Psychosocial Pathways to Racial/Ethnic Inequalities in Late-Life Memory Trajectories

Association of Racial Residential Segregation Throughout Young Adulthood and Cognitive Performance in Middle-aged Participants in the CARDIA Study

Importance

Neighborhood-level residential segregation is implicated as a determinant for poor health outcomes in black individuals, but it is unclear whether this association extends to cognitive aging, especially in midlife.

Objective

To examine the association between cumulative exposure to residential segregation during 25 years of young adulthood among black individuals and cognitive performance in midlife.

Design, Setting, and Participants

The ongoing prospective cohort Coronary Artery Risk Development in Young Adults (CARDIA) Study recruited 5115 black and white participants aged 18 to 30 years from 4 field centers at the University of Alabama, Birmingham; University of Minnesota, Minneapolis; Northwestern University, Chicago, Illinois; and Kaiser Permanente, Oakland, California. Data were acquired from February 1985 to May 2011. Among the surviving CARDIA cohort, 3671 (71.8%) attended examination year 25 of the study in 2010, when cognition was measured, and 3008 (81.9%) of those completed the cognitive assessments. To account for time-varying confounding and differential censoring, marginal structural models using inverse probability weighting were applied. Data were analyzed from April 16 to July 20, 2019.

Main Outcomes and Measures

Racial residential segregation was measured using the Getis-Ord Gi* statistic, and the mean cumulative exposure to segregation was calculated across 6 follow-up visits from baseline to year 25 of the study, then categorized into high, medium, and low segregation. Cognitive function was measured at year 25 of the study, using the Digit Symbol Substitution Test (DSST), Stroop color test (reverse coded), and Rey Auditory Verbal Learning Test. To facilitate comparison of estimates, z scores were calculated for all cognitive tests.

Results

A total of 1568 black participants with available cognition data were included in the analysis. At baseline, participants had a mean (SD) age of 25 (4) years and consisted of 936 women (59.7%). Greater cumulative exposure to segregated neighborhoods was associated with a worse DSST z score (for high segregation, β = -0.37 [95% CI, -0.61 to -0.13]; for medium segregation, β = -0.25 [95% CI, -0.51 to 0.0002]) relative to exposure to low segregation.

Conclusions and Relevance

In this cohort study, exposure to residential segregation throughout young adulthood was associated with worse processing speed among black participants as early as in midlife. This association may potentially explain black-white disparities in dementia risk at older age.

Trends in Relative Incidence and Prevalence of Dementia Across Non-Hispanic Black and White Individuals in the United States, 2000-2016

Importance

In the US, dementia risk is higher in non-Hispanic Black individuals than in non-Hispanic White individuals. To evaluate progress toward reducing such disparities, tracking secular trends in racial disparities in dementia prevalence is essential.

Objective

To examine whether relative racial disparities in dementia prevalence or incidence have changed in the US from 2000 to 2016.

Design, Settings, and Participants

The Health and Retirement Study (HRS) is a nationally representative study of adults 50 years or older. New participants are recruited every 6 years, and study visits occur biennially. Approximately 17 000 to 22 000 respondents have been surveyed at each wave since 2000, achieving response rates of 81% to 89%. Data for this cohort study were obtained from non-Hispanic White and non-Hispanic Black participants aged 70 years and older from the 2000 to 2016 waves. For analyses of secular trends in racial disparities in dementia prevalence, each HRS wave was considered separately (range of participants meeting eligibility criteria in each wave, 6322-7579). For analyses of secular trends in racial disparities in dementia incidence, 7 subcohorts were created (range of participants meeting eligibility criteria in each subcohort, 5322-5961) following up people without dementia for 4 years from subcohort baseline visits in 2000, 2002, 2004, 2006, 2008, 2010, and 2012. Data were analyzed from October 2019 to August 2020.

Exposures

Race based on self-response to closed-ended survey questions.

Main Outcomes and Measures

Dementia status was determined using 3 algorithms with similar sensitivity and specificity across non-Hispanic White and Black participants. Disparities were characterized using ratio measures.

Results

In this study, the mean age and percentage of male participants eligible for inclusion in analyses of racial disparities in dementia prevalence increased over time among non-Hispanic White participants (from 78.2 years and 40% in 2000 to 78.7 years and 44% in 2016) but remained steady in non-Hispanic Black participants during the same period (from 78.0 years and 37% in 2000 to 77.9 years and 38% in 2016). Prevalence ratios comparing Black and White participants ranged from approximately 1.5 to 1.9 across algorithms and years, whereas hazard ratios ranged from approximately 1.4 to 1.8. Although results suggest stable or declining dementia risk overall, there was no evidence suggesting change in relative racial disparities in dementia prevalence or incidence during follow-up.

