Activity of daily living is associated with circulating CD34+/KDR+ cells and granulocyte colony-stimulating factor levels in patients after myocardial infarction.

The study aimed to investigate whether the extent of activities of daily living (ADL) of patients after myocardial infarction affect numbers of circulating CD34(+)/KDR(+) and CD45(+)/CD34(+) cells, which are supposed to protect structural and functional endothelial integrity. In a cross-sectional study, 34 male coronary artery disease patients with a history of myocardial infarction were assessed for times spent per week for specific physical ADL, including basic activities (instrumental ADL), leisure time activities, and sport activities, using a validated questionnaire. Individual specific activity times were multiplied with respective specific metabolic equivalent scores to obtain levels of specific activities. Numbers of circulating CD34(+)/KDR(+) and CD45(+)/CD34(+) cells were analyzed by flow cytometry. Furthermore, the colony-forming capacity of CD34(+) cells and the level of granulocyte colony-stimulating factor (G-CSF) in serum were measured. Analysis revealed that the extent of total activities and basic activities, as well as total activity time, were positively correlated with numbers of circulating CD34(+)/KDR(+) cells (r = 0.60, 0.56, and 0.55, P < 0.05). Higher levels of total activity were also associated with increased colony-forming capacity of CD34(+) cells (r = 0.54, P < 0.05) and with higher systemic levels of G-CSF (r = 0.44, P < 0.05). These findings indicate that even ADL-related activities of coronary artery disease patients after myocardial infarction exert stimulating effects on CD34(+)/KDR(+) cell mobilization, potentially mediated by increased G-CSF levels. This, in turn, potentially contributes to the beneficial effects of exercise on the diseased cardiovascular system.