Endothelial Progenitor Cells and Risk Factors for Coronary Artery Disease
Information source: National Institutes of Health Clinical Center (CC)
Information obtained from ClinicalTrials.gov on June 20, 2008
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Coronary Arteriosclerosis
Sponsored by: National Heart, Lung, and Blood Institute (NHLBI)
This study will measure and compare the levels of endothelial progenitor cells (EPCs) in the
blood of people with and without risk factors for atherosclerosis (hardening of the arteries)
to see if there is a relationship between these cells and cardiovascular risk factors such as
smoking, high cholesterol level and high blood pressure.
Healthy male volunteers between the ages of 21 and 55 years with and without heart disease
risk factors may be eligible for this study. Candidates must have no evidence of coronary or
peripheral vascular disease, proliferative retinopathy, or other chronic disease and no
history of cancer, migraine-type headache, cluster headache, raised intraocular pressure,
raised intracranial pressure, hyperthyroidism.
Participants will undergo the following procedures at the NIH Clinical Center:
- Medical history and physical examination
- Blood tests to measure EPC level and various risk and growth factors
- Brachial reactivity study - This ultrasound study tests how well the subject's arteries
widen. The subject rests on a bed for 30 minutes. An ultrasound measuring device is
placed over the artery just above the elbow. The size of the artery and blood flow
through it are measured before and after inflating a pressure cuff around the forearm.
The pressure cuff stops the flow of blood to the arm for a few minutes. After a
15-minute rest, the drug nitroglycerin is sprayed under the subject's tongue. Before
the nitroglycerin spray and 3 minutes after it, the size of the artery and blood flow
through it are measured again.
Official title: Endothelial Progenitor Cells and Risk Factors for Coronary Artery Disease
Study design: N/A
Evidence suggests that risk factors for atherosclerosis contribute to atherogenesis by
causing endothelial injury. However, little is known about determinants of endothelial cell
repair and regeneration. We propose that mobilization of endothelial progenitor cells (EPCs)
constitutes one mechanism for ongoing endothelial repair. EPCs are a bone marrow derived
cell population that can be isolated from peripheral blood. Among human peripheral
mononuclear cells, EPCs are relatively abundant with an estimated frequency of 1 in 500 to 1
in 1000 cells. Evidence suggests that EPCs can participate in angiogenesis under
pathophysiological circumstances. Under normal conditions, however, adult organisms undergo
little if any active angiogenesis. One explanation for this set of observations is that high
circulating levels of EPCs may exist to allow these cells to participate in functions beyond
angiogenesis. We hypothesize that one such function is in the repair of ongoing endothelial
injury. To test this hypothesis, we will measure peripheral blood EPC activity by
ascertaining the number of EPC colony forming units from peripheral blood sampling. We
intend to correlate this biological determinant with the degree of endothelial dysfunction
assessed by flow-mediated brachial artery reactivity, and an atherosclerotic risk
stratification method developed by the Framingham study. We hypothesize that a correlation
will exist between the atherosclerotic risk profile, endothelial function and EPC activity
and that the EPC activity will therefore become a novel surrogate biological marker for
cumulative cardiovascular risk.
Minimum age: N/A.
Maximum age: N/A.
Men: aged 21 and above with or without cardiovascular risk factors
Women - post menopausal (based on clinical history) with and without cardiovascular risk
History of cancer
Evidence of proliferative retinopathy
History of migraine-type headache
History of cluster headache
History of raised intraocular pressure
History of raised intracranial pressure
Hypersensitivity to organic nitrates
History of hyperthyroidism
Any intercurrent illness
Any other chronic disease not including cardiovascular risk factors.
No current medications including vitamins for at least 1 week.
Locations and Contacts
National Heart, Lung and Blood Institute (NHLBI), Bethesda, Maryland 20892, United States
Shi Q, Rafii S, Wu MH, Wijelath ES, Yu C, Ishida A, Fujita Y, Kothari S, Mohle R, Sauvage LR, Moore MA, Storb RF, Hammond WP. Evidence for circulating bone marrow-derived endothelial cells. Blood. 1998 Jul 15;92(2):362-7.
Asahara T, Murohara T, Sullivan A, Silver M, van der Zee R, Li T, Witzenbichler B, Schatteman G, Isner JM. Isolation of putative progenitor endothelial cells for angiogenesis. Science. 1997 Feb 14;275(5302):964-7.
Ross R. The pathogenesis of atherosclerosis: a perspective for the 1990s. Nature. 1993 Apr 29;362(6423):801-9. Review.
Starting date: March 2001
Ending date: March 2003
Last updated: March 3, 2008