BACKGROUND
The relative effect of diabetes on the risk of cardiovascular disease in Asian population is much the same as that in Western populations. Although multiple atherosclerotic risk factors have been documented in Asia, precise estimates of vascular reactivity might provide more critical informations for the prevention and the control of diabetes-related cardiovascular mortality and morbidity. The aims of this study were to estimate the vascular reactivity directly and evaluate its relationship with other cardiovascular risk factors and carotid intimal-media thickness (IMT) in newly-diagnosed Korean type 2 diabetic patients. METHODS: We measured flow-mediated vasodilation (FMD) and endothelial-independent vasodilation (EID) of the brachial artery using high-resolution ultrasonography in total of 121 (M; N = 68, F; N = 53) diabetic patients. We assessed conventional cardiovascular risk factors such as age, smoking, obesity, hypertension, hyperlipidemia or family history of cardiovascular disease and analyzed the association among FMD/EID with cardiovascular risk factors, carotid IMT or the total number of risk factors. RESULTS: The mean values of age, smoking, BMI, waist, systolic blood pressure and diastolic blood pressure were 51.2 +/- 12.3 years, 11.0 +/- 15.8 pack years, 25.0 +/- 3.2 kg/m2, 86 +/- 9 cm, 123 +/- 16 mmHg and 79 +/- 12 mmHg. The mean values of HbA1c, fasting blood glucose, total cholesterol, triglyceride, LDL-cholesterol and HDL-cholesterol were 8.4 +/- 2.0%, 166 +/- 51 mg/dL, 187 +/- 37 mg/dL, 166 +/- 143 mg/dL, 114 +/- 30 mg/dL and 46 +/- 12 mg/dL. FMD and EID were estimated by 6.1 +/- 2.8% and 16.6 +/- 5.6% respectively. The mean/maximal carotid IMT were 0.63 +/- 0.12/0.76 +/- 0.16 mm and the number of risk factors besides diabetes mellitus were 2.3 +/- 1.3. After adjusting age, FMD was associated only with smoking, but EID was associated with smoking, systolic/diastolic blood pressure, mean/maximal carotid IMT and number of risk factors by partial correlations. Age, smoking and EID were independent risk variables for carotid IMT, analyzed by multiple regression test. CONCLUSION: These findings suggest that impaired vascular reactivity detected by EID is closely related to carotid IMT, an useful surrogate marker for atherosclerosis, in newly-diagnosed Korean type 2 diabetic patients.