Socioeconomic Position and DNA Methylation Age Acceleration Across the Life Course

AbstractSocioeconomic position (SEP) is a major determinant of health across the life course. Yet, little is known about the biological mechanisms explaining this relationship. One possible explanation is through an epigenetic process called DNA methylation (DNAm), wherein the socioeconomic environment causes no alteration in the DNA sequence but modifies gene activity, gene expression, and therefore long-term health. To understand the evidence supporting a potential SEP-DNAm link, we performed a systematic review of published empirical findings on the association between SEP (from prenatal development to adulthood) and DNAm measured across the life course, with an eye toward evaluating how the timing, duration, and type of SEP exposure influenced DNAm. Across the 37 studies we identified, there was some evidence for the effect of SEP timing and duration on DNAm, with early-life SEP and persistently low SEP being particularly strong indicators of DNAm. Different indicators of SEP also had some unique associations with DNAm profiles, suggesting that SEP is not a singular concept, but rather that different aspects of the socioeconomic environment can shift DNAm patterns through distinct pathways. These differences with respect to SEP timing, duration, and type were notable because they were detected even among heterogenous study designs. Overall, findings from this review underscore the importance of analyzing SEP timing, duration, and type, given the complex relationship between SEP and DNAm across the lifespan. To guide future research, we highlight current limitations in the literature and propose recommendations for overcoming some of these challenges.

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

Clinical Epigenetics ◽

10.1186/s13148-021-01189-0 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Janine Cerutti ◽

Alexandre A. Lussier ◽

Yiwen Zhu ◽

Jiaxuan Liu ◽

Erin C. Dunn

Keyword(s):

Dna Methylation ◽

Life Course ◽

Scoping Review ◽

Socioeconomic Position ◽

Prenatal Development ◽

Future Research ◽

Socioeconomic Environment ◽

The Life Course ◽

The Relationship ◽

Epigenetic Processes

Abstract Background Socioeconomic position (SEP) is a major determinant of health across the life course. Yet, little is known about the biological mechanisms explaining this relationship. One possibility widely pursued in the scientific literature is that SEP becomes biologically embedded through epigenetic processes such as DNA methylation (DNAm), wherein the socioeconomic environment causes no alteration in the DNA sequence but modifies gene activity in ways that shape health. Methods To understand the evidence supporting a potential SEP-DNAm link, we performed a scoping review of published empirical findings on the association between SEP assessed from prenatal development to adulthood and DNAm measured across the life course, with an emphasis on exploring how the developmental timing, duration, and type of SEP exposure influenced DNAm. Results Across the 37 identified studies, we found that: (1) SEP-related DNAm signatures varied across the timing, duration, and type of SEP indicator; (2) however, longitudinal studies examining repeated SEP and DNAm measures are generally lacking; and (3) prior studies are conceptually and methodologically diverse, limiting the interpretability of findings across studies with respect to these three SEP features. Conclusions Given the complex relationship between SEP and DNAm across the lifespan, these findings underscore the importance of analyzing SEP features, including timing, duration, and type. To guide future research, we highlight additional research gaps and propose four recommendations to further unravel the relationship between SEP and DNAm.

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Life course socioeconomic position and DNA methylation age acceleration in mid-life

Journal of Epidemiology & Community Health ◽

10.1136/jech-2020-215608 ◽

2021 ◽

pp. jech-2020-215608

Author(s):

Anitha George ◽

Rebecca Hardy ◽

Juan Castillo Fernandez ◽

Yvonne Kelly ◽

Jane Maddock

Keyword(s):

Social Class ◽

Life Course ◽

Socioeconomic Position ◽

First Generation ◽

Second Generation ◽

Social Disadvantage ◽

Biological Ageing ◽

Dna Methylation Age ◽

Using Data ◽

The Life Course

BackgroundAgeing biomarkers can help us better understand how well-established socioeconomic position (SEP) disparities in ageing occur. A promising new set of DNAm methylation (DNAm)-based ageing biomarkers indicate through their age acceleration (AA) measures if biological ageing is slower or faster than chronological ageing. Few studies have investigated the association between SEP and DNAm AA.MethodsWe used linear regression to examine the sex-adjusted relationships between childhood social class, adult social class, intergenerational social class change, education and adult household earnings with first (Horvath AA and Hannum AA) and second generation (PhenoAge AA and GrimAge AA) DNAm AA markers using data from the MRC National Survey of Health and Development.ResultsIn the first-generation biomarkers, there was little evidence of any associations with Horvath AA but associations of childhood social class and income with Hannum AA were observed. Strong associations were seen between greater disadvantage in childhood and adult SEP and greater AA in the second generation biomarkers. For example, those with fathers in an unskilled occupational social class in childhood had 3.6 years greater PhenoAge AA (95% CI 1.8 to 5.4) than those with fathers from a professional social class. Individuals without qualifications had higher AA compared with those with higher education (4.1 years greater GrimAge AA (95% CI 3.1 to 5.0)).ConclusionOur findings highlight the importance of exposure to social disadvantage in childhood to the biological ageing process. The second generation clocks appear to be more sensitive to the accumulation of social disadvantage across the life course.

