Sleep Duration and Risk of Liver Cancer in Postmenopausal Women: The Women's Health Initiative Study

J Womens Health (Larchmt). 2017 Dec;26(12):1270-1277. doi: 10.1089/jwh.2017.6412. Epub 2017 Sep 21.


Background: Sleep duration has been associated with nonalcoholic fatty liver disease, but its association with liver cancer remains unknown.

Material and methods: In the prospective Women's Health Initiative Study, 139,368 postmenopausal women reported sleep habits at baseline (1993-1998). We ascertained 175 incident liver cancer cases during an average 13.8 years of follow-up through August 2014. We used multivariable Cox proportional hazard regression models to estimate a hazard ratio (HR) and its 95% confidence interval (95% CI) for risk of liver cancer in association with nocturnal sleep duration.

Results: Compared to women reporting 6-8 hours of sleep, the HR for liver cancer was 1.94 (95% CI 1.07-3.53) for women reporting ≥9 hours of sleep. Among the obese women, the HR associated with ≥9 hours of sleep was 3.18 (95% CI 1.84-8.60). The HR was 0.93 (95% CI 0.34-2.53) among nonobese women (p value for interaction = 0.18). Short sleep duration (≤5 hours) was not associated with liver cancer risk.

Conclusion: Long sleep duration was associated with a moderate increase in liver cancer risk in obese postmenopausal women in the United States. Larger study is needed to confirm our observation on effect modification by adiposity status.

Keywords: WHI; circadian rhythm; liver cancer; obesity; risk factor; sleep.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aged
  • Circadian Rhythm
  • Female
  • Humans
  • Liver Neoplasms / epidemiology*
  • Liver Neoplasms / etiology*
  • Middle Aged
  • Obesity / complications*
  • Obesity / epidemiology*
  • Postmenopause*
  • Proportional Hazards Models
  • Prospective Studies
  • Risk Factors
  • Sleep / physiology*
  • Sleep Disorders, Circadian Rhythm / physiopathology*
  • Time Factors
  • United States / epidemiology
  • Women's Health