title: Comparison of T- and Z-score in identifying risk factors of osteoporosis in inflammatory bowel disease patients.
abstract: OBJECTIVE
  Most studies have shown contradictory results regarding predictive factors of osteoporosis in inflammatory bowel disease (IBD). Since in these studies either T- or Z-scores has been used, our aim was to compare T- and Z-score in identifying risk factors of osteoporosis in IBD patients.
  
  
  METHODS
  Bone density was measured by dual X-ray absorptiometry (DXA) at L2-L4 of the spine and femoral neck in 122 patients. Twenty-two clinical parameters were recorded prior to DXA and evaluated by univariate and multivariate analysis.
  
  
  RESULTS
  On multivariate analysis, cumulative steroid dose was a predictive factor of femoral neck T-score (p<0.001) and Z-score (p=0.001). Age was a predictive factor of femoral neck T-score (p<0.001). BMI was a predictive factor of femoral neck Z-score (p=0.03). None of the other 19 variables tested had any predictive value for bone density. Age >or=55 years was a risk factor of low femoral neck T-score (OR 5.08, 95% CI 1.90-13.57, p=0.001), as was cumulative dose of prednisolone >or=5 g (OR 3.41, 95% CI 1.50-7.73, p=0.004).
  
  
  CONCLUSIONS
  There is a discordance of results depending on whether T- or Z-scores are used in analysis. Among 22 parameters, cumulative steroid dose and age proved to be the most important factors.
authors.affiliation: Gastroenterology Unit, Attikon University General Hospital, Athens. etsironi@yahoo.com
authors.forename: E
authors.initials: E
authors.lastname: Tsironi
authors.forename: D
authors.initials: D
authors.lastname: Hadjidakis
authors.forename: E
authors.initials: E
authors.lastname: Mallas
authors.forename: C
authors.initials: C
authors.lastname: Tzathas
authors.forename: D G
authors.initials: DG
authors.lastname: Karamanolis
authors.forename: S D
authors.initials: SD
authors.lastname: Ladas
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density; D003093:Colitis, Ulcerative / Q000503:physiopathology*; D003424:Crohn Disease / Q000453:epidemiology*; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D012307:Risk Factors