Conclusions and Relevance

This study did not find evidence to suggest that the ratio of dementia risk across Black and White individuals changed in the US between 2000 and 2016. Additional efforts to identify and mitigate the source of these disparities is warranted.

Engagement in Enriching Early-Life Activities Is Associated With Larger Hippocampal and Amygdala Volumes in Community-Dwelling Older Adults

OBJECTIVES

Numerous studies show benefits of mid- and late-life activity on neurocognitive health. Yet, few studies have examined how engagement in enriching activities during childhood, when the brain is most plastic, may confer long-term neurocognitive benefits that may be especially important to individuals raised in low-income settings. We examined associations between enriching early-life activities (EELAs) and hippocampal and amygdala volumes in a sample of predominantly African-American, community-dwelling older adults. We further assessed whether these associations were independent of current activity engagement.

METHODS

Ninety participants from the baseline Brain Health Substudy of the Baltimore Experience Corps Trial (mean age: 67.4) completed retrospective activity inventories and an magnetic resonance imaging scan. Volumes were segmented using FreeSurfer.

RESULTS

Each additional EELA was associated with a 2.3% (66.6 mm3) greater amygdala volume after adjusting for covariates. For men, each additional EELA was associated with a 4.1% (278.9 mm3) greater hippocampal volume. Associations were specific to these regions when compared with the thalamus, used as a control region.

DISCUSSION

Enriching lifestyle activities during an important window of childhood brain development may be a modifiable factor that impacts lifelong brain reserve, and results highlight the importance of providing access to such activities in historically underserved populations.

Mechanisms of Racial Disparities in Cognitive Aging: An Examination of Material and Psychosocial Well-Being

OBJECTIVES

We tested the hypothesis that education's effect on cognitive aging operates in part through measures of material and psychosocial well-being.

METHOD

Our sample was of non-Latino black and white participants of the National Social Life Health and Aging Project who had valid cognitive assessments in Waves 2 and 3 (n = 2,951; age range: 48-95). We used structural equation modeling to test for mediation and moderated mediation by income, assets, perceived stress, social status, and allostatic load on the relationships between race, education, and cognition at two time points.

RESULTS

Education consistently mediated the race-cognition relationship, explaining about 20% of the relationship between race and cognition in all models. Income and assets were moderated by race; these factors were associated with cognition for whites but not blacks. Social status mediated the association between race and cognition, and social status and perceived stress mediated the education-cognition pathway. Allostatic load was not a mediator of any relationship.

DISCUSSION

Education remains the best explanatory factor for cognitive aging disparities, though material well-being and subjective social status help to explain a portion of the racial disparity in cognitive aging.

Informant-Reported Discrimination, Dementia, and Cognitive Impairment in Older Brazilians

BACKGROUND

Self-reported discrimination is a source of psychosocial stress that has been previously associated with poor cognitive function in older African Americans without dementia.

OBJECTIVE

Here, we examine the association of discrimination with dementia and cognitive impairment in racially diverse older Brazilians.

METHODS

We included 899 participants 65 years or older (34.3% Black) from the Pathology, Alzheimer's and Related Dementias Study (PARDoS), a community-based study of aging and dementia. A structured interview with informants of the deceased was conducted. The interview included the Clinical Dementia Rating (CDR) Scale for the diagnosis of dementia and cognitive impairment proximate to death and the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) as a second measure of cognitive impairment. Informant-reported discrimination was assessed using modified items from the Major and Everyday Discrimination Scales.

RESULTS

Discrimination was reported by informants of 182 (20.2%) decedents and was more likely reported by informants of Blacks than Whites (25.3% versus 17.6%, p = 0.006). Using the CDR, a higher level of informant-reported discrimination was associated with higher odds of dementia (OR: 1.24, 95% CI 1.08 -1.42, p = 0.002) and cognitive impairment (OR: 1.21, 95% CI: 1.06 -1.39, p = 0.004). Similar results were observed using the IQCODE (estimate: 0.07, SE: 0.02, p = 0.003). The effects were independent of race, sex, education, socioeconomic status, major depression, neuroticism, or comorbidities.

CONCLUSION

Higher level of informant-reported discrimination was associated with higher odds of dementia and cognitive impairment in racially diverse older Brazilians.

