It has long been known that socio-economic status (SES), whether assessed by income, education level or occupation, is a strong determinant of healthy aging and life expectancy. For instance, we have recently shown in an analysis of 1.7 million individuals as part of the LIFEPATH project, that participants with low SES had higher mortality compared to those with high SES (hazard ratio 1.42; 95%CI: 1.38,1.45, Stringini et al). This suggests that SES, as a potentially modifiable risk factor, should be given similar consideration in public health interventions to other established risk factors such the “25x25 risk factors” targeted by The World Health Organisation Global Action Plan for the Prevention and Control of Non-Communicable Diseases. The 25 x 25 risk factors include the harmful use of alcohol, insufficient physical activity, current tobacco use and raised blood pressure, intake of salt/sodium, and diabetes and obesity. While the distribution of these risk factors varies by SES, they do not account for the total effect on mortality observed with SES, with models additionally adjusted for these risk factors still demonstrating an independent association between SES and mortality (hazard ratio 1.34, 95%CI: 1.20,1.48, Stringini et al).

It is therefore hypothesised that additional pathways may explain the observed relationship between SES and health, with psycho-social stress induced inflammation one such potential pathway. Modern ‘omics technologies, which provide broad coverage of a range of biological pathways, may identify new mechanisms that link environmental factors to disease risk. The serum nuclear magnetic resonance based metabolomic platform available within the UCLEB cohorts covers a range of metabolic areas including lipoprotein and lipid metabolism, fluid balance, glycolysis, transamination and inflammation. Perturbation of metabolite levels within these areas may provide important new evidence of how SES gets ‘under the skin’ and influences disease risk.