女性腰椎峰值骨量与骨骼大小的关系

目的　了解女性腰椎骨骼大小对峰值骨密度 (BMD)的影响。方法　采用QDR 450 0A型扇形束DXA骨密度仪 ,测量 52 7例年龄 2 5～ 3 9岁健康女性前后位 (正位AP)腰椎 1～ 4椎体和侧位 (Lat)腰椎 2～ 4椎体的投射骨面积 (BA)、骨矿含量 (BMC)和面积BMD(aBMD)及AP/Lat相伴扫描测量腰椎的体积BMD(vBMD)。用直线和多元线性回归分析骨量与BA、身高和体重之间的关系。按不同BA分组 ,了解各组之间骨量的差异。结果　BA与BMC(r =0 .79和 0 .78,均P <0 .0 1)和aBMD(r =0 .40和 0 .3 8,均P<0 .0 0 1)呈正相关 ,Lat BA与vBMD相关有显著意义 (r =0 .14 ,P <0 .0 1)。AP BA每变化 1个标准差 ,AP BMC和AP aBMD在平均值的基础上分别相应变化 13 .1%和 4.47% ;Lat BA每变化 1个标准差 ,Lat BMC、Lat aBMD和vBMD在平均值的基础上分别相应变化 13 .3 %、4.4%和 1.5% ;AP BA的全距变化所致AP BMC和AP aBMD的变化分别约为 78.6%和 2 6.8% ,Lat BA的全距变化所致Lat BMC、Lat aBMD和vBMD的变化分别约为 79.8%、2 6.3 %和 8.94%。不同BA组之间的身高、体重、BMC和aBMD均具有非常显著性意义 (均P <0 .0 0 1)。影响BA、BMC和Lat aBMD的主要因素为身高 ,影响AP aBMD的主要因素为体重。结论　BMC除以BA不能完全消除骨骼大小对aBMD的影响

Relationship between peak bone mass and skeletal size at lumbar spine in women

Objective To st ud y the effect of skeletal size on the estimated peak bone mineral density (BMD) o f lumbar spine in women. Methods Bone area (BA) , bone mineral content (BMC), and areal BMD (aBMD) at anteroposterior (AP) (L 1-4 ) and lateral (Lat) lumbar spines (L 2-4 ), and volumetric BMD (vBM D) at the companion AP/Lat spine scan were measured by QDR-4500A fan beam DXA b one densitometer in 527 healthy women from 25 to 39 years of age. The relationsh ip between bone mass and BA, height, and weight were analyzed by linear and mult iple linear regression. The differences of bone mass among groups divided by var ious BA were investigated. Results BA showed si gnificantly positive correlations with BMC (r=0.79 and 0.78, both P<0.01) and aBMD (r=0.40 and 0.38 , both P<0.001),Lat-BAwas significantlycorrelatedwithvBMD (r=0.14, P<0.01). When BA at the AP spine (AP-BA) changed by one standard deviation (SD), AP-BMC and AP-aBMD correspondingly changed by 13.1% and 4.47% on the basis of their respec tive mean values. When a variation of 1SD was observed in BA at the Lat spine (L at-BA), lat-BMC, Lat-aBMD and vBMD correspondingly changed by 13.3%, 4.4% and 1.5% on the basis of their respective mean values. AP-BMC and AP-aBMD showed respective variational ranges of 78.6% and 26.8% as caused by the overall spread of AP-BA. Lat-BMC, Lat-aBMD and vBMD showed respective variational ranges of 79.8%, 26.3% and 8.94% as caused by the overal spread of Lat-BA. Mean height, weight, BMC, and aBMD showed significant differences among various groups of the AP-BA and Lat-BA (all P<0.001). The height is a major fa ctor affecting the BA, BMC and Lat-aBMD, while the weight is a major factor aff ecting the AP-aBMD by multiple linear regression. Conclusion The division of BMC by BA is not fully eliminated the effects of skeletal size on the aBMD. aBMD significantly varied with skeletal size.