REG1A and type 2 diabetes mellitus: Meanwhile, serum PSP/REG Iα levels negatively correlated with eGFR (r = −0.474, P < 0.001) and associated significantly with age (r = 0.335, P = 0.001), serum Cr (r = 0.366, P < 0.001), and BUN (r = 0.346, P < 0.001) in subjects without T2DM (Table 2).