title: [Normative data for quantitative ultrasound measurement of the calcaneus in a Portuguese population].
abstract: BACKGROUND
  Quantitative ultrasound (QUS) measurement of the calcaneus is a safe and reliable method for evaluating skeletal status. Although central bone densitometry (DXA) measurement is the gold-standard to classify osteopenic and osteoporotic patients, QUS can give supplementary information and its use is expanding. Up to now there are no published normative data for QUS measurements in the Portuguese population.
  
  
  OBJECTIVE
  The aims of this study were to determine normative QUS data in the Sahara Clinical Sonometer (Hologic) for the Portuguese population.
  
  
  METHODS
  Cross-sectional evaluation of consecutive subjects selected as part of the EpiPorto study, Portugal. Calcaneus QUS (Sahara Clinical Sonometer, Hologic) parameters were obtained: Broadband Ultrasound Attenuation (BUA), Speed of Sound (SOS), Quantitative Ultrasound Index (QUI) and Estimated Bone Mineral Density (EBMD) were determined for men and women, stratified by their age group.
  
  
  RESULTS
  1,482 consecutive subjects (1,010 females and 472 males), aged from 18 to 92 years. Higher levels of QUS parameters were found in the lower age group and, for both gender, progressive decrease with age were reported. Men showed higher values as compared to women in all parameters and differences between them increased with age. Differences were significant for BUA after the age of 39 and for SOS after the age of 59. Short-term in vivo precision was 5.5% for BUA and 0.4% for SOS, while in vitro precision was 3.23% for BUA and 0.15% for SOS.
  
  
  CONCLUSIONS
  Our data are comparable to other Southern European data and represent the first QUS normative data for the Portuguese population.
authors.affiliation: Serviço de Higiene e Epidemiologia, Faculdade de Medicina, Universidade do Porto. helenacanhao@netcabo.pt
authors.forename: Helena
authors.initials: H
authors.lastname: Canhão
authors.forename: Raquel
authors.initials: R
authors.lastname: Ferreira
authors.forename: Lúcia
authors.initials: L
authors.lastname: Costa
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Romeu
authors.forename: João Eurico
authors.initials: JE
authors.lastname: Fonseca
authors.forename: Jaime
authors.initials: J
authors.lastname: Branco
authors.forename: Henrique
authors.initials: H
authors.lastname: Barros
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002111:Calcaneus / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011174:Portugal; D012016:Reference Values; D014463:Ultrasonography