Role of the VEGF 936 C/T polymorphism in diabetic microvascular complications in type 2 diabetic patients

Aim:   Vascular endothelial growth factor (VEGF) is important in the pathogenesis of diabetic microvascular complications and the genetic polymorphism of this gene may contribute to the development and progression of diabetic microvascular complications. In this study, we investigated whether a genetic polymorphism of VEGF is associated with diabetic complications.
Methods:   A total of 398 type 2 diabetic patients and 526 healthy controls were enrolled. The study subjects were divided based on the state of nephropathy, retinopathy and neuropathy. The VEGF 936 C/T polymorphism was evaluated using standard PCR techniques, and plasma and urinary levels of VEGF were determined by enzyme-linked immunosorbent assay.
Results:   There was no difference in VEGF genotype distribution between the control and diabetic patients based on the state of diabetic nephropathy and neuropathy. However, a higher frequency of the TT genotype was observed in patients with proliferative diabetic retinopathy. Additionally, plasma levels of VEGF were significantly higher in the TT genotype. However, urinary levels of VEGF did not show a significant relationship with the VEGF genotype. Urinary VEGF levels showed a significant relationship with urinary albumin excretion, proteinuria, serum creatinine level and creatinine clearance, as well as fasting blood glucose levels, postprandial 2 h glucose levels and C-reactive protein.
Conclusion:   Our study suggests that the 936 C/T polymorphism of the VEGF gene may be an important factor determining plasma VEGF levels and that its polymorphism is related with diabetic retinopathy. Urinary levels of VEGF are not associated with plasma VEGF levels and associated with the stage of diabetic nephropathy.