Prevalence of dementia in three ethnic groups: the South Florida program on aging and health

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.

Analyzing direct effects of education level and estimated IQ between cognitively intact Mexican Americans and Non-Hispanic whites on a confrontational naming task

Confrontational naming is widely used in diagnosing neurodegenerative disorders like MCI and dementia, and previous research indicates that healthy Non-Hispanic Whites outperform Hispanics in such tasks. However, understanding the factors contributing to score differences among ethnic groups remains limited. This study focuses on cognitively intact Mexican Americans and Non-Hispanic White older adults from the TARCC Hispanic Cohort project. Hierarchical regression analyses reveal that sex, age, ethnicity, education level, and estimated IQ significantly predict performance on the Boston Naming Test (BNT). Notably, education level and estimated IQ more strongly influence BNT performance in Mexican Americans than in Non-Hispanic Whites. When controlling for education level, estimated IQ has a more pronounced impact on BNT performance in aging Mexican Americans compared to Non-Hispanic Whites. Conversely, after controlling for estimated IQ, the influence of education level is weaker for Mexican Americans than Non-Hispanic Whites. These findings emphasize the need for careful evaluation of confrontational naming task scores in diverse ethnic groups, emphasizing the critical role of education and estimated IQ in understanding performance disparities.

Understanding the Perspectives and Needs of Latinx Caregivers of Persons with Alzheimer's Disease in the Appalachians: An Interpretive Phenomenological Approach

Background

Alzheimer's disease and related dementias (ADRD) disproportionately impact Latinx and other communities of color in the United States. The challenges for patients with ADRD and their informal caretakers can be attributed, in part, to the gaps that exist within health care services and systems.

Objective

To understand the perspectives of barriers, beliefs, knowledge, and needs for the Latinx informal caregivers that take care of relatives with ADRD in the Upstate of South Carolina, region of Appalachia.

Methods

This study was approved by the GHS-Prisma Health and Clemson University IRB, Study #Pro00086707. In-depth phone interviews were conducted with a sample of Latinx informal caregivers. A descriptive and interpretive phenomenological approach was used for analysis. Participants were recruited through community partnerships with local organizations.

Results

Salient themes identified in this study included the relevance of caregiver's degree of awareness about the disease and a perspective of Alzheimer's disease as a progressive and degenerative disease. Critical moments identified encompassed challenges related to patient engagement with the outside world, their attitudes, and behaviors, as well as caregiver-related challenges with access to culturally and linguistically relevant resources needed to provide proper care. Caregivers identified several culturally relevant coping strategies used and motivators in providing care for their relatives with ADRD.

Conclusions

Linguistically and culturally sensitive programs and resources that account for knowledge, assets, and needs of Latinx informal caregivers of ADRD patients are needed to improve the quality of care and decrease disparities in health outcomes for Latinx older adults.

Primary care detection of cognitive impairment leveraging health and consumer technologies in underserved US communities: protocol for a pragmatic randomised controlled trial of the MyCog paradigm

INTRODUCTION

Early identification of cognitive impairment (CI), including Alzheimer's disease and related dementias (ADRD), is a top public health priority. Yet, CI/ADRD is often undetected and underdiagnosed within primary care settings, and in health disparate populations. The MyCog paradigm is an iPad-based, self-administered, validated cognitive assessment based on the National Institutes of Health (NIH) Toolbox Cognition Battery and coupled with clinician decision-support tools that is specifically tailored for CI/ADRD detection within diverse, primary care settings.

METHODS AND ANALYSIS

We will conduct a two-arm, primary care practice-randomised (N=24 practices; 45 257 active patients at the proposed practices), pragmatic trial among geographically diverse Oak Street Health sites to test the effectiveness of the MyCog paradigm to improve early detection CI/ADRD among low socioeconomic, black and Hispanic older adults compared with usual care. Participating practices randomised to the intervention arm will impart the MyCog paradigm as a new standard of care over a 3-year implementation period; as the cognitive component for Annual Wellness Visits and for any patient/informant-reported or healthcare provider-suspected cognitive concern. Rates of detected (cognitive test suggesting impairment) and/or diagnosed (relevant International Classification of Diseases-9/10 [ICD-9/10] code) cognitive deficits, impairments or dementias including ADRD will be our primary outcome of study compared between arms. Secondary outcomes will include ADRD severity (ie, mild or later stage), rates of cognitive-related referrals and rates of family member or caregiver involvement in ADRD care planning. We will use generalised linear mixed models to account for clustered study design. Secondary models will adjust for subject, clinic or visit-specific characteristics. We will use mixed-methods approaches to examine fidelity and cost-effectiveness of the MyCog paradigm.

ETHICS AND DISSEMINATION

The Institutional Review Board at Advarra has approved the study protocol (Pro00064339). Results will be published in peer-reviewed journals and summaries will be provided to the funders of the study.

TRIAL REGISTRATION NUMBER

NCT05607732.

Methods of a Study to Assess the Contribution of Cerebral Small Vessel Disease and Dementia Risk Alleles to Racial Disparities in Vascular Cognitive Impairment and Dementia

Background Non-Hispanic Black adults have a higher proportion of vascular cognitive impairment and Alzheimer's disease and related dementias compared with non-Hispanic White adults that may be due to differences in the burden of cerebral small vessel disease and risk alleles for Alzheimer's disease and related dementias. We describe here the methods of an ancillary study to the REGARDS (Reason for Geographic and and Racial Difference in Stroke) study, which will examine the role of magnetic resonance imaging markers of cerebral small vessel disease and vascular as well as genetic risk factors for Alzheimer's disease and related dementias in racial disparity in the prevalence and trajectory of vascular cognitive impairment and dementia in non-Hispanic White and non-Hispanic Black participants. Methods In participants with no prior history of stroke who had an incident stroke or transient ischemic attack after enrollment in the study, magnetic resonance imaging scans will be evaluated using the Standards for Reporting Vascular Changes on Neuroimaging international consensus criteria and automated analysis pipelines for quantification of cerebral small vessel disease. Participants will be genotyped for APOE ε4 and TREM2 risk alleles for Alzheimer's disease and related dementias. The 6-item screener will define global cognitive function and be the primary cognitive outcome. Conclusions With at least 426 non-Hispanic Black and 463 non-Hispanic White participants who have at least 2 prior and 2 poststroke or transient ischemic attack cognitive assessments, we will have at least 80% power to detect a minimum effect size of 0.09 SD change in Z score, with correction for as many as 20 tests (ie, at P<0.0025, after adjusting for up to 20 covariates) for cognitive decline.

Genetics of Alzheimer's Disease in the African American Population

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

Perceptions of the Role of Living Alone in Providing Services to Patients With Cognitive Impairment

Importance

The potential role of living alone in either facilitating or hampering access to and use of services for older adults with cognitive impairment is largely unknown. Specifically, it is critical to understand directly from health care and social services professionals how living alone creates barriers to the access and use of supportive health care and social services for racially and ethnically diverse patients with cognitive impairment.

Objective

To identify the potential role of living alone in the access and use of health care and social services for diverse patients with cognitive impairment by investigating professionals' perceptions of caring for such patients who live alone in comparison with counterparts living with others.

Design, Setting, and Participants

This qualitative study of 76 clinicians, social workers, and other professionals used semistructured interviews conducted between February 8, 2021, and June 8, 2022, with purposively sampled professionals providing services to diverse patients with cognitive impairment in Michigan, California, and Texas.

Main Outcomes and Measures

Clinicians, social workers, and other professionals compared serving patients with cognitive impairment and living alone vs counterparts living with others. An inductive content analysis was used to analyze the interview transcripts.

Results

A total of 76 professionals were interviewed (mean [SD] age, 49.3 [12.7] years); 59 were female (77.6%), 8 were Black or African American (11%), and 35 were White (46%). Participants included physicians, nurses, social workers, and home-care aides, for a total of 20 professions. Participants elucidated specific factors that made serving older adults living alone with cognitive impairment more challenging than serving counterparts living with others (eg, lacking an advocate, incomplete medical history, requiring difficult interventions), as well as factors associated with increased concerns when caring for older adults living alone with cognitive impairment, such as isolation and a crisis-dominated health care system. Participants also identified reasons for systematic unmet needs of older adults living alone with cognitive impairment for essential health care and social services, including policies limiting access and use to public home-care aides.

