Gene polymorphisms of superoxide dismutases and catalase in diabetes mellitus

Area of Science:

• Biochemistry
• Genetics
• Endocrinology

Background:

• Hyperglycemia in diabetes mellitus (DM) elevates reactive oxygen species (ROS), damaging vascular tissues.
• Reduced activity of scavenger enzymes is common in DM patients, potentially impairing antioxidant defenses.
• Oxidative stress exacerbates the protective role of scavenger enzymes.

Purpose of the Study:

• Investigate associations between gene polymorphisms of antioxidant enzymes and vascular complications in DM.
• Determine the impact of genetic variations on scavenger enzyme activity and diabetes control.

Main Methods:

• Genotyping of selected antioxidant enzyme genes (SOD1, SOD2, CAT).
• Measurement of serum superoxide dismutase (SOD) activity.
• Comparison of allele and genotype frequencies between diabetic patients (T1DM, T2DM) and controls.
• Analysis of associations with vascular complications (macroangiopathy, microangiopathy) and diabetes control.

Main Results:

• Significant differences in SOD1 and SOD2 allele/genotype distributions were found between diabetic and control groups (p < 0.01).
• Serum SOD activity was significantly lower in T1DM and T2DM patients (p < 0.05).
• SOD1 and SOD2 polymorphisms influenced SOD activity; specific genotypes (SOD1-AA, SOD2-CC) showed higher activity and better diabetes control.
• SOD2 gene polymorphism frequencies differed between diabetic patients with and without macroangiopathy.

Conclusions:

• Oxidative stress in DM is accelerated by increased ROS production and a diminished antioxidant defense system, partly due to single nucleotide polymorphisms (SNPs) in scavenger enzymes.
• SOD1 and SOD2 gene polymorphisms are associated with altered SOD activity and may contribute to vascular complications in diabetes.