骨代谢过程中脂联素的相关作用

Effects of adiponectin during bone metabolism

目的:脂联素是由脂肪组织分泌的脂源性激素,影响机体许多生理系统和代谢通路,并与许多疾病关系密切。回顾与分析脂联素与骨代谢的关系。资料来源:应用计算机检索Medline数据1995-01/2006-07期间的相关文章,检索词分别为“adiponectin,bone”和“adiponectin,bone mineral density”,限定文章语言种类为English。资料选择:对资料进行初审,选取包括脂联素的基础或者临床研究文献,然后筛出明显不相关的文献,对余下的文献开始查找全文,进一步判断是否符合纳入标准,纳入标准:①基础研究。②与人类疾病具有相关性临床研究。资料提炼:共检索到163篇与脂联素相关的文章,根据实验研究的质量及与人类疾病的相关性引用78篇文章。包含有关脂联素概述的文章12篇,脂联素与骨代谢的研究33篇,对其中密切相关、有代表性的31篇进行综述。资料综合:①脂联素是由脂肪组织分泌的脂源性激素,具有改善胰岛素抵抗、抗动脉粥样硬化、降血糖、血脂等作用。②体外研究和动物实验表明脂联素通过抑制破骨细胞的骨吸收活性,增加成骨细胞的活性和骨基质的矿化,增加骨量。脂联素可以从3个不同的途径影响骨代谢:骨骼局部产生的脂联素以自分泌或旁分泌的途径促进骨形成,而循环中的脂联素则以内分泌的抑制骨形成,另外脂联素通过影响胰岛素信号通路间接促进骨的形成,对骨代谢的作用是上述三者综合作用的结果。③临床研究方面,一些学者认为脂联素与骨密度呈负相关,而另一些研究者却末能找到脂联素与骨密度相关的证据。结论:脂联素作为脂肪组织特异性的分泌因子,具有改善胰岛素抵抗、抗动脉粥样硬化、降血糖、血脂等作用。目前认为脂联素通过内分泌和旁分泌3个不同的途径影响成骨细胞及破骨细胞的活性,参与骨代谢。脂联素在骨组织中生理作用有待于进一步的基础研究和临床试验以证实。总之,脂联素与骨转换、骨密度的相关性,为骨代谢相关疾病的防治提供了新的思路。

OBJECTIVE： Adiponectin, one of the hormones secreted from adipose tissues, has effects on many physiological systems and metabolism pathways and is closely related to many diseases. To review and analyze the relationship between adiponectin and bone metabolism. DATA SOURCES： The related articles were searched in Medline between January 1995 and July 2006 with the key words of ＂adiponectin, bone＂ and ＂adiponectin, bone mineral density＂ in English. STUDY SELECTION： After the first check up the articles about clinical or basic studies of adiponectin were selected and the obviously unrelated articles were excluded. The full texts of the rest articles were searched for to further judge whether they were accordant with the inclusive criteria： （1）basis studies, and （2） clinical research relevant to human disease. DATA EXTRACTION：Totally163 articles were related to adiponectin in which were cited on the basis of the quality of experimental studies, and these studies 78 relevance to human disease, including 12 articles about the summary of adipenectin, 33 about the study of adiponectin and bone metabolism, and a total of 31 closely related and representative articles were reviewed. DATA SYNTHESIS：（1）Adipenectin, an adipecyte-derived hormone, possessed anti-hyperglycemic, anti-atherogenic, and anti-inflammatory properties because of its influence on glucose and lipid metabolism. （2）In vitro and animal studies showed that adipenectin increased bone mass by suppressing osteoclastogenesis and possibly by activating osteoblasto-genesis, adiponectin actions on bone formation through three distinct pathways： a positive action through the autocrine/paracrine pathway by locally produced adiponectin, a negative action through the direct pathway bycirculating adiponectin, and a positive action through the indirect pathway by circulating adiponectin via enhancement of the insulin signaling. Human cross-sectional studies about the role of adiponectin in bone metabolism also were not conclusive.（3） Although some authors had reported a negative association between serum leptin levels and bone mineral density （BMD）, others failed to find any relationship. CONCLUSION： Adiponectin, one of the hormones secreted from adipose tissues, is initially proposed to possess anti-hyperglycamic, anti-atherogenic, and anti-inflammatory properties because of its influence on glucose and lipid metabolism. Now, it is realized that adiponectin is involved in bone metabolism by affecting the activities of osteoblasts and osteoclasts by 3 different pathways of internal secretion and paracrine secretion. More basic and clinical studies are necessary to consolidate adiponectin＇s role in the physiology of bone tissues. In a word, the correlation of adiponectin with bone transformation and BMD provides some new directions for the prevention and treatment of bone metabolism associated diseases.