Effect of hyperinsulinism on sensorineural hearing impairment in Ménière's disease: a cohort study.

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.