Diabetes and hearing impairment in the United States: Audiometric evidence from the National Health and Nutrition Examination Survey, 1999 to 2004

Background: Diabetes might affect the vasculature and neural system of the inner ear, leading to hearing impairment. Objective: To determine whether hearing impairment is more prevalent among U. S. adults with diabetes. Design: Cross-sectional analysis of nationally representative data. Setting: National Health and Nutrition Examination Survey, 1999 to 2004. Participants: 5140 noninstitutionalized adults age 20 to 69 years who had audiometric testing. Measurements: Hearing impairment was assessed from the pure tone average of thresholds over low or mid-frequencies (500, 1000, and 2000 Hz) and high frequencies (3000, 4000, 6000, and 8000 Hz) and was defined as mild or greater severity (pure tone average > 25 decibels hearing level [dB HL]) and moderate or greater severity (pure tone average > 40 dB HL). Results: Hearing impairment was more prevalent among adults with diabetes. Age-adjusted prevalence of low-or mid-frequency hearing impairment of mild or greater severity in the worse ear was 21.3% (95% CI, 15.0% to 27.5%) among 399 adults with diabetes compared with 9.4% (CI, 8.2% to 10.5%) among 4741 adults without diabetes. Similarly, age-adjusted prevalence of high-frequency hearing impairment of mild or greater severity in the worse ear was 54.1% (CI, 45.9% to 62.3%) among those with diabetes compared with 32.0% (CI, 30.5% to 33.5%) among those without diabetes. The association between diabetes and hearing impairment was independent of known risk factors for hearing impairment, such as noise exposure, ototoxic medication use, and smoking (adjusted odds ratios for low- or mid-frequency and high-frequency hearing impairment were 1.82 [CI, 1.27 to 2.60] and 2.16 [CI, 1.47 to 3.18], respectively). Limitations: The diagnosis of diabetes was based on self-report. The investigators could not distinguish between type 1 and type 2 diabetes. Noise exposure was based on participant recall. Conclusion: Hearing impairment is common in adults with diabetes, and diabetes seems to be an independent risk factor for the condition.