Hinoi E, Gao N, Jung DY, Yadav V, Yoshizawa T, Myers MG, Chua SC, Kim JK, Kaestner KH, Karsenty G. The sympathetic tone mediates leptin's inhibition of insulin secretion by modulating osteocalcin bioactivity. J Cell Biol. 2008 Dec 29; 183(7):1235-42.