Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
Division of Orthopaedics, Department of Trauma and Orthopaedic Surgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
J Bone Miner Res. 2021 Jul;36(7):1316-1325. doi: 10.1002/jbmr.4289. Epub 2021 Mar 30.
In patients with autoimmune hepatitis (AIH), osteoporosis represents a common extrahepatic complication, which we recently showed by an assessment of areal bone mineral density (aBMD) via dual-energy x-ray absorptiometry (DXA). However, it is well established that bone quality and fracture risk does not solely depend on aBMD, but also on bone microarchitecture. It is currently not known whether AIH patients exhibit a site-specific or compartment-specific deterioration in the skeletal microarchitecture. In order to assess potential geometric, volumetric, and microarchitectural changes, high-resolution peripheral quantitative computed tomography (HR-pQCT) measurements were performed at the distal radius and distal tibia in female patients with AIH (n = 51) and compared to age-matched female healthy controls (n = 32) as well as to female patients with AIH/primary biliary cholangitis (PBC) overlap syndrome (n = 25) and female patients with PBC alone (PBC, n = 36). DXA at the lumbar spine and hip, clinical characteristics, transient elastography (FibroScan) and laboratory analyses were also included in this analysis. AIH patients showed a predominant reduction of cortical thickness (Ct.Th) in the distal radius and tibia compared to healthy controls (p < .0001 and p = .003, respectively). In contrast, trabecular parameters such as bone volume fraction (BV/TV) did not differ significantly at the distal radius (p = .453) or tibia (p = .508). Linear regression models revealed significant negative associations between age and Ct.Th (95% confidence interval [CI], -14 to -5 μm/year, p < .0001), but not between liver stiffness, cumulative prednisolone dose (even after an adjustment for age), or disease duration with bone microarchitecture. The duration of high-dose prednisolone (≥7.5 mg) was negatively associated with trabecular thickness (Tb.Th) at the distal radius. No differences in bone microarchitecture parameters between AIH, AIH/PBC, and PBC could be detected. In conclusion, AIH patients showed a severe age-dependent deterioration of the cortical bone microarchitecture, which is most likely the major contribution to the observed increased fracture risk in these patients. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
在自身免疫性肝炎 (AIH) 患者中，骨质疏松症是一种常见的肝外并发症，我们最近通过双能 X 射线吸收法 (DXA) 评估了骨矿物质密度 (aBMD) 来证实了这一点。然而，众所周知，骨质量和骨折风险不仅取决于 aBMD，还取决于骨微观结构。目前尚不清楚 AIH 患者的骨骼微观结构是否存在特定部位或特定部位的恶化。为了评估潜在的几何形状、体积和微观结构变化，我们对 51 名 AIH 女性患者（AIH 组）和 32 名年龄匹配的健康女性对照者（对照组）以及 25 名 AIH/原发性胆汁性胆管炎重叠综合征女性患者（重叠综合征组）和 36 名单独患有原发性胆汁性胆管炎的女性患者（PBC 组）的桡骨远端和胫骨远端进行了高分辨率外周定量计算机断层扫描（HR-pQCT）测量。该分析还包括腰椎和髋部的 DXA、临床特征、瞬时弹性成像（FibroScan）和实验室分析。与健康对照组相比，AIH 患者的桡骨远端和胫骨远端的皮质厚度 (Ct.Th) 明显降低（p<0.0001 和 p=0.003）。相比之下，桡骨远端（p=0.453）或胫骨远端（p=0.508）的骨小梁参数，如骨体积分数 (BV/TV) 差异无统计学意义。线性回归模型显示，年龄与 Ct.Th 呈显著负相关（95%置信区间 [CI]，-14 至-5 μm/年，p<0.0001），但与肝硬度、累积泼尼松剂量（即使在调整年龄后）或疾病持续时间与骨微观结构无关。高剂量泼尼松（≥7.5 mg）的持续时间与桡骨远端的骨小梁厚度 (Tb.Th) 呈负相关。AIH、AIH/PBC 和 PBC 之间的骨微观结构参数无差异。总之，AIH 患者的皮质骨微观结构出现严重的年龄依赖性恶化，这很可能是这些患者观察到的骨折风险增加的主要原因。