Disparities in Physical and Psychological Symptoms in Hospitalized African American and White Persons with Dementia

Objectives: This study examined differences in physical function, delirium, depressive symptoms, and behavioral and psychological symptoms of dementia (BPSD) in hospitalized African American and white older adults with dementia. Methods: This secondary data analysis using baseline data from an ongoing trial testing family-centered function-focused care included African American (n = 159) and white persons (n =135) with dementia. Results: A multivariate analysis of covariance showed that controlling for relevant demographic and health characteristics, African Americans with dementia had lower physical function, more delirium, and more depressive symptoms upon admission than white participants. There were no significant differences in BPSD between African American and white persons. Discussion: To our knowledge, this is the first study to examine racial differences in admission symptoms of hospitalized persons with dementia. While the findings are preliminary, they can be used to inform the design of future research, including identifying the causes of disparities.

Death of a Child Prior to Midlife, Dementia Risk, and Racial Disparities

OBJECTIVES

This study considers whether experiencing the death of a child prior to midlife (by parental age 40) is associated with subsequent dementia risk, and how such losses, which are more common for black than for white parents, may add to racial disparities in dementia risk.

METHODS

We use discrete-time event history models to predict dementia incidence among 9,276 non-Hispanic white and 2,182 non-Hispanic black respondents from the Health and Retirement Study, 2000-2014.

RESULTS

Losing a child prior to midlife is associated with increased risk for later dementia, and adds to disparities in dementia risk associated with race. The death of a child is associated with a number of biosocial variables that contribute to subsequent dementia risk, helping to explain how the death of child may increase risk over time.

DISCUSSION

The death of a child prior to midlife is a traumatic life course stressor with consequences that appear to increase dementia risk for both black and white parents, and this increased risk is explained by biosocial processes likely activated by bereavement. However, black parents are further disadvantaged in that they are more likely than white parents to experience the death of a child, and such losses add to the already substantial racial disadvantage in dementia risk.

Everyday discrimination and subsequent cognitive abilities across five domains

OBJECTIVE

Previous research suggests that everyday discrimination is associated with worse concomitant performance in several cognitive domains, as well as faster subsequent declines in episodic memory. This study aimed to extend knowledge on the specificity, durability, and mechanisms of associations between everyday discrimination and cognition by using a comprehensive neuropsychological battery and a longitudinal mediation design.

METHOD

Participants included 3,304 older adults in the Health and Retirement Study Harmonized Cognitive Assessment Protocol. Discrimination was assessed using the Everyday Discrimination Scale. Depressive symptoms were assessed with the 8-item Center for Epidemiological Studies Depression Scale. Vascular diseases were quantified as the self-reported presence of hypertension, diabetes, and heart disease. Confirmatory factor analysis was used to estimate episodic memory, executive functioning, processing speed, language, and visuoconstruction across a battery of 13 neuropsychological tests. Structural equation models controlled for sociodemographics and baseline cognition ascertained 2 to 4 years prior.

RESULTS

Discrimination was associated with more depressive symptoms and vascular diseases. Depressive symptoms mediated negative effects of discrimination on subsequent functioning across all 5 cognitive domains. Vascular diseases additionally mediated negative effects of discrimination on processing speed. After accounting for mediators, direct negative effects of discrimination remained for executive functioning and visuoconstruction.

CONCLUSIONS

This national longitudinal study in the United States provides evidence for broad and enduring effects of everyday discrimination on cognitive aging, which appear to be partially mediated by mental and physical health. Future research should examine additional mechanisms as well as moderators of these associations to better understand points of intervention. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The impact of region and urbanicity on the discrimination-cognitive health link among older Blacks

Little research has examined how the link between discrimination and cognitive health varies by where people live. This study investigates how living in non-urban versus urban areas in different regions in the United States moderates the discrimination-cognitive health link among older non-Hispanic Blacks. Data are from the 2012 and 2014 waves of the Health and Retirement Study (HRS; N=2,347). Regression analyses indicate that experiencing more everyday discrimination is significantly associated with lower episodic memory when living in urban areas. Among non-Hispanic Blacks, the discrimination-episodic memory link does not significantly vary across U.S. regional contexts. Findings highlight variation in the association between everyday discrimination and cognitive health by where older non-Hispanic Blacks live. Results suggest the importance of socio-environmental factors in shaping how stressful experiences such as discrimination are linked to cognitive health in later life.

