Human leptin levels are pulsatile and inversely related to pituitary-adrenal function. - Licinio,J.; Mantzoros,C.; Negrao,A.; Cizza,G.; Wong,M.L.; Bongiorno,P.B.; Chrousos,G.P.; Karp,B.; Allen,C.; Flier,J.S.; Gold,P.W. (Nature Medicine, 1997)