1. Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, Berlin, Germany.
2. Experimental and Clinical Endocrinology, University of Lübeck, Lübeck, Germany.
3. Institute of Clinical Chemistry and Laboratory Medicine, University Medicine Greifswald, Greifswald, Germany.
4. Department of Endocrinology, Metabolism and Internal Medicine, University of Medical Sciences, Poland.
5. Department of Medicine for Endocrinology, Division of Clinical Endocrinology, Diabetes and Nutritional Medicine, Campus Mitte, Charité-Universitätsmedizin Berlin, Berlin, Germany.