Early Life Circumstances Research Articles

On the Origin of Cognition: How Childhood Conditions Shape Cognitive Function in Old Age

This paper examines the long-term impact of early childhood conditions on cognitive function in old age. Using unique data from a longitudinal survey of Chinese elderly, we find that people with adverse childhood conditions measured by the paternal occupation, parental education, nutrition and medical conditions, not only have lower cognitive ability, but also exhibit faster cognitive deterioration at older ages. The results also indicate that female elderly suffer more from the adverse childhood conditions than males. Further mechanism analyses suggest that the educational attainment accounts for 16 to 26 percent of the association between early-life circumstances and cognitive function in old age.

International differences in interspousal health correlations

Using objective measures of lung function, we document strong positive associations in health within couples in all European countries but large and significant differences in this correlation within broad European regions, with Southern Europe having by far stronger correlations than elsewhere. We analyze potential explanations for such differences, investigating the role of measures capturing current and past health behaviors, early life circumstances of each spouse, and measures capturing assortative mating in multiple dimensions. We show that marital sorting patterns by dimensions of early life health and socioeconomic position, as well as by geographical subregion within countries, are key to understanding the empirical patterns observed.

Dynamic variation in receptive vocabulary acquisitions: Further evidence from the Young Lives study

This study aims to reveal the trajectory of disparity in receptive vocabulary developments attributable to early-life circumstances. Using the cohort data collected from Ethiopia (N = 840), India (N = 1777), Peru (N = 1624) and Vietnam (N = 1831) as the Young Lives study, this study explores the dynamics of variation in receptive vocabulary acquisitions over a 15-year period. The random forest, which is one of the most popular and versatile machine learning algorithms, is adopted to model the association between receptive vocabulary skills and early-life circumstances. Then the constructed model quantifies how much of the observed variation is due to the early-life circumstances. Such variation has already been shaped by the age of 5 and it persists even when children reach early adolescence. The prediction by the random forest suggests that compensation for disadvantaged circumstances at the early developmental stage would help marginalised children catch up and mitigate the disparity when they reach early adolescence.

Socioeconomic circumstances and lung function growth from early adolescence to early adulthood.

A reduced lung function in early adulthood is associated with respiratory and non-respiratory diseases and is a long-term predictor of mortality. This study investigated the association between early socioeconomic circumstances (SEC) and lung function growth trajectories from early adolescence until early adulthood. We analysed data from the EPITeen population-based study, including adolescents born in 1990. Study waves occurred at 13, 17 and 21 yearsof age. Information on sociodemographic, behavioural and health factors, anthropometry and spirometry was collected. Early-life SEC were assessed using maternal education and paternal occupational position. The forced expiratory volume in the first second (FEV1) growth trajectories were drawn considering sex-and-height interactions over an 8-year period. Our sample included 2022 participants with complete informationfor the relevant variables. Participants from most disadvantaged SEC presented lower FEV1 at early adolescence compared to high-SEC counterparts, but differences seem to diminish with height growth. The effect of paternal occupational position in lung function growth trajectories was moderated by height, thus individuals from fathers with less advantaged occupational position had lower FEV1 at early adolescence, but they had a faster FEV1 growth over time. Individuals from most disadvantaged SEC presented lower lung function at early adolescence compared to high-SEC counterparts; nevertheless, a catch-up growth was observed. Lower socioeconomic circumstances were previously associated with reduced lung function and a higher risk of respiratory diseases in adults. Fewer studies analysed the effects of early-life socioeconomic circumstances in lung function growth during adolescence. Disadvantaged socioeconomic circumstances were associated with lower lung function in early adolescence. However, social differences diminished over adolescence, suggesting a catch-up growth of lung function among those from lower socioeconomic circumstances. An improved understanding of the mechanism underlying lung function catch-up (or the absence of catch-up) might support interventions to narrow social inequalities in respiratory health and should be further investigated.

