title: Influence of local exposure to static magnetic field on pain perception and bone turnover of osteoporotic patients with vertebral deformity - a randomized controlled trial.
abstract: OBJECTIVE
  Static magnetic field (SMF) could improve pain sensation and bone turnover. In a single-center randomized double-blind placebo-controlled study we investigated the effects of SMF exposure on subjective pain and bone turnover.
  
  
  METHODS
  Postmenopausal osteoporotic women (aged 50-70 years) with bone deformity and back pain were randomized to 10 weekly visits of 30-min SMF (n = 6) or treatment with non-magnetized pads (n = 5) on the back. Primary and secondary outcomes were changes in pain sensation on a visual analogue scale (VAS) during each visit and over 10 weeks, respectively. Tertiary outcomes were changes in osteocalcin and β-crosslaps. SMF was inhomogeneous with 192 millitesla peak-to-peak value by 19 tesla/meter gradient of the magnetic flux density at 3 mm.
  
  
  RESULTS
  Participants randomized to sham had higher VAS at baseline (mean difference: 2.8, 95% confidence interval (CI) 0.47-5.2 cm). Both SMF and sham similarly reduced short term pain (sham-SMF: 0.59, 95% CI - 0.31-1.49 cm, p = 0.195). VAS did not change in SMF, while it decreased in the sham group (between-group difference 0.27, 95% CI 0.04-0.50 cm/visit). Bone turnover markers remained stable.
  
  
  CONCLUSIONS
  SMF as used in this investigation is not recommended for pain relief in postmenopausal women with vertebral deformity. The finding on long-term pain relief may relate to unbalanced randomization.
authors.affiliation: 1st Department of Medicine, Semmelweis University Faculty of Medicine , Budapest , Hungary.
authors.forename: Szilvia
authors.initials: S
authors.lastname: Mészáros
authors.forename: Adam G
authors.initials: AG
authors.lastname: Tabák
authors.forename: Csaba
authors.initials: C
authors.lastname: Horváth
authors.forename: Miklos
authors.initials: M
authors.lastname: Szathmári
authors.forename: Janos F
authors.initials: JF
authors.lastname: László
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D001862:Bone Resorption / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D055909:Magnetic Field Therapy / Q000379:methods*; D008875:Middle Aged; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D010024:Osteoporosis / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy*; D058748:Pain Perception; D010446:Peptide Fragments / Q000378:metabolism; D013131:Spine / Q000002:abnormalities* / Q000378:metabolism* / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C110762:glutamyl-lysyl-alanyl-histidyl-aspartyl-glycyl-glycyl-arginine; D015675:Osteocalcin; D003094:Collagen