Implications of Lifecourse Epidemiology for Research on Determinants of Adult Disease

Methodological approaches, challenges, and opportunities in the application of Mendelian randomisation to lifecourse epidemiology: A systematic literature review

Diseases diagnosed in adulthood may have antecedents throughout (including prenatal) life. Gaining a better understanding of how exposures at different stages in the lifecourse influence health outcomes is key to elucidating the potential benefits of disease prevention strategies. Mendelian randomisation (MR) is increasingly used to estimate causal effects of exposures across the lifecourse on later life outcomes. This systematic literature review explores MR methods used to perform lifecourse investigations and reviews previous work that has utilised MR to elucidate the effects of factors acting at different stages of the lifecourse. We conducted searches in PubMed, Embase, Medline and MedRXiv databases. Thirteen methodological studies were identified. Four studies focused on the impact of time-varying exposures in the interpretation of "standard" MR techniques, five presented methods for repeat measures of the same exposure, and four described methodological approaches to handling multigenerational exposures. A further 127 studies presented the results of an applied research question. Over half of these estimated effects in a single generation and were largely confined to the exploration of questions regarding body composition. The remaining mostly estimated maternal effects. There is a growing body of research focused on the development and application of MR methods to address lifecourse research questions. The underlying assumptions require careful consideration and the interpretation of results rely on select conditions. Whilst we do not advocate for a particular strategy, we encourage practitioners to make informed decisions on how to approach a research question in this field with a solid understanding of the limitations present and how these may be affected by the research question, modelling approach, instrument selection, and data availability.

Psychosocial factors associated with 7-year change in cognition among middle-aged and older Hispanics/Latinos: The Hispanic Community Health Study/Study of Latinos-Investigation of Neurocognitive Aging (SOL-INCA) and Sociocultural ancillary studies

INTRODUCTION

Few studies have examined the associations of psychosocial factors with cognitive change in Hispanics/Latinos.

METHODS

Data from the Hispanic Community Health Study/Study of Latinos-Investigation of Neurocognitive Aging (HCHS/SOL INCA) and Sociocultural studies were used (n = 2,155; ages ≥45 years). Psychosocial exposures included intrapersonal (ethnic identity, optimism, purpose in life), interpersonal (family cohesion, familism, social networks, social support), and social factors (ethnic discrimination, loneliness, subjective social status). Survey-linear regression models examined associations between psychosocial exposures and 7-year cognitive change (global cognition [GC], verbal learning, memory, word fluency [WF], and digit symbol substitution [DSS]).

RESULTS

Familism predicted decline in GC, verbal learning, and memory; family cohesion predicted DSS decline; and loneliness predicted memory decline. Ethnic identity was protective against decline in GC and memory, optimism and social support were protective against decline in memory, and purpose in life was protective against WF decline.

DISCUSSION

Psychosocial factors are differentially related to cognitive changes. Culturally relevant factors should be explored in Hispanic/Latino cognitive aging research.

HIGHLIGHTS

Psychosocial factors are differentially related to cognitive changes in Latinos. Role of culturally relevant factors on cognition should be further explored. Familism predicted decline in global cognition, verbal learning, and memory. Ethnic identity predicted increase in global cognition and memory.

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.

Exposure to childhood maltreatment predicts adult physiological dysregulation, particularly inflammation

Although a growing literature describes the effects of negative childhood experiences on biological outcomes, it is difficult to compare results across studies because of differences in measures of childhood experiences, biological markers, sample characteristics, and included covariates. To ensure comparability across its analyses, this study used a single national survey of adults in the United States-the Midlife in the United States (MIDUS) study-to examine comprehensively the association between adverse childhood experiences, operationalized as childhood maltreatment (CM), and biological markers of risk for poor health and to assess whether these associations differ by type of maltreatment, sex, or race. The sample included 1254, mostly White (78%), adults aged 34-86 years (mean age 57 years), 57% of whom were female. We present incidence rate ratios (IRR) from negative binomial and Poisson regressions to examine the relationships between exposure to CM (emotional, physical, and sexual abuse; emotional and physical neglect; and a CM-index reflecting frequency across all five types of maltreatment) and four biological risk summary scores (overall physiological dysregulation, cardiometabolic risk, inflammation, and hypothalamic pituitary axis/sympathetic nervous system (HPA/SNS) function). We also tested whether the effect of each type of CM varied by sex and by race. The CM-index was associated with higher overall physiological dysregulation and inflammation, but the associations were weaker and not statistically significant for cardiometabolic risk and HPA/SNS function. With the exception of a possible sex difference in the association between sexual abuse and overall physiological dysregulation, there was little evidence that the associations varied systematically by type of CM or by sex or race. We conclude that exposure to CM predicts adult biological risk, particularly inflammation. Inconsistency with previous research suggests that additional research is needed to confirm findings regarding sex and race differences.

Association Between Age of Anal Sex Debut and Adult Health Behaviors Among Sexual Minoritized Men Living with HIV

Earlier age of anal sex debut (ASD) has been linked with contemporary and long-term health outcomes, including vulnerability to HIV acquisition. The goal of this study was to utilize a life course approach to examine associations between earlier ASD and recent health behaviors among sexual minoritized men (SMM) living with HIV. A total of 1156 U.S. SMM living with HIV recruited from social and sexual networking apps and websites completed online surveys as part of a longitudinal eHealth intervention. Data from baseline surveys were analyzed to determine associations between age of ASD and adult health outcomes, including mental health, HIV viral load, and substance use. The median age of ASD among these participants was 17 years old, consistent with other work. Earlier ASD was significantly associated with a greater likelihood of past 2-week anxiety (AOR = 1.45, 95% CI 1.07-1.97) and past 3-month opioid use (AOR = 1.60, 95% CI 1.13-2.26); no significant associations were found for recent depression, HIV viral load, or stimulant use. Earlier ASD may function as an important proxy measure for deleterious health outcomes in adulthood, particularly recent anxiety and opioid use. Expansion of comprehensive and affirming sexual health education is critical to early engagement of individuals with a higher risk of HIV acquisition, with plausible downstream health benefits lasting into adulthood among SMM living with HIV.

Beyond borders: A commentary on the benefit of promoting immigrant populations in genome-wide association studies

Immigrants are an important part of many high-income nations, in that they contribute to the sociocultural tapestry, economic well-being, and demographic diversity of their receiving countries and communities. Yet, genomic studies to date have generally focused on non-immigrant, European-ancestry populations. Although this approach has proven fruitful in discovering and validating genomic loci, within the context of racially/ethnically diverse countries like the United States-wherein half of immigrants hail from Latin America and another quarter from Asia-this approach is insufficient. There is a persistent diversity gap in genomic research in terms of both current samples and genome-wide association studies, meaning that the field's understanding of genetic architecture and gene-environmental interactions is being hampered. In this commentary, I provide motivating examples of recent research developments related to the following: (1) how the increased ancestral diversity, such as seen among Latin American immigrants, improves power to discover and document genomic loci, (2) informs how environmental factors, such as immigration-related exposures, interact with genotypes to influence phenotypes, and (3) how inclusion can be promoted through community-engaged research programs and policies. I conclude that greater inclusion of immigrants in genomic research can move the field forward toward novel discoveries and interventions to address racial/ethnic health disparities.

Examination of potentially modifiable dementia risk factors across the adult life course: The Framingham Heart Study

INTRODUCTION

We examined for associations between potentially modifiable risk factors across the adult life course and incident dementia.

METHODS

Participants from the Framingham Heart Study were included (n = 4015). Potential modifiable risk factors included education, alcohol intake, smoking, body mass index (BMI), physical activity, social network, diabetes, and hypertension. Cox models were used to examine associations between each factor and incident dementia, stratified by early adult life (33-44 years), midlife (45-65 years), and late life (66-80 years).