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Socioeconomic Position Across the Life Course and Stroke Risk at Older Ages

American Journal of Epidemiology ◽

10.1093/aje/163.suppl_11.s67-c ◽

2006 ◽

Vol 163 (suppl_11) ◽

pp. S67-S67

Author(s):

M.M Glymour ◽

M Avendano ◽

L.F Berkman

Keyword(s):

Life Course ◽

Socioeconomic Position ◽

Stroke Risk ◽

The Life Course

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Associations of fibrinogen and C-reactive protein with prevalent and incident coronary heart disease are attenuated by adjustment for confounding factors

Thrombosis and Haemostasis ◽

10.1160/th04-12-0805 ◽

2005 ◽

Vol 93 (05) ◽

pp. 955-963 ◽

Cited By ~ 44

Author(s):

George Smith ◽

Ann Rumley ◽

Gordon Lowe ◽

Shah Ebrahim ◽

Debbie Lawlor

Keyword(s):

Coronary Heart Disease ◽

Heart Disease ◽

Life Course ◽

Socioeconomic Position ◽

Cumulative Effect ◽

Positive Association ◽

Confounding Factors ◽

Cross Sectional ◽

Reactive Protein ◽

The Life Course

SummaryA cross sectional and prospective analysis of 3,745 British women aged 60–79 years at baseline was undertaken. Among these women there were 570 prevalent cases of coronary heart disease (CHD) and 151 new cases among 12,641 person-years of follow up of women who were free of CHD at baseline. Both fibrinogen and CRP were associated with indicators of socioeconomic position in childhood and adulthood and there was a cumulative effect of socioeconomic position from across the life course. The age-adjusted odds ratio (95% confidence interval) of prevalent CHD for a 1 unit (1 g/L) increase in fibrinogen was 1.29 (1.12, 1.49); with full adjustment for all potential confounding factors this attenuated to 1.09 (0.93, 1.28). The hazards ratio for incident CHD among those free of disease at baseline was 1.28 (1.00, 1.64); with full adjustment for all potential confounding factors this attenuated to 1.09 (0.84, 1.44). Similar effects of adjustment for confounding factors were seen for the associations between CRP and both prevalent and incident CHD. By contrast, the strong positive association between smoking (an established causal risk factor for CHD) and CHD was not attenuated by adjustment for life course socioeconomic position or other risk factors. We conclude that fibrinogen and CRP predict CHD but may not be causally related to it.

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Socioeconomic position over the life course from childhood and smoking status in mid-adulthood: results from a 25-year follow-up study

BMC Public Health ◽

10.1186/s12889-019-6483-0 ◽

2019 ◽

Vol 19 (1) ◽

Author(s):

Jing Tian ◽

Seana Gall ◽

Kira Patterson ◽

Petr Otahal ◽

Leigh Blizzard ◽

...

Keyword(s):

Life Course ◽

Socioeconomic Position ◽

Smoking Status ◽

Follow Up Study ◽

The Life Course

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Abstract 032: Life-Course Socioeconomic Position Relates to Higher Arterial Stiffness in Adults From the ELSA-Brasil Cohort Study

Circulation ◽

10.1161/circ.137.suppl_1.032 ◽

2018 ◽

Vol 137 (suppl_1) ◽

Author(s):

Debora M Coelho ◽

Lidyane V Camelo ◽

Luisa C Brant ◽

Luana G Giatti ◽

Antonio L Ribeiro ◽

...

Keyword(s):

Cardiovascular Disease ◽

Cohort Study ◽

Arterial Stiffness ◽

Life Course ◽

Socioeconomic Position ◽

Maternal Education ◽

Adult Life ◽

Linear Regression Models ◽

Subclinical Cardiovascular Disease ◽

The Life Course

Background: Although the association between socioeconomic adversity and risk for cardiovascular disease (CVD) is established, little is known about the effect of socioeconomic disadvantages across the life-course on arterial stiffness, an important marker of subclinical cardiovascular disease (CVD). Objective: To investigate whether exposure to adverse socioeconomic position (SEP) throughout the life course and especially in early life, is associated with increased arterial stiffness in adults. In addition, we assessed whether increasing number of unfavorable SEP events during the life course is associated with higher arterial stiffness. Methods: A total of 14,497 adults from the ELSA-Brasil cohort study baseline (2008-2010), aged between 34 and 75 years (45.5% men, mean age: 51.9, SD: 9.09), with validated values of femoral carotid pulse wave velocity (cfPWV), and with information available about maternal education were included. ELSA-Brazil is a multicenter cohort of civil servants from universities and research institutions of six Brazilian cities that aims to investigate the determinants of cardiovascular disease. Arterial stiffness was measured by cfPWV. Childhood and adulthood SEP was measured by maternal education and participants’ own education, respectively. Accumulation of SEP disadvantages across the life course was evaluated using a score including maternal and participants’ own education. The following variables were used for adjustments: age, sex, race, mean arterial pressure, heart rate, smoking, physical activity, diabetes, antihypertensive use. Multiple linear regression models were used. Results: Both lower childhood and adulthood SEP were associated with higher cfPWV in adult life, although the association with childhood SEP was not independent of adulthood SEP. However, cfPWV increased with increasing number of unfavorable SEP during the life course. Individuals exposed to low SEP in childhood and adulthood presented an average increase of 0.23m/s (95% CI: 0.13-0.34) in cfPWV in relation to individuals with high SEP in both periods of life. After all adjustments this association remained statically significant (β = 0.18, 95% CI: 0.07-0.29). Conclusion: Accumulation of exposures to socioeconomic disadvantages throughout life was associated with higher cfPWV in adults. Thus, it may imply that longer exposure to social disadvantages throughout life accelerates arterial aging.

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