title: Lower brain-derived neurotrophic factor levels associated with worsening fatigue in prostate cancer patients during repeated stress from radiation therapy.
abstract: Fatigue during cancer treatment is associated with depression. Neurotrophic factors play a major role in depression and stress and might provide insight into mechanisms of fatigue. This study investigated the association between plasma concentrations of three neurotrophic factors (BDNF, brain-derived neurotrophic factor; GDNF, glial-derived neurotrophic factor; and SNAPIN, soluble N-ethylmaleimide sensitive fusion attachment receptor-associated protein) and initial fatigue intensification during external beam radiation therapy (EBRT) in euthymic non-metastatic prostate cancer men.
  
  
  
  Fatigue, as measured by the 13-item Functional Assessment of Cancer Therapy-Fatigue (FACT-F), and plasma neurotrophic factors were collected at baseline (prior to EBRT) and mid-EBRT. Subjects were categorized into fatigue and no fatigue groups using a > 3-point change in FACT-F scores between the two time points. Multiple linear regressions analysed the associations between fatigue and neurotrophic factors.
  
  
  
  FACT-F scores of 47 subjects decreased from baseline (43.95 ± 1.3) to mid-EBRT (38.36 ± 1.5, P < 0.001), indicating worsening fatigue. SNAPIN levels were associated with fatigue scores (rs= 0.43, P = 0.005) at baseline. A significant decrease of BDNF concentration (P = 0.008) was found in fatigued subjects during EBRT (n = 39).
  
  
  
  Baseline SNAPIN and decreasing BDNF levels may influence worsening fatigue during EBRT. Further investigations are warranted to confirm their role in the pathophysiology and therapeutics of fatigue.
authors: a National Institute of Nursing Research, National Institutes of Health , Bethesda , MD , USA.
authors: L N
authors: LN
authors: Saligan
authors: a National Institute of Nursing Research, National Institutes of Health , Bethesda , MD , USA.|b University of Nevada, Las Vegas, School of Nursing , Las Vegas , NV , USA.
authors: N
authors: N
authors: Lukkahatai
authors: a National Institute of Nursing Research, National Institutes of Health , Bethesda , MD , USA.
authors: G
authors: G
authors: Holder
authors: a National Institute of Nursing Research, National Institutes of Health , Bethesda , MD , USA.
authors: B
authors: B
authors: Walitt
authors: c National Institute of Mental Health, National Institutes of Health , Bethesda , MD , USA.
authors: R
authors: R
authors: Machado-Vieira
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003863:Depression / Q000209:etiology; D005221:Fatigue / Q000209:etiology*; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000097:blood; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000097:blood* / Q000532:radiotherapy*; D011878:Radiotherapy / Q000009:adverse effects*; D012720:Severity of Illness Index; D014481:United States; D033921:Vesicular Transport Proteins / Q000097:blood
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C495039:GDNF protein, human; D051100:Glial Cell Line-Derived Neurotrophic Factor; C118519:SNAPIN protein, human; D033921:Vesicular Transport Proteins; C579455:BDNF protein, human
keywords: brain-derived neurotrophic factor; depression; fatigue; prostate neoplasm; radiation