Age and Sex Differences in the Associations Among Socioeconomic Status, Affective Reactivity to Daily Stressors, and Physical Health in the MIDUS Study

Lay Summary Individuals from low socioeconomic backgrounds tend to experience poor physical health, partially because they might be more vulnerable to stress exposure due to limited resources to cope with stress than those from high socioeconomic backgrounds. This study examined the indirect link between socioeconomic status (SES) and physical health through emotional responses following exposure to stress. We also explored whether there were age and sex differences in this indirect link. We analyzed the survey and daily diary data from 1,522 middle-aged and older adults. Individuals reported indicators of SES and a count of medical health conditions. Individuals also reported their experiences of stressors and negative and positive emotions each day over 8 days to capture changes in negative and positive emotions on stressor days versus non-stressor days. We found that among women, but not men, lower SES was related to larger increases in negative emotions on stressor days, which, in turn, was related to more chronic health conditions. Differences in individuals' negative emotions following exposure to daily stressors may be a critical indirect pathway linking SES to physical health. Background Low socioeconomic status (SES) is robustly associated with increased risks of morbidity and mortality. Affective reactivity to daily stressors has been proposed to be a mediator for this association. However, few longitudinal studies have empirically tested the indirect effect of SES on health through affective reactivity to daily stressors. Purpose This study aimed to test the indirect effect of SES on physical health via affective reactivity to daily stressors over a 10-year period and to explore age and sex differences in such indirect effect. Methods Data were drawn from a subsample of 1,522 middle-aged and older adults (34-83 years of age, 57.2% female, 83.5% White) from the Midlife in the United States study. SES (i.e., education, household income, indicators of financial distress) was assessed in 2004-2006. Affective reactivity to daily stressors was computed using data collected during the 8-day daily stress assessment in 2004-2009. Self-reported physical health conditions were assessed in 2004-2006 and 2013-2014. Results There was a significant indirect effect of lower SES on more physical health conditions via elevated negative affective reactivity to daily stressors among women but not men. The indirect effect of SES on physical health conditions via negative affective reactivity to daily stressors was consistent across the middle and older adulthood. Conclusions Our findings suggest that negative affective reactivity to daily stressors might be a key intermediate process contributing to persistent SES disparities in physical health, particularly among women.