Heterogeneity in cognitive profiles of monolingual and bilingual Hispanic/Latino older adults in HABS-HD.

OBJECTIVE: The present study characterized heterogeneity in the cognitive profiles of monolingual and bilingual Latino older adults enrolled in the HABS-HD. METHODS: A total of 859 cognitively unimpaired older adults completed neuropsychological testing. Raw scores for cognitive tests were converted to z-scores adjusted for age, education, sex, and language of testing. A latent profile analysis (LPA) was conducted for monolingual and bilingual speaker groups. A series of 2-5 class solutions were examined, and the optimal model was selected based on fit indices, posterior probabilities, proportion of sample sizes, and pattern of scores. Identified classes were compared on sociodemographic, psychosocial, and health characteristics. RESULTS: For the monolingual group (n = 365), a 3-class solution was optimal; this consisted of a Low Average Memory group with low average verbal memory performances on the SEVLT Total Learning and Delayed Recall trials, as well as an Average Cognition group and a High Average Cognition group. For the bilingual group (n = 494), a 3-class solution was observed to be optimal; this consisted of a Low Average Memory group, with low average verbal memory performances on the learning and delayed recall trials of Logical Memory; a Low Average Executive group, where performance on Trails A and B and Digit Substitution were the lowest; and a High Average Cognition group, where performance was generally in the high average range across most cognitive measures. CONCLUSIONS: Cognitive class solutions differed across monolingual and bilingual groups and illustrate the need to better understand cognitive variability in linguistically diverse samples of Latino older adults.

Integrating Diversity, Culture, and Equity into the Neuropsychological Evaluation.

Cognition is influenced by a host of factors, including the patient's medical, psychiatric, and developmental history; sociocultural and demographic factors; modifiable behavioral factors; and structural and social determinants of health. Neuropsychological approaches include interpreting test data in the context of these factors to classify impairment and derive a cognitive diagnosis accurately. Failure to integrate an individual's sociodemographic, sociocultural, and developmental background can result in diagnostic errors, which have critical clinical implications for patient care.

Health insurance coverage moderates the relationship between metabolic syndrome and baseline memory outcomes in Latino older adults.

Objective: Latino adults are at increased risk of metabolic syndrome (MetS) and have lower rates of health insurance (HI) coverage. Although inadequate HI coverage and MetS have been independently linked to poor cognition, their potential interactive effects have not yet been examined. The present study explored whether HI moderated the association between MetS and cognition. We hypothesized that Latinos with MetS that did not have HI would demonstrate poorer cognition than those with HI, whereas there would be minimal differences in cognition across HI status in those without MetS. Methods: Cross-sectional data from 805 Latino older adults enrolled in the Health and Aging Brain Study-Health Disparities was utilized. Analysis of covariance adjusting for sociodemographics examined MetS x HI interactions on memory and attention/executive functions composites. Results: Results revealed a significant MetS x HI interaction on memory (F = 4.33, p = 0.037, ηp2 = .01); Latino adults with MetS and no HI coverage had worse memory performance than those with MetS who had HI coverage (p = 0.022, ηp2 = .01), whereas there was no significant difference in memory between HI coverage groups in those without MetS (p > .05, ηp2 = .002). No MetS x HI interaction was observed for the attention/executive functions composite (F = 0.29, p = 0.588, ηp2 < .001). Conclusion: Latino older adults with MetS that do not have HI coverage may be at risk for poorer memory outcomes. Increasing the accessibility of HI coverage may help reduce cognitive health disparities in Latino older adults with vascular health comorbidities.

PTSD moderates the association between subjective cognitive decline and Alzheimer's disease biomarkers in older veterans.

