Medical and Social Determinants of Brain Health and Dementia in a Multicultural Community Cohort of Older Adults

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Assessing Alzheimer's Disease Knowledge and Cognitive Risk Among a Rural Older Afro-Caribbean Cohort

PURPOSE

Older, rural Afro-Caribbeans are a growing subset of the Black population who face increased risk for Alzheimer's disease and related dementias (ADRD), but research targeting ADRD is scarce in this group. The purpose of this study was to investigate dementia risk among older Afro-Caribbeans living in a rural area. We also examined age, sex, and years of education, and knowledge about Alzheimer's disease as potential predictors of dementia risk.

DESIGN

A pre-post, correlational design was employed.

METHODS

Cognitive screenings were conducted using Nasreddine's Mini-MoCA, with tests of language fluency/orientation/recall, and linear regression analysis. A basic knowledge of Alzheimer's disease survey (BKAD) was also administered.

FINDINGS

A total of 55 Afro-Caribbean participants (67.0 +10.8y (M ± SD), 65.5% with 10y or less of education residing in a rural area within the last 20 years were included.Over 50% of the convenience sample scored in the cognitive risk range. Significant associations were found between Mini-MoCA Total and Language scores and education (p < 0.01). Further, there was a significant change from pretest to posttest in BKAD scores. BKAD pretest and posttest scores were also significantly higher for those without dementia risk based on the Mini-MoCA Total.

CONCLUSION

While the Mini-MoCA showed good reliability in less-educated older Afro-Caribbeans, scores were strongly dependent on years of education. Offering a limited intervention resulted in increased BKAD scores in this Afro-Caribbean sample, and a low BKAD score was associated with a higher dementia risk category.

CLINICAL EVIDENCE

This study contributes to the limited but growing body of research about Alzheimer's disease knowledge, cognitive risk, and dementia detection among Afro-Caribbeans. The use of language-neutral cognitive assessments is recommended among rural older immigrants.

Effects of Cognitive Training on Alzheimer's Disease and Related Dementias: The Moderating Role of Social Determinants of Health

Objective: We examined whether social determinants of health (SDoH) are associated with Alzheimer's disease and related dementias (ADRD) risk and the effects of cognitive training over a 20-year follow-up period. Methods: Data were obtained from 1605 participants in ACTIVE. SDoH measures were created using baseline data at the individual and neighborhood level. Incident ADRD was defined using administrative claims data (1999-2019). Cause-specific hazard models estimated associations between SDoH and claims-based diagnosed ADRD. Results: Higher scores on neighborhood and built environment were associated with lower ADRD risk. Trained participants obtained a greater degree of protection from ADRD when they had higher scores for SDoH domains associated with health care and education access. However, there were fewer significant SDoH moderation effects on cognitive training than expected. Discussion: Future work should continue to explore culturally tailored cognitive training interventions to reduce ADRD risk associated with SDoH that disproportionately affects racially diverse aging populations.

Barriers and solutions to Alzheimer's disease clinical trial participation for Black Americans

Introduction

Black Americans are disproportionately burdened by Alzheimer's disease (AD) relative to other racial groups in the United States and continue to be underrepresented in AD clinical trials. This review explores the primary barriers for participation in clinical trials among Black Americans and provides literature-based recommendations to improve the inclusion of Black Americans in AD clinical trials.

Methods

We searched electronic databases and gray literature for articles published in the United States through January 1, 2023, ultimately identifying 26 key articles for inclusion.

Results

Barriers to participation in clinical trials for Black Americans are rooted in social determinants of health, including access to quality education and information, access to health care, economic stability, built environment, and community context. Best practices to improve the inclusion of Black Americans in clinical trials require pharmaceutical companies to adopt a multifaceted approach, investing in innovative strategies for site selection, development of local partnerships, outreach, and education.

Discussion

While multisectoral action must occur to effectively address the disproportionate burden of AD on Black Americans, the pharmaceutical industry has an important part to play in this space due to their central role in product development and clinical trials.

A Targeted Mass Spectrometry Approach to Identify Peripheral Changes in Metabolic Pathways of Patients with Alzheimer's Disease

Alzheimer's disease (AD), a neurodegenerative disorder, is the most common cause of dementia in the elderly population. Since its original description, there has been intense debate regarding the factors that trigger its pathology. It is becoming apparent that AD is more than a brain disease and harms the whole-body metabolism. We analyzed 630 polar and apolar metabolites in the blood of 20 patients with AD and 20 healthy individuals, to determine whether the composition of plasma metabolites could offer additional indicators to evaluate any alterations in the metabolic pathways related to the illness. Multivariate statistical analysis showed that there were at least 25 significantly dysregulated metabolites in patients with AD compared with the controls. Two membrane lipid components, glycerophospholipids and ceramide, were upregulated, whereas glutamic acid, other phospholipids, and sphingolipids were downregulated. The data were analyzed using metabolite set enrichment analysis and pathway analysis using the KEGG library. The results showed that at least five pathways involved in the metabolism of polar compounds were dysregulated in patients with AD. Conversely, the lipid pathways did not show significant alterations. These results support the possibility of using metabolome analysis to understand alterations in the metabolic pathways related to AD pathophysiology.