Interactive Effects of Chronic Health Conditions and Financial Hardship on Episodic Memory among Older Blacks: Findings from the Health and Retirement Study

Previous research links chronic health conditions and financial hardship to cognitive outcomes among older Blacks. However, few studies have explored the moderating effect of financial hardship on chronic disease burden and specific cognitive domains. This study examined whether financial hardship (as measured by difficulty paying monthly bills) modifies the impact of self-reported chronic health conditions (e.g., diabetes, stroke) on episodic memory among 871 older Blacks (50+ years) in the Health and Retirement Study (2006). Financial hardship modified the association between chronic disease burden and episodic memory performance such that individuals who reported very little difficulty paying their monthly bills had significantly lower memory scores at high levels of disease burden compared to those reporting high financial difficulty after controlling for age, gender and education (F 2, 49 = 5.03, p= 0.010). This cross-sectional study suggests that both financial and physical wellbeing may have joint effects on cognitive health in older Blacks.

Psychological predictors of memory decline in a racially and ethnically diverse longitudinal sample of older adults in the United States

OBJECTIVES

In the United States, racial and ethnic disparities in memory dysfunction and Alzheimer disease are evident even after accounting for many risk factors. Psychological factors, such as psychological well-being, perceived control, depressive symptoms, and negative affect, may influence memory dysfunction, and associations may differ by race and ethnicity. This study examined whether psychological factors are differentially associated with episodic memory trajectories across racial and ethnic groups in the United States.

METHODS/DESIGN

The National Health and Aging Trends Study (NHATS), is a US-representative, longitudinal study of Medicare-eligible adults 65+ years old. Analyses of 5 years of data, included a total of 9411 participants without dementia at baseline. Adjusting for relevant covariates, a linear mixed model estimated the associations between psychological predictors and a composite of immediate and delayed trials from a word list memory test.

RESULTS

More depressive symptoms (B = -0.02), lower psychological well-being (B = 0.03), and lower perceived control (B = 0.05) were independently associated with lower initial memory. Depressive symptoms were associated with faster rate of memory decline (B = -0.01). Black (B = -0.34) and Hispanic (B = -0.28) participants evidenced lower initial memory level than whites, but only Hispanic (B = -0.04) participants evidenced faster memory decline than whites. There were no significant interactions between the psychological variables and race and ethnicity.

CONCLUSIONS

Results extend previous studies showing racial and ethnic disparities in episodic memory trajectories, and the longitudinal effects of depressive symptoms on episodic memory in US samples. Epidemiological studies of cognitive aging should incorporate more psychological factors clarify cognitive decline and disparities.

Longitudinal associations between self-reported experiences of discrimination and depressive symptoms in young women and men post- myocardial infarction

Objectives

Research suggests that following a myocardial infarction (MI), women under the age of 60 have more elevated depressive symptoms and adverse outcomes than similarly aged men. Identifying risk factors that contribute to gender differences in depressive symptoms among this group may be critical to the development of psychosocial interventions. Experiences of discrimination may be an important correlate of depressive symptoms in this group; however, studies of this relationship have largely been cross-sectional and focused on healthy populations. This study examines longitudinal associations among gender, discrimination, and depressive symptoms in a young post-MI cohort.

Methods

Participants were 313 adults from the Myocardial Infarction and Mental Stress Ischemia Study 2 of young (≤60 yrs) post-MI patients. At baseline and 6 month follow-up, depressive symptoms were measured with the Beck Depression Inventory-II and discrimination was assessed with the 10-item version Everyday Discrimination scale. Linear regression models were used to assess the longitudinal association between reports of discrimination and depressive symptoms adjusted for sociodemographic characteristics, psychosocial factors and health status indicators and tested for gender differences.

Results

The mean age was 51.2, 49.6% were women, and 69.5% were African-American. Although the discrimination-by-gender interaction was marginally significant (p=.09) in the fully adjusted model, findings suggest that the association between changes in reports of discrimination and depressive symptoms over time may be more pronounced for women (β=.61, standard error=.15, p<.001) than men (β=.27, standard error=.13, p=.033).

Conclusion

Our findings suggest that discrimination is a risk factor for depressive symptoms in young post-MI populations over time.

Dimensions of Religious Involvement Represent Positive Pathways in Cognitive Aging

Older Black and Hispanic adults report more religious involvement, and religious involvement has been linked to better cognition. This study examined which aspects of religious involvement are associated with better longitudinal episodic memory and whether religious involvement offsets racial and ethnic inequalities in episodic memory. Using Health and Retirement Study data (N = 16,069), latent growth curves estimated independent indirect pathways between race and ethnicity and 6-year memory trajectories through religious attendance, private prayer, and religious belief, controlling for nonreligious social participation, depressive symptoms, chronic health diseases, age, education, and wealth. Negative direct effects of Black race and Hispanic ethnicity on memory were partially offset by positive indirect pathways through more private prayer and religious attendance. While results were significant for memory intercept and not subsequent memory change, religious attendance and private prayer were independently associated with better cognitive health among diverse older adults. Findings may inform culturally relevant intervention development to promote successful aging and reduce older adults' cognitive morbidity.

