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

Cerebral Small Vessel Disease: Early-Life Antecedents and Long-Term Implications for the Brain, Aging, Stroke, and Dementia

Cerebral small vessel disease is common in older adults and increases the risk of stroke, cognitive impairment, and dementia. While often attributed to midlife vascular risk factors such as hypertension, factors from earlier in life may contribute to later small vessel disease risk. In this review, we summarize current evidence for early-life effects on small vessel disease, stroke and dementia focusing on prenatal nutrition, and cognitive ability, education, and socioeconomic status in childhood. We discuss possible reasons for these associations, including differences in brain resilience and reserve, access to cognitive, social, and economic resources, and health behaviors, and we consider the extent to which these associations are independent of vascular risk factors. Although early-life factors, particularly education, are major risk factors for Alzheimer disease, they are less established in small vessel disease or vascular cognitive impairment. We discuss current knowledge, gaps in knowledge, targets for future research, clinical practice, and policy change.

Association of Childhood and Midlife Neighborhood Socioeconomic Position With Cognitive Decline

Importance

Early-life socioeconomic adversity may be associated with poor cognitive health over the life course.

Objective

To examine the association of childhood and midlife neighborhood socioeconomic position (nSEP) with cognitive decline.

Design, Setting, and Participants

This cohort study included 5711 men and women enrolled in the community-based Atherosclerosis Risk in Communities (ARIC) Study with repeated cognitive data measured over a median 27.0 years (IQR, 26.0-27.9 years) (1990-2019). Statistical analysis was performed from December 2022 through March 2023.

Exposure

Residence addresses for ARIC Study cohort participants were obtained at midlife (1990-1993) and as recalled addresses at 10 years of age (childhood). A composite nSEP z score was created as a sum of z scores for US Census-based measures of median household income; median value of owner-occupied housing units; percentage of households receiving interest, dividend, or net rental income; percentage of adults with a high school degree; percentage of adults with a college degree; and percentage of adults in professional, managerial, or executive occupations. Childhood nSEP and midlife nSEP were modeled as continuous measures and discretized into tertiles.

Main Outcomes and Measures

A factor score for global cognition was derived from a battery of cognitive tests administered at 5 in-person visits from baseline to 2019. The rate of cognitive decline from 50 to 90 years of age was calculated by fitting mixed-effects linear regression models with age as the time scale and adjusted for race, sex, birth decade, educational level, and presence of the apolipoprotein E ε4 allele.

Results

Among 5711 ARIC Study participants (mean [SD] baseline age, 55.1 [4.7] years; 3372 women [59.0%]; and 1313 Black participants [23.0%]), the median rate of cognitive decline was -0.33 SDs (IQR, -0.49 to -0.20 SDs) per decade. In adjusted analyses, each 1-SD-higher childhood nSEP score was associated with a slower (β, -9.2%; 95% CI, -12.1% to -6.4%) rate of cognitive decline relative to the sample median. A comparable association was observed when comparing the highest tertile with the lowest tertile of childhood nSEP (β, -17.7%; 95% CI, -24.1% to -11.3%). Midlife nSEP was not associated with the rate of cognitive decline.

Conclusions and Relevance

In this cohort study of contextual factors associated with cognitive decline, childhood nSEP was inversely associated with trajectories of cognitive function throughout adulthood.

Distinct domains of childhood disadvantage and cognitive performance among older Brazilians: Evidence from ELSI-Brazil

Objective

To investigate the relationship between of distinct domains of childhood disadvantage and cognitive performance among older adults within the context of a middle-income country.

Methods

This study used baseline data (2015/2016) from the Brazilian Longitudinal Study of Aging (ELSI), a nationally representative cohort of 9412 adults aged 50 and over. Nine childhood exposure variables were grouped into three domains (family SES, childhood health, and cultural capital), for which scores were created. Survey-weighted Ordinary Least Squares (OLS) regressions estimated the association childhood disadvantage with cognitive performance as measured by immediate memory, late memory and semantic verbal fluency. Mediation analysis assessed whether adulthood socioeconomic status (SES) mediated this relationship of interest.

Results

Important disparities in cognitive performance were observed, particularly in terms of age, education, income, occupational status. Before controlling for adulthood SES in the multivariable analysis, all domains of childhood disadvantage were found to be associated with lower cognitive performance across all three measures. After inclusion of adulthood SES variables, the observed associations only remained for semantic verbal fluency. Formal mediation analysis indicated that adulthood SES mediates 47.9% (95% CI: 34.3%-78.6%) of the association between later-life verbal fluency and poor childhood health, and 49.9% (95% CI: 43.6%-57.8%) of the association between later-life verbal fluency and low childhood cultural capital.

Conclusions

We found that childhood disadvantage is associated with low performance in memory tests and semantic verbal fluency tests among older Brazilians. Adulthood SES fully mediated the association between all domains of childhood disadvantage and memory performance and only partially mediated its association with verbal fluency. Our findings support policy efforts to enhance early childhood development and improve adulthood SES, and guide additional research to better the mechanisms driving these relationships.

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.

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.