title: Associations of self-reported sleep duration and snoring with colorectal cancer risk in men and women.
abstract: OBJECTIVE
  We assessed the relationship between sleep duration, snoring and colorectal cancer risk.
  
  
  METHODS
  Prospective cohort studies.
  
  
  METHODS
  United States.
  
  
  METHODS
  A total of 30,121 men aged 41 to 79 years in the Health Professionals Follow-up Study and 76,368 women aged 40 to 73 years in the Nurses' Health Study.
  
  
  METHODS
  None.
  
  
  RESULTS
  We queried information on sleep duration and snoring in 1986/87. Cox proportional hazards regression models were used to estimate multivariable hazard ratios (HRs, 95% CIs). We documented 1,973 incident colorectal cancer cases (709 men and 1,264 women) over a 22-year follow-up period. Compared to sleep an average 7 h, ≥ 9 h of sleep was significantly associated with a higher risk of colorectal cancer among men (HR = 1.35, 95% CI: 1.00, 1.82), and to a lesser degree, among women (HR = 1.11, 95% CI: 0.85, 1.44). The risk associated with longer sleep was restricted to individuals who regularly snored (men: HR = 1.80, 95% CI: 1.14, 2.84; women: HR = 2.32, 95% CI: 1.24, 4.36) and to overweight individuals (i.e., BMI ≥ 25 kg/m2) (men: HR = 1.52, 95% CI: 1.04, 2.21; women: HR = 1.37, 95% CI: 0.97, 1.94). Short sleep duration (≤ 5 h) was not associated with an increased risk of colorectal cancer in the entire sample or in subgroups stratified by snoring or BMI.
  
  
  CONCLUSIONS
  Longer sleep duration was associated with an increased risk of developing colorectal cancer among individuals who were overweight or snored regularly. This observation raises the possibility that sleep apnea and its attendant intermittent hypoxemia may contribute to cancer risk.
authors: Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA. xuehong.zhang@channing.harvard.edu
authors: Xuehong
authors: X
authors: Zhang
authors: Edward L
authors: EL
authors: Giovannucci
authors: Kana
authors: K
authors: Wu
authors: Xiang
authors: X
authors: Gao
authors: Frank
authors: F
authors: Hu
authors: Shuji
authors: S
authors: Ogino
authors: Eva S
authors: ES
authors: Schernhammer
authors: Charles S
authors: CS
authors: Fuchs
authors: Susan
authors: S
authors: Redline
authors: Walter C
authors: WC
authors: Willett
authors: Jing
authors: J
authors: Ma
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D057566:Self Report; D012890:Sleep / Q000502:physiology*; D012913:Snoring / Q000150:complications*; D013997:Time Factors
keywords: Sleep duration; colorectal cancer; incidence; prospective study; snoring
references: Sleep. 2004 May 1;27(3):440-4
references: 15164896
references: FEBS J. 2008 Jun;275(12):2991-3002
references: 18445039
references: Eur Respir J. 2012 Jan;39(1):215-7
references: 22210813
references: J Natl Cancer Inst. 2003 Jun 4;95(11):825-8
references: 12783938
references: PLoS One. 2012;7(1):e30972
references: 22295122
references: Am J Clin Nutr. 2007 Sep;86(3):s836-42
references: 18265477
references: Endocr Dev. 2010;17:11-21
references: 19955752
references: Sleep. 2010 May;33(5):585-92
references: 20469800
references: Carcinogenesis. 2008 Jun;29(6):1244-8
references: 18448486
references: Am J Epidemiol. 1992 May 15;135(10):1114-26; discussion 1127-36
references: 1632423
references: Cancer Res. 2005 Oct 15;65(20):9595-600
references: 16230426
references: Obesity (Silver Spring). 2008 Mar;16(3):643-53
references: 18239586
references: Sleep Med Rev. 2007 Oct;11(5):337-9
references: 17854737
references: Am J Respir Crit Care Med. 2012 Jul 15;186(2):190-4
references: 22610391
references: CA Cancer J Clin. 2011 Jul-Aug;61(4):212-36
references: 21685461
references: Gastroenterology. 2010 Jun;138(6):2029-2043.e10
references: 20420944
references: Br J Cancer. 2008 Nov 4;99(9):1502-5
references: 18813313
references: Cancer. 2011 Feb 15;117(4):841-7
references: 20936662
references: Int J Sports Med. 1997 Jul;18 Suppl 3:S162-70
references: 9272843
references: J Cell Biochem. 2010 Oct 15;111(3):554-63
references: 20568121
references: Sleep. 2006 Jul;29(7):881-9
references: 16895254
references: Circulation. 2011 Nov 8;124(19):2049-51
references: 22064955
references: Sleep. 2009 May;32(5):615-22
references: 19480228
references: Diabetes Care. 2003 Feb;26(2):380-4
references: 12547866
references: Arch Intern Med. 2003 Jan 27;163(2):205-9
references: 12546611
references: Am J Epidemiol. 2006 Nov 15;164(10):947-54
references: 16914506
references: Obesity (Silver Spring). 2009 Sep;17(9):1678-83
references: 19300426
references: Am J Epidemiol. 1985 Jul;122(1):51-65
references: 4014201
references: Ann N Y Acad Sci. 1998 Sep 29;856:148-59
references: 9917875
references: Cancer Causes Control. 1995 Mar;6(2):164-79
references: 7749056
references: Ann N Y Acad Sci. 2001 Mar;933:211-21
references: 12000022
references: Sleep. 1997 Oct;20(10):865-70
references: 9415946
references: Eur Heart J. 2011 Jun;32(12):1484-92
references: 21300732
references: Biol Psychiatry. 1991 Mar 15;29(6):575-84
references: 1647222