Hearing Loss and Cardiovascular Disease Risk Profiles: Data from the Hispanic Community Health Study/Study of Latinos.

BACKGROUND: Individual cardiovascular disease (CVD) risk factors (RFs) have been associated with hearing loss (HL). The relationship to aggregate risk is poorly understood and has not been explored in the Hispanic/Latino population. PURPOSE: The aim of this study was to characterize the association between aggregate CVD RF burden and hearing among Hispanics/Latinos. RESEARCH DESIGN: Cross-sectional examination. STUDY SAMPLE: Participants (18-74 years; n = 12,766) in the Hispanic Community Health Study/Study of Latinos. DATA COLLECTION AND ANALYSIS: Thresholds (0.5-8 kHz) were obtained, and HL was defined dichotomously as pure-tone average (PTA0.5,1, 2,4) > 25 dB HL. Optimal CVD risk burden was defined as follows: systolic blood pressure (SBP) < 120 mm Hg and diastolic blood pressure (DBP) < 80 mm Hg; total cholesterol < 180 mg/dL; nonsmoking; and no diabetes. Major CVD RFs were diabetes, currently smoking, SBP >160 or DBP > 100 mm Hg (or antihypertensives), and total cholesterol > 240 mg/dL (or statins). Thresholds were estimated by age (18-44 and ≥45 years) and sex using linear regression. The association between CVD risk burden and HL was assessed using multivariable logistic regression. Models were adjusted for age, sex, Hispanic/Latino background, center, education, income, alcohol use, body mass index, and noise exposure. RESULTS: In the target population, 53.03% were female and 18.81% and 8.52% had all RFs optimal and ≥2 major RFs, respectively. Elevated BP (SBP 120-139 mm Hg or DBP 80-89 mm Hg) was associated with HL in females < 45 years (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.14-4.16). Diabetes (OR, 1.37; 95% CI, 1.01-1.84) and tobacco smoking (OR, 1.44; 95% CI, 1.03-2.01) were associated with HL in females ≥ 45 years. The odds of HL were higher for females ≥ 45 years with ≥2 RFs versus those with all RFs optimal (OR, 1.99; 95% CI, 1.12-3.53). Elevated BP (SBP 140-159 mm Hg or DBP 90-99 mm Hg), but not aggregate risk burden, was associated with HL in males ≥ 45 years (OR, 1.49; 95% CI, 1.02-2.19). No relationships with major CVD RFs were significant in males < 45 years. CONCLUSIONS: HL is associated with elevated BP in females < 45 years, with diabetes and hypertension in males ≥ 45 years, and with diabetes, smoking, and having ≥2 major CVD RFs in females ≥ 45 years. Future studies are needed to examine if these factors are associated with incident HL.

Overlapping hearing and communication profiles for the deletion and the RAI1 variant form of Smith-Magenis Syndrome (SMS).

Smith-Magenis syndrome (SMS), a rare, genetically linked complex developmental disorder is associated with hearing loss and delays in speech-language development. Approximately 70 % of those with SMS have a genetic deletion within chromosome 17p11.2 and 10 % have a single gene mutation in the same area, known as the RAI1 variant form of SMS. Previous studies presented preliminary comparisons of the phenotype of those with deletion versus the mutation form of SMS, but none focused on hearing, speech-language, and communication profiles. The current study examined patient registry data and compared two groups of individuals with SMS to determine if genetic differences influence the communication phenotype and to determine the importance of the RAI1 gene in hearing, speech, and language abilities in children. Speech-language and hearing data from the international SMS Patient Registry for 33 subjects with SMS were analyzed: 23 with a genetic deletion (SMS (del)) and 10 with an RAI1 mutation (SMS (RAI1)). Hearing status, otopathology findings, early speech-language milestones, mode of communication, intelligibility, vocal quality, language abilities, and literacy skills were analyzed. There were small differences between the groups for hearing status, otopathological findings, mode of communication, voice quality, intelligibility, speech-language abilities, and literacy. Overlap in the speech-language phenotype between groups confirms previous hypotheses that suggest haploinsufficiency of the RAI1 gene is responsible for the SMS phenotype and that the RAI1 gene is critical for speech-language development. Future studies should include direct testing of receptive and expressive language abilities, including analyses of language samples, with larger groups of individuals to replicate and extend the current findings.

Associations Between Self-Reported Visual and Hearing Functioning and Cognitive Function Among Hispanics/Latino: Hispanic Community Health Study.

