1. From the Institute of Clinical Chemistry (C.C., P.M.O., L.R., A.v.E.), University and University Hospital Zurich, Zurich, Switzerland; Life Science Zurich PhD Program on Systems Biology of Complex Diseases (P.M.O.), Competence Center for Systems Physiology and Metabolic Diseases (P.M.O., A.v.E.), Swiss Federal Institute of Technology Zurich and University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (L.R., A.v.E.), University of Zurich, Zurich, Switzerland.