Early life development in a multiethnic sample and the relation to late life cognition

Parental Education, Midlife Hypertension, and Disparities in Late-Life Cognitive Test Scores: Application of an Equity-Focused Causal Decomposition Approach

BACKGROUND

Parental education is an important determinant of late-life cognition, but the extent to which intervening on midlife risk factors, such as hypertension, mitigates the impact of early-life factors is unclear. Novel methodological approaches, such as causal decomposition, facilitate the assessment of contributors to health inequities through hypothetical interventions on mediating risk factors.

METHODS

Using harmonized cohorts (Kaiser Healthy Aging and Diverse Life Experiences Study; Study of Healthy Aging in African Americans) and a ratio of mediator probability weights decomposition approach, we quantified disparities in late-life cognitive test scores (semantic memory, executive function, and verbal memory z-scores) across high versus low parental education, and evaluated whether socioeconomic disparities in late-life cognitive test scores would change if the corresponding disparity in midlife hypertension were eliminated.

RESULTS

We observed substantial disparities across levels of parental education in late-life cognitive test scores (eg, =-0.72 95% CI: -0.84 to -0.60 for semantic memory). Hypothetical intervention on midlife hypertension did not substantially reduce disparities in any cognitive domain. Patterns were similar when stratified by race.

CONCLUSIONS

Future work should evaluate other points of intervention across the lifecourse (eg, participant education) to reduce late-life cognitive disparities across levels of parental education.

Association between childhood parental literacy and late-life cognitive function: The Guangzhou Biobank Cohort Study

OBJECTIVES

Evidence on the associations of childhood parental education with late-life cognitive function remains inconsistent. Additionally, studies focusing on dimensions of cognitive function are scarce, with none from China. Therefore, we examined the associations of childhood parental education with late-life cognitive function and it's dimensions and investigated potential interactions.

STUDY DESIGN

A cross-sectional study.

METHODS

Participants were included from the third phase of Guangzhou Biobank Cohort Study. Mini-Mental State Examination (MMSE), Delayed 10-Word Recall Test (DWRT), and childhood parental literacy (could read or write) were collected. Multivariate linear and logistic regression were used.

RESULTS

Among 8891 participants aged ≥50 years, compared with those whose childhood parents could not read/write, those with only the father, only the mother, or both parents able to read/write during childhood had higher scores on the MMSE and its dimensions, and lower odds of mild cognitive impairment (MCI). The coefficients (β) and 95 % confidence intervals (CI) for scores of MMSE were 1.25 (1.10, 1.41), 1.36 (0.86, 1.86), and 2.05 (1.89, 2.21) respectively; the odds ratios and 95 % CIs for MCI were 0.38 (0.33, 0.45), 0.35 (0.18, 0.67), and 0.15 (0.12, 0.19) respectively. More pronounced effects were found in women, those aged ≥60, those with ≤ primary education, and in those whose childhood parents could read/write. Socioeconomic position mediated the association. Cognitive functions of attention and calculation in children of only fathers who could read/write (β = 0.43, 95%CI: 0.35, 0.50) and memory in children of only mothers who could read/write (β = 0.34, 95%CI: 0.16, 0.51) were associated with better outcomes. Consistent results were also found using scores from the DWRT.

CONCLUSIONS

Childhood parental literacy was associated with late-life cognitive function and it's dimensions, which mediated by socioeconomic position. Specifically, having only a father or only a mother who could read/write during childhood was associated with better cognitive function in attention/calculation and memory, respectively. These results add new evidence to support strategies for elderly cognitive health care.

School-based racial segregation, social support, and late-life cognitive function in the Study of Healthy Aging in African Americans (STAR)

INTRODUCTION

School-based social support for Black students may mediate or modify the association between school segregation and late-life cognition.

METHODS

Study of Healthy Aging in African Americans participants (n = 574) reported segregated school attendance and school-based social support. Associations of segregated schooling with domain-specific cognitive outcomes and effect modification or mediation by school-based social support were evaluated with linear mixed models.

RESULTS

Segregated school attendance was associated with increased likelihood of school-based social support. Segregated (vs. desegregated in 6th grade) school attendance was associated with lower executive function (β = -0.18 [-0.34, -0.02]) and semantic memory z-scores (β = -0.31 [-0.48, -0.13]). Social support did not mediate these associations. Estimates for segregated school attendance were attenuated among those who felt supported, although there was limited evidence of statistically significant effect modification.

DISCUSSION

Early-childhood school segregation was associated with poorer cognitive function. Sources of resilience within racialized educational experiences should be further evaluated to bridge inequities.

HIGHLIGHTS

School segregation is a form of structural racism that affected the educational experiences of Black youth with potentially lasting consequences for healthy brain aging. Black students who attended a segregated school experienced greater school-based social support, which may highlight a potential source of resilience and resistance against the effects of racism-related stressors on cognitive function. The estimated adverse association between attending a segregated school on cognition was larger for students without an adult at school who cared about them versus those with an adult at school who cared about them, but estimates were imprecise.

Charting Alzheimer's Disease and Dementia: Epidemiological Insights, Risk Factors and Prevention Pathways

Alzheimer's disease (AD), the most common cause of dementia, is a complex and multifactorial condition without cure at present. The latest treatments, based on anti-amyloid monoclonal antibodies, have only a modest effect in reducing the progression of cognitive decline in AD, whereas the possibility of preventing AD has become a crucial area of research. In fact, recent studies have observed a decrease in dementia incidence in developed regions such as the US and Europe. However, these trends have not been mirrored in non-Western countries (Japan or China), and the contributing factors of this reduction remain unclear. The Lancet Commission has delineated a constrained classification of 12 risk factors across different life stages. Nevertheless, the scientific literature has pointed to over 200 factors-including sociodemographic, medical, psychological, and sociocultural conditions-related to the development of dementia/AD. This narrative review aims to synthesize the risk/protective factors of dementia/AD. Essentially, we found that risk/protective factors vary between individuals and populations, complicating the creation of a unified prevention strategy. Moreover, dementia/AD explanatory mechanisms involve a diverse array of genetic and environmental factors that interact from the early stages of life. In the future, studies across different population-based cohorts are essential to validate risk/protective factors of dementia. This evidence would help develop public health policies to decrease the incidence of dementia.

Vietnamese Insights into Cognitive Aging Program (VIP): Objectives, study design, and cohort description

Introduction

There is a dearth of research on cognitive aging and dementia in Asian Americans, particularly in Vietnamese Americans, the fourth largest Asian subgroup in the United States.

Methods

The Vietnamese Insights into Cognitive Aging Program (VIP) investigates early life adversity and war-related trauma and their associations with cognitive health in a community-based sample of older Vietnamese Americans in Northern California (i.e., Sacramento and Santa Clara counties). Baseline measurements include a comprehensive neuropsychological battery, including measures of global cognition along with executive function, semantic memory, and episodic memory. Data also include measures of functioning, early life adversity and trauma exposure, and psychosocial and traditional cardiovascular disease risk factors. Cognitive assessments will be repeated twice over the course of the data collection period, approximately 12- and 24- months post-baseline. Blood samples collected during Wave 2 will be assayed for biochemical risk factors.

Results

Baseline assessments were conducted from January 2022 to November 2023, with N = 548 Vietnamese Americans; mean age ± SD was 73 ± 5.31 years and 55% of participants were women. There were significant differences in social factors by site, with Santa Clara participants having higher education (some college or higher: Sacramento, ≈25%; Santa Clara: ≈48%) and marginally higher incomes compared to Sacramento participants. A higher percentage of Santa Clara participants reported speaking English well or very well (24%) compared to Sacramento participants (13%), although the majority of the entire sample (81%) reported speaking some to no English (response options: not at all; some/a little bit; well/very well).

Discussion

This longitudinal study providea a unique opportunity to more fully delineate psychosocial factors that contribute to dementia disparities in diverse and under-engaged populations. Future work will examine cognition, the prevalence of mild cognitive impairment and dementia, and other health outcomes, while controlling for site differences in all analyses.

Highlights

Vietnamese Insights into Cognitive Aging Program (VIP) is a new study.VIP has detailed early life and health data on 548 older Vietnamese Americans.History of war and trauma may contribute to Alzheimer's disease and related dementias (ADRD)-related burden.VIP may provide insight into ADRD burden in other understudied groups.

