title: Gender and Endothelial Progenitor Cell Number in Middle-Aged Adults.
abstract: BACKGROUND: Between the ages of 45 and 65 years, the prevalence of cardiovascular disease is significantly lower in women compared with men. Circulating bone marrow-derived endothelial progenitor cells (EPCs) play an important role in vascular repair. Reduced EPC number is predictive of more cardiovascular events. It is currently unknown whether there is a sex-difference in EPC number in middle-aged adults.  OBJECTIVE: We tested the hypothesis that circulating EPC number is higher in middle-aged women than men.  METHODS: Peripheral blood samples were collected from 58 sedentary adults, 29 men (57 ± 1 yr) and 29 women (58 ± 1 yr). Mononuclear cells were isolated and fluorescence-activated cell sorting (FACS) analysis of cells negative for CD45 was performed for those positive for CD34, and triple positive for CD34, VEGFR-2, and CD133 according to the recommendations of the International Society for Hematotherapy and Graft Engineering.  RESULTS: The number of CD45(-)/CD34(+) and CD45(-)/CD34(+)/ VEGFR-2(+)/CD133(+) were not significantly different between women and men (0.055 ± 0.006% vs 0.069 ± 0.008% and 0.0013 ± 0.0003% vs 0.0018 ± 0.0004%, respectively).  CONCLUSIONS: These results demonstrate no sex-difference in EPC number in middle-age adults. Therefore, it is unlikely that differences in EPC number contribute to the gender-related differences in the prevalence of cardiovascular events in this population.
authors.affiliation: Integrative Vascular Biology Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, Colorado.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Stauffer
authors.forename: Owen J
authors.initials: OJ
authors.lastname: Maceneaney
authors.forename: Erich J
authors.initials: EJ
authors.lastname: Kushner
authors.forename: Jennifer N
authors.initials: JN
authors.lastname: Cech
authors.forename: Jared J
authors.initials: JJ
authors.lastname: Greiner
authors.forename: Christian M
authors.initials: CM
authors.lastname: Westby
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Desouza