Racial Disparities in Cognitive Performance in Mid- and Late Adulthood: Analyses of Two Cohort Studies

Associations of a toenail metal mixture with attention and memory in the Gulf long-term follow-up (GuLF) study

BACKGROUND

Research on metal-associated neurodegeneration has largely focused on single metals. Since metal exposures typically co-occur as combinations of both toxic and essential elements, a mixtures framework is important for identifying risk and protective factors. This study examined associations between toenail levels of an eight-metal mixture and attention and memory in men living in US Gulf states.

METHODS

We measured toenail concentrations of toxic (arsenic, chromium, lead, and mercury) and essential (copper, manganese, selenium, and zinc) metals in 413 non-smoking men (23-69 years, 46 % Black) from the Gulf Long-Term Follow-Up (GuLF) Study. Sustained attention and working memory were assessed at the time of toenail sample collection using the continuous performance test (CPT) and digit span test (DST), respectively. Associations between toenail metal concentrations and performance on neurobehavioral tests were characterized using co-pollutant adjusted general linear models and Bayesian Kernel Machine Regression.

RESULTS

Adjusting for other metals, one interquartile range (IQR) increase in toenail chromium was associated with a 0.19 (95 % CI: -0.31, -0.07) point reduction in CPT D Prime score (poorer ability to discriminate test signals from noise). One IQR increase in toenail manganese was associated with a 0.20 (95 % CI, -0.41, 0.01) point reduction on the DST Reverse Count (fewer numbers recalled). Attention deficits were greater among Black participants compared to White participants for the same increase in toenail chromium concentrations. No evidence of synergistic interaction between metals or adverse effect of the overall metal mixture was observed for either outcome.

CONCLUSIONS

Our findings support existing studies of manganese-related memory deficits and are some of the first to show chromium related attention deficits in adults. Longitudinal study of cognitive decline is needed to verify chromium findings. Research into social and chemical co-exposures is also needed to explain racial differences in metal-associated neurobehavioral deficits observed in this study.

Social determinants of health but not global genetic ancestry predict dementia prevalence in Latin America

INTRODUCTION

Leveraging the nonmonolithic structure of Latin America, which represents a large variability in social determinants of health (SDoH) and high levels of genetic admixture, we aim to evaluate the relative contributions of SDoH and genetic ancestry in predicting dementia prevalence in Latin American populations.

METHODS

Community-dwelling participants aged 65 and older (N = 3808) from Cuba, Dominican Republic, Mexico, and Peru completed the 10/66 protocol assessments. Dementia was diagnosed using the cross-culturally validated 10/66 algorithm. Multivariate linear regression models adjusted for SDoH were used in the main analysis. This study used cross-sectional data from the 1066 population-based study.

RESULTS

Individuals with higher proportions of Native American (>70%) and African American (>70%) ancestry were more likely to exhibit factors contributing to worse SDoH, such as lower educational levels (p < 0.001), lower socioeconomic status (p < 0.001), and higher frequency of vascular risk factors (p < 0.001). After adjusting for measures of SDoH, there was no association between ancestry proportion and dementia probability, and ancestry proportions no longer significantly accounted for the variance in cognitive performance (African predominant p = 0.31 [-0.19, 0.59] and Native predominant p = 0.74 [-0.24, 0.33]).

DISCUSSION

The findings suggest that social and environmental factors play a more crucial role than genetic ancestry in predicting dementia prevalence in Latin American populations. This underscores the need for public health strategies and policies that address these social determinants to effectively reduce dementia risk in these communities.

HIGHLIGHTS

Countries in Latin America express a large variability in social determinants of health and levels of admixture. After adjustment for downstream societal factors linked to SDoH, genetic ancestry shows no link to dementia. Population ancestry profiles alone do not influence cognitive performance. SDoH are key drivers of racial disparities in dementia and cognitive performance.

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.

Sex differences in the association between tau PET and cognitive performance in a non-Hispanic White cohort with preclinical AD

INTRODUCTION

We investigated how the associations between tau and cognitive measures differ by sex in the preclinical Alzheimer's disease (AD) stage.

METHODS

A total of 343 cognitively unimpaired, amyloid-positive individuals (205 women, 138 men) who self-identified as non-Hispanic White from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) Study were included. We assessed sex-stratified associations between 18 F-flortaucipir positron emission tomography (PET) standardized uptake value ratio (SUVR) in the meta-temporal region and Preclinical Alzheimer's Cognitive Composite (PACC) and Computerized Cognitive Composite (C3) components.

RESULTS

We observed that higher tau level was significantly associated with worse cognitive performance only in women: PACC and its components except for Mini-Mental State Examination (MMSE) and C3 components: First Letter Name Recall (FNLT) and One-Card Learning Reaction Time (OCL RT). These associations except for FNLT were apolipoprotein E (APOE) ε4 independent.

DISCUSSION

Women show stronger associations between tau PET and cognitive outcomes in preclinical AD. These findings have important implications for sex-specific tau-targeted preventive AD clinical trials.

HIGHLIGHTS

The tau positron emission tomography (PET) signal in the meta-temporal region was associated with poor cognitive performance in preclinical Alzheimer's disease (AD). After sex stratification, the associations between regional tau PET and cognitive outcomes were observed only in women. The associations between tau PET and some cognitive outcomes were independent of apolipoprotein E (APOE) ε4.

Genetics of Alzheimer's Disease in the African American Population

Black/African American (AA) individuals have a higher risk of Alzheimer's disease (AD) than White non-Hispanic persons of European ancestry (EUR) for reasons that may include economic disparities, cardiovascular health, quality of education, and biases in the methods used to diagnose AD. AD is also heritable, and some of the differences in risk may be due to genetics. Many AD-associated variants have been identified by candidate gene studies, genome-wide association studies (GWAS), and genome-sequencing studies. However, most of these studies have been performed using EUR cohorts. In this paper, we review the genetics of AD and AD-related traits in AA individuals. Importantly, studies of genetic risk factors in AA cohorts can elucidate the molecular mechanisms underlying AD risk in AA and other populations. In fact, such studies are essential to enable reliable precision medicine approaches in persons with considerable African ancestry. Furthermore, genetic studies of AA cohorts allow exploration of the ways the impact of genes can vary by ancestry, culture, and economic and environmental disparities. They have yielded important gains in our knowledge of AD genetics, and increasing AA individual representation within genetic studies should remain a priority for inclusive genetic study design.

Diversity of Studies on Neighborhood Greenspace and Brain Health by Racialized/Ethnic Group and Geographic Region: A Rapid Review

Studies examining associations between greenspace and Alzheimer's disease and related dementia (ADRD) outcomes are rapidly on the rise, yet no known literature reviews have summarized the racialized/ethnic group and geographic variation of those published studies. This is a significant gap given the known disparities in both greenspace access and ADRD risk between racialized/ethnic groups and between developed versus developing countries. In this rapid literature review, we (1) describe the diversity of published greenspace-brain health studies with respect to racialized/ethnic groups and geographic regions; (2) determine the extent to which published studies have investigated racialized/ethnic group differences in associations; and (3) review methodological issues surrounding studies of racialized/ethnic group disparities in greenspace and brain health associations. Of the 57 papers meeting our inclusion criteria as of 4 March 2022, 21% (n = 12) explicitly identified and included individuals who were Black, Hispanic/Latinx, and/or Asian. Twenty-one percent of studies (n = 12) were conducted in developing countries (e.g., China, Dominican Republic, Mexico), and 7% (n = 4) examined racialized/ethnic group differences in greenspace-brain health associations. None of the studies were framed by health disparities, social/structural determinants of health, or related frameworks, despite the known differences in both greenspace availability/quality and dementia risk by racialized/ethnic group and geography. Studies are needed in developing countries and that directly investigate racialized/ethnic group disparities in greenspace-brain health associations to target and promote health equity.

