Socioeconomic and psychosocial mechanisms underlying racial/ethnic disparities in cognition among older adults

Association between polycyclic aromatic hydrocarbon exposure and cognitive performance in older adults: a cross-sectional study from NHANES 2011-2014

Background: polycyclic aromatic hydrocarbons (PAHs) are classified as neurotoxins, but the relationship between exposure to PAHs and cognition in adults is unclear, and their non-linear and mixed exposure association hasn't been explored. Objective: to evaluate the non-linear and joint association between co-exposure to PAHs and multiple cognitive tests in U.S. older people. Methods: restricted cubic spline (RCS) and Bayesian kernel machine regression (BKMR) were conducted to evaluate the non-linear and mixed exposure association, based on the cross-sectional data from NHANES 2011-2014: 772 participants over 60 years old, 4 cognitive test scores, including the Immediate Recall Test (IRT), Delayed Recall Test (DRT), Animal Fluency Test (AFT), and Digit Symbol Substitution test (DSST), and 5 urinary PAH metabolites. Results: a V-shaped nonlinear relationship was found between 3-hydroxyfluorene (3-FLUO), 2-hydroxyfluorene (2-FLUO), and DRT. Negative trends between mixed PAH exposure and IRT, DRT, and DSST scores were observed. 2-FLUO contributed the most to the negative association of multiple PAHs with IRT and DRT scores and 2-hydroxynaphthalene (2-NAP) played the most important role in the decreasing relationship between mixed PAH exposure and DSST scores. Conclusion: our study suggested that PAH exposure in the U.S. elderly might be related to their poor performances in IRT, DRT and DSST. Further prospective studies are needed to validate the association.

Investigating the Effects of Discrimination Experiences on Everyday Metamemory Accuracy

OBJECTIVES

Lifetime and daily experiences of discrimination contribute to impaired performance on cognitive assessments. However, the underlying mechanism by which discrimination negatively affects cognition is unclear. Recent research investigating stress-induced impairment of metamemory may address the relationship between discrimination experiences and cognitive impairment.

METHODS

The aim of this study was to determine the relationship of lifetime and daily experiences of discrimination, daily affect balance, baseline objective cognitive performance, and sociodemographic variables (age, race, ethnicity, and sex) with metamemory accuracy across the lifespan (ages 20-75). Impaired metamemory accuracy was defined by the number of subjective cognitive complaints. Diary data from the Midlife in the United States (MIDUS Refresher 1) Daily Diary Project (N = 782) was used for these analyses.

RESULTS

Results from linear mixed model analyses showed significant within-person effects of daily discrimination, where people who reported more daily discrimination also reported lower metamemory accuracy, and daily affect balance, where people who reported very negative affect also reported lower metamemory accuracy. Additionally, linear mixed model analyses revealed significant between-person effects of race on metamemory accuracy, with individuals from minoritized racial groups generally reporting poorer metamemory accuracy. Daily discrimination experiences also interacted with other variables in predicting day-to-day metamemory accuracy.

DISCUSSION

These findings add to our understanding of how psychosocial stress in the form of daily discrimination experiences may impair metamemory processes contributing to increased subjective cognitive complaints. Future research should consider the contribution of daily experiences of discrimination across the lifespan to poor cognitive outcomes in later life.

Psychometric Reliability, Validity, and Generalizability of MoCA in American Indian Adults: The Strong Heart Study

Standardized neuropsychological instruments are used to evaluate cognitive impairment, but few have been psychometrically evaluated in American Indians. We collected Montreal Cognitive Assessment (MoCA) in 403 American Indians 70 to 95 years, as well as age, sex, education, bilingual status, depression symptoms, and other neuropsychological instruments. We evaluated inferences of psychometric validity, including scoring inference using confirmatory factor analysis and structural equation modeling, generalizability inference using reliability coefficient, and extrapolation inference by examining performance across different contexts and substrata. The unidimensional (total score) model had good fit criteria. Internal consistency reliability was high. MoCA scores were positively associated with crystallized cognition (ρ = 0.48, p < .001) and inversely with depression symptoms (ρ = -0.27, p < .001). Significant differences were found by education (d = 0.79, p < .05) depression (d = 0.484, p < .05), and adjudicated cognitive status (p = .0001) strata; however, MoCA was not sensitive or specific in discriminating cognitive impairment from normal cognition (area under the curve <0.5). MoCA scores had psychometric validity in older American Indians, but education and depression are important contextual features for score interpretability. Future research should evaluate cultural or community-specific adaptations, to improve test discriminability in this underserved population.

Racial differences in the effect of verbal and nonverbal memory on concrete planning for future care needs among older adults: a multi-group structural equation modeling approach

Concrete planning for future care needs may positively impact older adults' subsequent mental health and quality of life. However, the cognitive factors that facilitate concrete planning among Black and White older adults are still poorly understood. We investigated whether there are significant differences between Black (n = 159) and White (n = 262) older adults in concrete planning and explored racial differences in the relationship between verbal and nonverbal episodic memory and concrete planning. Results revealed that Blacks showed lower engagement in concrete planning and lower scores than Whites on each verbal and nonverbal memory task. For Blacks, but not Whites, verbal memory and nonverbal memory performance predicted concrete planning with higher nonverbal memory relating to less concrete planning and higher verbal memory associated with more concrete planning. Our findings suggest racial differences exist in how episodic verbal and nonverbal memory affect concrete planning, a crucial factor for older adults' preparation for future care.

