Saarelainen J, Rikkonen T, Honkanen R, Kröger H, Tuppurainen M, Niskanen L, Jurvelin J S
Bone and Cartilage Research Unit, Clinical Research Center, University of Kuopio, Kuopio, Finland.
J Clin Densitom. 2007 Jul-Sep;10(3):312-8. doi: 10.1016/j.jocd.2007.03.003. Epub 2007 Apr 23.
Screening of osteoporosis using peripheral bone measurements has become more common, even though diagnostic discrepancies are known to exist between peripheral dual-energy X-ray (pDXA) or quantitative ultrasound (QUS) and central DXA measurements. Values of diagnostic parameters such as bone mineral density, speed of (ultra)sound, and broadband ultrasound attenuation are affected by bone size and soft tissue composition. However, their significance for the discordance between peripheral and central techniques is unclear. In this study, bone status and total body composition of 139 women (mean age 68.3 yr [1.7 SD], mean body mass index 26.5 kg/m2 [3.6 SD]) were assessed by 3 GE Lunar devices. Heel pDXA and heel QUS were conducted using peripheral instantaneous X-ray imaging (PIXI) and Achilles, respectively, and central DXA measurements were taken at the posterior-anterior lumbar spine (L2-L4) and at the left femoral neck using Prodigy. Positive significant associations were found between body height or fat (%) and most DXA or QUS parameters. The discordance between the site-dependent DXA or QUS T-score values typically increased (p<0.05) as a function of body weight or fat (%), but not with body height. On an average, body adiposity accounted for less than 11% of the differences between the techniques; however, increase of total body fat from 20% to 45% led to a discrepancy of one T-score between DXA(HEEL) and QUS(HEEL). To avoid diagnostic bias, comparative assessment of the devices using the same population is recommended.
尽管已知外周双能X线（pDXA）或定量超声（QUS）与中央DXA测量之间存在诊断差异，但使用外周骨测量筛查骨质疏松症已变得更为普遍。诸如骨矿物质密度、（超）声速和宽带超声衰减等诊断参数的值会受到骨大小和软组织成分的影响。然而，它们在外周和中央技术不一致方面的意义尚不清楚。在本研究中，使用3台GE Lunar设备评估了139名女性（平均年龄68.3岁[标准差1.7]，平均体重指数26.5kg/m²[标准差3.6]）的骨状况和全身成分。分别使用外周瞬时X线成像（PIXI）和跟腱测量足跟pDXA和足跟QUS，并使用Prodigy在腰椎前后位（L2-L4）和左股骨颈进行中央DXA测量。发现身高或脂肪百分比（%）与大多数DXA或QUS参数之间存在显著正相关。部位依赖性DXA或QUS T评分值之间的不一致通常随体重或脂肪百分比（%）增加（p<0.05），但与身高无关。平均而言，身体肥胖占技术之间差异的比例不到11%；然而，全身脂肪从20%增加到45%会导致DXA（足跟）和QUS（足跟）之间的T评分差异为1分。为避免诊断偏差，建议使用同一人群对设备进行比较评估。
