This review examines the challenges posed by anatomical and biochemical barriers such as the blood-brain barrier (BBB), blood-cerebrospinal fluid barrier (BCSFB), and p-glycoproteins in delivering effective therapeutic agents to the central nervous system (CNS) for AD treatment. This article outlines the fundamental role of acetylcholinesterase inhibitors (AChEIs) and NMDA(N-Methyl-D-Aspartate) receptor antagonists in conventional AD therapy and highlights their limitations in terms of brain-specific delivery. It delves into the intricacies of BBB and pglycoprotein- mediated efflux mechanisms that impede drug transport to the CNS. The review further discusses cutting-edge nanomedicine-based strategies, detailing their composition and mechanisms that enable effective bypassing of BBB and enhancing drug accumulation in brain tissues. Conventional therapies, namely AChEIs and NMDA receptor antagonists, have shown limited efficacy and are hindered by suboptimal brain penetration. The advent of nanotechnology-driven therapeutic delivery systems offers promising strategies to enhance CNS targeting and bioavailability, thereby addressing the shortcomings of conventional treatments. Various nanomedicines, encompassing polymeric and metallic nanoparticles (MNPs), solid lipid nanoparticles (SLNs), liposomes, micelles, dendrimers, nanoemulsions, and carbon nanotubes, have been investigated for their potential in delivering anti-AD agents like AChEIs, polyphenols, curcumin, and resveratrol. These nanocarriers exhibit the ability to traverse the BBB and deliver therapeutic payloads to the brain, thereby holding immense potential for effective AD treatment and early diagnostic approaches. Notably, nanocarriers loaded with AChEIs have shown promising results in preclinical studies, exhibiting improved therapeutic efficacy and sustained release profiles. This review underscores the urgency of innovative drug delivery approaches to overcome barriers in AD therapy. Nanomedicine-based solutions offer a promising avenue for achieving effective CNS targeting, enabling enhanced bioavailability and sustained therapeutic effects. As ongoing research continues to elucidate the complexities of CNS drug delivery, these advancements hold great potential for revolutionizing AD treatment and diagnosis.

Risk of dementia in patients with age-related medical conditions: a retrospective cohort study

OBJECTIVE

This retrospective cohort study aimed to investigate the impact of age-related medical conditions on the incidence of dementia, considering factors such as hypertension, diabetes mellitus, cerebrovascular disease, cardiovascular disease, chronic kidney disease, osteoarthritis, osteoporosis, chronic obstructive pulmonary disease, and hearing difficulties.

METHODS

Data from 513 640 patients at Keimyung University Dongsan Hospital were analyzed using the Observational Medical Outcomes Partnership Common Data Model. Patients with and without age-related medical conditions were assigned to experimental and control groups, respectively, with propensity score matching. Cox proportional hazards models assessed the association between each condition and dementia incidence.

RESULTS

Hypertension, diabetes mellitus, cerebrovascular disease, cardiovascular disease, chronic kidney disease, osteoarthritis, osteoporosis, and hearing difficulties were associated with increased dementia risk. Chronic obstructive pulmonary disease showed no significant association with increased risk of dementia. Incidence rates ranged from 4.52 to 8.05 per 1000 person-years in the control group and 7.46 to 14.99 per 1000 person-years in the experimental group. Hazard ratios ranged from 1.38 to 2.36.

CONCLUSIONS

The study highlights the importance of managing age-related medical conditions to mitigate dementia risk. Understanding these risk factors can inform preventive strategies and improve cognitive health outcomes. Problems with deidentification data analysis and the need for further multicentred studies are among the limitations of this study.

Myeloproliferative Neoplasms and Dementia Risk: A Population-Based Cohort Study

Objectives

To estimate dementia risk for persons diagnosed with Philadelphia chromosome–negative myeloproliferative neoplasms (MPNs), which serve as a human chronic inflammation model.

Methods

We identified 9895 individuals in Denmark newly diagnosed with MPNs from 1995 to 2017; matched them 10:1 by age and sex with a general population cohort of 95 770 individuals; and followed them until dementia identification, death, emigration, or December 31, 2018. We applied a Cox proportional‐hazards regression model to estimate the cause‐specific hazard ratios (HRs) and 95% confidence intervals (CIs) for dementia. We included control diseases, like chronic lymphocytic leukemia (CLL), which is not characterized by chronic inflammation.

Results

Patients with MPNs showed a 1.15‐fold (95% CI: 1.04–1.27) increased incidence of dementia compared with members of the general population. Associations were stronger for men with MPNs (HR: 1.40, 95% CI: 1.19–1.63) than for women (HR: 1.02, 95% CI: 0.89–1.15). Patients with CLL showed a decreased dementia incidence (HR: 0.81, 95% CI: 0.72–0.90). The findings for CLL could be explained by depletion‐of‐susceptibles bias, suggesting that the findings for MPNs were underestimated by a similar bias.

