BackgroundCarotid stiffening is found to be present in patients with type 2 diabetes mellitus (T2DM) together with endothelial dysfunction and it remains unclear about the role of carotid elasticity in the development of diabetic vascular damage. The aim of the study was to investigate changes and significance of carotid artery elasticity in diabetic patients with or without microvascular complications using velocity vector imaging (VVI) analysis. MethodsFifty participants were enrolled and divided into health Control group, the uncomplicated DM (uDM) group and the complicated DM (cDM) group. All of them underwent carotid ultrasound examinations. VVI was used to evaluate the common carotid artery (CCA) elasticity and intima-media thickness (IMT) was also measured. Flow-mediated dilation (FMD) was performed to detect the vascular endothelial function. Then differences and correlations of variables between three groups were compared and analyzed. ResultsCCA elasticity measured by VVI decreased significantly between three groups (p < 0.05), while FMD decreased significantly only in cDM group (p < 0.01) and only IMT in cDM group was significantly thicker than that of Control group (p < 0.05). Representative VVI variables were independently, negatively related to the known duration and microalbuminuria (p < 0.05). All VVI variables were significantly correlated with FMD (0.5 <= |r | <0.8, p < 0.001), and just a small part of VVI variables were significantly correlated with IMT (0.3 <= |r | <0.5, p < 0.05). ConclusionCompared with FMD, CCA elasticity measured by VVI showed more obvious changes in diabetic patients with different levels of vascular damage and may be considered as an alternative indicator in evaluating arterial status of T2DM.