RESULTS

Increased dementia risk was associated with diabetes (hazard ratio [HR] = 1.62; 95% confidence interval [CI] = 1.07-2.46) and physical inactivity (HR = 1.57; 95% CI = 1.12-2.20) in midlife, and with obesity (HR = 1.76; 95% CI = 1.08-2.87) in late life. Having multiple potential modifiable risk factors in midlife and late life was associated with greater risk.

DISCUSSION

Potentially modifiable risk factors individually have limited impact on dementia risk in this population across the adult life course, although in combination they may have a synergistic effect.

HIGHLIGHTS

Diabetes and physical inactivity in midlife is associated with increased dementia risk. Obesity in late life is associated with increased dementia risk. Having more potentially modifiable risk factors in midlife and late life is associated with greater dementia risk.

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

Objective

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

Methods

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

Results

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

Conclusions

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

Maternal Mineral Nutrition Regulates Fetal Genomic Programming in Cattle: A Review

Maternal mineral nutrition during the critical phases of fetal development may leave lifetime impacts on the productivity of an individual. Most research within the developmental origins of the health and disease (DOHaD) field is focused on the role of macronutrients in the genome function and programming of the developing fetus. On the other hand, there is a paucity of knowledge about the role of micronutrients and, specifically, minerals in regulating the epigenome of livestock species, especially cattle. Therefore, this review will address the effects of the maternal dietary mineral supply on the fetal developmental programming from the embryonic to the postnatal phases in cattle. To this end, we will draw a parallel between findings from our cattle model research with data from model animals, cell lines, and other livestock species. The coordinated role and function of different mineral elements in feto-maternal genomic regulation underlies the establishment of pregnancy and organogenesis and, ultimately, affects the development and functioning of metabolically important tissues, such as the fetal liver, skeletal muscle, and, importantly, the placenta. Through this review, we will delineate the key regulatory pathways involved in fetal programming based on the dietary maternal mineral supply and its crosstalk with epigenomic regulation in cattle.

Effects of Pension Eligibility Expansion on Men's Cognitive Function: Findings from Rural South Africa

Two-thirds of people living with Alzheimer's disease and related dementias (ADRD) live in low- and middle-income countries, and this figure is expected to rise as these populations are rapidly aging. Since evidence demonstrates links between socioeconomic status and slower rates of cognitive decline, protecting older adults' cognitive function in resource-limited countries that lack the infrastructure to cope with ADRD is crucial to reduce the burden it places on these populations and their health systems. While cash transfers are a promising intervention to promote healthy cognitive aging, factors such as household wealth and level of education often confound the ability to make causal inferences on the impact of cash transfers and cognitive function. This study uses a quasi-experimental design, leveraging an exogenous expansion to the Old Age Pension for men in South Africa, to approximate causal associations with cognitive function. We found evidence that there is a potential benefit of cash transfers at an earlier age for older individuals. As such, transfers such as pensions or other forms of direct basic income transfers may hold promise as potential interventions to promote healthy cognitive aging.

The association between adverse childhood experiences and oral health: A systematic review

OBJECTIVE

It is well established that adverse childhood experiences (ACEs) negatively affect health and are associated with health-risk behaviors. This study aimed to provide a systematic review of the studies that examine the relationship between ACE exposure and oral health among adults aged 18 years and older.

METHODS

The following electronic databases were searched in January 2022: MEDLINE, Cochrane, Web of Science, CINAHL via EBSCOhost, ProQuest, ScienceDirect, and Google Scholar. Data were extracted independently by two reviewers. The quality of the studies was assessed using the Newcastle-Ottawa Scale.

RESULTS

Among the 292 articles identified, four met the eligibility criteria. All included studies were cross-sectional and of satisfactory quality. The dental outcomes included: last dental visit, last dental cleaning, number of filled teeth, number of extracted teeth, and number of remaining teeth. The studies showed that exposure to ACE was negatively associated with oral health. The relationship between ACE score and oral health outcome measures was found to be directly proportional.

CONCLUSION

There is an association between ACE and poor oral health. Moreover, the association was proven to have a dose-response relationship. Given that the studies in the literature were cross-sectional, causality cannot be determined with certainty, therefore interpretation of the results should be cautious. Longitudinal follow-up studies are needed to understand how ACEs contribute to oral diseases later in life.

Why Are Old-Age Disabilities Decreasing in Sweden and Denmark? Evidence on the Contribution of Cognition, Education, and Sensory Functions

OBJECTIVES

Improvements in educational attainment, cognitive and sensory functions, and a decline in the prevalence of disabilities have been observed in older adults in Sweden and Denmark. In the present study, it was investigated whether better cognition, higher educational attainment, and improved sensory function among older adults aged 60 and older in these countries have contributed to decreasing rates of old-age disabilities.

METHODS

The analyses were based on repeated cross-sectional data from the Survey of Health, Ageing, and Retirement in Europe for the 2004-2017 period. Descriptive data were used to benchmark the declining prevalence of disabilities, improving cognitive and sensory functions, and increased educational level. The association between time and disabilities was analyzed with logistic regression models, and the contribution of the improved cognitive function, education, and sensory function to the declining prevalence of old-age disabilities was estimated using the Karlson-Holm-Breen method for mediation analysis.

RESULTS

The analysis suggests that the declining prevalence of old-age disabilities in Sweden and Denmark between 2004 and 2017 can largely be attributed to improved cognitive function and vision and to a lesser extent by education and hearing ability.

DISCUSSION

These findings raise important questions about the causal mechanisms producing the associations between cognition, education, and sensory functions and disability in older age. Future studies should explore the causal nature of the associations between these mediators and old-age disabilities. In addition, they should explore whether these findings differ across regional and cultural contexts and over different time periods.

Parental Education and Delirium Risk after Surgery in Older Adults

OBJECTIVES

Efforts to conceptualize risk factors for postoperative delirium in older adults have focused on the time proximate to the episode, but how early-life exposures influence delirium risk is poorly understood.

METHODS

An observational cohort of 547 patients aged 70+undergoing major non-cardiac surgery at two academic medical centers in Boston. Demographic characteristics, cognition, parental education, health, and participation in cognitively stimulating activities were assessed prior to surgery. Delirium incidence and severity were measured daily during hospitalization.

RESULTS

Higher paternal education was associated with significantly lower incidence of delirium (X2(1, N =547)=8.35, p <.001; odds ratio OR=.93, 95% CI, .87 to .98) and inversely associated with delirium severity (r(545)=-.13, p <.001). Higher maternal education was associated with lower delirium incidence but did not reach statistical significance. The effect of paternal education on delirium incidence was independent of the patient's education, estimated premorbid intelligence, medical comorbidities, neighborhood disadvantage, and participation in cognitively stimulating activities (X2(2, N =547)=31.22, p <.001).

CONCLUSIONS

Examining early-life exposures may yield unique insights into the risks and pathogenesis of delirium.

CLINICAL IMPLICATIONS

Evaluating long-term factors that increase vulnerability to delirium may improve our ability to calculate risk. It may guide clinical decision-making and inform pre- and post-operative recommendations.

Global prevalence of depression in older adults: A systematic review and meta-analysis of epidemiological surveys

BACKGROUND

The reported prevalence of depressive symptoms (depression hereafter) among older adults varied widely across different studies. This was a meta-analysis to systematically examine the global prevalence of depression among older populations and its associated factors.

METHODS

A systematic literature search was performed in PubMed, EMBASE, PsycINFO, and Web of Science. Due to the differences in demographic and clinical characteristics between studies, random-effects model was used to calculate the pooled prevalence of depression and its 95% confidence interval (95% CI).

