Systematic review of dementia prevalence and incidence in United States race/ethnic populations

Understanding Racial Disparities in Dementia Prevalence Among Veterans

Background

Black and Hispanic older adults have greater incidence of Alzheimer's disease and related dementias relative to White adults, but factors underlying these disparities are not well understood, limiting the ability to address them.

Objective

To determine the impact of demographics, cardiovascular disease (CVD) and risk factors, social determinants of health (SDOH), and neuropsychiatric risk factors on racial/ethnic disparities in dementia risk among Veterans.

Methods

We examined a random sample of 1,579,919 older Veterans (age ≥55) without dementia who received care from the VHA from October 1, 1999 to September 30, 2021. All variables were extracted from national VHA data. We used Cox proportional hazard regression models to examine change in variance in risk of dementia across racial/ethnic groups.

Results

During follow up (mean 11.1 years), 13% of Veterans developed dementia. Relative to White Veterans, the adjusted hazard ratios (AHRs) for developing dementia in sex-adjusted models with age as timescale were 1.65 (95% CI, 1.63-1.67) for Black Veterans and 1.50 (95% CI, 1.44-1.56) for Hispanic Veterans. In the model examining CVD and risk factors, AHRs were 1.53 (95% CI, 1.50-1.55) for Black Veterans and 1.38 (95% CI, 1.33-1.44) for Hispanic Veterans. In the model examining SDOH, AHRs were 1.46 (95% CI, 1.43-1.49) for Black Veterans and 1.34 (95% CI, 1.29-1.40) for Hispanic Veterans.

Conclusions

SDOH and CVD and risk factors accounted for the greatest amount of variance in racial/ethnic disparities in dementia risk. Cardiovascular disease and SDOH are strong possible targets for interventions designed to reduce these disparities.

Extended genome-wide association study employing the African genome resources panel identifies novel susceptibility loci for Alzheimer's disease in individuals of African ancestry

INTRODUCTION

Despite a two-fold risk, individuals of African ancestry have been underrepresented in Alzheimer's disease (AD) genomics efforts.

METHODS

Genome-wide association studies (GWAS) of 2,903 AD cases and 6,265 controls of African ancestry. Within-dataset results were meta-analyzed, followed by functional genomics analyses.

RESULTS

A novel AD-risk locus was identified in MPDZ on chromosome (chr) 9p23 (rs141610415, MAF = 0.002, P = 3.68×10-9). Two additional novel common and nine rare loci were identified with suggestive associations (P < 9×10-7). Comparison of association and linkage disequilibrium (LD) patterns between datasets with higher and lower degrees of African ancestry showed differential association patterns at chr12q23.2 (ASCL1), suggesting that this association is modulated by regional origin of local African ancestry.

DISCUSSION

These analyses identified novel AD-associated loci in individuals of African ancestry and suggest that degree of African ancestry modulates some associations. Increased sample sets covering as much African genetic diversity as possible will be critical to identify additional loci and deconvolute local genetic ancestry effects.

HIGHLIGHTS

Genetic ancestry significantly impacts risk of Alzheimer's Disease (AD). Although individuals of African ancestry are twice as likely to develop AD, they are vastly underrepresented in AD genomics studies. The Alzheimer's Disease Genetics Consortium has previously identified 16 common and rare genetic loci associated with AD in African American individuals. The current analyses significantly expand this effort by increasing the sample size and extending ancestral diversity by including populations from continental Africa. Single variant meta-analysis identified a novel genome-wide significant AD-risk locus in individuals of African ancestry at the MPDZ gene, and 11 additional novel loci with suggestive genome-wide significance at P < 9×10-7. Comparison of African American datasets with samples of higher degree of African ancestry demonstrated differing patterns of association and linkage disequilibrium at one of these loci, suggesting that degree and/or geographic origin of African ancestry modulates the effect at this locus. These findings illustrate the importance of increasing number and ancestral diversity of African ancestry samples in AD genomics studies to fully disentangle the genetic architecture underlying AD, and yield more effective ancestry-informed genetic screening tools and therapeutic interventions.

Deep Learning Models for the Screening of Cognitive Impairment Using Multimodal Fundus Images

OBJECTIVE

We aimed to develop a deep learning system capable of identifying subjects with cognitive impairment quickly and easily based on multimodal ocular images.

DESIGN

Cross sectional study.

SUBJECTS

Participants of Beijing Eye Study 2011 and patients attending Beijing Tongren Eye Center and Beijing Tongren Hospital Physical Examination Center.

METHODS

We trained and validated a deep learning algorithm to assess cognitive impairment using retrospectively collected data from the Beijing Eye Study 2011. Cognitive impairment was defined as a Mini-Mental State Examination score < 24. Based on fundus photographs and OCT images, we developed 5 models based on the following sets of images: macula-centered fundus photographs, optic disc-centered fundus photographs, fundus photographs of both fields, OCT images, and fundus photographs of both fields with OCT (multimodal). The performance of the models was evaluated and compared in an external validation data set, which was collected from patients attending Beijing Tongren Eye Center and Beijing Tongren Hospital Physical Examination Center.

MAIN OUTCOME MEASURES

Area under the curve (AUC).

RESULTS

A total of 9424 retinal photographs and 4712 OCT images were used to develop the model. The external validation sets from each center included 1180 fundus photographs and 590 OCT images. Model comparison revealed that the multimodal performed best, achieving an AUC of 0.820 in the internal validation set, 0.786 in external validation set 1, and 0.784 in external validation set 2. We evaluated the performance of the multi-model in different sexes and different age groups; there were no significant differences. The heatmap analysis showed that signals around the optic disc in fundus photographs and the retina and choroid around the macular and optic disc regions in OCT images were used by the multimodal to identify participants with cognitive impairment.

CONCLUSIONS

Fundus photographs and OCT can provide valuable information on cognitive function. Multimodal models provide richer information compared with single-mode models. Deep learning algorithms based on multimodal retinal images may be capable of screening cognitive impairment. This technique has potential value for broader implementation in community-based screening or clinic settings.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

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

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

Diverging Patterns of Cognitive Decline by Sex and Race-Ethnicity in Seriously Ill Older Americans

Objectives

Differences in Cognitive decline are common in older adults in the last years of life, but differences across sex and race-ethnicity are poorly understood. This study investigated if sex and/or race-ethnicity moderated changes in cognitive function in older adults in the last years of life.

Methods

Data from the Health and Retirement Study (HRS) from 1993 to 2016 were used to analyze imputed cognition summary scores for total word recall and mental status of older adults aged 60-99. Loss of cognitive function was estimated using a multilevel mixed-effects model and accelerated cognitive decline was approximated by incorporating a change-point model using a restricted sample of decedent respondents who died aged 65-99.

Results

Notable disparities were seen in the rates of cognitive decline across sex and race-ethnic groups in the last years of life. Women consistently scored lower than men in word recall but higher in mental status, regardless of race-ethnicity. Non-Hispanic White respondents, men and women, consistently outperformed Hispanic and Black respondents in word recall tasks and mental status.

Conclusions

Our study shows that sex and race-ethnicity moderate cognitive decline in older adults during the last years of life. Older adults from underserved communities are at higher risk of cognitive decline. Our study could inform clinical practice and policy focused on mitigating the adverse impact of cognitive decline experienced by marginalized populations of older adults in the last years of life.

Environmental, Metabolic, and Nutritional Factors Concerning Dementia in African-Americans and Hispanic Populations

African-Americans and Hispanic Americans experience a higher incidence and prevalence of dementia than white Americans while also experiencing more environmental, metabolic and nutritional factors potentially promoting such disparities. Greater exposure to air, water and soil pollutants including toxic metals associated with neurodegeneration accrue to both minorities, as does worse dental care than whites exposing them to periodontitis raising dementia risk. Hispanic Americans experience greater occupational exposure to herbicides and pesticides develop more non-alcoholic fatty liver disease (NAFLD) predisposing to dementia. African-Americans have a greater likelihood of both Vitamin D deficiency and magnesium deficiency increasing neuroinflammation and dementia risk. Both have greater air pollution exposure, a known dementia risk. Nutritional changes including greater nut consumption and reduced sugar drink consumption, improved dental care, and reduced toxicant exposure may help reduce this higher risk of dementia among African Americans and Hispanic Americans.

Lower Prevalence of Asymptomatic Alzheimer's Disease Among Healthy African Americans

OBJECTIVE

Alzheimer's disease (AD) is believed to be more common in African Americans (AA), but biomarker studies in AA populations are limited. This report represents the largest study to date examining cerebrospinal fluid AD biomarkers in AA individuals.

