title: [Study of normal range of speed of sound in tibia in Beijing area].
abstract: OBJECTIVE
  To study the normal reference value of adult tibial speed of sound (tibia SOS) in Beijing region.
  
  
  METHODS
  951 normal volunteers (male/female = 461/490) were included in this study. Speed of sound were measured in the middle of tibia by ultrasound scan (Sound Scan 2000, Myrid, Isereal). According to their gender and age, all subjects were divided into different subgroup by 10 year-age period.
  
  
  RESULTS
  The peak value of SOS presented in 30-39 years period in both male and female. The peak value was higher in males than in females. After reach the peak value, the tibial SOS begin to decline. The decreasing rate was fast in SOS were found at 50-59 period in female and over 50-59 years old in male. The tibia values of SOS of postmenopausal was obviously lower than that of premenopausal women. The relationship of menopausal duration and the values if tibial SOS was found to be a non-linear curve, which included 3 stages: the quick decrease, stabilization and further decrease.
  
  
  CONCLUSIONS
  The tibia values of SOS provides a kind of meaningful diagnostic criteria of osteoporosis.
authors.affiliation: Department of Endocrine, PUMC Hospital, CAMS, PUMC, Beijing 100730, China.
authors.forename: H C
authors.initials: HC
authors.lastname: Liu
authors.forename: Y Y
authors.initials: YY
authors.lastname: Hu
authors.forename: X P
authors.initials: XP
authors.lastname: Xing
authors.forename: W B
authors.initials: WB
authors.lastname: Xia
authors.forename: X W
authors.initials: XW
authors.lastname: Meng
authors.forename: X Y
authors.initials: XY
authors.lastname: Zhou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015519:Bone Density / Q000502:physiology; D002681:China; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis; D012016:Reference Values; D012737:Sex Factors; D013977:Tibia / Q000000981:diagnostic imaging*; D014463:Ultrasonography