Progress and future challenges in aging and diversity research in the United States

Intergenerational Influence of African American, Caribbean and Hispanic/Latino Adults Regarding Decision to Participate in Health-Related Research

Introduction: Identifying effective strategies to enroll African American, Caribbean, and Hispanic/Latino adults ≥65 years of age in health research is a public health priority. This study aimed to explore intergenerational influence (IGI) among these populations living throughout Florida. Methods: African American, Caribbean, and Hispanic/Latino adults ≥65 years of age and a trusted family member/friend between 25-64 years participated in virtual listening sessions (LS). Culturally matched facilitators used a semi-structured guide to lead LS that was recorded, transcribed, and uploaded into NVivo©. The constant comparative method was used for analysis. Results: 363 African American, Caribbean, and Hispanic/Latino participated in LS. Five (5) themes relate to IGI emerged: (1) parent-child relationships; (2) family caregiving/parental illness experiences; (3) historical research maltreatment; (4) transfer of cultural knowledge; and (5) future generations. Discussion: Our findings support that IGI can be leveraged to increase the participation of African American, Caribbean, and Hispanic/Latino older adults in health research.

Revised criteria for diagnosis and staging of Alzheimer's disease: Alzheimer's Association Workgroup

The National Institute on Aging and the Alzheimer's Association convened three separate work groups in 2011 and single work groups in 2012 and 2018 to create recommendations for the diagnosis and characterization of Alzheimer's disease (AD). The present document updates the 2018 research framework in response to several recent developments. Defining diseases biologically, rather than based on syndromic presentation, has long been standard in many areas of medicine (e.g., oncology), and is becoming a unifying concept common to all neurodegenerative diseases, not just AD. The present document is consistent with this principle. Our intent is to present objective criteria for diagnosis and staging AD, incorporating recent advances in biomarkers, to serve as a bridge between research and clinical care. These criteria are not intended to provide step-by-step clinical practice guidelines for clinical workflow or specific treatment protocols, but rather serve as general principles to inform diagnosis and staging of AD that reflect current science. HIGHLIGHTS: We define Alzheimer's disease (AD) to be a biological process that begins with the appearance of AD neuropathologic change (ADNPC) while people are asymptomatic. Progression of the neuropathologic burden leads to the later appearance and progression of clinical symptoms. Early-changing Core 1 biomarkers (amyloid positron emission tomography [PET], approved cerebrospinal fluid biomarkers, and accurate plasma biomarkers [especially phosphorylated tau 217]) map onto either the amyloid beta or AD tauopathy pathway; however, these reflect the presence of ADNPC more generally (i.e., both neuritic plaques and tangles). An abnormal Core 1 biomarker result is sufficient to establish a diagnosis of AD and to inform clinical decision making throughout the disease continuum. Later-changing Core 2 biomarkers (biofluid and tau PET) can provide prognostic information, and when abnormal, will increase confidence that AD is contributing to symptoms. An integrated biological and clinical staging scheme is described that accommodates the fact that common copathologies, cognitive reserve, and resistance may modify relationships between clinical and biological AD stages.

Dying with dementia in nursing homes: A population-based study of decedents and their families

BACKGROUND

Families play a critical role in end-of-life (EOL) care for nursing home (NH) residents with dementia. Despite the important role of family, little is known about the availability and characteristics of families of persons with dementia who die in NHs.

METHODS

This is a retrospective cohort study of 18,339 individuals 65 years and older with dementia who died in a Utah NH between 1998 and 2016, linked to their first-degree family (FDF) members (n = 52,566; spouses = 11.3%; children = 58.3%; siblings = 30.3%). Descriptive statistics, chi-square tests, and t-tests were used to describe the study cohort and their FDF members and to compare sociodemographic and death characteristics of NH decedents with (n = 14,398; 78.5%) and without FDF (n = 3941; 21.5%).

RESULTS

Compared with NH decedents with FDF, NH decedents with dementia without FDF members were more likely to be older (mean age 86.5 vs 85.5), female (70.5% vs 59.3%), non-White/Hispanic (9.9% vs 3.2%), divorced/separated/widowed (84.4% vs 61.1%), less educated (<12th grade; 42.2% vs 33.7%), have Medicare and Medicaid (20.8% vs 12.5%), and die in a rural/frontier NH (25.0% vs 23.4%). NH decedents who did not have FDF were also more likely to die from cancer (4.2% vs 3.9%), chronic obstructive pulmonary disease (COPD; 3.9% vs 2.5%), and dementia (40.5% vs 38.4%) and were less likely to have 2+ inpatient hospitalizations at EOL (13.9% vs 16.2%), compared with NH decedents with FDF.

CONCLUSIONS

Findings highlight differences in social determinants of health (e.g., sex, race, marital status, education, insurance, rurality) between NH decedents with dementia who do and do not have FDF-factors that may influence equity in EOL care. Understanding the role of family availability and familial characteristics on EOL care outcomes for NH residents with dementia is an important next step to informing NH dementia care interventions and health policies.

Performance of SOBA-AD blood test in discriminating Alzheimer's disease patients from cognitively unimpaired controls in two independent cohorts

Amyloid-beta (Aβ) toxic oligomers are critical early players in the molecular pathology of Alzheimer's disease (AD). We have developed a Soluble Oligomer Binding Assay (SOBA-AD) for detection of these Aβ oligomers that contain α-sheet secondary structure that discriminates plasma samples from patients on the AD continuum from non-AD controls. We tested 265 plasma samples from two independent cohorts to investigate the performance of SOBA-AD. Testing was performed at two different sites, with different personnel, reagents, and instrumentation. Across two cohorts, SOBA-AD discriminated AD patients from cognitively unimpaired (CU) subjects with 100% sensitivity, > 95% specificity, and > 98% area under the curve (AUC) (95% CI 0.95-1.00). A SOBA-AD positive readout, reflecting α-sheet toxic oligomer burden, was found in AD patients, and not in controls, providing separation of the two populations, aside from 5 SOBA-AD positive controls. Based on an earlier SOBA-AD study, the Aβ oligomers detected in these CU subjects may represent preclinical cases of AD. The results presented here support the value of SOBA-AD as a promising blood-based tool for the detection and confirmation of AD.

Racial and ethnic differences in disease course Medicare expenditures for beneficiaries with dementia

BACKGROUND

Research on racial and ethnic disparities in costs of care during the course of dementia is sparse. We analyzed Medicare expenditures for beneficiaries with dementia to identify when during the course of care costs are the highest and whether they differ by race and ethnicity.

METHODS

We analyzed data from the 2000-2016 Health and Retirement Study (HRS) linked with corresponding Medicare claims to estimate total Medicare expenditures for four phases: (1) the year before a dementia diagnosis, (2) the first year following a dementia diagnosis, (3) ongoing care for dementia after the first year, and (4) the last year of life. We estimated each patient's phase-specific and disease course Medicare expenditures by using a race-specific survival model and monthly expenditures adjusted for patient characteristics. We investigated healthcare utilization by service type across races/ethnicities and phases of care.

RESULTS

Adjusted mean total Medicare expenditures for non-Hispanic (NH) Black ($165,730) and Hispanic beneficiaries with dementia ($160,442) exceeded corresponding expenditures for NH Whites ($136,326). In the year preceding and immediately following initial dementia diagnosis, mean Medicare expenditures for NH Blacks ($26,337 and $20,429) exceeded expenditures for Hispanics and NH Whites ($21,399-23,176 and 17,182-18,244). The last year of life was responsible for the greatest cost contribution: $51,294 (NH Blacks), $47,469 (Hispanics), and $39,499 (NH Whites). These differences were driven by greater use of high-cost services (e.g., emergency department, inpatient and intensive care), especially during the last year of life.

CONCLUSIONS

NH Black and Hispanic beneficiaries with dementia had higher disease course Medicare expenditures than NH Whites. Expenditures were highest for NH Black beneficiaries in every phase of care. Further research should address mechanisms of such disparities and identify methods to improve communication, shared decision-making, and access to appropriate services for all populations.

