Perceived discrimination and monocyte abundance in older adults: Findings from the Health and Retirement Study.

Perceived discrimination is a pervasive social stressor linked to adverse health outcomes, and these effects appear to be mediated at least in part by immune system alterations that may affect inflammation-related diseases. To determine the cellular mechanisms involved, we investigated the association between everyday perceived discrimination and circulating monocyte counts in data from the 2016 Health and Retirement Study Venous Blood Study (n = 6332). After adjusting for age, sex, race/ethnicity, body mass index, smoking, and alcohol consumption, individuals reporting higher levels of perceived discrimination exhibited increased total monocyte counts, with a 9 % relative increase in total monocyte counts per 4-standard deviation increase in perceived discrimination scores (95 % CI: 0.01, 0.17). These effects stemmed primarily from increased abundance of classical monocytes, with no significant associations for non-classical monocytes. These results suggest that perceived discrimination may contribute to disease at least in part via increased monocyte abundance. These findings underscore the importance of addressing perceived discrimination as a social determinant of health and highlight the need for further research on the immunological pathways involved.