The last two decades of life course epidemiology, and its relevance for research on ageing

The Association Between Adverse Childhood Experiences and Frailty: A Systematic Review

OBJECTIVE

Based on life-course theory, adverse childhood experiences (ACEs) have emerged as risk factors for health in later life. This study aimed to explore the association between ACEs and frailty.

DESIGN

Systematic review.

SETTING AND PARTICIPANTS

Frail older adults who have experienced ACEs.

METHODS

We searched 7 databases: PubMed, Cochrane Library, Embase, Web of Science, Scopus, PsycINFO, and China National Knowledge Infrastructure (CNKI). The last searched date was October 27, 2023. Included studies should have investigated the association between exposure to at least 1 ACE and frailty. Two researchers independently assessed the risk of bias in the included studies using the Newcastle-Ottawa Scale (NOS) and an adapted version of the NOS scale and also extracted relevant characteristics and outcomes of the included studies.

RESULTS

A total of 14 studies were finally included. Consistent associations with increased risk of frailty were only shown in studies that assessed family members with mental illness, low neighborhood quality, emotional abuse, sexual abuse, and combinations of ACEs. In addition, women exposed to ACEs were more likely to be at risk for frailty than men, and greater numbers or types of exposure to ACEs were associated with higher odds of frailty. The results of the quality assessment showed a moderate risk of bias in half of the studies.

CONCLUSIONS AND IMPLICATIONS

This study summarizes for the first time the evidence for an association between ACEs and frailty. Considered collectively, increased attention to ACEs may be one way to prevent frailty, and unhealthy lifestyles resulting from ACEs may serve as a breakthrough in developing interventions.

Lifetime Employment Trajectories and Cancer: A Population-Based Cohort Study

Working life is associated with lifestyle, screening uptake, and occupational health risks that may explain differences in cancer onset. To better understand the association between working life and cancer risk, we need to account for the entire employment history. We investigated whether lifetime employment trajectories are associated with cancer risk. We used data from 6,809 women and 5,716 men, average age 70 years, from the Survey of Health, Ageing, and Retirement in Europe. Employment history from age 16 to 65 was collected retrospectively using a life calendar and trajectories were constructed using sequence analysis. Associations between employment trajectories and self-reported cancer were assessed using logistic regression. We identified eight employment trajectories for women and two for men. Among women, the risk of cancer was higher in the trajectories "Mainly full-time to home/family", "Full-time or home/family to part-time", "Mainly full-time", and "Other" compared with the "Mainly home/family" trajectory. Among men, the risk of cancer was lower in the "Mainly self-employment" trajectory compared with "Mainly full-time". We could show how employment trajectories were associated with cancer risk, underlining the potential of sequence analysis for life course epidemiology. More research is needed to understand these associations and determine if causal relationships exist.

Life course epidemiology and public health

Life course epidemiology aims to study the effect of exposures on health outcomes across the life course from a social, behavioural, and biological perspective. In this Review, we describe how life course epidemiology changes the way the causes of chronic diseases are understood, with the example of hypertension, breast cancer, and dementia, and how it guides prevention strategies. Life course epidemiology uses complex methods for the analysis of longitudinal, ideally population-based, observational data and takes advantage of new approaches for causal inference. It informs primordial prevention, the prevention of exposure to risk factors, from an eco-social and life course perspective in which health and disease are conceived as the results of complex interactions between biological endowment, health behaviours, social networks, family influences, and socioeconomic conditions across the life course. More broadly, life course epidemiology guides population-based and high-risk prevention strategies for chronic diseases from the prenatal period to old age, contributing to evidence-based and data-informed public health actions. In this Review, we assess the contribution of life course epidemiology to public health and reflect on current and future challenges for this field and its integration into policy making.

Intergenerational reproduction and self-assessed mental health in adulthood in China

Physical and mental health disparities by socioeconomic status in China are well documented but the effects of the intergenerational reproduction in socioeconomic status on adult mental health have received little attention to date. We utilized cross-sectional data from the 2017 Chinese General Social Survey to examine the significance of intergenerational socioeconomic reproduction for differences in self-assessed mental health in a national sample of Chinese adults between the ages of 23 and 65. We documented substantial elasticities between the socioeconomic status of the survey respondents and their parents: father's education, mother's education and childhood social class were all associated with both respondent education and respondent household income. We also found that associations between parental socioeconomic status and their adult children's self-assessed mental health were partly explained by the children's own socioeconomic status. However, these pathways were noticeably moderated by age cohort. Among younger people, associations between parental socioeconomic status and mental health were mostly explained by educational attainment whereas among older people associations between parental socioeconomic status and mental health were mostly explained by household income. In general, parental socioeconomic status appear to have a greater influence on the mental health of people who grew up after the Chinese economic reform of the 1970s.

How and where does "care" fit within seminal life-course approaches? A narrative review and critical analysis

AIMS

To map the concepts of the caring life-course theory that are used in life-course approaches from different disciplines; establish whether there is a common recognition of, or language used, to describe care in those life-course approaches; and identify the role and contribution of care to the life-course literature.

DESIGN

This discursive paper uses a narrative review process to explore points of convergence and divergence between life-course approaches and the caring life-course theory.

METHODS

Categories for analysis were developed deductively and inductively, focusing on the constructs of fundamental care, capacity and capability, care network, care transition, care trajectory and care biography.

RESULTS

We identified four disciplinary perspectives: (1) life-course sociology; (2) life-course epidemiology; (3) lifespan developmental psychology; and (4) life-course health development. While six core constructs of the caring life-course theory were described, either explicitly or implicitly, in existing life-course approaches, no single approach fully describes the role and contribution of care across the lifespan.

CONCLUSION

Life-course approaches have largely neglected the contribution and role of care in informing the life-course discourse. This review highlights the significance of care beyond traditional healthcare settings and recognizes it as a fundamental human need for well-being and development, which can contribute to existing life-course literature.

IMPLICATION FOR THE PROFESSION AND/OR PATIENT CARE

There is a need to understand care as a complex system and embrace a whole-system, life-course approach to enable nurses and other healthcare professionals to provide high-quality, patient-centred care.

IMPACT

Incorporating care within a life-course approach provides opportunities to integrate and deliver care centred around the person, their life transitions, trajectories and care networks, including informal carers and healthcare professionals.

NO PATIENT OR PUBLIC CONTRIBUTION

Patients or members of the public were not involved in this study as it is a discursive paper based on the relevant literature.

A longitudinal analysis of health inequalities from adolescence to young adulthood and their underlying causes

Research suggests that children of low-educated parents face greater health burdens during the passage from adolescence to young adulthood, as they are more likely to become low-educated themselves, establish behavioural and psychosocial disadvantages, or being exposed to unhealthy working conditions. However, studies examining the development and drivers of health inequalities during this particular life stage are limited in number and have produced varied results. This study investigates trajectories of self-rated health and overweight from 14 to 25 years of age, stratified by parental education, and explores the role of potential mediators (educational achievement, health behaviours, psychosocial factors, working conditions). We rely on prospective cohort data from the National Educational Panel Study (NEPS), a representative sample of 14,981 German ninth graders interviewed yearly from 2011 to 2021 (n = 90,096 person-years). First, we estimated random-effects growth curves for self-rated health and overweight over participants' age and calculated the average marginal effect of high versus low parental education. Second, a series of simulation-based mediation analyses were performed to test how much of health inequalities were explained by children's educational attainment (years of school education, years in university), health behaviours (smoking, alcohol, physical inactivity), psychosocial factors (number of grade repetitions, years in unemployment, chronic stress, self-esteem) and working conditions (physical and psychosocial job demands). We accounted for potential confounding by controlling for age, sex, migration background, residential area, household composition, and interview mode. Results show that higher parental education was related to higher self-rated health and lower probabilities of being overweight. Interaction between parental education and age indicated that, after some equalisation in late adolescence, health inequalities increased in young adulthood. Furthermore, educational attainment, health behaviours, psychosocial factors, and early-career working conditions played a significant role in mediating health inequalities. Of the variables examined, the level of school education and years spent in university were particular strong mediating factors. School education accounted for around one-third of the inequalities in self-rated health and one-fifth of the differences in overweight among individuals. Results support the idea that the transition to adulthood is a sensitive period in life and that early socio-economic adversity increases the likelihood to accumulate health disadvantages in multiple dimensions. In Germany, a country with comparatively low educational mobility, intergenerational continuities in class location seem to play a key role in the explanation of health inequalities in youth.

