Table 1.

Studies that either directly or indirectly support a role for circadian disruption in inflammatory bowel disease.

Study (year)	Subjects	Intervention	Sleep measure	Circadian modification	Clinical outcome	Main finding	Histologic measure	Ref.
Selected pharmacologic interventional studies (melatonin)
Li et al. (2005)	TNBS-treated rats	Melatonin			Improved colitis	Mediated through NF-κB		[39]
Mei et al. (2002)	TNBS-treated rats	Melatonin			Improved colitis	Reduced oxidative injury		[40]
Observation studies in sleep and IBD
Keefer et al. (2006)	Inactive IBD, IBS, healthy controls		Polysomnography PSQI		Decreased total sleep time and sleep efficiency	Sleep impacted IBD-Q		[44]
Ranjbaran et al. (2007)	Inactive IBD, IBS, healthy controls		PSQI		Poor overall sleep quality	Sleep impacted IBD-Q		[45]
Burgess et al. (2010)	Inactive IBD		Wrist actigraphy DLMO		Decreased sleep efficiency	Some abnormal melatonin secretion		[42]
Biological physiological studies
Preuss et al. (2008)	DSS-treated mice			Phase shift	Worsened colitis increased mortality		Increased MPO	[49]
Tang et al. (2009)	DSS-treated mice			Acute and chronic sleep deprivation	Worsened colitis increased mortality		Increased MPO	[50]

DLMO: Dim light melatonin onset; DSS: Dextran sodium sulfate; IBD: Inflammatory bowel disease; IBD-Q: Inflammatory bowel disease questionnaire; IBS: Irritable bowel syndrome; MPO: Myeloperoxidase; PSQI: Pittsburgh Sleep Quality Index; TNBS: Trinitrobenzene sulfonic acid.