MRC Mineral Metabolism Research Unit, Department of Paediatrics, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa.
Bone. 2011 Apr 1;48(4):777-85. doi: 10.1016/j.bone.2010.12.032. Epub 2011 Jan 1.
We have previously shown ethnic differences in bone mass between pre-pubertal black and white children using DXA. To investigate these ethnic differences further, using pQCT, and to determine the influence of sex and pubertal development, we measured appendicular bone variables in 13-year-old children using pQCT. We collected pQCT data on a cohort of 471 black and white children at age 13years. Black boys and girls were shorter and had less lean mass than their white peers, and black boys were lighter than white boys at an earlier stage of pubertal development. Metaphyseal (4%) radial trabecular density was greater in the black girls than their white peers (239.5±49.5 vs. 222.7±34.2 mg/cm(3); p<0.05). Bone strength index was not different between the ethnic groups. All metaphyseal measures were 3-41% greater in boys than girls, after adjusting for height where appropriate. Diaphyseal (38%) tibial values, including total area, endosteal diameter, tibial diameter, periosteal circumference and polar strength-strain index were 4-22% greater in the black than white children and in boys than in girls. Cortical density was greater in black than white boys (1079.0±39.4 vs. 1058.7±34.5 mg/mm(3); p<0.001) and greater in the girls than boys (black: 1129.3±33.7 vs. 1079.0±39.4 mg/mm(3); p<0.001; white: 1126.8±28.3 vs. 1058.7±34.5mg/mm(3); p<0.001). Cortical thickness was less in the black groups. Lower leg muscle cross-sectional area (MCSA) was higher in white than black children, and forearm MCSA was higher in white than black boys. There was no difference in fat cross-sectional area between the ethnic groups. In conclusion, ethnic and sex differences in both metaphyseal and diaphyseal bone parameters exist during puberty, which are not accounted for by differences in body size or skeletal maturity. South African black children have wider diaphyseal regions of appendicular bones with greater measures of bone strength.
我们之前使用 DXA 研究显示了青春期前黑人和白人儿童的骨量存在种族差异。为了进一步研究这些种族差异，我们使用 pQCT 来确定性别的影响和青春期发育的影响，在 13 岁儿童的四肢骨骼变量进行 pQCT 测量。我们在 13 岁时收集了 471 名黑人和白人儿童的 pQCT 数据。黑人男孩和女孩比他们的白人同龄人更矮，瘦体重更少，而且在青春期发育的早期阶段，黑人男孩比白人男孩更轻。骺端（4%）桡骨小梁密度在黑人女孩中比白人同龄人更高（239.5±49.5 对 222.7±34.2mg/cm3；p<0.05）。骨强度指数在不同种族之间没有差异。在适当调整身高后，所有骺端测量值在男孩中比女孩高 3-41%。与白人儿童相比，黑人儿童的骨干（38%）胫骨值，包括总面积、内骨直径、胫骨直径、骨膜周长和极强度应变指数，都更高，男孩比女孩更高。与白人男孩相比，黑人男孩的皮质骨密度更高（1079.0±39.4 对 1058.7±34.5mg/mm3；p<0.001），女孩比男孩更高（黑人：1129.3±33.7 对 1079.0±39.4mg/mm3；p<0.001；白人：1126.8±28.3 对 1058.7±34.5mg/mm3；p<0.001）。黑人组的皮质骨厚度较小。白人儿童的小腿肌肉横截面积（CSA）高于黑人儿童，白人男孩的前臂 CSA 高于黑人男孩。不同种族之间的脂肪横截面积没有差异。总之，在青春期，四肢骨骼的骺端和骨干参数存在种族和性别差异，这些差异不能用身体大小或骨骼成熟度来解释。南非黑人儿童的四肢骨骼骨干区域更宽，骨骼强度更高。
