Trends in Relative Incidence and Prevalence of Dementia Across Non-Hispanic Black and White Individuals in the United States, 2000-2016

Modifiable and Non-Modifiable Risk Factors for Dementia Among Non-Hispanic White and Black Populations Aged 50-64 in the United States, 2006-2016

BACKGROUND AND OBJECTIVES

Non-Hispanic Black populations (NHB) have a significantly higher prevalence of dementia than non-Hispanic Whites in the U.S., and the underlying risk factors may play a role in this racial disparity. We aimed to calculate risk scores for dementia among non-Hispanic White (NHW) and non-Hispanic Black populations aged 50-64 years over a period of 10 years, and to estimate potential differences of scores between NHW and NHB.

RESEARCH DESIGN AND METHODS

The Health and Retirement Study from 2006 to 2016 was used to calculate the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) risk score, a validated score for predicting dementia risk. Weighted average CAIDE score, as well as CAIDE score for modifiable factors hypertension, obese, hypercholesterolemia, physical inactivity), and non-modifiable factors (age, sex, education) were calculated for adults aged 50-64 years with normal cognition for 2006-2008, 2010-2012, 2014-2016. The associations of race with CAIDE score and elevated CAIDE score were examined.

RESULTS

A total of 10,871 participants were included in the analysis. The CAIDE score showed declining trends for NHB from 2006 to 2016, while NHB consistently had a higher total CAIDE score and CAIDE score for modifiable factors from 2006 to 2016, but not for non-modifiable factors.

DISCUSSION AND IMPLICATIONS

NHB had a higher level of dementia risk factors than NHW among adults aged 50-64 years in the U.S. from 2006 to 2016, and the difference is attributable to modifiable risk factors, which holds promise for risk reduction of dementia.

2025 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2025 AHA Statistical Update is the product of a full year's worth of effort in 2024 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. This year's edition includes a continued focus on health equity across several key domains and enhanced global data that reflect improved methods and incorporation of ≈3000 new data sources since last year's Statistical Update.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Abdominal myosteatosis is associated with lower processing speed in a multiethnic cohort of older adults

Background

Prior research linking myosteatosis with cognition in older adults has been conducted in relatively homogenous populations with narrow age ranges. We evaluated if abdominal myosteatosis was associated with processing speed in a multiethnic cohort of middle aged and older adults.

Methods

The analytical sample included 1,268 adults (46-86 years old, mean 63±9 years, 53% female of 41% White, 20% Black, 14% Chinese, and 25% Hispanic), a subset from the Multi-Ethnic Study of Atherosclerosis (MESA). Bivariate analyses were performed between abdominal computed tomography derived muscle densities (a myosteatosis measure) at year 3 with Digit Symbol Coding (DSC) with cytokines. Multivariable models were first adjusted for demographics, education, and general cognition, and further adjusted for other known predictors of dementia: APOE -4, physical activity, diabetes, cholesterol, smoking, and blood pressure. We further assessed whether central adiposity, general adiposity, and cytokines modified this association. We tested interactions by ethnicity, sex, and age.

Results

Rectus abdominis myosteatosis was significantly associated with worse DSC (B= -0.247, 95% CI: 0.098,0.396, p=0.001) independent of demographics, education, general cognition, and dementia risk factors. Adjustment for central adiposity, and cytokines did not attenuate the associations. Tests for interactions by ethnicity, sex, and age were not statistically significant.

Conclusions

Rectus abdominis myosteatosis is associated with worse processing speed in this middle and older aged multiethnic population of men and women, independent of other known predictors of cognition. Longitudinal studies should assess the interplay of myosteatosis with other markers of adiposity, inflammation, and circulating mediators and their combined impact on processing speed.

Highlights

Abdominal myosteatosis correlated with lower cognitive processing speed in older adults.Myosteatosis links muscle density to cognitive function beyond dementia risk factors.Pro-inflammatory cytokines do not mediate the muscle-cognition association.Ethnicity, sex, and adiposity measures do not modify myosteatosis-cognition links.Abdominal CT scans could serve as diagnostic tools for cognitive health insights.

Incidence of dementia in the German Heinz Nixdorf Recall study over 20 years

INTRODUCTION

The aim of the study was to estimate the population-based dementia incidence in Germany over a period of two decades.

METHODS

We analyzed data from 4814 participants of the population-based Heinz Nixdorf Recall study (49.8% men, 45-75 years at baseline period 2000-2003), who have been monitored for the occurrence of cognitive decline and dementia. We calculated the cumulative incidence of dementia and its major subtypes and the incidence rate per 1000 person-years over two decades.

RESULTS

During a median follow-up of 18.2 (Q1-Q3: 11.3-20.6) years, a total of 298 participants (6.2%) developed dementia (22.1% Alzheimer´s disease, 23.5% vascular dementia, 15.1% mixed dementia, 9.1% other dementia, 30.2% unspecified). The overall incidence rate was 3.9 per 1000 person-years.

DISCUSSION

Our study is the only current population-based study in Germany that estimates the incidence of dementia. In order to reduce the high proportion of unspecific dementia diagnoses, diagnostics urgently need to be improved.

Highlights

New data on the incidence of dementia in Germany in participants ≥45 years of age.Participants have been monitored for dementia incidence over two decades.The overall incidence in our cohort was 3.9 per 1000 person-years.Many patients had unspecific dementia diagnoses in their medical records.Further diagnostic evaluation should be available for all dementia patients.

Retest reliability and reliable change of community-dwelling Black/African American older adults with and without mild cognitive impairment using NIH Toolbox-Cognition Battery and Cogstate Brief Battery for laptop

OBJECTIVE

With the increased use of computer-based tests in clinical and research settings, assessing retest reliability and reliable change of NIH Toolbox-Cognition Battery (NIHTB-CB) and Cogstate Brief Battery (Cogstate) is essential. Previous studies used mostly White samples, but Black/African Americans (B/AAs) must be included in this research to ensure reliability.

METHOD

Participants were B/AA consensus-confirmed healthy controls (HCs) (n = 49) or mild cognitive impairment (MCI) (n = 34) adults 60-85 years that completed NIHTB-CB and Cogstate for laptop at two timepoints within 4 months. Intraclass correlations, the Bland-Altman method, t-tests, and the Pearson correlation coefficient were used. Cut scores indicating reliable change provided.

RESULTS

NIHTB-CB composite reliability ranged from .81 to .93 (95% CIs [.37-.96]). The Fluid Composite demonstrated a significant difference between timepoints and was less consistent than the Crystallized Composite. Subtests were less consistent for MCIs (ICCs = .01-.89, CIs [-1.00-.95]) than for HCs (ICCs = .69-.93, CIs [.46-.92]). A moderate correlation was found for MCIs between timepoints and performance on the Total Composite (r = -.40, p = .03), Fluid Composite (r = -.38, p = .03), and Pattern Comparison Processing Speed (r = -.47, p = .006).On Cogstate, HCs had lower reliability (ICCs = .47-.76, CIs [.05-.86]) than MCIs (ICCs = .65-.89, CIs [.29-.95]). Identification reaction time significantly improved between testing timepoints across samples.

CONCLUSIONS

The NIHTB-CB and Cogstate for laptop show promise for use in research with B/AAs and were reasonably stable up to 4 months. Still, differences were found between those with MCI and HCs. It is recommended that race and cognitive status be considered when using these measures.

Achieving Inclusion in Pharmacological Clinical Trials for Alzheimer's Disease

Participant recruitment and retention into randomized controlled trials (RCTs) is a growing and evolving science. It varies dramatically by discipline given the important and key choices that must be made based on the unique trial design considerations. In the field of Alzheimer's Disease (AD) therapeutics, recruitment goals, approaches, and strategies vary based on the disease stage of the target population which can range from asymptomatic adults with biomarker evidence of the disease to end-stage symptom management. This chapter discusses existing barriers and provides recommendations to achieve inclusive and timely recruitment in multi-center AD trials. It proposes an evidence-based recruitment framework anchored on culturally cognizant and participant focused study level and study site level efforts.

The Effects of APOE Alleles, Cognitive Activities, and Social Activities on Cognitive Decline in African Americans

OBJECTIVES

Older African Americans are among the fastest-growing populations, yet are underrepresented in studies examining risk factors related to decline. The present study examines whether biological factors (apolipoprotein [APOE] alleles) interact with behavioral factors including cognitive activities (e.g., reading, playing games) and social activities (e.g., participating in social groups) to predict cognitive decline in African Americans.

METHODS

In total, 734 African American adults from the Minority Aging Research Study, aged 65 and older (with no known dementia at the time of enrollment), underwent annual cognitive testing for up to 10 years. At baseline, APOE status was determined and participants reported their frequency of participation in social and cognitive activities. Structural equation modeling was used to examine the effects of APOE, cognitive activities, and social activities on cognitive decline, and their interaction effects over a 10-year period.

RESULTS

The number of APOE alleles had an effect on cognitive decline, such that a greater number of APOE4 alleles was associated with greater cognitive decline, whereas a greater number of APOE2 alleles was associated with less cognitive decline. Cognitive and social activities did not interact with APOE count to predict cognitive decline; however, APOE4 and social activities had additive, independent effects on cognitive decline.

