| Purpose: To explore the feasibility of the common carotid artery(CCA)stiffness measured by velocity vector imaging(VVI)in evaluating the vascular endothelial function in people with diabetes mellitus(DM),also the relationship between macrovascular and microvascular endothelial function,and look for new and accurate indicators for early detection and prevention of diabetes microvascular complications.Methods: A total of 32 patients with T2 DM was enrolled,and they were divided into 3 groups: uncomplicated DM(uDM,n=16),complicated DM,(cDM,n=16),and matched subjects without DM(Control,n=18).Flow-mediated vasodilation(FMD)was used to detect vascular endothelial function in each group.Intima-media thickness(IMT)was measured by ultrasound in CCA.VVI was used to evaluate the carotid artery stiffness,images of radial and axial movement of CCA were collected.peak systolic displacement?velocity ?strain?strain rate(maximum displacement?velocity?strain?strain rate,Dmax,Vmax,Smax,SRmax)and corresponding peak time(T-Dmax?T-Vmax?T-Smax?T-SRmax),fractional area change(FAC)and total longitudinal displacement(t-LOD)were measured?recorded and compared.The correlation of VVI between the radial and axial axes of CCA was analyzed and assess the repeatability of VVI.In combination with urinary microalbumin(MAU)in uDM and cDM,the correlation between the VVI?FMD?MAU and IMT was compared,also the correlation between FMD and MAU.Results: FMD results: FMD in cDM was significantly lower than Control and uDM(P < 0.01),while no significant difference between the Control and uDM(P> 0.05).results: MAU in cDM significantly higher than uDM(P<0.05).IMT results: IMT in cDM was significantly higher than Control(P<0.05),while there was no significant difference between cDM and uDM?uDM and group(P>0.05).VVI results:(1)inter-group comparison: Dmax,Vmax,Smax,SRmax,FAC and t-LOD in radial and axial movement of CCA decreased and the corresponding peak time increased significantly in three groups as the condition advanced(P<0.05).(2)intra-group comparison: no significant difference in Dmax,Vmax,Smax,SRmax and corresponding peak time between the near and far wall of each group on radial movement of CCA(P>0.05).Dmax,Vmax,Smax,SRmax and t-LOD of the far wall of axial movement of CCA in each group were significantly lower than those of the near wall(P<0.05),and the corresponding peak time was significantly longer than that of the far wall(P<0.05).(3)the radial movement of CCA was highly and positively correlated with the axial movement(r=0.921,P<0.001).(4)VVI in radial and axial movement of CCA had very good repeatability(ICC>0.75).Results of correlation analysis:(1)VVI in radial and axial movement of CCA were moderately correlated with FMD(0.5?|r|<0.8,P<0.001);about half of the VVI variables in the radial axis of CCA were weakly correlated with MAU(0.3?|r|<0.5,P<0.05)?most of the VVI variables in the axial axis of CCA were moderately or weakly correlated with MAU(0.3?|r|<0.8,P<0.05);only a few VVI variables were weakly correlated with IMT(0.3?|r|<0.5,P<0.05)in both axial and radial axis of CCA.(2)FMD and MAU were weakly and negatively correlated(r=-0.459,P<0.05).Conclusions: 1.The stiffness of CCA changed significantly with the progression of diabetes.2.Changes in CCA stiffness are more sensitive than those in FMD and IMT in DM.3.The stiffness changes in CCA are significantly correlated with changes in vascular endothelial function in DM,which can be used to evaluate the endothelial function of large artery.4.There was no strong correlation between the changes in stiffness and structure of CCA.5.Certain correlation between macro-and micro-vascular endothelial function in DM. |
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