Conclusions

The findings support MPNs as risk factors for dementia and the role of chronic inflammation in dementia development.

Moving Beyond Depression: Mood Symptoms Across the Spectrum Relate to Tau Pathology in Older Women at Risk for Alzheimer's Disease

We examined how symptoms across the mood spectrum relate to Alzheimer's disease (AD) biomarkers in older women at high risk for AD. Participants included 25 women aged 65+ with mild cognitive deficits and elevated AD genetic risk. The Profile of Mood States Questionnaire measured mood symptoms and a total mood disturbance (TMD) score. Tau burden in the meta-temporal region of interest was measured using MK-6240 Tau positron emission tomography (PET) imaging. A subset (n = 12) also had p-Tau181, and Aß40/42 levels measured in plasma. Higher TMD scores related to higher tau PET standardized uptake value ratio (SUVR). Greater negative mood symptoms correlated with higher tau PET SUVR, while greater vigor correlated with lower SUVR. Similar results were seen with plasma p-Tau181 levels, but not with Aβ40/42 levels. In conclusion, positive and negative mood symptoms related to tau pathology in older women at high risk for AD, highlighting a role of mental well-being in AD risk.

Social patterning of cognitive impairment in Colombia: evidence from the SABE 2015 study

INTRODUCTION

Dementia, an increasingly critical public health concern in low and middle-income countries, is associated with lower socioeconomic status, early cognitive impairment, and elevated dementia-related mortality risk. This study seeks to estimate the prevalence of cognitive impairment, investigate its links with social indicators, and visualize social gradients across different regions in Colombia.

METHODS

Secondary data analysis from the SABE 2015 survey, multinomial regression analyses, and equiplot graphs.

RESULTS

A sample of 23,694 individuals 60 years or older from Colombia. Higher risks were observed among individuals with dark skin color (OR 1.27; 95%CI: 1.10 - 1.47), lower educational levels (OR 3.01; 95%CI:2.04 - 4.42) and reading illiteracy (OR 2.14; 95%CI: 1.87 - 2.46). Inequity patterns were identified by region of residence and income.

DISCUSSION

This study underscores the need for targeted interventions aimed at reducing health inequities. The results highlight the higher prevalence rates of cognitive impairment among socially disadvantaged individuals.

Alzheimer's disease: a comprehensive review of epidemiology, risk factors, symptoms diagnosis, management, caregiving, advanced treatments and associated challenges

Background

Alzheimer's disease (AD) is a chronic, progressive neurodegenerative disorder characterized by cognitive decline, memory loss, and impaired reasoning. It is the leading cause of dementia in older adults, marked by the pathological accumulation of amyloid-beta plaques and neurofibrillary tangles. These pathological changes lead to widespread neuronal damage, significantly impacting daily functioning and quality of life.

Objective

This comprehensive review aims to explore various aspects of Alzheimer's disease, including its epidemiology, risk factors, clinical presentation, diagnostic advancements, management strategies, caregiving challenges, and emerging therapeutic interventions.

Methods

A systematic literature review was conducted across multiple electronic databases, including PubMed, MEDLINE, Cochrane Library, and Scopus, from their inception to May 2024. The search strategy incorporated a combination of keywords and Medical Subject Headings (MeSH) terms such as "Alzheimer's disease," "epidemiology," "risk factors," "symptoms," "diagnosis," "management," "caregiving," "treatment," and "novel therapies." Boolean operators (AND, OR) were used to refine the search, ensuring a comprehensive analysis of the existing literature on Alzheimer's disease.

Results

AD is significantly influenced by genetic predispositions, such as the apolipoprotein E (APOE) ε4 allele, along with modifiable environmental factors like diet, physical activity, and cognitive engagement. Diagnostic approaches have evolved with advances in neuroimaging techniques (MRI, PET), and biomarker analysis, allowing for earlier detection and intervention. The National Institute on Aging and the Alzheimer's Association have updated diagnostic criteria to include biomarker data, enhancing early diagnosis.

Conclusion

The management of AD includes pharmacological treatments, such as cholinesterase inhibitors and NMDA receptor antagonists, which provide symptomatic relief but do not slow disease progression. Emerging therapies, including amyloid-beta and tau-targeting treatments, gene therapy, and immunotherapy, offer potential for disease modification. The critical role of caregivers is underscored, as they face considerable emotional, physical, and financial burdens. Support programs, communication strategies, and educational interventions are essential for improving caregiving outcomes. While significant advancements have been made in understanding and managing AD, ongoing research is necessary to identify new therapeutic targets and enhance diagnostic and treatment strategies. A holistic approach, integrating clinical, genetic, and environmental factors, is essential for addressing the multifaceted challenges of Alzheimer's disease and improving outcomes for both patients and caregivers.