Background and Objectives: To investigate the associations between self-reported visual functioning (VF) and hearing functioning with cognition in the Hispanic/Latino population. Research Design and Methods: We utilized data from the Miami Ocular Study of Latinos ancillary study to Hispanic Community Health Study/Study of Latinos with 1,056 participants aged 45 and older. The outcomes were cognitive performances assessed by the Digit Symbol Substitution Test (DSST), Word Fluency, Brief-Spanish English Verbal Learning Test-recall (B-SEVLT recall), words recalled over 3 trials, and the Six-Item Screener. VF was measured by National Eye Institute Visual Function Questionnaire (NEI-VFQ), and hearing function was measured by Hearing Handicap Inventory Screening Questionnaire for Adults and Elderly (HHIA/E-S). Multiple regressions were performed for each cognitive outcome while controlling for covariates and complex sampling design. Results: NEI-VFQ was associated with 3 of the 5 cognitive outcomes. A 4-point NEI-VFQ score difference was associated with a 0.56-point difference in DSST (standard error [SE] = 0.27, p < .001), 0.17 in Word fluency (SE = 0.16, p < .01), and 0.08 in B-SEVLT-recall (SE = 0.07, p < .01). HHIA/E-S was not associated with any of the cognitive measures examined. Discussion and Implications: These data suggest that impaired VF is associated with worse cognition in the Hispanic/Latino population. Although previous work in this cohort indicated hearing loss assessed by pure tone audiometry was associated with worse cognition, we found self-perceived hearing function was not associated with cognition, suggesting the potential limitation of self-reported hearing function as a proxy for hearing loss in epidemiological research in Hispanic/Latino populations. Results also imply impaired VF and hearing function may be linked to cognition differently in the Hispanic population, and more research is needed to better understand the underlying linking mechanisms. Visual and hearing impairments are common and treatable and represent important modifiable risk factors that can be treated to preserve cognitive function in Hispanics/Latinos.

Hearing Loss and Associated 7-Year Cognitive Outcomes Among Hispanic and Latino Adults.

Importance: Hearing loss appears to have adverse effects on cognition and increases risk for cognitive impairment. These associations have not been thoroughly investigated in the Hispanic and Latino population, which faces hearing health disparities. Objective: To examine associations between hearing loss with 7-year cognitive change and mild cognitive impairment (MCI) prevalence among a diverse cohort of Hispanic/Latino adults. Design, Setting, and Participants: This cohort study used data from a large community health survey of Hispanic Latino adults in 4 major US cities. Eligible participants were aged 50 years or older at their second visit to study field centers. Cognitive data were collected at visit 1 and visit 2, an average of 7 years later. Data were last analyzed between September 2023 and January 2024. Exposure: Hearing loss at visit 1 was defined as a pure-tone average (500, 1000, 2000, and 4000 Hz) greater than 25 dB hearing loss in the better ear. Main outcomes and measures: Cognitive data were collected at visit 1 and visit 2, an average of 7 years later and included measures of episodic learning and memory (the Brief-Spanish English Verbal Learning Test Sum of Trials and Delayed Recall), verbal fluency (word fluency-phonemic fluency), executive functioning (Trails Making Test-Trail B), and processing speed (Digit-Symbol Substitution, Trails Making Test-Trail A). MCI at visit 2 was defined using the National Institute on Aging-Alzheimer Association criteria. Results: A total of 6113 Hispanic Latino adults were included (mean [SD] age, 56.4 [8.1] years; 3919 women [64.1%]). Hearing loss at visit 1 was associated with worse cognitive performance at 7-year follow-up (global cognition: ß = -0.11 [95% CI, -0.18 to -0.05]), equivalent to 4.6 years of aging and greater adverse change (slowing) in processing speed (ß = -0.12 [95% CI, -0.23 to -0.003]) equivalent to 5.4 years of cognitive change due to aging. There were no associations with MCI. Conclusions and relevance: The findings of this cohort study suggest that hearing loss decreases cognitive performance and increases rate of adverse change in processing speed. These findings underscore the need to prevent, assess, and treat hearing loss in the Hispanic and Latino community.

Speech, Language, Hearing, and Otopathology Results From the International Smith-Magenis Syndrome Patient Registry.