Imprinting methylation predicts hippocampal volumes and hyperintensities and the change with age in later life

Epigenetic imprinting is important for neurogenesis and brain function. Hippocampal volumes and brain hyperintensities in late life have been associated with early life circumstances. Epigenetic imprinting may underpin these associations. Methylation was measured at 982 sites in 13 imprinted locations in blood samples from a longitudinal cohort by bisulphite amplicon sequencing. Hippocampal volumes and hyperintensities were determined at age 64y and 72y using MRI. Hyperintensities were determined in white matter, grey matter and infratentorial regions. Permutation methods were used to adjust for multiple testing. At 64y, H19/IGF2 and NESPAS methylation predicted hippocampal volumes. PEG3 predicted hyperintensities in hippocampal grey matter, and white matter. GNASXL predicted grey matter hyperintensities. Changes with age were predicted for hippocampal volume (MEST1, KvDMR, L3MBTL, GNASXL), white matter (MEST1, PEG3) and hippocampal grey matter hyperintensities (MCTS2, GNASXL, NESPAS, L3MBTL, MCTS2, SNRPN, MEST1). Including childhood cognitive ability, years in education, or socioeconomic status as additional explanatory variables in regression analyses did not change the overall findings. Imprinting methylation in multiple genes predicts brain structures, and their change over time. These findings are potentially relevant to the development of novel tests of brain structure and function across the life-course, strategies to improve cognitive outcomes, and our understanding of early influences on brain development and function.

Higher Parity Is Associated With Lower Mortality in a European Population of Women With High Fertility: Results From Ireland.

Research has often found a U- or J-shaped association between parity and mortality. Many researchers have suggested repeated pregnancy, childbirth, and lactation taxes the body beyond a certain parity level. Available research has concentrated on populations with controlled fertility or historic populations. Ireland presents an opportunity to explore these associations in a modern sample with high fertility. We use data from the Irish Longitudinal Study on Ageing (TILDA) to test whether parity is associated with mortality in women aged 50 years or over (n = 4177). We use Cox proportional hazards models to model survival and adjust for demographics and early life circumstances. We test whether a number of health characteristics mediate these effects. Models were also stratified by birth cohort to test possible cohort effects. Higher parity was associated with lower risk of mortality, even after adjustment for early life and socioeconomic circumstances. This effect was not mediated by current health characteristics. The effects were largely driven by those born between 1931 and 1950. Increasing parity is associated with decreasing mortality risk in this sample. The effects of parity could not be explained through any of the observed health characteristics. These findings are in contrast to much of the literature on this question in similar populations. Lack of fertility control in Ireland may have "selected" healthier women into high parity. Social explanations for these associations should be further explored.

Early-Life Circumstances, Health Behavior Profiles, and Later-Life Health in Great Britain.

Objectives: Drawing on UK Household Longitudinal Study data, this study assessed a pathway from early-life disadvantage to suboptimal later-life health via health behavior. Methods: Latent class analysis was used to identify distinct smoking, nutrition, alcohol, and physical activity health behavior profiles. Mediation analyses were performed to assess indirect effects of early-life disadvantage via health behavior on allostatic load, an objective measure of physiological wear and tear. Results: Four health behavior profiles were identified: (1) broadly healthy and high alcohol consumption, (2) low smoking and alcohol consumption, healthy nutrition, and physically inactive, (3) broadly unhealthy and low alcohol consumption, and (4) broadly moderately unhealthy and high alcohol consumption. Having grown up in a higher socioeconomic position family was associated with lower later-life allostatic load. This was partly attributable to health behavioral differences. Discussion: Growing up under disadvantageous socioeconomic circumstances may initiate a chain of risk by predisposing people to health behavior profiles associated with poorer later-life health.

Early Life Circumstances and Cognitive Aging: Longitudinal Evidence From China Health and Retirement Study

Objectives: This study examines the long-term relationship between early life circumstances and later life cognitive aging. In particular, we differentiate the long-term effects of early life circumstances on level of cognitive deficit and rate of cognitive decline. Methods: Cognitive trajectories were measured using three waves of China Health and Retirement Longitudinal Surveys (CHARLS 2011-2015). Linear mixed-effect model was used to decompose the individual level of cognitive deficit and rate of cognitive change in a sample of Chinese middle-aged and older adults 45-90 years of age (N=6,700). These two dimensions of cognition were matched to four domains of early life circumstances using CHARLS Life History Survey (2014), including childhood socioeconomic status, neighborhood environment, social relationships and health conditions. Their associations were examined by linear regressions. Stratification analysis was further conducted to investigate the mediating effect of education on early life circumstances and cognitive aging. Results: Childhood socioeconomic status, childhood friendship and early life health conditions were significantly associated with both the level of cognitive deficit and rate of decline. In contrast, the community environment, including childhood neighborhood safety and social cohesion, only affected the baseline level of cognitive deficit; and childhood relationship with parents only affected the rate of cognitive decline. Moreover, education was found to be a mediating factor of these relationships. Conclusion: Exposure to disadvantaged early life circumstances have significant negative effects on later life cognitive deficit as well as rate of cognitive decline. Nevertheless, these long-term impacts can be partially ameliorated by higher educational attainment.