Balance performance and grip strength as predictors of cognitive function among community-dwelling older adults in the USA

Objectives

To investigate how balance and grip strength predicts the probability of cognitive function impairment (i.e., executive function: mild and mild-to-moderate impairment, and delayed recall) over eight years in community-dwelling older adults in the US, controlling for sex and race/ethnicity.

Methods

The National Health and Aging Trends Study dataset (2011 - 2018) was employed. Dependent variables included the Clock Drawing Test (Executive Function) and Delayed Word Recall Test. Longitudinal ordered logistic regression examined the association between cognitive function and predictors (i.e., balance and grip strength) over eight waves (n=9800, 1,225 per wave).

Results

Those who could complete side-by-side standing and semi-tandem tasks were 33% and 38% less likely to have mild or mild-to-moderate executive function impairment, respectively, relative to those who could not complete these tests. One score decrease in grip strength increased the executive function impairment risk by 13% (Odds Ratio: 0.87, CI: 0.79-0.95). Those who completed the side-by-side tasks were 35% (Odds Ratio: 0.65, CI: 0.44-0.95) less likely to experience delayed recall impairments than those who could not complete this test. With one score decrease in grip strength, the risk of delayed recall impairment was increased by 11% (OR: 0.89, CI: 0.80-1.00).

Conclusions

A combination of these two simple tests (i.e., semi-tandem stance and grip strength) can screen for cognitive impairment among community-dwelling older adults to identify people with mild and mild-to-moderate cognitive impairment in clinical settings.

Longitudinal associations between racial discrimination and hippocampal and white matter hyperintensity volumes among older Black adults

RATIONALE

Non-Hispanic Black older adults are at higher risk of Alzheimer's disease and related dementias (ADRD) than non-Hispanic Whites, which reflects racial disparities in both brain and cognitive health. Discrimination may contribute to these disparities, but much of the research on discrimination and ADRD outcomes is cross-sectional and/or does not disaggregate experiences of discrimination by attribution. Focusing specifically on racial discrimination and considering longitudinal brain outcomes may advance our understanding of the role of discrimination in explaining disproportionate rates of ADRD among non-Hispanic Black older adults.

METHODS

In total, 221 non-Hispanic Black participants in the Washington Heights-Inwood Columbia Aging Project completed multiple measures of discrimination at one time point and structural magnetic resonance imaging (MRI) scans at two time points. Everyday discrimination and lifetime discrimination were operationalized first as aggregate experiences of discrimination (regardless of identity attributions) and then as racial discrimination per se. MRI outcomes included hippocampal and white matter hyperintensity (WMH) volumes. Latent difference score models estimated associations between the discrimination measures and each MRI outcome over four years.

RESULTS

Aggregate discrimination (regardless of attributions) was not associated with either outcome. Lifetime racial discrimination was associated with lower initial hippocampal volume. Everyday racial discrimination was associated with faster accumulation of WMH over time.

CONCLUSIONS

Racial discrimination may be detrimental for brain aging among non-Hispanic Black older adults, which may contribute to their disproportionate dementia burden. Disaggregating discrimination by attribution may clarify research on racial inequalities in brain and cognitive aging, as racial discrimination appears to be particularly toxic.

Resilience resources may buffer some middle-aged and older Black Americans from memory decline despite experiencing discrimination

RATIONALE

Experiences of discrimination have been associated with poorer episodic memory in Black Americans. However, resilience resources at multiple levels (individual, social, and endowed) may act as a buffer to protect future memory decline, especially in the face of discrimination.

OBJECTIVE

Using longitudinal data from the 2006-2016 Health and Retirement Study (N = 1862), we tested whether Black Americans aged 50 and older would show different trajectories of episodic memory depending on their reported experiences of discrimination (everyday and major lifetime) and resilience resources.

METHODS

Analyses were conducted in three steps: (1) joint latent cluster mixed modeling (JLCMM) to estimate the number of classes, (2) barycentric discriminant analyses (BADA) to model the combined influence of discrimination and resilience resources between each memory class, and (3) multinomial regression analyses to explore interactions between discrimination and resilience resources.

RESULTS

JLCMM resulted in three memory classes that differentiated baseline from longitudinal memory performance: "High Decliners," "Low Decliners," and "Low Stable." Two independent patterns described the relationships between the three classes in the context of discrimination and resilience resources. First, compared with High Decliners, the two lower baseline memory classes (Low Decliners and Low Stable) reported more everyday discrimination and lower individual and endowed resilience resources. Second, although the Low Stable class did not report different levels of discrimination, they had more social resilience resources (greater social support and more social contact) than both declining classes.

CONCLUSIONS

Black Americans in later life have heterogeneous patterns of memory trajectories as demonstrated by the three memory classes identified. Those with lower baseline memory experienced more everyday discrimination and had fewer resilience resources compared to those with high baseline performance (High Decliners). Greater social resilience resources were associated with maintained episodic memory over time in Black Americans.

Effect of Metabolic Syndrome Risk Factors on Processing Speed and Executive Function in Three Racialized Groups

BACKGROUND

Metabolic syndrome (MetS) has been associated with increased risk for Alzheimer's disease and related dementias (ADRD). Understanding the association of MetS risk factors to processing speed and executive function in the pre-clinical stages of ADRD in under-represented groups would offer insight on potential mechanisms through which MetS associates with ADRD risk.

OBJECTIVE

Examine association of MetS features and processing speed and executive function across three racial groups.

METHODS

Cognitively unimpaired adults from the Wisconsin Alzheimer's Disease Research Center and the Wisconsin Registry for Alzheimer's Disease Prevention completed blood-draws and neuropsychological testing. Six cognitive outcomes were assessed in association to MetS risk factors: Trailmaking Tests A and B, Animal Fluency, Digit Symbol, and composite scores for Processing Speed and Executive Function. Linear mixed effect models were used to assess the relationship between MetS risk factor count and longitudinal cognitive performance across three racialized groups.

RESULTS

Participant sample sizes varied by outcome analyzed (N = 714-1,088). African American and Native American groups exhibited higher rates of MetS than non-Hispanic Whites. MetS was associated with processing speed and executive function across all racialized groups. Three-way interaction by racialized group was limited to one cognitive outcome: Trailmaking Test A.

CONCLUSION

Metabolic dysfunction incrementally affects cognitive trajectory, with generally similar associations across racial groups. Since racialized groups exhibit higher levels of both MetS and ADRD, MetS may represent a driving factor for increased ADRD risk experience by racialized group and an important and modifiable target through which to reduce risk of ADRD.

