title: Coeliac disease-specific tissue transglutaminase autoantibodies are associated with osteoporosis and related fractures in middle-aged women.
abstract: OBJECTIVE
  To investigate whether the serological marker for coeliac disease, tissue transglutaminase autoantibody (tTGAb), is associated with decreased bone mass density (BMD) and increased frequency of fractures in middle-aged women screened for osteoporosis.
  
  
  METHODS
  The study comprised 6480 women (mean age 56 years, range 50-64) who answered a number of questionnaires and who underwent dual X-ray absorptiometry of the wrist bone. Serum samples were analysed for tTGAb using radioligand binding assays. A tTGAb level of >4 U/ml was used to determine a positive value and a level of >17 U/ml was used as an alternative discrimination of high levels.
  
  
  RESULTS
  A tTGAb level >4 U/ml was found among 90/6480 (1.4%) women and correlated with lower BMD (multiple linear regression coefficient -382.1; 95% CI = - 673.6-90.7, p=0.011) and with fracture frequency (r=0.18, p=0.023). The 59 women with tTGAb levels >or=17 U/ml had a lower BMD (0.41+/-0.08 g/cm(2) versus 0.44+/-0.08 g/cm(2), p=0.001) and a lower T-score (-1.40+/-1.28 versus -0.90+/-1.40, p=0.003) as well as a higher prevalence of osteoporosis (13.4% versus 6.5%, p=0.008) compared with the remaining 6421 women with tTGAb levels <17 U/ml. Furthermore, fracture frequency was more pronounced in women with tTGAb levels >or=17 U/ml, among whom 19/59 (32.2%) had fractures during the study period compared with 1204/6421 (18.8%) among women with tTGAb levels <17 U/ml (p=0.009).
  
  
  CONCLUSIONS
  High levels of tTGAb indicating coeliac disease are associated with lower BMD and higher fracture frequency in women between 50 and 64 years of age. Osteometry is therefore warranted in middle-aged women detected with tTGAb.
authors.affiliation: Unit of Diabetes and Coeliac Disease, Malmö University Hospital, Lund University, Sweden. daniel.agardh@med.lu.se
authors.forename: Daniel
authors.initials: D
authors.lastname: Agardh
authors.forename: Sara
authors.initials: S
authors.lastname: Björck
authors.forename: Carl-David
authors.initials: CD
authors.lastname: Agardh
authors.forename: Jonas
authors.initials: J
authors.lastname: Lidfeldt
mesh_terms: D015502:Absorptiometry, Photon; D017677:Age Distribution; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000502:physiology; D002446:Celiac Disease / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D005598:Fractures, Spontaneous / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D016014:Linear Models; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015999:Multivariate Analysis; D015663:Osteoporosis, Postmenopausal / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D011336:Probability; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D013548:Sweden / Q000453:epidemiology; D011503:Transglutaminases / Q000097:blood / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D011503:Transglutaminases