title: Relationship of Mitochondrial Enzymes to Fatigue Intensity in Men With Prostate Cancer Receiving External Beam Radiation Therapy.
abstract: OBJECTIVE
  Mitochondrial dysfunction is a plausible biological mechanism for cancer-related fatigue. Specific aims of this study were to (1) describe the levels of mitochondrial oxidative phosphorylation complex (MOPC) enzymes, fatigue, and health-related quality of life (HRQOL) before and at completion of external beam radiation therapy (EBRT) in men with nonmetastatic prostate cancer (PC); (2) examine relationships over time among levels of MOPC enzymes, fatigue, and HRQOL; and (3) compare levels of MOPC enzymes in men with clinically significant and nonsignificant fatigue intensification during EBRT.
  
  
  METHODS
  Fatigue was measured by the revised Piper Fatigue Scale and the Functional Assessment of Cancer Therapy-Fatigue subscale (FACT-F). MOPC enzymes (Complexes I-V) and mitochondrial antioxidant superoxide dismutase 2 were measured in peripheral blood using enzyme-linked immunosorbent assay at baseline and completion of EBRT. Participants were categorized into high or low fatigue (HF vs. LF) intensification groups based on amount of change in FACT-F scores during EBRT.
  
  
  RESULTS
  Fatigue reported by the 22 participants with PC significantly worsened and HRQOL significantly declined from baseline to EBRT completion. The HF group comprised 12 men with clinically significant change in fatigue (HF) during EBRT. Although no significant changes were observed in MOPC enzymes from baseline to EBRT completion, there were important differences in the patterns in the levels of MOPC enzymes between HF and LF groups.
  
  
  CONCLUSIONS
  Distinct patterns of changes in the absorbance of MOPC enzymes delineated fatigue intensification among participants. Further investigation using a larger sample is warranted.
authors.affiliation: National Institute of Nursing Research (NINR), National Institutes of Health (NIH), Bethesda, MD, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Filler
authors.affiliation: University of Florida, Gainesville, FL, USA.
authors.forename: Debra
authors.initials: D
authors.lastname: Lyon
authors.affiliation: Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: McCain
authors.affiliation: Department of Neurology, Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: James
authors.initials: J
authors.lastname: Bennett
authors.affiliation: Department of Mathematics, Universidad de Oviedo, Oviedo, Spain.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Fernández-Martínez
authors.affiliation: Department of Mathematics, Universidad de Oviedo, Oviedo, Spain.
authors.forename: Enrique Juan
authors.initials: EJ
authors.lastname: deAndrés-Galiana
authors.affiliation: Virginia Commonwealth University, Richmond, VA, USA.
authors.forename: R K
authors.initials: RK
authors.lastname: Elswick
authors.affiliation: University of Nevada Las Vegas, Las Vegas, NV, USA.
authors.forename: Nada
authors.initials: N
authors.lastname: Lukkahatai
authors.affiliation: National Institute of Nursing Research (NINR), National Institutes of Health (NIH), Bethesda, MD, USA saliganl@mail.nih.gov.
authors.forename: Leorey
authors.initials: L
authors.lastname: Saligan
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay; D005221:Fatigue / Q000209:etiology / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000378:metabolism* / Q000528:radiation effects; D024101:Mitochondrial Proteins / Q000097:blood; D010085:Oxidative Phosphorylation / Q000187:drug effects*; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000532:radiotherapy*; D011788:Quality of Life
chemical_list: D024101:Mitochondrial Proteins
keywords: fatigue; mitochondria; radiation therapy