Impact of Endothelial NOS VNTR Variant on Susceptibility to Diabetic Neuropathy and Type 2 Diabetes Mellitus

Purpose: The aim of this study was to evaluate whether the VNTR intron 4b/4a variant in the eNOS gene is associated with type 2 diabetes mellitus (T2DM) and DPN. Methods: A total of 598 subjects were enrolled in the study. eNOS VNTR 4b/4a variant was genotyped by polymerase chain reaction (PCR) method. Results: eNOS VNTR intron 4b/4b genotype and b allele increased in patients with both DPN and T2DM compared healthy controls (p=0.0005, OR:1.94, p= 0.000002, OR:4.10, respectively). 4a/4b genotype was more prevalent in controls than in DPN and T2DM patients (p=0.00008, OR:0.46; p=0.000004, OR:0.24, respectively). eNOS VNTR b allele was more common in DPN patients and T2DM patients compared with controls (p=0.007, p=0.00002, respectively). Conclusion: The eNOS VNTR “4b/4b” homozygous genotype and hence “4b”allele as a genetic risk factor for T2DM and DPN, which may serve as a useful marker of increased susceptibility to the risk of these disorders.