When Culture Influences Genes: Positive Age Beliefs Amplify the Cognitive-Aging Benefit of APOE ε2

Perceptions About Housing and Neighborhood Characteristics Among Aging Adult Black Americans in Two Predominantly Black, Low-Income Neighborhoods in Pittsburgh: A Multi-Method Analysis

The life expectancy gap between Black and White Americans has narrowed, but progress remains slow due to the persistent consequences of lifetime exposure to structural and interpersonal experiences of racism and discrimination in various settings, for example, disadvantaged housing, neighborhood, and economic conditions. It is important to understand challenges and facilitators to healthy aging among Black Americans, i.e., maintaining functional ability and well-being in older age. We explore the intersection of housing, neighborhoods, and healthy aging among Black adults who live in two predominantly Black, low-income neighborhoods in Pittsburgh, Pennsylvania. This complementary multi-method study combined survey data (n = 642) and qualitative interviews (n = 60) to delve into the perspectives of individuals aged 35 to 89. Survey and interview respondents were mostly renters (76% and 77% respectively), and about a fifth of those surveyed and interviewed reported any major home environment problems. Half of interviewees described poor quality housing as a source of stress, such as mold, building design, accessibility, and relational difficulties with their landlords and building managers. Buildings' social environment was an important dimension of housing quality among renters-behavioral and value differences between older and younger tenants caused frustration. Survey respondents were mostly (73%) satisfied with their neighborhoods' livability. Good access to transportation and community spaces were seen as positive factors to be sustained and encouraged in future. Policy implications include tracking health outcomes in housing programs for aging Black adults to inform improvements and enhanced oversight and coordination to ensure high-quality housing that meets the needs of older adults.

Beneficial Effect of Societal Factors on APOE-ε2 and ε4 Carriers' Brain Health: A Systematic Review

BACKGROUND

Apolipoprotein-E (APOE) ε4 and ε2 are the most prevalent risk-increasing and risk-reducing genetic predictors of Alzheimer's disease, respectively. However, the extent to which societal factors can reduce the harmful impact of APOE-ε4 and enhance the beneficial impact of APOE-ε2 on brain health has not yet been examined systematically.

METHODS

To fill this gap, we conducted a systematic review searching for studies in MEDLINE, Embase, PsycINFO, and Scopus until June 2023, that included: (a) 1 of 5 social determinants of health (SDH) identified by Healthy People 2030, (b) APOE-ε2 or APOE-ε4 allele carriers, (c) cognitive or brain-biomarker outcomes, and (d) studies with an analysis of how APOE-ε2 and/ or APOE-ε4 carriers differ on outcomes when exposed to SDH.

RESULTS

From 14 076 articles retrieved, 124 met the inclusion criteria. In most of the studies, exposure to favorable SDH reduced APOE-ε4's detrimental effect and enhanced APOE-ε2's beneficial effect on cognitive and brain-biomarker outcomes (cognition: 70.5%, n: 74/105; brain-biomarkers: 71.4%, n: 20/28). A similar pattern of results emerged in each of the 5 Healthy People 2030 SDH categories, where finishing high school, having resources to satisfy basic needs, less air pollution, less negative external stimuli that can generate stress (eg, negative age stereotypes), and exposure to multiple favorable SDH were associated with better cognitive and brain health among APOE-ε4 and APOE-ε2 carriers.

CONCLUSIONS

Societal factors can reduce the harmful impact of APOE-ε4 and enhance the beneficial impact of APOE-ε2 on cognitive outcomes. This suggests that plans to reduce dementia should include community-level policies promoting favorable SDH.

Aging Stigma and the Health of US Adults Over 65: What Do We Know?

This narrative review assessed the current state of research on aging stigma and health relevant to US adults ages 65 and older. We adopted a stigma framework to highlight aging stigma as a meaningful social construct and the complex ways in which it may be harmful for health. We identified 29 studies of various types (experimental, intervention, cross-sectional quantitative, longitudinal quantitative, and qualitative) published between 2010 and 2023 that investigated relationships between concepts related to aging stigma and health. Aging stigma was associated with poor short- and long-term health outcomes spanning cognition, psychological wellbeing, physical health, and hospitalizations. The premise that aging stigma is harmful to health was moderately well supported, while evidence that health influenced aging stigma was weak. Collectively, studies provided insight into several mechanisms through which aging stigma may affect the health of older US adults, while also highlighting areas for future research. Potential strategies for addressing aging stigma as a public health hazard were discussed.

