Medical Research Council (MRC) Elsie Widdowson Laboratory, Cambridge, UK.
South African Medical Research Council (SAMRC)/Wits Developmental Pathways for Health Research Unit, Department of Paediatrics, School of Clinical Medicine, University of the Witwatersrand, Johannesburg, South Africa.
J Bone Miner Res. 2017 Dec;32(12):2355-2366. doi: 10.1002/jbmr.3279. Epub 2017 Oct 9.
There are no longitudinal pQCT data of bone growth and development from sub-Saharan Africa, where rapid environmental, societal, and economic transitions are occurring, and where fracture rates are predicted to rise. The aim of this study was to compare skeletal development in black and white South African adolescents using longitudinal data from the Birth to Twenty study. The Birth to Twenty Bone Health subcohort consisted of 543 adolescents (261 [178 black] girls, 282 [201 black] boys). Annual pQCT measurements of the radial and tibial metaphysis and diaphysis were obtained between ages 12 and 22 years (distal metaphysis: cross-sectional area [CSA] and trabecular bone mineral density [BMD]; diaphysis: total and cortical CSA, cortical BMD, and polar stress-strain index [SSIp]). Age at peak height velocity (APHV) was calculated to account for differences in maturational timing between ethnic groups and sexes. Mixed-effects models were used to describe trajectories for each pQCT outcome. Likelihood-ratio tests were used to summarize the overall difference in trajectories between black and white participants within each sex. APHV (mean ± SD years) was similar in black (11.8 ± 0.8) and white (12.2 ± 1.0) girls, but delayed in black (14.2 ± 1.0) relative to white boys (13.3 ± 0.8). By 4 years post-APHV, white adolescents had significantly greater cortical CSA and SSIp than black adolescents at the radius. There were no significant differences at the radial metaphysis but there was some divergence, such that black adolescents had greater radial trabecular BMD by the end of follow-up. At the tibia, white adolescents had lower diaphyseal CSA and SSIp, and greater metaphyseal CSA. There was no ethnic difference in tibial trabecular BMD. There are ethnic differences in bone growth and development, independent of maturation, in South African adolescents. This work gives new insights into the possible etiology of childhood fractures, which occur most commonly as peripheral sites. © 2017 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.
目前，在骨骼生长和发育方面，还没有来自撒哈拉以南非洲的纵向 pQCT 数据。该地区正在经历快速的环境、社会和经济转型，预计骨折率将会上升。本研究的目的是通过 Birth to Twenty 研究的纵向数据比较南非黑人和白人青少年的骨骼发育情况。Birth to Twenty 骨骼健康子队列包括 543 名青少年（261 名[178 名黑人]女孩，282 名[201 名黑人]男孩）。在 12 至 22 岁之间，每年对桡骨和胫骨干骺端和骨干进行 pQCT 测量（干骺端：横截面积[CSA]和小梁骨矿物质密度[BMD]；骨干：总 CSA 和皮质 CSA、皮质 BMD 和极骨应变-应变指数[SSIp]）。为了考虑不同种族和性别的成熟时间差异，计算了身高增长高峰期年龄（APHV）。使用混合效应模型描述每个 pQCT 结果的轨迹。对数似然比检验用于总结每个性别中黑人参与者和白人参与者之间轨迹的总体差异。黑人（11.8±0.8 岁）和白人（12.2±1.0 岁）女孩的 APHV（平均±标准差年）相似，但黑人男孩（14.2±1.0 岁）比白人男孩（13.3±0.8 岁）延迟。在 APHV 后 4 年，白人青少年的桡骨皮质 CSA 和 SSIp 明显大于黑人青少年。在桡骨干骺端没有显著差异，但存在一些差异，例如，在随访结束时，黑人青少年的桡骨小梁 BMD 更高。在胫骨中，白人青少年的骨干 CSA 和 SSIp 较低，干骺端 CSA 较大。胫骨小梁 BMD 没有种族差异。南非青少年的骨骼生长和发育存在种族差异，与成熟无关。这项工作为儿童骨折的可能病因提供了新的见解，儿童骨折最常发生在四肢部位。
