title: Brain-derived neurotrophic factor plasma levels are increased in older women after an acute episode of low back pain.
abstract: BACKGROUND
  Low back pain (LBP) is a growing public health problem in old age, and it is associated with disabling pain and depressive disorders. We compared brain-derived neurotrophic factor (BDNF) plasma levels, a key neurotrophin in pain modulation, between older women after an acute episode of LBP and age-matched pain-free controls, and investigated potential differences in BDNF levels between controls and LBP subgroups based on pain severity, presence of depressive symptoms and use of analgesic and antidepressant drugs.
  
  
  METHODS
  A total of 221 participants (154 with LBP and 67 pain-free) were studied. A comprehensive assessment of sociodemographic and clinical variables was conducted including pain severity (11-point NRS), depressive symptoms (GDS-15), age, body mass index, physical activity and total number of comorbidities and medications in use.
  
  
  RESULTS
  BDNF levels in LBP group were significantly higher than controls (7515.9±3021.2; Md=7116.0 vs 6331.8±3364.0; Md=5897.5pg/mL, P=0.005). LBP subgroups exhibited higher BDNF levels than controls, regardless of pain severity, presence of depressive symptoms and use of analgesic drugs. BDNF levels were significantly higher in LBP subgroup without use of antidepressant drugs compared to both controls and LBP subgroup with use of antidepressant drugs.
  
  
  CONCLUSIONS
  This study provides evidence that older women with acute low back pain exhibit higher BDNF plasma levels compared to pain-free controls. Subgroup comparisons suggest that use of pain-relief drugs may influence BDNF levels. The study results offer a novel target for research on mechanisms of back pain in older adults.
authors.affiliation: Department of Physical Therapy, Postgraduate Program in Rehabilitation Sciences, Universidade Federal de Minas Gerais, 6627 Antônio Carlos Avenue, 31270-901, Belo Horizonte, Minas Gerais, Brazil. Electronic address: julianodiz@gmail.com.
authors.forename: Juliano Bergamaschine Mata
authors.initials: JBM
authors.lastname: Diz
authors.affiliation: Department of Physical Therapy, Postgraduate Program in Rehabilitation Sciences, Universidade Federal de Minas Gerais, 6627 Antônio Carlos Avenue, 31270-901, Belo Horizonte, Minas Gerais, Brazil. Electronic address: brunosouzamoreira@gmail.com.
authors.forename: Bruno
authors.initials: B
authors.lastname: de Souza Moreira
authors.affiliation: Department of Physical Therapy, Universidade Federal de Juiz de Fora, s/n Eugênio do Nascimento Avenue, 36038-330, Juiz de Fora, Minas Gerais, Brazil. Electronic address: diogofelicio@yahoo.com.br.
authors.forename: Diogo Carvalho
authors.initials: DC
authors.lastname: Felício
authors.affiliation: Department of Physical Therapy, Universidade do Vale do Sapucaí, 320 Coronel Alfredo Custódio de Paula Avenue, 37550-000, Pouso Alegre, Minas Gerais, Brazil. Electronic address: luizaft@yahoo.com.br.
authors.forename: Luiza Faria
authors.initials: LF
authors.lastname: Teixeira
authors.affiliation: Department of Physical Therapy, Faculty of Medicine, Universidade Federal do Ceará, 949 Alexandre Barúna Street, 60430-160, Fortaleza, Ceará, Brazil. Electronic address: fabiannamoraleida@gmail.com.
authors.forename: Fabianna Resende
authors.initials: FR
authors.lastname: de Jesus-Moraleida
authors.affiliation: Department of Physical Therapy, Postgraduate Program in Rehabilitation Sciences, Universidade Federal de Minas Gerais, 6627 Antônio Carlos Avenue, 31270-901, Belo Horizonte, Minas Gerais, Brazil. Electronic address: babzille@gmail.com.
authors.forename: Bárbara Zille
authors.initials: BZ
authors.lastname: de Queiroz
authors.affiliation: Department of Physical Therapy, Universidade Federal de Alfenas, 2600 Jovino Fernandes Sales Avenue, 31270-901, Alfenas, Minas Gerais, Brazil. Electronic address: daniele.sirineu@gmail.com.
authors.forename: Daniele Sirineu
authors.initials: DS
authors.lastname: Pereira
authors.affiliation: Department of Physical Therapy, Postgraduate Program in Rehabilitation Sciences, Universidade Federal de Minas Gerais, 6627 Antônio Carlos Avenue, 31270-901, Belo Horizonte, Minas Gerais, Brazil. Electronic address: leanismp.bh@terra.com.br.
authors.forename: Leani Souza Máximo
authors.initials: LSM
authors.lastname: Pereira
mesh_terms: D000208:Acute Disease; D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood*; D003430:Cross-Sectional Studies; D003863:Depression / Q000097:blood; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000097:blood*; D008875:Middle Aged
chemical_list: D000928:Antidepressive Agents; D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human
keywords: Brain-derived neurotrophic factor; Depressive symptoms; Low back pain; Older adults; Pain modulation