METHODS

We analyzed 3,006 cerebrospinal fluid samples from controls, AD cases, and non-AD cases, including 495 (16.5%) self-identified black/AA and 2,456 (81.7%) white/European individuals using cutoffs derived from the Alzheimer's Disease Neuroimaging Initiative, and using a data-driven multivariate Gaussian mixture of regressions.

RESULTS

Distinct effects of race were found in different groups. Total Tauand phospho181-Tau were lower among AA individuals in all groups (p < 0.0001), and Aβ42 was markedly lower in AA controls compared with white controls (p < 0.0001). Gaussian mixture of regressions modeling of cerebrospinal fluid distributions incorporating adjustments for covariates revealed coefficient estimates for AA race comparable with 2-decade change in age. Using Alzheimer's Disease Neuroimaging Initiative cutoffs, fewer AA controls were classified as biomarker-positive asymptomatic AD (8.0% vs 13.4%). After adjusting for covariates, our Gaussian mixture of regressions model reduced this difference, but continued to predict lower prevalence of asymptomatic AD among AA controls (9.3% vs 13.5%).

INTERPRETATION

Although the risk of dementia is higher, data-driven modeling indicates lower frequency of asymptomatic AD in AA controls, suggesting that dementia among AA populations may not be driven by higher rates of AD. ANN NEUROL 2024.

Exploring the influence of weather variability and climate change on health outcomes in people living with dementia: A scoping review protocol

Environmental factors resulting from climate change and air pollution are risk factors for many chronic conditions including dementia. Although research has shown the impacts of air pollution in terms of cognitive status, less is known about the association between climate change and specific health-related outcomes of older people living with dementia. In response, we outline a scoping review protocol to systematically review the published literature regarding the evidence of climate change, including temperature and weather variability, on health-related quality of life, morbidity, mobility, falls, the utilization of health resources, and mortality among older adults living with dementia. This scoping review will be guided by the framework proposed by Arksey and O'Malley. Electronic search (Medline, Embase, PsycINFO, CINAHL, Scopus, Web of Science) using relevant subject headings and synonyms for two concepts (older people with dementia, weather/ climate change). No publication date or other restrictions will be applied to the search strategy. No language restriction will be applied in order to understand the impact of non-English studies in the literature. Eligible studies must include older adults (65+years) with dementia living in the community and investigate the impacts of climate change and/or weather on their health-related quality of life, morbidity, mobility, falls, use of health resources and mortality. Two independent reviewers will screen abstracts and select those for a full-text review, perform these reviews, select articles for retention, and extract data from them in a standardized manner. This data will then be synthesized and interpreted. OSF registration: DOI: 10.17605/OSF.IO/YRFM8.

Distribution of informal caregiving for older adults living with or at risk of cognitive decline within and beyond family in rural South Africa

Objectives

Aging populations in rural areas of low and middle-income countries will increasingly need care. However, formal support is severely limited and adult children are frequently unavailable due to morbidity, early mortality, employment and migration. We aimed to describe how care is shared within and between households for older adults in a rural South African setting.

Methods

We conducted quantitative interviews with 1012 household members and non-household caregivers of 106 older adults living with or at risk of cognitive decline in rural Mpumalanga, South Africa. Using descriptive statistics and regression analysis, we described how care is shared, with particular attention to generational patterns of care.

Results

Informal care for older persons was spread among family, friends, and neighbours, with minimal paid support. This care was mostly provided by female relatives one or two generations younger than the recipient, and unemployed. However, a smaller number of paid caregivers, also mostly female, provided the most intensive care. Spouses commonly took on the role of primary caregiver for their partner.

Discussion

In our study, care mainly came from household members due to close family ties and practical considerations, with support from outside the household. This reflects shared history, reciprocal relationships, and easy access to care tasks within the household. A deeper understanding of how informal care for older adults is shared in low- and middle-income countries is essential for developing targeted interventions.

Are We Talking About the Same Thing? Black/African Americans' Response to the BRFSS Cognitive Decline and Caregiver Modules

The Behavioral Risk Factor Surveillance System (BRFSS) is a randomized national U.S. telephone survey administered by state health departments. This study aimed to identify how Black/African Americans understand BRFSS caregiver and cognitive decline surveys and terminology to inform health messaging that centers the Black/African American experience. In focus groups, BRFSS surveys were administered to Black/African Americans (n = 30) aged ≥ 45 in Oregon. Participants were asked how they interpreted BRFSS terms 'memory loss' and 'confusion,' how these terms related to Alzheimer's and dementia, and about caregiving and cognitive decline experiences. The culturally responsive Africana Worldview guided interpretation, which centers the Black/African American experience and individuals within interdependent relationships and community identity when explaining behaviors of people from the African diaspora. BRFSS survey responses differed from focus group responses to the same questions. Two participants reported providing care in the past two years on the survey; in discussions, 21 participants reported providing care in the past two years. Interpretations of BRFSS terminology varied greatly. Differences between age-related cognitive changes, dementia and Alzheimer's disease were unclear. Cognitive decline was largely understood in terms of identity loss and relationship changes with the affected individual, and how that individual's relationship changed within community. Caution is advised when using BRFSS data to frame messaging because key cognitive health terms are not universally understood. Messaging that apply the Africana Worldview centralizes relationships and community rather than impact on individual's day-to-day activities, may be more effective for Black/African Americans and for other groups with different cultural and life experiences.

Age exacerbates the negative effect of depression on executive functioning in racial and ethnic minorities

Age and depression may interact to produce a "double jeopardy" for cognitive impairment, and executive functioning, in cognitively unimpaired aging. Few studies have considered middle age or the ethnoracial diversity of subjects, despite evidence of more severe cognitive outcomes in historically minoritized people. In this pilot study, we investigated the impact of age on depression-related cognitive impairment and the underlying brain volumes in middle-aged non-Hispanic White adults (116), and Hispanic and Black adults (60), with a total number of 176 adults. The result shows a significant interaction between age and depression for executive functioning, specifically for middle-aged Hispanic and Black adults, but not non-Hispanic White adults. Prefrontal cortex volumes, which were reduced in the Black and Hispanic compared to the non-Hispanic White adults, partially mediated the relationship between depression level and executive functioning, across age and ethnoracial group. Collectively, these results suggest that the negative impact of depression on executive functioning and Prefrontal cortex volumes integrity may be exacerbated by age and that historically minoritized people may be particularly sensitive to this double jeopardy.

The African American Dementia and Aging Project (AADAPt): An Oregon-based Longitudinal Study

Objectives

The vast majority of studies on aging, cognition, and dementia focus on non-Hispanic white subjects. This paper adds to the extant literature by providing insight into the African American aging experience. Here we describe the study design and baseline characteristics of the African American Dementia and Aging Project (AADAPt) study, which is exploring aging and cognition in African American older adults in Oregon.

Methods

African American older adults (n=177) participated in AADAPt, a longitudinal study that collected data on cognitive, physical, and social functioning in annual visits since 2000.

Results

AADAPt participants had risk factors for developing dementia in future, such as hypertension and hyperlipidemia, but also reported protective factors such as high social engagement.

Conclusions

The AADAPt project offers new insights into aging in older African Americans that includes data on cognition, social engagement, and physical health, which are crucial for understanding the experience of under-represented groups and making future studies more inclusive. These findings reflect a window of time for a geographically-focused cohort, and the lessons learned from this study likely have broader implications for shaping the health of these older African American adults. Keywords: African American, Dementia, Observational Study.

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.

A systematic review/meta-analysis of prevalence and incidence rates illustrates systemic underrepresentation of individuals racialized as Asian and/or Asian-American in ADRD research

We investigate Alzheimer's disease and related dementia (ADRD) prevalence, incidence rate, and risk factors in individuals racialized as Asian and/or Asian-American and assess sample representation. Prevalence, incidence rate, risk factors, and heterogeneity of samples were assessed. Random-effects meta-analysis was conducted, generating pooled estimates. Of 920 records across 14 databases, 45 studies were included. Individuals racialized as Asian and/or Asian-American were mainly from Eastern and Southern Asia, had higher education, and constituted a smaller sample relative to non-Hispanic white cohorts. The average prevalence was 10.9%, ranging from 0.4% to 46%. The average incidence rate was 20.03 (12.01-33.8) per 1000 person-years with a range of 75.19-13.59 (12.89-14.33). Risk factors included physiological, genetic, psychological, behavioral, and social factors. This review underscores the systemic underrepresentation of individuals racialized as Asian and/or Asian-American in ADRD research and the need for inclusive approaches accounting for culture, language, and immigration status. HIGHLIGHTS: There is considerable heterogeneity in the prevalence of ADRD among studies of Asian-Americans. There is limited data on group-specific risk factors for ADRD among Asian-Americans. The average prevalence of (ADRD) among Asian-Americans was found to be 7.4%, with a wide range from 0.5% to 46%.