PURPOSE: Smith-Magenis syndrome (SMS), a rare, genetically linked complex developmental disorder caused by a deletion or mutation within chromosome 17p11.2, is associated with delays in speech-language development, otopathology, and hearing loss, yet previous studies lack comprehensive descriptions of hearing and communication profiles. Here, analyses of patient registry data expand what is known about speech, language, hearing, and otopathology in SMS. METHOD: International speech-language and hearing registry survey data for 82 individuals with SMS were analyzed using descriptive and inferential statistics. Hearing loss, history of otitis media and pressure equalization (PE) tubes, communication mode, expressive/receptive language, and vocal quality were analyzed for all subjects and subjects grouped by age. Statistical methods included descriptive statistics and Pearson's chi-square tests of independence to test for differences between age groups for each variable of interest. Association analyses included Pearson's correlations. RESULTS: Hearing and otological analyses revealed that 35% of subjects had hearing loss, 66% had a history of otitis media, and 62% had received PE tubes. Speech-language analyses revealed that 60% of subjects communicated using speech, 79% began speaking words at/after 24 months of age, 92% combined words at/after 36 months, and 41% used sign language before speech. There was a significant association between the age that first words were spoken and the age that PE tubes were first placed. Communication strengths noted in more than 40% of subjects included social interest, humor, and memory for people, past events, and/or facts. CONCLUSIONS: Significant delays and impairment in speech-language were common, but the majority of those with SMS communicated using speech by age 6 years. Age was a significant factor for some aspects of hearing loss and communication. Neither hearing loss nor otitis media exacerbated language impairment. These results confirm and extend previous findings about the nature of speech, language, hearing, and otopathology in those with SMS.

Recovery From Idiopathic Sudden Sensorineural Hearing Loss: Association With Cardiovascular Disease Risk.

PURPOSE: The purpose of this study is to investigate the association between cardiovascular disease (CVD) risk factors and idiopathic sudden sensorineural hearing loss (ISSNHL) disease severity and recovery. METHOD: A retrospective medical chart review was performed on 90 patients (n = 48 men; Mage = 59.8 years, SD = 15.8) evaluated for ISSNHL. Major CVD risk factors (current tobacco smoking, diabetes, total cholesterol ≥ 240 mg/dl or treatment, and hypertension [systolic blood pressure [BP]/diastolic BP ≥ 140/ ≥ 90 mmHg or treatment]) determined two CVD risk groups: lower (no major risk factors) and higher (one or more risk factors). Two pure-tone averages (PTAs) were computed: PTA0.5,1,2 and PTA3,4,6,8. Complete recovery of ISSNHL was defined as PTAinitial - PTAfollow-up ≥ 10 dB. Logistic regression estimated the odds of ISSNHL recovery by CVD risk status adjusting for age, sex, body mass index, noise exposure, and treatment. RESULTS: Most patients (67.8%) had one or more CVD risk factors. Severity of initial low- and high-frequency hearing loss was similar between CVD risk groups. Recovery was 53.2% for PTA0.5,1,2 and 32.9% for PTA3,4,6,8. With multivariable adjustment, current/former smoking was associated with lower odds of PTA0.5,1,2 recovery (OR = 0.27; 95% CI [0.08, 0.92]). Neither higher CVD risk status nor individual CVD risk factors had a significant association with recovery. For every one-unit increase in Framingham Risk Score, odds of PTA3,4,6,8 recovery were 0.95 times lower (95% CI [0.90, 1.00]) after accounting for age, sex, body mass index, noise exposure, and treatment/time-to-treatment grouping (p = .056). CONCLUSIONS: The prognosis of low-frequency ISSNHL recovery is worse among current/former smokers than nonsmokers. Other CVD risk factors and aggregate risk are not significantly related to recovery.

Jackson Heart Study: Aggregate cardiovascular disease risk and auditory profiles.