DISCUSSION

Results replicate prior findings linking APOE4 to cognitive decline and highlight the importance of APOE2 and social activities in delaying cognitive decline in African Americans.

The Interaction Between Indigenous Identity and Rural Residency in Dementia Prevalence Among Ecuadorian Older Adults

BACKGROUND AND OBJECTIVES

While recognizing the acknowledged difference in dementia prevalence between Indigenous and non-Indigenous populations, most previous studies were conducted in the Global North. This study aims to examine the relationship between Indigenous ethnic identity and dementia status with a special focus on urban-rural differences among older adults in Ecuador.

RESEARCH DESIGN AND METHODS

Data came from Ecuador's Survey of Health, Welfare, and Aging, derived from a probability sample of households in Ecuador. The final sample comprised 4,984 adults aged 60 or older. Dementia status was assessed through 3 indicators: low scores on a cognitive assessment, the number of difficulties in instrumental activities of daily living, and self-reported dementia diagnosis. Logistic regression and multivariate decomposition analyses were utilized.

RESULTS

Indigenous participants, even after adjusting for sociodemographic and health-related factors, exhibited a higher likelihood of having dementia compared to their non-Indigenous counterparts. Among Indigenous participants, those residing in rural areas had a higher likelihood of having dementia status, while there was no significant urban-rural difference observed among non-Indigenous participants. Rural residency and covariates explain 91.0% of the observed difference in dementia prevalence between Indigenous and non-Indigenous older adults.

DISCUSSION AND IMPLICATIONS

Indigenous older adults who are living in rural areas are at particularly high risk of having dementia largely because they have presently recognized modifiable risk factors. These findings underscore the urgent need to prioritize provisions of appropriate and equitable service related to dementia for Indigenous people living in rural areas outside high-income countries.

Using a Device-Free Wi-Fi Sensing System to Assess Daily Activities and Mobility in Low-Income Older Adults: Protocol for a Feasibility Study

BACKGROUND

Older adults belonging to racial or ethnic minorities with low socioeconomic status are at an elevated risk of developing dementia, but resources for assessing functional decline and detecting cognitive impairment are limited. Cognitive impairment affects the ability to perform daily activities and mobility behaviors. Traditional assessment methods have drawbacks, so smart home technologies (SmHT) have emerged to offer objective, high-frequency, and remote monitoring. However, these technologies usually rely on motion sensors that cannot identify specific activity types. This group often lacks access to these technologies due to limited resources and technology experience. There is a need to develop new sensing technology that is discreet, affordable, and requires minimal user engagement to characterize and quantify various in-home activities. Furthermore, it is essential to explore the feasibility of developing machine learning (ML) algorithms for SmHT through collaborations between clinical researchers and engineers and involving minority, low-income older adults for novel sensor development.

OBJECTIVE

This study aims to examine the feasibility of developing a novel channel state information-based device-free, low-cost Wi-Fi sensing system, and associated ML algorithms for localizing and recognizing different patterns of in-home activities and mobility in residents of low-income senior housing with and without mild cognitive impairment.

METHODS

This feasibility study was conducted in collaboration with a wellness care group, which serves the healthy aging needs of low-income housing residents. Prior to this feasibility study, we conducted a pilot study to collect channel state information data from several activity scenarios (eg, sitting, walking, and preparing meals) using the proposed Wi-Fi sensing system continuously over a week in apartments of low-income housing residents. These activities were videotaped to generate ground truth annotations to test the accuracy of the ML algorithms derived from the proposed system. Using qualitative individual interviews, we explored the acceptability of the Wi-Fi sensing system and implementation barriers in the low-income housing setting. We use the same study protocol for the proposed feasibility study.

RESULTS

The Wi-Fi sensing system deployment began in November 2022, with participant recruitment starting in July 2023. Preliminary results will be available in the summer of 2025. Preliminary results are focused on the feasibility of developing ML models for Wi-Fi sensing-based activity and mobility assessment, community-based recruitment and data collection, ground truth, and older adults' Wi-Fi sensing technology acceptance.

CONCLUSIONS

This feasibility study can make a contribution to SmHT science and ML capabilities for early detection of cognitive decline among socially vulnerable older adults. Currently, sensing devices are not readily available to this population due to cost and information barriers. Our sensing device has the potential to identify individuals at risk for cognitive decline by assessing their level of physical function by tracking their in-home activities and mobility behaviors, at a low cost.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/53447.

Trends in Memory Function and Memory Impairment Among Older Adults in the United States and Europe, 1996-2018

BACKGROUND

Single-country studies document varying time trends in memory function and impairment. Comparative analyses are limited.

METHODS

We used self-respondent data on adults aged 50+ years in 13 countries from 3 surveys (United States: Health and Retirement Study, 1998-2018; England: English Longitudinal Study of Ageing, 2002-2018; 11 European countries: Survey of Health, Ageing and Retirement in Europe, 2004-2019). Memory is measured with tests of immediate and delayed word recall. Unweighted age- and gender-adjusted mixed effects regression models as well as models with adjustments for additional sociodemographic characteristics and health behaviors were examined. Heterogeneity in trends by gender, age group, and educational attainment was measured.

RESULTS

The age-adjusted 10-year improvement in average test score is 0.04 standard deviations (SDs) (95% confidence interval [CI]: 0.03, 0.05) in the United States, 0.17 SDs (95% CI: 0.15, 0.19) in England, and 0.24 SDs (95% CI: 0.23, 0.25) in SHARE countries. Trends are largely similar across gender, age groups, and educational attainment. Regional differences in trends remain after adjustment for potential mechanisms. The difference between the United States and other countries is particularly large under 75 years of age compared to 75 years and older.

CONCLUSIONS

Pace of improvement in memory function varies strongly across countries. On average, the 11 European countries studied had the fastest improvement, followed by England. The trend in the United States indicates improvement, but at a much slower pace compared to that in England and other European countries. Uncovering the causes for the cross-country heterogeneity in time trends, and in particular the reasons for the comparatively poor performance of the United States, should be both a research and public health priority.

A health-equity framework for tailoring digital non-pharmacological interventions in aging

If designed with health equity in mind, digital non-pharmacological interventions (NPIs) represent a cost-effective, scalable means of reducing health disparities associated with age-related mental health disorders in older adults in the USA. However, disparities in technological access, literacy and effectiveness can limit the impact of these interventions in older adults from disadvantaged groups. We present a health-equity-promoting framework for the development of digital NPIs for age-related mental health disorders and provide an example from the literature that highlights how interventions can be targeted at specific groups to increase technological access, literacy and effectiveness to ensure that these interventions can meet their potential of reducing health disparities.

Sex-specific dementia risk in known or suspected obstructive sleep apnea: a 10-year longitudinal population-based study

Study Objectives

To evaluate sex-specific associations between known or suspected obstructive sleep apnea (OSA) and dementia risk over 10 years among older women and men.

Methods

This study included 18 815 women and men age 50+ years (dementia-free at baseline) who participated in the Health and Retirement Study (HRS), a nationally representative cohort of US adults. Presence of OSA was defined by self-reported diagnosis or key HRS items that correspond to elements of a validated OSA screening tool (STOP-Bang). Incident dementia cases were identified using a validated, HRS-based algorithm derived from objective cognitive assessments. Survey-weighted regression models based on pseudo-values were utilized to estimate sex- and age-specific differences in cumulative incidence of dementia by OSA status.

Results

Data from 18 815 adults were analyzed, of which 9% of women and 8% of men (weighted proportions) met criteria for incident dementia. Known/suspected OSA was more prevalent in men than in women (weighted proportions 68% vs. 31%). Unadjusted sex-stratified analyses showed that known/suspected OSA was associated with higher cumulative incidence of dementia across ages 60-84 years for women and men. By age 80, relative to adults without known/suspected OSA, the cumulative incidence of dementia was 4.7% higher (CI 2.8%, 6.7%) for women with known/suspected OSA, and 2.5% (CI 0.5%, 4.5%) for men with known/suspected OSA, respectively. Adjusted associations between age-specific OSA and cumulative incidence of dementia attenuated for both women and men but remained statistically significant.

Conclusions

OSA contributes to dementia risk in older adults, particularly women. This study illuminates the impact of a potentially modifiable yet frequently overlooked risk factor for dementia onset.

Psychosocial Health and the Association Between Cerebral Small Vessel Disease Markers With Dementia: The ARIC Study

BACKGROUND

Associations between magnetic resonance imaging markers of cerebral small vessel disease (CSVD) and dementia risk in older adults have been established, but it remains unclear how lifestyle factors, including psychosocial health, may modify this association.

METHODS

Social support and social isolation were assessed among participants of the community-based ARIC (Atherosclerosis Risk in Communities) Study, via self-reported questionnaires (1990-1992). Following categorization of both factors, participants were classified as having strong or poor mid-life social relationships. At visit 5 (2011-2013), participants underwent 3T brain magnetic resonance imaging quantifying CSVD measures: white matter hyperintensity volume, microbleeds (subcortical), infarcts (lacunar), and white matter integrity (diffusion tensor imaging). Incident dementia cases were identified from the time of imaging through December 31, 2020 with ongoing surveillance. Associations between CSVD magnetic resonance imaging markers and incident dementia were evaluated using Cox proportional-hazard regressions adjusted for demographic and additional risk factors (from visit 2). Effect modification by mid-life social relationships was evaluated.

