1. Department of Internal Medicine, University of Messina, 98125 Messina, Italy
2. Department of Clinical Pharmacology and Epidemiology, Fondazione Mario Negri Sud, Via Nazionale, 66030 S. Maria Imbaro, Italy
3. Diabetes and Metabolism Unit, ASL TO5, 10023 Chieri, Italy
4. Diabetes and Endocrinology Unit, Cardarelli Hospital, 86100 Campobasso, Italy
5. Diabetes and Metabolism Unit, Sandro Pertini Hospital, 00157 Rome, Italy
6. Diabetes and Metabolic Diseases Unit, San Martino Hospital, 09170 Oristano, Italy
7. Department of Clinical and Molecular Medicine, Faculty of Medicine and Psychology, S. Andrea Hospital, Sapienza University, 00189 Rome, Italy
8. Diabetes Unit, Montecchio Hospital, 42027 Montecchio Emilia, Italy