Thyroid Dysfunction in Ménière's Disease: A Comprehensive Review.

INTRODUCTION: The precise etiology of Ménière's disease (MD) remains unknown; however, given the association of MD with serum antibodies and human leukocyte antigen (HLA) complex, several studies have proposed a relationship between MD and thyroid disorders. Similarly, multiple hypotheses exist regarding the metabolic disturbances of fluctuating thyroid hormone as a potential contributing agent in the development of MD. METHODS: A total of 171 abstracts were identified and screened by 2 independent reviewers. Based on inclusion and exclusion criteria, 8 studies were selected for final analysis. Due to heterogeneity of clinical data, meta-analysis was not feasible. RESULTS: The prevalence of autoimmune thyroid disease and hypothyroidism in MD varied significantly from 1 to 38%. Notable bias was introduced given the lack of standardization of diagnostic criteria across studies. Articles that described autoimmune thyroid-specific antibodies and HLA types also presented inconclusive results. Multiple studies noted a potential etiologic role of hypothyroidism in MD, which was often confounded by thyroxine supplementation. CONCLUSIONS: Despite a potential correlation in the medical literature between thyroid disorders and MD, there is currently no definitive causal relationship. Although most of the present medical literature focuses on autoimmunity, dysregulated thyroid hormone levels may also be implicated in the association of MD with thyroid disorders.