Inoue Kazunori, Hamano Takayuki, Nango Nobuhito, Matsui Isao, Tomida Kodo, Mikami Satoshi, Fujii Naohiko, Nakano Chikako, Obi Yoshitsugu, Shimomura Akihiro, Kusunoki Yasuo, Rakugi Hiromi, Isaka Yoshitaka, Tsubakihara Yoshiharu
Department of Geriatric Medicine and Nephrology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan.
J Bone Miner Metab. 2014 May;32(3):271-80. doi: 10.1007/s00774-013-0485-2. Epub 2013 Jul 6.
Osteoporosis is one of the major complications of glucocorticoid therapy. Osteoporosis is usually defined by the levels of bone mineral density (BMD) assessed by dual energy X-ray absorptiometry (DEXA); however, glucocorticoids often induce fractures in patients with normal BMD. Thus, novel diagnostic approaches are required. In this study, we examined whether multidetector-row computed tomography (MDCT) is useful to assess the bone status in glucocorticoid-induced osteoporosis (GIO). Because bisphosphonates have been proven to prevent bone fracture in GIO, we tried to detect the therapeutic effects of bisphosphonates in GIO by MDCT. Fifteen Japanese patients with immunoglobulin A nephropathy who had normal renal function were enrolled in this open-label randomized trial. Patients were randomly divided into three groups-calcitriol (VD), menatetrenone (VK), or bisphosphonate (Bis). Bone conditions were analyzed twice by three different methods-bone turnover markers, DEXA, and MDCT-at the start and 6 months after the start of therapy. Both bone markers and DEXA could not detect significant differences among the therapeutic groups; however, MDCT-based analyses detected the preventive effects of bisphosphonates in GIO. Compared to VD, Bis improved structural indices, such as bone volume fraction, trabecular separation, marrow star volume, and structure model index whereas the difference between VD and VK was not significant. Finite element analysis revealed that simulated fracture load in the Bis group was significantly improved. These findings suggested that MDCT-based assessment is superior to bone markers and/or DEXA in assessing the therapeutic effect of bisphosphonates on GIO.
骨质疏松症是糖皮质激素治疗的主要并发症之一。骨质疏松症通常由双能X线吸收法（DEXA）评估的骨矿物质密度（BMD）水平来定义；然而，糖皮质激素常导致骨密度正常的患者发生骨折。因此，需要新的诊断方法。在本研究中，我们检测了多排螺旋计算机断层扫描（MDCT）是否有助于评估糖皮质激素诱导的骨质疏松症（GIO）的骨状态。由于双膦酸盐已被证明可预防GIO患者的骨折，我们试图通过MDCT检测双膦酸盐对GIO的治疗效果。15例肾功能正常的日本免疫球蛋白A肾病患者参与了这项开放标签随机试验。患者被随机分为三组——骨化三醇（VD）组、维生素K2（VK）组或双膦酸盐（Bis）组。在治疗开始时和开始后6个月，通过三种不同方法——骨转换标志物、DEXA和MDCT对骨状况进行两次分析。骨标志物和DEXA均未检测到治疗组之间的显著差异；然而，基于MDCT的分析检测到双膦酸盐对GIO的预防作用。与VD组相比，Bis组改善了结构指标，如骨体积分数、小梁间距、骨髓星体积和结构模型指数，而VD组和VK组之间的差异不显著。有限元分析显示，Bis组的模拟骨折负荷显著改善。这些发现表明，在评估双膦酸盐对GIO的治疗效果方面，基于MDCT的评估优于骨标志物和/或DEXA。
