title: Subclinical hyperthyroidism is a risk factor for poor functional outcome after ischemic stroke.
abstract: OBJECTIVE
  Subclinical hyperthyroidism is associated with adverse cardiovascular events, including stroke and atrial fibrillation. However, its impact on functional outcome after stroke remains unexplored.
  
  
  METHODS
  A total of 165 consecutively recruited patients admitted for ischemic stroke were included in this observational prospective study. Blood samples were taken in the morning within 3 days after symptom onset, and patients were divided into the following 3 groups: subclinical hyperthyroidism (0.1< thyroid-stimulating hormone ≤ 0.44 μU/mL), subclinical hypothyroidism (2.5 ≤ thyroid-stimulating hormone <20 μU/mL), and euthyroid state (0.44< thyroid-stimulating hormone <2.5 μU/mL). Patients with overt thyroid dysfunction were excluded. Follow-up took place 3 months after stroke. Primary outcome was functional disability (modified Rankin Scale), and secondary outcome was level of dependency (Barthel Index). Ordinal logistic regression analysis was used to adjust for possible confounders. Variables previously reported to be affected by thyroid function, such as atrial fibrillation, total cholesterol, or body mass index, were included in an additional model.
  
  
  RESULTS
  Nineteen patients (11.5%) had subclinical hyperthyroidism, and 23 patients (13.9%) had subclinical hypothyroidism. Patients with subclinical hyperthyroidism had a substantially increased risk of functional disability 3 months after stroke compared with subjects with euthyroid state (odds ratio, 2.63; 95% confidence interval, 1.02-6.82, adjusted for age, sex, smoking status, and time of blood sampling). The association remained significant, when including the baseline NIHSS, TIA, serum CRP, atrial fibrillation, body mass index, and total cholesterol as additional variables (odds ratio, 3.95; 95% confidence interval, 1.25-12.47), and was confirmed by the secondary outcome (Barthel Index: odds ratio, 9.12; 95% confidence interval, 2.08-39.89).
  
  
  CONCLUSIONS
  Subclinical hyperthyroidism is a risk factor for poor outcome 3 months after ischemic stroke.
authors.affiliation: Institute for Stroke and Dementia Research, Klinikum der Universität München, Ludwig-Maximilians-University, Marchioninistr. 15, 81377 Munich, Germany.
authors.forename: Frank Arne
authors.initials: FA
authors.lastname: Wollenweber
authors.forename: Vera
authors.initials: V
authors.lastname: Zietemann
authors.forename: Andreas
authors.initials: A
authors.lastname: Gschwendtner
authors.forename: Christian
authors.initials: C
authors.lastname: Opherk
authors.forename: Martin
authors.initials: M
authors.lastname: Dichgans
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood
chemical_list: D013972:Thyrotropin