Income, wealth, and Black-White disparities in cognition

We investigated the contributions of income and wealth (beyond education) to Black-White disparities in cognition and evaluated whether the role of socioeconomic status (SES) varies by age. Based on data from a national survey of Americans (aged 23-94), we used regression models to quantify the overall racial disparities in episodic memory, executive function, and overall cognition, adjusted for sex and age. Potential mediators (i.e., measures of childhood environment, educational attainment, marital status, occupation, income, and wealth) were added in subsequent models. The age- and sex-adjusted Black-White differential in overall cognitive function was around one standard deviation (SD) between ages 25 and 50, but declined to 0.6 SD by age 80. Executive function followed a similar pattern, but the racial disparity in episodic memory declined more rapidly between ages 35 (0.7 SD) and 80 (0.2 SD). Childhood environment and the respondent's educational attainment accounted for 20-25% of the racial disparities in overall cognition. The incremental contribution of household income was small (1-5%). Although wealth had only a small effect at younger ages, the contribution grew with age. Wealth was much more important than income in explaining Black-White disparities in cognition at older ages. Childhood environment, marital status, and SES (including wealth) accounted for one-third of the racial disparity in overall cognition at ages 35-65, but an even greater share at age 80. Our study is the first to demonstrate that, with increasing age, wealth explains more of the Black-White disparity in cognition. A widening racial gap in wealth and the disproportionate financial impact of the Great Recession and the COVID-19 pandemic on minorities do not bode well for Black-White differentials in cognition. Working-age Americans suffered the brunt of the economic impact of those events; the impact on cognition may increase as those cohorts grow older.

Race Inequity in School Attendance Across the Jim Crow South and Its Implications for Black-White Disparities in Trajectories of Cognitive Function Among Older Adults

OBJECTIVES

Although education is a key determinant of cognitive function, its role in determining Black-White disparities in cognitive function is unclear. This may be due, in part, to data limitations that have made it difficult to account for systemic educational inequities in the Jim Crow South experienced by older cohorts, including differences in the number of days Black students attended school compared to their White counterparts or Black peers in better-funded southern states. We determine if accounting for differential rates of school attendance across race, years, and states in the Jim Crow South better illuminates Black-White disparities in trajectories of cognitive function.

METHODS

We linked historical state-level data on school attendance from the 1919/1920 to 1953/1954 Biennial Surveys of Education to the Health and Retirement Study, a nationally representative, longitudinal study of U.S. adults older than age 50. We restricted our sample to Black and White older adults who attended school in the Jim Crow South and began primary school in/after 1919/1920 and completed primary/secondary school by 1953/1954 (n = 4,343). We used linear mixed models to estimate trajectories of total cognitive function, episodic memory, and working memory.

RESULTS

Self-reported years of schooling explained 28%-33% of the Black-White disparity in level of cognitive function, episodic memory, and working memory. Duration of school, a measure that accounted for differential rates of school attendance, explained 41%-55% of the Black-White disparity in these outcomes.

DISCUSSION

Our study highlights the importance of using a more refined measure of schooling for understanding the education-cognitive health relationship.

Does a Cancer Diagnosis in Mid-to-Later Life Modify Racial Disparities in Memory Aging?

BACKGROUND

It is unknown whether an incident cancer diagnosis differentially impacts acute and long-term memory aging between older White and Black Americans.

METHODS

Incident cancer diagnoses and memory (immediate and delayed recall, combined with proxy-reported memory) were assessed at biennial study interviews in the US Health and Retirement Study (N=14,235, 1998-2016). We used multivariable segmented linear mixed-effects models to evaluate the rate of change in standardized memory score (SD/decade) in the years before, acutely at the time of, and in the years following an incident cancer diagnosis, compared to cancer-free adults, by race.

RESULTS

Black participants experienced faster memory decline than White participants (cancer-free group: -1.211 vs. -1.077; P<0.0001). An incident cancer diagnosis was associated with an acute memory drop in White, but not Black participants (-0.065 vs. 0.024; P<0.0001). However, White cancer survivors experienced slower memory decline than cancer-free White adults before and after diagnosis, but this memory advantage was not observed among Black cancer survivors.

CONCLUSIONS

Racial disparities in memory aging are not modified by an incident cancer diagnosis. The acute cancer-related memory decline and long-term memory advantage experienced by White, but not Black, cancer survivors relative to cancer-free older adults, requires further investigation.

Carotid Intima-media Thickness and Midlife Cognitive Function: Impact of Race and Social Disparities in the Bogalusa Heart Study

BACKGROUND AND OBJECTIVE

Carotid intima-media thickness (c-IMT) is a measurement of atherosclerosis, a progressive disease that develops as early as childhood and has been linked with cognitive impairment and dementia in the elderly. However, the relationship between c-IMT and midlife cognitive function as well as race and social disparities on this relationship remains unclear. We examined the association between c-IMT and cognitive function in midlife among Black and White participants from a semi-rural community-based cohort in Bogalusa, Louisiana.

METHODS

In this cross-sectional analysis of participants from the Bogalusa Heart Study, linear regression models were used to determine the association between c-IMT dichotomized above the 50^th percentile (> 0.87mm), an a demographically standardized global cognitive (GCS) and individual cognitive domain-based z-scores. Stratified analyses were performed to evaluate the impact of race and the individual's education status.

RESULTS

A total of 1,217 participants (age 48 ± 5.28 years) were included, 66% (804) self-identified as White and 34% (413) as Black. Of those, 58% (708) were women, and 42% (509) were men Having a c-IMT > 50^th percentile was inversely associated with GCS ([B ± SE]: -0.39 ± 0.18, P=0.03), independent of cardiovascular risk factors (CVRFs) and achieved education. The effect remained significant in Black and White participants after adjustment for CVRFs (Blacks: [B ± SE]: -1.25 ± 0.45, P=0.005; Whites: [B ± SE]: -0.92 ± 0.35, P=0.008), but not for education. The interaction between c-IMT >50^th percentile and education was significant (P=0.03), and stratified analysis showed an association with GCS among those with lower achieved education ([B ± SE]: -0.81 ± 0.33, P=0.013) independent of major CVRFs.

DISCUSSION

Subclinical atherosclerosis, measured as c-IMT, was associated with worse midlife cognitive function, independent of major CVRFs. The association was buffered by education and may be stronger among Black than White participants, likely due to corresponding structural and social determinants. These findings underscore the importance of establishing preventive measures in midlife and suggest subclinical atherosclerosis as a potential target to prevent cognitive decline.

Racial Disparities in Cognitive Function Among Middle-Aged and Older Adults: The Roles of Cumulative Stress Exposures Across the Life Course

BACKGROUND

Racial disparities in cognitive function are well documented, but factors driving these disparities remain underexplored. This study aims to quantify the extent to which cumulative stress exposures across the life course explain Black-White disparities in executive function and episodic memory in middle-aged and older adults.

METHOD

Data were drawn from the 2004-2006 wave of the Midlife Development in the United States Study (MIDUS 2) and the MIDUS Refresher study (N = 5,947; 5,262 White and 685 Black). Cumulative stress exposures were assessed by 10 stressor domains (ie, childhood stress, stressful life events in adulthood, financial stress, work psychological stress, work physical stress, work-family conflicts, neighborhood disorder, relationship stress, perceived inequality, and perceived discrimination). Cognitive function was assessed using the Brief Test of Adult Cognition by Telephone. Marginal structural models were used to quantify the proportion of the effect of race/ethnicity status on cognitive function mediated through cumulative stress exposures.

