title: Combining bone resorption markers and heel quantitative ultrasound to discriminate between fracture cases and controls.
abstract: CONCLUSIONS
  This nested case-control analysis of a Swiss ambulatory cohort of elderly women assessed the discriminatory power of urinary markers of bone resorption and heel quantitative ultrasound for non-vertebral fractures. The tests all discriminated between cases and controls, but combining the two strategies yielded no additional relevant information.
  
  
  BACKGROUND
  Data are limited regarding the combination of bone resorption markers and heel quantitative bone ultrasound (QUS) in the detection of women at risk for fracture.
  
  
  METHODS
  In a nested case-control analysis, we studied 368 women (mean age 76.2 +/- 3.2 years), 195 with low-trauma non-vertebral fractures and 173 without, matched for age, BMI, medical center, and follow-up duration, from a prospective study designed to predict fractures. Urinary total pyridinolines (PYD) and deoxypyridinolines (DPD) were measured by high performance liquid chromatography. All women underwent bone evaluations using Achilles+ and Sahara heel QUS.
  
  
  RESULTS
  Areas under the receiver operating-characteristic curve (AUC) for discriminative models of the fracture group, with 95% confidence intervals, were 0.62 (0.56-0.68) and 0.59 (0.53-0.65) for PYD and DPD, and 0.64 (0.58-0.69) and 0.65 (0.59-0.71) for Achilles+ and Sahara QUS, respectively. The combination of resorption markers and QUS added no significant discriminatory information to either measurement alone with an AUC of 0.66 (0.60-0.71) for Achilles+ with PYD and 0.68 (0.62-0.73) for Sahara with PYD.
  
  
  CONCLUSIONS
  Urinary bone resorption markers and QUS are equally discriminatory between non-vertebral fracture patients and controls. However, the combination of bone resorption markers and QUS is not better than either test used alone.
authors.affiliation: Department of Ambulatory Care and Community Medicine, University of Lausanne, 44 Rue du Bugnon, 1011, Lausanne, Switzerland. david.nanchen@chuv.ch
authors.forename: D
authors.initials: D
authors.lastname: Nanchen
authors.forename: J
authors.initials: J
authors.lastname: Cornuz
authors.forename: C
authors.initials: C
authors.lastname: Ruffieux
authors.forename: W
authors.initials: W
authors.lastname: Riesen
authors.forename: P
authors.initials: P
authors.lastname: Burckhardt
authors.forename: M A
authors.initials: MA
authors.lastname: Krieg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000596:Amino Acids / Q000652:urine; D015415:Biomarkers / Q000652:urine; D001862:Bone Resorption / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002111:Calcaneus / Q000000981:diagnostic imaging*; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D058866:Osteoporotic Fractures / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014463:Ultrasonography
chemical_list: D000596:Amino Acids; D015415:Biomarkers; C015484:pyridinoline; C036020:deoxypyridinoline