Neighborhood and Family Environment of Expectant Mothers May Influence Prenatal Programming of Adult Cancer Risk: Discussion and an Illustrative DNA Methylation Example

Maternal adverse childhood experiences (ACEs) and offspring imprinted gene DMR methylation at birth

Adverse childhood experiences (ACEs) contribute to numerous negative health outcomes across the life course and across generations. Here, we extend prior work by examining the association of maternal ACEs, and their interaction with financial stress and discrimination, with methylation status within eight differentially methylated regions (DMRs) in imprinted domains in newborns. ACEs, financial stress during pregnancy, and experience of discrimination were self-reported among 232 pregnant women. DNA methylation was assessed at PEG10/SGCE, NNAT, IGF2, H19, PLAGL1, PEG3, MEG3-IG, and DLK1/MEG3 regulatory sequences using pyrosequencing. Using multivariable linear regression models, we found evidence to suggest that financial stress was associated with hypermethylation of MEG3-IG in non-Hispanic White newborns; discrimination was associated with hypermethylation of IGF2 and NNAT in Hispanic newborns, and with hypomethylation of PEG3 in non-Hispanic Black newborns. We also found evidence that maternal ACEs interacted with discrimination to predict offspring PLAGL1 altered DMR methylation, in addition to interactions between maternal ACEs score and discrimination predicting H19 and SGCE/PEG10 altered methylation in non-Hispanic White newborns. However, these interactions were not statistically significant after multiple testing corrections. Findings from this study suggest that maternal ACEs, discrimination, and financial stress are associated with newborn aberrant methylation in imprinted gene regions.

Racial and Ethnic Residential Segregation and Monocyte DNA Methylation Age Acceleration

Importance

Neighborhood segregation and poverty may be important drivers of health inequities. Epigenomic factors, including DNA methylation clocks that may mark underlying biological aging, have been implicated in the link between social factors and health.

Objective

To examine the associations of neighborhood segregation and poverty with 4 DNA methylation clocks trained to capture either chronological age or physiological dysregulation.

Design, Setting, and Participants

This cohort study uses data from the Multi-Ethnic Study of Atherosclerosis (MESA), a longitudinal study that started in 2000 to 2002, with follow-up in 2002 to 2004, 2004 to 2005, 2005 to 2007, and 2010 to 2012. In 2000 to 2002, adults who identified as White or Black race or Hispanic or Chinese ethnicity in 6 US sites (Baltimore, Maryland; Chicago, Illinois; Forsyth County, North Carolina; Los Angeles County, California; Northern Manhattan, New York; and St. Paul, Minnesota) were sampled for recruitment. A random subsample of 4 sites (Maryland, North Carolina, New York, and Minnesota) were selected for inclusion in the MESA epigenomics ancillary study at examination 5 (2010-2012). Participants who identified as White or Black race or Hispanic ethnicity, were aged 45 to 84 years, and did not have clinical cardiovascular disease were included in this analysis. Data were analyzed from May 2021 to October 2023.

Exposure

Information on 2000 census tract poverty and Getis-Ord G statistic segregation of Hispanic residents, non-Hispanic Black residents, or non-Hispanic White residents were linked to participant addresses at examination 1 (2000-2002).

Main Outcomes and Measures

At examination 5, DNA methylation was measured in purified monocytes. DNA methylation age acceleration was calculated using 4 clocks trained on either chronological age or physiological dysregulation. Linear regressions were used to test associations.

Results

A total of 1102 participants (mean [SD] age, 69.7 [9.4] years; 562 [51%] women) were included, with 348 Hispanic participants, 222 non-Hispanic Black participants, and 533 non-Hispanic White participants. For non-Hispanic Black participants, living in tracts with greater segregation of Black residents was associated with GrimAge DNA methylation age acceleration, a clock designed to capture physiological dysregulation. A 1-SD increase in segregation was associated with 0.42 (95% CI, 0.20-0.64) years age acceleration (P < .001); this association was not observed with other clocks. This association was particularly pronounced for participants living in high poverty tracts (interaction term, 0.24; 95% CI, 0.07-0.42; P = .006). In the overall sample, census tract poverty level was associated with GrimAge DNA methylation age acceleration (β = 0.45; 95% CI, 0.20-0.71; adjusted P = .005).

