Neighborhood characteristics influence DNA methylation of genes involved in stress response and inflammation: The Multi-Ethnic Study of Atherosclerosis

Epigenome-wide association study of long-term psychosocial stress in older adults

Long-term psychosocial stress is strongly associated with negative physical and mental health outcomes, as well as adverse health behaviours; however, little is known about the role that stress plays on the epigenome. One proposed mechanism by which stress affects DNA methylation is through health behaviours. We conducted an epigenome-wide association study (EWAS) of cumulative psychosocial stress (n = 2,689) from the Health and Retirement Study (mean age = 70.4 years), assessing DNA methylation (Illumina Infinium HumanMethylationEPIC Beadchip) at 789,656 CpG sites. For identified CpG sites, we conducted a formal mediation analysis to examine whether smoking, alcohol use, physical activity, and body mass index (BMI) mediate the relationship between stress and DNA methylation. Nine CpG sites were associated with psychosocial stress (all p < 9E-07; FDR q < 0.10). Additionally, health behaviours and/or BMI mediated 9.4% to 21.8% of the relationship between stress and methylation at eight of the nine CpGs. Several of the identified CpGs were in or near genes associated with cardiometabolic traits, psychosocial disorders, inflammation, and smoking. These findings support our hypothesis that psychosocial stress is associated with DNA methylation across the epigenome. Furthermore, specific health behaviours mediate only a modest percentage of this relationship, providing evidence that other mechanisms may link stress and DNA methylation.

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.

Epigenetic scores derived in saliva are associated with gestational age at birth

BACKGROUND

Epigenetic scores (EpiScores), reflecting DNA methylation (DNAm)-based surrogates for complex traits, have been developed for multiple circulating proteins. EpiScores for pro-inflammatory proteins, such as C-reactive protein (DNAm CRP), are associated with brain health and cognition in adults and with inflammatory comorbidities of preterm birth in neonates. Social disadvantage can become embedded in child development through inflammation, and deprivation is overrepresented in preterm infants. We tested the hypotheses that preterm birth and socioeconomic status (SES) are associated with alterations in a set of EpiScores enriched for inflammation-associated proteins.

RESULTS

In total, 104 protein EpiScores were derived from saliva samples of 332 neonates born at gestational age (GA) 22.14 to 42.14 weeks. Saliva sampling was between 36.57 and 47.14 weeks. Forty-three (41%) EpiScores were associated with low GA at birth (standardised estimates |0.14 to 0.88|, Bonferroni-adjusted p-value < 8.3 × 10-3). These included EpiScores for chemokines, growth factors, proteins involved in neurogenesis and vascular development, cell membrane proteins and receptors, and other immune proteins. Three EpiScores were associated with SES, or the interaction between birth GA and SES: afamin, intercellular adhesion molecule 5, and hepatocyte growth factor-like protein (standardised estimates |0.06 to 0.13|, Bonferroni-adjusted p-value < 8.3 × 10-3). In a preterm subgroup (n = 217, median [range] GA 29.29 weeks [22.14 to 33.0 weeks]), SES-EpiScore associations did not remain statistically significant after adjustment for sepsis, bronchopulmonary dysplasia, necrotising enterocolitis, and histological chorioamnionitis.

CONCLUSIONS

Low birth GA is substantially associated with a set of EpiScores. The set was enriched for inflammatory proteins, providing new insights into immune dysregulation in preterm infants. SES had fewer associations with EpiScores; these tended to have small effect sizes and were not statistically significant after adjusting for inflammatory comorbidities. This suggests that inflammation is unlikely to be the primary axis through which SES becomes embedded in the development of preterm infants in the neonatal period.

Neighborhood Deprivation and Breast Cancer Mortality Among Black and White Women

Importance

Neighborhood deprivation has been associated with increased breast cancer mortality among White women, but findings are inconsistent among Black women, who experience different neighborhood contexts. Accounting for interactions among neighborhood deprivation, race, and other neighborhood characteristics may enhance understanding of the association.

Objective

To investigate whether neighborhood deprivation is associated with breast cancer mortality among Black and White women and whether interactions with rurality, residential mobility, and racial composition, which are markers of access, social cohesion, and segregation, respectively, modify the association.

Design, Setting, and Participants

This population-based cohort study used Georgia Cancer Registry (GCR) data on women with breast cancer diagnosed in 2010 to 2017 and followed-up until December 31, 2022. Data were analyzed between January 2023 and October 2023. The study included non-Hispanic Black and White women with invasive early-stage (I-IIIA) breast cancer diagnosed between 2010 and 2017 and identified through the GCR.

Exposures

The Neighborhood Deprivation Index (NDI), assessed in quintiles, was derived through principal component analysis of 2011 to 2015 block group-level American Community Survey (ACS) data. Rurality, neighborhood residential mobility, and racial composition were measured using Georgia Public Health Department or ACS data.

Main Outcomes and Measures

The primary outcome was breast cancer-specific mortality identified by the GCR through linkage to the Georgia vital statistics registry and National Death Index. Cox proportional hazards regression was used to estimate age-adjusted and multivariable-adjusted hazard ratios (HRs) and 95% CIs for the association between neighborhood deprivation and breast cancer mortality.

Results

Among the 36 795 patients with breast cancer (mean [SD] age at diagnosis, 60.3 [13.1] years), 11 044 (30.0%) were non-Hispanic Black, and 25 751 (70.0%) were non-Hispanic White. During follow-up, 2942 breast cancer deaths occurred (1214 [41.3%] non-Hispanic Black women; 1728 [58.7%] non-Hispanic White women). NDI was associated with an increase in breast cancer mortality (quintile 5 vs 1, HR, 1.36; 95% CI, 1.19-1.55) in Cox proportional hazards models. The association was present only among non-Hispanic White women (quintile 5 vs 1, HR, 1.47; 95% CI, 1.21-1.79). Similar race-specific patterns were observed in jointly stratified analyses, such that NDI was associated with increased breast cancer mortality among non-Hispanic White women, but not non-Hispanic Black women, irrespective of the additional neighborhood characteristics considered.

Conclusions and Relevance

In this cohort study, neighborhood deprivation was associated with increased breast cancer mortality among non-Hispanic White women. Neighborhood racial composition, residential mobility, and rurality did not explain the lack of association among non-Hispanic Black women, suggesting that factors beyond those explored here may contribute to breast cancer mortality in this racial group.

The effect of enriched versus depleted housing on eucalyptus smoke-induced cardiovascular dysfunction in mice

Objectives: Living conditions play a major role in health and well-being, particularly for the cardiovascular and pulmonary systems. Depleted housing contributes to impairment and development of disease, but how it impacts body resiliency during exposure to environmental stressors is unknown. This study examined the effect of depleted (DH) versus enriched housing (EH) on cardiopulmonary function and subsequent responses to wildfire smoke. Materials and Methods: Two cohorts of healthy female mice, one of them surgically implanted with radiotelemeters for the measurement of electrocardiogram, body temperature (Tco) and activity, were housed in either DH or EH for 7 weeks. Telemetered mice were exposed for 1 h to filtered air (FA) and then flaming eucalyptus wildfire smoke (WS) while untelemetered mice, which were used for ventilatory assessment and tissue collection, were exposed to either FA or WS. Animals were continuously monitored for 5-7 days after exposure. Results: EH prevented a decrease in Tco after radiotelemetry surgery. EH mice also had significantly higher activity levels and lower heart rate during and after FA and WS. Moreover, EH caused a decreased number of cardiac arrhythmias during WS. WS caused ventilatory depression in DH mice but not EH mice. Housing enrichment also upregulated the expression of cardioprotective genes in the heart. Conclusions: The results of this study indicate that housing conditions impact overall health and cardiopulmonary function. More importantly, depleted housing appears to worsen the response to air pollution. Thus, non-chemical factors should be considered when assessing the susceptibility of populations, especially when it comes to extreme environmental events.

The Association of Neighborhood Socioeconomic Status with Executive Function and Processing Speed in Cognitively Normal Mexican American Elders from the Health and Aging Brains Study: Health Disparities Cohort

INTRODUCTION

Neighborhood socioeconomic status (NSES) has been linked with overall health, and this study will evaluate whether NSES is cross-sectionally associated with cognition in non-Hispanic whites (NHWs) and Mexican Americans (MAs) from the Health and Aging Brain: Health Disparities Study (HABS-HD).

METHODS

The HABS-HD is a longitudinal study conducted at the University of North Texas Health Science Center. The final sample analyzed (n = 1,312) were 50 years or older, with unimpaired cognition, and underwent an interview, neuropsychological examination, imaging, and blood draw. NSES was measured using the national area deprivation index (ADI) percentile ranking, which considered socioeconomic variables. Executive function and processing speed were assessed by the trail making tests (A and B) and the digit-symbol substitution test, respectively. Linear regression was used to assess the association of ADI and cognitive measures.

RESULTS

MAs were younger, more likely to be female, less educated, had higher ADI scores, performed worse on trails B (all p < 0.05), and had lower prevalence of APOE4 + when compared to NHWs (p < 0.0001). A higher percentage of MAs lived in the most deprived neighborhoods than NHWs. For NHWs, ADI did not predict trails B or DSS scores, after adjusting for demographic variables and APOE4. For MAs, ADI predicted trails A, trails B, and DSS after adjusting for demographic covariates and APOE4 status.