RESULTS

After adjusting for age, sex, and sample, on average, Black participants had lower levels of executive function (difference: -0.83 SD units, 95% CI: -0.91, -0.75) and episodic memory (difference: -0.53 SD units, 95% CI: -0.60, -0.45) scores than White participants. Cumulative stress exposures accounted for 8.4% of the disparity in executive function and 13.2% of the disparity in episodic memory.

CONCLUSIONS

Cumulative stress exposures across the life course explained modest proportions of Black-White disparities in cognitive function in this large cross-sectional study.

Examination of race and gender differences in predictors of neuropsychological decline and development of Alzheimer's disease

ObjectiveBlack adults are diagnosed with Alzheimer's disease (AD) at higher rates than White adults. Biopsychosocial risk factors that differentially affect individuals by race, including health, education, and APOE e4, may explain these findings. Some research suggests that the risk for AD associated with the APOE e4 allele may differ by race. Gender differences in AD have also been identified but remain understudied. We examined race, APOE status, vascular risk factors, education, and the interaction of APOE e4 status and race as predictors of cognitive decline and the development of Alzheimer's disease between genders in a large longitudinal sample of older adults. Methods: Participants (N = 4336) were selected from the National Alzheimer's Coordinating Center's Uniform Data Set who completed measures of verbal fluency, naming, and immediate/delayed story memory across 5 years. Analyses were stratified by gender. Follow up interactions examined statistical significance of differences. Results: APOE e4 by race interactions were largely non-significant and dropped from most models. When controlling for health, education, referral source, and Uniform Data Set form (when applicable), few racial differences in cognitive performance over time emerged. Black participants obtained lower scores than White participants on a majority of baseline measures. Race findings did not differ by gender. Hypertension was more strongly predictive of decline in delayed memory among women. Conclusions: Analyses did not support that APOE e4 differentially affects Black individuals. Hypertension may be a more relevant risk factor among women. Results raise questions regarding the accuracy of baseline scores in predicting decline for Black individuals.

Measurement invariance of a neuropsychological battery across urban and rural older adults in Costa Rica

This study evaluated the measurement invariance of a neuropsychological battery across rural and urban older adults from Costa Rica. Rural and urban older adults (N = 295) from the Epidemiology and Development of Alzheimer's Disease (EDAD) study in Costa Rica were assessed. The baseline factor model for the EDAD neuropsychological measures was identified with nine neuropsychological measures and three cognitive constructs: Verbal Memory, Spatial Reasoning, and Cognitive Flexibility. Measurement and structural invariance were established, and, then, group comparisons of the latent cognitive factors were conducted to explore regional disparities. The findings showed that most of the neuropsychological tests in EDAD can be directly compared across the groups, allowing for cognitive constructs comparisons. The rural sample showed a disadvantage in the Spatial Reasoning and Cognitive Flexibility abilities. When age and education were included in the models, differences between the regions disappeared. Having more years of education was associated with higher cognitive abilities, with a larger effect for the rural group. Norms for Costa Rican older adults should consider age and education adjustments. This study contributes to the growing area of measurement invariance in neuropsychological assessment as it highlights the importance of examining the comparability of assessment measures across different cultural groups.

Quantifying and Examining Reserve in Symptomatic Former National Football League Players

BACKGROUND

Repetitive head impacts (RHI) from contact sports have been associated with cognitive and neuropsychiatric disorders. However, not all individuals exposed to RHI develop such disorders. This may be explained by the reserve hypothesis. It remains unclear if the reserve hypothesis accounts for the heterogenous symptom presentation in RHI-exposed individuals. Moreover, optimal measurement of reserve in this population is unclear and likely unique from non-athlete populations.

OBJECTIVE

We examined the association between metrics of reserve and cognitive and neuropsychiatric functioning in 89 symptomatic former National Football League players.

METHODS

Individual-level proxies (e.g., education) defined reserve. We additionally quantified reserve as remaining residual variance in 1) episodic memory and 2) executive functioning performance, after accounting for demographics and brain pathology. Associations between reserve metrics and cognitive and neuropsychiatric functioning were examined.

RESULTS

Higher reading ability was associated with better attention/information processing (β=0.25; 95% CI, 0.05-0.46), episodic memory (β=0.27; 95% CI, 0.06-0.48), semantic and phonemic fluency (β=0.24; 95% CI, 0.02-0.46; β=0.38; 95% CI, 0.17-0.59), and behavioral regulation (β=-0.26; 95% CI, -0.48, -0.03) performance. There were no effects for other individual-level proxies. Residual episodic memory variance was associated with better attention/information processing (β=0.45; 95% CI, 0.25, 0.65), executive functioning (β=0.36; 95% CI, 0.15, 0.57), and semantic fluency (β=0.38; 95% CI, 0.17, 0.59) performance. Residual executive functioning variance was associated with better attention/information processing (β=0.44; 95% CI, 0.24, 0.64) and episodic memory (β=0.37; 95% CI, 0.16, 0.58) performance.

CONCLUSION

Traditional reserve proxies (e.g., years of education, occupational attainment) have limitations and may be unsuitable for use in elite athlete samples. Alternative approaches of reserve quantification may prove more suitable for this population.

Factors that influence the emotional impact of memory problems in older adults: A qualitative descriptive study

BACKGROUND

Associations among psychological health and memory concerns in older adults are well-established, but much of this research is quantitative.

OBJECTIVES

This study examined how memory problems influence emotional well-being in older adults without dementia, and whether this differs by cognitive status and current depressive or anxiety symptoms.

METHODS

A qualitative descriptive design was used to examine our research questions. Community-dwelling older adults without dementia (n = 49, M_age  = 74.5[10.1], 63% women) completed a cognitive assessment, questionnaires and two semi-structured interviews. Content analysis was used to code and categorise the transcribed interview data, then identify themes within and across participant groups.

RESULTS

Five themes described the influence of memory problems on emotional well-being: Evoking Emotions, Fearing Future, Undermining Self, Normalising Problems and Adjusting Thinking. Memory problems' impact on emotional well-being varied by current anxiety symptoms, characteristics of the problem and personal experience with dementia.

CONCLUSION

The emotional impact of memory problems tended to differ by affective symptoms, not cognitive status. Older adults who report memory concerns without objective evidence of impairment may be at risk for negative impacts to mental health and well-being.

IMPLICATIONS FOR PRACTICE

Cognitive screening guidelines should consider best practices for responding to memory concerns when cognitive testing results are normal.

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.

Risk factors for decline in cognitive performance following deployment-related mild traumatic brain injury: A preliminary report

Thorough identification of risk factors for delayed decline in cognitive performance following combat-related mild traumatic brain injury (mTBI) is important for guiding comprehensive post-deployment rehabilitation. In a sample of veterans who reported at least one deployment-related mTBI, preliminary results indicate that factors including a history of loss of consciousness over 1 min, current obesity and hypertension, and Black race were more prevalent in those with decreased scores on a measure of memory function. These factors should be considered by clinicians and researchers working with current and former military personnel.

