Effects Of Physiological Ischemia Training On Circulating Endothelial Progenitor Cells In Patients With Coronary Heart Disease

Background:Growth of collateral circulation in pathological ischemic myocardium is common protection mechanism in patients with coronary artery disease (CAD). Previous studies have shown that ischemic training of normal skeletal muscle can reduce infarct size and contribute to the myocardial protection. Physiological ischemia training (PIT), which is a kind of isometric exercise, has been shown to improve angiogenesis in remote ischemic heart region of animals. However, clinical research of PIT in CAD patients is still lack.Objective:To investigate the effects of physiological ischemia training (PIT) on the number of circulating endothelial progenitor cells (EPCs), the level of plasma vascular endothelial growth factor (VEGF) and the concentration of nitride oxide (NO) in CAD patients.Method:Twenty patients with CAD were divided into training group (n=10) and control group (n=10). The patients in training group involved a three-month PIT while patients in control group remained sedentary. PIT was induced by isometric exercise (handgrip) with maximal voluntary contraction. Circulation EPCs were measured by flow cytometry at baseline and after training. Plasma concentrations of VEGF and NO were determined by ELISA and the method of nitrate reductase, respectively.Result:EPCs increased significantly in training group, with the number of (0.044±0.016)%after training (P=0.015). VEGF levels in training patients also increased significantly after three months (P<0.01). We found a significant increase in the concentration of NO after three months (P=0.001). After three-month PIT, the number of EPCs was positively correlated with both, the level of VEGF (training group:r=0.727, P=0.017; control group:r=0.785, P=0.007) and the concentration of NO (training group:r=0.923, P=0.000; control group:r=0.778, P=0.008). A positive correlation was observed between the level of VEGF and NO in both groups after three months (P<0.05).Conclusion:PIT increased the number of circulating EPCs, the level of VEGF and the concentration of NO in CAD patients, which may contribute to collateral angiogenesis in the remote ischemia heart region.