RESULTS

In total, 55 studies with 59,851 individuals met the study criteria and were included in the analyses. The overall prevalence of depression was 35.1% (95%CI: 30.2-40.4%). Subgroup analyses revealed that different sampling methods (Q=10592.49, p = 0.037), Geriatric Depression Scale versions (Q=13712.55, p < 0.001) and income levels (Q=14.028, P < 0.001) were significantly associated with the pooled prevalence of depression in older adults. In the meta-regression analyses, time of survey (B=0.012, z = 2.30, p = 0.029) was positively associated, and mean age (B=-0.018, z = 2.10, p = 0.044) was negatively associated with the prevalence of depression in older populations. The funnel plot and Egger's test did not reveal any significant publication bias (Egger's test: t = 1.93, p = 0.059).

CONCLUSION

This meta-analysis found that over a third of older populations globally had depression. Effective preventive measures, regular screening and timely interventions are needed to address this highly prevalent public health problem among older adults.

Incidence, Clinical Correlates, and Prognostic Impact of Dementia in Heart Failure: A Population-Based Cohort Study

Background

Heart failure (HF) may increase the risk of dementia via shared risk factors.

Objectives

The authors investigated the incidence, types, clinical correlates, and prognostic impact of dementia in a population-based cohort of patients with index HF.

Methods

The previously territory-wide database was interrogated to identify eligible patients with HF (N = 202,121) from 1995 to 2018. Clinical correlates of incident dementia and their associations with all-cause mortality were assessed using multivariable Cox/competing risk regression models where appropriate.

Results

Among a total cohort aged ≥18 years with HF (mean age 75.3 ± 13.0 years, 51.3% women, median follow-up 4.1 [IQR: 1.2-10.2] years), new-onset dementia occurred in 22,145 (11.0%), with age-standardized incidence rate of 1,297 (95% CI: 1,276-1,318) per 10,000 in women and 744 (723-765) per 10,000 in men. Types of dementia were Alzheimer's disease (26.8%), vascular dementia (18.1%), and unspecified dementia (55.1%). Independent predictors of dementia included: older age (≥75 years, subdistribution hazard ratio [SHR]: 2.22), female sex (SHR: 1.31), Parkinson's disease (SHR: 1.28), peripheral vascular disease (SHR: 1.46), stroke (SHR: 1.24), anemia (SHR: 1.11), and hypertension (SHR: 1.21). The population attributable risk was highest for age ≥75 years (17.4%) and female sex (10.2%). New-onset dementia was independently associated with increased risk of all-cause mortality (adjusted SHR: 4.51; P < 0.001).

Conclusions

New-onset dementia affected more than 1 in 10 patients with index HF over the follow-up, and portended a worse prognosis in these patients. Older women were at highest risk and should be targeted for screening and preventive strategies.

Genetically-predicted placental gene expression is associated with birthweight and adult body mass index

The placenta is critical to human growth and development and has been implicated in health outcomes. Understanding the mechanisms through which the placenta influences perinatal and later-life outcomes requires further investigation. We evaluated the relationships between birthweight and adult body mass index (BMI) and genetically-predicted gene expression in human placenta. Birthweight genome-wide association summary statistics were obtained from the Early Growth Genetics Consortium (N = 298,142). Adult BMI summary statistics were obtained from the GIANT consortium (N = 681,275). We used S-PrediXcan to evaluate associations between the outcomes and predicted gene expression in placental tissue and, to identify genes where placental expression was exclusively associated with the outcomes, compared to 48 other tissues (GTEx v7). We identified 24 genes where predicted placental expression was significantly associated with birthweight, 15 of which were not associated with birthweight in any other tissue. One of these genes has been previously linked to birthweight. Analyses identified 182 genes where placental expression was associated with adult BMI, 110 were not associated with BMI in any other tissue. Eleven genes that had placental gene expression levels exclusively associated with BMI have been previously associated with BMI. Expression of a single gene, PAX4, was associated with both outcomes exclusively in the placenta. Inter-individual variation of gene expression in placental tissue may contribute to observed variation in birthweight and adult BMI, supporting developmental origins hypothesis.

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.

Socioeconomic and health-related inequalities in major depressive symptoms among older adults: a Wagstaff's decomposition analysis of data from the LASI baseline survey, 2017-2018

OBJECTIVES

To find out the association between socioeconomic and health status and depression among older adults and explore the contributing factors in the socioeconomic and health-related inequalities in late-life depression.

DESIGN

A cross-sectional study was conducted using large representative survey data.

SETTING AND PARTICIPANTS

Data for this study were derived from the baseline wave of the Longitudinal Ageing Study in India conducted during 2017-2018. The effective sample size was 30 888 older adults aged 60 years and above.

PRIMARY AND SECONDARY OUTCOME MEASURES

The outcome variable in this study was depression among older adults. Descriptive statistics along with bivariate analysis was conducted to report the preliminary results. Multivariable binary logistic regression analysis and Wagstaff's decomposition were used to fulfil the objectives of the study.

RESULTS

There was a significant difference for the prevalence of depression (4.3%; p<0.05) among older adults from poor (11.2%) and non-poor categories (6.8%). The value of the Concentration Index was -0.179 which also confirms that the major depression was more concentrated among poor older adults. About 38.4% of the socioeconomic and health-related inequality was explained by the wealth quintile for major depression among older adults. Moreover, about 26.6% of the inequality in major depression was explained by psychological distress. Self-rated health (SRH), difficulty in activities of daily living (ADL) and instrumental ADL (IADL) contributed 8.7%, 3.3% and 4.8% to the inequality, respectively. Additionally, region explained about 23.1% of inequality followed by life satisfaction (11.2) and working status (9.8%) for major depression among older adults.

CONCLUSIONS

Findings revealed large socioeconomic and health-related inequalities in depression in older adults which were especially pronounced by poor household economy, widowhood, poor SRH, ADL and IADL difficulty, and psychological distress. In designing prevention programmes, detection and management of older adults with depression should be a high priority, especially for those who are more vulnerable.

Education-related health inequities in noncommunicable diseases: an analysis of the Brazilian National Health Survey, 2013 and 2019

This study assesses changes in the prevalence and distribution of noncommunicable diseases (NCDs) and related risk factors among Brazilian adults from the 2013 and 2019 Brazilian National Health Surveys (PNS). It is based on the hypothesis that deteriorating socioeconomic conditions over this period would lead to increased NCDs among the least advantaged populations. We estimated adjusted prevalence ratios by education category and three inequality measures - the slope index of inequality (SII), the relative index of inequality (RII), and population attributable fraction (PAF) - for obesity, hypertension, arthritis, asthma, cancer, depression, diabetes, heart disease, having any chronic condition, and multimorbidity by survey year. We also estimated the 27 Brazilian Federative Units RII and prevalence rates for diabetes and multimorbidity per year and plotted the RII against prevalence by year. Results showed that all NCDs increased over the period observed, ranging from an 8% increase in the adjusted prevalence of arthritis to a 24% increase in the adjusted prevalence of obesity. Measures of inequality showed that most conditions exhibited significant educational inequities in both 2013 and 2019. However, on average, education-based inequities did not significantly change between the two periods. Considering the deterioration of the socioeconomic conditions of most Brazilians, the erosion of social protections, and the continuing economic, political, and health crises occurring in the nation, we observed an urgent need for discussion about the best way to adopt equity-promoting health policies and programs and action to reduce socioeconomic and geographic inequalities in NCDs throughout the country.

