1. Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
2. Department of Internal Medicine, Medical University Graz, Graz, Austria.
3. Department of Endocrinology, Diabetes, Nutrition, Montpellier University Hospital; Clinical Investigation Center INSERM 1001; and UMR CNRS5203/INSERM U661, Montpellier, France.
4. Department of Clinical and Experimental Medicine, University of Padova, Padova, Italy.
5. Profil Institut für Stoffwechselforschung GmbH, Neuss, Germany.