Association of XbaI <i>GLUT</i>1 Polymorphism with Susceptibility to Type 2 Diabetes Mellitus and Diabetic Nephropathy

Objectives: Diabetic nephropathy (DN) is one of the chronic microangiopathic complications of type 2 diabetes (T2DM) and has become the most frequent cause of end-stage renal disease. The XbaI polymorphism in the glucose transporter (GLUT1) has been suggested in the development of DN. We examined the association between XbaI polymorphism of GLUT1 and susceptibility to T2DM and development of DN. Methods: The study included 227 T2DM patients divided into 107 without DN (DM ? DN) and 120 with DN (DM + DN), in addition to 100 apparently healthy controls. Genotyping was done by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Results: The GLUT1 XbaI T allele was associated with increased susceptibility to T2DM, when comparing the healthy controls to the whole diabetic group, odds ratio (OR) = 1.899, 95% confidence interval (CI) (1.149 - 3.136), p = 0.011. This association was also significant between healthy controls and DM ? DN OR = 1.997 (1.079 - 3.699), p = 0.026 as well as between healthy controls and DM + DN OR = 1.818 (1.016 - 3.253), p = 0.042. However there was no significant association of XbaI polymorphism with DN when comparing DM ? DN to DM + DN OR = 0.910 (0.474 - 1.747), p = 0.777. Conclusion: XbaI T allele is associated with increased susceptibility to T2DM, but not to development of DN. Further studies are needed to replicate such findings.