Abstract 530: Diurnal and Day-to-Day Variability of Endothelial Progenitor Cells
Background Circulating endothelial progenitor cells (EPCs) may contribute to vascular repair. Whether a diurnal and/or day-to-day variability of circulating EPCs is physiologically present in healthy adults has not been investigated.
Methods Eighteen healthy adults underwent EPCs count on three different time points: two in the same day between 7:00 and 8:30 and between 12:30 and 14:00; and one in another day between 7:00 and 8:30. EPCs (CD34+CD45lo; CD34+CD45loCD133+; and CD34+CD45loCD31+) were quantified using multi-parameter flow cytometry and an ISHAGE based gating strategy. Variability of EPCs was assessed by coefficient of variation (CV) between time points in the same day and in different days.
Results Baseline participant characteristics are reported in table 1. EPCs measurements and CVs are reported in table 2.
Conclusions In healthy middle-aged adults, circulating EPCs appear to have a marked diurnal variability but a low day-to-day variability. Further study is needed to understand the mechanisms of EPCs variability and its biological significance.
- © 2013 by American Heart Association, Inc.