DPP4 and diabetes mellitus: Although the presence of diabetes was associated with elevated DPP4 concentrations among all participants, the aforementioned significant differences between groups remained unchanged in non-diabetic participants (UA: 72.22 ± 15.13 ng/dl, SCAD: 56.92 ± 11.21, Control:35.92 ± 9.21; p < 0.05).