1. Department of Clinical Pharmacology and Epidemiology, Consorzio Mario Negri Sud, S. Maria Imbaro (CH), Chieti, Abruzzo, Italy
2. Diabetes and Endocrinology Unit, Cardarelli Hospital, Campobasso, Italy
3. Department of Clinical and Experimental Medicine, Second University of Naples, Naples, Italy
4. Unit of Internal Medicine, Montecchio Hospital, Montecchio Emilia (RE), Emilia-Romagna, Italy
5. Diabetes and Metabolic Diseases Unit, San Martino Hospital, Oristano, Italy
6. Department of Clinical and Molecular Medicine, Faculty of Medicine and Psychology, S. Andrea Hospital, Sapienza University, Rome, Italy
7. Diabetes and Metabolism Unit, Sandro Pertini Hospital, Rome, Italy
8. Diabetes and Metabolism Unit, ASL TO5, Chieri (TO), Turin, Piedmont, Italy.