The relative roles of early life, physical activity, sedentarism and diet in social and economic inequalities in body mass index and obesity risk between 9 and 18.

Background: Studies in many middle and high-income countries describe an increasing prevalence of adiposity and obesity among children and adolescents. Prevalence is higher among families of low socioeconomic position (SEP) and systematic reviews have identified relevant factors, but have not quantified their relative importance to SEP differentials. This paper examines the relative importance of different factors to Body Mass Index (BMI) and obesity trajectories from age 9 to age 17/18. Methods: Multi-level models of child BMI/obesity risk trajectory by maternal education were conducted using a nationally representative cohort of children born in Ireland in 1998 and aged 9 at baseline (N = 8568), with follow-up at 13 and 17/18 years (88% and 73% response rate respectively). Models were stratified by sex and both time-varying (e.g. child physical activity, diet, sedentary activity) and time-invariant (e.g. early life) factors were tested. Results: Significant inverse gradients in BMI and obesity risk by level of maternal education were present across both sexes and at each age; unadjusted absolute differentials in obesity risk between highest/lowest education groups increased by 56% for males and 42% for females between age 9 and 17/18. Early life factors accounted for 22% of the differential in obesity risk between the lowest and highest education groups among males at age 9, falling to 13% at 17/18. Among females the proportion fell from 33 to 23%. Unadjusted absolute high/low maternal education group differentials in BMI were 7.5 times higher among males and 11 times higher among females at 17/18 than at age 9. Conclusions: Given the importance of early life exposures to subsequent differentials in BMI and obesity risk our findings suggest that policy makers should focus resources on primary prevention during the prenatal and early life period if they wish to reduce the prevalence of child and adolescent obesity.

Towards a consensus definition of allostatic load: a multi-cohort, multi-system, multi-biomarker individual participant data (IPD) meta-analysis.

BACKGROUND: Allostatic load (AL) is a multi-system composite index for quantifying physiological dysregulation caused by life course stressors. For over 30 years, an extensive body of research has drawn on the AL framework but has been hampered by the lack of a consistent definition. METHODS: This study analyses data for 67,126 individuals aged 40-111 years participating in 13 different cohort studies and 40 biomarkers across 12 physiological systems: hypothalamic-pituitary-adrenal (HPA) axis, sympathetic-adrenal-medullary (SAM) axis, parasympathetic nervous system functioning, oxidative stress, immunological/inflammatory, cardiovascular, respiratory, lipidemia, anthropometric, glucose metabolism, kidney, and liver. We use individual-participant-data meta-analysis and exploit natural heterogeneity in the number and type of biomarkers that have been used across studies, but a common set of health outcomes (grip strength, walking speed, and self-rated health), to determine the optimal configuration of parameters to define the concept. RESULTS: There was at least one biomarker within 9/12 physiological systems that was reliably and consistently associated in the hypothesised direction with the three health outcomes in the meta-analysis of these cohorts: dehydroepiandrosterone sulfate (DHEAS), low frequency-heart rate variability (LF-HRV), C-reactive protein (CRP), resting heart rate (RHR), peak expiratory flow (PEF), high density lipoprotein cholesterol (HDL-C), waist-to-height ratio (WtHR), HbA1c, and cystatin C. An index based on five biomarkers (CRP, RHR, HDL-C, WtHR and HbA1c) available in every study was found to predict an independent outcome - mortality - as well or better than more elaborate sets of biomarkers. DISCUSSION: This study has identified a brief 5-item measure of AL that arguably represents a universal and efficient set of biomarkers for capturing physiological 'wear and tear' and a further biomarker (PEF) that could usefully be included in future data collection.

Verification of the Goldilocks Hypothesis: the association between screen use, digital media and psychiatric symptoms in the Growing Up in Ireland study.

