以腰椎前后位骨矿含量、面积估价骨密度测量的准确性

Evaluation of human bone mineral density by estimation of lumbar bone content and area in anteroposterior position

目的针对前后位腰椎骨密度（ＢＭＤ）受骨质增生或压缩性骨折等因素影响而易造成判断结果的误差，根据ＢＭＤ＝骨矿含量（ＢＭＣ）／面积（Ａｒｅａ）的关系，旨通过对ＢＭＣ及Ａｒｅａ正常范围的评价，进一步判断ＢＭＤ测量的准确性。方法采用双能Ｘ线骨密度仪（ＤＥＸＡ）进行不同性别平衡峰值期ＢＭＤ年龄段的估价、计算其ＢＭＣ及Ａｒｅａ均值，以身高为自变量，ＢＭＤ为应变量分别作直线回归，建立ＢＭＣ、Ａｒｅａ与身高的回归方程，利用其回归方程进行ＢＭＤ正常值的预报。结果平衡峰值ＢＭＤ的年龄，男性为２０～４９岁，女性为３０～４９岁；ＢＭＣ及Ａｒｅａ的均值，男性分别为５６．４７ｇ及４６．３９ｃｍ２，女性分别为４７．４１ｇ及４１．１２ｃｍ２；９０％正常范围：男性ＢＭＣ＝０．３２７×身高（ｃｍ）±１４．７６、Ａｒｅａ＝０．２７１×身高（ｃｍ）±５．９６，女性ＢＭＣ＝０．２９４×身高（ｃｍ）±１１．８５，Ａｒｅａ＝０．２２５×身高（ｃｍ）±５．００。结论在临床工作中仅靠腰椎ＢＭＤ结果进行评价是远远不够的，而应正确评价腰椎的ＢＭＣ与Ａｒｅａ，方能对其ＢＭＤ测量的可靠程度作出判断。

bjective\ In the light of the error in estimation of lumbar bone mineral density (BMD) in anteroposterior position produced by lumbar hyperosteogeny,compression fracture,etc,we investigated the normal range of bone mineral content (BMC) and area.Methods\ Based on the epidemiological studies of lumbar BMD in 1567 cases by dual energy X ray absorptiomety (DEXA),the age groups at equilibrium peak value stage in both sexes was evaluated,the mean BMC and area values were established,and the forecast of normal BMD value was done by regression equations.Result\ The age groups at equilibrium peak value stage were 20 49 years in men and 30 49 years in women, respectively.The mean BMC and area were 56.47g and 46.39cm 2 in men and 47.41g and 41.12cm 2 in women,respectively.For the 90 percentile nomal range,BMC in males equals 0.327×height in cm±14.76,area equals 0.271×height in cm ±5.96,and BMC in females equals 0.294×height in cm±11.85,and area equals 0.225×height in cm±5.00.Conclusion\ Estimation of lumbar BMD only is quite insufficient in clinical evaluation.Both the lumbar BMC and area should be correctly evaluated to judge the reliability of estimated BMD value.