Objectives: Evaluate the relationship between cardiovascular disease (CVD) risk factors and cochlear function in African Americans. Methods: Relationships between hearing loss, cochlear function, and CVD risk factors were assessed in a cross-sectional analysis of 1106 Jackson Heart Study participants. Hearing loss was defined as puretone average (PTA0.5,1,2,4) > 15 dB HL. Distortion product otoacoustic emissions (DPOAEs) were collected for f 2 = 1.0-8.0 kHz. Two amplitude averages were computed: DPOAElow (f 2 ≤ 4 kHz) and DPOAEhigh (f 2 ≥ 6 kHz). Based on major CVD risk factors (diabetes, current smoking, total cholesterol ≥240 mg/dL or treatment, and systolic blood pressure [BP]/diastolic BP ≥ 140/≥90 mmHg or treatment), four risk groups were created: 0, 1, 2, and ≥3 risk factors. Logistic regression estimated the odds of hearing loss and absent/reduced DPOAElow and DPOAEhigh by CVD risk status adjusting for age, sex, education, BMI, vertigo, and noise exposure. Results: With multivariable adjustment, diabetes was associated with hearing loss (OR = 1.48 [95% CI: 1.04-2.10]). However, there was not a statistically significant relationship between CVD risk factors (individually or for overall risk) and DPOAEs. Conclusion: Diabetes was associated with hearing loss. Neither individual CVD risk factors nor overall risk showed a relationship to cochlear dysfunction. Level of Evidence: 2b.

Relationship of cardiovascular disease risk and hearing loss in a clinical population.

Hearing loss has been associated with individual cardiovascular disease (CVD) risk factors and, to a lesser extent, CVD risk metrics. However, these relationships are understudied in clinical populations. We conducted a retrospective study of electronic health records to evaluate the relationship between hearing loss and CVD risk burden. Hearing loss was defined as puretone average (PTA0.5,1,2,4) > 20 dB hearing level (HL). Optimal CVD risk was defined as nondiabetic, nonsmoking, systolic blood pressure (SBP) < 120 and diastolic (D)BP < 80 mm Hg, and total cholesterol < 180 mg/dL. Major CVD risk factors were diabetes, smoking, hypertension, and total cholesterol ≥ 240 mg/dL or statin use. We identified 6332 patients (mean age = 62.96 years; 45.5% male); 64.0% had hearing loss. Sex-stratified logistic regression adjusted for age, noise exposure, hearing aid use, and body mass index examined associations between hearing loss and CVD risk. For males, diabetes, hypertension, smoking, and ≥ 2 major CVD risk factors were associated with hearing loss. For females, diabetes, smoking, and ≥ 2 major CVD risk factors were significant risk factors. Compared to those with no CVD risk factors, there is a higher likelihood of hearing loss in patients with ≥ 2 major CVD risk factors. Future research to better understand sex dependence in the hearing loss-hypertension relationship is indicated.

Hearing Screening Age Considerations for Adults: National Health and Nutrition Examination Survey.

BACKGROUND: The United States Preventative Service Taskforce recently determined that there was insufficient evidence to recommend hearing screening in adults. PURPOSE: To determine the age to screen adults in the U.S. for hearing loss and identify factors related to increased odds of hearing loss. RESEARCH DESIGN: Epidemiological Cross-Sectional Study. STUDY SAMPLE: Data from 3,409 individuals aged 20-69 years(y) were analyzed from the 1999-2000 and 2000-2002 cycles of the National Health and Nutrition Examination Survey (NHANES). DATA COLLECTION AND ANALYSIS: Hearing sensitivity from 0.5-8 kHz was assessed and hearing loss was defined as pure tone average 0.5, 1, 2, 4 kHz (PTA4) > 15 dBHL for the worse ear. Thresholds were examined separately for men and women in 2-year intervals. A multivariate ordinal regression model adjusting for age, sex, race/ethnicity, and education was used to examine relationship to determinants. RESULTS: Slight (>15 dBHL) hearing loss based on threshold at a single audiometric frequency was first evident in males aged 28-29y. For females, this occurred at age 34-35y. The age at which average PTA4 increased above 15 dBHL (slight hearing loss) was 46-47y for males and 56-57y for females. Multivariate ordinal regression revealed the following "high risk" factors: increased age, male sex, tinnitus, perceived hearing loss, and diabetes. CONCLUSIONS: For the function of primary prevention, these data suggest screening should initiate at ∼30y for males and 35y for females, the ages when average hearing thresholds at a single frequency can be classified as slight hearing loss. For secondary prevention, the recommended screening ages are higher - 45y for males and 55y for females. Hearing screening is recommended for asymptomatic adults, especially those with high risk factors. Our results also highlight the limitations of PTA4 in identifying early indices of hearing loss.

Tobacco, but Neither Cannabis Smoking Nor Co-Drug Use, Is Associated With Hearing Loss in the National Health and Nutrition Examination Survey, 2011 to 2012 and 2015 to 2016.