Early-Life Circumstances and Late-Life Loneliness: Findings From In-Depth Interviews

This case study examines loneliness from the perspective of two older men, who were interviewed three times as part of a five-year qualitative longitudinal study on loneliness in later life. Both interviewees self-identified as feeling lonely “often” or “all the time” and had experienced loneliness also in previous life phases. The interviews revealed trajectories of long-term loneliness which were impacted by life events and circumstances in early life, childhood and youth. Two critical experiences were identified: childhood bereavement and sexual abuse. These factors contributed to emotional insecurities and impacted the ways the interviewees perceived their selves and their relations with others. The acknowledgement of past life experiences is important for the theoretical and conceptual understanding of loneliness and the development of different intervention strategies. However, more longitudinal analysis is needed on the cumulative disadvantages making people vulnerable to long-term loneliness.

Theory driven analysis of social class and health outcomes using UK nationally representative longitudinal data

BackgroundSocial class is frequently used as a means of ranking the population to expose inequalities in health, but less often as a means of understanding the social processes of causation. We explored how effectively different social class mechanisms could be measured by longitudinal cohort data and whether those measures were able to explain health outcomes.MethodsUsing a theoretically informed approach, we sought to map variables within the National Child Development Study (NCDS) to five different social class mechanisms: social background and early life circumstances; habitus and distinction; exploitation and domination; location within market relations; and power relations. Associations between the SF-36 physical, emotional and general health outcomes at age 50 years and the social class measures within NCDS were then assessed through separate multiple linear regression models. R2 values were used to quantify the proportion of variance in outcomes explained by the independent variables.ResultsWe were able to map the NCDS variables to the each of the social class mechanisms except ‘Power relations’. However, the success of the mapping varied across mechanisms. Furthermore, although relevant associations between exposures and outcomes were observed, the mapped NCDS variables explained little of the variation in health outcomes: for example, for physical functioning, the R2 values ranged from 0.04 to 0.10 across the four mechanisms we could map.ConclusionsThis study has demonstrated both the potential and the limitations of available cohort studies in measuring aspects of social class theory. The relatively small amount of variation explained in the outcome variables in this study suggests that these are imperfect measures of the different social class mechanisms. However, the study lays an important foundation for further research to understand the complex interactions, at various life stages, between different aspects of social class and subsequent health outcomes.

Early life circumstances and labor market outcomes over the life cycle

Some consequences of adverse events early in life for labor market outcomes may emerge early and others only later in adult life. We use data from the Survey of Health, Ageing and Retirement in Europe to investigate how early life circumstances—childhood health and socioeconomic status (SES)—are associated with various labor market outcomes over an individual’s entire life cycle. Our main new finding is that these associations change significantly over the life cycle. For instance, the association of childhood SES with lifetime earnings is shown to become stronger over the life cycle and to operate through both working years and annual earnings. We discuss how our findings can explain some of the mixed evidence on these associations in previous literature. Our results also shed light on the potential gains in the different labor market outcomes of public policies that invest in children’s health and parents’ SES.

Adverse Childhood Experiences and Risk Behaviours Later in Life: Evidence from SHARE Countries

In this paper we investigate whether exposure to adverse experiences during childhood such as physical and emotional abuse affects the likelihood of unhealthy habits and separately the insurgency of chronic diseases and disabilities later in life. The novelty of our approach consists in exploiting the recently published data on adverse childhood experiences for 19 SHARE countries, which enables us to account for country-specific heterogeneity and investigate the long-run effects of exposure to adverse early-life circumstances on risk behaviour such as smoking, drinking, overweight and obesity. Our results highlight a significant positive effect of exposure to adverse childhood experiences (ACEs) on the probability of unhealthy lifestyles as well as on the insurgency of chronic diseases and disabilities in the long run.

