Interplay between Nutrition and Hearing Loss: State of Art

Hearing and Diet (Narrative Review)

It seems that food factors and the type of nutrition have an effect on the function of the auditory system. Hearing is one of the most important senses for social communication and high cognitive behaviors. Sensorineural hearing loss leaves adverse and permanent consequences in all aspects of personal and social life of affected patients. Hence, this narrative review study was designed to determine the relationship between sensorineural hearing loss and type of diet. Based on the inclusion criteria, the full text of 62 articles published between 2005 and 2023 were extracted from Scopus, Medline [PubMed], Web of Science, and Google Scholar websites and constituted the sources of this research. The results of the studies showed that by limiting the consumption of foods rich in cholesterol, sugar, carbohydrates, and protein, hearing is protected against the factors that cause sensorineural hearing loss. Also, increasing the consumption of vegetables, fruits, omega-3, antioxidants in the form of vitamins A, C, E reduce hearing susceptibility due to noise exposure, presbycusis, ototoxic agents, and etc. Healthy diet includes eating all the nutrients the body needs in a balanced way. Healthy lifestyle factors including continuous physical activity, good sleep quality, quitting smoking, stay away from stressful factors or relaxation, and avoiding exposure to environmental noise. By following healthy eating and lifestyle patterns, the conditions for hearing, physical and mental health are provided.

Association between Serum Vitamin D Levels and Risk of Sudden Sensorineural Hearing Loss: A cross-sectional Study

Background

Sudden sensorineural hearing loss (SSNHL) is an autoimmune diseases of the inner ear which is usually defined by acute onset of hearing loss in one or both ears, of 30 dB or more on at least three contiguous audiometric frequencies within 3 days or less. This study aimed to compare the serum levels of 25-hydroxyvitamin D (VitD) between patients with SSNHL and healthy controls.

Methods

A total of 50 patients with SSNHL and 50 healthy individuals without hearing loss as control group were enrolled in this study. Serum levels of VitD and other related laboratory tests such as calcium (Ca), phosphorus (P), and parathyroid hormone (PTH) were measured and compared between two study groups.

Results

Serum level of VitD was significantly lower in patients suffering from SSNHL compared to the healthy controls (26.55 ± 14.44 vs. 33.51 ± 14.21, P = 0.017, respectively). VitD insufficiency was observed in 70% (n = 35) of the patients with SSNHL as compared to 44% (n = 22) of healthy individuals, demonstrating a significant difference between two study groups. However, no statistically difference was observed for serum levels of Ca, P, and PTH.

Conclusion

This study indicated an increased prevalence of VitD insufficiency in subjects with SSNHL, suggesting a possible association between serum VitD levels and the development of SSNHL. VitD may protect the hearing loss through its antioxidant role.

Association between HbA1c and hearing loss: a tertiary care center-based study

The purpose of this study was to investigate the correlation between glycated hemoglobin (HbA1c) levels and hearing loss (HL) using data from a tertiary hospital. Our hypothesis regarding the relationship between HL and HbA1c levels was that elevated HbA1c levels are associated with an increased risk of HL. We retrospectively reviewed the medical charts of patients diagnosed with sensorineural HL or diabetes between 2006 and 2021 at the Catholic Medical Center (CMC). Data were collected from the CMC's Clinical Data Warehouse. Participants were selected from patients who were prescribed pure-tone audiometry and an HbA1c blood test. The survey was completed for 5287 participants. The better ear pure-tone audiometry (PTA) for air conduction thresholds at 500, 1000, 2000, and 4000 Hz was calculated. Sensorineural HL was defined as a better ear PTA of 25 dB or higher. We used the HbA1c level as a diagnostic criterion for diabetes. The following criteria were used to define the HbA1c level: normal, HbA1c level below 5.6%; prediabetes, level between 5.6 and 6.4%; and diabetes, level of 6.5% or more. Among 5287 participants, 1129 were categorized as normal, 2119 as prediabetic, and 2039 as diabetic. The diabetic group was significantly older (p < 0.05). The PTA also significantly deteriorated in the diabetes group (p < 0.05). We analyzed the effects of age, sex, and HbA1c level on frequency-specific hearing using multiple regression. The hearing thresholds at all frequencies deteriorated significantly with increasing age and HbA1c level (p < 0.05). A case-control study was also performed to facilitate a comprehensive comparison between distinct groups. The participants were categorized into two groups: a case (PTA > 25 dB) and control group (PTA ≤ 25 dB), based on their PTA threshold of four frequencies. After adjusting for age and sex, we found no significant odds ratio (OR) of HL between the prediabetes group and the normal group. Notably, the OR of HL was significantly higher in the diabetes group with each PTA threshold and frequency. The 6.3% HbA1c level cutoff value was determined by analyzing the receiver operating characteristic curve for predicting hearing impairment > 25 dB. Diabetes was associated with hearing loss in all frequency ranges, particularly at high frequencies. Screening for HL is strongly recommended for patients with elevated HbA1c levels.