The blood metabolome of cognitive function and brain health in middle-aged adults - influences of genes, gut microbiome, and exposome

Increasing evidence suggests the involvement of metabolic alterations in neurological disorders, including Alzheimer's disease (AD), and highlights the significance of the peripheral metabolome, influenced by genetic factors and modifiable environmental exposures, for brain health. In this study, we examined 1,387 metabolites in plasma samples from 1,082 dementia-free middle-aged participants of the population-based Rotterdam Study. We assessed the relation of metabolites with general cognition (G-factor) and magnetic resonance imaging (MRI) markers using linear regression and estimated the variance of these metabolites explained by genes, gut microbiome, lifestyle factors, common clinical comorbidities, and medication using gradient boosting decision tree analysis. Twenty-one metabolites and one metabolite were significantly associated with total brain volume and total white matter lesions, respectively. Fourteen metabolites showed significant associations with G-factor, with ergothioneine exhibiting the largest effect (adjusted mean difference = 0.122, P = 4.65×10-7). Associations for nine of the 14 metabolites were replicated in an independent, older cohort. The metabolite signature of incident AD in the replication cohort resembled that of cognition in the discovery cohort, emphasizing the potential relevance of the identified metabolites to disease pathogenesis. Lifestyle, clinical variables, and medication were most important in determining these metabolites' blood levels, with lifestyle, explaining up to 28.6% of the variance. Smoking was associated with ten metabolites linked to G-factor, while diabetes and antidiabetic medication were associated with 13 metabolites linked to MRI markers, including N-lactoyltyrosine. Antacid medication strongly affected ergothioneine levels. Mediation analysis revealed that lower ergothioneine levels may partially mediate negative effects of antacids on cognition (31.5%). Gut microbial factors were more important for the blood levels of metabolites that were more strongly associated with cognition and incident AD in the older replication cohort (beta-cryptoxanthin, imidazole propionate), suggesting they may be involved later in the disease process. The detailed results on how multiple modifiable factors affect blood levels of cognition- and brain imaging-related metabolites in dementia-free participants may help identify new AD prevention strategies.

Population attributable fraction of total stroke associated with modifiable risk factors in the United States

Stroke is a leading cause of death in the United States across all race/ethnicity and sex groups, though disparities exist. We investigated the potential for primary prevention of total first stroke for Americans aged 20 years or older, stratified by sex and race/ethnicity. Specifically, we calculated population attributable fractions (PAFs) of first stroke for 7 potentially modifiable risk factors: smoking, physical inactivity, poor diet, obesity, hypertension, diabetes, and atrial fibrillation. Population attributable fractions are a function of (1) the relative risk of first stroke for people with the exposure and (2) the prevalence of the risk factor in the population. Relative risks came from recent meta-analyses, and sex- and race/ethnicity-specific prevalence estimates came from the 2015-2018 National Health and Nutrition Examination Survey or Multi-Ethnic Study of Atherosclerosis (for atrial fibrillation only). Approximately one-third of strokes (35.7% [95% CI, 21.6-49.0] for women; 32.7% [95% CI, 19.2-45.1] for men) were attributable to the 7 risk factors we considered. A 20% proportional reduction in stroke risk factors would result in approximately 37 000 fewer strokes annually in the United States. The estimated PAF was highest for non-Hispanic Black women (39.3%; 95% CI, 24.8-52.3) and lowest for non-Hispanic Asian men (25.5%; 95% CI, 14.6-36.2). For most groups, obesity and hypertension were the largest contributors to stroke rates.

Lifestyle empowerment for Alzheimer's prevention prescribed by physicians: Methods and adaptations to COVID-19

The health care system is insufficiently capitalizing on the benefits of physical exercise in America's aging population. Few tools exist to help clinicians incorporate physical activity into their clinical care, and barriers limit older adults from initiating and maintaining exercise programs. The Lifestyle Empowerment for Alzheimer's Prevention (LEAP! Rx) Program has been designed to support providers and participants in lifestyle change. LEAP! Rx uses two forms of participant enrollment: physician referrals through electronic health records and self-referrals to test the efficacy of delivering a community-based exercise and healthy lifestyle program to older adults. After referral into the program, participants are randomized to receive the LEAP! Rx Program or are placed in a standard-of-care group to receive the program later. The LEAP! Rx program consists of a personalized and structured exercise program, lifestyle education, and mobile health monitoring. This includes a 12-week Empowerment phase with coaching and supervised exercise training, followed by a 40-week Lifestyle phase with intermittent supervised exercise and coaching. Lifestyle education includes monthly, evidence-based classes on optimal aging. The evaluation of LEAP! Rx focuses on 1) the assessment of implementation and scalability of the LEAP!Rx Program for clinicians and patients 2) the effect of the LEAP! Rx Program on cardiorespiratory fitness, 3) the impact of the LEAP! Rx Program on secondary intervention outcome measures of chronic disease risk factors, including insulin resistance, body composition, and lipids. If successful, this study's findings could advance future healthcare practices, providing a new and practical approach to aging and chronic disease prevention.

