Dietary vitamin intake correlates with hearing thresholds in the older population: the Korean National Health and Nutrition Examination Survey

Vitamin C inhibits NLRP3 inflammasome activation and delays the development of age-related hearing loss in male C57BL/6 mice

The efficacy of vitamin C in age-related hearing loss, i.e., presbycusis, remains debatable. On a separate note, inflammation induced by the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is involved in the progression of presbycusis. In this study, we investigated the effect of vitamin C on male C57BL/6 mice's presbycusis and NLRP3 inflammasome. The results showed that vitamin C treatment improved hearing, reduced the production of inflammatory factors, inhibited NLRP3 inflammasome activation, and decreased cytosolic mitochondrial DNA (mtDNA) in the C57BL/6 mouse cochlea, inferior colliculus, and auditory cortex. According to this study, vitamin C protects auditory function in male C57BL/6 presbycusis mice through reducing mtDNA release, inhibiting the NLRP3 inflammasome activation in the auditory pathway. Our study provides a theoretical basis for applying vitamin C to treat presbycusis.

Association of oxidative balance score with hearing loss and tinnitus: NHANES 1999-2018

Background

Oxidative stress is associated with the occurrence of hearing loss and tinnitus. The oxidative balance score (OBS), a composite indicator evaluating the balance between antioxidant and pro-oxidative components across various dietary and lifestyle factors, indicates the overall oxidative balance status. However, the association of OBS with hearing loss and tinnitus has not been reported previously.

Methods

Cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 1999-2018 were analyzed. Weighted multivariable logistic regression, weighted multivariable linear regression, and restricted cubic spline curve (RCS) regression were employed to explore the relationship between OBS and hearing loss at speech, low, and high frequencies, along with tinnitus. Subgroup analysis and sensitivity analysis were used to ascertain the consistency across subgroups and stability of the results.

Results

We included 13,715 and 21,644 individuals to investigate the association between OBS and hearing loss, as well as between OBS and tinnitus, respectively. The second, third, and fourth quartiles of OBS were significantly associated with a lower risk of hearing loss at speech, low, and high frequencies, as well as tinnitus, compared to the lowest quartile. The RCS regression analysis indicated a negative linear association of OBS with hearing loss and tinnitus. Most associations were maintained in subgroup analysis and sensitivity analysis. Additionally, the dietary and lifestyle OBS independently contribute to the protection against hearing loss and tinnitus.

Conclusion

OBS is negatively correlated with the risk of hearing loss and tinnitus. The findings suggest that combined antioxidant diet and lifestyle hold promise as potential strategies for reducing the prevalence of hearing loss and tinnitus.

Insufficient nutrient intake in individuals with disabling hearing loss and the restoration of nutritional sufficiency in hearing aid users

Hearing loss affects some nutrient intake. Disabling hearing loss may exacerbate these issues. We aimed to evaluate nutrient intake and assess deficiencies based on functional hearing status. The study included 6907 participants with information on demographic factors, nutrient intake, weight, height, disease status, and hearing level in the eighth Korea National Health and Nutrition Examination Survey, conducted from 2019 to 2021. We categorized the participants into 3 groups based on their functional hearing status: bilateral hearing, unilateral hearing, and disabling hearing loss. The disabling hearing loss group showed lower intake of most major nutrients (P < 0.05), dietary fiber (P < 0.001), and most minerals and vitamins (P < 0.05), with some insufficiencies. The unilateral hearing group showed lower intake only for potassium (P = 0.036) compared to the bilateral hearing group and significantly higher intake of hydration (P = 0.039), dietary fiber (P = 0.039), and calcium (P = 0.009) than the disabling hearing loss group. Nutrient insufficiency in the disabling hearing loss group was more prominent in women, and was partially resolved by using hearing aids. Clinicians and nutritionists should consider undernourishment in these patients, and appropriate interventions for nutrition and hearing aids should be recommended.

The association between dietary total antioxidant capacity and hearing loss: results from the Tehran employees Cohort Study

BACKGROUND

Despite numerous studies that have explored the association between individual antioxidants or specific combinations and the risk of hearing loss, there is lack of information regarding the relationship between dietary total antioxidant capacity (dTAC) and hearing loss. The conflicting results on this association further highlight the need for more research in this area. This study aims to investigate the association between overall dietary antioxidant intake and the risk of hearing loss among Iranian adults.

METHODS

This cross-sectional study recruited 3443 adult participants aged between 19 and 67 years (with an average age of 41.4 years ± 8.8) who were employed at Tehran University of Medical Sciences in Iran. Participants underwent dietary assessment using a validated Food Frequency Questionnaire (FFQ). The hearing status of each participant was evaluated by a licensed audiologist in a soundproof room, using diagnostic audiometry that adhered to American National Standards specifications and followed standard audiometric clinical procedures. The dietary total antioxidant capacity (dTAC) was calculated using the Ferric Reducing-Antioxidant Power (FRAP) values.

RESULTS

43.6% of male participants had hearing loss, while 26.8% among female participants. After accounting for various confounding factors, no significant association was observed between higher levels of dTAC and reduced odds of hearing loss in the overall population. However, among men under the age of 40, higher levels of dTAC were associated with decreased odds of hearing loss, even after adjusting for several covariates (OR: 0.56, 95% CI: 0.31-1.02, Ptrend = 0.02). This relationship was not evident in men over 40 years of age or among women.

CONCLUSION

The study found an inverse relationship between higher antioxidant intake in the diet and lower odds of hearing loss, specifically among men who were 40 years old or younger. However, this relationship was not observed in the overall population or among women. Additional prospective studies are necessary to validate these results.

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.

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.