Conclusions and Relevance

In this qualitative study of professionals' perspectives, findings suggest that living alone is a social determinant of health among patients with cognitive impairment owing to substantial barriers in access to services. Results raised considerable concerns about safety because the US health care system is not well equipped to address the unique needs of older adults living alone with cognitive impairment.

Comprehensive review of task-based neuroimaging studies of cognitive deficits in Alzheimer's disease using electrophysiological methods

With an aging population, cognitive decline and neurodegenerative disorders are an emerging public health crises with enormous, yet still under-recognized burdens. Alzheimer's disease (AD) is the most common type of dementia, and the number of cases is expected to dramatically rise in the upcoming decades. Substantial efforts have been placed into understanding the disease. One of the primary avenues of research is neuroimaging, and while positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) are most common, crucial recent advancements in electrophysiological methods such as magnetoencephalography (MEG) and electroencephalography (EEG) have provided novel insight into the aberrant neural dynamics at play in AD pathology. In this review, we outline task-based M/EEG studies published since 2010 using paradigms probing the cognitive domains most affected by AD, including memory, attention, and executive functioning. Furthermore, we provide important recommendations for adapting cognitive tasks for optimal use in this population and adjusting recruitment efforts to improve and expand future neuroimaging work.

Primary outcome from the augmenting cognitive training in older adults study (ACT): A tDCS and cognitive training randomized clinical trial

BACKGROUND

There is a need for effective interventions to stave off cognitive decline in older adults. Cognitive training has variably produced gains in untrained tasks and daily functioning. Combining cognitive training with transcranial direct current stimulation (tDCS) may augment cognitive training effects; however, this approach has yet to be tested on a large-scale.

OBJECTIVE

This paper will present the primary findings of the Augmenting Cognitive Training in Older Adults (ACT) clinical trial. We hypothesize that receiving active stimulation with cognitive training will result in greater improvements on an untrained fluid cognition composite compared to sham following intervention.

METHODS

379 older adults were randomized, and 334 were included in intent-to-treat analyses for a 12-week multidomain cognitive training and tDCS intervention. Active or sham tDCS was administered at F3/F4 during cognitive training daily for two weeks then weekly for 10 weeks. To assess the tDCS effect, we fitted regression models for changes in NIH Toolbox Fluid Cognition Composite scores immediately following intervention and one year from baseline controlling for covariates and baseline scores.

RESULTS

Across the entire sample, there were improvements in NIH Toolbox Fluid Cognition Composite scores immediately post-intervention and one year following baseline; however, there were no significant tDCS group effects at either timepoint.

CONCLUSIONS

The ACT study models rigorous, safe administration of a combined tDCS and cognitive training intervention in a large sample of older adults. Despite potential evidence of near-transfer effects, we failed to demonstrate an additive benefit of active stimulation. Future analyses will continue to assess the intervention's efficacy by examining additional measures of cognition, functioning, mood, and neural markers.

2023 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease, including prevalence and incidence, mortality and morbidity, use and costs of care, and the overall impact on family caregivers, the dementia workforce and society. The Special Report examines the patient journey from awareness of cognitive changes to potential treatment with drugs that change the underlying biology of Alzheimer's. An estimated 6.7 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, slow or cure AD. Official death certificates recorded 121,499 deaths from AD in 2019, and Alzheimer's disease was officially listed as the sixth-leading cause of death in the United States. 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. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2019, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 145%. This trajectory of deaths from AD was likely exacerbated by the COVID-19 pandemic in 2020 and 2021. More than 11 million family members and other unpaid caregivers provided an estimated 18 billion hours of care to people with Alzheimer's or other dementias in 2022. 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 $339.5 billion in 2022. Its costs, however, extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes - costs that have been aggravated by COVID-19. Members of the paid health care workforce are involved in diagnosing, treating and caring for people with dementia. In recent years, however, a shortage of such workers has developed in the United States. This shortage - brought about, in part, by COVID-19 - has occurred at a time when more members of the dementia care workforce are needed. Therefore, programs will be needed to attract workers and better train health care teams. 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 2023 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $345 billion. The Special Report examines whether there will be sufficient numbers of physician specialists to provide Alzheimer's care and treatment now that two drugs are available that change the underlying biology of Alzheimer's disease.

Pathways of care: a qualitative study of barriers and facilitators to engaging dementia care among underserved and minority populations in the US and Germany

OBJECTIVE

To identify barriers and facilitators to the use of formal dementia services among underserved and minority groups (UMG) in the United States and Germany.

METHOD

Semi-structured qualitative interviews with caregivers (N = 18) of persons with dementia in the United States and Germany. Data were analyzed using thematic analysis.

RESULTS

Caregivers described their experiences in three stages of seeking, initiating, and utilizing care, and different factors served to hinder or enable the use of care services in each stage. The most important factors included limited knowledge about dementia, challenges interacting with healthcare systems, and how closely formal services met the expectations and needs of caregivers, particularly with regard to accommodating cultural or ethnic/racial identity. Caregivers preferred interacting with service care providers who shared a similar identity to receive information or services.

CONCLUSION

Barriers and facilitators to using dementia care services vary by stage of engaging services and may be shared across different healthcare contexts. Targeting specific barriers and strengthening facilitators could help reduce disparities in dementia care among UMG.

Diverse rural caregivers for individuals with Alzheimer's disease or related dementias: analysis of health factors at the individual, interpersonal, and community level

Objectives: Approximately 6.2 million Americans aged 65 or older have Alzheimer's disease or related dementias (ADRD). Unpaid family members and friends provide the bulk of caregiving for these individuals. Caregiving in rural areas adds unique challenges, particularly for ethnically/racially diverse caregivers. This study provides a profile of diverse, rural ADRD caregivers with an emphasis on multi-level factors that influence physical and mental health.Methods: A cross-sectional survey was conducted with 156 diverse rural ADRD caregivers.Results: 65% of participants identified as White/Non-Hispanic (WNH; n = 101) and 35% identified as ethnically/racially diverse (ERD; n = 55). The majority of participants reported economic deprivation. More ERD caregivers were uninsured and had at least one chronic health condition. Higher proportions of ERD caregivers smoked cigarettes, consumed alcohol regularly, and had not seen or talked to a doctor in the previous year. There were no ethnic/racial group differences in stress, anxiety, depressive symptoms, subjective health, or sleep quality.Conclusion: Rural caregivers, regardless of ethnicity/race, may benefit from extra supports in order to maintain optimal health. Further research is needed to disentangle the complex relationship between culture, caregiving, and health.

Screening and enrollment of underrepresented ethnocultural and educational populations in the Alzheimer's Disease Neuroimaging Initiative (ADNI)

INTRODUCTION

An analysis of the ethnocultural and socioeconomic composition of Alzheimer's Disease Neuroimaging Initiative (ADNI) participants is needed to assess the generalizability of ADNI data to diverse populations.

METHODS

ADNI data collected between October 2004 and November 2020 were used to determine ethnocultural and educational composition of the sample and differences in the following metrics: screening, screen fails, enrollment, biomarkers.

RESULTS

Of 3739 screened individuals, 11% identified as being from ethnoculturally underrepresented populations (e.g., Black, Latinx) and 16% had <12 years of education. Of 2286 enrolled participants, 11% identified as ethnoculturally underrepresented individuals and 15% had <12 years of education. This participation is considerably lower than US Census data for adults 60+ (ethnoculturally underrepresented populations: 25%; <12 years of education: 4%). Individuals with <12 years of education failed screening at a higher rate.

DISCUSSION

Our findings suggest that ADNI results may not be entirely generalizable to ethnoculturally diverse and low education populations.

Examination of the reliability and feasibility of two smartphone applications to assess executive functioning in racially diverse older adults

Inclusion of Black participants in clinical research is a national priority. Mobile applications and remote data collection may increase study access for diverse populations. This study examined the reliability and feasibility of two mobile smartphone application-based cognitive measures in a diverse middle aged and older adult sample. Black (n = 44; Mage = 59.93) and non-Hispanic white (NHW; n = 50; Mage = 61.06) participants completed traditional paper-based neuropsychological testing and two app-based measures, Arrows and Number Match. Intraclass correlations demonstrated poor to moderate reliability (range: .417-.569) between performance on the app-based versions and performance on the traditional versions. Performance score differences by racial group were not statistically significant. Both Black and NHW participants rated the app-based measures as feasible and acceptable, though Black participants endorsed a stronger likelihood of future use. These findings add to the growing literature on remote cognitive testing .