INTRODUCTION: A relationship between tobacco smoking and hearing loss has been reported; associations with cannabis smoking are unknown. In this cross-sectional population-based study, we examined relationships between hearing loss and smoking (tobacco, cannabis, or co-drug use). METHODS: We explored the relationship between hearing loss and smoking among 2705 participants [mean age = 39.41 (SE: 0.36) years] in the National Health and Nutrition Examination Survey (2011 to 12; 2015 to 16). Smoking status was obtained via questionnaire; four mutually exclusive groups were defined: nonsmokers, current regular cannabis smokers, current regular tobacco smokers, and co-drug users. Hearing sensitivity (0.5 to 8 kHz) was assessed, and two puretone averages (PTAs) computed: low- (PTA 0.5,1,2 ) and high-frequency (PTA 3,4,6,8 ). We defined hearing loss as threshold >15 dB HL. Multivariable logistic regression was used to examine sex-specific associations between smoking and hearing loss in the poorer ear (selected based on PTA 0.5,1,2 ) adjusting for age, sex, race/ethnicity, hypertension, diabetes, education, and noise exposure with sample weights applied. RESULTS: In the age-sex adjusted model, tobacco smokers had increased odds of low- and high-frequency hearing loss compared with non-smokers [odds ratio (OR) = 1.58, 95% confidence ratio (CI): 1.05 to 2.37 and OR = 1.97, 95% CI: 1.58 to 2.45, respectively]. Co-drug users also had greater odds of low- and high-frequency hearing loss [OR = 2.07, 95% CI: 1.10 to 3.91 and OR = 2.24, 95% CI: 1.27 to 3.96, respectively]. In the fully adjusted multivariable model, compared with non-smokers, tobacco smokers had greater odds of high-frequency hearing loss [multivariable adjusted odds ratio = 1.64, 95% CI: 1.28-2.09]. However, in the fully adjusted model, there were no statistically significant relationships between hearing loss (PTA 0.5,1,2 or PTA 3,4,6,8 ) and cannabis smoking or co-drug use. DISCUSSION: Cannabis smoking without concomitant tobacco consumption is not associated with hearing loss. However, sole use of cannabis was relatively rare and the prevalence of hearing loss in this population was low, limiting generalizability of the results. This study suggests that tobacco smoking may be a risk factor for hearing loss but does not support an association between hearing loss and cannabis smoking. More definitive evidence could be derived using physiological measures of auditory function in smokers and from longitudinal studies.

Electrocochleography and Auditory Brainstem Responses in Persons with Non-Optimal Blood Pressure.

BACKGROUND: Numerous cardiometabolic factors may underlie risk of hearing loss. Modifiable risk factors such as non-optimal blood pressure (BP) are of interest. PURPOSE: To investigate early auditory evoked potentials (AEPs) in persons with nonoptimal BP. RESEARCH DESIGN: A cross-sectional nonexperimental study was performed. STUDY SAMPLE: Fifty-two adults (18-55 years) served as subjects. Individuals were classified as having optimal (systolic [S] BP < 120 and diastolic [D] BP < 80 mm Hg, n = 25) or non-optimal BP (SBP ≥=120 or DBP ≥=80 mm Hg or antihypertensive use, n = 27). Thirteen subjects had hypertension (HTN) (SBP ≥130 or DBP ≥80 mm Hg or use of antihypertensives). DATA COLLECTION AND ANALYSIS: Behavioral thresholds from 0.25 to 16 kHz were collected. Threshold auditory brain stem responses (ABRs) were recorded using rarefaction clicks (17.7/second) from 80 dB nHL to wave V threshold. Electrocochleograms were obtained with 90 dB nHL 7.1/second alternating clicks and assessed for summating and compound action potentials (APs). Outcomes were compared via independent samples t tests. Linear mixed effects models for behavioral thresholds and ABR wave latencies were constructed to account for potential confounders. RESULTS: Wave I and III latencies were comparable between optimal and non-optimal BP groups. Wave I was prolonged in hypertensive versus optimal BP subjects at stimulus level 70 dB nHL (p = 0.016). ABR wave V latencies were prolonged in non-optimal BP at stimulus level 80 dB nHL (p = 0.048) and in HTN at levels of 80, 50, and 30 dB nHL (all p < 0.050). DBP was significantly correlated with wave V latency (r = 0.295; p = 0.039). No differences in ABR amplitudes were observed between optimal and non-optimal BP subjects. Electrocochleographic study showed statistically comparable action and summating potential amplitudes between optimal and non-optimal BP subjects. AP latencies were also similar between the groups. Analysis using a set baseline amplitude of 0 µV showed that hypertensive subjects had higher summating (p = 0.038) and AP (p = 0.047) amplitudes versus optimal BP subjects; AP latencies were comparable. CONCLUSION: Elevated BP and more specifically, HTN was associated with subtle AEP abnormalities. This study provides preliminary evidence that nonoptimal BP, and more specifically HTN, may be related to auditory neural dysfunction; larger confirmatory studies are warranted.

