Healthy sleep, mental health, genetic susceptibility, and risk of irritable bowel syndrome

We aimed to investigate the prospective association of individual and combined sleep behaviors and mental health (psychological distress and neuroticism) with incident irritable bowel syndrome (IBS). A total of 302,839 participants without prior IBS in the UK Biobank were enrolled. A healthy sleep score was created according to five sleep factors and defined the low-risk groups as follows: sleep 7–8 h/day, early chronotype, never/rarely insomnia, no snoring, and no frequent excessive daytime sleepiness. Psychological distress and neuroticism were ascertained using the Patient Health Questionnaire and the Eysenck Personality Questionnaire-Revised Short Form, respectively. The primary outcome was incident IBS, based on self-report or linkage to death register and/or primary care and/or hospital admission data. During a median follow-up of 12.0 years, 5574 participants developed IBS. Overall, low-risk sleep behaviors and a healthy sleep score (per one point increment, HR, 0.81, 95%CI, 0.79–0.83) were associated with a lower risk of incident IBS, 29.4 %–32.4 % of which was mediated by mental health. Psychological distress (per one point increment, HR, 1.16, 95%CI, 1.14–1.17) and neuroticism (HR, 1.11, 95%CI, 1.10–1.12) were positively associated with incident IBS, and healthy sleep scores mediated 8.3 %–9.7 % of the association. Moreover, participants with lowest healthy sleep score/highest mental health score and higher genetic risk of IBS showed the highest risk of incident IBS. Sleep behaviors and mental health were assessed by self-reported questionnaires. Healthy sleep scores and low psychological distress/neuroticism were associated with a lower risk of IBS, regardless of genetic predisposition.