1. Department of Paediatrics, University of Halle-Wittenberg, Halle, Germany
2. Department of Paediatrics, University of Leipzig, Leipzig, Germany
3. Institute of Experimental Paediatric Endocrinology; Charité, Universitätsmedizin Berlin, Germany
4. Department of Paediatrics, Hospital of Leverkusen, Leverkusen, Germany
5. Department of Paediatrics, St. Vincenz-Hospital, Paderborn, Germany
6. Department of Paediatrics, Medical University of Graz, Graz, Austria
7. Department of Paediatrics, Technical University of Munich, Munich, Germany
8. Department of Paediatrics and Neonatology, Saarland University Hospital, Homburg/Saar, Germany
9. Institute of Epidemiology and Medical Biometry, University of Ulm, Ulm, Germany