title: [Effect of age on the precision of dual X-ray absorptiometry measurement in middle-aged and elderly women].
abstract: OBJECTIVE
  To investigate whether age influence the precision of dual X-ray absorptiometry (DXA) measurement at the hip in middle-aged and elderly women.
  
  
  METHODS
  Totally 90 women were randomly selected and divided into three age groups: 45-55 years, 56-65 years, and 66-75 years. Each age group contained 30 women. Each woman was scanned twice at the same day. Bone mineral density (BMD) values of femoral neck, ward's triangle, and trochanter were collected and grouped by calculating the root mean square (RMS). Precision errors were expressed as RMS (standard deviation, SD).
  
  
  RESULTS
  For the femoral neck and trochanter, significant differences of SD of BMD existed among all age groups. For the ward's triangle, significant difference of BMD existed among all age groups except between the 45-55 group and 56-65 age group.
  
  
  CONCLUSIONS
  Age can influence the precision of DXA measurement at the hip in middle-aged and elderly women.
authors.affiliation: Department of Radiology, PUMC Hospital, CAMS and PUMC, Beijing 100730, China. LQ1010@hotmail.com
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lin
authors.forename: Wei
authors.initials: W
authors.lastname: Yu
authors.forename: Ming-wei
authors.initials: MW
authors.lastname: Qin
authors.forename: Wei
authors.initials: W
authors.lastname: Shang
authors.forename: Jun-ping
authors.initials: JP
authors.lastname: Tian
authors.forename: Shao-mei
authors.initials: SM
authors.lastname: Han
mesh_terms: D015502:Absorptiometry, Photon; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D015519:Bone Density; D005260:Female; D005269:Femur / Q000502:physiology*; D005272:Femur Neck / Q000502:physiology*; D006801:Humans; D008593:Menopause / Q000502:physiology; D008875:Middle Aged; D015203:Reproducibility of Results