title: Bone oedema on MRI is highly associated with low bone mineral density in patients with early inflammatory back pain: results from the DESIR cohort.
abstract: OBJECTIVE
  To assess bone mineral density (BMD) at lumbar spine and hip in a large cohort of patients with early inflammatory back pain (IBP) suggestive of axial spondyloarthritis (SpA), and to assess systemic and bone inflammation (according to MRI) as risk factors of low BMD.
  
  
  METHODS
  332 (52.4% male) patients with IBP suggestive of axial SpA defined by Calin or Berlin criteria were recruited; they had lumbar spine and hip BMD and body composition measurements. Low BMD was defined by Z≤-2 (at least one site). Clinical, biological (erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)) and imaging (x-rays, spine and sacroiliac joint MRI) parameters were compared in patients with and without low BMD (Z≤-2). Significant parameters in univariate analysis were tested in multivariate models.
  
  
  RESULTS
  Patients (mean age 33.8 years) had a short duration of axial symptoms (mean 1.6 years); 71.4% fulfilled the Assessment of Spondyloarthritis International Society criteria for axial SpA and HLA-B27 was present in 62.1%. 43 (13.0%) had low BMD (88% male). Multivariate logistic regression showed that parameters significantly associated with low BMD (any site) were the presence of bone marrow oedema (inflammatory lesions) on MRI (OR 4.63, p=0.001), either ESR or CRP (OR 2.60, p=0.037) and male gender (OR 9.60, p=0.0004).
  
  
  CONCLUSIONS
  This study conducted in a large cohort of young adults with early IBP suggestive of SpA shows that 13.0% of patients have a low BMD and that the main risk factor associated with low BMD was inflammation on MRI.
authors.affiliation: Department of Rheumatology, Cochin Hospital, Paris Descartes University, , Paris, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Briot
authors.forename: Anne
authors.initials: A
authors.lastname: Durnez
authors.forename: Simon
authors.initials: S
authors.lastname: Paternotte
authors.forename: Corinne
authors.initials: C
authors.lastname: Miceli-Richard
authors.forename: Maxime
authors.initials: M
authors.lastname: Dougados
authors.forename: Christian
authors.initials: C
authors.lastname: Roux
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000293:Adolescent; D000328:Adult; D001416:Back Pain / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D001799:Blood Sedimentation; D015519:Bone Density / Q000502:physiology; D001847:Bone Diseases / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D002097:C-Reactive Protein / Q000378:metabolism; D015331:Cohort Studies; D004487:Edema / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D005602:France / Q000453:epidemiology; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D012307:Risk Factors; D025241:Spondylarthritis / Q000150:complications* / Q000453:epidemiology / Q000503:physiopathology; D055815:Young Adult
chemical_list: D002097:C-Reactive Protein