Correlates of SuperAging in Two Population-Based Samples of Hispanic Older Adults

OBJECTIVES

"SuperAgers" are generally defined as people 80+ years old with episodic memory performance comparable to those 20 years younger. Limited knowledge exists to describe characteristics of SuperAgers, with even less known about Hispanic SuperAgers.

METHODS

We examined indicators of cognitive, physical, and psychological resilience in relation to the likelihood of being a SuperAger using data from 2 population-based studies of Hispanic older adults (Puerto Rican Elderly: Health Conditions [PREHCO] Study; Health and Retirement Study [HRS]). SuperAgers were defined as (1) ≥80 years old, (2) recall scores ≥ the median for Hispanic respondents aged 55-64, and (3) no cognitive impairment during the observation period. Overall, 640 PREHCO participants and 180 HRS participants were eligible, of whom 45 (7%) and 31 (17%) met SuperAging criteria.

RESULTS

Logistic regressions controlling for age and sex demonstrated that higher education (PREHCO: odds ratio [OR] = 1.20, p < .001; HRS: OR = 1.14, p = .044) and fewer instrumental activities of daily living limitations (PREHCO: OR = 0.79, p = .019; HRS: OR = 0.58, p = .077; cognitive resilience), fewer activities of daily living limitations (PREHCO: OR = 0.72, p = .031; HRS: OR = 0.67, p = .068; physical resilience), and fewer depressive symptoms (PREHCO: OR = 0.84, p = .015; HRS: OR = 0.69, p = .007; psychological resilience) were associated with SuperAging, although not all results reached threshold for statistical significance, presumably due to low statistical power. Additionally, known indicators of physical health (e.g., chronic conditions and self-rated health) did not relate to SuperAging.

DISCUSSION

Increasing access to education and recognizing/treating depressive symptoms represent potential pathways to preserve episodic memory among older Hispanic adults.

Physical exercise, cognition, and brain health in aging

Exercise training is an important strategy to counteract cognitive and brain health decline during aging. Evidence from systematic reviews and meta-analyses supports the notion of beneficial effects of exercise in cognitively unimpaired and impaired older individuals. However, the effects are often modest, and likely influenced by moderators such as exercise training parameters, sample characteristics, outcome assessments, and control conditions. Here, we discuss evidence on the impact of exercise on cognitive and brain health outcomes in healthy aging and in individuals with or at risk for cognitive impairment and neurodegeneration. We also review neuroplastic adaptations in response to exercise and their potential neurobiological mechanisms. We conclude by highlighting goals for future studies, including addressing unexplored neurobiological mechanisms and the inclusion of under-represented populations.

A Visualization Tool to Study Dyadic Caregiving Health Profiles

OBJECTIVES

Guided by a life course perspective and fundamental cause theory, this study aims to visualize co-trajectories of health between partners and examine how changes in one spouse's cognitive status can cohesively impact the health of the other spouse along three dimensions (functional, mental, and cognitive).

METHODS

Drawing longitudinal data from the Health and Retirement Study 2000-2016 (N = 3582), we measure women's health profiles by functional limitation (physical health), depression (mental health), and cognitive function (cognitive health). We use multivariate linear mixed models to summarize these paths in the same visual representation.

RESULTS

The approach provides a visualization tool that depicts data and model in the same spatial representation allowing assessment of model fit and comparison. This study advances the traditional life course studies by representing underlying processes as a multidimensional time vector of health outcomes.

DISCUSSION

The described approach provides a blueprint for studying complex health profiles or trajectories.

Gut Microbiome Multi-Omics and Cognitive Function in the Hispanic Community Health Study/Study of Latinos- Investigation of Neurocognitive Aging

INTRODUCTION

We conducted a study within the Hispanic Community Health Study/Study of Latinos- Investigation of Neurocognitive Aging (HCHS/SOL-INCA) cohort to examine the association between gut microbiome and cognitive function.

METHODS

We analyzed the fecal metagenomes of 2,471 HCHS/SOL-INCA participants to, cross-sectionally, identify microbial taxonomic and functional features associated with global cognitive function. Omnibus (PERMANOVA) and feature-wise analyses (MaAsLin2) were conducted to identify microbiome-cognition associations, and specific microbial species and pathways (Kyoto Encyclopedia of Genes and Genomes (KEGG modules) associated with cognition.

RESULTS

Eubacterium species( E. siraeum and E. eligens ), were associated with better cognition. Several KEGG modules, most strongly Ornithine, Serine biosynthesis and Urea Cycle, were associated with worse cognition.

DISCUSSION

In a large Hispanic/Latino cohort, we identified several microbial taxa and KEGG pathways associated with cognition.

Potentially Avoidable Hospitalizations Among Historically Marginalized Nursing Home Residents

Importance

Nursing home (NH) transfers to hospitals are common and have been associated with cognitive decline; approximately 45% of NH hospital transfers are potentially avoidable hospitalizations (PAHs).

Objective

To determine PAH incidence for historically marginalized NH residents with severe cognitive impairment compared with non-Hispanic White residents.

Design, Setting, and Participants

This cross-sectional study merged 2018 Centers for Medicaid & Medicare Services datasets and LTCFocus, a public dataset on US NH care, for US NH residents aged 65 years and older who had a hospitalization. Analyses were performed from January to May 2022.

Exposure

Race and ethnicity of NH residents.

Main Outcomes and Measures

Racial and ethnic differences in resident-level annual rates of PAHs were estimated for residents with and without severe cognitive impairment (measured using the Cognitive Function Scale), controlling for resident characteristics, comorbidities, dual eligibility, and time at risk. PAHs were defined as NH hospital transfers that resulted from neglectful NH care or for which NH treatment would have been appropriate.

Results

Of 2 098 385 NH residents nationwide included in the study, 7151 (0.3%) were American Indian or Alaska Native, 39 873 (1.9%) were Asian, 229 112 (10.9%) were Black or African American, 99 304 (4.7%) were Hispanic, 2785 (0.1%) were Native Hawaiian or Pacific Islander, 1 713 670 (81.7%) were White, and 6490 (0.3%) were multiracial; 1 355 143 (64.6%) were female; 128 997 (6.2%) were severely cognitively impaired; and the mean (SD) age was 81.8 (8.7) years. PAH incidence rate ratios (IRRs) were significantly greater for residents with severe cognitive impairment compared with those without. In unadjusted analyses comparing historically marginalized residents with severe cognitive impairment vs non-Hispanic White residents with severe cognitive impairment, American Indian or Alaska Native residents had a 49% higher PAH incidence (IRR, 1.49 [95% CI, 1.10-2.01]), Black or African American residents had a 64% higher incidence (IRR, 1.64 [95% CI, 1.48-1.81]), and Hispanic residents had a 45% higher incidence (IRR, 1.45 [95% CI, 1.29-1.62]). Higher incidences persisted for historically marginalized residents with severe cognitive impairment vs non-Hispanic White residents with severe cognitive impairment in adjusted analyses. Asian residents had a 24% higher PAH incidence (IRR, 1.24 [95% CI, 1.06-1.45]), Black or African American residents had a 48% higher incidence (IRR, 1.48 [95% CI, 1.36-1.60]), and Hispanic residents had a 27% higher incidence (IRR, 1.27 [95% CI, 1.16-1.39]).

Conclusions and Relevance

In this cross-sectional study of PAHs, compared with non-Hispanic White NH residents, historically marginalized residents had increased PAH incidence. In the presence of severe cognitive impairment, incidence rates increased significantly compared with rates for residents without severe cognitive impairment. These results suggest that identification of residents with severe cognitive impairment and proper NH care may help prevent further cognitive decline by avoiding PAHs.

