The aging immune system and all-cause mortality in older americans: differences across sex and race/ethnicity

Our findings demonstrate that associations between immune aging and mortality are not uniform but instead vary in magnitude and direction across sex and racial/ethnic subgroups. The strongest and most consistent associations were observed among Hispanic and non-Hispanic Black females-groups experiencing multiple forms of marginalization-suggesting that these populations may face heightened vulnerability to the downstream consequences of immune aging. However, the absence or reversal of expected associations in some subgroups-particularly non-Hispanic Black males-underscores the complexity of immune aging processes and their interaction with social and biological contexts. These results highlight the importance of disaggregated analyses and suggest that immune aging may manifest and impact mortality risk differently across populations.