González-Agüero Alex, Olmedillas Hugo, Gómez-Cabello Alba, Casajús José A, Vicente-Rodríguez Germán
*GENUD (Growth, Exercise, NUtrition and Development) Research Group, University of Zaragoza, Spain; †Faculty of Health and Sport Sciences (FCSD), Department of Physiatry and Nursing, University of Zaragoza, Huesca, Spain; ‡Centro Universitario de la Defensa, Zaragoza, Spain; and §Department of Functional Biology, Universidad de Oviedo, Asturias, Spain.
Clin J Sport Med. 2017 Jan;27(1):69-77. doi: 10.1097/JSM.0000000000000299.
To describe cortical and trabecular volumetric bone mineral density (vBMD), bone mineral content (BMC), cross-sectional area (CSA), and bone strength indexes (BSIs) in adolescent endurance-trained cyclists (CYC) and compare them with controls (CON).
Descriptive cohort study.
Twenty-five male adolescent CYC and 17 CON.
Peripheral quantitative computed tomography was used to evaluate proximal and distal sites of the radius and tibia.
Total, trabecular, and cortical BMC, vBMD, and CSA were measured. Also, cortical thickness, endosteal and periosteal circumferences, and different BSIs were calculated. Unadjusted analysis of variance and body weight-adjusted analysis of covariance tests were applied between cyclist and control groups.
Cyclists were almost 12% lighter than CON (P < 0.05). Unadjusted data showed lower distal total vBMD and proximal cortical BMC and vBMD in cyclists compared with CON at the radius (P < 0.05) and lower distal total and trabecular BMC, vBMD and bone area, proximal total and cortical BMC and vBMD, and cortical bone area at the tibia (P < 0.05). Body weight-adjusted data showed the same differences for distal total vBMD at the radius and total and trabecular BMC and vBMD at the tibia, diaphyseal radius cortical vBMD and tibia total vBMD, cortical BMC and area, and also for tibia cortical thickness and BSI. The rest of differences were no longer detectable and bone area at the distal radius become significantly higher in cyclist compared with CON (P < 0.05).
Adolescent CYC in this study showed lower values of BMC and vBMD at determined sites of the radius and tibia than CON, some of these differences were explained in part by their lower body weight. However, even further adjustment, some differences remained, which indicates that further longitudinal studies are needed to better understand if cycling influences these differences.
描述青少年耐力训练自行车运动员（CYC）的皮质骨和小梁骨体积骨密度（vBMD）、骨矿物质含量（BMC）、横截面积（CSA）和骨强度指数（BSIs），并与对照组（CON）进行比较。
描述性队列研究。
25名男性青少年CYC和17名CON。
采用外周定量计算机断层扫描评估桡骨和胫骨的近端和远端部位。
测量总骨、小梁骨和皮质骨的BMC、vBMD和CSA。此外，计算皮质厚度、骨内膜和骨膜周长以及不同的BSIs。在自行车运动员组和对照组之间进行未调整的方差分析和体重调整的协方差分析测试。
自行车运动员的体重比CON轻近12%（P<0.05）。未调整的数据显示，与CON相比，自行车运动员在桡骨处的远端总vBMD、近端皮质骨BMC和vBMD较低（P<0.05），在胫骨处的远端总骨和小梁骨BMC、vBMD和骨面积、近端总骨和皮质骨BMC和vBMD以及皮质骨面积较低（P<0.05）。体重调整后的数据显示，桡骨远端总vBMD、胫骨总骨和小梁骨BMC和vBMD、骨干桡骨皮质vBMD和胫骨总vBMD、皮质骨BMC和面积以及胫骨皮质厚度和BSI存在相同差异。其余差异不再明显，与CON相比，自行车运动员桡骨远端的骨面积显著更高（P<0.05）。
本研究中的青少年CYC在桡骨和胫骨的特定部位显示出比CON更低的BMC和vBMD值，其中一些差异部分是由于他们较低的体重。然而，即使进行了进一步调整，仍存在一些差异，这表明需要进一步的纵向研究，以更好地了解骑行是否会影响这些差异。