Role of mitochondrial dysfunction and oxidative stress in sensorineural hearing loss

Sensorineural hearing loss (SNHL) can either be genetically inherited or acquired as a result of aging, noise exposure, or ototoxic drugs. Although the precise pathophysiological mechanisms underlying SNHL remain unclear, an overwhelming body of evidence implicates mitochondrial dysfunction and oxidative stress playing a central etiological role. With its high metabolic demands, the cochlea, particularly the sensory hair cells, stria vascularis, and spiral ganglion neurons, is vulnerable to the damaging effects of mitochondrial reactive oxygen species (ROS). Mitochondrial dysfunction and consequent oxidative stress in cochlear cells can be caused by inherited mitochondrial DNA (mtDNA) mutations (hereditary hearing loss and aminoglycoside-induced ototoxicity), accumulation of acquired mtDNA mutations with age (age-related hearing loss), mitochondrial overdrive and calcium dysregulation (noise-induced hearing loss and cisplatin-induced ototoxicity), or accumulation of ototoxic drugs within hair cell mitochondria (drug-induced hearing loss). In this review, we provide an overview of our current knowledge on the role of mitochondrial dysfunction and oxidative stress in the development of SNHL caused by genetic mutations, aging, exposure to excessive noise, and ototoxic drugs. We also explore the advancements in antioxidant therapies for the different forms of acquired SNHL that are being evaluated in preclinical and clinical studies.

Aging and aging-related diseases: from molecular mechanisms to interventions and treatments

Aging is a gradual and irreversible pathophysiological process. It presents with declines in tissue and cell functions and significant increases in the risks of various aging-related diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic diseases, musculoskeletal diseases, and immune system diseases. Although the development of modern medicine has promoted human health and greatly extended life expectancy, with the aging of society, a variety of chronic diseases have gradually become the most important causes of disability and death in elderly individuals. Current research on aging focuses on elucidating how various endogenous and exogenous stresses (such as genomic instability, telomere dysfunction, epigenetic alterations, loss of proteostasis, compromise of autophagy, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, deregulated nutrient sensing) participate in the regulation of aging. Furthermore, thorough research on the pathogenesis of aging to identify interventions that promote health and longevity (such as caloric restriction, microbiota transplantation, and nutritional intervention) and clinical treatment methods for aging-related diseases (depletion of senescent cells, stem cell therapy, antioxidative and anti-inflammatory treatments, and hormone replacement therapy) could decrease the incidence and development of aging-related diseases and in turn promote healthy aging and longevity.

High Frequency Hearing Loss in Chronic Renal Disease: A Cross-Sectional Study

Introduction Chronic kidney disease (CKD) patients face multiple complications. One of them is involvement of the auditory system and it deserves more attention than is paid by the current approaches as hearing loss has major repercussions on the quality of life. Early detection can prevent further deterioration of hearing and improve the quality of life of patients suffering from CKD. Material and methods The high frequency (8-18 kHz) audiometry with pure tones was performed in 82 patients with CKD and compared with age and sexes matched healthy control group of 90 patients. Individual ear were used for statistical calculations. Results This study clearly observed that the hearing thresholds for frequencies 8-18 kHz increased in CKD patients when compared to sex and aged matched healthy control group, the thresholds significantly increased in CKD with diabetes mellitus as compared to nondiabetic with CKD. The high frequency thresholds significantly increased in patients on hemodialysis, and were significantly correlated with age, stage of CKD and duration of CKD. Conclusion This study highlights the presence of high frequency (8-18 kHz) hearing loss in patients of CKD. The severity is significantly correlated with age, stage and duration of CKD.

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.

Garland chrysanthemum consumption ameliorates age-related hearing loss in C57BL/6 mouse; model system to explore hearing loss prevention foods in a short period

Garland chrysanthemum (Glebionis coronaria L.) is an antioxidant-rich leafy vegetable. We found that garland chrysanthemum consumption ameliorated age-related hearing loss (AHL) in C57BL/6J mice, an early onset model. We also found that AHL progression was significantly ameliorated by three of ten products. Metabolome analysis of the 10 products using nuclear magnetic resonance (NMR) spectroscopy indicated that phytosterols may be involved in the amelioration of AHL. However, the direct inhibitory effect of phytosterol mixture on mouse AHL progression was not identified. These results suggest that garland chrysanthemum consumption delays AHL development in mice and its efficiency varies depending on the source of product. Our findings also suggest that phytosterol content in garland chrysanthemum function as an evaluation marker for the efficiency. Furthermore, to accelerate the search for foods that prevent AHL, we have used these data to develop an automatic threshold determination method for auditory brainstem response using machine learning.

Corticofugal and Brainstem Functions Associated With Medial Olivocochlear Cholinergic Transmission

Cholinergic transmission is essential for survival and reproduction, as it is involved in several physiological responses. In the auditory system, both ascending and descending auditory pathways are modulated by cholinergic transmission, affecting the perception of sounds. The auditory efferent system is a neuronal network comprised of several feedback loops, including corticofugal and brainstem pathways to the cochlear receptor. The auditory efferent system's -final and mandatory synapses that connect the brain with the cochlear receptor- involve medial olivocochlear neurons and outer hair cells. A unique cholinergic transmission mediates these synapses through α9/α10 nicotinic receptors. To study this receptor, it was generated a strain of mice carrying a null mutation of the Chrna9 gene (α9-KO mice), lacking cholinergic transmission between medial olivocochlear neurons and outer hair cells, providing a unique opportunity to study the role of medial olivocochlear cholinergic transmission in auditory and cognitive functions. In this article, we review behavioral and physiological studies carried out to research auditory efferent function in the context of audition, cognition, and hearing impairments. Auditory studies have shown that hearing thresholds in the α9-KO mice are normal, while more complex auditory functions, such as frequency selectivity and sound localization, are altered. The corticofugal pathways have been studied in α9-KO mice using behavioral tasks, evidencing a reduced capacity to suppress auditory distractors during visual selective attention. Finally, we discuss the evolutionary role of the auditory efferent system detecting vocalizations in noise and its role in auditory disorders, such as the prevention of age-related hearing loss.

Multidimensional Risk Factors of Age-Related Hearing Loss Among Malaysian Community-Dwelling Older Adults

Purpose

This study evaluates the prevalence of and the multidimensional risk factors associated with age-related hearing loss (ARHL) among community-dwelling older adults in Malaysia.

