骨骼為支持身體和保護內臟器官的組織，但近年來有越來越多的研究證據指出骨骼也具有內分泌的功能，分泌似荷爾蒙的骨鈣素(osteocalcin)。骨鈣素由成骨細胞(osteoblasts)製造，以羧化(carboxylated osteocalcin, cOC)及未羧化(undercarboxylated osteocalcin, ucOC)二種型式存在，未羧化的骨鈣素與調節能量代謝有關，包括維持血糖、血脂恆定，增加胰島素分泌、敏感性和改善葡萄糖耐受性。近來研究指出骨鈣素也與動脈硬化具關聯性，不過是否為直接作用在血管系統或是間接調節，結果尚未一致。運動也能使骨鈣素上升，增加肌肉質量、改善運動能力。綜合而言，骨鈣素具有治療糖尿病、肥胖代謝相關疾病的潛力，同時能改善老化性的肌肉量流失，因此本篇整理相關研究證據作文獻探討，希望對於骨鈣素及其與運動的關聯有更完整的了解，提供未來相關研究參考。

Bone supports the structure of the body and protects visceral organs. More and more evidence indicates that bones also have endocrine functions, secreting hormone-like osteocalcin. Osteocalcin is produced by osteoblasts and exists in two forms, carboxylated osteocalcin (cOC) and undercarboxylated osteocalcin (ucOC). Uncarboxylated osteocalcin is related to the regulation of energy metabolism, including homeostasis of glucose and lipids, increase of insulin secretion and sensitivity, and improvement of glucose tolerance. Recent studies also have shown that osteocalcin is associated with arteriosclerosis. However, whether osteocalcin functions independently on the vascular system or interprets the results as a mediator is inconclusive. In another aspect, exercise can increase the serum osteocalcin, relevant to muscle mass and optimum exercise capacity, but the mechanisms are unclear. Osteocalcin could be the potential treatment for diabetes, obesity, and age-associated muscle loss. Therefore, this literature review aims to summarize the current finding of osteocalcin, to provide a reference for future studies.