[1] Med Univ Graz, Clin Inst Med & Chem Lab Diagnost, Graz, Austria
[2] Univ Tubingen, Dept Internal Med, Div Endocrinol Diabetol Nephrol Vasc Dis & Clin C, D-7400 Tubingen, Germany
[3] Univ Freiburg, Dept Internal Med, Div Clin Chem, D-7800 Freiburg, Germany
[4] Cardiol Grp Frankfurt Sachsenhausen, Frankfurt, Germany
[5] Univ Ulm, Dept Internal Med, Div Endocrinol, D-7900 Ulm, Germany
[6] Heidelberg Univ, Mannheim Med Fac, Dept Publ Hlth Social & Prevent Med, D-6800 Mannheim, Germany
[7] Synlab Ctr Lab Diagnost, Heidelberg, Germany