Moving beyond disclosure: Stages of care in preclinical Alzheimer's disease biomarker testing

Alzheimer's disease (AD) begins with an asymptomatic "preclinical" phase, in which abnormal biomarkers indicate risk for developing cognitive impairment. Biomarker information is increasingly being disclosed in research settings, and is moving toward clinical settings with the development of cheaper and non-invasive testing. Limited research has focused on the safety and psychological effects of disclosing biomarker results to cognitively unimpaired adults. However, less is known about how to ensure equitable access and robust counseling for decision-making before testing, and how to effectively provide long-term follow-up and risk management after testing. Using the framework of Huntington's disease, which is based on extensive experience with disclosing and managing risk for a progressive neurodegenerative condition, this article proposes a conceptual model of pre-disclosure, disclosure, and post-disclosure phases for AD biomarker testing. Addressing research questions in each phase will facilitate the transition of biomarker testing into clinical practice.

2022 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including incidence and prevalence, mortality and morbidity, use and costs of care, and the overall impact on family caregivers, the dementia workforce and society. The Special Report discusses consumers' and primary care physicians' perspectives on awareness, diagnosis and treatment of mild cognitive impairment (MCI), including MCI due to Alzheimer's disease. An estimated 6.5 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, slow or cure AD. Official death certificates recorded 121,499 deaths from AD in 2019, the latest year for which data are available. Alzheimer's disease was officially listed as the sixth-leading cause of death in the United States in 2019 and the seventh-leading cause of death in 2020 and 2021, when COVID-19 entered the ranks of the top ten causes of death. Alzheimer's remains the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2019, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 145%. More than 11 million family members and other unpaid caregivers provided an estimated 16 billion hours of care to people with Alzheimer's or other dementias in 2021. 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 $271.6 billion in 2021. Its costs, however, extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes - costs that have been aggravated by COVID-19. Members of the dementia care workforce have also been affected by COVID-19. As essential care workers, some have opted to change jobs to protect their own health and the health of their families. However, this occurs at a time when more members of the dementia care workforce are needed. 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 2022 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $321 billion. A recent survey commissioned by the Alzheimer's Association revealed several barriers to consumers' understanding of MCI. The survey showed low awareness of MCI among Americans, a reluctance among Americans to see their doctor after noticing MCI symptoms, and persistent challenges for primary care physicians in diagnosing MCI. Survey results indicate the need to improve MCI awareness and diagnosis, especially in underserved communities, and to encourage greater participation in MCI-related clinical trials.

Counterfactual analysis of differential comorbidity risk factors in Alzheimer's disease and related dementias

Alzheimer's disease and related dementias (ADRD) is a multifactorial disease that involves several different etiologic mechanisms with various comorbidities. There is also significant heterogeneity in the prevalence of ADRD across diverse demographics groups. Association studies on such heterogeneous comorbidity risk factors are limited in their ability to determine causation. We aim to compare counterfactual treatment effects of various comorbidity in ADRD in different racial groups (African Americans and Caucasians). We used 138,026 ADRD and 1:1 matched older adults without ADRD from nationwide electronic health records, which extensively cover a large population's long medical history in breadth. We matched African Americans and Caucasians based on age, sex, and high-risk comorbidities (hypertension, diabetes, obesity, vascular disease, heart disease, and head injury) to build two comparable cohorts. We derived a Bayesian network of 100 comorbidities and selected comorbidities with potential causal effect to ADRD. We estimated the average treatment effect (ATE) of the selected comorbidities on ADRD using inverse probability of treatment weighting. Late effects of cerebrovascular disease significantly predisposed older African Americans (ATE = 0.2715) to ADRD, but not in the Caucasian counterparts; depression significantly predisposed older Caucasian counterparts (ATE = 0.1560) to ADRD, but not in the African Americans. Our extensive counterfactual analysis using a nationwide EHR discovered different comorbidities that predispose older African Americans to ADRD compared to Caucasian counterparts. Despite the noisy and incomplete nature of the real-world data, the counterfactual analysis on the comorbidity risk factors can be a valuable tool to support the risk factor exposure studies.

Cardio-Dance Exercise to Improve Cognition and Mood in Older African Americans: A Propensity-Matched Cohort Study

The current study sought to determine the influence of initial sleep quality and body mass index on the cognitive and mood outcomes of a community-based cardio-dance exercise program. Thirty-two older African Americans who participated in a 5-month cardio-dance exercise program were propensity-matched to 32 no-contact controls. Participants completed neuropsychological tests of attention, executive function, and memory and a self-reported depression measure at baseline and post-test. Among exercise participants, we observed significant improvements in depression (baseline = 6.16 ± 5.54, post-test = 4.66 ± 4.89, η p 2 = . 12 , p = .009) and attention (baseline = 40.53 ± 14.01, post-test = 36.63 ± 13.29, η p 2 = . 12 , p = .009) relative to controls. Improvements in executive function and attention were most pronounced among exercise participants with poor sleep quality (baseline = 7.71 ± 1.25, post-test = 8.29 ± 2.06, η p 2 = . 41 , p = .04) and with obesity (baseline = 38.05 ± 12.78, post-test = 35.67 ± 13.82, η p 2 = . 30 , p = .001), respectively. This study provides novel evidence that exercise has the potential to improve depression in older African Americans. For those with poor sleep quality or obesity, exercise can also improve some cognitive outcomes.

An Elicitation Study to Understand Black, Hispanic, and Male Older Adults' Willingness to Participate in Alzheimer's Disease-Focused Research Registries

BACKGROUND

There is a lack of racial, ethnic, and sex diversity in recruitment research registries and Alzheimer's disease (AD) research studies and trials. Theory-based recruitment messages may provide an opportunity to increase study participant diversity in AD research studies and trials.

OBJECTIVE

To identify behavioral, normative, and control beliefs that are associated with joining an AD-focused recruitment registry among historically underrepresented groups.

METHOD

Using a Reasoned Action Approach, we conducted 60 semi-structured phone interviews in 2020 among White, Black, and Hispanic adults ages 49-79 years in Philadelphia, PA. Underlying beliefs were elicited for the target behavior of "signing up to be on a registry for brain health research studies in the next month." Percentages based on counts are reported for the overall sample and by race and ethnicity and sex.

RESULTS

Participants were most concerned that if they were to sign up for a registry, they would be asked to participate in experimental studies. Advancing science to help others was a commonly reported positive belief about signing up. Participants' children and friends/neighbors were important from a normative perspective. Barriers to enrollment focused on logistical concerns and inconvenient sign-up processes, including using a computer. Results show generally few racial and ethnic or sex group differences.

CONCLUSION

The elicited beliefs from underrepresented groups offer a basis for understanding the behavior of signing up for research registries. However, there were few differences between the groups. Implications for outreach and recruitment are discussed.

Challenge of a dual burden in rapidly aging Delaware: Comorbid chronic conditions and subjective cognitive decline

BACKGROUND

Epidemiologic trends forecast a "dual burden"- increase in both physical chronic diseases and Alzheimer's disease (AD)- for Delaware. Estimating the burden and characteristics of this "dual burden" is critical. Cognizant of the unavailability of precise models to measure AD, SCD-a population-based measure- was used as an alternative. The primary objective was to delineate selected chronic conditions among Delaware adults with SCD in order to present: (i) prevalence of SCD by select sociodemographic characteristics, (ii) compare the prevalence of chronic conditions among people with and without SCD, and (iii) compare the prevalence of SCD associated functional limitations in Delawareans with and without comorbid chronic conditions.

METHODS

Combined data (2016 and 2020) for Delaware were obtained from the Behavioral Risk Factor Surveillance System. Analyses included 4,897 respondents aged 45 years or older who answered the SCD screening question as "yes" (n = 430) or "no" (n = 4,467). Descriptive statistics examined sociodemographic characteristics and chronic conditions in Delawareans with and without SCD.