OBJECTIVES: Post-traumatic stress disorder (PTSD) and subjective cognitive decline (SCD) are independent risk factors for Alzheimer's disease (AD) and dementia, but the association of their interaction on AD biomarkers have yet to be characterized. This study aimed to examine the impact of PTSD on the association between SCD and tau and amyloid positron emission tomography (PET) as well as global cognition in older Veterans. METHOD: This study included 87 Vietnam-Era Veterans without dementia (42 with PTSD; 45 without PTSD) from the Department of Defense-Alzheimer's Disease Neuroimaging Initiative. All participants had both tau and amyloid PET imaging as well as cognitive testing. SCD was measured using the Everyday Cognition questionnaire. RESULTS: While SCD was associated with tau PET, amyloid PET, and global cognition, PTSD moderated these associations for tau and amyloid PET levels. Specifically, Veterans without PTSD had a stronger positive relationship between SCD and AD biomarkers when compared to those with PTSD. CONCLUSION: Higher SCD was associated with greater tau and amyloid burden and worse cognitive performance across the sample, though the tau and amyloid associations were stronger for Veterans without PTSD. Results highlight the potential benefit of comprehensive clinical assessments including consideration of mental health among older Veterans with SCD to understand the underlying cause of the cognitive concerns. Additionally, more work is needed to understand alternative mechanisms driving SCD in older Veterans with PTSD.

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

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

Exercise: Just What the Doctor Ordered, But Why? Elucidating Mechanisms for Women's Increased High-Density Lipoprotein Benefit From Exercise and for the Health ABC Study.

High-density lipoprotein (HDL) is protective against cardiovascular disease. Exercise can increase HDL concentration, and some evidence suggests that this effect occurs more strongly in women than in men. Both HDL and exercise are associated with inflammation. We hypothesized a sex-by-exercise interaction on HDL level, whereby women would benefit from exercise more strongly than men, and tumor necrosis factor alpha and serum soluble tumor necrosis factor receptor-2 would mediate this relationship. This study included 2,957 older adult participants (1,520 women; 41% Black, 59% White; 73.6-years-old) from the Health, Aging, and Body Composition study. Regression models revealed a positive exercise-HDL relationship in women only (sex-by-exercise interaction: ß = 0.09, p = .013; exercise on HDL in women: ß = 0.07, p = .015), mediated by TNFα (axb = 0.15; CI: 0.01, 0.30), suggesting that exercise may increase HDL levels in women through reduced inflammation. Given that vascular risk contributes to Alzheimer's disease risk, findings have implications for sex differences in AD risk factors.

Cognition and Amyloid-ß in Older Veterans: Characterization and Longitudinal Outcomes of Data-Derived Phenotypes.

Background: Within older Veterans, multiple factors may contribute to cognitive difficulties. Beyond Alzheimer's disease (AD), psychiatric (e.g., PTSD) and health comorbidities (e.g., TBI) may also impact cognition. Objective: This study aimed to derive subgroups based on objective cognition, subjective cognitive decline (SCD), and amyloid burden, and then compare subgroups on clinical characteristics, biomarkers, and longitudinal change in functioning and global cognition. Methods: Cluster analysis of neuropsychological measures, SCD, and amyloid PET was conducted on 228 predominately male Vietnam-Era Veterans from the Department of Defense-Alzheimer's Disease Neuroimaging Initiative. Cluster-derived subgroups were compared on baseline characteristics as well as 1-year changes in everyday functioning and global cognition. Results: The cluster analysis identified 3 groups. Group 1 (n = 128) had average-to-above average cognition with low amyloid burden. Group 2 (n = 72) had the lowest memory and language, highest SCD, and average amyloid burden; they also had the most severe PTSD, pain, and worst sleep quality. Group 3 (n = 28) had the lowest attention/executive functioning, slightly low memory and language, elevated amyloid and the worst AD biomarkers, and the fastest rate of everyday functioning and cognitive decline. CONCLUSIONS: Psychiatric and health factors likely contributed to Group 2's low memory and language performance. Group 3 was most consistent with biological AD, yet attention/executive function was the lowest score. The complexity of older Veterans' co-morbid conditions may interact with AD pathology to show attention/executive dysfunction (rather than memory) as a prominent early symptom. These results could have important implications for the implementation of AD-modifying drugs in older Veterans.

