Reduced white matter maturation in the central auditory system of children living with HIV.

Introduction: School-aged children experience crucial developmental changes in white matter (WM) in adolescence. The human immunodeficiency virus (HIV) affects neurodevelopment. Children living with perinatally acquired HIV (CPHIVs) demonstrate hearing and neurocognitive impairments when compared to their uninfected peers (CHUUs), but investigations into the central auditory system (CAS) WM integrity are lacking. The integration of the CAS and other brain areas is facilitated by WM fibers whose integrity may be affected in the presence of HIV, contributing to neurocognitive impairments. Methods: We used diffusion tensor imaging (DTI) tractography to map the microstructural integrity of WM between CAS regions, including the lateral lemniscus and acoustic radiation, as well as between CAS regions and non-auditory regions of 11-year-old CPHIVs. We further employed a DTI-based graph theoretical framework to investigate the nodal strength and efficiency of the CAS and other brain regions in the structural brain network of the same population. Finally, we investigated associations between WM microstructural integrity outcomes and neurocognitive outcomes related to auditory and language processing. We hypothesized that compared to the CHUU group, the CPHIV group would have lower microstructural in the CAS and related regions. Results: Our analyses showed higher mean diffusivity (MD), a marker of axonal maturation, in the lateral lemniscus and acoustic radiations, as well as WM between the CAS and non-auditory regions predominantly in frontotemporal areas. Most affected WM connections also showed higher axial and radial diffusivity (AD and RD, respectively). There were no differences in the nodal properties of the CAS regions between groups. The MD of frontotemporal and subcortical WM-connected CAS regions, including the inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and internal capsule showed negative associations with sequential processing in the CPHIV group but not in the CHUU group. Discussion: The current results point to reduced axonal maturation in WM, marked by higher MD, AD, and RD, within and from the CAS. Furthermore, alterations in WM integrity were associated with sequential processing, a neurocognitive marker of auditory working memory. Our results provide insights into the microstructural integrity of the CAS and related WM in the presence of HIV and link these alterations to auditory working memory.

An Automated Virtual Reality Program Accurately Diagnoses HIV-Associated Neurocognitive Disorders in Older People With HIV.

Background: HIV-associated neurocognitive disorders (HANDs) remain prevalent despite antiretroviral therapy, particularly among older people with HIV (PWH). However, the diagnosis of HAND is labor intensive and requires expertise to administer neuropsychological tests. Our prior pilot work established the feasibility and accuracy of a computerized self-administered virtual reality program (DETECT; Display Enhanced Testing for Cognitive Impairment and Traumatic Brain Injury) to measure cognition in younger PWH. The present study expands this to a larger sample of older PWH. Methods: We enrolled PWH who were ≥60 years old, were undergoing antiretroviral therapy, had undetectable plasma viral loads, and were without significant neuropsychological confounds. HAND status was determined via Frascati criteria. Regression models that controlled for demographic differences (age, sex, education, race/ethnicity) examined the association between DETECT's cognition module and both HAND status and Global Deficit Score (GDS) derived via traditional neuropsychological tests. Results: Seventy-nine PWH (mean age, 66 years; 28% women) completed a comprehensive neuropsychological battery and DETECT's cognition module. Twenty-five (32%) had HAND based on the comprehensive battery. A significant correlation was found between the DETECT cognition module and the neuropsychological battery (r = 0.45, P < .001). Furthermore, in two separate regression models, HAND status (b = -0.79, P < .001) and GDS impairment status (b = -0.83, P < .001) significantly predicted DETECT performance. Areas under the curve for DETECT were 0.78 for differentiating participants by HAND status (HAND vs no HAND) and 0.85 for detecting GDS impairment. Conclusions: The DETECT cognition module provides a novel means to identify cognitive impairment in older PWH. As DETECT is fully immersive and self-administered, this virtual reality tool holds promise as a scalable cognitive screening battery.

Mild Cognitive Impairment, But Not HIV Status, is Related to Reduced Awareness of Level of Cognitive Performance Among Older Adults.