Community engagement strategies for population health research with culturally diverse adults

The purpose of this report is to describe the community engagement research (CEnR) strategies used to implement the Florida Statewide Registry for Aging Studies (FSRAS), a tri-institutional research project conducted during the height of the COVID-19 pandemic. We describe the CEnR strategies used to enroll adults aged ≥ 25 years old self-identifying as African American (AA), Caribbean (CN), or Hispanic/Latinx (H/L) into FSRAS health research studies. The second goal is to report the number of AA, CN, and H/L adults involved in FSRAS and discuss the implications of CEnR strategies used throughout this research. More than 1600 adults aged 25 years or older participated in FSRAS health-related research activities or studies. Specifically, 25 community leaders from throughout Florida served on the FL-SAGE Council, 587 AA, CN, and H/L adults aged ≥ 25 years old participated in listening sessions and completed surveys exploring intergenerational influence, 292 AA, CN, and H/L adults participated in marketing research, and at least 702 adults have enrolled in AgeWell, FSRAS's health registry for persons interested in healthy aging research. Implications are researchers should continue using several CEnR strategies including technology and social media. Examining how the foundational principles of trust and authenticity are maintained when using CEnR strategies in virtual settings is warranted. Research implications are that simultaneously using CEnR strategies to recruit and enroll underrepresented populations into research is most effective although further research is needed to identify which CEnR strategy is most effective for enrolling AA, CN, and H/L older adults in aging research.

Is the Montreal cognitive assessment culturally valid in a diverse geriatric primary care setting? Lessons from the Bronx

BACKGROUND

Efficacy and validity of the MoCA for cognitive screening in ethnoculturally and linguistically diverse settings is unclear. We sought to examine the utility and discriminative validity of the Spanish and English MoCA versions to identify cognitive impairment among diverse community-dwelling older adults.

METHODS

Participants aged ≥65 with cognitive concerns attending outpatient primary care in Bronx, NY, were recruited. MoCA and neuropsychological measures were administered in Spanish or English, and a neuropsychologist determined cognitive status (normal with subjective cognitive concerns [SCC], mild cognitive impairment [MCI], and dementia). One-way ANOVA compared cognitive statuses. ROC analyses identified optimal MoCA cutpoints for discriminating possible cognitive impairment.

RESULTS

There were 231 participants, with mean age 73, 72% women, 43% Hispanic; 39% Black/African American; 113 (49%) completed testing in English and 118 (51%) in Spanish. Overall MoCA mean was 17.7 (SD = 4.3). Neuropsychological assessment identified 90 as cognitively normal/SCC, average MoCA 19.9 (SD = 4.1), 133 with MCI, average MoCA 16.6 (SD = 3.7), and 8 with dementia, average MoCA 10.6 (SD = 3.1). Mean English MoCA average was 18.6 (SD = 4.1) versus Spanish 16.7 (SD = 4.3). The published cutpoint ≤23 for MCI yielded a high false-positive rate (79%). ROC analyses identified ≤18.5 as the score to identify MCI or dementia using the English MoCA (65% sensitivity; 77% specificity) and ≤16.5 for the Spanish MoCA (64% sensitivity;73% specificity) in this sample of older adults with cognitive concerns.

CONCLUSIONS

Current MoCA cutpoints were inappropriately high in a culturally/linguistically diverse urban setting, leading to a high false-positive rate. Lower Spanish and English MoCA cutpoints may improve diagnostic accuracy for identifying cognitive impairment in this group, highlighting the need for the creation and validation of accurate cognitive screeners for ethnoculturally and linguistically diverse older adults.

Looking Upstream to Understand Race/Ethnicity as a Moderator for Poststroke Neuroinflammation and a Social Determinant for Poststroke Aphasia Outcomes

INTRODUCTION

Over the past decade, the stroke literature has begun to acknowledge and explore explanations for longstanding racial/ethnic differences in stroke outcomes. Poststroke cognitive impairment (PSCI) and poststroke aphasia are two such negative poststroke outcomes where racial/ethnic differences exist. Physiological differences, such as stroke type and lesion size, have been used to partially explain the variation in PSCI and aphasia. However, there is some evidence, although limited, that suggests neuroinflammatory processes as part of allostatic load may be a key contributor to the observed disparities.

METHOD

In this tutorial, we explore the influence of race differences in inflammation on poststroke cognitive outcomes. We suggest lifetime stress and other external determinants of health such as neighborhood environment and discriminatory practices through "weathering" explain differences in inflammation. While using an allostatic load framework, we explore the literature focusing specifically on the role of neuroinflammation on poststroke outcomes.

CONCLUSIONS

Examination of the immune response poststroke provides a foundation for understanding the mechanisms of PSCI and poststroke aphasia and the potential contributions of neuroinflammatory processes on poststroke cognitive outcomes. Furthermore, understanding of racial differences in those processes may contribute to a better understanding of racial disparities in general stroke outcomes as well as poststroke aphasia.

Biomarkers of chronic inflammation and cognitive decline: A prospective observational study

We sought to determine whether the biomarkers of chronic inflammation predict cognitive decline in a prospective observational study. We measured baseline serum soluble urokinase plasminogen activator receptor (suPAR) and high sensitivity C-reactive protein (hs-CRP) levels in 282 participants of the University of Michigan Memory and Aging Project. Cognitive function was measured using the Montreal Cognitive Assessment (MoCA) and the Clinical Dementia Rating (CDR) scale for up to five time points. SuPAR and hs-CRP levels were not significantly higher in participants with mild cognitive impairment (n = 97) or dementia (n = 59), compared to those with normal cognitive function (n = 126). Overall, 14% of participants experienced significant cognitive decline over the study period. The change in MoCA or CDR scores over time did not differ significantly according to baseline suPAR or hs-CRP levels. Chronic systemic inflammation, as measured by serum suPAR or hs-CRP levels, is unlikely to contribute significantly to cognitive decline.

Black-White Racial Disparities in Disabilities Among Older Americans Between 2008 and 2017: Improvements in Cognitive Disabilities but no Progress in Activities of Daily Living or Functional Limitations

The objectives of this study were to examine the prevalence of race-based disparities in cognitive problems, functional limitations (FLs), and activity of daily living (ADL) limitations between US Black and White older adults in 2008 and 2017, to explore how age, sex, income, and education attenuate these racial disparities, and to determine if Black-White health disparities are narrowing. Secondary analysis of the nationally representative American Community Surveys including 423,066 respondents aged ≥65 (388,602 White, 34,464 Black) in 2008 and 536,984 (488,483 White, 48,501 Black) in 2017. Findings indicate that Black-White racial disparities were apparent for all three outcomes in 2008 and 2017. Approximately half of the racial disparities was attenuated when adjustments were made for education and income. Racial disparities in cognition declined between 2008 and 2017 (p < .001) but persisted unabated in FLs and ADL limitations. Further exploration on the mechanisms of racial disparities is warranted.

Synthesizing Best Practices to Promote Health Equity for Older Adults Through Community-Engaged Research

Achieving health equity requires creating evidence that reflects the nuance and diversity of experiences among populations disproportionately impacted by age- and race-related disparities. Community-engaged research (CEnR) is one way to pursue equity in research on health and aging to ensure the relevance and translational potential of findings. The current review synthesizes best practices regarding CEnR that promote health equity among older adults, including an overview of CEnR, benefits, and fundamental principles, and three research exemplars from the authors' CEnR. Finally, we discuss these best practices and considerations for advancing CEnR to reduce health disparities experienced by historically underserved older adults and their families. [Research in Gerontological Nursing, 17(1), 9-16.].

Blood Markers in Relation to a History of Traumatic Brain Injury Across Stages of Cognitive Impairment in a Diverse Cohort

BACKGROUND

Traumatic brain injury (TBI) has been linked to multiple pathophysiological processes that could increase risk for Alzheimer's disease and related dementias (ADRD). However, the impact of prior TBI on blood biomarkers for ADRD remains unknown.

OBJECTIVE

Using cross-sectional data, we assessed whether a history of TBI influences serum biomarkers in a diverse cohort (approximately 50% Hispanic) with normal cognition, mild cognitive impairment, or dementia.

METHODS

Levels of glial fibrillary acidic protein (GFAP), neurofilament light (NFL), total tau (T-tau), and ubiquitin carboxy-terminal hydrolase-L1 (UCHL1) were measured for participants across the cognitive spectrum. Participants were categorized based on presence and absence of a history of TBI with loss of consciousness, and study samples were derived through case-control matching. Multivariable general linear models compared concentrations of biomarkers in relation to a history of TBI and smoothing splines modelled biomarkers non-linearly in the cognitively impaired groups as a function of time since symptom onset.

RESULTS

Each biomarker was higher across stages of cognitive impairment, characterized by clinical diagnosis and Mini-Mental State Examination performance, but these associations were not influenced by a history of TBI. However, modelling biomarkers in relation to duration of cognitive symptoms for ADRD showed differences by history of TBI, with only GFAP and UCHL1 being elevated.

