Generalized Arteriosclerosis and Changes of the Cochlea in Young Adults

No causal relationship serum lipids on age-related hearing loss based on Mendelian randomized evidence

OBJECTIVES

Presbycusis, or age-related hearing loss (ARHL) has been a common disability disease among the elderly population. It is particularly essential to identify the underlying role of related risk factors for ARHL diagnosis and treatment. Observational studies have shown that cardiovascular disease may be a factor in ARHL. Serum lipids are a key risk factor for cardiovascular disease. Therefore, it may be a potentially influencing factor for elderly deafness. We conduct the study to analyze the causal relationship between serum lipids and European elderly deafness.

DESIGN

Using genetic variation data related to serum lipids (total cholesterol levels [TCL], total triglycerides levels [TGL], and lipoprotein fractions, including apolipoprotein A1 levels [APOA1L], apolipoprotein B levels [APOBL], high-density lipoprotein cholesterol levels [HDL], and low-density lipoprotein cholesterol levels [LDL]) as instrumental variables, the outcome events were summarized from the genome-wide association study data of elderly deafness, and Mendelian randomization (MR) analysis was used in our analysis. The relationship between serum lipids levels and ARHL was analyzed using five methods, including inverse variance weighted, weighted mode, MR-Egger, weighted median, and simple mode. The study aims to use bidirectional MR analysis.

RESULTS

Among all 5 methods, no significant causal effects were found between serum lipids (TCL OR = 0.936, p = .488; TGL OR = 0.955, p = 0.657; APOA1L OR = 0.864, p = .061; APOBL OR = 0.979, p = .786; HDL OR = 0.998, p = .979; LDL OR = 1.089, p = .281) and presbycusis.

CONCLUSION

The findings of MR causal inference analysis did not support the causal relationship between presbycusis and serum lipids, including cholesterol, triglycerides, and lipoprotein fractions (APOA1L, APOBL, HDL and LDL).

Lipids and Statin Medication With Sensorineural Hearing Loss: A Mendelian Randomization Study

BACKGROUND

Recent insights suggest that lipids and statin medication play a role in the development of sensorineural hearing loss (SNHL), yet the exact role remains controversial. This research applied Mendelian randomization (MR) to assess whether lipids and statin medication are associated with an increased risk of SNHL.

METHODS

A two-sample MR was used in this study. Genetic instruments were constructed from variants associated with risk factors. Data for lipids and statin medication were obtained from the IEU OpenGWAS project, and for SNHL from the Finngen research project, which comprises 32,487 individuals with SNHL and 331,736 control individuals.

RESULTS

Genetically predicted higher levels of triglycerides were associated with an increased risk of SNHL. The use of genetically predicted atorvastatin was associated with a lower risk of SNHL. Rosuvastatin has demonstrated potential in treating SNHL, yet further investigations are warranted to elucidate its relationship with SNHL. Insufficient evidence was available to suggest that the genetically predicted level of high-density lipoprotein cholesterol or low-density lipoprotein cholesterol or the use of simvastatin were associated with SNHL.

CONCLUSIONS

The study provides genetic evidence suggesting that increased levels of triglycerides in the blood could be a risk factor for SNHL and that the use of certain statin medications, including atorvastatin and rosuvastatin, could reduce the risk of SNHL. These results align with findings from previous observational studies that have linked hyperlipidemia with the risk of SNHL.

LEVEL OF EVIDENCE

According to the Oxford Centre for Evidence-Based Medicine 2011 levels of Evidence, the study has a third level of Evidence Laryngoscope, 134:4366-4373, 2024.

Association Between Hearing Loss and Cardiovascular Disease: A Meta-analysis

OBJECTIVE

Hearing loss (HL) has been postulated to be linked to cardiovascular diseases (CVDs) via vascular mechanisms, but epidemiological associations remain unclear. The study aims to clarify the association between HL and stroke, coronary artery disease (CAD), and any CVD.

DATA SOURCES

PubMed, Embase, and SCOPUS from inception until April 27, 2022.

REVIEW METHODS

Three blinded reviewers selected observational studies reporting stroke, CAD, and any CVD in patients with HL, compared to individuals without HL. We extracted data, evaluated study bias using the Newcastle-Ottawa scale, following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and a PROSPERO-registered protocol (CRD42022348648). We used random-effects inverse variance meta-analyses to pool the odds ratios (ORs) for the association of HL with stroke, CAD, and any CVD.

