Perceived discrimination and stress response profiles among Mexican-origin Adolescents

Abstract

The hypothalamic-pituitary-adrenal (HPA) axis is one of the major stress response systems in the human body and it is sensitive to social evaluative stress. The functioning of HPA axis is commonly measured with cortisol. Research on cortisol has focused on cortisol reactivity and its diurnal rhythm using salivary cortisol to inform short-term stress responses. Cortisol can also be measured through hair, which tracks individuals’ cumulative stress response. To more comprehensively understand cortisol levels and responses to stress, this study used a person-centered approach to examine stress response profiles based on individuals’ cortisol reactivity, diurnal cortisol rhythms, and hair cortisol concentration. Participants were 290 Mexican-origin adolescents (Mage = 17.38; 52% female). Latent profile analysis was used to characterize stress response profiles identified using three daily salivary samples across four days, seven saliva samples throughout the Trier Social Stress Test, and hair cortisol. The resulting profiles were examined in relation to discrimination and covariates. Analyses identified two stress response profiles. Most of the participants (88%) were in the “lower” profile (blunted diurnal cortisol rhythm and lower pattern of cortisol reactivity) and the remainder were in the “higher” profile (elevated diurnal cortisol rhythm and increased pattern of cortisol reactivity). Adolescents in the “lower” group reported more discrimination than those in the “higher” group. Findings of the study demonstrate the first attempt to integrate different aspects of stress responses in the HPA axis. Results also highlight the blunting effects of discrimination on Mexican-origin adolescents’ basal cortisol and responses to stress.