Association of Polymorphisms in Antioxidant Enzyme-Encoding Genes with Diabetic Nephropathy in a Group of Saudi Arabian Patients with Type II Diabetes Mellitus.

INTRODUCTION

An imbalance between reactive oxygen species (ROS) generation and the defence mechanisms underlying the activity of antioxidant enzymes has been demonstrated as the leading pathology in diabetes mellitus (DM)-related microvascular complications.

PURPOSE

This study aims to evaluate the association between polymorphisms in antioxidant enzyme-encoding genes: catalase (CAT); manganese superoxide dismutase (Mn-SOD); glutathione S transferase M1 (GSTM1); and GSTT1 glutathione S transferase T1 (GSTT1), and the risk of type II diabetic nephropathy (DN) in the Saudi population.

PATIENTS AND METHODS

The present study involved 64 type II DM patients with nephropathy and 64 type II diabetes patients without nephropathy from the King Abdulaziz University (KAU) Hospital. They underwent real-time PCR genotyping for the Mn-SOD and CAT genes. Multiplex PCR was used to detect GSTM1- and GSTT1-null polymorphisms.

RESULTS

A statistically significant difference was observed between the case and control groups with regard to polymorphisms in the CAT gene (P = 0.037), but not for polymorphisms in the Mn-SOD (P = 0.64) gene. In addition, a statistically significant association was observed between null polymorphisms of the GSTT1 and GSTM1 genes and DN in the case and control groups (P = 0.046 and P = 0.035, respectively).

CONCLUSION

Our results showed that the genetic ability to combat oxidative stress may play a major role in DN pathogenesis in Saudi type II DM patients. These polymorphisms in antioxidant enzyme-encoding genes could be used as independent genetic markers for the construction of risk prediction models for kidney-related complications in type II DM patients.