title: Endothelial function and circulating endothelial progenitor cells in patients with sleep apnea syndrome.
abstract: BACKGROUND
  Endothelial dysfunction and cardiovascular diseases are frequent in patients with obstructive sleep apnea (OSA). Circulating endothelial progenitor cells (EPCs) contribute to repair dysfunctional endothelium and have been related to increased cardiovascular risk.
  
  
  OBJECTIVE
  We tested the hypothesis that the number of circulating EPCs may be altered in OSA patients.
  
  
  METHODS
  EPCs (CD34+ VEGF-R2+) were isolated and quantified from peripheral blood samples of OSA patients (n = 13) and healthy controls (n = 13) matched for age and sex. All subjects were free of any other known cardiovascular risk factors. The plasma levels of vascular endothelial growth factor (VEGF) were also determined, and the endothelium-dependent and endothelium-independent vascular function was assessed in all subjects.
  
  
  RESULTS
  Patients with OSA had lower levels of EPCs (p < 0.05) and higher plasma levels of VEGF (p < 0.05) than controls. Endothelial function was not different between OSA and controls.
  
  
  CONCLUSIONS
  Patients with OSA free of any other known cardiovascular risk factor show a reduced number of circulating EPCs and an increase in plasma VEGF levels. These alterations may contribute to future endothelial dysfunction in these patients.
authors.affiliation: Servei de Pneumología, Hospital Universitari Son Dureta, Palma de Mallorca, España. mdelapena@hsd.es
authors.forename: Mónica
authors.initials: M
authors.lastname: de la Peña
authors.forename: Antonia
authors.initials: A
authors.lastname: Barceló
authors.forename: Ferran
authors.initials: F
authors.lastname: Barbe
authors.forename: Javier
authors.initials: J
authors.lastname: Piérola
authors.forename: Jaume
authors.initials: J
authors.lastname: Pons
authors.forename: Enric
authors.initials: E
authors.lastname: Rimbau
authors.forename: Olga
authors.initials: O
authors.lastname: Ayllón
authors.forename: Alvar G N
authors.initials: AG
authors.lastname: Agustí
mesh_terms: D018952:Antigens, CD34 / Q000097:blood; D001916:Brachial Artery; D042783:Endothelial Cells / Q000502:physiology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008297:Male; D008875:Middle Aged; D012891:Sleep Apnea Syndromes / Q000503:physiopathology*; D013234:Stem Cells / Q000502:physiology; D040301:Vascular Endothelial Growth Factor Receptor-2; D014664:Vasodilation
chemical_list: D018952:Antigens, CD34; D040301:Vascular Endothelial Growth Factor Receptor-2