Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 40, 3015 GD, the Netherlands; Department of Maxillofacial Surgery, Special Dental Care and Orthodontics, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 40, 3015 GD, the Netherlands; The Generation R Study, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 40, 3015 GD, the Netherlands.
Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 40, 3015 GD, the Netherlands; The Generation R Study, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 40, 3015 GD, the Netherlands; Department of Epidemiology, Erasmus MC, University Medical Center Rotterdam, Dr Molewaterplein 40, 3015 GD, the Netherlands.
Bone. 2019 May;122:150-155. doi: 10.1016/j.bone.2019.02.018. Epub 2019 Feb 21.
Bone modeling is an important process in the growing skeleton. An inadequate bone modeling in response to mechanical loads would lead some children to develop weaker bones than others. The resulting higher stresses in the bones would render them more susceptible to fracture. We aimed to examine the association between femoral stress (FS) derived from structural parameters and BMD in relation to incident fractures in children. Bone stress was evaluated at the medial femoral neck, a skeletal site subject to large forces during normal locomotion. This study comprises 1840 children from the Generation R Study, with whole body and hip DXA scans at a mean age of 6.01 years. Hip structural analysis (HSA) was used to measure femur geometry for the FS calculation. Data on fractures occurring over the following 4 years after the DXA assessment were obtained by questionnaire. Incident fracture was observed in 7.6% of the participating children. Cox-multivariate regression analysis, described as hazard ratios (HR), showed that after adjustment for sex, ethnicity, age, weight and lean mass fraction, there was a significant increase in the risk of incident fracture for every standard deviation (SD) decrease in total body BMD (HR: 1.35, 95% CI 1.05-1.74, p-value = 0.021), femoral neck BMD (HR: 1.31, 95% CI 1.09-1.58, p-value = 0.005) and narrow neck BMD (HR: 1.39, 95% CI 1.14-1.68, p-value = 0.001). Whereas, every increment of one SD in femoral stress resulted in 1.33 increased risk of incident fractures (HR: 1.33, 95% CI 1.13-1.57, p-value = 0.001). This association remained (borderline) significant after the adjustment for DXA derived BMD measurements. Our results show that increased bone stress may underlie greater susceptibility to traumatic fractures in children (partially independent of BMD) and underscore the utility of hip DXA scans for the assessment of paediatric bone health and specifically fracture risk.
骨骼建模是生长中骨骼的一个重要过程。如果对机械负荷的骨骼建模不足，一些儿童的骨骼就会比其他人的骨骼更脆弱。骨骼中由此产生的更高的应力会使它们更容易骨折。我们的目的是检查从结构参数中得出的股骨应力（FS）与儿童骨折事件之间的关联，以及与骨密度（BMD）的关系。骨骼应力是在股骨颈内侧评估的，股骨颈是在正常运动中承受较大力的骨骼部位。本研究包括来自 Generation R 研究的 1840 名儿童，他们在平均年龄为 6.01 岁时接受了全身和髋关节 DXA 扫描。使用髋关节结构分析（HSA）来测量股骨几何形状以进行 FS 计算。通过问卷调查获得了 DXA 评估后接下来 4 年内发生的骨折数据。1840 名参与儿童中，有 7.6%发生了骨折事件。多变量 Cox 回归分析（描述为风险比[HR]）表明，在校正性别、种族、年龄、体重和瘦体重分数后，全身 BMD（HR：1.35，95%CI 1.05-1.74，p 值=0.021）、股骨颈 BMD（HR：1.31，95%CI 1.09-1.58，p 值=0.005）和窄颈 BMD（HR：1.39，95%CI 1.14-1.68，p 值=0.001）每标准偏差（SD）下降，骨折事件的风险都会显著增加。而股骨应力每增加一个 SD，骨折事件的风险就会增加 1.33 倍（HR：1.33，95%CI 1.13-1.57，p 值=0.001）。在调整 DXA 测量的 BMD 后，这种关联仍然具有（临界）显著性。我们的研究结果表明，骨骼应力的增加可能是儿童（部分独立于 BMD）更容易发生外伤性骨折的原因之一，并强调髋关节 DXA 扫描在评估儿童骨骼健康和特定骨折风险方面的实用性。
