Social status differences in allostatic load among young adults in the United States

Allostatic load refers to wear and tear on the body due to repeated activation of the stress response and, thus, may be an early subclinical indicator of future disease and mortality risk. To date, few studies of allostatic load have focused on young adults, racial/ethnic comparisons that include Mexican Americans, or the interplay between race/ethnicity, gender, and educational attainment. To fill these gaps, we used data on non-Hispanic Black, non-Hispanic White, and Mexican-origin respondents from Waves I (1994-1995) and IV (2007-2008) of the National Longitudinal Study of Adolescent to Adult Health (Add Health; N = 11,807). We calculated allostatic load scores based on respondents' values for 10 metabolic, cardiovascular, and inflammatory biomarkers measured at Wave IV, when respondents were 24-34 years old. We then used negative binomial regression models to assess the combined effects of race/ethnicity, gender, and educational attainment on allostatic load, while controlling for key covariates. We found that Black women had significantly higher allostatic load scores than White women and Black men, net of educational attainment and other covariates. Yet, education modified the relationship between race/ethnicity, gender, and allostatic load. Obtaining a college education was protective for White males and females but no more or less protective for other women and deleterious for Black males. In other words, by the time they reach young adulthood, the cumulative physiological burden of stress on Black women and college-educated Black men is already greater than it is among their similarly or less educated White counterparts. These findings provide important information about the intermediate physiological dysregulation that underlies social inequalities in stress-related health outcomes, especially those that occur at the intersections of race/ethnicity, gender, and educational attainment. They also suggest that research on its antecedents should focus on earlier life periods.