CONCLUSION

Our study revealed that living in an area of higher deprivation was associated with lower cognitive function in MAs but not in NHWs, which is important to consider in future interventions to slow cognitive decline.

The association between neighborhood deprivation and DNA methylation in an autopsy cohort

Previous research has found that living in a disadvantaged neighborhood is associated with poor health outcomes. Living in disadvantaged neighborhoods may alter inflammation and immune response in the body, which could be reflected in epigenetic mechanisms such as DNA methylation (DNAm). We used robust linear regression models to conduct an epigenome-wide association study examining the association between neighborhood deprivation (Area Deprivation Index; ADI), and DNAm in brain tissue from 159 donors enrolled in the Emory Goizueta Alzheimer's Disease Research Center (Georgia, USA). We found one CpG site (cg26514961, gene PLXNC1) significantly associated with ADI after controlling for covariates and multiple testing (p-value=5.0e-8). Effect modification by APOE ε4 was statistically significant for the top ten CpG sites from the EWAS of ADI, indicating that the observed associations between ADI and DNAm were mainly driven by donors who carried at least one APOE ε4 allele. Four of the top ten CpG sites showed a significant concordance between brain tissue and tissues that are easily accessible in living individuals (blood, buccal cells, saliva), including DNAm in cg26514961 (PLXNC1). Our study identified one CpG site (cg26514961, PLXNC1 gene) that was significantly associated with neighborhood deprivation in brain tissue. PLXNC1 is related to immune response, which may be one biological pathway how neighborhood conditions affect health. The concordance between brain and other tissues for our top CpG sites could make them potential candidates for biomarkers in living individuals.

Emerging Theories of Allostatic-Interoceptive Overload in Neurodegeneration

Recent integrative multilevel models offer novel insights into the etiology and course of neurodegenerative conditions. The predictive coding of allostatic-interoception theory posits that the brain adapts to environmental demands by modulating internal bodily signals through the allostatic-interoceptive system. Specifically, a domain-general allostatic-interoceptive network exerts adaptive physiological control by fine-tuning initial top-down predictions and bottom-up peripheral signaling. In this context, adequate adaptation implies the minimization of prediction errors thereby optimizing energy expenditure. Abnormalities in top-down interoceptive predictions or peripheral signaling can trigger allostatic overload states, ultimately leading to dysregulated interoceptive and bodily systems (endocrine, immunological, circulatory, etc.). In this context, environmental stress, social determinants of health, and harmful exposomes (i.e., the cumulative life-course exposition to different environmental stressors) may interact with physiological and genetic factors, dysregulating allostatic interoception and precipitating neurodegenerative processes. We review the allostatic-interoceptive overload framework across different neurodegenerative diseases, particularly in the behavioral variant frontotemporal dementia (bvFTD). We describe how concepts of allostasis and interoception could be integrated with principles of predictive coding to explain how the brain optimizes adaptive responses, while maintaining physiological stability through feedback loops with multiple organismic systems. Then, we introduce the model of allostatic-interoceptive overload of bvFTD and discuss its implications for the understanding of pathophysiological and neurocognitive abnormalities in multiple neurodegenerative conditions.

The race-based stress reduction intervention (RiSE) study on African American women in NYC and Chicago: Design and methods for complex genomic analysis

RiSE study aims to evaluate a race-based stress-reduction intervention as an effective strategy to improve coping and decrease stress-related symptoms, inflammatory burden, and modify DNA methylation of stress response-related genes in older AA women. This article will describe genomic analytic methods to be utilized in this longitudinal, randomized clinical trial of older adult AA women in Chicago and NYC that examines the effect of the RiSE intervention on DNAm pre- and post-intervention, and its overall influence on inflammatory burden. Salivary DNAm will be measured at baseline and 6 months following the intervention, using the Oragene-DNA kit. Measures of perceived stress, depressive symptoms, fatigue, sleep, inflammatory burden, and coping strategies will be assessed at 4 time points including at baseline, 4 weeks, 8 weeks, and 6 months. Genomic data analysis will include the use of pre-processed and quality-controlled methylation data expressed as beta (β) values. Association analyses will be performed to detect differentially methylated sites on the targeted candidate genes between the intervention and non-intervention groups using the Δβ (changes in methylation) with adjustment for age, health behaviors, early life adversity, hybridization batch, and top principal components of the probes as covariates. To account for multiple testing, we will use FDR adjustment with a corrected p-value of <0.05 regarded as statistically significant. To assess the relationship between inflammatory burden and Δβ among the study samples, we will repeat association analyses with the inclusion of individual inflammation protein measures. ANCOVA will be used because it is more statistically powerful to detect differences.

Neighborhood Disadvantage and Breast Cancer-Specific Survival in the US

Importance

Despite improvements in breast cancer screening, treatment, and survival, disparate breast cancer-specific survival outcomes persist, particularly in disadvantaged neighborhoods. Most of these disparities are attributed to disparities in individual, tumor, and treatment characteristics. However, a critical knowledge gap exists as to whether disparities in breast cancer-specific survival remain after accounting for individual, tumor, and treatment characteristics.

Objective

To evaluate if neighborhood disadvantage is associated with shorter breast cancer-specific survival after controlling for individual, tumor, and treatment characteristics in a national population.

Design, Setting, and Participants

This national retrospective cohort study included patients with breast cancer diagnosed from 2013 to 2018 from the Surveillance, Epidemiology, and End Results 17 Census tract-level socioeconomic status and rurality database of the National Cancer Institute. Data analysis was performed from September 2022 to December 2023.

Exposures

Neighborhood disadvantage measured by Yost index quintiles.

Main Outcomes and Measures

Breast cancer-specific survival was evaluated using a competing risks cause-specific hazard model controlling for age, race, ethnicity, rurality, stage, subtype, insurance, and receipt of treatment.

Results

A total of 350 824 patients with breast cancer were included; 41 519 (11.8%) were Hispanic, 39 631 (11.3%) were non-Hispanic Black, and 234 698 (66.9%) were non-Hispanic White. A total of 87 635 patients (25.0%) lived in the most advantaged neighborhoods (group 5) and 52 439 (14.9%) lived in the most disadvantaged neighborhoods (group 1). A larger number of non-Hispanic White patients (66 529 patients [76.2%]) lived in advantaged neighborhoods, while disadvantaged neighborhoods had the highest proportion of non-Hispanic Black (16 141 patients [30.9%]) and Hispanic patients (10 168 patients [19.5%]). Breast cancer-specific survival analysis found the most disadvantaged neighborhoods (group 1) had the highest risk of mortality (hazard ratio, 1.43; 95% CI, 1.36-1.50; P < .001) compared with the most advantaged neighborhoods.

Conclusions and Relevance

In this national cohort study of patients with breast cancer, neighborhood disadvantage was independently associated with shorter breast cancer-specific survival even after controlling for individual-level factors, tumor characteristics, and treatment. This suggests potential unaccounted-for mechanisms, including both nonbiologic factors and biologic factors.

Epigenetic age acceleration is associated with blood lipid levels in a multi-ancestry sample of older U.S. adults

Background

Dyslipidemia, which is characterized by an unfavorable lipid profile, is a key risk factor for cardiovascular disease (CVD). Understanding the relationships between epigenetic aging and lipid levels may help guide early prevention and treatment efforts for dyslipidemia.

Methods

We used weighted linear regression to cross-sectionally investigate the associations between five measures of epigenetic age acceleration estimated from whole blood DNA methylation (HorvathAge Acceleration, HannumAge Acceleration, PhenoAge Acceleration, GrimAge Acceleration, and DunedinPACE) and four blood lipid measures (total cholesterol (TC), LDL-C, HDL-C, and triglycerides (TG)) in 3,813 participants (mean age = 70 years) from the Health and Retirement Study (HRS). As a sensitivity analysis, we examined the same associations in participants who fasted prior to the blood draw (n = and f) and in participants who did not take lipid-lowering medication (n = 1,869). Using interaction models, we also examined whether the relationships between epigenetic age acceleration and blood lipids differ by demographic factors including age, sex, and educational attainment.

Results

After adjusting for age, race/ethnicity, sex, fasting status, and lipid-lowering medication use, greater epigenetic age acceleration was associated with lower TC, HDL-C, and LDL-C, and higher TG (p < 0.05). GrimAge acceleration and DunedinPACE associations with all lipids remained significant after further adjusting for body mass index, smoking status, and educational attainment. These associations were stronger in participants who fasted and who did not use lipid-lowering medication, particularly for LDL-C. We observed the largest number of interactions between DunedinPACE and demographic factors, where the associations with lipids were stronger in younger participants, females, and those with higher educational attainment.

Conclusion

Epigenetic age acceleration, a powerful biomarker of cellular aging, is highly associated with blood lipid levels in older adults. A greater understanding of how these associations differ across demographic groups can help shed light on the relationships between aging and downstream cardiovascular diseases. The inverse associations between epigenetic age and TC and LDL-C could be due to sample limitations or the non-linear relationship between age and these lipids, as both TC and LDL-C decrease faster at older ages. More studies are needed to further understand the temporal relationships between epigenetic age acceleration on blood lipids and other health outcomes.

Perceived Experiences of racism in Relation to Genome-Wide DNA Methylation and Epigenetic Aging in the Black Women's Health Study

BACKGROUND

African American women have a disproportionate burden of disease compared to US non-Hispanic white women. Exposure to psychosocial stressors may contribute to these health disparities. Racial discrimination, a major stressor for African American women, could affect health through epigenetic mechanisms.

