Diabetes and hearing impairment in Mexican American adults: a population-based study.

Reports on the relationship between diabetes and hearing loss have been controversial. The present study examined this relationship in 1,740 Mexican American adults using data from the Hispanic Health and Nutrition Examination Survey. Hearing threshold levels were obtained for each participant at the following frequencies: 500, 1000, 2000, and 4000 Hertz (Hz). The thresholds from the worse hearing ear were used in the analyses. Diabetes and insulin use were assessed by self-report. The mean crude hearing thresholds in diabetics were significantly higher than in non-diabetics at each of the four frequencies. However, after adjustment for age, gender, and socioeconomic status, diabetics had a significantly higher mean threshold than non-diabetics only at 500 Hz (mean difference +/- SE: 2.8 +/- 1.2, p = 0.04). Diabetics who were not using insulin had significantly higher thresholds than those who were using insulin at 2000 (mean difference +/- SE: 5.6 +/- 2.6, p = 0.03) and 4000 Hz (7.7 +/- 3.3, p = 0.02). Also, at 4000 Hz, insulin users had a significantly lower mean threshold than non-diabetics (mean difference +/- SE: -4.9 +/- 1.6, p = 0.02). Our data suggest that associations between diabetes and decreased hearing acuity in the higher frequencies are present only amongst diabetic Mexican-Americans who do not use insulin.