Racial and ethnic differences in trends in dementia prevalence and risk factors in the United States

Global estimates on the number of persons across the Alzheimer's disease continuum

INTRODUCTION

Global estimates on numbers of persons in early stages of Alzheimer's disease (AD), including prodromal and preclinical, are lacking, yet are needed to inform policy decisions on preventive measures and planning for future therapies targeting AD pathology.

METHODS

We synthesized the literature on prevalence across the AD continuum and derived a model estimating the number of persons, stratified by 5-year age groups, sex, and disease stage (AD dementia, prodromal AD, and preclinical AD).

RESULTS

The global number of persons with AD dementia, prodromal AD, and preclinical AD were estimated at 32, 69, and 315 million, respectively. Together they constituted 416 million across the AD continuum, or 22% of all persons aged 50 and above.

DISCUSSION

Considering predementia stages, the number of persons with AD is much larger than conveyed in available literature. Our estimates are uncertain, especially for predementia stages in low- and middle-income regions where biomarker studies are missing.

A Web-Based Decision Aid for Caregivers of Persons With Dementia With Firearm Access (Safe at Home Study): Protocol for a Randomized Controlled Trial

BACKGROUND

Firearm safety among individuals with Alzheimer disease and related dementias (ADRD) is an underdiscussed and underresearched concern in the United States, especially given the growing population of community-dwelling adults with ADRD. The "Safety in Dementia" (SiD) web-based decision aid was developed to support caregivers in addressing firearm access; the efficacy of SiD is unknown.

OBJECTIVE

Through the SiD decision aid, the Safe at Home (S@H) study aims to support caregivers in making decisions about home safety that align with their goals and values, and behaviors regarding firearm access for persons with ADRD and firearm access.

METHODS

The S@H study is a 2-armed randomized controlled trial to test the effect of the SiD decision aid on caregivers of community-dwelling adults with ADRD who have firearm access. S@H aims to recruit 500 ADRD caregivers (age ≥18 years, fluent in English or Spanish, and in the United States) through online or social media advertisements and through relevant organizations. Participants are randomized to view SiD or a control website at their own pace; all participants complete web-based questionnaires at baseline, 2 weeks, 2 months, and 6 months. The primary outcome is immediate preparation for decision-making; secondary outcomes include longitudinal decision outcomes and self-reported modifications to firearm access. The relative reach and effectiveness of each recruitment method (online/social media and through relevant organizations) will be assessed by examining differences in caregiver participation, retention rates, and relative cost.

RESULTS

The study enrollment began in May 2022. As of December 2022, a total of 117 participants had enrolled.

CONCLUSIONS

The S@H study is the first randomized trial of a firearm safety decision aid for ADRD caregivers. The results from this study will inform how best to support caregivers in decision-making regarding firearm safety. Further, results may guide approaches for recruiting caregivers and for dissemination of resources.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05173922; https://clinicaltrials.gov/ct2/show/NCT05173922.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/43702.

Enhancing Clinical Data Analysis by Explaining Interaction Effects between Covariates in Deep Neural Network Models

Deep neural network (DNN) is a powerful technology that is being utilized by a growing number and range of research projects, including disease risk prediction models. One of the key strengths of DNN is its ability to model non-linear relationships, which include covariate interactions. We developed a novel method called interaction scores for measuring the covariate interactions captured by DNN models. As the method is model-agnostic, it can also be applied to other types of machine learning models. It is designed to be a generalization of the coefficient of the interaction term in a logistic regression; hence, its values are easily interpretable. The interaction score can be calculated at both an individual level and population level. The individual-level score provides an individualized explanation for covariate interactions. We applied this method to two simulated datasets and a real-world clinical dataset on Alzheimer's disease and related dementia (ADRD). We also applied two existing interaction measurement methods to those datasets for comparison. The results on the simulated datasets showed that the interaction score method can explain the underlying interaction effects, there are strong correlations between the population-level interaction scores and the ground truth values, and the individual-level interaction scores vary when the interaction was designed to be non-uniform. Another validation of our new method is that the interactions discovered from the ADRD data included both known and novel relationships.

Neuropsychiatric Symptoms and Trajectories of Dependence and Cognition in a Sample of Community-dwelling Older Adults with Dementia

BACKGROUND AND OBJECTIVES

Neuropsychiatric symptoms (NPS), including psychotic symptoms (hallucinations, illusions, delusions), agitation/aggression, and depressed mood, are common in individuals with Alzheimer's disease (AD) and predict poorer outcomes, including faster disease progression. We aimed to evaluate associations between NPS and cognition and dependence in a multi-ethnic sample of community-dwelling older adults with AD.

METHODS

Predictors 3 (P3) is a cohort study of AD disease courses recruiting older adults aged 65 and above residing in upper Manhattan. A total of 138 of 293 participants had probable AD at the study baseline. We fit linear mixed models to examine longitudinal associations of time-varying NPS (psychotic symptoms, agitation/aggression, and depressed mood) with dependence and cognition, adjusted for race-ethnicity, sex, education, age, clinical dementia rating score, APOE-ε4, and comorbidity burden; separate interaction models were fit for age, Hispanic ethnicity, and sex.

RESULTS

Psychotic symptoms were associated with faster rates of increasing dependence and declining cognition over time, agitation/aggression with faster rates of declining cognition, and depressed mood with faster rates of increasing dependence. Among psychotic symptoms, delusions, but not hallucinations or illusions, were associated with worse outcome trajectories. Depressed mood predicted an accelerated increase in dependence in males but not females.

CONCLUSION

Our results confirm and extend prior results in clinic-based samples. The presence of NPS was associated with worse trajectories of dependence and cognition in this muti-ethnic sample of older adults with AD. Importantly, sex modified the association between depressed mood and dependence. Our results on NPS as predictors of differential AD progression in a community-dwelling, ethnically diverse sample serve to better inform the clinical care of patients and the future development of AD therapies.

Racial/Ethnic Disparities in Misidentification of Dementia in Medicare Claims: Results from the Washington Heights-Inwood Columbia Aging Project

BACKGROUND

Misidentification of dementia in Medicare claims is quite common.

OBJECTIVE

We examined potential race/ethnic disparities in misidentification of dementia in Medicare claims in a diverse cohort of older adults who underwent careful clinical assessment.

METHODS

Participants were enrolled in the Washington Heights-Inwood Columbia Aging Project (WHICAP), a multiethnic, population-based, prospective study of cognitive aging in which dementia status was assessed using a rigorous clinical protocol. ICD-9-CM and ICD-10-CM diagnosis codes in all available Medicare claims (1999-2019) were compared to clinical dementia diagnosis and categorized into three mutually exclusive groups: 1) congruent-, 2) over-, and 3) under- identification during the study period. Multinomial logistic regression model was used to examine the relationship between race (White, African American/Black, other) and ethnicity (Hispanic/Latinx, non-Hispanic/Latinx) and congruency of dementia identification after controlling for clinical (cognition, function, comorbidities) and demographic characteristics (age, sex, education), and inpatient and outpatient utilization.

RESULTS

Across all person-years, 88.4% had congruent identification of dementia compared to clinical diagnosis, in 4.1% of the times participants were over-identified with dementia, and 7.5% of the times the participants were under-identified. Rates of misidentification was higher in minority participants than in White, non-Hispanic participants. Multivariable estimation results showed that the probability of over-identification with dementia was 2.2% higher for African American/Black than White (p = 0.05) and 2.7% higher for Hispanic participants than non-Hispanics (p = 0.03) participants. Differences in under-identification by race/ethnicity were not statistically significant.

CONCLUSIONS

African American/Black and Hispanic participants were more likely over-identified with dementia in Medicare claims.

Health equity considerations in pragmatic trials in Alzheimer's and dementia disease: Results from a methodological review

Introduction

To improve dementia care delivery for persons across all backgrounds, it is imperative that health equity is integrated into pragmatic trials.

Methods

We reviewed 62 pragmatic trials of people with dementia published 2014 to 2019. We assessed health equity in the objectives; design, conduct, analysis; and reporting using PROGRESS-Plus which stands for Place of residence, Race/ethnicity, Occupation, Gender/sex, Religion, Education, Socioeconomic status, Social capital, and other factors such as age and disability.

Results

Two (3.2%) trials incorporated equity considerations into their objectives; nine (14.5%) engaged with communities; 4 (6.5%) described steps to increase enrollment from equity-relevant groups. Almost all trials (59, 95.2%) assessed baseline balance for at least one PROGRESS-Plus characteristic, but only 10 (16.1%) presented subgroup analyses across such characteristics. Differential recruitment, attrition, implementation, adherence, and applicability across PROGRESS-Plus were seldom discussed.

Discussion

Ongoing and future pragmatic trials should more rigorously integrate equity considerations in their design, conduct, and reporting.

Highlights

Few pragmatic trials are explicitly designed to inform equity-relevant objectives.Few pragmatic trials take steps to increase enrollment from equity-relevant groups.Disaggregated results across equity-relevant groups are seldom reported.Adherence to existing tools (e.g., IMPACT Best Practices, CONSORT-Equity) is key.

