1Synlab Center of Laboratory Diagnostics, Eppelheim, Deutschland; 2Medical University of Graz, Clinical Institute of Medical and Chemical Laboratory Diagnostics, Graz, Oesterreich; 3University of Würzburg, Department of Medicine, Division of Nephrology, Würzburg, Deutschland; 4Medical University of Graz, Division of Endocrinology and Nuclear Medicine, Graz, Oesterreich; 5Medical Faculty Mannheim, Mannheim Institute of Public Health, Mannheim, Deutschland; 6Frankfurt Cardiology Centre, Frankfurt, Deutschland; 7Ulm University, Division of Endocrinology and Diabetes, Ulm, Deutschland; 8Ruperto Carola University Heidelberg, Division of Nephrology, Heidelberg, Deutschland