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

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.