Conclusions and Relevance

These findings suggest that epigenomic mechanisms may play a role in the associations of segregated and poor neighborhoods with chronic conditions.

Epigenetics of Early Cardiometabolic Disease: Mechanisms and Precision Medicine

Epigenetics has transformed our understanding of the molecular basis of complex diseases, including cardiovascular and metabolic disorders. This review offers a comprehensive overview of the current state of knowledge on epigenetic processes implicated in cardiovascular and metabolic diseases, highlighting the potential of DNA methylation as a precision medicine biomarker and examining the impact of social determinants of health, gut bacterial epigenomics, noncoding RNA, and epitranscriptomics on disease development and progression. We discuss challenges and barriers to advancing cardiometabolic epigenetics research, along with the opportunities for novel preventive strategies, targeted therapies, and personalized medicine approaches that may arise from a better understanding of epigenetic processes. Emerging technologies, such as single-cell sequencing and epigenetic editing, hold the potential to further enhance our ability to dissect the complex interplay between genetic, environmental, and lifestyle factors. To translate research findings into clinical practice, interdisciplinary collaborations, technical and ethical considerations, and accessibility of resources and knowledge are crucial. Ultimately, the field of epigenetics has the potential to revolutionize the way we approach cardiovascular and metabolic diseases, paving the way for precision medicine and personalized health care, and improving the lives of millions of individuals worldwide affected by these conditions.

Epigenetics as a Biomarker for Early-Life Environmental Exposure

PURPOSE OF REVIEW

There is interest in evaluating the developmental origins of health and disease (DOHaD) which emphasizes the role of prenatal and early-life environments on non-communicable health outcomes throughout the life course. The ability to rigorously assess and identify early-life risk factors for later health outcomes, including those with childhood onset, in large population samples is often limited due to measurement challenges such as impractical costs associated with prospective studies with a long follow-up duration, short half-lives for some environmental toxicants, and lack of biomarkers that capture inter-individual differences in biologic response to external environments.

RECENT FINDINGS

Epigenomic patterns, and DNA methylation in particular, have emerged as a potential objective biomarker to address some of these study design and exposure measurement challenges. In this article, we summarize the literature to date on epigenetic changes associated with specific prenatal and early-life exposure domains as well as exposure mixtures in human observational studies and their biomarker potential. Additionally, we highlight evidence for other types of epigenetic patterns to serve as exposure biomarkers. Evidence strongly supports epigenomic biomarkers of exposure that are detectable across the lifespan and across a range of exposure domains. Current and future areas of research in this field seek to expand these lines of evidence to other environmental exposures, to determine their specificity, and to develop predictive algorithms and methylation scores that can be used to evaluate early-life risk factors for health outcomes across the life span.

Prenatal Socioeconomic Disadvantage and Epigenetic Alterations at Birth Among Children Born to White British and Pakistani Mothers in the Born in Bradford Study

Prenatal socioeconomic disadvantage (SD) has been linked to DNA methylation (DNAm) in adulthood, but whether such epigenetic alterations are present at birth remains unclear. We carried out an epigenome-wide analysis of the association between several measures of individual- and area-level prenatal SD and DNAm assessed in neonatal cord blood via the Infinium EpicBeadChip among offspring born to mothers of White British (N = 455) and Pakistani (N = 493) origin in the Born in Bradford Study. Models were adjusted for mother's age, ethnicity, and education level as well as cell-type fractions and then for maternal health behaviours and neonate characteristics, and last, stratified by mother's ethnicity. P-values were corrected for multiple testing and a permutation-based approach was used to account for small cell sizes. Among all children, housing tenure (owning versus renting) as well as father's occupation (manual versus non-manual) were each associated with DNAm of one CpG site and index of multiple deprivation (IMD) was associated with DNAm of 11 CpG sites. Among children born to White British mothers, father's occupation (student or unemployed versus non-manual) was associated with DNAm of 1 CpG site and IMD with DNAm of 3 CpG sites. Among children born to Pakistani mothers, IMD was associated with DNAm of 1 CpG site. Associations were largely unchanged after further adjustment for maternal health behaviours or neonate characteristics and remained statistically significant. Our findings suggest that individual- and area-level prenatal SD may shape alterations to the neonatal epigenome, but associations vary across ethnic groups.

