1. Department of Clinical and Experimental Medicine, Policlinico Universitario Gaetano Martino, Messina, Italy.
2. Diabetes Research Institute, San Raffaele Scientific Institute, Milan, Italy.
3. Medical Affairs, Roche Diagnostics S.p.A., Monza, Italy.
4. Section of Medical Statistics and Biometry G.A. Maccacaro, Department of Occupational Health Clinica del Lavoro L. Devoto, School of Medicine, University of Milan, Milan, Italy.
5. San Raffaele Vita-Salute University, Milan, Italy.
6. Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari School of Medicine, Bari, Italy.
7. Division of Metabolic Diseases, Department of Clinical and Experimental Medicine, University of Padova, Padova, Italy.