The epidemiology of Parkinson's disease

The epidemiology of Parkinson's disease shows marked variations in time, geography, ethnicity, age, and sex. Internationally, prevalence has increased over and above demographic changes. There are several potential reasons for this increase, including the decline in other competing causes of death. Whether incidence is increasing, especially in women or in many low-income and middle-income countries where there is a shortage of high-quality data, is less certain. Parkinson's disease is more common in older people and men, and a variety of environmental factors have been suggested to explain why, including exposure to neurotoxic agents. Within countries, there appear to be ethnic differences in disease risk, although these differences might reflect differential access to health care. The cause of Parkinson's disease is multifactorial, and involves genetic and environmental factors. Both risk factors (eg, pesticides) and protective factors (eg, physical activity and tendency to smoke) have been postulated to have a role in Parkinson's disease, although elucidating causality is complicated by the long prodromal period. Following the establishment of public health strategies to prevent cardiovascular diseases and some cancers, chronic neurodegenerative diseases such as Parkinson's disease and dementia are gaining a deserved higher priority. Multipronged prevention strategies are required that tackle population-based primary prevention, high-risk targeted secondary prevention, and Parkinson's disease-modifying therapies for tertiary prevention. Future international collaborations will be required to triangulate evidence from basic, applied, and epidemiological research, thereby enhancing the understanding and prevention of Parkinson's disease at a global level.

Spillover effects of gestational age on sibling's literacy

Adverse health events within families can harm children's development, including their early literacy. Using data from a longitudinal Wisconsin birth cohort, we estimated the spillover effect of younger siblings' gestational ages on older siblings' kindergarten-level literacy. We sampled 20,014 sibling pairs born during 2007-2010 who took Phonological Awareness Literacy Screening-Kindergarten tests during 2012-2016. Exposures were gestational age (completed weeks), preterm birth (gestational age <37 weeks), and very preterm birth (gestational age <32 weeks). We used gain-score regression-a fixed effects strategy-to estimate spillover effect. A one-week increase in younger siblings' gestational age improved the older siblings' test score by 0.011 SD (95% confidence interval: 0.001, 0.021 SD). The estimated spillover effect was larger among siblings whose mothers reported having a high school diploma/equivalent only (0.024 SD; 95% CI: 0.004, 0.044 SD). The finding underscores the networked effects of one individual's early-life health shocks on their family members.

RAD140 (Testolone) negatively impacts skeletal muscle adaptation, frailty status and mortality risk in female mice

RAD140 is a selective androgen receptor modulator that produces anabolic effects within skeletal muscle. Thus, RAD140 may be effective at treating sarcopenia. No long-term studies have investigated how RAD140 influences strength in ageing muscle. This study aimed to determine how 10 weeks of RAD140 supplementation impacts strength, recovery from exercise, and overall health in ageing mice. Young and adult females were assigned to receive RAD140 (5 mg/kg) or a control solution. Dorsiflexor muscles were exposed to repeated bouts of eccentric contractions, and torque was measured before and after each bout. Adaptive potential and strength gains were calculated to assess the efficacy of RAD140 in muscle, while frailty status and mortality risk were used to measure health span. Supplementation of RAD140 increased frailty status and mortality risk in the young and adult treated groups compared to the controls (p ≤ 0.042). RAD140 decreased adaptive potential in young (p = 0.040) but not adult mice (p = 0.688). Torque did not differ between groups after 2-3 weeks of recovery (p ≥ 0.135). In conclusion, long-term RAD140 supplementation reduced indices of overall health and failed to improve strength in female mice, suggesting that RAD140 (at a 5mg/kg dosage) may be more detrimental than beneficial in delaying or preventing sarcopenia.

Accelerated biological aging six decades after prenatal famine exposure

To test the hypothesis that early-life adversity accelerates the pace of biological aging, we analyzed data from the Dutch Hunger Winter Families Study (DHWFS, N=951). DHWFS is a natural-experiment birth-cohort study of survivors of in-utero exposure to famine conditions caused by the German occupation of the Western Netherlands in Winter 1944-5, matched controls, and their siblings. We conducted DNA methylation analysis of blood samples collected when the survivors were aged 58 to quantify biological aging using the DunedinPACE, GrimAge, and PhenoAge epigenetic clocks. Famine survivors had faster DunedinPACE, as compared with controls. This effect was strongest among women. Results were similar for GrimAge, although effect-sizes were smaller. We observed no differences in PhenoAge between survivors and controls. Famine effects were not accounted for by blood-cell composition and were similar for individuals exposed early and later in gestation. Findings suggest in-utero undernutrition may accelerate biological aging in later life.

Education, Social Engagement, and Cognitive Function: A Cross-Lagged Panel Analysis

OBJECTIVES

Although education and social engagement are considered cognitive reserves, the pathway of both reserves on cognitive function has been rarely studied. This study aimed to examine the underlying mechanism between education, social engagement, and cognitive function.

METHODS

This study used 2-wave data (2010 and 2014) from Health and Retirement Study in the United States (N = 3,201). Education was measured by years of schooling. Social engagement was evaluated by 20 items including volunteering, physical activities, social activities, and cognitive activities. Cognitive function was assessed by a modified Telephone Interview for Cognitive Status. A cross-lagged panel model was fitted to test the mediating mechanism between education, social engagement, and cognitive function.

RESULTS

Controlling for covariates, higher education in early life was associated with better cognitive function in old age (b = 0.211, 95% confidence interval [CI] = [0.163, 0.259], p < .01). Late-life social engagement partially mediated the association between education and cognitive function (indirect effect = 0.021, 95% CI = [0.010, 0.033], p < .01). The indirect path between education and social engagement via cognition also existed (b = 0.009, 95% CI = [0.005, 0.012], p < .001).

DISCUSSION

Education in earlier life stage may exert a lifelong effect on cognitive function as well as an indirect effect via enhancing late-life cognitive reserve such as social engagement. The cross-lagged effect of social engagement on cognitive function is significant and vice versa. Future research may explore other cognitive reserves over the life course and its underlying mechanism to achieve healthy cognitive aging.

An integrative approach for the analysis of risk and health across the life course: challenges, innovations, and opportunities for life course research

Life course epidemiology seeks to understand the intricate relationships between risk factors and health outcomes across different stages of life to inform prevention and intervention strategies to optimize health throughout the lifespan. However, extant evidence has predominantly been based on separate analyses of data from individual birth cohorts or panel studies, which may not be sufficient to unravel the complex interplay of risk and health across different contexts. We highlight the importance of a multi-study perspective that enables researchers to: (a) Compare and contrast findings from different contexts and populations, which can help identify generalizable patterns and context-specific factors; (b) Examine the robustness of associations and the potential for effect modification by factors such as age, sex, and socioeconomic status; and (c) Improve statistical power and precision by pooling data from multiple studies, thereby allowing for the investigation of rare exposures and outcomes. This integrative framework combines the advantages of multi-study data with a life course perspective to guide research in understanding life course risk and resilience on adult health outcomes by: (a) Encouraging the use of harmonized measures across studies to facilitate comparisons and synthesis of findings; (b) Promoting the adoption of advanced analytical techniques that can accommodate the complexities of multi-study, longitudinal data; and (c) Fostering collaboration between researchers, data repositories, and funding agencies to support the integration of longitudinal data from diverse sources. An integrative approach can help inform the development of individualized risk scores and personalized interventions to promote health and well-being at various life stages.

Complexity in Epidemiology and Public Health. Addressing Complex Health Problems Through a Mix of Epidemiologic Methods and Data

Public health and the underlying disease processes are complex, often involving the interaction of biologic, social, psychologic, economic, and other processes that may be nonlinear and adaptive and have other features of complex systems. There is therefore a need to push the boundaries of public health beyond single-factor data analysis and expand the capacity of research methodology to tackle real-world complexities. This article sets out a way to operationalize complex systems thinking in public health, with a particular focus on how epidemiologic methods and data can contribute towards this end. Our proposed framework comprises three core dimensions-patterns, mechanisms, and dynamics-along which complex systems may be conceptualized. These dimensions cover seven key features of complex systems-emergence, interactions, nonlinearity, interference, feedback loops, adaptation, and evolution. We relate this framework to examples of methods and data traditionally used in epidemiology. We conclude that systematic production of knowledge on complex health issues may benefit from: formulation of research questions and programs in terms of the core dimensions we identify, as a comprehensive way to capture crucial features of complex systems; integration of traditional epidemiologic methods with systems methodology such as computational simulation modeling; interdisciplinary work; and continued investment in a wide range of data types. We believe that the proposed framework can support the systematic production of knowledge on complex health problems, with the use of epidemiology and other disciplines. This will help us understand emergent health phenomena, identify vulnerable population groups, and detect leverage points for promoting public health.