Limitations of the protective measure theory in explaining the role of childhood sexual abuse in eating disorders, addictions, and obesity: an updated model with emphasis on biological embedding

In addition to its immediate negative consequences, childhood sexual abuse is associated with lifelong deleterious mental and physical health outcomes. This review employs a biopsychosocial perspective to better understand pathways from childhood sexual abuse to eating disorders, food and drug addictions, and obesity across the life course. Guided by an updated conceptual model, this review delineates how the biological embedding of childhood sexual abuse triggers a cascade of interrelated conditions that often result in failed attempts at weight suppression and eventually obesity. Such biological embedding involves pathways such as inflammation, allostatic load, reward sensitivity, activation of the hypothalamic-pituitary-adrenal axis, epigenetics, and structural and functional changes in the brain. These pathways are in turn theorized to lead to food addiction, substance use disorder, and eating disorders-each with potential pathways toward obesity over time. Predisposing factors to childhood sexual abuse including gender, culture, and age are discussed. This model calls into question the longstanding "protective measure" theory that purports individuals exposed to sexual abuse will deliberately or subconsciously gain weight in attempt to prevent future victimization. A more comprehensive understanding of the mechanisms by which childhood sexual abuse becomes biologically embedded may help clinicians and survivors normalize and/or address disordered eating and weight-related outcomes, as well as identify intervention strategies.Level of evidence: Level V: opinions of respected authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

Multivariate decomposition analysis of sex differences in functional difficulty among older adults based on Longitudinal Ageing Study in India, 2017-2018

OBJECTIVES

This study investigates the gender disparities in difficulty in activities of daily living (ADL) and instrumental activities of daily living (IADL) and explores its contributing factors among older adults in India.

DESIGN

A cross-sectional study was conducted using country representative survey data.

SETTING AND PARTICIPANTS

The present study uses the data from the Longitudinal Ageing Study in India, 2017-2018. Participants included 15 098 male and 16 366 female older adults aged 60 years and above in India.

PRIMARY AND SECONDARY OUTCOME MEASURES

Difficulty in ADL and IADL were the outcome variables. Descriptive statistics and bivariate analysis were carried out to present the preliminary results. Multivariate decomposition analysis was used to identify the contributions of covariates that explain the group differences to average predictions.

RESULTS

There was a significant gender differential in difficulty in ADL (difference: 4.6%; p value<0.001) and IADL (difference: 17.3%; p value<0.001). The multivariate analysis also shows significant gender inequality in difficulty in ADL (coefficient: 0.046; p value<0.001) and IADL (coefficient: 0.051; p value<0.001). The majority of the gender gap in difficulty in ADL was accounted by the male-female difference in levels of work status (18%), formal education (15% contribution), marital status (13%), physical activity (9%), health status (8%) and chronic morbidity prevalence (5%), respectively. Equivalently, the major contributors to the gender gap in difficulty in IADL were the level of formal education (28% contribution), marital status (10%), alcohol consumption (9%), health status (4% contribution) and chronic morbidity prevalence (2% contribution).

CONCLUSION

Due to the rapidly increasing ageing population, early detection and prevention of disability or preservation of daily functioning for older adults and women in particular should be the highest priority for physicians and health decision-makers.

A longitudinal study shows stress proliferation effects from early childhood adversity and recent stress on risk for depressive symptoms among older adults

Objectives: We evaluated whether the effects of recent stressful life events (SLEs) and early childhood adversities (ECAs) on depressive symptoms are consistent between men and women and across older age, and whether there was evidence for the following: stress sensitization, whereby the psychological impact of SLEs is greater for individuals with ECAs compared with those without; or stress proliferation effect, whereby those with ECAs are more likely to report more SLEs than those without ECAs to effect depressive symptoms.Method: ECAs, SLEs in the past two years, and current depressive symptoms through a modified CES-D were obtained from 11,873 individuals participating in a population representative study of older adults, yielding 82,764 observations. Mixed-effects regression models on depressive symptoms were constructed to control for multiple observations per participant and evaluate within-person effects over time, thereby reducing bias from reverse causation.Results: Results suggest a stress proliferation effect and do not support stress sensitization. ECAs contribute to vulnerability for depressive symptoms, with a dosage effect for each additional ECA. Recent SLEs result in greater depressive symptom risk, with stable effects over age and dosage effects for each additional SLE that were smaller than the effects of ECAs among men, but not women. Belonging to an ethnic minority group, having less education, and less household income at baseline were associated with greater depressive symptom risk.Conclusions: Findings suggest the importance of addressing early childhood adversity and sociodemographic factors, among at-risk older adults to mitigate life-course stress proliferative processes and thereby reduce disparate risk for depression in older age.

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.

Active Ageing in Italy: An Evidence-Based Model to Provide Recommendations for Policy Making and Policy Implementation

In ageing societies, active ageing (AA) has been recognized as a useful conceptual tool due to its holistic approach to social issues and recognised benefits from it at multiple levels (micro, meso and macro) for addressing demographic challenges. However, one of the main problems identified in relation to AA, is to turn into practice, at the policy making level, the many positive aspects that it promises at the conceptual level, as is demonstrated by the available evidence based on experiences carried out in some European countries. As an advancement in this field, through an original research experience carried out in Italy between 2019 and 2021, this study for the first time provides a model for producing recommendations for policy making and policy implementation in the field of AA, by managing the main problematic aspects related to the operationalization, at the policy making level, of the AA concept, with the potential for replication in other countries. The main challenges were identified, as well as the way to deal with them through a model, for a proper operationalization of the AA concept, based, among other aspects, on a solid international framework concerning this matter, on a mainstreaming ageing approach (at the public policy level) and on a wide stakeholder participation through co-decisional tools. A multi-level (national-regional-local) perspective was adopted to consider cultural and geographical diversity, among other challenges.

Time-varying associations between an exposure history and a subsequent health outcome: a landmark approach to identify critical windows

BACKGROUND

Long-term behavioral and health risk factors constitute a primary focus of research on the etiology of chronic diseases. Yet, identifying critical time-windows during which risk factors have the strongest impact on disease risk is challenging. To assess the trajectory of association of an exposure history with an outcome, the weighted cumulative exposure index (WCIE) has been proposed, with weights reflecting the relative importance of exposures at different times. However, WCIE is restricted to a complete observed error-free exposure whereas exposures are often measured with intermittent missingness and error. Moreover, it rarely explores exposure history that is very distant from the outcome as usually sought in life-course epidemiology.

METHODS

We extend the WCIE methodology to (i) exposures that are intermittently measured with error, and (ii) contexts where the exposure time-window precedes the outcome time-window using a landmark approach. First, the individual exposure history up to the landmark time is estimated using a mixed model that handles missing data and error in exposure measurement, and the predicted complete error-free exposure history is derived. Then the WCIE methodology is applied to assess the trajectory of association between the predicted exposure history and the health outcome collected after the landmark time. In our context, the health outcome is a longitudinal marker analyzed using a mixed model.

RESULTS

A simulation study first demonstrates the correct inference obtained with this approach. Then, applied to the Nurses' Health Study (19,415 women) to investigate the association between body mass index history (collected from midlife) and subsequent cognitive decline (evaluated after age 70), the method identified two major critical windows of association: long before the first cognitive evaluation (roughly 24 to 12 years), higher levels of BMI were associated with poorer cognition. In contrast, adjusted for the whole history, higher levels of BMI became associated with better cognition in the last years prior to the first cognitive interview, thus reflecting reverse causation (changes in exposure due to underlying disease).

CONCLUSIONS

This approach, easy to implement, provides a flexible tool for studying complex dynamic relationships and identifying critical time windows while accounting for exposure measurement errors.

Passive Smoking Throughout the Life Course and the Risk of Incident Rheumatoid Arthritis in Adulthood Among Women

OBJECTIVE

To investigate passive smoking throughout the life course and the risk of rheumatoid arthritis (RA), while accounting for personal smoking.

