[1] Univ Zurich Hosp, Div Nephrol, Zurich, Switzerland
[2] Univ Zurich, Inst Physiol, CH-8006 Zurich, Switzerland
[3] Univ Zurich, Zurich Ctr Integrat Human Physiol, CH-8006 Zurich, Switzerland
[4] Univ Zurich, Inst Gen Practice & Hlth Serv Res, CH-8006 Zurich, Switzerland
[5] Univ Zurich Hosp, Inst Clin Chem, Zurich, Switzerland
[6] Univ Basel Hosp, Lab Med, Basel, Switzerland
[7] Univ Zurich Hosp, Div Diagnost Radiol, Zurich, Switzerland