Impact of genetic predisposition to late-onset neurodegenerative diseases on early life outcomes and brain structure

Most patients with late-onset neurodegenerative diseases such as Alzheimer's and Parkinson's have a complex aetiology resulting from numerous genetic risk variants of small effects located across the genome, environmental factors, and the interaction between genes and environment. Over the last decade, genome-wide association studies (GWAS) and post-GWAS analyses have shed light on the polygenic architecture of these diseases, enabling polygenic risk scores (PRS) to estimate an individual's relative genetic liability for presenting with the disease. PRS can screen and stratify individuals based on their genetic risk, potentially years or even decades before the onset of clinical symptoms. An emerging body of evidence from various research studies suggests that genetic susceptibility to late-onset neurodegenerative diseases might impact early life outcomes, including cognitive function, brain structure and function, and behaviour. This article summarises recent findings exploring the potential impact of genetic susceptibility to neurodegenerative diseases on early life outcomes. A better understanding of the impact of genetic susceptibility to neurodegenerative diseases early in life could be valuable in disease screening, detection, and prevention and in informing treatment strategies before significant neural damage has occurred. However, ongoing studies have limitations. Overall, our review found several studies focused on APOE haplotypes and Alzheimer's risk, but a limited number of studies leveraging polygenic risk scores or focused on genetic susceptibility to other late-onset conditions.

Early life adversity, race, and childhood socioeconomic status: intersecting drivers of later life cognition

OBJECTIVES

Research on associations between early life adversity (ELA) and later life cognition has yielded mixed results and generally have not considered how broader societal systems of stratification potentially influence associations. The current study addresses this gap by exploring if racialized identity and childhood socioeconomic status (cSES) moderate associations between ELA exposure and later life cognition.

METHODS

Using data from the Health and Retirement Study (Waves 2010-2018), we used growth curve modeling to examine if the confluence of ELA, cSES, and racialized identity is associated with cognition.

RESULTS

Among White participants, greater exposure to ELA was associated with poorer baseline cognitive functioning, and higher cSES buffered against this association. Among Black participants, exposure to ELA was not associated with baseline cognitive functioning, regardless of cSES. We did not find evidence of any associations between main predictors nor their interactions with change in cognition over time.

CONCLUSIONS

This study provides evidence that associations between ELA and later life cognition is contingent upon multiple social positions in the United States. These findings support the importance of integrating insights on intersecting social positions within life-course-oriented efforts to reduce racialized cognitive disparities.

Self-reported mid- to late-life physical and recreational activities: Associations with late-life cognition

OBJECTIVE

Physical and recreational activities are behaviors that may modify risk of late-life cognitive decline. We sought to examine the role of retrospectively self-reported midlife (age 40) physical and recreational activity engagement - and self-reported change in these activities from age 40 to initial study visit - in predicting late-life cognition.

METHOD

Data were obtained from 898 participants in a longitudinal study of cognitive aging in demographically and cognitively diverse older adults (Age: range = 49-93 years, M = 75, SD = 7.19). Self-reported physical and recreational activity participation at age 40 and at the initial study visit were quantified using the Life Experiences Assessment Form. Change in activities was modeled using latent change scores. Cognitive outcomes were obtained annually (range = 2-17 years) using the Spanish and English Neuropsychological Assessment Scales, which measure verbal episodic memory, semantic memory, visuospatial processing, and executive functioning.

RESULTS

Physical activity engagement at age 40 was strongly associated with cognitive performance in all four domains at the initial visit and with global cognitive slope. However, change in physical activities after age 40 was not associated with cognitive outcomes. In contrast, recreational activity engagement - both at age 40 and change after 40 - was predictive of cognitive intercepts and slope.

CONCLUSIONS

Retrospectively self-reported midlife physical and recreational activity engagement were strongly associated with late-life cognition - both level of performance and rate of future decline. However, the data suggest that maintenance of recreational activity engagement (e.g., writing, taking classes, reading) after age 40 is more strongly associated with late-life cognition than continued maintenance of physical activity levels.

Evaluating cognitive and affective abilities among medical students: behavioural and medicolegal perspectives

Medical students attending university for the first time experience a new environment, full of significant social, cultural, and intellectual challenges. Moreover, drug abuse and bullying among university students are major global concerns. The aim of the current study was to assess the impact of medicolegal issues on undergraduate and postgraduate students. It is a cross-sectional survey-based study, with each set of questions investigating cognitive functions, aggression, personality, and exposure to medicolegal issues. Males and those with a chronic disease have been significantly exposed to medicolegal issues; exposed students were significantly older than nonexposed ones. The scores of aggression were significantly higher among exposed and male students. The cognitive scores were higher for the students from rural areas than in urban areas, and females were more neurotic than males. The current study recommends conducting campaigns to educate university students on the importance of formally disclosing unethical behaviors and listening to the victims to facilitate overcoming their negative feelings. As many victims feel comfortable disclosing victimization to their friends, we recommend conducting peer educational programs to help friends support their colleagues regarding unethical misconduct.

Caregivers of People With Mild Cognitive Impairment and Dementia: Characterizing Social and Psychological Outcomes

OBJECTIVE

Little is known about caregiving across the spectrum of cognitive impairment [mild cognitive impairment (MCI) to dementia] and how early life and sociocultural factors affect caregiver health. In this study, we characterized differences between caregivers of those with MCI versus those with dementia.

METHODS

A total of 158 caregivers were enrolled in this cross-sectional study, most of whom were dementia caregivers (65%). Caregivers completed questionnaires on depressive symptoms, self-rated health (SRH), perceived burden and stress, as well as psychosocial and demographic measures.

RESULTS

Caregivers of those with MCI reported fewer depressive symptoms and lower stress and burden compared with dementia caregivers. In adjusted analyses caregivers with greater stress reported more depressive symptoms. For SRH, at lower stress levels, having a sibling die before age 18 (ie, early life adversity) was associated with poorer SRH; at higher stress levels, having early life adversity was associated with better SRH. At lower burden levels, more live births were associated with worse SRH; at higher burden levels, more live births were associated with better SRH.

CONCLUSIONS

Early life factors are relevant for caregivers of those with cognitive impairment and targeted prevention and early intervention may be helpful in alleviating caregiver burden and stress.

Childhood and Life-Course Socioeconomic Position and Cognitive Function in the Adult Population of the Hispanic Community Health Study/Study of Latinos

The Hispanic/Latino population experiences socioeconomic adversities across the lifespan and is at greater risk of cognitive impairment, yet little is known about the role of life-course socioeconomic position (SEP) in cognitive function in this population. Using baseline data (2008-2011) from adults (aged 45-74 years) of the Hispanic Community Health Study/Study of Latinos, we assessed the association between childhood SEP and socioeconomic mobility with cognitive function, and whether this association was mediated by midlife SEP. Childhood SEP was assessed using parental education. An index combining participants' education and household income represented midlife SEP. Socioeconomic mobility was categorized as stable low, downward or upward mobility, and stable high-SEP. Cognitive function measures were modeled using survey linear regression with inverse-probability weighting, accounting for covariates. We used mediation analysis to estimate the indirect effect of childhood SEP on cognition through midlife SEP. High childhood SEP was associated with global cognition in adulthood (coefficient for parental education beyond high school vs. less than high school = 0.26, 95% confidence interval: 0.15, 0.37). This association was partially mediated through midlife SEP (indirect effect coefficient = 0.16, 95% confidence interval: 0.15, 0.18). Low SEP through the life course was associated with the lowest cognitive function. This study provides evidence that life-course SEP influences cognitive performance in adulthood.

Effects of early-life environment and adulthood SES on cognitive change in a multiethnic cohort

OBJECTIVES

Early-life socioeconomic status (SES) and adversity are associated with late-life cognition and risk of dementia. We examined the association between early-life SES and adversity and late-life cross-sectional cognitive outcomes as well as global cognitive decline, hypothesizing that adulthood SES would mediate these associations.

METHODS

Our sample (N = 837) was a racially and ethnically diverse cohort of non-Hispanic/Latino White (48%), Black (27%), and Hispanic/Latino (19%) participants from Northern California. Participant addresses were geocoded to the level of the census tract, and US Census Tract 2010 variables (e.g., percent with high school diploma) were extracted and combined to create a neighborhood SES composite. We used multilevel latent variable models to estimate early-life (e.g., parental education, whether participant ever went hungry) and adult (participant's education, main occupation) SES factors and their associations with cross-sectional and longitudinal cognitive outcomes of episodic memory, semantic memory, executive function, and spatial ability.

RESULTS

Child and adult factors were strongly related to domain-specific cognitive intercepts (0.20-0.48 SD per SD of SES factor); in contrast, SES factors were not related to global cognitive change (0.001-0.01 SD per year per SD of SES factor). Adulthood SES mediated a large percentage (68-75%) of the total early-life effect on cognition.