OBJECTIVE: Self-assessment of cognitive abilities can be an important predictor of clinical outcomes. This study examined impairments in self-assessments of cognitive performance, assessed with traditional neuropsychological assessments and novel virtual reality tests among older persons with and without human immunodeficiency virus (HIV) and mild cognitive impairment (MCI). METHODS: One hundred twenty-two participants (82 persons with HIV; 79 MCI+) completed a traditional neuropsychological battery, DETECT virtual reality cognitive battery, and self-reported their general cognitive complaints, depressive symptoms, and perceptions of DETECT performance. Relationships between DETECT performance and self-assessments of performance were examined as were the correlations between general cognitive complaints and performance. These relations were evaluated across HIV and MCI status, considering the associations of depressive symptoms, performance, and self-assessment. RESULTS: We found no effect of HIV status on objective performance or self-assessment of DETECT performance. However, MCI+ participants performed worse on DETECT and traditional cognitive tests, while also showing a directional bias towards overestimation of their performance. MCI- participants showed a bias toward underestimation. Cognitive complaints were reduced compared to objective performance in MCI+ participants. Correlations between self-reported depressive symptoms and cognitive performance or self-assessment of performance were nonsignificant. CONCLUSIONS: MCI+ participants underperformed on neuropsychological testing, while overestimating performance. Interestingly, MCI- participants underestimated performance to approximately the same extent as MCI+ participants overestimated. Practical implications include providing support for persons with MCI regarding awareness of limitations and consideration that self-assessments of cognitive performance may be overestimated. Similarly, supporting older persons without MCI to realistically appraise their abilities may have clinical importance.

A review of the auditory-gut-brain axis.

Hearing loss places a substantial burden on medical resources across the world and impacts quality of life for those affected. Further, it can occur peripherally and/or centrally. With many possible causes of hearing loss, there is scope for investigating the underlying mechanisms involved. Various signaling pathways connecting gut microbes and the brain (the gut-brain axis) have been identified and well established in a variety of diseases and disorders. However, the role of these pathways in providing links to other parts of the body has not been explored in much depth. Therefore, the aim of this review is to explore potential underlying mechanisms that connect the auditory system to the gut-brain axis. Using select keywords in PubMed, and additional hand-searching in google scholar, relevant studies were identified. In this review we summarize the key players in the auditory-gut-brain axis under four subheadings: anatomical, extracellular, immune and dietary. Firstly, we identify important anatomical structures in the auditory-gut-brain axis, particularly highlighting a direct connection provided by the vagus nerve. Leading on from this we discuss several extracellular signaling pathways which might connect the ear, gut and brain. A link is established between inflammatory responses in the ear and gut microbiome-altering interventions, highlighting a contribution of the immune system. Finally, we discuss the contribution of diet to the auditory-gut-brain axis. Based on the reviewed literature, we propose numerous possible key players connecting the auditory system to the gut-brain axis. In the future, a more thorough investigation of these key players in animal models and human research may provide insight and assist in developing effective interventions for treating hearing loss.

Auditory and cognitive function in older adults living with and without HIV.

OBJECTIVES: To evaluate the peripheral hearing sensitivity and central auditory processing in persons with HIV (PWH) and persons without HIV (PWoH); and the association between cognitive function and central auditory processing in PWH and PWoH. DESIGN: Cross-sectional, observational study. METHODS: Participants included 67 PWH {70.2% men; mean age = 66.6 years [standard deviation (SD) = 4.7 years]} and 35 PWoH [51.4% men; mean age = 72.9 years (SD = 7.0 years)]. Participants completed a hearing assessment and a central auditory processing assessment that included dichotic digits testing (DDT). Pure-tone air-conduction thresholds were obtained at octave frequencies from 0.25 through 8 kHz. A pure-tone average (PTA) was calculated from 0.5, 1, 2, and 4 kHz thresholds for each ear. Participants also completed a neuropsychological battery assessing cognition in seven domains. RESULTS: PWH had slightly lower (i.e. better) PTAs compared with PWoH, but this was not statistically significant. Conversely, PWH and PWoH had similar DDT results for both ears. Poorer verbal fluency, learning, and working memory performance was significantly related to lower DDT scores, and those defined as having verbal fluency, learning, and working memory impairment had significantly poorer DDT scores (8-18% lower) in both ears. CONCLUSION: Hearing and DDT results were similar in PWH and PWoH. The relationship between verbal fluency, learning, and working memory impairment and poorer DDT results did not differ by HIV serostatus. Clinicians, particularly audiologists, should be mindful of cognitive functioning abilities when evaluating central auditory processing.

In Utero Antiretroviral Exposure and Risk of Neurodevelopmental Problems in HIV-Exposed Uninfected 5-Year-Old Children.