Association Between Nonoptimal Blood Pressure and Cochlear Function.

OBJECTIVES: The association between hearing loss and risk factors for cardiovascular disease, including high blood pressure (BP), has been evaluated in numerous studies. However, data from population- and laboratory-based studies remain inconclusive. Furthermore, most prior work has focused on the effects of BP level on behavioral hearing sensitivity. In this study, we investigated cochlear integrity using distortion product otoacoustic emissions (DPOAEs) in persons with subtle elevation in BP levels (nonoptimal BP) hypothesizing that nonoptimal BP would be associated with poorer cochlear function. DESIGN: Sixty individuals [55% male, mean age = 31.82 (SD = 11.17) years] took part in the study. The authors measured pure-tone audiometric thresholds from 0.25 to 16 kHz and computed four pure-tone averages (PTAs) for the following frequency combinations (in kHz): PTA0.25, 0.5, 0.75, PTA1, 1.5, 2, 3, PTA4, 6, 8, and PTA10, 12.5, 16. DPOAEs at the frequency 2f1-f2 were recorded for L1/L2 = 65/55 dB SPL using an f2/f1 ratio of 1.22. BP was measured, and subjects were categorized as having either optimal BP (systolic/diastolic <120 and <80 mm Hg) or nonoptimal BP (systolic ≥120 or diastolic ≥80 mm Hg or use of antihypertensives). Between-group differences in behavioral thresholds and DPOAE levels were evaluated using 95% confidence intervals. Pearson product-moment correlations were run to assess the relationships between: (1) thresholds (all four PTAs) and BP level and (2) DPOAE [at low (f2 ≤ 2 kHz), mid (f2 > 2 kHz and ≤10 kHz), and high (f2 > 10 kHz) frequency bins] and BP level. Linear mixed-effects models were constructed to account for the effects of BP status, stimulus frequency, age and sex on thresholds, and DPOAE amplitudes. RESULTS: Significant positive correlations between diastolic BP and all four PTAs and systolic BP and PTA0.25, 0.5, 0.75 and PTA4, 6, 8 were observed. There was not a significant effect of BP status on hearing thresholds from 0.5 to 16 kHz after adjustment for age, sex, and frequency. Correlations between diastolic and systolic BP and DPOAE levels were statistically significant at the high frequencies and for the relationship between diastolic BP and DPOAE level at the mid frequencies. Averaged across frequency, the nonoptimal BP group had DPOAE levels 1.50 dB lower (poorer) than the optimal BP group and differences were statistically significant (p = 0.03). CONCLUSIONS: Initial findings suggest significant correlations between diastolic BP and behavioral thresholds and diastolic BP and mid-frequency DPOAE levels. However, adjusted models indicate other factors are more important drivers of impaired auditory function. Contrary to our hypothesis, we found that subtle BP elevation was not associated with poorer hearing sensitivity or cochlear dysfunction. We consider explanations for the null results. Greater elevation in BP (i.e., hypertension itself) may be associated with more pronounced effects on cochlear function, warranting further investigation. This study suggests that OAEs may be a viable tool to characterize the relationship between cardiometabolic risk factors (and in particular, stage 2 hypertension) and hearing health.

An Exploratory Study of Early Auditory Evoked Potentials in Cannabis Smokers.

