[1] Med Univ Vienna, Dept Internal Med 3, Div Endocrinol & Metab, Vienna, Austria
[2] Med Univ Vienna, Dept Med, Vienna, Austria
[3] Med Univ Vienna, Chem Lab Diagnost, Vienna, Austria
[4] Univ Vienna, Div Gastroenterol, Dept Internal Med 3, Vienna, Austria
[5] Konventhosp Barmherzige Brueder, Dept Lab Med, Linz, Austria
[6] Konventhosp Barmherzige Brueder, Dept Internal Med, Linz, Austria