Abstract
Cortisol has been widely used as biomarker of stress and aging, but confounding effects and disruption of the hypothalamic–pituitary–adrenal axis can lead to misinterpretation of results based on a single measurement. A possible alternative is the co-measurement of cortisol and the adrenal hormone dehydroepiandrosterone-sulfate (DHEAS), a glucocorticoid antagonist that modulates the stress response. Using data from 969 individuals from the Midlife in the United States study, this study aimed to investigate the influence of age, sex, and self-identified biosocial group (SIBG) on DHEAS, cortisol, and the cortisol/DHEAS ratio, to test whether these hormones add predictive power to epigenetic age estimates, and to compare the performance of these three hormonal measures in predicting epigenetic age acceleration (EAA) using sex epigenetic clocks: Horvath, Horvath’s skin & blood (Horvath2), Hannum, PhenoAge, GrimAge, and DunedinPACE. Our findings revealed that age, sex and SIBG significantly influenced all three hormonal measures. Controlling for these biodemographic factors, we found that the cortisol/DHEAS was the best predictor of epigenetic clocks. There was a significant and positive correlation between cortisol and Hannum epigenetic age, and between cortisol/DHEAS ratio in three out of the six clocks (Hannum, Horvath2, PhenoAge), but no significant associations between DHEAS and epigenetic age. The cortisol/DHEAS ratio also had a significant and positive correlation with Hannum EAA. DHEAS and cortisol were not significantly associated with EAA for any epigenetic clock. Our results reinforce the importance of co-measuring cortisol and DHEAS in studies investigating the effect of stress in aging processes.