AIMS: This study aims to replicate Przybylski and Weinstein (Psychol Sci 28(2):204-215, 2017), using a large population cohort to examine the validity of the proposed Goldilocks Hypothesis, which states that moderate digital media engagement may be beneficial and that both high and low usage may have a negative relationship with mental wellbeing. METHODS: Using the GUI98 cohort, we used separate weekday and weekend time-based categorical variables indicating time spent online, playing video games, watching TV/films as well as a frequency variable indicating multiscreening, and their associations with SDQ internalizing and externalizing symptoms using linear and quadratic regression parameters. We followed procedures for confounder adjustments outlined in Przybylski and Weinstein (Psychol Sci 28(2):204-215, 2017). RESULTS: As hypothesized by the Goldilocks Hypothesis, time spent online watching TV/films at the weekend and multiscreening all had curvilinear relationships with internalizing and externalizing symptoms with significantly higher symptoms for no time as well as for higher exposures. internalizing and externalizing symptoms increased with time spent playing video games. CONCLUSIONS: This brief report supports the Goldilocks Hypothesis, that suggests that moderate use of digital technology is not intrinsically harmful and may instead be beneficial, even necessary in a world becoming ever more increasingly reliant on digital media (Przybylski and Weinstein in Psychol Sci 28(2):204-215, 2017).

The role of family, school and neighbourhood in explaining inequalities in physical activity trajectories between age 9 and 18.

Differentials in physical activity (PA) between social and economic groups has been shown to contribute significantly to social gradients in health and life expectancy, yet relatively little is known about why differentials in PA emerge. This paper uses longitudinal data on a nationally representative sample of 6,216 young people aged between 9 and 18, from Ireland, to measure the role of family, school and neighbourhood level factors in accounting for differentials in PA trajectories between groups of young people, defined by level of maternal education, whilst adjusting for the individual characteristics of the young person (sex, age, personality, body mass index and health-status). Levels of PA fall significantly across the sample between 9 and 18, and the decline in PA is larger for the children of lower educated mothers. We find a clear gradient in PA at each age by maternal education for both males and females. Descriptive analyses found social gradients in the majority of our risk factors. Using multi-level, linear spline regression models to decompose differentials between groups, we find that family-level mechanisms account for the biggest proportion of the differential in PA for both males (50.8%) and females (35.1%). Differences in income across maternal education categories accounted for 24.1% of the differential for males and 14.7% among females, making it the second most effective mechanism in explaining the social patterning of PA. Neighbourhood-level processes resulted in a modest reduction in the same differential, while school level processes had the effect of equalising differences in PA across maternal education groups.

Mediators of socioeconomic differences in overweight and obesity among youth in Ireland and the UK (2011-2021): a systematic review.

BACKGROUND: By 2025, adult obesity prevalence is projected to increase in 44 of 53 of European-region countries. Childhood obesity tracks directly onto adult obesity, and children of low socioeconomic position families are at disproportionately higher risk of being obese compared with their more affluent peers. A previous review of research from developed countries identified factors mediating this relationship. This systematic review updates and extends those findings specifically within the context of Ireland and the United Kingdom. OBJECTIVE: The aim of this systematic review is to summarise peer-reviewed research completed in Ireland and the United Kingdom between 2011-2021 examining mediators of socioeconomic differentials in adiposity outcomes for youth. DESIGN: An electronic search of four databases, Ovid MEDLINE, Embase, Web of Science and EBSCOhost was conducted. Quantitative studies, published in the English language, examining mediators of socioeconomic differentials in adiposity outcomes in youth, and conducted in Ireland and the United Kingdom between 2011-2021 were included. An appraisal of study quality was completed. The systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Following screening, a total of 23 papers were eligible for inclusion. Results indicate socioeconomic differentials for Ireland and the United Kingdom follow similar patterns to other developed countries and have similar mediating factors including early life and parent-level factors. However, this review identified additional factors that mediate the relationship, namely access to green space and favorable neighborhood conditions. Identifying these factors present further opportunities for potential interventions and confirm the requirement for tailored and appropriate research and interventions for Ireland and the United Kingdom. CONCLUSION: This review identified several modifiable factors that should be considered when planning interventions aimed at reducing socioeconomic differentials in adiposity among youth in Ireland and the United Kingdom. Support was found for interventions to be made as early as possible in an at-risk child's life, with the prenatal and preschool periods considered the most efficacious. Results were equivocal about the role of physical activity in the risk of childhood overweight and obesity. While multi-country analyses provide excellent overviews, country- or area-specific research may produce more nuanced, and potentially more powerful findings, which can help better inform policy responses and interventions.

