Social adversity and epigenetic aging: a multi-cohort study on socioeconomic differences in peripheral blood DNA methylation

Abstract

Low socioeconomic status (SES) is associated with earlier onset of age-related chronic conditions and reduced life-expectancy, but the underlying biomolecular mechanisms remain unclear. Evidence of DNA-methylation differences by SES suggests a possible association of SES with epigenetic age acceleration (AA). We investigated the association of SES with AA in more than 5,000 individuals belonging to three independent prospective cohorts from Italy, Australia, and Ireland. Low SES was associated with greater AA (β = 0.99 years; 95% CI 0.39,1.59; p = 0.002; comparing extreme categories). The results were consistent across different SES indicators. The associations were only partially modulated by the unhealthy lifestyle habits of individuals with lower SES. Individuals who experienced life-course SES improvement had intermediate AA compared to extreme SES categories, suggesting reversibility of the effect and supporting the relative importance of the early childhood social environment. Socioeconomic adversity is associated with accelerated epigenetic aging, implicating biomolecular mechanisms that may link SES to age-related diseases and longevity.

Epigenetic age is accelerated in schizophrenia with age- and sex-specific effects and associated with polygenic disease risk

“…The difference between (predicted) DNAm and chronological age (Δage) is associated with a wide-range of health and disease outcomes. For example, DNAm age acceleration in blood is associated with all-cause mortality [15][16][17][18] , socioeconomic adversity and smoking 19 , metabolic outcomes, such as body mass index and obesity 20,21 , and brain-related phenotypes, such as Parkinson's disease, posttraumatic stress disorder, insomnia, major depressive disorder, and bipolar disorder [22][23][24]25,26 .…”

Determinants of accelerated metabolomic and epigenetic ageing in a UK cohort

“…written for the R statistical computing environment, including background and color bias 571 correction, quantile normalization, and Beta MIxture Quantile dilation (BMIQ) procedure to 572 remove type I/type II probes bias, as described elsewhere (Fiorito et al, 2017). DNAm levels 573…”

“…Furthermore, it has been shown that 'age acceleration', defined as having a greater DNA 53 methylation age than chronological age, is associated with multiple risk factors of mortality 54 such as low social class, smoking, and alcohol use (Fiorito et al, 2017) 2016) combined a small set of markers to provide an overall assessment of biological 62…”

“…were generally of greater size than for mAA. Meta-analyses have shown that both PTSD 285 (Wolf & Morrison, 2017) and low socio-economic position (Fiorito et al, 2017) to be 286 associated with increases in DNAmAA. We did not observe any evidence for an association 287 between depression and DNAmAA, suggesting the two ageing measures may be sensitive 288…”

Associations between environmental breast cancer risk factors and DNA methylation-based risk-predicting measures

“…The variance of epigenetic age acceleration has also been suggested to be influenced by environmental factors [22]. Lifestyle factors, such as smoking, alcohol drinking, obesity, exercise and diet [23,19,[24][25][26], and hormone-related breast cancer risk factors, such as age at menarche and age at menopause [27,28], have been found to be associated with epigenetic age acceleration.…”