Increasing participant diversity in AD research: Plans for digital screening, blood testing, and a community-engaged approach in the Alzheimer's Disease Neuroimaging Initiative 4

INTRODUCTION

The Alzheimer's Disease Neuroimaging Initiative (ADNI) aims to validate biomarkers for Alzheimer's disease (AD) clinical trials. To improve generalizability, ADNI4 aims to enroll 50-60% of its new participants from underrepresented populations (URPs) using new biofluid and digital technologies. ADNI4 has received funding from the National Institute on Aging beginning September 2022.

METHODS

ADNI4 will recruit URPs using community-engaged approaches. An online portal will screen 20,000 participants, 4000 of whom (50-60% URPs) will be tested for plasma biomarkers and APOE. From this, 500 new participants will undergo in-clinic assessment joining 500 ADNI3 rollover participants. Remaining participants (∼3500) will undergo longitudinal plasma and digital cognitive testing. ADNI4 will add MRI sequences and new PET tracers. Project 1 will optimize biomarkers in AD clinical trials.

RESULTS AND DISCUSSION

ADNI4 will improve generalizability of results, use remote digital and blood screening, and continue providing longitudinal clinical, biomarker, and autopsy data to investigators.

Patterns of sleep disturbances across stages of cognitive decline

OBJECTIVES

The purpose of this study was to investigate insomnia symptoms and excessive sleep/sluggishness across stages of cognitive decline (cognitively normal [CN], Cognitively Impairment, Not Demented [CIND], dementia) in a large, racially/ethnically diverse sample of older adults (70+) in the US. We also examined whether sleep disturbances at baseline predicted conversion to CIND or dementia at follow-up.

METHODS

In this secondary analysis of the Aging, Demographics, and Memory Study (ADAMS) supplement of the Health Retirement Study, we analyzed patterns of informant-reported insomnia and excessive sleep symptoms among three groups of older adults (n = 846): CN, CIND, and dementia.

RESULTS

CIND adults were significantly more likely to have informant-reported insomnia symptoms than those in the CN group (p = 0.013). This was driven by a significant race/ethnicity-by-insomnia interaction with diagnostic status (p = 0.029), such that CIND Black and Hispanic older adults had increased insomnia symptom rates compared to CN, whereas White adults had similar insomnia symptoms across diagnostic status. Across all racial/ethnic groups, the prevalence of excessive sleep symptoms increased stepwise from CN to CIND to dementia (p < 0.001). Overall, insomnia symptoms at baseline predicted conversion from CN to CIND (p < 0.001, OR = 0.288; 95% CI: 0.143-0.580) at 4-year (approximate) follow-up; there was no relationship between baseline insomnia or excessive sleep/sluggishness symptoms and conversion from CIND to dementia.

DISCUSSION/CONCLUSION

This study provides evidence for the increased risk of insomnia symptoms among Hispanic and Black older adults with CIND, and indicates that insomnia symptoms may be associated with increased risk for development of cognitive impairment.

Sex Differences in the Associations of Obesity with Tau, Amyloid PET, and Cognitive Outcomes in Preclinical Alzheimer's Disease: Cross-Sectional A4 Study

BACKGROUND

The association between obesity and Alzheimer's disease (AD) is complex. Recent studies indicated the relationships between obesity and AD may differ by sex, and women may benefit from being overweight in terms of AD risk.

OBJECTIVE

We investigated whether sex modifies the associations of obesity with tau positron emission tomography (PET), amyloid PET, and cognition in preclinical AD.

METHODS

We included 387 cognitively-unimpaired amyloid-positive participants (221 women, 166 men, 87.6% non-Hispanic White) with available 18F-flortaucipir PET, 18F-florbetapir PET, and completed the Preclinical Alzheimer Cognitive Composite (PACC) tests from the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease (A4) study. Participants were categorized based on body mass index (BMI: kg/m2): normal-weight (BMI: 18.5-25), overweight (BMI: 25-30), and obese (BMI≥30).

RESULTS

Significant sex by BMI category interactions on PACC and its components: Mini-Mental State Examination (MMSE) and Reminding Test-Free+Total Recall (FCSRT96) revealed that overweight and obese women outperformed normal-weight women on FCSRT96, while obese men showed poorer MMSE performance than normal-weight men. These interactions were independent of APOE4. There were no significant interactions of sex by BMI category on tau and amyloid PET. However, sex-stratified analyses observed obesity was associated with less regional tau and mean cortical amyloid in women, not in men.

CONCLUSION

This study found that in preclinical AD, overweight and obesity were associated with better verbal memory in women, whereas obesity was associated with worse global cognition among men. Future studies focusing on the mechanism for this relationship may inform sex-specific interventions for AD prevention.

Hospital-based Health Information Technology Infrastructure: Evidence of Reduced Medicare Payments and Racial Disparities Among Patients With ADRD

BACKGROUND

Alzheimer disease and related dementia (ADRD) is one of the most expensive health conditions in the United States. Understanding the potential cost-savings or cost-enhancements of Health Information Technology (HIT) can help policymakers understand the capacity of HIT investment to promote population health and health equity for patients with ADRD.

OBJECTIVES

This study examined access to hospital-based HIT infrastructure and its association with racial and ethnic disparities in Medicare payments for patients with ADRD.

RESEARCH DESIGN

We used the 2017 Medicare Beneficiary Summary File, inpatient claims, and the American Hospital Association Annual Survey. Our study focused on community-dwelling Medicare fee-for-service beneficiaries who were diagnosed with ADRD. Our study focused on hospital-based telehealth-postdischarge (eg, remote patient monitoring) and telehealth-treatment (eg, psychiatric and addiction treatment) services.

RESULTS

Results showed that hospital-based telehealth postdischarge services were associated with significantly higher total Medicare payment and acute inpatient Medicare payment per person per year among patients with ADRD on average. The associations between hospital-based telehealth-treatment services and payments were not significant. However, the association varied by patient's race and ethnicity. The reductions of the payments associated with telehealth postdischarge and treatment services were more pronounced among Black patients with ADRD. Telehealth-treatment services were associated with significant payment reductions among Hispanic patients with ADRD.

CONCLUSION

Results showed that having hospital-based telehealth services might be cost-enhancing at the population level but cost-saving for Black and Hispanic patients with ADRD. Results suggested that personalized HIT services might be necessary to reduce the cost associated with ADRD treatment for racial and ethnic minority groups.

Associations Between Parity and Cognition: Race/Ethnic Differences

BACKGROUND

Race/ethnicity is associated with differences in reproductive history and cognition individually, yet it remains an understudied factor in the relationship between parity and later-life cognition.

OBJECTIVE

To evaluate if the association between parity and cognition differs between racial/ethnic groups.

METHODS

Participants included 778 older, postmenopausal women from the Health and Nutrition Examination Survey (Latina: n = 178, Non-Latino Black [NLB]: n = 169, Non-Latino White [NLW]: n = 431) who self-reported at least one birth. Cognitive outcomes included working memory, learning memory, and verbal fluency. Covariates included age, education, cardiovascular and other reproductive health factors, adult socioeconomic status (SES) and depressive symptoms. We fit a series of linear models to examine a) whether parity was associated with cognitive functioning, b) if this association varied by race/ethnicity through parity by race/ethnicity interactions, and c) individual parity with cognition associations stratified by race/ethnicity.

RESULTS

In the full sample, parity was significantly negatively associated with Digit Symbol Substitution Test (DSST) performance (b = -0.70, p = 0.024) but not Animal Fluency or word-list learning and memory. Tests of race/ethnicity-by-parity interactions were not statistically significant (ps > 0.05). However, stratified analyses by race/ethnicity showed a differential effect of parity on DSST performance, such that parity was significantly negatively associated with DSST performance (b = -1.66, p = 0.007) among Latinas but not in NLWs (b = -0.16, p = 0.74) or NLBs (b = -0.81, p = 0.191).

CONCLUSION

Among Latina, but not NLB or NLW women, greater parity was associated with worse processing speed/executive functioning later in life. Further research is needed to understand the mechanisms driving racial/ethnic differences.

Neighborhood disadvantage and dementia incidence in a cohort of Asian American and non-Latino White older adults in Northern California

INTRODUCTION

Some evidence suggests that neighborhood socioeconomic disadvantage is associated with dementia-related outcomes. However, prior research is predominantly among non-Latino Whites.

METHODS

We evaluated the association between neighborhood disadvantage (Area Deprivation Index [ADI]) and dementia incidence in Asian American (n = 18,103) and non-Latino White (n = 149,385) members of a Northern California integrated health care delivery system aged 60 to 89 at baseline. Race/ethnicity-specific Cox proportional hazards models adjusted for individual-level age, sex, socioeconomic measures, and block group population density estimated hazard ratios (HRs) for dementia.

RESULTS

Among non-Latino Whites, ADI was associated with dementia incidence (most vs. least disadvantaged ADI quintile HR = 1.09, 95% confidence interval [CI] = 1.02-1.15). Among Asian Americans, associations were close to null (e.g., most vs. least disadvantaged ADI quintile HR = 1.01, 95% CI = 0.85-1.21).

DISCUSSION

ADI was associated with dementia incidence among non-Latino Whites but not Asian Americans. Understanding the potentially different mechanisms driving dementia incidence in these groups could inform dementia prevention efforts.