Age-related hearing loss and its potential drug candidates: a systematic review

BACKGROUND

Age-related hearing loss (ARHL) is one of the main illnesses afflicting the aged population and has a significant negative impact on society, economy, and health. However, there is presently no appropriate therapeutic treatment of ARHL due to the absence of comprehensive trials.

OBJECTIVES

The goal of this review is to systematically evaluate and analyze recent statistics on the pathologic classifications, risk factors, treatment strategies, and drug candidates of ARHL, including that from traditional Chinese medicine (TCM), to provide potential new approaches for preventing and treating ARHL.

METHODS

Literature related to ARHL was conducted in databases such as PubMed, WOS, China National Knowledge Infrastructure (CNKI), and Wanfang from the establishment of the database to Jan, 2023. The pathology, causal factor, pathophysiological mechanism, treatment strategy, and the drug candidate of ARHL were extracted and pooled for synthesis.

RESULTS

Many hypotheses about the etiology of ARHL are based on genetic and environmental elements. Most of the current research on the pathology of ARHL focuses on oxidative damage, mitochondrial dysfunction, inflammation, cochlear blood flow, ion homeostasis, etc. In TCM, herbs belonging to the kidney, lung, and liver meridians exhibit good hearing protection. Seven herbs belonging to the kidney meridian, 9 belonging to the lung meridian, and 4 belonging to the liver meridian were ultimately retrieved in this review, such as Polygonum multiflorum Thunb., Panax ginseng C.A. Mey, and Pueraria lobata (Willd.) Ohwi. Their active compounds, 2,3,4',5-Tetrahydroxystilbene-2-O-D-glucoside, ginsenoside Rb1, and puerarin, may act as the molecular substance for their anti-ARHL efficacy, and show anti-oxidative, neuroprotective, anti-inflammatory, anti-apoptotic, or mitochondrial protective effects.

CONCLUSION

Anti-oxidants, modulators of mitochondrial function, anti-inflammation agents, vasodilators, K+ channel openers, Ca2+ channel blockers, JNK inhibitors, and nerve growth factors/neurotrophic factors all contribute to hearing protection, and herbs are an important source of potential anti-ARHL drugs.

Association of Vitamin D Deficiency in Patients with Tinnitus with Normal Audiogram

In the present study we aim to evaluate serum vitamin D levels in participants having tinnitus with normal audiometric findings. Total 98 participants in the age range 20-70 year were included in the study. Participants underwent detail case history, ear examination, pure tone audiometry and impedance audiometry. 68 participants with subjective tinnitus for more than 3 months and with normal audiometric thresholds and "A" type tympanogram were included in study group and 30 participants without tinnitus in the control group. The participants fullfillng the inclusion criteria underwent thorough tinnitus evaluation which included administration of tinnitus severity index tinnitus handicap inventory, psychophysical evaluation of tinnitus (pitch matching, loudness matching) and assessment of Vitamin D levels. It was seen that the mean Vitamin D levels were significantly lower in study group, and out of 68 participants only 11 had optimal Vitamin D levels, 57 (83%) had Vitamin D levels less that 30 mg/dl. In the control group 20 (66%) had vitamin D deficiency. The difference came out to be statistically significant. Our study suggests that there is a link between vitamin D and tinnitus, in view of these findings we recommend evaluating serum Vitamin D levels in patients of chronic idiopathic tinnitus, especially in adults with normal hearing. Our study suggests vitamin D deficiency may be one of the risk factor for tinnitus in people with normal hearing in the absence of other manifestations.

The association of bisphenol A and paraben exposure with sensorineural hearing loss in children

Bisphenol A (BPA) and parabens (PBs) are chemicals that are extensively used in personal care products (PCPs). In early childhood development, hearing is critical to speech and language development, communication, and learning. In vitro and in vivo, BPA/PBs exhibited neurotoxicity through elevated levels of oxidative stress. BPA also has the potential to be an ototoxicant. Therefore, this study aimed to determine the association of exposure to BPA/PBs with sensorineural hearing loss in children. A cross-sectional study based on hearing tests was conducted. This study enrolled 320 children aged 6-12 years from elementary school. Urinary BPA and PB concentrations were analyzed by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Logistic regression models were employed to determine the association of BPA/PB exposure with sensorineural hearing loss. Children with sensorineural hearing loss had higher BPA concentrations than normal-hearing children (0.22 ng/ml vs. 0.10 ng/ml, p = 0.05). After adjustment for covariates, the risk of hearing loss at middle frequencies reached 1.83-fold (95% CI: 1.12-2.99) when BPA concentrations increased by 1 log10. The risk of slight hearing loss reached 2.24-fold (95% CI: 1.05-4.78) when children had a tenfold increase in ethyl paraben (EP) concentration. This study clarifies the role of exposure to BPA/PBs in hearing loss in children. Future research needs to be expanded to include cohort designs and nationwide studies to identify causality.

