Musculoskeletal Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA 94158, USA.
J Bone Miner Res. 2013 Feb;28(2):313-24. doi: 10.1002/jbmr.1763.
The primary goal of this study was to assess peripheral bone microarchitecture and strength in postmenopausal women with type 2 diabetes with fragility fractures (DMFx) and to compare them with postmenopausal women with type 2 diabetics without fractures (DM). Secondary goals were to assess differences in nondiabetic postmenopausal women with fragility fractures (Fx) and nondiabetic postmenopausal women without fragility fractures (Co), and in DM and Co women. Eighty women (mean age 61.3 ± 5.7 years) were recruited into these four groups (DMFx, DM, Fx, and Co; n = 20 per group). Participants underwent dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HR-pQCT) of the ultradistal and distal radius and tibia. In the HR-pQCT images volumetric bone mineral density and cortical and trabecular structure measures, including cortical porosity, were calculated. Bone strength was estimated using micro-finite element analysis (µFEA). Differential strength estimates were obtained with and without open cortical pores. At the ultradistal and distal tibia, DMFx had greater intracortical pore volume (+52.6%, p = 0.009; +95.4%, p = 0.020), relative porosity (+58.1%, p = 0.005; +87.9%, p = 0.011) and endocortical bone surface (+10.9%, p = 0.031; +11.5%, p = 0.019) than DM. At the distal radius DMFx had 4.7-fold greater relative porosity (p < 0.0001) than DM. At the ultradistal radius, intracortical pore volume was significantly higher in DMFx than DM (+67.8%, p = 0.018). DMFx also displayed larger trabecular heterogeneity (ultradistal radius: +36.8%, p = 0.035), and lower total and cortical BMD (ultradistal tibia: -12.6%, p = 0.031; -6.8%, p = 0.011) than DM. DMFx exhibited significantly higher pore-related deficits in stiffness, failure load, and cortical load fraction at the ultradistal and distal tibia, and the distal radius than DM. Comparing nondiabetic Fx and Co, we only found a nonsignificant trend with increase in pore volume (+38.9%, p = 0.060) at the ultradistal radius. The results of our study suggest that severe deficits in cortical bone quality are responsible for fragility fractures in postmenopausal diabetic women.
本研究的主要目的是评估患有 2 型糖尿病脆性骨折（DMFx）的绝经后妇女的外周骨微结构和强度，并将其与无骨折的绝经后 2 型糖尿病妇女（DM）进行比较。次要目标是评估绝经后脆性骨折（Fx）和无脆性骨折（Co）的非糖尿病妇女以及 DM 和 Co 妇女之间的差异。80 名女性（平均年龄 61.3±5.7 岁）被纳入这四个组（DMFx、DM、Fx 和 Co；每组 20 名）。参与者接受了双能 X 射线吸收法（DXA）和远端桡骨和胫骨的高分辨率外周定量计算机断层扫描（HR-pQCT）检查。在 HR-pQCT 图像中，计算了体积骨矿物质密度和皮质和小梁结构测量值，包括皮质孔隙率。使用微有限元分析（µFEA）估计骨强度。使用和不使用开放皮质孔获得了差异强度估计值。在远端胫骨，DMFx 的皮质内孔体积增加了 52.6%（p=0.009）；相对孔隙率增加了 58.1%（p=0.005）；骨内表面增加了 10.9%（p=0.031）。DMFx 的皮质内孔体积比 DM 大 67.8%（p=0.018）。DMFx 的相对孔隙率也明显大于 DM（远端桡骨：4.7 倍，p<0.0001）。DMFx 的远端桡骨和胫骨的皮质和小梁骨密度均低于 DM（远端胫骨：-12.6%，p=0.031；-6.8%，p=0.011）。DMFx 在远端和胫骨远端的刚度、失效负荷和皮质负荷分数方面表现出明显更高的与孔相关的缺陷，高于 DM。与非糖尿病性 Fx 和 Co 相比，我们仅发现远端桡骨的孔体积增加（+38.9%，p=0.060）呈非显著趋势。我们的研究结果表明，绝经后糖尿病妇女的脆性骨折是由皮质骨质量的严重缺陷引起的。
