title: Serum erythropoietin and outcome after ischaemic stroke: a prospective study.
abstract: OBJECTIVE
  Erythropoietin (EPO), which is inversely associated with blood haemoglobin (Hb), exerts neuroprotective effects in experimental ischaemic stroke (IS). However, clinical treatment trials have so far been negative. Here, in patients with IS, we analysed whether serum EPO is associated with (1) initial stroke severity, (2) recovery and (3) functional outcome.
  
  
  METHODS
  Prospective. Controls available at baseline.
  
  
  METHODS
  A Swedish hospital-initiated study with outpatient follow-up after 3 months.
  
  
  METHODS
  Patients (n=600; 64% males, mean age 56 years, controls n=600) were included from the Sahlgrenska Academy Study on IS (SAHLSIS).
  
  
  METHODS
  In addition to EPO and Hb, initial stroke severity was assessed by the Scandinavian Stroke Scale (SSS) and compared with SSS after 3 months (follow-up) as a measure of recovery. Functional outcome was evaluated using the modified Rankin Scale (mRS) at follow-up. Serum EPO and SSS were divided into quintiles in the multivariate regression analyses.
  
  
  RESULTS
  Serum EPO was 21% and 31% higher than in controls at the acute phase of IS and follow-up, respectively. In patients, acute serum EPO was 19.5% higher in severe versus mild IS. The highest acute EPO quintile adjusted for sex, age and Hb was associated with worse stroke severity quintile (OR 1.70, 95% CI 1.00 to 2.87), better stroke recovery quintile (OR 1.93, CI 1.09 to 3.41) and unfavourable mRS 3-6 (OR 2.59, CI 1.15 to 5.80). However, the fourth quintile of EPO increase (from acute to follow-up) was associated with favourable mRS 0-2 (OR 3.42, CI 1.46 to 8.03). Only the last association withstood full adjustment.
  
  
  CONCLUSIONS
  The crude associations between EPO and worse stroke severity and outcome lost significance after multivariate modelling. However, in patients in whom EPO increased, the association with favourable outcome remained after adjustment for multiple covariates.
authors.affiliation: Department of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Center of Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: N David
authors.initials: ND
authors.lastname: Åberg
authors.affiliation: Department of Medical and Clinical Genetics, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Tara M
authors.initials: TM
authors.lastname: Stanne
authors.affiliation: Department for Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Katarina
authors.initials: K
authors.lastname: Jood
authors.affiliation: Department of Occupational and Environmental Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Linus
authors.initials: L
authors.lastname: Schiöler
authors.affiliation: Center of Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden Department for Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Christian
authors.initials: C
authors.lastname: Blomstrand
authors.affiliation: Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Andreasson
authors.affiliation: Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.affiliation: Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden UCL Institute of Neurology, London, UK.
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.affiliation: Department of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden School of Medicine and Public Health, University of Newcastle, New South Wales, Australia.
authors.forename: Jörgen
authors.initials: J
authors.lastname: Isgaard
authors.affiliation: Department of Medical and Clinical Genetics, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Jern
authors.affiliation: Department of Internal Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Svensson
mesh_terms: D002545:Brain Ischemia / Q000097:blood*; D004921:Erythropoietin / Q000097:blood*; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012720:Severity of Illness Index
chemical_list: D006454:Hemoglobins; D004921:Erythropoietin
keywords: EPIDEMIOLOGY; erythropoietin