Abstract 1290: Impaired Re-Endothelialization Capacity of Endothelial Progenitor Cells (EPCs) and Endothelial Dysfunction in Patients with Pre-Hypertension
Background. Prehypertension is thought to be a precursor of stage 1 hypertension and is associated with increased cardiovascular risk. Endothelial dysfunction has been suggested to contribute to development of hypertension, however, no data on endothelial function and functional capacity of EPCs are available in subjects with prehypertension (defined by a systolic blood pressure of 120–139 mmHg). We therefore examined endothelium-dependent vasodi-lation and in vivo re-endothelialization capacity of EPCs in subjects with prehypertension as compared to healthy subjects.
Methods. Endothelium-dependent, flow-mediated vasodilation (FDD) of the radial artery, a highly sensitive measure of endothelial function, was assessed using high-resolution ultrasound. In vivo re-endothelialization capacity of EPCs was determined after transplantation of 5 × 105 EPCs into nude mice using a carotid endothelial injury model and re-endothelialized area (REA) was assessed after 3 days. Healthy subjects, prehypertensive and hypertensive subjects (n=20) were matched for age, sex and body mass index. All participants had no hypercholesterolemia, no diabetes, no known cardiovascular disease, were non-smokers and did not take any medication.
Results. Endothelium-dependent vasodilation was impaired in prehypertensive subjects (FDD: 9.5±0.7% vs. 12.8±0.6%; P<0.05), and further impaired in hypertensive subjects (FDD: 5.7±0.8%; P<0.05 vs. prehypertensive). Importantly, re-endothelialization capacity of EPCs derived from pre-hypertensive subjects was markedly reduced as compared to EPCs from healthy subjects (REA 20.6±5.9 vs. 35.2±5.4%; P<0.05). In addition, hypertensive subjects had a substantially impaired re-endothelialization capacity of EPCs (21.6±1.4; P<0.05 vs. healthy subjects).
Conclusion. The present study demonstrates for the first time that prehypertensive subjects have an impaired endothelial function and a markedly reduced re-endothelialization capacity of endothelial progenitor cells. These findings provide novel mechanistic insight of how prehypertension may facilitate the development of hypertension and vascular disease in these subjects.