The Minority Aging Research Study: ongoing efforts to obtain brain donation in African Americans without dementia

Improving generalizability and study design of Alzheimer's disease cohort studies in the United States by including under-represented populations

The poor generalizability of clinical research data due to the enrollment of highly educated, non-Latinx White participants hampers the development of therapies for Alzheimer's disease (AD). Black and Latinx older adults have a greater risk for dementia, yet it is unclear how health-care disparities and sociocultural factors influence potential AD therapies and prognosis. Low enrollment of under-represented populations may be attributable to several factors including greater exclusion due to higher rates of comorbidities, lower access to AD clinics, and the legacy of unethical treatment in medical research. This perspective outlines solutions tested in the Brain Health Registry (BHR) and the Alzheimer's Disease Neuroimaging Initiative (ADNI), including culturally-informed digital research methods, community-engaged research strategies, leadership from under-represented communities, and the reduction of exclusion criteria based on comorbidities. Our successes demonstrate that it is possible to increase the inclusion and engagement of under-represented populations into US-based clinical studies, thereby increasing the generalizability of their results.

Subjective Cognitive Decline Is Associated With Lower Baseline Cognition and Increased Rate of Cognitive Decline

OBJECTIVES

Subjective cognitive decline (SCD) is a known risk factor for Alzheimer's disease. However, little research has examined whether healthy older adults with SCD (SCD+) exhibit lower cognition and increased rates of cognitive decline compared to those without SCD (SCD-). The goal of this study was to examine if cognitive change over a 15-year period differs between SCD+ and SCD-.

METHOD

3,019 cognitively normal older adults (831 SCD+) from 3 Rush Alzheimer's Disease Center cohort studies were followed annually for up to a maximum of 15 years. Due to attrition, the average follow-up time was 5.7 years. Cognition was measured using z-scores of global cognition, episodic memory, semantic memory, perceptual speed, visuospatial ability, and working memory. Linear mixed-effects models investigated whether SCD was associated with cognitive change.

RESULTS

Both baseline cognition and cognitive change over time differed between SCD+ and SCD-. People with SCD+ exhibited lower baseline scores and a steeper decline in global cognition, episodic memory, semantic memory, and perceptual speed. People with SCD+ did not differ from SCD- in baseline visuospatial ability or working memory but exhibited increased change over time in those two domains compared to SCD-.

DISCUSSION

The observed results reveal that older adults with SCD+ have lower baseline cognition and steeper declines in cognition over time compared to SCD-. Older adults with SCD may be aware of subtle cognitive declines that occur over time in global cognition, episodic memory, semantic memory, perceptual speed, visuospatial ability, and working memory compared to those without SCD.

Rationale for the selection of dual primary endpoints in prevention studies of cognitively unimpaired individuals at genetic risk for developing symptoms of Alzheimer's disease

BACKGROUND

There is a critical need for novel primary endpoints designed to detect early and subtle changes in cognition in clinical trials targeting the asymptomatic (preclinical) phase of Alzheimer's disease (AD). The Alzheimer's Prevention Initiative (API) Generation Program, conducted in cognitively unimpaired individuals at risk of developing AD (e.g., enriched by the apolipoprotein E (APOE) genotype), used a novel dual primary endpoints approach, whereby demonstration of treatment effect in one of the two endpoints is sufficient for trial success. The two primary endpoints were (1) time to event (TTE)-with an event defined as a diagnosis of mild cognitive impairment (MCI) due to AD and/or dementia due to AD-and (2) change from baseline to month 60 in the API Preclinical Composite Cognitive (APCC) test score.

METHODS

Historical observational data from three sources were used to fit models to describe the TTE and the longitudinal APCC decline, both in people who do and do not progress to MCI or dementia due to AD. Clinical endpoints were simulated based on the TTE and APCC models to assess the performance of the dual endpoints versus each of the two single endpoints, with the selected treatment effect ranging from a hazard ratio (HR) of 0.60 (40% risk reduction) to 1 (no effect).

RESULTS

A Weibull model was selected for TTE, and power and linear models were selected to describe the APCC score for progressors and non-progressors, respectively. Derived effect sizes in terms of reduction of the APCC change from baseline to year 5 were low (0.186 for HR = 0.67). The power for the APCC alone was consistently lower compared to the power of TTE alone (58% [APCC] vs 84% [TTE] for HR = 0.67). Also, the overall power was higher for the 80%/20% distribution (82%) of the family-wise type 1 error rate (alpha) between TTE and APCC compared to 20%/80% (74%).

CONCLUSIONS

Dual endpoints including TTE and a measure of cognitive decline perform better than the cognitive decline measure as a single primary endpoint in a cognitively unimpaired population at risk of AD (based on the APOE genotype). Clinical trials in this population, however, need to be large, include older age, and have a long follow-up period of at least 5 years to be able to detect treatment effects.

Perceptions of Caring Recruitment Among Older Adults: African Americans and Non-Latinx Whites

BACKGROUND

African Americans (AAs) are underrepresented in health-related research studies. Few studies have investigated how behaviors of study recruiters affect recruitment of older AAs versus non-Latinx Whites (NLWs).

OBJECTIVES

The aim of this study was to explore whether caring behaviors influence AA and NLW older adults' decision to participate in hypothetical, high-commitment, health-related research studies and differences in participants' enrollment decisions by race.

METHODS

Using a descriptive, cross-sectional study design, guided by Kristen Swanson's middle-range theory of caring, a research-savvy sample of 60 AA and 60 NLW adults (age > 65 years) were randomly assigned one of two written vignettes. The concept of caring behaviors was manipulated and illustrated in a hypothetical recruitment scenario. A participant feedback survey was used to assess (a) participants' perceptions of caring and uncaring behaviors exhibited by the fictitious research recruiter, (b) differences in their willingness to participate based on vignette type, and (c) participants' judgment of the research recruiter as being caring or uncaring. A chi-square test assessed the association among categorical variables (caring behavior and participants' race).

RESULTS

Participants who received the vignette with the high caring recruiter were more than twice as likely to agree to participate in the study than those who received the vignette with the low caring recruiter. AA and NLW participants did not differ in their likelihood to agree to participate. Participants who received the caring vignette and judged the recruiter as caring were 5 times as likely to agree to participate in the high-commitment study than those who received the uncaring vignette ( p < .001). Associations did not vary by race.

DISCUSSION

This experimental study of equally recruited older adults from an existing longitudinal study revealed that caring behaviors in recruitment strategies are associated with an increased likelihood of participation in high-commitment research with older adults. The research-savvy AA participants were just as likely to participate in the hypothetical high-commitment research as their NLW peers when the fictional research recruiter was perceived as having caring behaviors. When targeting specific populations, it is essential to employ nuanced recruitment approaches where the study recruiters are attuned to caring behaviors.

Decision Making and Blood Sugar Indicators in Older African American Adults

Objectives: Decision making is a modifiable behavior associated with health outcomes. We investigated the association of decision making with blood sugar indicators in older community-dwelling African American adults. Methods: Participants were 328 older African American adults from community-based studies (mean age = 78). Decision making was assessed using a performance-based measure (range: 0-12). Blood sugar indicators were non-fasting hemoglobin A1c and blood glucose. Using regression, we assessed the relationship between decision making and each blood sugar indicator, controlling for demographics. We additionally examined if an association varied by known diabetes diagnosis. Results: Lower decision making was associated with higher HbA1c (b: -0.05, p-value: .03), but not blood glucose. In an interaction analysis, the association of lower decision making with higher levels of HbA1c was present only among individuals with known diabetes (b (with diabetes): -0.13, p-value: <.01). Discussion: Decision making may contribute to glycemic control in African American older adults with diabetes.

A Qualitative Examination of Knowledge, Experiences, and Considerations of PET Brain Scan Participation Among Older Black and Latino Adults

BACKGROUND

Biological biomarkers yielded from positron emission tomography (PET) brain scans serve as a pathway to understanding Alzheimer's disease pathology. PET brain scan data remain limited for populations traditionally under-included in aging research.

OBJECTIVE

The purpose of this qualitative study was to examine participant-identified barriers to PET brain scan consent and characterize participant-informed elements of educational materials needed to facilitate PET brain scan participation among older Black and Latino adults.

METHODS

Participants (N = 31) were older adults (mean age = 71 years) who self-identified as either non-Latino Black (n = 15) or Latino (n = 16). Each participant took part in a one-time, in-depth individual interview. Researchers analyzed data guided by a Grounded Theory Approach with both Open Coding and Constant Comparative Coding.

RESULTS

Four overarching themes emerged across all participants: 1) knowledge limitations; 2) requirements for consent; 3) motivators for participation; and 4) social networks. Within the four themes, there were differences based on participant ethnoracial group. For example, for Theme Three, older Black adults indicated that they would expect compensation for PET brain scan participation. Conversely, older Latinos stated that they would appreciate, but not anticipate, a financial incentive. All participants stressed the importance of written educational materials with subsequent verbal discussions with studystaff.

CONCLUSION

Findings inform the development and implementation of scientifically-relevant and culturally-cognizant engagement approaches, educational materials, and recruitment strategies to increase PET brain scan participation by diverse older adults.

Acculturation in Context and Brain Health in Older Latino Adults: A Diffusion Tensor Imaging Study

BACKGROUND

Latinos are at higher risk of developing mild cognitive impairment (MCI) and Alzheimer's disease than non-Latino Whites. Acculturation factors may influence this risk, yet there are few studies that have examined associations of acculturation, particularly in the context of socioenvironmental and familial factors, and brain health in older Latinos.

