Njeh C F, Shaw N, Gardner-Medwin J M, Boivin C M, Southwood T R
Department of Nuclear Medicine, Queen Elizabeth Hospital, Birmingham, UK.
J Clin Densitom. 2000 Fall;3(3):251-60. doi: 10.1385/jcd:3:3:251.
Periarticular osteoporosis around inflammed joints and generalized osteoporosis have been shown to be markers of disease activity and severity in children with juvenile idiopathic arthritis (JIA). Bone mineral density (BMD) in adults can be assessed precisely by dual X-ray absorptiometry (DXA), but this technique has not been used widely in children. Quantitative ultrasound (QUS) may provide an alternative method for assessment of bone status. The aim of this pilot study was to compare QUS to DXA in assessing generalized osteoporosis in a cohort of patients JIA. Twenty-two Caucasian children (15 females, 7 males) with JIA of duration 19-142 months (mean 71 mo) and age 7-17 yr were recruited. Total body and lumbar spine BMD and bone mineral content (BMC) were measured by DXA using standard procedures on a Lunar DPX-L scanner. QUS was performed using Myriad SoundScan 2000. Speed of sound (SOS) was measured at the right midtibia. The DXA results were compared to QUS using linear regression analysis. Spine and total body BMD measured by DXA correlated significantly with tibia SOS (spine: r = 0.57, p < 0.007; total body: r = 0.68, p < 0.001). Spine BMC was similarly related to SOS as BMD (r = 0.58, p < 0.007). Individual patient weight and height were strong predictors of BMD, but only moderate predictors of SOS. The mean spine BMD was lower in the JIA patients compared to the normal ranges (mean Z-score of -1.19). BMD Z-scores were negatively associated with disease duration. Patients taking steroids were associated with lower Z-scores. In conclusion, SOS shows a significant correlation with BMD as measured by DXA, albeit with wide 95% confidence intervals in this small pilot study. QUS was also well tolerated and was technically easy to perform in these children. With the added advantage that it is free from radiation risk, further assessment of this potentially valuable tool for measuring bone status in children is warranted.
炎症关节周围的关节周围骨质疏松症和全身性骨质疏松症已被证明是幼年特发性关节炎（JIA）患儿疾病活动度和严重程度的标志物。成人的骨矿物质密度（BMD）可通过双能X线吸收法（DXA）精确评估，但该技术在儿童中尚未得到广泛应用。定量超声（QUS）可能为评估骨状态提供一种替代方法。这项初步研究的目的是在一组JIA患者中比较QUS和DXA在评估全身性骨质疏松症方面的差异。招募了22名白种儿童（15名女性，7名男性），他们患JIA的时间为19至142个月（平均71个月），年龄在7至17岁。使用标准程序在Lunar DPX-L扫描仪上通过DXA测量全身和腰椎的BMD以及骨矿物质含量（BMC）。使用Myriad SoundScan 2000进行QUS检查。在右胫骨中部测量声速（SOS）。使用线性回归分析将DXA结果与QUS进行比较。通过DXA测量的脊柱和全身BMD与胫骨SOS显著相关（脊柱：r = 0.57，p < 0.007；全身：r = 0.68，p < 0.001）。脊柱BMC与SOS的关系与BMD相似（r = 0.58，p < 0.007）。个体患者的体重和身高是BMD的强预测指标，但只是SOS的中度预测指标。与正常范围相比，JIA患者的平均脊柱BMD较低（平均Z值为-1.19）。BMD Z值与疾病持续时间呈负相关。服用类固醇的患者Z值较低。总之，在这项小型初步研究中，尽管95%置信区间较宽，但SOS与通过DXA测量的BMD显示出显著相关性。QUS在这些儿童中耐受性良好，技术上易于操作。由于其无辐射风险这一额外优势，有必要对这种潜在的用于测量儿童骨状态的有价值工具进行进一步评估。