RESULTS

We included 4 cohort studies (N = 940,771) and 6 cross-sectional studies (N = 680,349). Stroke, CAD, and any CVD were all strongly associated with HL. The overall pooled OR of the association between HL and stroke was 1.26 (95% confidence interval [CI] = 1.16-1.37, I2  = 78%), and was 1.33 (95% CI = 1.12-1.58) and 1.29 (95% CI = 1.14-1.45) for low- and high-frequency HL, respectively. Minimal publication bias was observed, with minimal change to pooled effect size following trim and fill. Similarly, the pooled OR of the association between HL and CAD was 1.36 (95% CI = 1.13-1.64, I2  = 96%), while that between HL and any CVD was 1.38 (95% CI = 1.07-1.77, I2  = 99%).

CONCLUSION

Our findings suggest that HL and CVD are closely related. Physicians treating patients with HL should be cognizant of this association and view HL in the broader context of general health and aging.

Age-related hearing loss was accelerated by apoptosis of spiral ganglion and stria vascularis cells in ApoE KO mice with hyperglycemia and hyperlipidemia

Age-related hearing loss (ARHL) is associated with diabetes and/or dyslipidemia in humans. However, the detailed mechanism for the development of ARHL by diabetes and/or dyslipidemia has not been elucidated. In this study, we investigated the etiology of ARHL in apolipoprotein E (ApoE)-deficient mice with diabetes and dyslipidemia. The atherosclerotic CD-STZ (mice fed with a control diet and received an STZ injection), WD-con (mice fed with a western diet), and WD-STZ (mice fed with a western diet and received an STZ injection) mice showed a 2.4-, 4.9-, and 6.8-fold larger area, respectively, occupied by lesions throughout the aorta compared with the CD-con mice. A significantly larger area under the curve (AUC) was observed in the STZ-treated groups than in the non-treated groups based on the oral glucose tolerance test (OGTT). At 20 weeks of age, HbA_1c levels were significantly higher in the CD-STZ and WD-STZ mice than in the CD-con and WD-con mice. In all the groups, the auditory brainstem response (ABR) thresholds of the 16-week-old mice were significantly higher compared with those of the 8-week-old mice. In particular, in the WD-STZ mice, the ABR thresholds of the left and right ears reached the maximum decibel peak equivalent sound pressure levels (130 dBpeSPL), which is a sign of deafness. The apoptotic spiral ganglion neurons (SGNs) of the WD-STZ mice were significantly increased compared with those of the other three groups, indicating that SGN apoptosis resulted in hearing loss in STZ-induced diabetic ApoE KO mice fed with a WD. A significant loss of the stria vascularis cells was observed in the WD-STZ group compared with the CD-con mice. In the organ of Corti, few apoptotic hair cells were found in all the groups; however, no significant difference was observed. Therefore, we consider that the reduced hearing ability in the STZ-treated and WD-fed groups was attributed to the damage to the SGN and stria vascularis in the cochlea. Thus, our results indicated that ototoxicity by diabetes and/or dyslipidemia accelerated ARHL in ApoE KO mice, thereby suggesting the importance of appropriate treatment of patients with diabetes and/or dyslipidemia to prevent ARHL.

Association between Speech Recognition in Noise and Risk Factors of Cardiovascular Disease

INTRODUCTION

Risk factors for cardiovascular disease (CVD) are associated with sensorineural hearing loss. CVD risk factors are known to cluster and interact, thereby increasing the cumulative risk for CVD. Previously, using the database of the Netherlands Longitudinal Study on Hearing (NL-SH), an association was found between a history of smoking and an increased decline in speech recognition in noise over 10 years of follow-up. Prospectively limited data are available on the association between CVD risk factors, interactions of these risk factors, and hearing loss. In this study, data from the NL-SH were used to study the association between CVD risk factors and speech recognition in noise longitudinally.

METHODS

Baseline, 5-year, and 10-year follow-up data of the NL-SH were included. The NL-SH is a web-based prospective cohort study which started in 2006. Participants were aged 18-70 years at baseline. Speech recognition in noise was determined with an online digit-triplet speech-in-noise test. In addition, participants completed online questionnaires on demographic, lifestyle, and health-related characteristics. The association of the ability to recognize speech in noise with CVD risk factors (i.e., obesity, rheumatoid arthritis [RA], hypertension, diabetes mellitus, and dyslipidemia) was analyzed longitudinally. We also analyzed the interaction between these risk factors (including age, sex, and history of smoking) and speech recognition in noise.