Neighborhood racial income inequality and cognitive health

INTRODUCTION

Neighborhood socioeconomic status (SES) has been linked to dementia, but the distribution of SES within a neighborhood may also matter.

METHODS

Data from 460 (47% Black, 46% White) older adults from the Michigan Cognitive Aging Project were linked to census tract-level data from the National Neighborhood Data Archive (NaNDA). Neighborhood SES included two composites reflecting disadvantage and affluence. Neighborhood racial income inequality was the ratio of median incomes for White versus Black residents. Generalized estimating equations examined associations between neighborhood factors and cognitive domains.

RESULTS

Neighborhood racial income inequality was uniquely associated with worse cognitive health, and these associations did not differ by participant race. Neighborhood disadvantage was only associated with worse cognitive health among Black participants.

DISCUSSION

Both the level and racial distribution of SES within a neighborhood may be relevant for dementia risk. Racial differences in the level and impact of neighborhood SES contribute to dementia inequalities.

HIGHLIGHTS

Black participants lived in neighborhoods with lower socioeconomic status (SES) than White participants, on average. Neighborhood SES and racial income inequality were associated with worse cognition. Effects of neighborhood racial income inequality did not differ across racial groups. Effects of neighborhood SES were only evident among Black participants.

The effects of residential segregation on cognition among U.S. older adults: a systematic review based on the social determinants of health model

OBJECTIVES

This systematic review aims to advance the understanding of the complicated effects of segregation on older adults' cognition and provide guidance for future research.

METHOD

A systematic review using the Social Determinants of Health framework to examine the relationship between segregation and cognition across the selected literature.

RESULTS

Eight papers met the criteria for inclusion. All selected studies examined the influence of living in a segregated area on older adults' cognition, covering older adults from different racial/ethnic groups. The association between segregation and cognition was found in different directions across different racial/ethnic groups. The effects can be varied depending on race/ethnicity, level of education, neighborhood socioeconomic status, or social context.

CONCLUSION

This review identified existing gaps in understanding the relationship between segregation and cognition. Future studies should carefully adopt the segregation measures, acknowledge the varying segregation experience among different racial/ethnic groups, and consider more social determinant factors in research.

Psychometric reliability, validity, and generalizability of 3MSE scores among American Indian adults: the Strong Heart Study

OBJECTIVE

Modified Mini-Mental State Examination (3MSE) is often used to screen for dementia, but little is known about psychometric validity in American Indians.

METHODS

We recruited 818 American Indians aged 65-95 for 3MSE examinations in 2010-2013; 403 returned for a repeat examination in 2017-2019. Analyses included standard psychometrics inferences for interpretation, generalizability, and extrapolation: factor analysis; internal consistency-reliability; test-retest score stability; multiple indicator multiple cause structural equation models.

RESULTS

This cohort was mean age 73, majority female, mean 12 years education, and majority bilingual. The 4-factor and 2nd-order models fit best, with subfactors for orientation and visuo-construction (OVC), language and executive functioning (LEF), psychomotor and working memory (PMWM), verbal and episodic memory (VEM). Factor structure was supported for both research and clinical interpretation, and factor loadings were moderate to high. Scores were generally consistent over mean 7 years. Younger participants performed better in overall scores, but not in individual factors. Males performed better on OVC and LEF, females better on PMWM. Those with more education performed better on LEF and worse on OVC; the converse was true for bilinguals. All differences were significant, but small.

CONCLUSION

These findings support use of 3MSE for individual interpretation in clinic and research among American Indians, with moderate consistency, stability, reliability over time. Observed extrapolations across age, sex, education, and bilingual groups suggest some important contextual differences may exist.

Psychometric Properties of Controlled Oral Word Association (COWA) Test and Associations With Education and Bilingualism in American Indian Adults: The Strong Heart Study

The Controlled Oral Word Association (COWA) test is used to assess phonemic fluency and executive function. Formal validation of test scores is important for accurate cognitive evaluation. However, there is a dearth of psychometric validation among American Indian adults. Given high burden of dementia risk and key contextual factors associated with cognitive assessments, this represents a critical oversight. In a large, longitudinal population-based cohort study of adult American Indians, we examined several validity inferences for COWA, including scoring, generalization, and extrapolation inferences, by investigation of factor structure, internal consistency, test-retest reliability, and differential test functioning. We found adequate unidimensional model fit, with high factor loadings. Internal consistency reliability and test-retest reliability were 0.88 and 0.77, respectively, for the full group. COWA scores were lowest among the oldest, lowest education, bilingual speakers; group effects for sex and bilingual status were small; age effect was medium; and education effect was largest. However, Wide Range Achievement Test (WRAT) score effect was stronger than education effect, suggesting better contextualization may be needed. These results support interpretation of total COWA score, including across sex, age, or language use strata.

Impact of age and apolipoprotein E ε4 status on regional white matter hyperintensity volume and cognition in healthy aging

OBJECTIVE

White matter hyperintensity (WMH) volume is a neuroimaging marker of lesion load related to small vessel disease that has been associated with cognitive aging and Alzheimer's disease (AD) risk.