RESULTS

Overall, 8.4% (CI: 7.4-9.5) of Delaware adults reported SCD. Delawareans with SCD were more likely to be in the younger age group (45-54 years), less educated, low income and living alone. Over 68 percent had not discussed cognitive decline with a health care professional. More than three in four Delawareans with SCD had a 1.5 times higher prevalence of having any one of the nine select chronic conditions as compared to those without SCD. Adults with SCD and at least one comorbid chronic condition were more likely to report SCD-related functional limitations.

CONCLUSIONS

Delaware cannot afford to postpone public policies to address the dual burden of SCD and chronic conditions. Results from this study can help public health stakeholders in Delaware to be informed and prepared for the challenges associated with cognitive decline and comorbidity.

Cognitive impairment in racially/ethnically diverse older adults: Accounting for sources of diagnostic bias

INTRODUCTION

The Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study enrolled Asian, Black, Latino, and White adults ages 65+ without prior dementia diagnosis (N = 1709). We evaluated the prevalence of cognitive impairment (mild cognitive impairment or dementia) accounting for potential biases.

METHODS

A random subgroup (N = 541) received clinical evaluation and others were evaluated if they failed a cognitive screen. Diagnoses were made under two conditions: (1) demographics-blind, based on clinical exam and demographically adjusted neuropsychological test scores; and (2) all available information (clinical exam, demographics, and adjusted and unadjusted test scores).

RESULTS

Cognitive impairment prevalence was 28% for blinded-adjusted diagnosis and 25% using all available information. Black participants had higher impairment rates than White (both conditions) and Latino (blinded-adjusted diagnosis) participants. Incomplete assessments negatively biased prevalence estimates for White participants.

DISCUSSION

Racial/ethnic disparities in cognitive impairment were amplified by attrition bias in White participants but were unaffected by type of test norms and diagnosticians' knowledge of demographics.

Female specific risk factors for the development of Alzheimer's disease neuropathology and cognitive impairment: Call for a precision medicine approach

Alzheimer's disease (AD) includes a long asymptomatic stage, which precedes the formal diagnosis of dementia. AD biomarker models provide a framework for precision medicine approaches during this stage. However, such approaches have ignored the possible influence of sex on cognition and brain health, despite female sex noted as a major risk factor. Since AD-related changes may emerge in midlife, intervention efforts are being redirected around this period. Midlife coincides with several endocrinological changes, such as the menopausal transition experienced by women. In this narrative review, we discuss evidence for sex-differences in AD neuropathological burden and outline key endocrinological mechanisms for both sexes, focussing on hormonal events throughout the lifespan that may influence female susceptibility to AD neuropathology and dementia onset. We further consider common non-modifiable (genetic) and modifiable (lifestyle and health) risk factors, highlighting possible sex-dependent differential effects for the AD disease course. Finally, we evaluate the studies selected for this review demonstrating sex-differences in cognitive, pathological and health factors, summarising the state of sex differences in AD risk factors. We further provide recommendations for targeted research on female-specific risk factors, to inform personalised strategies for AD-prevention and the promotion of female brain health.

Imaging-based indices of Neuropathology and gait speed decline in older adults: the atherosclerosis risk in communities study

Imaging markers of cerebrovascular disease and Alzheimer's disease (AD) are implicated in mobility impairment in older adults, but few studies have examined these relationships longitudinally in a racially-diverse population-based sample. At Visit 5 (2011-13) of the ARIC Study, 1859 participants had usual pace gait speed (cm/s) assessed and brain MRI (mean age = 76.3, 28.5% Black) and PET (n = 343; mean age = 75.9, 42.6% Black) measures including total/regional brain volume (cm3), white matter hyperintensities (WMH; cm3), infarcts (present/absent), microbleeds (count) and global beta-amyloid (Aβ). Participants returned at Visit 6 (n = 1264, 2016-17) and Visit 7 (n = 1108, 2018-19) for follow-up gait speed assessments. We used linear regression to estimate effects of baseline infarct presence, higher microbleed count, and a one interquartile range (IQR) poorer measures of continuous predictors (-1 IQR total brain volume, temporal-parietal lobe meta region of interest(ROI); +1 IQR WMH volume, global Aβ SUVR) on cross-sectional gait speed and change in gait speed adjusting for age, sex, education, study site, APOE e4, estimated intracranial volume, BMI, and cardiovascular risk factors. Cross-sectionally, slower gait speed outcome was associated with higher WMH volume, -3.38 cm/s (95%CI:-4.71, -2.04), infarct presence, -5.60 cm/s (-7.69, -3.51), microbleed count, -2.20 cm/s (-3.20, -0.91), smaller total brain volume, -9.26 cm/s (-12.1, -6.43), and smaller temporal-parietal lobe ROI -6.28 cm/s (-8.28, -4.28). Longitudinally, faster gait speed outcome decline was associated with higher WMH volume, -0.27 cm/s/year, (-0.51, -0.03) and higher global Aβ SUVR, -0.62 cm/s/year (-1.20, -0.03). Both cerebrovascular and AD pathology may contribute to mobility decline commonly seen with aging.

Alzheimer's disease: a step closer to understanding type 3 diabetes in African Americans

Alzheimer's disease (AD) is the fourth leading cause of death in the United States and the most common cause of adult-onset dementia. Recent results suggest an increased prevalence and severity in African Americans compared to Caucasians. Our understanding of the potential mechanism(s) underlying this ethnicity difference is limited. We previously described ethnicity-related differences in levels of neurodegenerative proteins and cytokines/chemokines in the BA21 region of African Americans and Caucasians with AD. Here, similar multiplex assays were used to examine those endpoints in patient postmortem cerebrospinal fluid (CSF). Additionally, we measured levels of C-peptide, ghrelin, gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), glucagon, insulin, leptin, PAI-1, resistin, and visfatin using a human diabetes 10-plex assay. The cytokine and chemokine assays revealed that levels of 26 chemokines or cytokines differed significantly with ethnicity, and three of those were significantly associated with gender. The neurodegenerative disease panel indicated that levels of soluble RAGE were significantly elevated in African Americans compared to Caucasians. All measures in the diabetes disease panel assay were significantly elevated in African Americans: ghrelin, GIP, GLP-1, glucagon, insulin, and visfatin. Through peripheral sample analysis, these results provide further evidence that ethnicity is critically involved in the manifestation of AD.

Sex, Race, and Age Differences in Prevalence of Dementia in Medicare Claims and Survey Data

OBJECTIVES

This study provides the first comparison of trends in dementia prevalence in the U.S. population using 3 different dementia ascertainments/data sources: neuropsychological assessment, cognitive tests, and diagnosis codes from Medicare claims.

METHODS

We used data from the nationally representative Health and Retirement Study and Aging, Demographics, and Memory Study, and a 20% random sample of Medicare beneficiaries. We compared dementia prevalence across the 3 sources by race, gender, and age. We estimated trends in dementia prevalence from 2006 to 2013 based on cognitive tests and diagnosis codes utilizing logistic regression.

RESULTS

Dementia prevalence among older adults aged 70 and older in 2004 was 16.6% (neuropsychological assessment), 15.8% (cognitive tests), and 12.2% (diagnosis codes). The difference between dementia prevalence based on cognitive tests and diagnosis codes diminished in 2012 (12.4% and 12.9%, respectively), driven by decreasing rates of cognitive test-based and increasing diagnosis codes-based dementia prevalence. This difference in dementia prevalence between the 2 sources by sex and for age groups 75-79 and 90 and older vanished over time. However, there remained substantial differences across measures in dementia prevalence among blacks and Hispanics (10.9 and 9.8 percentage points, respectively) in 2012.

DISCUSSION

Our results imply that ascertainment of dementia through diagnosis may be improving over time, but gaps across measures among racial/ethnic minorities highlight the need for improved measurement of dementia prevalence in these populations.

Associations between education and dementia in the Caribbean and the United States: An international comparison

INTRODUCTION

Despite high dementia prevalence in Hispanic populations globally, especially Caribbean Hispanics, no study has comparatively examined the association between education and dementia among Hispanics living in the Caribbean Islands and older adults in the United States.

