[1] Charite Univ Med Berlin, D-10117 Berlin, Germany
[2] Univ Munich, Med Klin Innenstadt, D-80336 Munich, Germany
[3] Univ Munich, Inst Prophylaxe & Epidemiol Kreislaufrankheiten, D-80336 Munich, Germany
[4] Univ Hosp Dusseldorf, Dept Nephrol, D-40225 Dusseldorf, Germany
[5] Univ Wurzburg, Dept Internal Med, Endocrine & Diabet Unit, D-97070 Wurzburg, Germany
[6] Endokrinologikum, D-10117 Berlin, Germany
[7] Univ Freiburg, Dept Med 2, D-79085 Freiburg, Germany