Diagnosing Mild Cognitive Impairment Among Racially Diverse Older Adults: Comparison of Consensus, Actuarial, and Statistical Methods

BACKGROUND

Actuarial and statistical methods have been proposed as alternatives to conventional methods of diagnosing mild cognitive impairment (MCI), with the aim of enhancing diagnostic and prognostic validity, but have not been compared in racially diverse samples.

OBJECTIVE

We compared the agreement of consensus, actuarial, and statistical MCI diagnostic methods, and their relationship to race and prognostic indicators among diverse older adults.

METHODS

Participants (N = 354; M age = 71; 68% White, 29% Black) were diagnosed with MCI or normal cognition (NC) according to clinical consensus, actuarial neuropsychological criteria (Jak/Bondi), and latent class analysis (LCA). We examined associations with race/ethnicity, longitudinal cognitive and functional change, and incident dementia.

RESULTS

MCI rates by consensus, actuarial criteria, and LCA were 44%, 53%, and 41%, respectively. LCA identified three MCI subtypes (memory; memory/language; memory/executive) and two NC classes (low normal; high normal). Diagnostic agreement was substantial, but agreement of the actuarial method with consensus and LCA was weaker than the agreement between consensus and LCA. Among cases classified as MCI by actuarial criteria only, Black participants were over-represented, and outcomes were generally similar to those of NC participants. Consensus diagnoses best predicted longitudinal outcomes overall, whereas actuarial diagnoses best predicted longitudinal functional change among Black participants.

CONCLUSION

Consensus diagnoses optimize specificity in predicting dementia, but among Black older adults, actuarial diagnoses may be more sensitive to early signs of decline. Results highlight the need for cross-cultural validity in MCI diagnosis and should be explored in community- and population-based samples.

Relationships Between Chronic Pain Stage, Cognition, Temporal Lobe Cortex, and Sociodemographic Variables

BACKGROUND

Non-Hispanic black (NHB) individuals have increased risk of Alzheimer's disease (AD) relative to non-Hispanic whites (NHW). Ethnicity/race can serve as a proxy sociodemographic variable for a complex representation of sociocultural and environmental factors. Chronic pain is a form of stress with high prevalence and sociodemographic disparities. Chronic pain is linked to lower cognition and accelerated biological aging.

OBJECTIVE

The purpose of this study is to seek understanding of potential cognitive and temporal lobe structural brain AD vulnerabilities based on chronic pain stage and ethnicity/race.

METHODS

Participants included 147 community dwelling NHB and NHW adults without dementia between 45-85 years old who had or were at risk of knee osteoarthritis. All participants received an MRI (3T Philips), the Montreal Cognitive Assessment (MoCA), and assessment of clinical knee pain stage.

RESULTS

There were ethnic/race group differences in MoCA scores but no relationships with chronic knee pain stage. Ethnicity/race moderated the relationship between AD-related temporal lobe thickness and chronic pain stage with quadratic patterns suggesting thinner cortex in high chronic pain stage NHB adults.

CONCLUSION

There appear to be complex relationships between chronic knee pain stage, temporal lobe cortex, and sociodemographic variables. Specifically, NHB participants without dementia but with high chronic knee pain stage appeared to have thinner temporal cortex in areas associated with AD. Understanding the effects of sociocultural and socioeconomic factors on health outcomes is the first step to challenging the disparities in healthcare that now appear to link disease conditions to neurodegenerative processes.

The Effects of Selective Survival on Black Adults' Cognitive Development

OBJECTIVES

The theory of selective survival suggests that possibly around 70-75 years of age, Blacks may display substantive changes in their pattern of cognitive decline. This study examined the age-graded pattern of cognitive decline within older Blacks by describing a trend that characterizes differences in the change of cognitive decline from ages 51.5 to 95.5, and hypothesized that this age-graded pattern is nonlinear.

METHOD

Utilizing 2 waves of longitudinal data from the Baltimore Study of Black Aging, this study used multilevel modeling to test whether the interaction between age and the 3-year study period (time between waves) had a positive effect on changes in inductive reasoning, declarative memory, working memory, and perceptual speed.

RESULTS

A significant positive interaction between age and wave was found for inductive reasoning, demonstrating an age-grade pattern of change/decline in cognitive pattern for Blacks aged 51.5-95.4. Simple slope probing via the Johnson-Neyman Technique suggested that Black adults ~64 years and younger experienced significant decline in inductive reasoning across study time, whereas for those older than 63.71, the decline was nonsignificant. No significant age-wave interactions were found for declarative memory, working memory, or perceptual speed.

DISCUSSION

Findings suggest a selective survival effect for inductive reasoning ability among Blacks. With decline evident so early, common cognitive intervention programs targeting adults 65+ may come too late for Blacks, signifying the importance and urgency for early health interventions and public policy designed to promote cognitive reserve.

Gendered racial differences and similarities in subjective cognitive decline and life satisfaction: results from a population-based sample

OBJECTIVE

The objectives of this study were to: 1) Determine the association between subjective cognitive decline (SCD) and life satisfaction; and 2) Assess the gendered racial/ethnic disparities in the association between SCD and life satisfaction.

METHOD

Data were obtained from 3,795 participants from the Behavioral Risk Factor Surveillance System survey. SCD was operationalized by "During the past 12 months, have you experienced confusion or memory loss that is happening more often or is getting worse?" Life satisfaction was operationalized by the question "In general how satisfied are you with your life?" Interaction terms of SCD*sex, SCD*race/ethnicity, and SCD*sex*race/ethnicity were used to determine potential effect measure modification. Crude and adjusted linear regression models, controlling for age, education, income and employment, were used to assess the association between SCD and life satisfaction by sex, race, and by gendered racial/ethnic groups: Black women, White women, Hispanic women, Other women; and Black men, White men, Hispanic men and Other men.

RESULTS

SCD was negatively associated with life satisfaction in the overall sample (β: -0.55; 95% CI: -0.66, -0.43). However, the negative associations seen across gender, race/ethnicity, and gendered racial/ethnic groups were statistically similar (p for interaction terms > 0.05). The highest effect estimate was seen for Other men (β: -1.22; 95% CI: -1.37, -1.09).

CONCLUSION

Interventions geared towards improving cognition may improve life satisfaction for all groups, irrespective of gender and/or race/ethnicity. Future research may include longitudinal studies to determine the temporal sequence between SCD and life satisfaction.

Racial differences in health and cognition as a function of HIV among older adults

The present study investigated the contribution of health risk factors (using the Charlson Comorbidity Index [CCI]) on cognitive outcomes in a sample of 380 HIV-positive (HIV+; n = 221) and HIV-seronegative (HIV-; n = 159) African American and European American adults aged 50+.

Participants were recruited from HIV clinics and community advertisements. HIV status was confirmed by serological testing. Self-report and chart history review was used to gather information about medical ssscomorbidities. The Charlson Comorbidity Index (CCI) was used to create a comorbidity score. Participants were administered a brief cognitive test battery.

