Retinal Microvascular Abnormalities and Age-Related Hearing Loss: The Blue Mountains Hearing Study

Sensory and motor correlates of frailty: dissociation between frailty phenotype and frailty index

Background

Frailty has been associated with a decline in sensory and motor function. However, given that different frailty measures were shown to overlap but also differ in their diagnostic properties, sensory and motor correlates of frailty might be different depending on the operationalization of frailty. Our objective was to identify sensory and motor determinants of frailty and compare the results between frailty phenotype (FP) and frailty index (FI).

Methods

Data from 44 pre-frail and frail subjects aged 65 and above were used. Frailty was measured using the FP and the FI. Sensory function in the visual, auditory, and tactile domain was assessed using visual acuity, absolute hearing threshold and mechanical detection threshold. Upper extremity motor performance was evaluated by the Purdue Pegboard Test and the Short Physical Performance Battery was used to assess lower extremity motor function. Multiple logistic regression models were employed to determine associations of sensory and motor function with frailty vs. pre-frailty for both frailty measures.

Results

The frailty measures were moderately correlated (0.497, p ≤ 0.01) and had a Kappa agreement of 0.467 (p = 0.002). Using the FP, frailty was significantly associated with reduced upper extremity motor function only (OR = 0.50, 95% CI 0.29–0.87, p = 0.014). Frailty as assessed by the FI was significantly related to higher hearing thresholds (OR = 1.21, 95% CI 1.02–1.43, p = 0.027) and reduced lower extremity performance (OR = 0.32, 95% CI 0.13–0.77, p = 0.012).

Conclusion

Frailty is related to reduced performance in measures of sensory and motor function. However, traditional measures of frailty might be differentially sensitive to capture sensory and motor decline, possibly contributing to the much-observed discordance between the diagnostic instruments. This should be taken into account by researchers and clinicians when planning and evaluating therapeutic interventions for frailty.

Trial registration

ClinicalTrials.gov NCT03666039. Registered 11 September 2018 – Retrospectively registered.

Subclinical Atherosclerosis Could Increase the Risk of Hearing Impairment in Males: A Community-Based Cross-Sectional Survey of the Kailuan Study

Objective

The relationship between subclinical atherosclerosis and hearing impairment (HI) has not been widely considered. Brachial ankle pulse wave velocity (baPWV) is a good indicator of muscular artery elasticity and could be a feasible method to screen for subclinical atherosclerosis. Our study aimed to elucidate the relationship between baPWV and HI.

Methods

This cross-sectional study was based on the Kailuan cohort. All participants completed a standardized questionnaire and underwent physical examinations and laboratory assessments at recruitment. Since 2010, some participants received additional baPWV testing during follow-up visits, and some who were exposed to occupational hazards such as noise received a pure-tone average hearing threshold (PTA) test after 2014. Male subjects with a complete physical examination, baPWV, and PTA data were recruited for this study. HI was defined as PTA > 25 dB. Multivariate linear and multivariate logistic regression analyses were used to evaluate the relationship between baPWV and PTA or HI.

Results

Among 11,141 subjects, the age range was 18–65 years, with mean age of 43.3 ± 8.9 years, the average PTA was 20.54 ± 10.40 dB, and the detection rate of HI was 1,821/11,141 (16.3%). Subjects were divided into four subgroups according to baPWV quartile. As the baPWV quartile increased, age, systolic blood pressure, diastolic blood pressure, body mass index, total cholesterol, high-density-lipoprotein cholesterol, fasting blood glucose, PTA, and proportions of subjects reporting smoking, alcohol consumption, hypertension, and diabetes increased significantly (p < 0.05 for trend). The odds of HI were higher in the fourth quartile group [adjusted odds ratio (aOR): 1.33, 95% CI: 1.10–1.62] than in the first quartile group. For every 100 m/s increase in baPWV, the PTA increased by 13 dB (95% CI: 4–23). When we divided the subjects into young (5,478 subjects; age range 22–44 years; mean age 35.6 ± 5.5 years) or non-young subgroups (5,663 subjects; age range 45–65 years; mean age 50.7 ± 3.7 years) based on a cut-off age of 45 years, the aOR of the fourth quartile group increased to 2.65 (95% CI: 1.68–4.19), and the PTA increment increased to 18 dB (95% CI: 10–27) for every 100 m/s increase in baPWV in the young subgroup. However, this relationship became statistically insignificant in the non-young subgroup.

Conclusion

Our study revealed the quantitative relationship between baPWV and HI in the Kailuan cohort subjects, although the results are not universally consistent in different populations.

Association of different severity of diabetic retinopathy and hearing loss in type 2 diabetes mellitus

PURPOSE

Microvascular involvement in patients with diabetes mellitus is one of the causes of retinopathy, nephropathy, and neuropathy. The same pathologic processes may occur in the inner ear structures. This case-control study aimed to evaluate the hearing thresholds in type 2 diabetic patients with different severity of diabetic retinopathy (DR) and to compare these findings with controls.

MATERIALS AND METHODS

We evaluated the hearing threshold in four groups of eligible subjects aged 20-70 years. These groups were controls, diabetic patients with no-DR, with mild-moderate non-proliferative DR (NPDR), and with severe NPDR/proliferative DR (PDR). Each group consisted of 105 subjects. Speech-frequency and high-frequency hearing levels (SFHL and HFHL, respectively) were measured and log-transformed. Analysis of covariance was used. The prevalence rate of moderate or more hearing loss in the groups was estimated.

RESULTS

In total, 194 men and 226 women participated. The ratio of means of SFHL and HFHL between PDR and controls was 0.18 and 0.20, respectively. Hearing loss was prevalent in severe NPDR/PDR (adjusted prevalence ratio 3.36 for SFHL and 1.51 for HFHL) compared to controls. Also, the prevalence of high-frequency hearing loss was more in mild-moderate NPDR (adjusted prevalence ratio 1.33).

CONCLUSIONS

The magnitude of the increase in hearing impairment prevalence between the severe NPDR/PDR patients and controls was about 24% for both SFHL and HFHL. We recommend hearing assessment in the screening of the DR patients.