Research hotspots and new trends in the impact of resistance training on aging, bibliometric and visual analysis based on CiteSpace and VOSviewer

Purpose

Resistance training (RT) can intervene in aging, which can effectively improve trainees' life. However, unhealthy living habits such as irregular life, obesity and hyperlipidemia, and chronic diseases lead to a significant decline in the energy level of the population, seriously affecting the health of the population. Our research identifies the research hotspots of RT to intervene in aging from the perspective of bibliometrics, predicts research frontiers and development trends, and provides more perspectives for research on aging populations.

Methods

In this study, we used CiteSpace and VOSviewer visualization software to draw the scientific knowledge map of countries/regions, institutions, authors, co-occurrence keywords, and co-cited references of published articles, and explore the Web of Science core collection database all about the RT intervention aging research status, hotspots, frontiers, and development trends of articles on aging.

Results

Among the 760 articles that meet the inclusion criteria, the number of articles published and the frequency of citations have increased steadily in the past 5 years. Judging from the countries/regions, institutions, scholars, and journals that published articles, the ones with the largest numbers are the USA, Univ Estadual Londrina, Cyrino ES, and Exp Gerontol. The ones with the highest influence are England, Univ Arkansas Med Sci, Frontera WR, and Biochem Biophys Rep Co. The top five co-occurrence keywords of include exercise, strength, resistance training, skeletal muscle, and muscle strength. The research frontier is physical function.

Conclusion

In the field of RT intervention aging research, relevant scholars deserve further in-depth research and exploration. The United States, Brazil, Canada, and other economically developed countries/regions, institutions, and authors have greater influence and productivity. These quantitative research results can provide references for relevant scholars' follow-up research and government departments to formulate and modify health policies or measures.

Life Course Predictors of Young Men Surviving to Age 90 in a Cohort Study: The Manitoba Follow-up Study

The purpose of this study was to identify factors at various time points in life that are associated with surviving to age 90. Data from men enrolled in a cohort study since 1948 were considered in 12-year intervals. Logistic regression models were constructed with the outcome of surviving to age 90. Factors were: childhood illness, blood pressure (BP), body mass index (BMI), chronic diseases, and electrocardiogram (ECG) findings. After 1996, the Short Form-36 was added. A total of 3,976 men were born in 1928 or earlier, and hence by the end of our study window in 2018, each had the opportunity of surviving to age 90. Of these, 721 did live to beyond his 90th birthday.The factors in 1948 which predicted surviving were: lower diastolic BP, lower BMI, and not smoking. In 1960, these factors were: lower BP, lower BMI, not smoking, and no major ECG changes. In 1972, these factors were lower BP, not smoking, and fewer disease states. In 1984, these factors were lower systolic BP, not smoking, ECG changes, and fewer disease states. In 1996, the factors were fewer disease states and higher physical and mental health functioning. In 2008, only higher physical functioning predicted survival to the age of 90. In young adulthood, risk factors are important predictors of surviving to age 90; in mid-life, chronic illnesses emerge, and in later life, functional status becomes predominant.

Promoting Temporal Investigations of Development in Context: a Systematic Review of Longitudinal Research Linking Childhood Circumstances and Learning-related Outcomes

Children’s learning and cognitive development have a distinct receptivity to the circumstances of childhood. However, not all children have equal opportunities and learning inequities continue to be influenced by the social and economic circumstances of childhood. Examining factors within the environments that children are growing up in, and the associations of these factors with learning, can help to identify leverage points for change, enabling more children to be supported to reach their potential. Specifically, turning attention to the timing and duration of exposure to specific social and economic factors across childhood can provide essential details to determine who is most susceptible to contextual effects and at what ages. This paper presents a systematic review of 75 longitudinal studies of families and children carried out between 2000 and 2021. These studies tracked social and economic circumstances between pregnancy and early adolescence in relation to educational and cognitive outcomes across the lifespan. The results of the included studies were examined and grouped into themes using reflexive thematic analysis. The findings largely suggest that the degree to which educational and cognitive outcomes are affected by specific social and economic circumstances depends on the duration, timing, and mobility across childhood. In particular, findings relating to the developmental timing of exposure, as well as persistent exposure, revealed distinct evidence of the effects of temporality. These findings provide detail into how much and in what instances temporality should be considered—results which can be used to inform avenues for reducing learning disparities.

Gestational age and trajectories of body mass index and height from birth through adolescence in the Danish National Birth Cohort

Preterm birth is associated with smaller body dimensions at birth. The impact on body size in later life, measured by body mass index (BMI) and height, remains unclear. A prospective register-based cohort study with 62,625 singletons from the Danish National Birth Cohort born 1996-2003 for whom information on gestational age (GA) at birth, length or weight at birth, and at least two growth measurements scheduled at the ages of 5 and 12 months, and 7, 11 and 18 years were available. Linear mixed effects with splines, stratified by sex, and adjusted for confounders were used to estimate standardised BMI and height. GA was positively associated with BMI in infancy, but differences between preterm and term children declined with age. By age 7, preterm children had slightly lower BMI than term children, whereas no difference was observed by adolescence (mean difference in BMI z-score - 0.28 to 0.15). GA was strongly associated with height in infancy, but mean differences between individuals born preterm and term declined during childhood. By adolescence, the most preterm individuals remained shorter than their term peers (mean difference in height z-score from - 1.00 to - 0.28). The lower BMI in preterm infants relative to term infants equalizes during childhood, such that by adolescence there is no clear difference. Height is strongly positively associated with GA in early childhood, whilst by end of adolescence individuals born preterm remain slightly shorter than term peers.

Life course research in physical activity: Pathway to Global Action Plan 2030

Current global trends in physical activity levels demonstrate that the world is not on track to achieve the 2030 target set by the Global Action Plan. The Action Plan posited that physical activity should be an integral component of "daily lives" of all individuals "across the life course." Potential contributions to achieve global physical activity goals include the utilization of compositional data analysis and life course epidemiology to provide a framework for the composite nature of physical activity and complex life course relationships. Combining these two traditionally disconnected fields represents a paradigm shift in physical activity research. Here, we discuss how these combined fields enable a reinterpretation of previous research findings and explore their impact on policy and potential advantages and challenges. Careful consideration needs to be given to the implications of both fields remaining disconnected and the alternate option of consolidation to realize ambitions.

Grip strength is inversely associated with DNA methylation age acceleration

BACKGROUND

There is a large body of evidence linking muscular weakness, as determined by low grip strength, to a host of negative ageing-related health outcomes. Given these links, grip strength has been labelled a 'biomarker of aging'; and yet, the pathways connecting grip strength to negative health consequences are unclear. The objective of this study was to determine whether grip strength was associated with measures of DNA methylation (DNAm) age acceleration.

METHODS

Middle age and older adults from the 2006 to 2008 waves of the Health and Retirement Study with 8-10 years of follow-up were included. Cross-sectional and longitudinal regression modelling was performed to examine the association between normalized grip strength (NGS) and three measures of DNAm age acceleration, adjusting for cell composition, sociodemographic variables and smoking. Longitudinal modelling was also completed to examine the association between change in absolute grip strength and DNAm age acceleration. The three DNAm clocks used for estimating age acceleration include the established DunedinPoAm, PhenoAge and GrimAge clocks.

RESULTS

There was a robust and independent cross-sectional association between NGS and DNAm age acceleration for men using the DunedinPoAm (β: -0.36; P < 0.001), PhenoAge (β: -8.27; P = 0.01) and GrimAge (β: -4.56; P = 0.01) clocks and for women using the DunedinPoAm (β: -0.36; P < 0.001) and GrimAge (β: -4.46; P = 0.01) clocks. There was also an independent longitudinal association between baseline NGS and DNAm age acceleration for men (β: -0.26; P < 0.001) and women (β: -0.36; P < 0.001) using the DunedinPoAm clock and for women only using the PhenoAge (β: -8.20; P < 0.001) and GrimAge (β: -5.91; P < 0.001) clocks. Longitudinal modelling revealed a robust association between change in grip strength from wave 1 to wave 3 was independently associated with PhenoAgeAA (β: -0.13; 95% CI: -0.23, -0.03) and GrimAgeAA (β: -0.07; 95% CI: -0.14, -0.01) in men only (both P < 0.05).

CONCLUSIONS

Our findings provide some initial evidence of age acceleration among men and women with lower NGS and loss of strength over time. Future research is needed to understand the extent to which DNAm age mediates the association between grip strength and chronic disease, disability and mortality.

Immigration Experience and Cognitive Function Trajectories Among Older Chinese Immigrants

OBJECTIVES

Although a number of studies have documented cognitive health among older immigrants in the United States, little is known about how the life-course immigration experiences are associated with cognitive trajectories among older Chinese immigrants. We assess patterns of cognitive functioning and change over time and examine whether age at migration, reasons for migration, acculturation, perceived discrimination, and preferred dialects are related to cognitive trajectories.