Distortion product otoacoustic emissions in newborn babies with and without late-term maternal iron deficiency anaemia

Background

Studies on animals have demonstrated that maternal iron deficiency anaemia (IDA) could result in decreased cochlear sensory hair cells and reduced amplitudes of distortion-product otoacoustic emissions (DPOAEs) of young guinea pigs. Thus, it is essential to study the functioning of cochlear hair cells using DPOAEs in human newborn babies with maternal IDA. The current study explores maternal IDA's effect on DPOAEs in newborn babies.

Method

A total of 110 newborn babies with gestational age ≥34 weeks were considered and a 'between-subjects' design was used. The participants were divided into 3 groups- "Normal" (61 babies without maternal IDA), "Mild" (28 babies with mild maternal IDA) and "Moderate" (21 babies with moderate maternal IDA). The cord blood was collected and the DPOAEs were recorded for each baby for a range of frequencies (1 k - 8 kHz) and a range of intensities (70-40 dB SPL in 10 dB steps).

Results

The analysis of both DP-gram and DP input-output (I/O) function showed that there was no significant difference (p > 0.05) across the normal, mild, and moderate groups in the overall presence of DPOAEs as well as the amplitude across frequencies or intensities (70-40 dB SPL). Also, the overall correlation of RBC indices with DPOAE amplitude across frequencies as well as the slope of the I/O function showed no relationship.

Conclusion

The current study concludes that there is no effect of late-term maternal IDA on the DPOAEs of newborn babies.

Obesity and risk of hearing loss in the middle-aged and elderly: a national cohort of Chinese adults

BACKGROUND

The relationship between obesity and hearing loss among the middle-aged and older population remained unclear. Moreover, few studies have focused on the impact of gender on this association.

METHODS

This cohort study extracted the data from the China Health and Retirement Longitudinal Study, a national survey of adults aged 45 years or over. Waist circumference was categorized into three groups: normal, pre-central obesity, and central obesity. We classified BMI into four categories: underweight, normal weight, overweight, and obese. The primary endpoint was the incidence of self-reported hearing loss.

RESULTS

Of the 14,237 participants, 1972 incidents of hearing loss were identified during a median 6.9 years of follow-up. The cumulative incidence of hearing loss was 13.9% (95% CI 13.3% -14.4%). Our study showed that central obesity was significantly associated with hearing loss (HR 0.84, 95%CI 0.75-0.94), and this relationship was more prominent in males (HR 0.76, 95%CI 0.63-0.91). Among male participants, the underweight group was at the highest risk of hearing loss (HR 1.39, 95%CI 1.08-1.79). Compared with the normal weight group, the adjusted HR for hearing loss in the obese groups was 0.69 (95%CI 0.51-0.94) among men. Among female participants, only the overweight group had a lower risk of hearing loss than the normal weight group (HR 0.83, 95%CI 0.71-0.96).

CONCLUSIONS

Being overweight and obese were significantly associated with a decreased risk of hearing loss, whereas being underweight was associated with an increased risk of hearing loss.

Cross-sectional associations of dietary intake with hearing and vision capacities and potential mediation effect of inflammation in older adults: the COGFRAIL study

BACKGROUND

Considering their prevalence and burden, information on the sensory impairment etiology is essential. Links between nutrition and sensory impairment through inflammation have been suggested. Although the decline in sensory capacities is age-related, few research included a geriatric population.

AIMS

Exploring the associations of nutrition with sensory capacities and test inflammation as a mediator among cognitively and physically impaired older adults.

METHODS

Cross-sectional data from the COGFRAIL cohort, including 164 participants with no hearing aid and 20 participants wearing no visual aid. Hearing was evaluated using the Hearing Handicap Inventory for the Elderly-screening version (on 40 points, the lower the better), and the Monoyer chart (one to ten out of ten points, the higher the better), and the Parinaud scale (from 1.5, the best, to 28 points, the worst) assessed distant and near vision, respectively. Dietary intake was assessed through a diet history interview and inflammation was measured by the C-Reactive Protein level. Multivariate linear regressions were performed and Structural Equation Modeling (SEM) framework was used to explore the potential mediation effect of inflammation on the diet-hearing relationships.

RESULTS

None of the nutrients was significantly associated with hearing acuity in the regressions or the SEM model. Regarding vision, a higher intake of saturated fatty acids was related to lower long-distance visual acuity, and greater Omega-3 consumption was associated with better near-vision capacity.

DISCUSSION

No nutrient was associated with hearing capacity and relationships between fatty acids quality and vision acuity were suggested.

CONCLUSION

These exploratory results require further investigations.

