title: Influence of high impact loading on ultrasound bone measurements in children: a cross-sectional report.
abstract: Evidence suggests that weight-bearing exercise during the growing years may enhance peak bone mass. The purpose of this study was to compare ultrasound bone measurements, serum alkaline phosphatase (S-ALP), serum osteocalcin (S-OC), and dietary calcium in highly active and normal healthy male children. Subjects were 33 elite and subelite male gymnasts and 40 normoactive controls matched for age (9.4 +/- 1.1 years), height (133.9 +/- 5.9 cm), and weight (30.1 +/- 3.8 kg). Measurements of broadband ultrasound attenuation (dB/MHz) through the calcaneus (CBUA) and ultrasound velocity (m/s) through the calcaneus (CVOS), distal radius (RVOS), and proximal phalanx of the index finger (PVOS) were performed using a Contact Ultrasonic Bone Analyzer (CUBA Research). Gymnasts had significantly greater CVOS (P < 0.001), RVOS (P < 0.0001), and PVOS (P < 0.05). There were no differences in CBUA, S-ALP, or S-OC between groups. RVOS correlated significantly with dietary calcium intake in all subjects (P < 0.05) and training time in the gymnasts (P < 0.05). Though gymnasts had significantly greater calcium intakes than controls (P < 0.05), whose mean value was below the RDA, after controlling for calcium intake in the gymnasts alone, RVOS was still significantly correlated with training time (P < 0.05). These preliminary results suggest that the heavy musculoskeletal loading inherent in gymnastics training produces positive adaptive responses in the growing skeleton. Furthermore, ultrasound appears to provide a safe, noninvasive means of comparing the skeletal status of exercising and normal healthy children, whereas single samples of biochemical markers did not discriminate between the groups.
authors.affiliation: Department of Anatomy and Physiology, Royal Melbourne Institute of Technology, P.O. Box 71, Plenty Rd., Bundoora, Melbourne, Australia 3083.
authors.forename: R M
authors.initials: RM
authors.lastname: Daly
authors.forename: P A
authors.initials: PA
authors.lastname: Rich
authors.forename: R
authors.initials: R
authors.lastname: Klein
mesh_terms: D015519:Bone Density; D001842:Bone and Bones / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D002111:Calcaneus; D002136:Calcium, Dietary; D002648:Child; D003430:Cross-Sectional Studies; D006173:Gymnastics; D006801:Humans; D008297:Male; D011884:Radius; D012016:Reference Values; D014463:Ultrasonography
chemical_list: D002136:Calcium, Dietary