Absence of otoacoustic emissions in insulin-dependent diabetic patients: is there evidence for diabetic cochleopathy?
In order to evaluate cochlear function in Type 1 diabetes mellitus, this study analyses otoacoustic emissions (OAEs) on normal hearing subjects with diabetes and on controls. Patients with Type 1 diabetes (n=60), with a mean age of 31+/-6.23 years, mean disease duration of 17.5+/-8.9 years, and mean HbA1c of 8.1+/-1.8%, of whom 43% had signs of retinopathy and 28% had clinical signs of neuropathy, were studied. All patients underwent an OAE analysis and brainstem-evoked potentials. Fifty-eight normal volunteers were used as controls for the OAE analysis. Seventeen patients (28.3%) had no OAEs in at least one ear and 10% in both ears. The mean intensity of the response was lower in diabetic subjects [7.1+/-4.4 vs. 10.9+/-9.3 dB SPL (sound pressure level)] than in controls. The cochlear impairment was over 5 dB for the 1-kHz frequency, which is the critical level for speech understanding. These findings suggest that cochleopathy can be detected in a relatively high proportion of subjects with Type 1 diabetes in spite of a normal audiometric hearing threshold.
IV Cattedra di Otorinolaringoiatria, Università degli Studi, Via Stampa 11, 20081 Abbiategrasso, Milan, Italy.
Francesco
F
Ottaviani
Nicoletta
N
Dozio
Cesare B
CB
Neglia
Stefano
S
Riccio
Marina
M
Scavini
D000328:Adult; D017668:Age of Onset; D015834:Cochlear Diseases / Q000175:diagnosis* / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000503:physiopathology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D012016:Reference Values