Abnormal hearing tests have been noted in human immunodeficiency virus (HIV)–infected patients in several studies, but the nature of the hearing deficit has not been clearly defined. The authors performed a cross-sectional study of both HIV+ and HIV− individuals in Tanzania by using an audiological test battery. The authors hypothesized that HIV+ adults would have a higher prevalence of abnormal central and peripheral hearing test results compared with HIV− controls. In addition, they anticipated that the prevalence of abnormal hearing assessments would increase with antiretroviral therapy (ART) use and treatment for tuberculosis (TB).
Pure-tone thresholds, distortion product otoacoustic emissions (DPOAEs), tympanometry, and a gap-detection test were performed using a laptop-based hearing testing system on 751 subjects (100 HIV− in the United States, plus 651 in Dar es Salaam, Tanzania, including 449 HIV+ [130 ART− and 319 ART+], and 202 HIV−, subjects. No U.S. subjects had a history of TB treatment. In Tanzania, 204 of the HIV+ and 23 of the HIV− subjects had a history of TB treatment. Subjects completed a video and audio questionnaire about their hearing, as well as a health history questionnaire.
HIV+ subjects had reduced DPOAE levels compared with HIV− subjects, but their hearing thresholds, tympanometry results, and gap-detection thresholds were similar. Within the HIV+ group, those on ART reported significantly greater difficulties understanding speech in noise, and were significantly more likely to report that they had difficulty understanding speech than the ART− group. The ART+ group had a significantly higher mean gap-detection threshold compared with the ART− group. No effects of TB treatment were seen.
The fact that the ART+/ART− groups did not differ in measures of peripheral hearing ability (DPOAEs, thresholds), or middle ear measures (tympanometry), but that the ART+ group had significantly more trouble understanding speech and had higher gap-detection thresholds indicates a central processing deficit. These data suggest that: (1) hearing deficits in HIV+ individuals could be a CNS side effect of HIV infection, (2) certain ART regimens might produce CNS side effects that manifest themselves as hearing difficulties, and/or (3) some ART regimens may treat CNS HIV inadequately, perhaps due to insufficient CNS drug levels, which is reflected as a central hearing deficit. Monitoring of central hearing parameters could be used to track central effects of either HIV or ART.
In this cross-sectional study, an audiological assessment was performed on a cohort of human immunodeficiency virus (HIV)+ and HIV− adults in Tanzania. HIV+ subjects had lower distortion product otoacoustic emission levels than HIV− subjects, but audiometric thresholds did not differ. No effect due to tuberculosis treatment was seen. Within the HIV+ group, subjects on antiretroviral therapy (ART) reported greater difficulty both hearing speech in noise and understanding speech. They also had higher gap-detection thresholds. Distortion product otoacoustic emissions and audiometric thresholds did not differ between ART+ and ART− groups. The ART+ group showed changes consistent with a reduction in central auditory processing abilities.Supplemental Digital Content is available in the text.
1DarDar Health Study, Dar es Salaam, Tanzania; 2Department of Otolaryngology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania; 3Creare, Inc., Hanover, New Hampshire, USA; 4Department of Medicine, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA; 5Harvard Medical School, Boston, Massachusetts, USA; 6Department of Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania; and 7Department of Speech, Language and Hearing Sciences, University of Connecticut, Storrs, Connecticut, USA.
This work is supported by grant R01DC009972 from the National Institute on Deafness and Other Communication Disorders (NIDCD).
Dr. von Reyn receives support from the Fogarty International Center, D43-TW006807.
The authors declare no other conflict of interest.
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