The Systematic Multi-domain Alzheimer's Risk Reduction Trial (SMARRT) intervention: A personalized approach to dementia risk reduction

BACKGROUND

Addressing modifiable risk factors such as physical inactivity and social isolation could reduce risk of Alzheimer's disease and all-cause dementia, but little is known about which factors individuals are most willing to address or how they prefer to address them.

OBJECTIVE

To examine and describe behavior change goals set by participants during the Systematic Multi-domain Alzheimer's Risk Reduction Trial (SMARRT).

METHODS

In SMARRT, older adults worked with a health coach and nurse over 2 years to set incremental, personalized goals to reduce dementia risk. We performed quantitative analyses to summarize the numbers of goals per risk factor and qualitative content analyses of health coach and nurse notes to describe types of goals and useful strategies.

RESULTS

82 dementia-free adults (70 to 89 years) with at least two dementia risk factors participated in the SMARRT intervention arm (mean age, 76 ± 5 years; 72% women; 11% Black/African American, 4% Asian, 3% Hispanic, 7% another non-White race). Participants set a median of 12 health coach goals and 1 nurse goals. The risk factors participants chose to work on most frequently were physical activity (95%), hypertension (72%), and cognitive activity (60%). Participants reported that the most useful strategies included support and accountability from the health coach/nurse, setting small goals, and learning to manage setbacks.

CONCLUSIONS

When given support, older adults at increased risk for dementia set a wide range of goals to reduce dementia risk. A flexible, personalized approach that focuses on setting feasible goals and managing setbacks provides a useful framework for dementia risk reduction.

Cardiovascular risk of dementia is associated with brain-behaviour changes in cognitively healthy, middle-aged individuals

Alzheimer's Disease (AD) neuropathology start decades before clinical manifestations, but whether risk factors are associated with early cognitive and brain changes in midlife remains poorly understood. We examined whether AD risk factors were associated with cognition and functional connectivity (FC) between the Locus Coeruleus (LC) and hippocampus - two key brain structures in AD neuropathology - cross-sectionally and longitudinally in cognitively healthy midlife individuals. Neuropsychological assessments and functional Magnetic Resonance Imaging were obtained at baseline (N=210), and two-years follow-up (N=188). Associations of cognition and FC with apolipoprotein ε4 (APOE ε4) genotype, family history of dementia, and the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) score were investigated. Cross-sectionally, higher CAIDE scores were associated with worse cognition. Menopausal status interacted with the CAIDE risk on cognition. Furthermore, the CAIDE score significantly moderated the relationship between cognition and LC-Hippocampus FC. Longitudinally, the LC-Hippocampus FC decreased significantly over 2 years. These results suggest that cardiovascular risk of dementia is associated with brain-behaviour changes in cognitively healthy, middle-aged individuals.

A Lack of Food for Thought: Midlife Food Insecurity and Its Association With Subsequent Cognitive Ability of Older Americans

OBJECTIVES

The 50-59 age group in the United States experience higher levels of food insecurity (FI) compared to older adults. While previous research has identified an association between FI and cognition outcomes in older populations, limited research has examined midlife as a specific FI exposure window and the association of this hardship with long-run cognition outcomes.

METHODS

Utilizing 14 waves of Health and Retirement Study (HRS) data (1995-2020), I applied mixed-effects models to assess the relationship between midlife FI exposure and later-life cognitive function, controlling for childhood disadvantages and other health-related and sociodemographic characteristics.

RESULTS

Findings indicate that both cumulative FI duration and ever experiencing FI during ages 50-59 are significantly associated with subsequent cognitive decline. Specifically, ever experiencing FI during midlife was linked to a decrease in cognitive function by 0.07 standard units (95% confidence interval [CI], -0.13 to -0.003; p < .05). In addition, each additional year of FI exposure during midlife was associated with a reduction in cognitive function by 0.01 standard units (95% CI: -0.03 to -0.003; p < .05). These associations remained robust even after accounting for a range of potential confounders and covariates.

DISCUSSION

The findings support the cumulative inequality model, suggesting that midlife FI is a significant predictor of lower cognitive function in later life. Both the timing and extent of FI during midlife are crucial factors in shaping cognitive health outcomes. Policy interventions targeting FI in the 50-59 age group could play a pivotal role in promoting healthy aging and mitigating cognitive decline in older adulthood.

Effects of age on the relationship between sleep quality and cognitive performance: Findings from the Human Connectome Project-Aging cohort

BACKGROUND

The association between sleep quality and cognition is widely established, but the role of aging in this relationship is largely unknown.

OBJECTIVE

To examine how age impacts the sleep-cognition relationship and determine whether there are sensitive ranges when the relationship between sleep and cognition is modified. This investigation could help identify individuals at risk for sleep-related cognitive impairment.

SUBJECTS

Sample included 711 individuals (ages 36.00-89.83, 59.66 ± 14.91, 55.7 % female) from the Human Connectome Project-Aging (HCP-A).

