The rs2442598 Polymorphism in ANGPT-2 Gene Is Associated With Risk for Diabetic Retinopathy in Patients With Type 1 Diabetes Mellitus From a Brazilian Population

Introduction: Angiopoietin-2 (ANGPT-2) is a member of a growth factor family that binds to the endothelial receptor tyrosine kinase 2 and regulates vascular development and function. Under hyperglycemic conditions, ANGPT-2 is upregulated and leads to vascular destabilization, pericyte dropout, and aggravation of inflammation. In this context, studies have reported the involvement of ANGPT-2 in the pathogenesis of diabetic retinopathy (DR). Thus, polymorphisms in ANGPT-2 gene may be of interest in this field. Objective: To investigate the association between the rs2442598 polymorphism in the ANGPT-2 gene and DR. Methods: This case-control study comprised 107 patients with type 1 diabetes mellitus (T1DM) and DR (cases) and 129 patients with T1DM without DR (controls) and with ≥10 years of DM. The ANGPT-2 rs2442598 (G/A) polymorphism was genotyped by real-time PCR using TaqMan MGB probes. Results: Genotype distributions of this polymorphism were consistent with Hardy-Weinberg Equilibrium. Frequency of the rs2442598 A allele was higher in cases compared to controls (P= 0.011). Moreover, the A/A genotype was higher in cases than controls (P= 0.017) and was associated with risk for DR after adjustment for duration of DM, HbA1c, triglycerides, estimated glomerular filtration rate, and presence of hypertension (OR= 5.19, IC95% 1.21 - 22.27). This association was maintained under the recessive (OR= 4.78, IC95% 1.14 - 19.99) and additive (OR= 6.861, IC95% 1.45 - 32.38) inheritance models. Conclusion: Our data demonstrate, for the first time, the association of the ANGPT-2 rs2442598 A allele with risk for DR in T1DM patients from Southern Brazil.