Purpose Cannabis is widely used for medicinal and recreational purposes. Studies have evaluated its health benefits and consequences, although there is limited work on its effects on the auditory system. In this exploratory study, we evaluate the effects of cannabis smoking on early auditory evoked potentials. Method We investigated auditory brainstem response (ABR) and electrocochleography waveforms in 18 cannabis smokers (44% women, 54% men; M age = 23.06 years, range: 21-28 years) and 19 nonsmoker controls (63% women, 37% men; M age = 23.74 years, range: 21-33 years). Threshold ABRs were recorded using rarefaction clicks at a rate of 17.7/s from 80 dB nHL to Wave V threshold. Resulting amplitudes and latencies for Waves I, III, and V were compared via independent-samples t tests. Electrocochleograms obtained with 90 dB nHL (7.1/s) alternating clicks were assessed for summating and compound action potentials, which were compared between groups using independent-samples t tests. Results ABR Wave I amplitudes were significantly lower in smokers (M = 0.14 µV, SD = 0.11) compared to nonsmokers (M = 0.21 µV, SD = 0.10, p = .039) at 80 dB nHL. Wave V latencies were significantly delayed in smokers at 80 dB nHL. Wave I and III latencies did not differ significantly between the two groups. Summating potential/compound action potential ratios were significantly elevated in smokers (M = 0.30, SD = 0.04) versus nonsmokers (M = 0.21, SD = 0.05, p = .042). Conclusion We identified significant differences in electrophysiological outcomes between cannabis smokers and nonsmokers. Cannabis smoking may have a subtle neurotoxic effect on the auditory system. Larger confirmatory studies are warranted.

Epidemiology of Diabetes and Hearing Loss.

Hearing loss is a highly prevalent chronic condition. In addition to age, sex, noise exposure, and genetic predisposition, cardiovascular disease and its antecedents may precipitate hearing loss. Of emerging interest is the connection between diabetes and auditory dysfunction. Cross-sectional studies consistently suggest that prevalence of hearing loss is higher in persons with diabetes compared with those without diabetes, especially among younger persons. Furthermore, longitudinal studies have demonstrated higher incidence of hearing loss in persons with diabetes compared to those without diabetes. These findings seem to hold for both type 1 and type 2 diabetes, although considerably more population-based evidence is available for type 2 diabetes. Data on gestational diabetes and hearing outcomes are limited, as are data relating diabetes to otologic sequelae such as fungal infection. Here, we examine evidence from epidemiologic studies of diabetes and hearing loss and consider clinical and laboratory data where population-based data are lacking.

Behavioral Hearing Thresholds and Distortion Product Otoacoustic Emissions in Cannabis Smokers.

Purpose Cannabis is a widely used drug both medically and recreationally. The aim of this study was to determine if cannabis smoking is associated with changes in auditory function, as measured by behavioral hearing thresholds and/or distortion product otoacoustic emissions (DPOAEs). Method We investigated hearing thresholds and 2f1-f2 DPOAEs in 20 cannabis smokers and 20 nonsmokers between 18 and 28 years old. Behavioral thresholds were obtained from 0.25 to 16 kHz. DPOAEs were measured using discrete tones between f2 of 0.5 and 19.03 kHz using an f2/f1 ratio of 1.22 and L1/L2 = 65/55 dB SPL. Thresholds and DPOAE amplitudes were compared between groups using linear mixed-effects models with sex and frequency as predictors. Results Behavioral thresholds in smokers did not differ significantly between smokers and nonsmokers (all ps > .05). Although not significant, long-term smokers exhibited poorer thresholds than short-term smokers and nonsmokers. Smokers generally exhibited lower DPOAE amplitudes than nonsmokers, although the differences were not significant. Male smokers had significantly poorer DPOAE amplitudes than male nonsmokers in the low frequencies (f2 ≤ 2 kHz; p = .0245). Conclusion Results indicate that smoking cannabis may negatively alter the function of outer hair cells in young men. This subtle cochleopathology is evident in the absence of measurable differences in behavioral hearing thresholds between cannabis smokers and nonsmokers.

Exploring Optimal Stimulus Frequency Ratio for Measurement of the Quadratic f2-f1 Distortion Product Otoacoustic Emission in Humans.