OBJECTIVE

To examine potential associations between acculturation in context and brain health in older Latinos.

METHODS

Using three previously established composites of acculturation-in-context, (acculturation-related: nativity status, language preference, acculturation scores; contextually-related socioenvironmental: perceived discrimination, loneliness/social isolation, social network size; and familism), and diffusion-tensor imaging (DTI), associations with white matter structural integrity were examined in 92 Latino adults without dementia participating in one of three epidemiological studies of aging. Linear regression models were used to test associations with DTI-derived metrics (fractional anisotropy, FA; trace) as separate outcomes and acculturation composite scores as individual predictors, while adjusting for age, sex, education, scanner, and white matter hyperintensities (voxelwise and total volumes normalized by intracranial volume).

RESULTS

Higher scores on the socioenvironmental composite were associated with lower FA in two clusters of left-hemisphere connections. Cluster 1 was dominated by both short association pathways connecting frontal regions and projection pathways connecting frontal regions with the thalamus. Cluster 2 was dominated by long association pathways connecting parietal, frontal, and temporal regions.

CONCLUSIONS

This study of older Latino adults demonstrated an association between reduced brain white matter integrity and contextually related socioenvironmental experiences known to increase risk of MCI and Alzheimer's disease.

Subjective cognitive decline is a better marker for future cognitive decline in females than in males

BACKGROUND

The identification of biomarkers for early detection of Alzheimer's disease (AD) is critical to the development of therapies and interventions targeted at symptom management and tracking the pathophysiology of disease. The endorsement of subjective cognitive decline (SCD) has emerged as a potential indicator of early change in cognitive status that may be predictive of future impairment at a time when measurable declines in neuropsychological performance cannot be detected. While there are numerous findings revealing sex differences in the prevalence of AD, there is a paucity of research examining sex differences in SCD. Therefore, the goal of this project was to determine if the relationship between the endorsement of SCD and future cognitive changes differ as a function of biological sex.

METHODS

A sample of 3019 male and female healthy older adults (2188 without SCD, 831 with SCD), with a mean follow-up time of 5.7 years, were included from the Rush Alzheimer's Disease Center Research Sharing Hub. Linear regressions were performed to determine group differences in baseline cognitive scores, while linear mixed-effects models were completed to determine group differences in the rate of cognitive change over time.

RESULTS

Individuals endorsing SCD had significantly lower baseline cognitive scores and increased rates of decline in all cognitive domains compared to those without SCD. Males exhibited significantly lower scores in baseline performance in global cognition, episodic memory, and perceptual speed regardless of SCD classification. Females with SCD were found to decline at significantly faster rates than both males with SCD and males and females without SCD in all cognitive domains over a maximum 15-year follow-up period.

CONCLUSIONS

SCD is related to lower baseline cognitive performance and faster cognitive decline compared to those who do not endorse SCD. Females with SCD have the fastest rate of decline suggesting that SCD may be more predictive of future decline in females than in males. Targeted assessments of SCD may allow for the identification of individuals for inclusion in intervention trials, and other research studies, aiming to attenuate casual disease processes, which may ultimately aid in the mitigation of sex disparities in AD.

Subjective socioeconomic status is associated with risk aversion in a community-based cohort of older adults without dementia

Attitudes towards risk impact financial decisions that are critical in older adulthood. Socioeconomic status (SES) influences an individual’s level of risk aversion; however, the association of subjective SES (i.e., social standing relative to others) with risk aversion has not been explored. We examined whether subjective SES is associated with risk aversion independent of objective SES (i.e., income, education). Participants were 933 older adults without dementia from the Rush Memory and Aging Project (MAP) or Minority Aging Research Study (MARS), two longitudinal epidemiologic studies of aging. Participants completed assessments of risk aversion, subjective SES, and cognition. We examined associations of subjective SES with risk aversion using mixed models adjusting for participant characteristics, objective markers of SES and global cognition. In bivariate analyses, lower global cognitive functioning, lower income, female sex, Black race, and lower subjective SES were associated with greater risk aversion. Results of the nonlinear mixed effects model revealed that higher subjective SES was associated with less risk aversion (Estimate = −0.238, SE = 0.083, p = 0.004), after controlling for covariates. Age, sex, race, and global cognition were also associated with risk aversion in the mixed effects model (ps ≤0.03), although income and education were not (ps ≥ 0.27) The relationship between subjective SES and risk aversion did not differ by sex or race (ps ≥ 0.31). Findings suggest that subjective SES contributes to risk aversion regardless of sex or race. Findings support the importance of considering subjective indicators of SES as they may impact an older adult’s economic preferences.

Cognitive decline and hippocampal functional connectivity within older Black adults

While there has been a proliferation of neuroimaging studies on cognitive decline in older non-Hispanic White adults, there is a dearth of knowledge regarding neuroimaging correlates of cognitive decline in Black adults. Resting-state functional neuroimaging approaches may be particularly sensitive to early cognitive decline, but there are no studies that we know of that apply this approach to examining associations of brain function to cognition in older Black adults. We investigated the association of cognitive decline with whole-brain voxel-wise functional connectivity to the hippocampus, a key brain region functionally implicated in early Alzheimer's dementia, in 132 older Black adults without dementia participating in the Minority Aging Research Study and Rush Memory and Aging Project, two longitudinal studies of aging that include harmonized annual cognitive assessments and magnetic resonance imaging brain imaging. In models adjusted for demographic factors (age, education, sex), global cognitive decline was associated with functional connectivity of the hippocampus to three clusters in the right and left frontal regions of the dorsolateral prefrontal cortex. In domain-specific analyses, decline in semantic memory was associated with functional connectivity of the hippocampus to bilateral clusters in the precentral gyrus, and decline in perceptual speed was inversely associated with connectivity of the hippocampus to the bilateral intracalcarine cortex and the right fusiform gyrus. These findings elucidate neurobiological mechanisms underlying cognitive decline in older Black adults and may point to specific targets of intervention for Alzheimer's disease.

Social Engagement and All-Cause Mortality: A Focus on Participants of the Minority Aging Research Study

INTRODUCTION

Social engagement is known to improve health; less is known about whether social activities at the core of African American life decrease mortality risk in this minoritized population. This study investigated whether and which aspects of social engagement predict mortality risk in older African Americans.

METHODS

Data from 768 African Americans (aged ∼73 years; nondemented at baseline) participating in the Minority Aging Research Study, a longitudinal community-based, cohort study of aging, was collected between 2004 and 2020 and analyzed in 2020. Participants self-reported late-life social activity, social network size, life space, and purpose in life at baseline and completed approximately 6.5 years of annual follow-up (range=15.70). Cox models included time from baseline to death or censoring and an indicator for death versus censored with age, sex, education, cardiovascular disease risk factor burden, depressive symptomatology, and motor gait performance as covariates.

RESULTS

As of March 2020, 25% of participants died (n=192; age at death ∼83 years). In fully adjusted Cox models, mortality risk decreased by 34% (hazard ratio=0.66; 95% CI=0.48, 0.91; p=0.012) for those with higher compared with that for those with lower social activity generally, with community/volunteer-, group-, and socially-related activities specifically driving these results.

CONCLUSIONS

Engaging in late-life social activity, especially group- and socially-based activities, was most consistently and robustly associated with reduced mortality risk in African Americans regardless of health. These results lay the foundation for considering community-based approaches to increase and/or maintain social participation in older African Americans as a potential means by which to increase longevity in this population.

Cancer and Vascular Comorbidity Effects on Dementia Risk and Neuropathology in the Oldest-Old

BACKGROUND

Dementia, vascular disease, and cancer increase with age, enabling complex comorbid interactions. Understanding vascular and cancer contributions to dementia risk and neuropathology in oldest-old may improve risk modification and outcomes.

OBJECTIVE

Investigate the contributions of vascular factors and cancer to dementia and neuropathology.

METHODS

Longitudinal clinicopathologic study of prospectively followed Mayo Clinic participants dying≥95 years-old who underwent autopsy. Participants were stratified by dementia status and compared according to demographics, vascular risk factors, cancer, and neuropathology.

RESULTS

Participants (n = 161; 83% female; 99% non-Hispanic whites)≥95 years (95-106 years-old) with/without dementia did not differ based on demographics. APOE ɛ2 frequency was higher in no dementia (20/72 [28%]) versus dementia (11/88 [12%]; p = 0.03), but APOE ɛ4 frequency did not differ. Coronary artery disease was more frequent in no dementia (31/72 [43%]) versus dementia (23/89 [26%]; p = 0.03) associated with 56% lower dementia odds (odds ratio [OR] = 0.44 [confidence interval (CI) = 0.19-0.98]; p = 0.04) and fewer neuritic/diffuse plaques. Diabetes had an 8-fold increase in dementia odds (OR = 8.42 [CI = 1.39-163]; p = 0.02). Diabetes associated with higher cerebrovascular disease (Dickson score; p = 0.05). Cancer associated with 63% lower dementia odds (OR = 0.37 [CI = 0.17-0.78]; p < 0.01) and lower Braak stage (p = 0.01).