METHODS

The association between sleep quality (Pittsburgh Sleep Quality Index, PSQI) and cognition (Crystallized Cognition Composite and Fluid Cognition Composite from the NIH Toolbox, the Trail Making Test, TMT, and the Rey Auditory Verbal Learning Test, RAVLT) was measured using linear regression models, with sex, race, use of sleep medication, hypertension, and years of education as covariates. The interaction between sleep and age on cognition was tested using the moderation analysis, with age as both continuous linear and nonlinear (quadratic) terms.

RESULTS

There was a significant interaction term between the PSQI and nonlinear age term (age2) on TMT-B (p = 0.02) and NIH Toolbox crystallized cognition (p = 0.02), indicating that poor sleep quality was associated with worse performance on these measures (sensitive age ranges 50-75 years for TMT-B and 66-70 years for crystallized cognition).

CONCLUSIONS

The sleep-cognition relationship may be modified by age. Individuals in the middle age to early older adulthood age band may be most vulnerable to sleep-related cognitive impairment.

Dementia risk scores, apolipoprotein E, and risk of Alzheimer's disease: One size does not fit all

INTRODUCTION

Evaluating the generalizability of dementia risk scores, primarily developed in non-Latinx White (NLW) participants, and interactions with genetic risk factors in diverse populations is crucial for addressing health disparities.

METHODS

We analyzed the association of the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) and modified CAIDE (mCAIDE) scores with dementia risk using logistic regression models stratified by race/ethnicity in National Alzheimer's Coordinating Center (NACC) and Alzheimer's Disease Neuroimaging Initiative (ADNI), and assessed their interaction with apolipoprotein E (APOE).

RESULTS

Higher CAIDE scores were associated with an increased risk of dementia in Asian, Latinx, and NLW participants but not in Black participants. In contrast, higher mCAIDE scores were also associated with an increased risk of dementia in Black participants. Unfavorable mCAIDE risk profiles exacerbated the apolipoprotein E*ε4 (APOE*ε4) risk effect and attenuated the APOE*ε2 protective effect.

DISCUSSION

Our findings underscore the importance of evaluating the validity of dementia risk scores in diverse populations for their use in personalized medicine approaches to promote brain health.

HIGHLIGHTS

Dementia risk scores demonstrate race/ethnic-specific effects on dementia risk. Unfavorable modifiable risk profiles moderate the effect of APOE on dementia risk. Dementia risk scores need to be validated in diverse populations.

Informing cognitively healthy research participants of modifiable dementia risk factors: Ethical implications

Research has shown that up to 40% of dementia incidence can be accounted for by 12 modifiable lifestyle risk factors. However, the predictive value of these risks factors at an individual level remains uncertain. Ethical considerations that are typically invoked with respect to the disclosure of individual research results-beneficence and non-maleficence, respect for autonomy, and justice-do not provide conclusive justification for, or against, disclosing modifiable risk factors for future dementia to cognitively unimpaired research participants. We argue for a different approach to evaluating the disclosure of individual-level modifiable risk factors for dementia. Rather than focusing on individual-level disease prediction and prevention, we suggest that disclosure should be evaluated based on the impact of behavioral and lifestyle changes on current brain health.

Age-dependent sex differences in cofilin1 pathway (LIMK1/SSH1) and its association with AD biomarkers after chronic systemic inflammation in mice

Chronic systemic inflammation (CSI) results in neuroinflammation and neurodegeneration. Cofilin1 is a stress protein that activates microglia and induces neuroinflammation, but its role in CSI at different aging stages remains unidentified. Therefore, the study aims to identify cofilin1 and its upstream regulators LIMK1 and SSH1 after CSI in young-, middle-, and advanced-aged mice. CSI was induced by injecting the male and female mice with a sub-lethal dose of Lipopolysaccharide weekly for six weeks. The results showed that normal male mice did not show cofilin pathway dysregulation, but a significant dysregulation was observed in CSI advanced-aged mice. In females, cofilin1 dysregulation was observed in healthy and CSI advanced-aged mice, while significant cofilin1 dysregulation was observed in middle-aged mice during CSI. Furthermore, cofilin1 pathway dysregulations correlated with Alzheimer's disease (AD) biomarkers in the brain and saliva, astrocyte activation, synaptic degeneration, neurobehavioral impairments, gut-microbiota abnormalities, and circulatory inflammation. These results provide new insights into cofilin1 sex and age-dependent mechanistic differences that might help identify targets for modulating neuroinflammation and early onset of AD.

Association of amyloid and cardiovascular risk with cognition: Findings from KBASE

BACKGROUND

Limited research has explored the effect of cardiovascular risk and amyloid interplay on cognitive decline in East Asians.

METHODS

Vascular burden was quantified using Framingham's General Cardiovascular Risk Score (FRS) in 526 Korean Brain Aging Study (KBASE) participants. Cognitive differences in groups stratified by FRS and amyloid positivity were assessed at baseline and longitudinally.

