Abstract 15663: Gender Differences in Circulating Progenitor Cells and Regenerative Capacity
Introduction: Lower levels of circulating progenitor cells (PCs) are reflective of reduced endogenous regenerative capacity and are associated with aging, subclinical vascular disease and higher mortality rates. Whether gender and menopausal state affects PC populations remains a subject of controversy.
Methods: 712 subjects (mean age 48, 65% female), free from coronary artery disease (CAD), and recruited into the Emory Predictive Health Study had circulating levels of PCs measured using flow cytometry of CD45med+ mononuclear cells expressing CD34. Subsets co-expressing CD133, CXCR4 and vascular endothelial growth factor receptor-2 (VEGFR2) epitopes were also measured. Testosterone and estradiol were measured for men and women, respectively.
Results: After adjustment for age, cardiovascular risk factors and body mass, CD34+ (β=-25%, P<0.001), CD34+/CD133+ (β=-22%, P<0.001), CD34+/CXCR4+ (β=-25%, P<0.001) and CD34+/CXCR4+/CD133+ (β=-23%, P<0.001) PCs, but not VEGFR2+ PCs, were lower in women compared to men. With the exception of VEGFR2-expressing progenitor cells, all PC subsets were lower in women compared to men. Estradiol levels positively correlated with PC counts in women (P<0.05), but there was no association between testosterone levels and PC counts in men (P>0.05). Each 100% increase in estradiol was associated with a 9% increase in the aforementioned PC populations (P<0.05) after adjustment for risk factors, menopause and hormone replacement therapy.
Conclusions: Women have lower circulating PC counts compared to men. Higher estrogen levels, but not menopause, was an independent determinant of PC levels in women. Since PCs are reflective of endogenous regenerative capacity, these findings may at least partially explain the risk in adverse CAD events in women with aging and menopause.
Author Disclosures: M.L. Topel: None. S.S. Hayek: None. Y. Ko: None. G.S. Martin: None. E.K. Waller: None. A.A. Quyyumi: None.
- © 2016 by American Heart Association, Inc.