Evaluation of Glutathione Peroxidase and KCNJ11 Gene Polymorphisms in Patients with New Onset Diabetes Mellitus After Renal Transplantation.

Genetic mutations such as C599T polymorphism in glutathione peroxidase [GPX1] gene and polymorphisms in potassium channel (KCNJ11) genes have recently been proposed in the etiopathogenesis of new onset diabetes mellitus after renal transplantation (NODAT). We aimed to examine the association of GPX1 and KCNJ11 polymorphisms in NODAT. This is a monocenter case-control study with a total of 118 renal transplant recipients who were divided into 2 groups; NODAT and normal glucose tolerance. Relation of GPX1 and KCNJ11 polymorphisms were investigated between these groups. PCR-RFLP method was used for genotyping of polymorphisms in the GPX1 (rs1050450) and KCNJ11 (rs1805127) genes. Two alleles were visualized for each gene (C/T for GPX1 and A/G for KCNJ11). NODAT was correlated with age at transplantation (p<0.001, r=0.380), post-transplant systolic blood pressure (BP) (p=0.02, r=0.211), post-transplant non-HDL cholesterol levels (p=0.01, r=0.803), degree of weight change at the end of the first year (p=0.01, r=0.471), presence of pre-transplant hypertension (HT) (p=0.02, r=0.201), family history of diabetes (p=0.01, r=0.29) and dyslipidemia (p=0.012, r=0.362). GPX1 polymorphism of TT (mutant) allele was significantly more frequent in patients with NODAT (p<0.001, r=0.396) independent from other diabetogenic risk factors. KCNJ11 polymorphisms were similar in both groups and did not show any significant association with NODAT (p=0.10). In addition to several diabetogenic risk factors, C599T polymorphisms in GPX1 gene might also contribute to the development of NODAT. Further studies on larger patient series are necessary in order to reach definitive suggestions.