Boivin G Y, Chavassieux P M, Santora A C, Yates J, Meunier P J
INSERM Unité 403, Faculté de Médecine R. Laennec, Lyon, France.
Bone. 2000 Nov;27(5):687-94. doi: 10.1016/s8756-3282(00)00376-8.
The mean degree of mineralization of bone (MDMB) was measured by quantitative microradiography on transiliac bone biopsies taken from 53 postmenopausal osteoporotic women who had been treated with alendronate (ALN; 10 mg/day) during 2 (9 patients) or 3 years (16 patients) or with placebo (PLA; 15 and 13 patients, respectively). In the same patients, bone mineral density (BMD) values were obtained by dual-energy X-ray absorptiometry of the lumbar spine and femoral neck at the beginning and end of treatment. Histomorphometric parameters and activation frequency of new remodeling units were also measured on the iliac biopsies. After 2 years of ALN, MDMB in compact bone was 9.3% (p = 0.0035) and in cancellous bone was 7.3% (p = 0.0009) higher, respectively, than PLA. After 3 years of ALN, MDMB in compact bone was 11.6% (p = 0.0002) and in cancellous bone was 11.4% (p = 0.0001) higher, respectively, than PLA. After 2 and 3 years of ALN, and compared with the corresponding PLA, the distribution of the degree of mineralization in compact and cancellous bone showed a clear shift toward the highest mineralization values and a decrease in the number of bone structure units having low values of mineralization. The between-group differences in MDMB were similar to those of BMD at the lumbar spine BMD (+8.7% after 2 years and +9.6% after 3 years, respectively), suggesting that MDMB augmentation probably accounted for the majority of the increase in BMD seen with ALN. The data support the hypothesis that the reduction in activation frequency caused by the antiresorptive effect of ALN is followed by a prolonged secondary mineralization that increases the percentage of bone structure units having reached a maximum degree of secondary mineralization and, through this mechanism, MDMB. That these effects contribute to improved bone strength is demonstrated by the reduction in fracture incidence previously demonstrated in these patients.
通过定量显微放射照相术测量了53名绝经后骨质疏松妇女的骨矿化平均程度（MDMB），这些妇女分别接受了2年（9例患者）或3年（16例患者）的阿仑膦酸盐（ALN；10毫克/天）治疗，或接受了安慰剂（PLA；分别为15例和13例患者）治疗。在同一批患者中，在治疗开始和结束时通过双能X线吸收法获得腰椎和股骨颈的骨密度（BMD）值。还对髂骨活检组织进行了组织形态计量学参数和新重塑单元激活频率的测量。接受ALN治疗2年后，密质骨的MDMB分别比PLA高9.3%（p = 0.0035），松质骨的MDMB比PLA高7.3%（p = 0.0009）。接受ALN治疗3年后，密质骨的MDMB分别比PLA高11.6%（p = 0.0002），松质骨的MDMB比PLA高11.4%（p = 0.0001）。接受ALN治疗2年和3年后，与相应的PLA组相比，密质骨和松质骨矿化程度的分布显示出明显向最高矿化值的偏移，以及矿化值低的骨结构单元数量的减少。MDMB的组间差异与腰椎BMD的差异相似（2年后为+8.7%，3年后为+9.6%），这表明MDMB的增加可能是ALN治疗后BMD增加的主要原因。这些数据支持以下假设：ALN的抗吸收作用导致激活频率降低，随后是延长的继发性矿化，这增加了达到最大继发性矿化程度的骨结构单元的百分比，并通过这种机制增加了MDMB。这些患者先前骨折发生率的降低证明了这些作用有助于提高骨强度。
