Farr Joshua N, Amin Shreyasee, LeBrasseur Nathan K, Atkinson Elizabeth J, Achenbach Sara J, McCready Louise K, Joseph Melton L, Khosla Sundeep
Division of Endocrinology, Department of Medicine (J.N.F., L.K.M., S.K.); Division of Epidemiology, Department of Health Sciences Research (S.A., L.J.M.); Division of Rheumatology, Department of Medicine (S.A.); Department of Physical Medicine and Rehabilitation (N.K.L); and Division of Biomedical Statistics and Informatics, Department of Health Sciences Research (E.J.A., S.J.A.); Mayo Clinic College of Medicine, Rochester, Minnesota, 55905.
J Clin Endocrinol Metab. 2014 Dec;99(12):4641-8. doi: 10.1210/jc.2014-1113.
Numerous studies have examined the association of body composition with bone development in children and adolescents, but none have used micro-finite element (μFE) analysis of high-resolution peripheral quantitative computed tomography images to assess bone strength.
This study sought to examine the relations of appendicular lean mass (ALM) and total body fat mass (TBFM) to bone strength (failure load) at the distal radius and tibia.
DESIGN, PARTICIPANTS, AND SETTING: This was a cross-sectional study of 198 healthy 8- to <15-year-old boys (n = 109) and girls (n = 89) performed in a Clinical Research Unit.
After adjusting for bone age, height, fracture history, ALM, and TBFM, multiple linear regression analyses in boys and girls, separately, showed robust positive associations between ALM and failure loads at both the distal radius (boys: β = 0.92, P < .001; girls: β = 0.66, P = .001) and tibia (boys: β = 0.96, P < .001; girls: β = 0.66, P < .001). By contrast, in both boys and girls the relationship between TBFM and failure load at the distal radius was virtually nonexistent (boys: β = -0.07; P = .284; girls: β = -0.03; P = .729). At the distal tibia, positive, albeit weak, associations were observed between TBFM and failure load in both boys (β = 0.09, P = .075) and girls (β = 0.17, P = .033).
Our data highlight the importance of lean mass for optimizing bone strength during growth, and suggest that fat mass may have differential relations to bone strength at weight-bearing vs non-weight-bearing sites in children and adolescents. These observations suggest that the strength of the distal radius does not commensurately increase with excess gains in adiposity during growth, which may result in a mismatch between bone strength and the load experienced by the distal forearm during a fall. These findings may explain, in part, why obese children are over-represented among distal forearm fracture cases.
众多研究探讨了儿童和青少年身体成分与骨骼发育之间的关联，但尚无研究使用高分辨率外周定量计算机断层扫描图像的微有限元（μFE）分析来评估骨骼强度。
本研究旨在探讨上肢瘦体重（ALM）和全身脂肪量（TBFM）与桡骨远端和胫骨的骨骼强度（破坏载荷）之间的关系。
设计、参与者和地点：这是一项在临床研究单位对198名8至<15岁健康男孩（n = 109）和女孩（n = 89）进行的横断面研究。
在调整骨龄、身高、骨折史、ALM和TBFM后，分别对男孩和女孩进行的多元线性回归分析显示，ALM与桡骨远端（男孩：β = 0.92，P <.001；女孩：β = 0.66，P =.001）和胫骨（男孩：β = 0.96，P <.001；女孩：β = 0.66，P <.001）的破坏载荷之间存在显著正相关。相比之下，在男孩和女孩中，TBFM与桡骨远端破坏载荷之间几乎不存在关系（男孩：β = -0.07；P =.284；女孩：β = -0.03；P =.729）。在胫骨远端，男孩（β = 0.09，P =.075）和女孩（β = 0.17，P =.033）的TBFM与破坏载荷之间均观察到正相关，尽管较弱。
我们的数据突出了瘦体重在生长过程中优化骨骼强度的重要性，并表明脂肪量在儿童和青少年的负重与非负重部位可能与骨骼强度存在不同的关系。这些观察结果表明，生长过程中肥胖过度增加时，桡骨远端的强度不会相应增加，这可能导致骨骼强度与跌倒时前臂远端承受的负荷不匹配。这些发现可能部分解释了为什么肥胖儿童在前臂远端骨折病例中占比过高。
