DPP4 and Insulin resistance: We previously revealed that serum TAGE levels independently correlated with serum levels of sRAGE [89], low-density lipoprotein cholesterol [90], serum pigment epithelium-derived factor, markers of insulin resistance (IR) [91], the homeostatic model assessment of IR (HOMA-IR) index [92], adiponectin (inversely) [93,94], and dipeptidyl peptidase-4 (DPP-4) [95] in a non-diabetic general population.