1. Division of Endocrinology, Department of Endocrinology, Diabetes, and Rheumatology, Medical Faculty, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany.
2. Institute of Experimental Psychology, Heinrich-Heine University Duesseldorf, Duesseldorf, Germany.
3. Department of Internal Medicine, Endocrinology and Diabetes, Municipal Hospital Bielefeld, Bielefeld, Germany