title: Discrepancies in pediatric bone mineral density reference data: potential for misdiagnosis of osteopenia.
abstract: OBJECTIVE
  To evaluate published pediatric dual-energy x-ray absorptiometry bone mineral density (BMD) reference data by comparing the diagnostic classification of measured BMD in children at risk for osteopenia as healthy or osteopenic according to reference source.
  
  
  METHODS
  Spine BMD was measured in 95 children, ages 9 to 15 years, at risk for osteopenia because of childhood disease. The BMD results were converted to age-specific z scores for each of the 5 reference data sets, and the z -score distributions were compared.
  
  
  RESULTS
  Between 11% and 30% of children were classified as osteopenic (z score < -2.0) depending on the reference data set. The 2 sex-specific reference data sets yielded similar diagnostic classification of boys and girls: 10% of boys and 11% to 16% of girls were osteopenic (P =.4). The 3 sex-nonspecific reference data sets classified 9% to 13% of girls and 24% to 44% of boys as osteopenic; the diagnosis of osteopenia was significantly greater in boys (P <.01).
  
  
  CONCLUSIONS
  The use of different published reference data for the assessment of children at risk for osteopenia results in inconsistent diagnostic classification of BMD results. These inconsistencies can be partially attributed to sex-nonspecific reference data that result in misclassification of boys as osteopenic.
authors.affiliation: Department of Pediatrics, The Children's Hospital of Philadelphia, Pennsylvania 19104, USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Leonard
authors.forename: K J
authors.initials: KJ
authors.lastname: Propert
authors.forename: B S
authors.initials: BS
authors.lastname: Zemel
authors.forename: V A
authors.initials: VA
authors.lastname: Stallings
authors.forename: H I
authors.initials: HI
authors.lastname: Feldman
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density / Q000502:physiology*; D001851:Bone Diseases, Metabolic / Q000175:diagnosis* / Q000453:epidemiology; D002648:Child; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology; D008297:Male; D012016:Reference Values; D012044:Regression Analysis; D014481:United States / Q000453:epidemiology