Mazess R B, Barden H, Mautalen C, Vega E
Lunar Corporation, Madison, Wisconsin.
J Bone Miner Res. 1994 Apr;9(4):541-8. doi: 10.1002/jbmr.5650090414.
We investigated several transformations of bone mineral content (BMC) and area density (BMD), in particular volumetric density (BMAD), to ascertain the influence on (1) body size dependence, (2) diagnostic sensitivity, and (3) precision. These transformations were examined in a group of 657 normal postmenopausal women and 327 women with osteoporotic fracture. First, expression of results as BMAD removed some of the slight dependence on body size; 21% of the variation in BMC and 15% of the variation i BMD were associated with body weight, but only 8% with BMAD. Second, the Z scores compared with those for age-matched controls for BMD and BMC were -1.85 and -1.71, respectively; the Z score for BMAD was -1.64. Third, the precision error for BMC was reduced by expressing results as BMD (1.1 versus 0.5%); BMAD degraded precision slightly (0.7%). BMD appeared to be the optimal expression for bone densitometry because it provided the best diagnostic sensitivity and lowest precision error; there was a minimal influence of body size on BMD results. This study also showed that osteoporotic women, even in the first postmenopausal decade, had low spine BMD, small vertebral area, and low body weight. Such women may be particularly at risk of crush fracture.
我们研究了骨矿物质含量（BMC）和面积密度（BMD）的几种转换形式，特别是体积密度（BMAD），以确定其对以下方面的影响：（1）身体大小依赖性；（2）诊断敏感性；（3）精密度。在一组657名正常绝经后女性和327名骨质疏松性骨折女性中对这些转换形式进行了研究。首先，以BMAD表示结果消除了一些对身体大小的轻微依赖性；BMC变化的21%和BMD变化的15%与体重相关，但与BMAD相关的仅为8%。其次，与年龄匹配对照组的BMD和BMC的Z分数分别为-1.85和-1.71；BMAD的Z分数为-1.64。第三，将结果表示为BMD时，BMC的精密度误差降低了（1.1%对0.5%）；BMAD使精密度略有下降（0.7%）。BMD似乎是骨密度测量的最佳表示形式，因为它提供了最佳的诊断敏感性和最低的精密度误差；身体大小对BMD结果的影响最小。这项研究还表明，骨质疏松女性即使在绝经后的第一个十年，脊柱BMD也较低，椎体面积较小，体重较轻。这类女性可能尤其有发生压缩性骨折的风险。
