Polymorphic differences in the SOD-2 gene may affect the pathogenesis of nephropathy in patients with diabetes and diabetic complications

The effective treatment of diabetes and the prevention of diabetic complications may be improved by a better understanding of the antioxidant function of intracellular defences against oxidative stress. Polymorphisms in antioxidant genes may determine cellular oxidative stress levels as a primary pathogenic role in diabetes and/or in its complications. SOD-2 was investigated in patients with type 1 diabetes mellitus (T1DM) to ascertain if specific genotypes have any protective influences in the pathogenic mechanisms in diabetes and/or in several different complications, including retinopathy, nephropathy and diabetic controls compared to normal healthy controls. 278 (136M:142F) T1DM patients and 135 (72M:63F) normal, healthy controls were investigated for SOD-2 polymorphism in the mitochondrial targeting sequence with Ala/Val (C-9T) substitution. A significant difference in the C-9-T genotype was observed between patients and normal controls but not between diabetic controls and patients with complications. There were significantly more of the diabetic control (DC, n=62) group (11.3%) than the patients with diabetic nephropathy (DN, n=73) (1.4%) with the CC genotype (p=0.03 and χ2=4.27, OR=9.16 (1.08