CONCLUSION

Cancer exposure in the oldest-old was associated with lower odds of dementia and tangle pathology, whereas history of coronary artery disease was associated with lower odds of dementia and amyloid-β plaque pathology. History of diabetes mellitus was associated with increased odds of dementia and cerebrovascular disease pathology. Cancer-related mechanisms and vascular risk factor reduction strategies may alter dementia risk and neuropathology in oldest-old.

Unobtrusive Sensing Technology Detects Ecologically Valid Spatiotemporal Patterns of Daily Routines Distinctive to Persons With Mild Cognitive Impairment

BACKGROUND

The ability to capture people's movement throughout their home is a powerful approach to inform spatiotemporal patterns of routines associated with cognitive impairment. The study estimated indoor room activities over 24 hours and investigated relationships between diurnal activity patterns and mild cognitive impairment (MCI).

METHODS

One hundred and sixty-one older adults (26 with MCI) living alone (age = 78.9 ± 9.2) were included from 2 study cohorts-the Oregon Center for Aging & Technology and the Minority Aging Research Study. Indoor room activities were measured by the number of trips made to rooms (bathroom, bedroom, kitchen, living room). Trips made to rooms (transitions) were detected using passive infrared motion sensors fixed on the walls for a month. Latent trajectory models were used to identify distinct diurnal patterns of room activities and characteristics associated with each trajectory.

RESULTS

Latent trajectory models identified 2 diurnal patterns of bathroom usage (high and low usage). Participants with MCI were more likely to be in the high bathroom usage group that exhibited more trips to the bathroom than the low-usage group (odds ratio [OR] = 4.1, 95% CI [1.3-13.5], p = .02). For kitchen activity, 2 diurnal patterns were identified (high and low activity). Participants with MCI were more likely to be in the high kitchen activity group that exhibited more transitions to the kitchen throughout the day and night than the low kitchen activity group (OR = 3.2, 95% CI [1.1-9.1], p = .03).

CONCLUSIONS

The linkage between bathroom and kitchen activities with MCI may be the result of biological, health, and environmental factors in play. In-home, real-time unobtrusive-sensing offers a novel way of delineating cognitive health with chronologically-ordered movement across indoor locations.

A guide for researchers seeking training in retrospective data harmonization for population neuroscience studies of Alzheimer's disease and related dementias

Due to needs surrounding rigor and reproducibility, subgroup specific disease knowledge, and questions of external validity, data harmonization is an essential tool in population neuroscience of Alzheimer's disease and related dementias (ADRD). Systematic harmonization of data elements is necessary to pool information from heterogeneous samples, and such pooling allows more expansive evaluations of health disparities, more precise effect estimates, and more opportunities to discover effective prevention or treatment strategies. The key goal of this Tutorial in Population Neuroimaging Curriculum, Instruction, and Pedagogy article is to guide researchers in creating a customized population neuroscience of ADRD harmonization training plan to fit their needs or those of their mentees. We provide brief guidance for retrospective data harmonization of multiple data types in this area, including: (1) clinical and demographic, (2) neuropsychological, and (3) neuroimaging data. Core competencies and skills are reviewed, and resources are provided to fill gaps in training as well as data needs. We close with an example study in which harmonization is a critical tool. While several aspects of this tutorial focus specifically on ADRD, the concepts and resources are likely to benefit population neuroscientists working in a range of research areas.

Limbic-predominant age-related TDP-43 encephalopathy neuropathological change (LATE-NC) is associated with lower R2 relaxation rate: an ex-vivo MRI and pathology investigation

Limbic predominant age-related transactive response DNA binding protein 43 (TDP-43) encephalopathy neuropathological change (LATE-NC) is common in persons older than 80 years of age and is associated with cognitive decline and increased likelihood of dementia. The MRI signature of LATE-NC has not been fully determined. In this study, the association of LATE-NC with the transverse relaxation rate, R2, was investigated in a large number of community-based older adults. Cerebral hemispheres from 738 participants of the Rush Memory and Aging Project, Religious Orders Study, and Minority Aging Research Study, were imaged ex-vivo with multi-echo spin-echo MRI and underwent detailed neuropathologic examination. Voxel-wise analysis revealed a novel spatial pattern of lower R2 for higher LATE-NC stage, controlling for other neuropathologies and demographics. This pattern was consistent with the distribution of LATE-NC in gray matter, and also involved white matter providing temporo-temporal, fronto-temporal, and temporo-basal ganglia connectivity. Furthermore, analysis at different LATE-NC stages showed that R2 imaging may capture the general progression of LATE-NC, but only when TDP-43 inclusions extend beyond the amygdala.

The Relationship of John Henryism With Cognitive Function and Decline in Older Black Adults

OBJECTIVE

This study aimed to investigate the relationship between John Henryism, a psychological trait typified by high-effort active coping that has been associated with adverse health outcomes among Blacks, and cognitive decline.

METHODS

In a cohort of community-dwelling older Black adults ( N = 611), we investigated the relationship between John Henryism and cognitive decline. John Henryism was measured using the John Henryism Active Coping Scale (JHACS), a nine-item validated measure of self-reported high-effort coping (mean [standard deviation] = 16.9 [4.8]; range, 4-27). We implemented a three-step modeling process using mixed-effects models to assess the relationship between the JHACS and global cognitive function as well as five cognitive domains. We adjusted for demographics and for factors known to be associated with cognitive function and decline including vascular risk factors, discrimination, and income.

RESULTS

The trait of high-effort active coping was associated with lower-average cognitive function ( β = -0.07, 95% confidence interval = -0.10 to -0.03), but not with decline. The results remained after further adjustment for experiences of discrimination, income, and vascular risk factors. In domain-specific analyses, we found that the JHACS was associated with baseline levels of working memory, semantic memory, and visuospatial ability, but not decline.

CONCLUSIONS

These results highlight the importance of using culturally specific measures in considering the heterogeneity of cognitive health outcomes in minoritized populations. Understanding how stress responses relate to late-life cognition among older Black adults could help promote aspects of behavioral resilience along with healthful coping responses.

Cerebral amyloid angiopathy interacts with neuritic amyloid plaques to promote tau and cognitive decline

Accumulating data suggest that cerebrovascular disease contributes to Alzheimer's disease pathophysiology and progression toward dementia. Cerebral amyloid angiopathy is a form of cerebrovascular pathology that results from the build-up of β-amyloid in the vessel walls. Cerebral amyloid angiopathy commonly co-occurs with Alzheimer's disease pathology in the ageing brain and increases the risk of Alzheimer's disease dementia. In the present study, we examined whether cerebral amyloid angiopathy influences tau deposition and cognitive decline independently or synergistically with parenchymal β-amyloid burden. Secondly, we examined whether tau burden mediates the association between cerebral amyloid angiopathy and cognitive decline. We included data from autopsied subjects recruited from one of three longitudinal clinical-pathological cohort studies: the Rush Memory and Aging Project, the Religious Orders Study and the Minority Aging Research Study. Participants completed annual clinical and cognitive evaluations and underwent brain autopsy. Cerebral amyloid angiopathy pathology was rated as none, mild, moderate or severe. Bielschowsky silver stain was used to visualize neuritic β-amyloid plaques and neurofibrillary tangles. We used linear regression and linear mixed models to test independent versus interactive associations of cerebral amyloid angiopathy and neuritic plaque burden with tau burden and longitudinal cognitive decline, respectively. We used causal mediation models to examine whether tau mediates the association between cerebral amyloid angiopathy and cognitive decline. The study sample included 1722 autopsied subjects (age at baseline = 80.2 ± 7.1 years; age at death = 89.5 ± 6.7 years; 68% females). Cerebral amyloid angiopathy interacted with neuritic plaques to accelerate tau burden and cognitive decline. Specifically, those with more severe cerebral amyloid angiopathy pathology and higher levels of neuritic plaque burden had greater tau burden and faster cognitive decline. We also found that tau mediated the association between cerebral amyloid angiopathy and cognitive decline among participants with higher neuritic plaque burden. In summary, more severe levels of cerebral amyloid angiopathy and higher parenchymal β-amyloid burden interacted to promote cognitive decline indirectly via tau deposition. These results highlight the dynamic interplay between cerebral amyloid angiopathy and Alzheimer's disease pathology in accelerating progression toward dementia. These findings have implications for Alzheimer's disease clinical trials and therapeutic development.

Dividing attention during the Timed Up and Go enhances associations of several subtask performances with MCI and cognition

We tested the hypothesis that dividing attention would strengthen the ability to detect mild cognitive impairment (MCI) and specific cognitive abilities from Timed Up and Go (TUG) performance in the community setting. While wearing a belt-worn sensor, 757 dementia-free older adults completed TUG during two conditions, with and without a concurrent verbal serial subtraction task. We segmented TUG into its four subtasks (i.e., walking, turning, and two postural transitions), and extracted 18 measures that were summarized into nine validated sensor metrics. Participants also underwent a detailed cognitive assessment during the same visit. We then employed a series of regression models to determine the combinations of subtask sensor metrics most strongly associated with MCI and specific cognitive abilities for each condition. We also compared subtask performances with and without dividing attention to determine whether the costs of divided attention were associated with cognition. While slower TUG walking and turning were associated with higher odds of MCI under normal conditions, these and other subtask associations became more strongly linked to MCI when TUG was performed under divided attention. Walking and turns were also most strongly associated with executive function and attention, particularly under divided attention. These differential associations with cognition were mirrored by performance costs. However, since several TUG subtasks were more strongly associated with MCI and cognitive abilities when performed under divided attention, future work is needed to determine how instrumented dual-task TUG testing can more accurately estimate risk for late-life cognitive impairment in older adults.