METHODS

We conducted an epigenome-wide association study (EWAS) to examine the association of interpersonal racism (in daily life and in institutional settings) with DNA methylation in blood in 384 participants of the Black Women's Health Study (BWHS). We also evaluated whether a greater number of perceived experiences of racism was associated with epigenetic aging as measured using different methylation clocks. Models were adjusted for chronological age, body mass index, years of education, neighborhood SES, geographic region of residence, alcohol drinking, smoking, and technical covariates.

RESULTS

Higher scores of racism in daily life were associated with higher methylation levels at the cg04494873 site in chromosome 5 (β = 0.64%; 95% CI = 0.41%, 0.87%; P = 6.35E-08). We also replicated one CpG site, cg03317714, which was inversely associated with racial discrimination in a previous EWAS among African American women. In the BWHS, higher scores of racism in daily life were associated with lower methylation levels at that CpG site (β = -0.94%; 95% CI = -1.37%, -0.51%; P = 2.2E-05). Higher racism scores were associated with accelerated epigenetic aging in more than one methylation clock.

CONCLUSIONS

Exposure to discriminatory events may affect the epigenome and accelerate biological aging, which may explain in part the earlier onset of disease in African American women.

Brain-Derived Neurotrophic Factor in Pediatric Acquired Brain Injury and Recovery

We review emerging preclinical and clinical evidence regarding brain-derived neurotrophic factor (BDNF) protein, genotype, and DNA methylation (DNAm) as biomarkers of outcomes in three important etiologies of pediatric acquired brain injury (ABI), traumatic brain injury, global cerebral ischemia, and stroke. We also summarize evidence suggesting that BDNF is (1) involved in the biological embedding of the psychosocial environment, (2) responsive to rehabilitative therapies, and (3) potentially modifiable. BDNF's unique potential as a biomarker of neuroplasticity and neural repair that is reflective of and responsive to both pre- and post-injury environmental influences separates it from traditional protein biomarkers of structural brain injury with exciting potential to advance pediatric ABI management by increasing the accuracy of prognostic tools and informing clinical decision making through the monitoring of therapeutic effects.

Neighborhood Perceptions Are Associated With Intrinsic Amygdala Activity and Resting-State Connectivity With Salience Network Nodes Among Older Adults

OBJECTIVE

Neighborhood perceptions are associated with physical and mental health outcomes; however, the biological associates of this relationship remain to be fully understood. Here, we evaluate the relationship between neighborhood perceptions and amygdala activity and connectivity with salience network (i.e., insula, anterior cingulate, thalamus) nodes.

METHODS

Forty-eight older adults (mean age = 68 [7] years, 52% female, 47% non-Hispanic Black, 2% Hispanic) without dementia or depression completed the Perceptions of Neighborhood Environment Scale. Lower scores indicated less favorable perceptions of aesthetic quality, walking environment, availability of healthy food, safety, violence (i.e., more perceived violence), social cohesion, and participation in activities with neighbors. Participants separately underwent resting-state functional magnetic resonance imaging.

RESULTS

Less favorable perceived safety ( β = -0.33, pFDR = .04) and participation in activities with neighbors ( β = -0.35, pFDR = .02) were associated with higher left amygdala activity, independent of covariates including psychosocial factors. Less favorable safety perceptions were also associated with enhanced left amygdala functional connectivity with the bilateral insular cortices and the left anterior insula ( β = -0.34, pFDR = .04). Less favorable perceived social cohesion was associated with enhanced left amygdala functional connectivity with the right thalamus ( β = -0.42, pFDR = .04), and less favorable perceptions about healthy food availability were associated with enhanced left amygdala functional connectivity with the bilateral anterior insula (right: β = -0.39, pFDR = .04; left: β = -0.42, pFDR = .02) and anterior cingulate gyrus ( β = -0.37, pFDR = .04).

CONCLUSIONS

Taken together, our findings document relationships between select neighborhood perceptions and amygdala activity as well as connectivity with salience network nodes; if confirmed, targeted community-level interventions and existing community strengths may promote brain-behavior relationships.

Impact of Neighborhood Disadvantage on Tumor Biology and Breast Cancer Survival

OBJECTIVE

The aim of this study was to evaluate the association between neighborhood disadvantage and Oncotype DX score, a surrogate for tumor biology, among a national cohort.

BACKGROUND

Women living in disadvantaged neighborhoods have shorter breast cancer (BC) survival, even after accounting for individual-level, tumor, and treatment characteristics. This suggests unaccounted social and biological mechanisms by which neighborhood disadvantage may impact BC survival.

METHODS

This cross-sectional study included stage I and II, ER + /HER2 - BC patients with Oncotype DX score data from the National Cancer Database (NCDB) from 2004 to 2019. Multivariate regression models tested the association of neighborhood-level income on Oncotype DX score controlling for age, race/ethnicity, insurance, clinical stage, and education. Cox regression assessed overall survival.

RESULTS

Of the 294,283 total BC patients selected, the majority were non-Hispanic White (n=237,197, 80.6%) with 7.6% non-Hispanic Black (n=22,495) and 4.5% other (n=13,383). 27.1% (n=797,254) of the population lived in the disadvantaged neighborhoods with an annual neighborhood-level income of <$48,000, while 59.62% (n=175,305) lived in advantaged neighborhoods with a neighborhood-level income of >$48,000. On multivariable analysis controlling for age, race/ethnicity, insurance status, neighborhood-level education, and pathologic stage, patients in disadvantaged neighborhoods had greater odds of high-risk versus low-risk Oncotype DX scores compared with those in advantaged neighborhoods [odds ratio=1.04 (1.01-1.07), P =0.0067].

CONCLUSION AND RELEVANCE

This study takes a translational epidemiologic approach to identify that women living in the most disadvantaged neighborhoods have more aggressive tumor biology, as determined by the Oncotype DX score.

Association of Neighborhood Deprivation and Depressive Symptoms With Epigenetic Age Acceleration: Evidence From the Canadian Longitudinal Study on Aging

BACKGROUND

Neighborhood deprivation and depression have been linked to epigenetic age acceleration. The next-generation epigenetic clocks including the DNA methylation (DNAm) GrimAge, and PhenoAge have incorporated clinical biomarkers of physiological dysregulation by selecting cytosine-phosphate-guanine sites that are associated with risk factors for disease, and have shown improved accuracy in predicting morbidity and time-to-mortality compared to the first-generation clocks. The aim of this study is to examine the association between neighborhood deprivation and DNAm GrimAge and PhenoAge acceleration in adults, and assess interaction with depressive symptoms.

METHODS

The Canadian Longitudinal Study on Aging recruited 51 338 participants aged 45-85 years across provinces in Canada. This cross-sectional analysis is based on a subsample of 1 445 participants at baseline (2011-2015) for whom epigenetic data were available. Epigenetic age acceleration (years) was assessed using the DNAm GrimAge and PhenoAge, and measured as residuals from regression of the biological age on chronological age.

RESULTS

A greater neighborhood material and/or social deprivation compared to lower deprivation (b = 0.66; 95% confidence interval [CI] = 0.21, 1.12) and depressive symptoms scores (b = 0.07; 95% CI = 0.01, 0.13) were associated with higher DNAm GrimAge acceleration. The regression estimates for these associations were higher but not statistically significant when epigenetic age acceleration was estimated using DNAm PhenoAge. There was no evidence of a statistical interaction between neighborhood deprivation and depressive symptoms.

CONCLUSIONS

Depressive symptoms and neighborhood deprivation are independently associated with premature biological aging. Policies that improve neighborhood environments and address depression in older age may contribute to healthy aging among older adults living in predominantly urban areas.

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.

Environment factors, DNA methylation, and cancer

Today, the rapid development of science and technology and the rapid change in economy and society are changing the way of life of human beings and affecting the natural, living, working, and internal environment on which human beings depend. At the same time, the global incidence of cancer has increased significantly yearly, and cancer has become the number one killer that threatens human health. Studies have shown that diet, living habits, residential environment, mental and psychological factors, intestinal flora, genetics, social factors, and viral and non-viral infections are closely related to human cancer. However, the molecular mechanisms of the environment and cancer development remain to be further explored. In recent years, DNA methylation has become a key hub and bridge for environmental and cancer research. Some environmental factors can alter the hyper/hypomethylation of human cancer suppressor gene promoters, proto-oncogene promoters, and the whole genome, causing low/high expression or gene mutation of related genes, thereby exerting oncogenic or anticancer effects. It is expected to develop early warning markers of cancer environment based on DNA methylation, thereby providing new methods for early detection of cancers, diagnosis, and targeted therapy. This review systematically expounds on the internal mechanism of environmental factors affecting cancer by changing DNA methylation, aiming to help establish the concept of cancer prevention and improve people's health.

Neighborhood Deprivation and DNA Methylation and Expression of Cancer Genes in Breast Tumors

Importance

The biological processes that underlie the association of neighborhood environment with chronic diseases, such as cancer, remain poorly understood.

Objective

To determine whether differences in breast tissue DNA methylation are associated with neighborhood deprivation among Black and White women with breast cancer.

Design, Setting, and Participants

This cross-sectional study collected breast tissue from women undergoing surgery for breast cancer between January 1, 1993, and December 31, 2003. Participants were recruited through the University of Maryland Medical Center, with additional collection sites at Baltimore-area hospitals. Data analysis was performed from March 1 through December 1, 2022.

