title: Comparison of calcaneal ultrasound and DXA in young women.
abstract: OBJECTIVE
  The purpose of the study was to assess quantitative ultrasound (QUS) parameters in collegiate female gymnasts, a population whose training incorporates high-impact loading, which is particularly osteogenic, and to determine the discriminative capacity of this relatively new radiation-free technique compared with bone densitometry in a young healthy population.
  
  
  METHODS
  We studied 19 collegiate gymnasts and 23 healthy controls undergoing regular weight-bearing activity, matched for age (gymnasts 19.2 +/- 1.2, controls 19.9 +/- 1.6 yr) and body weight (gymnasts 56.7 +/- 3.7, controls 57.7 +/- 7.8 kg). QUS parameters of the calcaneus (broadband ultrasound attenuation (BUA), bone velocity (BV), and speed of sound (SOS)) were measured by a Walker Sonix UBA 575+. Bone mineral density (BMD; g x cm(-2)) of the lumbar spine, hip (femoral neck, trochanter, Ward's triangle) and whole body was assessed by dual energy x-ray absorptiometry (DXA, Hologic QDR 1000/W). Data analysis included unpaired two-tailed Student's t-tests, analysis of variance, Pearson product-moment, and Spearman rank-order correlations.
  
  
  RESULTS
  Regional and whole body BMD of gymnasts was greater than controls (P < 0.001), with the difference being 7-28%. Average QUS parameters of the right and left calcaneus were also higher (P < 0.001) in the gymnasts. BUA, BV, and SOS were significantly (P < 0.001) correlated to each bone site with r = 0.54-0.79. Analysis of receiver operating characteristic (ROC) curves indicated no significant difference in sensitivity and specificity for QUS and DXA measures.
  
  
  CONCLUSIONS
  These results indicate that QUS parameters of the calcaneus are higher in young women gymnasts compared to individuals who undergo regular weight-bearing activity and that QUS parameters are able to discriminate between these two groups in a similar manner as does regional and whole body BMD.
authors.affiliation: The Musculoskeletal Research Laboratory, Aging Study Unit, Veterans Affairs Medical Center, Palo Alto, CA, USA.
authors.forename: D R
authors.initials: DR
authors.lastname: Taaffe
authors.forename: C
authors.initials: C
authors.lastname: Duret
authors.forename: C S
authors.initials: CS
authors.lastname: Cooper
authors.forename: R
authors.initials: R
authors.lastname: Marcus
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D015519:Bone Density; D002111:Calcaneus / Q000737:chemistry / Q000000981:diagnostic imaging*; D005260:Female; D006173:Gymnastics / Q000502:physiology*; D006801:Humans; D012016:Reference Values; D014463:Ultrasonography / Q000379:methods*; D016474:Weight-Bearing