Trajectory of inequality of opportunity in child height growth: Evidence from the Young Lives study

Background: Socioeconomic circumstances during infancy and in early childhood shape later developmental opportunities. Understanding whether inequality in children’s health becomes stronger with age from the evidence of longitudinal data is an important first step in revealing the mechanism by which the intergenerational transmission of poverty takes place and evolves. Objective: This study investigates the 15-year trajectory of inequality in height growth associated with early-life circumstances among children in Vietnam, Peru, Ethiopia, and India. Methods: This study uses the datasets of the Young Lives study project, which is a large-scale crosscountry longitudinal study on childhood poverty conducted in Vietnam, Peru, Ethiopia, and India since 2002. Machine learning approaches are employed to estimate the relationship between early-life circumstances and child height. Results: The inequality in height stemming from the difference in early-life circumstances persists even after children reach early adolescence. The proportion of inequality peaks when children are 5 years old. Our prediction using the random forest model shows that, if we were able to fully compensate for early-life socioeconomic disadvantages, we could increase the lower percentile of the height distribution and reduce the inequality in height at age 15 by half. Conclusions: The results suggest that children from marginalised households should be supported at the earlier developmental stage. Contribution: This study shows the life-course evolution of inequalities in child growth, explores the dynamic link between early-life circumstances and later consequences, and identifies optimal timing in terms of when circumstances and events matter the most.

Exploring the role of early-life circumstances, abilities and achievements on well-being at age 50 years: evidence from the 1958 British birth cohort study

ObjectivesWe aim to examine the relative contributions of pathways from middle childhood/adolescence to mid-life well-being, health and cognition, in the context of family socio-economic status (SES) at birth, educational achievement...

Early-life circumstances and the risk of function-limiting long-term conditions in later life

Older adults are particularly prone to function-limiting health issues that adversely affect their well-being. Previous work has identified factors from across the life course –childhood socio-economic status, childhood cognitive ability and education – that predict later-life functional outcomes. However, the independence of these contributions is unclear as later-in-the-life-course predictors are themselves affected by earlier ones. The present study capitalised on the recent linkage of the Scottish Mental Survey 1947 with the Scottish Longitudinal Study, using path analyses to examine the direct and indirect associations between life-course predictors and the risk of functional limitation at ages 55 (N = 2,374), 65 (N = 1,971) and 75 (N = 1,534). The odds of reporting a function-limiting long-term condition increased across later life. At age 55, reporting a functional limitation was significantly less likely in those with higher childhood socio-economic status, higher childhood cognitive ability and higher educational attainment; these associations were only partly mediated by other predictors. At age 65, adult socio-economic status emerged as a mediator of several associations, although direct associations with childhood socio-economic status and childhood cognitive ability were still observed. At age 75, only childhood socio-economic status and adult socio-economic status directly predicted the risk of a functional limitation, particularly those associated with disease or illness. A consistent pattern and direction of associations was observed with self-rated health more generally. These results demonstrate that early-life and adult circumstances are associated with functional limitations later in life, but that these associations are partly a product of complex mediation between life-course factors.

Work–family lifecourses and later-life health in the United Kingdom

AbstractSocio-economic inequalities in physical and mental health persist at older ages and previous studies have shown that partnership and parenthood histories are also associated with differentials in later-life health. These domains of adult life interact, and both may be influenced by earlier life circumstances, indicating a need for a holistic approach to understanding lifecourse influences on health at older ages. In this paper, we identify classes of lifecourse types for a United Kingdom (UK) cohort born 1933–1945 and investigate differences between the latent classes identified in physical and mental health, and changes in health over a five-year follow-up period. Data were drawn from Waves 1–5 (2009–2013) of the nationally representative UK Household Longitudinal Study. Multi-level models were used to analyse associations with summary indicators of physical and mental health measured using the SF-12, and changes in health, controlling for childhood circumstances and taking account of support from family and friends in later life. Lifecourses characterised by lower socio-economic position, early parenthood and large family size were associated with worse physical and mental health in later life, with respondents who had combined a high socio-economic position and two children being the most advantaged. The study indicates that socio-economic disparities in later-life health vary depending on the way in which individuals combine work and family life.

Health and voting over the course of adulthood: Evidence from two British birth cohorts.

