title: Bone Structure and Geometric Properties at the Radius and Tibia in Adolescent Endurance-Trained Cyclists.
abstract: OBJECTIVE
  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).
  
  
  METHODS
  Descriptive cohort study.
  
  
  METHODS
  Twenty-five male adolescent CYC and 17 CON.
  
  
  METHODS
  Peripheral quantitative computed tomography was used to evaluate proximal and distal sites of the radius and tibia.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: *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.
authors.forename: Alex
authors.initials: A
authors.lastname: González-Agüero
authors.forename: Hugo
authors.initials: H
authors.lastname: Olmedillas
authors.forename: Alba
authors.initials: A
authors.lastname: Gómez-Cabello
authors.forename: José A
authors.initials: JA
authors.lastname: Casajús
authors.forename: Germán
authors.initials: G
authors.lastname: Vicente-Rodríguez
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001642:Bicycling / Q000502:physiology*; D001835:Body Weight; D015519:Bone Density; D016022:Case-Control Studies; D018483:Diaphyses / Q000502:physiology; D006801:Humans; D008297:Male; D011884:Radius / Q000502:physiology*; D013977:Tibia / Q000502:physiology*