Associations between Thyroid Stimulating Hormone Levels and Both Severity and Early Outcome of Patients with Ischemic Stroke

Abstract : We aimed to investigate associations between serum thyroid stimulating hormone (TSH) levels and both severity and outcome after ischemic stroke (IS). A total of 731 patients consecutive IS patients were enrolled (mean age 69.4 +/- 15.4, 61.6% men), and serum TSH levels were measured at admission and analyzed according to the tertiles of their distribution (<0.822 vs. 0.822-1.6 vs. >1.6 mUI/l). Associations between TSH and both severity at admission (National Institutes of Health Stroke Scale (NIHSS) scores <5 vs. >= 5) and functional outcome at discharge assessed by the modified Rankin Scale were analyzed using logistic regression and ordinal logistic regression models, respectively. High TSH levels were independently associated with both a decreased risk of NIHSS score >= 5 at admission (prevalence proportion ratio = 0.62; 95% CI 0.41-0.94, p = 0.024 for tertile 3 vs. tertile 1). In addition, patients with high TSH levels had a better functional outcome at discharge (OR 0.43; 95% CI 0.30-0.60, p < 0.001 for tertile 2 vs. tertile 1; OR 0.39; 95% CI 0.27-0.56, p < 0.001 for tertile 3 vs. tertile 1). The mechanisms underlying these associations and their potential exploitation in terms of therapeutic strategies need to be explored.