# Association Between Thyroid Hormone Levels and Disease Prognosis in Guillain–Barré Syndrome: A Retrospective Study

## TL;DR

This study found that low thyroid hormone levels are linked to worse outcomes in Guillain–Barré syndrome patients and are associated with inflammatory markers.

## Contribution

The study identifies thyroid hormone levels as independent risk factors for poor prognosis in GBS and explores their relationship with inflammatory markers.

## Key findings

- Reduced FT4 and T4 levels were significantly associated with poor prognosis in GBS patients.
- Thyroid hormones showed significant correlations with inflammatory markers like ESR, neutrophil count, and NLR.
- PLR was strongly correlated with NLR, and WBC count was highly correlated with neutrophil count.

## Abstract

Guillain–Barré syndrome (GBS) is an immune‐mediated neuropathy characterized by progressive sensory and motor dysfunction, often accompanied by abnormal inflammatory markers and thyroid hormone levels. However, the underlying mechanisms and their impact on prognosis remain incompletely understood. This study aimed to investigate the correlation between thyroid hormone levels and prognosis in GBS, analyze the association between thyroid hormone levels and inflammatory markers, and further explore potential mechanisms and clinical implications.

We retrospectively analyzed clinical data from 182 GBS patients admitted to the First Affiliated Hospital of Shihezi University between December 2019 and April 2024. Data included thyroid hormone levels and inflammatory markers (e.g., neutrophils, leukocytes). Functional status was assessed using the Hughes Functional Grading Scale (HFGS) within 3 months post‐discharge. Patients were stratified into two groups: HFGS score < 3 (good prognosis group, n = 66) and ≥ 3 (poor prognosis group, n = 116). Logistic regression identified prognostic risk factors, Receiver operating characteristic (ROC) curves determined cut‐off values for FT4 and T4, and correlation analyses evaluated relationships between thyroid hormone levels and inflammatory markers.

Reduced FT4 and T4 levels were significantly associated with poor prognosis in GBS patients (p < 0.05). Spearman correlation analysis demonstrated significant associations between thyroid hormones and inflammatory markers. FT3 exhibited negative correlations with erythrocyte sedimentation rate (ESR) (r = −0.342, p < 0.01) and neutrophil count (r = −0.205, p < 0.05), whereas FT4 was positively correlated with NLR (r = 0.219, p < 0.05) and T4 levels (r = 0.506, p < 0.01). T3 was inversely associated with neutrophil count (r = −0.220, p < 0.05). Among inflammatory markers, PLR showed a strong positive correlation with NLR (r = 0.671, p < 0.01), and WBC count was highly correlated with neutrophil count (r = 0.889, p < 0.01). These findings suggest a potential interplay between thyroid hormone regulation and systemic inflammatory responses.

This study suggests that low FT4 and T4 levels are independent risk factors for poor prognosis in GBS patients, with thyroid hormone levels exhibiting certain associations with inflammatory markers.