Aging, exercise, and endothelial progenitor cell clonogenic and migratory capacity in men

Abstract

Numerical and functional impairment of circulating endothelial progenitor cells (EPCs) is thought to contribute to vascular aging and the associated increase in cardiovascular risk. We tested the following hypotheses: 1) EPC clonogenic and migratory capacity decrease progressively with age in healthy, sedentary adult men; and 2) regular aerobic exercise will improve EPC clonogenic and migratory capacity in previously sedentary middle-aged and older men. Peripheral blood samples were collected from 46 healthy sedentary men: 10 young (26 ± 1 yr), 15 middle-aged (47 ± 1 yr), and 21 older (63 ± 1 yr). Mononuclear cells were isolated and preplated for 2 days, and nonadherent cells were further cultured for 7 days to determine EPC colony-forming units. Migratory activity of EPCs was determined using a modified Boyden chamber. Ten sedentary middle-aged and older men (59 ± 3 yr) were studied before and after a 3-mo aerobic exercise intervention. The number of EPC colony-forming units was ∼75% lower ( P < 0.01) in middle-aged (12 ± 3) and older (8 ± 2) compared with young (40 ± 7) men. There was no difference in colony count between middle-aged and older men. EPC migration (fluorescent units) was significantly reduced in older (453 ± 72) compared with young (813 ± 114) and middle-aged (760 ± 114) men. The exercise intervention increased ( P < 0.05) both EPC colony-forming units (10 ± 3 to 22 ± 5) and migratory activity (683 ± 96 to 1,022 ± 123) in previously sedentary middle-aged and older men. These results provide further evidence that aging adversely affects EPC function. Regular aerobic-endurance exercise, however, is an effective lifestyle intervention strategy for improving EPC clonogenic and migratory capacity in middle-aged and older healthy men.