When compared with normal population, people suffering from HIV generally have hearing loss later on in the course of the disease. Previous speculations regarding this issue revolved around harm caused by severe opportunistic infections or the drug therapy that the people took. Since there was a need felt to find the cause of this particular issue, the researchers from the San Diego State University stepped up and did a research to find out exactly why the people suffering from HIV got hearing loss.
Peter Torre, the first author who led the study, is associate professor of Audiology at the San Diego State University collaborated with his colleagues at Georgetown University, Johns Hopkins University and the National Institute on Deafness and Other Communication Disorders (NIDCD).
For their study the researchers invited participants from two long-standing cohorts which involved HIV-infected patients. These patients had to go through an experimental screening procedure designed by Torre himself, where they were assessed for hearing loss and all related symptoms. The second step was a standard hearing test which each participant had to take at the university hospital. This test assessed the patients hearing for tones of various frequencies. The frequency these researchers tested the patients for were from 250 to 8000 Hz (hertz).
To see whether the patients had hearing loss due to other factors like the disease itself or the drug therapy, the patients had to get tested for their white cells levels and were asked about their drug regime as well as patient compliance.
“What we found was a little different from what we expected,” Torre said.
The researchers found that overtime the patients had developed a hearing threshold which was 10 decibel higher than those who did not have AIDS. They also found that these patients had hearing loss regardless of their drug therapy, compliance or blood cell counts. The pattern that emerged in their study, hearing loss for both high and low frequencies is also seen in diabetes. The researchers say they do not know the pathophysiology behind this occurrence.
“Our hope is that by understanding exactly how HIV relates to hearing loss, we can find or develop some medication that is therapeutic or protective against loss of hearing,” Torre said.