As expected, health risks were greater among those with HIV. There was a HIV × Race interaction on CCI scores, such that in the HIV + group, European Americans had significantly higher CCI scores (M = 3.74; SD = 2.1) than African American HIV + participants (M = 2.70; SD = 1.9). However, in the HIV - group, African Americans had significantly higher CCI scores (M = 2.20; SD = 1.1) than HIV - European American participants (M = 1.80; SD = 1.2). Also, consistent with hypotheses, across the entire sample CCI score was significantly associated with global cognition (β = -.24, p = .02).

Study results underscore the importance of considering HIV serostatus in studies examining racial disparities in health, and how multiple medical risks relate to cognitive outcomes. Neuropsychologists evaluating patients living with HIV should consider how the presence of multiple medical comorbidities may contribute to the course of cognitive decline as people age.

Subjective memory, objective memory, and race over a 10-year period: Findings from the ACTIVE study

The longitudinal associations between subjective and objective memory functioning in later life remain unclear. This may be due, in part, to sociodemographic differences across studies, given the hypothesis that these associations differ across racial groups. Using data from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE; N = 2,694; 26% African American), multiple-group, parallel-process latent growth curve models were used to explore relationships between subjective and objective memory over 10 years and assess racial differences in these associations. Across African Americans and whites, we found bidirectional associations between subjective and objective memory such that greater self-reported forgetting at baseline predicted faster subsequent verbal episodic memory declines, and higher baseline objective memory scores predicted less increase in self-reported forgetting over time. However, rates of change in self-reported frequency of forgetting were correlated with rates of change in verbal episodic memory in whites, but not in African Americans. Subjective memory complaints may be a harbinger of future memory declines across African Americans and whites but may not track with objective memory in the same way across these racial groups. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

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

Objective: Racial/ethnic disparities in cognitive aging are only partly attributable to socioeconomic indicators. Psychosocial factors, such as discrimination and perceived control, also differ across racial/ethnic groups, and emerging literature highlights their potential role in contributing to cognitive disparities in addition to socioeconomic status. Method: 1,463 older adults (51% Hispanic, 27% non-Hispanic Black, and 22% non-Hispanic White) in the Washington Heights-Inwood Columbia Aging Project completed cognitive and psychosocial measures, including a comprehensive neuropsychological battery, Everyday and Major Experiences of Lifetime Discrimination scales, and the Perceived Control scale. Mediation models quantified separate indirect effects of Black race and Hispanic ethnicity on global cognitive composite scores through education, income, discrimination, and external perceived control. Results: Educational attainment, income, and perceived control each mediated racial/ethnic disparities in global cognition. Socioeconomic indicators (i.e., lower education and lower income) explained approximately 50% of the Black-White and Hispanic-White disparities in global cognition, and more external perceived control explained an additional 5%-8%. Hispanics reported the lowest levels of discrimination, while non-Hispanic Blacks reported the highest levels. However, neither everyday nor major lifetime discrimination was associated with global cognition. Significant racial/ethnic disparities in global cognition remained after accounting for the included socioeconomic and psychosocial factors. Conclusions: This study suggests that psychosocial factors may explain racial/ethnic disparities in cognitive aging above and beyond socioeconomic indicators. More external perceived control, which could reflect chronic exposure to interpersonal and institutional marginalization, may be a particularly salient psychosocial risk factor for poorer cognitive aging among non-Hispanic Black and Hispanic older adults. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Predictors of cognitive decline in a multi-racial sample of midlife women: A longitudinal study

Objective: Hypertension, diabetes, depressive symptoms, and smoking are predictors of cognitive decline in late life. It is unknown if these risk factors are associated with cognition during midlife or if the associations between these risk factors and cognition vary by race. This longitudinal study examined (a) risk factors for decline in episodic memory, processing speed, and working memory in midlife women and (b) if the associations between risk factors and cognitive decline were moderated by race. Method: Participants (aged 42-52) were European American (n = 1,000), African American (n = 516), and Asian American (n = 437) women from the Study of Women's Health Across the Nation. Two-level hierarchical linear models tested risk factors, race, and their interactions as predictors of cognitive change over time. Results: African Americans had poorer baseline episodic memory, processing speed, and working memory and greater episodic memory decline compared to European Americans. Asian Americans had poorer episodic memory and working memory, but better processing speed than European Americans. Depressive symptoms were associated with poorer episodic memory and processing speed at baseline; further, diabetes was associated with poorer processing speed at baseline. Greater depressive symptoms were associated with poorer episodic memory at baseline for African Americans but not European Americans. Conclusions: Our study results highlight racial disparities in cognition during midlife. Depressive symptoms may be particularly detrimental to the cognitive health of African Americans. Clinical and public health interventions for healthy cognitive aging should be tailored to the unique risks of racial groups. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Perceived Discrimination, Nativity, and Cognitive Performance in a Multi-ethnic Study of Older Adults: Findings from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study

BACKGROUND

Despite growing research on the association between discrimination and disparities in cognitive aging, an evidence gap remains on how the association varies by racial/ethnic group. This study evaluates the associations of experiences of discrimination with cognitive function and whether these associations varied by race/ethnicity and nativity.

METHODS

Using the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) cohort (N=1,712) with approximately equal groups of Black, White, Latino, and Asian community-dwelling older adults aged 65 years and older, we evaluated the associations between self-reported experiences of everyday and major lifetime discrimination with overall cognitive performance and domain-specific cognition (verbal episodic memory, semantic memory and executive functioning) across race/ethnicity and nativity. Linear regression models examined the cross-sectional association between self-reported experiences of everyday and major lifetime discrimination with z-standardized coefficients for cognition. We tested for effect modification by race and nativity. All models controlled for age, sex and education.

RESULTS

Among KHANDLE participants (mean age: 76 years; standard deviation: 6.8), everyday discrimination was not associated with cognitive scores. Major lifetime discrimination was associated with better average cognitive scores among Black participants but not among other racial/ethnic groups. Major lifetime discrimination was associated with better average cognitive scores among US-born but not among non-US born individuals.

CONCLUSION

Our findings do not imply that discrimination improves cognition, but rather suggest that future research should include more detailed measures on discrimination and unfair treatment that could help disentangle the extent to which relationships are causal or reflect some other underlying factor.

Impact of Cardiovascular Risk Factors in Adolescence, Young Adulthood, and Midlife on Late-Life Cognition: Study of Healthy Aging in African Americans

BACKGROUND

Midlife cardiovascular risk factors (CVRFs) increase risk of dementia. Black Americans experience an elevated prevalence of CVRFs and dementia. However, little is known of how CVRFs prior to midlife affect late-life cognition. We examined CVRFs in adolescence, young adulthood, and midlife with late-life cognition in the Study of Healthy Aging in African Americans (STAR).

METHOD

STAR assesses cognitive aging among 764 Black Americans aged ≥50 (mean age = 69; SD = 9; range = 53-95). Participants' body mass index, blood pressure, glucose, and total cholesterol were collected during Multiphasic Health Checkups (MHC; 1964-1985). At STAR baseline (2018-2019), executive function, verbal episodic memory, and semantic memory were measured using the Spanish and English Neuropsychological Assessment Scales. Linear regression models examined associations between CVRFs and cognition adjusting for demographics and years since MHC.