METHODS

We used data on 6107 respondents aged 65 and older in the baseline wave of the population-based and harmonized 10/66 survey from Cuba, the Dominican Republic, and Puerto Rico, collected between 2003 and 2008, and 11,032 respondents aged 65 and older from the U.S.-based Health and Retirement Study data in 2014, a total of 17,139 individuals. We estimated multivariable logistic regression models examining the association between education and dementia, adjusted for age, income, assets, and occupation. The models were estimated separately for the Caribbean population (pooled and by setting) and the U.S. population by race/ethnicity (Hispanic, Black, and White), followed by pooled models across all populations.

RESULTS

In the Caribbean population, the relative risk of dementia among low versus high educated adults was 1.45 for women (95% confidence interval [CI] 1.17, 1.74) and 1.92 (95% CI 1.35, 2.49) for men, smaller compared to those in the United States, especially among non-Hispanic Whites (women: 2.78, 95% CI 1.94, 3.61; men: 5.98, 95% CI 4.02, 7.95).

DISCUSSION

The differential associations between education and dementia across the Caribbean and US settings may be explained by greater disparities in social conditions in the United States compared to the Caribbean, such as access to health care, healthy behaviors, and social stressors, which serve as potentially important mediators.

Racial and ethnic disparities in subjective cognitive decline: a closer look, United States, 2015-2018

BACKGROUND

Subjective cognitive decline (SCD), characterized by self-experience of deterioration in cognitive performance may be a precursor to Alzheimer's disease (AD). Given the association of AD with dependence and disability for a long duration, earlier the detection, the sooner people and their families can receive information regarding better management. It is critical to explore disparities amongst racial and ethnic populations with SCD in order to facilitate targeted interventions. The primary objective was to identify disparities in prevalence of SCD amongst Whites, Blacks and Hispanics by select sociodemographic characteristics and functional limitations in a U.S. population-based sample of non-institutionalized adults aged 45 and older. The secondary objective was to assess the association between SCD and select chronic conditions (angina, heart attack, stroke, diabetes, high blood pressure and high cholesterol) by race/ethnicity.

METHODS

Combined data (2015-2018) were obtained from the Behavioral Risk Factor Surveillance System (BRFSS) to conduct a population -based study. Analyses included 179,852 respondents aged 45 years or older who answered the SCD screening question as "yes" (n = 19,276) or "no" (n = 160,576). Descriptive statistics examined sociodemographic characteristics including functional limitations amongst racial/ethnic groups with SCD. Association of SCD with chronic conditions by race/ethnicity was also calculated.

RESULTS

Overall, 10.8% (CI: 10.6-11.1) of adults aged 45 years or older reported SCD.10.7% Whites, 12.3% Blacks and 9.9% Hispanics experienced SCD. Blacks and Hispanics with SCD were more likely to be in the younger age group (45-54 years), less educated, low income, without access to health care, living alone and with functional limitations. Only half had discussed cognitive decline with a health care professional. Prevalence of selected chronic conditions was significantly higher in all racial/ethnic groups with SCD.

CONCLUSIONS

Demographic trends predict a larger proportion of Hispanics and Blacks with SCD in the coming years. This information can lead to identification of opportunities for addressing negative SCD outcomes in minorities affected by inequitable conditions.

2021 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including incidence and prevalence, mortality and morbidity, use and costs of care, and the overall impact on caregivers and society. The Special Report discusses the challenges of providing equitable health care for people with dementia in the United States. An estimated 6.2 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, slow or cure AD. Official death certificates recorded 121,499 deaths from AD in 2019, the latest year for which data are available, making Alzheimer's the sixth-leading cause of death in the United States and the fifth-leading cause of death among Americans age 65 and older. Between 2000 and 2019, deaths from stroke, heart disease and HIV decreased, whereas reported deaths from AD increased more than 145%. This trajectory of deaths from AD was likely exacerbated in 2020 by the COVID-19 pandemic. More than 11 million family members and other unpaid caregivers provided an estimated 15.3 billion hours of care to people with Alzheimer's or other dementias in 2020. 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 $256.7 billion in 2020. Its costs, however, extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes - costs that have been aggravated by COVID-19. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are more than three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 23 times as great. Total payments in 2021 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $355 billion. Despite years of efforts to make health care more equitable in the United States, racial and ethnic disparities remain - both in terms of health disparities, which involve differences in the burden of illness, and health care disparities, which involve differences in the ability to use health care services. Blacks, Hispanics, Asian Americans and Native Americans continue to have a higher burden of illness and lower access to health care compared with Whites. Such disparities, which have become more apparent during COVID-19, extend to dementia care. Surveys commissioned by the Alzheimer's Association recently shed new light on the role of discrimination in dementia care, the varying levels of trust between racial and ethnic groups in medical research, and the differences between groups in their levels of concern about and awareness of Alzheimer's disease. These findings emphasize the need to increase racial and ethnic diversity in both the dementia care workforce and in Alzheimer's clinical trials.

Evaluation of Selective Survival and Sex/Gender Differences in Dementia Incidence Using a Simulation Model

IMPORTANCE

Dementia research is susceptible to bias arising from selective survival, a process that results in individuals with certain characteristics disproportionately surviving to old age. Spurious associations between risk factors and dementia may be induced when factors associated with longer survival also influence dementia incidence.

OBJECTIVE

To assess the role of selective survival in explaining reported sex/gender differences in dementia incidence.

DESIGN, SETTING, AND PARTICIPANTS

This decision analytical model used a simulated cohort of US participants aged 50 years and without dementia at baseline followed up for incident dementia through age 95 years. Selective survival was induced by a selection characteristic (eg, childhood social disadvantage or Alzheimer genetic risk) that influenced both mortality and dementia incidence at varying magnitudes. Data analysis was performed from April 2018 to May 2020.

EXPOSURE

Sex/gender, conceptualized as the combination of biological sex and social consequences of gender.

MAIN OUTCOMES AND MEASURES

Dementia incidence rate ratios (IRRs) for women compared with men. In all simulations, it was assumed that there would be no true effect of sex/gender on dementia incidence; all observed sex/gender differences were due to selective survival.

RESULTS

At baseline, the simulation included 100 000 participants aged 50 years (51 000 [51%] women, mirroring the 1919-1921 US birth cohort of non-Latino White individuals at age 50 years); distributions of the selection characteristic were standard normal (mean [SD], 0.0 [1.0]). Observed sex/gender differences in dementia incidence in individuals aged 85 years or older ranged from insignificant (IRR, 1.00; 95% CI, 0.91-1.11) to consistent with sex/gender differences (20% higher risk for women [IRR, 1.20; 95% CI, 1.08-1.32]) reported in an extant study. Simulations in which bias was large enough to explain prior findings required moderate to large differential effects of selective survival (eg, hazard ratio for selection characteristic on mortality at least 2.0 among men, no effect among women).

CONCLUSIONS AND RELEVANCE

These results suggest that selective survival may contribute to observed sex/gender differences in dementia incidence but do not preclude potential contributions of sex/gender-specific mechanisms. Further research on plausibility of selection characteristics with outcomes of the magnitude required for selective survival to explain sex/gender differences in dementia incidence and sex/gender-specific mechanisms represent an opportunity to understand prevention and treatment of dementia.

Ethnic Differences in Dementia Risk: A Systematic Review and Meta-Analysis

Background:

Globally around 50 million people have dementia. Risk factors for dementia such as hypertension and diabetes are more common in Black, Asian, and other ethnic minorities. There are also marked ethnic inequalities in care seeking, likelihood of diagnosis, and uptake of treatments for dementia. Nevertheless, ethnic differences in dementia incidence and prevalence remain under-explored.

Objective:

To examine published peer-reviewed observational studies comparing age-specific or age-adjusted incidence or prevalence rates of dementia between at least two ethnic groups.

Methods:

We searched seven databases on 1 September 2019 using search terms for ethnicity, dementia, and incidence or prevalence. We included population-based studies comparing incidence or prevalence of dementia after accounting for age of at least two ethnic groups in adults aged 18 or more. Meta-analysis was conducted for eligible ethnic comparisons.

