The Value of Delaying Alzheimer's Disease Onset

Patterns of Factors in the National Institute on Aging Health Disparities Research Framework Domains and Mild Cognitive Impairment Risk

Introduction

Alzheimer's disease and related dementias are public health and social care challenges. This study used the National Institute on Aging Health Disparities Research Framework to organize potential cognitive impairment risk factors. It aimed to examine patterns of environmental, sociocultural, behavioral, and biological factors and identify key components that predict mild cognitive impairment risk.

Methods

This study comprised 2,812 participants from the Mayo Clinic Study of Aging who were cognitively unimpaired at baseline (aged ≥50 years, mean age [SD]=68.9 [9.7] years, 50.4% female). Analyses utilized a 2-stage approach using factor and principal component analyses to group factors from multiple National Institute on Aging Health Disparities Research Framework domains and identify components that predict cognitive impairment risk. Using a cohort study design, the resulting composite scores were considered as covariates for incident mild cognitive impairment analysis using Cox proportional hazards models.

Results

Three principal components explained 40.30% of the variance and were differentially associated with mild cognitive impairment risk. One component (Principal Component 2), which included factors from all 4 domains of the National Institute on Aging Health Disparities Research Framework (including social, group, and playing game activities [sociocultural domain]; exercise and physical activity [behavioral domain]; education/occupation [environmental domain]; and absence of cardiometabolic risk factors/health self-rating [biological domain]), was associated with lower mild cognitive impairment risk (hazard ratio=0.80, 95% CI=0.73, 0.89). The other 2 principal components, also including factors from multiple framework domains, were associated with increased mild cognitive impairment risk.

Conclusions

Derived principal components included factors from multiple framework domains, supporting the multietiology pathways leading to cognitive impairment. These principal components were differentially associated with mild cognitive impairment risk. Identifying key factors from multiple National Institute on Aging Health Disparities Research Framework domains associated with cognitive impairment risk has implications for effectively targeting interventions at multiple levels (e.g., medical, societal, policy) to avert or delay cognitive impairment risk.

Topological influence of immediate-early genes in brain genetic networks and their link to Alzheimer's disease

Immediate-early genes (IEGs), a subset of activity-regulated genes (ARGs), are rapidly and transiently activated by neuronal activity independent of protein synthesis. While extensively researched, the role of IEGs within genetic networks and their potential as drug targets for brain diseases remain underexplored. This study aimed to investigate the topological influence of IEGs within genetic networks and explore their relevance to Alzheimer's disease (AD). To achieve this, we employed a multi-step approach: mouse ARG data were analysed and mapped to human genes to identify the topological properties that distinguish IEGs from other ARGs; the involvement of ARGs in biological pathways and diseases and their mutational constraints were examined; ARG-related variants in AD were assessed using genome-wide association study (GWAS) summary statistics and functional analysis; and network and GWAS findings were integrated to identify ARG-AD-associated genes. Our key findings were: (1) IEGs exhibit significantly higher topological influence across human and mouse gene networks compared to other ARGs; (2) ARGs are less frequently involved in diseases and exhibit higher mutational constraint than non-ARGs; (3) Several AD-associated variants are located in ARG regions, particularly in MARK4 near FOSB, with an AD risk eQTL that increases MARK4 expression in cortical areas; (4) MARK4 emerges as a key node in a dense AD multi-omic network and exhibits a high druggability score. These findings underscore the influential role of IEGs within genetic networks, providing valuable insights into their potential as intervention points for diseases characterised by downstream dysregulation, with MARK4 emerging as a promising and underexplored target for AD.

Pattern-VEP findings in individuals with mild cognitive impairment

BACKGROUND

Visual evoked potential (VEP) is a technique used to evaluate the electrical response of the brain to visual stimuli. This study aimed to examine neural transmission in the visual pathway by VEP test in individuals with mild cognitive impairment (MCI) and compare it with age-appropriate controls and also investigate for a correlation between VEP parameters and cognitive test domains.

METHODS

The groups consisted of 56 MCI and 50 healthy volunteers, aged 60-80 years, matched for age and education. Mini-Mental State Examination (MMSE) was applied to the participants for cognitive assessment. Patients were also subjected to other dementia screening tests and other treatable causes were excluded. In addition, groups were formed from those who completed the test. The pattern-reversal VEP method was used in this study.

RESULTS

The mean MMSE score in the MCI group was 21.42 ± 1.55 points. Our findings showed that individuals with MCI had a longer left P100 latency compared to controls (p = 0.027). In addition, right N75-P100 and right P100-N145 amplitudes of VEP parameters were found to be positively correlated with the recall test, which is one of the MMSE domains (p < 0.05, rho: 0.399,0.314).

CONCLUSION

The evidence provided by this study supports the possibility of using pattern VEP with clinical parameters to evaluate MCI patients. In addition, a positive correlation between interpeak amplitudes and the recall test highlights the importance of the VEP test in these patients.

Feasibility of Telephone-Based Cognitive Assessments and Healthcare Utilization in US Medicare-Enrolled Older Adults Following Emergency Department Discharge

BACKGROUND

Wider screening and assessment for Alzheimer's disease and other related dementias (ADRD) may increase access to supportive care, improve allocation of medical care, and foster the use of interventions that prevent or delay disease progression. Yet, the effect of diagnostic timing on clinical and utilization outcomes is poorly understood. Community-based settings such as a hospital emergency department (ED) may be an underrecognized opportunity to assess cognition and impacts on individuals and health systems. This study assessed the feasibility of recruiting older adults for telephone-based trials following presentation to the ED and administering telephone based cognitive assessments over the phone in this population.

METHODS

Medicare-enrolled individuals 65+ years of age (n = 160) presenting to the Oregon Health & Science University Emergency Department (Portland, Oregon) between May 2022 and February 2023 were recruited by telephone. Participants were administered the Telephone Interview for Cognitive Status (TICS) Assessment and the Patient Reported Outcomes Measurement Information System (PROMIS) Cognitive Measure Questions on Mental Clarity via telephone 1-12 weeks post-discharge to evaluate cognition. Electronic medical records (EMR) were reviewed for medical care utilization including primary care provider (PCP) visits, hospital admissions, and ED visits for the 3 years prior to ED presentation.

RESULTS

Twenty-six percent of eligible ED users contacted elected for study enrollment. The TICS Assessment score had a significant relationship with the three evaluated health care utilization measures (ED, PCP visits, or hospitalizations); the PROMIS Assessment had significant but weak correlations to ED and PCP visits.

CONCLUSIONS

Older adults 65+ years presenting to the ED are amenable to enroll in telephone-based cognition-focused trials and cognitive assessments can be carried out over the telephone in this population. The PROMIS Assessment may be a better cognition assessment tool when evaluating for cognition and care utilization in this population. In addition to the limits of the screening tools used in this study, a lack of a representative sample is a limitation of the study design. Future studies could use other validated cognitive assessment tools and utilize a study design with a recruitment strategy focused on obtaining a representative sample of older ED patients.

Design, synthesis, in vitro, and in silico study of benzothiazole-based compounds as a potent anti-Alzheimer agent

Alzheimer's disease (AD) is a multifactorial neurological disorder that involves multiple enzymes in the process of developing. Conventional monotherapies provide relief, necessitating alternative multi-targeting approaches to address AD complexity. Therefore, we synthesize N-(benzo[d]thiazol-2-yl) benzamide-based compounds and tested against monoamine oxidases (MAO-A and MAO-B). In the in vitro experimental evaluation of MAO, all the compounds displayed remarkable potency, having IC50 values in the lower micromolar range. The most potent MAO-A inhibitor was (3e) with an IC50 value of 0.92 ± 0.09 μM, whereas, (3d) was the most potent inhibitor of MAO-B with an IC50 value of 0.48 ± 0.04 μM. Moreover, Enzyme kinetics studies revealed that the potent inhibitors of MAO-A and MAO-B showed competitive mode of inhibition. Furthermore, molecular docking studies were also performed to confirm the mode of inhibition and obtain an intuitive picture of potent inhibitors. It also revealed several important interactions, particularly hydrogen bonding interaction. All the newly synthesized compounds showed good ADME pharmacokinetic profile and followed Lipinski rule; these compounds represent promising hits for the development of promising lead compounds for AD treatment.