METHOD

The present study sought to examine whether regional WMH volume mediates the relationship between APOE ε4 status, a strong genetic risk factor for AD, and cognition and if this association is moderated by age group differences within a sample of 187 healthy older adults (APOE ε4 status [carrier/non-carrier] = 56/131).

RESULTS

After we controlled for sex, education, and vascular risk factors, ANCOVA analyses revealed significant age group by APOE ε4 status interactions for right parietal and left temporal WMH volumes. Within the young-old group (50-69 years), ε4 carriers had greater right parietal and left temporal WMH volumes than non-carriers. However, in the old-old group (70-89 years), right parietal and left temporal WMH volumes were comparable across APOE ε4 groups. Further, within ε4 non-carriers, old-old adults had greater right parietal and left temporal WMH volumes than young-old adults, but there were no significant differences across age groups in ε4 carriers. Follow-up moderated mediation analyses revealed that, in the young-old, but not the old-old group, there were significant indirect effects of ε4 status on memory and executive functions through left temporal WMH volume.

CONCLUSIONS

These findings suggest that, among healthy young-old adults, increased left temporal WMH volume, in the context of the ε4 allele, may represent an early marker of cognitive aging with the potential to lead to greater risk for AD.

Cognition and Wealth Changes in Mid-to-later Life: A Latent Class Trajectories Approach Using the Health and Retirement Study

ObjectivesTo assess how cognitive trajectories from mid-to-later life relate to wealth change, overall and by mid-life income. Methods: Data were from participants (51-64 years) in the 2000-2018 U.S. Health and Retirement Study who were cognitively healthy at baseline (year 2000; unweighted n = 3821). Longitudinal latent class analyses generated cognitive and wealth trajectories, independently, and multinomial logistic regressions estimated the association between cognitive trajectories and wealth profiles, overall and by median income. Results: We identified three cognitive: cognitively healthy (CH), increasing cognitive impairment (ICI), and increasing dementia (ID) and four wealth profiles: stable wealth loss (SWL), delayed gradual wealth loss (DGWL), stable wealth gain (SWG), and gradual wealth gain (GWG). The ID group had higher probability of being in the SWL group and lower probability of SWG, which was more pronounced in respondents with greater median income. Discussion: Individuals with ID may be vulnerable to wealth loss, particularly for middle-class households.

Intersectional Effects of Race and Educational Attainment on Memory Function of Middle-Aged and Older Adults With Alzheimer's Disease

BACKGROUND

High educational attainment may protect individuals, particularly middle-aged and older adults, against a wide range of health risks, including memory decline with age; however, this protection is less clear in patients with Alzheimer's disease (AD). In addition, this effect may differ across racial groups. According to the Marginalized-Related Diminished Return (MDR) theory, for example, the protective effect of high educational attainment on mental and physical health shows a weaker protective effect for racial minority groups, particularly Black people compared to White individuals.

OBJECTIVES

This longitudinal study used data of middle-aged and older adults with AD with two aims: first, to test the association between educational attainment and memory, and second, to explore racial differences in this association in the USA.

METHODS

Data came from the Alzheimer's Disease Neuroimaging Initiative (ADNI) study. The total sample was 1673 American middle-aged and older adults. The independent variable was educational attainment measured as years of education. The main outcome was memory operationalized as Rey Auditory Verbal Learning Test (RAVLT) Verbal Forgetting percentage (VF%). Age, gender, and follow-up duration were covariates. Race was the effect modifier. Linear regression model was utilized to analyze the data.

RESULTS

Of all participants, 68 (4.1%) were Black, and the remaining were White, with a mean age of 75 years old. In the pooled sample, educational attainment did not show a significant association with memory, independent of confounders. Educational attainment showed a significant interaction with race on memory, with higher educational attainment having a different effect on memory in White patients compared to Black patients.

CONCLUSION

The effect of higher educational attainment on memory differs for Black patients with AD compared to White patients. To prevent cognitive disparities by race, we need to go beyond racial inequality in access to resources (e.g., education) and minimize diminished returns of educational attainment for racial minorities. To tackle health inequalities, social policies should not be limited to equalizing socioeconomic status but also help minority groups leverage their available resources, such as educational attainment, and secure tangible outcomes.

Memory and aging across cultures

Memory declines are commonly reported with age, but the majority of research has been conducted with narrow segments of the world's population. We argue for the importance of considering culture in the study of cognitive aging in order to have a representative, accurate understanding of the effects of aging on memory. Limited research thus far investigates the effects of culture on the use of categories and the self in memory with age, finding that cultural differences tend to be larger for older than younger adults. Frameworks drawing on top-down and bottom-up processes may account for when more or less cultural variation would be expected in cognitive performance. Promising future research directions include socio-emotional memory and expanding samples to address global inequities.

Race, community disadvantage, and cognitive decline: Findings from KHANDLE and STAR

INTRODUCTION

Community disadvantage is associated with late-life cognition. Few studies examine its contribution to racial disparities in cognition/cognitive change.