RESULTS

Of the 1977 participants with magnetic resonance imaging, 1617 participants (60.7% women; 26.5% Black participants; mean age at visit 2, 55.4 years) were examined. In this sample, mid-life social relationships significantly modified the association between white matter hyperintensity volume and dementia risk (P interaction=0.001). Greater white matter hyperintensity volume was significantly associated with risk of dementia in all participants, yet, more substantially in those with poor (hazard ratio, 1.84 [95% CI, 1.49-2.27]) versus strong (hazard ratio, 1.26 [95% CI, 1.08-1.47]) mid-life social relationships. Although not statistically significant, subcortical microbleeds in participants with poor mid-life social relationships were associated with a greater risk of dementia, relative to those with strong social relationships, in whom subcortical microbleeds were no longer associated with elevated dementia risk.

CONCLUSIONS

The elevated risk of dementia associated with CSVD may be reduced in participants with strong mid-life social relationships. Future studies evaluating psychosocial health through the life course and the mechanisms by which they modify the relationship between CSVD and dementia are needed.

Modeling the Population Equity of Alzheimer Disease Treatments in the US

Importance

The arrival of new medications for Alzheimer disease (AD) has prompted efforts to measure their value using conventional cost-effectiveness analyses; however, these analyses focus on how much health improvement new medications generate per dollar spent. As AD disproportionately affects older adults, women, racial and ethnic minority individuals, and individuals with lower socioeconomic and educational levels, it is critical to also examine the health equity outcomes of treatment.

Objective

To estimate the health equity impact of a hypothetical disease-modifying treatment for early AD in the US and to examine targeted policies to mitigate health care disparities.

Design, Setting, and Participants

This economic evaluation, which used a distributional cost-effectiveness analysis, was conducted from June 16, 2022, to January 11, 2024. The study included subgroups defined by race and ethnicity and by social vulnerability quintiles in the US.

Exposures

A hypothetical disease-modifying treatment compared with best supportive care.

Main Outcomes and Measures

The main outcomes were population-level quality-adjusted life-years (QALYs), lifetime costs, and net health benefits. The social welfare impact and change in health inequality were estimated using the Atkinson index.

Results

The distributional cost-effectiveness analysis simulated 316 037 100 individuals from the US population, including 25 subgroups defined by 5 categories of race and ethnicity and population quintiles of social vulnerability, with the fifth quintile representing the most socially vulnerable group. At an opportunity cost benchmark of $150 000 per QALY, treatment was associated with improved population health, adding 28 197 QALYs per year to the US population. Accounting for health inequality preferences (using an aversion level of 11, based on an Atkinson inequality aversion parameter that can range from 0 to infinity, with higher values assigning greater weight to health gains that accrue to the population with the lowest lifetime quality-adjusted life expectancy), treatment was associated with a 0.009% reduction in existing population health inequalities annually. Scenario analyses examining earlier and expanded treatment access suggested a population health improvement of up to 221 358 QALYs.

Conclusions and Relevance

The findings of this economic evaluation suggest that treatment for AD could improve population health and health equity. Policies to enable earlier diagnosis and treatment initiation, as well as expanded access to treatment, may further improve treatment and health equity impacts.

Case Definition for Diagnosed Alzheimer Disease and Related Dementias in Medicare

Importance

Lack of a US dementia surveillance system hinders efforts to support and address disparities among persons living with Alzheimer disease and related dementias (ADRD).

Objective

To review diagnosis and prescription drug code ADRD identification algorithms to develop and implement case definitions for national surveillance.

Design, Setting, and Participants

In this cross-sectional study, a systematic literature review was conducted to identify unique International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) and prescription drug codes used by researchers to identify ADRD in administrative records. Code frequency of use, characteristics of beneficiaries identified by codes, and expert and author consensus around code definitions informed code placement into categories indicating highly likely, likely, and possible ADRD. These definitions were applied cross-sectionally to 2017 to 2019 Medicare fee-for-service (FFS) claims and Medicare Advantage (MA) encounter data to classify January 2019 Medicare enrollees. Data analysis was conducted from September 2022 to March 2024.

Exposures

ICD-10-CM and national drug codes in FFS claims or MA encounters.

Main Outcomes and Measures

The primary outcome was counts and rates of beneficiaries meeting each case definition. Category-specific age, sex, race and ethnicity, MA enrollment, dual-eligibility, long-term care utilization, mortality, and rural residence distributions, as well as frailty scores and FFS monthly expenditures were also analyzed. Beneficiary characteristics were compared across categories, and age-standardized to minimize confounding by age.

Results

Of the 60 000 869 beneficiaries included (50 853 806 aged 65 years or older [84.8%]; 32 567 891 female [54.3%]; 5 555 571 Hispanic [9.3%]; 6 318 194 non-Hispanic Black [10.5%]; 44 384 980 non-Hispanic White [74.0%]), there were 4 312 496 (7.2%) with highly likely ADRD, 1 124 080 (1.9%) with likely ADRD, and 2 572 176 (4.3%) with possible ADRD, totaling more than 8.0 million with diagnostic evidence of at least possible ADRD. These beneficiaries were older, more frail, more likely to be female, more likely to be dual-eligible, more likely to use long-term care, and more likely to die in 2019 compared with beneficiaries with no evidence of ADRD. These differences became larger when moving from the possible ADRD group to the highly likely ADRD group. Mean (SD) FFS monthly spending was $2966 ($4921) among beneficiaries with highly likely ADRD compared with $936 ($2952) for beneficiaries with no evidence of ADRD. Differences persisted after age standardization.

Conclusions and Relevance

This cross-sectional study of 2019 Medicare beneficiaries identified more than 5.4 million Medicare beneficiaries with evidence of at least likely ADRD in 2019 using the diagnostic case definition. Pending validation against clinical and other methods of ascertainment, this approach can be adopted provisionally for national surveillance.

Identification of amnestic mild cognitive impairment among Black and White community-dwelling older adults using NIH Toolbox Cognition tablet battery

OBJECTIVES

Identify which NIH Toolbox Cognition Battery (NIHTB-CB) subtest(s) best differentiate healthy controls (HC) from those with amnestic mild cognitive impairment (aMCI) and compare the discriminant accuracy between a model using a priori "Norm Adjusted" scores versus "Unadjusted" standard scores with age, sex, race/ethnicity, and education controlled for within the model. Racial differences were also examined.

METHODS

Participants were Black/African American (B/AA) and White consensus-confirmed (HC = 96; aMCI = 62) adults 60-85 years old that completed the NIHTB-CB for tablet. Discriminant function analysis (DFA) was used in the Total Sample and separately for B/AA (n = 80) and White participants (n = 78).

RESULTS

Picture Sequence Memory (an episodic memory task) was the highest loading coefficient across all DFA models. When stratified by race, differences were noted in the pattern of the highest loading coefficients within the DFAs. However, the overall discriminant accuracy of the DFA models in identifying HCs and those with aMCI did not differ significantly by race (B/AA, White) or model/score type (Norm Adjusted versus Unadjusted).

CONCLUSIONS

Racial differences were noted despite the use of normalized scores or demographic covariates-highlighting the importance of including underrepresented groups in research. While the models were fairly accurate at identifying consensus-confirmed HCs, the models proved less accurate at identifying White participants with an aMCI diagnosis. In clinical settings, further work is needed to optimize computerized batteries and the use of NIHTB-CB norm adjusted scores is recommended. In research settings, demographically corrected scores or within model correction is suggested.

Early-Life Circumstances and Racial Disparities in Cognition Among Older Adults in the US

Importance

Given the critical role of neurocognitive development in early life, understanding the association between early-life circumstances and racial disparities in cognition has important implications.

Objective

To assess whether racial differences in early-life circumstances are collectively and individually associated with racial disparities in late-life cognition among older adults in the US.

Design, Setting, and Participants

This cross-sectional study used comprehensive life history data from the Health and Retirement Study, a nationally representative survey of US adults 50 years or older. Data analyses were performed from August 9, 2022, to January 20, 2024.

Main Outcomes and Measures

Racial differences in early-life circumstances and racial disparities in late-life cognition were investigated using a Blinder-Oaxaca decomposition regression model. Cognitive outcomes, including cognitive score and cognitive impairment, were evaluated using the Telephone Interview for Cognitive Status. Early-life educational experiences were primary explanatory variables; early-life cohort, regional, financial, health, trauma, family relationship factors, and educational attainment were additional explanatory variables; demographic and genetic factors were covariates.