Studies have observed neurodevelopmental (ND) challenges among young children perinatally HIV-exposed yet uninfected (CHEU) with in utero antiretroviral (ARV) exposure, without clear linkage to specific ARVs. Atazanavir (ATV) boosted with ritonavir has been a preferred protease inhibitor recommended for pregnant women, yet associations of ATV with ND problems in CHEU have been reported. Studies among early school-age children are lacking. The pediatric HIV/AIDS cohort study (PHACS) surveillance monitoring for antiretroviral therapy (ART) toxicities (SMARTT) study evaluated 5-year-old monolingual English-speaking CHEU using the behavior assessment system for children, Wechsler preschool and primary scales of intelligence, and test of language development-primary. A score ≥1.5 standard deviations worse than population norms defined a signal within each domain. Analyses of risk for signals were stratified by timing of any ARV initiation. Associations between ARV exposure and risk of ND signals were assessed using proportional odds models, adjusting for confounders. Among 230 children exposed to ARVs at conception, 15% had single and 8% had multiple ND problems; ATV exposure was not associated with higher risk of signals [adjusted cumulative odds ratio (cOR) = 0.66, confidence interval (CI): 0.28-1.56]. However, among 461 children whose mothers initiated ARVs during pregnancy, 21% had single and 12% had multiple ND problems; ATV exposure was associated with higher risk of signals (cOR = 1.70, CI: 0.82-3.54). The specific regimen tenofovir/emtricitabine/ATV was associated with higher risk (cOR = 2.31, CI: 1.08-4.97) relative to regimens using a zidovudine/lamivudine backbone combined with non-ATV ARVs. It remains important to monitor neurodevelopment of CHEU during early childhood and investigate the impact and the role of timing of in utero exposure to specific ARVs.

Auditory Function in the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol Up Young Adults: A Pilot Study.

BACKGROUND: To collect and compare selected hearing measures in a pilot study of young adults with perinatally acquired HIV (YAPHIV) and those with perinatal HIV exposure who are uninfected young adults with PHEU (YAPHEU). SETTING: Cross-sectional hearing measures in YAPHIV and YAPHEU enrolled in the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol (AMP) for Participants 18 Years of Age and Older (AMP Up). METHODS: Pure-tone air conduction audiometry and distortion product otoacoustic emission (DPOAE) data were collected in 1 visit. A low-frequency pure-tone average (PTA) (LFPTA, at 0.25, 0.5, 1, and 2 kHz), a speech-frequency PTA (SFPTA, at 0.5, 1, 2, and 4 kHz), and a high-frequency PTA (HFPTA, at 3, 4, 6, and 8 kHz) were calculated. Hearing loss was defined as worse ear SFPTA of ≥20 dB HL. Separate linear regression models were fit for worse ear LFPTA, SFPTA, and HFPTA to assess associations with PHIV status. DPOAE signal-to-noise ratios (SNRs) were obtained at 3 frequencies in each ear. RESULTS: Forty-seven YAPHIV and 9 YAPHEU completed hearing testing. All adjusted mean PTAs were similar between YAPHIV and YAPHEU. Hearing loss occurred more in YAPHIV (7/47, 15.2%; 95% CI: 6.3%-28.9%), compared with YAPHEU (0/9, 0%). No associations were detected between HIV disease severity measures and worse ear SFPTA. DPOAE SNRs were similar between YAPHIV and YAPHEU. CONCLUSIONS: In this pilot study, peripheral hearing (ie, PTAs) and cochlear function (ie, DPOAEs) were similar between YAPHIV and YAPHEU. A larger study is warranted to confirm these findings.

Gap detection responses modelled using the Hill equation in adults with well-controlled HIV.

OBJECTIVE: This study's objective was determining whether gap detection deficits are present in a longstanding cohort of people living with HIV (PLWH) compared to those living without HIV (PLWOH) using a new gap detection modelling technique (i.e. fitting gap responses using the Hill equation and analysing the individual gap detection resulting curves with non-linear statistics). This approach provides a measure of both gap threshold and the steepness of the gap length/correct detection relationship. DESIGN: The relationship between the correct identification rate at each gap length was modelled using the Hill equation. Results were analysed using a nonlinear mixed-effect regression model. STUDY SAMPLE: 45 PLWH (age range 41-78) and 39 PLWOH (age range 38-79) were enrolled and completed gap detection testing. RESULTS: The likelihood ratio statistic comparing the full regression model with the HIV effects to the null model, assuming one population curve for both groups, was highly significant (p < 0.001), suggesting a less precise relationship between gap length and correct detection in PLWH. CONCLUSIONS: PLWH showed degraded gap detection ability compared to PLWOH, likely due to central nervous system effects of HIV infection or treatment. The Hill equation provided a new approach for modelling gap detection ability.

