OBJECTIVETo investigate the correlation between circulating endothelial progenitor cells (EPCs) and the risk factors of coronary heart disease (CHD) as well as the severity of coronary lesions, and its clinical significance.

METHODS42 patients with CHD and 36 patients excluding CHD (control) were studied. Total mononuclear cells were isolated from peripheral blood by Ficoll density gradient centrifugation, and were cultured in M199 medium supplemented with 20% fetal bovine serum, 50 ng/ml vascular endothelial growth factor (VEGF). After 14 days cultured, the numbers of colony-forming units of EPCs were counted by phase-contrast microscope. The relationship between the number of colony-forming units of EPCs and the risk factors of CHD (such as age, gender, hypertension, hypercholesterolemia, diabetes, smoking, positive family history of CHD) as well as the severity of coronary lesions were assessed.

RESULTSThe number of risk factors of CHD was significantly correlated with a reduction of EPCs levels (r = -0.436, P = 0.014). Smoking was associated with significantly lower EPCs levels, whereas a minor but nonsignificant reduction of EPCs levels was detected in the presence of gender, hypertension, and a positive family history of CHD. It was observed that low density lipoprotein (LDL) and uric acid were negatively correlated with the number of colony-forming units of circulating EPCs (P < 0.05). A correlation existed between age, high density lipoprotein, apoprotein A and levels of circulating EPCs, however, this relation was not statistically significant. The number of colony-forming units of circulating EPCs in CHD groups was significantly lower than those in control group (12.8 +/- 6.34 versus 37.0 +/- 5.5, P < 0.001); and the circulating EPCs level of coronary artery lesion group (including single, double, triple vessels disease) was significantly lower than that of control group (P < 0. 01).

CONCLUSIONSThe level of circulating EPCs was inversely associated with the risk factor scores of CHD and the severity of coronary artery lesion. These finding imply that endothelial injury in the absence of sufficient circulating EPCs may affect the degree of the heart disorder and the clinical situation.