1. Department of Endocrinology and Diabetology, Medical Faculty and University Hospital, Heinrich Heine University, Düsseldorf, Germany
2. Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University, Düsseldorf, Germany
3. German Center for Diabetes Research, Partner Düsseldorf, München-Neuherberg, Germany
4. Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tanta University, Tanta, Egypt
5. Institute for Biometrics and Epidemiology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University, Düsseldorf, Germany
6. Obesity and Reflux Center, Neuwerk Hospital, Mönchengladbach, Germany
7. Institute of Pathology, Heinrich Heine University, Düsseldorf, Germany
8. Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University, Düsseldorf, Germany
9. Landesapotheke Salzburg, Salzburg, Austria
10. Department of Internal Medicine I, University Hospital Heidelberg, Heidelberg, Germany
11. Institute of Biochemistry and Molecular Biology I, Medical Faculty and University Hospital Düsseldorf, Heinrich Heine University, Düsseldorf, Germany