Thyroid hormone level is associated with the frequency and severity of Guillain-Barré syndrome.

OBJECTIVE: Guillain-Barré syndrome (GBS) is a neurodegenerative and inflammatory demyelination disorder, and oxidative stress is concerned with the pathogenesis of the disease. Also, we found that thyroid hormone level is correlated to the oxidative and antioxidant status in previous studies. Our study was aimed to find the possible relationship between the frequency and severity of GBS and thyroid hormone levels. MATERIALS AND METHODS: We measured serum levels of thyroid-stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3) in 238 individuals, including 90 GBS, 44 multiple sclerosis and 104 healthy controls. RESULTS: Our findings demonstrate that the patients with GBS had lower TSH and higher FT4, FT4/FT3 than healthy controls in the normal range. Furthermore, it was also shown in our study that TSH levels in patients with GBS were correlated with disease severity measured by the Hughes Functional Grading Scale. CONCLUSION: Lower TSH, higher FT4 and FT4/FT3 stand for the oxidative status and are associated with the incidence and severity of GBS.