Ethics
This study was conducted in accordance with the declaration of Helsinki and the good clinical practice guidelines. The study protocol as well as the written consent form were approved (EK 1494/2016) by the Ethics Committee of the Medical University of Vienna (Chairperson: Univ.-Doz. Dr. Martin Brunner; Borschkegasse 8b/E06, 1090 Vienna, Austria) on 24 August 2016. Written informed consent was obtained from all study participants.