Ammann P, Rizzoli R, Meyer J M, Bonjour J P
Division of Clinical Pathophysiology, WHO Collaborating Center for Osteoporosis and Bone Disease, Geneva, Switzerland.
Osteoporos Int. 1996;6(3):219-27. doi: 10.1007/BF01622738.
Areal bone mineral density (BMD) is a major determinant of bone strength and thereby of fracture risk. Other factors including trabecular microarchitecture and bone dimensions also contribute to bone strength. To investigate the relative importance for bone strength of BMD and bone dimensions, the relations between strength and the latter variables were evaluated under different experimental conditions in ovariectomized rats. Bone strength was assessed in compression and bending with measurement of BMD by dual-energy X-ray absorptiometry. Interventions were designed to increase trabecular BMD in rats with estrogen deficiency-induced bone loss (OVX) by treatment with pamidronate, an inhibitor of bone resorption, or to modify bone dimensions, particularly diameter, by administration of the growth factor IGF-I. In OVX rats, pamidronate treatment increased BMD with a commensurate increase in bone strength at the level of lumbar vertebrae and femoral neck (r = 0.789, p < 0.0001 and r = 0.535, p < 0.001, respectively). IGF-I increased the external diameter of midshaft tibia and femoral neck, which also correlated with bone strength (r = 0.678,p < 0.0001 and r = 0.507,p < 0.0002, respectively). Thus, both bone dimensions and BMD contributed to the determination of bone strength. In conclusion, adult rats with estrogen deficiency-induced bone loss represent a useful experimental model for investigating bone strength and its determinants such as BMD and external bone dimensions.
单位面积骨密度（BMD）是骨强度的主要决定因素，因此也是骨折风险的主要决定因素。其他因素，包括小梁微结构和骨骼尺寸，也对骨强度有影响。为了研究BMD和骨骼尺寸对骨强度的相对重要性，在去卵巢大鼠的不同实验条件下评估了强度与后两个变量之间的关系。通过双能X线吸收法测量BMD，在压缩和弯曲试验中评估骨强度。设计干预措施，通过使用骨吸收抑制剂帕米膦酸盐治疗，增加雌激素缺乏诱导的骨质流失（OVX）大鼠的小梁BMD，或通过给予生长因子IGF-I改变骨骼尺寸，特别是直径。在OVX大鼠中，帕米膦酸盐治疗增加了BMD，同时腰椎和股骨颈水平的骨强度也相应增加（分别为r = 0.789，p < 0.0001和r = 0.535，p < 0.001）。IGF-I增加了胫骨干中段和股骨颈的外径，这也与骨强度相关（分别为r = 0.678，p < 0.0001和r = 0.507，p < 0.0002）。因此，骨骼尺寸和BMD都有助于确定骨强度。总之，雌激素缺乏诱导的骨质流失成年大鼠是研究骨强度及其决定因素（如BMD和骨外径）的有用实验模型。