METHODS

Inverse probability weighted models estimated expected mean differences in cognition/cognitive change attributed to residing in less advantaged communities, defined as cohort top quintile of Area Deprivation Indices (ADI): childhood 66-100; adulthood ADI 5-99). Interactions by race tested.

RESULTS

More Black participants resided in less advantaged communities. Semantic memory would be lower if all participants had resided in less advantaged childhood (b = -0.16, 95% confidence interval [CI] = -0.30, -0.03) or adulthood (b = -0.14, 95% CI = -0.22, -0.04) communities. Race interactions indicated that, among Black participants, less advantaged childhood communities were associated with higher verbal episodic memory (interaction p-value = 0.007) and less advantaged adulthood communities were associated with lower semantic memory (interaction p-value = 0.002).

DISCUSSION

Examining racial differences in levels of community advantage and late-life cognitive decline is a critical step toward unpacking community effects on cognitive disparities.

Psychosocial factors associated with 7-year change in cognition among middle-aged and older Hispanics/Latinos: The Hispanic Community Health Study/Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) and Sociocultural ancillary studies

INTRODUCTION

Few studies have examined the associations of psychosocial factors with cognitive change in Hispanics/Latinos.

METHODS

Data from the Hispanic Community Health Study/Study of Latinos-Investigation of Neurocognitive Aging (HCHS/SOL INCA) and Sociocultural studies were used (n = 2,155; ages ≥45 years). Psychosocial exposures included intrapersonal (ethnic identity, optimism, purpose in life), interpersonal (family cohesion, familism, social networks, social support), and social factors (ethnic discrimination, loneliness, subjective social status). Survey-linear regression models examined associations between psychosocial exposures and 7-year cognitive change (global cognition [GC], verbal learning, memory, word fluency [WF], and digit symbol substitution [DSS]).

RESULTS

Familism predicted decline in GC, verbal learning, and memory; family cohesion predicted DSS decline; and loneliness predicted memory decline. Ethnic identity was protective against decline in GC and memory, optimism and social support were protective against decline in memory, and purpose in life was protective against WF decline.

DISCUSSION

Psychosocial factors are differentially related to cognitive changes. Culturally relevant factors should be explored in Hispanic/Latino cognitive aging research.

HIGHLIGHTS

Psychosocial factors are differentially related to cognitive changes in Latinos. Role of culturally relevant factors on cognition should be further explored. Familism predicted decline in global cognition, verbal learning, and memory. Ethnic identity predicted increase in global cognition and memory.

Aging with long-term physical disability: Cohort analysis of survey sample in the U.S

Background

Chronic health conditions, secondary conditions, and decreasing functional ability related to aging and/or changes in underlying impairment may influence participation for persons aging with long-term physical disability (AwD).

Objective

To examine sample integrity and baseline findings through exploration of associations of sociodemographic, health, and disability factors with social participation for persons AwD.

Methods

This is a longitudinal cohort study following persons AwD over three years, reporting baseline cohort study data. A convenience sample of 474 persons AwD aged 45-65 reporting physical disability of ≥5 years' duration was recruited through community organizations and social media. The cohort was majority female (66.7%) and single (62.0%), and over one-third (38.6%) was non-White. Pain, fatigue, depression, ability to participate in, and satisfaction with, social roles and activities were measured with the Patient Reported Outcomes Measurement Information System. Results were manually compared against AwD study samples identified through a focused literature review and national census data.

Results

Participants aged 55-60 and 61-65 had significantly lower rates of employment and marriage and higher rates of living alone than participants aged 45-54. Participants reported higher rates of fatigue, pain, and depression and lower ability to participate in, and satisfaction with, participation in, social roles and activities than the general population. Ability to participate and satisfaction with participation were highest among Black/African American participants.

Conclusions

Participants reported higher rates of common AwD symptoms and lower ability to participate and satisfaction with participation than the general population, consistent with prior studies of AwD samples. This cohort reflects the AwD population and can be considered an AwD sample, comparable to those found in existing literature. The focus of future analyses will be to gain a greater understanding of chronic health conditions, incidence of falls, engagement in everyday life activities, and the impact of the environment.

Aging with long-term physical disability: Cohort analysis of survey sample in the U.S

BACKGROUND

Chronic health conditions, secondary conditions, and decreasing functional ability related to aging and/or changes in underlying impairment may influence participation for persons aging with long-term physical disability (AwD).

OBJECTIVE

To examine sample integrity and baseline findings through exploration of associations of sociodemographic, health, and disability factors with social participation for persons AwD.

METHODS

This is a longitudinal cohort study following persons AwD over three years, reporting baseline cohort study data. A convenience sample of 474 persons AwD aged 45-65 reporting physical disability of ≥5 years' duration was recruited through community organizations and social media. The cohort was majority female (66.7%) and single (62.0%), and over one-third (38.6%) was non-White. Pain, fatigue, depression, ability to participate in, and satisfaction with, social roles and activities were measured with the Patient Reported Outcomes Measurement Information System. Results were manually compared against AwD study samples identified through a focused literature review and national census data.

RESULTS

Participants aged 55-60 and 61-65 had significantly lower rates of employment and marriage and higher rates of living alone than participants aged 45-54. Participants reported higher rates of fatigue, pain, and depression and lower ability to participate in, and satisfaction with, participation in, social roles and activities than the general population. Ability to participate and satisfaction with participation were highest among Black/African American participants.