Effects of cigarette smoking on sensorineural hearing impairment and age related macular degeneration

INTRODUCTION

Cigarette smoking has been causally associated with various diseases, and among the numerous harmful effects of smoking is included its impact on the senses of vision and hearing. The purpose of this study is to evaluate the impact of cigarette smoking on the visual and auditory functions.

METHODS

In this analytic study, hearing and smoking status of 40 patients with agerelated macular degeneration (AMD) were analyzed with 40 age-matched control subjects without AMD. In all subjects (n=80), retinal status was investigated by optical coherence tomography (OCT), with analyses of thickness central subfield (TCS) and thickness average cube (TAC) of the macula. All participants were examined with pure tone audiometry. Audiometric trials comprised pure tone bone and air conduction. The smoking history of all the subjects was recorded in detail.

RESULTS

A significant correlation was found between smoking status and visual (p<0.001) and hearing impairment (p<0.05). Cigarette smoking was found to be highly correlated with sensorineural hearing impairment and exudative macular degeneration.

CONCLUSIONS

Cigarette smoking damage anti-oxidative systems and tissue metabolism. We have underlined a clear correlation between the risk of sensorineural hearing impairment, exudative macular degeneration and cigarette smoking. Our findings may result in future screening of smokers to identify any hearing and vision impairment and for improving smoking cessation interventions.

Diabetic Retinopathy and Hearing Loss: Results from the Fifth Korean National Health and Nutrition Survey

We investigated the association between the severity of diabetic retinopathy (DR) and hearing loss based on vascular etiology. We used data from the Korean National Health and Nutrition Survey 2010–2012. Adults aged >40 years with diabetes were enrolled. Demographic, socioeconomic, general medical, noise exposure and biochemical data were used. Participants were classified into three groups: diabetes without DR, non-proliferative DR (NPDR), and proliferative DR (PDR); participants were also divided into two groups (middle age (40 ≤ age < 65 years) vs. old age (age ≥ 65 years)). The association between hearing loss and DR was determined using logistic regression analysis. A total of 1045 participants (n = 411, middle-aged group; n = 634, old-age group) were enrolled. Overall, the prevalence of hearing loss was 58.1%, 61.4%, and 85.0% in the no DR, NPDR, and PDR groups, respectively. After adjusting for confounding factors, the logistic regression model showed that there was no significant association between the prevalence of DR and hearing loss in the overall sample. However, the presence of PDR (OR 7.74, 95% CI 2.08–28.82) was significantly associated with hearing loss in the middle-aged group. Middle-aged people with diabetes may have an association between DR severity and hearing loss. The potential role of microvascular diseases in the development of hearing loss, especially in middle-aged patients, could be considered.

The role of self-reported hearing status in the risk of hospitalisation among Chinese middle-aged and older adults

OBJECTIVE

To determine the association between self-reported hearing status and risk of hospitalisation among Chinese middle-aged and older adults.

DESIGN

Prospective cohort study. Discrete-time hazards models and negative binomial models were fitted to examine the relationship.

STUDY SAMPLE

About 11,902 participants aged 45 years or older with no hospitalisation at baseline.

RESULTS

49.28-62.70% of the participants reported their hearing as fair or poor. For older adults aged 60 and above, compared to people with excellent and very good hearing, those with good, fair or poor hearing reported shorter time to first hospitalisation [hazard ratio (HR) = 1.38, 1.38, 1.63, respectively]. They also manifested greater number of hospitalisations [incident rate ratio (IRR) = 1.21, 1.25, 1.54, respectively], and longer duration of hospitalisation (IRR = 1.36, 1.26, 1.53, respectively). However, there was no significant association between hearing status and hospitalisation for middle-aged adults for none of the hearing categories.

CONCLUSIONS

Although no significant relationship between hearing and hospitalisation was found for middle-aged adults, older adults with poorer hearing experienced greater risk of hospitalisation. Given that hearing impairment is highly prevalent among older adults, future analyses are needed to investigate whether hearing rehabilitative therapies could help mitigate hospitalisations in hearing-impaired older adults.

Associations of Retinal Vessel Caliber With Hearing Status in Childhood and Midlife: A Cross-Generational Population-Based Study

Importance

Microvascular phenotypes, which can be assessed using retinal imaging, may be informative about the life course pathogenesis of hearing loss.

Objective

To investigate whether differences in retinal vessel caliber (specifically wider venules and narrower arterioles) are associated with hearing threshold and hearing loss in mid-childhood and midlife.

Design, Setting, and Participants

A population-based cross-sectional study (Child Health CheckPoint) was nested within the Longitudinal Study of Australian Children. A total of 1281 children and 1255 attending parents were assessed using retinal microvasculature and air conduction audiometry data at a main assessment center in 7 large cities in Australia.

Main Outcomes and Measures

Air conduction audiometry was used to calculate the high Fletcher index (mean threshold of 1, 2, and 4 kHz), and bilateral hearing loss was defined as a high Fletcher index greater than 15 dB hearing level in the better-hearing ear. Retinal arteriolar and venular caliber were measured from fundus photographs using validated computer-based software. Linear and logistic regression quantified the associations of retinal vessel caliber with hearing threshold and hearing loss, respectively.

Results

Of the 1281 included children (mean age, 11.4 years; 49.1% boys), the mean (SD) high Fletcher index was 7.9 (5.8) dB hearing level. Of the 1255 included adults (mean age, 43.8 years; 86.6% women), the mean (SD) high Fletcher index was 13.0 (6.8) dB hearing level; 109 of 1281 children (8.5%) and 328 of 1255 adults (26.1%) had hearing loss. In adults, each 1-SD (18.6-μm) wider retinal venular caliber (worse) was associated with higher (worse) hearing threshold at lower individual frequencies (eg, 2 kHz: β = 0.63; 95% CI, 0.10-1.17) and overall high Fletcher index (eg, 2 kHz: β = 0.52; 95% CI, 0.07-0.96), as well as a 1.20-fold (95% CI, 1.03-1.40) higher odds of hearing loss. In children, patterns of venular associations were similar but smaller and less certain. Narrower retinal arteriolar caliber (worse) was associated with a 1.16-fold (95% CI, 1.00-1.37) higher odds of hearing loss in adults (per 1-SD [14.0-μm] narrower arteriolar caliber) but not in children.

