SAN DIEGO – Hearing impairment was more than twice as likely in adults with diabetes, compared with adults without diabetes in a meta-analysis of 13 observational studies.
Screening for hearing impairment for patients with diabetes may improve their ability to communicate and their quality of life, the investigators suggested.
Age-related hearing loss had been found associated with diabetes, but the study may be the first to quantify the strength of that association, Dr. Hirohito Sone, Chika Horikawa, and their associates reported at the annual Scientific Sessions of the American Diabetes Association.
The findings suggest that diabetes contributes to the progression of hearing impairment, though the biological or pathological mechanisms of this are not known, said Dr. Sone, professor of medicine at the University of Tsukuba Mito Medical Center, Ibaraki, Japan, where Ms. Horikawa also is based. They speculated that neuropathy or vascular disease may contribute to the hearing loss.
Eight of the 13 studies were conducted in Asia and five in Western countries. A total of 20,061 participants were included, 7,797 of whom had diabetes. Nine studies focused on the general population and four focused on hospital-based patients.
The studies looked for nonidiopathic progressive hearing impairment that was not due to noise or heredity. Hearing impairment was defined by cutoff values of pure-tone thresholds measured at a frequency range that included 2,000 Hz. Three of the studies matched patients with and without diabetes by age and sex.
Overall, diabetes was associated with a doubling in the odds of developing hearing impairment, the meta-analysis found. The risk was higher for younger adults or hospital-based patients.
Hearing impairment was three times more common in adults younger than 60 years with diabetes, compared with those without diabetes. Hospital-based patients had nearly a fourfold increased risk for hearing impairment if they had diabetes.
In all subsets of participants, there was a positive association between diabetes and hearing impairment.
Further research is needed to determine whether hearing impairment is a complication of diabetes. Research might focus on potential relationships between diabetes severity or duration and the likelihood of hearing impairment, whether people with diabetes have an earlier onset of age-related hearing impairment, and whether good glycemic control might prevent the progression of hearing loss.
The investigators reported having no conflicts of interest.