Sleep duration affects risk for ulcerative colitis: a prospective cohort study.
OBJECTIVE
Sleep deprivation is associated with production of inflammatory cytokines. Disturbed sleep quality has been associated with increased risk of disease flare in patients with Crohn's disease (CD) or ulcerative colitis (UC). However, the association between sleep and risk of incident CD and UC has not been previously examined.


METHODS
We conducted a prospective study of women who were enrolled in the Nurses' Health Study (NHS) I since 1976 and NHS II since 1989 and followed through detailed biennial questionnaires with >90% follow-up. We examined the association of sleep duration reported in 1986 in NHS I and 2001 in NHS II with incident CD and UC, diagnosed through 2010, in NHS I and 2009 in NHS II. Cox proportional hazards models adjusting for potential confounders were used to calculate hazard ratios and 95% confidence intervals (CIs).


RESULTS
Among 151,871 women, we confirmed 191 cases of CD (incidence, 8/100,000 person-years) and 230 cases of UC (incidence, 10/100,000 person-years) over 2,292,849 person-years. Compared with women with reported usual sleep durations of 7-8 h/day (incidence, 8/100,000 person-years), women with reported sleep duration <6 h/day (11/100,000 person-years) or >9 h/day (20/100,000 person-years) had a higher incidence of UC (P < .05). The multivariate hazard ratios for UC were 1.51 (95% CI, 1.10-2.09) for sleep durations <6 h/day and 2.05 (95% CI, 1.44-2.92) for sleep durations >9 h/day, compared with sleep durations of 7-8 h/day. In contrast, sleep duration did not modify risk of CD. Duration of rotating night shift work was not associated with CD or UC.


CONCLUSIONS
On the basis of data from the NHS I and II, less than 6 hours sleep/day and more than 9 hours sleep/day are each associated with an increased risk of UC. Further studies are needed to evaluate sleep as a modifiable risk factor in the pathogenesis and progression of IBD.
Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts. Electronic address: aananthakrishnan@partners.org.
Ashwin N
AN
Ananthakrishnan
Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
Hamed
H
Khalili
Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
Gauree G
GG
Konijeti
Division of Gastroenterology and Nutrition, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts.
Leslie M
LM
Higuchi
Division of Gastroenterology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
Punyanganie
P
de Silva
Division of Gastroenterology and Nutrition, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts; Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
Charles S
CS
Fuchs
Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
James M
JM
Richter
Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; Division of Sleep Medicine, Harvard Medical School, Boston, Massachusetts.
Eva S
ES
Schernhammer
Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts; Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts.
Andrew T
AT
Chan
D000328:Adult; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D011446:Prospective Studies; D018570:Risk Assessment; D012890:Sleep; D011795:Surveys and Questionnaires; D013997:Time Factors
Circadian Clock; Epidemiology; Inflammation; Population; Risk Factor