title: Fatigue and sleep quality are associated with changes in inflammatory markers in breast cancer patients undergoing chemotherapy.
abstract: Fatigue and sleep disturbances are two of the most common and distressing symptoms reported by cancer patients. Fatigue and sleep are also correlated with each other. While fatigue has been reported to be associated with some inflammatory markers, data about the relationship between cancer-related sleep disturbances and inflammatory markers are limited. This study examined the relationship between fatigue and sleep, measured both subjectively and objectively, and inflammatory markers in a sample of breast cancer patients before and during chemotherapy. Fifty-three women with newly diagnosed stage I-III breast cancer scheduled to receive at least four 3-week cycles of chemotherapy participated in this longitudinal study. Fatigue was assessed with the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF), sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI) and objective sleep was measured with actigraphy. Three inflammatory markers were examined: Interleukin-6 (IL-6), Interleukin-1 receptor antagonist (IL-1RA) and C-reactive protein (CRP). Data were collected before (baseline) and during cycle 1 and cycle 4 of chemotherapy. Compared to baseline, more fatigue was reported, levels of IL-6 increased and IL-1RA decreased during chemotherapy. Reports of sleep quality remained poor. Mixed model analyses examining changes from baseline to each treatment time point revealed overall positive relationships between changes in total MFSI-SF scores and IL-6, between changes in total PSQI scores and IL-6 and IL-1RA, and between total wake time at night and CRP (all p's<0.05). These relationships suggest that cancer-related fatigue and sleep disturbances may share common underlying biochemical mechanisms.
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093-0733, USA.
authors.forename: Lianqi
authors.initials: L
authors.lastname: Liu
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Mills
authors.forename: Michelle
authors.initials: M
authors.lastname: Rissling
authors.forename: Lavinia
authors.initials: L
authors.lastname: Fiorentino
authors.forename: Loki
authors.initials: L
authors.lastname: Natarajan
authors.forename: Joel E
authors.initials: JE
authors.lastname: Dimsdale
authors.forename: Georgia Robins
authors.initials: GR
authors.lastname: Sadler
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Parker
authors.forename: Sonia
authors.initials: S
authors.lastname: Ancoli-Israel
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000523:psychology*; D002097:C-Reactive Protein / Q000378:metabolism; D016207:Cytokines / Q000096:biosynthesis; D003627:Data Interpretation, Statistical; D018450:Disease Progression; D005221:Fatigue / Q000209:etiology*; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D053590:Interleukin 1 Receptor Antagonist Protein / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008137:Longitudinal Studies; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000150:complications
chemical_list: D000970:Antineoplastic Agents; D016207:Cytokines; D018836:Inflammation Mediators; D053590:Interleukin 1 Receptor Antagonist Protein; D015850:Interleukin-6; D002097:C-Reactive Protein