Self-Reported Drug Use and Hearing Measures in Young Adults.

Purpose The purpose of this study was to examine marijuana or other substance use on pure-tone thresholds and distortion product otoacoustic emissions (DPOAEs) in young adults. Method Young adults (n = 243; 182 women, 61 men; M age = 20.9 years, SD = 2.7 years) participated in this study. Survey data included personal music system use, marijuana use, and misuse of prescription medications. Otoscopy, tympanometry, pure-tone audiometry, and DPOAEs were obtained. Pure tones from octave frequencies of 0.25 through 8 kHz were obtained, and DPOAEs were recorded between f2 frequencies of 1 and 6 kHz using two continuously presented stimulus tones swept in frequency. Results Those who reported marijuana or stimulant use had similar pure-tone averages (0.5, 1, 2, and 4 kHz) compared to those who reported never using marijuana or stimulants. Women who reported marijuana use in the past 30 days > two times had statistically significant higher mean DPOAEs compared to women who reported ≤ two times or no marijuana use in the past 30 days. Men, however, who reported marijuana use in the past 30 days > two times had lower, but not statistically significant, mean DPOAEs compared to men who reported ≤ two times or no marijuana use in the past 30 days. Women who reported ever using stimulants had statistically significant higher mean DPOAEs compared to women who reported never using stimulants; for men, mean DPOAEs were similar between those who reported ever using stimulants and those who never used stimulants. Conclusions The results of this study demonstrate different and contradictory associations between marijuana use, stimulant use, and hearing outcomes as a function of sex. Future research is needed to explore these associations utilizing larger sample sizes while accounting for additional harmful exposures to other noise exposures.

Words-in-Noise Test Performance in Young Adults Perinatally HIV Infected and Exposed, Uninfected.

Purpose The purpose of this study was to compare Words-in-Noise (WIN) data between young adults with perinatal HIV (PHIV) infection and those with PHIV exposure but uninfected (PHEU) and to evaluate associations between antiretroviral therapy (ART) exposures and WIN data. Method The WIN test and cognitive function were assessed in participants of the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol Up. Impaired WIN (IWIN) performance was defined as a signal-to-babble ratio of > +10 dB. Cognitive function was determined based on fluid cognition composite scores (FCCSs) and crystallized cognition composite scores, and < 70 was considered a fluid or crystallized cognitive impairment. Log binomial models were used to calculate the relative risks of IWIN between PHIV and PHEU. Results PHIV (n = 334) and PHEU (n = 52) participants had similar WIN thresholds and IWIN percentages. For young adults with FCCS ≥ 70, participants with PHIV were less likely to have IWIN for the better ear and worse ear as compared to participants with PHEU. For young adults with FCCS < 70, there was no association between HIV status and risk of IWIN for the better ear or worse ear. For those adults with crystallized cognition composite score of ≥ 70, young adults with PHIV were less likely to have IWIN for the better ear than young adults with PHEU; there was no association between HIV status and IWIN for the worse ear. For young adults with PHIV without a Centers for Disease Control and Prevention Class C diagnosis, a longer combination ART duration was associated with a higher risk of IWIN for the better ear. Conclusions For those without cognitive impairment, young adults with PHEU had poorer WIN thresholds than those young adults with PHIV. In young adults with PHIV who had no prior Centers for Disease Control and Prevention Class C diagnosis, a longer combination ART duration was associated with IWIN only in the better ear.

Birth Prevalence of Congenital Cytomegalovirus Infection in HIV-Exposed Uninfected Children in the Era of Combination Antiretroviral Therapy.