Results

The study sample comprised 9015 participants; 1634 non-Hispanic Black (hereafter, Black) individuals (18.1%) and 7381 non-Hispanic White (hereafter, White) individuals (81.9%). Among Black participants, the mean (SD) age was 69.2 (9.2) years and 1094 (67.0%) were women. Among White participants, the mean (SD) age was 73.2 (10.1) years and 4410 (59.7%) were women. Cognitive scores (scale, 0-27) were significantly lower among Black participants (13.5 [95% CI, 13.3-13.7] points) than among White participants (15.8 [95% CI, 15.7-15.9] points), while the prevalence of cognitive impairment (cognitive score <12) was significantly higher among Black participants (33.6 [95% CI, 31.3-35.9] percentage points [ppt]) than among White participants (16.4 [95% CI, 15.6-17.2] ppt). Substantial racial differences were observed in early-life circumstances. Overall, differences in early-life circumstances were associated with 61.5% of the racial disparities in cognitive score (1.4 [95% CI, 0.88-2.0] points), and 82.3% of the racial disparities in cognitive impairment (14.2 [95% CI, 8.8-19.5] ppt), respectively. In multivariable analyses, early-life educational experiences were associated with 35.2% of the disparities in cognitive score and 48.6% in cognitive impairment. Notably, school racial segregation (all segregated schooling before college) was associated with 28.8% to 39.7% of the racial disparities in cognition. These findings were consistent in a series of sensitivity analyses.

Conclusions and Relevance

The findings of this cross-sectional study suggest that less favorable early-life circumstances are associated with clinically meaningful racial disparities in late-life cognition. Policies that improve educational equity have the potential to reduce racial disparities in cognition in older ages. Clinicians may leverage early-life circumstances to promote the screening, prevention, and interventions of cognitive impairment more efficiently, thereby promoting health equity.

Traumatic Brain Injury, Seizures, and Cognitive Impairment Among Older Adults

Importance

Traumatic brain injury (TBI), seizures, and dementia increase with age. There is a gap in understanding the associations of TBI, seizures, and medications such as antiseizure and antipsychotics with the progression of cognitive impairment across racial and ethnic groups.

Objective

To investigate the association of TBI and seizures with the risk of cognitive impairment among cognitively normal older adults and the role of medications in moderating the association.

Design, Setting, and Participants

This multicenter cohort study was a secondary analysis of the Uniform Data Set collected between June 1, 2005, and June 30, 2020, from the National Alzheimer's Coordination Center. Statistical analysis was performed from February 1 to April 3, 2024. Data were collected from participants from 36 Alzheimer's Disease Research Centers in the US who were 65 years or older at baseline, cognitively normal at baseline (Clinical Dementia Rating of 0 and no impairment based on a presumptive etiologic diagnosis of AD), and had complete information on race and ethnicity, age, sex, educational level, and apolipoprotein E genotype.

Exposure

Health history of TBI, seizures, or both conditions.

Main Outcomes and Measures

Progression to cognitive impairment measured by a Clinical Dementia Rating greater than 0.

Results

Among the cohort of 7180 older adults (median age, 74 years [range, 65-102 years]; 4729 women [65.9%]), 1036 were African American or Black (14.4%), 21 were American Indian or Alaska Native (0.3%), 143 were Asian (2.0%), 332 were Hispanic (4.6%), and 5648 were non-Hispanic White (78.7%); the median educational level was 16.0 years (range, 1.0-29.0 years). After adjustment for selection basis using propensity score weighting, seizure was associated with a 40% higher risk of cognitive impairment (hazard ratio [HR], 1.40; 95% CI, 1.19-1.65), TBI with a 25% higher risk of cognitive impairment (HR, 1.25; 95% CI, 1.17-1.34), and both seizure and TBI were associated with a 57% higher risk (HR, 1.57; 95% CI, 1.23-2.01). The interaction models indicated that Hispanic participants with TBI and seizures had a higher risk of cognitive impairment compared with other racial and ethnic groups. The use of antiseizure medications (HR, 1.23; 95% CI, 0.99-1.53), antidepressants (HR, 1.32; 95% CI, 1.17-1.50), and antipsychotics (HR, 2.15; 95% CI, 1.18-3.89) was associated with a higher risk of cognitive impairment, while anxiolytic, sedative, or hypnotic use (HR, 0.88; 95% CI, 0.83-0.94) was associated with a lower risk.

Conclusions and Relevance

This study highlights the importance of addressing TBI and seizures as risk factors for cognitive impairment among older adults. Addressing the broader social determinants of health and bridging the health divide across various racial and ethnic groups are essential for the comprehensive management and prevention of dementia.

The mediating role of systemic inflammation and moderating role of racialization in disparities in incident dementia

BACKGROUND

Exposure to systemic racism is linked to increased dementia burden. To assess systemic inflammation as a potential pathway linking exposure to racism and dementia disparities, we investigated the mediating role of C-reactive protein (CRP), a systemic inflammation marker, and the moderating role of the racialization process in incident dementia.

METHODS

In the US Health and Retirement Study (n = 6,908), serum CRP was measured at baseline (2006, 2008 waves). Incident dementia was classified by cognitive tests over a six-year follow-up. Self-reported racialized categories were a proxy for exposure to the racialization process. We decomposed racialized disparities in dementia incidence (non-Hispanic Black and/or Hispanic vs. non-Hispanic white) into 1) the mediated effect of CRP, 2) the moderated portion attributable to the interaction between racialized group membership and CRP, and 3) the controlled direct effect (other pathways through which racism operates).

RESULTS

The 6-year cumulative incidence of dementia is 12%. Among minoritized participants (i.e., non-Hispanic Black and/or Hispanic), high CRP levels ( ≥ 75th percentile or 4.73μg/mL) are associated with 1.26 (95%CI: 0.98, 1.62) times greater risk of incident dementia than low CRP ( < 4.73μg/mL). Decomposition analysis comparing minoritized versus non-Hispanic white participants shows that the mediating effect of CRP accounts for 3% (95% CI: 0%, 6%) of the racial disparity, while the interaction effect between minoritized group status and high CRP accounts for 14% (95% CI: 1%, 27%) of the disparity. Findings are robust to potential violations of causal mediation assumptions.

CONCLUSIONS

Minoritized group membership modifies the relationship between systemic inflammation and incident dementia.

Baseline levels and longitudinal changes in plasma Aβ42/40 among Black and white individuals

Blood-based biomarkers of Alzheimer disease (AD) may facilitate testing of historically under-represented groups. The Study of Race to Understand Alzheimer Biomarkers (SORTOUT-AB) is a multi-center longitudinal study to compare AD biomarkers in participants who identify their race as either Black or white. Plasma samples from 324 Black and 1,547 white participants underwent analysis with C2N Diagnostics' PrecivityAD test for Aβ42 and Aβ40. Compared to white individuals, Black individuals had higher average plasma Aβ42/40 levels at baseline, consistent with a lower average level of amyloid pathology. Interestingly, this difference resulted from lower average levels of plasma Aβ40 in Black participants. Despite the differences, Black and white individuals had similar longitudinal rates of change in Aβ42/40, consistent with a similar rate of amyloid accumulation. Our results agree with multiple recent studies demonstrating a lower prevalence of amyloid pathology in Black individuals, and additionally suggest that amyloid accumulates consistently across both groups.

The network structures of depressive and insomnia symptoms among cancer patients using propensity score matching: Findings from the Health and Retirement Study (HRS)

OBJECTIVE

Both depression and insomnia are found to be more prevalent in cancer patients compared to the general population. This study compared the network structures of depression and insomnia among cancer patients versus cancer-free participants (controls hereafter).

METHOD

The 8-item Center for Epidemiological Studies Depression Scale (CESD-8) and the 4-item Jenkins Sleep Scale (JSS-4) were used to measure depressive and insomnia symptoms, respectively. Propensity score matching (PSM) was used to construct the control group using data from the Health and Retirement Study (HRS). In total, a sample consisting of 2216 cancer patients and 2216 controls was constructed. Central (influential) and bridge symptoms were estimated using the expected influence (EI) and bridge expected influence (bridge EI), respectively. Network stability was assessed using the case-dropping bootstrap method.

RESULT

The prevalence of depression (CESD-8 total score ≥ 4) in cancer patients was significantly higher compared to the control group (28.56 % vs. 24.73 %; P = 0.004). Cancer patients also had more severe depressive symptoms relative to controls, but there was no significant group difference for insomnia symptoms. The network structures of depressive and insomnia symptoms were comparable between cancer patients and controls. "Felt sadness" (EI: 6.866 in cancer patients; EI: 5.861 in controls), "Felt unhappy" (EI: 6.371 in cancer patients; EI: 5.720 in controls) and "Felt depressed" (EI: 6.003 in cancer patients; EI: 5.880 in controls) emerged as the key central symptoms, and "Felt tired in morning" (bridge EI: 1.870 in cancer patients; EI: 1.266 in controls) and "Everything was an effort" (bridge EI: 1.046 in cancer patients; EI: 0.921 in controls) were the key bridge symptoms across both groups.

CONCLUSION

Although cancer patients had more frequent and severe depressive symptoms compared to controls, no significant difference was observed in the network structure or strength of the depressive and insomnia symptoms. Consequently, psychosocial interventions for treating depression and insomnia in the general population could be equally applicable for cancer patients who experience depression and insomnia.

Social Environment, Lifestyle, and Genetic Predisposition With Dementia Risk: A Long-Term Longitudinal Study Among Older Adults

BACKGROUND

The role of social environment, that is, the aggregate effect of social determinants of health (SDOHs), in determining dementia is unclear.

METHODS

We developed a novel polysocial risk score for dementia based on 19 SDOH among 5 199 participants in the Health and Retirement Study, United States, to measure the social environmental risk. We used a survival analysis approach to assess the association between social environment and dementia risk in 2006-2020. We further studied the interaction between social environment and lifestyles, and explored racial disparities.