CONCLUSIONS

Early-life sociocontextual factors are more strongly associated with cross-sectional late-life cognitive performance compared to cognitive change; this effect is largely mediated through associations with adulthood SES.

Effects of adverse childhood health experiences on cognitive function in Chinese middle-aged and older adults: mediating role of depression

BACKGROUND

Adverse childhood experiences are critical factors in depression and cognitive decrease, but the effect of adverse childhood health experiences (ACHEs) on cognitive function and the role of depression have not been fully studied.

METHODS

Data were taken from the China Health and Retirement Longitudinal Study (CHARLS) of 2014 and 2018. This study used indicators of situational memory ability and mental status to measure cognitive capacity. Besides analyzing the different types of ACHEs, scores for ACHEs were calculated to represent the severity of ACHEs. The Center for Epidemiologic Studies Depression Scale (CES-D) was used to assess depression. The analysis of this study employed two different analytical strategies in order to examine the mediated effects of depression. We used Sobel's test and Baron and Kenny's causal step approach, which utilized a generalized least squares regression model. Furthermore, a logistic regression model was used to evaluate the robustness of the Karlson-Holm-Breen (KHB) approach.

RESULTS

In this study, 6301 individuals who met the requirements of the study were included. We found that being confined to bed (ACHE3) (β=-0.3846, p = 0.022) in childhood had a negative impact on cognitive function. Similarly, ACHEs had a negative effect on cognitive function (β=-0.0819, p = 0.090). And after the depression had been introduced into the model, the regression coefficient of ACHEs on cognitive function was no longer significant (β=-0.0170, p = 0.727). The Sobel test showed that for ACHE3, the mediated proportion of the total effect of depression was 36.92%. While for ACHEs, the proportion of the mediated effect of depression was 70.11%. Finally, a robustness test of the mediating effect using the KHB method revealed that the mediating effect still existed. Further, based on different gender, age, and educational levels, the heterogeneity test indicated that the relationship between ACHEs and cognitive function and mediating effects of the depression were different as well as passing the robustness test of the interaction.

CONCLUSION

The decline in cognition had been shown to be correlated with ACHEs and depression mediated this relationship. Positive interventions might help to improve cognitive performance in individuals suffering from ACHEs and depression.

Life-course inequalities in intrinsic capacity and healthy ageing, China

OBJECTIVE

To investigate the contribution of early-life factors on intrinsic capacity of Chinese adults older than 45 years.

METHODS

We used data on 21 783 participants from waves 1 (2011) and 2 (2013) of the China Health and Retirement Longitudinal Study (CHARLS), who also participated in the 2014 CHARLS Life History Survey to calculate a previously validated measure of intrinsic capacity. We considered 11 early-life factors and investigated their direct association with participants' intrinsic capacity later in life, as well as their indirect association through four current socioeconomic factors. We used multivariable linear regression and the decomposition of the concentration index to investigate the contribution of each determinant to intrinsic capacity inequalities.

FINDINGS

Participants with a favourable environment in early life (that is, parental education, childhood health and neighbourhood environment) had a significantly higher intrinsic capacity score in later life. For example, participants with a literate father recorded a 0.040 (95% confidence interval, CI: 0.020 to 0.051) higher intrinsic capacity score than those with an illiterate father. This inequality was greater for cognitive, sensory and psychological capacities than locomotion and vitality. Overall, early-life factors directly explained 13.92% (95% CI: 12.07 to 15.77) of intrinsic capacity inequalities, and a further 28.57% (95% CI: 28.19 to 28.95) of these inequalities through their influence on current socioeconomic inequalities.

CONCLUSION

Unfavourable early-life factors appear to decrease late-life health status in China, particularly cognitive, sensory and psychological capacities, and these effects are exacerbated by cumulative socioeconomic inequalities over a person's life course.

Inclusion of Vietnamese Americans: Opportunities to understand dementia disparities

There is a dearth of research on cognitive aging and dementia in Asian Americans, particularly Vietnamese Americans, who are the fourth largest Asian subgroup in the United States. The National Institutes of Health is mandated to make certain that racially and ethnically diverse populations are included in clinical research. Despite the widespread recognition to ensure that research findings can be generalizable to all groups, there are no estimates of the prevalence or incidence of mild cognitive impairment and Alzheimer's disease and related dementias (ADRD) in Vietnamese Americans, nor do we understand ADRD risk and protective factors in this group. In this article, we posit that studying Vietnamese Americans contributes to a better understanding of ADRD in general and offers unique opportunities for elucidating life course and sociocultural factors that contribute to cognitive aging disparities. That is, the unique context of Vietnamese Americans may provide understanding in terms of within-group heterogeneity and key factors in ADRD and cognitive aging. Here, we provide a brief history of Vietnamese American immigration and describe the large but often ignored heterogeneity of Asian Americans in the United States, elucidate how early life adversity and stress might influence late-life cognitive aging, and provide a basis for the role of sociocultural and health factors in the study of Vietnamese cognitive aging disparities. Research with older Vietnamese Americans provides a unique and timely opportunity to more fully delineate the factors that contribute to ADRD disparities for all populations.

Childhood socioeconomic status interacts with cognitive function to impact scam susceptibility among community-dwelling older adults

OBJECTIVES

We examined whether childhood socioeconomic status (SES) is related to scam susceptibility in old age and tested the hypothesis that childhood SES interacts with cognitive function to impact scam susceptibility.

METHODS

This study employed a cross-sectional design. All data were collected in participants' community-based residences. Participants were 1071 older adults (mean age = 81.05 years, SD = 7.53) without dementia (median MMSE score = 28.29, IQR = 27.86-30.00). Participants completed assessments of childhood SES, cognitive function, and scam susceptibility. We used linear regression models to examine the associations of childhood SES and cognitive function with scam susceptibility.

RESULTS

In a regression model adjusted for age, gender, and education, poorer cognitive function was associated with higher scam susceptibility, but childhood SES was not. However, in an additional model that included the interaction of childhood SES and cognitive function, the interaction was significant, such that lower childhood SES was associated with higher scam susceptibility among participants with lower cognitive function.

CONCLUSION

Lower childhood SES is associated with higher scam susceptibility among older adults with lower levels of cognitive function. Thus, older adults who experienced limited resources in childhood and have lower cognitive function may represent a specific group for interventions to increase scam awareness and prevent financial exploitation.

APOE Effects on Late Life Cognitive Trajectories in Diverse Racial/Ethnic Groups

OBJECTIVE

This study evaluated: (1) apolipoprotein E (APOE) ϵ4 prevalence among Black, Latino, and White older adults, (2) associations of APOE ϵ4 status with baseline level and change over time of cognitive outcomes across groups, and (3) combined impact of APOE ϵ4 prevalence and magnitude of effect on cognitive decline within each racial/ethnic group.

METHOD

Participants included 297 White, 138 Latino, and 149 Black individuals from the longitudinal UC Davis Diversity Cohort who had APOE genotyping and ≥2 cognitive assessments. Magnitude of associations of ϵ4 with cognitive baseline and change across racial/ethnic groups was tested with multilevel parallel process longitudinal analyses and multiple group models.

RESULTS

ϵ4 prevalence in Black (46%) and White participants (46%) was almost double that of Latino participants (24%). ϵ4 was associated with poorer baseline episodic memory only in White participants (p = .001), but had a moderately strong association with episodic memory change across all racial/ethnic groups (Blacks= -.061 SD/year, Latinos = -.055,Whites= -.055). ϵ4 association with semantic memory change was strongest in White participants (-.071), intermediate in Latino participants (-.041), and weakest in Black participants (-.022).

CONCLUSION

Calculated cognitive trajectories across racial/ethnic groups were influenced in an additive manner by ϵ4 prevalence and strength of association with cognitive decline within the group. Group differences in ϵ4 prevalences and associations of ϵ4 with cognition may suggest different pathways from APOE to cognitive decline, and, AD possibly having less salient impact on cognitive decline in non-White participants. Differential effects of APOE on episodic memory and non-memory cognition have important implications for understanding how APOE influences late life cognitive decline.

