Glucose, insulin and inner ear pathology.

One hundred consecutive patients with a clinical suspicion of metabolic inner ear disorder were submitted to a 5-hour glucose tolerance test with simultaneous titration of insulin. It was found that 82% of the patients presented abnormal glucose and/or insulin values. The analysis of the results revealed hypo- or hyperglycemia were present in only 41% of the cases, and that all patients had normal fast values for glucose. Hyperinsulinemia was the most frequent abnormality and was found to constitute the determining factor of the inner ear disorders. 26 of the patients presented Meniere's disease. The pathophysiological model for insulin-induced Meniere's disease is discussed. Follow-up data indicate that these patients respond well to a diet with reduced intake of small molecule carbohydrates.