Special Report: The Biology of Inequalities in Health: The Lifepath Consortium.

Funded by the European Commission Horizon 2020 programme, the Lifepath research consortium aimed to investigate the effects of socioeconomic inequalities on the biology of healthy aging. The main research questions included the impact of inequalities on health, the role of behavioral and other risk factors, the underlying biological mechanisms, the efficacy of selected policies, and the general implications of our findings for theories and policies. The project adopted a life-course and comparative approach, considering lifetime effects from childhood and adulthood, and pooled data on up to 1.7 million participants of longitudinal cohort studies from Europe, USA, and Australia. These data showed that socioeconomic circumstances predicted mortality and functional decline as strongly as established risk factors currently targeted by global prevention programmes. Analyses also looked at socioeconomically patterned biological markers, allostatic load, and DNA methylation using richly phenotyped cohorts, unraveling their association with aging processes across the life-course. Lifepath studies suggest that socioeconomic circumstances are embedded in our biology from the outset-i.e., disadvantage influences biological systems from molecules to organs. Our findings have important implications for policy, suggesting that (a) intervening on unfavorable socioeconomic conditions is complementary and as important as targeting well-known risk factors, such as tobacco and alcohol consumption, low fruit and vegetable intake, obesity and a sedentary lifestyle, and that (b) effects of preventive interventions in early life integrate interventions in adulthood. The report has an executive summary that refers to the different sections of the main paper.

Does maternal obesity explain trends in caesarean section rates? Evidence from a large Irish maternity hospital.

BACKGROUND: A feature of contemporary obstetrics in wealthy countries has been both the continuing increase in caesarean section (CS) rates and the emergence of high levels of maternal obesity. AIMS: The purpose of this study was to examine whether the increasing CS rate in a large university maternity hospital was attributable in part to maternal obesity. METHODS: We studied all women who delivered a baby weighing ≥ 500 g from 2009 to 2014 in one of the largest maternity hospitals in Europe. Logistic regression techniques were employed to examine the contribution of trends in maternal BMI on the prevalence of CS. RESULTS: Obese women were more likely to be delivered by CS in 2014 than in 2009. Multivariate analysis shows that the increase in CS rates could not be explained by changes in obesity levels in either nulliparas or multiparas. The increase in CS rates during the 6 years was strongly associated with advancing maternal age, particularly for nulliparas. CONCLUSIONS: The study found that although the prevalence of being overweight or obese changed little over the period, the odds of having a CS if a woman is obese have increased for multiparas. For nulliparas, increasing CS rates were found to be strongly associated with an increase in maternal age over the period which is important because of the evidence that Irish women are choosing to defer having their first baby until later in life.

Epigenetic Clocks and Allostatic Load Reveal Potential Sex-Specific Drivers of Biological Aging.

Allostatic load (AL) and epigenetic clocks both attempt to characterize the accelerated aging of biological systems, but at present it is unclear whether these measures are complementary or distinct. This study examines the cross-sectional association of AL with epigenetic age acceleration (EAA) in a subsample of 490 community-dwelling older adults participating in The Irish Longitudinal study on Aging (TILDA). A battery of 14 biomarkers representing the activity of four different physiological systems: immunological, cardiovascular, metabolic, renal, was used to construct the AL score. DNA methylation age was computed according to the algorithms described by Horvath, Hannum, and Levine allowing for estimation of whether an individual is experiencing accelerated or decelerated aging. Horvath, Hannum, and Levine EAA correlated 0.05, 0.03, and 0.21 with AL, respectively. Disaggregation by sex revealed that AL was more strongly associated with EAA in men compared with women as assessed using Horvath's clock. Metabolic dysregulation was a strong driver of EAA in men as assessed using Horvath and Levine's clock, while metabolic and cardiovascular dysregulation were associated with EAA in women using Levine's clock. Results indicate that AL and the epigenetic clocks are measuring different age-related variance and implicate sex-specific drivers of biological aging.