Conclusions and Relevance

Adverse retinal microvascular characteristics are associated with hearing loss by midlife, with venular associations possibly emerging by age 11 to 12 years. Microvascular health may contribute to the pathogenesis of hearing loss across the life course, warranting replication and mechanistic studies to inform causal inference and prevention efforts.

Association Between Microvascular Retinal Signs and Age-Related Hearing Loss in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

Importance

Given that age-related hearing loss is highly prevalent and treatable, understanding its causes may have implications for disease prevention.

Objective

To investigate whether microvascular retinal signs are associated with age-related hearing loss attributable to a hypothesized underlying shared pathologic entity involving microvascular disease.

Design, Setting, and Participants

The Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS) is a community-based prospective cohort study of 15 792 men and women aged 45 to 64 years at baseline. The ARIC-NCS participants returned for a fifth clinic visit in 2011-2013 and a sixth clinic visit in 2016-2017. Participants were recruited from 4 US communities (Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and Minneapolis suburbs, Minnesota). Participants included a subset of the ARIC-NCS cohort with complete covariate data who underwent retinal fundus photography at visit 5 (2011-2013) and completed hearing assessment at visit 6 (2016-2017) (N = 1458). Overall, 453 participants had diabetes; of those, 68 had retinopathy. Of 1005 participants without diabetes, 42 had retinopathy.

Exposures

Microvascular retinal signs included retinopathy, arteriovenous (AV) nicking, and generalized arteriolar narrowing measured using the central retinal arteriolar equivalent (CRAE).

Main Outcomes and Measures

Hearing was measured using the better-hearing ear pure-tone average (PTA) of air conduction speech thresholds (0.5, 1, 2, and 4 kHz). Multivariable-adjusted linear and ordered logistic regression was used to estimate the association between microvascular retinal signs and age-related hearing loss to describe the precision of the estimates and provide a plausible range for the true association.

Results

After full adjustment among 1458 individuals in the analytic cohort (mean [SD] age, 76.1 [5.0] years [age range, 67-90 years]; 825 women [56.6%]; 285 black [19.5%]), the difference in PTA per dB hearing level in persons with and without retinopathy was 2.21 (95% CI, -0.22 to 4.63), suggesting that retinopathy is associated with poorer hearing, although the width of the 95% CI prevents definitive conclusions about the strength of the observed association. Restricting the analysis to participants without diabetes, the difference in PTA associated with retinopathy was even greater (4.14; 95% CI, 0.10-8.17 dB hearing level), but the large width of the 95% CI prevents definitive conclusions about the association. In analyses quantifying the mean differences in hearing thresholds at individual frequencies by retinopathy status, the estimates trended toward retinopathy being associated, contrary to expectation, with better high-frequency hearing. At 8 kHz, the estimated difference in hearing thresholds in persons with retinopathy vs those without was -4.24 (95% CI, -7.39 to -1.09).

Conclusions and Relevance

In this population-based study, an association between the presence of microvascular retinal signs and hearing loss was observed, suggesting that retinopathy may have the potential to identify risk for hearing loss in persons without diabetes. The precision of these estimates is low; therefore, additional epidemiologic studies are needed to better define the degree of microvascular contributions to age-related hearing loss.

Retinal Vascular Density on Optical Coherence Tomography Angiography and Age-related Central and Peripheral Hearing Loss in a Southern Italian Older Population

BACKGROUND

Age-related hearing loss (ARHL) and retinal vessel changes have both been associated to neurodegeneration/dementia, suggesting a possible link between these two conditions in older age. We aimed to determine whether superficial and deep vascular density (SVD and DVD) of the capillary plexi of macular vasculature can be associated with peripheral ARHL and age-related central auditory central processing (CAPD).

METHODS

We analyzed data on 886 older participants (65 years+, age range:65-92 years) in the cross-sectional population-based Salus in Apulia Study. Optical coherence tomography angiography (OCT-A) was used to measure SVD and DVD of the capillary plexi of the macula at the 3-mm circle area centered on the fovea (whole retina), the parafoveal quadrant, and foveal quadrant. Disabling peripheral ARHL was defined as >40 dB HL of pure tone average on the frequencies from 0.5, 1, 2, and 4 KHz in the better ear, and age-related CAPD as <50% at the Synthetic Sentence Identification with Ipsilateral Competitive Message test in at least one ear.

RESULTS

DVD at the whole retina and at the parafoveal quadrant were inversely associated only with age-related CAPD [odds ratio (OR):0.93; 95% confidence interval (CI): 0.88-0.96 and OR:0.94; 95 CI:0.90-0.99, respectively]. No further associations with peripheral ARHL were evident.

CONCLUSIONS

Retinal vasculature is associated with central auditory processing pathology, possibly playing an important role in early detection and intervention. The association of retinal vascular density with age-related CAPD may bring us a further step forward in understanding the biological mechanisms underlying the links between neurodegeneration/dementia and ARHL.

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.

Relationships Among Self-Reported Hearing Problems, Psychological Distress, and Cardiovascular Disease in U.S. Adults, National Health Interview Survey 1997-2017

Objective The purpose of this study was to explore the hypothesis that the relationship between hearing problems and cardiovascular disease (CVD) includes a connection to psychological distress. Design We used generalized structural equation modeling to assess relationships between self-reported measures of hearing problems, psychological distress, and CVD in a pooled sample of 623,416 adult respondents in the 1997-2017 National Health Interview Survey. Hearing status without hearing aids was self-reported on an ordinal scale and further grouped for this study into 3 categories (excellent or good hearing, little or moderate trouble hearing, and a lot of trouble or deaf). Six CVDs (stroke, angina pectoris, hypertension, heart attack, coronary heart disease, or other heart condition/disease) were incorporated as a latent variable. Psychological distress was evaluated by the Kessler 6 Scale (Kessler et al., 2010). All estimates were population weighted, and standard errors were adjusted for a complex survey design. Results Nearly 83% reported excellent or good hearing, 14% reported a little or moderate trouble hearing, and 3% reported a lot of trouble hearing or said they were deaf. Hearing problems were positively associated with CVD. Relative to those reporting excellent/good hearing, adults reporting trouble hearing had a higher probability of CVD. Hearing problems were also significantly associated with psychological distress. When psychological distress was applied to the model, positive associations between hearing problems and CVD were attenuated but still significant. Results are consistent with the hypothesis that the connection between self-reported hearing problems and CVD is mediated through psychological distress. Conclusions The relationship between self-reported hearing problems and CVD is mediated by psychological distress. Further research is needed to identify causal pathways and psychophysiological mechanisms involved in this relationship and to identify effective methods for addressing cardiovascular health-related psychosocial factors in the treatment of hearing impairment.