CONCLUSIONS

Participants reported higher rates of common AwD symptoms and lower ability to participate and satisfaction with participation than the general population, consistent with prior studies of AwD samples. This cohort reflects the AwD population and can be considered an AwD sample, comparable to those found in existing literature. The focus of future analyses will be to gain a greater understanding of chronic health conditions, incidence of falls, engagement in everyday life activities, and the impact of the environment.

Measurement and structural invariance of a neuropsychological battery among Middle Eastern/North African, Black, and White older adults

OBJECTIVE

There is a lack of guidance on common neuropsychological measures among Arabic speakers and individuals who identify as Middle Eastern/North African (MENA) in the United States. This study evaluated measurement and structural invariance of a neuropsychological battery across race/ethnicity (MENA, Black, White) and language (Arabic, English).

METHOD

Six hundred six older adults (128 MENA-English, 74 MENA-Arabic, 207 Black, 197 White) from the Detroit Area Wellness Network were assessed via telephone. Multiple-group confirmatory factor analyses examined four indicators corresponding to distinct cognitive domains: episodic memory (Consortium to Establish a Registry for Alzheimer's Disease [CERAD] Word List), language (Animal Fluency), attention (Montreal Cognitive Assessment [MoCA] forward digit span), and working memory (MoCA backward digit span).

RESULTS

Measurement invariance analyses revealed full scalar invariance across language groups and partial scalar invariance across racial/ethnic groups suggesting a White testing advantage on Animal Fluency; yet this noninvariance did not meet a priori criteria for salient impact. Accounting for measurement noninvariance, structural invariance analyses revealed that MENA participants tested in English demonstrated lower cognitive health than Whites and Blacks, and MENA participants tested in Arabic demonstrated lower cognitive health than all other groups.

CONCLUSIONS

Measurement invariance results support the use of a rigorously translated neuropsychological battery to assess global cognitive health across MENA/Black/White and Arabic/English groups. Structural invariance results reveal underrecognized cognitive disparities. Disaggregating MENA older adults from other non-Latinx Whites will advance research on cognitive health equity. Future research should attend to heterogeneity within the MENA population, as the choice to be tested in Arabic versus English may reflect immigrant, educational, and socioeconomic experiences relevant to cognitive aging. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The association of perceived discrimination with dementia risk in Black older adults

INTRODUCTION

Non-Hispanic Black, compared to non-Hispanic White, older adults are at increased risk for dementia. This may be due partly to greater exposure to psychosocial stressors, such as discrimination; however, few studies have examined this association.

METHODS

We examined the association of perceived discrimination (e.g., everyday, lifetime, and discrimination burden) with dementia risk in 1583 Black adults co-enrolled in the Atherosclerosis Risk in Communities (ARIC) Study and the Jackson Heart Study (JHS). Perceived discrimination (defined continuously and using tertiles) was assessed at JHS Exam 1 (2000-2004; mean age ± SD:66.2 ± 5.5) and related to dementia risk through ARIC visit 6 (2017) using covariate-adjusted Cox proportional hazards models.

RESULTS

Associations of perceived everyday, lifetime, and burden of discrimination with dementia risk were not supported in age-adjusted models or demographic- and cardiovascular health-adjusted models. Results were similar across sex, income, and education.

DISCUSSION

In this sample, associations between perceived discrimination and dementia risk were not supported.

HIGHLIGHTS

In Black older adults perceived discrimination not associated with dementia risk. Younger age and greater education linked to greater perceived discrimination. Older age and less education among factors associated with dementia risk. Factors increasing exposure to discrimination (education) are also neuroprotective.

Impact of educational attainment on time to cognitive decline among marginalized older adults: Cohort study of 20,311 adults

BACKGROUND

The effect of years of education on the maintenance of healthy cognitive functioning may differ by race and ethnicity given historical and ongoing inequities in educational quality.

METHODS

We examined 20,311 Black, Latinx, and White adults aged 51-100 from the Health and Retirement Study (2008-2016). Telephone Interview for Cognitive Status-27 data was used to measure cognitive functioning. Generalized additive mixed models were stratified by race and ethnicity and educational attainment (≥12 vs. <12 years). Selected social determinants of health, all-cause mortality, time-varying health and healthcare utilization characteristics, and study wave were included as covariates.

RESULTS

On average, Black and Latinx adults scored lower at baseline compared to White adults regardless of educational attainment (p < 0.001), with a significant overlap in the distributions of scores. The rate of cognitive decline was non-linear for Black, Latinx, and White adults (p < 0.001), and a period of stability was witnessed for those with higher educational attainment irrespective of race and ethnicity. Compared to Black, Latinx, and White adults with lower educational attainment, higher-educated White adults received the greatest protection from cognitive decline (13 years; 64 vs. 51), followed by Latinx (12 years; 67 vs. 55), and Black adults (10 years; 61 vs. 51). Latinx adults experienced cognitive decline beginning at a later age.

CONCLUSIONS

The extent to which higher educational attainment protects adults from cognitive decline differs by race and ethnicity, such that higher-educated White adults received a greater benefit than higher-educated Black or Latinx adults.

