Diurnal cortisol patterns in chronic pain: Associations with work-family spillover, work, and home stress.

Chronic pain is a prevalent condition with significant impacts on individuals' lives, including heightened stress and impaired physiological functioning. Given that work and family are the two main social domains where stress manifests, this study aimed to investigate the interactions between chronic pain, work-family stressors, and diurnal cortisol patterns to understand how chronic pain affects daily life and physiological stress responses. We identified 1,413 adults with chronic pain and 1,413 matched controls within MIDUS II samples to examine work-family spillover, daily work and home stressors, and cortisol levels across multiple days. The chronic pain group reported more negative work to family spillover and experienced more instances of stressful home events, particularly avoided arguments. These results align with literature suggesting chronic pain exacerbates tensions in close relationships and increases stress. The chronic pain group also had higher cortisol levels cross late-day periods, indicative of hypothalamic-pituitary-adrenal (HPA) axis dysregulation. This dysregulation is associated with poorer health outcomes, including increased inflammation and psychological distress. We did not find any differences in previously identified cortisol profiles, which are higher-level summaries of cortisol levels within each day. We discuss why such difference might not have appeared in this sample.