Pulse pressure and APOE ε4 dose interact to affect cerebral blood flow in older adults without dementia.

This study assessed whether the effect of vascular risk on cerebral blood flow (CBF) varies by gene dose of apolipoprotein (APOE) ε4 alleles. 144 older adults without dementia from the Alzheimer's Disease Neuroimaging Initiative underwent arterial spin labeling and T1-weighted MRI, APOE genotyping, fluorodeoxyglucose positron emission tomography (FDG-PET), lumbar puncture, and blood pressure (BP) assessment. Vascular risk was assessed using pulse pressure (systolic BP - diastolic BP). CBF was examined in six AD-vulnerable regions: entorhinal cortex, hippocampus, inferior temporal cortex, inferior parietal cortex, rostral middle frontal gyrus, and medial orbitofrontal cortex. Linear regressions tested the interaction between APOE ε4 dose and pulse pressure on CBF in each region, adjusting for age, sex, cognitive classification, antihypertensive medication use, FDG-PET, reference CBF region, and AD biomarker positivity. There was a significant interaction between pulse pressure and APOE ɛ4 dose on CBF in the entorhinal cortex, hippocampus, and inferior parietal cortex, such that higher pulse pressure was associated with lower CBF only among ε4 homozygous participants. These findings demonstrate that the association between pulse pressure and regional CBF differs by APOE ε4 dose, suggesting that targeting modifiable vascular risk factors may be particularly important for those genetically at risk for AD.

Empirically derived psychosocial-behavioral phenotypes in Black/African American and Hispanic/Latino older adults enrolled in HABS-HD: Associations with AD biomarkers and cognitive outcomes.

INTRODUCTION: Identification of psychosocial-behavioral phenotypes to understand within-group heterogeneity in risk and resiliency to Alzheimer's disease (AD) within Black/African American and Hispanic/Latino older adults is essential for the implementation of precision health approaches. METHODS: A cluster analysis was performed on baseline measures of socioeconomic resources (annual income, social support, occupational complexity) and psychiatric distress (chronic stress, depression, anxiety) for 1220 racially/ethnically minoritized adults enrolled in the Health and Aging Brain Study-Health Disparities (HABS-HD). Analyses of covariance adjusting for sociodemographic factors examined phenotype differences in cognition and plasma AD biomarkers. RESULTS: The cluster analysis identified (1) Low Resource/High Distress (n = 256); (2) High Resource/Low Distress (n = 485); and (3) Low Resource/Low Distress (n = 479) phenotypes. The Low Resource/High Distress phenotype displayed poorer cognition and higher plasma neurofilament light chain; differences between the High Resource/Low Distress and Low Resource/Low Distress phenotypes were minimal. DISCUSSION: The identification of psychosocial-behavioral phenotypes within racially/ethnically minoritized older adults is crucial to the development of targeted AD prevention and intervention efforts.

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

INTRODUCTION: The effects of bilingualism on neuropsychological test performance in bilinguals with and without cognitive impairment are not well-understood and are relatively limited by small sample sizes of Latinos. METHODS: Using analysis of covariance (ANCOVA), we explored patterns of cognitive performance and impairment across a large sample of community-dwelling bilingual and monolingual Latino older adults with (n = 180) and without (n = 643) mild cognitive impairment (MCI) enrolled in HABS-HD. RESULTS: Bilinguals demonstrated cognitive resiliency in the form of significantly better performance on the Trail Making Test and Digit Symbol Substitution Test, observed across the cognitively unimpaired and MCI groups. In contrast, bilinguals demonstrated cognitive vulnerability in the form of significantly poorer performance and higher impairment rates on phonemic fluency in the MCI phase, only. Follow-up analyses revealed less balanced bilinguals demonstrated poorer performance and higher impairment rates on this measure, supported by lower levels of plasma Aß 42/40. DISCUSSION: Patterns of cognitive performance and impairment differ as a function of bilingualism. Bilingualism must be considered when evaluating cognitive and biomarker outcomes in Latino older adults. Highlights: Latino bilinguals perform better on measures of processing speed and coding.Latino bilinguals with MCI demonstrate cognitive vulnerability in verbal fluency.Less balanced bilinguals demonstrate greatest vulnerability anchored by Aß 42/40.

