Analysis Of Bone Mineral Density And Body Composition In Healthy Children And Adolescents

ObjectiveBased on the precision of the measurement of bone mineral density (BMD) and body composition using dual-energy X-ray absorptiometry (DXA),We measured the children and adolescents 5-19 years of age to establish the BMD normal reference values and the assessment tools and propsed the database that included normal growth and development of children and adolescents in the south of China. Our aim was to investigate the BMD regulation and provide an important basis for assessing the status of their growth and development.MethodsWe used a Lunar Prodigy DXA densitometer to measure total body bone mineral density and body composition for 1541 healthy Chinese children and adolescents (776 boys,765 girls) aged 5-19 yr to obtain the results of BMD and body composition including lean mass(LM),fat mass(FM) and bone mineral content(BMC). SPSS 13.0 and 1msChartMaker program were used to analyse the data and make the charts and to offer the BMD normal reference values and the assessment tools.ResultsIn both genders, BMD, bone mineral content(BMC) and bone area(BA) increased with age at both the total body and the subcranial skeleton. After evaluations of different models, the exponential model was found best fit for the association between age and bone measurements(BMD, BMC, and BA) and subcranial skeleton measurements(subcranial skeleton BMD, subcranial skeketon BMC, and subcranial skeleton BA). Fat mass and lean mass increased with age in both genders, the exponential model was found best fit for the association between age and fat mass and lean mass. Stepwise linear regression identified lean mass as the strongest predictor of total body BMC and subcranial skeleton BMC while the fat mass contributed little. We poposed the assessment tools about the total body BMD and body composition:Height-Age, BA-Height, BMC-BA, LM-Height, BMC-LM. ConclusionThe study had built up the BMD normal reference values, the body composition database and the assessment tools that were applied to evaluate the status of bone growth and development regarding to children and adolescents in the south of China.