title: Circulating plasma levels of vascular endothelial growth factor in patients with sleep disordered breathing.
abstract: BACKGROUND
  Cellular vascular endothelial growth factor (VEGF) expression is increased in response to regional hypoxia, however, contradictory results were reported on the effects of systemic hypoxemia on circulating VEGF levels. This study investigated plasma concentrations of VEGF in patients with a variable degree of overnight hypoxemia due to sleep disordered breathing (SDB).
  
  
  METHODS
  VEGF levels were assessed by ELISA in non-activated (VEGFbl) and thrombin stimulated platelet rich plasma (VEGFprp) of 45 patients with SDB: Group 1 patients with obstructive sleep apnea and an apnea-hypopnea index (AHI) > 15/h; Group 2 subjects with an AHI < 5/h; Group 3 patients on CPAP treatment for sleep apnea.
  
  
  RESULTS
  39 patients were included in the final analysis. Patients in Group 1 had a higher %time of sleep with SaO2 <90% and a significantly lower mean and minimum overnight oxygen saturation than subjects in Group 2 and patients in Group 3 (P<0.05). Despite significant differences in overnight oxygenation, VEGFbl and VEGFprp concentrations were not significantly different between the three study groups. However, plasma levels of VEGFbl were significantly higher (P = 0.02) in SDB patients with arterial hypertension (n = 19; VEGFbl: 14.0+/-3.3 pg/ml) than in those without arterial hypertension (n = 20; VEGFbl: 10.9+/-5.2 pg/ml). There were no relationships between VEGF levels and polysomnographic oxygenation parameters. In univariate analysis we observed significant relationships for VEGFbl with BMI (C: 0.393; P<0.05) and serum fibrinogen (C: 0.399; P<0.05).
  
  
  CONCLUSIONS
  Circulating plasma VEGF levels in patients with sleep disordered breathing may be unrelated to night time hypoxemia (257 Words).
authors.affiliation: Department of Respiratory and Critical Care Medicine Otto-Wagner-Spital, Vienna, Austria. arschang.valipour@wienkav.at
authors.forename: Arschang
authors.initials: A
authors.lastname: Valipour
authors.forename: Brigitte
authors.initials: B
authors.lastname: Litschauer
authors.forename: Friedrich
authors.initials: F
authors.lastname: Mittermayer
authors.forename: Helmuth
authors.initials: H
authors.lastname: Rauscher
authors.forename: Otto Chris
authors.initials: OC
authors.lastname: Burghuber
authors.forename: Michael
authors.initials: M
authors.lastname: Wolzt
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D045422:Continuous Positive Airway Pressure; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D017286:Polysomnography; D012891:Sleep Apnea Syndromes / Q000097:blood* / Q000628:therapy; D042442:Vascular Endothelial Growth Factors / Q000097:blood*
chemical_list: D042442:Vascular Endothelial Growth Factors; D005340:Fibrinogen; D010100:Oxygen