Is evaluation of endothelial dysfunction and carotid intima media thickness valuable for predicting coronary heart disease in patients with type II diabetes mellitus?

DOES ENDOTHELIAL DYSFUNCTION AND CAROTID INTIMAMEDIA THICKNESS HAVE A PREDICTIVE VALUE FORCORONARY ARTERY DISEASE IN PATIENTS WITH TYPE IIDIABETES MELLITUS?SUMMARYIs evaluation of endothelial dysfunction and carotid intima media thicknessvaluable for predicting coronary heart disease in patients with type II diabetesmellitus?Purpose: Coronary heart disease (CHD) is frequently encountered in diabeticpatients; however some of the diabetic patients have normal coronary arteries. Thiscross-sectional study was designed to investigate the role of endothelial dysfunction,assessed by flow mediated dilation (FMD) and carotid intima media thickness (IMT),for the prediction of coronary heart disease in patients with type II diabetes mellitus.Methods: Sixty five patients with type II diabetes mellitus (38 male, mean age:56 years), who underwent coronary angiography due to the clinically suspected CHDwere enrolled to this study. Study population was consisted of two groups; one of themhad normal coronary arteries (Group-I) and the other group had significant CHD(Group-II). B-Mode ultrasonography was used to assess both IMT of common carotidartery and FMD at brachial artery. Other confounding biochemical and inflammatorymarkers that may play a role of atherosclerosis, including lipid profiles, fasting andpostprandial glucose levels, HbA1c as well as high sensitivity C- reactive protein andsoluble CD40 ligand, were measured in all patients. Additionally asymmetricdimethylarginine (ADMA) reflecting the endothelial function was also determined.Binary logistic regression analysis was conducted in order to determine the impact ofthese parameters on predicting coronary heart disease.Results: HbA1c and carotid IMT were significantly higher in Group-II (MeanHbA1c: 7.02% in Group-I and 8.63% in Group-II, p=0.001-Mean Carotid IMT: 0.85mm. in Group-I and 1.03 mm. in Group-II, p=0.003). FMD was significantly lower inGroup-II (Mean FMD: 9% in Group-I and 4.93% in Group-II, p=0.001). Highsensitivity C- reactive protein, soluble CD40 ligand and ADMA values did not showany significant difference between two groups (p>0.05). In the binary logisticiregression analysis, four independent variables were found to predict significant CHD;age (OR= 1.14, 95% CI: 1-1.29, p= 0.046), HbA1c (OR=2.08, 95% CI: 1.31-3.31, p=0.002), FMD (OR= 0.81, 95% CI: 0.69-0.97, p= 0.019) and carotid IMT OR=75.87,95% CI: 2.20-2613.72, p= 0.017). The equation derived from the logistic regressionanalysis for predicting the probability of CHD in patients with type II diabetes mellitushad a sensitivity of 85.7%, and a specificity of 80% with an overall accuracy of 83.1%.The area under the receiver operating characteristics (ROC) curve was 0.26 (95% CI:0.14-0.38, p=0.001) for FMD (best cut-off: 6.88%) and 0.74 (95% CI: 0.61-0.87,p=0.001) for IMT (best cut-off: 0.88 mm).Conclusion: We suggested that flow mediated dilation and carotid intima mediathickness with contribution of HbA1c, and age were found to have significantpredictive value for coronary heart disease in patients with type II diabetes. We canuse these parameters in clinical practice before coronary angiography in order toestimate the risk of significant CHD in diabetic patients. Further investigations onindependent patient samples are needed to confirm these findings.ii