A Narrative Review of Lifestyle Risk Factors and the Role of Oxidative Stress in Age-Related Hearing Loss

Age-related hearing loss affects a significant proportion of adults aged 60 years and above, with a prevalence of 65%. This condition has a negative impact on both physical and mental well-being, and while hearing interventions can help alleviate the effects of hearing loss, they cannot completely restore normal hearing or halt the progression of age-related hearing loss. Oxidative stress and inflammation have been identified as potential contributors to this condition. By addressing modifiable lifestyle risk factors that exacerbate oxidative stress, there may be an opportunity to prevent hearing loss. Therefore, this narrative review provides an overview of the major modifiable lifestyle risk factors associated with age-related hearing loss, that is, exposure to noise and ototoxic chemicals, smoking, diet, physical activity, and the presence of chronic lifestyle diseases, and offers an overview of the role of oxidative stress in the pathophysiology of this condition.

The Influence of Diet on Tinnitus Severity: Results of a Large-Scale, Online Survey

Optimization of dietary intake is an essential component in the multidimensional effort to prevent and manage chronic disease. Recently, demand has increased for nutrition-focused management strategies for chronic tinnitus. The primary aim of this study was to evaluate 10 dietary items for their association with changes in subjective tinnitus severity. A secondary aim was to develop an algorithm to better identify those individuals who might benefit from dietary modification strategies. A total of 5017 anonymous users of the TinnitusTalk forum completed an online survey regarding how various dietary items affected the severity of their tinnitus. Results suggest that, while intake of caffeine [positive effect (PE): 0.4%; negative effect (NE): 16.2%], alcohol (PE: 2.7%; NE: 13.3%, and salt (PE: 0.1%; NE: 9.9%) was most likely to influence tinnitus severity, it did so only for a small proportion of participants and reported effects were most commonly mild. Further, though a classification algorithm was able to leverage participant demographic, comorbidity, and tinnitus characteristics to identify those individuals most likely to benefit from dietary modification above chance levels, further efforts are required to achieve significant clinical utility. Taken together, these results do not support dietary modification as a primary treatment strategy for chronic tinnitus in the general population, though clinically meaningful effects might be observable in certain individuals.

Altering gene expression using antisense oligonucleotide therapy for hearing loss

Hearing loss affects more than 430 million people, worldwide, and is the third most common chronic physical condition in the United States and Europe (GBD Hearing Loss Collaborators, 2021; NIOSH, 2021; WHO, 2021). The loss of hearing significantly impacts motor and cognitive development, communication, education, employment, and overall quality of life. The inner ear houses the sensory organs for both hearing and balance and provides an accessible target for therapeutic delivery. Antisense oligonucleotides (ASOs) use various mechanisms to manipulate gene expression and can be tailor-made to treat disorders with defined genetic targets. In this review, we discuss the preclinical advancements within the field of the highly promising ASO-based therapies for hereditary hearing loss disorders. Particular focus is on ASO mechanisms of action, preclinical studies on ASO treatments of hearing loss, timing of therapeutic intervention, and delivery routes to the inner ear.

Effects of Diet and Lifestyle on Audio-Vestibular Dysfunction in the Elderly: A Literature Review

BACKGROUND

The world's age-related health concerns continue to rise. Audio-vestibular disorders, such as hearing loss, tinnitus, and vertigo, are common complaints in the elderly and are associated with social and public health burdens. Various preventative measures can ease their impact, including healthy food consumption, nutritional supplementation, and lifestyle modification. We aim to provide a comprehensive summary of current possible strategies for preventing the age-related audio-vestibular dysfunction.

METHODS

A PubMed, Embase, and Cochrane review databases search was conducted to identify the relationship between diet, lifestyle, and audio-vestibular dysfunction. "Diet", "nutritional supplement", "lifestyle", "exercise", "physical activity", "tinnitus", "vertigo" and "age-related hearing loss" were used as keywords.

RESULTS

Audio-vestibular dysfunction develops and progresses as a result of age-related inflammation and oxidative stress. Diets with anti-inflammatory and antioxidant effects have been proposed to alleviate this illness. A high-fat diet may induce oxidative stress and low protein intake is associated with hearing discomfort in the elderly. Increased carbohydrate and sugar intake positively correlate with the incidence of audio-vestibular dysfunction, whereas a Mediterranean-style diet can protect against the disease. Antioxidants in the form of vitamins A, C, and E; physical activity; good sleep quality; smoking cessation; moderate alcohol consumption; and avoiding noise exposure are also beneficial.

CONCLUSIONS

Adequate diet or nutritional interventions with lifestyle modification may protect against developing audio-vestibular dysfunction in elderly individuals.