Patients and Methods

A total of 253 participants aged 60 years and above participated in this cross-sectional study. The participants were subjected to pure tone audiometric assessment. The hearing threshold was calculated for the better ear and classified into pure-tone average (PTA) for the octave frequencies from 0.5 to 4 kHz and high-frequency pure-tone average (HFA) for the octave from 2 to 8kHz. Then, the risk factors associated with PTA hearing loss (HL) and HFAHL were identified by using multivariate logistic regression analysis.

Results

The prevalence of ARHL based on PTA and HFA among the community-dwelling older adults was 75.5% and 83.0%, respectively. Following multifactorial adjustments, being older (OR: 1.239; 95% CI: 1.062–1.445), having higher waist circumference (OR: 1.158; 95% CI: 1.015–1.322), lower intake of niacin (OR: 0.909; 95% CI: 0.831–0.988) and potassium (OR: 0.998; 95% CI: 0.996–1.000), and scoring lower in RAVLT T5 (OR: 0.905; 95% CI: 0.838–0.978) were identified as the risk factors of PTAHL. Meanwhile, being older (OR: 1.117; 95% CI: 1.003–1.244), higher intake of carbohydrate (OR: 1.018; 95% CI: 1.006–1.030), lower intake of potassium (OR: 0.998; 95% CI: 0.997–0.999), and lower scores on the RAVLT T5 (OR: 0.922; 95% CI: 0.874–0.973) were associated with increased risk of having HFAHL.

Conclusion

Increasing age, having higher waist circumference, lower intake of niacin and potassium, higher intake of carbohydrates and having lower RAVLT T5 score were associated with increased risk of ARHL. Modifying these risk factors may be beneficial in preventive and management strategies of ARHL among older persons.

Relationship Between Diet, Tinnitus, and Hearing Difficulties

OBJECTIVES

Diet may affect susceptibility of the inner ear to noise and age-related effects that lead to tinnitus and hearing loss. This study used complementary single nutrient and dietary pattern analysis based on statistical grouping of usual dietary intake in a cross-sectional analysis of tinnitus and hearing difficulties in a large population study sample.

DESIGN

The research was conducted using the UK Biobank resource. Tinnitus was based on report of ringing or buzzing in one or both ears that lasts more than five minutes at a time and is currently experienced at least some of the time. Identification of a hearing problem was based on self-reported difficulties with hearing. Usual dietary intake and dietary patterns (involving statistical grouping of intake to account for how foods are combined in real-life diets) were estimated based on between two and five administrations of the Oxford Web-Q 24-hour dietary recall questionnaire over the course of a year for 34,576 UK adult participants aged 40 to 69.

RESULTS

In a multivariate model, higher intake of vitamin B12 was associated with reduced odds of tinnitus, while higher intakes of calcium, iron, and fat were associated with increased odds (B12, odds ratio [OR] 0.85, 95% confidence interval [CI] 0.75 to 0.97; Calcium, OR 1.20, 95% CI 1.08 to 1.34; Iron, OR 1.20, 95% CI 1.05 to 1.37; Fat, OR 1.33, 95% CI 1.09 to 1.62, respectively, for quintile 5 versus quintile 1). A dietary pattern characterised by high protein intake was associated with reduced odds of tinnitus (OR 0.90, 95% CI 0.82 to 0.99 for quintile 5 versus quintile 1). Higher vitamin D intake was associated with reduced odds of hearing difficulties (OR 0.90, 95% CI 0.81 to 1.00 for quintile 5 versus quintile 1), as were dietary patterns high in fruit and vegetables and meat and low in fat (Prudent diet: OR 0.89, 95% CI 0.83 to 0.96; High protein: OR 0.88, 95% CI 0.82 to 0.95; High fat: OR 1.16, 95% CI 1.08 to 1.24, respectively, for quintile 5 versus quintile 1).

CONCLUSIONS

There were associations between both single nutrients and dietary patterns with tinnitus and hearing difficulties. Although the size of the associations was small, universal exposure for dietary factors indicates that there may be a substantial impact of diet on levels of tinnitus and hearing difficulties in the population. This study showed that dietary factors might be important for hearing health.

Age-related hearing loss and cognitive decline: MRI and cellular evidence

Extensive evidence supports the association between age-related hearing loss (ARHL) and cognitive decline. It is, however, unknown whether a causal relationship exists between these two, or whether they both result from shared mechanisms. This paper intends to study this relationship through a comprehensive review of MRI findings as well as evidence of cellular alterations. Our review of structural MRI studies demonstrates that ARHL is independently linked to accelerated atrophy of total and regional brain volumes and reduced white matter integrity. Resting-state and task-based fMRI studies on ARHL also show changes in spontaneous neural activity and brain functional connectivity; and alterations in brain areas supporting auditory, language, cognitive, and affective processing independent of age, respectively. Although MRI findings support a causal relationship between ARHL and cognitive decline, the contribution of potential shared mechanisms should also be considered. In this regard, the review of cellular evidence indicates their role as possible common mechanisms underlying both age-related changes in hearing and cognition. Considering existing evidence, no single hypothesis can explain the link between ARHL and cognitive decline, and the contribution of both causal (i.e., the sensory hypothesis) and shared (i.e., the common cause hypothesis) mechanisms is expected.

Associations between Age-Related Hearing Loss and DietaryAssessment Using Data from Korean National Health andNutrition Examination Survey

Age-related hearing loss (ARHL) is a major and rapidly growing public health problem that causes disability, social isolation, and socioeconomic cost. Nutritional status is known to cause many aging-related problems, and recent studies have suggested that there are interaction effects between ARHL and dietary factors. We aimed to investigate the association between ARHL and dietary assessment using data from the fifth Korean National Health and Nutrition Examination Survey, which is a nationwide cross-sectional survey that included 5201 participants aged ≥50 years from 2010 to 2012. All participants had normal findings on otoscopic examination and symmetric hearing thresholds of <15 dB between both sides. Nutritional survey data included food consumption and nutrient intake using the 24 h recall method. Data were analyzed using multiple regression models with complex sampling adjusted for confounding factors, such as age, sex, educational level, and history of diabetes. Higher intake of seeds and nuts, fruits, seaweed, and vitamin A were positively associated with better hearing. Our findings suggest that dietary antioxidants or anti-inflammatory food may help reduce ARHL.

