title: Plasma endothelin-1 levels neither increase nor correlate with neurological scores, stroke risk factors, or outcome in patients with ischemic stroke.
abstract: OBJECTIVE
  Endothelins (ETs) are potent vasoconstrictors and may play a role in the pathophysiology of several diseases. Limited and controversial data exist on their role in human ischemic stroke. We planned a prospective, observational, and longitudinal clinical study to test whether ET-1 levels increase in various phases of ischemic stroke and whether the ET-1 levels correlate with neurological scores, stroke etiology, stroke risk factors, or final outcome.
  
  
  METHODS
  We measured plasma ET-1 levels with a sandwich-enzyme immunoassay method in 101 consecutive patients with ischemic stroke on admission and 1 week, 1 month, and 3 months after stroke and in 101 sex- and age-matched control subjects. At each sampling, the patients underwent a complete neurological evaluation. All stroke risk factors were recorded, an array of laboratory tests were performed, and the subtype of ischemic stroke was determined. The patients were contacted 3 years later for prognostic determination.
  
  
  RESULTS
  ET-1 levels in patients (2.4+/-1.3 pg/mL on admission, 2.2+/-1.4 pg/mL at 1 week, 2.1+/-1.4 pg/mL at 1 month, and 2.1+/-1.2 pg/mL at 3 months) were not different from those of the control subjects (2.2+/-0.9 pg/mL) at any time point. No correlation was found between the ET-1 levels and stroke etiology, stroke risk factors, stroke recurrence risk, age, sex, or neurological scores, except that ET-1 levels correlated with the use of warfarin and with body mass index.
  
  
  CONCLUSIONS
  Plasma ET-1 levels were normal in patients with ischemic stroke. Our findings cannot exclude a role of ETs in the pathophysiology of ischemic stroke because plasma levels might not accurately reflect intracerebral concentrations, but they also do not support the occurrence of a major plasma ET-1 level increase at any phase of stroke. Our patient population is the largest ever reported in whom ET-1 levels were measured, but it consisted of mild and moderately ill patients with stroke due to the study design, of which the aim was long-term observation, which excludes severely ill patients.
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: E
authors.initials: E
authors.lastname: Haapaniemi
authors.forename: T
authors.initials: T
authors.lastname: Tatlisumak
authors.forename: K
authors.initials: K
authors.lastname: Hamel
authors.forename: L
authors.initials: L
authors.lastname: Soinne
authors.forename: C
authors.initials: C
authors.lastname: Lanni
authors.forename: T J
authors.initials: TJ
authors.lastname: Opgenorth
authors.forename: M
authors.initials: M
authors.lastname: Kaste
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use; D015992:Body Mass Index; D002545:Brain Ischemia / Q000150:complications*; D019332:Endothelin-1 / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009420:Nervous System / Q000503:physiopathology*; D011379:Prognosis; D012016:Reference Values; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology*; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D019332:Endothelin-1; D014859:Warfarin