Exercise training and endothelial progenitor cells in haemodialysis patients.

Haemodialysis patients have few endothelial progenitor cells (EPCs) and an unfavourable cardiovascular outcome. The effects on peripheral blood CD34(+) cells and EPCs of a 6-month walking exercise programme were studied. Thirty dialysis patients (20 males, age 67 +/- 12 years) were prescribed exercise (two daily 10-min home walking sessions at moderate intensity, group E, n = 16) or not prescribed exercise (control, group C, n = 14). On entry and after 6 months peripheral blood CD34(+) cells, EPCs (assessed as CD34(+) cells co-expressing AC133 and vascular endothelial growth factor receptor 2 [VEGFR2], and as endothelial colony-forming units [e-CFU]) and exercise capacity (6-min walking distance, 6MWD) were evaluated. In group E, 6MWD and e-CFU increased significantly during the study period, with no significant changes in CD34(+) or CD34(+) AC133(+) VEGFR2(+) cell numbers. The change in e-CFU was directly and significantly correlated to patient-reported training load. Group C showed no significant change in any variable. In haemodialysis patients, moderate-intensity exercise selectively increased the number of e-CFU.