title: Sleep disturbance, cytokines, and fatigue in women with ovarian cancer.
abstract: Pro-inflammatory cytokines, such as interleukin-6 (IL-6), have been implicated in the underlying processes contributing to sleep regulation and fatigue. Despite evidence for sleep difficulties, fatigue, and elevations in IL-6 among women with ovarian cancer, the association between these symptoms and IL-6 has not been investigated. To address this knowledge gap, we examined relationships between sleep disturbance, fatigue, and plasma IL-6 in 136 women with ovarian cancer prior to surgery. These relationships were also examined in 63 of these women who were disease-free and not receiving chemotherapy one year post-diagnosis. At both time-points, higher levels of IL-6 were significantly associated with sleep disturbances (p<0.05), controlling for potentially confounding biological and psychosocial covariates. Higher IL-6 was significantly associated with fatigue prior to surgery (p<0.05); however, when sleep disturbance was included in the model, the relationship was no longer significant. IL-6 was not significantly associated with fatigue at one year. Changes in sleep over time were significantly associated with percent change in IL-6 from pre-surgery to one year, adjusting for covariates (p<0.05). These findings support a direct association of IL-6 with sleep disturbances in this population, whereas the relationship between IL-6 and fatigue prior to surgery may be mediated by poor sleep. As this study is the first to examine cytokine contributions to sleep and fatigue in ovarian cancer, further research is warranted to clarify the role of biological correlates of sleep and fatigue in this population.
authors.affiliation: Department of Psychology, University of Iowa, Iowa City, IA 52242, United States.
authors.forename: Lauren
authors.initials: L
authors.lastname: Clevenger
authors.forename: Andrew
authors.initials: A
authors.lastname: Schrepf
authors.forename: Desire
authors.initials: D
authors.lastname: Christensen
authors.forename: Koen
authors.initials: K
authors.lastname: DeGeest
authors.forename: David
authors.initials: D
authors.lastname: Bender
authors.forename: Amina
authors.initials: A
authors.lastname: Ahmed
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Goodheart
authors.forename: Frank
authors.initials: F
authors.lastname: Penedo
authors.forename: David M
authors.initials: DM
authors.lastname: Lubaroff
authors.forename: Anil K
authors.initials: AK
authors.lastname: Sood
authors.forename: Susan K
authors.initials: SK
authors.lastname: Lutgendorf
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use; D001007:Anxiety / Q000523:psychology; D015992:Body Mass Index; D016207:Cytokines / Q000097:blood*; D003710:Demography; D005221:Fatigue / Q000209:etiology*; D005260:Female; D015438:Health Behavior; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000150:complications* / Q000188:drug therapy / Q000601:surgery; D012893:Sleep Wake Disorders / Q000209:etiology*; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D016207:Cytokines; D015850:Interleukin-6