RESULTS

The study participants (mean age = 73.4 years, SD = 8.3; 58.0% female; 11.6% African American) were followed up for an average of 6.2 years, and 1 089 participants developed dementia. Every 1-point increase in the polysocial risk score (ranging from 0 to 10) was associated with a 21.6% higher risk (adjusted hazard ratio [aHR] = 1.21, 95% confidence intervals [95% CI] = 1.15-1.26) of developing dementia, other things being equal. Among participants with high social environmental risk, regular exercise and moderate drinking were associated with a 43%-60% lower risk of developing dementia (p < .001). In addition, African Americans were 1.3 times (aHR = 2.28, 95% CI = 1.96-2.66) more likely to develop dementia than European Americans, other things being equal.

CONCLUSION

An adverse social environment is linked to higher dementia risk, but healthy lifestyles can partially offset the increased social environmental risk. The polysocial risk score can complement the existing risk tools to identify high-risk older populations, and guide the design of targeted social environmental interventions, particularly focusing on improving the companionship of the older people, to prevent dementia.

Subjective cognitive concerns, APOE ε4, PTSD symptoms, and risk for dementia among older veterans

BACKGROUND

Posttraumatic stress disorder (PTSD) and traumatic brain injury (TBI) are associated with self-reported problems with cognition as well as risk for Alzheimer's disease and related dementias (ADRD). Overlapping symptom profiles observed in cognitive disorders, psychiatric disorders, and environmental exposures (e.g., head injury) can complicate the detection of early signs of ADRD. The interplay between PTSD, head injury, subjective (self-reported) cognitive concerns and genetic risk for ADRD is also not well understood, particularly in diverse ancestry groups.

METHODS

Using data from the U.S. Department of Veterans Affairs (VA) Million Veteran Program (MVP), we examined the relationship between dementia risk factors (APOE ε4, PTSD, TBI) and subjective cognitive concerns (SCC) measured in individuals of European (n = 140,921), African (n = 15,788), and Hispanic (n = 8,064) ancestry (EA, AA, and HA, respectively). We then used data from the VA electronic medical record to perform a retrospective survival analysis evaluating PTSD, TBI, APOE ε4, and SCC and their associations with risk of conversion to ADRD in Veterans aged 65 and older.

RESULTS

PTSD symptoms (B = 0.50-0.52, p < 1E-250) and probable TBI (B = 0.05-0.19, p = 1.51E-07 - 0.002) were positively associated with SCC across all three ancestry groups. APOE ε4 was associated with greater SCC in EA Veterans aged 65 and older (B = 0.037, p = 1.88E-12). Results of Cox models indicated that PTSD symptoms (hazard ratio [HR] = 1.13-1.21), APOE ε4 (HR = 1.73-2.05) and SCC (HR = 1.18-1.37) were positively associated with risk for ADRD across all three ancestry groups. In the EA group, probable TBI also contributed to increased risk of ADRD (HR = 1.18).

CONCLUSIONS

The findings underscore the value of SCC as an indicator of ADRD risk in Veterans 65 and older when considered in conjunction with other influential genetic, clinical, and demographic risk factors.

The longitudinal trajectory of CSF sTREM2: the alzheimer's disease neuroimaging initiative

BACKGROUND

The soluble triggering receptor expressed on myeloid cells 2 (sTREM2) in cerebrospinal fluid (CSF) is considered a biomarker of microglia activity. The objective of this study was to investigate the trajectory of CSF sTREM2 levels over time and examine its association with sex.

METHODS

A total of 1,017 participants from the Alzheimer's Disease Neuroimaging Initiative Study (ADNI) with at least one CSF sTREM2 record were included. The trajectory of CSF sTREM2 was analyzed using a growth curve model. The association between CSF sTREM2 levels and sex was assessed using linear mixed-effect models.

RESULTS

CSF sTREM2 levels were increased with age over time (P < 0.0001). No significant sex difference was observed in sTREM2 levels across the entire sample; however, among the APOE ε4 allele carriers, women exhibited significantly higher sTREM2 levels than men (β = 0.146, P = 0.002).

CONCLUSION

Our findings highlight the association between CSF sTREM2 levels and age-related increments, underscoring the potential influence of aging on sTREM2 dynamics. Furthermore, our observations indicate a noteworthy association between sex and CSF sTREM2 levels, particularly in individuals carrying the APOE ε4 allele.

Testing the 'Faith Moves Mountains model' to increase Alzheimer's disease awareness, detection, and diagnosis among rural, racially, and ethnically diverse older adults

OBJECTIVES

Racially and ethnically diverse populations have recently contributed to the majority of rural and small-town growth. Consequently, the disproportionately high risk and prevalence of Alzheimer's disease and related dementias (ADRD) among rural and minoritized older residents will likely increase. To address this threat, we tested the hypotheses that (1) a faith-based, resident-led approach would increase basic ADRD knowledge and diagnosis, and (2) older age, female gender, lower educational levels, and more years lived rural would predict number of referrals, new dementia diagnoses, and treatment.

METHODS

An adaptation of Schoenberg's Faith Moves Mountains model, previously successful in detection and management of other chronic illnesses in rural settings, guided this community-based participatory research. Local faith community members were trained as research assistants to recruit, administer surveys, conduct brief memory assessments, teach brain health strategies, and follow-up with residents. Outreaches were offered virtually during the pandemic, then in-person monthly at rotating church sites, and repeated ∼1 year later.

RESULTS

This rural sample was racially and ethnically diverse (74.5% non-White), with 28% reporting eight or less years of formal education. Findings included that referrals and years lived rural were significant and positive predictors of new ADRD treatments [(b = 3.74, χ2(1, n = 235) = 13.01, p < 0.001); (b = 0.02, χ2(1, n = 235 = 3.93, p = 0.048)], respectively, regardless of participant characteristics.

CONCLUSION

Resident-led action research in rural, diverse, faith communities is a successful approach to increasing ADRD disease knowledge, detection, diagnosis, and treatment.

Disparate benefits of higher childhood socioeconomic status on cognition in young adulthood by intersectional social positions

OBJECTIVES

Emerging evidence supports the protective effects of higher childhood socioeconomic status (cSES) on cognition over the life course. However, less understood is if higher cSES confers benefits equally across intersecting social positions. Guided by a situational intersectionality perspective and the theory of Minority Diminished Returns (MDR), this study examined the extent to which associations between cSES and cognition in young adulthood are jointly moderated by racialized identity and region of childhood residence.

METHODS

Using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), we used multilevel modeling to test associations between cSES and delayed recall and working memory 14 years later when participants were ages 25-34. Further, we examined the influence of racialized identity and region of childhood residence on these associations.

RESULTS

Higher cSES was associated with higher delayed recall and working memory scores across social positions. However, the strength of the association between higher cSES and working memory differed across racialized subgroups and region of childhood residence. We found a statistically significant three-way interaction between cSES, race and region of childhood residence. Of particular important, a small yet statistically robust association was found in all groups, but was especially strong among White Southerners and especially weak among Black participants from the South.

CONCLUSIONS

This study contributes to a growing body of research indicating that the protective effects of higher cSES on cognition are not universal across subgroups of intersecting social positions, consistent with the theory of MDR. These findings provide evidence for the importance of considering the role of systemic racism across geographic contexts as part of initiatives to promote equity in life course cognitive aging and brain health.

Analysis of gene expression in the postmortem brain of neurotypical Black Americans reveals contributions of genetic ancestry

Ancestral differences in genomic variation affect the regulation of gene expression; however, most gene expression studies have been limited to European ancestry samples or adjusted to identify ancestry-independent associations. Here, we instead examined the impact of genetic ancestry on gene expression and DNA methylation in the postmortem brain tissue of admixed Black American neurotypical individuals to identify ancestry-dependent and ancestry-independent contributions. Ancestry-associated differentially expressed genes (DEGs), transcripts and gene networks, while notably not implicating neurons, are enriched for genes related to the immune response and vascular tissue and explain up to 26% of heritability for ischemic stroke, 27% of heritability for Parkinson disease and 30% of heritability for Alzheimer's disease. Ancestry-associated DEGs also show general enrichment for the heritability of diverse immune-related traits but depletion for psychiatric-related traits. We also compared Black and non-Hispanic white Americans, confirming most ancestry-associated DEGs. Our results delineate the extent to which genetic ancestry affects differences in gene expression in the human brain and the implications for brain illness risk.

Antiviral Treatment and Response are Associated With Lower Risk of Dementia Among Hepatitis C Virus-Infected Patients

OBJECTIVE

Eradication of hepatitis C virus (HCV) infection has been linked with improvement in neurocognitive function, but few studies have evaluated the effect of antiviral treatment/ response on risk of dementia. Using data from the Chronic Hepatitis Cohort Study (CHeCS), we investigated how antiviral therapy impacts the risk of developing dementia among patients with HCV.

METHODS

A total of 17,485 HCV patients were followed until incidence of dementia, death, or last follow-up. We used an extended landmark modeling approach, which included time-varying covariates and propensity score justification for treatment selection bias, as well as generalized estimating equations (GEE) with a link function as multinominal distribution for a discrete time-to-event data. Death was considered a competing risk.