METHODS

We analyzed the Nurses' Health Study II prospective cohort, using information collected via biennial questionnaires. We assessed the influence of 1) maternal smoking during pregnancy (in utero exposure), 2) childhood parental smoking, and 3) years lived with smokers since age 18. Incident RA and serostatus were determined by medical record review. Using the marginal structural model framework, we estimated the controlled direct effect of each passive smoking exposure on adult incident RA risk by serologic phenotype, controlling for early-life factors and time-updated adulthood factors including personal smoking.

RESULTS

Among 90,923 women, we identified 532 incident RA cases (66% seropositive) during a median of 27.7 years of follow-up. Maternal smoking during pregnancy was associated with RA after adjustment for confounders, with a hazard ratio (HR) of 1.25 (95% confidence interval [95% CI] 1.03-1.52), but not after accounting for subsequent smoking exposures. Childhood parental smoking was associated with seropositive RA after adjustment for confounders (HR 1.41 [95% CI 1.08-1.83]). In the controlled direct effect analyses, childhood parental smoking was associated with seropositive RA (HR 1.75 [95% CI 1.03-2.98]) after controlling for adulthood personal smoking, and the association was accentuated among ever smokers (HR 2.18 [95% CI 1.23-3.88]). There was no significant association of adulthood passive smoking with RA (HR 1.30 for ≥20 years of living with a smoker versus none [95% CI 0.97-1.74]).

CONCLUSION

We found a potential direct influence of childhood parental smoking on adult-onset incident seropositive RA even after controlling for adulthood personal smoking.

Does Prolonged Education Causally Affect Dementia Risk When Adult Socioeconomic Status Is Not Altered? A Swedish Natural Experiment in 1.3 Million Individuals

Intervening on modifiable risk factors to prevent dementia is of key importance, since progress-modifying treatments are not currently available. Education is inversely associated with dementia risk, but causality and mechanistic pathways remain unclear. We aimed to examine the causality of this relationship in Sweden using, as a natural experiment, data on a compulsory schooling reform that extended primary education by 1 year for 70% of the population between 1936 and 1949. The reform introduced substantial exogenous variation in education that was unrelated to pupils' characteristics. We followed 18 birth cohorts (n = 1,341,842) from 1985 to 2016 (up to ages 79-96 years) for a dementia diagnosis in the National Inpatient and Cause of Death registers and fitted Cox survival models with stratified baseline hazards at the school-district level, chronological age as the time scale, and cohort indicators. Analyses indicated very small or negligible causal effects of education on dementia risk (main hazard ratio = 1.01, 95% confidence interval: 0.98, 1.04). Multiple sensitivity checks considering only compliers, the pre-/post- design, differences in health-care-seeking behavior, and the impact of exposure misclassification left the results essentially unaltered. The reform had limited effects on further adult socioeconomic outcomes, such as income. Our findings suggest that without mediation through adult socioeconomic position, education cannot be uncritically considered a modifiable risk factor for dementia.

Effects of combined training on neuropsychiatric symptoms and quality of life in patients with cognitive decline

BACKGROUND AND AIMS

Cognitive impairments associated with aging and dementia are major sources of neuropsychiatric symptoms (NPs) and deterioration in quality of life (QoL). Preventive measures to both reduce disease and improve QoL in those affected are increasingly targeting individuals with mild cognitive impairment (MCI) at early disease stage. However, NPs and QoL outcomes are too commonly overlooked in intervention trials. The purpose of this study was to test the effects of physical and cognitive training on NPs and QoL in MCI.

METHODS

Baseline data from an MCI court (N = 93, mean age 74.9 ± 4.7) enrolled in the Train the Brain (TtB) study were collected. Subjects were randomized in two groups: a group participated to a cognitive and physical training program, while the other sticked to usual standard care. Both groups underwent a follow-up re-evaluation after 7 months from baseline. NPs were assessed using the Neuropsychiatric Inventory (NPI) and QoL was assessed using Quality of Life-Alzheimer's Disease (QOL-AD) scale.

RESULTS

After 7 months of training, training group exhibited a significant reduction of NPs and a significant increase in QOL-AD with respect to no-training group (p = 0.0155, p = 0.0013, respectively). Our preliminary results suggest that a combined training can reduce NPs and improve QoL.

CONCLUSIONS

Measuring QoL outcomes is a potentially important factor in ensuring that a person with cognitive deficits can 'live well' with pathology. Future data from non-pharmacological interventions, with a larger sample and a longer follow-up period, could confirm the results and the possible implications for such prevention strategies for early cognitive decline.

Psychosocial Factors Associated with Cognitive Function Among Middle-Aged and Older Hispanics/Latinos: The Hispanic Community Health Study/Study of Latinos and its Sociocultural Ancillary Study

BACKGROUND

Evidence suggests that psychosocial factors are associated with cognitive health in older adults; however, associations of psychosocial factors with cognition remain largely unexamined in middle-aged and older Hispanics/Latinos.

OBJECTIVE

To examine the cross-sectional associations of psychosocial factors with cognitive function among middle-aged and older Hispanics/Latinos living in the US.

METHODS

Baseline (2008-2011) data from the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study (n = 2,818; ages 45-74) were used to examine the associations of each psychosocial factor with global cognition (GC), verbal learning, verbal memory, verbal fluency, and processing speed independent of age, sex, education, Hispanic/Latino background, income, language, and depressive symptoms. Psychosocial variables included: intrapersonal factors (ethnic identity, optimism, and purpose in life), interpersonal factors (family cohesion, familism, social network embeddedness, and social support), and social stressors (perceived ethnic discrimination, loneliness, and subjective social status).

RESULTS

In fully-adjusted models, purpose in life and social support were each positively associated with all five cognitive variables. Loneliness was negatively associated with GC, verbal learning, memory, and processing speed. Ethnic identity was positively and familism negatively associated with GC, verbal fluency, and processing speed. Family cohesion was positively associated with verbal learning.

CONCLUSION

These findings extend previous evidence from older, largely non-Hispanic White cohorts to show that higher purpose in life and social support are also strongly associated with cognitive health among middle-aged and older Hispanics/Latinos. We also highlight that intrapersonal factors, interpersonal factors, and social stressors have differential relationships with individual cognitive tests.

Testing Age Differences in the links between Recent Financial Difficulties and Cognitive Deficits: Longitudinal Evidence from the PATH Through Life Study

OBJECTIVE

This study investigates whether the within-person associations between a recent major financial crisis and deficits in cognitive performance vary across the lifecourse.

METHOD

Four waves of data from 7442 participants (49% men) spanning 12-years and comprising three narrow age birth cohorts (baseline age: 20-25, 40-45, and 60-65) were drawn from a representative prospective survey from Canberra, Australia (1999-2014). Cognitive performance was assessed by the California Verbal Leaning Test (CVLT) immediate recall trails, Symbol Digit Modalities Test (SDMT), Backwards Digitspan (BDS), and Trail Making Test B (TMT B). A single item from the Threatening Life Experiences Questionnaire assessed self-reported major financial crisis in the past 6-months. Multi-variable adjusted fixed effect regression models tested the time-dependent association between financial crisis and cognition.

RESULTS

A recent financial crisis coincided with contemporaneous declines in CVLT (Mean change = -0.14, 95% CI = -0.262, -0.025), SDMT (Mean change = -0.08, 95% CI = -0.147,-0.004) and TMT-B (Mean change = -0.17, 95% CI = -0.293,-0.039) for adults in the oldest age group, and these associations were larger than in the younger age groups. In contrast, there was an overall association between financial crisis and deficits in BDS (Mean change = -0.06, 95% CI = -0.105, -0.007), with weak evidence of stronger associations in mid-life relative to other age groups. These associations were independent of changes in health and socio-economic circumstances.

DISCUSSION

This study provides important new evidence that financial difficulties in later life are potent stressors associated with occasion specific deficits in cognitive performance.

