Department of Neurology, The Medical College of Wisconsin, Milwaukee, WI 53226-0509, USA.
Exp Biol Med (Maywood). 2012 Sep;237(9):1101-9. doi: 10.1258/ebm.2012.012043. Epub 2012 Sep 3.
Insufficient sleep over long durations of the lifespan is believed to adversely affect proper development and healthful aging, although how this might become manifested is unknown. In the present study, rats were repeatedly sleep-restricted during 72 days to permit maladaptations to evolve, thereby permitting study. Densitometric and histomorphometric analyses were performed on harvested bone. In sleep-restricted rats, bone lined by osteoid was reduced 45-fold and osteoid thickness was decreased, compared with controls. This corresponded to a decrease in osteoblast number and activity. The percentage of bone lined by osteoclasts did not differ from that of controls. Plasma concentrations of an osteoclast marker (TRACP 5b) were increased in sleep-restricted rats, indicating increased bone resorption. The low amount of new bone formation without a reduction in bone resorption is diagnostic of osteopenia. Bone mineral density was decreased in femurs from sleep-restricted rats compared with controls, indicating osteoporosis. Red marrow in sleep-restricted rats contained only 37% of the fat and more than twice the number of megakaryocytes compared with that of the control rats. These findings in marrow suggest changed plasticity and increased hematopoiesis. Plasma concentrations of insulin-like growth factor-1, a known, major mediator of osteoblast differentiation and the proliferation of progenitor cells, was decreased by 30% in sleep-restricted rats. Taken together, these findings suggest that chronically inadequate sleep affects bone metabolism and bone marrow composition in ways that have implications for development, aging, bone healing and repair, and blood cell differentiation.
长期睡眠不足被认为会对正常发育和健康衰老产生不利影响，尽管其具体表现形式尚不清楚。在本研究中，通过反复限制睡眠来使大鼠在 72 天内睡眠受限，从而使适应不良得以发展，进而进行研究。对采集的骨进行密度计量和组织形态计量学分析。与对照组相比，睡眠受限大鼠的矿化骨表面被覆的类骨质减少了 45 倍，类骨质厚度也降低了。这对应于成骨细胞数量和活性的减少。被破骨细胞包绕的骨的百分比与对照组没有差异。睡眠受限大鼠的血浆中破骨细胞标志物（TRACP 5b）浓度升高，表明骨吸收增加。没有减少骨吸收而新骨形成量低是骨质疏松的诊断标准。与对照组相比，睡眠受限大鼠的股骨骨矿物质密度降低，表明发生了骨质疏松症。与对照组相比，睡眠受限大鼠的红骨髓中仅含有 37%的脂肪，巨核细胞的数量则增加了一倍以上。骨髓中的这些发现表明可塑性发生了改变，并且造血增加。胰岛素样生长因子-1（IGF-1）的血浆浓度在睡眠受限大鼠中降低了 30%，IGF-1 是已知的成骨细胞分化和祖细胞增殖的主要介质。综上所述，这些发现表明长期睡眠不足会以影响发育、衰老、骨愈合和修复以及血细胞分化的方式影响骨代谢和骨髓组成。