METHODS

The sample comprised 2,075 participants from the Population Study of Chinese Elderly (PINE), who completed a battery of cognitive tests at four time points (2011-2019). Latent class growth analysis and multinomial logistic regression were utilized.

RESULTS

Three latent classes of cognitive trajectories were identified: the low functioning with the fastest decline (LCF, 12%), the moderate functioning with a medium decline rate (MCF, 39%), and the high functioning with the slowest decline (HCF, 48%). Perceiving more discrimination reduced, whereas speaking Taishanese increased the odds of being in the LCF and MCF. High acculturation only distinguished MCF from HCF after controlling for the known factors of cognitive health such as age, education, and social engagement.

DISCUSSION

This study identifies a group of older Chinese immigrants who are especially vulnerable to cognitive impairment and indicates that the risk of cognitive decline appears to be elevated with lower levels of acculturation and unidentified racial discrimination. More research is needed to fully understand the underlying mechanisms that link the life-course immigration experiences to cognitive health outcomes in later life.

Toward a conceptual framework of health and its operational definition: an application in the 1958 British birth cohort

BACKGROUND

Defining and measuring Health presents a challenge, partly due to its conceptual pluralism. To measure Health as an ability to adapt and self-manage, we developed an approach within the theoretical framework of resources and reserves over the life course, recently proposed in the literature. We aimed to (i) use the conceptual framework developed to identify indicators of deteriorating health reserves, (ii) construct an overall health measure from these indicators, (iii) evaluate the association between the overall health measure and subsequent health outcomes and (iv) assess the robustness of our method.

METHODS

We used data from 7,043 individuals born in 1958 in Great Britain included in the National Child Development Study. An overall health measure was constructed via the sum of three selected indicators of deteriorating health reserves in mid-life: chronic widespread pain (CWP), Clinical Interview Schedule - revised (CIS-r), and allostatic load (AL). A three-category variable was defined: impaired/medium/optimal overall health. We explored criterion validity by modelling the relationships between the overall health measure, or each reserve taken separately at 44-45 years, and self-rated health at 46 years and mortality up to 58 years, corresponding to 14 years of follow up, using Cox and logistic regressions respectively. We performed comparative analyses to assess the robustness of the method.

RESULTS

Having an impaired overall health measure was significantly associated with all-cause premature mortality (HR_impaired = 2.74 [1.86; 4.05]) and an increased risk of later fair/poor/very poor self-rated health (OR_impaired = 7.50 [6.29; 8.95]). The overall health measure had a greater effect on the self-rated health estimates than each indicator of deteriorating health reserves considered separately (OR_{AL medium} = 1.82 [1.59; 2.09]; OR_{AL high} = 2.74 [2.37; 3.16]; OR_CIS-r = 5.20 [4.45; 6.08]; OR_CWP = 2.85 [2.53; 3.21]). CIS-r and allostatic load were also associated with premature mortality contrary to chronic widespread pain (HR_{AL medium}1.82 [1.27; 2.61]; HR_{AL high} = 3.10 [2.19; 4.40]; HR_CIS-r = 1.77 [1.22; 2.56]; HR_CWP = 1.32 [0.98; 1.76]). The multiple comparative analyses conducted allowed us to assess the robustness of our method within this cohort.

CONCLUSIONS

We proposed a method for measuring Health in mid-life in line with the concept of Health as the ability to adapt and self-manage and the concept of health reserves. This method may be applied and further developed within the field of social and positive epidemiology.

Interactive effects of intrinsic capacity and obesity on the KDIGO chronic kidney disease risk classification in older patients with type 2 diabetes mellitus

BACKGROUND

Intrinsic capacity (IC) is a novel concept focusing on normal and healthy aging. The effect of IC on the risk of chronic kidney disease (CKD) according to KDIGO category in older type 2 diabetes mellitus (T2DM) patients has rarely been studied. We investigated whether a decline in IC is associated with the risk of CKD according to KDIGO 2012 categories.

METHODS

This is a cross-sectional study. The exposure variables (IC score and body mass index) and outcome variable (KDIGO categories of the risk of CKD) were collected at the same timepoint. A total of 2482 older subjects with T2DM managed through a disease care program were enrolled. The five domains of IC, namely locomotion, cognition, vitality, sensory, and psychological capacity were assessed. Based on these domains, the IC composite score was calculated. CKD risk was classified according to the KDIGO 2012 CKD definition. Univariate and multivariate analyses were used to assess the association between IC score and KDIGO categories of risk of CKD.

RESULTS

The KDIGO CKD risk category increased in parallel with IC score (p for trend < 0.0001). In multivariate analysis, compared to those with an IC score 0, the odds ratio of having a KDIGO moderately increased to very high risk category of CKD was 1.76 (1.31-2.37) times higher for those with an IC score of 2-5. Furthermore, an increased IC score was associated with a higher prevalence of moderate and severe obesity. Moreover, there was a synergistic interaction between IC score and obesity on the KDIGO moderately increased to very high risk category of CKD (synergy index = 1.683; 95% CI 0.630-3.628), and the proportion of the KDIGO moderately increased to very high risk category of CKD caused by this interaction was 25.6% (attributable proportion of interaction = 0.256).

CONCLUSIONS

Our findings indicate that IC score may be closely related to the KDIGO moderately increased to very high risk category of CKD. In addition, there may be a synergistic interaction between IC score and obesity, and this synergistic interaction may increase the KDIGO CKD risk stage.

Vulnerability to chronic stress and the phenotypic heterogeneity of presbycusis with subjective tinnitus

Age-related functional reserve decline and vulnerability of multiple physiological systems and organs, as well as at the cellular and molecular levels, result in different frailty phenotypes, such as physical, cognitive, and psychosocial frailty, and multiple comorbidities, including age-related hearing loss (ARHL) and/or tinnitus due to the decline in auditory reserve. However, the contributions of chronic non-audiogenic cumulative exposure, and chronic audiogenic stress to phenotypic heterogeneity of presbycusis and/or tinnitus remain elusive. Because of the cumulative environmental stressors throughout life, allostasis systems, the hypothalamus-pituitary-adrenal (HPA) and the sympathetic adrenal-medullary (SAM) axes become dysregulated and less able to maintain homeostasis, which leads to allostatic load and maladaptation. Brain-body communication via the neuroendocrine system promotes systemic chronic inflammation, overmobilization of energetic substances (glucose and lipids), and neuroplastic changes via the non-genomic and genomic actions of glucocorticoids, catecholamines, and their receptors. These systemic maladaptive alterations might lead to different frailty phenotypes and physical, cognitive, and psychological comorbidities, which, in turn, cause and exacerbate ARHL and/or tinnitus with phenotypic heterogeneity. Chronic audiogenic stressors, including aging accompanying ontological diseases, cumulative noise exposure, and ototoxic drugs as well as tinnitus, activate the HPA axis and SAM directly and indirectly by the amygdala, promoting allostatic load and maladaptive neuroplasticity in the auditory system and other vulnerable brain regions, such as the hippocampus, amygdala, and medial prefrontal cortex (mPFC). In the auditory system, peripheral deafferentation, central disinhibition, and tonotopic map reorganization may trigger tinnitus. Cross-modal maladaptive neuroplasticity between the auditory and other sensory systems is involved in tinnitus modulation. Persistent dendritic growth and formation, reduction in GABAergic inhibitory synaptic inputs induced by chronic audiogenic stresses in the amygdala, and increased dendritic atrophy in the hippocampus and mPFC, might involve the enhancement of attentional processing and long-term memory storage of chronic subjective tinnitus, accompanied by cognitive impairments and emotional comorbidities. Therefore, presbycusis and tinnitus are multisystem disorders with phenotypic heterogeneity. Stressors play a critical role in the phenotypic heterogeneity of presbycusis. Differential diagnosis based on biomarkers of metabonomics study, and interventions tailored to different ARHL phenotypes and/or tinnitus will contribute to healthy aging and improvement in the quality of life.

When the Pandemic Will Be Over: Lots of Hope and Some Concerns

The COVID-19 pandemic significantly threatened healthcare systems worldwide. The worst-hit population has been represented by older people with underlying chronic comorbidities, while children and adolescents developed mild or asymptomatic forms of the disease. However, certain medical conditions (i.e., obesity, respiratory, or neurological or immune disorders) may increase the risk for poor health outcomes even in young and middle-aged people. Beyond the direct negative effects of the infection, the pandemic posed several health challenges through an increase in psycho-social issues (i.e., anxiety, depression, fatigue, sleep alterations, loneliness, reduced assistance, and loss of income). Accordingly, the pandemic is negatively impacting the accumulation of the functional reserves of each individual, starting from early life. With the long-term effects of the pandemic to be seen in the coming years, clinicians must be prepared to manage such high clinical complexity of people they encounter, through the implementation of multidimensional and multidisciplinary interventions.