Socioeconomic Disparities and Gender Inequalities in Dementia: a Community-Dwelling Population Study from a Middle-Income Country

The proportion of the world's older adults and of its dementia cases is increasing in low and middle-income countries. This is particularly true in Colombia. There, the number of individuals with dementia may increase five-fold by 2050. Yet research is lacking on dementia in such settings. This work estimates the prevalence of dementia in a community-dwelling population in Colombia. It also assesses how gender-based differences in cardiovascular conditions and socioeconomic disparities affect dementia. This work analyzes data on 2000 respondents at least 60 years of age in the Health, Well-Being, And Aging (SABE) study in Bogota. Respondents with dementia are those who have cognitive impairment and at least two limitations in instrumental activities of daily living. The SABE study finds 8.4% of respondents have dementia. Age, cardiovascular risks, and socioeconomic disparities contributed to higher odds of dementia. The contributors to dementia can differ for men and women. For example, socioeconomic disparities were a larger contributor to dementia for women than men. The findings support the cognitive reserve hypothesis on dementia. This holds that pre-existing cognitive processes and compensatory mechanisms influence dementia. Women in Latin America are more likely to suffer from socioeconomic disparities that limit their cognitive reserve. This research points to several policy implications that can help offset these disparities and reduce the prevalence of dementia.

Inflammation, Cognition, and White Matter in Older Adults: An Examination by Race

Objectives

Non-Latino Black adults have greater risk for Alzheimer’s dementia compared to non-Latino White adults, possibly due to factors disproportionally affecting Black adults including cardiovascular disease (CVD). Chronic peripheral inflammation is implicated in both Alzheimer’s dementia and CVD and is known to impact cognition and cerebral white matter, yet little work has examined these associations by race. This study examined associations between inflammation, cognition, and cerebral white matter generally, and by race.

Methods

Eighty-six non-demented older Black and White participants (age = 69.03; 50% female; 45% Black participants) underwent fasting venipuncture, cognitive testing, and MRI. Serum was assayed for interleukin-6 (IL-6), C-reactive protein (CRP), and interleukin 1-beta. Cognitive domains included memory, executive function, and attention/information processing. MRI measures included white matter hyperintensity volumes (WMH) and quantification of white matter integrity in areas outside WMHs via DTI-derived fractional anisotropy (FA) and mean diffusivity, as well as multi-component relaxometry derived myelin water fraction (MWF).

Results

Black and White participants did not differ on age, sex, or CVD risk. Separate linear regression models adjusting for relevant confounders revealed that higher IL-6 associated with lower executive function and higher CRP levels associated with lower FA and MWF. Stratified analyses revealed that these association were significant for Black participants only.

Discussion

These findings suggest that peripheral inflammation is inversely associated with select cognitive domains and white matter integrity (but not WMHs), particularly in older Black adults. It is important to consider race when investigating inflammatory associates of brain and behavior.

Sociodemographic inequalities in depression among older adults: cross-sectional evidence from 18 countries

BACKGROUND

Sociodemographic inequalities in depression are well established. However, less is known about variation in inequalities across countries. In this study, we describe cross-national variation in sociodemographic inequalities in depression among older adults. Comparing inequalities across countries is an important step towards understanding how the social environment shapes depression risk.

METHODS

In this cross-sectional study, we harmonised data from eight large ageing cohort studies from 18 countries. We restricted our study to adults aged 55 years and older, and measured depression using established cut points in shortened Center for Epidemiologic Studies Depression or EURO-D scales. Next, we estimated prevalence ratios for each country by age, marital status, educational attainment, and gender with logistic regression. To compare estimates across countries, we standardised estimates to the mean sociodemographic distribution across our sample.

FINDINGS

Between Jan 1, 2007, and May 31, 2015, 93 590 older adults completed questions related to depressive symptoms. Sociodemographic inequalities in depression varied substantially across countries. Variation was most apparent for age: prevalence ratios (adults aged 75 years or older vs adults aged 55-65 years) ranged from 2·66 (95% CI 2·13-3·20) in Israel to 0·78 (95% CI 0·72-0·84) in the USA. Heterogeneity by other factors was also apparent. Gender prevalence ratios (women vs men) ranged from 1·07 (95% CI 1·01-1·14) in Korea to 1·96 (95% CI 1·55-2·36) in Greece. Educational prevalence ratios (less than secondary education vs some post-secondary education) ranged from 1·01 (95% CI 0·88-1·14) in Japan to 2·34 (95% CI 2·14-2·55) in the USA. Marital status prevalence ratios (divorced or separated vs married) ranged from 1·11 (95% CI 1·01-1·21) in Chile to 2·01 (95% CI 1·73-2·29) in England.

INTERPRETATION

Inequalities in depression among older adults vary substantially across countries, which might be due to country-specific aspects of the social environment. Future research should investigate social inequality determinants of mental health that might inform the design and evaluation of social, economic, and mental health-related policies and interventions to reduce depression.

FUNDING

US National Institute of Mental Health and Chilean National Commission for Scientific and Technological Research.

Predicting mortality from 57 economic, behavioral, social, and psychological factors

In our prospective study using nationally representative data from 13,611 adults in the US Health and Retirement Study, we used traditional and machine-learning statistical approaches to reveal the most important factors across the behavioral and social sciences that predict mortality in older adults. In the study, we found that top predictors of mortality spanned all investigated domains, opening up opportunities for future hypothesis generation in observational and clinical studies and the identification of potential new targets for screening and policy.

Behavioral and social scientists have identified many nonbiological predictors of mortality. An important limitation of much of this research, however, is that risk factors are not studied in comparison with one another or from across different fields of research. It therefore remains unclear which factors should be prioritized for interventions and policy to reduce mortality risk. In the current investigation, we compare 57 factors within a multidisciplinary framework. These include (i) adverse socioeconomic and psychosocial experiences during childhood and (ii) socioeconomic conditions, (iii) health behaviors, (iv) social connections, (v) psychological characteristics, and (vi) adverse experiences during adulthood. The current prospective cohort investigation with 13,611 adults from 52 to 104 y of age (mean age 69.3 y) from the nationally representative Health and Retirement Study used weighted traditional (i.e., multivariate Cox regressions) and machine-learning (i.e., lasso, random forest analysis) statistical approaches to identify the leading predictors of mortality over 6 y of follow-up time. We demonstrate that, in addition to the well-established behavioral risk factors of smoking, alcohol abuse, and lack of physical activity, economic (e.g., recent financial difficulties, unemployment history), social (e.g., childhood adversity, divorce history), and psychological (e.g., negative affectivity) factors were also among the strongest predictors of mortality among older American adults. The strength of these predictors should be used to guide future transdisciplinary investigations and intervention studies across the fields of epidemiology, psychology, sociology, economics, and medicine to understand how changes in these factors alter individual mortality risk.

Associations between perceived neighborhood environment and cognitive function among middle-aged and older women and men: Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study

PURPOSE

To examine cross-sectional associations between perceived neighborhood environment and cognitive function among middle-aged and older Hispanic/Latino women and men.

METHODS

Data from the Hispanic Community Health Study/Study of Latinos (2008-2011) and its Sociocultural Ancillary Study (2009-2010) were used. Participants were Hispanic/Latino women (n = 1812) and men (n = 1034) aged 45-74 years. Survey-weighted linear regression models were used to examine associations between self-reported perceived neighborhood environment (i.e., neighborhood social cohesion and problems categorized as quintiles, and neighborhood safety from crime categorized as low, medium, or high) with cognitive function (i.e., global cognition, verbal learning, memory, verbal fluency, and processing speed scores) in women and men. Final model adjusted for age, Hispanic/Latino background, language, field site, household income, education, years lived in neighborhood, and depressive symptoms.