CONCLUSIONS

Serum GFAP, NFL, T-tau, and UCHL1 were higher across stages of cognitive impairment in this diverse clinical cohort, regardless of TBI history, though longitudinal investigation of the timing, order, and trajectory of the biomarkers in relation to prior TBI is warranted.

How Generalizable Are Findings from a Community-Based Prospective Cohort Study? Extending Estimates from the Adult Changes in Thought Study to Its Source Population

Background

The Adult Changes in Thought (ACT) study is a cohort of Kaiser Permanente Washington members ages 65+ that began in 1994.

Objective

We wanted to know how well ACT participants represented all older adults in the region, and how well ACT findings on eye disease and its relationship with Alzheimer's disease generalized to all older adults in the Seattle Metropolitan Region.

Methods

We used participation weights derived from pooling ACT and Behavioral Risk Factor Surveillance System (BRFSS) data to estimate prevalences of common eye diseases and their associations with Alzheimer's disease incidence. Cox proportional hazards models accounted for age, education, smoking, sex, and APOE genotype. Confidence intervals for weighted analyses were bootstrapped to account for error in estimating the weights.

Results

ACT participants were fairly similar to older adults in the region. The largest differences were more self-reported current cholesterol medication use in BRFSS and higher proportions with low education in ACT. Incorporating the weights had little impact on prevalence estimates for age-related macular degeneration or glaucoma. Weighted estimates were slightly higher for diabetic retinopathy (weighted 5.7% (95% Confidence Interval 4.3, 7.1); unweighted 4.1% (3.6, 4.6)) and cataract history (weighted 51.8% (49.6, 54.3); unweighted 48.6% (47.3, 49.9)). The weighted hazard ratio for recent diabetic retinopathy diagnosis and Alzheimer's disease was 1.84 (0.34, 4.29), versus 1.32 (0.87, 2.00) in unweighted ACT.

Conclusions

Most, but not all, associations were similar after participation weighting. Even in community-based cohorts, extending inferences to broader populations may benefit from evaluation with participation weights.

Under-Diagnosis of Dementia with Lewy Bodies in Individuals Racialized as Black: Hypotheses Regarding Potential Contributors

Dementia with Lewy bodies (DLB) is one of the most common degenerative dementias after Alzheimer's disease (AD) dementia. DLB is under-diagnosed across populations but may be particularly missed in older Black adults. The object of this review was to examine key features of DLB and potential associations with race in order to hypothesize why DLB may be under-diagnosed in Black adults in the U.S. In terms of dementia, symptoms associated with high rates of co-pathology (e.g., AD, vascular disease) in older Black adults may obscure the clinical picture that might suggest Lewy body pathology. Research also suggests that clinicians may be predisposed to give AD dementia diagnoses to Black adults, potentially missing contributions of Lewy body pathology. Hallucinations in Black adults may be misattributed to AD or primary psychiatric disease rather than Lewy body pathology. Research on the prevalence of REM sleep behavior in diverse populations is lacking, but REM sleep behavior disorder could be under-diagnosed in Black adults due to sleep patterns or reporting by caregivers who are not bed partners. Recognition of parkinsonism could be reduced in Black adults due to clinician biases, cultural effects on self-report, and potentially underlying differences in the frequency of parkinsonism. These considerations are superimposed on structural and systemic contributions to health (e.g., socioeconomic status, education, structural racism) and individual-level social exposures (e.g., social interactions, discrimination). Improving DLB recognition in Black adults will require research to investigate reasons for diagnostic disparities and education to increase identification of core symptoms in this population.

Does the Cognitive Change Index Predict Future Cognitive and Clinical Decline? Longitudinal Analysis in a Demographically Diverse Cohort

Background

The Cognitive Change Index (CCI) is a widely-used measure of self-perceived cognitive ability and change. Unfortunately, it is unclear if the CCI predicts future cognitive and clinical decline.

Objective

We evaluated baseline CCI to predict transition from normal cognition to cognitive impairment in nondemented older adults and in predementia groups including, subjective cognitive decline, motoric cognitive risk syndrome, and mild cognitive impairment. Different versions of the CCI were assessed to uncover any differential risk sensitivity. We also examined the effect of ethnicity/race on CCI.

Methods

Einstein Aging Study participants (N = 322, Mage = 77.57±4.96, % female=67.1, Meducation = 15.06±3.54, % non-Hispanic white = 46.3) completed an expanded 40-item CCI version (CCI-40) and neuropsychological evaluation (including Clinical Dementia Rating Scale [CDR], Montreal Cognitive Assessment, and Craft Story) at baseline and annual follow-up (Mfollow - up=3.4 years). CCI-40 includes the original 20 items (CCI-20) and the first 12 memory items (CCI-12). Linear mixed effects models (LME) and generalized LME assessed the association of CCI total scores at baseline with rate of decline in neuropsychological tests and CDR.

Results

In the overall sample and across predementia groups, the CCI was associated with rate of change in log odds on CDR, with higher CCI at baseline predicting faster increase in the odds of being impaired on CDR. The predictive validity of the CCI broadly held across versions (CCI-12, 20, 40) and ethnic/racial groups (non-Hispanic black and white).

Conclusions

Self-perception of cognitive change on the CCI is a useful marker of dementia risk in demographically/clinically diverse nondemented samples. All CCI versions successfully predicted decline.

Sufficient component cause simulations: an underutilized epidemiologic teaching tool

Simulation studies are a powerful and important tool in epidemiologic teaching, especially for understanding causal inference. Simulations using the sufficient component cause framework can provide students key insights about causal mechanisms and sources of bias, but are not commonly used. To make them more accessible, we aim to provide an introduction and tutorial on developing and using these simulations, including an overview of translation from directed acyclic graphs and potential outcomes to sufficient component causal models, and a summary of the simulation approach. Using the applied question of the impact of educational attainment on dementia, we offer simple simulation examples and accompanying code to illustrate sufficient component cause-based simulations for four common causal structures (causation, confounding, selection bias, and effect modification) often introduced early in epidemiologic training. We show how sufficient component cause-based simulations illuminate both the causal processes and the mechanisms through which bias occurs, which can help enhance student understanding of these causal structures and the distinctions between them. We conclude with a discussion of considerations for using sufficient component cause-based simulations as a teaching tool.

Music Therapy Increases Social and Emotional Well-Being in Persons With Dementia: A Randomized Clinical Crossover Trial Comparing Singing to Verbal Discussion

The number of people living with Alzheimer's disease and related dementias (ADRD) is growing proportional to our aging population. Although music-based interventions may offer meaningful support to these individuals, most music therapy research lacks well-matched comparison conditions and specific intervention focus, which limits evaluation of intervention effectiveness and possible mechanisms. Here, we report a randomized clinical crossover trial in which we examined the impact of a singing-based music therapy intervention on feelings, emotions, and social engagement in 32 care facility residents with ADRD (aged 65-97 years), relative to an analogous nonmusic condition (verbal discussion). Both conditions were informed by the Clinical Practice Model for Persons with Dementia and occurred in a small group format, three times per week for two weeks (six 25-minute sessions), with a two-week washout at crossover. We followed National Institutes of Health Behavior Change Consortium strategies to enhance methodological rigor. We predicted that music therapy would improve feelings, positive emotions, and social engagement, significantly more so than the comparison condition. We used a linear mixed model approach to analysis. In support of our hypotheses, the music therapy intervention yielded significant positive effects on feelings, emotions, and social engagement, particularly for those with moderate dementia. Our study contributes empirical support for the use of music therapy to improve psychosocial well-being in this population. Results also highlight the importance of considering patient characteristics in intervention design and offer practical implications for music selection and implementation within interventions for persons with ADRD.

Connecting memory and functional brain networks in older adults: a resting-state fMRI study

Limited research exists on the association between resting-state functional network connectivity in the brain and learning and memory processes in advanced age. This study examined within-network connectivity of cingulo-opercular (CON), frontoparietal control (FPCN), and default mode (DMN) networks, and verbal and visuospatial learning and memory in older adults. Across domains, we hypothesized that greater CON and FPCN connectivity would associate with better learning, and greater DMN connectivity would associate with better memory. A total of 330 healthy older adults (age range = 65-89) underwent resting-state fMRI and completed the Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-Revised (BVMT-R) in a randomized clinical trial. Total and delayed recall scores were assessed from baseline data, and a learning ratio calculation was applied to participants' scores. Average CON, FPCN, and DMN connectivity values were obtained with CONN Toolbox. Hierarchical regressions controlled for sex, race, ethnicity, years of education, and scanner site, as this was a multi-site study. Greater within-network CON connectivity was associated with better verbal learning (HVLT-R Total Recall, Learning Ratio), visuospatial learning (BVMT-R Total Recall), and visuospatial memory (BVMT-R Delayed Recall). Greater FPCN connectivity was associated with better visuospatial learning (BVMT-R Learning Ratio) but did not survive multiple comparison correction. DMN connectivity was not associated with these measures of learning and memory. CON may make small but unique contributions to learning and memory across domains, making it a valuable target in future longitudinal studies and interventions to attenuate memory decline. Further research is necessary to understand the role of FPCN in learning and memory.

