Purpose of review: Insulin-like growth factor 1 (IGF-1) is a hormone necessary for the development, growth, and maintenance of various organs, and has been used as a therapeutic agent in clinical settings. This review aimed to illustrate its role in the auditory systems and its potential use as a therapeutic in the field of otology.
Recent findings: Previous animal studies have indicated the critical role of IGF-1 in the development and maintenance of the auditory system, especially in the cochlea. A clinical study demonstrated a close relationship between the serum level of IGF-1 and the progression of age-related hearing impairment, suggesting its importance in the maintenance of hearing in humans. More recently, its effect on the regeneration of cochlear synapses has been reported using explant cultures, which could explain the course of hearing recovery in patients who underwent topical IGF-1 application for the treatment of sudden sensorineural hearing loss.
Summary: Recent advances in experimental and clinical investigations have revealed the importance of IGF-1 in the maintenance of the auditory function. On the basis of broad targets, its clinical application will expand to the field of otology in the future.