The role of ethnicity, biological sex, and psychotropic agents in early and late onset Alzheimer's disease

Objective

This study investigates differences in pharmacological and demographic factors among male and female patients with Late-onset Alzheimer's disease (LOAD) and Early-onset Alzheimer's disease (EOAD).

Method

Data are from 10,126 AD patients, 9,290 were diagnosed with LOAD, while 836 were diagnosed with EOAD. Data were collected from the Prisma Health Upstate Alzheimer's patients' registry between 2016 and 2021. The logistic regression analysis was used to assess the association between pharmacological and demographic factors in males and females with LOAD and EOAD.

Results

In the adjusted analysis for males, patients that were administered memantine [odd ratio (OR) = 1.588, 95% CI, 1.175-2.145, p = 0.003], and buspirone [OR = 1.971, 95% CI, 1.221-3.183, p = 0.006] were more likely to be associated with EOAD, while increasing age [OR = 0.816, 95% CI, 0.799-0.834, p < 0.001] was associated with LOAD. Female patients with a history of alcohol (ETOH) use were more likely to be associated with EOAD while increasing age [OR = 0.845, 95% CI, 0.834-0.857, p < 0.001], treatment with memantine [OR = 0.774, 95% CI, 0.627-0.956, p = 0.017], African Americans [OR = 0.621, 95% CI, 0.462-0.835, p = 0.002] and tobacco use [OR = 0.529, 95% CI, 0.424-0.660, p < 0.001] were associated with LOAD.

Conclusion

Our findings identified specific demographic and pharmacological factors associated with males and females with LOAD and EOAD. These findings suggest the need to develop strategies to eliminate disparity in the care of LOAD or EOAD patients.

Modelling Alzheimer's disease using human brain organoids: current progress and challenges

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterised by gradual memory loss and declining cognitive and executive functions. AD is the most common cause of dementia, affecting more than 50 million people worldwide, and is a major health concern in society. Despite decades of research, the cause of AD is not well understood and there is no effective curative treatment so far. Therefore, there is an urgent need to increase understanding of AD pathophysiology in the hope of developing a much-needed cure. Dissecting the cellular and molecular mechanisms of AD pathogenesis has been challenging as the most commonly used model systems such as transgenic animals and two-dimensional neuronal culture do not fully recapitulate the pathological hallmarks of AD. The recent advent of three-dimensional human brain organoids confers unique opportunities to study AD in a humanised model system by encapsulating many aspects of AD pathology. In the present review, we summarise the studies of AD using human brain organoids that recapitulate the major pathological components of AD including amyloid-β and tau aggregation, neuroinflammation, mitochondrial dysfunction, oxidative stress and synaptic and circuitry dysregulation. Additionally, the current challenges and future directions of the brain organoids modelling system are discussed.

Perceptions About Discrimination in a Rural, Older, Racially and Ethnically Diverse Cohort

Purpose

The purpose of this pilot study was to examine perceptions of discrimination among a small cohort of rural older, retired minority Florida farmworkers. Potential sources of discrimination were explored, such as health literacy, age, sex, gender, racial/ethnic background, or rural residency.

Sample

The study occurred in a rural area that is designated as a "hot zone" due to its HRSA designation as a medically underserved area (MUA), health provider shortage area (HPSA), and medically underserved population, despite lying only 50 miles due west of the affluent town of Palm Beach, Florida. More than 40% of residents live below the poverty level, and only 65% have received a high school diploma.

Method

A descriptive, correlational pilot study was conducted to investigate potential contributors to discrimination. Independent variables examined were age, sex, gender, rural residency, racial/ethnic background, and health literacy, using the Rapid Estimate of Health Literacy in Medicine, short form (REALM-SF) (Arozullah, 2007). The incidence of self-reported discrimination was investigated. Chi-square and Pearson correlation analysis were employed to examine survey results. Findings were supplemented with a brief narrative inquiry, and responses were analyzed using Saldaña's (2015) model of cyclical coding.

Findings

Twenty-five residents in a subsidized housing unit agreed to participate in this study. This convenience sample was 96% racially/ethnically diverse (68% African American, 24% Haitian Creole, and 4% Hispanic American.) Most (78%) were retired field workers, and largely self-identified as female (72%). The residents' average reading level was 4th-6th grade. Health literacy (44%) and rural residency (24%) were the greatest sources of discrimination. Female gender discrimination was associated with ethnicity discrimination (r = 0.6, p = .002).

Conclusions

Providers are strongly encouraged to assess their patients' health literacy levels and experiences with discrimination to inform effective care delivery.

Association of Race and Income with Incident Diagnosis of Alzheimer's Disease and Related Dementias among Black and White Older Adults

To investigate how differences in income and education levels may contribute to disparities in incidence of Alzheimer's disease and related dementia (ADRD), we compared ADRD incidence in traditional Medicare claims for 11,132 Black and 7703 White participants aged 65 and over from a predominantly low-income cohort. We examined whether the relationship between ADRD incidence and race varied by income or education. Based on 2015 incident ADRD diagnoses, Black and White participants had unadjusted incidence rates of 26.5 and 23.2 cases per 1000 person-years, respectively (rate ratio 1.14, 95% CI 1.05-1.25). In multivariable Cox proportional hazard models, the relationship between race and incident ADRD diagnosis did not vary by education level (p-interaction = 0.748) but was modified by income level (p-interaction = 0.007), with higher ADRD incidence among Black participants observed only among higher income groups. These results highlight the importance of understanding how race and economic factors influence ADRD incidence and diagnosis rates.

Links between inflammation and immune functioning with cognitive status among older Americans in the Health and Retirement Study

Elevated inflammation and poor immune functioning are tied to worse cognitive health. Both processes are fundamental to aging and are strongly implicated in the development of age-related health outcomes, including cognitive status. However, results from prior studies evaluating links between indicators of inflammation and immune function and cognitive impairment have been inconsistent due to biomarker selection, sample selection, and cognitive outcome. Using the Health and Retirement Study (HRS), a nationally representative study of older adults in the United States, we assessed how indicators of inflammation (neutrophil-lymphocyte ratio (NLR), albumin, CRP, IL6, IL10, IL-1Ra, sTNFR1, and TGFβ1) and immune functioning (CMV, CD4+ TN/TM, and CD8+ TN/TM) are associated with cognitive status. First, to examine the association between each biomarker and cognitive status, we tested whether markers of inflammation and immune functioning varied across cognitive status categories. We found that dementia and cognitive impairment without dementia (CIND) were associated with elevated inflammation and poorer immune functioning across biomarkers except for CD4+ TN/TM. Next, we estimated multinomial logistic regression models to assess which biomarkers would continue to be associated with dementia and CIND, net of each other. In these models, albumin, cytokines, CMV, CD4+ TN/TM, and CD8+ TN/TM are associated with cognitive status. Because poor immune functioning and increased inflammation are associated with cognitive impairment, improving immune functioning and reducing inflammation may provide a mechanism for reducing ADRD risk in the population.

Racial/ethnic disparities in initiation and persistent use of anti-dementia medications

BACKGROUND

Racial/ethnic disparities in anti-dementia medications use in longitudinally followed research participants are unclear.

METHODS

The study included initially untreated participants followed in National Alzheimer's Coordinating Center Uniform Data Set who were ≥65 at baseline with Alzheimer's disease dementia.

OUTCOMES

Outcomes for acetylcholinesterase inhibitor (AChEI) treatment included (1) any new AChEI treatment during follow-up, and (2) persistence of treatment during follow-up categorized into: intermittent treatment (< 50% follow-ups reporting treatment), persistent (≥50% follow-ups), and always treated. Outcomes for memantine treatment were similarly constructed.

RESULTS

Controlling for participant characteristics, Black and Hispanic participants remained less likely than White participants to report any new AChEI or memantine treatment during follow-up. Among those who reported new treatment during follow-up, both Black and Hispanic participants were less likely than White participants to be persistently treated with AChEI and memantine.

DISCUSSION

Substantial racial/ethnic treatment disparities remain in controlled settings of longitudinal research in which participants have access to dementia experts, suggesting wider disparities in the larger community.

The Contribution of Chronic Conditions to Hospitalization, Skilled Nursing Facility Admission, and Death: Variation by Race

Multimorbidity (≥2 chronic conditions) is a common and important marker of aging. To better understand racial differences in multimorbidity burden and associations with important health-related outcomes, we assessed differences in the contribution of chronic conditions to hospitalization, skilled nursing facility admission, and mortality among non-Hispanic Black and non-Hispanic White older adults in the United States. We used data from a nationally representative study, the National Health and Aging Trends Study, linked to Medicare claims from 2011-2015 (n = 4,871 respondents). This analysis improved upon prior research by identifying the absolute contributions of chronic conditions using a longitudinal extension of the average attributable fraction for Black and White Medicare beneficiaries. We found that cardiovascular conditions were the greatest contributors to outcomes among White respondents, while the greatest contributor to outcomes for Black respondents was renal morbidity. This study provides important insights into racial differences in the contributions of chronic conditions to costly health-care utilization and mortality, and it prompts policy-makers to champion delivery reforms that will expand access to preventive and ongoing care for diverse Medicare beneficiaries.