Childhood deprivations predict late-life cognitive impairment among older adults in India

Large population-based studies on the associations of childhood factors with late-life cognition are lacking in many low and middle income countries including India. In this study, we assessed the prevalence of late-life cognitive impairment and examined the associations of childhood socioeconomic status (SES) and health conditions with cognitive impairment among older adults in India. Data for this study were derived from the Longitudinal Ageing Study in India conducted in 2017-18. The effective sample size was 31,464 older adults aged 60 years and above. Cognitive functioning was measured through five global domains (memory, orientation, arithmetic function, executive function, and object naming). The overall score ranged between 0 and 43, and the score was reversed indicating cognitive impairment. Descriptive statistics along with mean scores of cognitive impairment were presented. Additionally, moderated multivariable linear regression models were employed to examine the association between explanatory variables, including childhood SES and health conditions and late-life cognitive impairment. The mean score of cognitive functioning among the study participants was 21.72 (CI 2.64-21.80). About 15% of older adults had poor health conditions, and 44% had lower financial status during their childhood. Older adults who had a fair health during their childhood were more likely to suffer from cognitive impairment in comparison to older adults who had good health during their childhood (Coef: 0.60; CI 0.39, 0.81). In comparison to older adults who had good childhood financial status, those who had poor childhood financial status were more likely to suffer from cognitive impairment (Coef: 0.81; CI 0.56, 1.07). Older adults who had fair childhood health status and poor childhood financial status were more likely to suffer from cognitive impairment in comparison to older adults who had good childhood health and good financial status (Coef: 1.26; CI 0.86, 1.66). Social policies such as improving educational and financial resources in disadvantaged communities and socioeconomically poor children and their families, would help to enhance a better cognitive ageing and a healthy and dignified life in old age.

Including ethnic minorities in dementia research: Recommendations from a scoping review

Introduction

Ethnicity influences dementia etiology, prognosis, and treatment, while culture shapes help-seeking and care. Despite increasing population diversity in high-income settlement countries, ethnic minorities remain underrepresented in dementia research. We investigated approaches to enhance the recruitment, and consistent collection and analysis of variables relevant to, ethnic minorities in dementia studies to make recommendations for consistent practice in dementia research.

Methods

We did a scoping review, searching Embase, PsycINFO, Medline, CENTRAL, and CINAHL between January 1, 2010 and January 7, 2020. Dementia clinical and cohort studies that actively recruited ethnic minorities in high-income countries were included. A steering group of experts developed criteria through which high-quality studies were identified.

Results

Sixty-six articles were retrieved (51 observational; 15 experimental). Use of interpreters and translators (n = 17) was the most common method to facilitate participant recruitment. Race and ethnicity (n = 59) were the most common variables collected, followed by information on native language (n = 14), country of birth (n = 9), and length of time in country of settlement (n = 8). Thirty-three studies translated or used a culturally validated instrument. Twenty-three articles conducted subgroup analyses based on ethnicity. Six high-quality studies facilitated inclusion through community engagement, collected information on multiple aspects of ethnic diversity, and adjusted/substratified to analyze the impact of ethnicity on dementia.

Discussion

We make recommendations for consistent recruitment, collection, and reporting of variables relating to ethnic and cultural diversity in dementia research.

Life course linkages between enriching early-life activities and later life cognition: Evidence from the Wisconsin Longitudinal Study

Prior research suggests that participation in enriching early-life activities (EELAs) has long-term benefits for cognitive health and aging. This study aims to examine the life course processes underlying these associations by drawing on theoretical models from life course epidemiology. Specifically, we tested sensitive-period effects, social pathways, and selection effects as potential explanations for linkages between greater participation in EELAs and better later life cognition. We drew on data from the Wisconsin Longitudinal Study (WLS), which is among the longest-running cohort studies in the U.S. that has followed graduates (all identified as non-Hispanic White) from Wisconsin high schools since 1957. We used prospective measures of key variables, including information from high school yearbooks, with assessments of cognitive performance at ages 65 and 72. Results from multilevel modeling indicated that greater participation in cognitively oriented extracurricular activities (but not physically nor socially oriented activities) was associated with both better language/executive functioning and memory at age 65. Although the size of these associations was reduced when accounting for other cognitive resources in adolescence (childhood socioeconomic status and adolescent cognitive ability) and in midlife (adult socioeconomic status and formal group participation), there remained small, yet statistically robust, associations. We did not find robust associations between greater EELA engagement and slower rates of decline in cognition between ages 65 and 72, nor did we find evidence of gender differences. Results suggest that for this cohort of older adults, EELA participation is part of life course "protective chains," whereby exposures to assets at one point in the life course increase the likelihood of subsequent exposures, each sequentially and in their own right, toward better later life cognition. We discuss how results support the importance of policies and practices to promote healthy cognitive development among youth for the long-term cognitive health of a rapidly aging U.S. population.

The long arm of childhood socioeconomic deprivation on mid- to later-life cognitive trajectories: A cross-cohort analysis

Introduction

Earlier studies of the effects of childhood socioeconomic status (SES) on later-life cognitive function consistently report a social gradient in later-life cognitive function. Evidence for their effects on cognitive decline is, however, less clear.

Methods

The sample consists of 5324 participants in the Whitehall II study, 8572 in the Health and Retirement Study (HRS), and 1413 in the Kame Project, who completed self-report questionnaires on their early life experiences and underwent repeated cognitive assessments. We characterized cognitive trajectories using latent class mixed models, and explored associations between childhood SES and latent class membership using logistic regressions.

Results

We identified distinct trajectories classes for all cognitive measures examined. Childhood socioeconomic deprivation was associated with an increased likelihood of being in a lower trajectory class.

Discussion

Our findings support the notions that cognitive aging is a heterogeneous process and early life circumstances may have lasting effects on cognition across the life-course.

Promoting brain health through physical activity among adults exposed to early life adversity: Potential mechanisms and theoretical framework

Adverse childhood experiences such as abuse, neglect, and poverty, profoundly alter neurobehavioral development in a manner that negatively impacts health across the lifespan. Adults who have been exposed to such adversities exhibit premature and more severe age-related declines in brain health. Unfortunately, it remains unclear whether the negative effects of early life adversity (ELA) on brain health can be remediated through intervention in adulthood. Physical activity may represent a low-cost behavioral approach to address the long-term consequences of ELA on brain health. However, there has been limited research examining the impact of physical activity on brain health among adults with a history of ELA. Accordingly, the purpose of this review is to (1) review the influence of ELA on brain health in adulthood and (2) highlight evidence for the role of neurotrophic factors, hypothalamic-adrenal-pituitary axis regulation, inflammatory processes, and epigenetic modifications in mediating the effects of both ELA and physical activity on brain health outcomes in adulthood. We then propose a theoretical framework to guide future research in this area.

The Impact of Adverse Childhood Experiences on Cognition in African American Older Adults: An Integrated Literature Review

The current integrative literature review examined the existing evidence on the connection between adverse childhood experiences (ACEs) and cognitive changes in African American older adults. Using the Covidence platform, several databases were searched, resulting in 266 publications dated 2008-2020. Ten articles met inclusion criteria and were reviewed. Findings indicate that four ACEs (physical, sexual, and verbal abuse, and low socioeconomic status) are associated with impaired cognition in African American older adults. Four gaps were identified: lack of (a) older adult participants in research investigating original and expanded ACEs; (b) exclusively African American samples of participants in studies examining the relationship between ACEs and cognition; (c) consensus about what specific ACEs contribute to changes in cognition in older adults; and (d) information about successful interventions created to prevent and mitigate the effects of ACEs in older adults. This review provides a synthesis of the limited evidence on the effects of ACEs on cognition among other outcomes. Findings on the effects of ACEs on African American older adults' cognition are limited, thus making a compelling case for further investigating the role of childhood adversity in the disparity of cognitive changes in African American communities. [Research in Gerontological Nursing, 14(5), 265-272.].

Socioeconomic status across the life course and dementia-status life expectancy among older Americans

This study examines how socioeconomic status (SES) across the life course is associated with individuals' lifetime dementia experience - the years of life persons can expect to live and without with dementia. Conceptually, dementia-free life expectancy reflects the ability to postpone dementia onset while dementia life expectancy reflects the average lifetime period with the condition. How SES across the life course contributes to dementia-status life expectancy is the focus of this study. We assess whether persons who are advantaged in their lifetime SES live the most years without dementia and the fewest years with dementia compared to less advantaged persons. Using the Health and Retirement Study (2000-2016), we examine these questions for U.S. adults aged 65 and older using multistate life tables and a microsimulation approach. The results show that higher SES persons can expect to live significantly more years of life without dementia and that the period of life with dementia is compressed compared to less advantaged persons. The results also underscore that importance of cumulative exposure, showing that adults from disadvantaged childhoods who achieve high education levels often have dementia experiences that are similar to or better than those of adults from advantaged childhoods who achieved low education levels.

