Objective:To study the relationship between plasma adiponectin concentration and the functional activities of circulating endothelial progenitor cells(EPCs) in patients with coronary artery disease(CAD).Methods:Circulating EPCs were enumerated as AC133+/KDR+ cells via flow cytometry and identified by co-staining with DiI-acLDL and fluorescein isothiocy-anate(FITC)-conjugated lectin under a fluorescent microscope.The migratory capacity of EPCs was measured by modified Boyden chamber assay.Adhesion capacity was performed to count adherent cells after replating EPCs on six-well culture dishes coated with fibronectin.Results:The number of circulating EPCs(AC133+/KDR+ cells) decreased significantly in CAD patients,compared with control subjects [(74.2±12.3) vs(83.5±12.9) cells/ml blood,P<0.01].In addition,the number of EPCs also decreased in CAD patients after ex vivo cultivation [(54.4±8.6) vs(71.9±11.6) EPCs/field,P<0.01].Both circulating EPCs and differentiated EPCs were positively correlated with plasma adiponectin concentration.The functional activities of EPCs from CAD patients,such as migratory and adherent capacities,were also impaired,compared with control subjects,and positively correlated with plasma adiponectin concentration.Conclusion:The study demonstrates that the impairment of the number and functional activities of EPCs in CAD patients is correlated with their lower plasma adiponectin concentrations. Objective: To study the relationship between plasma adiponectin concentration and the functional activities of circulating endothelial progenitor cells (EPCs) in patients with coronary artery disease (CAD). Methods: Circulating EPCs were enumerated as AC133 + / KDR + cells via flow cytometry and identified by co -staining with DiI-acLDL and fluorescein isothiocy-anate (FITC) -conjugated lectin under a fluorescent microscope. The migratory capacity of EPCs was measured by modified Boyden chamber assay. Adhesion capacity was performed to count adherent cells after replating EPCs on six-well culture dishes coated with fibronectin. Results: The number of circulating EPCs (AC133 + / KDR + cells) decreased significantly in CAD patients compared with control subjects [(74.2 ± 12.3) vs (83.5 ± 12.9) cells / ml blood, .In addition, the number of EPCs also decreased in CAD patients after ex vivo cultivation [(54.4 ± 8.6 vs 71.9 ± 11.6 EPCs / field, P <0.01] .Both circulating EPCs and differentiated EPCs were positively c orrelated with plasma adiponectin concentration. The functional activities of EPCs from CAD patients, such as migratory and adherent capacities, were also impaired, compared with control subjects, and positively correlated with plasma adiponectin concentration. Conlusion: The study demonstrates that the impairment of the number and functional activities of EPCs in CAD patients are correlated with their lower plasma adiponectin concentrations.