Understanding Health Inequalities Through the Lens of Social Epigenetics

Longstanding racial/ethnic inequalities in morbidity and mortality persist in the United States. Although the determinants of health inequalities are complex, social and structural factors produced by inequitable and racialized systems are recognized as contributing sources. Social epigenetics is an emerging area of research that aims to uncover biological pathways through which social experiences affect health outcomes. A growing body of literature links adverse social exposures to epigenetic mechanisms, namely DNA methylation, offering a plausible pathway through which health inequalities may arise. This review provides an overview of social epigenetics and highlights existing literature linking social exposures—i.e., psychosocial stressors, racism, discrimination, socioeconomic position, and neighborhood social environment—to DNA methylation in humans.We conclude with a discussion of social epigenetics as a mechanistic link to health inequalities and provide suggestions for future social epigenetics research on health inequalities.

Associations between indicators of socioeconomic position and DNA methylation: a scoping review

BACKGROUND

Socioeconomic position (SEP) is a major determinant of health across the life course. Yet, little is known about the biological mechanisms explaining this relationship. One possibility widely pursued in the scientific literature is that SEP becomes biologically embedded through epigenetic processes such as DNA methylation (DNAm), wherein the socioeconomic environment causes no alteration in the DNA sequence but modifies gene activity in ways that shape health.

METHODS

To understand the evidence supporting a potential SEP-DNAm link, we performed a scoping review of published empirical findings on the association between SEP assessed from prenatal development to adulthood and DNAm measured across the life course, with an emphasis on exploring how the developmental timing, duration, and type of SEP exposure influenced DNAm.

RESULTS

Across the 37 identified studies, we found that: (1) SEP-related DNAm signatures varied across the timing, duration, and type of SEP indicator; (2) however, longitudinal studies examining repeated SEP and DNAm measures are generally lacking; and (3) prior studies are conceptually and methodologically diverse, limiting the interpretability of findings across studies with respect to these three SEP features.

CONCLUSIONS

Given the complex relationship between SEP and DNAm across the lifespan, these findings underscore the importance of analyzing SEP features, including timing, duration, and type. To guide future research, we highlight additional research gaps and propose four recommendations to further unravel the relationship between SEP and DNAm.

Neighborhood Socioeconomic Deprivation and Mortality in Children with Central Nervous System Tumors

BACKGROUND

Although there is evidence of socioeconomic disparities in survival of children diagnosed with central nervous system (CNS) tumors, the impact of neighborhood socioeconomic deprivation on the survival of these malignancies has not been adequately studied. We investigated the association between area deprivation index (ADI), a measure of neighborhood socioeconomic disadvantage, and pediatric CNS tumor survival.

METHODS

Demographic and clinical characteristics, geocoded addresses at diagnosis, and vital status of pediatric CNS tumor cases (n = 5,477) for the period 1995 to 2017 were obtained from the Texas Cancer Registry. ADI scores were computed for census tracts in Texas using the U.S. Census Bureau 2010 geography. Tracts were classified into quartiles as least, third-most, second-most, and most disadvantaged. Children were mapped to quartiles based on residency at diagnosis. The adjusted hazard ratio (HR) and 95% confidence interval (CI) were calculated.

RESULTS

The results showed a significantly increased HR for death among children in the most (HR, 1.29; 95% CI, 1.09-1.51), second-most (HR, 1.18; 95% CI, 1.01-1.38), and third-most disadvantaged census tracts (HR, 1.18; 95% CI, 1.02-1.37) compared with children in the least disadvantaged tracts.

CONCLUSIONS

Children living in the most disadvantaged neighborhoods experienced a significantly higher risk of mortality, indicating the important role of socioeconomic disparities in the survival of pediatric CNS tumors.

IMPACT

The demographic and socioeconomic disparities identified by this study should be considered when planning treatment strategies for these susceptible groups and thus, lead to a better outcome in socioeconomically disadvantaged children diagnosed with CNS tumors.