Acute versus chronic inflammatory markers and cognition in older black adults: Results from the Minority Aging Research Study

Peripheral inflammation is elevated in older Black adults, an elevation which prior work has suggested may be due to chronic stress associated with systemic racism and related adverse cardiovascular health conditions. Inflammation is also involved in the pathogenic processes of dementia; however, limited (and mixed) results exist concerning inflammation and cognitive decline in Black adults. We characterized patterns of inflammation and their role in cognitive decline in 280 older Black adults (age = 72.99 ± 6.00 years; 69.6% female) from the Minority Aging Research Study (MARS) who were without dementia at baseline and followed between 2 and 15 years (mean = 9 years). Participants completed a blood draw at baseline and annual cognitive evaluations. Serum was assayed for 9 peripheral inflammatory markers; 19 neuropsychological test scores were used to create indices of global cognition and five cognitive domains. Principal component analysis with varimax rotation characterized patterns of inflammation with factor loadings > 0.6 per component contributing to two composite scores representing acute/upstream and chronic/downstream inflammation. These composites were used as separate predictors in linear mixed regression models to determine associations with level and change in cognition adjusting for relevant covariates. Higher baseline upstream/acute inflammation associated with lower baseline semantic memory (p = .040) and perceptual speed (p = .046); it was not related to cognitive decline. By contrast, higher baseline downstream/chronic inflammation associated with faster declines in global cognition (p = .010), episodic (p = .027) and working memory (p = .006); it was not related to baseline cognition. For older Black adults, chronic, but not acute, inflammation may be a risk factor for changes in cognition.

Identification of Dementia in Recent Medicare Claims Data, Compared With Rigorous Clinical Assessments

BACKGROUND

Medicare fee-for-service (FFS) claims data are increasingly leveraged for dementia research. Few studies address the validity of recent claim data to identify dementia, or carefully evaluate characteristics of those assigned the wrong diagnosis in claims.

METHODS

We used claims data from 2014 to 2018, linked to participants administered rigorous, annual dementia evaluations in 5 cohorts at the Rush Alzheimer's Disease Center. We compared prevalent dementia diagnosed through the 2016 cohort evaluation versus claims identification of dementia, applying the Bynum-standard algorithm.

RESULTS

Of 1 054 participants with Medicare Parts A and B FFS in a 3-year window surrounding their 2016 index date, 136 had prevalent dementia diagnosed during cohort evaluations; the claims algorithm yielded 217. Sensitivity of claims diagnosis was 79%, specificity 88%, positive predictive value 50%, negative predictive value 97%, and overall accuracy 87%. White participants were disproportionately represented among detected dementia cases (true positive) versus cases missed (false negative) by claims (90% vs 75%, respectively, p = .04). Dementia appeared more severe in detected than missed cases in claims (mean Mini-Mental State Exam = 15.4 vs 22.0, respectively, p < .001; 28% with no limitations in activities of daily living versus 45%, p = .046). By contrast, those with "over-diagnosis" of dementia in claims (false positive) had several worse health indicators than true negatives (eg, self-reported memory concerns = 51% vs 29%, respectively, p < .001; mild cognitive impairment in cohort evaluation = 72% vs 44%, p < .001; mean comorbidities = 7 vs 4, p < .001).

CONCLUSIONS

Recent Medicare claims perform reasonably well in identifying dementia; however, there are consistent differences in cases of dementia identified through claims than in rigorous cohort evaluations.

Association of Statins With Cerebral Atherosclerosis and Incident Parkinsonism in Older Adults

BACKGROUND AND OBJECTIVES

The burden of cerebrovascular disease pathologies is associated with progressive parkinsonism in older adults. We tested the hypothesis that older adults using statins have a lower risk of developing parkinsonism.

METHODS

We studied older adults with annual clinical testing of 4 parkinsonian signs and assessment of statin use based on inspection of all medications. Parkinsonism was present if there was clinical evidence of ≥2 parkinsonian signs. Postmortem brain examination collected indices of pathologies, including atherosclerosis of the large vessels of the circle of Willis. We examined whether baseline statin use was related to incident parkinsonism. Then in decedents, we examined whether statin use before death was related to pathologies and whether pathologies linked the association of statin use to parkinsonism.

RESULTS

Mean age of the participants (n = 2,841) at study baseline was 76.3 years (SD 7.4 years), and 75% were women. During an average follow-up of 6 years (mean 5.6 years, SD 4.9 years), 50% (n = 1,432) of participants developed parkinsonism. Statin use at baseline (n = 936) was associated with a lower risk of parkinsonism (hazard ratio 0.84, 95% CI 0.74-0.96, p = 0.008), controlling for demographics, vascular risk factors, and diseases. Among the decedents (n = 1,044, mean age at death 89.2 years, SD 6.7 years), statin use before death was associated with a lower odds of atherosclerosis (odds ratio [OR] 0.63, 95% CI 0.50-0.79, p < 0.001). In a mediation analysis, both a direct (OR 0.73, 95% CI 0.54-0.93, p = 0.008) and an indirect (OR 0.92, 95% CI 0.88-0.97, p = 0.002) pathway via less severe atherosclerosis linked statins to parkinsonism, indicating that atherosclerosis mediated 17% of the association between statins and parkinsonism.

DISCUSSION

Adults using statins have a lower risk of parkinsonism that may be partially mediated by a lower odds of brain atherosclerosis. These findings highlight the role of cerebrovascular pathologies in late-life parkinsonism and suggest a potential role for statins in decreasing its magnitude.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that statin use is associated with a lower risk of parkinsonism in older adults.

Relationship of Blood Pressure and White Matter Hyperintensity Burden With Level of and Change in Cognition in Older Black Adults

OBJECTIVE

Elevations in blood pressure (BP) and associated white matter hyperintensities (WMHs) are chronic comorbid conditions among older Black adults. We investigated whether WMHs modify the association between late-life BP and cognition within older Black adults.

METHODS

A total of 167 Black adults (age, ~75 years; without dementia at baseline) participating in neuroimaging studies at the Rush Alzheimer's Disease Center were evaluated for BP markers of cardiovascular health, including systolic BP, diastolic BP, pulse pressure, mean arterial pressure (MAP), and hypertension, and were assessed for global and domain-specific cognition at baseline and annually for up to 8 years. WMHs adjusted for intracranial volume were quantified at baseline.

RESULTS

Models adjusted for relevant confounders and the interaction of these variables with time revealed differential associations between BP markers and baseline cognition; however, only elevated diastolic BP predicted faster cognitive, that is, episodic memory, decline (estimate = -0.002, standard error = 0.0009, p = .002). Although WMH burden did not modify the association between diastolic BP and episodic memory decline, it did interact with diastolic BP to lower episodic memory at baseline (estimate = -0.051, standard error = 0.012, p = .0001); that is, greater WMHs combined with higher diastolic BP resulted in the lowest baseline episodic memory scores. A similar profile was noted for WMHs, MAP, and baseline episodic memory. Hypertension was neither associated with cognition nor modified by WMH burden after multiple comparisons correction.

CONCLUSION

Late-life diastolic BP was associated with faster rates of episodic memory decline in older Black adults; together with higher WMH burden, it (and MAP) lowered the point at which individuals begin their course of decline toward pathological aging.

Development of a Comprehensive Battery to Collect Social and Structural Determinants of Health (SSDOH) in Cognitively Normal or Very Mildly Impaired Persons

INTRODUCTION

Research addressing Alzheimer disease and related dementias must examine nonbiological factors influencing the risk for and expression of Alzheimer disease and related dementias. These factors address the interplay of cognition with lived experiences and social and structural determinants of health (SSDOH). However, coordinated measures of SSDOH are limited.

METHODS

The Knight Alzheimer Disease Research Center (ADRC) at Washington University in St. Louis developed and piloted a comprehensive battery to measure SSDOH. One hundred and twelve participants, very mildly cognitively impaired or unimpaired, enrolled in memory studies completed the electronic SSDOH battery. The Clinical Dementia Rating (CDR) determined the presence or absence of cognitive impairment.

RESULTS

Four domains demonstrated above acceptable intraclass correlation scores for test-retest reliability (≥0.70), including adverse childhood events, discrimination, social status, and early education. Twenty very mildly impaired participants completed the electronic pilot study.

CONCLUSION

Our findings indicate that participants with early-stage symptomatic Alzheimer disease are able to participate in electronic SSDOH data collection. In collaboration with the University of Pennsylvania ADRC, we replaced/modified certain assessments to increase intraclass correlation. The resulting battery, Social and Structural Life-courses Influencing Aging and Dementia (SS-DIAD), can serve as a SSDOH collection tool and is currently utilized in cognitively impaired and unimpaired research participants at both ADRCs.

Association of Traumatic Brain Injury With and Without Loss of Consciousness With Neuropathologic Outcomes in Community-Dwelling Older Persons

Importance

A history of traumatic brain injury (TBI) has been considered a risk factor for Alzheimer dementia. However, the specific association of TBI, even without loss of consciousness (LOC), with pathologic findings that underlie Alzheimer dementia, including Alzheimer disease (AD), non-AD neurodegenerative, and vascular pathologic findings, remains unclear.