Childhood Socioeconomic Status Does Not Predict Late-Life Cognitive Decline in the 1936 Lothian Birth Cohort

This study examined childhood socioeconomic status (SES) as a predictor of later life cognitive decline. Data came from 519 participants in the Lothian Birth Cohort 1936 (LBC1936) study. SES measures at 11 years of age included parental educational attainment, father's occupational status, household characteristics and a composite measure of global childhood SES (i.e., a total of low SES childhood indicators). Cognitive abilities were assessed by the Mini-Mental State Exam at ages 69.8, 72.8 and 76.7 years. Most indicators of low childhood SES (i.e., father manual worker, less than secondary school father education, household overcrowding, exterior located toilet, and global childhood SES) did not predict cognitive decline between the ages of 69.8 and 76.7. Participants with less educated mothers showed an increase in cognitive decline (β = -0.132, p = 0.048, and CI = -0.80, -0.00). The relationship between maternal educational attainment and cognitive decline became non-significant when controlling for adult SES (i.e., participant educational attainment and occupation). Adult SES did not mediate the latter relationship. This study provides new evidence that childhood SES alone is not strongly associated with cognitive decline. New knowledge is critical to improving population health by identifying life span stages in which interventions might be effective in preventing cognitive decline.

Adverse childhood circumstances and cognitive function in middle-aged and older Chinese adults: Lower level or faster decline?

We examine the long-term relationship between childhood circumstances and cognitive aging. In particular, we differentiate the level of cognitive deficit from the rate of cognitive decline. Applying a linear mixed-effect model to three waves of China Health and Retirement Longitudinal Surveys (CHARLS 2011, 2013, 2015) and matching cognitive outcomes to CHARLS Life History Survey (2014), we find that key domains of childhood circumstances, including family socioeconomic status (SES), neighborhood cohesion, friendship, and health conditions, are significantly associated with both the level of cognitive deficit and the rate of decline. In contrast, childhood neighborhood safety only affects the level of cognitive deficit. Childhood relationship with mother only affects the rate of cognitive decline. The effects of adverse childhood circumstances are generally larger on level of cognitive deficit than on rate of cognitive decline. Moreover, education plays a more important role in mediating the relationships compared to other later-life factors. These findings suggest that exposure to disadvantaged childhood circumstances can exacerbate cognitive deficit as well as cognitive decline over time, which may be partially ameliorated by educational attainment.

Impact of Cardiovascular Risk Factors in Adolescence, Young Adulthood, and Midlife on Late-Life Cognition: Study of Healthy Aging in African Americans

BACKGROUND

Midlife cardiovascular risk factors (CVRFs) increase risk of dementia. Black Americans experience an elevated prevalence of CVRFs and dementia. However, little is known of how CVRFs prior to midlife affect late-life cognition. We examined CVRFs in adolescence, young adulthood, and midlife with late-life cognition in the Study of Healthy Aging in African Americans (STAR).

METHOD

STAR assesses cognitive aging among 764 Black Americans aged ≥50 (mean age = 69; SD = 9; range = 53-95). Participants' body mass index, blood pressure, glucose, and total cholesterol were collected during Multiphasic Health Checkups (MHC; 1964-1985). At STAR baseline (2018-2019), executive function, verbal episodic memory, and semantic memory were measured using the Spanish and English Neuropsychological Assessment Scales. Linear regression models examined associations between CVRFs and cognition adjusting for demographics and years since MHC.

RESULTS

At MHC, 36% of participants had 1 CVRF and 26% had ≥2. Twenty-two percent of participants were adolescents (age 12-20), 62% young adults (age 21-34), and 16% midlife adults (age 35-56). Overweight/obesity was not associated with cognition. Hypertension was associated with worse executive function (β [95% CI]: -0.14 [-0.28, -0.0003]) and verbal episodic memory (β [95% CI]: -0.22 [-0.37, -0.07]) compared to normotension. Diabetes was associated with worse executive function (β [95% CI]: -0.43 [-0.83, -0.03]). Having ≥2 CVRFs (vs 0) was associated with worse executive function (β [95% CI]: -0.19 [-0.34, -0.03]) and verbal episodic memory (β [95% CI]: -0.25 [-0.41, -0.08]). Adolescents with hypertension had lower late-life executive function compared to normotensive adolescents (β [95% CI]: -0.39 [-0.67, -0.11]). Young adulthood hypertension (β [95% CI]: -0.29 [-0.49, -0.09]) and midlife hyperlipidemia (β [95% CI]: -0.386 [-0.70, -0.02]) were associated with lower verbal episodic memory.

CONCLUSIONS

Among Black Americans, life-course CVRFs were associated with poorer executive function and verbal episodic memory emphasizing the importance of cardiovascular health on the aging brain.

Lifecourse socioeconomic changes and late-life cognition in a cohort of U.S.-born and U.S. immigrants: findings from the KHANDLE study

BACKGROUND

Low socioeconomic status (SES) in early and late life has been associated with lower late-life cognition. Less is known about how changes in SES from childhood to late life are associated with late-life cognition, especially among diverse populations of older adults.

METHODS

In a multi-ethnic sample (n = 1353) of older adults, we used linear regression to test associations of change in comprehensive measures of SES (financial, cultural, and social domains) from childhood to late life with semantic memory, episodic memory, and executive function. We tested whether the association between SES trajectory and late-life cognition differed by populations who resided in the U.S. during childhood or immigrated to the U.S. as adults.

RESULTS

Participants with low childhood/high late-life financial capital had better semantic memory (β = 0.18; 95% CI: 0.04, 0.32) versus those with low financial capital in both childhood and late life, regardless of childhood residence. We observed a significant interaction in the association of verbal episodic memory and cultural capital by childhood residence (p = 0.08). Participants with a foreign childhood residence had higher verbal episodic memory if they had low childhood/high late-life cultural capital (β = 0.32; 95% CI: 0.01, 0.63), but lower verbal episodic memory if they had high childhood/low late-life cultural capital (β = - 0.40; 95% CI: - 0.94, 0.13). Having high lifecourse social capital was associated with better verbal episodic memory scores among those with a U.S. childhood (β = 0.34; 95% CI: 0.14, 0.55), but lower verbal episodic memory among those with a foreign childhood (β = - 0.10; 95% CI: - 0.51, 0.31).

CONCLUSIONS

High financial and cultural capital in late life is associated with better cognition, regardless of early childhood SES or childhood residence.

Comparison of Education and Episodic Memory as Modifiers of Brain Atrophy Effects on Cognitive Decline: Implications for Measuring Cognitive Reserve

OBJECTIVE

This study compared the level of education and tests from multiple cognitive domains as proxies for cognitive reserve.

METHOD

The participants were educationally, ethnically, and cognitively diverse older adults enrolled in a longitudinal aging study. We examined independent and interactive effects of education, baseline cognitive scores, and MRI measures of cortical gray matter change on longitudinal cognitive change.

RESULTS

Baseline episodic memory was related to cognitive decline independent of brain and demographic variables and moderated (weakened) the impact of gray matter change. Education moderated (strengthened) the gray matter change effect. Non-memory cognitive measures did not incrementally explain cognitive decline or moderate gray matter change effects.

CONCLUSIONS

Episodic memory showed strong construct validity as a measure of cognitive reserve. Education effects on cognitive decline were dependent upon the rate of atrophy, indicating education effectively measures cognitive reserve only when atrophy rate is low. Results indicate that episodic memory has clinical utility as a predictor of future cognitive decline and better represents the neural basis of cognitive reserve than other cognitive abilities or static proxies like education.

Measuring cognitive health in ethnically diverse older adults

OBJECTIVE

Understanding racial/ethnic disparities in late-life cognitive health is a public health imperative. We used baseline data from the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study to examine how age, education, gender, and clinical diagnosis, a proxy for brain health, are associated with cross-sectional measures of cognition in diverse racial/ethnic groups.

METHOD

Comprehensive measures of cognition were obtained using the Spanish and English Neuropsychological Assessment Scales and the NIH Toolbox Cognitive Health Battery in a sample of 1695 KHANDLE participants (Asians 24%, Blacks 26%, Latinos 20%, Whites 29%). A 25% random subsample was clinically evaluated and diagnosed with normal cognition, mild cognitive impairment (MCI), or dementia. Cognitive test scores were regressed on core demographic variables and diagnosis in the combined sample and in multiple group analyses stratified by racial/ethnic group.

RESULTS

Race/ethnicity and education were variably associated with test scores with strongest associations with tests of vocabulary and semantic memory. Older age was associated with poorer performance on all measures, and gender differences varied across cognitive tests. Clinical diagnosis of MCI or dementia was associated with average decrements in test scores that ranged from -0.41 to -0.84 SD, with largest differences on tests of executive function and episodic memory. With few exceptions, associations of demographic variables and clinical diagnosis did not differ across racial/ethnic groups.