Subjective cognitive decline in Brazil: Prevalence and association with dementia modifiable risk factors in a population-based study

Introduction

Subjective cognitive decline (SCD) may be an early symptom of Alzheimer's disease. We aimed to estimate the prevalence of SCD in Brazil and its association with dementia modifiable risk factors.

Methods

We used data of 8138 participants from the Brazilian Longitudinal Study of Aging (ELSI-Brazil), a population-based study that included clinical and demographic variables of individuals across the country. We calculated the prevalence of SCD and its association with dementia modifiable risk factors.

Results

We found that the prevalence of SCD in Brazil was 29.21% (28.22%-30.21%), varying according to region, sex, and age. SCD was strongly associated with hearing loss, low education, psychological distress, Brown/Pardo and Black races.

Discussion

The prevalence of SCD in Brazil is higher than in high-income countries. Brown/Black races and dementia modifiable risk factors were associated with SCD. Public strategies that target SCD may help mitigate the incidence of dementia.

Differential Impact of Stroke on Cognitive Impairment in Mexican Americans and Non-Hispanic White Americans

BACKGROUND

The association between stroke and dementia is well established. Less is known about this association in underrepresented ethnic groups. In a large ethnically diverse cohort, we examined whether history of stroke was associated with cognitive impairment, and whether this relationship differed by ethnicity (Mexican American [MA] versus non-Hispanic White).

METHODS

This was a population-based cohort study conducted in Nueces County, TX, a biethnic community with a large and primarily nonimmigrant MA population. Residents aged ≥65 were recruited door-to-door or by telephone between May 2018 and December 2021. The primary exposure was history of stroke, obtained by self-report. Demographic, medical, and educational histories were also obtained. The primary outcome was the Montreal Cognitive Assessment (MoCA), a scale that evaluates multiple domains of cognitive performance. Scores were divided into 3 ordinal categories, roughly corresponding to normal cognition (MoCA 26-30), mild cognitive impairment (MoCA 20-25), or probable dementia (MoCA 0-19).

RESULTS

One thousand eight hundred one participants completed MoCA screening (55% female; 50% MA, 44% Non-Hispanic White, 6% other), of whom 12.4% reported history of stroke. Stroke prevalence was similar across ethnicities (X2 2.1; P=0.34). In a multivariable cumulative logit regression model for the ordinal cognition outcome, a stroke by ethnicity interaction was observed (P=0.01). Models stratified by ethnicity revealed that stroke was associated with cognitive impairment across ethnicities, but had greater impact on cognition in non-Hispanic Whites (cumulative odds ratio=3.81 [95% CI, 2.37-6.12]) than in MAs (cumulative odds ratio=1.58 [95% CI, 1.04-2.41]). Increased age and lower educational attainment were also associated with cognitive impairment, regardless of ethnicity.

CONCLUSIONS

History of stroke was associated with increased odds of cognitive impairment after controlling for other factors in both MA and Non-Hispanic White participants. The magnitude of the impact of stroke on cognition was less in MA than in Non-Hispanic White participants.

BDNF Val66Met Moderates the Effects of Hypertension on Executive Functioning in Older Adults Diagnosed With aMCI

OBJECTIVE

To investigate whether the BDNF Val66Met polymorphism influences the associations of hypertension, executive functioning and processing speed in older adults diagnosed with amnestic Mild Cognitive Impairment (aMCI).

DESIGN

Secondary data analysis using moderation modeling.

SETTING

Veterans Affairs Hospital, Palo Alto, CA.

PARTICIPANTS

Sample included 108 community-dwelling volunteers (mean age 71.3 ± 9.2 years) diagnosed with aMCI.

MEASUREMENTS

Cognitive performance was evaluated from multiple baseline assessments (Trail Making Test; Stroop Color-Word Test; Symbol Digit Modality Test) and grouped into standardized composite scores representing executive function and processing speed domains. BDNF genotypes were determined from whole blood samples. Hypertension was assessed from resting blood pressures or by self-report.

RESULTS

Controlling for age, BDNF Val66Met moderated the effects of hypertension on executive functioning, but added no significant variance to processing speed scores. Specifically, hypertensive carriers of the BDNF Met allele performed significantly below the sample mean on tasks of executive functioning, and evidenced significantly lower scores when compared to Val-Val homozygotes and normotensive participants.

CONCLUSIONS

Results posit that the executive functioning of non-demented older adults may be susceptible to interactions between BDNF genotype and hypertension, and Val-Val homozygotes and normotensive older adults may be more resilient to these effects of cognitive change. Further research is needed to understand the underlying processes and to implement strategies that target modifiable risk factors and promote cognitive resilience.

Racial and Ethnic Differences in Amyloid PET Positivity in Individuals With Mild Cognitive Impairment or Dementia: A Secondary Analysis of the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) Cohort Study

Importance

Racial and ethnic groups with higher rates of clinical Alzheimer disease (AD) are underrepresented in studies of AD biomarkers, including amyloid positron emission tomography (PET).

Objective

To compare amyloid PET positivity among a diverse cohort of individuals with mild cognitive impairment (MCI) or dementia.

Design, Setting, and Participants

Secondary analysis of the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS), a single-arm multisite cohort study of Medicare beneficiaries who met appropriate-use criteria for amyloid PET imaging between February 2016 and September 2017 with follow-up through January 2018. Data were analyzed between April 2020 and January 2022. This study used 2 approaches: the McNemar test to compare amyloid PET positivity proportions between matched racial and ethnic groups and multivariable logistic regression to assess the odds of having a positive amyloid PET scan. IDEAS enrolled participants at 595 US dementia specialist practices. A total of 21 949 were enrolled and 4842 (22%) were excluded from the present analysis due to protocol violations, not receiving an amyloid PET scan, not having a positive or negative scan, or because of small numbers in some subgroups.

Exposures

In the IDEAS study, participants underwent a single amyloid PET scan.

Main Outcomes and Measures

The main outcomes were amyloid PET positivity proportions and odds.

Results

Data from 17 107 individuals (321 Asian, 635 Black, 829 Hispanic, and 15 322 White) with MCI or dementia and amyloid PET were analyzed between April 2020 and January 2022. The median (range) age of participants was 75 (65-105) years; 8769 participants (51.3%) were female and 8338 (48.7%) were male. In the optimal 1:1 matching analysis (n = 3154), White participants had a greater proportion of positive amyloid PET scans compared with Asian participants (181 of 313; 57.8%; 95% CI, 52.3-63.2 vs 142 of 313; 45.4%; 95% CI, 39.9-50.9, respectively; P = .001) and Hispanic participants (482 of 780; 61.8%; 95% CI, 58.3-65.1 vs 425 of 780; 54.5%; 95% CI, 51.0-58.0, respectively; P = .003) but not Black participants (359 of 615; 58.4%; 95% CI, 54.4-62.2 vs 333 of 615; 54.1%; 95% CI, 50.2-58.0, respectively; P = .13). In the adjusted model, the odds of having a positive amyloid PET scan were lower for Asian participants (odds ratio [OR], 0.47; 95% CI, 0.37-0.59; P < .001), Black participants (OR, 0.71; 95% CI, 0.60-0.84; P < .001), and Hispanic participants (OR, 0.68; 95% CI, 0.59-0.79; P < .001) compared with White participants.

Conclusions and Relevance

Racial and ethnic differences found in amyloid PET positivity among individuals with MCI and dementia in this study may indicate differences in underlying etiology of cognitive impairment and guide future treatment and prevention approaches.

Association of physical activity levels and brain white matter in older Latino adults

OBJECTIVE

Investigate the associations between self-reported physical activity (PA) engagement and white matter (WM) health (i.e. volume, integrity, and hyperintensities) in older Latinos.

DESIGN

Cross-sectional study with community-dwelling older adults from predominantly Latino neighborhoods. Participants: Thirty-four cognitively healthy older Latinos from two different cohorts. Measurements: Participants self-reported demographic information, PA engagement [Community Healthy Activities Model Program for Seniors (CHAMPS) Physical Activity Questionnaire for Older Adults] and magnetic resonance imaging (MRI). We used high-resolution three-dimensional T1- and T2-FLAIR weighted images and diffusion tensor imaging acquired via 3 T MRI. We performed a series of hierarchical linear regression models with the addition of relevant covariates to examine the associations between self-reported PA levels and WM volume, integrity, and hyperintensities (separately). We adjusted p-values with the use of the Benjamini-Hochberg's false discovery rate procedure.

RESULTS

Higher reported levels of leisure-time moderate-to-vigorous PA were significantly associated with higher WM volume of the posterior cingulate (β = 0.220, SE = 0.125, 95% CI 0.009-0.431, p = 0.047) and isthmus cingulate (β = 0.212, SE = 0.110, 95% CI 0.001-0.443, p = 0.044) after controlling for intracranial volume. Higher levels of total PA were significantly associated with higher overall WM volume of these same regions (posterior cingulate: β = 0.220, SE = 0.125, CI 0.024-0.421, p = 0.046; isthmus cingulate: β = 0.220, SE = 0.125, 95% CI 0.003-0.393; p = 0.040). Significant p-values did not withstand Benjamini-Hochberg's adjustment. PA was not significantly associated with WM integrity or WM hyperintensities.