2024 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including prevalence and incidence, mortality and morbidity, use and costs of care and the ramifications of AD for family caregivers, the dementia workforce and society. The Special Report discusses the larger health care system for older adults with cognitive issues, focusing on the role of caregivers and non-physician health care professionals. An estimated 6.9 million Americans age 65 and older are living with Alzheimer's dementia today. This number could grow to 13.8 million by 2060, barring the development of medical breakthroughs to prevent or cure AD. Official AD death certificates recorded 119,399 deaths from AD in 2021. In 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death, Alzheimer's was the seventh-leading cause of death in the United States. Official counts for more recent years are still being compiled. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2021, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 140%. More than 11 million family members and other unpaid caregivers provided an estimated 18.4 billion hours of care to people with Alzheimer's or other dementias in 2023. These figures reflect a decline in the number of caregivers compared with a decade earlier, as well as an increase in the amount of care provided by each remaining caregiver. Unpaid dementia caregiving was valued at $346.6 billion in 2023. Its costs, however, extend to unpaid caregivers' increased risk for emotional distress and negative mental and physical health outcomes. Members of the paid health care and broader community-based workforce are involved in diagnosing, treating and caring for people with dementia. However, the United States faces growing shortages across different segments of the dementia care workforce due to a combination of factors, including the absolute increase in the number of people living with dementia. Therefore, targeted programs and care delivery models will be needed to attract, better train and effectively deploy health care and community-based workers to provide dementia care. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are almost three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 22 times as great. Total payments in 2024 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $360 billion. The Special Report investigates how caregivers of older adults with cognitive issues interact with the health care system and examines the role non-physician health care professionals play in facilitating clinical care and access to community-based services and supports. It includes surveys of caregivers and health care workers, focusing on their experiences, challenges, awareness and perceptions of dementia care navigation.

Plasma biomarkers for Alzheimer's and related dementias: A review and outlook for clinical neuropsychology

Recent technological advances have improved the sensitivity and specificity of blood-based biomarkers for Alzheimer's disease and related dementias. Accurate quantification of amyloid-ß peptide, phosphorylated tau (pTau) isoforms, as well as markers of neurodegeneration (neurofilament light chain [NfL]) and neuro-immune activation (glial fibrillary acidic protein [GFAP] and chitinase-3-like protein 1 [YKL-40]) in blood has allowed researchers to characterize neurobiological processes at scale in a cost-effective and minimally invasive manner. Although currently used primarily for research purposes, these blood-based biomarkers have the potential to be highly impactful in the clinical setting - aiding in diagnosis, predicting disease risk, and monitoring disease progression. Whereas plasma NfL has shown promise as a non-specific marker of neuronal injury, plasma pTau181, pTau217, pTau231, and GFAP have demonstrated desirable levels of sensitivity and specificity for identification of individuals with Alzheimer's disease pathology and Alzheimer's dementia. In this forward looking review, we (i) provide an overview of the most commonly used blood-based biomarkers for Alzheimer's disease and related dementias, (ii) discuss how comorbid medical conditions, demographic, and genetic factors can inform the interpretation of these biomarkers, (iii) describe ongoing efforts to move blood-based biomarkers into the clinic, and (iv) highlight the central role that clinical neuropsychologists may play in contextualizing and communicating blood-based biomarker results for patients.

A dual approach to addressing gaps in scholar diversity in aging research

The number of people with Alzheimer's disease and related dementias (ADRD) in the United States is steadily increasing, with minoritized populations having a disproportionate burden of disease. One strategy to address the racial and ethnic disparities in aging is to diversify scholars in the field of aging, to increase dynamic solution development and create cultural congruence among researchers and participants. The National Institute on Aging has a committed effort to increase and diversify the number of scientists who conduct aging and ADRD research, placing a call for Centers to focus on this effort. In response to the National Institute on Aging call, the Carolina Center for Alzheimer's Disease and Minority Research, housed at the University of South Carolina, proposed a dual approach to addressing these gaps through a joint national conference and mentorship program for underrepresented minoritized faculty. After one year of the program, the participating scholars were surveyed, and successes and growth points of the program were identified to help guide the improvement of this dual approach to addressing gaps in scholar diversity in aging research.

Recruitment of a Diverse Community-based Older Adult Cohort for a Longitudinal Aging Study: The 15104 Seniors Project

INTRODUCTION

Enrolling individuals from underrepresented ethnoracial groups in aging research is often a challenge.

METHODS

We sought a diverse sample of older adults from a small-town area for a longitudinal aging study. We employed an intensive community engagement approach encompassing a range of recruitment strategies.

RESULTS

Over 4 years a steady trickle of individuals, 66% self-identifying as Black, signed up for study information; the proportion of those who eventually enroll in the study has been rising each year, from 68% to 94%. Community events, word-of-mouth referrals, and mailed postcards brought in the most contacts. The highest percentage of contacts who ultimately enrolled were from postcards, flyers, and word-of-mouth. Significantly more word-of-mouth referrals were endorsed by Black individuals than White and by Black men than other race/sex groups.

CONCLUSIONS

We have had some success in building relationships and trust with the local community, enrolling Black study participants in a proportion equal to their representation in the target community using a variety of recruitment methods. Patience, immersion in the community, and partnerships with key community members alongside traditional advertisements, and the utilization of study participants as recruiters are critical to designing optimal, targeted, recruitment strategies.

Personality and cognitive errors in the Healthy Aging in Neighborhoods of Diversity across the Life Span study

This study examines the association between personality and cognitive errors in the Healthy Aging in Neighborhoods of Diversity across the Life Span study, a sample diverse across race (Black, White) and SES (above, below 125% of the federal poverty line). Participants (N=1,062) completed a comprehensive personality questionnaire and were administered a brief mental status screener of cognitive errors. Higher neuroticism was associated with more cognitive errors, whereas higher openness and conscientiousness were associated with fewer errors. These associations were independent of age, sex, race, poverty status, and education and were generally not moderated by these factors. These findings support the associations between personality and cognition across race and SES.

TOMM40 and APOC1 variants differentiate the impacts of the APOE ε4 allele on Alzheimer's disease risk across sexes, ages, and ancestries

INTRODUCTION

The variability in apolipoprotein E (APOE) ε4-attributed susceptibility to Alzheimer's disease (AD) across ancestries, sexes, and ages may stem from the modulating effects of other genetic variants.

METHODS

We examined associations of compound genotypes (CompGs) comprising the ε4-encoding rs429358, TOMM40 rs2075650, and APOC1 rs12721046 polymorphisms with AD in White (7181/16,356 AD-affected/unaffected), Hispanic/Latino (2305/2921), and Black American (547/1753) participants across sexes and ages.

RESULTS

The absence and presence of the rs2075650 and/or rs12721046 minor alleles in the ε4-bearing CompGs define lower- and higher-AD-risk profiles, respectively, in White participants. They differentially impact AD risks in men and women of different ancestries, exhibiting an increasing, decreasing, flat, and nonlinear-with lower risks at ages younger than 65/70 years and older than 85 years compared to the ages in between-patterns across ages.

DISCUSSION

The ε4-bearing CompGs have a potential to differentiate biological mechanisms of sex-, age-, and ancestry-specific AD risks and serve as AD biomarkers.

Highlights

Younger White women carrying the lower-risk (LR) CompG are at small risk of AD.Black carriers of the LR CompG are at negligible risk of AD at 85 years and older.The higher-risk (HR) CompGs confer high AD risk in Whites and Blacks at 70 to 85 years.AD risk decreases with age for Hispanic/Lation women carrying the HR CompGs.Hispanic/Lation carriers of the LR CompG but not HR CompGs have higher AD risk than Blacks.

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

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

Perceptions of cognitive decline among American Indian and Alaska Native elders

INTRODUCTION

American Indian and Alaska Native elders aged ≥ 65 years are experiencing increased life expectancy. Elders are critical to intergenerational knowledge, yet limited data exist on the health challenges faced by this group.

METHODS

This study engaged individuals attending the National Indian Council on Aging 2021 Annual Meeting in Reno, Nevada. A 19-question survey, designed to examine perceptions about cognitive decline and to identify comfort with potential risk and protective factors, was disseminated to 50 participants.

RESULTS

Participants indicated that they are concerned about cognitive decline, are willing to plan for their future care and cognitive testing, and articulated a desire for Tribally led long-term support services.

DISCUSSION

This study found similar results to studies on White individuals, which include a lack of knowledge, stigma around the aging process, and gaps in services available. More work is necessary to address the gap in literature and policy.

Highlights

American Indian and Alaska Natives (AI/ANs) are underrepresented in literature on Alzheimer's disease and related dementia (ADRD).AI/ANs believe that they will experience cognitive decline as they age.AI/ANs indicate a willingness to plan for future care and participate in future research on ADRD.