OBJECTIVES: To estimate birth prevalence of congenital cytomegalovirus (cCMV) in HIV-exposed uninfected children born in the current era of combination antiretroviral therapy and describe cCMV-related neurodevelopmental and hearing outcomes. STUDY DESIGN: The Surveillance Monitoring for ART Toxicities cohort study follows HIV-exposed uninfected children at 22 sites in the US and Puerto Rico. Birth cCMV prevalence was estimated in a subset of participants who had blood pellets collected within three weeks of birth and underwent ≥1 of 6 assessments evaluating cognitive and language development including an audiologic examination between 1 and 5 years of age. Detection of CMV DNA by polymerase chain reaction testing of peripheral blood mononuclear cells was used to diagnose cCMV. Proportions of suboptimal assessment scores were compared by cCMV status using Fisher exact test. RESULTS: Mothers of 895 eligible HIV-exposed uninfected children delivered between 2007 and 2015. Most (90%) were on combination antiretroviral therapy, 88% had an HIV viral load of ≤400 copies/mL, and 93% had CD4 cell counts of ≥200 cells/µL. Eight infants were diagnosed with cCMV, yielding an estimated prevalence of 0.89% (95% CI, 0.39%-1.75%). After adjusting for a sensitivity of 70%-75% for the testing method, projected prevalence was 1.2%-1.3%. No differences were observed in cognitive, language and hearing assessments by cCMV status. CONCLUSIONS: Although birth cCMV prevalence in HIV-exposed uninfected children born to women with well-controlled HIV is trending down compared with earlier combination antiretroviral therapy-era estimates, it is above the 0.4% reported for the general US population. HIV-exposed uninfected children remain at increased risk for cCMV.

Can Self-Reported Personal Audio System Volume Predict Actual Listening Levels in Young Adults?

BACKGROUND: Most young adults report using personal audio systems (PAS) with earphones as part of their daily activities. PAS exposure is intermittent and research examining the levels these young adults are listening to is increasing. On average, preferred listening levels are below what would be considered at risk in an occupational setting. PURPOSE: The purpose of this study was to evaluate how two questions predicted preferred listening level in young adults with normal hearing; specifically, whether these young adults could identify if they listen at a high level or not. STUDY SAMPLE: One hundred and sixty young adults (111 women, 49 men) with normal hearing completed a questionnaire that had questions about PAS listening habits and then had preferred listening level assessed using a probe microphone system while listening to 1 hour of music through earphones. DATA COLLECTION AND ANALYSIS: Otoscopy, tympanometry, and pure-tone thresholds were completed in a randomly determined test ear. As part of the Risk Factors Survey, two closed-set questions were completed. First, "For a typical day, what is the most common volume used during this day?" with the following response options "Low," "Medium/Comfortable," "Loud," or "Very Loud." And second, "Do you listen to your personal music system at a volume where you…" with the following response options "Easily hear people," "Have a little trouble hearing people," "Have a lot of trouble hearing people," or "Cannot hear people." Using a probe microphone, chosen listening level (A-weighted, diffuse-field correction and a conversion to free-field equivalent [LDFeq]) was calculated over 1 hour while the participant listened to music with earphones. Sensitivity and specificity were determined to see how well young adults could identify themselves as listening at a high level (>85 dBA) or not. Linear regression analyses were performed to determine the amount of variance explained by the two survey questions as predictors of measured LDFeq. RESULTS: Almost half of the participants reported a longest single use of a PAS as <1 hour daily and more than half reported listening at a medium/comfortable volume and had a little trouble hearing people. Mean LDFeq was 72.5 dBA, with young adult men having a significantly higher mean LDFeq (76.5 dBA) compared with young adult women (70.8 dBA). Sensitivity was 88.9% and specificity was 70.6% for the question asking about volume on a typical day. For the question asking about being able to hear other people while listening to music sensitivity was 83.3% and specificity was 82.5%. Two variables, listening volume on a typical day and sex, accounted for 28.4% of the variability associated with LDFeq; the answer to the question asking about being able to hear others and sex accounted for 22.8% of the variability associated with LDFeq. CONCLUSIONS: About 11% of young adults in the present study listen to a PAS with earphones at a high level (>85 dBA) while in a quiet background. The participants who do report listening at a high level, however, do well at self-reporting this risk behavior in survey questions.

Early Indication of Noise-Induced Hearing Loss in Young Adult Users of Personal Listening Devices.

OBJECTIVES: The recent integration of portable music players into cell phones has further increased the use of personal listening devices (PLD) among young adults, raising concerns about potentially hazardous effects on hearing. METHODS: Assessment of young adults' hearing ability and listening preferences by subjective and objective measurement. Young adult users of PLDs (n = 50; 30 females, 20 males; mean age = 24.1 ± 4.2 years; average PLD use = 6.1 ± 2.1 years) were included. Subjective assessment of listening preferences was performed via a questionnaire as well as objective assessment of preferred volume levels in different background noise environments and hearing tests. RESULTS: Preferred volume levels were significantly correlated with hearing thresholds. Most participants exhibited safe listening behavior according to National Institute for Occupational Safety and Health criteria. We identified a substantial high-risk subgroup of PLD users (22% of participants, daily use ⩾2 h at ⩾91 dB) in which pure tone audiometry showed increased hearing thresholds at 4000 and 6000 Hz, potentially indicating an early manifestation of noise-induced hearing loss (NIHL). CONCLUSIONS: These findings suggest that preventive measures may be warranted to prevent a future increase of clinically relevant NIHL among heavy users of PLDs.