Exposure

Year 2000 census tract-level socioeconomic deprivation measured via neighborhood deprivation index (NDI) as a standardized score, with Black and White race being ascertained through self-report.

Main Outcome and Measures

The primary outcome was tissue DNA methylation using genome-wide measurements. The secondary outcome was tissue gene expression.

Results

Participants included 185 women with breast cancer (110 Black [59.5%], 75 White [40.5%]). Mean (SD) age at surgery was 56.0 (14.1) years. Neighborhood deprivation was higher for Black women than for White women (Mean [SD] NDI, 2.96 [3.03] for Black women and -0.54 [1.91] for White women; difference, -3.50; 95% CI, -4.22 to -2.79; P < .001). In unstratified analysis, 8 hypomethylated CpG sites were identified as associated with the NDI, including sites in 2 tumor suppressor genes, LRIG1 and WWOX. Moreover, expression of the 2 genes inversely correlated with neighborhood deprivation. In the race-stratified analysis, the negative correlation between the LRIG1 gene body CpG site cg26131019 and the NDI remained significant in Black women. A neighborhood deprivation-associated decrease in gene expression was also observed for LRIG1 and WWOX in tumors from Black women.

Conclusions and Relevance

In this study, high neighborhood deprivation was associated with differences in tissue DNA methylation and gene expression among Black women. These findings suggest that continued investment in public health interventions and policy changes at the neighborhood level may help to remedy biological alterations that could make minoritized populations more susceptible to chronic diseases.

Effects of neighborhood disadvantage on cortisol and interviewer-rated anxiety symptoms in breast cancer patients initiating treatment

PURPOSE

Shorter breast cancer (BC) survival outcomes persist by neighborhood disadvantage independent of patient, tumor, and treatment characteristics. This suggests unaccounted mechanisms by which neighborhood disadvantage "gets under the skin" to impact BC survival outcomes. Here, we evaluate the relationship between neighborhood disadvantage and clinical and neuroendocrine markers of stress in BC patients.

METHODS

Women with stage 0-III BC were enrolled 2-10 weeks post-surgery and before initiating adjuvant treatment in a study examining stress and stress management processes. Women provided an afternoon-evening (PM) serum cortisol sample and were administered the Hamilton Anxiety Rating Scale (HAM-A). Home addresses were used to determine the Area Deprivation Index (ADI), a validated measure of neighborhood disadvantage. Multiple regression assessed the relationship between ADI and PM serum cortisol and the presence of elevated HAM-A symptoms.

RESULTS

Our sample (n = 225) was predominately middle-aged (M = 50.4 years; range 23-70 years), non-Hispanic White (64.3%), with stage I (38.1%), or II (38.6%) disease. The majority (n = 175) lived in advantaged neighborhoods (ADI 1-3). After controlling for age, stage, and surgery type, women from high ADI (4-10) (vs low ADI) neighborhoods had higher PM cortisol levels (β = 0.19, 95% CI [0.24, 5.00], p = 0.031) and were nearly two times as likely to report the presence of elevated anxiety symptoms (OR = 1.96, 95% CI [1.00, 3.86], p = 0.050).

CONCLUSION

Neighborhood disadvantage is significantly associated with higher levels of PM cortisol and elevated anxiety symptoms suggesting stress pathways could potentially contribute to relationships between neighborhood disadvantage and BC survival.

The application of epiphenotyping approaches to DNA methylation array studies of the human placenta

BACKGROUND

Genome-wide DNA methylation (DNAme) profiling of the placenta with Illumina Infinium Methylation bead arrays is often used to explore the connections between in utero exposures, placental pathology, and fetal development. However, many technical and biological factors can lead to signals of DNAme variation between samples and between cohorts, and understanding and accounting for these factors is essential to ensure meaningful and replicable data analysis. Recently, "epiphenotyping" approaches have been developed whereby DNAme data can be used to impute information about phenotypic variables such as gestational age, sex, cell composition, and ancestry. These epiphenotypes offer avenues to compare phenotypic data across cohorts, and to understand how phenotypic variables relate to DNAme variability. However, the relationships between placental epiphenotyping variables and other technical and biological variables, and their application to downstream epigenome analyses, have not been well studied.

RESULTS

Using DNAme data from 204 placentas across three cohorts, we applied the PlaNET R package to estimate epiphenotypes gestational age, ancestry, and cell composition in these samples. PlaNET ancestry estimates were highly correlated with independent polymorphic ancestry-informative markers, and epigenetic gestational age, on average, was estimated within 4 days of reported gestational age, underscoring the accuracy of these tools. Cell composition estimates varied both within and between cohorts, as well as over very long placental processing times. Interestingly, the ratio of cytotrophoblast to syncytiotrophoblast proportion decreased with increasing gestational age, and differed slightly by both maternal ethnicity (lower in white vs. non-white) and genetic ancestry (lower in higher probability European ancestry). The cohort of origin and cytotrophoblast proportion were the largest drivers of DNAme variation in this dataset, based on their associations with the first principal component.

CONCLUSIONS

This work confirms that cohort, array (technical) batch, cell type proportion, self-reported ethnicity, genetic ancestry, and biological sex are important variables to consider in any analyses of Illumina DNAme data. We further demonstrate the specific utility of epiphenotyping tools developed for use with placental DNAme data, and show that these variables (i) provide an independent check of clinically obtained data and (ii) provide a robust approach to compare variables across different datasets. Finally, we present a general framework for the processing and analysis of placental DNAme data, integrating the epiphenotype variables discussed here.

The Role of Selected Epigenetic Pathways in Cardiovascular Diseases as a Potential Therapeutic Target

Epigenetics is a rapidly developing science that has gained a lot of interest in recent years due to the correlation between characteristic epigenetic marks and cardiovascular diseases (CVDs). Epigenetic modifications contribute to a change in gene expression while maintaining the DNA sequence. The analysis of these modifications provides a thorough insight into the cardiovascular system from its development to its further functioning. Epigenetics is strongly influenced by environmental factors, including known cardiovascular risk factors such as smoking, obesity, and low physical activity. Similarly, conditions affecting the local microenvironment of cells, such as chronic inflammation, worsen the prognosis in cardiovascular diseases and additionally induce further epigenetic modifications leading to the consolidation of unfavorable cardiovascular changes. A deeper understanding of epigenetics may provide an answer to the continuing strong clinical impact of cardiovascular diseases by improving diagnostic capabilities, personalized medical approaches and the development of targeted therapeutic interventions. The aim of the study was to present selected epigenetic pathways, their significance in cardiovascular diseases, and their potential as a therapeutic target in specific medical conditions.

Epigenetic Implications of Neighborhood Disorder and Psychological Distress among Pregnant Black Women

Background: In the United States, Black women experience preterm birth (PTB; <37 weeks gestation) at more than 1.5 times the rate of non-Hispanic White women. Social determinants of health including the neighborhood environment have been recognized as contributing to the risk of PTB. Due to historical segregation, Black women are more likely to live in neighborhoods with higher levels of neighborhood disorder compared with White women. Perceived neighborhood disorder appears to be a risk factor for maternal psychological distress in Black women and psychological distress has mediated the association between neighborhood disorder and the risk for PTB. However, the biological pathways underpinning these associations are not clear. Objective: We examined the associations among neighborhood disorder; psychological distress; DNA methylation of six stress-related, glucocorticoid candidate genes (AVP, CRH, CRHBP, FKBP5, HSD11B2, NR3C1); and gestational age at birth among 44 Black pregnant women. Methods: Women who were 18-45 years old and 8-18 weeks gestation had blood drawn and completed questionnaires measuring perceived neighborhood disorder, neighborhood crime, and psychological distress. Results: Three CpG sites were associated with neighborhood disorder (cg03405789 [CRH], cg14939152 and cg15910486 [NR3C1]). One CpG site, cg03098337 (FKBP5) was associated with psychological distress. Three of the identified CpG sites were located within gene CpG islands or shores-areas at which DNA methylation is known to affect gene transcription. Conclusion: These findings warrant further research to clarify intermediate biological pathways and potential biomarkers to identify women at risk for PTB. Identification of PTB risk early in pregnancy would allow for interventions to prevent PTB.

Translational Epidemiology: Genetic Ancestry in Breast Cancer: What Is the Role of Genetic Ancestry and Socioeconomic Status in Triple-Negative Breast Cancer?

Racial/ethnic and socioeconomic disparities seen in triple-negative breast cancer (TNBC) have prompted questions regarding the role of genetic ancestry in breast cancer (BC) subtype development, tumor biology, and ultimately prognosis. The causes of disparities in TNBC are influenced greatly by both sociopolitical factors and genetic ancestry, and now, the potential genomic underpinnings of social factors. To comprehensively understand disparities in TNBC, it is critical to take a translational epidemiologic approach that takes into account genomic and non-genomic factors. Understanding the interplay between genetic ancestry and social genomics and their proportional influence on outcomes can guide our priorities for screening, diagnosis, and interventions for this aggressive BC subtype.

