OGTT provides estimates of IR11 but also captures additional physiologic processes by stimulating gut-derived incretin hormones known to augment insulin secretion.12,13 Metabolomic profiling of the response to OGTT may reveal specific metabolites and metabolic pathways underlying impaired glucose homeostasis in CKD, thus identifying therapeutic targets for improving insulin sensitivity in this vulnerable population. The gene discussed is INS; the disease is chronic kidney disease.