Social network characteristics and cognitive functioning in ethnically diverse older adults: The role of network size and composition

OBJECTIVES

Social engagement has been linked to preserved cognitive functioning in later life. While social engagement is often operationalized as social network size, social networks can vary not only in size, but also in composition. Previous work has found that having a greater proportion of family in a network is associated with worse socioemotional and cognitive outcomes compared to having a greater proportion of friends. In addition, social resources may differentially affect cognition in minority groups at higher risk of cognitive impairment. Therefore, the current study aimed to examine racial/ethnic differences in the relationship between network characteristics and cognition.

METHOD

Ethnically and racially diverse older adults from the Washington Heights-Inwood Columbia Aging Project (n = 548, 60-93 years) were used. Multiple regressions were conducted to examine the effects of ethnicity/race, size, composition, and their interaction on global cognition.

RESULTS

Analyses revealed that networks with a greater proportion of friends were associated with better global cognition than networks with a greater proportion of family. Additionally, larger social network size was only associated with better global cognition among individuals who had a greater proportion of friends in their networks. Race further moderated this effect, as it was limited to African Americans.

DISCUSSION

Overall, these findings highlight the importance of looking at both composition and size when examining the relationship between social network characteristics and global cognition. These findings suggest that friendships may be especially important and further suggest that social network characteristics and cognitive aging may be more strongly related among African Americans. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Longitudinal effects of race, ethnicity, and psychosocial disadvantage on systemic inflammation

Objective

Psychosocial factors likely contribute to racial and ethnic inequalities in cardiovascular diseases (CVDs). However, precise social, psychological, and physiological pathways linking race and ethnicity to the development of CVDs are not well understood. Systemic inflammation, commonly indexed by C-reactive protein (CRP), is a biomarker for CVD risk and progression. The objective of this study was to identify mediating pathways from race and ethnicity to CRP through social, psychological, and behavioral variables.

Methods

Using data from 12,382 participants aged 51 and older in the Health and Retirement Study, structural equation models tested for direct and indirect effects of race and ethnicity on CRP measured over four years through educational disadvantage, everyday discrimination, depressive symptoms, external locus of control, and smoking.

Results

Educational disadvantage mediated Black-White and Hispanic-White disparities in baseline CRP directly, as well as indirectly through elevated depressive symptoms, higher external locus of control, and smoking. Educational disadvantage also mediated Black-White and Hispanic-White disparities in CRP change directly, as well as indirectly through higher external locus of control and smoking. Independent of education, discrimination mediated Black-White differences in baseline CRP via elevated depressive symptoms, higher external locus of control, and smoking. Discrimination also mediated Black-White disparities in CRP change via external locus of control.

Conclusions

Results from this population-based, longitudinal study support the view that racially patterned social disadvantage is prospectively associated with longitudinal inflammatory processes, and some of these effects are independently mediated by psychological and behavioral factors. Biopsychosocial pathways to health disparities also differ between minority groups.

Arab American Cognitive Aging: Opportunities for Advancing Research on Alzheimer's Disease Disparities

BACKGROUND AND OBJECTIVES

This article highlights the dearth of and need for research on Arab American cognitive aging. We propose that studying cognitive health issues among older Arab Americans provides an innovative opportunity to advance knowledge about causes and consequences of Alzheimer's disease (AD) disparities and refine understanding of factors linked to immigrant health in the United States.

RESEARCH DESIGN AND METHODS

Demographic information is provided on Arab Americans, who are on the cusp of being recognized by the U.S. government as a distinct ethnic group separate from whites. In the tradition of minority aging, we present a broad review of specific issues in the contemporary case of Arab Americans.

RESULTS

We detail how including Arab Americans provides unique information on the importance of: (i) extending racial/ethnic group comparisons; (ii) linking social experiences to late-life cognitive health; and (iii) incorporating ethnic factors related to immigration and religion in the study of AD disparities.

DISCUSSION AND IMPLICATIONS

Studying Arab American cognitive aging provides an innovative opportunity to more fully delineate factors that create and sustain health disparities, with special insights into both causes and consequences.