CpG Methylation Levels in HPA Axis Genes Predict Chronic Pain Outcomes Following Trauma Exposure

Chronic post-traumatic musculoskeletal pain (CPTP) is a common outcome of traumatic stress exposure. Biological factors that influence the development of CPTP are poorly understood, though current evidence indicates that the hypothalamic-pituitary-adrenal (HPA) axis plays a critical role in its development. Little is known about molecular mechanisms underlying this association, including epigenetic mechanisms. Here, we assessed whether peritraumatic DNA methylation levels at 248 5'-C-phosphate-G-3' (CpG) sites in HPA axis genes (FKBP5, NR3C1, CRH, CRHR1, CRHR2, CRHBP, POMC) predict CPTP and whether identified CPTP-associated methylation levels influence expression of those genes. Using participant samples and data collected from trauma survivors enrolled into longitudinal cohort studies (n = 290), we used linear mixed modeling to assess the relationship between peritraumatic blood-based CpG methylation levels and CPTP. A total of 66 (27%) of the 248 CpG sites assessed in these models statistically significantly predicted CPTP, with the three most significantly associated CpG sites originating from the POMC gene region (ie, cg22900229 [β = .124, P < .001], cg16302441 [β = .443, P < .001], cg01926269 [β = .130, P < .001]). Among the genes analyzed, both POMC (z = 2.36, P = .018) and CRHBP (z = 4.89, P < .001) were enriched in CpG sites significantly associated with CPTP. Further, POMC expression was inversely correlated with methylation levels in a CPTP-dependent manner (6-months NRS<4: r = -.59, P < .001; 6-months NRS ≥ 4: r = -.18, P = .2312). Our results suggest that methylation of HPA axis genes including POMC and CRHBP predict risk for and may contribute to vulnerability to CPTP. PERSPECTIVE: Peritraumatic blood levels of CpG methylation sites in HPA axis genes, particularly CpG sites in the POMC gene, predict CPTP development. This data substantially advances our understanding of epigenetic predictors and potential mediators of CPTP, a highly common, morbid, and hard-to-treat form of chronic pain.

Epigenomic Links Between Social Determinants of Health and Symptoms: A Scoping Review

Social determinants of health (SDoH) impact health and wellness. The link between SDoH and adverse health outcomes, including symptom occurrence and severity, may be explained by an individual's physiologic response to one or more SDoH. One potential mechanism underlying this physiologic response linking SDoH and symptoms is the dynamic epigenome. The purpose of this scoping review of the literature was to examine differential susceptibility for symptoms by identifying and summarizing research linking SDoH and symptoms through epigenomic mechanisms. PubMed was searched to identify empirical research where at least one SDoH was an independent or dependent variable, at least one symptom was investigated, and the investigation included an epigenomic measure. Of the 484 articles initially retrieved, after thorough vetting, 41 articles met eligibility. The most studied symptom was depressive symptoms followed by anxiety, cognitive function, sleep dysfunction, and pain. The most frequently studied SDoH were: 1) stress, particularly early life stress and acculturative stress; and 2) trauma, predominantly childhood trauma. DNA methylation and telomere length were the most studied epigenomic measures. Four genes (SLC6A4, BDNF, NR3C1, OXTR) had evidence from multiple studies and across methodological approaches linking SDoH to symptoms. This review supports the inclusion of epigenomic approaches to better understand the link between SDoH and symptoms and provides evidence that SDoH impact telomere length and the methylation of genes involved in neurotransmitter signaling, neuronal survival, behavior, inflammation and stress response.

The application of epiphenotyping approaches to DNA methylation array studies of the human placenta

Background : Genome-wide DNA methylation (DNAme) profiling of the placenta with Illumina Infinium Methylation bead arrays is often used to explore the connections between in utero exposures, placental pathology, and fetal development. However, many technical and biological factors can lead to signals of DNAme variation between samples and between cohorts, and understanding and accounting for these factors is essential to ensure meaningful and replicable data analysis. Recently, "epiphenotyping" approaches have been developed whereby DNAme data can be used to impute information about phenotypic variables such as gestational age, sex, cell composition, and ancestry. These epiphenotypes offer avenues to compare phenotypic data across cohorts, and to understand how phenotypic variables relate to DNAme variability. However, the relationships between placental epiphenotyping variables and other technical and biological variables, and their application to downstream epigenome analyses, have not been well studied. Results : Using DNAme data from 204 placentas across three cohorts, we applied the PlaNET R package to estimate epiphenotypes gestational age, ancestry, and cell composition in these samples. PlaNET ancestry estimates were highly correlated with independent polymorphic ancestry informative markers, and epigenetic gestational age, on average, was estimated within 4 days of reported gestational age, underscoring the accuracy of these tools. Cell composition estimates varied both within and between cohorts, but reassuringly were robust to placental processing time. Interestingly, the ratio of cytotrophoblast to syncytiotrophoblast proportion decreased with increasing gestational age, and differed slightly by both maternal ethnicity (lower in white vs. non-white) and genetic ancestry (lower in higher probability European ancestry). The cohort of origin and cytotrophoblast proportion were the largest drivers of DNAme variation in this dataset, based on their associations with the first principal component. Conclusions : This work confirms that cohort, array (technical) batch, cell type proportion, self-reported ethnicity, genetic ancestry, and biological sex are important variables to consider in any analyses of Illumina DNAme data. Further, we demonstrate that estimating epiphenotype variables from the DNAme data itself, when possible, provides both an independent check of clinically-obtained data and can provide a robust approach to compare variables across different datasets.

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.

Epigenetic Changes Associated with Different Types of Stressors and Suicide

Stress is associated with various epigenetic changes. Some stress-induced epigenetic changes are highly dynamic, whereas others are associated with lasting marks on the epigenome. In our study, a comprehensive narrative review of the literature was performed by investigating the epigenetic changes that occur with acute stress, chronic stress, early childhood stress, and traumatic stress exposures, along with examining those observed in post-mortem brains or blood samples of suicide completers and attempters. In addition, the transgenerational effects of these changes are reported. For all types of stress studies examined, the genes Nr3c1, OXTR, SLC6A4, and BDNF reproducibly showed epigenetic changes, with some modifications observed to be passed down to subsequent generations following stress exposures. The aforementioned genes are known to be involved in neuronal development and hormonal regulation and are all associated with susceptibility to mental health disorders including depression, anxiety, personality disorders, and PTSD (post-traumatic stress disorder). Further research is warranted in order to determine the scope of epigenetic actionable targets in individuals suffering from the long-lasting effects of stressful experiences.

Neighborhood Disadvantage and Breast Cancer-Specific Survival

Importance

Neighborhood-level disadvantage is an important factor in the creation and persistence of underresourced neighborhoods with an undue burden of disparate breast cancer-specific survival outcomes. Although studies have evaluated neighborhood-level disadvantage and breast cancer-specific survival after accounting for individual-level socioeconomic status (SES) in large national cancer databases, these studies are limited by age, socioeconomic, and racial and ethnic diversity.

Objective

To investigate neighborhood SES (using a validated comprehensive composite measure) and breast cancer-specific survival in a majority-minority population.

Design, Setting, and Participants

This retrospective multi-institutional cohort study included patients with stage I to IV breast cancer treated at a National Cancer Institute-designated cancer center and sister safety-net hospital from January 10, 2007, to September 9, 2016. Mean (SD) follow-up time was 60.3 (41.4) months. Data analysis was performed from March 2022 to March 2023.

Exposures

Neighborhood SES was measured using the Area Deprivation Index (tertiles), a validated comprehensive composite measure of neighborhood SES.

Main Outcomes and Measures

The primary outcome was breast cancer-specific survival. Random effects frailty models for breast cancer-specific survival were performed controlling for individual-level sociodemographic, comorbidity, breast cancer risk factor, access to care, tumor, and National Comprehensive Cancer Network guideline-concordant treatment characteristics. The Area Deprivation Index was calculated for each patient at the census block group level and categorized into tertiles (T1-T3).

Results

A total of 5027 women with breast cancer were included: 55.8% were Hispanic, 17.5% were non-Hispanic Black, and 27.0% were non-Hispanic White. Mean (SD) age was 55.5 (11.7) years. Women living in the most disadvantaged neighborhoods (T3) had shorter breast cancer-specific survival compared with those living in the most advantaged neighborhoods (T1) after controlling for individual-level sociodemographic, comorbidity, breast cancer risk factor, access to care, tumor, and National Comprehensive Cancer Network guideline-concordant treatment characteristics (T3 vs T1: hazard ratio, 1.29; 95% CI, 1.01-1.65; P < .04).

Conclusions and Relevance

In this cohort study, a shorter breast cancer-specific survival in women from disadvantaged neighborhoods compared with advantaged neighborhoods was identified, even after controlling for individual-level sociodemographic, comorbidity, breast cancer risk factor, access to care, tumor, and National Comprehensive Cancer Network guideline-concordant treatment characteristics. The findings suggest potential unaccounted mechanisms, including unmeasured social determinants of health and access to care measures. This study also lays the foundation for future research to evaluate whether social adversity from living in a disadvantaged neighborhood is associated with more aggressive tumor biologic factors, and ultimately shorter breast cancer-specific survival, through social genomic and/or epigenomic alterations.

