1. Department of Clinical Sciences, Sapienza University of Rome, Rome, Italy;
2. Unit of Endocrinology, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy;
3. Department of Clinical and Experimental Medicine, Magna Græcia University of Catanzaro, Catanzaro, Italy;
4. Department of Medical Pathophysiology, Sapienza University of Rome, Rome, Italy;
5. Research Unit of Diabetes and Endocrine Diseases, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy;
6. IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo e Istituto CSS-Mendel, Rome, Italy.