Catherine C. Cowie, PhD, director, diabetes epidemiology program, National Institute of Diabetes and Digestive and Kidney Diseases, reported data in 5,140 individuals aged 20 to 69 years who underwent audiometric testing from 1999 through 2004 as part of the National Health and Nutrition Examination Survey (NHANES).
"The pathologic changes that accompany diabetes could plausibly affect the vasculature or the neural system of the inner ear, resulting in sensorineural hearing impairment," Dr. Cowie explained in a presentation..
In the NHANES trial, pure tone thresholds over lower frequency were obtained for each ear at 500, 1000, 2000, 3000, 4000, 6000, and 8000 Hz using a calibrated audiometer in a soundproof booth. A pure tone average exceeding 25 decibels over a given frequency range in both ears indicated hearing impairment.
After adjusting for age, 31.6% of self-reported diabetics had hearing impairment at the lower frequency range versus 14.5% of the nondiabetic subjects. The figures were 56.8% and 35.8% for the two groups, respectively, at the higher frequency range.
The analysis also revealed that diabetics had higher age-adjusted mean pure tone thresholds at all frequencies than nondiabetics.
Dr. Cowie pointed out that the mechanism for hearing loss in diabetics has not been clarified but may be vascular or neurological.
"The high prevalence of hearing impairment among people with diabetes in our nationally representative sample suggests that screening diabetic patients for hearing impairment is appropriate," she said.
[Presentation title: Diabetes and Hearing Impairment: Audiometric Evidence From the National Health and Nutrition Examination Survey, 1999-2004. Abstract 991-P]
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