Longitudinal Analysis of Electronic Health Records Reveals Medical Conditions Associated with Subsequent Alzheimer's Disease Development

Background

Several health conditions are known to increase the risk of Alzheimer's disease (AD). We aim to systematically identify medical conditions that are associated with subsequent development of AD by leveraging the growing resources of electronic health records (EHRs).

Methods

This retrospective cohort study used de-identified EHRs from two independent databases (MarketScan and VUMC) with 153 million individuals to identify AD cases and age- and gender-matched controls. By tracking their EHRs over a 10-year window before AD diagnosis and comparing the EHRs between AD cases and controls, we identified medical conditions that occur more likely in those who later develop AD. We further assessed the genetic underpinnings of these conditions in relation to AD genetics using data from two large-scale biobanks (BioVU and UK Biobank, total N=450,000).

Results

We identified 43,508 AD cases and 419,455 matched controls in MarketScan, and 1,320 AD cases and 12,720 matched controls in VUMC. We detected 406 and 102 medical phenotypes that are significantly enriched among the future AD cases in MarketScan and VUMC databases, respectively. In both EHR databases, mental disorders and neurological disorders emerged as the top two most enriched clinical categories. More than 70 medical phenotypes are replicated in both EHR databases, which are dominated by mental disorders (e.g., depression), neurological disorders (e.g., sleep orders), circulatory system disorders (e.g. cerebral atherosclerosis) and endocrine/metabolic disorders (e.g., type 2 diabetes). We identified 19 phenotypes that are either associated with individual risk variants of AD or a polygenic risk score of AD.

Conclusions

In this study, analysis of longitudinal EHRs from independent large-scale databases enables robust identification of health conditions associated with subsequent development of AD, highlighting potential opportunities of therapeutics and interventions to reduce AD risk.

Perceptions About Dyadic Physical Activity Intervention for Rural-Dwelling People With Cognitive Impairment

BACKGROUND/OBJECTIVES

Rural populations face an elevated risk of Alzheimer's disease and related dementias partially attributed to modifiable risk factors such as physical inactivity. The study gathered key community partners' perspectives about (a) feasibility of implementing the telerehabilitation physical activity behavioral (TPAB) intervention, a virtual program aimed at increasing daily stepping with sensor-based monitoring, and (b) necessary adaptions for implementation for rural-dwelling people with cognitive impairment and care partners (dyads).

METHODS

Eleven rural-dwelling individuals (three medical providers, four older adults, and four care partners of individuals with mild cognitive impairment) in Nebraska were recruited for a focus group via fliers and word of mouth. The person-based approach was used to gain the perspectives of participants during a 1-hr group discussion regarding six dimensions of feasibility. Session transcriptions were analyzed using thematic analysis.

RESULTS

Participants highlighted the need to improve physical activity in the community and supported care partners receiving TPAB alongside individuals with mild cognitive impairment. Suggested modifications to TPAB included, establishing a local champion, integrating local resources, involving primary care providers, setting recruitment deadlines, using participant testimonies for recruitment, and emphasizing program individualization.

CONCLUSION

Overall, participants perceived TPAB was practical, feasible, and necessary for rural-dwelling participants with cognitive impairment and their care partners; however, several adaptations and the creation of the Cognitive Impairment Rural Community-TPAB are required to optimize rural implementation. Significance/Implications: There is an identified need for the TPAB intervention with outlined redesign approaches to facilitate intervention development and rural implementation.

Psychological Stress and Cognitive Brain Health: Policies to Reduce Dementia Risk

Alzheimer's disease and related dementias (ADRD) pose a massive public health challenge, affecting over 6.7 million Americans aged 65 and older-a number projected to double by 2050. Despite advances in pharmacological treatments, there remains no cure or method to reverse the disease. This paper highlights the role of psychological stress as a critical yet underappreciated risk factor for cognitive decline and reviews its complex interplay with behavioral, social, and biological mechanisms. Chronic psychological stress drives physiological and behavioral changes that are linked to accelerated cognitive deterioration, particularly in older adults. Early interventions can target stress management and behavioral prevention strategies, which include physical activity, healthy diet, and social engagement. Further, key barriers to meaningful policy change to prevent and slow ADRD include lack of public awareness, stigma around mental health and aging, and misaligned funding incentives. Policy initiatives can improve brain health literacy, increase equitable access to services, and enhance community-level and environmental factors to promote healthy aging. Prioritizing stress reduction and promoting early detection and prevention can meaningfully reduce ADRD risk and progression, improving public health broadly.

Blood DNA methylation signature for incident dementia: Evidence from longitudinal cohorts

INTRODUCTION

Distinguishing between molecular changes that precede dementia onset and those resulting from the disease is challenging with cross-sectional studies.

METHODS

We studied blood DNA methylation (DNAm) differences and incident dementia in two large longitudinal cohorts: the Offspring cohort of the Framingham Heart Study (FHS) and the Alzheimer's Disease Neuroimaging Initiative (ADNI) study. We analyzed blood DNAm samples from > 1000 cognitively unimpaired subjects.

RESULTS

Meta-analysis identified 44 CpGs and 44 differentially methylated regions consistently associated with time to dementia in both cohorts. Our integrative analysis identified early processes in dementia, such as immune responses and metabolic dysfunction. Furthermore, we developed a methylation-based risk score, which successfully predicted future cognitive decline in an independent validation set, even after accounting for age, sex, apolipoprotein E ε4, years of education, baseline diagnosis, and baseline Mini-Mental State Examination score.

DISCUSSION

DNAm offers a promising source as a biomarker for dementia risk assessment.

HIGHLIGHTS

Blood DNA methylation (DNAm) differences at individual CpGs and differentially methylated regions are significantly associated with incident dementia. Pathway analysis revealed DNAm differences associated with incident dementia are significantly enriched in biological pathways involved in immune responses and metabolic processes. Out-of-sample validation analysis demonstrated that a methylation-based risk score successfully predicted future cognitive decline in an independent dataset, even after accounting for age, sex, apolipoprotein E ε4, years of education, baseline diagnosis, and baseline Mini-Mental State Examination score.

Sense of purpose in life and extending the cognitive healthspan: evidence from multistate survival modeling

Having a sense of purpose in life predicts better maintenance of cognitive function in older adulthood and reduced risk of mild cognitive impairment (MCI) and dementia. However, little research has examined its influence on the rate of cognitive decline and length of cognitive healthspan. This study evaluated the role of sense of purpose on the risk and timing of transitions between normal cognition, MCI, and dementia. Older adults from the Memory and Aging Project (MAP; n = 1821) and the Health and Retirement Study (HRS; n = 10,542) were followed annually for 19 years and biennially for 12 years, respectively. Multistate survival models assessed whether sense of purpose predicted transitions across normal cognition, MCI, dementia, and death. More purposeful older adults had lower risk of developing MCI (HR = 0.82 in MAP; HR = 0.93 in HRS), higher likelihood of cognitive improvement, and longer cognitively healthy life expectancies. Results suggest sense of purpose may extend the cognitive healthspan.

Association of Dementia Severity at Diagnosis With Health Care Utilization and Costs Around the Time of Incident Diagnosis

Background and Objectives

This study provides the first analysis of heterogeneity in health care use and costs by level of dementia symptom severity around the time of incident dementia diagnosis for a population-representative sample of older Americans.

Research Design and Methods

We used the Aging, Demographics, and Memory Study (ADAMS), the Health Retirement Study (HRS), and traditional Medicare (TM) claims. We modeled dementia severity measured by the Clinical Dementia Rating scale for ADAMS respondents and applied parameter estimates to HRS respondents older than 70 years who had a claims-based incident dementia diagnosis in 2000-2016. We used claims-based measures of health care costs and use and quantified levels in the quarters before, at, and after a dementia diagnosis. We reported separate results for groups of persons diagnosed at mild, moderate, and severe stages of dementia.

Results

Health care use and costs increased a quarter before dementia diagnosis and increased most significantly in the quarter of diagnosis. Both use and costs declined thereafter but remained elevated relative to prediagnosis. This general pattern was consistent for persons diagnosed at different stages of dementia. Acute care costs were similar across dementia severity categories throughout the period, whereas outpatient use and costs were consistently higher among persons diagnosed at mild stage disease.