Objective

To examine the association between TBI with and without LOC and neuropathologic findings in community-based cohorts.

Design, Setting, and Participants

This cross-sectional analysis used neuropathologic data from 1689 participants from the Religious Orders Study, the Rush Memory and Aging Project, and the Minority Aging Research Study. These studies began enrollment in 1994, 1997, and 2004, respectively. The current study's data set was frozen on April 3, 2021, when the mean (SD) length of follow-up for the participants was 8.7 (5.5) years.

Exposure

Traumatic brain injury exposure was assessed using a standardized, self-reported questionnaire at baseline and annual follow-up visits. Participants were categorized into those (1) without TBI exposure (n = 1024), (2) with TBI with LOC (n = 161), or (3) with TBI without LOC (n = 504).

Main Outcomes and Measures

Neuropathologic measures of amyloid-β, paired helical filament tangles, neocortical Lewy bodies, transactive response DNA-binding protein 43, hippocampal sclerosis, gross infarcts, and microinfarcts were assessed. Multiple linear regression and logistic regression models were used to determine whether TBI with or without LOC (compared with no TBI exposure as the reference group) was associated with neuropathologic outcomes after adjusting for age at death, sex, and educational level. Whether the apolipoprotein E (APOE) ε4 allele and sex differences modified associations was also examined.

Results

A total of 1689 participants (1138 [67%] women and 551 [33%] men; mean [SD] age at death, 89.2 [6.7] years; 80 [5%] Black, 46 [3%] Latino, 1639 [97%] non-Latino, and 1601 [95%] White) participated in the study. Compared with participants without TBI, participants with TBI with LOC had a greater amyloid-β load (estimate, 0.25; 95% CI, 0.06-0.43; P = .008) and higher odds of having 1 or more gross infarcts (odds ratio [OR], 1.45; 95% CI, 1.04-2.02; P = .02) and 1 or more microinfarcts (OR, 1.70; 95% CI, 1.21-2.38; P = .002), particularly subcortical microinfarcts (OR, 1.85; 95% CI, 1.23-2.79; P = .002). Those with TBI without LOC had higher odds of neocortical Lewy bodies (OR, 1.37; 95% CI, 1.01-1.87; P = .04) and 1 or more cortical microinfarcts (OR, 1.43; 95% CI, 1.09-1.87; P = .008). The association of TBI with and without LOC with vascular pathologic outcomes persisted after controlling for vascular risk factors and vascular disease burden. Traumatic brain injury with or without LOC was not associated with paired helical filament tangles, transactive response DNA-binding protein 43, or hippocampal sclerosis. No interactions occurred with APOE ε4 or sex.

Conclusions and Relevance

This cross-sectional analysis suggests that a history of TBI, even without LOC, is associated with age-related neuropathologic outcomes, both neurodegenerative and vascular. The variation in the neuropathologic outcomes in individuals with and without LOC may provide clues to potential mechanisms, diagnoses, and management in persons with TBI.

Negative and Positive Psychosocial Factors in Relation to Cognitive Health in Older African Americans

Background and Objectives

Identifying potential intervention strategies to reduce cognitive decline, particularly among older African Americans at high risk for Alzheimer’s dementia, is critical. This study aimed to investigate whether depressive symptoms, purpose in life, and their interrelations are associated with cognitive decline in older African Americans.

Research Design and Methods

We included older African Americans from the Minority Aging Research Study (n = 748) and Rush Memory and Aging Project (n = 109), without dementia at baseline. We assessed associations of depressive symptoms, purpose in life, and their interrelations, with baseline levels and change in global cognition using linear mixed-effects models.

Results

At baseline, each unit increment in depressive symptoms was related to worse initial global cognition (mean difference = −0.03 standard unit; p = .003), while higher purpose in life was related to better cognition (mean difference = 0.12; p = .002). Further, participants with ≥1 depressive symptom who had a purpose in life score above the median appeared to have better global cognition (mean difference = 0.10; p = .01), compared to those with depressive symptoms but lower levels of purpose in life. However, we did not find relations of depressive symptoms or purpose in life with rates of cognitive decline over time, likely due to the modest follow-up.

Discussion and Implications

In older African Americans, we found that lower depressive symptoms and greater purpose in life were independently related to higher initial levels of global cognition, but not cognitive decline. Preliminary findings of higher global cognition in individuals with depressive symptoms but greater purpose in life merit further investigation if purpose may eventually be considered as an intervention.

Exposing the Brain Proteomic Signatures of Alzheimer's Disease in Diverse Racial Groups: Leveraging Multiple Data Sets and Machine Learning

Recent studies have highlighted that the proteome can be used to identify potential biomarker candidates for Alzheimer's disease (AD) in diverse cohorts. Furthermore, the racial and ethnic background of participants is an important factor to consider to ensure the effectiveness of potential biomarkers for representative populations. A promising approach to survey potential biomarker candidates for diagnosing AD in diverse cohorts is the application of machine learning to proteomics data sets. Herein, we leveraged six existing bottom-up proteomics data sets, which included non-Hispanic White, African American/Black, and Hispanic participants, to study protein changes in AD and cognitively unimpaired participants. Machine learning models were applied to these data sets and resulted in the identification of amyloid-β precursor protein (APP) and heat shock protein β-1 (HSPB1) as two proteins that have high ability to distinguish AD; however, each protein's performance varied based upon the racial and ethnic background of the participants. HSPB1 particularly was helpful for generating high areas under the curve (AUCs) for African American/Black participants. Overall, HSPB1 improved the performance of the machine learning models when combined with APP and/or participant age and is a potential candidate that should be further explored in AD biomarker discovery efforts.

Associations of deformation-based brain morphometry with cognitive level and decline within older Blacks without dementia

Blacks are at higher risk of developing cognitive impairment with age than non-Hispanic Whites, yet most brain morphometry and cognition research is performed with White samples or with mixed samples that control for race or compare across racial groups. A deeper understanding of the within-group variability in associations between brain structure and cognitive decline in Blacks is critically important for designing appropriate outcomes for clinical trials, predicting adverse outcomes, and developing interventions to preserve cognitive function, but no studies have examined these associations longitudinally within Blacks. We performed deformation-based morphometry in 376 older Black participants without dementia and examined associations of deformation-based morphometry with cognitive level and decline for global cognition and five cognitive domains. After correcting for widespread age-associated effects, there remained regions with less tissue and more cerebrospinal fluid associated with level and rate of decline in global cognition, memory, and perceptual speed. Further study is needed to examine the moderators of these associations, identify adverse outcomes predicted by brain morphometry, and deepen knowledge of underlying biological mechanisms.

Financial fragility and scam susceptibility in community dwelling older adults

We tested the hypothesis that financial fragility is associated with higher scam susceptibility in older adults without dementia. Data came from nearly 900 community-dwelling participants from two ongoing cohort studies of aging. Financial fragility was determined by assessing an individual's ability to access $2,000 within a month for an unexpected expense. Scam susceptibility was assessed via a 5-item instrument that measures perceptions and behaviors that predispose older adults to financial fraud and scams. On average, participants were 82 years of age. Nearly 10% reported financial fragility. Financial fragility was higher in Blacks and among those with fewer years of education, lower income, lower global cognition, lower literacy, and poorer financial decision-making. Regression analysis revealed that financially fragile older adults were more susceptible to scams. These data suggest that targeted efforts to reduce financial fragility and improve literacy and cognitive health are needed to prevent elder exploitation among diverse populations.

Diagnostic accuracy and differential associations between ratings of functioning and neuropsychological performance in non-Hispanic Black and White older adults

ObjectiveWe recently demonstrated that relative to consensus-based methods, actuarial methods may improve diagnostic accuracy across the continuum of cognitively normal (CN), mild cognitive impairment (MCI), and dementia in the overall National Alzheimer's Coordinating Center (NACC) cohort. However, the generalizability and comparative utility of current methods of diagnosing MCI and dementia due to Alzheimer's disease and related disorders (ADRD) are significantly understudied in non-Hispanic Black (NHB) older adults. Thus, we extended our previous investigation to more specifically explore the utility of consensus-based and actuarial diagnostic methods in NHB older adults.Method: We compared baseline consensus and actuarial diagnostic rates, and associations of ratings of functioning with neuropsychological performance and diagnostic outcomes, in NHB (n = 963) and non-Hispanic White (NHW; n = 4577) older adults in the NACC cohort.Results: 60.0% of the NHB subsample, versus 29.2% of the NHW subsample, included participants who met actuarial criteria for MCI despite being classified as CN or impaired-not-MCI per consensus. Additionally, associations between ratings of functioning and neuropsychological performance were less consistent in NHB participants than in NHW participants.Conclusions: Our results provide evidence of differential degrees of association between reported functioning and neuropsychological performance in NHB and NHW older adults, which may contribute to racial group differences in diagnostic rates, and prompt consideration of the strengths and weaknesses of consensus-based and actuarial diagnostic approaches in assessing neurocognitive functioning in NHB older adults.

Representation of U.S. Black Americans in neuropsychology research: How well do our reporting practices show that Black lives matter?

OBJECTIVE

Black American individuals comprise about 13% of the population in the United States (U.S.). It is estimated by 2045, approximately 50% of U.S. residents will belong to an ethnic minority group underscoring the importance of the provision of culturally competent services. The present study provides a critical/systematic review of the literature to examine the representation of Black Americans in recent neuropsychological research in U.S. neuropsychology journals. We examined the representation of U.S. Black American individuals across journals, year of study, and by study sample.