Association between carotid intima-media thickness and cognitive decline differs by race

INTRODUCTION

Common carotid intima-media thickness (cIMT) is a marker of subclinical atherosclerosis and is associated with cognitive decline. Although carotid atherosclerosis is more frequent in White than in Black participants, little is known whether race modifies the association between cIMT and cognitive decline.

METHODS

In this longitudinal analysis of the ELSA-Brasil, we assessed cIMT using ultrasound and cognitive performance using different domain tests. We used linear mixed models, interaction analysis, and race stratified analyses.

RESULTS

Baseline high IMT values were associated with memory (p < 0.001), verbal fluency (p < 0.001), TMT-B (p < 0.001)), and global cognitive decline (p < 0.001). Race was an effect modifier in the association between IMT and global cognitive decline (0.043), with stronger association in White (p < 0.001) than in Black (p = 0.009) participants.

DISCUSSION

Baseline IMT was associated with global and domain-specific cognitive decline and race modified this relationship, with stronger associations in White participants.

HIGHLIGHTS

Carotid intima-media thickness (cIMT) was associated with cognitive decline. cIMT and cognitive decline association was stronger in White than in Black participants. We used inverse probability weighting to address attrition bias.

Cognitive and Functional Improvement via Novel Skill Learning for Low-Income Minoritized Middle-Aged and Older Adults

Prior research has demonstrated beneficial outcomes for learning new skills in older adulthood, including increased cognitive and functional abilities, which help prevent age-related declines and foster healthy aging. However, these studies largely have included participants not typically considered at risk for cognitive and functional decline (i.e., White, highly educated, higher income). Cognitive and functional disparities exist among minoritized racial and ethnic individuals, particularly Black and Latinx populations, because of a lifetime of inequalities associated with low socioeconomic status, low education, and discrimination. This theoretical paper proposes a potential pathway in which such disparities could be mitigated by increasing cognitive and functional abilities via novel skill learning in these at-risk populations in middle and later life to prevent decline. We also discuss indirect barriers (e.g., financial and health issues), direct barriers (e.g., limited learning opportunities), and motivational barriers (e.g., self-beliefs, values) that these adults may encounter. We further highlight that addressing these barriers to novel skill learning by providing appropriate resources is necessary to maximize the feasibility and potential effectiveness of this pathway. Lastly, we encourage future research to test this pathway and help inform policymakers and existing learning programs to implement better ways of promoting lifelong learning in an inclusive and equitable manner to prevent decline.

Volume atrophy in medial temporal cortex and verbal memory scores in American Indians: Data from the Strong Heart Study

INTRODUCTION

Distinguishing Alzheimer's disease (AD) patient subgroups may optimize positive clinical outcomes. Cortical atrophy is correlated with memory deficits, but these associations are understudied in American Indians.

METHODS

We collected imaging and cognition data in the Strong Heart Study (SHS), a cohort of 11 tribes across three regions. We processed 1.5T MRI using FreeSurfer and iterative principal component analysis. Linear mixed models estimated volumetric associations with diabetes.

RESULTS

Over mean 7 years follow-up (N = 818 age 65-89 years), overall volume loss was 0.5% per year. Significant losses associated with diabetes were especially strong in the right hemisphere. Annualized hippocampal, parahippocampal, entorhinal atrophy were worse for men, older age, diabetes, hypertension, stroke; and associated with both encoding and retrieval memory losses.

DISCUSSION

Our findings suggest that diabetes is an important risk factor in American Indians for cortical atrophy and memory loss. Future research should examine opportunities for primary prevention in this underserved population.

Coping Styles and Cognitive Function in Older Non-Hispanic Black and White Adults

OBJECTIVES

Coping styles refer to cognitive and behavioral patterns used to manage the demands of stressors, and effective coping represents a psychological resource. Some studies have linked coping styles to executive functioning, but less is known about coping styles and their associations with cognition across social groups known to differ in stress exposure and dementia risk. This study aimed to characterize associations between coping styles and cognitive functioning across non-Hispanic Black and non-Hispanic White older adults.

METHODS

Participants were drawn from the Michigan Cognitive Aging Project (N = 453; age mean (SD) = 63.6 (3.2); 53% non-Hispanic Black). Problem-focused and emotion-focused coping were measured using the Coping Orientation to Problems Experienced Inventory. Global cognition was a composite of 5 cognitive domain scores derived from comprehensive neuropsychological tests. Cross-sectional associations between coping styles and cognition were examined using race-stratified regressions controlling for demographic and health covariates.

RESULTS

Black older adults reported more emotion-focused coping than White older adults, but there were no race differences in problem-focused coping. Among Black older adults, less problem-focused coping and more emotion-focused coping were each associated with worse cognition. Among White older adults, emotion-focused coping was marginally linked to cognition.

DISCUSSION

Greater emotion-focused coping among Black older adults may reflect greater exposure to stressors that are uncontrollable. Patterns of racial differences in coping-cognition links are in line with the social vulnerabilities hypothesis. Coping style may be a particularly important psychosocial resource for cognitive health among Black older adults that could be incorporated into culturally relevant interventions.

