Circulating angiogenic cell populations, vascular function, and arterial stiffness

Objective: Several bone marrow-derived cell populations have been identified that may possess angiogenic activity and contribute to vascular homeostasis in experimental studies. We examined the extent to which lower quantities of these circulating angiogenic cell phenotypes may be related to impaired vascular function and greater arterial stiffness. Methods: We studied 1948 Framingham Heart Study participants (mean age, 66 ± 9 years; 54% women) who were phenotyped for circulating angiogenic cells: CD34+, CD34+/KDR+, and early outgrowth colony forming units (CFU). Participants underwent non-invasive assessments of vascular function including peripheral arterial tone (PAT), arterial tonometry, and brachial reactivity testing. Results: In unadjusted analyses, higher CD34+ and CD34+/KDR+ concentrations were modestly associated with lower PAT ratio (β= -0.052 ± 0.011, P< 0.001 and β= -0.030 ± 0.011, P= 0.008, respectively) and with higher carotid-brachial pulse wave velocity (β= 0.144 ± 0.043, P= 0.001 and β= 0.112 ± 0.043, P= 0.009), but not with flow-mediated dilation; higher CD34+ was also associated with lower carotid-femoral pulse wave velocity (β= -0.229 ± 0.094, P= 0.015). However, only the association of lower CD34+ concentration with higher PAT ratio persisted in multivariable analyses that adjusted for standard cardiovascular risk factors. In all analyses, CFU was not associated with measures of vascular function or arterial stiffness. Conclusions: In our large, community-based sample of men and women, circulating angiogenic cell phenotypes largely were not associated with measures of vascular function or arterial stiffness in analyses adjusting for traditional risk factors.