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

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

Learning from Transmasculine Experiences with Health Care: Tangible Inlets for Reducing Health Disparities through Patient-Provider Relationships

Purpose: We examined health care experiences of transmasculine young adults to clarify factors contributing to mistrust in the health care system and identify tangible and modifiable means to address health disparities through improved patient-provider interactions. Thematic analysis highlights patterns within historical relationships between medical models and transmasculine embodiment, and provides guidance for health care clinicians, researchers, and policy makers to deliver competent services for transgender and gender diverse (TGD) individuals. Methods: The study team used qualitative methodology guided by interpretive phenomenological analysis. Semistructured interviews with 12 participants who self-identified as transmasculine were conducted, transcribed, and coded thematically. Results: Participants were a community sample of 12 young adults 18-35 years of age (M=23, standard deviation=3.74), who self-identified as transmasculine. Three participants identified as a racial/ethnic minority. Participants were highly educated, with most completing at least some college. The superordinate thematic domain Perspectives on Health Care emerged, under which three subthemes were nested: (1) an essentialist, binary medical model is inaccurate and oppressive, (2) consequences of medicalizing gender (i.e., gender as a diagnosis), and (3) recommendations to improve health care. Conclusions: Qualitative analysis revealed specific ways in which the relationship between transmasculine individuals and current health care systems are fraught with difficulties, including the impact of stigma, gatekeeping, and inaccuracies, in current diagnostic criteria. Participants shared lived experiences and offered innovative ideas to improve health care delivery, such as challenging socialized biases, increased education, and immersion in TGD communities to advocate for change in research, practice, and policy

Addressing the disparities in dementia risk, early detection and care in Latino populations: Highlights from the Second Latinos and Alzheimer's Symposium

The Alzheimer's Association hosted the second Latinos & Alzheimer's Symposium in May 2021. Due to the COVID-19 pandemic, the meeting was held online over 2 days, with virtual presentations, discussions, mentoring sessions, and posters. The Latino population in the United States is projected to have the steepest increase in Alzheimer's disease (AD) in the next 40 years, compared to other ethnic groups. Latinos have increased risk for AD and other dementias, limited access to quality care, and are severely underrepresented in AD and dementia research and clinical trials. The symposium highlighted developments in AD research with Latino populations, including advances in AD biomarkers, and novel cognitive assessments for Spanish-speaking populations, as well as the need to effectively recruit and retain Latinos in clinical research, and how best to deliver health-care services and to aid caregivers of Latinos living with AD

Self-reported health behaviors and longitudinal cognitive performance in late middle age: Results from the Wisconsin Registry for Alzheimer's Prevention.

BackgroundStudies have suggested associations between self-reported engagement in health behaviors and reduced risk of cognitive decline. Most studies explore these relationships using one health behavior, often cross-sectionally or with dementia as the outcome. In this study, we explored whether several individual self-reported health behaviors were associated with cognitive decline when considered simultaneously, using data from the Wisconsin Registry for Alzheimer's Prevention (WRAP), an Alzheimer's disease risk-enriched cohort who were non-demented and in late midlife at baseline.MethodWe analyzed longitudinal cognitive data from 828 participants in WRAP, with a mean age at baseline cognitive assessment of 57 (range = 36-78, sd = 6.8) and an average of 6.3 years (standard deviation = 1.9, range = 2-10) of follow-up. The primary outcome was a multi-domain cognitive composite, and secondary outcomes were immediate/delayed memory and executive function composites. Predictors of interest were self-reported measures of physical activity, cognitive activity, adherence to a Mediterranean-style diet (MIND), and interactions with each other and age. We conducted linear mixed effects analyses within an Information-theoretic (IT) model averaging (MA) approach on a set of models including covariates and combinations of these 2- and 3-way interactions. The IT approach was selected due to the large number of interactions of interest and to avoid pitfalls of traditional model selection approaches.ResultsModel-averaged results identified no significant self-reported health behavior*age interactions in relationship to the primary composite outcome. In secondary outcomes, higher MIND diet scores associated with slower decline in executive function. Men showed faster decline than women on delayed memory, independent of health behaviors. There were no other significant interactions among any other health behaviors and cognitive trajectories.ConclusionsWhen multiple covariates and health behaviors were considered simultaneously, there were limited weak associations with cognitive decline in this age range. These results may be explained alone or in combination by three alternative explanations: 1) the range of cognitive decline is in middle age is too small to observe relationships with health behaviors, 2) the putative associations of these health behaviors on cognition may not be robust in this age range, or 3) the self-reported measures of the health behaviors may not be optimal for predicting cognitive decline. More study may be needed that incorporates sensitive measures of health behaviors, AD biomarker profiles, and/or other disease comorbidities

