GENUD Growth, Exercise, Nutrition and Development Research Group, University of Zaragoza, 50009 Zaragoza, Spain.
Osteoporos Int. 2012 Mar;23(3):937-47. doi: 10.1007/s00198-011-1649-3. Epub 2011 May 12.
While the association of lean mass (LM) with bone mass is well understood, the association of fat mass (FM) with bone mass is controversial. Our results support that adolescents with higher levels of adiposity have greater bone mass, but this association is fully explained by their higher levels of LM.
We aimed (1) to study the independent association of FM and LM with bone mass and (2) to study the differences in bone mass by weight status in adolescents, after controlling for relevant confounders, such as physical activity (PA), calcium intake, and LM.
Participants were 330 adolescents (167 boys, 12.5-17.5 years) from the HELENA study. The relationships of FM (DXA, n = 330; BodPod, n = 282) and LM (DXA, n = 330) with different bone variables (whole body, total hip, lumbar spine, and femoral neck) were analyzed by linear regression, and differences between weight status were analyzed by ANCOVA.
Fat mass (DXA) was positively associated with bone variables in both sexes, after adjustment for height, calcium intake, and sexual maturation. Additional adjustment by PA slightly increases the associations. However, adjustment for LM inverted these associations. Similar results were obtained using BodPod instead of DXA for assessing FM. Overweight/obese adolescents had higher BMC than their non-overweight peers in most of regions studied. Additional adjustment for PA slightly increased the differences between weight status groups, while adjusting for LM inverted the associations. LM was strong and positively associated with all bone variables in both sexes. Additional adjustment for PA or FM did not change the results.
Adolescents with higher levels of adiposity have greater bone mass, but this association is explained by their higher levels of LM.
虽然瘦体重（LM）与骨量的关系已经得到很好的理解，但脂肪量（FM）与骨量的关系仍存在争议。我们的研究结果支持脂肪含量较高的青少年骨量较大，但这种关联完全可以用他们更高的 LM 水平来解释。
我们旨在（1）研究 FM 和 LM 与骨量的独立关联，（2）在控制相关混杂因素（如体力活动（PA）、钙摄入量和 LM）后，研究青少年体重状况对骨量的差异。
参与者为 HELENA 研究中的 330 名青少年（男 167 名，12.5-17.5 岁）。采用线性回归分析 FM（DXA，n=330；BodPod，n=282）和 LM（DXA，n=330）与不同骨变量（全身、全髋、腰椎和股骨颈）的关系，并采用协方差分析（ANCOVA）分析体重状况的差异。
在调整身高、钙摄入量和性成熟后，男性和女性的 FM（DXA）与骨变量呈正相关。PA 的额外调整略微增加了这些关联。然而，LM 的调整则使这些关联发生逆转。使用 BodPod 代替 DXA 评估 FM 也得到了类似的结果。超重/肥胖青少年在研究的大多数部位的 BMC 均高于非超重同龄人。PA 的额外调整略微增加了体重状况组之间的差异，而 LM 的调整则使这些关联发生逆转。LM 与两性的所有骨变量均呈强正相关。PA 或 FM 的额外调整并未改变结果。
脂肪含量较高的青少年骨量较大，但这种关联可以用他们更高的 LM 水平来解释。