Can Nutritional Intervention for Obesity and Comorbidities Slow Down Age-Related Hearing Impairment?

BACKGROUND

Age-related hearing impairment (ARHI), the most common sensory deficit in the elderly, is associated with enormous social and public health burdens. Emerging evidence has suggested that obesity and comorbidities might increase the risk of ARHI. However, no reviews have been published that address the role of nutritional interventions for obesity and comorbidities in the prevention of ARHI.

METHODS

A PubMed database search was conducted to identify the relationship between obesity and ARHI. "Obesity", "metabolic syndrome", "adipose-derived hormone", "fatty acid", and "age-related hearing impairment" were included as keywords.

RESULTS

A total of 89 articles was analyzed with 39 articles of relevance to ARHI. A high-fat diet may induce oxidative stress, mitochondrial damage, and apoptosis in the inner ear. Statins have been shown to delay the progression of ARHI by improving the lipid profile, reducing oxidative stress, and inhibiting endothelial inflammation. Aldosterone could exert protective effects against ARHI by upregulating the Na-K-2Cl co-transporter 1 in the cochlea. Omega-3 polyunsaturated fatty acids could preserve the cochlear microcirculation by reducing dyslipidemia and inhibiting inflammation. Alpha-lipoic acid and lecithin might delay the progression of ARHI by protecting cochlear mitochondrial DNA from damage due to oxidative stress. Tea and ginseng might protect against ARHI through their anti-obesity and anti-diabetic effects.

CONCLUSIONS

Nutritional interventions for obesity and comorbidities, including a low-fat diet, supplementation with statins, aldosterone, omega-3 polyunsaturated fatty acids, alpha-lipoic acids, lecithin, tea, and ginseng, may protect against the development of ARHI.

Poorer Speech Reception Threshold in Noise Is Associated With Lower Brain Volume in Auditory and Cognitive Processing Regions

Purpose Hearing loss is associated with changes in brain volume in regions supporting auditory and cognitive processing. The purpose of this study was to determine whether there is a systematic association between hearing ability and brain volume in cross-sectional data from a large nonclinical cohort of middle-aged adults available from the UK Biobank Resource ( http://www.ukbiobank.ac.uk ). Method We performed a set of regression analyses to determine the association between speech reception threshold in noise (SRTn) and global brain volume as well as predefined regions of interest (ROIs) based on T1-weighted structural images, controlling for hearing-related comorbidities and cognition as well as demographic factors. In a 2nd set of analyses, we additionally controlled for hearing aid (HA) use. We predicted statistically significant associations globally and in ROIs including auditory and cognitive processing regions, possibly modulated by HA use. Results Whole-brain gray matter volume was significantly lower for individuals with poorer SRTn. Furthermore, the volume of 9 predicted ROIs including both auditory and cognitive processing regions was lower for individuals with poorer SRTn. The greatest percentage difference (-0.57%) in ROI volume relating to a 1 SD worsening of SRTn was found in the left superior temporal gyrus. HA use did not substantially modulate the pattern of association between brain volume and SRTn. Conclusions In a large middle-aged nonclinical population, poorer hearing ability is associated with lower brain volume globally as well as in cortical and subcortical regions involved in auditory and cognitive processing, but there was no conclusive evidence that this effect is moderated by HA use. This pattern of results supports the notion that poor hearing leads to reduced volume in brain regions recruited during speech understanding under challenging conditions. These findings should be tested in future longitudinal, experimental studies. Supplemental Material https://doi.org/10.23641/asha.7949357.

Metabolic syndrome is associated with hearing disturbance

BACKGROUND

Although metabolic syndrome (MetS) has been associated with various diseases, few studies to date have addressed the association between MetS and hearing loss.

AIMS/OBJECTIVES

This cross-sectional review of health examination center data sought to determine the association between MetS and hearing disturbance.

MATERIAL AND METHODS

This study involved 28,866 subjects. Height, weight, waist circumference, and blood pressure were measured, and basic blood tests and pure-tone audiometry (PTA) were performed. Other factors analyzed included body mass index, hypertension, diabetes mellitus, and hyperlipidemia.

RESULTS

Age and gender did not differ between subjects with and without MetS. PTA was slightly higher in subjects with than without MetS, but the difference was not statistically significant (p = .47). The incidence of hearing loss was no higher in subjects who met three of the five diagnostic criteria of MetS than in those who met 0-2 criteria, but was significantly higher in subjects who met four (p = .04) and five (p < .01) criteria.

CONCLUSIONS AND SIGNIFICANCE

MetS may be associated with hearing loss, especially in subjects who meet four or five of the diagnostic criteria for MetS.

The Influence of Social Interaction and Physical Health on the Association Between Hearing and Depression With Age and Gender

Recent epidemiological data suggest the relation between hearing difficulty and depression is more evident in younger and middle-aged populations than in older adults. There are also suggestions that the relation may be more evident in specific subgroups; that is, other factors may influence a relationship between hearing and depression in different subgroups. Using cross-sectional data from the UK Biobank on 134,357 community-dwelling people and structural equation modelling, this study examined the potential mediating influence of social isolation and unemployment and the confounding influence of physical illness and cardiovascular conditions on the relation between a latent hearing variable and both a latent depressive episodes variable and a latent depressive symptoms variable. The models were stratified by age (40s, 50s, and 60s) and gender and further controlled for physical illness and professional support in associations involving social isolation and unemployment. The latent hearing variable was primarily defined by reported hearing difficulty in noise. For all subgroups, poor hearing was significantly related to both more depressive episodes and more depressive symptoms. In all models, the direct and generally small association exceeded the indirect associations via physical health and social interaction. Significant (depressive episodes) and near significant (depressive symptoms) higher direct associations were estimated for males in their 40s and 50s than for males in their 60s. There was at each age-group no significant difference in estimated associations across gender. Irrespective of the temporal order of variables, findings suggest that audiological services should facilitate psychosocial counselling.