DISCUSSION

The robust associations of cognitive test results with clinical diagnosis independent of core demographic variables and race/ethnicity supports the validity of cognitive tests as indicators for brain health in diverse older adults.

Life-Course Individual and Neighborhood Socioeconomic Status and Risk of Dementia in the Atherosclerosis Risk in Communities Neurocognitive Study

We examined associations of individual- and neighborhood-level life-course (LC) socioeconomic status (SES) with incident dementia in the Atherosclerosis Risk in Communities cohort. Individual- and neighborhood-level SES were assessed at 3 life epochs (childhood, young adulthood, midlife) via questionnaire (2001-2002) and summarized into LC-SES scores. Dementia was ascertained through 2013 using cognitive exams, telephone interviews, and hospital and death certificate codes. Cox regression was used to estimate hazard ratios of dementia by LC-SES scores in race-specific models. The analyses included data from 12,599 participants (25% Black) in the United States, with a mean age of 54 years and median follow-up of 24 years. Each standard-deviation greater individual LC-SES score was associated with a 14% (hazard ratio (HR) = 0.86, 95% confidence interval (CI): 0.81, 0.92) lower risk of dementia in White and 21% (HR = 0.79, 95% CI: 0.71, 0.87) lower risk in Black participants. Education was removed from the individual LC-SES score and adjusted for separately to assess economic factors of LC-SES. A standard-deviation greater individual LC-SES score, without education, was associated with a 10% (HR = 0.90, 95% CI: 0.84, 0.97) lower dementia risk in White and 15% (HR = 0.85, 95% CI: 0.76, 0.96) lower risk in Black participants. Neighborhood LC-SES was not associated with dementia. We found that individual LC-SES is a risk factor for dementia, whereas neighborhood LC-SES was not associated.

Factors associated with head circumference and indices of cognitive development in early childhood

BACKGROUND

While head circumference (HC) has been related to intracranial volume and brain size, its association with cognitive function remains unclear. We sought to understand the relationship among various biological and socioeconomic risk factors, HC and cognitive development.

METHODS

We analysed data across resource-poor settings in Bangladesh, India, Nepal, Peru, South Africa and Tanzania from the Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development longitudinal birth cohort study. Participating children were enrolled and followed up between 2009 and 2014. A final sample of 1210 children aged 0-24 months were included in the analyses. The main outcomes were HC for age Z-score and cognitive, gross motor and language scores from Bayley Scales of Infant Development-III tests. Length, weight and HC were measured monthly, and cognitive tests were administered at 6, 15 and 24 months of age. To disentangle the associations between risk factors and HC from linear growth and to distinguish the direct and indirect effects of these risk factors on cognitive function, we conducted mediation analysis using longitudinal models to account for all data measured during follow-up.

RESULTS

Average HC-for-age Z-score (HCAZ) was -0.54 (95% CI -0.47 to -0.62) near birth and -1.01 (95% CI -0.94 to -1.08) at 24 months. Children with higher enrolment weight (p<0.0001), higher socioeconomic score (p=0.00037) and taller mothers (p=0.00084) had higher HCAZ at all ages, while enteropathogen infection (p=0.013) and more febrile episodes (p=0.013) were associated with lower HCAZ. The associations between HCAZ and enrolment weight-for-age, maternal height, socioeconomic status or pathogen burden were partly mediated through their associations with length-for-age. HCAZ showed no association with cognitive, gross motor or language skills at 6, 15 and 24 months of age.

CONCLUSIONS

The main risk factors associated with HC are similar to those associated with body length, and HC is not related to cognitive function.

Socioeconomic Status and Parenting Style From Childhood: Long-Term Effects on Cognitive Function in Middle and Later Adulthood

OBJECTIVES

This study assesses whether childhood socioeconomic status (SES) is related to cognitive function and cognitive change at mid and later life and explores the buffering effects of parenting style and adulthood SES.

METHOD

Data were derived from the 3 waves of the Midlife in the United States (MIDUS) study, a national survey including 7,108 participants aged from 24 to 75 years at baseline. We used multiple regression and multilevel models to investigate the associations between childhood SES, adulthood SES, and cognitive performance and change at midlife and the role of parents' affection and discipline.

RESULTS

Low childhood SES was associated with lower cognitive function and more cognitive decline at mid and later life. Adulthood SES moderated the effect of childhood SES on cognitive function. Interactions showed that paternal discipline was positively related to cognitive function among participants with low childhood SES, and negatively related to cognitive function among participants with high childhood SES. High paternal affection was associated with less cognitive decline at mid and later life.

DISCUSSION

The findings advance the understanding of the long-term consequences of SES and psychosocial factors in early life that can lead to optimal cognitive function in middle and old age.

Differential Item Functioning of the Everyday Cognition (ECog) Scales in Relation to Racial/Ethnic Groups

OBJECTIVE

The Everyday Cognition (ECog) scales measure cognitively based across domains of everyday abilities that are affected early in the course of neurodegenerative disorders such as Alzheimer's disease. However, the degree to which the ECog may be differentially influenced by ethnic/racial background is unknown. This study evaluates measurement invariance of the ECog across non-Hispanic White (NHW), Black, and Hispanic individuals.

METHODS

Participants included 1177 NHW, 243 Black, and 216 Hispanic older adults from the UC Davis Alzheimer's Disease Center Cohort who had an ECog. Differential item functioning (DIF) for each ECog domain was evaluated separately for Black and Hispanic participants compared to NHW participants. An iterative multiple group confirmatory factor analysis approach for ordinal scores was used to identify items whose measurement properties differed across groups and to adjust scores for DIF. Adjusted scores were then evaluated to test whether they were more strongly associated with cognitive function (concurrent and longitudinal change in cognition) and brain volumes (measured by brain imaging).

RESULTS

Varying levels, patterns, and impacts of DIF were found across domains and groups. However, the impact of DIF was relatively small, and DIF effects on scores generally were less than one-half standard error of measurement. There were no meaningful differences in associations with cognition and brain injury between DIF adjusted and unadjusted scores.

CONCLUSIONS

Varying patterns of DIF were observed across the Black and Hispanic participants across select ECog domains. Overall, DIF effects were relatively small and did not change the relationship between the ECog and other indicators of disease.

Long-term exposure to ambient air pollution, APOE-ε4 status, and cognitive decline in a cohort of older adults in northern Manhattan

BACKGROUND

There is mounting evidence that long-term exposure to air pollution is related to accelerated cognitive decline in aging populations. Factors that influence individual susceptibility remain largely unknown, but may involve the apolipoprotein E genotype E4 (APOE-ε4) allele.

OBJECTIVES

We assessed whether the association between long-term exposure to ambient air pollution and cognitive decline differed by APOE-ε4 status and cognitive risk factors.

METHODS

The Washington Heights Inwood Community Aging Project (WHICAP) is a prospective study of aging and dementia. Neuropsychological testing and medical examinations occur every 18-24 months. We used mixed-effects models to evaluate whether the association between markers of ambient air pollution (nitrogen dioxide [NO2]), fine [PM2.5], and coarse [PM10] particulate matter) and the rate of decline in global and domain-specific cognition differed across strata defined by APOE-ε4 genotypes and cognitive risk factors, adjusting for sociodemographic factors and temporal trends.

RESULTS

Among 4821 participants with an average of 6 years follow-up, higher concentrations of ambient air pollution were associated with more rapid cognitive decline. This association was more pronounced among APOE-ε4 carriers (p < 0.001). A one interquartile range increase in NO2 was associated with an additional decline of 0.09 standard deviations (SD) (95%CI -0.1, -0.06) in global cognition across biennial visits among APOE-ε4 positive individuals and a 0.07 SD (95%CI -0.09, -0.05) decline among APOE-ε4 negative individuals. Results for PM2.5, PM10 and cognitive domains were similar. The association between air pollutants and rate of cognitive decline also varied across strata of race-ethnicity with the association strongest among White non-Hispanic participants.

CONCLUSIONS

These results add to the body of evidence on the adverse impact of ambient air pollution on cognitive aging and brain health and provide new insights into the genetic and behavioral factors that may impact individual susceptibility.