Maternal educational inequalities in measured body mass index trajectories in three European countries.

BACKGROUND: Social inequalities in the prevalence of childhood overweight and obesity are well-established, but less is known about when the social gradient first emerges and how it evolves across childhood and adolescence. OBJECTIVE: This study examines maternal education differentials in children's body mass trajectories in infancy, childhood and adolescence using data from four contemporary European child cohorts. METHODS: Prospective data on children's body mass index (BMI) were obtained from four cohort studies-Generation XXI (G21-Portugal), Growing Up in Ireland (GUI) infant and child cohorts, and the Millennium Cohort Study (MCS-UK)-involving a total sample of 41,399 children and 120,140 observations. Children's BMI trajectories were modelled by maternal education level using mixed-effect models. RESULTS: Maternal educational inequalities in children's BMI were evident as early as three years of age. Children from lower maternal educational backgrounds were characterised by accelerated BMI growth, and the extent of the disparity was such that boys from primary-educated backgrounds measured 0.42 kg/m2 (95% CI 0.24, 0.60) heavier at 7 years of age in G21, 0.90 kg/m2 (95% CI 0.60, 1.19) heavier at 13 years of age in GUI and 0.75 kg/m2 (95% CI 0.52, 0.97) heavier in MCS at 14 years of age. The corresponding figures for girls were 0.71 kg/m2 (95% CI 0.50, 0.91), 1.31 kg/m2 (95% CI 1.00, 1.62) and 0.76 kg/m2 (95% CI 0.53, 1.00) in G21, GUI and MCS, respectively. CONCLUSIONS: Maternal education is a strong predictor of BMI across European nations. Socio-economic differentials emerge early and widen across childhood, highlighting the need for early intervention.

Adverse childhood experiences are associated with an increased risk of obesity in early adolescence: a population-based prospective cohort study.

OBJECTIVE: To determine whether adverse childhood experiences were associated with weight gain and obesity risk in adolescence. METHODS: We analyzed data from 6942 adolescents followed between 9 and 13 years of age in the Growing Up in Ireland cohort study. The main exposures were 14 adverse childhood experiences, 4 of which were included in the Adverse Childhood Experience (ACE) study. The primary outcome was incident overweight and obesity at 13 years. Secondary outcomes included prevalent overweight/obesity and weight gain. RESULTS: More than 75% of the youth experienced an adverse experience and 17% experienced an ACE-specific experience before 9 years. At 13 years, 48% were female and 31.4% were overweight or obese. After adjusting for confounding, exposure to any adverse experience was associated with prevalent overweight/obesity (aOR: 1.56; 1.19-2.05) and incident overweight/obesity (adjusted IRR: 2.15; 95% CI: 1.37-3.39), while exposure to an ACE-specific exposure was associated weight gain (BMI Z score change = 0.202; 95% CI: 0.100-0.303). A significant interaction between income and adverse childhood experiences was observed for both incident overweight/obesity and weight gain (BMI Z change: -0.046; 95% CI: -0.092 to 0.000). CONCLUSIONS: Adverse childhood experiences and low income interact and independently predict obesity risk in early adolescence.

How does socio-economic position (SEP) get biologically embedded? A comparison of allostatic load and the epigenetic clock(s).

Individuals of lower socio-economic position (SEP) carry a heavier burden of disease and morbidity and live shorter lives on average compared with their more advantaged counterparts. This has sparked research interest in the processes and mechanisms via which social adversity gets biologically embedded. The present study directly compares the empirical worth of two candidate mechanisms: Allostatic Load (AL) and the Epigenetic Clock(s) for advancing our understanding of embodiment using a sub-sample of 490 individuals from the Irish Longitudinal Study (TILDA) who were explicitly selected for this purpose based on their inter-generational life course social class trajectory. A battery of 14 biomarkers representing the activity of 4 different physiological systems: Immunological, Cardiovascular, Metabolic, and Renal was used to construct the AL score. Biomarkers were dichotomised into high and low risk groups according to sex-specific quartiles of risk and summed to create a count ranging from 0-14. Three measures of epigenetic age acceleration were computed according to three sets of age-associated Cytosine-phosphate-Guanine (CpG) sites described by Horvath, Hannum and Levine. AL was strongly socially patterned across a number of measures of SEP, while the epigenetic clocks were not. AL partially mediated the association between measures of SEP and an objective measure of physiological functioning: performance on the Timed Up and Go (TUG test). We conclude that AL may represent the more promising candidate for understanding the pervasive link between SEP and health.