Discussion and Implications

Findings from this study provide new insights on how heterogeneity of dementia severity at diagnosis is associated with health care use and costs. Under the current system of care in TM, early dementia diagnosis may not substantially reduce health care use and spending around the time of dementia diagnosis.

Late-life social activity and subsequent risk of dementia and mild cognitive impairment

INTRODUCTION

Social activity is associated with better cognitive health in old age. To better translate epidemiological research for public health communication, we estimated relations of levels of social activity to average age at dementia onset.

METHODS

In the Rush Memory and Aging Project (MAP), we followed 1923 dementia-free older adults and conducted annual clinical evaluations of dementia/mild cognitive impairment (MCI).

RESULTS

During a mean follow-up of 6.7 (SD = 4.7) years, 545 participants developed dementia, and 695 developed MCI. Using Accelerated Failure Time models adjusted for age, sex, education, race/ethnicity, and marital status, we found predicted mean age of dementia onset for the least socially active was 87.7 years, approximately 5 years earlier than the most socially active (mean age = 92.2, p < .01); we found a similar 5-year difference in age at MCI onset by social activity.

DISCUSSION

Our findings highlight the value of social activity as a possible community-level intervention for reducing dementia.

HIGHLIGHTS

Accelerated failure time models estimated age at dementia onset by social activity level to aid interpretation. Higher social activity was associated with a 5-year older age at dementia onset. Economic research shows a 5-year delay translates to US$500,000 of healthcare savings per capita. Our findings help understand the public health significance of social activity.

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.

Developing Evidence-Based Health Policy for Dementia Care

This JAMA Forum discusses developments in health policy that may help address issues, including rising costs and complex care delivery, in the treatment of patients with Alzheimer disease and related dementias in the US.

Blood DNA Methylation Signature for Incident Dementia: Evidence from Longitudinal Cohorts

INTRODUCTION

Distinguishing between molecular changes that precede dementia onset and those resulting from the disease is challenging with cross-sectional studies.

METHODS

We studied blood DNA methylation (DNAm) differences and incident dementia in two large longitudinal cohorts: the Offspring cohort of the Framingham Heart Study (FHS) and the Alzheimer's Disease Neuroimaging Initiative (ADNI) study. We analyzed blood DNAm samples from over 1,000 cognitively unimpaired subjects.

RESULTS

Meta-analysis identified 44 CpGs and 44 differentially methylated regions consistently associated with time to dementia in both cohorts. Our integrative analysis identified early processes in dementia, such as immune responses and metabolic dysfunction. Furthermore, we developed a Methylation-based Risk Score, which successfully predicted future cognitive decline in an independent validation set, even after accounting for age, sex, APOE ε4, years of education, baseline diagnosis, and baseline MMSE score.

DISCUSSION

DNA methylation offers a promising source of biomarker for early detection of dementia.

Long-term cognitive training enhances fluid cognition and brain connectivity in individuals with MCI

Amnestic mild cognitive impairment (aMCI) is a risk factor for Alzheimer's disease (AD). Multi-domain cognitive training (CT) may slow cognitive decline and delay AD onset. However, most work involves short interventions, targeting single cognitive domains or lacking active controls. We conducted a single-blind randomized controlled trial to investigate the effect of a 6-month, multi-domain CT on Fluid Cognition, functional connectivity in memory and executive functioning networks (primary outcomes), and white matter microstructural properties (secondary outcome) in aMCI. Sixty participants were randomly assigned to either a multi-domain CT or crossword training (CW) group, and thirty-four participants completed the intervention. We found a significant group-by-time interaction in Fluid Cognition (p = 0.007, F (1,28) = 8.26, Cohen's d = 0.38, 95% confidence interval [CI]: 2.45-14.4), with 90% of CT patients showing post-intervention improvements (p < 0.01, Cohen's d = 0.7). The CT group also showed better post-intervention Fluid Cognition than healthy controls (HCs, N = 45, p = 0.045). Functional connectivity analyses showed a significant group-by-time interaction (Cohen's d ≥ 0.8) in the dorsolateral prefrontal cortex (DLPFC) and inferior parietal cortex (IPC) networks. Specifically, CT displayed post-intervention increases whereas CW displayed decreases in functional connectivity. Moreover, increased connectivity strength between the left DLPFC and medial PFC was associated with improved Fluid Cognition. At a microstructural level, we observed a decline in fiber density (FD) for both groups, but the CT group declined less steeply (1.3 vs. 2%). The slower decline in FD for the CT group in several tracts, including the cingulum-hippocampus tract, was associated with better working memory. Finally, we identified regions in cognitive control and memory networks for which baseline functional connectivity and microstructural properties were associated with changes in Fluid Cognition. Long-term, multi-domain CT improves cognitive functioning and functional connectivity and delays structural brain decline in aMCI (ClinicalTrials.gov number: NCT03883308).

A feasibility randomized controlled trial of a community-level physical activity strategy for older adults with motoric cognitive risk syndrome

The motoric cognitive risk syndrome (MCR) is a syndrome characterized by subjective memory complaints and slow walking speeds that can identify older adults at increased risk for developing Alzheimer's disease or a related dementia (ADRD). To date, the feasibility of community-based physical activity (PA) programs for improving outcomes in MCR have yet to be examined. To address this knowledge gap, we conducted a translational randomized controlled trial (RCT) comparing 24-weeks of PA to a healthy aging education (HE) control intervention delivered within the infrastructure of an urban senior center in Greater Boston (clincaltrials.gov identifier: NCT03750682). An existing senior center employee was trained to administer the multimodal group-based PA program that included moderate-intensity aerobic walking, strength, flexibility and balance training. A total of 79 older adults attended the senior center for a screening visit, of whom 29 met the MCR criteria and 25 were randomized to PA or HE (mean age: 74.4 ± 7 years; BMI: 32.4 ± 7 kg/m2; 85% female; 3MSE score: 92.4 ± 7; gait speed: 0.52 ± 0.1 m/s; SPPB score 4.8 ± 1.9). Due to the Covid-19 pandemic the study was stopped prematurely. Participants could successfully adhere to the study interventions (overall attendance rate: PA: 69% vs. HE:70% at study termination). Participants also successfully completed baseline and follow-up study assessments that included a computerized cognitive testing battery and objective tests of physical performance and functional exercise capacity. No study-related adverse events occurred. Notable trends for improved cognitive performance, gait speed and 6-min walk distance were exhibited in PA compared to HE. Our study provides important preliminary information to aid the design of larger-scale RCTs of PA that may help to preserve the independence of vulnerable older adults at high risk for ADRD in community-based settings.

Initial Perspectives From Rural-Residing Adults on a Digital Cognitive Health Coaching Intervention: Exploratory Qualitative Analysis

BACKGROUND

A growing body of research has examined lifestyle-based interventions for dementia prevention. Specifically, health coaching interventions have been linked to decreased risk of Alzheimer disease (AD) comorbidities, such as diabetes. Despite the association, there is a lack of research examining the efficacy and perception of digital health coaching on reducing AD risk. Understanding the perceived benefits of participating in a digital health coach program is critical to ensure long-term use, including participant adherence and engagement.

OBJECTIVE

The purpose of this study is to examine the initial attitudes toward a digital health coaching intervention aimed at preventing cognitive decline among at-risk, rural participants.

METHODS

This exploratory qualitative study is part of the ongoing Digital Cognitive Multidomain Alzheimer Risk Velocity Study (DC-MARVel; ClinicalTrials.gov NCT04559789), a 2-year randomized control trial examining the effects of a digital health coaching intervention on dementia risk, cognitive decline, and general health outcomes. Participants were recruited from the northwest region of Arkansas via word of mouth, email, local radio, and social media. At the time of the analysis, 103 participants randomly assigned to the health coaching group completed an average of 4 coaching sessions over a 4-month period. The intervention included asynchronous messages 1-2 times per week from their health coach that contained health education articles based on the participant's goals (eg, increase physical activity), unlimited access to their coach for questions and recommendations, and monthly meetings with their coach via videoconference or phone to discuss their goals. Participants were asked 2 open-ended questions, "What were your top 1 or 2 takeaways from your recent Health Coaching session?" and "Is there anything you would change about our Health Coaching sessions?" A thematic analysis was conducted using feedback responses from 80 participants (mean age, SD 7.6 years).