RESULTS

Baseline analyses revealed that amyloid-negative (Aβ-) cognitively normal (CN) individuals with high FRS had lower cognition compared to Aβ- CN individuals with low FRS (p < 0.0001). Longitudinally, amyloid pathology predominantly drove cognitive decline, while FRS alone had negligible effects on cognition in CN and mild cognitive impairment (MCI) groups.

CONCLUSION

Our findings indicate that managing vascular risk may be crucial in preserving cognition in Aβ- individuals early on and before the clinical manifestation of dementia. Within the CN and MCI groups, irrespective of FRS status, amyloid-positive individuals had worse cognitive performance than Aβ- individuals.

HIGHLIGHTS

Vascular risk significantly affects cognition in amyloid-negative older Koreans. Amyloid-negative CN older adults with high vascular risk had lower baseline cognition. Amyloid pathology drives cognitive decline in CN and MCI, regardless of vascular risk. The study underscores the impact of vascular health on the AD disease spectrum.

APOE4 and Chronic Health Risk Factors are Associated with Sex-Specific Preclinical Alzheimer's Disease Neuroimaging Biomarkers

Introduction

Two thirds of Alzheimer's disease (AD) patients are female. Genetic and chronic health risk factors for AD affect females more negatively compared to males.

Objective

This exploratory multimodal neuroimaging study aimed to examine sex differences in cognitively unimpaired older adults on: (1) amyloid-β via 18F-AV-45 Florbetapir PET imaging, (2) neurodegeneration via T1 weighted MRI volumetrics, (3) cerebral blood flow via ASL-MRI. We identified AD risk factors including genetic (APOE genotype status) and health markers (fasting glucose, mean arterial pressure, waist-to-hip ratio, and android and gynoid body fat) associated with neuroimaging outcomes for which we observed sex differences.

Methods

Participants were sedentary, amyloid-β positive older adults (N = 112, ages 65-87 years) without evidence of cognitive impairment (CDR = 0).

Results

Multivariate analysis of covariance models adjusted for intracranial volume, age, and years of education demonstrated lower volume (F (7, 102) = 2.67, p = 0.014) and higher blood flow F (6, 102) = 4.25, p =<0.001) among females compared to males in regions of interest connected to AD pathology and the estrogen receptor network. We did not observe sex differences in amyloid-β levels. Higher than optimal waist to hip ratio was most strongly associated with lower volume, while higher android fat percentage and APOE ε4 carrier status were most strongly associated with higher blood flow among female participants.

Discussion

Findings suggest genetic and chronic health risk factors are associated with sex-specific AD neuroimaging biomarkers. Underlying sex-specific biological pathways may explain these findings. Our results highlight the importance of considering sex differences in neuroimaging studies and when developing effective interventions for AD prevention and risk reduction.

A Mindfulness-Based Lifestyle Intervention for Dementia Risk Reduction: Protocol for the My Healthy Brain Feasibility Randomized Controlled Trial

BACKGROUND

Lifestyle behavior change and mindfulness have direct and synergistic effects on cognitive functioning and may prevent Alzheimer disease and Alzheimer disease-related dementias (AD/ADRD). We are iteratively developing and testing My Healthy Brain (MHB), the first mindfulness-based lifestyle group program targeting AD/ADRD risk factors in older adults with subjective cognitive decline. Our pilot studies (National Institutes of Health [NIH] stage 1A) have shown that MHB is feasible, acceptable, and associated with improvement in lifestyle behavior and cognitive outcomes.

OBJECTIVE

We will compare the feasibility of MHB versus an education control (health enhancement program [HEP]) in 50 older adults (aged ≥60 y) with subjective cognitive decline and AD/ADRD risk factors. In an NIH stage 1B randomized controlled trial (RCT), we will evaluate feasibility benchmarks, improvements in cognitive and lifestyle outcomes, and engagement of hypothesized mechanisms.

METHODS

We are recruiting through clinics, flyers, web-based research platforms, and community partnerships. Participants are randomized to MHB or the HEP, both delivered in telehealth groups over 8 weeks. MHB participants learn behavior modification and mindfulness skills to achieve individualized lifestyle goals. HEP participants receive lifestyle education and group support. Assessments are repeated after the intervention and at a 6-month follow-up. Our primary outcomes are feasibility, acceptability, appropriateness, credibility, satisfaction, and fidelity benchmarks. The secondary outcomes are cognitive function and lifestyle (physical activity, sleep, nutrition, alcohol and tobacco use, and mental and social activity) behaviors. Data analyses will include the proportion of MHB and HEP participants who meet each benchmark (primary outcome) and paired samples 2-tailed t tests, Cohen d effect sizes, and the minimal clinically important difference for each measure (secondary outcomes).