Hearing Function and Nutritional Status in Aviation Pilots from Spain Exposed to High Acoustic Damage

Noise-induced hearing loss is the most frequent and preventable occupational disease. Aviation pilots are a vulnerable population, as they spend many hours exposed to noise pollution in their working environment. Different studies suggest that certain dietary compounds may play a key role in the etiology and prevention of this pathology. We aimed to study the relationship linking auditory function, dietary intake, and some serum biomarkers in pilots, exposed to noise in the work environment. A total of 235 pilots, who undergo a periodic medical examination at the Centro de Instrucción de Medicina Aeroespacial (Madrid, SPAIN), were evaluated. Auditory function was assessed by tonal audiometry. Energy and nutrient intakes were estimated by 24 h recall (DIALTM program). Serum homocysteine (Hcy) was determined in a Cobas 6000TM multi-analyzer while folate, vitamin B12, and D were analyzed in a Cobas e411TM. The prevalence of hearing loss (HL) was 64.3%. HL was significantly related to age (r = 0.588, p ≤ 0.001) and flight hours (r = 0.283, p ≤ 0.001). A multiple linear regression model was used to assess the relationship among HL, flight hours, serum folate, and Hcy serum levels. HL was significantly (p < 0.050) associated with flight hours (β = 0.246), serum folate (β = −0.143), and serum Hcy (β = 0.227). Nutritional interventions would be of great interest to monitor and slow down the HL progression in populations exposed to noise pollution in their workplace.

Exploring Shared Effects of Multisensory Impairment, Physical Dysfunction, and Cognitive Impairment on Physical Activity: An Observational Study in a National Sample

Multisensory, physical, and cognitive dysfunction share age-related physiologic disturbances and may have common health effects. We determined whether the effect of multisensory impairment on physical activity (PA) is explained by physical (timed up and go) or cognitive (Short Portable Mental Status Questionnaire) dysfunction. A National Social Life, Health, and Aging Project participant subset (n = 507) underwent objective sensory testing in 2005-2006 and wrist accelerometry in 2010-2011. We related multisensory impairment to PA using multivariate mixed-effects linear regression and compared the effect magnitude after adjusting for physical then cognitive dysfunction. Worse multisensory impairment predicted lower PA across three scales (Global Sensory Impairment: β = -0.04, 95% confidence interval [-0.07, -0.02]; Total Sensory Burden: β = -0.01, 95% confidence interval [-0.03, -0.003]; and Number of Impaired Senses: β = -0.02, 95% confidence interval [-0.04, -0.004]). Effects were similar after accounting for physical and cognitive dysfunction. Findings suggest that sensory, physical, and cognitive dysfunction have unique mechanisms underlying their PA effects.

The correlation between fibroblast growth factor-23 and ESRD patients with hearing impairment

Background

End-stage renal disease (ESRD) patients often experience hearing impairment, resulting in a high rate of disability and a decline in their quality of life. Fibroblast growth factor-23 (FGF23) is a diagnostic biomarker for chronic kidney disease (CKD) and a pathogenic contributor to CKD progression. However, the correlation between FGF23 level and CKD patients with hearing impairment remains elusive. This study aimed to investigate the relationship between the FGF23 and ESRD accompanied with hearing impairment.

Methods

A total of 144 ESRD patients, who were admitted to the First Affiliated Hospital of Kunming Medical University from November to December 2020, were enrolled in this study. Firstly, 144 ESRD patients underwent pure-tone audiometry (PTA). Secondly, it was attempted to randomly select 20 ESRD patients with normal hearing, and 20 ESRD patients with hearing impairment (match ratio, 1:1). Age- and gender-matched healthy people (n = 20) were also recruited as controls group. The expression levels of FGF23 was detected by enzyme-linked immunosorbent assay (ELISA).

Results

The results of pure-tone audiometry showed that the prevalence of hearing impairment in ESRD patients was 80.5%. Male ESRD patients were more likely to develop hearing impairment compared to female patients. The incidence rate of hearing impairment at a high frequency was significantly higher than that at a low frequency (P < 0.01). The serum levels of FGF23, phosphorus, and parathyroid hormone (PTH) in ESRD patients with hearing impairment significantly increased compared with those with normal hearing and healthy controls.

Conclusion

ESRD patients had a higher risk of hearing loss, especially high-frequency hearing impairment. As FGF23 level increased, the risk of hearing loss was also elevated. The hearing impairment in ESRD patients was associated with the degree of kidney injury, and serum FGF23 level.

Association Between Central and Peripheral Age-Related Hearing Loss and Different Frailty Phenotypes in an Older Population in Southern Italy

Importance

The association between age-related hearing loss (ARHL) and physical or cognitive frailty has been poorly explored. These associations could define new perspectives for delaying frailty-related processes in older age.

Objective

To examine whether peripheral ARHL and age-related central auditory processing disorder (CAPD) are independently associated with physical or cognitive frailty.

Design, Setting, and Participants

This cross-sectional study analyzed registry data from December 31, 2014, on 1929 older (≥65 years) participants of the Salus in Apulia Study (Southern Italy) who underwent audiologic, physical, and neuropsychological assessment. Data analysis was performed from December 12, 2019, to January 4, 2020.

Main Outcomes and Measures

Prevalence of peripheral ARHL in older individuals with physical and/or cognitive frailty and those without frailty assessed using the Fried criteria (physical) and the Mini-Mental State Examination (cognitive). Multivariable logistic regression models were used to assess associations of audiologic variables with frailty phenotype.