RESULTS

The following four themes emerged from participants' feedback: (1) healthy lifestyle and behavioral changes, (2) a sense of self-awareness through introspection, (3) value in coach support, and (4) a desire for a change in program format (eg, frequency). In total, 93% (n=74) of participants expressed that the intervention needed no changes.

CONCLUSIONS

Initial participation in the digital cognitive health coaching intervention was well received, as evidenced by participants reporting value in goal setting and strategies for healthy lifestyle and behavioral changes as well as self-reflection on their personal lifestyle choices. Feedback about their assigned coach also offers insight into the importance of the coach-participant relationship and may serve as a significant factor in overall participant success. Given the exploratory nature of this study, more robust research is needed to elicit more information from participants about their experiences to fully understand the acceptability of the digital health coaching intervention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04559789; https://clinicaltrials.gov/show/NCT04559789.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/31841.

Machine Learning Classification of Patients with Amnestic Mild Cognitive Impairment and Non-Amnestic Mild Cognitive Impairment from Written Picture Description Tasks

Individuals with Mild Cognitive Impairment (MCI), a transitional stage between cognitively healthy aging and dementia, are characterized by subtle neurocognitive changes. Clinically, they can be grouped into two main variants, namely patients with amnestic MCI (aMCI) and non-amnestic MCI (naMCI). The distinction of the two variants is known to be clinically significant as they exhibit different progression rates to dementia. However, it has been particularly challenging to classify the two variants robustly. Recent research indicates that linguistic changes may manifest as one of the early indicators of pathology. Therefore, we focused on MCI's discourse-level writing samples in this study. We hypothesized that a written picture description task can provide information that can be used as an ecological, cost-effective classification system between the two variants. We included one hundred sixty-nine individuals diagnosed with either aMCI or naMCI who received neurophysiological evaluations in addition to a short, written picture description task. Natural Language Processing (NLP) and a BERT pre-trained language model were utilized to analyze the writing samples. We showed that the written picture description task provided 90% overall classification accuracy for the best classification models, which performed better than cognitive measures. Written discourses analyzed by AI models can automatically assess individuals with aMCI and naMCI and facilitate diagnosis, prognosis, therapy planning, and evaluation.

Molecular Role of Protein Phosphatases in Alzheimer's and Other Neurodegenerative Diseases

Alzheimer's disease (AD) is distinguished by the gradual loss of cognitive function, which is associated with neuronal loss and death. Accumulating evidence supports that protein phosphatases (PPs; PP1, PP2A, PP2B, PP4, PP5, PP6, and PP7) are directly linked with amyloid beta (Aβ) as well as the formation of the neurofibrillary tangles (NFTs) causing AD. Published data reported lower PP1 and PP2A activity in both gray and white matters in AD brains than in the controls, which clearly shows that dysfunctional phosphatases play a significant role in AD. Moreover, PP2A is also a major causing factor of AD through the deregulation of the tau protein. Here, we review recent advances on the role of protein phosphatases in the pathology of AD and other neurodegenerative diseases. A better understanding of this problem may lead to the development of phosphatase-targeted therapies for neurodegenerative disorders in the near future.

Understanding the Link Between Retirement Timing and Cognition: A Scoping Review

Organization for Economic Co-operation and Development (OECD) countries have increased the age for full retirement benefits to alleviate financial pressures. Older age is linked to higher rates of cognitive impairment. Therefore, it is crucial for public policymakers to understand the relationship between retirement timing and cognition. The purpose of this scoping review was to review the retirement timing and cognition literature and to assess possible modifying factors. A search across three databases yielded a total of 10 studies. Five studies revealed mixed findings regarding the relationship between retirement timing and cognitive decline, with reported positive, negative, and null associations. In contrast, five studies found that later retirement age reduced the risk of dementia. More cross-sectional and longitudinal studies are needed to investigate modifiable factors such as job characteristics and leisure activities to clarify the mechanisms underlying the relationship between retirement timing and cognition.

2024 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including prevalence and incidence, mortality and morbidity, use and costs of care and the ramifications of AD for family caregivers, the dementia workforce and society. The Special Report discusses the larger health care system for older adults with cognitive issues, focusing on the role of caregivers and non-physician health care professionals. An estimated 6.9 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060, barring the development of medical breakthroughs to prevent or cure AD. Official AD death certificates recorded 119,399 deaths from AD in 2021. In 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death, Alzheimer's was the seventh-leading cause of death in the United States. Official counts for more recent years are still being compiled. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2021, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 140%. More than 11 million family members and other unpaid caregivers provided an estimated 18.4 billion hours of care to people with Alzheimer's or other dementias in 2023. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $346.6 billion in 2023. Its costs, however, extend to unpaid caregivers' increased risk for emotional distress and negative mental and physical health outcomes. Members of the paid health care and broader community-based workforce are involved in diagnosing, treating and caring for people with dementia. However, the United States faces growing shortages across different segments of the dementia care workforce due to a combination of factors, including the absolute increase in the number of people living with dementia. Therefore, targeted programs and care delivery models will be needed to attract, better train and effectively deploy health care and community-based workers to provide dementia care. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are almost three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 22 times as great. Total payments in 2024 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $360 billion. The Special Report investigates how caregivers of older adults with cognitive issues interact with the health care system and examines the role non-physician health care professionals play in facilitating clinical care and access to community-based services and supports. It includes surveys of caregivers and health care workers, focusing on their experiences, challenges, awareness and perceptions of dementia care navigation.

Non-Invasive Tools in Perioperative Stroke Risk Assessment for Asymptomatic Carotid Artery Stenosis with a Focus on the Circle of Willis

This review aims to explore advancements in perioperative ischemic stroke risk estimation for asymptomatic patients with significant carotid artery stenosis, focusing on Circle of Willis (CoW) morphology based on the CTA or MR diagnostic imaging in the current preoperative diagnostic algorithm. Functional transcranial Doppler (fTCD), near-infrared spectroscopy (NIRS), and optical coherence tomography angiography (OCTA) are discussed in the context of evaluating cerebrovascular reserve capacity and collateral vascular systems, particularly the CoW. These non-invasive diagnostic tools provide additional valuable insights into the cerebral perfusion status. They support biomedical modeling as the gold standard for the prediction of the potential impact of carotid artery stenosis on the hemodynamic changes of cerebral perfusion. Intraoperative risk assessment strategies, including selective shunting, are explored with a focus on CoW variations and their implications for perioperative ischemic stroke and cognitive function decline. By synthesizing these insights, this review underscores the potential of non-invasive diagnostic methods to support clinical decision making and improve asymptomatic patient outcomes by reducing the risk of perioperative ischemic neurological events and preventing further cognitive decline.

Agmatine as a novel intervention for Alzheimer's disease: Pathological insights and cognitive benefits

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by progressive cognitive decline and a significant societal burden. Despite extensive research and efforts of the multidisciplinary scientific community, to date, there is no cure for this debilitating disease. Moreover, the existing pharmacotherapy for AD only provides symptomatic support and does not modify the course of the illness or halt the disease progression. This is a significant limitation as the underlying pathology of the disease continues to progress leading to the deterioration of cognitive functions over time. In this milieu, there is a growing need for the development of new and more efficacious treatments for AD. Agmatine, a naturally occurring molecule derived from L-arginine, has emerged as a potential therapeutic agent for AD. Besides this, agmatine has been shown to modulate amyloid beta (Aβ) production, aggregation, and clearance, key processes implicated in AD pathogenesis. It also exerts neuroprotective effects, modulates neurotransmitter systems, enhances synaptic plasticity, and stimulates neurogenesis. Furthermore, preclinical and clinical studies have provided evidence supporting the cognition-enhancing effects of agmatine in AD. Therefore, this review article explores the promising role of agmatine in AD pathology and cognitive function. However, several limitations and challenges exist, including the need for large-scale clinical trials, optimal dosing, and treatment duration. Future research should focus on mechanistic investigations, biomarker studies, and personalized medicine approaches to fully understand and optimize the therapeutic potential of agmatine. Augmenting the use of agmatine may offer a novel approach to address the unmet medical need in AD and provide cognitive enhancement and disease modification for individuals affected by this disease.