Impact of paternal education on epigenetic ageing in adolescence and mid-adulthood: a multi-cohort study in the USA and Mexico

BACKGROUND

Both parental and neighbourhood socio-economic status (SES) are linked to poorer health independently of personal SES measures, but the biological mechanisms are unclear. Our objective was to examine these influences via epigenetic age acceleration (EAA)-the discrepancy between chronological and epigenetic ages.

METHODS

We examined three USA-based [Coronary Artery Risk Disease in Adults (CARDIA) study, Fragile Families and Child Wellbeing Study (FFCWS) and Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS)] and one Mexico-based (Project Viva) cohort. DNA methylation was measured using Illumina arrays, personal/parental SES by questionnaire and neighbourhood disadvantage from geocoded address. In CARDIA, we examined the most strongly associated personal, parental and neighbourhood SES measures with EAA (Hannum's method) at study years 15 and 20 separately and combined using a generalized estimating equation (GEE) and compared with other EAA measures (Horvath's EAA, PhenoAge and GrimAge calculators, and DunedinPoAm).

RESULTS

EAA was associated with paternal education in CARDIA [GEEs: βsome college = -1.01 years (-1.91, -0.11) and β<high school = 1.05 (0.09, 2.01) vs college graduates] and FFCWS [GEEs: β<high school = 0.62 (0.00, 1.24)]. We found stronger associations for some paternal education categories among White adults (for GEE, βsome college = -1.39 (-2.41, -0.38)], men (βsome college = -1.76 (-3.16, -0.35)] and women [β<high school = 1.77 (0.42, 3.11)].

CONCLUSIONS

These findings suggest that EAA captures epigenetic impacts of paternal education independently of personal SES later in life. Longitudinal studies should explore these associations at different life stages and link them to health outcomes. EAA could be a useful biomarker of SES-associated health and provide important insight into the pathogenesis and prevention of chronic disease.

Prenatal Neighborhood Ethnocultural Context and the Mental Health of Mothers and Children in Low-Income Mexican American Families

Socioeconomically disadvantaged neighborhoods increase the risk for poor mental health among residents, yet protective factors may operate alongside risk. This study evaluated the influence of the prenatal neighborhood ethnocultural context on child behavior problems and maternal depressive symptoms. Prenatal maternal role expectations, prenatal culture-specific stress, and postpartum depression (PPD) symptoms were evaluated as mediators. Participants included 322 low-income, Mexican American mother-child dyads. Women (Mage  = 27.8) reported on proposed mediators, maternal depressive symptoms, and child behavior problems at 4.5 years. Neighborhood Latinx concentration was obtained from census data. Higher Latinx concentration predicted fewer maternal depressive symptoms and child behavior problems, mediated through role expectations and PPD symptoms. Results suggest prenatal neighborhood context to impact later maternal and child mental health.

Neighborhood environment, social cohesion, and epigenetic aging

Living in adverse neighborhood environments has been linked to risk of aging-related diseases and mortality; however, the biological mechanisms explaining this observation remain poorly understood. DNA methylation (DNAm), a proposed mechanism and biomarker of biological aging responsive to environmental stressors, offers promising insight into potential molecular pathways. We examined associations between three neighborhood social environment measures (poverty, quality, and social cohesion) and three epigenetic clocks (Horvath, Hannum, and PhenoAge) using data from the Detroit Neighborhood Health Study (n=158). Using linear regression models, we evaluated associations in the total sample and stratified by sex and social cohesion. Neighborhood quality was associated with accelerated DNAm aging for Horvath age acceleration (β = 1.8; 95% CI: 0.4, 3.1), Hannum age acceleration (β = 1.7; 95% CI: 0.4, 3.0), and PhenoAge acceleration (β = 2.1; 95% CI: 0.4, 3.8). In models stratified on social cohesion, associations of neighborhood poverty and quality with accelerated DNAm aging remained elevated for residents living in neighborhoods with lower social cohesion, but were null for those living in neighborhoods with higher social cohesion. Our study suggests that living in adverse neighborhood environments can speed up epigenetic aging, while positive neighborhood attributes may buffer effects.

