Early detection of atherosclerosis in type 2 diabetic patients by endothelial dysfunction and intima-media thickness.

UNLABELLED: Endothelial dysfunction (ED) is regarded as an early functional marker and intima-media thickness (IMT) as an early morphological marker of atherosclerosis. The aim of this study was to evaluate whether peripheral endothelial function and common carotid IMT are impaired in type 2 diabetic patients with inadequate glycemic control. MATERIAL AND METHODS: We examined 20 subjects--10 controls (aged 54.2 +/- 4.37 years) and 10 type 2 diabetic patients (aged 55.6 +/- 3.66 years) with HbA1c level >8.5% (mean 9.25% +/- 0.54%), with an average duration of diabetes of 5.65 +/- 2.34 years, all without clinical evidence of atherosclerosis. B-mode ultrasonography was used to assess both intima-media thickness in the common carotid artery and endothelium function in the brahial artery. In order to evaluate endothelium function brachial artery diameter was measured at rest, during reactive hyperemia, which causes endothelium-dependent vasodilation and after sublingual administration of nitroglycerin (500 microg), which causes endothelium-independent vasodilation. RESULTS: There was no statistical difference between the two groups regarding age. Systolic blood pressure, diastolic blood pressure, total cholesterol were higher and HDL-cholesterol was lower in the diabetic group, but the differences didn't reach statistical significance. Triglycerides concentration and BMI were significant greater in the diabetic group (triglycerides-204 +/- 48.5 mg/dl vs. 117 +/- 22.2 mg/dl, p<0.0001; BMI-28.6 +/- 1.28 kg/m2 vs. 26.7 +/- 1.93 kg/m2, p=0.021). Diabetic subjects had significantly impaired flow-mediated vasodilation (FMD) in the brachial artery compared with control group (5.65% +/- 1.42% vs. 7.11% +/- 1.01%, p=0.016). Endothelium-independent vasodilation induced by nitroglycerin did not differ between the two groups (15.4% +/- 2.01% in diabetic subjects vs. 15.7% +/- 2.58% in control subjects, p=0.75). Intima-media thickness was significantly increased in diabetic patients (0.87 +/- 0.07 mm vs. 0.77 +/- 0.06, p=0.0022). CONCLUSION: In diabetic patients with inadequate glycemic control and without clinical evidence of atherosclerosis endothelial function assessed by FMD is significantly impaired and IMT is significantly greater compared to nondiabetic healty subjects. Large clinical trials should evaluate if in clinical practice FMD and IMT are useful in identification of high-risk subjects.