Low vitamin D status is associated with hearing loss in the elderly: a cross-sectional study

BACKGROUND

The elderly are at increased risk of both hearing loss (HL) and osteoporosis. Bone mineral density (BMD) has been putatively linked to HL. However, the roles of serum calcium concentrations and vitamin D status have yet to be elucidated.

OBJECTIVES

The purpose of this study was to examine the relation between vitamin D status, parathyroid hormone (PTH), total calcium, BMD, and HL in a nationally representative sample of elderly adults.

METHODS

Using the NHANES (2005-2010), audiometry and BMD data of 1123 participants aged ≥70 y were analyzed in a cross-sectional manner. HL was defined as pure tone averages >25 dB HL at 500, 1000, and 2000 Hz (low frequency); 500, 1000, 2000, and 4000 Hz (speech frequency); and 3000, 4000, 6000, and 8000 Hz (high frequency) in either ear. Multivariable logistic regression was used to examine the relation between HL and total 25-hydroxyvitamin D [25(OH)D], PTH, total calcium, and BMD, adjusting for covariates.

RESULTS

In multivariable analyses, total 25(OH)D < 20 ng/mL was found to be associated with greater odds of low-frequency HL (OR: 2.02; 95% CI: 1.28, 3.19) and speech-frequency HL (OR: 1.96; 95% CI: 1.12, 3.44). A 1-unit decrease in femoral neck BMD (OR: 4.55; 95% CI: 1.28, 16.67) and a 1-unit decrease in total spine BMD (OR: 6.25; 95% CI: 1.33, 33.33) were found to be associated with greater odds of low-frequency HL. Serum PTH and total calcium were not found to be associated with HL.

CONCLUSIONS

In the elderly, low vitamin D status was associated with low-frequency and speech-frequency HL. Low vitamin D status may be a potential risk factor for age-related HL.

Progresses in processing technologies for special foods with ultra-long shelf life

Foods for special applications have recently received much attention due to rapid development of space and military industries as well as to frequent occurrence of natural and man-made disasters. Since the way such foods are processed clearly and directly affects their consumer's acceptability and shelf life, it is of interest to explore in detail how these special foods can be processed. This article presents a review on the difficulties in the processing, application and storage as well as on how to ensure the shelf life and acceptability of special foods through the use of efficient processing technologies. Emphasis is made on the use of both conventional and alternative thermal processing and irradiation technologies. Appropriate packaging technologies for each of the discussed special foods are also mentioned along with the way to overcome the problem of product quality degradation. Through comparison and analysis, it is found that foods with different attributes require different technologies and processes to achieve desirable results. Combined use of multiple technologies has also noted to be advantageous.

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.

Presbycusis: An Update on Cochlear Mechanisms and Therapies

Age-related hearing impairment (ARHI), also referred to as presbycusis, is the most common sensory impairment seen in the elderly. As our cochlea, the peripheral organ of hearing, ages, we tend to experience a decline in hearing and are at greater risk of cochlear sensory-neural cell degeneration and exacerbated age-related hearing impairments, e.g., gradual hearing loss, deterioration in speech comprehension (especially in noisy environments), difficulty in the localization sound sources, and ringing sensations in the ears. However, the aging process does not affect people uniformly; nor, in fact, does the aging process appear to be uniform even within an individual. Here, we outline recent research into chronological cochlear age in healthy people, and exacerbated hearing impairments during aging due to both extrinsic factors including noise and ototoxic medication, and intrinsic factors such as genetic predisposition, epigenetic factors, and aging. We review our current understanding of molecular pathways mediating ARHL and discuss recent discoveries in experimental hearing restoration and future prospects.

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.

Association between cadmium exposure and hearing impairment: a population-based study in Korean adults

Background

The present study aimed to evaluate the clinical association between cadmium exposure and hearing impairment among the Korean population.

Methods

This retrospective cross-sectional study used the data obtained from the Korean National Health and Nutrition Examination Survey were used for our study. Finally, 3,228 participants were included in our study, which were then divided into quartiles based on their blood cadmium levels: first quartile (1Q), second quartile (2Q), third quartile (3Q), and fourth quartile (4Q) groups. The hearing thresholds were measured using an automatic audiometer at 0.5, 1, 2, 3, 4, and 6 kHz. Hearing loss (HL) was defined as >25 dB average hearing threshold (AHT).

Results

All the groups had 807 participants each. The area under the receiver operating characteristic curves of cadmium level for HL were 0.634 (95% confidence interval [CI], 0.621–0.646). The participants in the 4Q group had higher Low/Mid-Freq, High-Freq, and AHT values than those in the other groups in the multivariate analysis after adjusting for confounding factors. The logistic regression showed that the OR for HL per 1 µg/L increase in cadmium was 1.25 (95% CI, 1.09–1.44; p=0.002) on the multivariate analysis. Moreover, the multivariate logistic regression analyses revealed that the participants in the 4Q group exhibited a 1.59-, 1.38-, and 1.41-fold higher odds for HL than those in the 1Q, 2Q, and 3Q groups, respectively.

Conclusion

High cadmium level quartile was associated with increased hearing thresholds and HL among the Korean adult population.

