Oxidative Stress as a Risk Factor for Hearing Changes in HIV-positive Normal Listeners

Area of Science:

• Otolaryngology
• Infectious Diseases
• Neuroscience

Background:

• Human immunodeficiency virus (HIV) infection can lead to decreased antioxidant levels.
• This deficiency increases vulnerability of inner ear cells and synapses to oxidative stress.
• Oxidative stress can cause auditory alterations, even with normal hearing thresholds.

Purpose of the Study:

• To compare audiological findings in HIV+ individuals (with and without antiretroviral treatment) to healthy controls.
• To investigate the impact of highly active anti-retroviral therapy (HAART) on auditory function in HIV+ individuals.
• To identify subclinical auditory changes in normal-hearing HIV+ individuals.

Main Methods:

• Cross-sectional observational study of 42 normal-hearing adults.
• Groups included: HIV-negative controls (CG), HIV+ without HAART (GI), and HIV+ with HAART (GII).
• Audiological assessments included: conventional and high-frequency audiometry, TEOAEs, efferent pathway assessment, BAEPs, and P300 cognitive potential.

Main Results:

• Statistically significant poorer hearing thresholds in GII compared to CG and GI.
• Reduced presence of TEOAEs and efferent pathway inhibitory effect in HIV+ groups (GI and GII) compared to CG.
• Increased BAEP interpeak intervals I-V in GII compared to CG, indicating slower neural conduction.

Conclusions:

• Normal-hearing HIV+ individuals exhibit audiological deficits, suggesting subclinical auditory pathway alterations.
• Antiretroviral therapy (HAART) may be associated with more pronounced auditory pathway changes.
• Further research is needed to understand the mechanisms and clinical implications of these auditory findings in HIV+ patients.