Impact of cardiovascular risk factors on the relationships of physical activity with mood and cognitive function in a diverse sample

Physical activity has well-known benefits for older adults' mood and cognitive functioning; however, it is not clear whether risk factors for cardiovascular disease (CVD) affect the relationships of physical activity with these health outcomes among diverse older adults. This study investigated the impact of CVD risk burden on the relationships among self-reported physical activity, mood, and cognitive functioning in a diverse sample of 62 adults age 45 and older. We found that higher physical activity was associated with better attention and verbal working memory at lower CVD risk, but with worse attention and verbal working memory at higher CVD risk levels. Thus, higher CVD risk might limit the effectiveness of exercise interventions for mood and cognitive functioning. Future studies are needed to further clarify individual differences that impact the relationships among physical activity, CVD risk, and cognitive outcomes.

Effects of race, baseline cognition, and APOE on the association of affective dysregulation with incident dementia: A longitudinal study of dementia-free older adults

BACKGROUND

Affective symptoms are dementia risk factors. Mild behavioral impairment (MBI) is a neurobehavioral syndrome that refines incorporation of psychiatric symptomatology into dementia prognostication by stipulating symptoms must emerge de novo in later life and persist for ≥6 months. Here, we investigated the longitudinal association of MBI-affective dysregulation with incident dementia.

METHODS

National Alzheimer Coordinating Centre participants with normal cognition (NC) or mild cognitive impairment (MCI) were included. MBI-affective dysregulation was operationalized as Neuropsychiatric Inventory Questionnaire-measured depression, anxiety, and elation at two consecutive visits. Comparators had no neuropsychiatric symptoms (no NPS) in advance of dementia. Cox proportional hazard models were implemented to assess the risk of dementia, adjusted for age, sex, years of education, race, cognitive diagnosis, and APOE-ε4 status, with interaction terms as appropriate.

RESULTS

The final sample included 3698 no-NPS (age:72.8; 62.7 % female), and 1286 MBI-affective dysregulation participants (age:75; 54.5 % female). MBI-affective dysregulation had lower dementia-free survival (p < 0.0001) and greater incidence of dementia (HR = 1.76, CI:1.48-2.08, p < 0.001) versus no NPS. Interaction analyses revealed that MBI-affective dysregulation was associated with higher dementia incidence in Black participants than White (HR = 1.70, CI:1.00-2.87, p = 0.046), NC than MCI (HR = 1.73, CI:1.21-2.48, p = 0.0028), and APOE-ε4 noncarriers than carriers (HR = 1.47, CI:1.06-2.02, p = 0.0195). Of MBI-affective dysregulation converters to dementia, 85.5 % developed Alzheimer's disease, which increased to 91.4 % in those with amnestic MCI.

LIMITATIONS

MBI-affective dysregulation was not stratified by symptom to further examine dementia risk.

CONCLUSIONS

Emergent and persistent affective dysregulation in dementia-free older adults is associated with substantial risk for dementia and should be considered in clinical assessments.

Intersectionality in Alzheimer's Disease: The Role of Female Sex and Black American Race in the Development and Prevalence of Alzheimer's Disease

It is well known that vascular factors and specific social determinants of health contribute to dementia risk and that the prevalence of these risk factors differs according to race and sex. In this review, we discuss the intersection of sex and race, particularly female sex and Black American race. Women, particularly Black women, have been underrepresented in Alzheimer's disease clinical trials and research. However, in recent years, the number of women participating in clinical research has steadily increased. A greater prevalence of vascular risk factors such as hypertension and type 2 diabetes, coupled with unique social and environmental pressures, puts Black American women particularly at risk for the development of Alzheimer's disease and related dementias. Female sex hormones and the use of hormonal birth control may offer some protective benefits, but results are mixed, and studies do not consistently report the demographics of their samples. We argue that as a research community, greater efforts should be made to not only recruit this vulnerable population, but also report the demographic makeup of samples in research to better target those at greatest risk for the disease.

Trends in Postmortem Neurodegenerative and Cerebrovascular Neuropathologies Over 25 Years

Importance

With rapid aging of the US population, understanding trends over time in dementia occurrence is essential to public health planning and intervention; this understanding includes trends in neuropathologies underlying clinical dementia.

Objective

To characterize trends in pathways underlying dementia by examining prevalence of postmortem neuropathologies in birth cohorts across 25 years.

Design, Setting, and Participants

Two longitudinal cohorts, the Religious Orders Study and the Rush Memory and Aging Project, with autopsy data from 1997 to 2022 with up to 27 years follow-up were analyzed. Deceased individuals with complete postmortem neuropathology evaluations were included, and 177 individuals with most distant (<1905) or recent (>1930) years of birth were excluded.

Exposures

Four categories of year of birth: 1905-1914, 1915-1919, 1920-1924, and 1925-1930.

Main Outcomes and Measures

Outcomes included pathologic diagnosis of Alzheimer disease (AD), global AD pathology, amyloid load, tau tangles, neocortical Lewy bodies, limbic-predominant age-related TDP-43 encephalopathy neuropathological change, atherosclerosis, arteriolosclerosis, gross chronic infarcts, and chronic microinfarcts. For comparison, pathologies in each birth epoch were age-standardized to age distribution of the cohorts. χ2 Tests were used for categorical outcomes, and analysis of variance was used to compare means across birth epochs.

Results

Overall, 1554 participants were examined (510 [33%] male; median [range] age at death, 90 [66-108] years). Participants were distributed fairly evenly across birth epochs (1905-1914: n = 374; 1915-1919: n = 360; 1920-1924: n = 466; 1925-1930: n = 354). Across year of birth groups, no differences were found in prevalence of pathologic AD diagnosis; age-standardized prevalence fluctuated between 62% and 68% in the birth cohorts (χ2 test: P = .76 across birth epochs). Similarly, no differences were found in mean levels of global AD pathology, although there was greater density specifically of tau tangles in later birth cohorts (eg, age-standardized mean [SD], 1.53 [1.20] years for the 1905-1914 cohort and 1.87 [1.47] years for the 1925-1930 cohort; analysis of variance test: P = .01 across birth cohorts). There were no differences over time in other neurodegenerative pathologies. In contrast, atherosclerosis and arteriosclerosis were dramatically lower over time; for example, age-standardized prevalence of moderate to severe atherosclerosis ranged from 54% among those born from 1905-1914 to 22% for 1925-1930 (χ2 test: P < .001 across birth epochs).

Conclusion and Relevance

In this study, few differences in neurodegenerative pathologies were found, but there may be worse levels of tau tangles across birth cohorts over 25 years. This indicates that any improvements over time in clinical dementia observed by cohorts are likely in part associated with improved resilience to pathology rather than reduced AD pathology. Finally, vessel pathologies were markedly lower over birth cohorts, indicating the assocation with brain health of populationwide improvements in several vascular risk factors.

Independent effect of cardiometabolic syndromes and depression on dementia in Parkinson's disease: A 12-year longitudinal follow-up study of a nationwide cohort

BACKGROUND

We aimed to investigate the incidence rate of Parkinson's disease dementia (PDD) according to age and disease duration by sex. Furthermore, we explored the effect of each cardiometabolic syndrome and depression on the incidence of PDD.

METHODS

Using data from the Korean National Health Insurance Service, 79,622 patients with de novo Parkinson's disease (PD) aged ≥40 years between January 2002 and December 2010 were followed to December 2019. We analyzed the incidence of PDD according to age at PD diagnosis and disease duration. To determine cardiometabolic syndromes and depression that affected PDD, we used Fine and Gray competing regression after controlling for age and sex.

RESULTS

During the 12.5-year follow-up period, the incidence of PDD increased with age at PD diagnosis (0.81-45.31 per 1000 person-years among those aged 40-44 and over 80 years, respectively) and longer disease duration (22.68 per 1000 person-years in 1-2 years to 34.16 per 1000 person-years in 15-16 years). Hypertension (subdistribution hazard ratio [SHR] = 1.11; 95% confidence interval [CI] 1.07-1.16), diabetes (SHR = 1.09; 95% CI 1.05-1.14), dyslipidemia (SHR = 1.15; 95% CI 1.11-1.20), and depression (SHR = 1.36; 95% CI 1.30-1.41) independently increased the risk for PDD.

