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

Abstract

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.

Accelerated epigenetic aging mediates link between adverse childhood experiences and depressive symptoms in older adults: Results from the Health and Retirement Study

“…This study builds on a large body of past research examining the association between ACEs and mental and physical health, and a few studies linking ACEs to epigenetic age acceleration. Our findings are consistent with past findings that suggest second generation clocks are more consistently associated with ACEs in adults ( George et al, 2021 ), potentially because these clocks were trained to predict phenotypic indicators of accelerated aging and are more consistently associated with age-related health problems ( Horvath & Raj, 2018 ). This study also builds on this past body of research examining the association between ACEs and epigenetic clocks by utilizing a representative sample of US adults over the age of 50.…”

“…Past research has reported both significant ( Colich et al, 2020 ; Jovanovic et al, 2017 ; Lawn et al, 2018 ; Marini et al, 2020 ) and null ( Austin et al, 2018 ; Fiorito et al, 2017 ; Simons et al, 2016 ; Verhoeven et al, 2018 ) results using the first generation clocks. Research using the second generation clocks has been more consistently supportive ( Belsky et al, 2020 ; George et al, 2021 ; Hamlat et al, 2021 ); however, prior research using the Health and Retirement Study suggests childhood adversity only accounts for a small proportion of PhenoAge ( Liu et al, 2019 ). Past investigations have been limited because they typically investigate only one epigenetic aging measure in a given analysis.…”

A blood DNA methylation biomarker for predicting short-term risk of cardiovascular events

“…This result is partially explained by our selection procedure in the training set, based on the time-to-CVD event. Also, it may support a previous report about DNAm as biomarkers of life course accumulation of exposure and stressors [52], leading to a better prediction of short-term outcomes rather than long-term risk. Thus, methylation levels are likely to have undergone severe changes as the follow-up time increased.…”

Understanding Health Inequalities Through the Lens of Social Epigenetics

“…While decades of research demonstrate the long-term consequences of low childhood social position, recent studies suggest that the effects on epigenetic aging continue well into adulthood, but findings are mixed. Two separate studies found that low parental occupational status during childhood was associated with accelerated epigenetic aging in adulthood ( 6 , 47 ). These findings differ from those of a more recent study observing no association between parental occupational status during childhood and epigenetic aging in adulthood among participants in the Irish Longitudinal Study on Aging ( 85 ).…”

“…Like early life SEP, low adult SEP is associated with differential DNAm levels at stress- and inflammation-related genes, including at the AVP gene (stress-related pathway) and the CD1D, F8, KLRG1, NLRP12, and TLR3 genes (inflammation-related pathways) ( 95 ). Furthermore, studies of SEP and epigenetic aging in adulthood demonstrate effects across epigenetic clocks, with low SEP attainment associated with accelerated DNAm aging across several epigenetic clocks, including Hannum’s clock,Levine’s PhenoAge,GrimAge,and (with weaker evidence of associations) Horvath’s clock ( 30 , 44 , 47 , 115 ).…”