Abstract
Exposure to areas high in violent crime is a potent stressor that influences health outcomes by chronically undermining safety and upregulating biological stress responses. We tested the hypothesis that the association between cortisol, as measured in head hair, and inflammation, as measured by C-Reactive Protein (CRP) in capillary blood, is dependent on the degree of violent crime within adolescents' everyday activity spaces. Because structural inequities cause Black adolescents to spend more time in areas with higher rates of violent crime, we tested this hypothesis in Black and White youth separately. 137 adolescents (M(age) = 15.55, 57 % female, 52 % Black, 48 % White) participated in the study. We obtained continuous GPS-tracked data for one week to assess the average violent crime rate across the areas where participants spent time; biosamples were collected at the end of the week. Among Black adolescents, there was an interaction such that higher GPS-tracked activity space violent crime levels were associated with a positive and significant association between CRP and cortisol, consistent with models suggesting that stress can dysregulate immune-endocrine functioning. Conversely, for Black adolescents with low rates of exposure, cortisol had a negative association with CRP, consistent with a normative effect of glucocorticoid inhibition of inflammation. For White adolescents, cortisol and violence levels were significantly lower than for Black adolescents, and in this context, there was a weak main effect of violence exposure on CRP but no significant interaction. Results suggest the association between cortisol and inflammation varies across violent crime levels within the areas adolescents spend time and emphasize the importance of studying how an adolescent's environment shapes biological responses to chronic stressors.