Brain-derived neurotrophic factor (BDNF) epigenomic modifications and brain-related phenotypes in humans: A systematic review

Epigenomic modifications of the brain-derived neurotrophic factor (BDNF) gene have been postulated to underlie the pathogenesis of neurodevelopmental, psychiatric, and neurological conditions. This systematic review summarizes current evidence investigating the association of BDNF epigenomic modifications (DNA methylation, non-coding RNA, histone modifications) with brain-related phenotypes in humans. A novel contribution is our creation of an open access web-based application, the BDNF DNA Methylation Map, to interactively visualize specific positions of CpG sites investigated across all studies for which relevant data were available. Our literature search of four databases through September 27, 2021 returned 1701 articles, of which 153 met inclusion criteria. Our review revealed exceptional heterogeneity in methodological approaches, hindering the identification of clear patterns of robust and/or replicated results. We summarize key findings and provide recommendations for future epigenomic research. The existing literature appears to remain in its infancy and requires additional rigorous research to fulfill its potential to explain BDNF-linked risk for brain-related conditions and improve our understanding of the molecular mechanisms underlying their pathogenesis.

Neighborhood deprivation, racial segregation and associations with cancer risk and outcomes across the cancer-control continuum

The racial/ethnic disparities in cancer incidence and outcome are partially due to the inequities in neighborhood advantage. Mounting evidences supported a link between neighborhood deprivation and cancer outcomes including higher mortality. In this review, we discuss some of the findings related to work on area-level neighborhood variables and cancer outcomes, and the potential biological and built/natural environmental mechanisms that might explain this link. Studies have also shown that residents of deprived neighborhoods or of racially or economically segregated neighborhoods have worse health outcomes than residents of more affluent neighborhoods and/or less racially or economically segregated neighborhoods, even after adjusting for the individual-level socioeconomic status. To date, little research has been conducted investigating the biological mediators that may play roles in the associations of neighborhood deprivation and segregation with cancer outcomes. The psychophysiological stress induced by neighborhood disadvantage among people living in these neighborhoods could be a potential underlying biological mechanism. We examined a number of chronic stress-related pathways that may potentially mediate the relationship between area-level neighborhood factors and cancer outcomes, including higher allostatic load, stress hormones, altered epigenome and telomere maintenance and biological aging. In conclusion, the extant evidence supports the notion that neighborhood deprivation and racial segregation have unfavorable impacts on cancer. Understanding how neighborhood factors influence the biological stress response has the potential to inform where and what types of resources are needed within the community to improve cancer outcomes and reduce disparities. More studies are warranted to directly assess the role of biological and social mechanisms in mediating the relationship between neighborhood factors and cancer outcomes.

DNA Methylation Is a Potential Biomarker for Cardiometabolic Health in Mexican Children and Adolescents

DNA methylation (DNAm) is a plausible mechanism underlying cardiometabolic abnormalities, but evidence is limited among youth. This analysis included 410 offspring of the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) birth cohort followed up to two time points in late childhood/adolescence. At Time 1, DNAm was quantified in blood leukocytes at long interspersed nuclear elements (LINE-1), H19, and 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD-2), and at Time 2 in peroxisome proliferator-activated receptor alpha (PPAR-α). At each time point, cardiometabolic risk factors were assessed including lipid profiles, glucose, blood pressure, and anthropometry. Linear mixed effects models were used for LINE-1, H19, and 11β-HSD-2 to account for the repeated-measure outcomes. Linear regression models were conducted for the cross-sectional association between PPAR-α with the outcomes. DNAm at LINE-1 was associated with log glucose at site 1 [β = -0.029, p = 0.0006] and with log high-density lipoprotein cholesterol at site 3 [β = 0.063, p = 0.0072]. 11β-HSD-2 DNAm at site 4 was associated with log glucose (β = -0.018, p = 0.0018). DNAm at LINE-1 and 11β-HSD-2 was associated with few cardiometabolic risk factors among youth in a locus-specific manner. These findings underscore the potential for epigenetic biomarkers to increase our understanding of cardiometabolic risk earlier in life.

Racial and Ethnic Disparities in Early-Onset Colorectal Cancer Survival

BACKGROUND

Young adults diagnosed with colorectal cancer (CRC) comprise a growing, yet understudied, patient population. We estimated 5-year relative survival of early-onset CRC and examined disparities in survival by race-ethnicity in a population-based sample.

METHODS

We used the National Cancer Institute's Surveillance, Epidemiology, and End Results program of cancer registries to identify patients diagnosed with early-onset CRC (20-49 years of age) between January 1, 1992, and December 31, 2013. For each racial-ethnic group, we estimated 5-year relative survival, overall and by sex, tumor site, and stage at diagnosis. To illustrate temporal trends, we compared 5-year relative survival in 1992-2002 vs 2003-2013. We also used Cox proportional hazards regression models to examine the association of race-ethnicity and all-cause mortality, adjusting for age at diagnosis, sex, county type (urban vs rural), county-level median household income, tumor site, and stage at diagnosis.

RESULTS

We identified 33,777 patients diagnosed with early-onset CRC (58.5% White, 14.0% Black, 13.0% Asian, 14.5% Hispanic). Five-year relative survival ranged from 57.6% (Black patients) to 69.1% (White patients). Relative survival improved from 1992-2002 to 2003-2013 for White patients only; there was no improvement for Black, Asian, or Hispanic patients. This pattern was similar by sex, tumor site, and stage at diagnosis. In adjusted analysis, Black (adjusted hazard ratio [aHR], 1.42; 95% confidence interval [CI], 1.36-1.49), Asian (aHR, 1.06; 95% CI, 1.01-1.12), and Hispanic (aHR, 1.16; 95% CI, 1.10-1.21) race-ethnicity were associated with all-cause mortality.

CONCLUSION

Our study adds to the well-documented disparities in CRC in older adults by demonstrating persistent racial-ethnic disparities in relative survival and all-cause mortality in patients with early-onset CRC.

Childhood adverse events and BDNF promoter methylation in later-life

Studies have shown that the effects of early-life stress and trauma can be enduring, with long-term negative effects on health. Epigenetics, including DNA methylation, have been implicated as a potential mechanism for these effects. Brain-derived neurotropic factor (BDNF) is a neurotransmitter involved in learning and memory, and altered BDNF promoter methylation measured in peripheral tissue has been found with early-life stress. However, whether such methylation differences remain stable into later life, is unknown. This study aimed to investigate the association between childhood adversity and BDNF promoter methylation in adults aged 65 years and over. Data came from a large study of older community-dwelling individuals in France (ESPRIT). Information on three major childhood adverse events, namely abuse/maltreatment, war/natural disaster, and financial difficulties/poverty, was obtained by retrospective reporting from participants of ESPRIT study. BDNF promoter I and IV methylation was assessed in blood and buccal tissue. Linear regression analysis was performed, adjusting for age, sex, education, depression, and morbidity. Among 927 participants, there was no strong evidence that childhood abuse/maltreatment or financial difficulties/poverty were associated with BDNF methylation in older individuals. For war/natural disaster, differential methylation at four of twenty-nine CpG sites was observed, however, these would not have remained significant after correction for multiple testing. Together, these findings do not support a long-term association between adverse childhood events and BDNF methylation in older age, but further large prospective studies are needed, which do not target specific genes, but consider DNA methylation across the genome.

DNA methylation signatures as biomarkers of socioeconomic position

This review article provides a framework for the use of deoxyribonucleic acid (DNA) methylation (DNAm) biomarkers to study the biological embedding of socioeconomic position (SEP) and summarizes the latest developments in the area. It presents the emerging literature showing associations between individual- and neighborhood-level SEP exposures and DNAm across the life course. In contrast to questionnaire-based methods of assessing SEP, we suggest that DNAm biomarkers may offer an accessible metric to study questions about SEP and health outcomes, acting as a personal dosimeter of exposure. However, further work remains in standardizing SEP measures across studies and evaluating consistency across domains, tissue types, and time periods. Meta-analyses of epigenetic associations with SEP are offered as one approach to confirm the replication of DNAm loci across studies. The development of DNAm biomarkers of SEP would provide a method for examining its impact on health outcomes in a more robust way, increasing the rigor of epidemiological studies.

Integrated analyses of the methylome and transcriptome to unravel sex differences in the perirenal fat from suckling lambs

In sheep, differences were observed regarding fat accumulation and fatty acid (FA) composition between males and females, which may impact the quality and organoleptic characteristics of the meat. The integration of different omics technologies is a relevant approach for investigating biological and genetic mechanisms associated with complex traits. Here, the perirenal tissue of six male and six female Assaf suckling lambs was evaluated using RNA sequencing and whole-genome bisulfite sequencing (WGBS). A multiomic discriminant analysis using multiblock (s)PLS-DA allowed the identification of 314 genes and 627 differentially methylated regions (within these genes), which perfectly discriminate between males and females. These candidate genes overlapped with previously reported QTLs for carcass fat volume and percentage of different FAs in milk and meat from sheep. Additionally, differentially coexpressed (DcoExp) modules of genes between males (nine) and females (three) were identified that harbour 22 of these selected genes. Interestingly, these DcoExp were significantly correlated with fat percentage in different deposits (renal, pelvic, subcutaneous and intramuscular) and were associated with relevant biological processes for adipogenesis, adipocyte differentiation, fat volume and FA composition. Consequently, these genes may potentially impact adiposity and meat quality traits in a sex-specific manner, such as juiciness, tenderness and flavour.

