1. Division of Endocrinology and Metabolism, Department of Internal Medicine III, University of Vienna (H.S., M.K., E.B., M.G.B., M.R.), A-1090 Vienna, Austria;
2. Department of Internal Medicine, University of Graz (W.J.S., T.L.), A-8036 Graz, Austria;
3. Institute of Systems Science and Biomedical Engineering, University of Padova (G.P.), I-35127 Padova, Italy