Research Letter: TBI Severity Moderates the Association Between Subjective and Objective Attention in Older Veterans.

OBJECTIVE: This study examined the moderating effect of traumatic brain injury (TBI) history on subjective and objective cognition across multiple cognitive domains. SETTING, PARTICIPANTS, AND DESIGN: Participants included 242 Vietnam-era veterans with a history of no TBI (n = 86), mild TBI (n = 74), or moderate-to-severe TBI (n = 82) from the observational Department of Defense-Alzheimer's Disease Neuroimaging Initiative (DoD-ADNI) study. MAIN MEASURES: Objective cognition was the outcome and was measured using neuropsychological measures in the domains of memory, attention/executive functioning, and language. Subjective cognition was measured using the memory, divided attention, and language subscales from the Everyday Cognition (ECog) measure. TBI severity status was the moderating variable. RESULTS: Veterans with a history of moderate-to-severe TBI had a stronger negative association between subjective and objective attention relative to participants without a TBI (P = .002). Although this association did not differ between mild TBI and no TBI history groups (P = .100), the association between subjective and objective attention for the mild TBI group was intermediate to the no TBI and moderate-to-severe TBI history groups. TBI status did not moderate associations between subjective and objective memory or language. CONCLUSION: Results highlight the importance of assessing subjective and objective cognition in older veterans and the relevance of attention in the context of TBI history. More work is needed to better understand the intersection of TBI and aging and how these factors may be used to guide individualized assessment and treatment approaches for older veterans.

Lower Body Mass Index at Baseline Is Related to Steeper Cognitive Decline in the Alzheimer's Disease Neuroimaging Initiative Cohort.

OBJECTIVE: Midlife obesity is a risk factor for dementia, whereas obesity in older age may be protective of cognition, a phenomenon known as the "obesity paradox." The mechanisms underlying this phenomenon and the relationship between body mass index (BMI) and cognitive function over time remain unclear. METHODS: In 1399 adults with and without mild cognitive impairment (median age 73.6 years) from the Alzheimer's Disease Neuroimaging Initiative, we modeled the effects of baseline BMI on within-person trajectories of cognitive decline using Latent Growth Curve Modeling. We also tested if the effects of BMI on cognitive decline are global or specific to memory, executive function, or language. RESULTS: Higher baseline BMI was associated with better memory ( ßBMI = 0.06, p < .05) and worse executive function ( ßBMI = -0.05, p < .05) and not associated with language. Independent of baseline diagnosis, higher baseline BMI was associated with slower rate of decline in executive function, memory, and language ( ßBMI = 0.13, 0.12, and 0.12, respectively; p < .01). Higher BMI was not associated with the intercept ( ßBMI = 0.04, p = .059) or change ( ßBMI = 0.04, p = .415) in a global cognitive factor. CONCLUSIONS: We found that higher baseline BMI was associated with slower cognitive decline in participants with and without mild cognitive impairment diagnosis. Higher BMI in this context seems to be protective of cognitive function for people at risk for dementia. Our findings also support domain-specific effects of obesity on various cognitive functions rather than a final common pathway.

What does Juneteenth mean in STEMM?

Juneteenth commemorates the freeing of the last large group of enslaved people in 1865 at the end of the American Civil War. We asked several Black scientists what Juneteenth means to them in the context of science, technology, engineering, mathematics, and medicine (STEMM)? Their answers run the emotional gamut.