CONCLUSIONS

Our findings provide insights into cardiometabolic syndromes as modifiable risk factors for incident PDD. Furthermore, our results will help in designing public health policies with respect to controlling cardiometabolic syndromes and depression to prevent incident PDD in patients with PD.

Classification statistics of the Montreal Cognitive Assessment (MoCA): Are we interpreting the MoCA correctly?

OBJECTIVE

The Montreal Cognitive Assessment (MoCA) is a common cognitive screener for detecting mild cognitive impairment (MCI). However, previously suggested cutoff scores of 26/30 and above is often criticized and lacks racial diversity. The purpose of this study is to investigate the potential influence of race on MoCA classification cutoff score accuracy.

METHOD

Data were obtained from the National Alzheimer's Coordinating Center (NACC) Uniform Data Set and yielded 4,758 total participants. Participants were predominately White (82.8%) and female (61.7%) with a mean age of 69.3 years (SD = 10.3) and education level of 16.3 years (SD = 2.6). Based on NACC's classification, participants were either cognitively normal (n = 3,650) or MCI (n = 1,108).

RESULTS

Sensitivity and specificity analyses revealed that when using the cutoff score of ≤26/30, the MoCA correctly classified 73.2% of White cognitively normal participants and 83.1% of White MCI participants. In contrast, this criterion correctly classified 40.5% of Black cognitively normal participants and 90.8% of Black MCI participants. Our sample was highly educated; therefore, we did not observe significant differences in scores when accounting for education across race. Classification statistics are presented.

CONCLUSIONS

Black participants were misclassified at a higher rate than White participants when applying the ≤26/30 cutoff score. We suggest cutoff scores of ≤25/30 be applied to White persons and ≤22/30 for Black persons. These findings highlight the need for racially stratified population-based norms given the high misclassification of Black participants without such adjustment.

Social isolation and 9-year dementia risk in community-dwelling Medicare beneficiaries in the United States

BACKGROUND

Social isolation can influence whether older adults develop dementia. We examine the association between social isolation and incident dementia among older adults in a nationally representative sample of community dwelling older adults in the United States (U.S.). We also investigate whether this association varies by race and ethnicity.

METHODS

Data (N = 5022) come from the National Health and Aging Trends Study, a longitudinal and nationally representative cohort of older adults in the U.S. A composite measure of social isolation was used to classify older adults as socially isolated or not socially isolated at baseline. Demographic and health factors were measured at baseline via self-report. Dementia was measured at each round of data collection. Discrete-time proportional hazard time-to-event models were used to assess the association between social isolation and incident dementia over 9 years (2011-2020).

RESULTS

Of 5022 older adults, 1172 (23.3%) were socially isolated, and 3850 (76.7%) were not socially isolated. Adjusting for demographic and health factors, being socially isolated (vs. not socially isolated) was associated with a 1.28 (95% CI: 1.10-1.49) higher hazard of incident dementia over 9 years. There was no statistically significant difference by race and ethnicity.

CONCLUSION

Social isolation among older adults is associated with greater dementia risk. Elucidating the pathway by which social isolation impacts dementia may offer meaningful insights for the development of novel solutions to prevent or ameliorate dementia across diverse racial and ethnic groups.

Testing the Reserve Capacity Model: Does Race Moderate the Relationship Between Negative Emotions and Neurocognition?

OBJECTIVE

To test whether race moderates the relationship between negative emotions and neurocognition by applying the reserve capacity model within a large sample that spans adulthood.

METHOD

The study sample (N = 1,020) consisted of community-dwelling adults between 18 and 84 years of age who were drawn from the Virginia Cognitive Aging Project. Demographic variables were used to match a sample of Black participants to a sample of White participants. Race was examined as a moderator of the relationship between negative emotions (i.e., depressive symptoms, trait anxiety, and the negative affect subscale from the Positive and Negative Affect Schedule) and neurocognitive variables (episodic memory, reasoning, spatial visualization, and processing speed) with multiple-group structural equation modeling.

RESULTS

After accounting for sociodemographic variables, depressive symptoms were negatively associated with processing speed in both groups, and with worse reasoning in the White subsample. Negative affect was associated with lower reasoning performance in both groups and with lower spatial visualization in the White subsample. Trait anxiety was not significantly associated with the neurocognitive constructs in either group. Multigroup structural equation models showed that the magnitudes of the associations were not different between the Black and White subsamples. Thus, race did not moderate the relationships between depressive symptoms, trait anxiety, and negative affect with neurocognition.

CONCLUSIONS

Negative emotions are associated with lower performance on different neurocognitive tasks, but race does not moderate these relationships. Future research should examine perceived discrimination or other psychosocial variables when examining the relationships among negative emotions and neurocognition.

Co-occurring pathogenic variants in 6q27 associated with dementia spectrum disorders in a Peruvian family

Evidence suggests that there may be racial differences in risk factors associated with the development of Alzheimer's disease and related dementia (ADRD). We used whole-genome sequencing analysis and identified a novel combination of three pathogenic variants in the heterozygous state (UNC93A: rs7739897 and WDR27: rs61740334; rs3800544) in a Peruvian family with a strong clinical history of ADRD. Notably, the combination of these variants was present in two generations of affected individuals but absent in healthy members of the family. In silico and in vitro studies have provided insights into the pathogenicity of these variants. These studies predict that the loss of function of the mutant UNC93A and WDR27 proteins induced dramatic changes in the global transcriptomic signature of brain cells, including neurons, astrocytes, and especially pericytes and vascular smooth muscle cells, indicating that the combination of these three variants may affect the neurovascular unit. In addition, known key molecular pathways associated with dementia spectrum disorders were enriched in brain cells with low levels of UNC93A and WDR27. Our findings have thus identified a genetic risk factor for familial dementia in a Peruvian family with an Amerindian ancestral background.

Association Between Hippocampal Volume and African Neuropsychology Memory Tests in Adult Individuals with Probable Alzheimer's Disease in Democratic Republic of Congo

BACKGROUND

Western studies indicate potential associations between hippocampal volume and memory in the trajectory of Alzheimer's disease (AD). However, limited availability of neuroimaging technology and neuropsychological tests appropriate for sub-Saharan African (SSA) countries makes it difficult to establish neuroanatomical associations of hippocampus and memory in this locale.

OBJECTIVE

This study examined hippocampal volumes and memory in healthy control (HC) and probable AD groups in the Democratic Republic of Congo (DRC).

METHODS

Forty-six subjects with probable AD and 29 HC subjects were screened using the Community Instrument for Dementia and the Alzheimer Questionnaire. Participants underwent neuroimaging in Kinshasa, DRC, and memory was evaluated using the African Neuropsychology Battery (ANB). Multiple linear regression was used to determine associations between hippocampal volumes and memory.

RESULTS

Patients with probable AD performed significantly worse than HCs on ANB memory measures, and exhibited greater cerebral atrophy, which was significantly pronounced in the medial temporal lobe region (hippocampus, entorhinal cortex). Both AD and HC subjects exhibited high rates of white matter hyperintensities compared to international base rate prevalence, which was significantly worse for probable AD. Both also exhibited elevated rates of microhemorrhages. Regression analysis demonstrated a significant association between hippocampal volume and ANB memory tests. Hippocampal atrophy discriminated probable AD from the HC group.

CONCLUSIONS

This study establishes the feasibility of conducting neuroimaging research in the SSA, demonstrates many known neuroimaging findings in probable AD patients hold up using culturally appropriate memory tasks, and suggest cardiovascular problems are a greater issue in SSA than in Western countries.

Dementia with Lewy bodies: Impact of co-pathologies and implications for clinical trial design

Dementia with Lewy bodies (DLB) is clinically defined by the presence of visual hallucinations, fluctuations, rapid eye movement (REM) sleep behavioral disorder, and parkinsonism. Neuropathologically, it is characterized by the presence of Lewy pathology. However, neuropathological studies have demonstrated the high prevalence of coexistent Alzheimer's disease, TAR DNA-binding protein 43 (TDP-43), and cerebrovascular pathologic cases. Due to their high prevalence and clinical impact on DLB individuals, clinical trials should account for these co-pathologies in their design and selection and the interpretation of biomarkers values and outcomes. Here we discuss the frequency of the different co-pathologies in DLB and their cross-sectional and longitudinal clinical impact. We then evaluate the utility and possible applications of disease-specific and disease-nonspecific biomarkers and how co-pathologies can impact these biomarkers. We propose a framework for integrating multi-modal biomarker fingerprints and step-wise selection and assessment of DLB individuals for clinical trials, monitoring target engagement, and interpreting outcomes in the setting of co-pathologies.

