1Depts Clinical Research and Radiology, University of Bern, Bern, Switzerland, 2Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland, 3Dept. of Nephrology, Hypertension and Clinical Pharmacology, University of Bern, Bern, Switzerland, 4Dept. of Endocrinology, Diabetes and Clinical Nutrition, University of Bern, Bern, Switzerland