Relations between eNOS Glu298Asp polymorphism and progression of diabetic nephropathy

Background: Nitric oxide (NO) is related to the pathogenesis of renal hemodynamics in diabetes mellitus. Endothelial nitric oxide synthase (eNOS) gene polymorphism is considered the deterioration factor for progressive renal disease. It has been reported that an interaction of angiotensin II (Ang II) and NO is involved in the control of glomerular hemodynamics. This study aimed to elucidate the roles of eNOS and the angiotensin-converting enzyme (ACE) gene polymorphism for the progression of type 2 diabetic nephropathy (DN). Methods: Korean type 2 diabetic patients (n=177) were studied. eNOS and ACE genotypes were determined by polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) analysis. They were divided into three groups: group 1 consisted of patients with normoalbuminruia (n=59), group 2 had microalbuminuria (n=35) and group 3 had overt nephropathy (n=83) Results: Group 3 had a higher frequency of eNOS(GT) than groups 1 and 2. Patients with eNOS(GT) genotype showed more rapid deterioration in renal function, higher incidence of overt nephropathy and lower renal survival than those with eNOS(GG) genotype. However, there was no significant association between the ACE genotypes and DN, and no interaction between eNOS and ACE gene polymorphism. Conclusion: These results imply that eNOS(GT) genotype is associated with the progression of type 2 DN in Korean patients.