A longitudinal evaluation of alcohol intake throughout adulthood and colorectal cancer risk

BACKGROUND

Alcohol intake is an established risk factor for colorectal cancer (CRC); however, there is limited knowledge on whether changing alcohol drinking habits during adulthood modifies CRC risk.

OBJECTIVE

Leveraging longitudinal exposure assessments on alcohol intake at different ages, we examined the relationship between change in alcohol intake and subsequent CRC risk.

METHODS

Within the European Prospective Investigation into Cancer and Nutrition, changes in alcohol intake comparing follow-up with baseline assessments were investigated in relation to CRC risk. The analysis included 191,180, participants and 1530 incident CRC cases, with exclusion of the first three years of follow-up to minimize reverse causation. Trajectory profiles of alcohol intake, assessed at ages 20, 30, 40, 50 years, at baseline and during follow-up, were estimated using latent class mixed models and related to CRC risk, including 407,605 participants and 5,008 incident CRC cases.

RESULTS

Mean age at baseline was 50.2 years and the follow-up assessment occurred on average 7.1 years later. Compared to stable intake, a 12 g/day increase in alcohol intake during follow-up was positively associated with CRC risk (HR = 1.15, 95%CI 1.04, 1.25), while a 12 g/day reduction was inversely associated with CRC risk (HR = 0.86, 95%CI 0.78, 0.95). Trajectory analysis showed that compared to low alcohol intake, men who increased their alcohol intake from early- to mid- and late-adulthood by up to 30 g/day on average had significantly increased CRC risk (HR = 1.24; 95%CI 1.08, 1.42), while no associations were observed in women. Results were consistent by anatomical subsite.

CONCLUSIONS

Increasing alcohol intake during mid-to-late adulthood raised CRC risk, while reduction lowered risk.

Developmental Origins of Health and Disease, resilience and social justice in the COVID era

The COVID-19 pandemic has shone a spotlight on how health outcomes are unequally distributed among different population groups, with disadvantaged communities and individuals being disproportionality affected in terms of infection, morbidity and mortality, as well as vaccine access. Recently, there has been considerable debate about how social disadvantage and inequality intersect with developmental processes to result in a heightened susceptibility to environmental stressors, economic shocks and large-scale health emergencies. We argue that DOHaD Society members can make important contributions to addressing issues of inequality and improving community resilience in response to COVID-19. In order to do so, it is beneficial to engage with and adopt a social justice framework. We detail how DOHaD can align its research and policy recommendations with a social justice perspective to ensure that we contribute to improving the health of present and future generations in an equitable and socially just way.

Health as temporally extended: theoretical foundations and implications

This paper seeks to develop a theory of health that aligns with the shift in contemporary medical practice and research toward a temporally extended epidemiological view of health. The paper describes how such a theory is at the core of life course based approaches to health, and finds theoretical grounding in recent work in the philosophy of biology promulgating a process theory of life.

Estimation of causal effects of a time-varying exposure at multiple time points through multivariable mendelian randomization

Mendelian Randomisation (MR) is a powerful tool in epidemiology that can be used to estimate the causal effect of an exposure on an outcome in the presence of unobserved confounding, by utilising genetic variants as instrumental variables (IVs) for the exposure. The effect estimates obtained from MR studies are often interpreted as the lifetime effect of the exposure in question. However, the causal effects of some exposures are thought to vary throughout an individual's lifetime with periods during which an exposure has a greater effect on a particular outcome. Multivariable MR (MVMR) is an extension of MR that allows for multiple, potentially highly related, exposures to be included in an MR estimation. MVMR estimates the direct effect of each exposure on the outcome conditional on all the other exposures included in the estimation. We explore the use of MVMR to estimate the direct effect of a single exposure at different time points in an individual's lifetime on an outcome. We use simulations to illustrate the interpretation of the results from such analyses and the key assumptions required. We show that causal effects at different time periods can be estimated through MVMR when the association between the genetic variants used as instruments and the exposure measured at those time periods varies. However, this estimation will not necessarily identify exact time periods over which an exposure has the most effect on the outcome. Prior knowledge regarding the biological basis of exposure trajectories can help interpretation. We illustrate the method through estimation of the causal effects of childhood and adult BMI on C-Reactive protein and smoking behaviour.

Applications of conceptual models from lifecourse epidemiology in ecology and evolutionary biology

In ecology and evolutionary biology (EEB), the study of developmental plasticity seeks to understand ontogenetic processes underlying the phenotypes upon which natural selection acts. A central challenge to this inquiry is ascertaining a causal effect of the exposure on the manifestation of later-life phenotype due to the time elapsed between the two events. The exposure is a potential cause of the outcome-i.e. an environmental stimulus or experience. The later phenotype might be a behaviour, physiological condition, morphology or life-history trait. The latency period between the exposure and outcome complicates causal inference due to the inevitable occurrence of additional events that may affect the relationship of interest. Here, we describe six distinct but non-mutually exclusive conceptual models from the field of lifecourse epidemiology and discuss their applications to EEB research. The models include Critical Period with No Later Modifiers, Critical Period with Later Modifiers, Accumulation of Risk with Independent Risk Exposures, Accumulation of Risk with Risk Clustering, Accumulation of Risk with Chains of Risk and Accumulation of Risk with Trigger Effect. These models, which have been widely used to test causal hypotheses regarding the early origins of adult-onset disease in humans, are directly relevant to research on developmental plasticity in EEB.

Spelling out some unaddressed conceptual and methodological challenges in empirical lifespan research

The importance of taking a lifespan approach to describe and understand human development has long been acknowledged (e.g., Baltes, 1987). Nevertheless, theoretical or empirical research that actually encompasses the entire lifespan, that is, from early childhood to old age, is rare. This is not surprising given the challenges such an approach entails. Many of these challenges (e.g., establishing measurement invariance between age groups) have been addressed in the previous literature, but others have not yet been sufficiently considered. The main purpose of this article is to present several examples of such largely unaddressed conceptual and methodological challenges and reflect upon possible ways to address them. We discuss the usefulness of a lifespan approach and the generalization of the challenges to other research comparing different groups, such as gender, culture, or species.

Ischemic Preconditioning Improves Handgrip Strength and Functional Capacity in Active Elderly Women

Background: Aging decreases some capacities in older adults, sarcopenia being one of the common processes that occur and that interfered with strength capacity. The present study aimed to verify the acute effect of IPC on isometric handgrip strength and functional capacity in active elderly women. Methods: In a single-blind, placebo-controlled design, 16 active elderly women (68.1 ± 7.6 years) were randomly performed on three separate occasions a series of tests: (1) alone (control, CON); (2) after IPC (3 cycles of 5-min compression/5-min reperfusion at 15 mmHg above systolic blood pressure, IPC); and (3) after placebo compressions (SHAM). Testing included a handgrip isometric strength test (HIST) and three functional tests (FT): 30 s sit and stand up from a chair (30STS), get up and go time (TUG), and 6 min walk distance test (6MWT). Results: HIST significantly increased in IPC (29.3 ± 6.9 kgf) compared to CON (27.3 ± 7.1 kgf; 7.1% difference; p = 0.01), but not in SHAM (27.7 ± 7.9; 5.5%; p = 0.16). The 30STS increased in IPC (20.1 ± 4.1 repetitions) compared to SHAM (18.5 ± 3.5 repetitions; 8.7%; p = 0.01) and CON (18.5 ± 3.9 repetitions; 8.6%; p = 0.01). TUG was significantly lower in IPC (5.70 ± 1.35 s) compared to SHAM (6.14 ± 1.37 s; −7.2%; p = 0.01), but not CON (5.91 ± 1.45 s; −3.7%; p = 0.24). The 6MWT significantly increased in IPC (611.5 ± 93.8 m) compared to CON (546.1 ± 80.5 m; 12%; p = 0.02), but not in SHAM (598.7 ± 67.6 m; 2.1%; p = 0.85). Conclusions: These data suggest that IPC can promote acute improvements in handgrip strength and functional capacity in active elderly women.

Childhood police encounters, social isolation and epigenetic age acceleration among older U.S. adults

OBJECTIVES

This study examined associations of childhood police encounters with biological age acceleration in later life, and their mediation by subjective or objective social isolation.

METHODS

Data were from the Health and Retirement Study, nationally representative of older U.S. adults. Age acceleration was proxied through newly available epigenetic measures. Doubly robust estimation was used to establish baseline linkages, and heterogenous treatment effect models to examine variations in effects by one's increasing propensity for early police encounters. Mediation analysis was through a recently developed regression-with-residuals approach for structural nested mean models.

