Three decade change in the prevalence of hearing impairment and its association with diabetes in the United States.

OBJECTIVE: To examine the secular change of the prevalence of hearing impairment over three decades in U.S. adults with and without diabetes.

METHODS: The cross-sectional National Health and Nutrition Examination Surveys (NHANES, the 1971-1973 [NHANES I] and the 1999-2004 [NHANES 1999-2004]) were used. Average pure-tone audiometry thresholds in decibels (dB) at 1, 2, 3, and 4 kHz frequencies of the worse ear were used to represent the participants' hearing status. Any hearing impairment was defined as average pure-tone audiometry threshold of the worse ear >25 dB.

RESULTS: From 1971 to 2004, among adults without diabetes aged 25 to 69 years, the unadjusted prevalence of hearing impairment decreased from 27.9% to 19.1% (P<0.001), but among adults with diabetes there was no significant change (46.4% to 48.5%). After adjustment for age, sex, race, and education, the prevalence of hearing impairment in the NHANES I and NHANES 1999-2004, respectively, was 24.4% (95% confidence interval [CI], 22.3-26.6%) and 22.3% (95% CI, 20.4-24.2) for adults without diabetes and 28.5% (95% CI, 20.4-36.6%) and 34.4 (95% CI, 29.1-39.7%) for adults with diabetes. The adjusted prevalence ratios of hearing impairment for persons with diabetes vs. those without diabetes was 1.17 (95% CI, 0.87-1.57) for the NHANES I and 1.53 (95% CI, 1.28-1.83) for NHANES 1999-2004.

CONCLUSIONS: Persons with diabetes have a higher prevalence of hearing impairment, and they have not achieved the same reductions in hearing impairment over time as have persons without diabetes.