骨礦物質密度因種族的不同而有所差異。有愈來愈多的證據顯示停經後年數可作爲骨質流失的良好指標。經由問卷調查,理學檢查及查看病曆,總共篩檢出278位正常的中國婦女。我們使用Norland 2600雙光子吸收儀(dual photon absorptiometry,OPA)測量患者的腰椎骨、近端髖體及全身骨礦物質密度。此機型長期的精確度爲1.6%。測量所得的結果,經由回歸分析,比較實際年齡(chronological age)及停經後年數(year since menopause)其骨礦物質密度的變化情形。實際年齡與骨礦物質密度的關係如下:腰椎骨:y=-0.00413x±1.21,r=0.345;近端髖骨:y=-0.00727x±1.03,r=0.552;全身體礦物質密度平均值:y=-0.00470x±1.11,r=0.448;而停經後年數與骨礦物質密度的關係如下:腰椎骨:y=-0.00675x±1.02,r=0.357;近端髖骨:y=-0.01165x±0.705,r=0.537;全身骨礦物質密度平均值:y=-0.00975x±0.925,r=0.545。比較骨礦物質密度的每年齡層相差的程度以回歸線斜率表示,用停經後年數來表示均比以實際年齡來表示還快。而比較骨礦物質密度各年齡層的變化,三個部位均於50歲左右,開始明顯降低。以迴歸線斜率代表每年度變化的程度用停經後年數來表示,均比實際年齡來表示還快。而比較各r值,用停經後年數來表示和用實際年齡來表示,以Anoco分析兩者相差不大。
The bone mineral density (BMD) may vary in different ethnic groups. There is a growing evidence that in postmenopausal women, year since menopause (YSM) is a better determinant of bone mineral loss than chronological. Screening with questionnaire and chart, we collected 278 postmenopausal women. We measured their BMD with Norland 2600 dual photon absorptiometry (DPA). The long term precision was 1.6% on a lumbar spine phanton. DPA was performed in lumbar spine, hip, and whole body BMD. Regression analysis was performed in order to assess the contribution of chronological age and year since menopause to the change of BMD. The relationship between BMD and chronological age was as follows: lumbar spine: y=-0.0413x±1.21, r=0.345; hip: y=-0.00727x±1.03, r=0.552; whole body BMD: y=-0.0047x±1.11, r=0.447. The relationship between BMD and YSM was as follows: lumbar spine: y=-0.00675x±1.02, r=0.357; hip: y=-0.01165x±0.705, r=0.537; whole body BMD y=-0.00975x±0.925, r=0.545. In comparing with the loss of average BMD, expressed by slope of regression, YSM is better than chronological age. The greatest loss of BMD per year occurred around 50 years of age at the mentioned regions. Anoco analysis was performed to compare the two r values of chronological age and YSM, but no significant difference was found.