Department of Public Health, Kindai University Faculty of Medicine, 377-2 Oono-Higashi, Osaka-Sayama 589-8511, Japan.
Department of Health Promotion and Education, Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada, Kobe 657-8501, Japan.
Bone. 2018 Feb;107:222-227. doi: 10.1016/j.bone.2017.12.003. Epub 2017 Dec 5.
The independent impact of fat mass (FM) on bone health is difficult to assess, as FM is correlated with lean soft tissue mass (LSTM). In a previous cross-sectional study, FM was suggested to help promote high bone mass acquisition in adolescents with small LSTM. The present prospective cohort study investigated the effects of FM on bone in pubertal children after stratification by height-normalized index of LSTM (LSTMI). The source population was all 5th grade children enrolled in either one of the two public elementary schools in Hamamatsu, Japan. Of these, 545 children who participated in both baseline (at age 11) and follow-up (at age 14) surveys were included in the present analysis. Body composition and whole body areal bone mineral density (aBMD) were measured using dual-energy X-ray absorptiometry. From baseline to follow-up, significant (P<0.05) differences were observed in changes in aBMD among tertiles of change in FM in both sexes after adjusting for confounding factors including LSTMI. After stratification by tertiles of sex-specific LSTMI, adjusted means of changes in aBMD according to tertiles of change in FM within the lowest and second lowest tertiles of LSTMI in both sexes showed a significant increase from the lower tertiles to the highest tertile of change in FM. In the highest tertile of LSTMI, changes in FM showed no significant association with changes in aBMD. These findings suggest that adipose tissue might help promote high bone mass acquisition in pubertal children with small or normal LSTMI.
脂肪量（FM）对骨骼健康的独立影响难以评估，因为 FM 与瘦体软组织量（LSTM）相关。在之前的一项横断面研究中，FM 被认为有助于促进 LSTM 较小的青少年获得较高的骨量。本前瞻性队列研究通过身高归一化 LSTM 指数（LSTMI）分层，调查了 FM 对青春期儿童骨骼的影响。该研究的源人群为日本滨松市两所公立小学的所有五年级学生。其中，有 545 名儿童参加了基线（11 岁）和随访（14 岁）调查，他们被纳入了本分析。使用双能 X 射线吸收法测量身体成分和全身面积骨矿物质密度（aBMD）。在调整了包括 LSTMI 在内的混杂因素后，从基线到随访，在两性中，根据 FM 变化的三分位，观察到 aBMD 变化的差异具有统计学意义（P<0.05）。在按照两性特异性 LSTMI 的三分位分层后，在两性的 LSTMI 最低和第二低三分位中，根据 FM 变化的三分位，aBMD 变化的调整均值显示从 FM 变化的较低三分位到最高三分位呈显著增加趋势。在 LSTMI 的最高三分位中，FM 的变化与 aBMD 的变化没有显著关联。这些发现表明，脂肪组织可能有助于促进 LSTM 较小或正常的青春期儿童获得较高的骨量。
