A SOD2 Polymorphism is Associated with Abnormal Quantitative Sensory Testing in Type 2 Diabetic Patients

Area of Science:

• Neurology
• Genetics
• Metabolic Disorders

Background:

• Diabetes mellitus (DM) frequently leads to peripheral nerve damage, known as diabetic polyneuropathy (DPN).
• Mitochondrial dysfunction and increased oxidative stress are implicated as key contributors to DPN pathogenesis.

Purpose of the Study:

• To investigate the association between a specific superoxide dismutase 2 (SOD2) gene single nucleotide polymorphism (SNP) and diabetic polyneuropathy (DPN).
• To evaluate the role of oxidative stress markers in DPN development and progression.

Main Methods:

• Nerve conduction studies and quantitative sensory testing (QST) were conducted on 20 type 2 diabetes mellitus (DM) patients (11 with DPN) and 15 healthy controls.
• Genotyping for the SOD2 SNP (rs5746136) was performed using polymerase chain reaction (PCR).
• Perception thresholds for cold, warm, and vibration were assessed using QST.

Main Results:

• DPN patients exhibited significantly elevated sensory perception thresholds compared to controls and DM patients without DPN.
• The TT genotype of the SOD2 SNP (rs5746136) was found to be more prevalent in patients with DM and DPN.
• DM patients carrying the TT variant demonstrated higher sensory threshold values, suggesting a functional impact.

Conclusions:

• The SOD2 SNP (rs5746136) is associated with increased sensory thresholds in diabetic patients, reinforcing the link between oxidative stress and DPN.
• Quantitative sensory testing and standard nerve conduction studies are valuable diagnostic tools for DPN.