A Comparative Analysis of the Status Anxiety Hypothesis of Socio-economic Inequalities in Health Based on 18,349 individuals in Four Countries and Five Cohort Studies.

The status anxiety hypothesis proposes that systematic inflammation as a consequence of chronic psycho-social stress is a possible pathway linking socio-economic position (SEP) to premature ageing and is a possible explanation for cross-national variation in patterns of health and well-being. Harmonised data from the LIFEPATH consortium on 18,349 individuals aged 50 to 75 and 30,632 observations are used to measure variation in the association between inflammation measured as C-reactive protein and SEP across four countries (Britain, Ireland, Portugal and Switzerland) and five studies (ELSA, Whitehall II, TILDA, EPIPorto and SKIPOGH). Adjusting for population composition, mean concentrations of CRP are highest in Portugal, the country with the highest income inequality and lowest in Switzerland, a lower income inequality country. Across all of the studies, lower SEP groups have higher mean concentrations of CRP and, as predicted by the theory, absolute differentials between SEP groups reflect the pattern of societal income inequality. Adjustment for lifestyle indicators reduces SEP differentials by between 45% and 52% but cannot account for country variation in mean inflammation.

Sexual Activity and Relationship Quality in Middle and Older Age: Findings From The Irish Longitudinal Study on Ageing (TILDA).

Objectives: This study assessed the association between sexual activity, mismatches in the importance attributed to sex within couples, and relationship quality in older Irish adults. Method: We used data from the Irish Longitudinal Study on Ageing (TILDA) to derive a scale of subjective relationship strain in married or cohabiting individuals. Negative binomial regression was used to assess the association between relationship strain and sexual activity. Separate models assessed the associations with importance of sex and within-couple mismatch in the importance attributed to sex and whether these associations were independent from sexual activity. Age interactions were tested. Results: Sexual activity and within-couple mismatch in the importance attributed to sex were associated with relationship strain. The frequency of sexual activity was consistently associated with less relationship strain for men, but less so for women when the importance attributed to sex was accounted for. Results were largely consistent across age groups for men, but sexual activity and importance of sex varied with age in women. Discussion: Frequent sexual activity was associated with less strain within-intimate relationships. For women, this association was weakened when accounting for the importance attributed to sex. Within-couple mismatch in the importance attributed to sex was associated with relationship strain, independent from frequency of sexual activity, for both men and women at all ages.

Fiscal crises and personal troubles: the great recession in Ireland and family processes.

BACKGROUND: Social disadvantage is often associated with worse child psychological adjustment which itself is implicated in educational failure and poor adult social position. The family stress model holds that the association between social disadvantage and psychological adjustment stems from the impact of economic pressure on parental mental health mediated through the parent/child relationship. METHODS: We take advantage of a natural experiment offered by the 'great recession' in Ireland between 2008 and 2012. Structural equation models using causal modelling and Longitudinal data from the Growing Up in Ireland cohort study are used to test whether the experience of recession in families impacts on children's psychological adjustment and whether this occurs directly or is mediated by the processes identified in the family stress model. RESULTS: More than 70% of families experienced a reduction in income between 2008 and 2011 and 26% reported cutting back on basics such as clothing and food. Family experience of recession was significantly associated with negative change in all of the components of the family stress model, particularly parental mental health. However, less than half of the effect of recession was mediated by the processes of the family stress model. Tests showed that a model with a direct effect of recession on child psychological adjustment provided a better fit to the data. CONCLUSIONS: Recession and economic pressure had a significant effect on child psychological adjustment, but only a minority of this effect was indirect via the mental health of parents and parent/child relationship. The family stress model only offers a partial account of the mechanisms through which economic hardship impacts on families and children.

