Understanding the sleep-pain relationship in patients with interstitial cystitis/bladder pain syndrome.

Introduction: Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic pelvic pain condition with critical symptoms of urinary urgency and frequency, persistent bladder-related pain, and reduced quality of life. Poor-quality sleep can lead to significant disturbances in daily life and increased pain in IC/BPS patients. Resilience, depressive symptoms, and pain catastrophizing have univariate associations with sleep and pain in IC/BPS, suggesting they may be mechanisms in this sleep and pain relationship.

Methods: This online study recruited patients self-reporting a diagnosis of IC/BPS through support groups, social media posts (Facebook, Reddit, and Instagram), and urology clinic advertisements. Participants completed questionnaires on demographics, urologic symptoms, pain, pain catastrophizing, depressive symptoms, and resilience. Only those participants who met the RAND Interstitial Cystitis Epidemiology (RICE) criteria for IC/BPS diagnosis were included. A multiple mediation model was first examined, followed by a serial mediation model.

Results: Seventy-four participants (M= 47.0, standard deviation [SD ] 16.7, range 18-83 years) met inclusion criteria. A multiple mediation model showed greater sleep disturbance was associated with greater pain severity through depressive symptoms and pain catastrophizing, but not resilience (b=0.79, bootSE =0.26, bootCI [0.33, 1.35]). A serial mediation showed that the sleep-to-pain relationship had a significant indirect effect through pain catastrophizing and depressive symptoms (b=0.78, bootSE =0.26, bootCI [0.35, 1.32]).

Conclusions: Findings suggest depressive symptoms and pain catastrophizing may be important psychosocial mechanisms in the sleep-to-pain relationship. These results help guide future sleep and pain research in IC/BPS and aid in developing and refining treatments.