Associations Between Maternal Community Deprivation and Infant DNA Methylation of the SLC6A4 Gene

Introduction: Poverty is negatively associated with health and developmental outcomes. DNA methylation (DNAm) has been proposed as a mechanism that underlies the association between adversity experienced by mothers in poverty and health and developmental outcomes in their offspring. Previous studies have identified associations between individual-level measures of stress and adversity experienced by a mother during pregnancy and infant DNAm. We hypothesized that independent of individual stresses, a mother's community-level deprivation while she is pregnant may also be associated with DNAm among the genes of her offspring that are related to stress response and/or development. Methods: Pregnant mothers (N = 53) completed assessments that measured stress, adversity, and mental health. To evaluate community-level deprivation, mothers' addresses were linked to census-level socioeconomic measures including a composite index of deprivation that combines multiple community-level indicators such as income and highest level of education received. Infant buccal cells were collected at about age 4 weeks to measure DNAm of candidate genes including NR3C1, SCG5, and SLC6A4, which are associated with the stress response and or social and emotional development. Multivariable models were employed to evaluate the association between maternal community deprivation and infant DNAm of candidate genes. Results: No significant associations were identified between maternal community-level deprivation and the methylation of NR3C1 or SCG5, however, maternal community-level deprivation was significantly associated with higher mean methylation across 8 CpG sites in SLC6A4. Conclusion: This study identified an association between community-level measures of deprivation experienced by a mother during pregnancy and DNAm in their offspring. These findings may have implications for understanding how the community context can impact early biology and potential function in the next generation.

Multilevel prenatal socioeconomic determinants of Mexican American children's weight: Mediation by breastfeeding

Objective: Mexican American (MA) children are more likely to grow up in poverty than their non-Hispanic/Latinx white peers and are at an elevated risk for early onset obesity. The current study evaluated the effects of prenatal family- and neighborhood-level disadvantage on children's weight and weight gain from 12 months through 4.5 years of age. Maternal breastfeeding duration was evaluated as a potential mechanism underlying the relation between multilevel disadvantage and weight. Methods: Data was collected from 322 low-income, MA mother-child dyads. Women reported the degree of family socioeconomic disadvantage and breastfeeding status. Neighborhood disadvantage was evaluated with census-level metrics. Children's weight and height were measured at laboratory visits. Results: Greater prenatal neighborhood disadvantage predicted higher child Body Mass Index (BMI) at 12 months, over and above family-level disadvantage; this effect remained stable through 4.5 years. Breastfeeding duration partially mediated the effect of neighborhood disadvantage on child BMI. Breastfeeding duration predicted child BMI at all timepoints. Conclusions: Maternal prenatal residence in a neighborhood with high concentrated disadvantage may place low-income, MA children at increased risk of elevated weight status during the first few years of life. Breastfeeding duration emerged as potentially modifiable pathway through which the prenatal neighborhood impacts children's early life weight. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Use of an Exposome Approach to Understand the Effects of Exposures From the Natural, Built, and Social Environments on Cardio-Vascular Disease Onset, Progression, and Outcomes

Obesity, diabetes, and hypertension have increased by epidemic proportions in recent years among African Americans in comparison to Whites resulting in significant adverse cardiovascular disease (CVD) disparities. Today, African Americans are 30% more likely to die of heart disease than Whites and twice as likely to have a stroke. The causes of these disparities are not yet well-understood. Improved methods for identifying underlying risk factors is a critical first step toward reducing Black:White CVD disparities. This article will focus on environmental exposures in the external environment and how they can lead to changes at the cellular, molecular, and organ level to increase the personal risk for CVD and lead to population level CVD racial disparities. The external environment is defined in three broad domains: natural (air, water, land), built (places you live, work, and play) and social (social, demographic, economic, and political). We will describe how environmental exposures in the natural, built, and social environments "get under the skin" to affect gene expression though epigenetic, pan-omics, and related mechanisms that lead to increased risk for adverse CVD health outcomes and population level disparities. We also will examine the important role of metabolomics, proteomics, transcriptomics, genomics, and epigenomics in understanding how exposures in the natural, built, and social environments lead to CVD disparities with implications for clinical, public health, and policy interventions. In this review, we apply an exposome approach to Black:White CVD racial disparities. The exposome is a measure of all the exposures of an individual across the life course and the relationship of those exposures to health effects. The exposome represents the totality of exogenous (external) and endogenous (internal) exposures from conception onwards, simultaneously distinguishing, characterizing, and quantifying etiologic, mediating, moderating, and co-occurring risk and protective factors and their relationship to disease. Specifically, it assesses the biological mechanisms and underlying pathways through which chemical and non-chemical environmental exposures are associated with CVD onset, progression and outcomes. The exposome is a promising approach for understanding the complex relationships among environment, behavior, biology, genetics, and disease phenotypes that underlie population level, Black: White CVD disparities.