CONCLUSION

Higher levels of PA, particularly higher leisure-time moderate-to-vigorous PA, might be associated with greater WM volume in select white matter regions key to brain network integration for physical and cognitive functioning in older Latinos. More research is needed to further confirm these associations.

Effect of cognitive impairment on risk of death in Hispanic/Latino adults over the age of 50 residing in the United States with and without diabetes: Data from the Health and Retirement Study 1995-2014

OBJECTIVE

To understand the relationship between mortality and cognitive function among older US Hispanic adults with and without diabetes.

METHODS

Data from the Health and Retirement Study (1995-2014) were analyzed. Cox proportional hazard models were used to estimate the association between mortality and cognitive function. Models were stratified by diabetes.

RESULTS

Four thousand thirteen older US Hispanic adults were included. Fully adjusted models for individuals with diabetes showed those with mild cognitive impairment (MCI; hazard ratio [HR]: 1.61; 95% confidence interval [CI]: 1.06, 2.45; P = .025) and dementia (HR: 2.14; 95% CI: 1.25, 3.67; P = .006) had increased mortality compared to normal cognition. Fully adjusted models for individuals without diabetes showed those with MCI (HR: 1.87; 95% CI: 1.28, 2.74; P = .001) and dementia (HR: 3.25; 95% CI: 1.91, 5.55; P < .001) had increased mortality compared to normal cognition.

CONCLUSIONS

Cognitive impairment is associated with increased mortality in older US Hispanic adults with and without diabetes. Clinicians should regularly assess cognitive function in this group to quickly identify declines and make appropriate referrals for support to optimize health and reduce mortality.

The role of demographic change in explaining the growth of Australia's older migrant population living with dementia, 2016-2051

OBJECTIVE

To examine the demographic drivers contributing to the future growth in the population of older migrants in Australia living with dementia.

METHODS

Using birthplace-specific cohort-component projection models, we projected the number of older migrants living with dementia. ABS data on births, deaths, migration and birthplace were used, alongside Australian Institute of Health and Welfare (AIHW) estimates of dementia prevalence with birthplace dementia weights calculated from administrative data.

RESULTS

The number of older migrants living with dementia is projected to increase from about 134,423 in 2016 to 378,724 by 2051. Increases in populations with dementia varied considerably, from a slight decrease for those born in Southern & Eastern Europe to over 600% increases amongst the South-East Asia, Southern & Central Asia, and Sub-Saharan Africa-born populations.

CONCLUSIONS

Cohort flow is the primary driver increasing the number of older migrants living with dementia. This growth is largely inevitable because the cohorts are already living in Australia as part of the migrant population, but currently at ages below 60 years.

IMPLICATIONS FOR PUBLIC HEALTH

High relative growth and shifting birthplace composition in the number of migrants living with dementia poses implications for culturally appropriate care, health care access and workforce needs to support migrant families, carers and their communities.

The long shadow of residential racial segregation: Associations between childhood residential segregation trajectories and young adult health among Black US Americans

Residential racial segregation is a key manifestation of anti-Black structural racism, thought to be a fundamental cause of poor health; evidence has shown that it yields neighborhood disinvestment, institutional discrimination, and targeting of unhealthy products like tobacco and alcohol. Yet research on the long-term impacts of childhood exposure to residential racial segregation is limited. Here, we analyzed data on 1823 Black participants in the Panel Study of Income Dynamics, estimating associations between childhood segregation trajectories and young adult health. Black young adults who consistently lived in high-segregation neighborhoods throughout childhood experienced unhealthier smoking and drinking behaviors and higher odds of obesity compared to other trajectory groups, including children who moved into or out of high-segregation neighborhoods. Results were robust to controls for neighborhood and family poverty. Findings underscore that for Black children who grow up in segregated neighborhoods, the roots of structurally-determined health inequities are established early in life.

Longitudinal associations of pain and cognitive decline in community-dwelling older adults

Pain is inversely associated with cognitive function in older adults, but the effects of pain on cognitive decline are not fully clear. This study examined the associations of baseline pain, pain persistence, and incident pain with changes in cognition across 10 years in a sample of healthy community-dwelling older adults (n = 688; Mage = 74, SD = 6.05) from the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial. While ACTIVE was a four-arm single-blind cognitive training randomized controlled trial, the present study includes only participants from the no-contact control group. Pain was examined using the Medical Outcomes Survey SF-36-Item (MOS SF-36) and cognitive tests examined simple processing speed, complex processing speed, divided and selective attention, memory, reasoning, and cognitive status. Multilevel models tested the associations of baseline pain, incident pain, and pain persistence on cognitive function and cognitive decline, adjusted for baseline age, time (years after follow-up), race, gender, education, marital status, and depressive symptoms at baseline and over time. Thirty-one percent reported pain at baseline which was related to worse baseline memory and accelerated decline in processing speed. Forty-two percent of older adults reported incident pain had accelerated decline in complex processing speed, divided attention, memory, reasoning, and cognitive status. On average, older adults reported a mean of two waves of pain persistence related to accelerated decline in memory. In sum, pain is common in community-dwelling older adults and is related to accelerated cognitive decline, especially when the incident. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Regional variation in U.S dementia trends from 2000-2012

Although recent studies report a decline in dementia prevalence among U.S. older adults, national trends may mask subnational variation, particularly given large health and social inequalities linked to geography. To address this gap, we determined if there was subnational variation in reported national dementia trends and if region-specific trends were explained by sociodemographic and health characteristics. Data come from the 2000 (n = 10,447) and 2012 (10,426) waves of the Health and Retirement Study. We used validated methods for dementia classification using proxy and self-respondents. Logistic regression models, adjusted for within-person clustering over time, estimated trends in dementia prevalence by region and census division. We found subnational variation in dementia prevalence in both 2000 and 2012, as well as in change in dementia prevalence during this period. In 2000, dementia prevalence was lowest in the West (8.6%), higher in the Midwest (10.0%) and Northeast (11.1%), and highest in the South (14.6%). Dementia prevalence declined over time across all regions of the U.S. from 2000 to 2012 but remained highest in the South (10.7%) compared to the other regions (7.0-7.8%). Despite downward trends in dementia across the U.S., the prevalence of dementia in the South in 2012 approximated levels found in other regions in 2000. There was relatively less change over time in the West compared to other regions, but dementia prevalence was already quite low in the West in 2000. Within region, trends in dementia prevalence between 2000 and 2012 also varied slightly across census divisions. Subnational variation in changes in dementia prevalence were largely explained by education and health status. Variation in baseline prevalence, as well as differential rates of change, highlight the importance of examining subnational variation in dementia trends.

Black-White variation in the relationship between early educational experiences and trajectories of cognitive function among US-born older adults

Black adults face a substantially higher risk for dementia in later life compared to their White peers. Given the critical role of educational attainment and cognitive function in later life dementia risk, this paper aims to determine if early educational experiences and educational attainment are differentially related to trajectories of cognitive status across race and if this further varies by education cohort. We use data from the Life History Mail Survey (LHMS) and prospective data on cognition from the Health and Retirement Study (HRS). We restrict our sample to Black and White US-born adults who provided at least one measure of cognitive status from 1995/6–2016. We find evidence of Black-White differences in the association between educational experiences and level of cognitive function, episodic memory, and working memory, but little evidence of Black-White differences in these associations with decline. Having a learning problem was associated with lower levels of cognitive function, episodic memory, and working memory for White and Black older adults, but was more strongly related to these outcomes among Black older adults. Further, the Black-White difference in this association was generally found in older cohorts that completed schooling after enactment of federal policies that improved educational resources for children with learning disabilities. Attending racially discordant schools was positively associated with level of these cognitive outcomes for Black older adults but not for White older adults. We also find that the educational gradient in level of cognitive function was larger for Black compared to White older adults in older cohorts not benefiting from the Brown v Board of Education decision but was similar for Black and White older adults attending school in the post-Brown era.

•

Black adults are twice as likely to have dementia than White adults.

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The roots of this risk are poorly understood but may be due to educational experiences.

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Three educational experiences differentially predicted cognitive status by race.

•

These included having a learning problem, desegregated schooling, and attainment.

Alzheimer's disease biomarkers in Black and non-Hispanic White cohorts: A contextualized review of the evidence

Black Americans are disproportionately affected by dementia. To expand our understanding of mechanisms of this disparity, we look to Alzheimer's disease (AD) biomarkers. In this review, we summarize current data, comparing the few studies presenting these findings. Further, we contextualize the data using two influential frameworks: the National Institute on Aging-Alzheimer's Association (NIA-AA) Research Framework and NIA's Health Disparities Research Framework. The NIA-AA Research Framework provides a biological definition of AD that can be measured in vivo. However, current cut-points for determining pathological versus non-pathological status were developed using predominantly White cohorts-a serious limitation. The NIA's Health Disparities Research Framework is used to contextualize findings from studies identifying racial differences in biomarker levels, because studying biomakers in isolation cannot explain or reduce inequities. We offer recommendations to expand study beyond initial reports of racial differences. Specifically, life course experiences associated with racialization and commonly used study enrollment practices may better account for observations than exclusively biological explanations.