METHOD

We evaluated 1,151 journal articles published in 4 neuropsychology journals published in 2011, 2014, 2017 and 2019. Articles were coded for reporting of age, sex/gender, years of education, ethnicity/race, and if race was a focus of the study. We also recorded sample size and type of sample.

RESULTS

Out of the 397 articles meeting inclusion criteria, 37.5% did not report ethnic or racial demographic information. Additionally, 96% of the articles were not racially/ethnically focused. Black participants comprised 10.7% of participants in articles that reported race/ethnicity. The proportion of Black participants increased by 3.7% between 2011 and 2019.

CONCLUSION

Our results demonstrate the underrepresentation of U.S. Black Americans in neuropsychological research over the targeted years. This highlights our shortcomings as a field in demonstrating the importance of including Black Americans in research.

Purpose in Life May Delay Adverse Health Outcomes in Old Age

OBJECTIVE

Test the hypothesis that a higher level of purpose in life is associated with an older age of Alzheimer's dementia onset and later mortality.

DESIGN

Prospective cohort studies of aging and Alzheimer's dementia.

SETTING

Community-based.

PARTICIPANTS

Two thousand five hundred fifty-eight older adults initially free of dementia underwent assessments of purpose in life and detailed annual clinical evaluations to document incident Alzheimer's dementia and mortality. General accelerated failure time models examined the relation of baseline purpose in life with age at Alzheimer's dementia diagnosis and mortality.

EXPOSURES

Purpose in life was assessed at baseline.

MAIN OUTCOMES

Alzheimer's dementia diagnosis was documented annually based on detailed clinical evaluations and mortality was documented via regular contacts and annual evaluations.

RESULTS

During a mean of 6.89 years of follow-up, 520 individuals were diagnosed with incident Alzheimer's dementia at a mean age of 88 (SD = 6.7; range: 64.1-106.5). They had a mean baseline level of purpose in life of 3.7 (SD = 0.47; range: 1-5). A higher level of purpose in life was associated with a considerably later age of dementia onset (estimate = 0.044; 95% CI: 0.023, 0.065); specifically, individuals with high purpose (90th percentile) developed Alzheimer's dementia at a mean age of about 95 compared to a mean age of about 89 for individuals with low purpose (10th percentile). Further, the estimated mean age of death was about 89 for individuals with high purpose compared to 85 for those with low purpose. Results persisted after controlling for sex and education.

CONCLUSION AND RELEVANCE

Purpose in life delays dementia onset and mortality by several years. Interventions to increase purpose in life among older persons may increase healthspan and offer considerable public health benefit.

The accelerated aging phenotype: The role of race and social determinants of health on aging

The pursuit to discover the fundamental biology and mechanisms of aging within the context of the physical and social environment is critical to designing interventions to prevent and treat its complex phenotypes. Aging research is critically linked to understanding health disparities because these inequities shape minority aging, which may proceed on a different trajectory than the overall population. Health disparities are characteristically seen in commonly occurring age-associated diseases such as cardiovascular and cerebrovascular disease as well as diabetes mellitus and cancer. The early appearance and increased severity of age-associated disease among African American and low socioeconomic status (SES) individuals suggests that the factors contributing to the emergence of health disparities may also induce a phenotype of 'premature aging' or 'accelerated aging' or 'weathering'. In marginalized and low SES populations with high rates of early onset age-associated disease the interaction of biologic, psychosocial, socioeconomic and environmental factors may result in a phenotype of accelerated aging biologically similar to premature aging syndromes with increased susceptibility to oxidative stress, premature accumulation of oxidative DNA damage, defects in DNA repair and higher levels of biomarkers of oxidative stress and inflammation. Health disparities, therefore, may be the end product of this complex interaction in populations at high risk. This review will examine the factors that drive both health disparities and the accelerated aging phenotype that ultimately contributes to premature mortality.

Complex Profiles of Cerebrovascular Disease Pathologies in the Aging Brain and Their Relationship With Cognitive Decline

BACKGROUND AND PURPOSE

Cerebrovascular disease (CVD) pathologies including vessel disease (atherosclerosis, arteriolosclerosis, and cerebral amyloid angiopathy) and tissue injury (macroinfarcts and microinfarcts) each contribute to Alzheimer and other forms of dementia. CVD is often a complex mix of neuropathologies, with little known about the frequencies of differing combinations or their associations with cognition.

METHODS

We investigated 32 possible CVD combinations (3 types of vessel disease and 2 types of tissue injury) using autopsy data from 1474 decedents (≈88 years at death; 65% female) of Rush Alzheimer's Disease Center studies. We determined frequencies of all 32 CVD combinations and their relationships with global and domain-specific cognitive decline using mixed-effect models adjusted for demographics, neuropathologies, time before death, and interactions of these variables with time.

RESULTS

Of the 1184 decedents with CVD neuropathology (80% of the total sample), 37% had a single CVD (67-148 decedents/group) while 63% had mixed CVD profiles (11-54 decedents/group). When considered as 2 distinct groups, the mixed CVD profile group (but not the single CVD profile group) showed a faster cognitive decline across all domains assessed compared with decedents without CVD neuropathology. Most mixed CVD profiles, especially those involving both atherosclerosis and arteriolosclerosis, showed faster cognitive decline than any single CVD profile considered alone; specific mixed CVD profiles differentially associated with individual cognitive domains.

CONCLUSIONS

Mixed CVD, more common than single CVD, is associated with cognitive decline, and distinct mixed CVD profiles show domain-specific associations with cognitive decline. CVD is not monolithic but consists of heterogenous person-specific combinations with distinct contributions to cognitive decline.

Estimation of dementia prevalence at the local level in the United States

INTRODUCTION

Ensuring adequate and equitable distribution of resources to support persons living with dementia relies on understanding the burden and distribution of dementia in a population. Our goal was to develop an approach to estimate dementia prevalence at the local level in the United States using publicly available data.

METHODS

Our approach combines publicly available data on dementia prevalence and demographic data from the US Census to estimate dementia prevalence. We illustrate this approach by estimating dementia prevalence in persons aged 65 and older in Philadelphia, PA; Chicago, IL; and Atlanta, GA.

RESULTS

Overall, we estimate the prevalence of dementia among those 65 and older to be 11.9% in Philadelphia, 11.8% Chicago, and 12.3% in Atlanta. Estimates across Philadelphia localities vary from 9.3% to 15.9%.

DISCUSSION

Our approach provides a cost-effective method to generate estimates of dementia prevalence at the local level.

HIGHLIGHTS

Brain health needs assessments require understanding of local dementia prevalence.Our approach can be used to estimate dementia prevalence in individual communities.This information can inform decisions about distribution of resources.

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.

Correlates of perceived stress among community-dwelling older African Americans

BACKGROUND

The purpose of this study was to identify correlates of perceived stress among older African Americans.

METHODS AND FINDINGS

Guided by the National Institute on Aging's (NIA) Health Disparities Research Framework, we grouped correlates into four levels-environmental, sociocultural, behavioral, and biological, and performed a cross-sectional analysis using ordinal logistic regression models. Participants included 722 African Americans [mean age = 73.61 years (SD = 6.33)] from the Minority Aging Research Study (MARS). Several protective correlates from environmental (e.g., larger life space), sociocultural (e.g., larger social network size), behavioral (e.g., more purpose in life), and biological (e.g., higher global cognition) levels were associated with a lower odds of having higher levels of perceived stress.

CONCLUSIONS

Perceived stress was associated with established and novel correlates from every level. Future research is needed to examine how changes in these correlates may impact perceived stress in older African Americans.

Association of White Matter Hyperintensities With Pathology and Progression of Parkinsonism in Aging

Importance

Progressive parkinsonism is common in older adults without a diagnosis of Parkinson disease and is associated with adverse health outcomes, but its pathologic basis is controversial.

Objective

To examine if the burden of cerebral white matter hyperintensity (WMH), a common manifestation of cerebrovascular disease pathologies, is associated with the rate of progressive parkinsonism.

Design, Setting, and Participants

This community-based cohort study included participants recruited in 3 ongoing cohorts that began enrollment in 1994, 1997, and 2004. Prior to death, participants were observed for a mean of 7.5 years, with annual clinical assessments. From 4427 participants enrolled in the 3 cohorts, 2134 died. Postmortem autopsy was performed in 1725 decedents, and 598 also had ex vivo brain magnetic resonance imaging. Participants were excluded if they were missing any of the 9 postmortem pathology indices (n = 22) or repeated parkinsonism assessment (n = 41) or had received a clinical diagnosis of Parkinson disease at any point before or during the study (n = 19). Data were analyzed from April 2020 to August 2021.

Exposures

WMH burden was assessed using a modified Fazekas rating scale.

Main Outcomes and Measures

Parkinsonism was assessed annually using 26 items of a modified motor portion of the Unified Parkinson's Disease Rating Scale. A summary score was developed from the item scores, with higher scores indicating more severe parkinsonism.

Results

Of 516 included decedents, 364 (70.5%) were female, and the mean (SD) age at death was 90.2 (6.4) years. Higher WMH was associated with faster progressive parkinsonism (estimate, 0.024; SE, 0.008; P = .002). The attenuation of this association was greater when controlling for indices of cerebrovascular disease pathologies than when controlling for neurodegenerative pathologies (cerebrovascular disease: estimate, 0.019; SE, 0.008; P = .02; neurodegenerative: estimate, 0.022; SE, 0.008; P = .003), but both remained significant.