Systematic differences in voter turnout limit the capacity of public institutions to address the needs of under-represented groups. One critical question relates to the role of health as a mechanism driving these inequalities. This study explores the associations of self-rated health (SRH) and limitations in everyday activities with voting over the course of adulthood in the 1958 National Child Development Study and the 1970 British Cohort Study. We used data from participants who reported voting in the last general election at least once between the ages of 23 and 55 in the 1958 cohort and between the ages of 30 and 42 in the 1970 cohort. We examined associations controlling for a range of early-life and adult circumstances using random-effects models. Compared with those in good or better health: those in fair health had 15% and 18% lower odds of voting in the 1958 and 1970 cohorts; those in poor or worse health had 17% and 32% lower odds of voting in the 1958 and 1970 cohorts. These effects varied with age and were most marked among those in poor health at the ages of 23/30 in the 1958 and 1970 cohorts. Controlling for SRH, having limitations in everyday activities was not associated with voting in main models. Examining age-based differences, however, we found that reporting limitations was associated with a higher probability of voting at the age of 55 in the 1958 cohort and at the age of 30 in the 1970 cohort. Building on the qualities of the British birth cohorts, we offer nuanced evidence about the role of health on voting, which involves considerable life-course processes. Future studies need to examine how these findings progress after the age of 55, extend to mental wellbeing and health practices, and contribute to explain social inequalities in voter turnout.

Oral Microbiota Development in Early Childhood

Early life determinants of the oral microbiota have not been thoroughly elucidated. We studied the association of birth and early childhood characteristics with oral microbiota composition using 16 S ribosomal RNA (rRNA) gene sequencing in a population-based Swedish cohort of 59 children sampled at 6, 12 and 24 months of age. Repeated-measurement regression models adjusted for potential confounders confirmed and expanded previous knowledge about the profound shift of oral microbiota composition in early life. These alterations included increased alpha diversity, decreased beta diversity and alteration of bacterial composition with changes in relative abundance of 14 of the 20 most common operational taxonomic units (OTUs). We also found that birth characteristics, breastfeeding and antibiotic use were associated with overall phyla distribution and/or with the relative abundance of specific OTUs. Further, we detected a novel link between morning salivary cortisol level, a physiological marker of neuroendocrine activity and stress, and overall phyla distribution as well as with decreased abundance of the most common OTU mapped to the Streptococcaceae family. In conclusion, a major part of the maturation of the oral microbiome occurs during the first two years of life, and this development may be influenced by early life circumstances.

Designing Retrospective Measures on Childhood for Older African American Adults.

A growing body of research addresses the long-term implications of early-life circumstances for adult health and aging by drawing on retrospective reports on childhood. There has been little scholarly discourse on considerations for the design of such questions for members of racial/ethnic minority groups specifically. This article aims to encourage greater attention to this area by presenting insights from the process of designing a childhood history questionnaire within an ongoing study of cognition, health, and aging among older African American adults in greater Newark, New Jersey. The article presents on three overarching themes, including the importance of (a) adopting a resilience orientation with attention to protective factors, (b) being sensitive to concerns about questions on adverse childhood experiences, and (c) orienting to ethnoracially embedded cohort influences. The article concludes by describing the particular importance of cultural humility-with attention to intersectional social positions-among researchers who are engaged in studies on childhood with older adults from underrepresented racial/ethnic groups.

Childhood cognitive ability and the use of long-term care in later life

Background As the population ages the demand for care is predicted to increase. Previous studies have reported that individuals with poorer post-morbid cognitive ability are at higher risk of entering long-term care, both institutionalised care and home-based care. Given that post-morbid cognitive ability is sensitive to the type and severity of morbidity, it remains unclear whether higher cognitive ability, as a trait-level measure of individual differences, contributes to care usage. Some success has been observed using non-cognitive early-life circumstances such as socioeconomic circumstances as pre-morbid predictors of care risk. However, the contribution of early-life cognitive ability has yet to be examined.
 Main Aim We investigate the association between early-life circumstances, particularly cognitive ability, and the risk of entry into long-term care in later life (age 65+).
 Methods Veterans were identified using the South London and Maudsley Biomedical Research Centre (SLaM) case register – a database holding secondary mental health care electronic records for the South London and Maudsley National Health Service Trust of 300,000 patients. We developed two methods. An NLP and machine learning tool were developed to automatically evaluate personal history statements written by clinicians.
 Results This study uses a large sample of individuals born in Scotland in 1936 and who took part in the Scottish Mental Survey 1947. It links research data from childhood to routinely-collected administrative and healthcare records from across the life course.
 Conclusion We demonstrate the importance of early-life factors for predicting care usage in later life and how this role differs between types of long-term care. The implications of the results for research and policy will be discussed.