Circulating microparticles may influence early carotid artery remodeling

Objectives To test associations of circulating microparticles with large artery remodeling before atherosclerosis is detectable. Methods In 232 untreated symptom-free individuals, we measured microparticles of various cellular origins (platelet, endothelial and leukocyte) by specific anti-GPIb (glycoprotein Ib), anti-cluster of differentiation (CD) 105 and anti-CD11a antibodies, and common carotid artery intima media thickness (IMT), internal and external diameters by ultrasound. Results Except for CD105 microparticles with IMT to lumen ratio (IMT/D, P<0.05), microparticles correlated with no carotid dimensions. Significant interactions existed between each microparticle type and IMT on internal and external diameters (GPIb, P<0.01; CD105 and CD11a microparticles P<0.001) consisting of lower trend in increased diameter with increasing IMT in individuals with high than in those with low microparticle level (according to the median) of each origin. As a result, individuals within the third IMT tertile had lower internal diameter in the presence of high than in the presence of low level of GPIb, CD105 or CD11a microparticles (P=0.001, <0.05 or 0.01, respectively), and lower external diameter in the presence of high than in the presence of low level of GPIb and CD11a microparticles (P=0.001 and 0.01). Also, individuals within third IMT tertile exhibited positive correlations of IMT with CD105 and CD11a microparticles (P<0.05), negative correlations of internal diameter with GPIb (P<0.05), CD105 (P<0.05) and CD11a microparticles (P<0.01) and of external diameter with GPIb and CD11a microparticles (P<0.05), and positive correlations of IMT/D with CD105 and CD11a microparticles (P<0.001). Conclusion Increased levels of leukocyte and endothelial-derived microparticles are associated with carotid inward remodeling in individuals with the greatest IMT before atherosclerosis is detectable. J Hypertens 28:789-796 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.