Results

Data from 1929 participants (mean [SD] age, 73.6 [6.3] years; 974 male [50.5%]) were eligible for the analyses. The prevalence of peripheral ARHL was higher in the physical frailty group (96 [26.6%]) than in the nonfrail group (329 [21.0%]) (difference, 5.61 percentage points; 95% CI, 0.63-10.59 percentage points) and in the cognitive frailty group (40 [38.8%]) than in the nonfrail group (385 [21.1%]) (difference, 17.75 percentage points; 95% CI, 8.2-27.3 percentage points). Age-related CAPD was more prevalent in the physical frailty group (62 [17.2%]) than in the nonfrail group (219 [14.0%]) (difference, 3.21 percentage points; 95% CI, -1.04 to 7.46 percentage points) and in the cognitive frailty group (28 [27.2%]) than in the nonfrail group (253 [13.9%]) (difference, 13.33 percentage points; 95% CI, 4.10-22.21 percentage points). In the multivariable models, age-related CAPD was associated with cognitive frailty in the fully adjusted model (odds ratio [OR], 1.889; 95% CI, 1.094-3.311). There was also an inverse association between the unitary increase in Synthetic Sentence Identification With the Ipsilateral Competitive Message scores, indicating a lower likelihood of this disorder, and cognitive frailty (OR, 0.989; 95% CI, 0.988-0.999). Peripheral ARHL was associated with cognitive frailty only in the partially adjusted model (OR, 1.725; 95% CI, 1.008-2.937).

Conclusions and Relevance

In this cross-sectional study of 1929 participants, age-related CAPD was independently associated with cognitive frailty. Whether the management of ARHL may help prevent the development of different frailty phenotypes or improve their clinical consequences should be addressed in longitudinal studies and, eventually, well-designed randomized clinical trials.

Diet Quality and the Risk of Impaired Speech Reception Threshold in Noise: The UK Biobank cohort

OBJECTIVE

Previous studies have examined the association between several diet quality indexes and risk of hearing loss, based on self-reported information or on audiometry test, with inconsistent results. However, the impact of healthy diets on the capacity to listening in noise, a proxy of disability due to hearing loss, is unknown. This research assessed the prospective association between five diet quality indexes and the speech reception threshold in noise in the UK Biobank study.

DESIGN

Prospective cohort with 105,592 participants aged ≥40 years. At baseline, adherence to the Mediterranean Diet Adherence Screener, the alternate Mediterranean Diet score, the Dietary Approaches to Stop Hypertension, the Alternate Healthy Eating Index-2010, and the healthful Plant-Based Diet Index were assessed. Functional auditory capacity was measured with a digit triplet test, and impairment was defined as a speech reception threshold in noise >-3.5 dB in any physical exam during the follow-up.

RESULTS

Over a median follow-up of 3.2 (SD: 2.1) years, 1704 participants showed impaired speech reception threshold in noise. After adjusting for potential confounders, the hazard ratios (95% confidence interval) of impairment per 1-SD increase in the Mediterranean Diet Adherence Screener, alternate Mediterranean Diet score, Dietary Approaches to Stop Hypertension, Alternate Healthy Eating Index-2010 and healthful Plant-Based Diet Index scores were, respectively, 0.98 (0.94 to 1.03), 1.01 (0.96 to 1.06), 1.02 (0.97 to 1.07), 1.01 (0.96 to 1.06), and 1.00 (0.96 to 1.05). Results were similar when analyses were restricted to those >60 years, with British ethnicity, without chronic disease, without tinnitus or with optimal cognitive function.

CONCLUSIONS

Adherence to a healthy diet did not show an association with the speech reception threshold in noise. More research is needed to identify the impact of individual foods or nutrients on this outcome.

Dietary fat intake and risk of disabling hearing impairment: a prospective population-based cohort study

Purpose

To examine the associations of specific dietary fats with the risk of disabling hearing impairment in the UK Biobank study.

Methods

This cohort study investigated 105,592 participants (47,308 men and 58,284 women) aged ≥ 40 years. Participants completed a minimum of one valid 24-h recall (Oxford Web-Q). Dietary intake of total fatty acids, polyunsaturated fatty acids (PUFA), saturated fatty acids (SFA), and monounsaturated fatty acids (MUFA) was assessed at baseline. Functional auditory capacity was measured with a digit triplet test (DTT), and disabling hearing impairment was defined as a speech reception threshold in noise > − 3.5 dB in any physical exam performed during the follow-up.