Systematic Review of Longitudinal Evidence and Methodologies for Research on Neighborhood Characteristics and Brain Health

Objective: Synthesize longitudinal research evaluating neighborhood environments and cognition to identify methodological approaches, findings, and gaps. Methods: Included studies evaluated associations between neighborhood and cognition longitudinally among adults >45 years (or mean age of 65 years) living in developed nations. We extracted data on sample characteristics, exposures, outcomes, methods, overall findings, and assessment of disparities. Results: Forty studies met our inclusion criteria. Most (65%) measured exposure only once and a majority focused on green space and/or blue space (water), neighborhood socioeconomic status, and recreation/physical activity facilities. Similarly, over half studied incident impairment, cognitive function or decline (70%), with one examining MRI (2.5%) or Alzheimer's disease (7.5%). While most studies used repeated measures analysis to evaluate changes in the brain health outcome (51%), many studies did not account for any type of correlation within neighborhoods (35%). Less than half evaluated effect modification by race/ethnicity, socioeconomic status, and/or sex/gender. Evidence was mixed and dependent on exposure or outcome assessed. Conclusion: Although longitudinal research evaluating neighborhood and cognitive decline has expanded, gaps remain in types of exposures, outcomes, analytic approaches, and sample diversity.

Associations Between Ultra-processed Food Consumption and Cardiometabolic Health Among Older US Adults: Comparing Older Asian Americans to Older Adults From Other Major Race-Ethnic Groups

Using data from the National Health and Nutrition Examination Survey (2001-2018; N = 19,602), this study examined whether ultra-processed food (UPF) consumption is associated with cardiometabolic health (obesity, hypertension, high cholesterol, and diabetes), among White, Black, Hispanic, and Asian Americans (AA) US adults 50 or older. Diet was assessed using 24 hour dietary recall. NOVA dietary classification system was used to calculate the percentage of caloric intake derived from UPFs. Cardiometabolic information was assessed through physical examination, blood tests, and self-reported medication information. A median of 54% (IQR: 40%, 68%) of caloric intake was attributed to UPFs and was lowest for AAs (34%, IQR: 20%, 49%) and highest for White adults (56%; IQR: 42, 69%). In multivariable adjusted models, UPF consumption was associated with greater odds of obesity, high cholesterol, and diabetes. UPF consumption is associated with poor cardiometabolic health among all US older adults. For AAs, UPFs may be particularly obesogenic.

Personality predictors of dementia diagnosis and neuropathological burden: An individual participant data meta-analysis

INTRODUCTION

The extent to which the Big Five personality traits and subjective well-being (SWB) are discriminatory predictors of clinical manifestation of dementia versus dementia-related neuropathology is unclear.

METHODS

Using data from eight independent studies (Ntotal = 44,531; Ndementia = 1703; baseline Mage = 49 to 81 years, 26 to 61% female; Mfollow-up range = 3.53 to 21.00 years), Bayesian multilevel models tested whether personality traits and SWB differentially predicted neuropsychological and neuropathological characteristics of dementia.

RESULTS

Synthesized and individual study results indicate that high neuroticism and negative affect and low conscientiousness, extraversion, and positive affect were associated with increased risk of long-term dementia diagnosis. There were no consistent associations with neuropathology.

DISCUSSION

This multistudy project provides robust, conceptually replicated and extended evidence that psychosocial factors are strong predictors of dementia diagnosis but not consistently associated with neuropathology at autopsy.

HIGHLIGHTS

N(+), C(-), E(-), PA(-), and NA(+) were associated with incident diagnosis. Results were consistent despite self-report versus clinical diagnosis of dementia. Psychological factors were not associated with neuropathology at autopsy. Individuals with higher conscientiousness and no diagnosis had less neuropathology. High C individuals may withstand neuropathology for longer before death.

Dietary Adherence and Cognitive Performance in Older Adults by Nativity Status: Results from the National Health and Nutrition Examination Survey (NHANES), 2011-2014

Although adherence to dietary guidelines is associated with better cognitive performance, there may be differences by nativity status. This study aimed to investigate the association between adherence to the healthy eating index (HEI) and cognitive performance (CP) among United States (US)-born and foreign-born older adults (60+ years). Data were obtained from the 2011-2014 NHANES (n = 3065). Dietary adherence was assessed with HEI quintiles. CP (adequate vs. low) was examined using word listing (CERAD), animal naming (AFT), and the digit symbol substitution test (DSST). Weighted multivariable logistic regressions were used to examine associations. The US-born participants in higher dietary quintiles had adequate CP when compared to foreign-born participants. In adjusted models, the US-born participants in the highest HEI quintile had increased odds of adequate DSST scores (odds ratio: 1.95, 95% confidence interval: 1.15-3.28) compared with those in the lowest quintile. Patterns of association were generally reversed for foreign-born participants and were non-statistically significant. Future research should consider the influence of diets in delaying or preventing decline in cognition and evaluate nutritional factors that contribute to cognitive outcomes for the foreign-born population.

Racial and Ethnic Differences in the Population-Attributable Fractions of Alzheimer Disease and Related Dementias

BACKGROUND AND OBJECTIVES

Previous studies estimated that modifiable risk factors explain up to 40% of the dementia cases in the United States and that this population-attributable fraction (PAF) differs by race and ethnicity-estimates of future impact based on the risk factor prevalence in contemporary surveys. The aim of this study was to determine the race-specific and ethnicity-specific PAF of late-onset Alzheimer disease and related dementias (ADRDs) based on the risk factor prevalence and associations observed on the same individuals within a prospective cohort.

METHODS

Data were from Multiethnic Cohort Study participants (African American, Japanese American, Latino, Native Hawaiian, and White) enrolled in Medicare Fee-for-Service. We estimated the PAF based on the prevalence of risk factors at cohort baseline and their mutually adjusted association with subsequent ADRD incidence. Risk factors included low educational attainment and midlife exposures to low neighborhood socioeconomic status, unmarried status, history of hypertension, stroke, diabetes or heart disease, smoking, physical inactivity, short or long sleep duration, obesity, and low-quality diet, as well as APOE ε4 for a subset.

RESULTS

Among 91,881 participants (mean age 59.3 at baseline, 55.0% female participants), 16,507 incident ADRD cases were identified from Medicare claims (1999-2016, mean follow-up 9.3 years). The PAF for nongenetic factors combined was similar in men (24.0% [95% CI 21.3-26.6]) and women (22.8% [20.3-25.2]) but varied across Japanese American (14.2% [11.1-17.2]), White (21.9% [19.0-24.7]), African American (27.8% [22.3-33.0]), Native Hawaiian (29.3% [21.0-36.7]), and Latino (33.3% [27.5-38.5]) groups. The combined PAF was attenuated when accounting for competing risk of death, in both men (10.4%) and women (13.9%) and across racial and ethnic groups (4.7%-25.5%). The combined PAF was also different by age at diagnosis and ADRD subtypes, higher for younger (65-74 years: 43.2%) than older (75-84 years: 32.4%; ≥85 years: 11.3%) diagnoses and higher for vascular or unspecified ADRD than for AD or Lewy body dementia. An additional PAF of 11.8% (9.9-13.6) was associated with APOE ε4, which together with nongenetic risk factors accounted for 30.6% (25.8-35.1) of ADRD.

DISCUSSION

Known risk factors explained about a third of the ADRD cases but with unequal distributions across racial and ethnic groups.

Comorbid Conditions Are Associated With Cognitive Impairment in Native Hawaiians and Pacific Islanders

We examined the association between comorbid conditions and mild cognitive impairment (MCI) in Native Hawaiians and Pacific Islanders (NHPI) (n = 54). Cross-sectional, self-reported questionnaires were utilized to collect demographic, comorbid conditions, and MCI (via the AD8 index) data. Separate logistic regression models were conducted to investigate the relationship between comorbid conditions and MCI, adjusting for other covariates. We found significantly increased odds of MCI in those reporting high blood pressure (OR = 5.27; 95% CI: [1.36, 20.46]; p = 0.016), high cholesterol (OR = 7.30; 95% CI: [1.90, 28.14], p = 0.004), and prediabetes or borderline diabetes (OR = 4.53; 95% CI: [1.27, 16.16], p = 0.02) compared with those not reporting these respective conditions. These data show that hypertension, hypercholesterolemia, and prediabetes are associated with MCI in the NHPI community, suggesting that preventive strategies to reduce chronic conditions may also potentially slow cognitive decline in underrepresented/understudied NHPI.

