Beck T J, Stone K L, Oreskovic T L, Hochberg M C, Nevitt M C, Genant H K, Cummings S R
Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
J Bone Miner Res. 2001 Nov;16(11):2103-10. doi: 10.1359/jbmr.2001.16.11.2103.
It is assumed that estrogen influences bone strength and risk of fractures by affecting bone mineral density (BMD). However, estrogen may influence the mechanical strength of bones by altering the structural geometry in ways that may not be apparent in the density. Repeated dual energy X-ray absorptiometry (DXA) hip scan data were analyzed for bone density and structural geometry in elderly women participating in the Study of Osteoporotic Fractures (SOF). Scans were studied with a hip structural analysis program for the effects of estrogen replacement therapy (ERT) on BMD and structural geometry. Of the 3,964 women with ERT-use data, 588 used ERT at both the start and end of the approximately 3.5-year study, 1,203 had past use which was discontinued by clinic visit 4, and 2,163 women had never used ERT. All groups lost BMD at the femoral neck, but the reduced BMD among users of ERT was entirely due to subperiosteal expansion and not bone loss, whereas both bone loss and expansion occurred in past or nonusers. BMD increased 0.8%/year at the femoral shaft among ERT users but decreased 0.8%/year among nonusers. Section moduli increased at both the neck and shaft among ERT users but remained unchanged in past and nonusers. Current, but not past, use of estrogen therapy in elderly women seems to increase mechanical strength of the proximal femur by improving its geometric properties. These effects are not evident from changes in femoral neck BMD.
一般认为，雌激素通过影响骨矿物质密度（BMD）来影响骨强度和骨折风险。然而，雌激素可能通过改变结构几何形状来影响骨骼的机械强度，而这些方式在密度上可能并不明显。对参加骨质疏松性骨折研究（SOF）的老年女性的重复双能X线吸收法（DXA）髋部扫描数据进行了骨密度和结构几何形状分析。使用髋部结构分析程序研究扫描结果，以评估雌激素替代疗法（ERT）对BMD和结构几何形状的影响。在3964名有ERT使用数据的女性中，588名在大约3.5年研究的开始和结束时都使用了ERT，1203名曾使用过ERT，但在第4次临床访视时停用，2163名女性从未使用过ERT。所有组的股骨颈骨密度均下降，但ERT使用者骨密度降低完全是由于骨膜下扩张而非骨质流失，而既往使用者或未使用者则同时出现骨质流失和骨膜下扩张。ERT使用者股骨干的骨密度每年增加0.8%，而非使用者每年下降0.8%。ERT使用者的颈部和骨干的截面模量均增加，而既往使用者和未使用者则保持不变。老年女性当前（而非既往）使用雌激素疗法似乎通过改善近端股骨的几何特性来增加其机械强度。这些影响在股骨颈BMD的变化中并不明显。
