title: Inflammatory Mediators and Pain in the First Year After Acute Episode of Low-Back Pain in Elderly Women: Longitudinal Data from Back Complaints in the Elders-Brazil.
abstract: OBJECTIVE
  The aims of this study were to determine the course of plasma levels of inflammatory mediators (interleukin 6 [IL-6], tumor necrosis factor α [TNF-α], soluble TNF receptor 1 [sTNF-R1]) and the severity of low-back pain (LBP) over 6 to 12 months after an acute episode of LBP in elderly women and to establish an association between inflammatory mediators and LBP recovery.
  
  
  METHODS
  This was a longitudinal study of a subsample (155 elderly women with acute LBP, aged ≥65 years) of the international Back Complaints in the Elders cohort study. Plasma levels of IL-6, TNF-α, and sTNF-R1 were measured using enzyme-linked immunosorbent assays and pain severity using the numerical pain scale.
  
  
  RESULTS
  There was a decrease in the severity of LBP (P = 0.033) and in the levels of IL-6 and TNF-α (P < 0.001) and an increase in sTNF-R1 (P < 0.001) in the first year after an acute episode of LBP. The probability of occurrence of pain relief at the 12-month follow-up was 2.22 times higher in elderly women who had low levels of IL-6 (<1.58 pg/mL) at baseline.
  
  
  CONCLUSIONS
  Our findings showed a relationship between inflammation and LBP by establishing that low IL-6 plasma levels preceded outcome (LBP recovery), supporting the concept that proinflammatory cytokines promote pain.
authors.affiliation: From the Rehabilitation Sciences Program, Physical Therapy Department, Federal University of Minas Gerais, Belo Horizonte (BZQ, NMBR, RAL, AGPA, RMFVSJ, AAOL, JPS, LSMP); Federal University of Alfenas, Alfenas (DSP); and Federal University of Juiz de Fora, Juiz de Fora (DCF), Minas Gerais, Brazil.
authors.forename: Bárbara Zille
authors.initials: BZ
authors.lastname: Queiroz
authors.forename: Daniele Sirineu
authors.initials: DS
authors.lastname: Pereira
authors.forename: Nayza Maciel de Britto
authors.initials: NMB
authors.lastname: Rosa
authors.forename: Renata Antunes
authors.initials: RA
authors.lastname: Lopes
authors.forename: André Gustavo Pereira
authors.initials: AGP
authors.lastname: Andrade
authors.forename: Diogo Carvalho
authors.initials: DC
authors.lastname: Felício
authors.forename: Renata Muniz Freire Vinhal Siqueira
authors.initials: RMFVS
authors.lastname: Jardim
authors.forename: Amanda Aparecida Oliveira
authors.initials: AAO
authors.lastname: Leopoldino
authors.forename: Juscélio Pereira
authors.initials: JP
authors.lastname: Silva
authors.forename: Leani Souza Máximo
authors.initials: LSM
authors.lastname: Pereira
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D008137:Longitudinal Studies; D017116:Low Back Pain / Q000097:blood*; D010147:Pain Measurement / Q000379:methods; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000097:blood*; D012720:Severity of Illness Index; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha