[1] Univ Sassari, Policlin, Ctr Chirurg Gen & Grande Obes, I-07100 Sassari, Italy
[2] Univ Sassari, Ist Clin Med, Serv Diabetol, I-07100 Sassari, Italy
[3] Univ Sassari, Ist Sci Radiol, I-07100 Sassari, Italy
[4] Univ Perugia, Dipartimento Sci Chirurg, I-06100 Perugia, Italy