Association between a High-Potassium Diet and Hearing Thresholds in the Korean Adult Population

The aim of this study was to determine and evaluate the association between potassium intake and hearing thresholds in the Korean adult population. Data from the Korean National Health and Nutrition Examination Survey were analyzed. Participants were divided into tertiles on the basis of their potassium intake as follows: low, middle, and high. Pure-tone audiometry was performed using an automated audiometer. We calculated as the average threshold at the low-frequency pure-tone average (0.5 and 1 kHz), mid-frequency pure-tone average (2 and 3 kHz), and high-frequency pure-tone average (4 and 6 kHz). The average hearing threshold (AHT) was calculated as the pure-tone average of the thresholds at 0.5~3 kHz. Hearing loss (HL) was defined as an AHT of >40 dB in the better ear. There were 1975 participants each in the low, middle, and high tertile groups. The four different average hearing thresholds significantly decreased with an increase in the potassium intake tertile. Multivariate analysis revealed that the four different average hearing thresholds were significantly lower in the high tertile group than in the other two groups. In addition, univariate and multivariate linear regression analyses showed that the potassium intake level was inversely associated with each of the four different average hearing thresholds. Analyses of participants matched based on propensity scores and participants not matched based on propensity scores yielded similar results. The results of this study suggest that high potassium intake levels were associated with a lower prevalence of HL and lower hearing thresholds in the Korean adult population.

Cmah deficiency may lead to age-related hearing loss by influencing miRNA-PPAR mediated signaling pathway

Background

Previous evidence has indicated CMP-Neu5Ac hydroxylase (Cmah) disruption inducesaging-related hearing loss (AHL). However, its function mechanisms remain unclear. This study was to explore the mechanisms of AHL by using microarray analysis in the Cmah deficiency animal model.

Methods

Microarray dataset GSE70659 was available from the Gene Expression Omnibus database, including cochlear tissues from wild-type and Cmah-null C57BL/6J mice with old age (12 months, n = 3). Differentially expressed genes (DEGs) were identified using the Linear Models for Microarray data method and a protein–protein interaction (PPI) network was constructed using data from the Search Tool for the Retrieval of Interacting Genes database followed by module analysis. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis was performed using the Database for Annotation, Visualization and Integrated Discovery. The upstream miRNAs and potential small-molecule drugs were predicted by miRwalk2.0 and Connectivity Map, respectively.

Results

A total of 799 DEGs (449 upregulated and 350 downregulated) were identified. Upregulated DEGs were involved in Cell adhesion molecules (ICAM1, intercellular adhesion molecule 1) and tumor necrosis factor (TNF) signaling pathway (FOS, FBJ osteosarcoma oncogene; ICAM1), while downregulated DEGs participated in PPAR signaling pathway (PPARG, peroxisome proliferator-activated receptor gamma). A PPI network was constructed, in which FOS, ICAM1 and PPARG were ranked as hub genes and PPARG was a transcription factor to regulate other target genes (ICAM1, FOS). Function analysis of two significant modules further demonstrated PPAR signaling pathway was especially important. Furthermore, mmu-miR-130b-3p, mmu-miR-27a-3p, mmu-miR-27b-3p and mmu-miR-721 were predicted to regulate PPARG. Topiramate were speculated to be a potential small-molecule drug to reverse DEGs in AHL.

Conclusions

PPAR mediated signaling pathway may be an important mechanism for AHL. Downregulation of the above miRNAs and use of topiramate may be potential treatment strategies for ALH by upregulating PPARG.

Mitochondria-Targeted Antioxidants for Treatment of Hearing Loss: A Systematic Review

Mitochondrial dysfunction is associated with the etiologies of sensorineural hearing loss, such as age-related hearing loss, noise- and ototoxic drug-induced hearing loss, as well as hearing loss due to mitochondrial gene mutation. Mitochondria are the main sources of reactive oxygen species (ROS) and ROS-induced oxidative stress is involved in cochlear damage. Moreover, the release of ROS causes further damage to mitochondrial components. Antioxidants are thought to counteract the deleterious effects of ROS and thus, may be effective for the treatment of oxidative stress-related diseases. The administration of mitochondria-targeted antioxidants is one of the drug delivery systems targeted to mitochondria. Mitochondria-targeted antioxidants are expected to help in the prevention and/or treatment of diseases associated with mitochondrial dysfunction. Of the various mitochondria-targeted antioxidants, the protective effects of MitoQ and SkQR1 against ototoxicity have been previously evaluated in animal models and/or mouse auditory cell lines. MitoQ protects against both gentamicin- and cisplatin-induced ototoxicity. SkQR1 also provides auditory protective effects against gentamicin-induced ototoxicity. On the other hand, decreasing effect of MitoQ on gentamicin-induced cell apoptosis in auditory cell lines has been controversial. No clinical studies have been reported for otoprotection using mitochondrial-targeted antioxidants. High-quality clinical trials are required to reveal the therapeutic effect of mitochondria-targeted antioxidants in terms of otoprotection in patients.

Associations of Dietary Riboflavin, Niacin, and Retinol with Age-related Hearing Loss: An Analysis of Korean National Health and Nutrition Examination Survey Data

Because age-related hearing loss (ARHL) is irreversible, prevention is very important. Thus, investigating modifying factors that help prevent ARHL is critical for the elderly. Nutritional status or nutritional factors for the elderly are known to be associated with many problems related to aging. Emerging studies suggest that there was the interaction between nutrition and ARHL. We aimed to investigate the possible impact of dietary nutrients on ARHL using data from the fifth Korean National Health and Nutrition Examination Survey (KNHANES) which included 4742 subjects aged ≥ 65 years from 2010 to 2012. All participants underwent an otologic examination, audiologic evaluation, and nutritional survey. The associations between ARHL and nutrient intake were analyzed using simple and multiple regression models with complex sampling adjusted for confounding factors, such as BMI, smoking status, alcohol consumption, and history of hypertension and diabetes. Higher intake groups of riboflavin, niacin and retinol was inversely associated with ARHL prevalence (riboflavin aOR, 0.71; 95% CI, 0.54-0.94; p = 0.016, niacin aOR, 0.72; 95% CI, 0.54-0.96; p = 0.025, retinol aOR 0.66; 95% CI, 0.51-0.86; p = 0.002, respectively). Our findings suggest the recommended intake levels of riboflavin, niacin, and retinol may help reduce ARHL in the elderly.

