Participant education, spousal education and dementia risk in a diverse cohort of members of an integrated health care delivery system in Northern California

Patterns of Factors in the National Institute on Aging Health Disparities Research Framework Domains and Mild Cognitive Impairment Risk

Introduction

Alzheimer's disease and related dementias are public health and social care challenges. This study used the National Institute on Aging Health Disparities Research Framework to organize potential cognitive impairment risk factors. It aimed to examine patterns of environmental, sociocultural, behavioral, and biological factors and identify key components that predict mild cognitive impairment risk.

Methods

This study comprised 2,812 participants from the Mayo Clinic Study of Aging who were cognitively unimpaired at baseline (aged ≥50 years, mean age [SD]=68.9 [9.7] years, 50.4% female). Analyses utilized a 2-stage approach using factor and principal component analyses to group factors from multiple National Institute on Aging Health Disparities Research Framework domains and identify components that predict cognitive impairment risk. Using a cohort study design, the resulting composite scores were considered as covariates for incident mild cognitive impairment analysis using Cox proportional hazards models.

Results

Three principal components explained 40.30% of the variance and were differentially associated with mild cognitive impairment risk. One component (Principal Component 2), which included factors from all 4 domains of the National Institute on Aging Health Disparities Research Framework (including social, group, and playing game activities [sociocultural domain]; exercise and physical activity [behavioral domain]; education/occupation [environmental domain]; and absence of cardiometabolic risk factors/health self-rating [biological domain]), was associated with lower mild cognitive impairment risk (hazard ratio=0.80, 95% CI=0.73, 0.89). The other 2 principal components, also including factors from multiple framework domains, were associated with increased mild cognitive impairment risk.

Conclusions

Derived principal components included factors from multiple framework domains, supporting the multietiology pathways leading to cognitive impairment. These principal components were differentially associated with mild cognitive impairment risk. Identifying key factors from multiple National Institute on Aging Health Disparities Research Framework domains associated with cognitive impairment risk has implications for effectively targeting interventions at multiple levels (e.g., medical, societal, policy) to avert or delay cognitive impairment risk.

Spousal Education and Memory Decline: Evidence From the English Longitudinal Study of Aging

BACKGROUND AND OBJECTIVES

Most studies on educational links to health focus on individuals' own educational attainment, with little attention to a spouse's education. This study examines spouse's educational attainment in relation to both partners' memory trajectories among married and cohabiting older couples.

RESEARCH DESIGN AND METHODS

Data were drawn from 9 waves of the English Longitudinal Study of Ageing 2002/3-2018/9, including 6,918 different-sex couple dyads (6,468 married and 450 cohabiting). Latent growth curve Actor-Partner Interdependence Models were used to estimate the associations of husbands' and wives' education with each other's memory trajectories, with a focus on economic resources and health behaviors as potential mediators. We further examined potential differences between married and cohabitating couples.

RESULTS

Wives' lower education was associated with both lower initial levels and an accelerated decline in memory for themselves (actor effects) and their husbands (partner effects). Husbands' lower education was associated with lower initial memory levels for both themselves (actor effects) and their wives (partner effects) but not with changes in memory trajectories. These patterns were primarily evident in married couples, with no significant partner effects in cohabiting couples. Economic resources were the primary mechanism linking spousal education to memory trajectories.

DISCUSSION AND IMPLICATIONS

Older adults with lower-educated spouses face a higher risk of memory decline, highlighting the need for targeted interventions to promote healthy cognitive aging in this vulnerable group.

A national longitudinal dyadic analysis of spousal education and cognitive decline in the United States

Education plays a significant role in shaping cognitive functioning throughout an individual's life. However, existing research has not adequately explored how the educational attainment of the spouse can impact cognitive functioning over time. This study presents one of the first longitudinal analyses of how spousal education is linked to cognitive trajectories of each member within couples during their later life in the United States. Guided by the linked lives perspective, we analyze data from 8370 couples in the Health and Retirement Study spanning from 2000 to 2018. Results from the Actor-Partner Interdependence Model (APIM) integrated with latent growth curve models reveal that cognitive trajectories exhibit a correlation between spouses over time. Moreover, our analysis uncovers gender-specific effects of spousal education on cognition, shedding light on the underlying mechanisms driving this connection. Notably, the lower educational attainment of husbands is associated with a faster cognitive decline in both themselves and their wives. This association is partially explained by economic resources, but not by health and social behaviors. The lower educational attainment of wives is linked to their own faster cognitive decline as well as lower initial cognitive levels of their husbands, in part via economic resources. However, wives' educational attainment is largely unrelated to their husbands' cognitive decline. Intriguingly, wives' education has a more pronounced impact on the health and social behaviors of their husbands than vice versa, although these health and social behaviors do not appear to influence husbands' cognitive decline. In conclusion, these results underscore the importance of considering spousal education in comprehending the complexities of cognitive decline within dyadic relationships.