Early-life socioeconomic status, adolescent cognitive ability, and cognition in late midlife: Evidence from the Wisconsin Longitudinal Study

Although the association between childhood socioeconomic status (SES) and late-life cognition is well-established, the mechanisms underlying this association are less clear. One important potential mediator seldom examined is adolescent cognitive ability. To address this gap, we examined 5,880 respondents from the Wisconsin Longitudinal Study, which follows a random sample of high school students who graduated from Wisconsin high schools in 1957. Structural equation models were used to examine the direct and indirect effects of childhood SES on cognition in late midlife through adolescent cognitive ability, educational attainment, midlife economic condition, and midlife health. Cognitive function was measured as a latent variable composed of scores from 6 cognitive assessments including immediate and delayed recall, digit ordering, letter and category fluency, and a subset of the Wechsler Adult Intelligence Scale similarities test. We found that childhood SES predicts cognition in late midlife, and this association is largely mediated by adolescent cognitive ability and educational attainment and to a lesser extent by midlife economic condition and health. The findings underscore the long-arm of childhood SES in cognitive function in later life and highlight the complex life-course pathways underlying the association between childhood SES and cognition.

Group differences in normal neuropsychological test performance for older non-Hispanic White and Black/African American adults

OBJECTIVE

Although researchers have documented the influence of cultural factors on neuropsychological test performance, few studies have examined the distribution of test scores among neurologically healthy older adults from different ethnic groups. The objective of this study was to determine whether there are group differences in neuropsychological test score distributions with ethnicity-specific norms for non-Hispanic White and Black/African American older adults.

METHOD

Participants from the National Alzheimer's Coordinating Center were selected if they were not diagnosed with dementia within 5 years (Mage = 75.26, SDage = 6.98; Meducation = 15.70, SDeducation = 2.91). Groups were formed based on self-identified ethnicity of White (n = 5,311) or Black/African American (n = 1,098). All participants completed neuropsychological testing, including the Mini Mental State Exam, Logical Memory Immediate and Delayed, Digit Span Forward and Backward, Trail Making Test A & B, Animal Naming, Vegetable Naming, Digit Symbol, and Boston Naming Test.

RESULTS

Based on combined ethnicity norms, the scores of Black participants were overrepresented in the below-average and low-average clinical ranges, and the scores of White participants were overrepresented in the high-average and superior clinical ranges for all 11 neuropsychological measures. When group specific norms were used, the unbalanced pattern of score categorization was no longer present for any of the neuropsychological measures.

CONCLUSIONS

These findings emphasize the importance of developing and using ethnically and culturally appropriate neuropsychological test norms as well as the risk of interpreting some Black individual's scores as below average when they likely are not. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Dynamic change of cognitive reserve: associations with changes in brain, cognition, and diagnosis

Cognitive reserve is inherently a dynamic construct; however, traditional methods of estimating reserve have focused on static proxy variables. A recently proposed psychometric approach entails modeling reserve as residual cognition not explained by demographic and brain variables. In this study, we extended this approach to longitudinal measurement and examined how change in reserve relates to clinical outcomes in late life and influences the effect of brain atrophy on cognitive decline. Results indicated that cognitive reserve changes were associated with progression of clinical diagnosis. More rapid depletion of cognitive reserve was associated with faster decline in nonmemory cognitive functions, even after accounting for longitudinal brain atrophy. The effect of longitudinal brain atrophy on cognitive decline differed based on the extent to which an individual's reserve changed. Whereas depletion of reserve appeared to unmask the effects of brain atrophy on cognitive decline, maintenance of reserve buffered against the negative effects of brain atrophy. Study results highlight that changes in reserve may have important implications for individual differences in cognitive aging trajectories.

Early-life adversity and neurological disease: age-old questions and novel answers

Neurological illnesses, including cognitive impairment, memory decline and dementia, affect over 50 million people worldwide, imposing a substantial burden on individuals and society. These disorders arise from a combination of genetic, environmental and experiential factors, with the latter two factors having the greatest impact during sensitive periods in development. In this Review, we focus on the contribution of adverse early-life experiences to aberrant brain maturation, which might underlie vulnerability to cognitive brain disorders. Specifically, we draw on recent robust discoveries from diverse disciplines, encompassing human studies and experimental models. These discoveries suggest that early-life adversity, especially in the perinatal period, influences the maturation of brain circuits involved in cognition. Importantly, new findings suggest that fragmented and unpredictable environmental and parental signals comprise a novel potent type of adversity, which contributes to subsequent vulnerabilities to cognitive illnesses via mechanisms involving disordered maturation of brain 'wiring'.

Variety of Enriching Early-Life Activities Linked to Late-Life Cognitive Functioning in Urban Community-Dwelling African Americans

OBJECTIVES

The early environment is thought to be a critical period in understanding the cognitive health disparities African Americans face today. Much is known about the positive role enriching environments have in mid- and late-life and the negative function adverse experiences have in childhood; however, little is known about the relationship between enriching childhood experiences and late-life cognition. The current study examines the link between a variety of enriching early-life activities and late-life cognitive functioning in a sample of sociodemographic at-risk older adults.

METHOD

This study used data from African Americans from the Brain and Health Substudy of the Baltimore Experience Corps Trial (M = 67.2, SD = 5.9; N = 93). Participants completed a battery of neuropsychological assessments and a seven-item retrospective inventory of enriching activities before age 13.

RESULTS

Findings revealed that a greater enriching early-life activity score was linked to favorable outcomes in educational attainment, processing speed, and executive functioning.

DISCUSSION

Results provide promising evidence that enriching early environments are associated with late-life educational and cognitive outcomes. Findings support the cognitive reserve and engagement frameworks, and have implications to extend life-span prevention approaches when tackling age-related cognitive declines, diseases, and health disparities.

Everyday memory difficulties in children and adolescents with Fetal Alcohol Spectrum Disorder

Purpose: To investigate whether significant differences exist in everyday memory between youth with Fetal Alcohol Spectrum (FASD) compared with a nonexposed (NE) control group, while controlling for socioeconomic status and other comorbidities. Methods: Caregiver ratings using the Everyday Memory Questionnaire were obtained for 105 youth (9-17 years of age). Scores were compared between youth with a FASD diagnosis (N = 41; 56% male) and the NE group (N = 64; 53% male) using multivariate analysis of variance. Results: Significantly poorer scores were found across all domains of everyday memory in youth with FASD (p<0.01 for all comparisons). Findings maintained significance after controlling for group differences in socioeconomic status, presence of learning, and attention disorders, as well as exposure to other teratogens. Conclusions: This study provides important insights regarding the memory issues that underlie daily functional challenges faced by youth with FASD and the need for future intervention research.

Childhood Socioeconomic Status and Later Life Cognition: Evidence From the Wisconsin Longitudinal Study

Objectives:This study examined childhood socioeconomic status (SES) as a predictor of later life cognition and the extent to which midlife SES accounts for associations. Methods: Data came from 5,074 participants in the Wisconsin Longitudinal Study. Measures from adolescence included parents' educational attainment, father's occupational status, and household income. Memory and language/executive function were assessed at ages 65 and 72 years. Results: Global childhood SES was a stronger predictor of baseline levels of language/executive function than baseline memory. Associations involving parents' education were reduced in size and by statistical significance when accounting for participants' midlife SES, whereas associations involving parental income and occupational status became statistically nonsignificant. We found no associations between childhood SES and change in cognition. Discussion: Findings contribute to growing evidence that socioeconomic differences in childhood have potential consequences for later life cognition, particularly in terms of the disparate levels of cognition with which people enter later life.

Size at birth and cognitive ability in late life: A systematic review

INTRODUCTION

Recent evidence suggests that growth restriction in utero may lead to neurocognitive disorders in late life, either through impaired brain development or adverse metabolic programming.

METHODS

Systematic review of literature investigating the relationship between size at birth and cognitive abilities in late life. The search, data extraction, and rating for the quality of reporting were conducted independently by two researchers.

RESULTS

Of 533 selected studies, 11 were included in this systematic review and 10 of these were from high-income setting. Of these 11 studies, eight indicated that lower birth weight is a risk factor for lower cognitive function in late life, at least in high-income countries. The reported effect sizes were small and it was not possible to conduct meta-analyses because of clinical heterogeneity DISCUSSION: A modest association of lower birth weight with lower cognitive abilities in late life is consistent with persisting effects of the prenatal environment on brain function. As with all observational studies, confounding is an alternative explanation. Further studies are required to elucidate the mechanisms.

Migration and cognitive function: a conceptual framework for Global Health Research

BACKGROUND

Migration is a fundamental demographic process that has been observed globally. It is suggested that migration is an issue of global health importance that can have an immediate and lasting impact on an individual's health and well-being. There is now an increasing body of evidence linking migration with cognitive function in older adults. In this paper, we synthesized the current evidence to develop a general conceptual framework to understand the factors contributing to the association between migration and cognitive function.