Psychological well-being and cognitive aging in Black, Native American, and White Alzheimer's Disease Research Center participants

Psychological well-being is associated with cognition in later life but has not been examined across diverse populations-including minoritized communities at disproportionately high risk of dementia. Further, most previous work has not been able to examine links between specific facets of psychological well-being and performance within distinct cognitive domains that can capture subclinical impairment. Using a well-characterized sample followed through enrollment in an NIH-funded Alzheimer's Disease Center, we sought to test these associations within three racial groups at baseline. Participants were N = 529 cognitively unimpaired Black, American Indian/Alaska Native (AI/AN), and white middle-aged and older adults (mean age = 63.6, SD = 8.1, range = 45-88 years) enrolled in the Wisconsin Alzheimer's Disease Research Center's Clinical Core. Predictors included validated NIH Toolbox Emotion Battery scales assessing positive affect, general life satisfaction, and meaning and purpose. Outcomes included performance on widely used tests of executive functioning and episodic memory. We conducted race-stratified regression models to assess within-group relationships. Black and AI/AN participants reported lower life satisfaction than white participants. Racial disparities were not observed for positive affect or meaning and purpose scores. Across groups, life satisfaction predicted better executive functioning. Similar associations were observed for positive affect in Black and AI/AN samples but not among whites. In general, well-being measures were not related to performance on tests of episodic memory. Our results highlight well-being as a potentially important determinant of late-life cognitive health, particularly executive functioning, that is modifiable if older adults are connected with appropriate resources and supports. Further, psychological well-being may represent a potent target for brain health interventions tailored for Black and Native communities.

Increasing engagement of Hispanics/Latinos in clinical trials on Alzheimer's disease and related dementias

Introduction

Despite evidence that Hispanic/Latino populations are 1.5 times more likely than non-Latino Whites to develop Alzheimer's disease and related dementias (ADRD), Latinos are underrepresented in clinical trials testing treatments for ADRD. Data are needed on facilitators of ADRD clinical trial participation in Latinos. We leveraged in-depth qualitative methods to elucidate barriers and facilitators to participating in ADRD clinical trials in a large and diverse sample of Latinos; and to provide timely and actionable strategies to accelerate representation of Latinos in clinical trials on ADRD.

Methods

Data were collected in California between January 2019 and June 2020 from 25 focus groups (FGs): eight with Latino adults ages 18 to 49 (n = 54), nine with Latino adults ages 50+ (n = 75), and eight with caregivers of Latino older adults with ADRD (n = 52). Twelve community-based organization administrators were also interviewed. Transcripts of FGs and interviews were entered into Atlas.ti software. Three independent team members analyzed the transcripts with inductive/deductive qualitative content analysis. We triangulated data from stakeholder groups across sites, we used collaborative coding, and used the Consolidated Criteria for Reporting Qualitative Research.

Results

An overarching theme was a tension between wanting to learn more about ADRD and to participate in ADRD research but having limited awareness and opportunity. Five themes were identified: (1) remaining in limbo, (2) wanting information about ADRD, (3) wanting information on research about ADRD, (4) clearing researchers through trusted local organizations, and (5) practicing altruism through engagement in research opportunities.

Discussion

To increase representation of Latino communities in clinical trials on ADRD, bilingual information and education on ADRD and clinical trials needs to be better disseminated. Also, working with trusted local, regional, and national organizations can increase participation. Importantly, Latino participation can increase when research teams demonstrate altruistic actions and inform participants of public health reasons requiring their involvement.

HIGHLIGHTS

Participation in clinical trials on Alzheimer's disease and related dementias (ADRD) is limited among Latinos/Hispanics.Knowing the high prevalence of ADRD in Latinos increases willingness to participate.Observing altruism from researchers increases willingness to participate.Invitations from multiple organizations increases willingness to participate.Researchers should include public health reasons requiring Latinos' involvement.

High visit-to-visit blood pressure variability predicts global cognitive decline: The Multi-Ethnic Study of Atherosclerosis

Background

Research of hypertension-related risk factors for Alzheimer's disease has typically focused on blood pressure (BP) levels, despite evidence that high blood pressure variability (BPV) over time may predict poorer cardiovascular, neuropathological, and neurocognitive outcomes. We evaluated associations between BPV and cognitive function in the Multi-Ethnic Study of Atherosclerosis (MESA).

Methods

Multivariable linear and logistic regression analyses of BP data across six examinations were used to determine associations that BPV (average real variability [ARV], variability independent of the mean [VIM]) and group-based latent BP trajectories have with cognitive function, decline, and impairment, measured by the Cognitive Abilities Screening Instrument (CASI), Digit Symbol Coding (DSC), and Digit Span tests.

Results

Participants (N = 1314; mean baseline age = 57) were 50% female, and 48% White. Higher systolic (β = -0.06, 95% confidence interval [CI]: -0.12, -0.0001) and diastolic (β = -0.08, 95% CI: -0.14, -0.02) ARV predicted increased global cognitive decline after covariate adjustment. Stronger relationships between BPV and global cognition were in older, White and Black participants, apolipoprotein E (APOE) ε4 non-carriers, male participants, and non-antihypertensive medication users.

Conclusion

Results suggest that higher systolic and diastolic BPV is an independent risk factor for cognitive dysfunction and decline in this multi-ethnic cohort. This relationship differs across demographic and clinical characteristics.

Difficulties with Activities of Daily Living and Receipt of Care Among Older Adults with Cognitive Impairment: Differences Between Those Living Alone and Those Living with Others

We compared the prevalence of reporting difficulty with basic and instrumental activities of daily living without help received for persons with cognitive impairment living alone versus those living with others. We used data on 13,782 community-dwelling participants aged 55+ with cognitive impairment in the Health and Retirement Study (2000–2016). Models were stratified by gender and race/ethnicity. Among cognitively impaired older adults, those living alone were more likely to report difficulty without help received than those living with others. Results were similar by gender and race/ethnicity. Providers and policymakers might focus their efforts on ensuring the adequate provision of home and community-based services for older adults living alone with cognitive impairment.

Prevalence of Alzheimer's disease and related dementias among veterans experiencing housing insecurity

INTRODUCTION

Housing insecure veterans are aging, but the prevalence of Alzheimer's disease and related dementias (AD/ADRD) in the population is unknown.

METHODS

We calculated the prevalence of AD/ADRD diagnoses in 2018 among veterans that experienced homelessness, were at-risk for homelessness, or were stably housed. We determined acute care (emergency department, hospitalizations, psychiatric hospitalizations), and any long-term care (nursing home, and community-based) use by housing status among veterans with an AD/ADRD diagnosis.

RESULTS

The overall prevalence of AD/ADRD diagnoses for homeless, at-risk, and stably housed veterans was 3.66%, 13.48%, and 3.04%, respectively. Housing insecure veterans with AD/ADRD used more acute care, and were more likely to have a nursing home admission compared to stably housed veterans. At risk, but not homeless veterans, were more likely to use US Department of Veterans Affairs-paid home and community-based care than stably housed veterans.

DISCUSSION

The prevalence of AD/ADRD diagnoses is greater among housing insecure veterans than stably housed veterans.

Clinical perspectives and strategies for confronting disparities in social determinants of health for Hispanic bilinguals with aphasia

Disparities in social determinants of health (SDOH) such as socioeconomic status and access to quality healthcare present serious barriers to enrollment in clinical rehabilitation programs for individuals who have experienced a stroke, especially for those who identify with a racial-ethnic minority group. Hispanic bilinguals with aphasia (HBWA) are one marginalized group who face even greater enrollment challenges since post-stroke language impairment and limited English proficiency make it difficult to advocate for one's needs and identify appropriate rehabilitation programs. Given the increasing representation of Hispanic individuals in the U.S. (projected to be 30% of the population in 2050), it is imperative that clinicians counter disparities in stroke care by facilitating access to clinical services for HBWA. However, the Hispanic population remains largely understudied in the stroke and aphasia literature, due in part to reduced opportunities to enroll in large-scale clinical research studies. In this paper we highlight how our team at Boston University has designed and implemented a variety of recruitment practices, assessment modifications, and treatment accommodations to circumvent the known barriers to participation in clinical research experienced by HBWA. Furthermore, we discuss the importance of cultural responsiveness and demonstrate how including principles of sensitivity and humility in clinical trial protocols improves participant enrollment and retention. Although clinical adjustments in this study were developed for use with HBWA, the effectiveness of the procedures suggests they may be useful blueprints for expanding access to research opportunities for various marginalized groups.

Risk Factors Associated With Alzheimer Disease and Related Dementias by Sex and Race and Ethnicity in the US

Importance

Previous estimates suggested that 1 in 3 cases of Alzheimer disease and related dementia (ADRDs) in the US are associated with modifiable risk factors, the most prominent being physical inactivity, depression, and smoking. However, these estimates do not account for changes in risk factor prevalence over the past decade and do not consider potential differences by sex or race and ethnicity.

Objective

To update estimates of the proportion of ADRDs in the US that are associated with modifiable risk factors and to assess for differences by sex and race and ethnicity.