The aging brain: risk factors and interventions for long term brain health in women

PURPOSE OF REVIEW

Poor cognitive aging and dementia pose a significant public health burden, and women face unique risks compared to men. Recent research highlights the role of genetics, menopause, chronic disease, and lifestyle in risk and resilience in women's cognitive aging. This work suggests avenues for clinical action at midlife that may change the course of brain health in aging.

RECENT FINDINGS

Studies indicate women's risk for poor cognitive aging relates in part to hormone changes at menopause, a time when memory, brain structure and function, and Alzheimer's pathology may be observed in women and not men. Medical and lifestyle risks including diabetes, hypertension, and low physical activity also contribute to women's unique risks. At the same time, literature on resilience suggests women may benefit from lifestyle and chronic disease intervention, possibly more than men. Current studies emphasize the importance of interacting genetic and lifestyle risks, and effects of social determinants of health.

SUMMARY

Women have greater risk than men for poor cognitive aging; however, by treating the whole person, including genetics, lifestyle, and social environment, clinicians have an opportunity to support healthy cognitive aging in women and reduce the future public health burden of dementia.

Migration and Cognitive Health Disparities: The Arab American and Refugee Case

OBJECTIVES

This study investigates whether the year of arrival to the United States (U.S.) and birthplace relate to postmigration cognitive difficulties among foreign- and U.S.-born Arab Americans in later life.

METHODS

We analyzed 19 years (2000-2019) of data from the American Community Survey Public Use Microdata Samples (weighted N = 393,501; ages ≥ 50 years). Cognitive difficulty was based on self-reported data, and weighted means, percentages, adjusted prevalence estimates, and adjusted odds ratio were calculated.

RESULTS

Controlling only for demographics, foreign-born Arabs reported higher odds of cognitive difficulty compared to U.S.-born Arabs across all arrival cohorts (p < .001). After accounting for economic and integration factors, those who arrived between 1991 and 2000 had higher odds (odds ratio [OR] = 1.06, 95% confidence interval [CI] =1.00, 1.19, p < .01), while those who arrived after 2001 had lower odds (OR = 0.87, 95% CI = 0.78, 0.97, p < .001) of cognitive difficulty. Lacking English proficiency (OR = 1.90, 95% CI = 1.82, 1.98, p < .001) was related to higher odds, whereas not being a U.S. citizen was significantly associated with lower odds (OR = 0.89, 95% CI = 0.52, 0.94, p < .001) of cognitive difficulty. Yet, results varied by birthplace. Migrants born in Iraq consistently reported the highest odds of cognitive difficulty across all arrival cohorts.

DISCUSSION

Migration history and birthplace may be important factors explaining cognitive disparities among the diverse group of Arab migrants and Arab Americans. Future research examining mechanisms underlying these associations and the impact of migration on cognitive health is needed to address cognitive disparities in migrants.

The CERAD Word List Memory Test: Normative Data Based on a Norwegian Population-Based Sample of Healthy Older Adults 70 Years and Above. The HUNT Study

BACKGROUND

The CERAD Word List Memory Test (WLMT) is widely used in the assessment of older adults with suspected dementia. Although normative data of the WLMT exist in many different regions of the world, normative data based on large population-based cohorts from the Scandinavian countries are lacking.

OBJECTIVE

To develop normative data for the WLMT based on a large population-based Norwegian sample of healthy older adults aged 70 years and above, stratified by age, gender, and education.

METHODS

A total of 6,356 older adults from two population-based studies in Norway, HUNT4 70 + and HUNT4 Trondheim 70+, were administered the WLMT. Only persons with normal cognitive function were included. We excluded persons with a diagnosis of mild cognitive impairment (MCI) and dementia, and persons with a history of stroke and/or depression. This resulted in 3,951 persons aged between 70 and 90 years, of whom 56.2% were females. Regression-based normative data were developed for this sample.

RESULTS

Age, gender, and education were significant predictors of performance on the WLMT list-learning subtests and the delayed recall subtest, i.e., participants of younger age, female sex, and higher education level attained higher scores compared to participants of older age, male sex, and lower level of education.

CONCLUSION

Regression-based normative data from the WMLT, stratified by age, gender, and education from a large population-based Norwegian sample of cognitively healthy older adults aged 70 to 90 years are presented. An online norm calculator is available to facilitate scoring of the subtests (in percentiles and z-scores).

Associations Between Parity and Cognition: Race/Ethnic Differences

BACKGROUND

Race/ethnicity is associated with differences in reproductive history and cognition individually, yet it remains an understudied factor in the relationship between parity and later-life cognition.

OBJECTIVE

To evaluate if the association between parity and cognition differs between racial/ethnic groups.

METHODS

Participants included 778 older, postmenopausal women from the Health and Nutrition Examination Survey (Latina: n = 178, Non-Latino Black [NLB]: n = 169, Non-Latino White [NLW]: n = 431) who self-reported at least one birth. Cognitive outcomes included working memory, learning memory, and verbal fluency. Covariates included age, education, cardiovascular and other reproductive health factors, adult socioeconomic status (SES) and depressive symptoms. We fit a series of linear models to examine a) whether parity was associated with cognitive functioning, b) if this association varied by race/ethnicity through parity by race/ethnicity interactions, and c) individual parity with cognition associations stratified by race/ethnicity.

