June 16 (HealthDay News) -- Hearing impairment may be a common, under-recognized complication of diabetes, suggests a U.S. study.

"We found that hearing loss was much more common in people with diabetes than people without the disease. The hearing loss we detected did not seem to be caused by other factors such as exposure to loud noises, certain medicines, and smoking," lead researcher Kathleen E. Bainbridge said in a prepared statement.

She and her colleagues analyzed data from 5,140 people, ages 20 to 69, who completed a hearing test and a diabetes questionnaire as part of the National Health and Nutrition Examination Survey from 1999 to 2004.

The age-adjusted prevalence of low- or mid-frequency hearing impairment of mild or greater severity in the ear with the worst hearing was 21.3 percent among the 399 adults with diabetes compared to 9.4 percent among the 4,741 adults without diabetes.

The age-adjusted prevalence of high-frequency hearing impairment of mild or greater severity in the ear with the worst hearing was 54.1 percent among adults with diabetes and 32 percent among those without diabetes.

Diabetes can damage small blood vessels and nerves in the body.

"It is possible that high blood sugar levels damage the small blood vessels and nerves of the inner ear, resulting in hearing impairment. People with diabetes might benefit from having their hearing checked," Bainbridge said.

The study was published on the Web site of the journal Annals of Internal Medicine.

The editors of the journal noted that diabetes was self-reported by the people in this study and was verified in only a small percentage of participants. In addition, the researchers didn't distinguish between type 1 and type 2 diabetes, and participants self-reported their history of noise exposure.

SOURCE: Annals of Internal Medicine, news release, June 16, 2008