Association of tumor necrosis factor α, interleukin 6, and interleukin 10 promoter polymorphism with proliferative diabetic retinopathy in type 2 diabetic subjects

PURPOSE: New blood vessel formation in the retina because of prolonged hypoxia is believed to be directly associated with increased expression of several growth factors and angiogenic cytokines. In the present study, we made an attempt to investigate the possible association of the promoter polymorphisms of interleukin 6, tumor necrosis factor α, and interleukin 10 for the pathogenesis of proliferative diabetic retinopathy (PDR). METHODS: This case-control study comprised 493 volunteers (253 PDR cases and 240 diabetic controls). Cases and controls were ascertained such that age, sex, nutrition, and glycemic status were matched. Genotypes were determined by polymerase chain reaction-based methods. RESULTS: Interleukin 10-1082GG (P = 0.0037; odds ratio [OR] = 2.232), tumor necrosis factor α-238AA (P = 0.0001; OR = 5.791), and GA (P = 0.0015; OR = 1.909) genotypes were significantly associated with PDR occurrence. The interleukin 10-1082G allele (P = 0.0048, OR = 1.4442) and the tumor necrosis factor α-238A allele (P = 0.0001; OR = 2.2897) were significantly increased among PDR cases. CONCLUSION: From our study, it may be concluded that the genetic variation, that is, tumor necrosis factor α-238A and interleukin 10-1082G alleles are the potent risk factors for the pathogenesis of PDR.