Results:

We included 12 cohort studies and seven cross-sectional studies. Thirteen were from the US, and two studies each from the UK, Singapore, and Xinjiang Uyghur Autonomous Region in China. The pooled risk ratio for dementia incidence obtained from four studies comparing Black and White ethnic groups was 1.33 (95% CI 1.07–1.65; I-squared = 58.0%). The pooled risk ratio for dementia incidence comparing the Asian and White ethnic groups was 0.86 (95% CI 0.728–1.01; I-squared = 43.9%). There was no difference in the incidence of dementia for Latino ethnic group compared to the White ethnic group.

Conclusion:

Evidence to date suggest there are ethnic differences in risk of dementia. Better understanding of the drivers of these differences may inform efforts to prevent or treat dementia.

Plasma Biomarkers of Alzheimer's Disease in African Americans

Background/Objective:

The aim of this study was to determine if plasma concentrations of 5 surrogate markers of Alzheimer’s disease (AD) pathology and neuroinflammation are associated with disease status in African Americans.

Methods:

We evaluated 321 African Americans (159 AD, 162 controls) from the Florida Consortium for African-American Alzheimer’s Disease Studies (FCA³DS). Five plasma proteins reflecting AD neuropathology or inflammation (Aβ₄₂, tau, IL6, IL10, TNFα) were tested for associations with AD, age, sex, APOE and MAPT genotypes, and for pairwise correlations.

Results:

Plasma tau levels were higher in AD when adjusted for biological and technical covariates. APOEɛ4 was associated with lower plasma Aβ₄₂ and tau levels. Older age was associated with higher plasma Aβ₄₂, tau, and TNFα. Females had lower IL10 levels. Inflammatory proteins had strong pairwise correlations amongst themselves and with Aβ₄₂.

Conclusion:

We identified effects of demographic and genetic variants on five potential plasma biomarkers in African Americans. Plasma inflammatory biomarkers and Aβ₄₂ may reflect correlated pathologies and elevated plasma tau may be a biomarker of AD in this population.

Therapeutic implications of hypothalamic-pituitaryadrenal-axis modulation in Alzheimer's disease: A narrative review of pharmacological and lifestyle interventions

With disease-modifying treatments for Alzheimer's disease (AD) still elusive, the search for alternative intervention strategies has intensified. Growing evidence suggests that dysfunction in hypothalamic-pituitaryadrenal-axis (HPAA) activity may contribute to the development of AD pathology. The HPAA, may therefore offer a novel target for therapeutic action. This review summarises and critically evaluates animal and human studies investigating the effects of pharmacological and non-pharmacological intervention on HPAA modulation alongside cognitive performance. The interventions discussed include glucocorticoid receptor antagonists and 11β-hydroxysteroid dehydrogenase inhibitors as well as lifestyle treatments such as physical activity, diet, sleep and contemplative practices. Pharmacological HPAA modulators improve pathology and cognitive deficit in animal AD models, but human pharmacological trials are yet to provide definitive support for such benefits. Lifestyle interventions may offer promising strategies for HPAA modification and cognitive health, but several methodological caveats across these studies were identified. Directions for future research in AD studies are proposed.

Comparing fluid biomarkers of Alzheimer's disease between African American or Black African and white groups: A systematic review and meta-analysis

RATIONALE

Biomarker research for Alzheimer's disease (AD) has grown rapidly in recent years, ensuing the integration of the AD fluid biomarker profile: Aβ1-42, t-tau, and p-tau₁₈₁, into clinical and research criteria. However, current insights of AD arise almost exclusively from studies on white individuals. Some studies have revealed that epidemiology, clinical features, and genetics of AD show variations between individuals from black and white backgrounds, conveying the importance of ethnoracial differences, and the possibility of such differences also influencing AD biomarker levels. This systematic review explored whether AD fluid biomarker levels differ between African American (AA) or Black African and white groups.

AIM

To compare AD fluid biomarkers (Aβ1-42, p-tau₁₈₁, and t-tau) levels between AA or Black Africans and white individuals.

METHOD

PubMed, Scopus, and other sources were explored for studies that quantified AD biomarkers in biological fluid from whites and AA or Black African groups. Meta-analyses were performed to find the standardized mean difference for biomarkers that were quantified in ≥3 studies.

RESULTS

Five studies were included; studies on Black Africans were not found. The meta-analyses found CSF t-tau and p-tau₁₈₁ were consistently lower in AA than white individuals, in samples with normal cognition or with mild cognitive impairment/dementia.

CONCLUSIONS

The meta-analyses found significant differences for CSF tau between AA and white individuals with normal cognition and within the dementia spectrum, expressing the importance of taking into account ethnoracial factors when interpreting CSF AD biomarkers levels. However, the generalisability of these differences is restricted by small samples' size, lack of unified methodologies and recruitment's biases within studies; further large multicentre studies with harmonized protocols and sufficient power are imperative to investigate the extent of ethnoracial differences across the spectrum of cognitive decline, with vaster efforts necessary to diversify recruitment.

Framework for creating storytelling materials to promote African American/Black adult enrollment in research on Alzheimer's disease and related disorders

INTRODUCTION

African American/Black adults are severely underrepresented in basic, clinical, and behavioral research studies in Alzheimer's disease and related disorders (ADRD). Innovative, evidence-based, and culturally salient strategies can maximize the recruitment of African American/Black adults into ADRD research.

METHODS

We conducted and analyzed semi-structured interviews to capture the research participation stories of African American/Black participants and study partners from the University of Pittsburgh's Alzheimer's Disease Research Center. The themes and messaging principles generated through this process informed the development of video- and text-based materials that were evaluated for community member acceptance using focus groups.

RESULTS

Focus group individuals (N = 36) generally favorably rated the video and text materials, characterizing them as "interesting," "realistic," and "convincing."

DISCUSSION

Capturing the narratives of African American/Black research participants is a critical component to developing culturally relevant materials for broader dissemination and is essential to advancing beyond information-only recruitment approaches, which tend to rely disproportionately on negative messages.

Defining and predicting transdiagnostic categories of neurodegenerative disease

The prevalence of concomitant proteinopathies and heterogeneous clinical symptoms in neurodegenerative diseases hinders the identification of individuals who might be candidates for a particular intervention. Here, by applying an unsupervised clustering algorithm to post-mortem histopathological data from 895 patients with degeneration in the central nervous system, we show that six non-overlapping disease clusters can simultaneously account for tau neurofibrillary tangles, α-synuclein inclusions, neuritic plaques, inclusions of the transcriptional repressor TDP-43, angiopathy, neuron loss and gliosis. We also show that membership to the six transdiagnostic disease clusters, which explains more variance in cognitive phenotypes than can be explained by individual diagnoses, can be accurately predicted from scores of the Mini-Mental Status Exam, protein levels in cerebrospinal fluid, and genotype at the APOE and MAPT loci, via cross-validated multiple logistic regression. This combination of unsupervised and supervised data-driven tools provides a framework that could be used to identify latent disease subtypes in other areas of medicine.

Diagnostic accuracy of the repeatable battery of the assessment of neuropsychological status update, Spanish version, in predicting Alzheimer's disease among Hispanic older adults in the United States reporting memory problems

Objectives: There are few standardized, Spanish-language diagnostic tools to help identify Hispanic persons at early stages of Alzheimer's disease (AD). This study evaluated the accuracy of the Spanish version of the Repeatable Battery for the Assessment of Neuropsychological Status-Update (RBANS) in predicting AD in older Hispanic adults in the United States reporting memory problems.Methods: We analyzed data from age, sex, and education level propensity score-matched Hispanic memory clinic patients with (n = 38) and without (n = 38) a clinical diagnosis of AD. Estimates of diagnostic accuracy included sensitivity, specificity, predictive value, and receiver operating characteristic analysis.Results: After controlling for sex and matched pairs, the Total Scale score [area under curve (AUC) = 0.7417] and the Immediate (AUC = 0.7258) and Delayed (AUC = 0.7735) Memory index scores provided better estimates of diagnostic accuracy than Language, Attention, and Visuospatial/Constructional index scores. A minus 2-standard deviation (SD) cut point enhanced the predictive probability of the Delayed Memory index score. A cut point of -1.5 SD optimized the predictive probability of the Total Scale score.Conclusions: These results suggest that optimal cutoff values for the RBANS Delayed Memory index and Total Scale scores that may help identify Hispanic patients with AD as part of a comprehensive diagnostic AD assessment.