RESULTS

None of the CVD risk factors or interactions of 2 CVD risk factors was significantly associated with a decline in SRT over time. Obesity (p = 0.016), RA (p = 0.027), and hypertension (p = 0.044) were associated with overall higher (more unfavorable) SRTs. No overall interactions between CVD risk factors were found.

CONCLUSION

Obesity, RA, and hypertension were overall associated with a higher SRT, but no longitudinal associations between these or other CVD factors with SRTs were found. Also, no interactions between 2 CVD risk factors and SRTs were found. Although no longitudinal associations between CVD risk factors and decline in SRTs were found, clinicians should be alert about the concurrent association between CVD risk factors and hearing loss.

Stroke risk in African Americans with subclinical auditory dysfuntion evidenced by Distortion Product Otoacoustic Emissions: the Jackson heart study

Objective: Distortion product otoacoustic emissions (DPOAEs) are sensitive to early indices of cochlear pathology. Pathology to the cochlea is in part mediated by ischaemic related mechanisms. We propose that DPOAEs may provide an objective measure of cardiovascular risk.Design: Cross-sectional.Study sample: The relationships between stroke risk and DPOAEs of 1,107 individuals from the Jackson Heart Study (JHS), an all-African-American cohort, were assessed. Linear regression models were used for analysis among all participants and delimited to normal hearing, defined as either a pure-tone threshold average of 500, 1000, 2000, and 4000 Hz (PTA4) ≤ 25 dBHL or pure-tone thresholds for all individual tested frequencies for each ear (500, 1000, 2000, 4000, and 8000 Hz) ≤ 25 dBHL.Results: We observed a significant inverse relationship between DPOAE amplitudes and stroke risk scores in the pooled cohort and in the subgroups with normal hearing defined by pure tone thresholds. Participants in the high-risk group had significantly lower DPOAE amplitudes than those in the low stroke risk group.Conclusions: Our results indicate that auditory dysfunction as measured by DPOAEs are related to stroke risk. Further prospective studies are needed to determine if DPOAEs could be used as a predictive tool for cardiovascular disease.

Descriptive and topographical analysis of the labyrinthine artery in human fetuses

Hearing or/and balance impairments may be caused by disorders of the labyrinthine artery (LA) and their branches. Most findings regarding the LA anatomy have been acquired through investigation of the cerebellopontine angle (CPA) in animal or adult human specimens. Eighty-eight CPAs and LAs of human fetuses were investigated using angio-techniques and microdissections. We found 15 intricate forms of distribution of LA. The LA usually originated from the extra-meatus loop in the anterior inferior cerebellar artery (AICA). The distribution of its terminal branches was 53.42% uni-arterial, 44.31% bi-arterial, and 2.27% tri-arterial systems. In the uni-arterial system, the LA described an anterior superior path to the cochlear nerve (CN) and originated its terminal branches in the gap between CN and the inferior part of the vestibular nerve. In the bi-arterial system, the anterior LA was located anterior and superior to the CN while the posterior LA appeared posterosuperior to the superior part of the vestibular nerve. In the tri-arterial system, the terminal branches originated directly from the AICA loop. Our results provide anatomical support to explain how compressions in the LA branches inside the internal acoustic meatus, as evoked by Schwannomas in the VII and VIII nerves, can lead to hearing and balance loss. The zone of the posterior vestibular nerve appeared to be a "safe area" for invasive procedures in these specimens.

Possible Effects of Proton Pump Inhibitors on Hearing Loss Development

Considered safe and often available as over-the-counter (OTC) drugs, proton pump inhibitors (PPI) are one of the most frequently used medicines. Over recent years much research analyzing PPI has been conducted and these studies shed light on PPI side effects and the mechanisms of these processes. In this study we summarize the findings of these studies and through deduction present some hypotheses on the impact of PPI on health. Of particular interest is the impact of PPI on hearing loss development. However, despite this side effect being localized, its mechanisms are complex, systemic and involve changes in whole body. This paper summarizes how through, inter alia, alterations in the circulatory system, respiratory system, central nervous system and metabolism PPI can cause hearing impairment, which can occur in every age group and is connected with long-term use of this group of drugs. This article also discusses the role PPI plays in the acceleration of presbycusis development, in relation to the fact that older people are the group who most frequently use PPI in long term. Hearing loss negatively impacts affects quality of life, especially among older patients who are also the most afflicted group; administration of PPI should therefore be considered carefully, taking into consideration all potential benefits and side effects.

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.

Does dyslipidemia worsen the hearing level in diabetics?