Conclusions and Relevance

In this cohort study, higher levels of both WMH and indices of cerebrovascular disease pathologies in aging brains were associated with more rapid progressive parkinsonism. Further studies are needed to determine if in vivo brain imaging of older adults for evidence of WMH and aggressive medical treatment of vascular risk factors and diseases can reduce the occurrence or severity of late-life parkinsonism.

Caring in the recruitment of older African American adults with chronic health disease: An integrative review

OBJECTIVES

The aim of this integrative review is to accrue a comprehensive understanding of caring behavioral characteristics in the recruitment of older African-American adults into health-related research studies centered on chronic diseases.

METHODS

Combined methodologies, Whittemore & Knafl and Kable, Pich & Maslin-Prothero in accordance with preferred items for systematic reviews and meta-analysis, were used to guide the data collection and to report the findings. The data were analyzed based upon recruitment categorization and Kristen Swanson's middle-range theory of caring.

RESULTS

Ten out of 260 publications comprised the final sample. They were analyzed and then aggregated by chronic illnesses, recruitment activities, contact level, and Swanson's five caring behavioral concepts. Select cancers, diabetes, hypertension, and Alzheimer's disease were the chronic illness foci of eight publications. Cardiovascular disease and stroke were the focus of two publications. Only three studies utilized all five Swanson's caring concepts, and the frequently used concept throughout all 10 studies was enabling.

DISCUSSION

Recruitment approaches employed to accrue older African-American adults into chronic illness-related research studies necessitate proactive recruitment strategies that incorporate caring behaviors. Future researchers ought to develop multi-modality recruitment strategies to improve older African-American adults' representation.

In-Home Mobility Frequency and Stability in Older Adults Living Alone With or Without MCI: Introduction of New Metrics

Background: Older adults spend a considerable amount of time inside their residences; however, most research investigates out-of-home mobility and its health correlates. We measured indoor mobility using room-to-room transitions, tested their psychometric properties, and correlated indoor mobility with cognitive and functional status. Materials and Methods: Community-dwelling older adults living alone (n = 139; age = 78.1 ± 8.6 years) from the Oregon Center for Aging & Technology (ORCATECH) and Minority Aging Research Study (MARS) were included in the study. Two indoor mobility features were developed using non-parametric parameters (frequency; stability): Indoor mobility frequency (room-to-room transitions/day) was detected using passive infrared (PIR) motion sensors fixed on the walls in four geographic locations (bathroom; bedroom; kitchen; living room) and using door contact sensors attached to the egress door in the entrance. Indoor mobility stability was estimated by variances of number of room-to-room transitions over a week. Test-retest reliability (Intra-class coefficient, ICC) and the minimal clinically important difference (MCID) defined as the standard error of measurement (SEM) were generated. Generalized estimating equations models related mobility features with mild cognitive impairment (MCI) and functional status (gait speed). Results: An average of 206 days (±127) of sensor data were analyzed per individual. Indoor mobility frequency and stability showed good to excellent test-retest reliability (ICCs = 0.91[0.88-0.94]; 0.59[0.48-0.70]). The MCIDs of mobility frequency and mobility stability were 18 and 0.09, respectively. On average, a higher indoor mobility frequency was associated with faster gait speed (β = 0.53, p = 0.04), suggesting an increase of 5.3 room-to-room transitions per day was associated with an increase of 10 cm/s gait speed. A decrease in mobility stability was associated with MCI (β = -0.04, p = 0.03). Discussion: Mobility frequency and stability in the home are clinically meaningful and reliable features. Pervasive-sensing systems deployed in homes can objectively reveal cognitive and functional status in older adults who live alone.

Inhibitory Fcγ Receptor and Paired Immunoglobulin Type 2 Receptor Alpha Genotypes in Alzheimer's Disease

We investigated whether FCGRIIB (rs1050501 C/T) and PILRA (rs1859788 A/G) genotypes contributed to the development of Alzheimer's disease (AD). We genotyped 209 African American (AA) and 638 European American (EA) participants for the FCGRIIB and PILRA alleles. In the AA cohort, subjects homozygous for the C allele of FCGRIIB were more than 4 times as likely to develop AD as those homozygous for the alternative T allele. This SNP also interacted with PILRA: participants who were the carriers of the FCGRIIB C allele and PILRA A allele were 3 times as likely to develop AD as those who lacked these alleles.

Using Vignette-Based Methodology to Examine Study Recruitment in Older African American Adults: A Methods Paper

This study's objective was to assess which caring recruitment behaviors correlate with the successful recruitment of older African-American adults-a two-step cross-sectional design employing a vignette-based survey methodology. Kristen Swanson's middle-range theory of caring was used to guide the examination of African-American adults' (65 years of age and older) perceptions of research-study-recruiter recruitment behaviors. This study's main findings are twofold: Step 1: Seven of ten invited experts identified major revisions of the two core vignettes, written at an eighth-grade reading level and high school comprehension. Step 2: A 51% response rate yielded findings that this methodology successfully captured older African-American adults' perception of research study recruiters' behavioral characteristics during the recruitment process. Older African-Americans who received the hypothetical caring vignette were twice as likely to indicate their willingness to enroll in a research study with a high commitment (i.e., brain donation) compared to their counterparts who received the hypothetical uncaring recruitment scenario. Vignette-based survey methodology holds promise as a tool for informing the recruitment of older African-American adults and other minorities into federally funded health-related research studies.

Alzheimer's disease: a step closer to understanding type 3 diabetes in African Americans

Alzheimer's disease (AD) is the fourth leading cause of death in the United States and the most common cause of adult-onset dementia. Recent results suggest an increased prevalence and severity in African Americans compared to Caucasians. Our understanding of the potential mechanism(s) underlying this ethnicity difference is limited. We previously described ethnicity-related differences in levels of neurodegenerative proteins and cytokines/chemokines in the BA21 region of African Americans and Caucasians with AD. Here, similar multiplex assays were used to examine those endpoints in patient postmortem cerebrospinal fluid (CSF). Additionally, we measured levels of C-peptide, ghrelin, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), glucagon, insulin, leptin, PAI-1, resistin, and visfatin using a human diabetes 10-plex assay. The cytokine and chemokine assays revealed that levels of 26 chemokines or cytokines differed significantly with ethnicity, and three of those were significantly associated with gender. The neurodegenerative disease panel indicated that levels of soluble RAGE were significantly elevated in African Americans compared to Caucasians. All measures in the diabetes disease panel assay were significantly elevated in African Americans: ghrelin, GIP, GLP-1, glucagon, insulin, and visfatin. Through peripheral sample analysis, these results provide further evidence that ethnicity is critically involved in the manifestation of AD.

The association of Lewy bodies with limbic-predominant age-related TDP-43 encephalopathy neuropathologic changes and their role in cognition and Alzheimer's dementia in older persons

Lewy bodies (LBs) and limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) are common in older persons and associated with cognitive impairment. However, little is known about the relationship between LBs and LATE-NC and their combined roles in cognitive impairment and Alzheimer's dementia in community-dwelling participants. The study included 1670 community-based participants (mean age-at-death, 89.5 years (SD = 6.65); 69% females) who underwent annual assessments of cognition to create summary measures of global cognition and cognitive domains and evaluation for Alzheimer's dementia. Systematic neuropathologic evaluations were performed to assess LBs, LATE-NC, and Alzheimer's disease (AD) pathology. We excluded cases with pathologically confirmed frontotemporal lobar degeneration in this study. Logistic and linear regression analyses were used, adjusted for demographics and AD pathology. LBs were present in 428 (25.6%) decedents (29 nigra-predominant, 165 limbic-type, and 234 neocortical-type) while 865 (51.7%) decedents exhibited LATE-NC (307 stage 1, 167 stage 2, and 391 stage 3). LBs combined with LATE-NC were common (15% of all participants) and in those with Alzheimer's dementia (25%). Neocortical-type, but not nigral-predominant or limbic-type LBs increased the odds of stage 2/3 LATE-NC (odds ratio = 1.70; 95% confidence interval = 1.26-2.30). The association between neocortical-type LBs and stage 2/3 LATE-NC was stronger in those under 90 years of age and in women. In analyses of cognition and Alzheimer's dementia, LATE-NC and neocortical-type LBs, separately, were related to lower global cognition, five specific cognitive domains, and an increased odds of Alzheimer's dementia, above and beyond the AD pathology. Limbic-type LBs were related to lower global cognition, and the domains of episodic, working, and semantic memory, and increased odds of Alzheimer's dementia. Furthermore, there was no interaction between limbic/neocortical-type LBs and LATE-NC on cognitive function, cognitive domains, or Alzheimer's dementia. These findings suggest that neocortical-type LBs are associated with LATE-NC, specifically in the younger old and in women. Limbic/neocortical-type LBs and LATE-NC have separate and additive effects on cognitive function and odds of Alzheimer's dementia.

Within-Person Associations Among Self-Perceptions of Memory, Depressive Symptoms, and Activity Participation in Older Adults

BACKGROUND AND OBJECTIVES

Self-perceptions of memory problems may impact older adults' mood as well as their activity participation, thereby negatively affecting health and well-being. We examined within-person associations among self-reported memory, depressive symptoms, as well as physical, social, and cognitive activity participation in older adults without cognitive impairment.

