1. Section of Nephrology and Hypertension, 1st Department of Medicine, AHEPA Hospital, Aristotle University of Thessaloniki , Thessaloniki , Greece
2. 2nd Department of Gastroenterology , Iatriko Athinon, Athens , Greece
3. Department of Electrical and Computer Engineering, University of Western Macedonia , Kozani , Greece
4. Division of Nephrology, Department of Medicine, Indiana University School of Medicine and Richard L. Roudebush Veterans Administration Medical Center , Indianapolis, IN , USA