The advent of Alzheimer treatments will change the trajectory of human aging

Slowing neurodegenerative disorders of late life has lagged behind progress on other chronic diseases. But advances in two areas, biochemical pathology and human genetics, have now identified early pathogenic events, enabling molecular hypotheses and disease-modifying treatments. A salient example is the discovery that antibodies to amyloid ß-protein, long debated as a causative factor in Alzheimer's disease (AD), clear amyloid plaques, decrease levels of abnormal tau proteins and slow cognitive decline. Approval of amyloid antibodies as the first disease-modifying treatments means a gradually rising fraction of the world's estimated 60 million people with symptomatic disease may decline less or even stabilize. Society is entering an era in which the unchecked devastation of AD is no longer inevitable. This Perspective considers the impact of slowing AD and other neurodegenerative disorders on the trajectory of aging, allowing people to survive into late life with less functional decline. The implications of this moment for medicine and society are profound.

Immediate-Early Genes as Influencers in Genetic Networks and their Role in Alzheimer's Disease

Immediate-early genes (IEGs) are a class of activity-regulated genes (ARGs) that are transiently and rapidly activated in the absence of de novo protein synthesis in response to neuronal activity. We explored the role of IEGs in genetic networks to pinpoint potential drug targets for Alzheimer's disease (AD). Using a combination of network analysis and genome-wide association study (GWAS) summary statistics we show that (1) IEGs exert greater topological influence across different human and mouse gene networks compared to other ARGs, (2) ARGs are sparsely involved in diseases and significantly more mutational constrained compared to non-ARGs, (3) Many AD-linked variants are in ARGs gene regions, mainly in MARK4 near FOSB, with an AD risk eQTL that increases MARK4 expression in cortical areas, (4) MARK4 holds an influential place in a dense AD multi-omic network and a high AD druggability score. Our work on IEGs' influential network role is a valuable contribution to guiding interventions for diseases marked by dysregulation of their downstream targets and highlights MARK4 as a promising underexplored AD-target.

Leisure-Time Physical Activity May Attenuate the Impact of Diabetes on Cognitive Decline in Middle-Aged and Older Adults: Findings From the ELSA-Brasil Study

OBJECTIVE

To assess leisure-time physical activity (LTPA) as a modifier of the diabetes/cognitive decline association in middle-aged and older participants in the Estudo Longitudinal de Saude do Adulto (ELSA-Brasil) study.

RESEARCH DESIGN AND METHODS

ELSA-Brasil is a cohort of 15,105 participants (age 35-74 years) enrolled between 2008 and 2010. We evaluated global cognitive function, summing the scores of six standardized tests evaluating memory and verbal fluency, including the Trail-Making Test, at baseline and follow-up. Incident cognitive impairment was defined as a global cognitive function score at follow-up lower than -1 SD from baseline mean. Participants reporting ≥150 min/week of moderate to vigorous LTPA at baseline were classified as physically active. We assessed the association of LTPA with global cognition change in those with diabetes in the context of our overall sample through multivariable regression models.

RESULTS

Participants' (N = 12,214) mean age at baseline was 51.4 (SD 8.8) years, and 55.5% were women. During a mean follow-up of 8.1 (SD 0.6) years, 9,345 (76.5%) inactive participants and 1,731 (14.1%) participants with diabetes at baseline experienced faster declines in global cognition than those who were active (β = -0.003, -0.004, and -0.002) and those without diabetes (β = -0.004, -0.005, and -0.003), respectively. Diabetes increased the risk of cognitive impairment (hazard ratio [HR] 1.71; 95% Cl 1.22, 2.39) in inactive but not in active adults (HR 1.18; 95% CI 0.73, 1.90). Among participants with diabetes, those who were active showed a delay of 2.73 (95% CI 0.94, 4.51) years in the onset of cognitive impairment.

CONCLUSIONS

In adults living with diabetes, LTPA attenuated the deleterious association between diabetes and cognitive function.

Mapping the landscape: A bibliometric analysis of information and communication technology adoption by older adults with cognitive frailty or impairment

The adoption of information and communication technology (ICT) by older adults with cognitive frailty and impairment is beneficial to support aging in place and promote healthy aging. However, data are scarce regarding the use of ICT by this demographic in comparison with other age groups. This bibliometric analysis was aimed at systematically mapping the literature on ICT-related research on older adults with cognitive frailty and cognitive impairment to provide insights into research trends, patterns and knowledge gaps. Data were extracted from the Web of Science database, which identified 324 publications between 1980 and 2023. Performance analysis and science mapping were carried out using Microsoft® Excel, VOSViewer and Harzing's Publish or Perish. The analysis showed an upsurge in the research output trend over time. Notable journals, authors, citations, nations and research areas have been documented. Four key clusters were identified, including: (i) caregiver concern, support and involvement; (ii) technology as a tool for cognitive training and cognitive rehabilitation; (iii) cognitive improvement; and (iv) the use of technology for prevention and self-management. The findings derived from this analysis provide an appropriate reference for future researchers to bridge the gap in ICT-related studies among this population, and distinguish the relevant articles that are required for further investigation. These include the need for further long-term research, the incorporation of ICT-based approaches to counter cognitive frailty and the importance of multidomain telehealth interventions. Geriatr Gerontol Int 2024; 24: 251-262.

Cost of care for Alzheimer's disease and related dementias in the United States: 2016 to 2060

Medical and long-term care for Alzheimer's disease and related dementias (ADRDs) can impose a large economic burden on individuals and societies. We estimated the per capita cost of ADRDs care in the in the United States in 2016 and projected future aggregate care costs during 2020-2060. Based on a previously published methodology, we used U.S. Health and Retirement Survey (2010-2016) longitudinal data to estimate formal and informal care costs. In 2016, the estimated per patient cost of formal care was $28,078 (95% confidence interval [CI]: $25,893-$30,433), and informal care cost valued in terms of replacement cost and forgone wages was $36,667 ($34,025-$39,473) and $15,792 ($12,980-$18,713), respectively. Aggregate formal care cost and formal plus informal care cost using replacement cost and forgone wage methods were $196 billion (95% uncertainty range [UR]: $179-$213 billion), $450 billion ($424-$478 billion), and $305 billion ($278-$333 billion), respectively, in 2020. These were projected to increase to $1.4 trillion ($837 billion-$2.2 trillion), $3.3 trillion ($1.9-$5.1 trillion), and $2.2 trillion ($1.3-$3.5 trillion), respectively, in 2060.

Targeting misfolding and aggregation of the amyloid-β peptide and mutant p53 protein using multifunctional molecules

Biomolecule misfolding and aggregation play a major role in human disease, spanning from neurodegeneration to cancer. Inhibition of these processes is of considerable interest, and due to the multifactorial nature of these diseases, the development of drugs that act on multiple pathways simultaneously is a promising approach. This Feature Article focuses on the development of multifunctional molecules designed to inhibit the misfolding and aggregation of the amyloid-β (Aβ) peptide in Alzheimer's disease (AD), and the mutant p53 protein in cancer. While for the former, the goal is to accelerate the removal of the Aβ peptide and associated aggregates, for the latter, the goal is reactivation via stabilization of the active folded form of mutant p53 protein and/or aggregation inhibition. Due to the similar aggregation pathway of the Aβ peptide and mutant p53 protein, a common therapeutic approach may be applicable.

Investigating the application of "Guttmann Cognitest"® in older adults and people with acquired brain injury

Introduction

Digital solutions for cognitive assessment are currently not only widely used in experimental contexts but can also be useful in clinical practice for efficient screening and longitudinal follow-up. The "Guttmann Cognitest"®, which includes seven computerized tasks designed to assess main cognitive functions, revealed in a previous validation study to be a potential useful tool to assess cognitive functioning in healthy middle-aged adults.

Method

Here, we present results from a validation in two different populations: one consisting of older adults, and the other comprising young and middle-aged individuals, some of them affected by acquired brain injury. To perform a convergent validity test, older adults were also administered with the MOCA, while young and middle-aged individuals were administered with a short neuropsychological assessment including gold-standard neuropsychological tests. We also conducted sensitivity and specificity analysis to establish the utility of this instrument in identifying potential cognitive dysfunctions in the two groups.

Results

Results demonstrated strong convergent validity as well as good specificity and sensitivity characteristics.

Discussion

This tool is a valid and useful instrument to assess cognitive functioning and detecting potential cases of cognitive dysfunctions in older adults and clinical populations.