RESULTS

At MHC, 36% of participants had 1 CVRF and 26% had ≥2. Twenty-two percent of participants were adolescents (age 12-20), 62% young adults (age 21-34), and 16% midlife adults (age 35-56). Overweight/obesity was not associated with cognition. Hypertension was associated with worse executive function (β [95% CI]: -0.14 [-0.28, -0.0003]) and verbal episodic memory (β [95% CI]: -0.22 [-0.37, -0.07]) compared to normotension. Diabetes was associated with worse executive function (β [95% CI]: -0.43 [-0.83, -0.03]). Having ≥2 CVRFs (vs 0) was associated with worse executive function (β [95% CI]: -0.19 [-0.34, -0.03]) and verbal episodic memory (β [95% CI]: -0.25 [-0.41, -0.08]). Adolescents with hypertension had lower late-life executive function compared to normotensive adolescents (β [95% CI]: -0.39 [-0.67, -0.11]). Young adulthood hypertension (β [95% CI]: -0.29 [-0.49, -0.09]) and midlife hyperlipidemia (β [95% CI]: -0.386 [-0.70, -0.02]) were associated with lower verbal episodic memory.

CONCLUSIONS

Among Black Americans, life-course CVRFs were associated with poorer executive function and verbal episodic memory emphasizing the importance of cardiovascular health on the aging brain.

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.

UDSNB 3.0 Neuropsychological Test Norms in Older Adults from a Diverse Community: Results from the Einstein Aging Study (EAS)

BACKGROUND

The Uniform Data Set, Version 3 Neuropsychological Battery (UDSNB3.0), from the database of the University of Washington's National Alzheimer's Coordinating Center (NACC), is widely used to characterize cognitive performance in clinical and research settings; however, norms for underrepresented community-based samples are scarce.

OBJECTIVE

We compared UDSNB 3.0 test scores between the Einstein Aging Study (EAS), composed of racially/ethnically diverse, community-dwelling older adults aged≥70 and the NACC, and report normative data from the EAS.

METHODS

Analyses included 225 cognitively normal EAS participants and comparable data from 5,031 NACC database participants. Linear regression models compared performance between the samples, adjusting for demographics (sex, age, education, race/ethnicity), depressive symptoms, and whether English was the first language. Linear regression models to examine demographic factors including age, sex, education and race/ethnicity as predictors for the neuropsychological tests were applied in EAS and NACC separately and were used to create a demographically adjusted z-score calculator.

RESULTS

Cognitive performance across all domains was worse in the EAS than in the NACC, adjusting for age, sex, education, race/ethnicity, and depression, and the differences remained in visuo-construction, visuospatial memory, confrontation naming, visual attention/processing speed, and executive functioning after further adjusting for whether English was the first language. In both samples, non-Hispanic Whites outperformed non-Hispanic Blacks and more education was associated with better cognitive performance.

CONCLUSION

Differences observed in demographic, clinical, and cognitive characteristics between the community-based EAS sample and the nationwide NACC sample suggest that separate normative data that more accurately reflect non-clinic, community-based populations should be established.

Perspective on the "African American participation in Alzheimer disease research: Effective strategies" workshop, 2018

The Washington University School of Medicine Knight Alzheimer Disease Research Center's "African American Participation in Alzheimer Disease Research: Effective Strategies" Workshop convened to address a major limitation of the ongoing scientific progress regarding Alzheimer's disease and related dementias (ADRD): participants in most ADRD research programs overwhelmingly have been limited to non-Hispanic white persons, thus precluding knowledge as to how ADRD may be represented in non-white individuals. Factors that may contribute to successful recruitment and retention of African Americans into ADRD research were discussed and organized into actionable next steps as described within this report.

Race/Ethnic Differences in Social Resources as Cognitive Risk and Protective Factors

Overall social network size, often the sum of common lifetime relationships, including children, family, and friends, has been linked to cognitive impairment and Alzheimer's Disease. However, little research has examined the association between network size composition and cognitive function in middle-aged and older adults in the context of race/ethnicity. We investigated the associations between the number of close children, family, and friends independently with executive function (EF) and memory across a subsample of non-Hispanic Black, Hispanic, and non-Hispanic White participants who completed the Health and Retirement Study Harmonized Cognitive Assessment Protocol (N = 2,395). We found that network size composition was more closely linked to EF than memory and that these associations varied by race/ethnicity. Specifically, the strongest associations existed between EF and quadratic estimates of the number of close children of non-Hispanic Black participants, and number of close family members for Hispanic participants. Among Black participants, a curvilinear relationship indicated that two close children were associated with greater EF, while a smaller or larger number of close children were associated with lower EF. On the other hand, among Hispanic participants, higher EF was associated with fewer (0-1) and greater (4-5+) numbers of family member contacts. Overall, these results indicate that examining children, family, and friends independently may be more useful than the common practice of aggregation of overall network size, especially in the context of race/ethnicity.

Long-term exposure to ambient air pollution, APOE-ε4 status, and cognitive decline in a cohort of older adults in northern Manhattan

BACKGROUND

There is mounting evidence that long-term exposure to air pollution is related to accelerated cognitive decline in aging populations. Factors that influence individual susceptibility remain largely unknown, but may involve the apolipoprotein E genotype E4 (APOE-ε4) allele.

OBJECTIVES

We assessed whether the association between long-term exposure to ambient air pollution and cognitive decline differed by APOE-ε4 status and cognitive risk factors.

METHODS

The Washington Heights Inwood Community Aging Project (WHICAP) is a prospective study of aging and dementia. Neuropsychological testing and medical examinations occur every 18-24 months. We used mixed-effects models to evaluate whether the association between markers of ambient air pollution (nitrogen dioxide [NO2]), fine [PM2.5], and coarse [PM10] particulate matter) and the rate of decline in global and domain-specific cognition differed across strata defined by APOE-ε4 genotypes and cognitive risk factors, adjusting for sociodemographic factors and temporal trends.

RESULTS

Among 4821 participants with an average of 6 years follow-up, higher concentrations of ambient air pollution were associated with more rapid cognitive decline. This association was more pronounced among APOE-ε4 carriers (p < 0.001). A one interquartile range increase in NO2 was associated with an additional decline of 0.09 standard deviations (SD) (95%CI -0.1, -0.06) in global cognition across biennial visits among APOE-ε4 positive individuals and a 0.07 SD (95%CI -0.09, -0.05) decline among APOE-ε4 negative individuals. Results for PM2.5, PM10 and cognitive domains were similar. The association between air pollutants and rate of cognitive decline also varied across strata of race-ethnicity with the association strongest among White non-Hispanic participants.

CONCLUSIONS

These results add to the body of evidence on the adverse impact of ambient air pollution on cognitive aging and brain health and provide new insights into the genetic and behavioral factors that may impact individual susceptibility.

Episodic Memory in Later Life: Benefits of Prayer and Meditation

Purpose: To examine the effects of prayer and meditation on the episodic memory of older adults. Design: Secondary analysis of Health and Retirement Study (HRS). Method: Drawing from a subsample of HRS ( n = 1,135), this study utilized generalized estimating equation regression models to examine the effects of meditation and prayer on changes in episodic memory of older adults over time. Findings: Findings show a statistically significant positive effect of the use of prayer (0.50, p < .05) on episodic memory score at baseline. We also observed a slight gain in episodic memory over time for older adults who used prayer (0.04, p = .05). Meditation was not found to have a statistically significant effect on changes in memory in later life. Conclusion: This study illustrates the benefits of prayer in preserving memory and provides much needed empirical basis for community-level interventions to enhance memory in later life.