The Interplay of Epigenetic, Genetic, and Traditional Risk Factors on Blood Pressure: Findings from the Health and Retirement Study

The epigenome likely interacts with traditional and genetic risk factors to influence blood pressure. We evaluated whether 13 previously reported DNA methylation sites (CpGs) are associated with systolic (SBP) or diastolic (DBP) blood pressure, both individually and aggregated into methylation risk scores (MRS), in 3070 participants (including 437 African ancestry (AA) and 2021 European ancestry (EA), mean age = 70.5 years) from the Health and Retirement Study. Nine CpGs were at least nominally associated with SBP and/or DBP after adjusting for traditional hypertension risk factors (p < 0.05). MRSSBP was positively associated with SBP in the full sample (β = 1.7 mmHg per 1 standard deviation in MRSSBP; p = 2.7 × 10-5) and in EA (β = 1.6; p = 0.001), and MRSDBP with DBP in the full sample (β = 1.1; p = 1.8 × 10-6), EA (β = 1.1; p = 7.2 × 10-5), and AA (β = 1.4; p = 0.03). The MRS and BP-genetic risk scores were independently associated with blood pressure in EA. The effects of both MRSs were weaker with increased age (pinteraction < 0.01), and the effect of MRSDBP was higher among individuals with at least some college education (pinteraction = 0.02). In AA, increasing MRSSBP was associated with higher SBP in females only (pinteraction = 0.01). Our work shows that MRS is a potential biomarker of blood pressure that may be modified by traditional hypertension risk factors.

Incarceration exposure and epigenetic aging in neighborhood context

OBJECTIVE

Research has implicated incarceration exposure as a social determinant of health, with recent work suggesting incarceration may trigger a stress response that accelerates physiological deterioration. The objective of the current study is to assess whether neighborhood stressors intensify the health consequences of incarceration exposure.

METHODS

We test whether two neighborhood context measures - socioeconomic disadvantage and perceived crime - moderate the association between incarceration exposure and a measure of accelerated epigenetic aging based on the GrimAge index. Our sample included 408 African American young adults from the Family and Community Health study.

RESULTS

Results from regression analyses with inverse probability of treatment weights suggest that incarceration exposure and neighborhood disadvantage are independently associated with accelerated biological aging. The results also show that the impact of incarceration exposure on accelerated aging is amplified for individuals in neighborhoods with higher levels of perceived crime.

CONCLUSIONS

These findings indicate that the neighborhood contexts where formerly incarcerated individuals return have a substantial impact on their pace of biological aging. Policies aimed at reducing ambient stressors after release may promote healthy aging among formerly incarcerated African American adults.

The Geographic Context of Racial Disparities in Aggressive Endometrial Cancer Subtypes: Integrating Social and Environmental Aspects to Discern Biological Outcomes

The number of Endometrial Carcinoma (EC) diagnoses is projected to increase substantially in coming decades. Although most ECs have a favorable prognosis, the aggressive, non-endometrioid subtypes are disproportionately concentrated in Black women and spread rapidly, making treatment difficult and resulting in poor outcomes. Therefore, this study offers an exploratory spatial epidemiological investigation of EC patients within a U.S.-based health system's institutional cancer registry (n = 1748) to search for and study geographic patterns. Clinical, demographic, and geographic characteristics were compared by histotype using chi-square tests for categorical and t-tests for continuous variables. Multivariable logistic regression evaluated the impact of risks on these histotypes. Cox proportional hazard models measured risks in overall and cancer-specific death. Cluster detection indicated that patients with the EC non-endometrioid histotypes exhibit geographic clustering in their home address, such that congregate buildings can be identified for targeted outreach. Furthermore, living in a high social vulnerability area was independently associated with non-endometrioid histotypes, as continuous and categorical variables. This study provides a methodological framework for early, geographically targeted intervention; social vulnerability associations require further investigation. We have begun to fill the knowledge gap of geography in gynecologic cancers, and geographic clustering of aggressive tumors may enable targeted intervention to improve prognoses.

Neighborhood disadvantage and biological aging biomarkers among breast cancer patients

Living in a disadvantaged neighborhood is associated with adverse clinical outcomes among breast cancer patients, but the underlying pathway is still unclear. Limited evidence has suggested that accelerated biological aging may play an important role. In this study, using a sub-sample of 906 women with newly diagnosed breast cancer at M.D. Anderson, we examined whether levels of selected markers of biological aging (e.g., allostatic load, telomere length, and global DNA methylation) were affected by neighborhood disadvantage. The Area Deprivation Index was used to determine the neighborhood disadvantage. Based on the median ADI at the national level, the study population was divided into low and high ADI groups. Overall, breast cancer patients from the high ADI group were more likely to be younger and non-Hispanic Black than those from the low ADI group (P < 0.001, respectively). They were also more likely to have higher grade and poorly differentiated breast tumors (P = 0.029 and 0.019, respectively). For the relationship with markers, compared to the low ADI group, high ADI group had higher median levels of allostatic load (P = 0.046) and lower median levels of global DNA methylation (P < 0.001). Compared to their counterparts, those from the high ADI group were 20% more likely to have increased allostatic load and 51% less likely to have increased levels of global DNA methylation. In summary, we observed that levels of allostatic load and global DNA methylation are influenced by neighborhood disadvantage among breast cancer patients.

The Socioeconomic Gradient in Epigenetic Ageing Clocks: Evidence from the Multi-Ethnic Study of Atherosclerosis and the Health and Retirement Study

Epigenetic clocks have been widely used to predict disease risk in multiple tissues or cells. Their success as a measure of biological ageing has prompted research on the connection between epigenetic pathways of ageing and the socioeconomic gradient in health and mortality. However, studies examining social correlates of epigenetic ageing have yielded inconsistent results. We conducted a comprehensive, comparative analysis of associations between various dimensions of socioeconomic status (SES) (education, income, wealth, occupation, neighbourhood environment, and childhood SES) and eight epigenetic clocks in two well-powered US ageing studies: The Multi-Ethnic Study of Atherosclerosis (MESA) (n = 1,211) and the Health and Retirement Study (HRS) (n = 4,018). In both studies, we found robust associations between SES measures in adulthood and the GrimAge and DunedinPoAm clocks (Bonferroni-corrected p-value < 0.01). In the HRS, significant associations with the Levine and Yang clocks were also evident. These associations were only partially mediated by smoking, alcohol consumption, and obesity, which suggests that differences in health behaviours alone cannot explain the SES gradient in epigenetic ageing in older adults. Further analyses revealed concurrent associations between polygenic risk for accelerated intrinsic epigenetic ageing, SES, and the Levine clock, indicating that genetic risk and social disadvantage may contribute additively to faster biological aging.

DNA Methylation Mediates the Association Between Individual and Neighborhood Social Disadvantage and Cardiovascular Risk Factors

Low socioeconomic status (SES) and living in a disadvantaged neighborhood are associated with poor cardiovascular health. Multiple lines of evidence have linked DNA methylation to both cardiovascular risk factors and social disadvantage indicators. However, limited research has investigated the role of DNA methylation in mediating the associations of individual- and neighborhood-level disadvantage with multiple cardiovascular risk factors in large, multi-ethnic, population-based cohorts. We examined whether disadvantage at the individual level (childhood and adult SES) and neighborhood level (summary neighborhood SES as assessed by Census data and social environment as assessed by perceptions of aesthetic quality, safety, and social cohesion) were associated with 11 cardiovascular risk factors including measures of obesity, diabetes, lipids, and hypertension in 1,154 participants from the Multi-Ethnic Study of Atherosclerosis (MESA). For significant associations, we conducted epigenome-wide mediation analysis to identify methylation sites mediating the relationship between individual/neighborhood disadvantage and cardiovascular risk factors using the JT-Comp method that assesses sparse mediation effects under a composite null hypothesis. In models adjusting for age, sex, race/ethnicity, smoking, medication use, and genetic principal components of ancestry, epigenetic mediation was detected for the associations of adult SES with body mass index (BMI), insulin, and high-density lipoprotein cholesterol (HDL-C), as well as for the association between neighborhood socioeconomic disadvantage and HDL-C at FDR q < 0.05. The 410 CpG mediators identified for the SES-BMI association were enriched for CpGs associated with gene expression (expression quantitative trait methylation loci, or eQTMs), and corresponding genes were enriched in antigen processing and presentation pathways. For cardiovascular risk factors other than BMI, most of the epigenetic mediators lost significance after controlling for BMI. However, 43 methylation sites showed evidence of mediating the neighborhood socioeconomic disadvantage and HDL-C association after BMI adjustment. The identified mediators were enriched for eQTMs, and corresponding genes were enriched in inflammatory and apoptotic pathways. Our findings support the hypothesis that DNA methylation acts as a mediator between individual- and neighborhood-level disadvantage and cardiovascular risk factors, and shed light on the potential underlying epigenetic pathways. Future studies are needed to fully elucidate the biological mechanisms that link social disadvantage to poor cardiovascular health.

Epigenetic Determinants of Racial Disparity in Breast Cancer: Looking beyond Genetic Alterations

Simple Summary

A substantial disparity in breast cancer incidence and mortality exists between African American (AA) and European American (EA) women. However, the basis for these disparities is poorly understood. In this article, we describe that gene–environment interactions mediated through epigenetic modifications may play a significant role in racial disparities in BC incidence and outcomes. Our in silico analyses and an in-depth literature survey suggest that there exists a significant difference in epigenetic patterns between AA and EA women with breast cancer. Herein, we describe the environmental factors that contribute to these epigenetic changes, which may underlie the disparate racial burden in patients with breast cancer. We suggest that AA women with higher basal epigenetic changes, may have higher pre-disposition to cancer onset, and an aggressive disease course. Pre-existing racial differences in epigenetic profiles of breast tissues raises the possibility of examining these profiles for early diagnosis.

