title: Higher serum S100B and BDNF levels are correlated with a lower pressure-pain threshold in fibromyalgia.
abstract: BACKGROUND
  Fibromyalgia (FM) is conceptualized as a central sensitization (CS) condition, that presents high serum brain-derived neurotrophic factor (BDNF) and neuroglia activation. Although the S100B protein regulates neuroglia functions, it has been traditionally used as a proxy of central nervous system damage. However, neither BDNF nor S100B association with the clinical picture of FM has been elucidated. To explore their association with the pressure-pain threshold (PPT) in FM, we performed a cross-sectional study, including 56 females with confirmed FM aged 18-65 years. Linear regression models were used to adjust for potential confounding factors between serum BDNF, S100B and PPT.
  
  
  RESULTS
  Serum BDNF and S100B were correlated (Spearman's Rho = 0.29). Serum BDNF (log) and S100B (log) were correlated with the PPT (log) (Partial η2 = 0.129, P = 0.012 for the BDNF (log), and Partial η2 = 0.105, P = 0.025 for the S100B (log)). Serum BDNF (log) was inversely associated with PPT (log) (β = -1.01, SE = 0.41), age (β = -0.02, SE = 0.15) and obsessive compulsive disorder (β = -0.36, SE = 0.15), while serum S100B (log) was inversely associated with PPT (log) (β = -1.38, SE = 0.50), only.
  
  
  CONCLUSIONS
  Both neuroglia key mediators in the CS process were inversely correlated with the PPT. Serum assessment of BDNF and S100B deserve further study to determine its potential as a proxy for the CS spectrum in FM.
authors.forename: Simone Azevedo
authors.initials: SA
authors.lastname: Zanette
authors.forename: Jairo Alberto
authors.initials: JA
authors.lastname: Dussan-Sarria
authors.forename: Andressa
authors.initials: A
authors.lastname: Souza
authors.forename: Alicia
authors.initials: A
authors.lastname: Deitos
authors.forename: Iraci Lucena Silva
authors.initials: IL
authors.lastname: Torres
authors.affiliation: Post Graduate Program in Medical Sciences, UFRGS, Porto Alegre, Brazil. caumo@cpovo.net.
authors.forename: Wolnei
authors.initials: W
authors.lastname: Caumo
mesh_terms: D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D005356:Fibromyalgia / Q000097:blood* / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D008297:Male; D017288:Pain Threshold / Q000502:physiology*; D011312:Pressure / Q000009:adverse effects*; D012189:Retrospective Studies; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human