1. Department of Endocrinology and Metabolism and Division of Laboratory Research, University Hospital of Essen, University of Duisburg-Essen, Germany
2. Department of Cardiology, West-German Heart Centre Essen, University Hospital of Essen, University of Duisburg-Essen, Germany
3. Institute for Medical Informatics, Biometry and Epidemiology, University Hospital of Essen, University Duisburg-Essen, Germany
4. Department of Neurosurgery, University Hospital of Essen, University of Duisburg-Essen, Germany