A prognostic role for Low tri-iodothyronine syndrome in acute stroke patients: A systematic review and meta-analysis

Clin Neurol Neurosurg. 2018 Jun:169:55-63. doi: 10.1016/j.clineuro.2018.03.025. Epub 2018 Mar 31.


Background: Low triiodothyronine (T3) syndrome could be a powerful prognostic factor for acute stroke; yet, a prognostic role for low T3 has not been given enough importance in stroke management. This meta-analysis aimed to evaluate whether low T3 among acute stroke patients could be used as a prognostic biomarker for stroke severity, functional outcome, and mortality.

Methods: Studies that investigated low T3 prognostic roles in acute stroke patients were sought from PubMed/Medline, Embase, and Cochrane databases through 11/23/2016. Pooled estimates of baseline stroke severity, mortality, and functional outcomes were assessed from fixed-effect (FE) and random-effects (RE) models.

Results: Eighteen studies met the inclusion criteria. Six studies (1,203 patients) provided data for low-T3 and normal-T3 patients and were meta-analyzed. Using the FE model, pooled results revealed low-T3 patients exhibited a significantly higher stroke severity, as assessed by the National Institutes of Health Stroke Scale (NIHSS) score at admission (mean difference = 3.18; 95%CI = 2.74, 3.63; I2 = 61.9%), had 57% higher risk of developing poor functional outcome (RR = 1.57; 95%CI = 1.33,1.8), and had 83% higher odds of mortality (Peto-OR = 1.83; 95%CI = 1.21, 1.99) compared to normal-T3 patients. In a univariate meta-regression analysis, the low-T3 and stroke severity association was reduced in studies with higher smokers% (slope = -0.11; P = 0.02), higher hypertension% (slope = -0.11; P = 0.047), older age (slope = -0.54; P = 0.02), or longer follow-up (slope = -0/17, P < 0.01). RE models yielded similar results. No significant publication bias was observed for either outcome using Begg's and Egger's tests.

Conclusions: Low-T3 syndrome in acute stroke patients is an effective prognostic factor for predicting greater baseline stroke severity, poorer functional outcome, and higher overall mortality risk.

Keywords: Ischemic; Neurological; Outcomes; Stroke; Thyroid; Tri-iodothyronine.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Biomarkers / blood
  • Cohort Studies
  • Humans
  • Mortality / trends
  • Prognosis
  • Stroke / blood*
  • Stroke / diagnosis*
  • Stroke / mortality
  • Syndrome
  • Triiodothyronine / blood*


  • Biomarkers
  • Triiodothyronine