RESULTS

Recruitment began in January 2024. We received 225 inquiries. Of these 225 individuals, 40 (17.8%) were eligible. Of the 40 eligible participants, 21 (52.5%) were enrolled in 2 group cohorts, 17 (42.5%) were on hold for future group cohorts, and 2 (5%) withdrew before enrollment. All participants have completed before the intervention assessments. All cohort 1 participants (9/21, 43%) have completed either MHB or the HEP (≥6 of 8 sessions) and after the intervention assessments. The intervention for cohort 2 (12/21, 57%) is ongoing. Adherence rates for the Garmin Vivosmart 5 (128/147, 87.1% weeks) and daily surveys (105/122, 86.1% weeks) are high. No enrolled participants have dropped out. Enrollment is projected to be completed by December 2024.

CONCLUSIONS

The RCT will inform the development of a larger efficacy RCT (NIH stage 2) of MHB versus the HEP in a more diverse sample of older adults, testing mechanisms of improvements through theoretically driven mediators and moderators. The integration of mindfulness with lifestyle behavior change in MHB has the potential to be an effective and sustainable approach for increasing the uptake of AD/ADRD risk reduction strategies among older adults.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05934136; https://www.clinicaltrials.gov/study/NCT05934136.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/64149.

The Combined Impact of Physical Activity and Sedentary Behavior on Executive Functions in Older Adults: A Cross-Sectional Study

Background

The interplay between physical activity (PA) and sedentary behavior (SB) significantly influences cognitive health in older adults, with executive functions (EFs) being particularly vulnerable to lifestyle factors. However, previous research on older adults focused mainly on PA and is limited due to the lack of comprehensive consideration of other factors that influence EFs. Current guidelines suggest an association between sedentary behavior (SB) and EFs, yet few studies have examined the combined effects of PA and SB on EFs.

Objective

This cross-sectional study aimed to explore the relationship between PA, SB, and EFs in older adults.

Methods

A total of 116 healthy older adults aged ≥65 years were recruited and categorized into four groups based on activity lifestyles: higher PA and higher SB (PHSH); higher PA and lower SB (PHSL); lower PA and higher SB (PLSH); and lower PA and lower SB (PLSL). EFs were assessed using the Tower of London (TOL) task and the Stroop test, which measure high-order EFs (planning and problem-solving) and core EFs (inhibitory control), respectively.

Results

The PHSL group performed better on the TOL task, with lower total move scores and shorter total problem-solving times, compared to the PLSH group. The total move score of the PLSL group was better, and the total problem-solving time of the PHSH group was shorter than those of the PLSH group. However, the Stroop test scores did not differ between the four groups.

Conclusion

These findings suggest that increasing PA or reducing SB selectively enhances executive functions, particularly in planning and problem-solving, while less impacting inhibitory control in older adults. This highlights the importance of considering the nuanced effects of PA and SB on different aspects of executing functioning in older adults.

Poststroke seizures and epilepsy increase the risk of dementia among stroke survivors: A population-based study

OBJECTIVE

With global aging, the occurrence of stroke and associated outcomes like dementia are on the rise. Seizures and epilepsy are common poststroke complications and have a strong connection to subsequent dementia. This study examines the relationship between poststroke seizures (PSS) or poststroke epilepsy (PSE) and dementia using a national health care database.

METHODS

We conducted a retrospective study using data from the Taiwan National Health Insurance Research Database from 2009 to 2020. We identified acute stroke patients from 2010 to 2015, excluding those with pre-existing neurological conditions. Based on age, sex, stroke severity level, and the year of index stroke, patients with PSS or PSE were matched to those without. The main outcome was incident dementia.

RESULTS

This study included 62 968 patients with an average age of 63 years, with males accounting for 62.9%. Of them, 60.3% had ischemic strokes, and 39.7% had hemorrhagic strokes. After an average follow-up period of 5.2 years, dementia developed in 15.9% of patients who had PSS or PSE, as opposed to 8.4% of those without these conditions. A time-dependent Fine and Gray competing risk analysis showed that PSS and PSE were significantly associated with dementia across all stroke types. Subgroup analyses revealed significantly increased risk of dementia across all age groups (<50, 50-64, and ≥65 years), sexes, and various stroke severity levels. The link between PSS or PSE and dementia was particularly pronounced in men, with a less distinct correlation in women.

SIGNIFICANCE

The risk of incident dementia was higher in patients with PSS or PSE. The potential for therapeutic interventions for seizures and epilepsy to reduce poststroke dementia underscores the importance of seizure screening and treatment in stroke survivors.