Diabetes Among Racial and Ethnically Diverse Older Adults in the United States with Cognitive Limitations

Diabetes is one of the most common coexisting conditions among adults with cognitive limitations. Complexities of diabetes care present challenges for older adults and their caregivers. Few studies have evaluated disparities in the prevalence of coexisting diabetes among older adults with cognitive limitations by race/ethnicity and nativity. Our objectives were to (1) estimate the odds of coexisting diabetes among US- and foreign-born racial/ethnic groups compared to US-born non-Hispanic White older adults and (2) compare US- and foreign-born older adults within each racial/ethnic group. We linked and analyzed 2000-2017 National Health Interview Survey and 2001-2018 Medical Expenditure Panel Survey data among older adults with cognitive limitations (ages ≥ 65 years, n = 4688). The overall prevalence of coexisting diabetes among older adults with cognitive limitations was 30.3%. Among older adults with cognitive limitations and after adjusted for age, sex, education, and risk factors for diabetes and cognitive limitations, non-Hispanic Black (US-born OR = 1.56, 95%CI = 1.23-1.98; foreign-born OR = 2.69, 95%CI = 1.20-6.05) and Hispanic (US-born OR = 2.13, 95%CI = 1.34-3.40; foreign-born OR = 2.02, 95%CI = 1.49-2.72) older adults had higher odds of coexisting diabetes compared to US-born non-Hispanic Whites. There were no differences in the odds of coexisting diabetes among foreign-born non-Hispanic Black and Hispanic adults compared to US-born counterparts. Findings suggest a large potential burden of coexisting diabetes among this growing populations of US- and foreign-born racially/ethnically diverse older adults with cognitive limitations. Future studies are needed to examine how diabetes self-efficacy, treatment, and monitoring are impacted by cognitive limitations and determine ways to improve care in collaboration with caregivers and healthcare providers.

Distinct structural motifs are necessary for targeting and import of Tim17 in Trypanosoma brucei mitochondrion

Nuclear-encoded mitochondrial proteins are correctly translocated to their proper sub-mitochondrial destination using location-specific mitochondrial targeting signals and via multi-protein import machineries (translocases) in the outer and inner mitochondrial membranes (TOM and TIMs, respectively). However, targeting signals of multi-pass Tims are less defined. Here, we report the characterization of the targeting signals of Trypanosoma brucei Tim17 (TbTim17), an essential component of the most divergent TIM complex. TbTim17 possesses a characteristic secondary structure including four predicted transmembrane (TM) domains in the center with hydrophilic N- and C-termini. After examining mitochondrial localization of various deletion and site-directed mutants of TbTim17 in T. brucei using subcellular fractionation and confocal microscopy, we located at least two internal targeting signals (ITS): (i) within TM1 (31-50 AAs) and (ii) TM4 + loop 3 (120-136 AAs). Both signals are required for proper targeting and integration of TbTim17 in the membrane. Furthermore, a positively charged residue (K122) is critical for mitochondrial localization of TbTim17. This is the first report of characterizing the ITS for a multipass inner membrane protein in a divergent eukaryote, like T. brucei.IMPORTANCEAfrican trypanosomiasis (AT) is a deadly disease in human and domestic animals, caused by the parasitic protozoan Trypanosoma brucei. Therefore, AT is not only a concern for human health but also for economic development in the vast area of sub-Saharan Africa. T. brucei possesses a single mitochondrion per cell that imports hundreds of nuclear-encoded mitochondrial proteins for its functions. T. brucei Tim17 (TbTim17), an essential component of the TbTIM17 complex, is a nuclear-encoded protein; thus, it is necessary to be imported from the cytosol to form the TbTIM17 complex. Here, we demonstrated that the internal targeting signals within the transmembrane 1 (TM1) and TM4 with loop 3, and residue K122 are required collectively for import and integration of TbTim17 in the T. brucei mitochondrion. This information could be utilized to block TbTim17 function and parasite growth.

White matter hyperintensities in diverse populations: A systematic review of literature in the United States

As the United States' (US) elderly population becomes increasingly diverse, it is imperative that research studies address cognitive health in diverse populations of older Americans. White Matter Hyperintensities (WMH) are useful imaging findings that can be studied in elderly individuals and have been linked to an increased risk of neurological conditions, such as stroke, cognitive impairment, and dementia. We performed a systematic review of literature using PubMed sources to compile all the studies that investigated the prevalence of ethnic and racial differences of WMH burden amongst diverse groups in the US. We identified 23 unique articles that utilized 16 distinct cohorts of which 94 % were prospective, longitudinal studies that included community-based and family-based populations. The overall results were heterogenous in all aspects of data collection and analysis, limiting our ability to run meta-analyses and draw definitive conclusions. General observations suggest increased vascular risk on African American populations, contributing to greater WMH burden in that population. Overall, the findings of this study indicate a need for a standardized approach to investigating WMH in efforts to measure its clinical impact on diverse populations.

Estimating dementia risk in an African American population using the DCTclock

The prevalence of Alzheimer's disease (AD) and related dementias (ADRD) is increasing. African Americans are twice as likely to develop dementia than other ethnic populations. Traditional cognitive screening solutions lack the sensitivity to independently identify individuals at risk for cognitive decline. The DCTclock is a 3-min AI-enabled adaptation of the well-established clock drawing test. The DCTclock can estimate dementia risk for both general cognitive impairment and the presence of AD pathology. Here we performed a retrospective analysis to assess the performance of the DCTclock to estimate future conversion to ADRD in African American participants from the Rush Alzheimer's Disease Research Center Minority Aging Research Study (MARS) and African American Clinical Core (AACORE). We assessed baseline DCTclock scores in 646 participants (baseline median age = 78.0 ± 6.4, median years of education = 14.0 ± 3.2, 78% female) and found significantly lower baseline DCTclock scores in those who received a dementia diagnosis within 3 years. We also found that 16.4% of participants with a baseline DCTclock score less than 60 were significantly more likely to develop dementia in 5 years vs. those with the highest DCTclock scores (75-100). This research demonstrates the DCTclock's ability to estimate the 5-year risk of developing dementia in an African American population. Early detection of elevated dementia risk using the DCTclock could provide patients, caregivers, and clinicians opportunities to plan and intervene early to improve cognitive health trajectories. Early detection of dementia risk can also enhance participant selection in clinical trials while reducing screening costs.

Undiagnosed Cirrhosis and Hepatic Encephalopathy in a National Cohort of Veterans With Dementia

Importance

Dementia and hepatic encephalopathy (HE) are challenging to distinguish clinically. Undiagnosed cirrhosis in a patient with dementia can lead to missed opportunities to treat HE.

Objective

To examine the prevalence and risk factors of undiagnosed cirrhosis and therefore possible HE in veterans with dementia.

Design, Setting, and Participants

A retrospective cohort study was conducted between 2009 and 2019 using data from the Veterans Health Administration (VHA) and 2 separate validation cohorts from the Richmond Veterans Affairs Medical Center. Data analysis was conducted from May 20 to October 15, 2023. Participants included 177 422 US veterans with a diagnosis of dementia at 2 or more clinic visits, no prior diagnosis of cirrhosis, and with sufficient laboratory test results to calculate the Fibrosis-4 (FIB-4) score.

Exposures

Demographic and clinical characteristics.

Main Outcomes and Measures

An FIB-4 score (>2.67 suggestive of advanced fibrosis and >3.25 suggestive of cirrhosis), capped at age 65 years even for those above this cutoff who were included in the analysis.

Results

Among 177 422 veterans (97.1% men; 80.7% White; mean (SD) age, 78.35 [10.97] years) 5.3% (n = 9373) had an FIB-4 score greater than 3.25 and 10.3% (n = 18 390) had an FIB-4 score greater than 2.67. In multivariable logistic regression models, FIB-4 greater than 3.25 was associated with older age (odds ratio [OR], 1.07; 95% CI, 1.06-1.09), male gender (OR, 1.43; 95% CI, 1.26-1.61), congestive heart failure (OR, 1.48; 95% CI, 1.43-1.54), viral hepatitis (OR, 1.79; 95% CI, 1.66-1.91), Alcohol Use Disorders Identification Test score (OR, 1.56; 95% CI, 1.44-1.68), and chronic kidney disease (OR, 1.11; 95% CI, 1.04-1.17), and inversely associated with White race (OR, 0.79; 95% CI, 0.73-0.85), diabetes (OR, 0.78; 95% CI, 0.73-0.84), hyperlipidemia (OR, 0.84; 95% CI, 0.79-0.89), stroke (OR, 0.85; 95% CI, 0.79-0.91), tobacco use disorder (OR, 0.78; 95% CI, 0.70-0.87), and rural residence (OR, 0.92; 95% CI, 0.87-0.97). Similar findings were associated with the FIB-4 greater than 2.67 threshold. These codes were associated with cirrhosis on local validation. A local validation cohort of patients with dementia showed a similar percentage of high FIB-4 scores (4.4%-11.2%).

Conclusions and Relevance

The findings of this cohort study suggest that clinicians encountering patients with dementia should be encouraged to screen for cirrhosis using the FIB-4 score to uncover reversible factors associated with cognitive impairment, such as HE, to enhance outcomes.