Who Benefited Most from the Internet-Based Conversational Engagement RCT (I-CONECT)? Application of the Personalized Medicine Approach to a Behavioral Intervention Study

BACKGROUND

Many Alzheimer's Disease (AD) clinical trials have failed to demonstrate treatment efficacy on cognition. It is conceivable that a complex disease like AD may not have the same treatment effect due to many heterogeneities of disease processes and individual traits.

OBJECTIVES

We employed an individual-level treatment response (ITR) approach to determine the characteristics of treatment responders and estimated time saved in cognitive decline using the Internet-based Conversational Engagement Clinical Trial (I-CONECT) behavioral intervention study as a model.

DESIGN AND SETTING

I-CONECT is a multi-site, single-blind, randomized controlled trial aimed to improve cognitive functions through frequent conversational interactions via internet/webcam. The experimental group engaged in video chats with study staff 4 times/week for 6 months; the control group received weekly 10-minute check-in phone calls.

PARTICIPANTS

Out of 186 randomized participants, current study used 139 participants with complete information on both baseline and 6-month follow-up (73 with mild cognitive impairment (MCI), 66 with normal cognition; 64 in the experimental group, and 75 in the control group).

MEASUREMENTS

ITR scores were generated for the Montreal Cognitive Assessment (MoCA) (global cognition, primary outcome) and Category Fluency Animals (CFA) (semantic fluency, secondary outcome) that showed significant efficacy in the trial. ITR scores were generated through 300 iterations of 3-fold cross-validated random forest models. The average treatment difference (ATD) curve and the area between the curves (ABC) were estimated to measure the heterogeneity of treatment responses. Responder traits were identified using SHapley Additive exPlanations (SHAP) and decision tree models. The time saved in cognitive decline was explored to gauge clinical meaningfulness.

RESULTS

ABC statistics showed substantial heterogeneity in treatment response with MoCA but modest heterogeneity in treatment response with CFA. Age, cognitive status, time spent with family and friends, education, and personality were important characteristics that influenced treatment responses. Intervention group participants in the upper 30% of ITR scores demonstrated potential delays of 3 months in semantic fluency (CFA) and 6 months in global cognition (MoCA), assuming a 5-fold faster natural cognitive decline compared to the control group during the post-treatment period.

CONCLUSIONS

ITR-based analyses are valuable in profiling treatment responders for features that can inform future trial design and clinical practice. Reliably measuring time saved in cognitive decline is an area of ongoing research to gain insight into the clinical meaningfulness of treatment.

Assessing Quality of Life, Economic Burden, and Independence Across the Alzheimer's Disease Continuum Using Patient-Caregiver Dyad Surveys

Background

Alzheimer's disease (AD) and mild cognitive impairment (MCI) have negative quality of life (QoL) and economic impacts on patients and their caregivers and may increase along the disease continuum from MCI to mild, moderate, and severe AD.

Objective

To assess how patient and caregiver QoL, indirect and intangible costs are associated with MCI and AD severity.

Methods

An on-line survey of physician-identified patient-caregiver dyads living in the United States was conducted from June-October 2022 and included questions to both patients and their caregivers. Dementia Quality of Life Proxy, the Care-related Quality of Life, Work Productivity and Activity Impairment, and Dependence scale were incorporated into the survey. Regression analyses investigated the association between disease severity and QoL and cost outcomes with adjustment for baseline characteristics.

Results

One-hundred patient-caregiver dyads were assessed with the survey (MCI, n = 27; mild AD, n = 27; moderate AD, n = 25; severe AD, n = 21). Decreased QoL was found with worsening severity in patients (p < 0.01) and in unpaid (informal) caregivers (n = 79; p = 0.02). Dependence increased with disease severity (p < 0.01). Advanced disease severity was associated with higher costs to employers (p = 0.04), but not with indirect costs to caregivers. Patient and unpaid caregiver intangible costs increased with disease severity (p < 0.01). A significant trend of higher summed costs (indirect costs to caregivers, costs to employers, intangible costs to patients and caregivers) in more severe AD was observed (p < 0.01).

Conclusions

Patient QoL and functional independence and unpaid caregiver QoL decrease as AD severity increases. Intangible costs to patients and summed costs increase with disease severity and are highest in severe AD.

Alzheimer's Disease Stage Transitions Among United States Veterans

BACKGROUND

Alzheimer's disease (AD) and related dementias are progressive neurological disorders with stage-specific clinical features and challenges. An important knowledge gap is the "window of time" within which patients transition from mild cognitive impairment or mild AD to moderate or severe AD. Better characterization/establishment of transition times would help clinicians initiating treatments, including anti-amyloid therapy.

OBJECTIVE

To describe cognitive test score-based AD stage transitions in Veterans with AD in the US Veterans Affairs Healthcare System (VAHS).

METHODS

This retrospective analysis (2010-2019) identified Veterans with AD from the VAHS Electronic Health Record (EHR) notes. AD stage was based on Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), or Saint Louis University Mental Status (SLUMS) Examination scores in the EHR.

RESULTS

We identified 296,519 Veterans with cognitive test-based AD staging. Over the 10-year study, the proportion of veterans with MMSE scores declined from 24.9% to 9.5% while those with SLUMS rose from 9.0% to 17.8%; and MoCA rose from 5.0% to 25.4%. The average forward transition times between each stage were approximately 2-4 years, whether assessed by MMSE, MoCA, or SLUMS.

CONCLUSION

The average transition time for cognitive test-based assessments of initial cognitive decline, early-stage AD, and moderate/severe AD in the VAHS is 2-4 years. In view of the short window for introducing disease-modifying therapy and the significant benefits of early treatment of AD, our data suggest a critical need for treatment guidelines in the management of AD.

The importance of education for understanding variability of dementia onset in the United States

BACKGROUND

Greater levels of education are associated with lower risk of dementia, but less is known about how education is also associated with the compression of dementia incidence.

OBJECTIVE

We extend the literature on morbidity compression by evaluating whether increased levels of education are associated with greater dementia compression. We evaluate these patterns across race and gender groups.

METHODS

We use the Health and Retirement Study (2000-2016), a nationally representative longitudinal study of older adults in the United States. To evaluate the onset and compression of dementia across education groups, we examine the age-specific distribution of dementia events, identifying the modal age of onset and the standard deviation above the mode (a measure of compression).

RESULTS

While the modal age of onset is around 85 years among adults with a college degree, the modal age for adults with less than a high school education occurs before age 65 - at least a 20-year difference. The standard deviation of dementia onset is about three times greater for adults with less than a high school education compared to adults with a college degree. Patterns were consistent across race and gender groups.

CONCLUSION

This research highlights the variability of dementia experiences in the older population by documenting differences in longevity without dementia and compression of dementia onset among more educated adults and less educated adults.

CONTRIBUTION

We incorporate conceptual insights from the life span variability and compression literature to better understand education-dementia disparities in both the postponement and uncertainty of dementia onset in the US population.

Pemphigus and pemphigoid are associated with Alzheimer's disease in older adults: evidence from the US Nationwide inpatient sample 2016-2018

BACKGROUND

Pemphigus and pemphigoid are rare autoimmune skin disorders caused by autoantibodies against structural proteins and characterized by blistering of the skin and/or mucous membranes. Associations have been noted between skin diseases and Alzheimer's dementia (AD). Dementia is a neurological disorder of progressive cognitive impairment with increasing incidence among older adults. This study aimed to assess the potential associations between pemphigus, pemphigoid and AD in a large, nationally representative US cohort.

METHODS

All data of hospitalized patients aged 60 years or older were extracted from the US Nationwide Inpatient Sample (NIS) database 2016-2018. Patients with a history of head trauma, diagnosis of vascular dementia, history of cerebrovascular disease, or malformation of cerebral vessels were excluded. The study population was divided into those with and without pemphigus (cohort 1) and with and without pemphigoid (cohort 2).

RESULTS

Pemphigus was independently associated with a 69% increased risk of AD. Adults ≥80 years old with pemphigus were 72% more likely to develop AD than adults without pemphigus. Women with pemphigus were 78% more likely to develop AD than women without pemphigus. On the other hand, pemphigoid was independently associated with a 39% increased risk for AD and subjects ≥80 years with pemphigoid were 40% more likely to have AD than those without pemphigoid. Females with pemphigoid were 63% more likely to have AD than those without pemphigoid. Moreover, Hispanic older adults with pemphigus were 3-times more likely to have AD than those without pemphigoid.

