Significance of serum 8-Hydroxydeoxyguanosine levels to the intima-media thickness of the carotid artery in type 2 diabetes

Background: Cardiovascular disease is the largest cause of morbidity and mortality in patients with type 2 diabetes mellitus. Interestingly, previous studies demonstrated that type 2 diabetic patients had a significantly higher concentration of 8-Hydroxydeoxyguanosine (8-OHdG) although it role in the pathogenesis of carotid artery atheroma and insulin resistance has not been identified.

Objective: We investigated the role of serum 8-OHdG levels in the intima-media thickness (IMT) of the carotid artery, and its significance in insulin resistance in type 2 diabetes.

Methods: Fifty patients with disease-onset type 2 diabetes were enrolled and divided into two groups according to the intima-media thickness of the carotid artery (<1.0 mm = group A or ≥1.0 mm = group B). Blood samples from patients were used within one month for the determination of 8-OHdG using a competitive ELISA kit, and other coronary heart disease (CHD) risk factors were also measured.

Results: Patients in Group B showed significant higher levels of serum 8-OHdG compared to that of group A and control. Serum 8-OHdG had significant positive correlations with BMI, SBP, FPG, FINS, HbA1c, TC, and Homa-IR. Similarly, a significant positive correlation existed between the serum 8-OHdG and IMT levels. 8-OHdG, Homa-IR, HbA1c and TC were independently associated with increased IMT in type 2 diabetes patients.

Conclusion: Serum 8-OHdG is a useful indicator for the severity of IMT of the carotid artery and reflects the severity of insulin resistance in type 2 diabetes.