Background. Pain is common in inflammatory bowel disease (IBD), particularly during disease flares, and often after clinical remission is achieved. Cross-sectional and longitudinal data in people with IBD suggest that depression, sleep disturbances, fatigue, and worry about pain may all impact the pain experience. There is a bidirectional relationship between sleep and pain, though this relationship has received minimal attention in IBD, particularly in Crohn’s disease (CD). Our prior work indicates that the relationship between sleep quality and next day pain in IBD may be stronger than the relationship between daytime pain during and subsequent sleep quality. Herein, we expand on this finding in a population with greater night-to-night symptom variability; patients with self-reported active CD and insomnia.

Method. Patients were recruited from the Dartmouth-Hitchcock IBD Center as part of a clinical trial on insomnia treatment in CD. Inclusion criteria: self-reported symptoms consistent with insomnia disorder and mild-to-moderate CD. Exclusion criteria: other sleep disorders, significant psychiatric concerns, and/or presence of other common behavioral or physiological influences on sleep.
Participants completed 14-day diaries on sleep patterns and CD symptoms at baseline. Temporal and bidirectional associations between pain and sleep were assessed using cross-lagged path analysis adjusted for the autoregressive effect of previous day’s pain and previous night’s sleep. Models controlled for age, sex, and menstrual cycle.

Results. Overall, 26 participants completed 14-day diaries (Table 1). Analyses indicated that taking longer to fall asleep, more nightly awakenings, longer time awake during the night, lower sleep efficiency, and lower sleep quality were all associated with worse abdominal pain the next day (ps <.01; Table 2). Controlling for the previous day/night’s experiences, time to fall asleep predicted next day pain (p=.03) and pain during the day predicted time to fall asleep that night (p=.04). Similarly, nightly awakenings predicted next day pain (p=.03) and vice versa (p=.04). Finally, sleep quality ratings strongly predicted next day pain (p<.001), whereas pain did not significantly predict that night’s sleep quality (p=.37).

Discussion. Our findings are broadly consistent with the extant literature on sleep and pain. However, research in both chronic pain populations and irritable bowel syndrome suggests that sleep drives the day-to-day relationship between sleep and pain. In CD, it appears that while prolonged initial sleep latency may impact next day pain, daytime pain may play a more prominent role in nightly sleep disturbance. As interventions for pain in IBD are limited, it may be important to capitalize on the impact of sleep disturbance on pain to optimize overall wellbeing in people with CD.

Michael Smith

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