Bone mineral in prepubertal children: Gender and ethnicity

Previous reports of gender and ethnic differences in bone mineral in prepub ertal children have been inconsistent due to different methodologies, the p roblematic nature of bone density by dual-energy X-ray absorptiometry (DXA) calculated as the ratio of bone mineral mass to projected bone area (BA), and the generally small study populations. The aim of this study was to tes t the hypothesis that gender and ethnic differences in bone mineral by DXA are present in prepubertal children. The subjects were 336 healthy Asian, b lack, and white prepubertal children (172 females and 164 males), Total bod y bone mineral content (TBBMC) was adjusted for total body BA (TBBA), age, height, and weight. Adjusted mean TBBMC was greater in males than in female s (p = 0.01). The gender difference was independent of ethnicity. Adjusted mean TBBMC was different for black compared with nonblack children (p = 0.0 01). The ethnic difference was a function of TBBA and weight. This study in a multiethnic population of prepubertal children shows (1) a gender differ ence in TBBMC and (2) an ethnic difference in TBBMC.