Associations of Nativity and the Role of the Hispanic Paradox on the Cognitive Health of Older Latinos Living in the United States

Background

US-based Latinos have lower education and income combined with higher health risks than non-Latino whites, but often 'paradoxically' evidence better health-related outcomes. Less work has investigated this paradox for cognitive-related outcomes despite nativity diversity.

Objective

We evaluated cognitive aging within older Latinos of diverse nativity currently living in the US and participating in Rush Alzheimer's Disease Center studies.

Methods

Participants without baseline dementia, who completed annual neuropsychological assessments (in English or Spanish) were grouped by US-born (n = 117), Mexico-born (n = 173), and born in other Latin American regions (LAr-born = 128). Separate regression models examined associations between nativity and levels of (N = 418) or change in (n = 371; maximum follow-up ∼16 years) global and domain-specific cognition.

Results

Demographically-adjusted linear regression models indicated that foreign-born nativity was associated with lower levels of global cognition and select cognitive domains compared to US-born Latinos. No associations of nativity with cognitive decline emerged from demographically-adjusted mixed-effects models; however, Mexico-born nativity appeared associated with slower declines in working memory compared to other nativity groups (p-values ≥ 0.051). Mexico-born Latinos had relatively higher vascular burden and lower education levels than other nativity groups; however, this did not alter results.

Conclusions

Nativity differences in baseline cognition may be due, in part, to accumulated stressors related to immigration and acculturation experienced by foreign-born Latinos which may hasten meeting criteria for dementia later in life. In contrast, Mexico-born participants' slower working memory declines, taken in the context of other participant characteristics including vascular burden, suggests the Hispanic Paradox may relate to factors with the potential to affect cognition.

Comparing Symmetric Dimethylarginine and Amyloid-β42 as Predictors of Alzheimer's Disease Development

Background

Physicians may soon be able to diagnose Alzheimer's disease (AD) in its early stages using fluid biomarkers like amyloid. However, it is acknowledged that additional biomarkers need to be characterized which would facilitate earlier monitoring of AD pathogenesis.

Objective

To determine if a potential novel inflammation biomarker for AD, symmetric dimethylarginine, has utility as a baseline serum biomarker for discriminating prodromal AD from cognitively unimpaired controls in comparison to cerebrospinal fluid amyloid-β42 (Aβ42).

Methods

Data including demographics, magnetic resonance imaging and fluorodeoxyglucose-positron emission tomography scans, Mini-Mental State Examination and Functional Activities Questionnaire scores, and biomarker concentrations were obtained from the Alzheimer's Disease Neuroimaging Initiative for a total of 146 prodromal AD participants and 108 cognitively unimpaired controls.

Results

Aβ42 (p = 0.65) and symmetric dimethylarginine (p = 0.45) were unable to predict age-matched cognitively unimpaired controls and prodromal AD participants. Aβ42 was negatively associated with regional brain atrophy and hypometabolism as well as cognitive and functional decline in cognitively unimpaired control participants (p < 0.05) that generally decreased in time. There were no significant associations between Aβ42 and symmetric dimethylarginine with imaging or neurocognitive biomarkers in prodromal AD patients.

Conclusions

Correlations were smaller between Aβ42 and neuropathological biomarkers over time and were absent in prodromal AD participants, suggesting a plateau effect dependent on age and disease stage. Evidence supporting symmetric dimethylarginine as a novel biomarker for AD as a single measurement was not found.

Empathy as a crucial skill in disrupting disparities in global brain health

Brain health refers to the state of a person's brain function across various domains, including cognitive, behavioral and motor functions. Healthy brains are associated with better individual health, increased creativity, and enhanced productivity. A person's brain health is intricately connected to personal, social and environmental factors. Racial, ethnic, and social disparities affect brain health and on the global scale these disparities within and between regions present a hurdle to brain health. To overcome global disparities, greater collaboration between practitioners and healthcare providers and the people they serve is essential. This requires cultural humility driven by empathy. Empathy is a core prosocial value, a cognitive-emotional skill that helps us understand ourselves and others. This position paper aims to provide an overview of the vital roles of empathy, cooperation, and interdisciplinary partnerships. By consciously integrating this understanding in practice, leaders can better position themselves to address the diverse challenges faced by communities, promote inclusivity in policies and practices, and further more equitable solutions to the problem of global brain health.

Greater socioenvironmental risk factors and higher chronic pain stage are associated with thinner bilateral temporal lobes

INTRODUCTION

Previous research indicates ethnic/race group differences in pain and neurodegenerative diseases. Accounting for socioenvironmental factors reduces ethnic/race group differences in clinical and experimental pain. In the current study sample, we previously reported that in individuals with knee pain, ethnic/race group differences were observed in bilateral temporal lobe thickness, areas of the brain associated with risk for Alzheimer's disease, and related dementias. The purpose of the study was to determine if socioenvironmental factors reduce or account for previously observed ethnic/race group differences and explore if a combined effect of socioenvironmental risk and chronic pain severity on temporal lobe cortices is evident.

METHODS

Consistent with the prior study, the sample was comprised of 147 adults (95 women, 52 men), 45-85 years of age, who self-identified as non-Hispanic Black (n = 72) and non-Hispanic White (n = 75), with knee pain with/at risk for osteoarthritis. Measures included demographics, health history, pain questionnaires, cognitive screening, body mass index, individual- and community-level socioenvironmental factors (education, income, household size, marital and insurance status, and area deprivation index), and brain imaging. We computed a summative socioenvironmental risk index.

RESULTS

Regression analyses showed that with the inclusion of socioenvironmental factors, the model was significant (p < .001), and sociodemographic (ethnic/race) group differences were not significant (p = .118). Additionally, findings revealed an additive stress load pattern indicating thinner temporal lobe cortices with greater socioenvironmental risk and chronic pain severity (p = .048).

IMPLICATIONS

Although individual socioenvironmental factors were not independent predictors, when collectively combined in models, ethnic/race group differences in bilateral temporal lobe structures were not replicated. Further, combined socioenvironmental risk factors and higher chronic pain severity were associated with thinner bilateral temporal lobes.

Life-Course Brain Health as a Determinant of Late-Life Mental Health: American Association for Geriatric Psychiatry Expert Panel Recommendations

This position statement of the Expert Panel on Brain Health of the American Association for Geriatric Psychiatry (AAGP) emphasizes the critical role of life course brain health in shaping mental well-being during the later stages of life. Evidence posits that maintaining optimal brain health earlier in life is crucial for preventing and managing brain aging-related disorders such as dementia/cognitive decline, depression, stroke, and anxiety. We advocate for a holistic approach that integrates medical, psychological, and social frameworks with culturally tailored interventions across the lifespan to promote brain health and overall mental well-being in aging adults across all communities. Furthermore, our statement underscores the significance of prevention, early detection, and intervention in identifying cognitive decline, mood changes, and related mental illness. Action should also be taken to understand and address the needs of communities that traditionally have unequal access to preventive health information and services. By implementing culturally relevant and tailored evidence-based practices and advancing research in geriatric psychiatry, behavioral neurology, and geroscience, we can enhance the quality of life for older adults facing the unique challenges of aging. This position statement emphasizes the intrinsic link between brain health and mental health in aging, urging healthcare professionals, policymakers, and a broader society to prioritize comprehensive strategies that safeguard and promote brain health from birth through later years across all communities. The AAGP Expert Panel has the goal of launching further activities in the coming months and years.

Childhood and Life-Course Socioeconomic Position and Cognitive Function in the Adult Population of the Hispanic Community Health Study/Study of Latinos

The Hispanic/Latino population experiences socioeconomic adversities across the lifespan and is at greater risk of cognitive impairment, yet little is known about the role of life-course socioeconomic position (SEP) in cognitive function in this population. Using baseline data (2008-2011) from adults (aged 45-74 years) of the Hispanic Community Health Study/Study of Latinos, we assessed the association between childhood SEP and socioeconomic mobility with cognitive function, and whether this association was mediated by midlife SEP. Childhood SEP was assessed using parental education. An index combining participants' education and household income represented midlife SEP. Socioeconomic mobility was categorized as stable low, downward or upward mobility, and stable high-SEP. Cognitive function measures were modeled using survey linear regression with inverse-probability weighting, accounting for covariates. We used mediation analysis to estimate the indirect effect of childhood SEP on cognition through midlife SEP. High childhood SEP was associated with global cognition in adulthood (coefficient for parental education beyond high school vs. less than high school = 0.26, 95% confidence interval: 0.15, 0.37). This association was partially mediated through midlife SEP (indirect effect coefficient = 0.16, 95% confidence interval: 0.15, 0.18). Low SEP through the life course was associated with the lowest cognitive function. This study provides evidence that life-course SEP influences cognitive performance in adulthood.