Racial/Ethnic Disparities in Misidentification of Dementia in Medicare Claims: Results from the Washington Heights-Inwood Columbia Aging Project

BACKGROUND

Misidentification of dementia in Medicare claims is quite common.

OBJECTIVE

We examined potential race/ethnic disparities in misidentification of dementia in Medicare claims in a diverse cohort of older adults who underwent careful clinical assessment.

METHODS

Participants were enrolled in the Washington Heights-Inwood Columbia Aging Project (WHICAP), a multiethnic, population-based, prospective study of cognitive aging in which dementia status was assessed using a rigorous clinical protocol. ICD-9-CM and ICD-10-CM diagnosis codes in all available Medicare claims (1999-2019) were compared to clinical dementia diagnosis and categorized into three mutually exclusive groups: 1) congruent-, 2) over-, and 3) under- identification during the study period. Multinomial logistic regression model was used to examine the relationship between race (White, African American/Black, other) and ethnicity (Hispanic/Latinx, non-Hispanic/Latinx) and congruency of dementia identification after controlling for clinical (cognition, function, comorbidities) and demographic characteristics (age, sex, education), and inpatient and outpatient utilization.

RESULTS

Across all person-years, 88.4% had congruent identification of dementia compared to clinical diagnosis, in 4.1% of the times participants were over-identified with dementia, and 7.5% of the times the participants were under-identified. Rates of misidentification was higher in minority participants than in White, non-Hispanic participants. Multivariable estimation results showed that the probability of over-identification with dementia was 2.2% higher for African American/Black than White (p = 0.05) and 2.7% higher for Hispanic participants than non-Hispanics (p = 0.03) participants. Differences in under-identification by race/ethnicity were not statistically significant.

CONCLUSIONS

African American/Black and Hispanic participants were more likely over-identified with dementia in Medicare claims.

Gender, Age of Migration, and Cognitive Life Expectancies Among Older Latinos: Evidence From the Health and Retirement Study

OBJECTIVES

Migration and gender are important factors that differentiate the Latino immigrant experience in the United States. We investigate the association between nativity status, age of migration, and cognitive life expectancies among a nationally representative sample of Latino adults aged 50 and older to explore whether age of migration and gender influence cognitive aging across the life course.

METHODS

This study used data from the Health and Retirement Study (1998-2016) to estimate Sullivan-based life tables of cognitive life expectancies by nativity, age of migration, and gender for older Latino adults. Cognitive status was based on the Langa-Weir algorithm. We test for both within-group (i.e., nativity and age of migration) and gender differences to explore the overall burden of disease among this rapidly growing population.

RESULTS

Foreign-born Latinos, regardless of age of migration or gender, spend a greater number of years after age 50 with cognitive impairment/no dementia than U.S.-born Latinos. However, the number of years spent with dementia varied by subgroup with midlife immigrant men and late-life immigrant men and women exhibiting a significant disadvantage relative to the U.S.-born. Furthermore, we document a gender disadvantage for all Latino women, regardless of immigrant status.

DISCUSSION

The robust relationship between nativity, age of migration, and cognitive aging suggests that older foreign-born Latinos experiencing cognitive decline may place serious burdens on families. Future research should target the needs of different subgroups of older Latinos who are entering their last decades of life to develop culturally appropriate long-term care programs.

Screening and enrollment of underrepresented ethnocultural and educational populations in the Alzheimer's Disease Neuroimaging Initiative (ADNI)

INTRODUCTION

An analysis of the ethnocultural and socioeconomic composition of Alzheimer's Disease Neuroimaging Initiative (ADNI) participants is needed to assess the generalizability of ADNI data to diverse populations.

METHODS

ADNI data collected between October 2004 and November 2020 were used to determine ethnocultural and educational composition of the sample and differences in the following metrics: screening, screen fails, enrollment, biomarkers.

RESULTS

Of 3739 screened individuals, 11% identified as being from ethnoculturally underrepresented populations (e.g., Black, Latinx) and 16% had <12 years of education. Of 2286 enrolled participants, 11% identified as ethnoculturally underrepresented individuals and 15% had <12 years of education. This participation is considerably lower than US Census data for adults 60+ (ethnoculturally underrepresented populations: 25%; <12 years of education: 4%). Individuals with <12 years of education failed screening at a higher rate.

DISCUSSION

Our findings suggest that ADNI results may not be entirely generalizable to ethnoculturally diverse and low education populations.

Epidemiology of neurodegenerative diseases in the East African region: A meta-analysis

INTRODUCTION

There is a scarcity of epidemiological data on neurodegenerative diseases (NDs) in East Africa. This meta-analysis provides the regional prevalence of NDs, their contributing factors, and evidence of change over time concerning gender per age or year.

METHODS

Articles were retrieved from electronic databases following the PRISMA standard.

RESULTS

Forty-two studies were reviewed, and 25 were meta-analyzed with a random-effects model. The pool estimate proportion of 15.27%, 95% CI (0.09-0.23) (I² = 98.25%), (Q = 1,369.15, p < 0.0001) among a population of 15,813 male/female and 1,257 with NDs. Epidemiological characteristics associated with NDs include Dyskinesias prevalence 55.4%, 95% CI (13.5; 90.9), I² (96%) and subsistence farming prevalence 11.3%, 95% CI (5.8; 20.9), I² (99%). Publication bias by Egger test was (z = 4.1913, p < 0.0001), while rank correlation test using Kendall's model was (tau = 0.1237, p = 0.3873). Heterogeneity (R² design = 5.23%, p design < 0.0001; R² size = 52.163%, p size < 0.001; and R² period = 48.13, p period < 0.0001. Covariates (R² design + size + period = 48.41%, p < 0.001).

CONCLUSION

There is a high prevalence of NDs in the East African region, which could impact life expectancy, morbidity, and quality of life. Thus, early screening and regular surveillance could assist in management strategies.

Longitudinal neighbourhood determinants with cognitive health and dementia disparities: protocol of the Multi-Ethnic Study of Atherosclerosis Neighborhoods and Aging prospective cohort study

INTRODUCTION

The burden of Alzheimer's disease (AD) and AD-related dementias (ADRD) is increasing nationally and globally, with disproportionate impacts on lower-income, lower education and systematically marginalised older adults. Presence of inequalities in neighbourhood factors (eg, social context, physical and built environments) may affect risk of cognitive decline and be key for intervening on AD/ADRD disparities at the population level. However, existing studies are limited by a dearth of longitudinal, detailed neighbourhood measures linked to rich, prospective cohort data. Our main objective is to identify patterns of neighbourhood change related to prevalence of-and disparities in-cognitive decline and dementia.

METHODS AND ANALYSES

We describe the process of collecting, processing and linking extensive neighbourhood data to the Multi-Ethnic Study of Atherosclerosis (MESA), creating a 25+ years dataset. Within the MESA parent study, the MESA Neighborhoods and Aging cohort study will characterise dynamic, longitudinal neighbourhood social and built environment variables relevant to cognition for residential addresses of MESA participants. This includes administering new surveys, expanding residential address histories, calculating new measures derived from spatial data and implementing novel deep learning algorithms on street-level imagery. Applying novel statistical techniques, we will examine associations of neighbourhood environmental characteristics with cognition and clinically relevant AD/ADRD outcomes. We will investigate determinants of disparities in outcomes by socioeconomic position and race/ethnicity and assess the contribution of neighbourhood environments to these disparities. This project will provide new evidence about pathways between neighbourhood environments and cognitive outcomes, with implications for policies to support healthy ageing.

ETHICS AND DISSEMINATION

This project was approved by the University of Washington and Drexel University Institutional Review Boards (protocols #00009029 and #00014523, and #180900605). Data will be distributed through the MESA Coordinating Center. Findings will be disseminated in peer-reviewed scientific journals, briefs, presentations and on the participant website.

Accounting for lack of representation in dementia research: Generalizing KHANDLE study findings on the prevalence of cognitive impairment to the California older population

INTRODUCTION

Most dementia studies are not population-representative; statistical tools can be applied to samples to obtain critically-needed population-representative estimates, but are not yet widely used.

