Evaluation of vascular endothelial function in metabolic syndrome by ultrasonography

Objective To evaluate the value of vascular endothelial function in patients with metabolic syndrome by high resolution ultrasonography. Methods Totally 42 patients with metabolic syndrome (MS) and 20 healthy subjects were enrolled in the study. The patients with MS were divided into two subgroups according to the presence of carotid plaque or not. By using Celermajar's method, high resolution ultrasonography was used to measure the changes in diameter of brachial artery during reactive hyperemia and after sublingual administration of 0.5mg nitroglycerin. At the same time, intima-medial thickness and carotid plaque of carotid artery were determined. Results There were significant differences of changes in diameter of brachial artery during reactive hyperemia between control subjects and patients with MS(P0.01), and significant differences of change in diameter of brachial artery evoked by sublingual administration of nitroglycerin between control subjects and MS subgroup Ⅱ were also observed (P0.01). There were significant differences of intima-media thickness between control subjects and MS subgroup Ⅱ, but there were no significant differences of such changes between control subjects and subgroupⅠ(P0.05). It was demonstrated by simple linear regression analysis that the percentage of change in diameter of brachial artery during reactive hyperemia was significantly and negatively related to age, systolic blood pressure, diastolic blood pressure, triglyceride, blood glucose and body mass index in patients with MS. Conclusion The impairment of vascular endothelium-dependent dilatation in patients with MS is apparent. The Dysfunction of endothelium-independent dilatation can be seen in the patients with carotid plaque as well.