Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
J Bone Miner Res. 2011 Sep;26(9):2235-44. doi: 10.1002/jbmr.427.
Chronic kidney disease (CKD) is associated with increased fracture risk and skeletal deformities. The impact of CKD on volumetric bone mineral density (vBMD) and cortical dimensions during growth is unknown. Tibia quantitative computed tomographic scans were obtained in 156 children with CKD [69 stages 2 to 3, 51 stages 4 to 5, and 36 stage 5D (dialysis)] and 831 healthy participants aged 5 to 21 years. Sex-, race-, and age- or tibia length-specific Z-scores were generated for trabecular BMD (TrabBMD), cortical BMD (CortBMD), cortical area (CortArea) and endosteal circumference (EndoC). Greater CKD severity was associated with a higher TrabBMD Z-score in younger participants (p < .001) compared with healthy children; this association was attenuated in older participants (interaction p < .001). Mean CortArea Z-score was lower (p < .01) in CKD 4-5 [-0.49, 95% confidence interval (CI) -0.80, -0.18)] and CKD 5D (-0.49, 95% CI -0.83, -0.15) compared with healthy children. Among CKD participants, parathyroid hormone (PTH) levels were positively associated with TrabBMD Z-score (p < .01), and this association was significantly attenuated in older participants (interaction p < .05). Higher levels of PTH and biomarkers of bone formation (bone-specific alkaline phosphatase) and resorption (serum C-terminal telopeptide of type 1 collagen) were associated with lower CortBMD and CortArea Z-scores and greater EndoC Z-score (r = 0.18-0.36, all p ≤ .02). CortBMD Z-score was significantly lower in CKD participants with PTH levels above versus below the upper limit of the Kidney Disease Outcome Quality Initiative (KDOQI) CKD stage-specific target range: -0.46 ± 1.29 versus 0.12 ± 1.14 (p < .01). In summary, childhood CKD and secondary hyperparathyroidism were associated with significant reductions in cortical area and CortBMD and greater TrabBMD in younger children. Future studies are needed to establish the fracture implications of these alterations and to determine if cortical and trabecular abnormalities are reversible.
慢性肾脏病（CKD）与骨折风险增加和骨骼畸形有关。CKD 对生长过程中体积骨矿物质密度（vBMD）和皮质维度的影响尚不清楚。对 156 名患有 CKD [69 期 2-3 期，51 期 4-5 期和 36 期 5D（透析）]和 831 名健康参与者的儿童进行了胫骨定量计算机断层扫描，年龄为 5 至 21 岁。生成了针对骨小梁骨密度（TrabBMD），皮质骨密度（CortBMD），皮质面积（CortArea）和内骨周径（EndoC）的性别，种族和年龄或胫骨长度特异性 Z 分数。与健康儿童相比，年轻参与者的 CKD 严重程度越高，TrabBMD Z 分数越高（p <.001）；这种关联在年龄较大的参与者中减弱（交互作用 p <.001）。与健康儿童相比，CKD 4-5 [-.49，95％置信区间（CI）-.80，-0.18]和 CKD 5D（-.49，95％CI-.83，-0.15）的平均 CortArea Z 分数较低。在 CKD 参与者中，甲状旁腺激素（PTH）水平与 TrabBMD Z 分数呈正相关（p <.01），而在年龄较大的参与者中，这种关联明显减弱（交互作用 p <.05）。较高的 PTH 和骨形成生物标志物（骨碱性磷酸酶）和骨吸收生物标志物（血清 1 型胶原 C 末端肽）与 CortBMD 和 CortArea Z 分数降低以及内骨周径 Z 分数升高有关（r = 0.18-0.36，所有 p ≤.02）。与甲状旁腺激素水平处于肾脏病结局质量倡议（KDOQI）CKD 特定阶段目标范围上限以下的参与者相比，CKD 参与者的 CortBMD Z 分数显着降低：-0.46 ± 1.29 比 0.12 ± 1.14（p <.01）。总之，儿童期 CKD 和继发性甲状旁腺功能亢进症与儿童早期皮质面积和 CortBMD 显着降低以及 TrabBMD 增加有关。需要进一步研究以确定这些改变的骨折意义，并确定皮质和小梁异常是否可逆。