Serum Methylarginines and Hearing Loss in a Population-based Cohort of Older Adults

OBJECTIVE

Age-related hearing loss is associated with endothelial dysfunction and increased cardiovascular risk, suggesting a vascular etiology. Methylarginines are endogenous nitric oxide synthase inhibitors that cause endothelial dysfunction and increase cardiovascular disease risk. This study is the first to examine the hypothesis that higher serum concentrations of methylarginines are associated with greater hearing loss prevalence.

STUDY DESIGN/PATIENTS

Cross-sectional audiometric data on hearing levels, and serum methylarginines were collected from a population-based sample of 630 older community-dwelling adults.

RESULTS

Linear regression analysis showed a statistically significant association between higher serum concentrations of asymmetric dimethylarginine (ADMA) and L-arginine and greater degrees of hearing loss for males, particularly over 75 years. Higher body mass index and previous history of stroke were also associated with hearing loss. For females, ADMA concentration was not associated with hearing loss, but higher serum L-arginine concentrations were associated with reduced hearing loss prevalence in older females. Antihypertensive medication use was also associated with reduced hearing loss prevalence. LDL cholesterol and previous myocardial infarction were associated with greater hearing loss.

CONCLUSION

This study showed a significant association between serum concentrations of ADMA and hearing loss for males, consistent with the association between endothelial dysfunction and hearing loss. The opposite effect of L-arginine on hearing loss in males versus females might reflect a different role of this precursor toward nitric oxide versus methylated arginines synthesis. These findings are potentially clinically significant if the association between ADMA and hearing loss is causal, as serum methylarginine levels are modifiable through pharmacotherapeutic/lifestyle interventions.

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.

Secondhand Smoke is Associated with Hearing Threshold Shifts in Obese Adults

Hearing loss resulted from multiple intrinsic and extrinsic factors. Secondhand smoke (SHS) and obesity had been reported to be related to hearing loss. This study explored the possible associations of SHS and obesity with the hearing threshold. The relations between SHS and the hearing threshold in subjects from three different body mass index classes were analyzed. Our study included data from 1,961 subjects aged 20–69 years that were obtained from the National Health and Nutrition Examination Survey for the years 1999–2004. After adjusting for potential confounding factors, the subjects with the higher tertiles of serum cotinine levels tended to have higher hearing thresholds than those with the lowest tertile of serum cotinine levels (for both trends, p < 0.05). Notably, the obese subjects with the higher tertiles of serum cotinine levels had significantly higher hearing thresholds for high frequencies and low frequencies than those with the lowest tertile of serum cotinine levels (for both trends, p < 0.05). Our study showed a significant positive association between SHS exposure and hearing thresholds in the adult population, especially in obese individuals. Based on our findings, avoiding exposure to SHS, especially in obese adults, may decrease the risk of hearing loss.

Association of Hearing Impairment With Incident Frailty and Falls in Older Adults

OBJECTIVE

We aimed to determine whether hearing impairment (HI) in older adults is associated with the development of frailty and falls.

METHOD

Longitudinal analysis of observational data from the Health, Aging and Body Composition study of 2,000 participants aged 70 to 79 was conducted. Hearing was defined by the pure-tone-average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better hearing ear. Frailty was defined as a gait speed of <0.60 m/s and/or inability to rise from a chair without using arms. Falls were assessed annually by self-report.

RESULTS

Older adults with moderate-or-greater HI had a 63% increased risk of developing frailty (adjusted hazard ratio [HR] = 1.63, 95% confidence interval [CI] = [1.26, 2.12]) compared with normal-hearing individuals. Moderate-or-greater HI was significantly associated with a greater annual percent increase in odds of falling over time (9.7%, 95% CI = [7.0, 12.4] compared with normal hearing, 4.4%, 95% CI = [2.6, 6.2]).

DISCUSSION

HI is independently associated with the risk of frailty in older adults and with greater odds of falling over time.

Association of Age Related Macular Degeneration and Age Related Hearing Impairment

Purpose:

To evaluate the association between age-related macular degeneration (ARMD) and sensory neural hearing impairment (SHI).

Methods:

In this case-control study, hearing status of 46 consecutive patients with ARMD were compared with 46 age-matched cases without clinical ARMD as a control group. In all patients, retinal involvements were confirmed by clinical examination, fluorescein angiography (FA) and optical coherence tomography (OCT). All participants were examined with an otoscope and underwent audiological tests including pure tone audiometry (PTA), speech reception threshold (SRT), speech discrimination score (SDS), tympanometry, reflex tests and auditory brainstem response (ABR).

Results:

A significant (P = 0.009) association was present between ARMD, especially with exudative and choroidal neovascularization (CNV) components, and age-related hearing impairment primarily involving high frequencies. Patients had higher SRT and lower SDS against anticipated presbycusis than control subjects. Similar results were detected in exudative, CNV and scar patterns supporting an association between late ARMD with SRT and SDS abnormalities. ABR showed significantly prolonged wave I and IV latency times in ARMD (P = 0.034 and 0.022, respectively). Average latency periods for wave I in geographic atrophy (GA) and CNV, and that for wave IV in drusen patterns of ARMD were significantly higher than controls (P = 0.030, 0.007 and 0.050, respectively).

Conclusion:

The association between ARMD and age-related SHI may be attributed to common anatomical components such as melanin in these two sensory organs.

Slowing the progression of age-related hearing loss: Rationale and study design of the ASPIRIN in HEARING, retinal vessels imaging and neurocognition in older generations (ASPREE-HEARING) trial

BACKGROUND

Age-related hearing loss (ARHL) is a leading cause of disability in the elderly. Low-grade inflammation and microvessel pathology may be responsible for initiating or exacerbating some of the hearing loss associated with aging. A growing body of evidence demonstrates an association of hearing loss with cognitive decline. A shared etiological pathway may include a role of inflammation, alongside vascular determinants. The ASPREE-HEARING study aims to determine whether low-dose aspirin decreases the progression of ARHL, and if so, whether this decrease in progression is also associated with retinal microvascular changes and/or greater preservation of cognitive function.