State-Level Indicators of Childhood Educational Quality and Incident Dementia in Older Black and White Adults

Importance

Higher educational attainment is associated with reduced dementia risk, but the role of educational quality is understudied, presenting a major evidence gap, especially as it may contribute to racial inequities.

Objective

To evaluate the association between state-level educational quality during childhood and dementia risk.

Design, Setting, and Participants

This cohort study analyzed longitudinal data collected from January 1, 1997, through December 31, 2019 (23-year follow-up period). The sample comprised members of Kaiser Permanente Northern California (KPNC), a large integrated health care delivery system, who completed an optional survey during 1964-1972. Eligible individuals were US born; non-Hispanic Black or non-Hispanic White; aged 65 years or older as of January 1, 1996; were still alive; and did not have a dementia diagnosis or lapse in KPNC membership greater than 90 days between January 1 and December 31, 1996.

Exposures

Historical state-level administrative indicators of school quality (school term length, student-teacher ratio, and attendance rates) linked to participants using birth state and birth year (with a 6-year lag) and divided into tertiles using the pooled sample.

Main Outcomes and Measures

Dementia diagnoses from electronic health records between 1997 and 2019 were analyzed between March 1 and August 31, 2022. The associations of educational quality with incident dementia were estimated using Cox proportional hazards regression models.

Results

Among 21 450 KPNC members who participated in the optional survey, individuals born before availability of educational quality records (n = 87) and missing educational attainment (n = 585) were excluded. The final analytic sample was 20 778 individuals (56.5% women, 43.5% men; mean [SD] age, 74.7 [6.5] years; 18.8% Black; 81.2% White; 41.0% with less than high school education). Among Black individuals, 76.2% to 86.1% (vs 20.8%-23.3% of White individuals) attended schools in states in the lowest educational quality tertiles. Highest (vs lowest) educational quality tertiles were associated with lower dementia risk (student-teacher ratio: hazard ratio [HR], 0.88 [95% CI, 0.83-0.94]; attendance rates: HR, 0.80 [95% CI, 0.73-0.88]; term length: HR, 0.79 [95% CI, 0.73-0.86]). Effect estimates did not differ by race and were not attenuated by adjustment for educational attainment.

Conclusions and Relevance

In this cohort study, lower state-average educational quality was more common among Black individuals and associated with higher dementia risk. Differential investment in high-quality education due to structural racism may contribute to dementia disparities.

Consideration of sex and gender in Alzheimer's disease and related disorders from a global perspective

Sex or gender differences in the risk of Alzheimer's disease and related dementias (ADRD) differ by world region, suggesting that there are potentially modifiable risk factors for intervention. However, few epidemiological or clinical ADRD studies examine sex differences; even fewer evaluate gender in the context of ADRD risk. The goals of this perspective are to: (1) provide definitions of gender, biologic sex, and sexual orientation. and the limitations of examining these as binary variables; (2) provide an overview of what is known with regard to sex and gender differences in the risk, prevention, and diagnosis of ADRD; and (3) discuss these sex and gender differences from a global, worldwide perspective. Identifying drivers of sex and gender differences in ADRD throughout the world is a first step in developing interventions unique to each geographical and sociocultural area to reduce these inequities and to ultimately reduce global ADRD risk. HIGHLIGHTS: The burden of dementia is unevenly distributed geographically and by sex and gender. Scientific advances in genetics and biomarkers challenge beliefs that sex is binary. Discrimination against women and sex and gender minority (SGM) populations contributes to cognitive decline. Sociocultural factors lead to gender inequities in Alzheimer's disease and related dementias (ADRD) worldwide.