CONCLUSIONS

Pemphigus and pemphigoid were both independently associated with AD in older adults, especially among females and octogenarians. Further studies addressing the etiology and mechanisms underlying these associations are highly warranted.

Associations of circulating saturated long-chain fatty acids with risk of mild cognitive impairment and Alzheimer's disease in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort

BACKGROUND

No study has examined the associations between peripheral saturated long-chain fatty acids (LCFAs) and conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD). This study aimed to examine whether circulating saturated LCFAs are associated with both risks of incident MCI from cognitively normal (CN) participants and incident AD progressed from MCI in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort.

METHODS

We conducted analysis of data from older adults aged 55-90 years who were recruited at 63 sites across the USA and Canada. We examined associations between circulating saturated LCFAs (i.e., C14:0, C16:0, C18:0, C20:0) and risk for incident MCI in CN participants, and incident AD progressed from MCI.

FINDINGS

829 participants who were enrolled in ADNI-1 had data on plasma saturated LCFAs, of which 618 AD-free participants were included in our analysis (226 with normal cognition and 392 with MCI; 60.2% were men). Cox proportional-hazards models were used to account for time-to-event/censor with a 48-month follow-up period for the primary analysis. Other than C20:0, saturated LCFAs were associated with an increased risk for AD among participants with MCI at baseline (Hazard ratios (HRs) = 1.3 to 2.2, P = 0.0005 to 0.003 in fully-adjusted models). No association of C20:0 with risk of AD among participants with MCI was observed. No associations were observed between saturated LCFAs and risk for MCI among participants with normal cognition.

INTERPRETATION

Saturated LCFAs are associated with increased risk of progressing from MCI to AD. This finding holds the potential to facilitate precision prevention of AD among patients with MCI.

FUNDING

National Institutes of Health.

Availability of Cognitive Resources in Early Life Predicts Transitions Between Cognitive States in Middle and Older Adults From Europe

Background and Objectives

The existing literature highlights the importance of reading books in middle-to-older adulthood for cognitive functioning; very few studies, however, have examined the importance of childhood cognitive resources for cognitive outcomes later in life.

Research Design and Methods

Using data from 11 countries included in the Survey of Health, Ageing, and Retirement in Europe (SHARE) data set (N = 32,783), multistate survival models (MSMs) were fit to examine the importance of access to reading material in childhood on transitions through cognitive status categories (no cognitive impairment and impaired cognitive functioning) and death. Additionally, using the transition probabilities estimated by the MSMs, we estimated the remaining years of life without cognitive impairment and total longevity. All models were fit individually in each country, as well as within the pooled SHARE sample.

Results

Adjusting for age, sex, education, and childhood socioeconomic status, the overall pooled estimate indicated that access to more books at age 10 was associated with a decreased risk of developing cognitive impairment (adjusted hazard ratio = 0.79, confidence interval: 0.76-0.82). Access to childhood books was not associated with risk of transitioning from normal cognitive functioning to death, or from cognitive impairment to death. Total longevity was similar between participants reporting high (+1 standard deviation [SD]) and low (-1 SD) number of books in the childhood home; however, individuals with more access to childhood books lived a greater proportion of this time without cognitive impairment.

Discussion and Implications

Findings suggest that access to cognitive resources in childhood is protective for cognitive aging processes in older adulthood.

Pathways explaining racial/ethnic disparities in incident all-cause dementia among middle-aged US adults

INTRODUCTION

Racial disparities in dementia incidence exist, but less is known about their presence and drivers among middle-aged adults.

METHODS

We used time-to-event analysis among a sample of 4378 respondents (age 40-59 years at baseline) drawn from the third National Health and Nutrition Examination Surveys (NHANES III) with administrative linkage-spanning the years 1988-2014-to evaluate potential mediating pathways through socioeconomic status (SES), lifestyle, and health-related characteristics.

RESULTS

Compared with Non-Hispanic White (NHW) adults, Non-White adults had a higher incidence of AD-specific (hazard ratio [HR] = 2.05, 95% confidence interval [CI]: 1.21, 3.49) and all-cause dementia (HR = 2.01, 95% CI: 1.36, 2.98). Diet, smoking, and physical activity were among characteristics on the pathway between race/ethnicity, SES, and dementia, with health-mediating effects of smoking and physical activity on dementia risk.

DISCUSSION

We identified several pathways that may generate racial disparities in incident all-cause dementia among middle-aged adults. No direct effect of race was observed. More studies are needed to corroborate our findings in comparable populations.

Assessing out-of-pocket expenses and indirect costs for the Alzheimer disease continuum in the United States

BACKGROUND: The societal costs of Alzheimer disease (AD) are considerable. Cost data stratified by cost category (direct and indirect) and AD severity in the United States are limited. OBJECTIVE: To describe out-of-pocket (OOP) expenses and indirect costs from unpaid caregiving and work impairment among patients with AD by severity and among patients with mild cognitive impairment (MCI) in a representative sample of the US population. METHODS: Data from the Health and Retirement Study (HRS) were used. HRS respondents were included if they reported an AD diagnosis or were considered as having MCI based on their cognitive performance. MCI and AD severity staging was performed using a crosswalk from results of the modified Telephone Interview of Cognitive Status to the Mini-Mental State Examination. OOP expenses were assessed along with indirect costs (costs to caregivers from providing unpaid help and costs to employers). Sensitivity analyses were performed by varying assumptions of caregiver employment, missed workdays, and early retirement. Patients with AD were stratified by nursing home status, type of insurance, and income level. All cost calculations applied sampling weights. RESULTS: A total of 18,786 patients were analyzed. Patients with MCI (n = 17,885) and AD (n = 901) were aged 67.8 ± 10.7 and 80.9 ± 9.3 years, were 55.7% and 63.3% female, and were 28.3% and 0.9% employed, respectively. OOP expenses per patient per month increased with AD severity, ranging from $420 in mild to $903 in severe AD but were higher in MCI ($554) than in mild AD. Indirect costs to employers were similar across the AD continuum ($197-$242). Costs from unpaid caregiving generally increased by disease severity, from $72 (MCI) to $1,298 (severe AD). Total OOP and indirect costs increased by disease severity, from $869 (MCI) to $2,398 (severe AD). Sensitivity analysis assuming nonworking caregivers and zero costs to employers decreased the total OOP and indirect costs by 32%-53%. OOP expenses were higher for patients with AD who had private insurance (P < 0.01), had higher incomes (P < 0.01), or were in nursing homes (P < 0.01). Indirect costs to caregivers were lower for patients with AD in nursing homes ($600 vs $1,372, P < 0.01). Total indirect costs were higher for patients with AD with lower incomes ($1,498 vs $1,136, P < 0.01) and for those not in nursing homes ($1,571 vs $799, P < 0.01). CONCLUSIONS: This study shows that OOP expenses and indirect costs increase with AD severity, OOP expenses increase with higher income, subscription of private insurance, and nursing home residency, and total indirect costs decrease with higher income and nursing home residency in the United States. DISCLOSURES This study was financially sponsored by Eisai. Drs Zhang and Tahami are employees of Eisai. Drs Chandak, Khachatryan, and Hummel are employees of Certara; Certara is a paid consultant to Eisai. The views expressed here are those of the authors and are not to be attributed to their respective affiliations. Laura De Benedetti, BSc, provided medical writing support to the manuscript; she is an employee of Certara.

Adherence to cognitive and physical exercise engagement: a challenge to successful dementia risk reduction and prevention efforts

With human life expectancy and proportion of older adults increasing, global use of evidence-supported preventative methods to minimize risk of brain-related disabilities such as Alzheimer's disease and other dementias-as well as interventions to slow rate of disease progression-is important. Sustained engagement in cognitive and physical exercise programs may prevent or delay dementia onset as well as maximize health and function of those with dementia. Despite awareness of the importance of cognitive and physical exercise to brain health, exercise program adherence by older adults is extremely challenging. In this Perspective article, we summarize what is known about contributors to exercise program adherence and strategies to promote it. We discuss our viewpoint on knowledge gaps regarding exercise adherence and research that needs to be conducted. We conclude by proposing a multi-dimensional exercise adherence assessment framework that includes portable neurophysiologic technologies to inform initial design and updating of individualized exercise programs that optimize sustained exercise program engagement and, ultimately, maximize brain health in older adults with and without mild cognitive impairment and dementia.