DESIGN AND METHODS

A three year double-blind, randomized controlled trial of oral 100mg enteric-coated aspirin or matching placebo, enrolling 1262 Australians aged ≥70years with normal cognitive function and no overt cardiovascular disease. The primary outcome is the change in mean pure tone average hearing threshold (decibels) in the better ear, over a 3-year period. Secondary outcomes consist of changes in retinal microvascular indicators, and changes in cognitive function. Participants are recruited from a larger trial, ASPirin in Reducing Events in the Elderly (ASPREE), which is designed to assess whether daily low dose aspirin will extend disability-free life.

DISCUSSION

ASPREE-HEARING will determine whether aspirin slows development or progression of ARHL, and will interrogate the relationship between inflammatory and microvascular mechanisms that may underlie the effects of aspirin on ARHL. This study will improve understanding of the patterns of comorbidity with, and the relationships between, aging and ARHL, alongside modeling the impacts of ARHL.

Association Between Hearing Impairment and Risk of Hospitalization in Older Adults

OBJECTIVES

To determine the association between hearing impairment (HI) and risk and duration of hospitalization in community-dwelling older adults in the United States.

DESIGN

Prospective observational study.

SETTING

Health, Aging and Body Composition Study.

PARTICIPANTS

Well-functioning community-dwelling white and black Medicare beneficiaries aged 70 to 79 at study enrollment in 1997-98 were followed for a median of 12 years.

MEASUREMENTS

Incidence, annual rate, and duration of hospitalization were the primary outcomes. Hearing was defined as the pure-tone average (PTA) of hearing thresholds in decibels re: hearing level (dB HL) at octave frequencies from 0.5 to 4.0 kHz. Mild HI was defined as a PTA from 25 to 40 dB HL, and moderate or greater HI was defined as a PTA greater than 40 dB HL.

RESULTS

Of the 2,148 participants included in the analysis, 1,801 (83.5%) experienced one or more hospitalizations, with 7,007 adjudicated hospitalization events occurring during the study period. Eight hundred eighty-two (41.1%) participants had normal hearing, 818 (38.1%) had mild HI, and 448 (20.9%) had moderate or greater HI. After adjusting for demographic characteristics and cardiovascular comorbidities, persons with mild HI experienced a 16% (hazard ratio (HR) = 1.16, 95% confidence interval (CI) = 1.04-1.29) greater risk of incident hospitalization and a 17% (incidence rate ratio (IRR) = 1.17, 95% CI = 1.04-1.32) greater annual rate of hospitalization, and those with moderate or greater HI experienced a 21% (HR = 1.21, 95% CI = 1.06-1.38) greater risk of incident hospitalization and a 19% (IRR = 1.19, 95% CI = 1.04-1.38) greater annual rate of hospitalization than persons with normal hearing. There was no significant association between HI and mean duration of hospitalization.

CONCLUSION

Hearing-impaired older adults experience a greater incidence and annual rate of hospitalization than those with normal hearing. Investigating whether rehabilitative therapies could affect the risk of hospitalization in older adults requires further study.

Assessment of perfused foveal microvascular density and identification of nonperfused capillaries in healthy and vasculopathic eyes

PURPOSE

To analyze the foveal microvasculature of young healthy eyes and older vasculopathic eyes, imaged using in vivo adaptive optics scanning light ophthalmoscope fluorescein angiography (AOSLO FA).

METHODS

AOSLO FA imaging of the superficial retinal microvasculature within an 800-μm radius from the foveal center was performed using simultaneous confocal infrared (IR) reflectance (790 nm) and fluorescence (488 nm) channels. Corresponding IR structural and FA perfusion maps were compared with each other to identify nonperfused capillaries adjacent to the foveal avascular zone. Microvascular densities were calculated from skeletonized FA perfusion maps.

RESULTS

Sixteen healthy adults (26 eyes; mean age 25 years, range, 21-29) and six patients with a retinal vasculopathy (six eyes; mean age 55 years, range, 44-70) were imaged. At least one nonperfused capillary was observed in five of the 16 healthy nonfellow eyes and in four of the six vasculopathic eyes. Compared with healthy eyes, capillary nonperfusion in the vasculopathic eyes was more extensive. Microvascular density of the 16 healthy nonfellow eyes was 42.0 ± 4.2 mm(-1) (range, 33-50 mm(-1)). All six vasculopathic eyes had decreased microvascular densities.

CONCLUSIONS

AOSLO FA provides an in vivo method for estimating foveal microvascular density and reveals occult nonperfused retinal capillaries. Nonperfused capillaries in healthy young adults may represent a normal variation and/or an early sign of pathology. Although limited, the normative data presented here is a step toward developing clinically useful microvascular parameters for ocular and/or systemic diseases.

Association of hearing impairment and mortality in older adults

BACKGROUND

Hearing impairment (HI) is highly prevalent in older adults and is associated with social isolation, depression, and risk of dementia. Whether HI is associated with broader downstream outcomes is unclear. We undertook this study to determine whether audiometric HI is associated with mortality in older adults.

METHODS

Prospective observational data from 1,958 adults ≥70 years of age from the Health, Aging, and Body Composition Study were analyzed using Cox proportional hazards regression. Participants were followed for 8 years after audiometric examination. Mortality was adjudicated by obtaining death certificates. Hearing was defined as the pure-tone average of hearing thresholds in decibels re: hearing level (dB HL) at frequencies from 0.5 to 4kHz. HI was defined as pure-tone average >25 dB HL in the better ear.

RESULTS

Of the 1,146 participants with HI, 492 (42.9%) died compared with 255 (31.4%) of the 812 with normal hearing (odds ratio = 1.64, 95% CI: 1.36-1.98). After adjustment for demographics and cardiovascular risk factors, HI was associated with a 20% increased mortality risk compared with normal hearing (hazard ratio = 1.20, 95% CI: 1.03-1.41). Confirmatory analyses treating HI as a continuous predictor yielded similar results, demonstrating a nonlinear increase in mortality risk with increasing HI (hazard ratio = 1.14, 95% CI: 1.00-1.29 per 10 dB of threshold elevation up to 35 dB HL).

CONCLUSIONS

HI in older adults is associated with increased mortality, independent of demographics and cardiovascular risk factors. Further research is necessary to understand the basis of this association and whether these pathways might be amenable to hearing rehabilitation.

