[1] Univ Messina, Dept Internal Med, Policlin Univ G Martino, I-98124 Messina, Italy
[2] Univ Pavia, Dept Hlth Sci, Unit Med Stat & Epidemiol, I-27100 Pavia, Italy
[3] ASL Turin 5, Metab & Diabet Unit, Chieri, Italy
[4] Univ Messina, Dept Biochem Sci, I-98124 Messina, Italy