1. From the Division of Endocrinology and Metabolism (T.N.K., H.J.Y., S.J.Y., H.J.Y., H.Y.K., J.A.S., S.G.K., N.H.K., S.H.B., D.S.C., K.M.C.), Department of Internal Medicine, and Department of Nuclear Medicine (S.K.), Korea University College of Medicine, Seoul, Korea.