RESULTS

Childhood police encounters was prospectively associated with age acceleration. Those with such early experiences also reported more loneliness and isolation from their community, although their ties to family and friends seemed stronger. Associations did not significantly decline with increasing propensity for such childhood experiences. Treatment effects on age acceleration seemed partly mediated by loneliness and by community isolation.

DISCUSSION

Findings add to the growing evidence on the "long arm of childhood," and highlight public health implications of policy-driven social exposures.

Long-term mortality of academy award winning actors and actresses

Background

Social status gradients are powerful health determinants for individuals living in poverty. We tested whether winning an Academy award (Oscar) for acting was associated with long-term survival.

Methods

We conducted a longitudinal cohort analysis of all actors and actresses nominated for an Academy award in a leading or a supporting role. For each, a control was identified based on age, sex, and co-staring in the same film.

Results

Overall, 2,111 individuals were analyzed with 1,122 total deaths occurring during a median follow-up of 68.8 years. Comparisons of winners to controls yielded a 4.8% relative difference average life-span (95% confidence interval: 1.6 to 7.9, p = 0.004), a 5.1 year absolute increase in life expectancy (95% confidence interval: 3.0 to 7.2, p < 0.001), and a 41% improvement in mortality hazard (95% confidence interval: 19 to 68, p < 0.001). The increased survival tended to be greater in recent years, for individuals winning at a younger age, and among those with multiple wins. The increased survival replicated in secondary analyses comparing winners to nominees and was not observed in analyses comparing nominees to controls.

Conclusions

Academy award winning actors and actresses show a positive association between success and survival, suggesting the importance of behavioral, psychological, or other modifiable health factors unrelated to poverty.

Using linear and natural cubic splines, SITAR, and latent trajectory models to characterise nonlinear longitudinal growth trajectories in cohort studies

BACKGROUND

Longitudinal data analysis can improve our understanding of the influences on health trajectories across the life-course. There are a variety of statistical models which can be used, and their fitting and interpretation can be complex, particularly where there is a nonlinear trajectory. Our aim was to provide an accessible guide along with applied examples to using four sophisticated modelling procedures for describing nonlinear growth trajectories.

METHODS

This expository paper provides an illustrative guide to summarising nonlinear growth trajectories for repeatedly measured continuous outcomes using (i) linear spline and (ii) natural cubic spline linear mixed-effects (LME) models, (iii) Super Imposition by Translation and Rotation (SITAR) nonlinear mixed effects models, and (iv) latent trajectory models. The underlying model for each approach, their similarities and differences, and their advantages and disadvantages are described. Their application and correct interpretation of their results is illustrated by analysing repeated bone mass measures to characterise bone growth patterns and their sex differences in three cohort studies from the UK, USA, and Canada comprising 8500 individuals and 37,000 measurements from ages 5-40 years. Recommendations for choosing a modelling approach are provided along with a discussion and signposting on further modelling extensions for analysing trajectory exposures and outcomes, and multiple cohorts.

RESULTS

Linear and natural cubic spline LME models and SITAR provided similar summary of the mean bone growth trajectory and growth velocity, and the sex differences in growth patterns. Growth velocity (in grams/year) peaked during adolescence, and peaked earlier in females than males e.g., mean age at peak bone mineral content accrual from multicohort SITAR models was 12.2 years in females and 13.9 years in males. Latent trajectory models (with trajectory shapes estimated using a natural cubic spline) identified up to four subgroups of individuals with distinct trajectories throughout adolescence.

CONCLUSIONS

LME models with linear and natural cubic splines, SITAR, and latent trajectory models are useful for describing nonlinear growth trajectories, and these methods can be adapted for other complex traits. Choice of method depends on the research aims, complexity of the trajectory, and available data. Scripts and synthetic datasets are provided for readers to replicate trajectory modelling and visualisation using the R statistical computing software.

General and Vulnerable Population’s Satisfaction With the Healthcare System in Urban and Rural Areas: Findings From the European Social Survey

Introduction: Access to the healthcare system when patients are vulnerable and living outside metropolitan areas can be challenging. Our objective was to explore healthcare system satisfaction of urban and rural inhabitants depending on financial and health vulnerabilities.

Methods: Repeated cross-sectional data from 353,523 European citizens (2002–2016). Multivariable associations between rural areas, vulnerability factors and satisfaction with the healthcare system were assessed with linear mixed regressions and adjusted with sociodemographic and control factors.

Results: In unadjusted analysis, the people who lived in houses in the countryside and those who lived in the suburbs were the most satisfied with the healthcare system. In the adjusted model, residents living in big cities had the highest satisfaction. Financial and health vulnerabilities were associated with less satisfaction with the healthcare system, with a different effect according to the area of residence: the presence of health vulnerability was more negatively correlated with the healthcare system satisfaction of big city inhabitants, whereas financial vulnerability was more negatively correlated with the satisfaction of those living in countryside homes.

Conclusion: Vulnerable residents, depending on their area of residence, may require special attention to increase their satisfaction with the healthcare system.

Metal mixtures are associated with increased anxiety during pregnancy

BACKGROUND

Exposure to low-dose toxic metals in the environment is ubiquitous. Several murine studies have shown metals induce anxiety-like behaviors, and mechanistic research supports that metals disrupt neurotransmitter signaling systems implicated in the pathophysiology of anxiety. In this study, we extend prior research by examining joint exposure to six metals in relation to maternal anxiety symptoms during pregnancy.

METHODS

The sample includes 380 participants enrolled in the PRogramming of Intergenerational Stress Mechanisms (PRISM) pregnancy cohort. Spot urine was collected during pregnancy (mean ± standard deviation: 31.1 ± 6.1 weeks), and concentrations of six metals (barium [Ba], cadmium [Cd], chromium [Cr], cesium [Cs], lead [Pb], antimony [Sb]) were measured by Inductively Coupled Plasma - Mass Spectrometry. Trait anxiety symptoms were measured during pregnancy using a short version of the Spielberger State Trait Anxiety Inventory (STAI-T) and information on covariates was collected by questionnaire. We used weighted quantile sum (WQS) regression as the primary modeling approach to examine metals, treated as a mixture, in relation to higher (≥20) vs. lower anxiety symptoms while adjusting for urinary creatinine and key sociodemographic variables.

RESULTS

The sample is socioeconomically and racially/ethnically diverse. Urinary metal concentrations were log-normally distributed and 25% of the sample had an STAI-T score ≥20. Joint exposure to metals was associated with elevated anxiety symptoms (OR_WQS = 1.56, 95% CI: 1.24, 1.96); Cd (61.8%), Cr (14.7%), and Cs (12.7%) contributed the greatest weight to the mixture effect.

CONCLUSION

Exposure to metals in the environment may be associated with anxiety symptoms during pregnancy. This is a public health concern, as anxiety disorders are highly prevalent and associated with significant co-morbidities, especially during pregnancy when both the mother and developing fetus are susceptible to adverse health outcomes.

Estimating sibling spillover effects with unobserved confounding using gain-scores

PURPOSE

A growing area of research in epidemiology is the identification of health-related sibling spillover effects, or the effect of one individual's exposure on their sibling's outcome. The health within families may be confounded by unobserved factors, rendering identification of sibling spillovers challenging.

METHODS

We demonstrate a gain-score (fixed effects) regression method for identifying exposure-to-outcome spillover effects within sibling pairs in linear models. The method identifies the exposure-to-outcome spillover effect if only one sibling's exposure affects the other's outcome, and it identifies the difference between the spillover effects if both siblings' exposures affect the others' outcomes. The method fails with outcome-to-exposure spillover or with outcome-to-outcome spillover. Analytic results, Monte Carlo simulations, and a brief application demonstrate the method and its limitations.

RESULTS

We estimate the spillover effect of a child's preterm birth on an older sibling's literacy skills, measured by the Phonological Awareness Literacy Screening-Kindergarten test. We analyze 20,010 sibling pairs from a population-wide, Wisconsin-based (United States) birth cohort. Without covariate adjustment, we estimate that preterm birth modestly decreases an older sibling's test score.

CONCLUSIONS

Gain-scores are a promising strategy for identifying exposure-to-outcome spillover effects in sibling pairs while controlling for sibling-invariant unobserved confounding.

