Advancing health equity through integrated biology and population health research: A community-based sample cortisol feasibility and exploratory study

BACKGROUND: Community-based research inclusive of self-assessment and objective environmental metrics can be enhanced by the collection of biomarker data in unity toward assessing the health impacts of the totality of environmental stress driven by structural racism. Cortisol dynamic range (CDR), a measure of chronic stress burden, may underpin place-based connections to health, but a gap remains in elucidating community-based CDR methodology. PURPOSE: To 1) assess the feasibility of cortisol collection and CDR measurement in a community-based study with home-based, participant-directed specimen collection, and 2) explore the association between CDR and other individual and environmental measures in a sample of predominantly Black participants. Methods: In this cross-sectional, observational study in predominantly Black urban neighborhoods, participants (n = 73) completed health assessments and in-home, self-collected salivary cortisol. For feasibility, CDR (peak-nadir) was compared to cortisol awakening response (CAR) slope over time. Comparisons of CDR quartile by person and place variables were explored (ANOVA). RESULTS: The cohort (77% Black, 39.7% <$15 k/year income, high perceived stress) completed 98.6% of cortisol collection timepoints. CDR was calculated in all participants without interruptions to sleep-wake cycle as seen with CAR collection. Participants in the lowest quartile of CDR were the oldest (p = 0.03) with lowest reported mental health (p = 0.048) with no associations seen for CAR. CONCLUSION: Participant-collected 10.13039/501100011622CDR is more feasible than cortisol measures dependent on slopes over time in a community-based, predominately Black cohort with exploratory findings supporting relevance to outcomes of interest to future work. Future community-based studies should integrate CDR with environment and psychosocial measures.