1. Division of Nephrology and Hypertension, 1st Department of Internal Medicine, AHEPA Hospital, School of Medicine, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece
2. Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
3. Department of Nephrology, Democritus University of Thrace, 68100 Alexandroupolis, Greece
4. Department of Nephrology and Renal Transplantation, Patras University Hospital, 26504 Patras, Greece