METHODS

A comprehensive review of the literature was conducted on the associations between migration and cognition among middle-aged and older adults.

RESULTS

Five potential mechanisms were identified from the literature: 1) socioeconomic status-including education, occupation, and income; 2) psychosocial factors-including social networks, social support, social stressors, and discrimination; 3) behavioral factors-including smoking, drinking, and health service utilization; 4) physical and psychological health status-including chronic conditions, physical function, and depression; and 5) environmental factors-including both physical and social environment. Several underlying factors were also identified-including early-life conditions, gender, and genetic factors.

CONCLUSIONS

The factors linking migration and cognitive function are multidimensional and complex. This conceptual framework highlights potential implications for global health policies and planning on healthy aging and migrant health. Additional studies are needed to further examine these mechanisms to extend and refine our general conceptual framework.

Education modifies the relationship between height and cognitive function in a cross-sectional population-based study of older adults in Rural South Africa

We aimed to estimate the relationship between height (a measure of early-life cumulative net nutrition) and later-life cognitive function among older rural South African adults, and whether education modified this relationship. Data were from baseline in-person interviews with 5059 adults ≥ 40 years in the population-based "Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa" (HAALSI) study in Agincourt sub-district, South Africa, in 2015. Linear regression was used to estimate the relationship between height quintile and latent cognitive function z-score (representing episodic memory, time orientation, and numeracy), with adjustment for life course covariates and a height-by-education interaction. Mean (SD) height was 162.7 (8.9) cm. Nearly half the sample had no formal education (46%; 2307/5059). Mean age- and sex-adjusted cognitive z-scores increased from - 0.68 (95% CI: - 0.76 to - 0.61) in those with no education in the shortest height quintile to 0.62 (95% CI: 0.52-0.71) in those with at least 8 years of education in the tallest height quintile. There was a linear height disparity in cognitive z-scores for those with no formal education (adjusted β = 0.10; 95% CI: 0.08-0.13 per height quintile), but no height disparity in cognitive z-scores in those with any level of education. Short stature is associated with poor cognitive function and may be a risk factor for cognitive impairment among older adults living in rural South Africa. The height disparity in cognitive function was negated for older adults who had any level of education.

Associations of childhood socioeconomic status with mid-life and late-life cognition in Chinese middle-aged and older population based on a 5-year period cohort study

OBJECTIVES

A prospective study was performed to examine the relationship of childhood socioeconomic status (SES) with cognition and the rate of change in a nationally representative sample of community-dwelling middle-aged and older Chinese population.

METHODS

This study mainly focused on 3 composite measures of cognitive function, including Telephone Interview of Cognitive Status, word recall, and drawing a figure successfully. Childhood SES was evaluated by parental occupation and education, childhood residence, and self-evaluated financial status. We designed an analysis strategy adding predictors incrementally in different models to examine the changes of effects of childhood SES on cognition by latent growth curve models.

RESULTS

Finally, a total of 10 533 respondents were prospectively studied, including 5980 respondents aged 45-59 and 4553 aged 60-90. Cognition in younger cohort showed a curvilinear change, while cognition in older cohort showed a linear decline. After controlling for covariates, middle-aged respondents with higher self-evaluated financial status (β: -0.22, P < .001), better health status (β: -0.13, P < .001), higher parental education (β: 0.17 and 0.10, P < .001), who had lived in city/town before 16 years (β: 0.69, P < .001), and whose fathers engaged in nonfarming work (β: 0.43, P < .001) were associated with the better baseline cognition. Similar results were found in older cohort. Additionally, early-life SES was not associated with cognitive decline in both cohorts.

CONCLUSIONS

This study indicates that childhood SES is associated with mid-life and late-life baseline cognition, but it is not contributed to cognition decline. Interventions in early-life focused on improving childhood SES might have positive impacts on baseline cognition in later-life.

Does selective survival before study enrolment attenuate estimated effects of education on rate of cognitive decline in older adults? A simulation approach for quantifying survival bias in life course epidemiology

Background

The relationship between education and late-life cognitive decline is controversial. Selective survival between early life, when education is typically completed, and late life, when cognitive ageing studies take place, could attenuate effect estimates.

Methods

We quantified potential survival bias (collider-stratification bias) in estimation of the effect of education on late-life cognitive decline by simulating hypothetical cohorts of 20-year-olds and applying cumulative mortality from US life tables. For each of four causal scenarios (2000 replications each), we compared the estimated versus causal effect of education on cognitive decline over 9 years, starting at age 60, 75 or 90 in random samples of n = 2000 people who survived to each age.

Results

Effects of education on cognitive decline were underestimated when both education and U, another determinant of cognitive decline, influenced mortality (collider-stratification bias). The magnitude of bias was sensitive to the magnitude of the effect of U on cognitive decline and whether there was a multiplicative interaction between education and U on mortality. For example, when there was a multiplicative interaction between education and U on mortality, 95% confidence interval coverage of the causal effect ranged from 83.4% to 50.4% at age 60 and 25.8% to 0.2% at age 90.

Conclusions

Selective survival could lead to underestimation of effects of education on late-life cognitive decline. Our simulations map survival bias to testable assumptions about underlying causal structures.

Control beliefs are associated with preserved memory function in the face of low hippocampal volume among diverse older adults

Growing evidence supports a link between locus of control and memory in older adults. Control beliefs may directly predict larger hippocampal volume (i.e., brain maintenance). Alternatively, control beliefs may be associated with smaller hippocampal volume at any given level of memory (i.e., cognitive reserve). Multivariable regression analyses examined associations between verbal episodic memory, locus of control and hippocampal volume among 236 non-demented older adults in the community-based Washington Heights-Inwood Columbia Aging Project. Control beliefs were negatively associated with hippocampal volume when controlling for memory performance, indicating that individuals with stronger control beliefs were able to maintain memory function in the face of lower hippocampal volume. Subsequent exploratory models stratified by race/ethnicity indicated that this association was more prominent among racial/ethnic minorities (particularly Caribbean Hispanic older adults) than among non-Hispanic White older adults. Control beliefs were not associated with hippocampal volume before memory was taken into account. Results are consistent with the view that control beliefs facilitate the maintenance of memory function despite hippocampal volume loss. Results are not consistent with the view that locus of control contributes to brain maintenance. Culturally-appropriate interventions are needed to test whether strengthening control beliefs provides cognitive resistance to neuropathology.

Ethnoracial differences in brain structure change and cognitive change

OBJECTIVE

The purpose of this study was to examine longitudinal associations between structural MRI and cognition in a diverse sample.

METHOD

Older adults (n = 444; Mage = 74.5)-121 African Americans, 212 Whites, and 111 Hispanics-underwent an average of 5.3 annual study visits. Approximately half were cognitively normal at baseline (global Clinical Dementia Rating M = 0.5). Of the patients with dementia, most (79%) were diagnosed with Alzheimer's disease (AD). MRI measures of gray matter volume (baseline and change), and hippocampal and white matter hyperintensity (WMH) volumes (baseline), were used to predict change in global cognition. Multilevel latent variable modeling was used to test the hypothesis that brain effects on cognitive change differed across ethnoracial groups.

RESULTS

In a multivariable model, global gray matter change was the strongest predictor of cognitive decline in Whites and African Americans and specific temporal lobe change added incremental explanatory power in Whites. Baseline WMH volume was the strongest predictor of cognitive decline in Hispanics and made an incremental contribution in Whites.

CONCLUSIONS

We found ethnoracial group differences in associations of brain variables with cognitive decline. The unique patterns in Whites appeared to suggest a greater influence of AD in this group. In contrast, cognitive decline in African Americans and Hispanics was most uniquely attributable to global gray matter change and baseline WMH, respectively. Brain changes underlying cognitive decline in older adults are heterogeneous and depend on fixed and modifiable risk factors that differ based on ethnicity and race. (PsycINFO Database Record

The Role of Nutrition and Literacy on the Cognitive Functioning of Elderly Poor Individuals

Maintaining cognitive function is a prerequisite of living independently, which is a highly valued component in older individuals' well-being. In this article we assess the role of early-life and later-life nutritional status, education, and literacy on the cognitive functioning of older adults living in poverty in Peru. We exploit the baseline sample of the Peruvian noncontributory pension program Pension 65 and find that current nutritional status and literacy are strongly associated with cognitive functioning for poor older adults. In a context of rising popularity of noncontributory pension programs around the world, our study intends to contribute to the discussion of designing accompanying measures to the pension transfer, such as adult literacy programs and monitoring of adequate nutrition of older adults.