Thyroid hormones and hearing loss

Hearing loss is a growing global public health issue. Major causes of deafness include infection, genetic mutations, ototoxic drug exposure, aging and endocrine disorders. Thyroid hormone plays a critical role in the development and maturation of the mammalian auditory system. Thyroid dysfunction, the most common endocrine abnormality, frequently leads to hearing impairment. Nevertheless, this thyroid-related deafness is often underrecognized in both patients and clinicians. Previous studies have indicated that thyroid hormone regulates the development of the organ of Corti, the greater epithelial ridge, the stria vascularis, and peripheral auditory neurons. Congenital thyroid dysfunction often results in hearing loss by hindering inner ear development. Acquired thyroid dysfunction can increase the incidence of deafness. Currently, most studies support the efficacy of thyroid hormone replacement therapy for hypothyroidism-related deafness, establishing it as a promising approach. However, treatment for hyperthyroidism-related deafness remains under investigation. This review focuses on the relationship between thyroid dysfunction and hearing loss. The clinical audiological characteristics, pathophysiological mechanisms, and typical pathological manifestations of thyroid-related hearing loss are summarized. And thyroid hormone replacement therapy is concluded. This will help provide new insights and research directions for the precise prevention and treatment of hearing loss associated with thyroid dysfunction.