title: Sleep disturbance and incidence of thyroid cancer in postmenopausal women the Women's Health Initiative.
abstract: Sleep disturbance has been found to be associated with numerous adverse health outcomes, including cancers. However, no epidemiologic study has examined the relation between sleep disturbance and thyroid cancer risk. A total of 142,933 postmenopausal women who were 50-79 years of age and enrolled in the Women's Health Initiative between September 1, 1993, and December 31, 1998, were followed up for a mean of 11 years. Cox proportional-hazard regression models were used to estimate hazard ratios and 95% confidence intervals for sleep disturbance (insomnia and sleep duration) and risk of thyroid cancer. Insomnia score was measured using a validated 5-item Women's Health Initiative Insomnia Rating Scale. Overall, a total of 295 thyroid cancer cases were identified. After adjustment for potential confounders, women with greater insomnia scores had a significantly higher risk of thyroid cancer than did women with low scores (hazard ratio = 1.44, 95% confidence interval: 1.01, 2.05). The significant association between insomnia score and thyroid cancer was confined to nonobese women (hazard ratio = 1.71, 95% confidence interval: 1.12, 2.62) and was not seen in obese women (hazard ratio = 0.94 95% confidence interval: 0.48, 1.84) (P for interaction = 0.07). In conclusion, postmenopausal women with greater insomnia scores, especially nonobese women, had a significantly increased risk of thyroid cancer. More studies are needed to confirm these findings.
authors.affiliation: Department of Community Medicine, Mary Babb Randolph Cancer Center, Robert C. Byrd Health Sciences Center, School of Medicine, West Virginia University, P.O. Box 9190, Morgantown, WV 26506, USA. Jiluo@hsc.wvu.edu
authors.forename: Juhua
authors.initials: J
authors.lastname: Luo
authors.forename: Megan
authors.initials: M
authors.lastname: Sands
authors.forename: Jean
authors.initials: J
authors.lastname: Wactawski-Wende
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Song
authors.forename: Karen L
authors.initials: KL
authors.lastname: Margolis
mesh_terms: D000368:Aged; D015992:Body Mass Index; D003863:Depression / Q000453:epidemiology; D005260:Female; D015438:Health Behavior; D020249:Hormone Replacement Therapy; D006801:Humans; D008875:Middle Aged; D017698:Postmenopause; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D013964:Thyroid Neoplasms / Q000453:epidemiology*; D016387:Women's Health