RESEARCH DESIGN AND METHODS

Samples were drawn from the Einstein Aging Study (EAS), National Health and Aging Trends Study (NHATS), Rush Memory and Aging Project (MAP), and Minority Aging Research Study (MARS), with over 8,000 participants (65+ years) included across data sets. In a series of coordinated analyses, multilevel structural equation modeling was used to examine within-person relationships over periods of up to 20 years.

RESULTS

Across EAS, NHATS, and MAP/MARS samples, we found that older adults' self-perceptions of memory did not directly covary with activity participation over time. However, we did find an indirect association in NHATS such that within-person changes in depressive symptoms were associated with changes in self-reported memory, and these contributed to lower physical as well as social activity participation.

DISCUSSION AND IMPLICATIONS

Older adults' activity participation is important for health, but maximizing engagement requires understanding potentially impeding factors. We found some evidence that as self-perceptions of memory change over time, associated depressive symptoms may contribute to lower activity participation. Inconsistent findings across data sets, however, suggest future research is needed to understand individual characteristics that may influence these relationships.

Making a family decision to donate the brain for genomic research: lessons from the genotype-tissue expression project (GTEx)

This study sheds light on the attitudes and circumstances that influence decisions by families to donate the brain of a deceased family member for research. This study, a part of the Genotype-Tissue Expression (GTEx) project, interviewed families of patients who had authorized organ and/or tissue donation for transplantation. A total of 384 family decision makers (FDMs) who decided to donate organs and/or tissues for transplantation were also asked to donate to GTEx. Of these, 297 families were asked to donate their loved one's whole brain and 87 families responded to a hypothetical request for brain donation. The decision to donate the brain to GTEx, actually or hypothetically, was the major outcome measure. The majority of the FDMs would choose to donate the brain, 78%. Unwillingness to donate the brain was associated with four attitudes: (1) the FDM unwillingness to donate their own tissues for research (OR 1.91, 95% CI .67 to 2.96; p = .05), (2) concern with potential for-profit use of tissues (OR 2.12, 95% CI 1.2 to 3.7; p = .008), (3) reported squeamishness about tissue donation (OR 1.34, 95% CI 1.1 to 1.7; p = .006), and (4) belief that FDMs should have a say in how the donated tissues are used (OR 1.36, 95% CI 1.13 to 1.5; p = .01). Organ and tissue donors may present a plenteous source of brains for research. Family concerns about tissue use and collection should be addressed by requesters.

Longitudinal Relationships Between Subjective Cognitive Decline and Objective Memory: Depressive Symptoms Mediate Between-Person Associations

BACKGROUND

Subjective cognitive decline (SCD) may be an early indicator of cognitive impairment, but depressive symptoms can confound this relationship. Associations may be influenced by differences between individuals (i.e., between-persons) or how each individual changes in their experiences over time (i.e., within-persons).

OBJECTIVE

We examined depressive symptoms as a mediator of the between- and within-person associations of SCD and objective memory in older adults.

METHODS

Coordinated analyses were conducted across four datasets drawn from large longitudinal studies. Samples (range: n = 1,889 to n = 15,841) included participants 65 years of age or older with no dementia at baseline. We used multilevel structural equation modeling to examine the mediation of SCD and objective memory through depressive symptoms, as well as direct relationships among SCD, objective memory, and depressive symptoms.

RESULTS

Older adults who were more likely to report SCD had lower objective memory on average (between-person associations), and depressive symptoms partially mediated this relationship in three of four datasets. However, changes in depressive symptoms did not mediate the relationship between reports of SCD and declines in objective memory in three of four datasets (within-person associations).

CONCLUSION

Individual differences in depressive symptoms, and not changes in an individual's depressive symptoms over time, partially explain the link between SCD and objective memory. Older adults with SCD and depressive symptoms may be at greater risk for poor cognitive outcomes. Future research should explore how perceived changes in memory affect other aspects of psychological well-being, and how these relationships influence cognitive decline and Alzheimer's disease risk.

Parkinson's Disease in African Americans: A Review of the Current Literature

Parkinson’s disease (PD) is the second most common neurodegenerative disease, though evidence suggests that this disorder does not affect all racial groups similarly. Research in African Americans, in particular, has been conflicting. Some studies have found similar prevalence rates in African Americans and whites whereas other studies have found much lower prevalence and incidence rates in African Americans. A few studies identify potential factors underlying these discrepancies, including biologic differences as well as disparities in healthcare access. However, African Americans remain underrepresented in research studies, which make understanding the underlying reasons for these differences difficult. The purpose of this paper is to summarize existing research in African Americans with PD, highlight some of the reasons why differences exist in diagnostic rates of PD in this population, and briefly discuss interventions that may need to be made in order to ensure adequate care is provided to these patients.

Self-reported experiences of discrimination in older black adults are associated with insula functional connectivity

Self-reported experiences of discrimination are associated with a number of negative health outcomes. However, the neurobiological correlates of discrimination remain elusive. Recent neuroimaging work suggests that the amygdala is sensitive to forms of social adversity and the insula is involved in assessments of trust. We hypothesized that functional connectivity (FC) of these brain regions may be associated with discrimination in older Black adults. One-hundred and twenty-four nondemented older Black adults participating in the Minority Aging Research Study or the Clinical Core study of the Rush Alzheimer's Disease Center completed a measure of self-reported experiences of discrimination and a 3T MRI brain scan including structural T1 and resting-state fMRI EPIBOLD sequences. The right and left amygdala and insula regions were anatomically delineated as ROIs according to the Harvard-Oxford Brain Atlas and whole-brain voxelwise FC analyses were conducted using default parameters in the CONN toolbox. In regression analyses controlling for demographics and global cognition, self-reported experiences of discrimination were associated with greater FC between the left insula and the bilateral intracalcarine cortex, weaker FC between the left insula and the left dorsolateral prefrontal cortex, and weaker FC between the right insula and the left supplementary motor area. Amygdala analyses yielded no significant findings. Greater self-reported experiences of discrimination are associated with differential insula functional connectivity in older adults. More specifically, results suggest that discrimination is associated with differential connectivity of a key region (the insula) involved in trust perception.

ARTS: A novel In-vivo classifier of arteriolosclerosis for the older adult brain

Brain arteriolosclerosis, one of the main pathologies of cerebral small vessel disease, is common in older adults and has been linked to lower cognitive and motor function and higher odds of dementia. In spite of its frequency and associated morbidity, arteriolosclerosis can only be diagnosed at autopsy. Therefore, the purpose of this work was to develop an in-vivo classifier of arteriolosclerosis based on brain MRI. First, an ex-vivo classifier of arteriolosclerosis was developed based on features related to white matter hyperintensities, diffusion anisotropy and demographics by applying machine learning to ex-vivo MRI and pathology data from 119 participants of the Rush Memory and Aging Project (MAP) and Religious Orders Study (ROS), two longitudinal cohort studies of aging that recruit non-demented older adults. The ex-vivo classifier showed good performance in predicting the presence of arteriolosclerosis, with an average area under the receiver operating characteristic curve AUC = 0.78. The ex-vivo classifier was then translated to in-vivo based on available in-vivo and ex-vivo MRI data on the same participants. The in-vivo classifier was named ARTS (short for ARTerioloSclerosis), is fully automated, and provides a score linked to the likelihood a person suffers from arteriolosclerosis. The performance of ARTS in predicting the presence of arteriolosclerosis in-vivo was tested in a separate, 91% dementia-free group of 79 MAP/ROS participants and exhibited an AUC = 0.79 in persons with antemortem intervals shorter than 2.4 years. This level of performance in mostly non-demented older adults is notable considering that arteriolosclerosis can only be diagnosed at autopsy. The scan-rescan reproducibility of the ARTS score was excellent, with an intraclass correlation of 0.99, suggesting that application of ARTS in longitudinal studies may show high sensitivity in detecting small changes. Finally, higher ARTS scores in non-demented older adults were associated with greater decline in cognition two years after baseline MRI, especially in perceptual speed which has been linked to arteriolosclerosis and small vessel disease. This finding was shown in a separate group of 369 non-demented MAP/ROS participants and was validated in 72 non-demented Black participants of the Minority Aging Research Study (MARS) and also in 244 non-demented participants of the Alzheimer's Disease Neuroimaging Initiative 2 and 3. The results of this work suggest that ARTS may have broad implications in the advancement of diagnosis, prevention and treatment of arteriolosclerosis. ARTS is publicly available at https://www.nitrc.org/projects/arts/.

Susceptibility to Scams in Older Black and White Adults

Previous reports on racial differences in scam susceptibility have yielded mixed findings, and few studies have examined reasons for any observed race differences. Older Black and White participants without dementia (N = 592) from the Minority Aging Research Study and the Rush Memory and Aging Project who completed a susceptibility to scam questionnaire and other measures were matched according to age, education, sex, and global cognition using Mahalanobis distance. In adjusted models, older Black adults were less susceptible to scams than older White adults (Beta = -0.2496, SE = 0.0649, p = 0.0001). Contextual factors did not mediate and affective factors did not moderate this association. Analyses of specific items revealed Black adults had greater knowledge of scam targeting of older adults and were less likely to pick up the phone for unidentified callers. Older Black adults are less susceptible to scams than demographically-matched older White adults, although the reasons remain unknown.