RESULTS

In the full sample, parity was significantly negatively associated with Digit Symbol Substitution Test (DSST) performance (b = -0.70, p = 0.024) but not Animal Fluency or word-list learning and memory. Tests of race/ethnicity-by-parity interactions were not statistically significant (ps > 0.05). However, stratified analyses by race/ethnicity showed a differential effect of parity on DSST performance, such that parity was significantly negatively associated with DSST performance (b = -1.66, p = 0.007) among Latinas but not in NLWs (b = -0.16, p = 0.74) or NLBs (b = -0.81, p = 0.191).

CONCLUSION

Among Latina, but not NLB or NLW women, greater parity was associated with worse processing speed/executive functioning later in life. Further research is needed to understand the mechanisms driving racial/ethnic differences.

Accelerometer-Measured Latent Physical Activity Profiles and Neurocognition Among Middle-Aged and Older Hispanic/Latino Adults in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

OBJECTIVES

Derive latent profiles of accelerometry-measured moderate-vigorous physical activity (MVPA) for Hispanic/Latino adults, examine associations between latent MVPA profiles and neurocognition, and describe profiles via self-reported MVPA.

METHODS

Complex survey design methods were applied to cross-sectional data from 7,672 adults ages 45-74 years in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL; 2008-2011). MVPA was measured via hip-worn accelerometers. Latent profile analysis was applied to derive latent MVPA profiles (minutes/day of week). Neurocognition was assessed with the Brief-Spanish English Verbal Learning Test (B-SEVLT) Sum, B-SEVLT Recall, Controlled Oral Word Association Test (word fluency), and Digit Symbol Substitution (DSS) test. All tests were z-scored, and a global neurocognition score was generated by averaging across scores. Survey linear regression models were used to examine associations between latent MVPA profiles and neurocognitive measures. Self-reported MVPA domains were estimated (occupational, transportation, and recreational) for each latent profile.

RESULTS

Four latent MVPA profiles from the overall adult target population (18-74 years) were derived and putatively labeled: No MVPA, low, moderate, and high. Only the high MVPA profile (compared to moderate) was associated with lower global neurocognition. Sensitivity analyses using latent MVPA profiles with only participants aged 45-74 years showed similar profiles, but no associations between latent MVPA profiles and neurocognition. The occupational MVPA domain led in all latent MVPA profiles.

DISCUSSION

We found no consistent evidence to link accelerometry-measured MVPA profiles to neurocognitive function. Research to better characterize the role of high occupational MVPA in relation to neurocognition among Hispanic/Latino adults are needed.

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.

Diversity in Alzheimer's disease drug trials: The importance of eligibility criteria

INTRODUCTION

To generalize safety and efficacy findings, it is essential that diverse populations are well represented in Alzheimer's disease (AD) drug trials. In this review, we aimed to investigate participant diversity in disease-modifying AD trials over time, and the frequencies of participant eligibility criteria.

METHODS

A systematic review was performed using Medline, Embase, the Cochrane Library, and Clinicaltrials.gov, identifying 2247 records.

RESULTS

In the 101 included AD trials, participants were predominantly White (median percentage: 94.7%, interquartile range: 81.0-96.7%); and this percentage showed no significant increase or decrease over time (2001-2019). Eligibility criteria such as exclusion of persons with psychiatric illness (78.2%), cardiovascular disease (71.3%) and cerebrovascular disease (68.3%), obligated caregiver attendance (80.2%), and specific Mini-Mental State Examination scores (90.1%; no significant increase/decrease over time) may have led to a disproportionate exclusion of ethnoracially diverse individuals.

DISCUSSION

Ethnoracially diverse participants continue to be underrepresented in AD clinical trials. Several recommendations are provided to broaden eligibility criteria.

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.

Psychosocial Protective Factors in Cognitive Aging: A Targeted Review

OBJECTIVE

The lack of disease-modifying pharmacological agents for dementia highlights the critical importance of prevention, but known modifiable factors (e.g., education, physical health and health behaviors, depression, and social isolation) do not fully represent potential intervention targets. Positive psychosocial factors predict cognitive aging outcomes above and beyond known risk factors and may also correspond to upstream determinants that open up new avenues for prevention and intervention, as well as for reducing racial/ethnic inequalities in dementia. In this brief report, I summarize contemporary evidence for three positive psychosocial factors that appear to be particularly relevant to cognitive aging: perceived control, religious involvement, and social relations.

METHODS

Targeted review and synthesis of published studies.

RESULTS

Each of the multidimensional constructs appears to contain "active ingredients" that could help to optimize cognitive aging through disparate mechanisms. Although historically marginalized racial/ethnic groups face disproportionate barriers to accessing certain psychosocial protective factors (e.g., perceived control), these same groups also exhibit naturally occurring sources of psychosocial resilience (e.g., religious involvement) that allow them to achieve better late-life cognitive health than would be otherwise expected. With regard to social relations, converging evidence from disparate studies shows that fostering late-life friendships in particular may have high potential for building cognitive reserve and promoting healthy cognitive aging.

CONCLUSIONS

Positive psychosocial factors represent culturally relevant resources that, through careful research, could ultimately be harnessed to promote better cognitive aging for a growing and increasingly diverse population of older adults.