Post-puberty, bone mass displays clear sex-specific patterns. However, research has suggested that a sexual dimorphism in bone mass is evident in younger children and is likely attributable to differences in lean mass. Thus, we aimed to determine whether the association with both overall muscle mass and/or muscle strength was different between the sexes in a paediatric population. Participants were recruited as part of the Vitamin D in Pregnancy Study, Australia. There were 209/402 (52.3%) children at the 11-year follow-up, and 172 had complete data. Children were assessed for bone mineral content (BMC), bone mineral density (BMD) and lean mass by DXA (Lunar). Handgrip strength (kg) was measured using a dynamometer (JAMAR). Linear regression models were adjusted for height, weight, age and pubertal stage. In adjusted models, including both muscle strength and lean mass, the observed association differed between boys and girls. At the spine in boys, BMC and BMD were associated with muscle strength (β 0.34 [95%CI 0.09-0.59] and 0.008 [95%CI 0.003-0.014]; respectively) but not total muscle mass. However, muscle mass was associated with BMC and BMD at the total body (less head). In girls, spine BMC and BMD were associated with total lean mass (β 0.95 [95%CI 0.61-1.3] and β 0.01 [95%CI 0.005-0.02], respectively), with a similar pattern of association with total body (less head) measures. Muscle mass and strength appear to have sexually dimorphic effects on bone mass in school-aged children. These findings should be replicated in longitudinal studies.

中文翻译：

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小儿人群的肌肉质量和力量之间的关联与骨骼测量的关系：特定性别的影响。

青春期后，骨量显示明确的性别特定模式。但是，研究表明，在幼儿中，骨量性二态性很明显，并且可能归因于瘦体重的差异。因此，我们旨在确定小儿人群中性别与总体肌肉质量和/或肌肉力量的相关性是否不同。在澳大利亚的妊娠研究中，参与者是维生素D的一部分。在11年的随访中，有209/402（52.3％）个儿童，其中172个有完整的数据。通过DXA（月球）对儿童的骨矿物质含量（BMC），骨矿物质密度（BMD）和瘦体重进行了评估。使用测力计（JAMAR）测量握力（kg）。调整了线性回归模型的身高，体重，年龄和青春期。在调整后的模型中 包括肌肉力量和瘦体重，所观察到的关联在男孩和女孩之间是不同的。在男孩的脊柱处，BMC和BMD与肌肉力量有关（分别为β0.34 [95％CI 0.09-0.59]和0.008 [95％CI 0.003-0.014]），但与总肌肉质量无关。但是，肌肉质量与全身（头较小）的BMC和BMD有关。在女孩中，脊柱BMC和BMD与总瘦体重相关（分别为β0.95 [95％CI 0.61-1.3]和β0.01 [95％CI 0.005-0.02]），与全身的相似模式（较少）头）措施。肌肉质量和力量似乎对学龄儿童的骨质具有性二态性影响。这些发现应在纵向研究中重复使用。BMC和BMD与肌肉力量有关（分别为β0.34 [95％CI 0.09-0.59]和0.008 [95％CI 0.003-0.014]），但与总肌肉质量无关。但是，肌肉质量与全身（头较小）的BMC和BMD有关。在女孩中，脊柱BMC和BMD与总瘦体重相关（分别为β0.95 [95％CI 0.61-1.3]和β0.01 [95％CI 0.005-0.02]），与全身的相似模式（较少）头）措施。肌肉质量和力量似乎对学龄儿童的骨质具有性二态性影响。这些发现应在纵向研究中重复使用。BMC和BMD与肌肉力量有关（分别为β0.34 [95％CI 0.09-0.59]和0.008 [95％CI 0.003-0.014]），但与总肌肉质量无关。但是，肌肉质量与全身（头较小）的BMC和BMD有关。在女孩中，脊柱BMC和BMD与总瘦体重相关（分别为β0.95 [95％CI 0.61-1.3]和β0.01 [95％CI 0.005-0.02]），与全身的相似模式（较少）头）措施。肌肉质量和力量似乎对学龄儿童的骨质具有性二态性影响。这些发现应在纵向研究中重复使用。脊柱BMC和BMD与总瘦体重相关（分别为β0.95 [95％CI 0.61-1.3]和β0.01 [95％CI 0.005-0.02]），与全身测量（少头）的相关模式相似。肌肉质量和力量似乎对学龄儿童的骨质具有性二态性影响。这些发现应在纵向研究中重复使用。脊柱BMC和BMD与总瘦体重相关（分别为β0.95 [95％CI 0.61-1.3]和β0.01 [95％CI 0.005-0.02]），与全身测量（少头）的相关模式相似。肌肉质量和力量似乎对学龄儿童的骨质具有性二态性影响。这些发现应在纵向研究中重复使用。