Speech audiometry findings from HIV+ and HIV- adults in the MACS and WIHS longitudinal cohort studies.

The purpose of this study was to compare various speech audiometry measures between HIV+ and HIV- adults and to further evaluate the association between speech audiometry and HIV disease variables in HIV+ adults only. Three hundred ninety-six adults from the Multicenter AIDS Cohort Study (MACS) and Women's Interagency HIV Study (WIHS) completed speech audiometry testing. There were 262 men, of whom 117 (44.7%) were HIV+, and 134 women, of whom 105 (78.4%) were HIV+. Speech audiometry was conducted as part of the standard clinical audiological evaluation that included otoscopy, tympanometry, and pure-tone air- and bone-conduction thresholds. Specific speech audiometry measures included speech recognition thresholds (SRT) and word recognition scores in quiet presented at 40dB sensation level (SL) in reference to the SRT. SRT data were categorized in 5-dB steps from 0 to 25dB hearing level (HL) with one category as ≥30dB HL while word recognition scores were categorized as <90%, 90-99%, and 100%. A generalized estimating equations model was used to evaluate the association between HIV status and both ordinal outcomes. The SRT distributions across HIV+ and HIV- adults were similar. HIV+ and HIV- adults had a similar percentages of word recognition scores <90%, a lower percentage of HIV- adults had 90-99%, but HIV- adults had a higher percentage of 100%. After adjusting for covariables, HIV+ adults were borderline significantly more likely to have a higher SRT than HIV- adults (odds ratio [OR]=1.45, p=0.06). Among HIV+ adults, HIV-related variables (i.e., CD4+ T-cell counts, HIV viral load, and ever history of clinical AIDS) were not significantly associated with either SRT or word recognition score data. There was, however, a ceiling effect for word recognition scores, probably the result of obtaining this measure in quiet with a relatively high presentation level. A more complex listening task, such as speech-in-noise testing, may be a more clinically informative test to evaluate the effects of HIV on speech communication.

Hearing Impairment Prevalence and Associated Risk Factors in the Hispanic Community Health Study/Study of Latinos.

IMPORTANCE: Hearing impairment is common in adults, but few studies have addressed it in the US Hispanic/Latino population. OBJECTIVE: To determine the prevalence of hearing impairment among US Hispanic/Latino adults of diverse backgrounds and determine associations with potential risk factors. DESIGN, SETTING, AND PARTICIPANTS: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL) is a population-based sample of Hispanics/Latinos in four US communities (Bronx, New York; Chicago, Illinois; Miami, Florida; and San Diego, California). Examinations were conducted from 2008 through 2011. The HCHS/SOL examined 16,415 self-identified Hispanic/Latino persons aged 18 to 74 years recruited from randomly selected households using a stratified 2-stage area probability sample design based on census block groups and households within block groups. MAIN OUTCOMES AND MEASURES: Hearing thresholds were measured by pure-tone audiometry. Hearing impairment was defined as a pure-tone average (PTA) of thresholds at 0.5, 1, 2, and 4 kHz greater than 25 dB hearing level. Bilateral hearing impairment required a PTA greater than 25 dB hearing level in both ears. Multivariable analyses included adjustments for sociodemographic and lifestyle variables, body mass index, and medical conditions. RESULTS: The prevalence of hearing impairment was 15.06% (SE, 0.44%) overall, and 8.24% (SE, 0.33%) had bilateral hearing impairment. The prevalence of hearing impairment was higher among people 45 years and older, ranging by Hispanic/Latino background from 29.35% to 41.20% among men and 17.89% to 32.11% among women. The multivariable-adjusted odds of hearing impairment was greater for participants of Puerto Rican background compared with Mexican background (odds ratio [OR], 1.57 [95% CI, 1.10-2.25]). The odds of hearing impairment were lower with more education (OR, 0.71 [95% CI, 0.59-0.86] for at least high school) and higher income (OR, 0.58 [95% CI, 0.36-0.92] for >$75,000 vs ≤$10,000). Noise exposure (OR, 1.35 [95% CI, 1.07-1.70]), diabetes (OR, 1.57 [95% CI, 1.27-1.94]), and prediabetes (OR, 1.37 [95% CI, 1.12-1.67]) were associated with hearing impairment. CONCLUSIONS AND RELEVANCE: Hearing impairment is a common problem for older Hispanics/Latinos in these communities and is associated with socioeconomic factors, noise exposure, and abnormal glucose metabolism. Longitudinal studies are needed to determine whether these factors are involved in the etiology of hearing impairment and to identify ways to prevent or delay age-related changes in hearing.

