Lower serum free triiodothyronine levels are associated with symptoms of depression after ischemic stroke.

Objective: Anxiety and depression symptoms are common after stroke. Changes in thyroid axis hormones have been reported to contribute to these symptoms in clinically euthyroid subjects with and without adjacent somatic pathology. This study aimed to determine associations between serum thyroid axis hormone levels, depression and anxiety symptoms in patients who experienced acute ischemic stroke (AIS).

Methods: In total, 169 patients participated in the study. Serum thyroid stimulating hormone, free tetraiodothyronine (FT4) and free triiodothyronine (FT3) levels were assayed on admission and upon discharge from the hospital. Screening for anxiety and depression symptoms was performed with the Hospital Anxiety and Depression Scale twice - while in the hospital and at the end of rehabilitation course.

Results: In the acute period after AIS, 19.2% of all patients showed symptoms of anxiety and 26.0% - symptoms of depression, while during the subacute period these proportions have increased up to 30.3% and 32.6%. No significant associations between thyroid axis hormones and anxiety were determined for both periods. Serum FT3 levels and FT3/FT4 ratio on admission were significantly lower in patients with symptoms of depression compared to those without. After controlling for possible confounders, lower serum FT3 levels remained significantly associated with higher odds of depression in the acute (OR = 1.85; 95% CI: 1.05-3.23, p = 0.03) and subacute periods (OR = 2.50; 95% CI: 1.06-5.88, p = 0.04) after AIS.

Conclusions: FT3 serum levels on admission while in the hospital as well as at the end of rehabilitation course may predict post-stroke depression symptoms.