The Effects Of Physique Characteristics On Bone Mineral Density Of Forearm For Children From 6 To 8 Years Old:A Longitudinal Study

Objectives:To explore the developing characteristics of childhood bone mineral density of focile and its associations with phsique characteristics.Methods:A study population of 289 grade one students(aged 6,146 males and 143 females)from Huilongguan primary school affiliated to Capital Normal University,China were followed up for 3 years,without missing value.Data of height,weight,body fat composition,forearm bone mineral density and bone age were collected.Results: 1.Forearm bone mineral density(g/cm2)for the male and female were 0.238±0.063 and 0.225±0.061 for children aged 6,0.224±0.045 and 0.199±0.031 for 7 years old children,while 0.220±0.039 and 0.199±0.040 when children were 8 years old.Statistical significant differences were found between male and female for 7 and 8 years old children(p<0.05).Interestingly,this data showed a decreasing trend of the bone mineral density for the followed-up male and female children(p<0.05),especially for the female.2.Children of early,normal and delayed development account for 28.4%,63.0% and 8.6%,respectively.There was no statistical significance for the differences of bone mineral density among different development types,controlling for the covariates of weight and body mass index.3.Weak partial correlations were found between weight(r=0.200?r=0.124?r=0.176),BMI(r=0.223?r=0.134?r=0.183)and bone mineral density for 6 to 8 years old.As for the relationships between body fat ratio?FFM ratio and bone mineral density,there are no partial correlations(p>0.05).4.There was weak partial correlation between height growth and the reduction of bone mineral density(r=-0.138),but not for the associations between weight,body mass index,body fat ratio and bone mineral density.Height was significantly different between children with the highest 25% and the lowest 25% bone mineral density.5.After multiple stepwise linear regression model.At the age of 7,the adjustment of R2 is the highest.The gender and body mass index entered the model.6.The proportion of children with overweight or obese problem was larger than 30%.In the longitudinal study,the rate of obese for the male increased from 21.9% to 27.4%,while the female decreased from 20.3% to 18.2%.Conclusion:In this study,Decreasing trend was found for the bone mineral density,with the female having a more significant reduction than the male.Weight and BMI are the effects of BMD.The growth of height was weakly correlated with bone mineral density reduction.