Trait hostility and cortisol sensitivity following a stressor: The moderating role of stress-induced heart rate variability

Hostility and adverse health outcomes are inconsistently associated in the literature. Self-regulation and cortisol secretion may play important roles in differentiating those hostile individuals who are at greater risk of negative health outcomes from those who are not. In the present study, we sought to examine if having high self-regulatory strength, as indexed by high stress-induced high-frequency heart rate variability (HF-HRV), buffered the effects of hostility on cortisol secretion. Participants (N = 213) completed a self-report measure of hostility and measurement of HF-HRV at rest and during a social stress task. Saliva samples were collected immediately before (one sample), and over a 50 min period after (six samples), the stress task to evaluate cortisol secretion over time. Hostile individuals were less likely to demonstrate cortisol sensitivity (i.e., high change in cortisol over time) when they had high stress-induced HF-HRV. Such findings are important given that cortisol sensitivity increases risk of metabolic and inflammatory disorders via glucocorticoid resistance and inflammation. Therefore, interventions that increase stress-induced HF-HRV may reduce the impact of hostility on health outcomes.