REGIONAL AND TOTAL-BODY BONE-MINERAL CONTENT, BONE-MINERAL DENSITY, AND TOTAL-BODY TISSUE COMPOSITION IN CHILDREN 8-16 YEARS OF AGE

Normative values for total body hone mineral content (TBBM) and total body bone mineral density (TBMD) were derived from measurements on 234 children 8-16 years of age. In addition, bone mineral content (BMC) a nd bone mineral density (BMD) values for selected regions of interest and soft tissue (bone free lean and fat) for the total body are presen ted. Bone mineral and soft tissue values were determined by dual energ y X-ray absorptiometry (DXA) using a Hologic QDR-2000 in the array mod e. Results of a stepwise multiple regression analysis revealed a signi ficant correlation between bone-free lean tissue (BFLT) and BMD (r2 = 0.80) in girls. Adding age to the equation accounted for an additional 2% of the variance (P < 0.05) and height accounted for another 1% of the variance (P < 0.05). Body weight and fat tissue (FT) did not accou nt for any additional variance. In boys BFLT correlated significantly with BMD (r2 = 0.75; P < 0.05); none of the other predictor variables accounted for additional variance. No significant differences were fou nd in TBBM or TBMD between boys and girls at any age. There was a sign ificant overall gender effect for only three regions of interest. Boys had greater BMC in the head region and had greater BMD in the upper l imbs, but post hoc analysis revealed no significant differences for an y specific age groups. Girls had greater overall BMD in the pelvis, bu t this difference was only significant at the 15-16-year age group. Th e changes in BFLT and FT over the age ranges were consistent with the growth literature. The normative values can be applied to the assessme nt of children and adolescents with health problems that may impact on the skeleton as well as to research studies investigating one mineral development in children.