Basal SIgA and cortisol levels predict stress-related health outcomes

The present study investigates the relationship between stress and health in young adults. We predicted that academic stressor exposure would lead to an increase in self-reported stress and health symptoms, as well as alterations in salivary secretory immunoglobulin A (SIgA) and salivary cortisol concentration. Thirty-four healthy participants were administered stress and health inventories and tested to assess SIgA and cortisol levels during a baseline (low-stress) session and during an examination (high-stress) session. Self-report stress and health scores increased between low- and high-stress sessions in all participants. Cortisol level also increased between study sessions, but only in those participants who experienced an increase in perceived stress. No changes in SIgA were observed. Multiple linear regression revealed that baseline SIgA and cortisol level moderated the relationship between stressor exposure and health outcome. Participants with low basal SIgA levels and high basal cortisol levels bad poorer health outcomes during the examination session than did participants with high basal SIgA levels and low basal cortisol levels. Neither cortisol reactivity, nor SIgA reactivity moderated the relationship between stressor exposure and health outcome. These findings suggest that individual differences in basal immune and endocrine activity predict stress-related susceptibility to ill health. Copyright (c) 2006 John Wiley & Sons, Ltd.