Putative endothelial progenitor cells are associated with flow-mediated dilation in refractory hypertensives

• Published in: Blood pressure 2008, Vol.17 (5-6), p.298-305
• Main Authors: Oliveras, Anna, de la Sierra, Alejandro, MartÍnez-Estrada, Ofelia M., Larrousse, MarÍa, Vázquez, Susana, Soler, Maria José, Zuasti, Mercedes, Vila, Joan S., Reina, Manuel, Roca-Cusachs, Àlex, Lloveras, Josep
• Format: Article
• Language: English
• Subjects: Adult; Cell Count; Cell Separation; Dilatation, Pathologic - diagnosis; Dilatation, Pathologic - pathology; Endothelial Cells - pathology; Endothelial progenitor cells; endothelium-dependent vasodilation; Flow Cytometry; flow-mediated dilation; Homocysteine - blood; Humans; Hypertension - pathology; Middle Aged; Predictive Value of Tests; reactive hyperaemia; refractory hypertension; Regression Analysis; Stem Cells - pathology; Vasodilation
• ISSN: 0803-7051; 1651-1999
• DOI: 10.1080/08037050802584446

Background. Hypertension has been related to endothelial dysfunction. Patients with refractory hypertension (RH) have a reduced number of endothelial progenitor cells (EPCs). Aim. To evaluate if blood EPC levels relate to endothelium-dependent vasodilation (ED-VD) in RH. Methods. We analyzed 29 RH confirmed by 24-h ambulatory blood pressure monitoring and assessed complete clinical and laboratory evaluation. EPCs were isolated from peripheral mononuclear cells (MNC) by flow cytometry. ED-VD was determined measuring flow-mediated dilation (FMD) by venous occlusion plethysmography. Results. Circulating EPCs 105 MNC (median [Q1-Q3]): 23.0 [4.5-53.8]. FMD (median [Q1-Q3]): 211.7 [79.5-365.8]%. Significant correlations with log-FMD: EPCs (r = 0.469; p = 0.018) and homocysteine (r = −0.414; p = 0.045). There was no collinearity between EPCs and homocysteine. FMD did not correlate with age, gender, office BP, 24-h systolic blood pressure or 24-h diastolic blood pressure, laboratory parameters, C-reactive-protein, left ventricular-mass index, dyslipidaemia, smoking habit and statin or angiotensin system blockers treatment. Multiple linear regression analysis showed that after age-adjustment, EPC (p = 0.027) and homocysteine (p = 0.004) were the only variables that predicted FMD (R = 0.740). After dividing patients according to EPC number, patients in the lower tertile showed a significantly reduced FMD compared with those in the group of the two upper tertiles of EPC: log-FMD (mean±SD): 4.7±0.9 vs 5.6±0.8, respectively (p = 0.031). Conclusions. ED-VD independently correlates with circulating EPCs in RH. Homocysteine is also an independent predictor of lower FMD in such patients.