RESULTS

Women in the lowest quintile of perceived neighborhood problems (vs. highest quintile) had higher global cognition (β 0.48, 95% CI 0.03, 0.94, p trend 0.229) and memory scores (0.60, 95% CI 0.11, 1.09, p trend: 0.060). Women in the highest quintile of perceived neighborhood social cohesion (vs. lowest quintile) had lower global cognition (β - 0.56, 95% CI - 1.02, - 0.09, p trend 0.004), verbal learning (B - 1.01, 95% CI - 2.00, - 0.03, p trend 0.015), verbal fluency (B - 2.00, 95% CI - 3.83, - 0.16, p trend 0.006), and processing speed (B - 2.11, 95% CI - 3.87, - 0.36, p trend 0.009). There was no association between perceived neighborhood safety from crime and cognition among women, or between any perceived neighborhood environment measure and cognition among men.

CONCLUSIONS

Middle-aged and older Hispanic/Latina women living in neighborhoods with the lowest perceived problems had higher global cognition and memory. Women living in neighborhoods with the highest perceived social cohesion had lower global cognition, verbal learning, verbal fluency, and processing speed.

CATSLife: A Study of Lifespan Behavioral Development and Cognitive Functioning

The purpose of this update is to provide the most current information about both the Colorado Adoption Project (CAP) and the Longitudinal Twin Study (LTS) and to introduce the Colorado Adoption/Twin Study of Lifespan behavioral development and cognitive aging (CATSLife), a product of their merger and a unique study of lifespan behavioral development and cognitive aging. The primary objective of CATSLife is to assess the unique saliency of early childhood genetic and environmental factors to adult cognitive maintenance and change, as well as proximal influences and innovations that emerge across development. CATSLife is currently assessing up to 1600 individuals on the cusp of middle age, targeting those between 30 and 40 years of age. The ongoing CATSLife data collection is described as well as the longitudinal data available from the earlier CAP and LTS assessments. We illustrate CATSLife via current projects and publications, highlighting the measurement of genetic, biochemical, social, sociodemographic and environmental indices, including geospatial features, and their impact on cognitive maintenance in middle adulthood. CATSLife provides an unparalleled opportunity to assess prospectively the etiologies of cognitive change and test the saliency of early childhood versus proximal influences on the genesis of cognitive decline.

Is it possible to overcome the 'long arm' of childhood socioeconomic disadvantage through upward socioeconomic mobility?

OBJECTIVES

Socioeconomically disadvantaged children have worse adult health; we test if this 'long arm' of childhood disadvantage can be overcome through upward socioeconomic mobility in adulthood.

METHODS

Four SES trajectories (stable low, upwardly mobile, downwardly mobile and stable high) were created from median dichotomized childhood socioeconomic status (SES; childhood human and financial capital) and adult SES (wealth at age 67) from Health and Retirement Study respondents (N = 6669). Healthy ageing markers, in tertiles, were walking speed, peak expiratory flow (PEF), and grip strength measured in 2008 and 2010. Multinomial logistic regression models, weighted to be nationally representative, controlled for age, gender, race, birthplace, outcome year and childhood health and social capital.

RESULTS

Upwardly mobile individuals were as likely as the stable high SES group to be in the best health tertile for walking speed (OR = 0.81; 95% CI: 0.63, 1.05; P = 0.114), PEF (OR = 0.97; 95% CI: 0.78, 1.21; P = 0.810) and grip strength (OR = 0.97; 95%CI: 0.74, 1.27; P = 0.980).

DISCUSSION

Findings suggest the 'long arm' of childhood socioeconomic disadvantage can be overcome for these markers of healthy ageing through upward socioeconomic mobility.

Association between psychosocial factors at work and health outcomes after retirement: a protocol for a systematic review and meta-analysis

INTRODUCTION

The world's population is rapidly ageing, and health among older people is thus an important issue. Several previous studies have reported an association between adverse psychosocial factors at work before retirement and postretirement health. The objective of this systematic review and meta-analysis is to examine the association between psychosocial factors at work and health outcomes after retirement, based on a synthesis of well-designed prospective studies.

METHODS AND ANALYSIS

The participants, exposures, comparisons and outcomes of the studies in this systematic review and meta-analysis are defined as follows: (P) people who have retired from their job, (E) presence of adverse psychosocial factors at work before retirement, (C) absence of adverse psychosocial factors at work before retirement and (O) any physical and mental health outcomes after retirement. Published studies were searched using the following electronic databases: MEDLINE, EMBASE, PsycINFO, PsycARTICLES and Japan Medical Abstracts Society. The included studies will be statistically synthesised in a meta-analysis to estimate pooled coefficients and 95% CIs. The quality of each included study will be assessed using the Risk Of Bias In Non-randomised Studies-of Interventions. For the assessment of meta-bias, publication bias will be assessed by using Egger's test, as well as visually on a funnel plot. Heterogeneity will be assessed using the χ² test with Cochran's Q statistic and I².

ETHICS AND DISSEMINATION

Results and findings will be submitted and published in a scientific peer-reviewed journal and will be disseminated broadly to researchers and policy-makers interested in the translatability of scientific evidence into good practices.

PROSPERO REGISTRATION NUMBER

CRD42018099043.

APOE effects on cognition from childhood to adolescence

The ε4 allele of APOE is a well-established genetic risk factor for cognitive aging and dementia, but its influence on early life cognition is unknown. Consequently, we assessed associations of APOE genotypes with cognitive performance during 7, 12, and 16 year-assessments in our ongoing Colorado Adoption/Twin Study of Lifespan behavioral development (CATSLife). In general, APOE ε4 was associated with lower Verbal, Performance, and Full Scale IQ scores during childhood and adolescence (e.g., Full Scale IQ was lower by 1.91 points per ε4 allele, d = -0.13), with larger effects in females (e.g., average Full Scale IQ scores were 3.41 points lower in females per each ε4 allele vs. 0.33 points lower in males). Thus, these results suggest that deleterious effects of the APOE ε4 allele are manifested before adulthood, especially in females, and support both early origin theories and differential life-course vulnerabilities for later cognitive impairment.

Stress and Salivary Telomere Length in the Second Half of Life: A Comparison of Life-course Models

Background

Previous research has explored the relationship between childhood and adulthood stressful life events (SLEs) and adult salivary telomere length (TL), but no research to date has tested different life-course models in which stress in adulthood may fully, partly, or not mediate the relationship between childhood stress and adult TL.

Methods

To fill this gap, we elaborate over previous work by Puterman et al. (2016) and other standard models that do not account for the temporal order of stressors in childhood and adulthood, by using structural equation modeling (SEM) for a sample of 5,754 Health and Retirement Study (HRS) participants to compare the fit of three nested life-course models-social trajectory, early critical period, and cumulative risk.

Results

Results indicated that the social trajectory model, in which the association between childhood SLEs and TL in later adulthood is fully mediated by adulthood SLEs, fit the data better than the early critical period (no mediation) and cumulative risk (partial mediation) models.

Conclusion

In the social trajectory model, childhood SLEs are related to TL in later life only through adulthood SLEs. The direct physiological effect of childhood SLEs on TL in later life would be overestimated if adulthood SLEs are overlooked.

Genetic regulation of the placental transcriptome underlies birth weight and risk of childhood obesity

GWAS identified variants associated with birth weight (BW), childhood obesity (CO) and childhood BMI (CBMI), and placenta is a critical organ for fetal development and postnatal health. We examined the role of placental transcriptome and eQTLs in mediating the genetic causes for BW, CO and CBMI, and applied integrative analysis (Colocalization and MetaXcan). GWAS loci associated with BW, CO, and CBMI were substantially enriched for placenta eQTLs (6.76, 4.83 and 2.26 folds, respectively). Importantly, compared to eQTLs of adult tissues, only placental eQTLs contribute significantly to both anthropometry outcomes at birth (BW) and childhood phenotypes (CO/CBMI). Eight, six and one transcripts colocalized with BW, CO and CBMI risk loci, respectively. Our study reveals that placental transcription in utero likely plays a key role in determining postnatal body size, and as such may hold new possibilities for therapeutic interventions to prevent childhood obesity.

