Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, United States of America; Department of Medicine, Stanford University School of Medicine, Stanford, CA, United States of America.
Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States of America.
Bone. 2019 Oct;127:271-279. doi: 10.1016/j.bone.2019.05.022. Epub 2019 May 31.
End stage renal disease (ESRD) is associated with sarcopenia and skeletal fragility. The objectives of this cross-sectional study were to (1) characterize body composition, bone mineral density (BMD) and bone structure in hemodialysis patients compared with controls, (2) assess whether DXA areal BMD (aBMD) correlates with peripheral quantitative CT (pQCT) measures of volumetric BMD (vBMD), cortical dimensions and MRI measures of trabecular microarchitecture, and (3) determine the magnitude of bone deficits in ESRD after adjustment for muscle mass. Thirty ESRD participants, ages 25 to 64 years, were compared with 403 controls for DXA and pQCT outcomes and 104 controls for MRI outcomes; results were expressed as race- and sex- specific Z-scores relative to age. DXA appendicular lean mass index (ALMI kg/m) and total hip, femoral neck, ultradistal and 1/3rd radius aBMD were significantly lower in ESRD, vs. controls (all p < 0.01). pQCT trabecular vBMD (p < 0.01), cortical vBMD (p < 0.001) and cortical thickness (due to a greater endosteal circumference, p < 0.02) and MRI measures of trabecular number, trabecular thickness, and whole bone stiffness were lower (all p < 0.01) in ESRD, vs. controls. ALMI was positively associated with total hip, femoral neck, ultradistal radius and 1/3rd radius aBMD and with tibia cortical thickness (R = 0.46 to 0.64). Adjustment for ALMI significantly attenuated bone deficits at these sites: e.g. mean femoral neck aBMD was 0.79 SD lower in ESRD, compared with controls and this was attenuated to 0.33 with adjustment for ALMI. In multivariate models within the dialysis participants, pQCT trabecular vBMD and cortical area Z-scores were significant and independently (all p < 0.02) associated with DXA femoral neck, total hip, and ultradistal radius aBMD Z-scores. Cortical vBMD (p = 0.01) and cortical area (p < 0.001) Z-scores were significantly and independently associated with 1/3rd radius areal aBMD Z-scores (R = 0.62). These data demonstrate that DXA aBMD captures deficits in trabecular and cortical vBMD and cortical area. The strong associations with ALMI, as an index of skeletal muscle, highlight the importance of considering the role of sarcopenia in skeletal fragility in patients with ESRD.
终末期肾病（ESRD）与肌肉减少症和骨骼脆弱有关。本横断面研究的目的是：(1) 比较血液透析患者与对照组的身体成分、骨矿物质密度（BMD）和骨结构；(2) 评估双能 X 线吸收法（DXA）的面积 BMD（aBMD）是否与外周定量 CT（pQCT）的体积 BMD（vBMD）、皮质维度和 MRI 评估的小梁微结构相关；(3) 确定 ESRD 患者在调整肌肉质量后骨骼缺陷的程度。30 名年龄在 25 至 64 岁的 ESRD 患者与 403 名对照组进行 DXA 和 pQCT 检测，与 104 名对照组进行 MRI 检测；结果表示为种族和性别特定的 Z 分数相对于年龄。与对照组相比，ESRD 患者的 DXA 四肢瘦体重指数（ALMI kg/m）和全髋、股骨颈、远段桡骨和 1/3 半径 aBMD 明显较低（均 p < 0.01）。pQCT 小梁 vBMD（p < 0.01）、皮质 vBMD（p < 0.001）和皮质厚度（由于更大的内骨周长，p < 0.02）以及 MRI 评估的小梁数量、小梁厚度和整体骨刚度较低（均 p < 0.01）在 ESRD 中，与对照组相比。ALMI 与全髋、股骨颈、远段桡骨和 1/3 半径 aBMD 以及胫骨皮质厚度呈正相关（R = 0.46 至 0.64）。在这些部位，通过调整 ALMI，骨骼缺陷明显减弱：例如，与对照组相比，ESRD 患者的股骨颈平均 aBMD 低 0.79 个标准差，而通过调整 ALMI，该值降低至 0.33。在透析患者的多元模型中，pQCT 小梁 vBMD 和皮质面积 Z 分数显著且独立（均 p < 0.02）与 DXA 股骨颈、全髋和远段桡骨 aBMD Z 分数相关。皮质 vBMD（p = 0.01）和皮质面积（p < 0.001）Z 分数与 1/3 半径面积 aBMD Z 分数显著且独立相关（R = 0.62）。这些数据表明，DXA 的 aBMD 可捕捉到小梁和皮质 vBMD 和皮质面积的缺陷。与四肢骨骼肌的 ALMI 呈强相关，突出了在 ESRD 患者中考虑肌肉减少症对骨骼脆弱的作用的重要性。
