title: Prostaglandin D synthase (beta trace) levels in sleep apnea patients with and without sleepiness.
abstract: BACKGROUND
  Excessive daytime sleepiness (EDS) occurs often in patients with obstructive sleep apnea syndrome (OSAS). However, not all patients present EDS. We hypothesized that the prostaglandin D2 system (PGD2) may be involved in the pathogenesis of EDS associated with OSAS.
  
  
  METHODS
  We measured the levels of lipocalin-type PGD synthase (L-PGDS), the enzyme that produces PGD2, in the serum of 47 patients with OSAS (26 with and 21 without EDS) and 18 healthy controls.
  
  
  RESULTS
  Patients with EDS had higher levels of L-PGDS (0.73+/-0.06 mg/L) than patients without EDS (0.58+/-0.03 mg/L, p<0.05) and controls (0.62+/-0.02 mg/L, p<0.05). L-PGDS levels in patients without EDS and controls were similar.
  
  
  CONCLUSIONS
  The increased levels of circulating L-PGDS detected in OSAS patients with EDS suggest a possible role of the prostaglandin D system in the pathophysiology of daytime sleepiness in these patients.
authors.affiliation: Servei de Analisis Cliniques and Pneumologia, C/Andrea Doria 55, 07014 Palma de Mallorca, Spain. abarcelo@hsd.es
authors.forename: A
authors.initials: A
authors.lastname: Barceló
authors.forename: M
authors.initials: M
authors.lastname: de la Peña
authors.forename: F
authors.initials: F
authors.lastname: Barbé
authors.forename: J
authors.initials: J
authors.lastname: Pierola
authors.forename: M
authors.initials: M
authors.lastname: Bosch
authors.forename: A G N
authors.initials: AG
authors.lastname: Agustí
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D006970:Disorders of Excessive Somnolence / Q000150:complications / Q000201:enzymology*; D005260:Female; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000097:blood*; D054834:Lipocalins; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000379:methods; D011863:Radioimmunoassay; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000201:enzymology*
chemical_list: D054834:Lipocalins; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase