Effects of Insulin-Like Growth Factor (IGF-1) in Patients with Sensorineural Hearing Loss

(1) To test the effect of local administration of insulin-like growth factor-1 (IGF-1) in patients with sensorineural hearing loss (SNHL). (2) To test the effect of local administration of IGF-1 in patients with ototoxicity.

Forty patients with SNHL were included in the study. Their hearing thresholds at different frequencies (0.5, 1, 2, and 4 kHz) along with the average hearing threshold were noted. The patients were then randomly allocated to 2 groups and were treated with IGF-1 via one of the following routes: (1) intratympanic injection and (2) Gelfoam. Patients were followed-up at weekly intervals for 6 weeks but follow-up PTA was done at 3 weeks, 6 weeks, and 6 months only.

Forty patients (25 male, 15 female) participated in the study. Their age ranged from 13 to 63 years, with a mean of 31.3 years. Nineteen (47.5%) patients exhibited some degree of recovery after 6 months of follow-up, while 21 (52.5%) did not exhibit any recovery. Fourteen (35%) patients showed slight recovery (SR), 1 (4%) patient showed marked recovery, and complete recovery was observed in 4 (10%) patients. Twelve of the 20 patients who underwent treatment using Gelfoam showed improvement in hearing (measured as a reduction in hearing threshold), while only 7 of the 20 patients who underwent intratympanic injection showed such improvement. Among adverse reactions, the most common was pain (88%) which typically did not last beyond 3 days. Other adverse reactions observed were dizziness (24%) and headache (20%). One patient suffered from acute suppurative otitis media (ASOM) and had a perforation in the tympanic membrane. However, this was treated successfully with medications.

Intratympanic IGF-1 is a novel drug that has shown early promise in controlling and reversing SNHL.