The Relationship between Subjective Aging and Cognition in Elderly People: A Systematic Review

There is a growing body of evidence on the effects of subjective aging on health, well-being and quality of life. This review aims to synthesize findings about the link between subjective aging and cognition and cognitive decline. Furthermore, it provides an examination of variation sources such as subjective aging construct, cognitive domains, measures employed, age and moderator variables. A systematic search was performed in PubMed, PsychInfo and Web of Science, as well as grey literature searches in Google Scholar, OpenGrey, WorldCat and NDLTD, which resulted in 59 reports being included. Subjective aging is a relevant construct in the explanation and prediction of cognitive aging and cognitive decline in elderly adults. More positive views about own aging and self-perceptions of aging, as well as a younger subjective age, were consistently related to better cognition and lower risk of cognitive decline. However, there were differences due to subjective aging subdimensions and cognitive domains, as well as an effect of age. Additionally, there were concerns about the content validity of some measures employed, such as the Philadelphia Geriatric Center Morale Scale for subjective aging and the Mini Mental State Examination for global cognition. Further studies should employ longitudinal designs with a process-based approach to cognition and precise subjective aging measures.

Cognition and brain health among older adults in Iceland: the AGES-Reykjavik study

The paper aimed to compare how factors previously identified as predictive factors for cognitive decline and dementia related to cognitive performance on the one hand and brain health on the other. To that aim, multiple linear regression was applied to the AGES-Reykjavik study epidemiological data. Additionally, a regression analysis was performed for change in cognition over 5 years, using the same exposure factors. The study ran from 2002 to 2011, and the sample analyzed included 1707 participants between the ages of 66 and 90. The data contains MR imaging, cognitive testing, background data, and physiological measurements. Overall, we conclude that risk factors linked to dementia relate differently to cognition and brain health. Mobility, physical strength, alcohol consumption, coronary artery disease, and hypertension were associated with cognition and brain volume. Smoking, depression, diabetes, and body fat percentage were only associated with brain volume, not cognitive performance. Modifiable factors previously linked to cognitive reserve, such as educational attainment, participation in leisure activities, multilingualism and good self-reported health, were associated with cognitive function but did not relate to brain volume. These findings show that, within the same participant pool, cognitive reserve proxy variables have a relationship with cognitive performance but have no association with relative brain volume measured simultaneously.

APOE alleles are associated with sex-specific structural differences in brain regions affected in Alzheimer's disease and related dementia

Alzheimer's disease is marked by intracellular tau aggregates in the medial temporal lobe (MTL) and extracellular amyloid aggregates in the default network (DN). Here, we examined codependent structural variations between the MTL's most vulnerable structure, the hippocampus (HC), and the DN at subregion resolution in individuals with Alzheimer's disease and related dementia (ADRD). By leveraging the power of the approximately 40,000 participants of the UK Biobank cohort, we assessed impacts from the protective APOE ɛ2 and the deleterious APOE ɛ4 Alzheimer's disease alleles on these structural relationships. We demonstrate ɛ2 and ɛ4 genotype effects on the inter-individual expression of HC-DN co-variation structural patterns at the population level. Across these HC-DN signatures, recurrent deviations in the CA1, CA2/3, molecular layer, fornix's fimbria, and their cortical partners related to ADRD risk. Analyses of the rich phenotypic profiles in the UK Biobank cohort further revealed male-specific HC-DN associations with air pollution and female-specific associations with cardiovascular traits. We also showed that APOE ɛ2/2 interacts preferentially with HC-DN co-variation patterns in estimating social lifestyle in males and physical activity in females. Our structural, genetic, and phenotypic analyses in this large epidemiological cohort reinvigorate the often-neglected interplay between APOE ɛ2 dosage and sex and link APOE alleles to inter-individual brain structural differences indicative of ADRD familial risk.