Chronological changes of bone mass indices by quantitative ultrasound in the calcaneus in women *
We studied chronological changes in bone mass indices in the calcaneus of women using quantitative ultrasound. The subjects were 701 healthy women;age of 56.0±12.4（mean±SD）years old. Multiple yearly measurements were made for seven years, with a follow-up of 3.3 years. As indices of bone mass, the speed of sound（80S）, broadband ultrasound attenuation（BUA）, and the Stiffness Index, which was calculated mathematically from both SOS and BUA, were used. Subjects were classified into three groups;21～44 years old a premenopausal group（N＝129）, 45～59 years old a early postmenopausal group（N＝265）, and 60～87 years old a late postmenopausal group（N＝307）, and chronological changes in the bone mass indices in each group were studied. The results indicated that there were no significant changes in SOS（＋0.2～＋0.9％ for seven years）among the three groups. As for the other indices, BUA showed the greatest reduction（－5.6～10.7％ for seven years）in all three groups, and BUAs in the early and late postmenopausal groups showed more reduction than that for the premenopausal group（－5.6％ for group of the premenopousal, －9.2％ the early postmenopausal group, and －10.7％ for the latepostmenopausal group）. The Stiffness Index showed a slight reduction（－0.9％）in the premenopausal group and more reduction in the other two groups（－8.3％ for the early postmenopausal group, and －7.6％ for the late postmenopausal group）. As a bone mass index associated with aging in the calcaneus, BUA, which reflected not only bone mineral density（BMD）but also bone quality showed more reduction then SOS, which reflected BMD alone. Based on the results of the present study, in which we obtained standard values for the chronological rate of change in bone mass indices in three age groups, it will be possible to detect patients with a more rapid loss of bone mass. （Accepted on May 6，2005）