Integrating Environment and Aging Research: Opportunities for Synergy and Acceleration

Despite significant overlaps in mission, the fields of environmental health sciences and aging biology are just beginning to intersect. It is increasingly clear that genetics alone does not predict an individual’s neurological aging and sensitivity to disease. Accordingly, aging neuroscience is a growing area of mutual interest within environmental health sciences. The impetus for this review came from a workshop hosted by the National Academies of Sciences, Engineering, and Medicine in June of 2020, which focused on integrating the science of aging and environmental health research. It is critical to bridge disciplines with multidisciplinary collaborations across toxicology, comparative biology, epidemiology to understand the impacts of environmental toxicant exposures and age-related outcomes. This scoping review aims to highlight overlaps and gaps in existing knowledge and identify essential research initiatives. It begins with an overview of aging biology and biomarkers, followed by examples of synergy with environmental health sciences. New areas for synergistic research and policy development are also discussed. Technological advances including next-generation sequencing and other-omics tools now offer new opportunities, including exposomic research, to integrate aging biomarkers into environmental health assessments and bridge disciplinary gaps. This is necessary to advance a more complete mechanistic understanding of how life-time exposures to toxicants and other physical and social stressors alter biological aging. New cumulative risk frameworks in environmental health sciences acknowledge that exposures and other external stressors can accumulate across the life course and the advancement of new biomarkers of exposure and response grounded in aging biology can support increased understanding of population vulnerability. Identifying the role of environmental stressors, broadly defined, on aging biology and neuroscience can similarly advance opportunities for intervention and translational research. Several areas of growing research interest include expanding exposomics and use of multi-omics, the microbiome as a mediator of environmental stressors, toxicant mixtures and neurobiology, and the role of structural and historical marginalization and racism in shaping persistent disparities in population aging and outcomes. Integrated foundational and translational aging biology research in environmental health sciences is needed to improve policy, reduce disparities, and enhance the quality of life for older individuals.

Moderating or mediating effects of family characteristics on socioeconomic inequalities in child health in high-income countries - a scoping review

BACKGROUND

By explaining the development of health inequalities, eco-social theories highlight the importance of social environments that children are embedded in. The most important environment during early childhood is the family, as it profoundly influences children's health through various characteristics. These include family processes, family structure/size, and living conditions, and are closely linked to the socioeconomic position (SEP) of the family. Although it is known that the SEP contributes to health inequalities in early childhood, the effects of family characteristics on health inequalities remain unclear. The objective of this scoping review is to synthesise existing research on the mediating and moderating effects of family characteristics on socioeconomic health inequalities (HI) during early childhood in high-income countries.

METHODS

This review followed the methodology of "Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews". To identify German and English scientific peer-reviewed literature published from January 1^st, 2000, to December 19^th, 2019, the following search term blocks were linked with the logical operator "AND": (1) family structure/size, processes, living conditions, (2) inequalities, disparities, diversities, (3) income, education, occupation, (4) health and (5) young children. The search covered the electronic databases PubMed, PsycINFO, and Scopus.

RESULTS

The search yielded 7,089 records. After title/abstract and full-text screening, only ten peer-reviewed articles were included in the synthesis, which analysed the effects of family characteristics on HI in early childhood. Family processes (i.e., rules /descriptive norms, stress, parental screen time, parent-child conflicts) are identified to have mediating or moderating effects. While families' living conditions (i.e., TVs in children's bedrooms) are suggested as mediating factors, family structure/size (i.e., single parenthood, number of children in the household) appear to moderate health inequalities.

CONCLUSION

Family characteristics contribute to health inequalities in early childhood. The results provide overall support of models of family stress and family investment. However, knowledge gaps remain regarding the role of family health literacy, regarding a wide range of children's health outcomes (e.g., oral health, inflammation parameters, weight, and height), and the development of health inequalities over the life course starting at birth.

A tipping point in cancer epidemiology: embracing a life course exposomic framework

The pathogenesis of multifactorial malignant diseases, with variable onset, severity, and natural history, reflects development-specific exposures and individual responses to these exposures influenced by underlying genetic predisposition. Embedded in life course theory, exposomics provides a framework to more fully elucidate how environmental factors alter cancer risk, disease course, and response to treatment across the lifespan.

Associations of Adverse Childhood Experiences with Frailty in Older Adults: A Cross-Sectional Analysis of Data from the Canadian Longitudinal Study on Aging

INTRODUCTION

Frailty in older adults, characterized by a decline in multiple physiological systems and increasing vulnerability to loss of independence, disability, and death, is a public health priority in developed countries. Etiology of frailty extends across the lifespan and may begin in early life, but empirical evidence for this association is scarce. In this study, we examined whether adverse childhood experiences (ACEs) are associated with frailty in later life.

METHODS

We conducted a cross-sectional analysis of data for a population-based sample of 27,748 adults aged 45-85 years from the Canadian Longitudinal Study on Aging. The frailty index (FI) was computed with 76 health-related characteristics of physical and cognitive performance, self-rated health, chronic conditions, visual and hearing ability, activities of daily living, and well-being. Self-reported exposure to ACEs included physical, emotional, and sexual abuse, neglect, and witnessing intimate partner violence prior age of 16 and parental death, divorce, and living with a family member with mental illness prior age of 18. Generalized linear regression models with gamma error distribution and identity link function, adjusted for age and sex, were used to examine associations of each ACE type and the number of ACE types (0, 1, 2, or 3+) reported by an individual with FI. All models were adjusted for income, education, smoking, and alcohol consumption in sensitivity analysis.

RESULTS

Individuals exposed to ACEs had elevated levels of FI (mean = 0.13, SD = 0.09) than those unexposed, with the largest difference observed for neglect (B [95% CI]: 0.05 [0.04, 0.06]) and the smallest for parental death and divorce (0.015 [0.01,0.02]). The ACE count was associated with frailty in a graded manner, with the FI difference reaching 0.04 [0.037, 0.044] for participants exposed to 3+ ACE types. The association between ACEs and frailty tended to be stronger for women than men and for men aged 45-64 years than older men.

CONCLUSIONS

Our study supports previous studies showing that exposure to ACEs is associated with frailty in adults. Our findings suggest that screening for ACEs involving childhood maltreatment may be useful for identifying individuals at risk of frailty and prevention of ACEs may have long-term benefits for healthy aging.

A short form of the Crisis in Family Systems (CRISYS) in a racially diverse sample of pregnant women

Assessing stressful life events in large-scale epidemiologic studies is challenged by the need to measure potential stressful events in a reasonably comprehensible manner balanced with burden on participants and research staff. The aim of this paper was to create a short form of the Crisis in Family Systems-Revised (CRISYS-R) plus 17 acculturation items, a measure that captures contemporary life stressors across 11 domains. Latent class analysis (LCA) was used to segment the sample of 884 women from the PRogramming of Intergenerational Stress Mechanisms (PRISM) study experiencing different patterns of exposure to stressful events and identify items from each domain that best discriminate between individuals with different patterns of stressful-event exposures (high vs. low stress exposure). The results from the LCA, in conjunction with the expert opinions provided by the original developers of the CRISYS, yielded a 24-item item short form (CRISYS-SF) with at least one question from each of the original domains. Scores on the 24-item CRISYS-SF had high correlations with scores on the 80-item CRISYS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12144-021-02335-w.

Healthy Aging-Relevant Goals: The Role of Person-Context Co-construction

OBJECTIVES

This article considers how individuals' motivation for healthy aging manifests within the myriad of different contexts that older adults are embedded in as they move through later life.

METHODS

Drawing on the concept of co-construction, we argue that persons and contexts both contribute to the emergence, maintenance, and disengagement from healthy aging relevant goals in adulthood and old age.

RESULTS

To promote the understanding of such co-constructive dynamics, we propose four conceptual refinements of previous healthy aging models. First, we outline various different, often multidirectional, ways in which persons and contexts conjointly contribute to how people set, pursue, and disengage from health goals. Second, we promote consideration of context as involving unique, shared, and interactive effects of socio-economic, social, physical, care/service, and technology dimensions. Third, we highlight how the relevance, utility, and nature of these context dimensions and their role in co-constructing health goals change as individuals move through the Third Age, the Fourth Age, and a terminal stages of life. Finally, we suggest that these conceptual refinements be linked to established (motivational) theories of lifespan development and aging.

DISCUSSIONS

In closing, we outline a set of research questions that promise to advance our understanding of the mechanisms by which contexts and aging persons co-construct healthy aging relevant goals and elaborate on the applied significance of this approach for common public health practices.

Childhood growth and development and DNA methylation age in mid-life

BACKGROUND

In the first study of its kind, we examine the association between growth and development in early life and DNAm age biomarkers in mid-life.