Objective

To identify the effect of dyslipidemia on auditory function detected by Pure Tone Audiometry. To check if dyslipidemia worsens the hearing level in diabetics.

Design

This was a comparative study where 120 subjects between the age group of 20 and 50 years underwent pure tone audiometry, lipid profile and blood sugars. Group 1 consisted of 30 subjects with type 2 diabetes and dyslipidemia; Group 2 had 30 subjects with isolated diabetes; Group 3 had 30 with isolated dyslipidemia and Group 4 included 30 normal subjects as control.

Results

Significant hearing loss was seen only in the group with isolated diabetes (63%). The most common type of hearing loss was high frequency sensorineural hearing loss. When comparison was made between the combinations of different lipid profiles, no association was found to the level of hearing.

Conclusions

Diabetics are more prone to high frequency hearing loss. Altered lipid profile has no role in causing hearing loss.

Impact of Aging on the Auditory System and Related Cognitive Functions: A Narrative Review

Age-related hearing loss (ARHL), presbycusis, is a chronic health condition that affects approximately one-third of the world's population. The peripheral and central hearing alterations associated with age-related hearing loss have a profound impact on perception of verbal and non-verbal auditory stimuli. The high prevalence of hearing loss in the older adults corresponds to the increased frequency of dementia in this population. Therefore, researchers have focused their attention on age-related central effects that occur independent of the peripheral hearing loss as well as central effects of peripheral hearing loss and its association with cognitive decline and dementia. Here we review the current evidence for the age-related changes of the peripheral and central auditory system and the relationship between hearing loss and pathological cognitive decline and dementia. Furthermore, there is a paucity of evidence on the relationship between ARHL and established biomarkers of Alzheimer's disease, as the most common cause of dementia. Such studies are critical to be able to consider any causal relationship between dementia and ARHL. While this narrative review will examine the pathophysiological alterations in both the peripheral and central auditory system and its clinical implications, the question remains unanswered whether hearing loss causes cognitive impairment or vice versa.

Relationship of stroke risk and hearing loss in African Americans: The Jackson Heart Study

OBJECTIVES/HYPOTHESIS

To evaluate the relationships among measures of stroke risk and hearing in an African American cardiovascular study cohort.

STUDY DESIGN

Prospective cohort study.

METHODS

The relationships between stroke risk profiles and hearing of 1,107 individuals from a cohort of African Americans were assessed. Several different hearing pure-tone averages (PTAs) were constructed representing different frequency regions of hearing, namely PTA low, PTA mid, and PTA high. Stroke risk profiles were calculated using validated 10-year cardiovascular disease risk scores. Gamma regression analyses were performed for each PTA given as a continuous variable with change in stroke risk score. Logistic regression analyses, presented as odds ratios, were performed with hearing loss defined as any PTA >25 dB hearing level. Stratification models were analyzed for age quarterlies and among sex.

RESULTS

Single unit increases of stroke risk percentage were found to be predictive of increases in all PTA threshold levels in gamma regression analyses for the overall pooled sample. The relationship was influenced by age, where fewer significant relationships were observed at higher ages. When analyzed with respect to stroke risk categories, using low risk as the reference group, there was found to be a significant association between stroke risk and hearing loss in the medium- and high-risk groups, with a stronger relationship in the high-risk group for all PTA threshold levels.

CONCLUSIONS

This study provides evidence that stroke risk has a positive predictive relationship with hearing pure-tone threshold.

LEVEL OF EVIDENCE

2b. Laryngoscope, 128:1438-1444, 2018.

Cochlear Histopathologic Findings in Patients With Systemic Lupus Erythematosus: A Human Temporal Bone Study

HYPOTHESIS

We hypothesized that, in archived human temporal bone samples from patients with systemic lupus erythematosus (SLE), a pathologic condition exists in the stria vascularis and cochlear hair cells.

BACKGROUND

Sensorineural hearing loss is a common feature in SLE patients. However, the pathophysiologic mechanism of cochlear dysfunction is unclear.

METHODS

We examined 15 temporal bone samples from 8 SLE patients, along with 17 samples from 10 age-matched healthy control patients. The samples were serially sectioned in the horizontal plane and stained with hematoxylin and eosin. We determined the area of the stria vascularis in a midmodiolar section of each cochlear turn. Then, we made cytocochleograms and calculated the percentage of missing inner and outer hair cells.