Body mass index, waist circumference, physical activity, and risk of hearing loss in women

BACKGROUND

Acquired hearing loss is highly prevalent, but prospective data on potentially modifiable risk factors are limited. In cross-sectional studies, higher body mass index (BMI), larger waist circumference, and lower physical activity have been associated with poorer hearing, but these have not been examined prospectively.

METHODS

We examined the independent associations between BMI, waist circumference, and physical activity, and self-reported hearing loss in 68,421 women in the Nurses' Health Study II from 1989 to 2009. Baseline and updated information on BMI, waist circumference, and physical activity was obtained from biennial questionnaires.

RESULTS

After more than 1.1 million person-years of follow-up, 11,286 cases of hearing loss were reported to have occurred. Higher BMI and larger waist circumference were associated with increased risk of hearing loss. Compared with women with BMI <25 kg/m(2), the multivariate-adjusted relative risk (RR) for women with BMI ≥ 40 was 1.25 (95% confidence interval [CI], 1.14-1.37). Compared with women with waist circumference <71 cm, the multivariate-adjusted RR for waist circumference >88 cm was 1.27 (95% CI, 1.17-1.38). Higher physical activity was related inversely to risk; compared with women in the lowest quintile of physical activity, the multivariate-adjusted RR for women in the highest quintile was 0.83 (95% CI, 0.78-0.88). Walking 2 hours per week or more was associated inversely with risk. Simultaneous adjustment for BMI, waist circumference, and physical activity slightly attenuated the associations but they remained statistically significant.

CONCLUSIONS

Higher BMI and larger waist circumference are associated with increased risk, and higher physical activity is associated with reduced risk of hearing loss in women. These findings provide evidence that maintaining healthy weight and staying physically active, potentially modifiable lifestyle factors, may help reduce the risk of hearing loss.

White matter hyperintensities predict low frequency hearing in older adults

Vascular disease has been proposed as a contributing factor for presbyacusis (age-related hearing loss). While this hypothesis is supported by pathological evidence of vascular decline in post-mortem human and animal studies, evidence in human subjects has been mixed with associations typically reported between a measure of vascular health and low frequency hearing in older women. Given the difficulty of characterizing the in vivo health of the cochlear artery in humans, an estimate of cerebral small vessel disease was used to test the prediction that age-related change in low frequency hearing and not high frequency hearing is related to a global decline in vascular health. We examined the extent to which these associations were specific to women and influenced by a history of high blood pressure in 72 older adults (mean age 67.12 years, SD = 8.79). Probability estimates of periventricular white matter hyperintensities (WMH) from T1- and fluid attenuated T2-weighted magnetic resonance images were significantly associated with a low frequency hearing metric across the sample, which were independent of age, but driven by women and people with a history of high blood pressure. These results support the premise that vascular declines are one mechanism underlying age-related changes in low frequency hearing.

Auditory cortex signs of age-related hearing loss

Age-related hearing loss, or presbyacusis, is a major public health problem that causes communication difficulties and is associated with diminished quality of life. Limited satisfaction with hearing aids, particularly in noisy listening conditions, suggests that central nervous system declines occur with presbyacusis and may limit the efficacy of interventions focused solely on improving audibility. This study of 49 older adults (M = 69.58, SD = 8.22 years; 29 female) was designed to examine the extent to which low and/or high frequency hearing loss was related to auditory cortex morphology. Low and high frequency hearing constructs were obtained from a factor analysis of audiograms from these older adults and 1,704 audiograms from an independent sample of older adults. Significant region of interest and voxel-wise gray matter volume associations were observed for the high frequency hearing construct. These effects occurred most robustly in a primary auditory cortex region (Te1.0) where there was also elevated cerebrospinal fluid with high frequency hearing loss, suggesting that auditory cortex atrophies with high frequency hearing loss. These results indicate that Te1.0 is particularly affected by high frequency hearing loss and may be a target for evaluating the efficacy of interventions for hearing loss.

Association between hearing and vision impairments in older adults

PURPOSE

To determine which, if any, vision variables are associated with moderate bilateral hearing loss in an elderly population.

METHODS

Four hundred and forty-six subjects completed a hearing screening in conjunction with measurements on a variety of vision tests including high contrast acuity, low contrast acuity measured under a variety of lighting conditions, contrast sensitivity, stereopsis, and colour vision. Logistic regression analyses were used to assess the relationship between various vision variables and hearing impairment while controlling for demographic and other co-morbid conditions.

RESULTS

In this sample of older adults with a mean age of 79.9 years, 5.4% of individuals were moderately visually impaired (binocular high contrast VA worse than 0.54 logMAR, Snellen equivalent 6/21 or 20/70) and 12.8% were moderately bilaterally hearing impaired (hearing none of the 40 dB tones at 500, 2000 or 4000 Hz in either ear). Three measures of low contrast acuity, but not high contrast acuity or other vision measures, were significantly associated with hearing loss when controlling for age, cataract surgery history, glaucoma history and self reported stroke, all of which were significantly associated with hearing loss, although the association of glaucoma with hearing loss was negative.

CONCLUSIONS

Poorer vision for low contrast targets was associated with an increased risk of hearing impairment in older adults. Audiologists and optometrists should enquire about the other sense in cases in which a deficit is measured as individuals with dual sensory loss are at a marked disadvantage in daily life.

Hearing sensitivity in older adults: associations with cardiovascular risk factors in the health, aging and body composition study

OBJECTIVES

To examine the association between cardiovascular disease (CVD) and its risk factors and age-associated hearing loss in a cohort of older black and white adults.

DESIGN

Cross-sectional cohort study.

SETTING

The Health, Aging, and Body Composition (Health ABC) Study, a community-based cohort study of older adults from Pittsburgh, Pennsylvania, and Memphis, Tennessee.

PARTICIPANTS

Two thousand forty-nine well-functioning adults (mean age 77.5; 37% black).

MEASUREMENTS

Pure-tone audiometry measurement and history of clinical CVD were obtained at the fourth annual follow-up visit. Pure-tone averages in decibels reflecting low (250, 500, and 1,000 Hz), middle (500, 1,000, and 2,000 Hz), and high (2,000, 4,000, and 8,000 Hz) frequencies were calculated for each ear. CVD risk factors, aortic pulse-wave velocity (PWV), and ankle-arm index (AAI) were obtained at study baseline.