Antiamyloid Monoclonal Antibody Therapy for Alzheimer Disease: Emerging Issues in Neurology

With recent data demonstrating that lecanemab treatment can slow cognitive and functional decline in early symptomatic Alzheimer disease (AD), it is widely anticipated that this drug and potentially other monoclonal antibody infusions targeting β-amyloid protein will imminently be realistic options for some patients with AD. Given that these new antiamyloid monoclonal antibodies (mAbs) are associated with nontrivial risks and burdens of treatment that are radically different from current mainstays of AD management, effectively and equitably translating their use to real-world clinical care will require systematic and practice-specific modifications to existing workflows and infrastructure. In this Emerging Issues in Neurology article, we provide practical guidance for a wide audience of neurology clinicians on logistic adaptations and decision making around emerging antiamyloid mAbs. Specifically, we briefly summarize the rationale and available evidence supporting antiamyloid mAb use in AD to facilitate appropriate communication with patients and care partners on potential benefits. We also discuss pragmatic approaches to optimizing patient selection and treatment monitoring, with a particular focus on the value of incorporating shared decision making and multidisciplinary collaboration. In addition, we review some of the recognized limitations of current knowledge and highlight areas of future evolution to guide the development of sustainable and flexible models for treatment and follow-up. As the field enters a new era with disease-modifying treatment options for AD, it will be critical for neurology practices to prepare and continually innovate to ensure optimal outcomes for patients.

Longitudinal Associations Between Sleep and Cognitive Function in a Cohort of Older Puerto Rican Adults: Sex and Age Interactions

BACKGROUND

Evidence on sleep duration or quality and cognitive function in diverse older adults is limited. We examined prospective associations between subjective sleep measures and cognitive function, with modifying effects of sex and age (<65 vs ≥65 years).

METHODS

Data are from the longitudinal Boston Puerto Rican Health Study, Waves 2 (n = 943) and 4 (n = 444), with mean follow-up of 10.5 years (range 7.2-12.8). Subjective measures of sleep duration (short <7, ref. 7, or long ≥8 hours) and insomnia symptoms (sum of difficulty falling asleep, waking up at night, and early morning awakening), were assessed at Wave 2. Linear regression models were used to assess changes in global cognition, executive function, memory, and Mini-Mental State Examination, and tested for modifying roles of sex and age.

RESULTS

Significant 3-way interaction (sex × age × cognition) in fully adjusted models showed greater decline in global cognitive function in older men with short (β [95% confidence interval]: -0.67 [-1.24, -0.10]) or long sleep duration (-0.92 [-1.55, -0.30]), compared to women, younger men, and older men with 7 hours of sleep. Insomnia symptoms were associated with a greater decline in memory (-0.54, [-0.85, -0.22]) among older men, compared to women and younger men.

CONCLUSION

Sleep duration showed a U-shaped association with cognitive decline, and insomnia symptoms were associated with memory decline in fully adjusted models. Older men, versus women and younger men, were at relatively greater risk for cognitive decline associated with sleep factors. These findings are important for personalizing sleep interventions to support cognitive health.

Pathways explaining racial/ethnic disparities in incident all-cause dementia among middle-aged US adults

INTRODUCTION

Racial disparities in dementia incidence exist, but less is known about their presence and drivers among middle-aged adults.

METHODS

We used time-to-event analysis among a sample of 4378 respondents (age 40-59 years at baseline) drawn from the third National Health and Nutrition Examination Surveys (NHANES III) with administrative linkage-spanning the years 1988-2014-to evaluate potential mediating pathways through socioeconomic status (SES), lifestyle, and health-related characteristics.

RESULTS

Compared with Non-Hispanic White (NHW) adults, Non-White adults had a higher incidence of AD-specific (hazard ratio [HR] = 2.05, 95% confidence interval [CI]: 1.21, 3.49) and all-cause dementia (HR = 2.01, 95% CI: 1.36, 2.98). Diet, smoking, and physical activity were among characteristics on the pathway between race/ethnicity, SES, and dementia, with health-mediating effects of smoking and physical activity on dementia risk.

DISCUSSION

We identified several pathways that may generate racial disparities in incident all-cause dementia among middle-aged adults. No direct effect of race was observed. More studies are needed to corroborate our findings in comparable populations.

Bilingual neurocognitive resiliency, vulnerability, and Alzheimer's disease biomarker correlates in Latino older adults enrolled in the Health and Aging Brain Study - Health Disparities (HABS-HD)

INTRODUCTION

The effects of bilingualism on neuropsychological test performance in bilinguals with and without cognitive impairment are not well-understood and are relatively limited by small sample sizes of Latinos.

METHODS

Using analysis of covariance (ANCOVA), we explored patterns of cognitive performance and impairment across a large sample of community-dwelling bilingual and monolingual Latino older adults with (n = 180) and without (n = 643) mild cognitive impairment (MCI) enrolled in HABS-HD.

RESULTS

Bilinguals demonstrated cognitive resiliency in the form of significantly better performance on the Trail Making Test and Digit Symbol Substitution Test, observed across the cognitively unimpaired and MCI groups. In contrast, bilinguals demonstrated cognitive vulnerability in the form of significantly poorer performance and higher impairment rates on phonemic fluency in the MCI phase, only. Follow-up analyses revealed less balanced bilinguals demonstrated poorer performance and higher impairment rates on this measure, supported by lower levels of plasma Aβ 42/40.

DISCUSSION

Patterns of cognitive performance and impairment differ as a function of bilingualism. Bilingualism must be considered when evaluating cognitive and biomarker outcomes in Latino older adults.

Highlights

Latino bilinguals perform better on measures of processing speed and coding.Latino bilinguals with MCI demonstrate cognitive vulnerability in verbal fluency.Less balanced bilinguals demonstrate greatest vulnerability anchored by Aβ 42/40.

Do Associations Between Vascular Risk and Mild Cognitive Impairment Vary by Race?

Objectives: Given prevalence differences of mild cognitive impairment (MCI) among Black and white older adults, this study aimed to examine whether overall vascular risk factor (VRF) burden and individual VRF associations with amnestic (aMCI) and nonamnestic (naMCI) MCI status varied by Black/white race. Methods: Participants included 2755 older adults without dementia from the ACTIVE study. Comprehensive neuropsychological criteria were used to classify cognitively normal, aMCI, and naMCI. VRFs were primarily defined using subjective report and medication data. Multinomial logistic regression was run predicting MCI subtype. Results: Greater overall VRF burden, high cholesterol, and obesity evinced greater odds of naMCI in Black participants than whites. Across participants, diabetes and hypertension were associated with increased odds of aMCI and naMCI, respectively. Discussion: Results may reflect known systemic inequities on dimensions of social determinants of health for Black older adults. Continued efforts toward examining underlying mechanisms contributing to these findings are critical.

Alzheimer's disease and its related dementias in US Native Americans: A major public health concern

Alzheimer's disease (AD) and Alzheimer's related dementias (ADRD) are growing public health concerns in aged populations of all ethnic and racial groups. AD and ADRD are caused by multiple factors, such as genetic mutations, modifiable and non-modifiable risk factors, and lifestyle. Studies of postmortem brains have revealed multiple cellular changes implicated in AD and ADRD, including the accumulation of amyloid beta and phosphorylated tau, synaptic damage, inflammatory responses, hormonal imbalance, mitochondrial abnormalities, and neuronal loss. These changes occur in both early-onset familial and late-onset sporadic forms. Two-thirds of women and one-third of men are at life time risk for AD. A small proportion of total AD cases are caused by genetic mutations in amyloid precursor protein, presenilin 1, and presenilin 1 genes, and the APOE4 allele is a risk factor. Tremendous research on AD/ADRD, and other comorbidities such as diabetes, obesity, hypertension, and cancer has been done on almost all ethnic groups, however, very little biomedical research done on US Native Americans. AD/ADRD prevalence is high among all ethnic groups. In addition, US Native Americans have poorer access to healthcare and medical services and are less likely to receive a diagnosis once they begin to exhibit symptoms, which presents difficulties in treating Alzheimer's and other dementias. One in five US Native American people who are 45 years of age or older report having memory issues. Further, the impact of caregivers and other healthcare aspects on US Native Americans is not yet. In the current article, we discuss the history of Native Americans of United States (US) and health disparities, occurrence, and prevalence of AD/ADRD, and shedding light on the culturally sensitive caregiving practices in US Native Americans. This article is the first to discuss biomedical research and healthcare disparities in US Native Americans with a focus on AD and ADRD, we also discuss why US Native Americans are reluctant to participate in biomedical research.