Sex Differences in Body Composition in Prepubertal Korean Children by Dual-energy X-ray Absorptiometry

Lee, Hyun Jae; Lee, Kang Min; Kim, Dong Ho; Kim, Dong Hwan; Lee, Jun A; Park, Kyung Duk; Lim, Jung Sub

Abstract

PURPOSE: To find sexual dimorphism of total body composition (BC) and to establish regression equations for each BC by anthropometric data in prepubertal children.
METHODS
Cross-sectional study of 118 healthy children (58 boys, 60 girls, age; 5.1-9.9y) was done. We examined total BC (bone mineral contents, BMC; lean tissue mass, LTM; and fat mass, FM) and regional BC by dual-energy x-ray absorptiometry (DXA). We evaluated the differences in BC between both sexes by independent T-test and performed regression analysis for each BC using SPSS ver 15.0.
RESULTS
In total BC, boys had more LTM than girls (P<0.01), while girls had more FM (P=0.05). The percent body fat (PBF) of girls was higher than that of boys (15.0+/-5.4 vs. 11.6+/-5.2, P<0.01). In regional BC, boys had more LTM than girls except arms region. Girls had greater leg and gynoid FM than boys. As a result, girls showed more PBF in all regions. When we did multiple regression analysis including age and anthropometric values, height (Ht) and weight (Wt) were related to BMC and LTM. The regression equations were as follows. For boys: BMC (g)=12.2xHt (cm)+16.1xWt (kg)- 1,025, LTM (kg)= 0.21xHt+0.35xWt-14.3. For girls: BMC (g)=8.0xHt+21.1xWt-881, LTM (kg)=0.18xHt+0.31xWt-10.7.
CONCLUSION
We identified sex differences in total BC and regional fat distribution and made regression equations for each BC in prepubertal Korean children.