Socioeconomic status, non-communicable disease risk factors, and walking speed in older adults: multi-cohort population based study.

OBJECTIVE: To assess the association of low socioeconomic status and risk factors for non-communicable diseases (diabetes, high alcohol intake, high blood pressure, obesity, physical inactivity, smoking) with loss of physical functioning at older ages. DESIGN: Multi-cohort population based study. SETTING: 37 cohort studies from 24 countries in Europe, the United States, Latin America, Africa, and Asia, 1990-2017. PARTICIPANTS: 109 107 men and women aged 45-90 years. MAIN OUTCOME MEASURE: Physical functioning assessed using the walking speed test, a valid index of overall functional capacity. Years of functioning lost was computed as a metric to quantify the difference in walking speed between those exposed and unexposed to low socioeconomic status and risk factors. RESULTS: According to mixed model estimations, men aged 60 and of low socioeconomic status had the same walking speed as men aged 66.6 of high socioeconomic status (years of functioning lost 6.6 years, 95% confidence interval 5.0 to 9.4). The years of functioning lost for women were 4.6 (3.6 to 6.2). In men and women, respectively, 5.7 (4.4 to 8.1) and 5.4 (4.3 to 7.3) years of functioning were lost by age 60 due to insufficient physical activity, 5.1 (3.9 to 7.0) and 7.5 (6.1 to 9.5) due to obesity, 2.3 (1.6 to 3.4) and 3.0 (2.3 to 4.0) due to hypertension, 5.6 (4.2 to 8.0) and 6.3 (4.9 to 8.4) due to diabetes, and 3.0 (2.2 to 4.3) and 0.7 (0.1 to 1.5) due to tobacco use. In analyses restricted to high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was 8.0 (5.7 to 13.1) for men and 5.4 (4.0 to 8.0) for women, whereas in low and middle income countries it was 2.6 (0.2 to 6.8) for men and 2.7 (1.0 to 5.5) for women. Within high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was greater in the United States than in Europe. Physical functioning continued to decline as a function of unfavourable risk factors between ages 60 and 85. Years of functioning lost were greater than years of life lost due to low socioeconomic status and non-communicable disease risk factors. CONCLUSIONS: The independent association between socioeconomic status and physical functioning in old age is comparable in strength and consistency with those for established non-communicable disease risk factors. The results of this study suggest that tackling all these risk factors might substantially increase life years spent in good physical functioning.

Choice and Constraint in the Negotiation of the Grandparent Role: A Mixed-Methods Study.

Few studies have examined how the allocation and consequences of grandchild care vary across different socioeconomic groups. We analyze qualitative data alongside data from The Irish Longitudinal Study on Ageing (TILDA), in a convergent mixed-methods approach. Regression models examined characteristics associated with grandchild care, and the relationship between grandchild care and depressive symptoms and well-being. Qualitative data shed light on processes and choices that explain patterns of grandchild care provision. Tertiary-educated grandparents provided less intensive grandchild care compared with primary educated. Qualitative data indicated that this pattern stems from early boundary-drawing among higher educated grandparents while lower socioeconomic groups were constrained and less able to say no. Intensive grandchild care was associated with more depressive symptoms and lower well-being and was moderated by participation in social activities and level of education attainment. The effect of grandchild care on well-being of grandparents depends on whether it is provided by choice or obligation.

The Great Recession and the Health of Young Children: A Fixed-Effects Analysis in Ireland.