The Impact of Multiple Dimensions of Socioeconomic Status on Physical Functioning Across the Life Course

Objective: We used the Physical Performance Across the LifeSpan Study to investigate the relationships of multiple indicators of socioeconomic status (SES), both in early life and late life, with physical function. Method: We examined associations between multiple early and late life SES indicators with physical function measured by aerobic endurance, gait speed, and lower body strength. Results: Higher participant education and household income were associated with increased physical function. In our age-stratified analysis, we observed widening SES disparities with increasing age among those in the two younger strata with lower SES associated with worse physical function. Finally, we observed an association between socioeconomic trend and gait speed, aerobic endurance, and lower body strength. There was also an association between lower aerobic endurance and being in a downward socioeconomic trend. Discussion: These findings highlight the significance of considering multiple dimensions of the social environment as important correlates of physical functioning across the life course.

Cognitive Disparities: The Impact of the Great Depression and Cumulative Inequality on Later-Life Cognitive Function

Population aging has driven a spate of recent research on later-life cognitive function. Greater longevity increases the lifetime risk of memory diseases that compromise the cognitive abilities vital to well-being. Alzheimer's disease, thought to be the most common underlying pathology for elders' cognitive dysfunction (Willis and Hakim 2013), is already the sixth leading cause of death in the United States (Alzheimer's Association 2016). Understanding social determinants of pathological cognitive decline is key to crafting interventions, but evidence is inconclusive for how social factors interact over the life course to affect cognitive function. I study whether early-life exposure to the Great Depression is directly associated with later-life cognitive function, influences risky behaviors over the life course, and/or accumulates with other life-course disadvantages. Using growth curve models to analyze the Health and Retirement Study, I find that early-life exposure to the Great Depression is associated with fluid cognition, controlling for intervening factors-evidence for a critical period model. I find little support for a social trajectory model. Disadvantage accumulates over the life course to predict worse cognitive function, providing strong evidence for a cumulative inequality model.

Green space and cognitive ageing: A retrospective life course analysis in the Lothian Birth Cohort 1936

International evidence suggests that green space has beneficial effects on general and mental health but little is known about how lifetime exposure to green space influences cognitive ageing. Employing a novel longitudinal life course approach, we examined the association between lifetime availability of public parks and cognitive ageing. Lifetime residential information was gathered from the participants of the Lothian Birth Cohort 1936 using a "life-grid" questionnaire at age 78 years. Parks information from 1949, 1969 and 2009 was used to determine a percentage of parks within a 1500 m buffer zone surrounding residence for childhood, adulthood, and later adulthood periods. Linear regressions were undertaken to test for association with age-standardised, residualised change in cognitive function (Moray House Test score) from age 11 to 70 years, and from age 70 to 76 (n = 281). The most appropriate model was selected using the results of a partial F-test, and then stratified by demographic, genetic and socioeconomic factors. The local provision of park space in childhood and adulthood were both important in explaining the change in cognitive function in later life. The association between childhood and adulthood park availability and change in the Moray House Test Score from age 70 to 76 was strongest for women, those without an APOE e4 allele (a genetic risk factor), and those in the lowest socioeconomic groups. Greater neighbourhood provision of public parks from childhood through to adulthood may help to slow down the rate of cognitive decline in later life, recognising that such environmental associations are always sensitive to individual characteristics.

Healthy Ageing: Raising Awareness of Inequalities, Determinants, and What Could Be Done to Improve Health Equity

PURPOSE OF THE STUDY

Social and scientific discourses on healthy ageing and on health equity are increasingly available, yet from a global perspective limited conceptual and analytical work connecting both has been published. This review was done to inform the WHO World Report on Ageing and Health and to inform and encourage further work addressing both healthy aging and equity.

DESIGN AND METHODS

We conducted an extensive literature review on the overlap between both topics, privileging publications from 2005 onward, from low-, middle-, and high-income countries. We also reviewed evidence generated around the WHO Commission on Social Determinants of Health, applicable to ageing and health across the life course.

RESULTS

Based on data from 194 countries, we highlight differences in older adults' health and consider three issues: First, multilevel factors that contribute to differences in healthy ageing, across contexts; second, policies or potential entry points for action that could serve to reduce unfair differences (health inequities); and third, new research areas to address the cause of persistent inequities and gaps in evidence on what can be done to increase healthy ageing and health equity.

IMPLICATIONS

Each of these areas warrant in depth analysis and synthesis, whereas this article presents an overview for further consideration and action.

Perceived Neighborhood Safety Better Predicts Risk of Mortality for Whites than Blacks

AIM

The current study had two aims: (1) to investigate whether single-item measures of subjective evaluation of neighborhood (i.e., perceived neighborhood safety and quality) predict long-term risk of mortality and (2) to test whether these associations depend on race and gender.

METHODS

The data came from the Americans' Changing Lives Study (ACL), 1986-2011, a nationally representative longitudinal cohort of 3361 Black and White adults in the USA. The main predictors of interest were perceived neighborhood safety and perceived neighborhood quality, as measured in 1986 using single items and treated as dichotomous variables. Mortality due to all internal and external causes was the main outcome. Confounders included baseline age, socioeconomic status (education, income), health behaviors (smoking, drinking, and exercise), and health (chronic medical conditions, self-rated health, and depressive symptoms). Race and gender were focal effect modifiers. Cox proportional hazard models were ran in the pooled sample and stratified by race and gender.

RESULTS

In the pooled sample, low perceived neighborhood safety and quality predicted increased risk of mortality due to all causes as well as internal causes, net of all covariates. Significant interaction was found between race and perceived neighborhood safety on all-cause mortality, indicating a stronger association for Whites compared to Blacks. Race did not interact with perceived neighborhood quality on mortality. Gender also did not interact with perceived neighborhood safety or quality on mortality. Perceived neighborhood safety and quality were not associated with mortality due to external causes.

CONCLUSION

Findings suggest that single items are appropriate for the measurement of perceived neighborhood safety and quality. Our results also suggest that perceived neighborhood safety better predicts increased risk of mortality over the course of 25 years among Whites than Blacks.

Model Selection of the Effect of Binary Exposures over the Life Course

Supplemental Digital Content is available in the text.

Epidemiologists are often interested in examining the effect on a later-life outcome of an exposure measured repeatedly over the life course. When different hypotheses for this effect are proposed by competing theories, it is important to identify those most supported by observed data as a first step toward estimating causal associations. One method is to compare goodness-of-fit of hypothesized models with a saturated model, but it is unclear how to judge the “best” out of two hypothesized models that both pass criteria for a good fit. We developed a new method using the least absolute shrinkage and selection operator to identify which of a small set of hypothesized models explains most of the observed outcome variation. We analyzed a cohort study with repeated measures of socioeconomic position (exposure) through childhood, early- and mid-adulthood, and body mass index (outcome) measured in mid-adulthood. We confirmed previous findings regarding support or lack of support for the following hypotheses: accumulation (number of times exposed), three critical periods (only exposure in childhood, early- or mid-adulthood), and social mobility (transition from low to high socioeconomic position). Simulations showed that our least absolute shrinkage and selection operator approach identified the most suitable hypothesized model with high probability in moderately sized samples, but with lower probability for hypotheses involving change in exposure or highly correlated exposures. Identifying a single, simple hypothesis that represents the specified knowledge of the life course association allows more precise definition of the causal effect of interest.