Effects of sex, race, ethnicity, and education on online aging research participation

INTRODUCTION

This study aimed to identify the relationship of sociodemographic variables with older adults participation in an online registry for recruitment and longitudinal assessment in cognitive aging.

METHODS

Using Brain Health Registry (BHR) data, associations between sociodemographic variables (sex, race, ethnicity, education) and registry participation outcomes (task completion, willingness to participate in future studies, referral/enrollment in other studies) were examined in adults aged 55+ (N = 35,919) using logistic regression. All models included sex, race, ethnicity, education, age, and subjective memory concern.

RESULTS

Non-white race, being Latino, and lower educational attainment were associated with decreased task completion and enrollment in additional studies. Results for sex were mixed.

DISCUSSION

The findings provide novel information about engagement in online aging-related registries, and highlight a need to develop improved engagement strategies targeting underrepresented sociodemographic groups. Increasing registry diversity will allow researchers to refer more representative populations to Alzheimer's and related dementias prevention and treatment trials.

Subjective Memory Complaints in White and African American Participants

OBJECTIVE

Subjective memory complaints (SMCs) are associated with mild cognitive impairment and dementia but are understudied in African Americans (AAs). We compared SMC endorsement in white and AA participants and evaluated predictors of diagnostic progression.

METHODS

Initial visit variables, including SMC and memory performance, were compared within a cognitively normal race-matched sample of white and AA participants (N_total = 912; 456_{each race}) to assess the presence and predictors of SMC, the predictors of future diagnostic progression, and the change in memory performance over time.

RESULTS

More white (32.9%) than AA (24.3%) participants reported SMC (P < .01, ϕ = -.10). Subjective memory complaint was predicted by memory performance (B = -0.03, standard error [SE] = 0.013, odds ratio [OR] = .968, P < .05) and race (B = -0.99, SE = 0.080, OR = .373, P < .001). Subjective memory complaints and memory performance were associated with progression, χ² (3, n = 912) = 102.37, P < .001. African American race (-2.05 ± 0.24 SE) and SMC (-0.45 ± 0.21 SE) were associated with worse memory performance at baseline and over time, χ²(3) = 13.54, P < .01.

CONCLUSIONS

In contrast to previous research, our study found that SMC is associated with diagnostic progression and objective memory declines in both white and AA participants.

2020 Alzheimer's disease facts and figures

This article describes the public health impact of Alzheimer's disease (AD), including incidence and prevalence, mortality and morbidity, use and costs of care, and the overall impact on caregivers and society. The Special Report discusses the future challenges of meeting care demands for the growing number of people living with Alzheimer's dementia in the United States with a particular emphasis on primary care. By mid-century, the number of Americans age 65 and older with Alzheimer's dementia may grow to 13.8 million. This represents a steep increase from the estimated 5.8 million Americans age 65 and older who have Alzheimer's dementia today. Official death certificates recorded 122,019 deaths from AD in 2018, the latest year for which data are available, making Alzheimer's the sixth leading cause of death in the United States and the fifth leading cause of death among Americans age 65 and older. Between 2000 and 2018, deaths resulting from stroke, HIV and heart disease decreased, whereas reported deaths from Alzheimer's increased 146.2%. In 2019, more than 16 million family members and other unpaid caregivers provided an estimated 18.6 billion hours of care to people with Alzheimer's or other dementias. This care is valued at nearly $244 billion, but its costs extend to family caregivers' increased risk for emotional distress and negative mental and physical health outcomes. Average per-person Medicare payments for services to beneficiaries age 65 and older with AD or other dementias are more than three times as great as payments for beneficiaries without these conditions, and Medicaid payments are more than 23 times as great. Total payments in 2020 for health care, long-term care and hospice services for people age 65 and older with dementia are estimated to be $305 billion. As the population of Americans living with Alzheimer's dementia increases, the burden of caring for that population also increases. These challenges are exacerbated by a shortage of dementia care specialists, which places an increasing burden on primary care physicians (PCPs) to provide care for people living with dementia. Many PCPs feel underprepared and inadequately trained to handle dementia care responsibilities effectively. This report includes recommendations for maximizing quality care in the face of the shortage of specialists and training challenges in primary care.

Epigenetic Age Acceleration and Cognitive Function in African American Adults in Midlife: The Atherosclerosis Risk in Communities Study

Methylation levels measured at defined sites across the genome have recently been shown to be correlated with an individual's chronological age. Age acceleration, or the difference between age estimated from DNA methylation status and chronological age, has been proposed as a novel biomarker of aging. In this study, the cross-sectional association between two different measures of age acceleration and cognitive function was investigated using whole blood samples from 2,157 African American participants 47-70 years of age in the population-based Atherosclerosis Risk in Communities (ARIC) Study. Cognition was evaluated using three domain-specific tests. A significant inverse association between a 1-year increase in age acceleration calculated using a blood-based age predictor and scores on the Word Fluency Test was found using a general linear model adjusted for chronological age, gender, and years of education (β = -0.140 words; p = .001) and after adding other potential confounding variables (β = -0.104 words, p = .023). The results were replicated in 1,670 European participants in the Generation Scotland: Scottish Family Health Study (fully adjusted model: β = -0.199 words; p = .034). A significant association was also identified in a trans-ethnic meta-analysis across cohorts that included an additional 708 European American ARIC study participants (fully adjusted model: β = -0.110 words, p = .003). There were no associations found using an estimate of age acceleration derived from multiple tissues. These findings provide evidence that age acceleration is a correlate of performance on a test of verbal fluency in middle-aged adults.

Interethnic differences in neuroimaging markers and cognition in Asians, a population-based study

We examined interethnic differences in the prevalence of neuroimaging markers of cerebrovascular and neurodegenerative disease in 3 major Asian ethnicities (Chinese, Malays, and Indians), as well as their role in cognitive impairment. 3T MRI brain scans were acquired from 792 subjects (mean age: 70.0 ± 6.5years, 52.1% women) in the multi-ethnic Epidemiology of Dementia In Singapore study. Markers of cerebrovascular disease and neurodegeneration were identified. Cognitive performance was evaluated using Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and a neuropsychological assessment. Compared to Chinese, Malays had a higher burden of intracranial stenosis (OR: 2.28. 95%CI: 1.23-4.20) and cortical atrophy (β: -0.60. 95%CI: -0.78, -0.41), while Indians had a higher burden of subcortical atrophy (β: -0.23. 95%CI: -0.40, -0.06). Moreover, Malay and Indian ethnicities were likely to be cognitively impaired (OR for Malays: 3.79. 95%CI: 2.29-6.26; OR for Indians: 2.87. 95%CI: 1.74-4.74) and showed worse performance in global cognition (β for Malays: -0.51. 95%CI: -0.66, -0.37; and Indians: -0.32. 95%CI: -0.47, -0.17). A higher burden of cerebrovascular and neurodegenerative markers were found in Malays and Indians when compared to Chinese. Further research is required to fully elucidate the factors and pathways that contribute to these observed differences.

Ethnicity and risk of diagnosed dementia after stroke: a cohort study using the Clinical Practice Research Datalink

INTRODUCTION

The UK has over 1.2 million stroke survivors. Stroke is a major risk factor for dementia, and along with other risk factors such as hypertension and diabetes, is more common among Black, Asian and other ethnic minorities (BAME). We aimed to explore whether diagnosed dementia differed by ethnicity among adult stroke survivors.

METHODOLOGY

Using the UK Clinical Practice Research Datalink and linked hospital data, we conducted a cohort study among patients aged ≥40 years who had an incident stroke between 2005 and 2016. We fitted multivariable Cox proportional hazard models to estimate ethnic differences in the risk of poststroke dementia, adjusting for major clinical and social confounders.

RESULTS

Our cohort comprised 45 474 stroke survivors (mean age 72.6 years, 49% female), of whom 95.7% were White, 2.0% South Asian, 1.2% Black and 1.1% of Mixed/Other ethnicity. Of these, 4624 (10.2%) were diagnosed with poststroke dementia over a median follow-up of 3.26 years. Compared with the White ethnic group, those of Black ethnicity were 42% more likely to be diagnosed with dementia (adjusted HR 1.42, 95% CI 1.05 to 1.93). There was no association between any other ethnic group and poststroke dementia diagnosis.

