title: Low free triiodothyronine predicts poor functional outcome after acute ischemic stroke.
abstract: OBJECTIVE
  The aim of this study was to investigate the association of admission serum thyroid hormone concentration with clinical characteristics and functional outcomes in patients after acute ischemic stroke.
  
  
  METHODS
  We retrospectively enrolled 398 consecutive patients admitted to our stroke center between July 2010 and April 2012. Serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were evaluated upon admission. Neurological severity was evaluated using the National Institutes of Health Stroke Scale (NIHSS) upon admission and the modified Rankin Scale (mRS) upon discharge. Poor outcome was defined as a mRS score of 3-5 or death (mRS score 6). Separate analyses were conducted according to outcome and quartile serum FT3 concentration.
  
  
  RESULTS
  In total, 164 patients (41.2%) demonstrated a poor outcome. Age, male gender, blood glucose level, arterial fibrillation, dyslipidemia, smoking, NIHSS score, cardioembolic stroke type, and periventricular hyperintensities, but not FT4 or TSH, were significantly associated with poor functional outcome. Furthermore, poor functional outcome was independently associated with low FT3 (<2.29pg/mL). In comparisons between FT3 quartiles (Q1 [≤2.11pg/mL], Q2 [2.12-2.45pg/mL], Q3 [2.46-2.77pg/mL], Q4 [≥2.78pg/mL]), patients with poor outcomes were more frequent in Q1 than in Q4 after multivariate adjustment. Death was more frequent in Q1 than in Q4 after adjustment for risk factors and comorbidities, but this difference was non-significant after additional adjustment for age and NIHSS score.
  
  
  CONCLUSIONS
  Our data suggest that a lower FT3 value upon admission may predict a poor functional outcome in patients with acute ischemic stroke. Further large-scale prospective studies are required to clarify the role of thyroid hormone in the acute phase of ischemic stroke.
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan. Electronic address: suda-sa@nms.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Suda
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Muraga
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Kanamaru
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Okubo
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Arata
authors.initials: A
authors.lastname: Abe
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Junya
authors.initials: J
authors.lastname: Aoki
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Sakamoto
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Shimoyama
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Chikako
authors.initials: C
authors.lastname: Nito
authors.affiliation: Department of Neurological Science, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kimura
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001921:Brain / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000097:blood* / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy; D005260:Female; D006760:Hospitalization; D006801:Humans; D016015:Logistic Models; D008297:Male; D011379:Prognosis; D020127:Recovery of Function / Q000502:physiology*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000097:blood* / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D015415:Biomarkers; D014284:Triiodothyronine; D013972:Thyrotropin; D013974:Thyroxine
keywords: Acute ischemic stroke; Free triiodothyronine; Stroke outcome; Thyroid hormone