A task force for diagnosis and treatment of people with Alzheimer's disease in Latin America

Alzheimer's disease (AD) represents a substantial burden to patients, their caregivers, health systems, and society in Latin America and the Caribbean (LAC). This impact is exacerbated by limited access to diagnosis, specialized care, and therapies for AD within and among nations. The region has varied geographic, ethnic, cultural, and economic conditions, which create unique challenges to AD diagnosis and management. To address these issues, the Americas Health Foundation convened a panel of eight neurologists, geriatricians, and psychiatrists from Argentina, Brazil, Colombia, Ecuador, Guatemala, Mexico, and Peru who are experts in AD for a three-day virtual meeting to discuss best practices for AD diagnosis and treatment in LAC and create a manuscript offering recommendations to address identified barriers. In LAC, several barriers hamper diagnosing and treating people with dementia. These barriers include access to healthcare, fragmented healthcare systems, limited research funding, unstandardized diagnosis and treatment, genetic heterogeneity, and varying social determinants of health. Additional training for physicians and other healthcare workers at the primary care level, region-specific or adequately adapted cognitive tests, increased public healthcare insurance coverage of testing and treatment, and dedicated search strategies to detect populations with gene variants associated with AD are among the recommendations to improve the landscape of AD.

Role of light walking pace on cognition: Findings from the Maine-Syracuse Longitudinal Study

Moderate- to vigorous intensities of physical activity are recommended for health promotion, including brain health. Regular physical activity is considered a modifiable factor to delay -perhaps prevent- onset of dementias such as Alzheimer's disease. Little is known about the benefits of light physical activity. We analyzed data from a 998 community-dwelling, cognitively unimpaired participants from the Maine-Syracuse Longitudinal Study (MSLS) and investigated the role of light physical activity, defined by walking pace, across two time points. Results revealed light levels of walking pace were associated with higher performance at the first timepoint and less decline by time 2 in the domains of verbal abstract reasoning and visual scanning and tracking, which includes both processing speed and executive function skills. When examining change over time (N = 583), increasing walking pace was associated with less decline at time two for the domains of visual scanning and tracking, working memory, visual spatial ability, and working memory, but not verbal abstract reasoning. These findings highlight the relevance of light physical activity and the need to investigate its contribution to cognitive function. From a public health perspective, this may encourage more adults to adopt a light level of exercise and still reap health benefits.

What Can Economics Say about Alzheimer's Disease?

Alzheimer's disease (AD) affects one in ten people aged 65 or older and is the most expensive disease in the United States. We describe the central economic questions raised by AD. Although there is overlap with the economics of aging and health, the defining feature of the "economics of Alzheimer's disease" is an emphasis on choice by cognitively impaired patients that affects health and financial well-being, and situations in which dynamic contracts between patients and caregivers are useful but difficult to enforce. A focus on innovation in AD prevention, treatment, and care is also critical given the enormous social cost of AD and present lack of understanding of its causes, which raises questions of optimal resource allocation and alignment of private and social incentives. The enormous scope for economists to contribute to our understanding of AD-related issues including drug development, efficient care delivery, dynamic contracting, long-term care risk, financial decision-making, and the design of public programs for AD suggests a rich research program for many areas of economics.

Cholesterol twists the transmembrane Di-Gly region of amyloid-precursor protein

Nearly 95% of Alzheimer's disease (AD) occurs sporadically without genetic linkage. Aging, hypertension, high cholesterol content, and diabetes are known nongenomic risk factors of AD. Aggregation of Aβ peptides is an initial event of AD pathogenesis. Aβ peptides are catabolic products of a type I membrane protein called amyloid precursor protein (APP). Aβ40 is the major product, whereas the 2-residue-longer version, Aβ42, induces amyloid plaque formation in the AD brain. Since cholesterol content is one risk factor for sporadic AD, we aimed to explore whether cholesterol in the membrane affects the structure of the APP transmembrane region, thereby modulating the γ-secretase cutting behavior. Here, we synthesized several peptides containing the APP transmembrane region (sequence 693-726, corresponding to the Aβ_22-55 sequence) with one or two Cys mutations for spin labeling. We performed three electron spin resonance experiments to examine the structural changes of the peptides in liposomes composed of dioleoyl phosphatidylcholine and different cholesterol content. Our results show that cholesterol increases membrane thickness by 10% and peptide length accordingly. We identified that the di-glycine region of Aβ_36-40 (sequence VGGVV) exhibits the most profound change in response to cholesterol compared with other segments, explaining how the presence of cholesterol affects the γ-secretase cutting site. This study provides spectroscopic evidence showing how cholesterol modulates the structure of the APP transmembrane region in a lipid bilayer.

Social participation and risk of developing dementia

The increasing number of people with dementia globally illustrates the urgent need to reduce dementia's scale and impact. Lifetime social participation may affect dementia risk by increasing cognitive reserve, and through brain maintenance by reducing stress and improving cerebrovascular health. It may therefore have important implications for individual behavior and public health policy aimed at reducing dementia burden. Observational study evidence indicates that greater social participation in midlife and late life is associated with 30-50% lower subsequent dementia risk, although some of this may not be causal. Social participation interventions have led to improved cognition but, partly due to short follow-up and small numbers of participants, no reduction in risk of dementia. We summarize the evidence linking social participation with dementia, discuss potential mechanisms by which social participation is likely to reduce and mitigate the impact of neuropathology in the brain, and consider the implications for future clinical and policy dementia prevention interventions.

Inequality in housing transitions during cognitive decline

Independent living can become challenging for people experiencing cognitive decline. With reduced functioning and greater care needs, many people with dementia (PWD) may need to move to another home with better safety features, move to live closer to or with relatives who can provide care, or enter a nursing home. Housing plays a key role in supporting quality of life for both PWD and their caregivers, so the ability to move when needed is crucial for their well-being. Yet the substantial costs of moving, housing, and care mean that PWD with limited financial resources may be unable to afford moving, exacerbating inequalities between more and less advantaged PWD. Emerging qualitative research considers the housing choices of PWD and their caregivers, yet little is known on a broader scale about the housing transitions PWD actually make over the course of cognitive decline. Prior quantitative research focuses specifically on nursing home admissions; questions remain about how often PWD move to another home or move in with relatives. This study investigates socioeconomic and racial/ethnic disparities in the timing and type of housing transitions among PWD in the United States, using Health and Retirement study data from 2002 through 2016. We find that over half of PWD move in the years around dementia onset (28% move once, and 28% move twice or more) while 44% remain in place. Examining various types of moves, 35% move to another home, 32% move into nursing homes, and 11% move in with relatives. We find disparities by educational attainment and race/ethnicity: more advantaged PWD are more likely to move to another home and more likely to enter a nursing home than less advantaged groups. This highlights the importance of providing support for PWD and their families to transition into different living arrangements as their housing needs change.

Deep learning-based polygenic risk analysis for Alzheimer's disease prediction

BACKGROUND

The polygenic nature of Alzheimer's disease (AD) suggests that multiple variants jointly contribute to disease susceptibility. As an individual's genetic variants are constant throughout life, evaluating the combined effects of multiple disease-associated genetic risks enables reliable AD risk prediction. Because of the complexity of genomic data, current statistical analyses cannot comprehensively capture the polygenic risk of AD, resulting in unsatisfactory disease risk prediction. However, deep learning methods, which capture nonlinearity within high-dimensional genomic data, may enable more accurate disease risk prediction and improve our understanding of AD etiology. Accordingly, we developed deep learning neural network models for modeling AD polygenic risk.

METHODS

We constructed neural network models to model AD polygenic risk and compared them with the widely used weighted polygenic risk score and lasso models. We conducted robust linear regression analysis to investigate the relationship between the AD polygenic risk derived from deep learning methods and AD endophenotypes (i.e., plasma biomarkers and individual cognitive performance). We stratified individuals by applying unsupervised clustering to the outputs from the hidden layers of the neural network model.

RESULTS

The deep learning models outperform other statistical models for modeling AD risk. Moreover, the polygenic risk derived from the deep learning models enables the identification of disease-associated biological pathways and the stratification of individuals according to distinct pathological mechanisms.

CONCLUSION

Our results suggest that deep learning methods are effective for modeling the genetic risks of AD and other diseases, classifying disease risks, and uncovering disease mechanisms.