Age-Related Hearing Loss Associations With Changes in Brain Morphology

Age-related hearing loss has been associated with varied auditory cortex morphology in human neuroimaging studies. These findings have suggested that peripheral auditory system declines cause changes in brain morphology but could also be due to latent variables that affect the auditory periphery and brain. The current longitudinal study was designed to evaluate these explanations for pure-tone threshold and brain morphology associations. Thirty adults (mean age at Time 1 = 64.12 ± 10.32 years) were studied at two time points (average duration between visits = 2.62 ± 0.81 years). Small- to medium-effect size associations were observed between high-frequency pure-tone thresholds and auditory cortex gray matter volume at each time point. Although there were significant longitudinal changes in low- and high-frequency hearing measures and brain morphology, those longitudinal changes were not significantly correlated across participants. High-frequency hearing measures at Time 1 were significantly related to more lateral ventricle expansion, such that participants with higher measures exhibited larger increases in ventricle size. This ventricle effect was statistically independent of high-frequency hearing associations with auditory cortex morphology. Together, these results indicate that there are at least two mechanisms for associations between age-related hearing loss and brain morphology. Potential explanations for a direct hearing loss effect on brain morphology, as well as latent variables that likely affect both the inner ear and brain, are discussed.

Interplay between Nutrition and Hearing Loss: State of Art

Hearing loss has been recently ranked as the fifth leading cause of years lived with disability, ahead of many other chronic diseases such as diabetes, dementia, or chronic obstructive pulmonary disease. Moreover, according to the World Health Organization, moderate-to-profound hearing loss affects about 466 million people worldwide. Its incidence varies in each population segment, affecting approximately 10% of children and increasing to 30% of the population over 65 years. However, hearing loss receives still very limited research funding and public awareness. This sensory impairment is caused by genetic and environmental factors, and among the latter, the nutritional status has acquired relevance due its association to hearing loss detected in recent epidemiological studies. Several experimental models have proved that the onset and progression of hearing loss are closely linked to the availability of nutrients and their metabolism. Here, we have reviewed studies focused on nutrient effects on auditory function. These studies support the potential of nutritional therapy for the protection against hearing loss progression, which is especially relevant to the aging process and related quality of life.

Vitamin D was not associated with survival or cerebrospinal fluid cathelicidin levels in children with bacterial meningitis

AIM

Vitamin D deficiency impairs the immunological system and has been associated with worse outcomes of infectious diseases, but its role in bacterial meningitis remains unknown. We investigated whether serum 25-hydroxyvitamin D concentrations related to disease outcomes and to cerebrospinal fluid (CSF) cathelicidin concentrations in childhood bacterial meningitis.

METHODS

All consecutively enrolled patients in a clinical trial on childhood bacterial meningitis in Latin America in 1996-2003 were considered, and 142 children, with a median age of seven months who had a confirmed bacterial aetiology and frozen serum available for further analyses, were included in this study. Serum 25-hydroxyvitamin D concentrations were determined with a chemiluminescence immunoassay analyser, while CSF cathelicidin was measured by enzyme-linked immunosorbent assay.

RESULTS

The median serum 25-hydroxyvitamin D concentration was 96 (range 19-251) nmol/L. No relationship was found with patient survival, but children with any neurological sequelae had lower serum 25-hydroxyvitamin D levels than children without sequelae. Serum 25-hydroxyvitamin D was unrelated to cathelicidin concentrations in CSF.

CONCLUSION

Although serum 25-hydroxyvitamin D in children with bacterial meningitis was not associated with survival or CSF cathelicidin concentrations, its relationship with more detailed disease outcomes warrants further study.

Toward Cochlear Therapies

Sensorineural hearing impairment is the most common sensory disorder and a major health and socio-economic issue in industrialized countries. It is primarily due to the degeneration of mechanosensory hair cells and spiral ganglion neurons in the cochlea via complex pathophysiological mechanisms. These occur following acute and/or chronic exposure to harmful extrinsic (e.g., ototoxic drugs, noise...) and intrinsic (e.g., aging, genetic) causative factors. No clinical therapies currently exist to rescue the dying sensorineural cells or regenerate these cells once lost. Recent studies have, however, provided renewed hope, with insights into the therapeutic targets allowing the prevention and treatment of ototoxic drug- and noise-induced, age-related hearing loss as well as cochlear cell degeneration. Moreover, genetic routes involving the replacement or corrective editing of mutant sequences or defected genes are showing promise, as are cell-replacement therapies to repair damaged cells for the future restoration of hearing in deaf people. This review begins by recapitulating our current understanding of the molecular pathways that underlie cochlear sensorineural damage, as well as the survival signaling pathways that can provide endogenous protection and tissue rescue. It then guides the reader through to the recent discoveries in pharmacological, gene and cell therapy research towards hearing protection and restoration as well as their potential clinical application.

Differential Association of Vitamin D Deficiency With Albuminuria by Sex in the Korean General Population: A Cross-sectional Study of the Korea National Health and Nutrition Examination Survey 2011-2012

Objectives

Albuminuria has emerged as a biomarker for several medical conditions, and vitamin D has received attention due to its associations with various disorders. We evaluated the association between low serum vitamin D levels and prevalent albuminuria by sex in the Korean general population.

Methods

We analyzed 9823 participants (4401 males, 5422 females) from the Korea National Health and Nutrition Examination Survey 2011-2012 (KNHANES V-2), and categorized them as having a normal range of vitamin D levels, vitamin D insufficiency, or vitamin D deficiency. A multivariable logistic regression model was used to compare the risk of albuminuria across these groups. Stratified analyses were conducted by smoking status, obesity, and renal function.

Results

Albuminuria was found in 325 of the 4401 male participants (7.4%) and in 455 of the 5422 female participants (8.4%). Among the males, vitamin D deficiency was associated with an odds ratio (OR) for albuminuria of 1.78 (95% confidence interval [CI], 1.07 to 2.97, p<0.05). However, such an association was not found in females. The association was stronger in male current smokers (OR, 3.54; 95% CI, 1.47 to 8.50; p=0.005).

