Characterizing the Effects of Chronic Substance Misuse on Auditory and Vestibular Function - Accumulating reports indicate that substance use disorders (SUDs) and overdoses result in hearing loss (HL) and vestibular loss (VL). This is problematic because hearing and balance are important for communication, employment, mental health, physical independence, and overall quality of life. HL and VL would have a greater negative impact on people with SUDs, as this population already struggles with a higher incidence of mental health issues, unemployment, and poorer quality of life. People of minority status with HL/VL are further marginalized because of socioeconomic and/or cultural barriers to audiological healthcare. Unfortunately, the literature on substance-misuse-related HL is sporadic and primarily consists of case reports describing various degrees of either temporary or permanent HL from illicit drugs or prescribed opioid misuse. Even less is known about the effects of SUDs on the vestibular system. A few studies indicate alcohol misuse impairs balance, and opioids and alcohol disrupt peripheral and central vestibular function. The existing studies suggest differential effects on the inner ear based on substance type and use patterns. There is a critical lack of rigorous research using objective measures to identify the peripheral and central effects of SUDs on hearing and vestibular function. Likewise, the influence of health comorbidity, demographics, socioeconomic position, and substance-use patterns on HL/VL in the SUD population has not been investigated. Our project goals are to improve our knowledge of the impact of SUDs on hearing and vestibular function and to identify who is most at risk for HL/VL. To accomplish these goals, we will be the first to investigate peripheral and central hearing (Aim 1) and vestibular (Aim 2) function in a large cohort of diverse people who have SUDs, recruited across three regionally unique study sites. Data will be compared to an age-sex-race or ethnicity-matched control group without SUDs. Last, we will determine the predictive health, demographic, socioeconomic, and substance-use factors that increase the risk of developing HL/VL secondary to substance misuse (Aim 3). We hypothesize that chronic substance misuse will affect the auditory and/or vestibular systems like mechanisms underlying oto- vestibulotoxic medications. Based on the literature, we hypothesize that more health comorbidities, older age, being of non-Hispanic White background, lower socioeconomic position, and riskier substance-use patterns will predict the severity of HL or VL. Biological sex differences are unclear in the existing HL/VL literature; however, our results will help elucidate sex differences in HL/VL and SUDs. SUDs and overdoses have significantly increased since the coronavirus pandemic and disproportionately so among minority populations. Thus, this work is timely and important because early HL/VL intervention is key to minimizing health and social burdens, but care is impeded in SUD and minority populations. Our findings will enhance awareness among professionals who serve people with SUDs so they can make appropriate diagnoses and recommendations. The results will inform our future work to develop accessible, equitable interventions for people with SUDs and health disparities.
