Circulating level of microparticles and their correlation with arterial elasticity and endothelium-dependent dilation in patients with type 2 diabetes mellitus

Objective: This study was designed to measure the circulating level of microparticles (MP) in patients with type 2 diabetes mellitus versus healthy volunteers and to evaluate their correlation with arterial elasticity and endothelium-dependent dilation.

Methods: Flow cytometry was used to measure the circulating levels of MP, including annexinV+MP, platelet-derived microparticles (PMP), leukocyte-derived microparticles (LMP) and endothelial microparticles (EMP), in 63 patients with type 2 diabetes mellitus and 29 healthy volunteers. Brachial ankle pulse wave velocity (baPWV) and endothelium-dependent flow-mediated dilation (FMD) of the brachial artery were also measured.

Results: The levels of annexinV+MP, PMP, LMP, CD31+/CD42-EMP and CD51+EMP increased significantly in diabetic patients compared with healthy controls (P<0.001). Correlation analysis showed that HbA(1c) was positively correlated to CD31+/CD42-EMP (r(s)=0.337, P=0.008) and CD51+EMP (r(s)=0.266, P=0.038). FMD in diabetic patients was significantly lower than that in healthy individuals (P=0.007). FMD was negatively correlated to CD31+/CD42-EMP (r(s)=-0.441, P=0.008) and CD51+EMP (r(s)=-0.405, P=0.016). baPWV level in diabetic patients was significantly higher than that in healthy individuals (P<0.001). baPWV was positively correlated to CD31+/CD42-EMP (r(s)=0.497, P<0.001) and CD51+EMP (r(s)=0.428, P=0.001). Multiple regression analysis indicated that EMP was an independent risk factor of FMD and baPWV.

Conclusions: The circulating level of microparticles increases in patients with type 2 diabetes. The level of endothelial microparticles is closely associated with vascular dysfunction.