Association of Neighborhood Disadvantage in Childhood With DNA Methylation in Young Adulthood

IMPORTANCE

DNA methylation has been proposed as an epigenetic mechanism by which the childhood neighborhood environment may have implications for the genome that compromise adult health.

OBJECTIVE

To ascertain whether childhood neighborhood socioeconomic disadvantage is associated with differences in DNA methylation by age 18 years.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal cohort study analyzed data from the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative birth cohort of children born between 1994 and 1995 in England and Wales and followed up from age 5 to 18 years. Data analysis was performed from March 15, 2019, to June 30, 2019.

EXPOSURES

High-resolution neighborhood data (indexing deprivation, dilapidation, disconnection, and dangerousness) collected across childhood.

MAIN OUTCOMES AND MEASURES

DNA methylation in whole blood was drawn at age 18 years. Associations between neighborhood socioeconomic disadvantage and methylation were tested using 3 prespecified approaches: (1) testing probes annotated to candidate genes involved in biological responses to growing up in socioeconomically disadvantaged neighborhoods and investigated in previous epigenetic research (stress reactivity-related and inflammation-related genes), (2) polyepigenetic scores indexing differential methylation in phenotypes associated with growing up in disadvantaged neighborhoods (obesity, inflammation, and smoking), and (3) a theory-free epigenome-wide association study.

RESULTS

A total of 1619 participants (806 female individuals [50%]) had complete neighborhood and DNA methylation data. Children raised in socioeconomically disadvantaged neighborhoods exhibited differential DNA methylation in genes involved in inflammation (β = 0.12; 95% CI, 0.06-0.19; P < .001) and smoking (β = 0.18; 95% CI, 0.11-0.25; P < .001) but not obesity (β = 0.05; 95% CI, -0.01 to 0.11; P = .12). An epigenome-wide association study identified multiple CpG sites at an arraywide significance level of P < 1.16 × 10-7 in genes involved in the metabolism of hydrocarbons. Associations between neighborhood disadvantage and methylation were small but robust to family-level socioeconomic factors and to individual-level tobacco smoking.

CONCLUSIONS AND RELEVANCE

Children raised in more socioeconomically disadvantaged neighborhoods appeared to enter young adulthood epigenetically distinct from their less disadvantaged peers. This finding suggests that epigenetic regulation may be a mechanism by which the childhood neighborhood environment alters adult health.

Neighborhood Environment and DNA Methylation: Implications for Cardiovascular Disease Risk

Exposure to chronic stress such as living in disadvantaged neighborhoods has been related to cardiovascular disease (CVD). Chronic stress may increase the risk for CVD by increasing levels of systemic inflammation (e.g., higher levels of pro-inflammatory cytokines). Differential DNA methylation of inflammation-related candidate genes is also related to higher risk for CVD. Thus, the purpose of this review was to examine the association of neighborhood disadvantage with DNA methylation. A search of literature was conducted using Scopus, CINAHL, PubMed, Medline, and Embase databases. The keywords neighborhood, neighborhood disorder, neighborhood crime, neighborhood violence, neighborhood safety, built environment, and housing vacancy were combined with the keywords DNA methylation and epigenetics. Five studies were included in this review (n = 3 adult blood samples and n = 2 fetal blood samples). Four of the five studies reported an association of neighborhood socioeconomic status, social environment, and crime with either global or gene-specific DNA methylation. Only two studies examined the association of neighborhood disadvantage with inflammation-related candidate genes. One of these studies found a significant association of neighborhood socioeconomic disadvantage and social environment with DNA methylation in inflammation-related candidate genes. Thus, data are limited on the association between neighborhood disadvantage and DNA methylation of inflammation-related candidate genes, as well as genes in other potential mechanistic pathways including psychosocial stress, toxin response, and adiposity. Future studies should examine these associations and the potential epigenetic mechanisms by which neighborhood disadvantage increases the risk for CVD.

