Mazur Courtney M, Edwards W Brent, Haider Ifaz T, Fang Ying, Morse Leslie R, Schnitzer Thomas J, Simonian Narina, Troy Karen L
Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; McCaig Institute for Bone and Joint Health, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
J Clin Densitom. 2023 Jul-Sep;26(3):101380. doi: 10.1016/j.jocd.2023.101380. Epub 2023 May 5.
Spinal cord injury (SCI) causes rapid bone loss and increases risk of fragility fractures in the lower extremities. The majority of individuals with SCI are men, and few studies have investigated sex as a biological variable in SCI-induced osteoporosis. This cross-sectional study aimed to quantify sex-specific differences in bone mineral following SCI.
Quantitative computed tomography (QCT) scans of the distal femur and proximal tibia were obtained at baseline of one of four clinical trials enrolling people who sustained SCI 1 month to 50 years prior to recruitment. Bone volume (BV), bone mineral content (BMC), bone mineral density (BMD), and bending strength index (BSI) were quantified in the integral, trabecular, and cortical bone in the epiphysis, metaphysis and diaphysis. Scans from 106 men and 31 women were analyzed to measure sex-specific effects on bone loss over time post-SCI.
BMC and BSI declined exponentially as a function of time post-SCI and were best described by separate decay curves for men and women. Women had BV, BMC, and BSI at 58-77% that of men in the acute and plateau phases, with both sexes showing similar rates of loss as a function of time post-SCI. Trabecular BMD was best described as an exponential decay versus time post-SCI, with no sex-specific differences.
Due to consistently lower BV, BMC, and BSI, women may be more susceptible to fractures after SCI than men.
脊髓损伤（SCI）会导致快速的骨质流失，并增加下肢脆性骨折的风险。大多数脊髓损伤患者为男性，很少有研究将性别作为脊髓损伤所致骨质疏松的生物学变量进行调查。这项横断面研究旨在量化脊髓损伤后骨矿物质的性别差异。
在四项临床试验之一的基线期，对招募前1个月至50年发生脊髓损伤的患者进行股骨远端和胫骨近端的定量计算机断层扫描（QCT）。对骨骺、干骺端和骨干的整体骨、小梁骨和皮质骨中的骨体积（BV）、骨矿物质含量（BMC）、骨矿物质密度（BMD）和弯曲强度指数（BSI）进行量化。分析了106名男性和31名女性的扫描结果，以测量脊髓损伤后随时间推移性别对骨质流失的影响。
BMC和BSI随脊髓损伤后的时间呈指数下降，男性和女性分别用不同的衰减曲线能最好地描述这种情况。在急性期和平稳期，女性的BV、BMC和BSI分别为男性的58%-77%，两性随脊髓损伤后时间的流失率相似。小梁骨密度随脊髓损伤后的时间最好描述为指数衰减，无性别差异。
由于女性的BV、BMC和BSI一直较低，脊髓损伤后女性可能比男性更容易发生骨折。