Results

Over a median follow-up of 3.2 (SD: 2.1) years, 832 men and 872 women developed disabling hearing impairment. After adjustment for potential confounders, including lifestyles, exposure to high-intensity sounds, ototoxic medication and comorbidity, the hazard ratios (HRs), and 95% confidence interval (CI) of disabling hearing function, comparing extreme quintiles of intakes were 0.91 (0.71–1.17) for total fat, 1.09 (0.83–1.44) for PUFA, 0.85 (0.64–1.13) for SFA and 1.01 (0.74–1.36) for MUFA among men. Among women, HRs comparing extreme intakes were 0.98 (0.78–1.24) for total fat, 0.69 (0.53–0.91) for PUFA, 1.26 (0.96–1.65) for SFA, and 0.91 (0.68–1.23) for MUFA. Replacing 5% of energy intake from SFA with an equivalent energy from PUFA was associated with 25% risk reduction (HR: 0.75; 95% CI: 0.74–0.77) among women.

Conclusions

PUFA intake was associated with decreased risk of disabling hearing function in women, but not in men.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02644-7.

Incidence of Hearing Impairment and Changes in Pure-Tone Average Across Generations

Importance

Age-adjusted prevalence of hearing impairment (HI) decreased across generations in the 20th century, suggesting that HI is partially preventable. It is not known whether HI incidence differs by generation.

Objectives

To examine whether HI incidence and change in pure-tone average (PTA) differ by generation and identify factors underlying these differences.

Design, Setting, and Participants

This cohort study used data from the Epidemiology of Hearing Loss Study (EHLS) and Beaver Dam Offspring Study (BOSS), a pair of studies of adults in Beaver Dam, Wisconsin. Baseline examinations occurred from 1993 to 1995 in the EHLS and 2005 to 2008 in BOSS, with two 5-year follow-up examinations in each cohort. This longitudinal cohort study assessed 3651 participants without HI at baseline who had follow-up data.

Main Outcomes and Measures

The primary outcome was incident HI measured by pure-tone audiometry, defined as PTA greater than 25-dB hearing level (dB HL) in either ear. Associations of 5-year incidence were estimated by relative risks (RRs) and 10-year cumulative incidence with generation, as categorized by commonly used sociodemographic descriptors of year of birth, by hazard ratios (HRs). The 10-year change in PTA was investigated using a generation × time interaction term in generalized estimating equation models.

Results

Among the 3651 participants (mean [SD] age at baseline 53.1 [10.6] years; 2255 [61.8%] female; and 3567 [97.7%] non-Hispanic White), the 5-year HI incidence was 14.1% (95% CI, 13.0%-15.3%) and the 10-year cumulative incidence was 26.0% (95% CI, 24.6%-27.6%). The incidence increased with age. The risk of 5-year incident HI decreased by generation (RR, 0.80; 95% CI, 0.66-0.97) when adjusting for multiple covariates. The decreased risk was similar in the 10-year period (HR, 0.86; 95% CI, 0.73-1.01). The PTA change rate (per 5 years of follow-up) decreased by generation, with the Greatest Generation (born 1901-1924) experiencing the highest rate (7.03 dB HL). The rates were all significantly lower for the other generations (Silent Generation [born 1925-1945], 3.30 dB HL; Baby Boom Generation [born 1946-1964], 3.36 dB HL; and Generation X [born 1965-1984], 2.33 dB HL).

Conclusions and Relevance

This study suggests that the risk of HI and rate of PTA change is lower for the Silent Generation and Baby Boom Generation compared with the Greatest Generation. Part of this lower risk is likely associated with changes in modifiable factors. A potential continued benefit may exist for Generation X. Combined with the reduced risk of HI for the Silent Generation and Baby Boom Generation, this finding implies that the future HI burden may be lower than current estimates suggest.

Healthy Aging-Nutrition Matters: Start Early and Screen Often

The amount of time spent in poor health at the end of life is increasing. This narrative review summarizes consistent evidence indicating that healthy dietary patterns and maintenance of a healthy weight in the years leading to old age are associated with broad prevention of all the archetypal diseases and impairments associated with aging including: noncommunicable diseases, sarcopenia, cognitive decline and dementia, osteoporosis, age-related macular degeneration, diabetic retinopathy, hearing loss, obstructive sleep apnea, urinary incontinence, and constipation. In addition, randomized clinical trials show that disease-specific nutrition interventions can attenuate progression-and in some cases effectively treat-many established aging-associated conditions. However, middle-aged and older adults are vulnerable to unhealthy dietary patterns, and typically consume diets with inadequate servings of healthy food groups and essential nutrients, along with an abundance of energy-dense but nutrient-weak foods that contribute to obesity. However, based on menu examples, diets that are nutrient-dense, plant-based, and with a moderately low glycemic load are better equipped to meet the nutritional needs of many older adults than current recommendations in US Dietary Guidelines. These summary findings indicate that healthy nutrition is more important for healthy aging than generally recognized. Improved public health messaging about nutrition and aging, combined with routine screening and medical referrals for age-related conditions that can be treated with a nutrition prescription, should form core components of a national nutrition roadmap to reduce the epidemic of unhealthy aging.

