Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), German Center for Diabetes Research, Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), University of Leipzig - Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig - Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, German Center for Diabetes Research, Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I), Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I) and Heidelberg University - Department of Endocrinology, Diabetology and Clinical Chemistry (Internal Medicine I)