Diabetes Center, Amsterdam University Medical Centers, location VUmc, Amsterdam, the Netherlands ma.muskiet@amsterdamumc.nl. Diabetes Center, Amsterdam University Medical Centers, location VUmc, Amsterdam, the Netherlands. Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Düsseldorf, Germany. German Center for Diabetes Research (DZD), Muenchen-Neuherberg, Germany. Department of Endocrinology, Ghent University Hospital, Ghent, Belgium. Department of Biomedical Sciences, Panum Institute, University of Copenhagen, Copenhagen, Denmark. Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, Groningen, the Netherlands. Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands. Department of Nephrology and Hypertension, University Medical Center, Utrecht, the Netherlands.