Interactive Effects of Racial Identity and Repetitive Head Impacts on Cognitive Function, Structural MRI-Derived Volumetric Measures, and Cerebrospinal Fluid Tau and Aβ

BACKGROUND

Factors of increased prevalence among individuals with Black racial identity (e.g., cardiovascular disease, CVD) may influence the association between exposure to repetitive head impacts (RHI) from American football and later-life neurological outcomes. Here, we tested the interaction between racial identity and RHI on neurobehavioral outcomes, brain volumetric measures, and cerebrospinal fluid (CSF) total tau (t-tau), phosphorylated tau (p-tau181), and Aβ1 - 42 in symptomatic former National Football League (NFL) players.

METHODS

68 symptomatic male former NFL players (ages 40-69; n = 27 Black, n = 41 White) underwent neuropsychological testing, structural MRI, and lumbar puncture. FreeSurfer derived estimated intracranial volume (eICV), gray matter volume (GMV), white matter volume (WMV), subcortical GMV, hippocampal volume, and white matter (WM) hypointensities. Multivariate generalized linear models examined the main effects of racial identity and its interaction with a cumulative head impact index (CHII) on all outcomes. Age, years of education, Wide Range Achievement Test, Fourth Edition (WRAT-4) scores, CVD risk factors, and APOEε4 were included as covariates; eICV was included for MRI models. P-values were false discovery rate adjusted.

RESULTS

Compared to White former NFL players, Black participants were 4 years younger (p = 0.04), had lower WRAT-4 scores (mean difference = 8.03, p = 0.002), and a higher BMI (mean difference = 3.09, p = 0.01) and systolic blood pressure (mean difference = 8.15, p = 0.03). With regards to group differences on the basis of racial identity, compared to White former NFL players, Black participants had lower GMV (mean adjusted difference = 45649.00, p = 0.001), lower right hippocampal volume (mean adjusted difference = 271.96, p = 0.02), and higher p-tau181/t-tau ratio (mean adjusted difference = -0.25, p = 0.01). There was not a statistically significant association between the CHII with GMV, right hippocampal volume, or p-tau181/t-tau ratio. However, there was a statistically significant Race x CHII interaction for GMV (b = 2206.29, p = 0.001), right hippocampal volume (b = 12.07, p = 0.04), and p-tau181/t-tau ratio concentrations (b = -0.01, p = 0.004).

CONCLUSION

Continued research on racial neurological disparities could provide insight into risk factors for long-term neurological disorders associated with American football play.

The role of education in a vascular pathway to episodic memory: brain maintenance or cognitive reserve?

Educational attainment is associated with cognition among older adults, but this association is complex and not well understood. While associated with better cognition among healthy adults, more education predicts faster decline in older adults with cognitive impairment. Education may influence cognitive functioning through mechanisms involving brain maintenance (BM: reduced age-related pathology) or cognitive reserve (CR: altered pathology-cognition association). We examined evidence for each mechanism by quantifying main and interaction effects of education within a well-studied pathway involving systolic blood pressure, white matter hyperintensities (WMH), and episodic memory in 2 samples without dementia at the baseline (total N = 1136). There were no effects of education on systolic blood pressure or WMH, suggesting a lack of evidence for BM. In the sample less likely to progress to dementia, education attenuated the effect of WMH on memory at the baseline. In the sample more likely to progress to dementia, education exacerbated this effect at the baseline. These moderations provide evidence for a CR mechanism and are consistent with previous findings of faster decline once CR is depleted.

Pathways, Contributors, and Correlates of Functional Limitation Across Specialties: Workshop Summary

Traditional clinical care models focus on the measurement and normalization of individual organ systems and de-emphasize aspects of health related to the integration of physiologic systems. Measures of physical, cognitive and sensory, and psychosocial or emotional function predict important health outcomes like death and disability independently from the severity of a specific disease, cumulative co-morbidity, or disease severity measures. A growing number of clinical scientists in several subspecialties are exploring the utility of functional assessment to predict complication risk, indicate stress resistance, inform disease screening approaches and risk factor interpretation, and evaluate care. Because a substantial number of older adults in the community have some form of functional limitation, integrating functional assessment into clinical medicine could have a large impact. Although interest in functional implications for health and disease management is growing, the science underlying functional capacity, functional limitation, physical frailty, and functional metrics is often siloed among different clinicians and researchers, with fragmented concepts and methods. On August 25-26, 2016, participants at a trans-disciplinary workshop, supported by the National Institute on Aging and the John A. Hartford Foundation, explored what is known about the pathways, contributors, and correlates of physical, cognitive, and sensory functional measures across conditions and disease states; considered social determinants and health disparities; identified knowledge gaps, and suggested priorities for future research. This article summarizes those discussions.

Differences in the cognitive profile of depression between racial groups

BACKGROUND

There is little research concerning whether race is associated with different clinical presentations of psychiatric disorders. Understanding the racial aspects of cognitive differences among depressed adults could help identify specific targets for depression treatment.

METHODS

We recruited 59 participants (52.5% white, 47.5% African American), age 18 to 60, with a current diagnosis of major depressive disorder (MDD). All participants underwent a cognitive battery that included tasks assessing decision-making, response inhibition, working memory, and executive planning. Differences between white and African American groups were analyzed using analysis of variance or equivalent nonparametric tests.

RESULTS

There were no differences in demographic variables of age, sex, and education, but white individuals reported a significantly earlier age of first depressive episode compared with African American individuals. The African American group, however, showed significantly lower quality of decision-making and less risk adjustment on the Cambridge Gambling Task, and made more errors on the Spatial Working Memory task.

CONCLUSIONS

Our finding that specific cognitive domains differ as a function of racial differences in MDD might have differential prognostic and treatment implications.

Socioeconomic, health, and psychosocial mediators of racial disparities in cognition in early, middle, and late adulthood

Racial disparities in cognitive performance exist across the life course, but it is not known whether mediators of disparities differ by age. Understanding sources of cognitive disparities at different ages can inform policies and interventions. Data were obtained for non-Hispanic Black and White respondents to The National Survey of Midlife Development in the United States from 3 age groups: 28-44 (N = 1210; 20% Black); 45-64 (N = 2693; 15% Black); and 65-85 (N = 1298; 11% Black). Moderated mediation models characterized direct and indirect effects of race on episodic memory and executive function composite scores through economic, health, and psychosocial variables as a function of age group. Education, income, chronic health conditions, and external locus of control mediated cognitive disparities across the life course, although income was a stronger mediator at younger ages. Perceived discrimination was a weaker mediator among young adults due to an absence of racial differences in perceived discrimination in that group. Despite multiple indirect effects, there were still significant unexplained effects of race on cognition that were not moderated by age group. Interventional work is needed to determine whether increasing educational attainment and income, and reducing chronic health conditions and perceived constraints among Blacks, reduce cognitive disparities. Targeting income inequality and discrimination (or buffering the impact of those variables) may be differently effective at reducing cognitive disparities at different stages of the adult life course. (PsycINFO Database Record