Economic recessions have been linked to adult health, but few studies have examined how recessions influence the health of young children. This study examined the impact of life transitions linked to the recent financial crisis on the health of young children in Ireland. Data came from the Growing Up in Ireland Infant Cohort Study (n = 11,134), which assessed children before (2008), during (2011), and after (2013) the Great Recession that followed the financial crisis of 2008 and incorporated questions on the impacts of the financial crisis on families. Using fixed-effects models to control for confounding, we found that a reduction in welfare benefits during the recession was associated with a significant increase in the risks of asthma (ß = 0.014, 95% confidence interval (95% CI): 0.004, 0.023) and atopy (ß = 0.014, 95% CI: 0.001, 0.027). While parental job loss was not associated with child health, a reduction in working hours was associated with increased reports of child health problems (ß = 0.024, 95% CI: 0.004, 0.043), as were difficulties affording basic necessities (ß = 0.019, 95% CI: 0.001, 0.038). Results suggest that failing to protect vulnerable families and children during economic recessions may have long-lasting implications for child health.

Social adversity and epigenetic aging: a multi-cohort study on socioeconomic differences in peripheral blood DNA methylation.

Low socioeconomic status (SES) is associated with earlier onset of age-related chronic conditions and reduced life-expectancy, but the underlying biomolecular mechanisms remain unclear. Evidence of DNA-methylation differences by SES suggests a possible association of SES with epigenetic age acceleration (AA). We investigated the association of SES with AA in more than 5,000 individuals belonging to three independent prospective cohorts from Italy, Australia, and Ireland. Low SES was associated with greater AA (ß = 0.99 years; 95% CI 0.39,1.59; p = 0.002; comparing extreme categories). The results were consistent across different SES indicators. The associations were only partially modulated by the unhealthy lifestyle habits of individuals with lower SES. Individuals who experienced life-course SES improvement had intermediate AA compared to extreme SES categories, suggesting reversibility of the effect and supporting the relative importance of the early childhood social environment. Socioeconomic adversity is associated with accelerated epigenetic aging, implicating biomolecular mechanisms that may link SES to age-related diseases and longevity.

Socioeconomic differences in children's growth trajectories from infancy to early adulthood: evidence from four European countries.

BACKGROUND: Height is regarded as a marker of early-life illness, adversity, nutrition and psychosocial stress, but the extent to which differences in height are determined by early-life socioeconomic circumstances, particularly in contemporary populations, is unclear. This study examined socioeconomic differences in children's height trajectories from birth through to 21 years of age in four European countries. METHODS: Data were from six prospective cohort studies-Generation XXI, Growing Up in Ireland (infant and child cohorts), Millennium Cohort Study, EPITeen and Cardiovascular Risk in Young Finns Study-comprising a total of 49 492 children with growth measured repeatedly from 1980 to 2014. We modelled differences in children's growth trajectories over time by maternal educational level using hierarchical models with fixed and random components for each cohort study. RESULTS: Across most cohorts at practically all ages, children from lower educated mothers were shorter on average. The gradient in height was consistently observed at 3 years of age with the difference in expected height between maternal education groups ranging between -0.55 and -1.53 cm for boys and -0.42 to -1.50 cm for girls across the different studies and widening across childhood. The height deficit persists into adolescence and early adulthood. By age 21, boys from primary educated maternal backgrounds lag the tertiary educated by -0.67 cm (Portugal) and -2.15 cm (Finland). The comparable figures for girls were -2.49 cm (Portugal) and -2.93 cm (Finland). CONCLUSIONS: Significant differences in children's height by maternal education persist in modern child populations in Europe.

The impact of transitions in insurance coverage on GP visiting among children in Ireland.

The use of direct out-of-pocket payments to finance general practitioner (GP) care by the majority of the population in Ireland is unusual in a European context. Currently, approximately 40 per cent of the population have means-tested access to free GP care, while the remainder must pay the full out-of-pocket cost. In this paper, we use nationally representative data from the Growing up in Ireland (GUI) study to examine the impact of transitions in insurance coverage on GP utilisation among children. GUI surveys two cohorts of nearly 20,000 children (aged 9 months and 9 years at baseline); we use data from the first two waves of each cohort (which covers the period 2007-2012). Using difference-in-difference propensity score matching methods, we find significant effects of changes in public health insurance coverage on GP utilisation (i.e., introducing user fees reduces utilisation, while removing them increases utilisation). The results have direct implications for current Irish health policy, and add to the international literature on the effects of insurance on healthcare utilisation.