White Matter Hyperintensity Volume and Amyloid-PET Synergistically Impact Memory Independent of Tau-PET in Older Adults Without Dementia.

BACKGROUND: Alzheimer's disease (AD) and cerebrovascular disease are common, co-existing pathologies in older adults. Whether the effects of cerebrovascular disease and AD biomarkers on cognition are additive or synergistic remains unclear. OBJECTIVE: To examine whether white matter hyperintensity (WMH) volume moderates the independent association between each AD biomarker and cognition. METHODS: In 586 older adults without dementia, linear regressions tested the interaction between amyloid-ß (Aß) positron emission tomography (PET) and WMH volume on cognition, independent of tau-PET. We also tested the interaction between tau-PET and WMH volume on cognition, independent of Aß-PET. RESULTS: Adjusting for tau-PET, the quadratic effect of WMH interacted with Aß-PET to impact memory. There was no interaction between either the linear or quadratic effect of WMH and Aß-PET on executive function. There was no interaction between WMH volume and tau-PET on either cognitive measure. CONCLUSION: Results suggest that cerebrovascular lesions act synergistically with Aß to affect memory, independent of tau, highlighting the importance of incorporating vascular pathology into biomarker assessment of AD.

Subjective memory complaints are associated with decreased cortical thickness in Veterans with histories of mild traumatic brain injury.

Objective: Memory problems are frequently endorsed in Veterans following mild traumatic brain injury (mTBI), but subjective complaints are poorly associated with objective memory performance. Few studies have examined associations between subjective memory complaints and brain morphometry. We investigated whether self-reported memory problems were associated with objective memory performance and cortical thickness in Veterans with a history of mTBI. Methods: 40 Veterans with a history of remote mTBI and 29 Veterans with no history of TBI completed the Prospective-Retrospective Memory Questionnaire (PRMQ), PTSD Checklist (PCL), California Verbal Learning Test-2nd edition (CVLT-II), and 3 T T1 structural magnetic resonance imaging. Cortical thickness was estimated in 14 a priori frontal and temporal regions. Multiple regressions adjusting for age and PCL scores examined associations between PRMQ, CVLT-II scores, and cortical thickness within each Veteran group. Results: Greater subjective memory complaints on the PRMQ were associated with lower cortical thickness in the right middle temporal gyrus (ß = 0.64, q = .004), right inferior temporal gyrus (ß = 0.56, q = .014), right rostral middle frontal gyrus (ß = 0.45, q = .046), and right rostral anterior cingulate gyrus (ß = 0.58, q = .014) in the mTBI group but not the control group (q's > .05). These associations remained significant after adjusting for CVLT-II learning. CVLT-II performance was not associated with PRMQ score or cortical thickness in either group. Conclusions: Subjective memory complaints were associated with lower cortical thickness in right frontal and temporal regions, but not with objective memory performance, in Veterans with histories of mTBI. Subjective complaints post-mTBI may indicate underlying brain morphometry independently of objective cognitive testing.

Self-reported physical functioning, cardiometabolic health conditions, and health care utilization patterns in Million Veteran Program enrollees with Traumatic Brain Injury Screening and Evaluation Program data.

