Number and migratory activity of circulating endothelial progenitor cells inversely correlate with risk factors for coronary artery disease

Recent studies provide increasing evidence that postnatal neovascularizatio n involves bone marrow-derived circulating endothelial progenitor cells (EP Cs). The regulation of EPCs in patients with coronary artery disease (CAD) is unclear at present. Therefore, we determined the number and functional a ctivity of EPCs in 45 patients with CAD and 15 healthy volunteers. The numb ers of isolated EPCs and circulating CD34/kinase insert domain receptor (KD R)positive precursor cells were significantly reduced in patients with CAD by approximate to 40% and 48%, respectively. To determine the influence of atherosclerotic risk factors, a risk factor score including age, sex, hyper tension, diabetes, smoking, positive family history of CAD, and LDL cholest erol levels was used. The number of risk factors was significantly correlat ed with a reduction of EPC levels (R=-0.394, P=0.002) and CD34-/KDR-positiv e cells (R=-0.537, P <0.001). Analysis of the individual risk factors demon strated that smokers had significantly reduced levels of EPCs (P <0.001) an d CD34-/KDR-positive cells (P=0.003). Moreover, a positive family history o f CAD was associated with reduced CD34-/KDR-positive cells (P=0.011). Most importantly, EPCs isolated from patients with CAD also revealed an impaired migratory response, which was inversely correlated with the number of risk factors (R=-0.484, P=0.002). By multivariate analysis, hypertension was id entified as a major independent predictor for impaired EPC migration (P=0.0 43). The present study demonstrates that patients with CAD revealed reduced levels and functional impairment of EPCs, which correlated with risk facto rs for CAD. Given the important role of EPCs for neovascularization of isch emic tissue, the decrease of EPC numbers and activity may contribute to imp aired vascularization in patients with CAD. The full text of this article i s available at http://www.circresaha.org.