1. Division of Pediatric Endocrinology and Diabetology, Department of Pediatrics II, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
2. Department of Child and Adolescent Psychiatry and Psychotherapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
3. Department of Epidemiology and Health Monitoring, Robert Koch Institute, Berlin, Germany.
4. Department of Pediatrics and Center for Rare Diseases Ruhr CeSER, St. Josef Hospital, Ruhr University Bochum, Bochum, Germany.