Association of Erythropoietin Gene Polymorphisms With Type 2 Diabetic Retinopathy in Adult Patients From Northern India

Abstract

ObjectivesOur aim in this study was to determine the association of erythropoietin (EPO) gene polymorphisms with diabetic retinopathy in patients with type 2 diabetes from northern India. MethodsIn this case-control study, we recruited 614 participants, consisting of 302 diabetic retinopathy cases and 312 individuals with confirmed type 2 diabetes without retinopathy as controls. EPO polymorphism analysis was performed in all participants using polymerase chain reaction and direct DNA sequence analysis. ResultsThe genotype distribution and allele frequency of the c.246+265G>A (rs507392) polymorphism differed significantly (p<0.05) between the retinopathy and control groups. For the −1306C>A (rs1617640) polymorphism, genotype distribution among the 2 groups analyzed differed significantly (p=0.047), but the distribution of allele frequency was not found to be statistically significant (p=0.07). For the c.∗772G>T (rs551238) variant, genotype distribution did not differ significantly when comparing the 2 groups (p=0.062), but allele frequency distribution did differ significantly (p=0.045). For the polymorphisms analyzed, namely rs507392 and rs1617640, a statistically significant association with retinopathy was observed (dominant model: adjusted odds ratio [OR], 2.23; 95% confidence interval [CI], 1.36 to 3.35; p<0.01; codominant model: adjusted OR, 1.45; 95% CI, 1.00 to 2.09; p=0.048). However, no significant association between c.∗772G>T (rs551238) polymorphism and diabetic retinopathy was found. ConclusionsOur findings show 2 polymorphisms (c.246+265G>A [rs507392] and −1306C>A [rs1617640]) in EPO to be risk factors for type 2 diabetic retinopathy in a northern Indian cohort. To our knowledge, this is the first report from India to demonstrate an association between EPO gene polymorphisms and retinopathy.