Human induced pluripotent stem cells and CRISPR/Cas-mediated targeted genome editing: Platforms to tackle sensorineural hearing loss

Hearing loss (HL) is a major global health problem of pandemic proportions. The most common type of HL is sensorineural hearing loss (SNHL) which typically occurs when cells within the inner ear are damaged. Human induced pluripotent stem cells (hiPSCs) can be generated from any individual including those who suffer from different types of HL. The development of new differentiation protocols to obtain cells of the inner ear including hair cells (HCs) and spiral ganglion neurons (SGNs) promises to expedite cell-based therapy and screening of potential pharmacologic and genetic therapies using human models. Considering age-related, acoustic, ototoxic, and genetic insults which are the most frequent causes of irreversible damage of HCs and SGNs, new methods of genome editing (GE), especially the CRISPR/Cas9 technology, could bring additional opportunities to understand the pathogenesis of human SNHL and identify novel therapies. However, important challenges associated with both hiPSCs and GE need to be overcome before scientific discoveries are correctly translated to effective and patient-safe applications. The purpose of the present review is (a) to summarize the findings from published reports utilizing hiPSCs for studies of SNHL, hence complementing recent reviews focused on animal studies, and (b) to outline promising future directions for deciphering SNHL using disruptive molecular and genomic technologies.

Role of nutrition in the development and prevention of age-related hearing loss: A scoping review

Age-related hearing loss (ARHL) is a major and increasingly prevalent health problem worldwide, causing disability and social isolation in the people who present it. This impairment is caused by genetic and environmental factors. Nutritional status has been identified as a related risk associated with hearing loss (HL). This scoping review aimed to characterize the links between HL and nutritional status. PubMed, Embase, Cochrane and Scopus databases were searched up to December 2019. Studies examining the relation between nutrition and dietary habits and HL were included. After screening 3510 citations, 22 publications were selected for inclusion in the current review, all of which were published between 2010 and 2019. Diets rich in saturated fats and cholesterol have deleterious effects on hearing that could be prevented by lower consumption. Conversely, greater consumption of fruit and vegetables, and of polyunsaturated fatty acids (omega-3) and anti-oxidants in the form of vitamins A, C, and E, prevent the development of ARHL. The current literature suggests a possible association between nutritional status and hearing loss. More studies are needed to better characterize the clinical consequences of this association.

Relationship between Inflammatory Food Consumption and Age-Related Hearing Loss in a Prospective Observational Cohort: Results from the Salus in Apulia Study

Age related hearing loss (ARHL) affects about one third of the elderly population. It is suggested that the senescence of the hair cells could be modulated by inflammation. Thus, intake of anti- and pro-inflammatory foods is of high interest.

METHODS

From the MICOL study population, 734 participants were selected that participated in the 2013 to 2018 examination including hearing ability and from which past data collected in 2005/2008 was available. ARHL status was determined and compared cross-sectionally and retrospectively according to clinical and lifestyle data including food and micronutrient intake.

RESULTS

ARHL status was associated with higher age but not with education, smoking, relative weight (BMI), and clinical-chemical blood markers in the crossectional and retrospective analyses. Higher intake of fruit juices among ARHL-participants was seen cross-sectionally, and of sugary foods, high-caloric drinks, beer, and spirits retrospectively. No difference was found for the other 26 food groups and for dietary micronutrients with the exception of past vitamin A, which was higher among normal hearing subjects.

CONCLUSIONS

Pro-inflammatory foods with a high-sugar content and also beer and spirits were found to be assocated with positive ARHL-status, but not anti-inflammatory foods. Diet could be a candidate for lifestyle advice for the prevention of ARHL.

The role of diet in vulnerability to noise-induced cochlear injury and hearing loss

The influence of dietary nutrient intake on the onset and trajectory of hearing loss during aging and in mediating protection from challenges such as noise is an important relationship yet to be fully appreciated. Dietary intake provides essential nutrients that support basic cellular processes related to influencing cellular stress response, immune response, cardiometabolic status, neural status, and psychological well-being. Dietary quality has been shown to alter risk for essentially all chronic health conditions including hearing loss and tinnitus. Evidence of nutrients with antioxidant, anti-inflammatory, and anti-ischemic properties, and overall healthy diet quality as otoprotective strategies are slowly accumulating, but many questions remain unanswered. In this article, the authors will discuss (1) animal models in nutritional research, (2) evidence of dietary nutrient-based otoprotection, and (3) consideration of confounds and limitations to nutrient and dietary study in hearing sciences. Given that there are some 60 physiologically essential nutrients, unraveling the intricate biochemistry and multitude of interactions among nutrients may ultimately prove infeasible; however, the wealth of available data suggesting healthy nutrient intake to be associated with improved hearing outcomes suggests the development of evidence-based guidance regarding diets that support healthy hearing may not require precise understanding of all possible interactions among variables. Clinical trials evaluating otoprotective benefits of nutrients should account for dietary quality, noise exposure history, and exercise habits as potential covariates that may influence the efficacy and effectiveness of test agents; pharmacokinetic measures are also encouraged.

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.