METHODS

We pooled data from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study and the California Behavioral Risk Factor Surveillance System (CA-BRFSS), a population-representative study. Using weights accounting for sociodemographic/health differences between KHANDLE and CA-BRFSS, we estimated cognitive impairment prevalence and age- and sex-adjusted racial/ethnic inequalities in California adults 65+ without prior dementia diagnosis.

RESULTS

After weighting KHANDLE, the estimated cognitive impairment prevalence in California was 20.3% (95% confidence interval 17.8-23.0); unweighted prevalence was 24.8% (23.1%-26.6%). Inequalities (larger prevalences) were observed among Black and Asian groups versus whites.

DISCUSSION

We used a novel statistical approach to estimate population-representative cognitive impairment prevalence and inequalities. Such statistical tools can help obtain population-representative estimates from existing studies and inform efforts to reduce racial/ethnic disparities.

Digital culturally tailored marketing for enrolling Latino participants in a web-based registry: Baseline metrics from the Brain Health Registry

INTRODUCTION

This culturally tailored enrollment effort aims to determine the feasibility of enrolling 5000 older Latino adults from California into the Brain Health Registries (BHR) over 2.25 years.

METHODS

This paper describes (1) the development and deployment of culturally tailored BHR websites and digital ads, in collaboration with a Latino community science partnership board and a marketing company; (2) an interim feasibility analysis of the enrollment efforts and numbers, and participant characteristics (primary aim); as well as (3) an exploration of module completion and a preliminary efficacy evaluation of the culturally tailored digital efforts compared to BHR's standard non-culturally tailored efforts (secondary aim).

RESULTS

In 12.5 months, 3603 older Latino adults were enrolled (71% of the total California Latino BHR initiative enrollment goal). Completion of all BHR modules was low (6%).

DISCUSSION

Targeted ad placement, culturally tailored enrollment messaging, and culturally tailored BHR websites increased enrollment of Latino participants in BHR, but did not translate to increased module completion.

HIGHLIGHTS

Culturally tailored social marketing and website improvements were implemented. The efforts enrolled 5662 Latino individuals in 12.5 months. The number of Latino Brain Health Registry (BHR) participants increased by 122.7%. We failed to adequately enroll female Latinos and Latinos with lower education. Future work will evaluate effects of a newly released Spanish-language BHR website.

Cognability: An Ecological Theory of neighborhoods and cognitive aging

While a growing body of evidence points to potentially modifiable individual risk factors for dementia, the built and social environments in which people develop and navigate cognitive decline are largely overlooked. This paper proposes a new theoretical concept, Cognability, to conceptualize how supportive an area is to cognitive health among aging residents. Cognability incorporates a constellation of both positive and negative neighborhood features related to physical activity, social interaction and cognitive stimulation in later life. We analyzed data from the REasons for Geographic And Racial Differences in Stroke Study, a national sample of older Black and white adults in the United States (n = 21,151; mean age at assessment = 67; data collected 2006-2017). Generalized additive multilevel models examined how cognitive function varied by neighborhood features. Access to civic and social organizations, recreation centers, fast-food and coffee establishments, arts centers, museums, and highways were significantly associated with cognitive function. Race-, gender-, and education-specific models did not yield substantial improvements to the full-model. Our results suggest that the unequal distribution of amenities and hazards across neighborhoods may help account for considerable inequities observed in cognitive health among older adults. Cognability advances ecological theories of aging through an innovative "whole neighborhood" approach. It aims to identify which specific neighborhood features are most protective of cognitive health among aging adults to inform upstream public health initiatives, community interventions, and policy.

The survey for memory, attention, and reaction time (SMART): Preliminary normative online panel data and user attitudes for a brief web-based cognitive performance measure

ObjectiveThe Survey for Memory, Attention, and Reaction Time (SMART) was recently introduced as a brief (<5 min), self-administered, web-based measure of cognitive performance in older adults. The purpose of this study was threefold: (1) to develop preliminary norms on the SMART; (2) to examine the relationship between demographic variables (i.e. age, sex, education), device type used, and SMART performance; and (3) to assess user attitudes of the SMART. Method A sample of 1,050 community-dwelling adults (M age =59.5 (15.2), M education = 16.5 (2.1), 67.1% female, 96% white) was recruited from an ongoing web-based research cohort. Participants completed the SMART, which consists of four face-valid cognitive tasks assessing visual memory, attention/processing speed, and executive functioning. SMART performance outcome metrics were subtest completion time (CT), click count, and total CT. Participants provided demographic information and completed a survey of user attitudes toward the SMART (i.e. usability, acceptability). Results Older age was the only demographic variable associated with slower SMART total CT (r = .60, p <.001). Education was not associated with SMART CT or click counts overall (p > .05). Male sex was generally associated with longer SMART CT (p < .001, partial eta squared = .14) on all sub-tests. Regarding acceptability, 97.3% indicated willingness to take the SMART again, with more than half willing to complete it on a weekly basis. Conclusion The preliminary normative data on the SMART indicates that it is a feasible and well-accepted web-based cognitive assessment tool that can be administered on multiple device platforms.

Traversing the Aging Research and Health Equity Divide: Toward Intersectional Frameworks of Research Justice and Participation

Meaningful reductions in racial and ethnic inequities in chronic diseases of aging remain unlikely without major advancements in the inclusion of minoritized populations in aging research. While sparse, studies investigating research participation disparities have predominantly focused on individual-level factors and behavioral change, overlooking the influence of study design, structural factors, and social determinants of health on participation. This is also reflected in conventional practices that consistently fail to address established participation barriers, such as study requirements that impose financial, transportation, linguistic, and/or logistical barriers that disproportionately burden participants belonging to minoritized populations. These shortcomings not only risk exacerbating distrust toward research and researchers, but also introduce significant selection biases, diminishing our ability to detect differential mechanisms of risk, resilience, and response to interventions across subpopulations. This forum article examines the intersecting factors that drive both health inequities in aging and disparate participation in aging research among minoritized populations. Using an intersectional, social justice, and emancipatory lens, we characterize the role of social determinants, historical contexts, and contemporaneous structures in shaping research accessibility and inclusion. We also introduce frameworks to accelerate transformative theoretical approaches to fostering equitable inclusion of minoritized populations in aging research.

Modifiable psychosocial risk factors and delayed onset of dementia in older populations: analysis of two prospective US cohorts

OBJECTIVE

Preventing Alzheimer's dementia (AD) fundamentally equates to delaying onset. Thus, we quantified associations of modifiable, psychosocial risk factors to years of delayed onset of dementia.

DESIGN

Two prospective cohorts (n=2860) with negative and positive psychosocial factors measured at baseline (depressive symptoms, neuroticism, cognitive activity).

SETTING AND PARTICIPANTS

Religious Orders Study of older priests, nuns and brothers across the USA, initiated in 1994; Rush Memory and Aging Project, of older persons in Chicago area, initiated in 1997.

OUTCOME MEASURE

We conducted annual neurological and neuropsychological assessments to identify AD (n=785 incident cases). We compared age at diagnosis of AD across psychosocial risk factor groups, controlling for confounders, using accelerated failure time models.

RESULTS

We found strong relations of three or more depressive symptoms with age at AD diagnosis; estimated mean age at diagnosis was 86.9 years with significant symptoms versus 92.1 years with no symptoms (p=0.001). In addition, neuroticism was inversely related to age at AD diagnosis; estimated mean age at diagnosis was 88.8 years for the highest neuroticism tertile and 93.1 years in the lowest tertile (p<0.001). Participants with higher cognitive activity (such as reading books) had later AD diagnosis; estimated mean age at diagnosis was 89.2 years for the lowest cognitive activity group and 92.6 years for the highest activity group (p<0.001).

CONCLUSIONS

Higher depressive symptoms were associated with 5-year acceleration in AD; higher neuroticism with 4-year acceleration and higher cognitive activity with a 3.5-year delay. To translate findings, prior health services research in the USA indicates delaying dementia 5 years could add 3 years of life and reduce individual costs of care >$60 000. These results provide a rigorous, easily translatable metric for communicating and evaluating the potential public health impact of psychosocial and experiential interventions.

Dementia Incidence, APOE Genotype, and Risk Factors for Cognitive Decline in Aboriginal Australians: A Longitudinal Cohort Study

BACKGROUND AND OBJECTIVES

Aboriginal Australians are disproportionately affected by dementia, with incidence in remote populations approximately double non-Indigenous populations. This study aimed to identify dementia incidence and risk factors in Aboriginal Australians residing in urban areas, which are currently unknown.

