Socioeconomic inequalities in molecular risk for chronic diseases observed in young adulthood

Abstract

Many common chronic diseases of aging are negatively associated with socioeconomic status (SES). This study examines whether inequalities can already be observed in the molecular underpinnings of such diseases in the 30s, before many of them become prevalent. Data come from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a large, nationally representative sample of US subjects who were followed for over two decades beginning in adolescence. We now have transcriptomic data (mRNA-seq) from a random subset of 4,543 of these young adults. SES in the household-of-origin and in young adulthood were examined as covariates of a priori -defined mRNA-based disease signatures and of specific gene transcripts identified de novo . An SES composite from young adulthood predicted many disease signatures, as did income and subjective status. Analyses highlighted SES-based inequalities in immune, inflammatory, ribosomal, and metabolic pathways, several of which play central roles in senescence. Many genes are also involved in transcription, translation, and diverse signaling mechanisms. Average causal-mediated effect models suggest that body mass index plays a key role in accounting for these relationships. Overall, the results reveal inequalities in molecular risk factors for chronic diseases often decades before diagnoses and suggest future directions for social signal transduction models that trace how social circumstances regulate the human genome.

Measuring Attributions 50 Years on: From within-Country Poverty to Global Inequality

“…As in this example, the causes of poverty are often located within the poor when they are confused with the traces poverty leaves on the individual. In fact, epigenetic studies show that people’s genetics can be predicted by their ancestors’ exposure to sustained poverty and social inequality [ 78 ]. In this case, claiming that “poverty is in genetics” is not saying that there is a genetic cause but rather that these particular genetics could also be the consequence or correlation of ancestral poverty.…”

Socioeconomic inequalities in young adulthood disrupt the immune transcriptomic landscape via upstream regulators

“…Functional enrichment of the SES -differentially expressed genes (423 upregulated genes and 389 downregulated genes) showed a majority upregulated for pathways involving metabolism, signal transduction and cellular response to stress by a core of ribosomal and translational genes. Interestingly, these cytosolic ribosomal genes (RPL-and RPS-genes) were found to be downregulated with aging in an analysis of the human peripheral blood and previously linked with SES 35 . Indeed, a combined WGCNA and SESdifferential expression analysis (see Fig.…”

“…The access to restricted use Add Health transcriptomic data was obtained by completing a contractual and data use agreement. Additional detailed information on the study design, interview procedures, consent procedures, demographic assessments, collection, sequencing and quality control of the blood sample, and derivation of the analytical samples is reported in previous studies [33][34][35] . Furthermore, the data analysis and all methods presented in this work were carried out in accordance with the relevant ethical guidelines and regulations.…”

Socioeconomic inequalities in early adulthood disrupt the immune transcriptomic landscape via upstream regulators

“…The access to restricted use Add Health transcriptomic data was obtained by completing a contractual and data use agreement. Additional detailed information on the study design, interview procedures, consent procedures, demographic assessments, collection, sequencing and quality control of the blood sample, and derivation of the analytical samples is reported in Supplementary Methods and in previous studies 40 – 42 . Furthermore, the data analysis and all methods presented in this work were carried out in accordance with the relevant ethical guidelines and regulations.…”