Change and significance of serum pigment epithelium-derived factor in type 2 diabetic nephropathy

Abstract

To investigate the change of pigment epithelium-derived factor (PEDF) in type 2 diabetic nephropathy, and to explore the significance of PEDF in the development of diabetic nephropathy. ELISA was used to detect the serum PEDF and immunoturbidimetry was used to measure the urinary albumin excretion (UAE) in 49 healthy controls and 132 type 2 diabetic patients, including 48 with normal urinary albumin excretion rate (NA group), 50 with microalbuminuria (MA group), and 34 with overt diabetic nephropathy (PR group). HbA1c, triglyceride (TG), total cholesterol, high density lipoprotein cholesterol (HDL-c), and highly sensitive C-reactive protein (hs-CRP) were simultaneously determined. The serum PEDF levels of the NA, MA, and PR groups were (3.7 +/- 2.2) mg/L, (4.7 +/- 2.9) mg/L, and (5.7 +/- 2.8) mg/L respectively, all significantly higher than that of the control group (2.7 +/- 1.3) mg/L. P < 0.05, 0.01, and 0.01 respectively). The serum PEDF levels of the MA and PR groups were significantly higher than that of the NA group (both P < 0.01), and that of the PR group was significantly higher than that of the MA group (P < 0.05). Correlation analysis demonstrated that serum PEDF level was positively correlated with HbA1c (r = 0.198, P < 0.01), FPG (r = 0.231, P < 0.01), TG (r = 0.302, P < 0.01), hs-CRP (r = 0.214, P < 0.01), and urinary albumin excretion rate (UAER) (r = 0.169, P < 0.05), significantly, but negatively correlated with HDL-c (r = -0.237, P < 0.01). Stepwise multiple linear regression analysis showed that TG (beta = 0.314, P < 0.01), hs-CRP (beta = 0.260, P < 0.01), and UAER (beta = 0.148, P < 0.05) were significant independent determinants for serum PEDF. Serum PEDF level significantly increases in type 2 diabetic patients, and the magnitude of PEDF is related to the severity of diabetic nephropathy. TG, hs-CR and UAER are significant independent determinant for serum PEDF. The increase of PEDF may involve in the development of diabetic nephropathy.