METHODS

A population-based cohort of Aboriginal Australians aged 60+ was assessed at baseline and 6-year follow-up. Life-course risk factors (baseline) were examined for incident dementia or mild cognitive impairment (MCI) using logistic regression analyses; adjustments were made for age. APOE genotyping was available for 86 people.

RESULTS

Data were included from 155 participants aged 60-86 years (mean=65.70, SD=5.65; 59 male). There were 16 incident dementia cases (age-standardised rate 35.97/1,000 person-years, 95% CI 18.34-53.60); and 36 combined incident MCI and dementia cases. Older age (OR 2.29, 1.42-3.70), male sex (OR 4.14, 1.60-10.77), unskilled work history (OR 5.09, 1.95-13.26), polypharmacy (OR 3.11, 1.17-8.28), and past smoking (OR 0.24, 0.08-0.75) were associated with incident MCI/dementia in the final model. APOE ε4 allele frequency was 24%; heterozygous or homozygous ε4 was associated with incident MCI/dementia (bivariate OR 3.96, 1.25-12.50).

DISCUSSION

These findings provide the first evidence for higher dementia incidence in Aboriginal Australians from urban areas, where the majority of Aboriginal people reside. This study also sheds light on sociodemographic, health and genetic factors associated with incident MCI/dementia at older ages in this population, which is critical for targeted prevention strategies.

Current status of inclusion of black participants in neuropsychological studies: A scoping review and call to action

In recognition that insufficient diversity in research impedes the generalizability of findings and negatively impacts clinical outcomes, the 1993 National Institutes of Health (NIH) Revitalization Act required NIH-funded clinical trials to include and assess outcomes for women and minority participants. Since that time, the American Psychological Association (APA) and the American Academy of Clinical Neuropsychology (AACN) have also acknowledged the reporting of this information as an essential element of research, and they have established similar aspirational goals. Nevertheless, Black communities remain disproportionately underrepresented in neuropsychology research. The objective of this study was to investigate current levels of inclusion and reporting of Black research participation in neuropsychological studies.

Publications from high impact neuropsychology journals between 2019-2020 were selected via established methodologies. Studies were analyzed to determine the rates of demographic inclusion and reporting of minority, particularly Black, participants.

A total of 1,764 articles were reviewed across seven neuropsychology journals. Of the 653 studies not excluded for other reasons, 43% neglected to include sufficient information about participants' race/ethnicity. Of the subset of eligible studies that did include racial/ethnic demographic information (n = 349), only 61% included any Black participants at all. Only 34.1% of them included enough Black participants equal to or greater than the proportion of Black individuals within the United States.

Setting a standard of routinely reporting and analytically reflecting on demographic information is necessary to make valid inferences regarding disease sequelae, treatment, and public health strategies. The authors offer specific recommendations to improve the inclusion and reporting of Black research participation, ensure compliance with established policies, and improve the quality of neuropsychological research.

Diversifying Recruitment Registries: Considering Neighborhood Health Metrics

BACKGROUND

Disparities in clinical research participation perpetuate broader health disparities. Recruitment registries are novel tools to address known challenges in accrual to clinical research. Registries may accelerate accrual, but the utility of these tools to improve generalizability is unclear.

OBJECTIVE

To examine the diversity of a local on-line recruitment registry using the Area Deprivation Index (ADI), a publicly available metric of neighborhood disadvantage.

DESIGN

Retrospective analysis.

SETTING

Data were collected in the University of California Irvine Consent-to-Contact Registry.

PARTICIPANTS

We categorized N=2,837 registry participants based on the ADI decile (collapsed into quintiles) using a state-based rankings.

MEASUREMENTS

We examined the proportion of enrollees per ADI quintile and quantified the demographics of these groups. We assessed willingness to participate in studies involving unique research procedures among the ADI groups.

RESULTS

Although registry enrollees represented the full spectrum of the ADI, they disproportionately represented less disadvantaged neighborhoods (lowest to highest quintiles: 42%, 30%, 15%, 6%, 7%). Compared to participants from less disadvantaged neighborhoods, participants from more disadvantaged neighborhoods were more often female, of non-white race, and Hispanic ethnicity. Despite demographic differences, ADI groups were observed to have similar willingness to participate in research studies.

CONCLUSIONS

People from more disadvantaged neighborhoods may be underrepresented in recruitment registries, increasing the risk that they will be underrepresented when using these tools to facilitate prospective recruitment to clinical research. Once enrolled in registries, participants from more disadvantaged neighborhoods may be equally willing to participate in research. Efforts to increase representation of participants from disadvantaged neighborhoods in registries could be an important first step toward increasing the generalizability of clinical research.

Alzheimer disease in African American individuals: increased incidence or not enough data?

Research on racial differences in Alzheimer disease (AD) dementia has increased in recent years. Older African American individuals bear a disproportionate burden of AD and cognitive impairment compared with non-Latino white individuals. Tremendous progress has been made over the past two decades in our understanding of the neurobiological substrates of AD. However, owing to well-documented challenges of study participant recruitment and a persistent lack of biological data in the African American population, knowledge of the drivers of these racial disparities has lagged behind. Therapeutic targets and effective interventions for AD are increasingly sought, but without a better understanding of the disease in African American individuals, any identified treatments and/or cures will evade this rapidly growing at-risk population. In this Perspective, I introduce three key obstacles to progress in understanding racial differences in AD: uncertainty about diagnostic criteria, disparate cross-sectional and longitudinal findings; and a dearth of neuropathological data. I also highlight evidence-informed strategies to move the field forward.

In this Perspective, Barnes introduces three key obstacles to progress in our understanding of racial differences in Alzheimer disease and highlights evidence-informed strategies that can move the field forward.

Stress Is Associated With Neurocognitive Function in Hispanic/Latino Adults: Results From HCHS/SOL Socio-Cultural Ancillary Study

OBJECTIVES

The purpose of this study was to evaluate the hypothesis that chronic and acculturative stress would be negatively associated with neurocognitive function among middle aged to older Hispanics/Latinos.

METHOD

Our analytic sample consisted of 3,265 participants (mean age = 56.7 (±0.24)) from the Hispanic Community Health Study/Study of Latinos who participated in its Sociocultural Ancillary Study. During the baseline phase of this project, participants were assessed on multiple domains of neurocognitive function, and completed self-report measures of chronic and acculturative stress.

RESULTS

Each standard deviation increase in chronic stress was associated with lower performance in a verbal learning task (B = -.17, 95% CI [-.32, -.01]); this association was no longer significant after adjusting for mental and physical health symptoms, including depression and anxiety symptoms, and cardiovascular health. A standard deviation increase in acculturative stress was associated with poorer performance in all cognitive measures (Bs range = -.13 to -1.03). Associations of acculturation stress with psychomotor speed, verbal learning, and word fluency remained significant after adjusting for mental and physical health symptoms.

DISCUSSION

Our results suggest that mental and physical health may help explain some cross-sectional associations between stress and cognition and highlight the need to examine culture-specific psychosocial stressors to better understand the context of psychosocial risk factors for neurocognitive performance.

Reasons for undergoing amyloid imaging among cognitively unimpaired older adults

OBJECTIVES

Preclinical Alzheimer's disease (AD) clinical trials screen cognitively unimpaired older adults for biomarker criteria and disclose their results. We examined whether participants in the Anti-Amyloid Treatment in Asymptomatic Alzheimer's disease Study with "elevated" and "not elevated" amyloid differed in scores on the "Views and Perceptions of Amyloid Imaging" questionnaire. We hypothesized that, prior to disclosure, those with elevated amyloid would score higher than those with not elevated amyloid. We also quantified how responses changed after result disclosure.

METHODS

We assessed data from 4327 individuals who completed the questionnaire at screening visit 1 and after amyloid disclosure. We used linear regression models to assess the relationship between questionnaire category scores and amyloid status. We also quantified the relationship between category score changes and amyloid status.

RESULTS

Overall, participants scored altruism and contribution to research as the strongest motivations for undergoing amyloid imaging. Those with elevated amyloid scored 0.23 points higher in the Perceived Risk category, on average, than those who had not elevated amyloid prior to disclosure; this effect attenuated towards zero after adjusting for Cognitive Function Instrument score. After disclosure, participants with elevated amyloid demonstrated less within-subject change in Perceived Risk, on average, compared to those with similar pre-disclosure scores who had not elevated amyloid, while demonstrating greater changes in the altruism and planning categories.

INTERPRETATION

Altruism and learning disease risk motivated enrollment in this preclinical AD trial. Participants with elevated amyloid differed from their not elevated counterparts in their perceptions of amyloid imaging, even before undergoing the procedure.