Conclusions

The findings of this study suggest that sex differences exist in the association between serum vitamin D deficiency and albuminuria. Additionally, we observed that the association was stronger in current smokers than in the overall male population, but was not seen in non-smokers. Therefore, different approaches by sex and smoking status might be needed when considering using vitamin D as a biomarker for renal function.

Protective Effects of Silymarin Against Age-Related Hearing Loss in an Aging Rat Model

Age-related hearing loss (ARHL) is one of the most common chronic degenerative disorders. Several studies have indicated that supplementation with some antioxidants can slow down the progression of ARHL. Despite several lines of evidence about the potent antioxidant and anti-aging effects of silymarin, its protective effect against ARHL has not evaluated yet. The aim of the current study was to investigate the effects of silymarin in prevention of ARHL in a d-Galactose-induced aging rat model for the first time. 45 male wistar rats aged 3-month old were divided into 5 groups: group 1, 2 and 3 received 500 mg/kg/day d-Gal plus 100, 200 and 300 mg/kg/day silymarin respectively for 8 weeks, placebo group received 500 mg/kg/day d-Gal plus propylene glycol as placebo, and control group received normal saline during this period of time. Auditory brainstem responses were measured at several frequencies (4, 6, 8, 12 and 16 kHz) before and after the intervention. Placebo group and group 3 showed significant ABR threshold increase across frequencies of 4, 6, 16 kHz compared with the other groups (P < 0.05). However, rats treated with silymarin 100 and 200 mg/kg/day plus d-Gal did not show any significant ABR threshold shifts. Similarly, ABR amplitude of P2 at 4, 8 kHz and P1, P4 at 4 kHz in the placebo group and group 3 were decreased significantly compared with other groups (P < 0.05). However, no significant differences are found in ABR absolute and inter-peak latencies between groups (P > 0.05). The findings indicates that silymarin with doses of 100 and 200 mg/kg/day has protective effect against ARHL and it can be supplemented into the diet of older people to slow down the progression of age-related hearing loss.

A Cross-Sectional Study on the Hearing Threshold Levels Among People in Qinling, Qinghai, and Nanjing, China

PURPOSE

This study aimed to investigate the hearing threshold among different age groups, genders, and geographic areas in China to provide some insight into the appropriate clinical interventions for hearing loss.

METHOD

Using a systematic random sampling technique, 562 participants from Qinling, Qinghai, and Nanjing were included. Participants in the same area were divided into 3 groups according to their age. Pure-tone audiometric thresholds were measured at octave and interoctave frequencies of 0.125-16 kHz for each subject.

RESULTS

There were significant differences in auditory thresholds at nearly all frequencies among young, middle-aged, and elderly people, and hearing thresholds increased with increasing age. People generally had the best hearing ability in Nanjing, better hearing ability in Qinghai, and the worst hearing ability in Qinling. Significant differences in hearing thresholds were found between males and females at several frequencies in Qinling.

CONCLUSION

People living in the rural area of Qinling in China had higher hearing threshold levels, particularly males, and hearing thresholds increased with age.

Association Between Hearing Impairment and Albuminuria With or Without Diabetes Mellitus

Objectives

Few studies have evaluated the accurate association between hearing loss (HL) and albuminuria in patients with or without diabetes mellitus (DM). The aim of our study was to identify the clinical effects of albuminuria on HL with or without DM.

Methods

This study included 9,762 patients from the Korean National Health and Nutrition Examination Survey between 2011 and 2013. Participants were divided into 4 groups based on DM and urine albumin/creatinine ratio levels: group 1 included participants with neither DM nor albuminuria, group 2 included participants without DM and with albuminuria, group 3 included patients with DM and without albuminuria, and group 4 included patients with both DM and albuminuria. The low- or mid-frequency and high-frequency, and average hearing threshold values were obtained.

Results

There were 7,508, 545, 1,325, and 384 participants in groups 1, 2, 3, and 4, respectively. Univariate and multivariate analyses showed that the 3 hearing thresholds in group 1 were the lowest and those in group 4 were the highest among the 4 groups. No significant differences were observed in those thresholds between groups 2 and 3. Group 4 was associated with HL compared with the other groups, but moderate to severe HL was not associated with DM or albuminuria.

Conclusion

The presence of albuminuria was associated with a modest effect on hearing thresholds regardless of presence of DM.

Emerging therapeutic interventions against noise-induced hearing loss

INTRODUCTION

Noise-induced hearing loss (NIHL) due to industrial, military, and recreational noise exposure is a major, but also potentially preventable cause of acquired hearing loss. For the United States it is estimated that 26 million people (15% of the population) between the ages of 20 and 69 have a high-frequency NIHL at a detriment to the quality of life of the affected individuals and great economic cost to society. Areas covered: This review outlines the pathology and pathophysiology of hearing loss as seen in humans and animal models. Results from molecular studies are presented that have provided the basis for therapeutic strategies successfully applied to animals. Several compounds emerging from these studies (mostly antioxidants) are now being tested in field trials. Expert opinion: Although no clinically applicable intervention has been approved yet, recent trials are encouraging. In order to maximize protective therapies, future work needs to apply stringent criteria for noise exposure and outcome parameters. Attention needs to be paid not only to permanent NIHL due to death of sensory cells but also to temporary effects that may show delayed consequences. Existing results combined with the search for efficacious new therapies should establish a viable treatment within a decade.