BACKGROUND: Examining the health outcomes of veterans who have completed the United States Veterans Health Administration's (VHA's) Traumatic Brain Injury (TBI) Screening and Evaluation Program may aid in the refinement and improvement of clinical care initiatives within the VHA. This study compared self-reported physical functioning, cardiometabolic health conditions, and health care utilization patterns in Million Veteran Program enrollees with TBI Screening and Evaluation Program data (collected between 2007 and 2019), with the goal of enhancing understanding of potentially modifiable health conditions in this population. METHODS: In this observational cohort study, veterans (n = 16,452) were grouped based on the diagnostic outcome of the TBI Screening and Evaluation Program: 1) negative TBI screen (Screen-); 2) positive TBI screen but no confirmed TBI diagnosis [Screen+/ Comprehensive TBI Evaluation (CTBIE)-]; or 3) positive TBI screen and confirmed TBI diagnosis (Screen+/CTBIE+). Chi-square tests and analysis of covariance were used to explore group differences in physical functioning, cardiometabolic health conditions, and health care utilization patterns, and logistic regressions were used to examine predictors of Screen+/- and CTBIE+/- group status. RESULTS: The results showed that veterans in the Screen+/CTBIE- and Screen+/CTBIE+ groups generally reported poorer levels of physical functioning (P's < 0.001, np2 = 0.02 to 0.03), higher rates of cardiometabolic health conditions (P's < 0.001, φ = 0.14 to 0.52), and increased health care utilization (P's < 0.001, φ = 0.14 to > 0.5) compared with the Screen- group; however, health outcomes were generally comparable between the Screen+/CTBIE- and Screen+/CTBIE+ groups. Follow-up analyses confirmed that while physical functioning, hypertension, stroke, healthcare utilization, and prescription medication use reliably distinguished between the Screen- and Screen+ groups (P's < 0.02, OR's 0.78 to 3.38), only physical functioning distinguished between the Screen+/CTBIE- and Screen+/CTBIE+ groups (P < 0.001, OR 0.99). CONCLUSIONS: The findings suggest that veterans who screen positive for TBI, regardless of whether they are ultimately diagnosed with TBI, are at greater risk for negative health outcomes, signifying that these veterans represent a vulnerable group that may benefit from increased clinical care and prevention efforts.

An Examination of Racial/Ethnic Differences on the Neurobehavioral Symptom Inventory Among Veterans Completing the Comprehensive Traumatic Brain Injury Evaluation: A Veterans Affairs Million Veteran Program Study.

OBJECTIVE: The purpose of this study was to explore racial/ethnic differences in neurobehavioral symptom reporting and symptom validity testing among military veterans with a history of traumatic brain injury (TBI). METHOD: Participants of this observational cross-sectional study (N = 9,646) were post-deployed Iraq-/Afghanistan-era veterans enrolled in the VA's Million Veteran Program with a clinician-confirmed history of TBI on the Comprehensive TBI Evaluation (CTBIE). Racial/ethnic groups included White, Black, Hispanic, Asian, Multiracial, Another Race, American Indian or Alaska Native, and Native Hawaiian or Other Pacific Islander. Dependent variables included neurobehavioral symptom domains and symptom validity assessed via the Neurobehavioral Symptom Inventory (NSI) and Validity-10, respectively. RESULTS: Chi-square analyses showed significant racial/ethnic group differences for vestibular, somatic/sensory, and affective symptoms as well as for all Validity-10 cutoff scores examined (≥33, ≥27, ≥26, >22, ≥22, ≥13, and ≥7). Follow-up analyses compared all racial/ethnic groups to one another, adjusting for sociodemographic- and injury-related characteristics. These analyses revealed that the affective symptom domain and the Validity-10 cutoff of ≥13 revealed the greatest number of racial/ethnic differences. CONCLUSIONS: Results showed significant racial/ethnic group differences on neurobehavioral symptom domains and symptom validity testing among veterans who completed the CTBIE. An enhanced understanding of how symptoms vary by race/ethnicity is vital so that clinical care can be appropriately tailored to the unique needs of all veterans. Results highlight the importance of establishing measurement invariance of the NSI across race/ethnicity and underscore the need for ongoing research to determine the most appropriate Validity-10 cutoff score(s) to use across racially/ethnically diverse veterans.

Sex moderates the association between age and myelin water fraction in the cingulum and fornix among older adults without dementia.

