1. Department of Medicine and Diabetes Center (I.D.G., B.A.M., J.F.Y.), University of California, San Francisco, California 94115
2. Division of Cardiovascular Medicine (G.R.), Stanford University School of Medicine, Stanford, California 94305
3. Diabetes Center (D.A.), Columbia University, New York, New York 10032
4. Department of Clinical Sciences (V.T.), Sapienza University, 00198 Rome, Italy
5. Research Unit of Diabetes and Endocrinology (V.T.), Scientific Institute Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
6. Casa Sollievo Della Sofferenza-Mendel Institute (V.T.), 00198 Rome, Italy
7. and Endocrinologia (R.V., L.F.), Ospedale Garibaldi, University of Catania, 95122 Catania, Italy