RESULTS

The area of the stria vascularis in our SLE group was significantly smaller than in our control group. The number of remaining inner hair cells in our SLE group was smaller than in our control group; however, the difference did not reach statistical significance. The loss of outer hair cells in our SLE group was significantly higher than in our control group. There was a tendency toward a positive correlation between the loss of cochlear hair cells and the duration of SLE.

CONCLUSION

The stria vascularis and cochlear hair cells are affected in SLE patients. Our findings could provide the histopathologic basis for the cochlear dysfunction, including sensorineural hearing loss, experienced by SLE patients.

Associations between cardiovascular disease and its risk factors with hearing loss-A cross-sectional analysis

OBJECTIVES

To investigate the relationship between hearing loss and cardiovascular disease risk factors.

DESIGN

Cross-sectional study.

METHODS

Participants were recruited between May 2010 and December 2015 and answered a health and risk factor questionnaire. Physical and biochemical assessments were performed.

SETTING

A community-based population.

PARTICIPANTS

A total of 5107 participants born within the years 1946-1964 enrolled in the Busselton Healthy Ageing Study.

MAIN OUTCOME MEASURES

Hearing was assessed behaviourally through the best ear pure-tone average (500, 1000, 2000, 4000 Hz), low-frequency average (250, 500, 1000 Hz) and high-frequency average (4000, 8000 Hz). Self-reported hearing loss, tinnitus and hyperacusis were assessed via questionnaire. Cardiovascular risk factors were assessed via a patient-completed questionnaire and objective measurements including blood pressure, body mass index, waist circumference, lipid profile and glycated haemoglobin.

RESULTS

Of the participants, 54% were female, with the mean age of 58 years (range 45-69 years). Age, sex and family history of hearing loss were consistently strong determinants of hearing loss outcomes. After adjusting for these, obesity, current smoking, peripheral arterial disease and history of cardiovascular disease were significantly associated with pure-tone, low-frequency and high-frequency hearing loss. In addition, high blood pressure, triglyceride and glycated haemoglobin were significantly associated with low-frequency hearing loss. There was a graded association between hearing loss and Framingham Risk Score for cardiovascular risk (P<0.001).

CONCLUSIONS

Established cardiovascular disease and individual and combined cardiovascular disease risk factors were found to be associated with hearing loss. Future research should prospectively investigate whether targeting cardiovascular disease can prevent hearing loss.

Investigations into Audiovestibular Manifestations in Patients with Psoriatic Arthritis

Objective.

Although psoriatic arthritis (PsA) is a common chronic inflammatory rheumatic disease, little is known about audiovestibular impairment in this condition. We aimed to establish whether audiovestibular manifestations were present in patients with PsA.

Methods.

A set of 60 consecutive patients who fulfilled the Moll and Wright criteria for PsA and 60 matched controls were studied. During the period of recruitment, individuals were excluded who had a history of cardiovascular disease, cerebrovascular complications, peripheral artery disease, renal insufficiency, syphilis, Meniere disease and other vestibular syndromes, infections involving the inner ear, barotrauma, or were in treatment with ototoxic drugs.

Results.

Most patients with PsA were men (63%). The mean age at the time of our study was 52.9 years and the mean age at the onset of symptoms was 33 years. Thirty-six (60%) of the 60 patients showed abnormal hearing loss in the audiogram compared to only 5 (8.3%) of the 60 controls (p < 0.001). Values of audiometric tests (pure-tone average and speech reception threshold) yielded significant differences between patients and controls (p < 0.001). The audiogram disclosed a bilateral and symmetrical sensorineural hearing loss (SNHL) in PsA with predominant pattern of high frequency SNHL in patients with PsA (46.7%) compared to controls (8.3%, p < 0.001). Patients with PsA exhibited abnormal vestibular tests more commonly than controls. A significantly increased frequency of abnormal computerized dynamic posturography with a predominant vestibular loss pattern was also observed in patients (23.3%) compared to controls (0%, p < 0.001).

Conclusion.

Our current study demonstrates strong evidence for inner ear damage in patients with PsA.

Benign paroxysmal positional vertigo and clinical test of sensory interaction and balance in ankylosing spondylitis

OBJECTIVE

To assess the frequency and characteristics of benign paroxysmal positional vertigo (BPPV) and clinical test of sensory interaction and balance (CTSIB) abnormalities in patients with ankylosing spondylitis (AS).

STUDY DESIGN

A series of consecutive patients that fulfilled the modified New York diagnostic criteria for AS and matched controls were studied.

SETTING

The study was performed at the Otolaryngology Division of a tertiary reference center.