The early diagnosis of Alzheimer's disease: Blood-based panel biomarker discovery by proteomics and metabolomics

Diagnosis and prediction of Alzheimer's disease (AD) are increasingly pressing in the early stage of the disease because the biomarker-targeted therapies may be most effective. Diagnosis of AD largely depends on the clinical symptoms of AD. Currently, cerebrospinal fluid biomarkers and neuroimaging techniques are considered for clinical detection and diagnosis. However, these clinical diagnosis results could provide indications of the middle and/or late stages of AD rather than the early stage, and another limitation is the complexity attached to limited access, cost, and perceived invasiveness. Therefore, the prediction of AD still poses immense challenges, and the development of novel biomarkers is needed for early diagnosis and urgent intervention before the onset of obvious phenotypes of AD. Blood-based biomarkers may enable earlier diagnose and aid detection and prognosis for AD because various substances in the blood are vulnerable to AD pathophysiology. The application of a systematic biological paradigm based on high-throughput techniques has demonstrated accurate alterations of molecular levels during AD onset processes, such as protein levels and metabolite levels, which may facilitate the identification of AD at an early stage. Notably, proteomics and metabolomics have been used to identify candidate biomarkers in blood for AD diagnosis. This review summarizes data on potential blood-based biomarkers identified by proteomics and metabolomics that are closest to clinical implementation and discusses the current challenges and the future work of blood-based candidates to achieve the aim of early screening for AD. We also provide an overview of early diagnosis, drug target discovery and even promising therapeutic approaches for AD.

Intersectionality of gender with social determinants of health and asymptomatic Alzheimer's disease neuropathology

BACKGROUND

Women comprise approximately two-thirds of Alzheimer's disease cases.

OBJECTIVE

This is the first known study to investigate the role of intersectionality between gender and other social determinants of health (SDOH) in the presentation of cognitive symptoms (i.e., being asymptomatic or symptomatic) among those with pathologically confirmed Alzheimer's disease.

METHODS

We studied 3107 individuals with Alzheimer's disease neuropathology (ADNP) confirmed at autopsy. Asymptomatic ADNP was defined as the absence of a clinical diagnosis of mild cognitive impairment (MCI) or dementia before death (versus symptomatic: diagnosis of MCI/dementia). SDOH included gender, education, ethnoracial group, living alone, and primary language. Multivariable logistic regression tested associations between SDOH and asymptomatic ADNP (versus symptomatic); models were also stratified by gender.

RESULTS

Women, Hispanics, those living alone, and more educated individuals were found to have higher odds of asymptomatic ADNP. Non-English speakers had lower odds of asymptomatic ADNP. Both women and men had higher odds of asymptomatic ADNP if Hispanic or living alone. In only women, non-English speakers had lower odds while in only men, more education was associated with higher odds of asymptomatic ADNP.

CONCLUSIONS

Gender, education, ethnicity, primary language, and living alone, and intersectionality of gender with primary language, may differentially influence MCI and dementia diagnosis prior to death among those with underlying ADNP. These findings emphasize the need for future Alzheimer's disease research to prioritize social determinants of brain health including their intersectionality with gender and how to inform targeted interventions.

Effects of exercise on brain-derived neurotrophic factor in Alzheimer's disease models: A systematic review and meta-analysis

A growing body of research examining effects of exercise on brain-derived neurotrophic factor (BDNF) in Alzheimer's disease (AD) models, while due to differences in gender, age, disease severity, brain regions examined, and type of exercise intervention, findings of available studies were conflicting. In this study, we aimed to evaluate current evidence regarding effects of exercise on BDNF in AD models. Searches were performed in PubMed, Web of Science, Cochrane, and EBSCO electronic databases, through July 20, 2023. We included studies that satisfied the following criteria: eligible studies should (1) report evidence on experimental work with AD models; (2) include an exercise group and a control group (sedentary); (3) use BDNF as the outcome indicator; and (4) be randomized controlled trials (RCTs). From 1196 search records initially identified, 36 studies met the inclusion criteria. There was a significant effect of exercise on increasing BDNF levels in AD models [standardized mean differences (SMD) = 0.98, P < 0.00001]. Subgroup analysis showed that treadmill exercise (SMD = 0.92, P< 0.0001), swimming (SMD = 1.79, P< 0.0001), and voluntary wheel running (SMD = 0.51, P= 0.04) were all effective in increasing BDNF levels in AD models. In addition, exercise significantly increased BDNF levels in the hippocampus (SMD = 0.92, P< 0.00001) and cortex (SMD = 1.56, P= 0.02) of AD models. Exercise, especially treadmill exercise, swimming, and voluntary wheel running, significantly increased BDNF levels in hippocampus and cortex of AD models, with swimming being the most effective intervention type.

Boosting Brain Health: Interventions for the Prevention and Treatment of Mild Cognitive Impairment and Early Neurodegenerative Disease

Mild Cognitive Impairment (MCI) and dementia are becoming more common with an aging population, and the numbers are expected to rise. These conditions can have a significant impact on patients, family, and health care systems. Lifestyle changes including physical activity, nutrition, quality sleep, socialization, cognitive activity and mental stimulation, routine medical care, and mental health care have the potential to prevent cognitive and functional decline and optimize daily living in all individuals, including those with MCI and early neurodegenerative disease. Brain Boosters is an important group intervention used to provide psychoeducation on lifestyle factors and strategies that can improve brain health, cognition, and functioning.