Design, Setting, and Participants

For this cross-sectional study, risk factor prevalence and communality were obtained from the nationally representative US Behavioral Risk Factor Surveillance Survey data from January 2018 to December 2018, and relative risks for each risk factor were extracted from meta-analyses. Data were analyzed from December 2020 to August 2021. Respondents included 378 615 noninstitutionalized adults older than 18 years. The number before exclusion was 402 410. Approximately 23 795 (~6%) had missing values on at least 1 of the variables of interest.

Exposures

Physical inactivity, current smoking, depression, low education, diabetes, midlife obesity, midlife hypertension, and hearing loss.

Main Outcomes and Measures

Individual and combined population-attributable risks (PARs) associated with ADRDs, accounting for nonindependence between risk factors.

Results

Among 378 615 individuals, 171 161 (weighted 48.7%) were male, and 134 693 (weighted 21.1%) were 65 years and older. Race and ethnicity data were self-reported and defined by the US Behavioral Risk Factor Surveillance System Data; 6671 participants (weighted 0.9%) were American Indian and Alaska Native, 8043 (weighted 5.1%) were Asian, 29 956 (weighted 11.7%) were Black, 28 042 (weighted 16.0%) were Hispanic (any race), and 294 394 (weighted 64.3%) were White. Approximately 1 in 3 of ADRD cases (36.9%) in the US were associated with 8 modifiable risk factors, the most prominent of which were midlife obesity (17.7%; 95% CI, 17.5-18.0), physical inactivity (11.8%; 95% CI, 11.7-11.9), and low educational attainment (11.7%; 95% CI, 11.5-12.0). Combined PARs were higher in men (35.9%) than women (30.1%) and differed by race and ethnicity: American Indian and Alaska Native individuals, 39%; Asian individuals, 16%; Black individuals, 40%; Hispanic individuals (any race), 34%; and White individuals, 29%. The most prominent modifiable risk factors regardless of sex were midlife obesity for American Indian and Alaska Native individuals, Black individuals, and White individuals; low education for Hispanic individuals; and physical inactivity for Asian individuals.

Conclusions and Relevance

The findings suggest that risk factors associated with ADRDs have changed over the past decade and differ based on sex and race and ethnicity. Alzheimer risk reduction strategies may be more effective if they target higher-risk groups and consider current risk factor profiles.

Proximal improvement and higher-order resting state network change after multidomain cognitive training intervention in healthy older adults

Prior randomized control trials have shown that cognitive training interventions resulted in improved proximal task performance, improved functioning of activities of daily living, and reduced dementia risk in healthy older adults. Neural correlates implicated in cognitive training include hub brain regions of higher-order resting state networks including the default mode network, dorsal attention network, frontoparietal control network, and cingulo-opercular network. However, little is known about resting state network change after cognitive training, or the relation between functional brain changes and improvement in proximal task performance. We assessed the 1) change in proximal task performance, 2) change in higher-order resting state network connectivity via functional magnetic resonance imaging, and 3) association between these variables after a multidomain attention/speed-of-processing and working memory randomized control trial in a sample of 58 healthy older adults. Participants in the cognitive training group improved significantly on seven out of eight training tasks immediately after the training intervention with the largest magnitude of improvement in a divided attention/speed-of-processing task, the Double Decision task. Only the frontoparietal control network had significantly strengthened connectivity in the cognitive training group at the post-intervention timepoint. Lastly, higher frontoparietal control network connectivity was associated with improved Double Decision task performance after training in the cognitive training group. These findings show that the frontoparietal control network may strengthen after multidomain cognitive training interventions, and this network may underlie improvements in divided attention/speed-of-processing proximal improvement.

Racial/Ethnic Disparities in Length of Life after Dementia Diagnosis: an 18-Year Follow-up Study of Medicare Beneficiaries

Background

Methods

Findings

Interpretation

Sex Differences in Demographic and Pharmacological Factors in Alzheimer Patients With Dementia and Cognitive Impairments

Objective

The current study investigates sex differences associated with pharmacological and demographic characteristics in Alzheimer patients (AD) with dementia (ADD) or mild cognitive impairment (MCI).

Method

A retrospective analytical approach was used to analyze data from 45,696 AD patients with MCI or ADD. The univariate analysis was used to determine differences in demographic, and pharmacological characteristics for male and female ADD and MCI-AD patients. Multivariate analysis was used to predict specific pharmacological and demographic factors that are associated with male and female MCI and ADD patients.

Result

In the adjusted analysis for male patients, Hispanics [0.166,0.020 – 1.355, P = 0.094] or African Americans [OR = 2.380, 95% CI,2.120 – 2.674, P &lt; 0.001], were more likely to have MCI-AD and be treated with galantamine [OR = 0.559, 95% CI, 0.382 – 0.818, P = 0.003], donepezil [OR = 1.639, 95% CI,1.503 – 1.787, P &lt; 0.001], rivastigmine [OR = 1.394, 95% CI,1.184 – 1.642, P &lt; 0.001], olanzapine [OR = 2.727, 95% CI,2.315 – 3.212, P &lt; 0.001], risperidone [OR = 2.973, 95% CI,2.506 – 3.526, P &lt; 0.001], present with increasing age [1.075,1.071 – 1.079, P &lt; 0.001], and are on tobacco use [OR = 1.150, 95% CI,1.054 – 1.254, P = 0.002]. For female patients, buspirone [OR = 0.767, 95% CI, 0.683 – 0.861, P &lt; 0.001] and a history of alcohol (ETOH) use [OR = 0.484, 95% CI, 0.442 – 0.529, P &lt; 0.001] were associated with MCI-AD. Increasing age [OR = 1.096, 95% CI, 1.093 – 1.100, P &lt; 0.001], donepezil [OR = 2.185, 95% CI, 2.035 – 2.346, P &lt; 0.001], memantine [OR = 2.283, 95% CI, 2.104 – 2.477, P &lt; 0.001] aripiprazole [OR = 1.807, 95% CI, 1.544 – 2.113, P &lt; 0.001] olanzapine [OR = 2.289, 95% CI, 1.986 – 2.640, P &lt; 0.001] risperidone [OR = 2.548, 95% CI, 2.246 – 2.889, P &lt; 0.001] buspirone [OR = 0.767, 95% CI, 0.683 – 0.861, P &lt; 0.001] escitalopram [OR = 1.213, 95% CI,1.119 – 1.315, P &lt; 0.001] African Americans [OR = 1.395, 95% CI, 1.268 – 1.535, P &lt; 0.001] and tobacco use [OR = 1.150, 95% CI, 1.073 – 1.233, P &lt; 0.001] were associated with ADD.

Conclusion

Our findings reveal that MCI-AD patients were more likely to be Hispanics or African American males treated with rivastigmine, olanzapine and citalopram. African American females were associated with ADD and more likely to be treated with buspirone and presented with a history of ETOH. This finding suggests the need for a pharmacological treatment approach encompassing sex-sensitive strategies for MCI-AD and ADD patients.

Association of Echocardiographic Measures of Left Atrial Function and Size With Incident Dementia

IMPORTANCE

Atrial myopathy-characterized by alterations in left atrial (LA) function and size-is associated with ischemic stroke, independent of atrial fibrillation (AF). Electrocardiographic markers of atrial myopathy are associated with dementia, but it is unclear whether 2-dimensional echocardiographic (2DE)-defined LA function and size are associated with dementia.

OBJECTIVE

To examine the association of LA function and size with incident dementia.

DESIGN, SETTING, AND PARTICIPANTS

The Atherosclerosis Risk in Communities (ARIC) study is a community-based prospective cohort. An exploratory, retrospective analysis was conducted. ARIC centers are located in Forsyth County, North Carolina; Jackson, Mississippi; Washington County, Maryland; and suburban Minneapolis, Minnesota. For this analysis, visit 5 (2011-2013) served as the baseline. Participants without prevalent AF and stroke and who had 2DEs in 2011-2013 were included and surveilled through December 31, 2019.

EXPOSURES

LA function (reservoir strain, conduit strain, contractile strain, emptying fraction, passive emptying fraction, and active emptying fraction), and LA size (maximal and minimal volume index) as evaluated by 2DE.

MAIN OUTCOMES AND MEASURES

Dementia cases were identified using in-person and phone cognitive assessments, hospitalization codes, and death certificates. Cox proportional hazards models were used.

RESULTS

Among 4096 participants (mean [SD] age, 75 [5] years; 60% women; 22% Black individuals), 531 dementia cases were ascertained over a median follow-up of 6 years. Dementia incidence for the lowest LA quintile was 4.80 for reservoir strain, 3.94 for conduit strain, 3.29 for contractile strain, 4.20 for emptying fraction, 3.67 for passive emptying fraction, and 3.27 for active emptying fraction per 100 person-years. After full-model adjustments, there were statistically significant associations between measures of LA function and dementia; the hazard ratios (HRs) from the lowest vs highest quintile for reservoir strain were 1.98 (95% CI, 1.42-2.75); for conduit strain, 1.50 (95% CI, 1.09-2.06); for contractile strain, 1.57 (95% CI, 1.16-2.14); for emptying fraction, 1.87 (95% CI, 1.31-2.65); and for active emptying fraction, 1.43 (95% CI, 1.04-1.96). LA passive emptying fraction was not significantly associated with dementia (HR, 1.26 [95% CI, 0.93-1.71]). Dementia incidence for the highest LA maximal volume index quintile was 3.18 per 100 person-years (HR for highest vs lowest quintile, 0.77 [95% CI, 0.58-1.02]) and for the highest minimal volume index quintile was 3.50 per 100 person-years (HR for the highest vs lowest quintile, 0.95 [95% CI, 0.71-1.28]). Both measures were not significantly associated with dementia. These findings were robust to sensitivity analyses that excluded participants with incident AF or stroke.

