SPP1 and type 2 diabetes mellitus: Serum creatinine and occurrence rate of mild or moderate renal insufficiency were higher in T2DM patients with OPN levels greater than the median compared with those with OPN levels lower than the median (creatinine 90.3 ± 30.2 vs. 79.2 ± 19.5 μmol/L, respectively (P < 0.001); mild renal insufficiency 78.8% vs. 63.6%, respectively (P < 0.01); and moderate renal insufficiency 21.9% vs 11.2%, respectively (P < 0.05)); in contrast, eGFR was higher in T2DM patients with OPN levels below the median (84.1 ± 19.5 vs 75.5 ± 21.3 mL/min per 1.73 m2; P < 0.001; Table 2).