RESULTS

After 15 years of follow-up, 342 patients were diagnosed with incident dementia. Patients who achieved sustained virological response (SVR) had significantly decreased risk of dementia compared to untreated patients, with hazard ratios (HRs) of 0.32 (95% CI 0.22-0.46) among patients who received direct-acting antiviral (DAA) treatment and 0.41 (95% CI 0.26-0.60) for interferon-based (IFN) treatment. Risk reduction remained even when patients failed antiviral treatment (HR 0.38, 95% CI 0.38-0.51). Patients with cirrhosis, Black/African American patients, and those without private insurance were at significantly higher risk of dementia.

CONCLUSION

Antiviral treatment independently reduced the risk of dementia among HCV patients, regardless of cirrhosis. Our findings support the importance of initiation antiviral therapy in chronic HCV-infected patients.

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.

Histories of neighborhood socioeconomic status contribute to race differences in later-life cognition

INTRODUCTION

Neighborhood characteristics are increasingly implicated in cognitive health disparities, but no research has investigated how the historical context of neighborhoods shapes these disparities.

METHODS

Four hundred sixty-four Black (55%) and White older adults (Mage = 63.6) were drawn from the Michigan Cognitive Aging Project, a community-based, prospective study of older adults. Participants' addresses at baseline (2017-2020) were geocoded and linked to 2000-2017 measures of neighborhood socioeconomic status (NSES): disadvantage [NDis] and affluence [NAff]. Latent class growth analysis (LCGA) characterized 18 interpolated year trajectories of NSES across 1344 census tracts. Path analysis examined whether NSES trajectory classes mediated the association between race and a global cognition composite.

RESULTS

LCGA identified three NDis and two NAff trajectory classes, which were associated with participant race. Only one NDis class was associated with cognition, and it mediated the association between the Black race and cognition.

DISCUSSION

Disinvestment in neighborhoods may be particularly salient in race disparities in cognitive function.

HIGHLIGHTS

Race is implicated in the likelihood of living in more disadvantaged neighborhoods. Historical trends in neighborhood disadvantage are associated with cognitive function in older adulthood. Identifying patterns of neighborhood change may inform neighborhood-level interventions.

A review of dairy food intake for improving health among black geriatrics in the US

The transition to older adulthood is generally marked by progressive declines in body composition, metabolism, cognitive function, and immunity. For socially disadvantaged geriatric populations such as Black Americans, this life stage may also include additional stressors, including dealing with discrimination, poor access to healthcare, and food insecurity. These types of chronic stressors are linked to a higher allostatic load, which is associated with accelerated biological aging, higher rates of adverse health outcomes, and an overall lower quality of life. Of the numerous factors involved in healthy aging, a growing body of research indicates that consuming a higher quality diet that is rich in fruits, vegetables, whole grains, protein foods, and dairy foods, is one of the most potent factors for helping to protect against age-related disease progression. Among the food groups listed above that are recommended by the 2020-2025 Dietary Guidelines for Americans dairy foods are unique in their ability to provide several of the essential nutrients (e.g., high-quality protein, calcium, potassium, vitamin B12, and vitamin D in fortified products) that are most often inadequately consumed by older Black Americans. However, dairy is the most inadequately consumed food group in the US, with older Black adults consuming fewer than half of the 3 daily recommended servings. Therefore, this review examines the current body of evidence exploring the links between dairy intake and age-related disease risk, with a special focus on health and disparities among older Black Americans. Overall, the evidence from most systematic reviews and/or meta-analyses focused on dairy intake and musculoskeletal health suggest that higher dairy intake across the life span, and especially from fermented and fortified products, is associated with better bone and muscle health outcomes in older adults. The evidence on dairy intake and neurocognitive and immune outcomes among older adults holds significant promise for potential benefits, but most of these results are sourced from individual studies or narrative reviews and are not currently corroborated in systematic reviews or meta-analyses. Additionally, most of the research on dairy intake and age-related disease risk has been performed in White populations and can only be extrapolated to Black populations. Nonetheless, older Black populations who do not meet the DGA recommended 3 servings of dairy per day due to lactose intolerance, restrictive dietary patterns, or for other reasons, are likely falling short of several of the nutritional requirements necessary to support healthy aging.

Relationships of Cognitive Measures with Cerebrospinal Fluid but Not Imaging Biomarkers of Alzheimer Disease Vary between Black and White Individuals

OBJECTIVE

Biomarkers of Alzheimer disease vary between groups of self-identified Black and White individuals in some studies. This study examined whether the relationships between biomarkers or between biomarkers and cognitive measures varied by racialized groups.

METHODS

Cerebrospinal fluid (CSF), amyloid positron emission tomography (PET), and magnetic resonance imaging measures were harmonized across four studies of memory and aging. Spearman correlations between biomarkers and between biomarkers and cognitive measures were calculated within each racialized group, then compared between groups by standard normal tests after Fisher's Z-transformations.

RESULTS

The harmonized dataset included at least one biomarker measurement from 495 Black and 2,600 White participants. The mean age was similar between racialized groups. However, Black participants were less likely to have cognitive impairment (28% vs 36%) and had less abnormality of some CSF biomarkers including CSF Aβ42/40, total tau, p-tau181, and neurofilament light. CSF Aβ42/40 was negatively correlated with total tau and p-tau181 in both groups, but at a smaller magnitude in Black individuals. CSF Aβ42/40, total tau, and p-tau181 had weaker correlations with cognitive measures, especially episodic memory, in Black than White participants. Correlations of amyloid measures between CSF (Aβ42/40, Aβ42) and PET imaging were also weaker in Black than White participants. Importantly, no differences based on race were found in correlations between different imaging biomarkers, or in correlations between imaging biomarkers and cognitive measures.

INTERPRETATION

Relationships between CSF biomarkers but not imaging biomarkers varied by racialized groups. Imaging biomarkers performed more consistently across racialized groups in associations with cognitive measures. ANN NEUROL 2024;95:495-506.

Care sequences leading to the diagnosis of Alzheimer's disease and related dementias: An analysis of electronic health records

BACKGROUND

We examined the sequences of clinical care leading to diagnoses of Alzheimer's disease and related dementias (ADRD) using electronic health records from a large academic medical center.

METHODS

We included patients aged 65+ with their first ADRD diagnoses from January 1, 2014 to December 31, 2019. Using state sequence analysis, care sequences were defined by the ordering of healthcare utilizations occurred in the 2 years before ADRD diagnosis.

RESULTS

Of 3621 patients (median age 80), nearly half followed a care sequence of having one primary care visit close to their ADRD diagnosis. Additional care sequences included periodic (n = 322, 8.9%) and multiple (n = 416, 11.5%) outpatient visits to primary care and having one (n = 395, 10.9%), multiple (n = 469, 13.0%), or highly frequent (n = 357, 10.7%) outpatient visits to other specialties. Patients' sociodemographic traits contributed to the variability in care sequences.

CONCLUSIONS

Several distinct patterns of care leading to ADRD diagnoses were identified. Integrated care models are needed to promote early identification of ADRD.

HIGHLIGHTS

Dementia patients followed distinct care pathways prior to their dementia diagnoses. Key sociodemographic traits contributed to the variation in the sequences of care. Racial differences in the sequencing of care were also found, but only in women.

Mechanisms underlying the association between adverse childhood experiences and racial disparities in later-life cognition

OBJECTIVE

Adverse childhood experiences (ACEs) may be a risk factor for later-life cognitive disorders such as dementia; however, few studies have investigated underlying mechanisms, such as cardiovascular health and depressive symptoms, in a health disparities framework.

METHOD

418 community-dwelling adults (50% nonHispanic Black, 50% nonHispanic White) aged 55+ from the Michigan Cognitive Aging Project retrospectively reported on nine ACEs. Baseline global cognition was a z-score composite of five factor scores from a comprehensive neuropsychological battery. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale. Cardiovascular health was operationalized through systolic blood pressure. A mediation model controlling for sociodemographics, childhood health, and childhood socioeconomic status estimated indirect effects of ACEs on global cognition via depressive symptoms and blood pressure. Racial differences were probed via t-tests and stratified models.

RESULTS

A negative indirect effect of ACEs on cognition was observed through depressive symptoms [β = -.040, 95% CI (-.067, -.017)], but not blood pressure, for the whole sample. Black participants reported more ACEs (Cohen's d = .21), reported more depressive symptoms (Cohen's d = .35), higher blood pressure (Cohen's d = .41), and lower cognitive scores (Cohen's d = 1.35) compared to White participants. In stratified models, there was a negative indirect effect through depressive symptoms for Black participants [β = -.074, 95% CI (-.128, -.029)] but not for White participants.

CONCLUSIONS

These results highlight the need to consider racially patterned contextual factors across the life course. Such factors could exacerbate the negative impact of ACEs and related mental health consequences and contribute to racial disparities in cognitive aging.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Retinal perfusion is linked to cognition and brain MRI biomarkers in Black Americans

INTRODUCTION

We investigated whether retinal capillary perfusion is a biomarker of cerebral small vessel disease and impaired cognition among Black Americans, an understudied group at higher risk for dementia.

