1. Department of Internal Medicine III, Division of Endocrinology and Metabolism, University of Vienna, Vienna, Austria
2. Metabolic Unit, Institute of Biomedical Engineering, National Research Council (ISIB-CNR), Padova, Italy
3. Institute for Medical Laboratory Diagnostics, University of Vienna, Vienna, Austria
4. Division of Endocrinology, University of Hannover, Hannover, Germany
5. Institute of Biostatistics, University of Vienna, Vienna, Austria