Background: Decreasing white matter integrity in limbic pathways including the fornix and cingulum have been reported in Alzheimer's disease (AD), although underlying mechanisms and potential sex differences remain understudied. We therefore sought to explore sex as a moderator of the effect of age on myelin water fraction (MWF), a measure of myelin content, in older adults without dementia (N = 52). Methods: Participants underwent neuropsychological evaluation and 3 T MRI at two research sites. Multicomponent driven equilibrium single pulse observation of T1 and T2 (mcDESPOT) quantified MWF in 3 a priori regions including the fornix, hippocampal cingulum (CgH), and cingulate cingulum (CgC). The California Verbal Learning Test-Second Edition assessed learning and delayed recall. Multiple linear regressions assessed for (1) interactions between age and sex on regional MWF and (2) associations of regional MWF and memory. Results: (1) There was a significant age by sex interaction on MWF of the fornix (p = 0.002) and CgC (p = 0.005), but not the CgH (p = 0.192); as age increased, MWF decreased in women but not men. (2) Fornix MWF was associated with both learning and recall (ps < 0.01), but MWF of the two cingulum regions were not (p > 0.05). Results were unchanged when adjusting for hippocampal volume. Conclusion: The current work adds to the literature by illuminating sex differences in age-related myelin decline using a measure sensitive to myelin and may help facilitate detection of AD risk for women.

Associations between social determinants of health and 10-year change in everyday functioning within Black/African American and White older adults enrolled in ACTIVE.

Introduction: Given prior work showing racial differences on baseline social determinants of health (SDoH) and 10-year trajectories of everyday functioning, we examined associations between SDoH and longitudinal everyday functioning performance in Black/African American and White older adults. Methods: Participants were 2505 older adults (Mage = 73.5; 28% Black/African American) without dementia. SDoH included economic stability/status, education access/quality, health-care access, neighborhood/built environment, and social/community contexts. The Observed Tasks of Daily Living (OTDL) measured everyday functioning and was administered at baseline and 1-, 2-, 3-, 5-, and 10-year visits. Results: Across the sample, social and community context and economic stability/status were associated with steeper age-related OTDL declines (ßs = 0.05 to 0.07, Ps < 0.001). Lower levels of social and community context (ß = 0.08, P = 0.002) and economic stability/status (ß = 0.07, P = 0.04) were associated with OTDL linear age declines in Black/African American participants, but not in White participants (Ps > 0.30). Discussion: Inequities across SDoH accelerate age-related declines in everyday functioning among Black/African American older adults.

Cerebral blood flow, tau imaging, and memory associations in cognitively unimpaired older adults.

Objective: Cerebral blood flow (CBF) has been independently linked to cognitive impairment and traditional Alzheimer's disease (AD) pathology (e.g., amyloid-beta [Aß], tau) in older adults. However, less is known about the possible interactive effects of CBF, Aß, and tau on memory performance. The present study examined whether CBF moderates the effect of Aß and tau on objective and subjective memory within cognitively unimpaired (CU) older adults. Methods: Participants included 54 predominately white CU older adults from the Alzheimer's Disease Neuroimaging Initiative. Multiple linear regression models examined meta-temporal CBF associations with (1) meta-temporal tau PET adjusting for cortical Aß PET and (2) and cortical Aß PET adjusting for tau PET. The CBF and tau meta region was an average of 5 distinct temporal lobe regions. CBF interactions with Aß or tau PET on memory performance were also examined. Covariates for all models included age, sex, education, pulse pressure, APOE-ε4 positivity, and imaging acquisition date differences. Results: CBF was significantly negatively associated with tau PET (t = -2.16, p = .04) but not Aß PET (t = 0.98, p = .33). Results revealed a CBF by tau PET interaction such that there was a stronger effect of tau PET on objective (t = 2.51, p = .02) and subjective (t = -2.67, p = .01) memory outcomes among individuals with lower levels of CBF. Conclusions: Cerebrovascular and tau pathologies may interact to influence cognitive performance. This study highlights the need for future vascular risk interventions, which could offer a scalable and cost-effective method for AD prevention.