A new survey has reviewed current studies on the connection between type 2 diabetes and hearing impairment, revealing that there is ample evidence supporting the idea that diabetes can damage the auditory system. The findings push for clinicians to conduct hearing testing in the management of type 2 diabetes.

People suffering from type 2 diabetes do not produce insulin properly, causing their blood glucose levels to rise higher than normal and preventing their body from maintaining normal glucose levels.

"An association between diabetes and hearing impairment in human subjects has been shown in many, but not all, studies," said Elizabeth Helzner, assistant professor in the Department of Epidemiology and Biostatistics in the School of Public Health at SUNY Downstate Medical Center and first author on the study. "Direct comparison of these studies is complicated due to a lack of consistency in defining hearing impairment and other factors."

Despite this lack of consistency, the connection between type 2 diabetes and hearing impairment is more pronounced in studies that included younger participants, a finding that Helzner believes could be due to the fact that in older samples, alternate causes of age-related hearing impairment prevent researchers from observing the role of diabetes in hearing impairment.

Helzner and her co-author claim that the study of the connection between diabetes and hearing impairment is fairly new, pushing the necessity of well-designed longitudinal studies in order to further explore if patients with diabetes are more prone to early-onset hearing impairment. Furthermore, they believe that we should also focus on determining if the progression of this impairment is connected to diabetes status and disease management factors after controlling for other contributors to hearing sensitivity.

Hearing impairments affects 16.1 percent of adults in the U.S., making it one of the most pervasive disabling conditions in the country. In addition, two-thirds of adults have significant hearing impairment by the age of 70. The condition is associated with numerous detrimental effects, including social isolation, depression and cognitive decline, all of which increase the chances of patient hospitalization and mortality rates.

The findings were published in the January 2016 issue of the journal Current Diabetes Reports.