METHODS

We enrolled 96 Black Americans without known cognitive impairment. Four retinal perfusion measures were derived using optical coherence tomography angiography. Neurocognitive assessment and brain magnetic resonance imaging (MRI) were performed. Multiple linear regression analyses were performed.

RESULTS

Lower retinal capillary perfusion was correlated with worse Oral Symbol Digit Test (P < = 0.005) and Fluid Cognition Composite scores (P < = 0.02), but not with the Crystallized Cognition Composite score (P > = 0.41). Lower retinal perfusion was also correlated with higher free water and peak width of skeletonized mean diffusivity, and lower fractional anisotropy (all P < 0.05) on MRI (N = 35).

DISCUSSION

Lower retinal capillary perfusion is associated with worse information processing, fluid cognition, and MRI biomarkers of cerebral small vessel disease, but is not related to crystallized cognition.

Baseline levels and longitudinal rates of change in plasma Aβ42/40 among self-identified Black/African American and White individuals

Objective

The use of blood-based biomarkers of Alzheimer disease (AD) may facilitate access to biomarker testing of groups that have been historically under-represented in research. We evaluated whether plasma Aβ42/40 has similar or different baseline levels and longitudinal rates of change in participants racialized as Black or White.

Methods

The Study of Race to Understand Alzheimer Biomarkers (SORTOUT-AB) is a multi-center longitudinal study to evaluate for potential differences in AD biomarkers between individuals racialized as Black or White. Plasma samples collected at three AD Research Centers (Washington University, University of Pennsylvania, and University of Alabama-Birmingham) underwent analysis with C2N Diagnostics' PrecivityAD™ blood test for Aβ42 and Aβ40. General linear mixed effects models were used to estimate the baseline levels and rates of longitudinal change for plasma Aβ measures in both racial groups. Analyses also examined whether dementia status, age, sex, education, APOE ε4 carrier status, medical comorbidities, or fasting status modified potential racial differences.

Results

Of the 324 Black and 1,547 White participants, there were 158 Black and 759 White participants with plasma Aβ measures from at least two longitudinal samples over a mean interval of 6.62 years. At baseline, the group of Black participants had lower levels of plasma Aβ40 but similar levels of plasma Aβ42 as compared to the group of White participants. As a result, baseline plasma Aβ42/40 levels were higher in the Black group than the White group, consistent with the Black group having lower levels of amyloid pathology. Racial differences in plasma Aβ42/40 were not modified by age, sex, education, APOE ε4 carrier status, medical conditions (hypertension and diabetes), or fasting status. Despite differences in baseline levels, the Black and White groups had a similar longitudinal rate of change in plasma Aβ42/40.

Interpretation

Black individuals participating in AD research studies had a higher mean level of plasma Aβ42/40, consistent with a lower level of amyloid pathology, which, if confirmed, may imply a lower proportion of Black individuals being eligible for AD clinical trials in which the presence of amyloid is a prerequisite. However, there was no significant racial difference in the rate of change in plasma Aβ42/40, suggesting that amyloid pathology accumulates similarly across racialized groups.

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

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

Dementia incidence trend in England and Wales, 2002-19, and projection for dementia burden to 2040: analysis of data from the English Longitudinal Study of Ageing

BACKGROUND

Dementia incidence declined in many high-income countries in the 2000s, but evidence on the post-2010 trend is scarce. We aimed to analyse the temporal trend in England and Wales between 2002 and 2019, considering bias and non-linearity.

METHODS

Population-based panel data representing adults aged 50 years and older from the English Longitudinal Study of Ageing were linked to the mortality register across wave 1 (2002-03) to wave 9 (2018-19) (90 073 person observations). Standard criteria based on cognitive and functional impairment were used to ascertain incident dementia. Crude incidence rates were determined in seven overlapping initially dementia-free subcohorts each followed up for 4 years (ie, 2002-06, 2004-08, 2006-10, 2008-12, 2010-14, 2012-16, and 2014-18). We examined the temporal trend of dementia incidence according to age, sex, and educational attainment. We estimated the trend of dementia incidence adjusted by age and sex with Cox proportional hazards and multistate models. Restricted cubic splines allowed for potential non-linearity in the time trend. A Markov model was used to project future dementia burden considering the estimated incidence trend.

FINDINGS

Incidence rate standardised by age and sex declined from 2002 to 2010 (from 10·7 to 8·6 per 1000 person-years), then increased from 2010 to 2019 (from 8·6 to 11·3 per 1000 person-years). Adjusting for age and sex, and accounting for missing dementia cases due to death, estimated dementia incidence declined by 28·8% from 2002 to 2008 (incidence rate ratio 0·71, 95% CI 0·58-0·88), and increased by 25·2% from 2008 to 2016 (1·25, 1·03-1·54). The group with lower educational attainment had a smaller decline in dementia incidence from 2002 to 2008 and a greater increase after 2008. If the upward incidence trend continued, there would be 1·7 million (1·62-1·75) dementia cases in England and Wales by 2040, 70% more than previously forecast.

INTERPRETATION

Dementia incidence might no longer be declining in England and Wales. If the upward trend since 2008 continues, along with population ageing, the burden on health and social care will be large.

FUNDING

UK Economic and Social Research Council.

Algorithmic Fairness of Machine Learning Models for Alzheimer Disease Progression

Importance

Predictive models using machine learning techniques have potential to improve early detection and management of Alzheimer disease (AD). However, these models potentially have biases and may perpetuate or exacerbate existing disparities.

Objective

To characterize the algorithmic fairness of longitudinal prediction models for AD progression.

Design, Setting, and Participants

This prognostic study investigated the algorithmic fairness of logistic regression, support vector machines, and recurrent neural networks for predicting progression to mild cognitive impairment (MCI) and AD using data from participants in the Alzheimer Disease Neuroimaging Initiative evaluated at 57 sites in the US and Canada. Participants aged 54 to 91 years who contributed data on at least 2 visits between September 2005 and May 2017 were included. Data were analyzed in October 2022.

Exposures

Fairness was quantified across sex, ethnicity, and race groups. Neuropsychological test scores, anatomical features from T1 magnetic resonance imaging, measures extracted from positron emission tomography, and cerebrospinal fluid biomarkers were included as predictors.

Main Outcomes and Measures

Outcome measures quantified fairness of prediction models (logistic regression [LR], support vector machine [SVM], and recurrent neural network [RNN] models), including equal opportunity, equalized odds, and demographic parity. Specifically, if the model exhibited equal sensitivity for all groups, it aligned with the principle of equal opportunity, indicating fairness in predictive performance.

Results

A total of 1730 participants in the cohort (mean [SD] age, 73.81 [6.92] years; 776 females [44.9%]; 69 Hispanic [4.0%] and 1661 non-Hispanic [96.0%]; 29 Asian [1.7%], 77 Black [4.5%], 1599 White [92.4%], and 25 other race [1.4%]) were included. Sensitivity for predicting progression to MCI and AD was lower for Hispanic participants compared with non-Hispanic participants; the difference (SD) in true positive rate ranged from 20.9% (5.5%) for the RNN model to 27.8% (9.8%) for the SVM model in MCI and 24.1% (5.4%) for the RNN model to 48.2% (17.3%) for the LR model in AD. Sensitivity was similarly lower for Black and Asian participants compared with non-Hispanic White participants; for example, the difference (SD) in AD true positive rate was 14.5% (51.6%) in the LR model, 12.3% (35.1%) in the SVM model, and 28.4% (16.8%) in the RNN model for Black vs White participants, and the difference (SD) in MCI true positive rate was 25.6% (13.1%) in the LR model, 24.3% (13.1%) in the SVM model, and 6.8% (18.7%) in the RNN model for Asian vs White participants. Models generally satisfied metrics of fairness with respect to sex, with no significant differences by group, except for cognitively normal (CN)-MCI and MCI-AD transitions (eg, an absolute increase [SD] in the true positive rate of CN-MCI transitions of 10.3% [27.8%] for the LR model).

Conclusions and Relevance

In this study, models were accurate in aggregate but failed to satisfy fairness metrics. These findings suggest that fairness should be considered in the development and use of machine learning models for AD progression.

Associations Between Circulating Levels of Myostatin and Plasma β-Amyloid 42/40 in a Biracial Cohort of Older Adults

BACKGROUND

Myostatin, a cytokine produced by skeletal muscle, may influence Alzheimer's disease (AD) pathogenesis, but sparse evidence exists in humans. We assessed the association between circulating levels of myostatin at Year 1 and plasma levels of β-amyloid 42/40 at Year 2, a marker of AD pathology, in a biracial cohort of older adults.

METHODS

We studied 403 community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from Memphis, Tennessee, and Pittsburgh, PA. Mean age was 73.8 ± 3 years; 54% were female; and 52% were Black. Serum myostatin levels were measured at Year 1, plasma β-amyloid 42/40 levels in Year 2 (higher ratio indicating lower amyloid load). Multivariable linear regression analyses tested the association of serum myostatin with plasma levels of β-amyloid 42/40 adjusted for computed-tomography-derived thigh muscle cross-sectional area, demographics, APOe4 allele, and risk factors for dementia. We tested for 2-way.interactions between myostatin and race or sex; results were stratified by race and sex.

