1. Second Department of Critical Care, Attikon General University Hospital, Medical School, National and Kapodistrian University of Athens, 1 Rimini St., Haidari, 12462 Athens, Greece
2. Department of Biological Chemistry, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias St., Goudi, 11527 Athens, Greece
3. Diabetes Center, First Department of Propaedeutic Internal Medicine, Laiko General Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
4. Department of Internal Medicine, Sismanogleio General Hospital, 1 Sismanogleiou St., 15126 Athens, Greece
5. First Department of Internal Medicine, University Hospital of Alexandroupolis, Democritus University of Thrace, 68100 Alexandroupolis, Greece