Exploring the Link Between Exogenous Thyroid Hormones and Dementia Symptoms: A Real-World Disproportionality Analysis of FDA Adverse Event Reporting System

Background: A growing body of evidence indicates a strong association between exogenous thyroid hormone (ETH) and brain health. Establishing the potential relationship between ETH therapy and dementia symptoms is crucial for patients with thyroid disorders. Objective: In this study, we investigate the potential association between ETH therapy and dementia symptoms by exploring the Food and Drug Administration Adverse Event Reporting System (FAERS) database. Methods: Disproportionality analysis (DPA) was conducted using postmarketing data from the FAERS repository (Q1 2004 to Q4 2023). Cases of dementia symptoms associated with ETH therapy were identified and analyzed through DPA using reporting odds ratios and information component methods. Dose and time-to-onset analyses were performed to assess the association between ETH therapy and dementia symptoms. Results: A total of 9889 cases of ETH-associated symptoms were identified in the FAERS database. Dementia accounted for a consistent proportion of adverse drug reactions each year (3.4%-6.3%). The DPA indicated an association between ETH therapy and dementia symptoms, which remained significant even across sex, age, and indications. The median time-to-onset of dementia symptoms was 7.5 days, and the median treatment time was 40.5 days. No significant dose-response relationship was observed. Conclusion and relevance: This study provides evidence for a link between ETH therapy and dementia. Clinicians are therefore advised to exercise vigilance, conduct comprehensive monitoring, and consider individualized dosing to mitigate potential reactions to ETH drug administration.