Yang Chao, Chen Jian, Wu Feng, Li Jinqiao, Liang Peilong, Zhang Hongyu, Wang Honghui, Li Yu, Wan Yumin, Qin Ling, Liang Kwok Sui, Dai Zhongquan, Li Yinghui
School of Life Science and Technology, Haerbin Institute of Technology, Haerbin, China; State key Lab of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, China.
Clin Endocrinol (Oxf). 2014 Nov;81(5):671-8. doi: 10.1111/cen.12535. Epub 2014 Jul 23.
Bone loss and subclinical diabeteslike are developed during long-term spaceflight. Recently, it was demonstrated that bone was able to regulate energy metabolism and testosterone synthesis via osteocalcin. The aim of this study was to determine whether serum osteocalcin level is associated with glycolipid metabolism or testosterone under the influence of microgravity with or without resistive vibration exercise (RVE).
A total of 14 healthy adult male volunteers (25-40 years) were randomly assigned to two groups (n = 7 each): control (CON) group and RVE group. Radioimmunoassay kits and ELISA kits were used for measurement of serum indices.
During 60-day bed rest, serum osteocalcin of both groups increased at day 4 during bed rest. Serum OPG started decreasing and reached its lowest value at day 30 during bed rest. In control group, serum insulin increased at day 4 during bed rest. IGF-I did not change significantly during the entire period of bed rest. The serum glucose decline 10% and 14% in CON and RVE groups at day 4 during bed rest. Relatively, the same results as glucose were found in serum HDL and LDL for both groups. Leptin rose and became highest at day 60 during bed rest in both groups. The level of serum testosterone was declined in control group at day 4 during bed rest. Cortisol kept stable in both group during bed rest. By spearman correlation analysis, serum osteocalcin was significantly associated with serum insulin (P < 0·05), LDL (P < 0·01) and Leptin (P < 0·01).
Our findings suggested that the mutual regulation may exist between skeletal and energy metabolism under simulated microgravity.
长期太空飞行会导致骨质流失和出现类似亚临床糖尿病的症状。最近有研究表明，骨骼能够通过骨钙素调节能量代谢和睾酮合成。本研究旨在确定在有无抗阻振动运动（RVE）影响的微重力环境下，血清骨钙素水平是否与糖脂代谢或睾酮有关。
14名健康成年男性志愿者（25 - 40岁）被随机分为两组（每组n = 7）：对照组（CON）和RVE组。使用放射免疫分析试剂盒和酶联免疫吸附测定试剂盒测量血清指标。
在60天卧床休息期间，两组的血清骨钙素在卧床第4天均升高。血清骨保护素在卧床第30天开始下降并达到最低值。在对照组中，血清胰岛素在卧床第4天升高。胰岛素样生长因子I在整个卧床休息期间无明显变化。卧床第4天，CON组和RVE组的血清葡萄糖分别下降了10%和14%。相对地，两组血清高密度脂蛋白和低密度脂蛋白的变化与葡萄糖相同。两组的瘦素在卧床第60天升高并达到最高值。对照组血清睾酮在卧床第4天下降。两组在卧床休息期间皮质醇保持稳定。通过斯皮尔曼相关性分析，血清骨钙素与血清胰岛素（P < 0·05）、低密度脂蛋白（P < 0·01）和瘦素（P < 0·01）显著相关。
我们的研究结果表明，在模拟微重力环境下，骨骼与能量代谢之间可能存在相互调节作用。
