There is a growing interest in understanding how the experience of socioeconomic status (SES) adversity across the life course may accumulate to negatively affect the functioning of biological regulatory systems important to functioning and health in later adulthood. The goal of the present analyses was to examine whether greater life course SES adversity experience would be associated with higher scores on a multi-system allostatic load (AL) index of physiological function in adulthood. Data for these analyses are from 1,008 participants (92.2% White) from the Biomarker Substudy of the Study of Midlife in the US (MIDUS). Multiple indicators of SES adversity in childhood (parent educational attainment, welfare status, financial situation) and two points in adulthood (educational attainment, household income, difficulty paying bills, availability of money to meet basic needs, current financial situation) were used to construct SES adversity measures for each life course phase. An AL score was constructed using information on 24 biomarkers from 7 different physiological systems (sympathetic and parasympathetic nervous systems, hypothalamic-pituitary-adrenal axis, cardiovascular, lipid metabolism, glucose metabolism, inflammatory immune activity). Analyses indicate higher AL as a function of greater SES adversity at each phase of, and cumulatively across, the life course. Associations were only moderately attenuated when accounting for a wide array of health status, behavioral and psychosocial factors. Findings suggest that SES adversity experience may cumulate across the life course to have a negative impact on multiple biological systems in adulthood. An important aim of future research is the replication of current findings in this predominantly White sample in more ethnically diverse populations.

Data from the nationally representative US National Health and Nutrition Examination Survey (NHANES) III cohort were used to examine the hypothesis that socio-economic status is consistently and negatively associated with levels of biological risk, as measured by nine biological parameters known to predict health risks (diastolic and systolic blood pressure, pulse, HDL and total cholesterol, glycosylated hemoglobin, c-reactive protein, albumin and waist-hip ratio), resulting in greater cumulative burdens of biological risk among those of lower education and/or income. As hypothesized, consistent education and income gradients were seen for biological parameters reflecting cardiovascular, metabolic and inflammatory risk: those with lower education and income exhibiting greater prevalence of high-risk values for each of nine individual biological risk factors. Significant education and income gradients were also seen for summary indices reflecting cumulative burdens of cardiovascular, metabolic and inflammatory risks as well as overall total biological risks. Multivariable cumulative logistic regression models revealed that the education and income effects were each independently and negatively associated with cumulative biological risks, and that these effects remained significant independent of age, gender, ethnicity and lifestyle factors such as smoking and physical activity. There were no significant ethnic differences in the patterns of association between socio-economic status and biological risks, but older age was associated with significantly weaker education and income gradients.

Objectives To determine whether there is a relationship between early life adversity (ELA) and biological parameters known to predict health risks and to examine the extent to which circumstances in midlife mediate this relationship. Methods We analyzed data on 1,180 respondents from the biomarker subsample of the second wave of the National Survey of Midlife Development in the United States (MIDUS) study. ELA assessments were based on childhood socioeconomic disadvantage (i.e. on welfare, perceived low income, less-educated parents) and other stressors (e.g., parental death, parental divorce, and parental physical abuse). The outcome variable was cumulative allostatic load (AL), a marker of biological risk. We also incorporate information on adult circumstances, including: education, social relationships, and health behaviors. Results Childhood socioeconomic adversity was associated with increased AL (B=0.094, SE=0.041) and physical abuse (B=0.263, SE=0.091), with non-significant associations for parental divorce and death. Adult education mediated the relationship between socioeconomic ELA and cumulative allostatic load to the point of non-significance, with this factor alone explaining nearly 40% of the relationship. The association between childhood physical abuse and AL remained even after adjusting for adult educational attainments, social relationships, and health behaviors. These associations were most pronounced for secondary stress systems, including inflammation, cardiovascular function, and lipid metabolism. Conclusions The physiological consequences of early life socioeconomic adversity are attenuated by achieving high levels of schooling later on. The adverse consequences of childhood physical abuse, on the other hand, persist in multivariable adjusted analysis.