Page 1 of 46 Diabetes Metabolomics identifies a biomarker revealing in vivo loss of functional ß-cell mass before diabetes onset Lingzi Li1,2,7, Petra Krznar3,4,7, Alexander Erban5, Andrea Agazzi6, Juliette Martin-Levilain1,2, Sachin Supale1,2, Joachim Kopka5, Nicola Zamboni3 and Pierre Maechler1,2 1Department of Cell Physiology and Metabolism & 2Faculty Diabetes Centre, University of Geneva Medical Centre, Geneva, Switzerland 3Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland 4PhD Program Systems Biology, Life Science Zurich Graduate School, Zurich, Switzerland 5Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam, Germany. 6Theoretical Physics Department, University of Geneva, Geneva, Switzerland 7These authors contributed equally to this work Correspondence to: Pierre Maechler, Department of Cell Physiology, University of Geneva Medical Center, rue Michel- Servet 1, 1211 Geneva 4, Switzerland. Email:
[email protected] , Phone: +41 22 379 55 54. Nicola Zamboni, Institute of Molecular Systems Biology, ETH Zurich, Otto-Stern-Weg 3, 8093 Zürich, Switzerland. Email:
[email protected] , Phone: +41 44 633 31 41. Keywords: pre-diabetes; beta-cell; biomarker; 1,5-anhydroglucitol Running title: biomarkers of beta-cell loss Word count: 5’246 1 Diabetes Publish Ahead of Print, published online September 19, 2019 Diabetes Page 2 of 46 ABSTRACT Identification of pre-diabetic individuals with decreased functional ß-cell mass is essential for the prevention of diabetes. However, in vivo detection of early asymptomatic ß-cell defect remains unsuccessful. Metabolomics emerged as a powerful tool in providing read-outs of early disease states before clinical manifestation. We aimed at identifying novel plasma biomarkers for loss of functional ß-cell mass in the asymptomatic pre-diabetic stage.