CONCLUSIONS AND RELEVANCE

In this exploratory analysis of a US community-based cohort, several echocardiographic measures of lower LA function were significantly associated with an increased risk of subsequent dementia. Measures of LA size were not significantly associated with dementia risk. These findings suggest that impaired LA function may be a risk factor associated with dementia.

HCBS Service Spending and Nursing Home Placement for Patients With Alzheimer's Disease and Related Dementias: Does Race Matter?

OBJECTIVES

We examined the extent to which home and community-based services (HCBS) spending affected the likelihood of nursing home (NH) placement among black and white HCBS users with Alzheimer's disease and related dementias (ADRD).

METHODS

The study population included new HCBS users with ADRD between 2010 and 2013 (N = 1,046,200).

RESULTS

We found that a one hundred dollar increase in monthly HCBS spending was associated with a 0.3 percentage points decrease in the NH placement rate among Whites, but a 0.3 percentage points increase in the NH placement rate among Blacks. The overall NH placement rate was 68.2% and 56.7% for Whites and Blacks, respectively.

DISCUSSION

A higher HCBS spending was associated with a decreased likelihood of NH placements for Whites but not for Blacks. It is important to understand how states' HCBS expansion efforts influence Blacks and Whites with ADRD so that resources can be tailored to communities with different race-mix.

Effects of Medicare comprehensive medication review on racial/ethnic disparities in nonadherence to statin medications among patients with Alzheimer's Disease: an observational analysis

Background

Alzheimer’s Disease (AD) is the mostcommon cause of dementia, a neurological disorder characterized by memory loss and judgment impairment. Hyperlipidemia, a commonly co-occurring condition, should be treated to prevent associated complications. Medication adherence may be difficult for individuals with AD due to the complexity of AD management. Comprehensive Medication Reviews (CMRs), a required component of Medicare Part D Medication Therapy Management (MTM), have been shown to improve medication adherence. However, many MTM programs do not target AD. Additionally, racial/ethnic disparities in MTM eligibility have been revealed. Thus, this study examined the effects of CMR receipt on reducing racial/ethnic disparities in the likelihood of nonadherence to hyperlipidemia medications (statins) among the AD population.

Methods

This retrospective study used 2015-2017 Medicare data linked to the Area Health Resources Files. The likelihood of nonadherence to statin medications across racial/ethnic groups was compared between propensity-score-matched CMR recipients and non-recipients in a ratio of 1 to 3. A difference-in-differences method was utilized to determine racial/ethnic disparity patterns using a logistic regression by including interaction terms between dummy variables for CMR receipt and each racial/ethnic minority group (non-Hispanic Whites, or Whites, as reference).

Results

The study included 623,400 Medicare beneficiaries. Blacks and Hispanics had higher statin nonadherence than Whites: Compared to Whites, Blacks’ nonadherence rate was 4.53% higher among CMR recipients and 7.35% higher among non-recipients; Hispanics’ nonadherence rate was 2.69% higher among CMR recipients and 7.38% higher among non-recipients. Differences in racial/ethnic disparities between CMR recipients and non-recipients were significant for each minority group (p < 0.05) except Others. The difference between Whites and Hispanics in the odds of statin nonadherence was 11% lower among CMR recipients compared to non-recipients (OR = 0.89; 95% Confidence Interval = 0.85-0.94 for the interaction term between dummy variables for CMR and Hispanics). Interaction terms between dummy variables for CMR and other racial/ethnic minorities were not significant.

Conclusions

Receiving a CMR was associated with a disparity reduction in nonadherence to statin medications between Hispanics and Whites among patients with AD. Strategies need to be explored to increase the number of MTM programs that target AD and promote CMR completion.

Interventions to promote dementia knowledge among racial/ethnic minority groups: A systematic review

BACKGROUND

Certain racial/ethnic minority groups have a higher risk of developing dementia, yet studies have demonstrated that they often have limited knowledge and understanding of this disease. An increasing number of educational and advocacy programs have been developed to promote dementia knowledge. We aimed at assessing current evidence and quality regarding educational interventions for promoting dementia knowledge.

METHODS

We searched for intervention studies published in English that focused on educational interventions for promoting dementia knowledge among racial/ethnic minority groups. We identified 25 relevant studies through PubMed, PsycINFO, CINAHL, and Scopus, using tailored search terms. We screened titles and abstracts, reviewed full texts, synthesized relevant evidence, and evaluated the studies' quality based on the Mixed Methods Appraisal Tool. Relevant intervention studies took place in communities, hospitals or clinics, and schools, and online.

RESULTS

Most studies were conducted in the United States (n = 21), followed by the UK (n = 3). Over half of the studies included Asian/Pacific Islander groups (n = 14), followed by Black groups (n = 12) and Hispanic groups (n = 11). The intervention delivery mode varied across studies-from workshops hosted in a faith community to talk shows on YouTube. Target populations included middle-aged and older adults, caregivers and family members, health students and professionals, and elementary school students. Common content included symptoms and signs of dementia, protective and risk factors, and local resources. The assessment of study outcomes varied across studies. Improvement in dementia knowledge and attitudes towards dementia was reported in many studies. Among the included studies, intervention satisfaction was high. The overall quality of the interventions was low.

CONCLUSION

Formally evaluated educational interventions promoting dementia knowledge are at an early stage. Existing published interventions showed adequate acceptability and promise in promoting better understanding and awareness of dementia in minority groups. More well-designed randomized controlled trials are needed.

Higher-order resting state network association with the useful field of view task in older adults

Speed-of-processing abilities decline with age yet are important in performing instrumental activities of daily living. The useful field of view, or Double Decision task, assesses speed-of-processing and divided attention. Performance on this task is related to attention, executive functioning, and visual processing abilities in older adults, and poorer performance predicts more motor vehicle accidents in the elderly. Cognitive training in this task reduces risk of dementia. Structural and functional neural correlates of this task suggest that higher-order resting state networks may be associated with performance on the Double Decision task, although this has never been explored. This study aimed to assess the association of within-network connectivity of the default mode network, dorsal attention network, frontoparietal control network, and cingulo-opercular network with Double Decision task performance, and subcomponents of this task in a sample of 267 healthy older adults. Multiple linear regressions showed that connectivity of the cingulo-opercular network is associated with visual speed-of-processing and divided attention subcomponents of the Double Decision task. Cingulo-opercular network and frontoparietal control network connectivity is associated with Double Decision task performance. Stronger connectivity is related to better performance in all cases. These findings confirm the unique role of the cingulo-opercular network in visual attention and sustained divided attention. Frontoparietal control network connectivity, in addition to cingulo-opercular network connectivity, is related to Double Decision task performance, a task implicated in reduced dementia risk. Future research should explore the role these higher-order networks play in reduced dementia risk after cognitive intervention using the Double Decision task.

Human microRNA (miR-20b-5p) modulates Alzheimer's disease pathways and neuronal function, and a specific polymorphism close to the MIR20B gene influences Alzheimer's biomarkers

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with loss of cognitive, executive, and other mental functions, and is the most common form of age-related dementia. Amyloid-β peptide (Aβ) contributes to the etiology and progression of the disease. Aβ is derived from the amyloid-β precursor protein (APP). Multiple microRNA (miRNA) species are also implicated in AD. We report that human hsa-miR20b-5p (miR-20b), produced from the MIR20B gene on Chromosome X, may play complex roles in AD pathogenesis, including Aβ regulation. Specifically, miR-20b-5p miRNA levels were altered in association with disease progression in three regions of the human brain: temporal neocortex, cerebellum, and posterior cingulate cortex. In cultured human neuronal cells, miR-20b-5p treatment interfered with calcium homeostasis, neurite outgrowth, and branchpoints. A single-nucleotide polymorphism (SNP) upstream of the MIR20B gene (rs13897515) associated with differences in levels of cerebrospinal fluid (CSF) Aβ1-42 and thickness of the entorhinal cortex. We located a miR-20b-5p binding site in the APP mRNA 3'-untranslated region (UTR), and treatment with miR-20b-5p reduced APP mRNA and protein levels. Network analysis of protein-protein interactions and gene coexpression revealed other important potential miR-20b-5p targets among AD-related proteins/genes. MiR-20b-5p, a miRNA that downregulated APP, was paradoxically associated with an increased risk for AD. However, miR-20b-5p also reduced, and the blockade of APP by siRNA likewise reduced calcium influx. As APP plays vital roles in neuronal health and does not exist solely to be the source of "pathogenic" Aβ, the molecular etiology of AD is likely to not just be a disease of "excess" but a disruption of delicate homeostasis.