Plasma Aβ42/40 and cognitive variability are associated with cognitive function in Black Americans: Findings from the AA‐FAIM cohort

Abstract Introduction It is critical to develop more inclusive Alzheimer's disease (AD) research protocols to ensure that historically excluded groups are included in preclinical research and have access to timely diagnosis and treatment. If validated in racialized groups, plasma AD biomarkers and measures of subtle cognitive dysfunction could provide avenues to expand diversity in preclinical AD research. We sought to evaluate the utility of two easily obtained, low‐burden disease markers, plasma amyloid beta (Aβ)42/40, and intra‐individual cognitive variability (IICV), to predict concurrent and longitudinal cognitive performance in a sample of Black adults. Methods Two hundred fifty‐seven Black participants enrolled in the African Americans Fighting Alzheimer's in Midlife (AA‐FAIM) study underwent at least one cognitive assessment visit; a subset of n = 235 had plasma samples. Baseline IICV was calculated as the standard deviation across participants’ z scores on five cognitive measures: Rey Auditory Verbal Learning Test Delayed Recall, Trail Making Test Parts A and B (Trails A and B), and Boston Naming Test. Using mixed effects regression models, we compared concurrent and longitudinal models to baseline plasma Aβ42/40 or IICV by age interactions. PrecivityAD assays quantified baseline plasma Aβ42/40. Results IICV was associated with concurrent/baseline performance on several outcomes but did not modify associations between age and cognitive decline. In contrast, plasma Aβ42/40 was unrelated to baseline cognitive performance, but a pattern emerged in interactions with age in longitudinal models of Trails A and B and Rey Auditory Verbal Learning Test total learning trials. Although not significant after correcting for multiple comparisons, low Aβ42/40 was associated with faster cognitive declines over time. Discussion Our results are promising as they extend existing findings to an Black American sample using low‐cost, low‐burden methods that can be implemented outside of a research center, thus supporting efforts for inclusive AD biomarker research

The structural and social determinants of Alzheimer\u27s disease related dementias

INTRODUCTION: The projected growth of Alzheimer\u27s disease (AD) and AD-related dementia (ADRD) cases by midcentury has expanded the research field and impelled new lines of inquiry into structural and social determinants of health (S/SDOH) as fundamental drivers of disparities in AD/ADRD. METHODS: In this review, we employ Bronfenbrenner\u27s ecological systems theory as a framework to posit how S/SDOH impact AD/ADRD risk and outcomes. RESULTS: Bronfenbrenner defined the macrosystem as the realm of power (structural) systems that drive S/SDOH and that are the root cause of health disparities. These root causes have been discussed little to date in relation to AD/ADRD, and thus, macrosystem influences, such as racism, classism, sexism, and homophobia, are the emphasis in this paper. DISCUSSION: Under Bronfenbrenner\u27s macrosystem framework, we highlight key quantitative and qualitative studies linking S/SDOH with AD/ADRD, identify scientific gaps in the literature, and propose guidance for future research. HIGHLIGHTS: Ecological systems theory links structural/social determinants to AD/ADRD. Structural/social determinants accrue and interact over the life course to impact AD/ADRD. Macrosystem is made up of societal norms, beliefs, values, and practices (e.g., laws). Most macro-level determinants have been understudied in the AD/ADRD literature

Addressing the disparities in dementia risk, early detection and care in Latino populations: Highlights from the second Latinos & Alzheimer's Symposium.

The Alzheimer's Association hosted the second Latinos & Alzheimer's Symposium in May 2021. Due to the COVID-19 pandemic, the meeting was held online over 2 days, with virtual presentations, discussions, mentoring sessions, and posters. The Latino population in the United States is projected to have the steepest increase in Alzheimer's disease (AD) in the next 40 years, compared to other ethnic groups. Latinos have increased risk for AD and other dementias, limited access to quality care, and are severely underrepresented in AD and dementia research and clinical trials. The symposium highlighted developments in AD research with Latino populations, including advances in AD biomarkers, and novel cognitive assessments for Spanish-speaking populations, as well as the need to effectively recruit and retain Latinos in clinical research, and how best to deliver health-care services and to aid caregivers of Latinos living with AD