1. Department of Internal Medicine, Division of Endocrinology and Metabolism; Medical University of Graz; Graz Austria
2. Department of Internal Medicine, Division of Endocrinology and Diabetes; Ulm University; Ulm Germany
3. Clinical Institute of Medical and Chemical Laboratory Diagnostics; Medical University of Graz; Graz Austria
4. Department of Public Health, Social and Preventive Medicine, Mannheim Medical Faculty; University of Heidelberg; Mannheim Germany
5. Synlab Center of Laboratory Diagnostics; Heidelberg Germany