Abstract

Breast cancer (BC) is the most commonly diagnosed cancer in women. Despite advancements in BC screening, prevention, and treatment, BC incidence and mortality remain high among African American (AA) women. Compared with European American (EA) women, AA women tend to be diagnosed with more advanced and aggressive tumors and exhibit worse survival outcomes. Most studies investigating the determinants of racial disparities in BC have focused on genetic factors associated with African ancestry. However, various environmental and social stressors over an individual’s life course can also shape racial stratification in BC. These social and environmental exposures result in long-term changes in gene expression mediated by epigenetic mechanisms. Epigenetics is often portrayed as an intersection of socially patterned stress and genetic expression. The enduring nature of epigenetic changes makes them suitable for studying the effects of different environmental exposures over an individual’s life course on gene expression. The role of differential social and environmental exposures in racial disparities in BC suggests varied epigenetic profiles or signatures associated with specific BC subtypes in AA and EA women. These epigenetic profiles in EA and AA women could be used as biomarkers for early BC diagnosis and disease prognosis and may prove valuable for the development of targeted therapies for BC. This review article discusses the current state of knowledge regarding epigenetic differences between AA and EA women with BC. We also discuss the role of socio-environmental factors, including psychosocial stress, environmental toxicants, and dietary factors, in delineating the different epigenetic profiles in AA and EA patients with BC.

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.

Social Determinants of Cardiovascular Disease

Social determinants of health (SDoH), which encompass the economic, social, environmental, and psychosocial factors that influence health, play a significant role in the development of cardiovascular disease (CVD) risk factors as well as CVD morbidity and mortality. The COVID-19 pandemic and the current social justice movement sparked by the death of George Floyd have laid bare long-existing health inequities in our society driven by SDoH. Despite a recent focus on these structural drivers of health disparities, the impact of SDoH on cardiovascular health and CVD outcomes remains understudied and incompletely understood. To further investigate the mechanisms connecting SDoH and CVD, and ultimately design targeted and effective interventions, it is important to foster interdisciplinary efforts that incorporate translational, epidemiological, and clinical research in examining SDoH-CVD relationships. This review aims to facilitate research coordination and intervention development by providing an evidence-based framework for SDoH rooted in the lived experiences of marginalized populations. Our framework highlights critical structural/socioeconomic, environmental, and psychosocial factors most strongly associated with CVD and explores several of the underlying biologic mechanisms connecting SDoH to CVD pathogenesis, including excess stress hormones, inflammation, immune cell function, and cellular aging. We present landmark studies and recent findings about SDoH in our framework, with careful consideration of the constructs and measures utilized. Finally, we provide a roadmap for future SDoH research focused on individual, clinical, and policy approaches directed towards developing multilevel community-engaged interventions to promote cardiovascular health.

Association of Neighborhood-Level Socioeconomic Measures With Cognition and Dementia Risk in Australian Adults

IMPORTANCE

Up to 40% of dementia cases are potentially preventable; therefore, it is important to identify high-risk groups to whom resources could be targeted for maximal impact in preventing late-life dementia. The association of neighborhood-level socioeconomic status (SES) with cognition and dementia risk is not well known, particularly in midlife when late-life dementia may still be preventable through established interventions, such as blood pressure management.

OBJECTIVE

To examine whether neighborhood-level SES is associated with differences in cognitive performance and dementia risk scores.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study analyzed data collected between November 17, 2016, and April 14, 2020, from 4656 participants in the longitudinal population-based Healthy Brain Project cohort. This large online cohort comprised community-dwelling individuals geographically dispersed across Australia. Participants were aged 40 to 70 years without dementia or other major neurological conditions.

EXPOSURES

Neighborhood-level SES was computed by matching participants' residential addresses to the Australian Bureau of Statistics Index of Relative Socio-economic Advantage and Disadvantage (IRSAD). Postcodes provided by each participant were used to derive an IRSAD score that ranked participants according to deciles of neighborhood-level SES (range, 1-10, with higher deciles indicating greater socioeconomic advantage); neighborhoods in deciles 1 to 7 were considered to have low or intermediate SES, and neighborhoods in deciles 8 to 10 were considered to have high SES.

MAIN OUTCOMES AND MEASURES

Dementia risk estimated using the dementia risk score from the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) tool (n = 4656) and cognitive composite scores for memory and attention measured by the Cogstate Brief Battery (n = 2181).

RESULTS

Of 4656 participants (mean [SD] age, 56.1 [7.2] years; 3445 women [74.0%]), 2688 individuals (57.7%) lived in areas with high neighborhood-level SES (IRSAD decile ≥8), and 1968 (42.3%) lived in areas with low or intermediate neighborhood-level SES (IRSAD decile <8), with 1263 individuals (27.1%) residing in rural or regional areas. A total of 6 participants (0.1%) identified as African, 121 (2.6%) as Asian, 57 (1.2%) as Indigenous Australian, 24 (0.5%) as Latin American, 9 (0.2%) as Pacific Islander, 3671 (78.8%) as White or European, and 768 (16.5%) indicated other race (not specified). Each decile unit increase in neighborhood-level SES was associated with a lower CAIDE dementia risk score after adjustment for race and rurality (β [SE] = -0.070 [0.019]; P = .004). Each decile unit increase was also associated with better memory (β [SE] = 0.022 [0.006]; P = .006) but not with better attention (β [SE] = 0.009 [0.007]; P = .34), as measured by Cogstate Brief Battery composite z scores after adjustment for age, sex, race, years of education, and rurality. When comparing memory performance between individuals with IRSAD scores higher and lower than decile 8, neighborhood-level SES interacted with age (F1-2171 = 6.33; P = .02) and CAIDE dementia risk scores (F1-2173 = 4.02; P = .08). Differences in memory between neighborhood-level SES categories were larger among participants who were older and had a higher risk of dementia.

CONCLUSIONS AND RELEVANCE

In this study, higher neighborhood-level SES was associated with better memory and lower dementia risk scores. These results suggest that efforts to lower dementia risk factors in disadvantaged areas are needed to curtail the increasing burden of dementia and that inclusion of individuals living in areas with lower SES in research on dementia is warranted to improve understanding and potential interventions.

Does DNA methylation mediate the association of age at puberty with FVC or FEV1?

Background

Age of pubertal onset is associated with lung function in adulthood. However, the underlying role of epigenetics as a mediator of this association remains unknown.

Methods

DNA methylation (DNAm) in peripheral blood was measured at age 18 years in the Isle of Wight birth cohort (IOWBC) along with data on age of pubertal events, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁) at 26 years. Structural equation models were applied to examine mediation effects of DNAm on the association of age at pubertal events with FVC and FEV₁. Findings were further tested in the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort.

Results

In the IOWBC, for females, 21 cytosine-phosphate-guanine sites (CpGs) were shown to mediate the association of age at puberty with FVC or FEV₁ at 26 years (p<0.05). In males, DNAm at 20 CpGs was found to mediate the association of age at puberty with FVC (p<0.05). At almost all these CpGs, indirect effects (effects of age at pubertal events on FVC or FEV₁via DNAm) contributed a smaller portion to the total effects compared to direct effects (e.g. at cg08680129, ∼22% of the estimated total effect of age at menarche on FVC at age 26 was contributed by an indirect effect). Among the IOWBC-discovered CpGs available in ALSPAC, none of them was replicated in ALSPAC (p>0.05).

Conclusions

Our findings suggest that post-adolescence DNAm in peripheral blood is likely not to mediate the association of age at pubertal onset with young adulthood FVC or FEV₁.

The association between age at pubertal onset and lung function parameters FVC or FEV₁ in young adulthood is not likely to be mediated by DNA methylation in peripheral bloodhttps://bit.ly/31G8hDi

Neighborhood characteristics and breast tumor methylation: using epigenomics to explore cancer outcome disparities

BACKGROUND

Social exposures may drive epigenetic alterations that affect racial disparities in breast cancer outcomes. This study examined the association between neighborhood-level factors and DNA methylation in non-Hispanic Black and White women diagnosed with breast cancer.

METHODS

Genome-wide DNA methylation was measured using the EPIC array in the tumor tissue of 96 women. Linear regression models were used to examine the association between nine neighborhood-level factors and methylation, regressing β values for each cytosine-phosphate guanine dinucleotide (CpG) site on neighborhood-level factors while adjusting for covariates. Neighborhood data were obtained from the Opportunity Atlas. We used a false discovery rate (FDR) threshold < 0.05, and for CpGs below this threshold, we examined interactions with race. We employed multivariable Cox proportional-hazards models to estimate whether aberrant methylation was associated with all-cause mortality.

RESULTS

26 of the CpG sites were associated with job density or college education (FDR < 0.05). Further exploration of these 26 CpG sites revealed no interactions by race, but a single probe in TMEM204 was associated with all-cause mortality.

CONCLUSION

We identified novel associations between neighborhood-level factors and the breast tumor DNA methylome. Our data are the first to show that dysregulation in neighborhood associated CpG sites may be associated with all-cause mortality. Neighborhood-level factors may contribute to differential tumor methylation in genes related to tumor progression and metastasis. This contributes to the increasing body of evidence that area-level factors (such as neighborhood characteristics) may play an important role in cancer disparities through modulation of the breast tumor epigenome.