DNA methylation and socioeconomic status in a Mexican-American birth cohort

Background

Maternal social environmental stressors during pregnancy are associated with adverse birth and child developmental outcomes, and epigenetics has been proposed as a possible mechanism for such relationships.

Methods

In a Mexican-American birth cohort of 241 maternal-infant pairs, cord blood samples were measured for repeat element DNA methylation (LINE-1 and Alu). Linear mixed effects regression was used to model associations between indicators of the social environment (low household income and education, neighborhood-level characteristics) and repeat element methylation. Results from a dietary questionnaire were also used to assess the interaction between maternal diet quality and the social environment on markers of repeat element DNA methylation.

Results

After adjusting for confounders, living in the most impoverished neighborhoods was associated with higher cord blood LINE-1 methylation (β = 0.78, 95%CI 0.06, 1.50, p = 0.03). No other neighborhood-, household-, or individual-level socioeconomic indicators were significantly associated with repeat element methylation. We observed a statistical trend showing that positive association between neighborhood poverty and LINE-1 methylation was strongest in cord blood of infants whose mothers reported better diet quality during pregnancy (pinteraction = 0.12).

Conclusion

Our findings indicate a small yet unexpected positive association between neighborhood-level poverty during pregnancy and methylation of repetitive element DNA in infant cord blood and that this association is possibly modified by diet quality during pregnancy. However, our null findings for other adverse SES indicators do not provide strong evidence for an adverse association between early-life socioeconomic environment and repeat element DNA methylation in infants.

Neighborhood Disadvantage and Telomere Length: Results from the Fragile Families Study

Telomeres are repetitive nucleotide sequences located at the ends of chromosomes that protect genetic material. We use data from the Fragile Families and Child Wellbeing Study to analyze the relationship between exposure to spatially concentrated disadvantage and telomere length for white and black mothers. We find that neighborhood disadvantage is associated with shorter telomere length for mothers of both races. This finding highlights a potential mechanism through which the unique spatially concentrated disadvantage faced by African Americans contributes to racial health disparities. We conclude that equalizing the health and socioeconomic status of black and white Americans will be very difficult without reducing levels of residential segregation in the United States.

Developmental Origins of Health Span and Life Span: A Mini-Review

BACKGROUND

A vast body of research has demonstrated that disease susceptibility and offspring health can be influenced by perinatal factors, which include both paternal and maternal behavior and environment. Offspring disease risk has the potential to affect the health span and life span of offspring.

KEY FINDINGS

Various maternal factors, such as environmental toxicant exposure, diet, stress, exercise, age at conception, and longevity have the potential to influence age-associated diseases such as cardiovascular disease, obesity, diabetes, and cancer risk in offspring. Paternal factors such as diet, age at conception, and longevity can potentially impact offspring health span and life span-reducing traits as well.

PRACTICAL IMPLICATIONS

Continued research could go a long way toward defining mechanisms of the developmental origins of life span and health span, and eventually establishing regimens to avoid negative developmental influences and to encourage positive interventions to potentially increase life span and improve health span in offspring.

Challenges and Opportunities in Social Epigenomics and Cancer

Social epigenomics is an area of science that evaluates why and how different social factors and processes affect different components of the epigenome. As it happens with most of the new areas in science, social epigenetics being a relatively new area, only limited progress has been made. However, the potential of implicating social epigenomics in improving health and health related policies is tremendous. Epidemiologic studies evaluating social, behavior, family, and environmental factors have helped understand social inequality and develop the area of social epigenomics. Most of the information in social epidemiology has been gathered from genetic studies. Now the time has come that we may apply similar approaches in social epigenomics because technologies of determining methylation, histone, and noncoding RNA profiling are well developed. The focus of this chapter is to understand the role of epigenetic regulation in social experiences at various stages in life due to altered function of genes and affecting health in populations with different races/ethnicity. Here we discuss the current challenges and opportunities in the field.