Objective: To compare the degree of sensorineural hearing loss in patients with Ménière's disease (MD) with and without hyperinsulinism by different methods of assessment.
Study design: Historical cohort study.
Setting: Ménière's Disease Care and Research Clinics of Hospital de Clinicas de Porto Alegre, a tertiary care university hospital in Southern Brazil.
Patients: Patients with a definite diagnosis of MD based on the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) guidelines.
Intervention: Patients were assessed by glucose overload tests (5-h glucose and insulin curves) and under baseline physiological conditions (Homeostasis Model Assessment/Insulin Resistance [HOMA-IR], Quantitative Insulin Sensitivity Check Index [QUICKI], and glucose/insulin ratio). These patients underwent annual pure-tone audiometry and were analyzed using 4-tone average (FTA), that is, arithmetic mean of 500, 1,000, 2,000, and 3,000 Hz, during the third, fourth, and fifth years of disease progression.
Main outcome measure: Hearing loss assessed by FTA and classified in Stages I to IV (AAO-HNS).
Results: Forty-nine (76.6%) patients were defined as hyperinsulinemic and 15 (23.4%) as normoinsulinemic. Impairment on FTA was higher in the hyperinsulinemic group (52.04 ± 17.5 versus 39.75 ± 9.20, p = 0.027) when assessed by the 5-hour insulin curve. Hyperinsulinemic subjects were 3.5 times more likely to develop hearing damage greater than 40 dB (i.e., Stages III and IV) than normoinsulinemic subjects (OR = 3.52; 95% CI, 1.05-11.76). A moderate correlation between the insulin curve and the HOMA-IR was found (r = 0.524, p = 0.001).
Conclusion: Hyperinsulinism in MD is associated with greater clinical hearing damage.