1. University Hospital Medical Center Bežanijska Kosa, 11000 Belgrade, Serbia
2. Faculty of Medicine, University of Belgrade, 11000 Belgrade, Serbia
3. Department of Internal Medicine, General Hospital Novi Pazar, 36300 Novi Pazar, Serbia
4. Department of Cardiology, Emergency Center, University Clinical Center of Serbia, 11000 Belgrade, Serbia
5. Clinic of Gastroenterology and Hepatology, University Clinical Center of Serbia, 11000 Belgrade, Serbia