Purpose: Distortion product otoacoustic emissions (DPOAEs) are a by-product of active cochlear processes that lead to the compressive nonlinearity of healthy ears. The most commonly studied emission is at the frequency 2f1-f2, but there has been recent interest in using the quadratic distortion product at the frequency f2-f1 to detect cochleopathies including endolymphatic hydrops. Before the DPOAE at f2-f1 can be applied clinically in any capacity, optimal stimulus parameters for its elicitation must be established. Method: We investigated stimulus parameters for the DPOAEs at f2-f1 and 2f1-f2 in 23 adults with normal hearing. Logarithmically swept tones between approximately 0.6 and 20 kHz (L1 = L2 = 70 dB SPL) served as the higher frequency stimulus (f2). DPOAEs were measured for 6 f2/f1 ratios: 1.14, 1.18, 1.22, 1.30, 1.32, and 1.36. Results: Both DPOAEs were consistently measurable. In line with previous investigations, the highest levels of the DPOAE at 2f1-f2 were generated between f2/f1 ratios of 1.14-1.22, with a peak in the level ratio function at 1.22. In contrast, f2-f1 was less influenced by ratio, although the narrowest ratio (1.14) produced slightly higher levels across frequency. Conclusion: The DPOAE at f2-f1 is measurable in individuals with normal hearing up to f2 of 20 kHz at narrow f2/f1 ratios. Measurements at additional stimulus levels and in subjects with hearing impairment will be needed before clinical implementation.

Annotated Primary Literature: A Professional Development Opportunity in Science Communication for Graduate Students and Postdocs.

Formal training in communicating science to a general audience is not traditionally included in graduate and postdoctoral-level training programs. However, the ability to effectively communicate science is increasingly recognized as a responsibility of professional scientists. We describe a science communication professional development opportunity in which scientists at the graduate-level and above annotate primary scientific literature, effectively translating complex research into an accessible educational tool for undergraduate students. We examined different types of annotator training, each with its own populations and evaluation methods, and surveyed participants about why they participated, the confidence they have in their self-reported science communication skills, and how they plan to leverage this experience to advance their science careers. Additionally, to confirm that annotators were successful in their goal of making the original research article easier to read, we performed a readability analysis on written annotations and compared that with the original text of the published paper. We found that both types of annotator training led to a gain in participants' self-reported confidence in their science communication skills. Also, the annotations were significantly more readable than the original paper, indicating that the training was effective. The results of this work highlight the potential of annotator training to serve as a value-added component of scientific training at and above the graduate level.

Spontaneous otoacoustic emissions, threshold microstructure, and psychophysical tuning over a wide frequency range in humans.

Hearing thresholds have been shown to exhibit periodic minima and maxima, a pattern known as threshold microstructure. Microstructure has previously been linked to spontaneous otoacoustic emissions (SOAEs) and normal cochlear function. However, SOAEs at high frequencies (>4 kHz) have been associated with hearing loss or cochlear pathology in some reports. Microstructure would not be expected near these high-frequency SOAEs. Psychophysical tuning curves (PTCs), the expression of frequency selectivity, may also be altered by SOAEs. Prior comparisons of tuning between ears with and without SOAEs demonstrated sharper tuning in ears with emissions. Here, threshold microstructure and PTCs were compared at SOAE frequencies ranging between 1.2 and 13.9 kHz using subjects without SOAEs as controls. Results indicate: (1) Threshold microstructure is observable in the vicinity of SOAEs of all frequencies; (2) PTCs are influenced by SOAEs, resulting in shifted tuning curve tips, multiple tips, or inversion. High frequency SOAEs show a greater effect on PTC morphology. The influence of most SOAEs at high frequencies on threshold microstructure and PTCs is consistent with those at lower frequencies, suggesting that high-frequency SOAEs reflect the same cochlear processes that lead to SOAEs at lower frequencies.

Association between cardiovascular health and hearing function: pure-tone and distortion product otoacoustic emission measures.

PURPOSE: A reduction in hearing sensitivity is often considered to be a normal age-related change. Recent studies have revisited prior ways of thinking about sensory changes over time, uncovering health variables other than age that play a significant role in sensory changes. METHOD: In this cross-sectional study, cardiovascular (CV) health, pure-tone thresholds at 1000 to 4000 Hz, and distortion product otoacoustic emissions (DPOAEs), with and without contralateral noise, were measured in 101 participants age 10-78 years. RESULTS: Persons in the "old" age category (49-78 years) had worse pure-tone hearing sensitivity and DPOAEs than persons in the younger age categories (p < .05), affirming an age effect. Although hearing decline occurred in all persons in all CV fitness categories of every age group, those with low CV fitness in the old age group had significantly worse pure-tone hearing at 2000 and 4000 Hz (p <.05). Otoacoustic emission measurements were better for the old high-fit group but not significantly influenced by CV fitness level across age groups. CONCLUSIONS: Results of the current study elucidate the potentially positive impact of CV health on hearing sensitivity over time. This finding was particularly robust among older adults.