Mazess R B, Barden H S, Ettinger M
Department of Medical Physics, University of Wisconsin, Madison.
Arthritis Rheum. 1988 Jul;31(7):891-7. doi: 10.1002/art.1780310710.
Density of the radius (by single-photon absorptiometry) and the spine (by dual-photon absorptiometry) was measured in 281 normal young women and in a large heterogeneous group of 1,622 consecutive female patients. Both spinal and radial density were useful measurements when performed on patients with medical indications; spine and radius densities in these patients averaged 10-20% below those of age-matched controls. However, patients younger than 60 years of age had deficits of spine density that were twice as large as those in the radius, and twice as many of these patients had spinal osteopenia, compared with those with radial osteopenia. After age 70, loss of density in the radius approximated that in the spine and the prevalence of osteopenia was similar at both sites. The poorer sensitivity of the radius measurement reflected the fact that it did not predict spine density. The standard error of the estimate was 0.12 gm/cm2 in normal subjects and 0.15 gm/cm2 in patients. At any given radial density, the spinal density of patients averaged 0.18 gm/cm2 (15-20%) below that in normal subjects. Predictions of spinal density from body weight were as accurate as predictions from radial density. Preferential spinal osteopenia occurring without radial osteopenia precluded radial densitometry as a screening method for individuals with osteoporosis before age 60. However, measurement of the radius was more effective than body weight for defining groups at risk, even though the radius did not reliably predict individual spine density. A radius shaft density less than 0.55 gm/cm2 occurring with a body weight less than 55 kg was associated with a high prevalence of spinal osteopenia.
对281名正常年轻女性以及1622名连续就诊的女性患者组成的大样本异质性群体，采用单光子吸收法测量桡骨密度，采用双能X线吸收法测量脊柱密度。对有医学指征的患者进行测量时，脊柱和桡骨密度均为有用的测量指标；这些患者的脊柱和桡骨密度平均比年龄匹配的对照组低10%-20%。然而，年龄小于60岁的患者，脊柱密度不足是桡骨的两倍，与桡骨骨质减少的患者相比，脊柱骨质减少的患者数量也是其两倍。70岁以后，桡骨密度丢失与脊柱相近，两个部位骨质减少的患病率相似。桡骨测量的敏感性较差，这反映出它不能预测脊柱密度。正常受试者的估计标准误差为0.12g/cm²，患者为0.15g/cm²。在任何给定的桡骨密度下，患者的脊柱密度平均比正常受试者低0.18g/cm²（15%-20%）。根据体重预测脊柱密度与根据桡骨密度预测同样准确。在无桡骨骨质减少的情况下出现的脊柱骨质减少占优，这使得桡骨密度测量不能作为60岁以下骨质疏松个体的筛查方法。然而，测量桡骨对于确定高危人群比测量体重更有效，尽管桡骨不能可靠地预测个体的脊柱密度。桡骨干密度低于0.55g/cm²且体重低于55kg与脊柱骨质减少的高患病率相关。