RESULTS

In multivariable models, myostatin was positively associated with plasma levels of β-amyloid 42/40 (standardized regression coefficient: 0.145, p = .004). Results were significant for white men and women (0.279, p = .009, and 0.221, p = .035, respectively) but not for Black men or women; interactions by race and gender were not statistically significant.

CONCLUSIONS

Higher serum myostatin was associated with lower amyloid burden, independently of APOe4 alleles, muscle area and other established risk factors for dementia. The role of myostatin in AD pathogenesis and the influence of race should be further investigated.

The Long-Term Impacts of Dementia on Preventive Care Utilization and Health Behaviors

Dementia has large impact on individuals' decision making, independent living, and wellbeing. Identifying early signals of dementia risk may offer people more time to prepare for the future, helping to delay the onset or slow the progression of dementia. Using the 1995-2018 waves of Health and Retirement Study, we offer novel evidence on the impacts of dementia on a rich set of preventive care utilization and health behaviors. Leveraging both within- and between-individual variations in an event study design, we characterize long-term dynamic changes in preventive care and health behaviors relative to the incidence of dementia and find early behavioral indicators of the disorder. We show that relative to the group of people who never develop dementia during the study periods, people with dementia have consistent and escalating declines in the use of cholesterol test, dental visit, prostate test and mammogram around the incidence of dementia. Significant declines are also found in physical activities and social engagement. Importantly, we demonstrate that the behavioral changes can occur up to 6 years before the incidence of dementia; and these patterns are absent in other chronic or acute conditions. The results are robust to sample selection, model specification, and the further control of aging and cohort effects. Overall, our findings highlight the salient impact of dementia risk on preventive care utilization and health behaviors, which may increase individuals' vulnerability to health shocks. Detecting early signals of dementia and facilitating targeted interventions are thus called for to prevent individuals from adverse behavioral and health consequences.

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.

Comparison of Particulate Air Pollution From Different Emission Sources and Incident Dementia in the US

Importance

Emerging evidence indicates that exposure to fine particulate matter (PM2.5) air pollution may increase dementia risk in older adults. Although this evidence suggests opportunities for intervention, little is known about the relative importance of PM2.5 from different emission sources.

Objective

To examine associations of long-term exposure of total and source-specific PM2.5 with incident dementia in older adults.

Design, Setting, and Participants

The Environmental Predictors of Cognitive Health and Aging study used biennial survey data from January 1, 1998, to December 31, 2016, for participants in the Health and Retirement Study, which is a nationally representative, population-based cohort study in the US. The present cohort study included all participants older than 50 years who were without dementia at baseline and had available exposure, outcome, and demographic data between 1998 and 2016 (N = 27 857). Analyses were performed from January 31 to May 1, 2022.

Exposures

The 10-year mean total PM2.5 and PM2.5 from 9 emission sources at participant residences for each month during follow-up using spatiotemporal and chemical transport models.

Main Outcomes and Measures

The main outcome was incident dementia as classified by a validated algorithm incorporating respondent-based cognitive testing and proxy respondent reports. Adjusted hazard ratios (HRs) were estimated for incident dementia per IQR of residential PM2.5 concentrations using time-varying, weighted Cox proportional hazards regression models with adjustment for the individual- and area-level risk factors.

Results

Among 27 857 participants (mean [SD] age, 61 [10] years; 15 747 [56.5%] female), 4105 (15%) developed dementia during a mean (SD) follow-up of 10.2 [5.6] years. Higher concentrations of total PM2.5 were associated with greater rates of incident dementia (HR, 1.08 per IQR; 95% CI, 1.01-1.17). In single pollutant models, PM2.5 from all sources, except dust, were associated with increased rates of dementia, with the strongest associations for agriculture, traffic, coal combustion, and wildfires. After control for PM2.5 from all other sources and copollutants, only PM2.5 from agriculture (HR, 1.13; 95% CI, 1.01-1.27) and wildfires (HR, 1.05; 95% CI, 1.02-1.08) were robustly associated with greater rates of dementia.

Conclusion and Relevance

In this cohort study, higher residential PM2.5 levels, especially from agriculture and wildfires, were associated with higher rates of incident dementia, providing further evidence supporting PM2.5 reduction as a population-based approach to promote healthy cognitive aging. These findings also indicate that intervening on key emission sources might have value, although more research is needed to confirm these findings.

Racial, ethnic and neighborhood socioeconomic differences in incidence of dementia: A regional retrospective cohort study

BACKGROUND

Evidence on the effects of neighborhood socioeconomic disadvantage on dementia risk in racially and ethically diverse populations is limited. Our objective was to evaluate the relative extent to which neighborhood disadvantage accounts for racial/ethnic variation in dementia incidence rates. Secondarily, we evaluated the spatial relationship between neighborhood disadvantage and dementia risk.

METHODS

In this retrospective study using electronic health records (EHR) at two regional health systems in Northeast Ohio, participants included 253,421 patients aged >60 years who had an outpatient primary care visit between January 1, 2005 and December 31, 2015. The date of the first qualifying visit served as the study baseline. Cumulative incidence of composite dementia outcome, defined as EHR-documented dementia diagnosis or dementia-related death, stratified by neighborhood socioeconomic deprivation (as measured by Area Deprivation Index) was determined by competing-risk regression analysis, with non-dementia-related death as the competing risk. Fine-Gray sub-distribution hazard ratios were determined for neighborhood socioeconomic deprivation, race/ethnicity, and clinical risk factors. The degree to which neighborhood socioeconomic position accounted for racial/ethnic disparities in the incidence of composite dementia outcome was evaluated via mediation analysis with Poisson rate models.

RESULTS

Increasing neighborhood disadvantage was associated with increased risk of EHR-documented dementia diagnosis or dementia-related death (most vs. least disadvantaged ADI quintile HR = 1.76, 95% confidence interval = 1.69-1.84) after adjusting for age and sex. The effect of neighborhood disadvantage on this composite dementia outcome remained after accounting for known medical risk factors of dementia. Mediation analysis indicated that neighborhood disadvantage accounted for 34% and 29% of the elevated risk for composite dementia outcome in Hispanic and Black patients compared to White patients, respectively.

CONCLUSION

Neighborhood disadvantage is related to the risk of EHR-documented dementia diagnosis or dementia-related death and accounts for a portion of racial/ethnic differences in dementia burden, even after adjustment for clinically important confounders.

Quantification of race/ethnicity representation in Alzheimer's disease neuroimaging research in the USA: a systematic review

BACKGROUND

Racial and ethnic minoritized groups are disproportionately at risk for Alzheimer's Disease (AD), but are not sufficiently recruited in AD neuroimaging research in the United States. This is important as sample composition impacts generalizability of findings, biomarker cutoffs, and treatment effects. No studies have quantified the breadth of race/ethnicity representation in the AD literature.

METHODS

This review identified median race/ethnicity composition of AD neuroimaging US-based research samples available as free full-text articles on PubMed. Two types of published studies were analyzed: studies that directly report race/ethnicity data (i.e., direct studies), and studies that do not report race/ethnicity but used data from a cohort study/database that does report this information (i.e., indirect studies).

RESULTS

Direct studies (n = 719) have median representation of 88.9% white or 87.4% Non-Hispanic white, 7.3% Black/African American, and 3.4% Hispanic/Latino ethnicity, with 0% Asian American, Native Hawaiian/Pacific Islander, and American Indian/Alaska Native, Multiracial, and Other Race participants. Cohort studies/databases (n = 44) from which indirect studies (n = 1745) derived are more diverse, with median representation of 84.2% white, 83.7% Non-Hispanic white, 11.6% Black/African American, 4.7% Hispanic/Latino, and 1.75% Asian American participants. Notably, 94% of indirect studies derive from just 10 cohort studies/databases. Comparisons of two time periods using a median split for publication year, 1994-2017 and 2018-2022, indicate that sample diversity has improved recently, particularly for Black/African American participants (3.39% from 1994-2017 and 8.29% from 2018-2022).

CONCLUSIONS

There is still underrepresentation of all minoritized groups relative to Census data, especially for Hispanic/Latino and Asian American individuals. The AD neuroimaging literature will benefit from increased representative recruitment of ethnic/racial minorities. More transparent reporting of race/ethnicity data is needed.

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.

Self-reported experiences of discrimination and incident dementia

INTRODUCTION

Discrimination negatively impacts health and may contribute to racial/ethnic disparities in dementia risk.

METHODS

Experiences of lifetime and everyday discrimination were assessed among 6509 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We assessed the association of discrimination with incidence of dementia including adjustment for important risk factors, cohort attrition, and we assessed for effect modification by race/ethnicity.

RESULTS

Prevalence of any lifetime discrimination in MESA was 42%, highest among Black adults (72%). Over a median 15.7 years of follow-up, there were 466 incident cases of dementia. Lifetime discrimination, but not everyday discrimination, was associated with incident dementia (Wald p = 0.03). Individuals reporting lifetime discrimination in ≥2 domains (compared to none) had greater risk for dementia (hazard ratio: 1.40; 95%: 1.08, 1.82) after adjustment for sociodemographic, clinical, and behavioral risk factors. Associations did not differ by race/ethnicity.

CONCLUSIONS

These findings demonstrate an association of greater experiences of lifetime discrimination with incident dementia.