Distortion product otoacoustic emission data in perinatally HIV-infected and HIV-exposed but uninfected children and adolescents in the Pediatric HIV/AIDS Cohort Study.

The effect of perinatal HIV infection and exposure on sub-clinical auditory function can be measured with distortion product otoacoustic emissions (DPOAEs). DPOAEs were obtained at 4 frequency bins (1, 2, 3 and 4 kHz) and categorized by a signal-to-noise ratio. HIV infection was not associated with poorer DPOAEs. Among HIV-infected children, HIV viral load≥400 copies/mL had significantly lower odds of better DPOAEs.

Hearing assessment data in HIV-infected and uninfected children of Cape Town, South Africa.

Researchers are showing that the rate of hearing loss in children with perinatal HIV infection (PHIV) is higher than in HIV-unexposed, uninfected children. These data, however, have been collected mostly in the USA; extensive hearing data from low- and middle-income countries are lacking. The purpose of this study was to collect audiometric data in PHIV and HIV-uninfected children living in Cape Town, South Africa. Questionnaire data along with distortion product otoacoustic emissions (DPOAEs) and pure-tone testing were completed. Hearing loss was determined using the pure-tone thresholds defined as a pure-tone average (PTA) of 500, 1000, 2000, and 4000 Hz of >15 dB HL in the poorer ear. All data were compared between PHIV and HIV-uninfected children. Sixty-one (37 PHIV and 24 HIV-uninfected) children had hearing data. HIV status was not significantly associated with DPOAEs. The rate of conductive hearing loss was 11.5%; five PHIV and two HIV-uninfected children. The rate of any hearing loss was higher in PHIV children, but this difference was not statistically significant. PHIV children had a significantly higher mean PTA in the poorer ear than HIV-uninfected children. Conductive type of hearing loss was more common than sensorineural hearing loss. The underlying cause of hearing loss in the present study therefore remains unclear. Future research should include an examination of auditory neural function in an effort to determine the possible reason for differences in hearing.

Efficacy and safety of N-acetylcysteine in prevention of noise induced hearing loss: a randomized clinical trial.

Despite a robust hearing conservation program, military personnel continue to be at high risk for noise induced hearing loss (NIHL). For more than a decade, a number of laboratories have investigated the use of antioxidants as a safe and effective adjunct to hearing conservation programs. Of the antioxidants that have been investigated, N-acetylcysteine (NAC) has consistently reduced permanent NIHL in the laboratory, but its clinical efficacy is still controversial. This study provides a prospective, randomized, double-blinded, placebo-controlled clinical trial investigating the safety profile and the efficacy of NAC to prevent hearing loss in a military population after weapons training. Of the 566 total study subjects, 277 received NAC while 289 were given placebo. The null hypothesis for the rate of STS was not rejected based on the measured results. While no significant differences were found for the primary outcome, rate of threshold shifts, the right ear threshold shift rate difference did approach significance (p = 0.0562). No significant difference was found in the second primary outcome, percentage of subjects experiencing an adverse event between placebo and NAC groups (26.7% and 27.4%, respectively, p = 0.4465). Results for the secondary outcome, STS rate in the trigger hand ear, did show a significant difference (34.98% for placebo-treated, 27.14% for NAC-treated, p-value = 0.0288). Additionally, post-hoc analysis showed significant differences in threshold shift rates when handedness was taken into account. While the secondary outcomes and post-hoc analysis suggest that NAC treatment is superior to the placebo, the present study design failed to confirm this. The lack of significant differences in overall hearing loss between the treatment and placebo groups may be due to a number of factors, including suboptimal dosing, premature post-exposure audiograms, or differences in risk between ears or subjects. Based on secondary outcomes and post hoc analyses however, further studies seem warranted and are needed to clarify dose response and the factors that may have played a role in the observed results.

Hearing loss among HIV-seropositive and HIV-seronegative men and women.