PATIENTS

Fifty-nine patients with AS (47 men [79.6%]) attending hospital outpatient rheumatology clinics between March and October 2008, and 46 controls (34 men [73.9%]) were studied.

INTERVENTION

Dix-Hallpike and cephalic rotational tests and CTSIB were performed in AS patients and age-, sex-, and ethnically frequency-matched controls.

MAIN OUTCOME MEASURE

Type and frequency of BPPV and CTSIB conditions were assessed.

RESULTS

BPPV was diagnosed in 6 patients (10.1%) with AS and in 2 (4.3%) of the controls (p = 0.24). Abnormal caloric test was more commonly observed in patients with AS (n = 15 [25.4%]) than the controls (n = 0) (p < 0.001). Increased frequency of abnormal CTSIB also was observed in patients (19/59 [32%]) compared with the controls (3 [6.5%]) (odds ratio, 6.81 [95% confidence interval, 1.77-38.0]; p = 0.001). Among the abnormal CTSIB patterns, the vestibular loss was the most commonly observed in patients with AS (15/59 [25.4%]).

CONCLUSION

The present study shows an increased frequency of abnormal postural control in CTSIB test of vestibular origin in patients with AS.

Audiovestibular manifestations in patients with ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown origin affecting up to 1% of the population. Little is known about audiovestibular impairment in patients with AS, especially the presence of cochleovestibular dysfunction in these patients. To investigate audiovestibular manifestations in AS, we studied a series of 50 consecutive patients who fulfilled the modified New York diagnostic criteria for AS and 44 matched controls. Individuals with history of cardiovascular disease, cerebrovascular complications, peripheral artery disease, renal insufficiency, syphilis, Meniere and other vestibular syndromes, infections involving the inner ear, barotrauma, or in treatment with ototoxic drugs were excluded. Most patients with AS were men (80%). The mean age at the time of study was 52.5 years, and mean age at the onset of symptoms was 34.4 years. Twenty-nine (58%) patients showed abnormal hearing loss in the audiogram compared to only 8 (18%) controls (p < 0.001). Values of audiometric tests (pure-tone average and speech reception threshold) yielded significant differences between patients and controls (p < 0.001). It is noteworthy that the audiogram shape disclosed a predominant pattern of high-frequency sensorineural hearing loss in AS patients (50%) compared to controls (18%) (p = 0.002). Also, AS patients exhibited abnormal vestibular tests more commonly than controls. AS patients had an increased frequency of head-shaking nystagmus (20%) compared to controls (0%) (p < 0.001). Moreover, patients (26%) showed a significantly increased frequency of abnormal caloric test compared to controls (0%) (p < 0.001). Finally, a significantly increased frequency of abnormal clinical test of sensory integration and balance with a predominant vestibular loss pattern was observed in patients (36%) compared to controls (5%) (p < 0.001). In conclusion, the current study demonstrates strong evidence for inner ear compromise in patients with AS.

Environmental and genetic factors in age-related hearing impairment

Age-related hearing impairment (ARHI), or presbycusis, is a complex disease with multifactorial etiology. It is the most prevalent sensory impairment in the elderly, and may have detrimental effects on their quality of life and psychological well-being. The aim of this paper is to give an overview of the current data on ARHI, focusing mainly on environmental agents and genetic predisposition in animal models and in humans. With improvement of our understanding of ARHI, treatment other than with amplification will be hopefully possible in the long term.

The influence of cardiovascular health on peripheral and central auditory function in adults: a research review

PURPOSE

This article provides a comparative review of research that has been conducted over the past 60+ years on the influence of cardiovascular health on the function of the peripheral and central auditory systems, and findings on the influence of improvements in cardiovascular health on those same systems.

METHOD

Research spanning the past 6 decades reviewed for this article has both hypothesized and confirmed the cardiovascular system's effects on the peripheral and central auditory systems. A review of the influence of the cardiovascular system is presented in this article, and a potential new avenue for auditory rehabilitation is postulated. The review presented in this article does not represent all studies conducted in the topic area but does provide an in-depth look into this fascinating area of research.

CONCLUSIONS

The negative influence of impaired cardiovascular health on both the peripheral and central auditory system and the potential positive influence of improved cardiovascular health on these same systems have been found through a sizable body of research that has been conducted over more than 6 decades. The most significant positive relationship between improved cardiovascular health and improvements in those auditory systems has been found among older adults. If that relationship continues to be confirmed, then a potential new avenue for auditory rehabilitation on behalf of adults who possess impaired auditory function may be discovered.