1. Section of Bioanalytical Chemistry, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London , London SW7 2AZ, UK
2. National Phenome Centre, Department of Metabolism, Digestion and Reproduction, Imperial College London , London W12 0NN, UK
3. Metabolomics Core, Mayo Clinic , Rochester, MN 55905, USA
4. Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Imperial College London , London W12 0NN, UK
5. Clinical Biochemistry, Blood Sciences, North West London Pathology, Charing Cross Hospital , London W6 8RF, UK
6. Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic , Rochester, MN 55905, USA
7. Department of Biochemistry and Molecular Biology, Mayo Clinic , Rochester, MN 55905, USA