0233 Pain, Fatigue, and Altered Reactivity to a Repeated Physiological Stressor in Insomnia Patients: An Explanatory-Driven Analysis

Abstract

IntroductionFatigue and pain are prominent features of functional impairment in insomnia. This study aimed to better understand behavioral and physiological mechanisms of these complex relationships.Methods22 participants with insomnia disorder (DSM-5 criteria, 18 female, age 18-49yrs) and 22 good-sleeper controls (19 female, age 18-47yrs) completed two-weeks sleep logs and actigraphy recordings prior to coming to the laboratory for overnight polysomnography and subsequent daytime testing that included questionnaires, three trials of cold pressor test (CPT), and pain testing with blood draws collected throughout. Insomnia diagnosis was determined by a board-certified sleep specialist, and exclusion criteria included psychiatric history within past 6 months, other sleep disorder, significant medical conditions, and any medications within past two weeks with significant effects on inflammation, autonomic function, or other psychotropic effects. For CPT, participants were instructed to immerse hand in ice cold water for at least one minute and rate pain intensity throughout the immersion and 3-minute recovery. Data were analyzed with linear mixed models.ResultsPer inclusion criteria, PSQI scores were differed between groups (insomnia: 10.2±2.7, range 7–16; control: 1.9±1.3, range 0–5; p