title: Phenotypic and Molecular Evidence Suggests That Decrements in Morning and Evening Energy Are Distinct but Related Symptoms.
abstract: BACKGROUND
  Little is known about energy levels in oncology patients and their family caregivers.
  
  
  OBJECTIVE
  This study sought to identify latent classes of participants, based on self-reported energy levels and evaluate for differences in phenotypic and genotypic characteristics between these classes.
  
  
  METHODS
  Energy subscale scores from the Lee Fatigue Scale were used to determine latent class membership. Morning and evening energy scores were obtained just before, during, and for four months after the completion of radiation therapy. Genetic associations were evaluated for 15 proinflammatory and anti-inflammatory cytokine genes.
  
  
  RESULTS
  Two latent classes with distinct morning energy trajectories were identified. Participants who were younger, female, not married/partnered, black, and had more comorbidities, and a lower functional status were more likely to be in the low morning energy class. Two polymorphisms (IL2 rs1479923 and NFKB1 rs4648110) were associated with morning energy latent class membership. Two latent classes with distinct evening energy trajectories were identified. Participants who were younger and male and who had more comorbidities, decreased body weight, and a lower functional status were more likely to be in the moderate evening energy class. Five different polymorphisms (IL1R2 rs4141134, IL6 rs4719714, IL17A rs8193036, NFKB2 rs1056890, and TNFA rs1800683) were associated with evening energy latent class membership.
  
  
  CONCLUSIONS
  This study provides preliminary evidence that decrements in morning and evening energy are associated with different phenotypic risk factors and cytokine gene variations.
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA; Institute for Human Genetics, University of California, San Francisco, California, USA.
authors.forename: Bradley E
authors.initials: BE
authors.lastname: Aouizerat
authors.affiliation: School of Medicine, University of California, San Francisco, California, USA.
authors.forename: Anand
authors.initials: A
authors.lastname: Dhruva
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Paul
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Cooper
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA.
authors.forename: Kord M
authors.initials: KM
authors.lastname: Kober
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA. Electronic address: chris.miaskowski@ucsf.edu.
authors.forename: Christine
authors.initials: C
authors.lastname: Miaskowski
mesh_terms: D000368:Aged; D016207:Cytokines / Q000235:genetics; D005221:Fatigue / Q000145:classification / Q000453:epidemiology / Q000235:genetics* / Q000503:physiopathology*; D005260:Female; D056726:Genetic Association Studies; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology / Q000235:genetics / Q000503:physiopathology / Q000532:radiotherapy; D010641:Phenotype; D017440:Photoperiod; D020641:Polymorphism, Single Nucleotide; D012720:Severity of Illness Index
chemical_list: D016207:Cytokines
keywords: Energy; cancer; cytokines; family caregivers; fatigue; growth mixture modeling; radiation therapy; single nucleotide polymorphisms