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.

Exploring Reasons for Differential Vulnerability and Alzheimer's Disease Risk in Racial and Ethnic Minorities

BACKGROUND

African American and Hispanic older adults are reported to have up to a 2-fold higher risk of Alzheimer's disease and related disorders (ADRD), but the reasons for this increased vulnerability have not been fully explored. The Vulnerability Index (VI) was designed to identify individuals who are at risk of developing cognitive impairment in the future, capturing 12 sociodemographic variables and modifiable medical comorbidities associated with higher ADRD risk. However, a prior limitation of the VI was that the original study cohort had limited diversity. We examined the association of the VI within and between non-Hispanic White, African American, and Hispanic older adults with and without cognitive impairment and different socioeconomic strata enrolled in a community-based dementia screening study.

OBJECTIVE

To explore reasons for reported higher ADRD vulnerability in African Americans and Hispanics.

METHODS

In a cross-sectional study of 300 non-Hispanic White, African American, and Hispanic older adults with and without cognitive impairment, we studied the association between cognitive status, the VI, and socioeconomic status (SES).

RESULTS

When considering race/ethnicity, the presence of more vascular comorbidities drove greater vulnerability. When considering SES, vascular comorbidities played a less prominent role suggesting resources and access to care drives risk. The VI had differential effects on cognitive performance with the greatest effect in the earlier stages of impairment.

CONCLUSION

Findings from this study provide a deeper understanding of the differential risk of ADRD in multicultural older adults captured by the VI and how barriers to healthcare access may increase vulnerability in racial/ethnic minorities.

Different item characteristics of a mild cognitive impairment screening tool in the community-based Yilan Study: application of the item response theory

BACKGROUND

This study aimed to use item response theory (IRT) to explore the item-by-item characteristics of a mild cognitive impairment (MCI) screening tool using community-based data.

METHODS

The Yilan Study is a community-based study that has been conducted since 2012. Until March 2020, 2230 older adults were interviewed according to the household registration data. IRT was applied to determine the item-by-item distinctive characteristics of the Eight-item Interview to Differentiate Aging and Dementia (AD8).

RESULTS

The MCI characteristics in the AD8 items have varying degrees of item response threshold. In all circumstances, item AD8-8, which is related to self-rated memory ability, had a low item response threshold. AD8-5 and AD8-7, which are related to the comparisons of time-oriented functional status, had slightly lower thresholds, especially for those aged 65-79 years or without activity limitations. Conversely, AD8-1, AD8-2, AD8-3, AD8-4, and AD8-6 had similar item response thresholds and discriminative power; these items have more detailed functional descriptions or examples for illustration.

CONCLUSIONS

Concise and understandable elements are often expected in community-based screening tools. For community-based health screening and population empowerment in the early detection of MCI, assessment tool items with detailed functional descriptions and examples for illustration have similar validities in most of the population. Items related to self-rated memory ability might be less valid. More examples may be needed for items constructed for comparing time-oriented functional status, especially in extremely old adults and individuals with activity limitations.

The Brain Health Platform: Combining Resilience, Vulnerability, and Performance to Assess Brain Health and Risk of Alzheimer's Disease and Related Disorders

BACKGROUND

It is difficult to assess brain health status and risk of cognitive impairment, particularly at the initial evaluation. To address this, we developed the Brain Health Platform to quantify brain health and identify Alzheimer's disease and related disorders (ADRD) risk factors by combining a measure of brain health: the Resilience Index (RI), a measure of risk of ADRD; the Vulnerability Index (VI); and the Number-Symbol Coding Task (NSCT), a measure of brain performance.

OBJECTIVE

The Brain Health Platform is intended to be easily and quickly administered, providing an overview of a patient's risk of developing future impairment based on modifiable and non-modifiable factors as well as current cognitive performance.

METHODS

This cross-sectional study comprehensively evaluated 230 participants (71 controls, 71 mild cognitive impairment, 88 ADRD). VI and RI scores were derived from physical assessments, lifestyle questionnaires, demographics, medical history, and neuropsychological examination including the NSCT.

RESULTS

Individuals with abnormal scores were 95.7% likely to be impaired, with a misclassification rate of 9.7%. The combined model had excellent discrimination (AUC:0.923±0.053; p < 0.001), performing better than the Montreal Cognitive Assessment.

CONCLUSION

The Brain Health Platform combines measures of resilience, vulnerability, and performance to provide a cross-sectional snapshot of overall brain health. The Brain Health Platform can effectively and accurately identify even the very mildest impairments due to ADRD, leveraging brief yet powerful and actionable indices of brain health and risk that could be used to develop personalized, precision medicine-like interventions.