DISCUSSION

There was good evidence that those of Black ethnicity had higher risk of diagnosed dementia poststroke. Further understanding of the mechanisms of this relationship could help target interventions at communities most at risk of dementia poststroke.

Increased inflammation in BA21 brain tissue from African Americans with Alzheimer's disease

Chronic neuroinflammation is strongly associated with AD and altered peripheral and central levels of chemokines and cytokines have been frequently described in those with AD. Given the increasing evidence of ethnicity-related differences in AD, it was of interest to determine if those altered chemokine and cytokine levels are ethnicity-related. Because African Americans exhibit a higher incidence of AD and increased symptom severity, we explored chemokine and cytokine concentrations in post-mortem brain tissue from the BA21 region of African Americans and Caucasians with AD using multiplex assays. IL-1β, MIG, TRAIL, and FADD levels were significantly increased in African Americans while levels of IL-3 and IL-8 were significantly decreased. Those effects did not interact with gender; however, overall levels of CCL25, CCL26 and CX3CL1 were significantly decreased in women. The NLRP3 inflammasome is thought to be critically involved in AD. Increased activation of this inflammasome in African Americans is consistent with the current results.

Rural stakeholder perceptions about cognitive screening

Objectives: The study aims were to explore stakeholder perceptions about cognitive screening in a rural, ethnically diverse, underserved setting, and to examine whether perceptions varied by years lived in a rural area, career, health literacy, willingness to be screened, ethnicity, education, or age. Methods: Twenty-one rural, ethnically diverse stakeholders completed an open-ended interview of five questions and a measure regarding perceptions about cognitive screening (PRISM-PC, Boustani, et al., 2008 ). Open coding using the in vivo process (Saldaña, 2015 ) to "derive codes from the actual participant language" (p. 77) was used to analyze the qualitative data. We used Pearson correlation to examine relationships between the PRISM-PC and sociodemographics including age, years of education, health literacy, years lived in rural areas, and willingness to participate in cognitive screening. Results: Eight codes and two themes were identified from the in vivo analysis. The eight codes were "a sentence being pronounced over the lives", "keep everybody at home", "Education is big", the trust issues is everything here", "identify support systems", "access to care", and "there is a cost to do that". The two themes were "Trust is the essential component of connecting with Community", and (2) "The Community recognizes the importance of knowledge in improving care. PRISM-PC results added new information in that persons were concerned about the emotional and financial burden on their families. Overall, regardless of age, careers, care involvement, health literacy, or education, 81% of stakeholders indicated they would seek annual cognitive screening. Discussion: It is important for rural health professionals to consider that contrary to previous stigma concerns, stakeholders may support earlier dementia detection.

Disparities in Diffuse Cortical White Matter Integrity Between Socioeconomic Groups

There is a growing literature demonstrating a link between lower socioeconomic status (SES) and poorer neuroanatomical health, such as smaller total and regional gray and white matter volumes, as well as greater white matter lesion volumes. Little is known, however, about the relation between SES and white matter integrity. Here we examined the relation between SES and white matter integrity of the brain’s primary cortical regions, and evaluated potential moderating influences of age and self-identified race. Participants were 192 neurologically intact, community-dwelling African American and White adults (mean age = 52 years; 44% male, 60% White, low SES = 52%) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) SCAN study. Participants underwent 3.0-T cranial magnetic resonance imaging. Diffusion tensor imaging was used to estimate regional fractional anisotropy (FA) to quantify the brain’s white matter integrity and trace to capture diffusivity. Multiple regression analyses examined independent and interactive associations of SES, age, and race with FA of the frontal, temporal, parietal, and occipital lobes bilaterally. Sensitivity analyses assessed the influence of several biopsychosocial risk factors on these associations. Exploratory analyses examined these relations with trace and using additional SES indicators. Results indicated there were no significant interactions of SES, age, and race for any region. Individuals with low SES had lower FA in all regions, and higher trace in the right and left frontal, right and left temporal, and left occipital lobes. Findings remained largely unchanged after inclusion of sensitivity variables. Older age was associated with lower FA and greater trace for all regions, except for the right temporal lobe with FA. No main effects were found for race in FA, and Whites had higher trace values in the parietal lobes. Novel findings of this study indicate that relative to the high SES group, low SES was associated with poorer white matter integrity and greater diffusivity. These results may, in part, reflect exposures to various biopsychosocial risk factors experienced by those of lower SES across the lifespan, and may help explain the preponderance of cognitive and functional disparities between socioeconomic groups.

Hispanic Dementia Family Caregiver's Knowledge, Experience, and Awareness of Self-Management: Foundations for Health Information Technology Interventions

PURPOSE

As a first step toward developing a web-based Family-Health Information Management System intervention, we explored Hispanic dementia family caregiver's knowledge, use, and awareness of self-management principles and skills to address health and health care needs for themselves and the person with dementia (PWD).

METHOD

Twenty caregivers and 11 caregiver counselors attended an English or Spanish language focus group ranging from 4 to 6 participants. We conducted a directed content analysis informed by Lorig and Holman's conceptualization of self-management.

RESULTS

A complement of six skills (i.e., problem solving, decision making, resource utilization, patient-provider partnership, action planning, and self-tailoring) to achieve one of three tasks (i.e., emotional, medical, and role management) can fully represent Hispanic dementia family caregivers' ability to self-manage health and health care needs. While not prominent in our study, caregivers and caregiver counselors pointed out existing and potential uses of personal consumer technology to schedule reminders and search for resources.

DISCUSSION

A broad conceptualization of self-management may be necessary to understand Hispanic dementia family caregiver's ability and needs to address emotional, medical, and role challenges of caregiving.

CONCLUSIONS

These findings and advances in the use of consumer health information technology support the development of self-management caregiver interventions.

Cerebral Amyloid Angiopathy: Similarity in African-Americans and Caucasians with Alzheimer's Disease

Cerebral amyloid angiopathy (CAA) of the Aβ type is variably present in the brains of patients with Alzheimer's disease (AD). CAA contributes to cognitive decline and increases the risk of lobar hemorrhage; because both AD-typical dementia and lobar hemorrhage are more common in African-Americans than in Caucasians, we postulated that African-Americans with AD might be particularly susceptible to CAA. To test this hypothesis, we analyzed CAA histopathologically in the large vessels and capillaries of autopsy-derived frontal, temporal, parietal, and occipital cortical samples from African-Americans (n = 18) and Caucasians (n = 19) with end-stage AD. In the combined cohort of 37 subjects, 22% of the subjects had severe CAA in large vessels, and 11% had severe CAA in capillaries. However, the prevalence and histopathologic characteristics of CAA were similar in the African-Americans and Caucasians. This conclusion was substantiated in an independent sample from the National Alzheimer's Coordinating Center database, in which the degree of CAA was comparable in 1,554 Caucasians and 68 African-Americans with end-stage AD. These findings support a growing consensus that the fundamental histopathologic features of AD are largely impartial to the race of the afflicted.

Ethnoracial differences in Alzheimer's disease from the FLorida Autopsied Multi-Ethnic (FLAME) cohort

Introduction:

Our primary goal was to examine demographic and clinicopathologic differences across an ethnoracially diverse autopsy-confirmed cohort of Alzheimer’s disease cases.

Methods:

A retrospective study was conducted in the Florida Autopsied Multi-Ethnic cohort on 1625 Alzheimer’s disease cases, including decedents who self-reported as Hispanic/Latino (n = 67), black/African American (n = 19), and white/European American (n = 1539).

Results:

Hispanic decedents had a higher frequency of family history of cognitive impairment (58%), an earlier age at onset (median age of 70 years), longer disease duration (median of 12 years), and lower MMSE proximal to death (median of 4 points) compared with the other ethnoracial groups. Black decedents had a lower Braak tangle stage (stage V) and higher frequency of coexisting hippocampal sclerosis (21%); however, only hippocampal sclerosis differences survived adjustment for sex, age at onset, and disease duration. Neither Thal amyloid phase nor coexisting Lewy body disease differed across ethnoracial groups.

Discussion:

Despite a smaller sample size, Hispanics demonstrated longer disease duration with Alzheimer’s disease, but not greater lifespan. Neuropathologic differences across ethnoracial groups supported differences in tau pathology distribution and coexisting hippocampal sclerosis, which may impact biomarker studies.