Study: Diabetes Linked to Hearing Loss in Nationally Representative Study

More than 17 percent of the U.S. adult population (36 million people) has hearing loss, including an estimated 30 percent of the U.S. population over 65 years of age. Risk for hearing impairment is most strongly associated with males of lower education with an industrial or military background and leisure-time noise exposure. Given the known associations with hearing loss— cognitive decline, brain atrophy, increased risk of falls— high prevalence rates imply that many individuals are susceptible to possible functional and social limitations.

Nearly 10 percent of the U.S. adult population has diabetes, which has been associated with complications of the retinas, kidneys, and the arteries and nerves in the arms and legs. Other changes that have been known
to occur in the bodies of those with diabetes include a hardening of the internal auditory artery and damage or atrophy to nerves associated with auditory centers in the brain.

These detrimental effects on the auditory system led to this national survey study, which was meant to examine data regarding the relationship between hearing loss and diabetes. Data for this study, “Diabetes and Hearing Impairment in the United States: Audiometric Evidence from the National Health and Nutrition Examination Survey,” was collected by the National Center for Health Statistics from 1999 to 2004. The 5,140 participants were adults aged 20 to 69.

The resulting data showed that changes caused by diabetes could injure the tiny arteries and nerves in the inner ear, causing permanent hearing damage (defined as an impairment of 25 dB or more). On average, individuals with a hearing loss were older than those with normal hearing by an average of 13 years, were more likely to be white, and were more likely to have less than a high school education. Those with a hearing loss were also more likely to have served in the military, worked a job with heavy noise exposure, and more likely to have used ototoxic medications.

All people with a hearing loss were more likely to have diabetes with the exception of those aged 60 to 69 in the testing group, indicating that the effect of diabetes on hearing loss lessened as age became a greater factor. All diabetics had higher hearing thresholds at all frequencies than those without diabetes — and the gap widened at frequencies greater than 2,000 Hz.

Overall, the results indicated that those with diabetes were 28 percent more likely to have a hearing loss of mild or greater severity. Associations between diabetes and high-frequency hearing loss were stronger than associations between diabetes and low- or mid- frequency hearing loss.

Knowing the risks associated with hearing loss and diabetes will help our local community healthcare providers create a happier, healthier local community — and we look forward to doing our part.

Bainbridge KE, Cowie CC, Ho man HJ. Diabetes and Hearing Impairment in the United States: Audiometric Evidence from the National Health and Nutrition Examination Survey, 1999 to 2004. Annals of Internal Medicine. 2008;149(1):1–10.