RESULTS

In sex-stratified models, after adjustment for age, race, study site, and occupational noise exposure, risk factors associated with poorer hearing sensitivity in men included high triglyceride levels, high resting heart rate, and history of smoking. In women, poor hearing sensitivity was associated with high body mass index, high resting heart rate, fast PWV, and low AAI.

CONCLUSION

Modifiable risk factors for CVD may play a role in the development of age-related hearing loss.

The prevalence of hearing impairment and associated risk factors: the Beaver Dam Offspring Study

OBJECTIVE

To estimate the prevalence of hearing impairment (HI) and evaluate the cross-sectional associations of environmental and cardiovascular disease risk factors and HI in middle-aged adults.

DESIGN

Data were collected as part of the Beaver Dam Offspring Study, an epidemiological cohort study of aging. Hearing impairment was defined as a pure-tone average (0.5, 1.0, 2.0, and 4.0 kHz) greater than 25 db hearing level in either ear. Word recognition in competing message (WRCM) was measured using the Northwestern University No. 6 word list. Questionnaire information about behaviors, environmental factors, and medical history was also collected.

PARTICIPANTS

The participants (N = 3285) were offspring of participants of the population-based Epidemiology of Hearing Loss Study and ranged in age from 21 to 84 years (mean age, 49 years).

RESULTS

The prevalence of HI was 14.1%, and the mean (SD) WRCM score was 64% (15%). In a multivariate model, after age, sex, education, and occupational noise were controlled for, a history of ear surgery (odds ratio [OR], 4.11; 95% confidence interval [CI], 2.37-7.15), a larger central retinal venular equivalent (OR, 1.77; 95% CI, 1.20-2.60 [fourth quartile vs first quartile]), and a higher hematocrit percentage (OR, 0.77; 95% CI, 0.63-0.95 [per 5%]) were independently associated with HI. Factors associated with lower WRCM scores were similar but also included mean intima-media thickness (mean difference, -0.63%; 95% CI, -1.06% to -0.19%; P = .005 [per 0.1 mm]) and statin use (mean difference, -2.09%; 95% CI, -3.58% to -0.60%; P = .005).

CONCLUSIONS

Hearing impairment is a common condition in middle-aged adults. Cardiovascular disease risk factors may be important correlates of age-related auditory dysfunction.

Consumption of omega-3 fatty acids and fish and risk of age-related hearing loss

BACKGROUND

Identification of modifiable risk factors that could prevent or slow the development of age-related hearing loss (presbycusis) would be valuable. Dietary polyunsaturated fatty acid (PUFA) intake may be related to age-related hearing loss.

OBJECTIVE

We aimed to determine the association between dietary intakes of omega-3 (n-3) PUFAs and fish and the risk of presbycusis.

DESIGN

The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss (1997-1999 to 2002-2004). We collected dietary data by using a semiquantitative food-frequency questionnaire and calculated PUFA and fish intakes. In 2956 participants (aged > or =50 y), we measured presbycusis, which we defined as the pure-tone average of frequencies 0.5, 1.0, 2.0, and 4.0 kHz >25 decibels of hearing loss.

RESULTS

There was an inverse association between total n-3 PUFA intake and prevalent hearing loss [odds ratio (OR) per SD increase in energy-adjusted n-3 PUFAs: 0.89; 95% CI: 0.81, 0.99]. There was an inverse association between long-chain n-3 PUFAs and incident hearing loss (OR per SD increase in long-chain n-3 PUFAs: 0.76; 95% CI: 0.60, 0.97). Participants who had > or =2 servings of fish/wk compared with participants who had <1 serving of fish/wk had a significantly reduced risk (42%) of developing presbycusis at follow-up (multivariate-adjusted OR: 0.58; 95% CI: 0.35, 0.95). There was an association between consumption of > or =1 to <2 servings/wk of fish and a reduced risk of a progression of hearing loss (OR: 0.53; 95% CI: 0.32, 0.88).

CONCLUSIONS

There was an inverse association between higher intakes of long-chain n-3 PUFAs and regular weekly consumption of fish and hearing loss. Dietary intervention with n-3 PUFAs could prevent or delay the development of age-related hearing loss.

The impact of arterial sclerosis on hearing with and without occupational noise exposure: a population-based aging study in males

OBJECTIVES

Arterial sclerosis contributes to inadequate blood supply to multiple organs, suggesting that general atherosclerosis may play an important role in the inner ear. Since noise is a major etiology for hearing loss, the aim of this study was to evaluate both the respective and the combined effects of arterial sclerosis and occupational noise exposure on hearing after accounting for age in middle-aged and elderly men.

METHODS

The evaluation was conducted using 773 subjects from a population-based sample of 1189 men, aged 40-83 years. The impact of carotid atherosclerosis (CA) or retinal arteriolosclerosis (RA) on hearing was assessed according to history of occupational noise exposure (Noise) obtained in a questionnaire. Differences in the mean pure-tone thresholds at each frequency, between the CA (+) and CA (-) groups or between the RA (+) and RA (-) groups, based on noise exposure were compared using the general linear model (GLM) Procedure in SAS, with adjustments for age. Then, the main effect of CA or RA, and the interactive effect of noise and either CA or RA on pure-tone threshold at seven frequencies were analyzed using an analysis of covariance (ANCOVA), after adjusting for age.

RESULTS

In the Noise (+) group, a statistically significant deterioration in hearing was found in the CA (+) group compared with the CA (-) group at 500 and 1000 Hz. The results in RA were significant at even lower frequencies than in CA. In the results from ANCOVA, the significant main effect of CA was shown in the pure-tone threshold at 8000 Hz, but not in the analysis of RA. A significant interactive effect of either CA or RA and Noise was observed in hearing at the range from 125 to 1000 Hz.

CONCLUSIONS

The present study suggests that the impact of arterial sclerosis on hearing is limited but significantly hazardous in middle-aged and elderly men, and that arterial sclerosis exacerbates the deleterious effects of noise on hearing. Early recognition of arterial sclerosis might be contributory to the hearing prognosis after middle age, especially for noise-exposed men.