Osteocalcin (OC) secreted by osteoblasts is a sensitive and specific indicator of osteoblast activity.Recently,it has been found that osteocalcin serves as an important mediator of endocrine function.Undercarboxylated OC can promote insulin secretion and β-cell proliferation,and lower glucose and lipid levels,suggesting that osteocalcin might play a major role in the regulation of energy metabolism.These findings provide a new insight for the treatment of metabolic diseases such as obesity and diabetes.