IMPORTANCE: Age-related hearing loss affects quality of life. Data on hearing loss among aging human immunodeficiency virus-seropositive (HIV+) adults are limited. OBJECTIVE: To evaluate pure-tone hearing thresholds among HIV+ and HIV-seronegative (HIV-) adults and to determine whether HIV disease variables and antiretroviral therapy are associated with pure-tone threshold levels. DESIGN, SETTING, AND PARTICIPANTS: A total of 262 men (117 HIV+) from the Baltimore, Maryland/Washington, DC, site of the Multicenter AIDS Cohort Study and 134 women (105 HIV+) from the Washington, DC, site of the Women's Interagency HIV Study participated. Pure-tone air conduction thresholds were collected in a sound-treated room for each ear at frequencies from 250 through 8000 Hz. Linear mixed regression models tested the effect of HIV on hearing after adjustment for age, sex, race, and noise exposure history. MAIN OUTCOMES AND MEASURES: Low-frequency pure-tone average (LPTA) at 250, 500, 1000, and 2000 Hz and high-frequency PTA (HPTA) at 3000, 4000, 6000, and 8000 Hz. Differential HIV effects for LPTA and HPTA and better/worse ear were also examined. CD4⁺ and CD8⁺ T-cell counts, log10 plasma HIV RNA concentrations, receipt of AIDS diagnosis, and cumulative duration of antiretroviral therapy were included in the models for HIV+ participants only. RESULTS: HPTA and LPTA were significantly higher (18%: estimated ratio, 1.18 [95% CI, 1.02-1.36]; P = .02; and 12%: estimated ratio, 1.12 [95% CI, 1.00-1.26]; P = .05, respectively) for HIV+ participants compared with HIV- participants for the better ear. The direction of the effect was consistent across both the better and worse ears. There were no significant associations between HIV disease variables or treatment variables and LPTA or HPTA. CONCLUSIONS AND RELEVANCE: The HIV+ adults had significantly poorer lower-frequency and higher-frequency hearing than HIV- adults. High-frequency hearing loss is consistent with an accelerated aging (presbycusis); low-frequency hearing loss in middle age is unexpected. Because some vowels and consonants have predominantly low-frequency acoustic energy, poor low-frequency hearing may impair communication in HIV+ individuals.

Changes in distortion product otoacoustic emission components after music exposure.

BACKGROUND: Young adults experience some type of recreational noise exposure on a daily basis; this includes using personal music (PM) systems with earphones. In most cases, this exposure is intermittent and the short-term effects of this exposure on the auditory system are becoming better understood. PURPOSE: The purpose of this study was to examine the effects of one hour of music exposure using a PM system on distortion product otoacoustic emission (DPOAE) absolute levels and generator and characteristic frequency (CF) component levels. STUDY SAMPLES: Young adults (n = 101) between 18-30 years with normal hearing participated listened to one hour of music through earphones. A second group of young adults (n = 21) served as controls and did not listen to music, but sat in the sound-treated room for one hour. DATA COLLECTION AND ANALYSIS: Otoscopy, tympanometry, and a hearing screening (≤20 dB HL at 0.5, 1, 2, and 4 kHz) were completed in a randomly determined test ear. Preferred listening level, in dBA, was obtained and DPOAEs (2f1-f2) were measured between 1 and 6 kHz with stimulus levels fixed at L1,L2 = 55,40 dB SPL. Absolute DPOAE levels, along with generator and CF components levels were measured before and after each participant listened to one hour of music at their preferred level in a quiet setting. For data analyses, absolute DPOAE and generator and CF component levels were collapsed into 1/3rd octave bands centered around 1, 1.5, 2, 3, 4, and 6 kHz. RESULTS: Mean preferred listening level was 57.8 dBA, with males having a higher mean level of 61.1 dBA compared with females who had a mean level of 55.7 dBA. Females and males had negligible mean changes in absolute DPOAE levels at 1, 1.5, and 2 kHz, but males had 0.4-1 dB mean decreases after music at 3, 4, and 6 kHz compared to females, although not statistically significant. For DPOAE generator component data, females had small mean decreases for the two lower frequencies whereas males had mean decreases of 0.4-0.8 dB at 3, 4, and 6 kHz. Because of missing data, analyses of the CF component were limited, although females had small mean decreases at four frequencies while males had small mean decreases at two frequencies. There was no effect of listening to music on changes in DPOAEs but control participants had strong reliability (i.e., little or no change) after sitting in quiet for one hour. CONCLUSIONS: Young adults listened to music well below what would be considered hazardous. Because of the lower listening levels, DPOAEs showed very little change after music. Although there were no significant short-term changes in DPOAEs after music, the cumulative effect of this noise exposure is still unknown.