title: Chronic low back pain is associated with reduced vertebral bone mineral measures in community-dwelling adults.
abstract: BACKGROUND
  Chronic low back pain (CLBP) experienced in middle-age may have important implications for vertebral bone health, although this issue has not been investigated as a primary aim previously. This study investigated the associations between CLBP and dual energy X-ray absorptiometry (DXA)-derived vertebral bone mineral measures acquired from postero-anterior and lateral-projections, among community-dwelling, middle-aged adults.
  
  
  METHODS
  Twenty-nine adults with CLBP (11 male, 18 female) and 42 adults with no history of LBP in the preceding year (17 male, 25 female) were evaluated. Self-reported demographic and clinical data were collected via questionnaires. Areal bone mineral density (aBMD) was measured in the lumbar spine by DXA. Apparent volumetric (ap.v) BMD in the lumbar spine was also calculated. Multiple linear regression models were used to examine associations between study group (CLBP and control) and vertebral DXA variables by gender, adjusting for height, mass and age.
  
  
  RESULTS
  There was no difference between groups by gender in anthropometrics or clinical characteristics. In the CLBP group, the mean (SD) duration of CLBP was 13.3 (10.4) years in males and 11.6 (9.9) years in females, with Oswestry Disability Index scores of 16.2 (8.7)% and 15.4 (9.1)%, respectively. Males with CLBP had significantly lower adjusted lateral-projection aBMD and lateral-projection ap.vBMD than controls at L3 with mean differences (standard error) of 0.09 (0.04) g/cm2 (p = 0.03) and 0.02 (0.01) g/cm3 (p = 0.04). These multivariate models accounted for 55% and 53% of the variance in lateral-projection L3 aBMD and lateral-projection L3 ap.vBMD.
  
  
  CONCLUSIONS
  CLBP in males is associated with some lumbar vertebral BMD measures, raising important questions about the mechanism and potential clinical impact of this association.
authors.affiliation: School of Physiotherapy, Curtin University, Perth, Australia. A.Briggs@curtin.edu.au
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Briggs
authors.forename: Leon M
authors.initials: LM
authors.lastname: Straker
authors.forename: Angus F
authors.initials: AF
authors.lastname: Burnett
authors.forename: John D
authors.initials: JD
authors.lastname: Wark
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000367:Age Factors; D015519:Bone Density; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D059350:Chronic Pain / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D016014:Linear Models; D017116:Low Back Pain / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010147:Pain Measurement; D018570:Risk Assessment; D012307:Risk Factors; D057566:Self Report; D012720:Severity of Illness Index; D012737:Sex Factors; D014904:Western Australia; D055815:Young Adult