METHODS

Participants were from the Medical Research Council National Survey of Health and Development (n = 1376). Four DNAm age acceleration (AgeAccel) biomarkers were measured when participants were aged 53 years: AgeAccelHannum; AgeAccelHorvath; AgeAccelLevine; and AgeAccelGrim. Exposure variables included: relative weight gain (standardised residuals from models of current weight z-score on current height, and previous weight and height z-scores); and linear growth (standardised residuals from models of current height z-score on previous height and weight z-scores) during infancy (0-2 years, weight gain only), early childhood (2-4 years), middle childhood (4-7 years) and late childhood to adolescence (7-15 years); age at menarche; and pubertal stage for men at 14-15 years. The relationship between relative weight gain and linear growth and AgeAccel was investigated using conditional growth models. We replicated analyses from the late childhood to adolescence period and pubertal timing among 240 participants from The National Child and Development Study (NCDS).

RESULTS

A 1SD increase in relative weight gain in late childhood to adolescence was associated with 0.50 years (95% CI 0.20, 0.79) higher AgeAccelGrim. Although the CI includes the null, the estimate was similar in NCDS [0.57 years (95% CI - 0.01, 1.16)] There was no strong evidence that relative weight gain and linear growth in childhood was associated with any other AgeAccel biomarker. There was no relationship between pubertal timing in men and AgeAccel biomarkers. Women who reached menarche ≥ 12 years had 1.20 years (95% CI 0.15, 2.24) higher AgeAccelGrim on average than women who reached menarche < 12 years; however, this was not replicated in NCDS and was not statistically significant after Bonferroni correction.

CONCLUSIONS

Our findings generally do not support an association between growth and AgeAccel biomarkers in mid-life. However, we found rapid weight gain during pubertal development, previously related to higher cardiovascular disease risk, to be associated with older AgeAccelGrim. Given this is an exploratory study, this finding requires replication.

Fostering healthy aging: The interdependency of infections, immunity and frailty

Untangling the interdependency of infections, immunity and frailty may help to clarify their roles in the maintenance of health in aging individuals, and the recent COVID-19 pandemic has further highlighted such priority. In this scoping review we aimed to systematically collect the evidence on 1) the impact of common infections such as influenza, pneumonia and varicella zoster on frailty development, and 2) the role played by frailty in the response to immunization of older adults. Findings are discussed under a unifying framework to identify knowledge gaps and outline their clinical and public health implications to foster a healthier aging. Twenty-nine studies (113,863 participants) selected to answer the first question provided a moderately strong evidence of an association between infections and physical as well as cognitive decline - two essential dimensions of frailty. Thirteen studies (34,520 participants) investigating the second aim, showed that frailty was associated with an impaired immune response in older ages, likely due to immunosenescence. However, the paucity of studies, the absence of tools to predict vaccine efficacy, and the lack of studies investigating the efficacy of newer vaccines in presence of frailty, strongly limit the formulation of more personalized immunization strategies for older adults. The current evidence suggests that infections and frailty repeatedly cross each other pathophysiological paths and accelerate the aging process in a vicious circle. Such evidence opens to several considerations. First, the prevention of both conditions pass through a life course approach, which includes several individual and societal aspects. Second, the maintenance of a well-functioning immune system may be accomplished by preventing frailty, and vice versa. Third, increasing the adherence to immunization may delay the onset of frailty and maintain the immune system homeostasis, beyond preventing infections.

The Early Life Course of Body Weight and Gene Expression Signatures for Disease

We examined the way body-weight patterns through the first 4 decades of life relate to gene expression signatures of common forms of morbidity, including cardiovascular disease (CVD), type 2 diabetes (T2D), and inflammation. As part of wave V of the nationally representative National Longitudinal Study of Adolescent to Adult Health (1997–2018) in the United States, mRNA abundance data were collected from peripheral blood (n = 1,132). We used a Bayesian modeling strategy to examine the relative associations between body size at 5 life stages—birth, adolescence, early adulthood, young adulthood, and adulthood—and gene expression–based disease signatures. We compared life-course models that consider critical or sensitive periods, as well as accumulation over the entire period. Our results are consistent with a sensitive-period model when examining CVD and T2D gene expression signatures: Birth weight has a prominent role for the CVD and T2D signatures (explaining 33.1% and 22.1%, respectively, of the total association accounted for by body size), while the most recent adult obesity status (ages 33–39) is important for both of these gene expression signatures (24.3% and 35.1%, respectively). Body size in all life stages was associated with inflammation, consistent with the accumulation model.

Prevalence and early-life determinants of mid-life multimorbidity: evidence from the 1970 British birth cohort

BACKGROUND

We sought to: [1] estimate the prevalence of multimorbidity at age 46-48 in the 1970 British Cohort Study-a nationally representative sample in mid-life; and [2] examine the association between early-life characteristics and mid-life multimorbidity.

METHOD

A prospective longitudinal birth cohort of a community-based sample from the 1970 British Cohort Study (BCS70). Participants included all surviving children born in mainland Britain in a single week in April 1970; the analytical sample included those with valid data at age 46-48 (n = 7951; 2016-2018). The main outcome was multimorbidity, which was operationalised as a binary indicator of two or more long-term health conditions where at least one of these conditions was of physical health. It also included symptom complexes (e.g., chronic pain), sensory impairments, and alcohol problems.

RESULTS

Prevalence of mid-life multimorbidity was 33.8% at age 46-48. Those with fathers from unskilled social occupational class (vs professional) at birth had 43% higher risk of mid-life multimorbidity (risk ratio = 1.43, 95% confidence interval 1.15 to 1.77). After accounting for potential child and family confounding, an additional kilogram of birthweight was associated with 10% reduced risk of multimorbidity (risk ratio = 0.90, 95% confidence interval 0.84 to 0.96); a decrease of one body mass index point at age 10 was associated with 3% lower risk (risk ratio = 1.03, 95% confidence interval 1.01 to 1.05); one standard deviation higher cognitive ability score at age 10 corresponded to 4% lower risk (risk ratio = 0.96, 95% confidence interval 0.91 to 1.00); an increase of one internalising problem at age 16 was equated with 4% higher risk (risk ratio = 1.04, 95% confidence interval 1.00 to 1.08) and of one externalising problem at age 16 with 6% higher risk (risk ratio = 1.06, 1.03 to 1.09).

CONCLUSION

Prevalence of multimorbidity was high in mid-life (33.8% at age 46-48) in Britain. Potentially modifiable early-life exposures, including early-life social circumstances, cognitive, physical and emotional development, were associated with elevated risk of mid-life multimorbidity.

Health Inequalities in Children and Adolescents: A Scoping Review of the Mediating and Moderating Effects of Family Characteristics

This scoping review systematically mapped evidence of the mediating and moderating effects of family characteristics on health inequalities in school-aged children and adolescents (6-18 years) in countries with developed economies in Europe and North America. We conducted a systematic scoping review following the PRISMA extension for Scoping Reviews recommendations. We searched the PubMed, PsycINFO and Scopus databases. Two reviewers independently screened titles, abstracts and full texts. Evidence was synthesized narratively. Of the 12,403 records initially identified, 50 articles were included in the synthesis. The included studies were conducted in the United States (n = 27), Europe (n = 18), Canada (n = 3), or in multiple countries combined (n = 2). We found that mental health was the most frequently assessed health outcome. The included studies reported that different family characteristics mediated or moderated health inequalities. Parental mental health, parenting practices, and parent-child-relationships were most frequently examined, and were found to be important mediating or moderating factors. In addition, family conflict and distress were relevant family characteristics. Future research should integrate additional health outcomes besides mental health, and attempt to integrate the complexity of families. The family characteristics identified in this review represent potential starting points for reducing health inequalities in childhood and adolescence.

A Structured Approach to Evaluating Life-Course Hypotheses: Moving Beyond Analyses of Exposed Versus Unexposed in the -Omics Context

The structured life-course modeling approach (SLCMA) is a theory-driven analytical method that empirically compares multiple prespecified life-course hypotheses characterizing time-dependent exposure-outcome relationships to determine which theory best fits the observed data. In this study, we performed simulations and empirical analyses to evaluate the performance of the SLCMA when applied to genomewide DNA methylation (DNAm). Using simulations (n = 700), we compared 5 statistical inference tests used with SLCMA, assessing the familywise error rate, statistical power, and confidence interval coverage to determine whether inference based on these tests was valid in the presence of substantial multiple testing and small effects-2 hallmark challenges of inference from -omics data. In the empirical analyses (n = 703), we evaluated the time-dependent relationship between childhood abuse and genomewide DNAm. In simulations, selective inference and the max-|t|-test performed best: Both controlled the familywise error rate and yielded moderate statistical power. Empirical analyses using SLCMA revealed time-dependent effects of childhood abuse on DNAm. Our findings show that SLCMA, applied and interpreted appropriately, can be used in high-throughput settings to examine time-dependent effects underlying exposure-outcome relationships over the life course. We provide recommendations for applying the SLCMA in -omics settings and encourage researchers to move beyond analyses of exposed versus unexposed individuals.