Role of antioxidants in prevention of age-related hearing loss: a review of literature

Age-related hearing loss (ARHL), also known as presbycusis, is one of the most prevalent chronic degenerative conditions. It is characterized by a decline in auditory function. ARHL is caused by the interaction of multiple factors, including cochlear aging, environment, genetic predisposition, and health comorbidities. The primary pathology of ARHL includes the hair cells loss, stria vascularis atrophy, and loss of spiral ganglion neurons as well as the changes in central auditory pathways. The research to date suggests that oxidative stress and mitochondrial DNA deletion (mtDNA) play a major role in pathophysiology of ARHL. Therefore, similar to other otological conditions, several studies have also showed that antioxidants can slow ARHL, but some also indicate that antioxidant therapy is not a magic elixir that will prevent or treat hearing loss associated with aging completely, but why? All available clinical trials, including animal and human studies, in English language that examined the protective effects of antioxidants against ARHL were reviewed. Materials were obtained by searching ELSEVIER, PubMed, Scopus, Web of knowledge, Google Scholar databases, Clinical trials, and Cochrane database of systematic reviews. Although ARHL has been shown to be slowed by supplementation with antioxidants, particularly in laboratory animals, a few studies have investigated the effect of interventions against ARHL in humans. High-quality clinical trials are needed to investigate if ARHL can be delayed or prevented in humans. However, it seems that targeting several cell-death pathways is better than targeting the only oxidative stress pathway.

Prevalence and associated factors of facial palsy and lifestyle characteristics: data from the Korean National Health and Nutrition Examination Survey 2010-2012

OBJECTIVES

To report the nationwide prevalence of facial palsy (FP) of grade III or worse in the House-Brackmann (H-B) grading system in South Korea and assess the associated factors.

DESIGN

Cross-sectional analysis of a nationwide health survey.

SETTINGS

South Korea.

METHODS

We obtained data from the 2010 to 2012 Korea National Health and Nutrition Examination Surveys, which were cross-sectional surveys of the South Korean civilian population living in households and aged ≥1 year (N=23 533). A field survey team performed interviews, physical examinations and laboratory tests. Facial expression was evaluated based on the H-B grading system.

RESULTS

Among the population aged ≥1 year, the prevalence of FP of grade III or worse in the H-B grading system was 0.12% (95% CI 0.07% to 0.17%). FP was more prevalent in women (p=0.01) and the prevalence rate increased with age (p<0.001). In participants aged ≥19 years, age, female gender, history of cardiovascular disease and the serum total cholesterol level were associated with FP in a multivariable analysis. In the evaluation of lifestyle, the individuals with FP had a higher rate of depressive mood and were more restricted in their daily activities.

CONCLUSIONS

Considering the significance of facial expression in psychosocial activities, public acknowledgement and further intervention are required to support patients with this distressing condition.

Evaluation of Audiometric Test Results to Determine Hearing Impairment in Patients with Rheumatoid Arthritis: Analysis of Data from the Korean National Health and Nutrition Examination Survey

This study aimed to evaluate the association between rheumatoid arthritis (RA) and hearing impairment in the Korean adult population. Audiometric and laboratory test data from the 2010–2012 Korean National Health and Nutrition Examination Survey (KNHANES) were used for analysis. The relationship between RA and hearing impairment was analyzed, adjusting for various known risk factors associated with hearing impairment. RA was defined in the questionnaire as “RA diagnosed by a physician (yes/no) through a standardized interview.” We defined hearing impairment according to 2 categories of frequency (low/mid and high) as follows (average values in kHz): low/mid frequency, 0.5, 1.0, and 2.0, and high frequency, 3.0, 4.0, and 6.0. Of the subjects, 15,158 (weighted n = 32,035,996) completed the audiometric tests. The overall weighted prevalence of RA was 1.5%. The prevalence of hearing impairment was higher in the subjects with RA than in those without RA, in both, the low/mid- and high-frequency categories (21.1% vs 7.5%, p < 0.001 and 43.3% vs. 26.2%, p < 0.001, respectively). In the multivariable logistic analysis, RA (odds ratios [OR] 1.47, 95% confidence interval [CI] 1.05–2.06, p = 0.025) was an independent risk factor of low/mid-frequency hearing impairment along with age (OR 1.12, 95% CI 1.12–1.13, p < 0.001), current smoking (OR 1.27, 95% CI 1.03–1.56, p = 0.026), and college graduation (OR 0.53, 95% CI 0.39–0.72, p < 0.001). In the multivariable analysis of high-frequency hearing impairment, RA did not show any association with hearing impairment. This study suggests that RA is associated with low/mid-frequency hearing impairment after adjustment for various known risk factors. Further study is needed to verify the hearing impairment in RA.

Disability of Hearing Impairment Is Positively Associated With Urine Albumin/Creatinine Ratio in Korean Adults: The 2011-2012 Korea National Health and Nutrition Examination Survey

OBJECTIVES

The aim of this study was to determine whether chronic kidney disease (CKD) is associated with hearing thresholds in the nationwide, large-scaled Korean population.

METHODS

This study analyzed the data of 9,798 subjects of 19 years and older (4,387 males and 5,411 females). Urine albumin-to-creatinine ratio (ACR) was measured from first-voided spot urine samples. The air-conduction hearing threshold was measured at 0.5, 1, 2, 3, 4, and 6 kHz and pure tone audiogram (PTA) average was calculated as the four-frequency average of 0.5, 1, 2, and 4 kHz.

RESULTS

Urine ACR was significantly correlated with the PTA average of better ear in both genders, especially at 3 and 6 kHz in males and at 1, 3, 4, and 6 kHz in females. After adjusting, urine ACR also increased the risk of hearing loss in female, especially if urine ACR was 30 mg/g and more (odds ratio, 1.636-2.229. This study showed that the degree of hearing loss was significantly different according to categories of urine ACR in both genders. Hearing loss without disability was found less but that with bilateral hearing disability was found more as urine ACR increased. In generally, prevalence of hearing loss with disability was higher in males than females.

CONCLUSION

This study demonstrated that urine ACR was significantly correlated with the PTA average of better ear in Korean adults of both genders. This study suggests that clinicians should carefully monitor the hearing level for subjects with elevated urine ACR, even though high urine ACR within the normal range.

Association of Bone Mineral Density With Hearing Impairment in Postmenopausal Women in Korea

OBJECTIVES

Previous studies examining the association between osteoporosis (OP) and hearing loss (HL) have shown conflicting results. The objective of the present study was to examine the association between hearing impairment and OP in postmenopausal women, using appropriate statistical analyses.

METHODS

Total 1,009 participants were included in the current study. The propensity score matched (PSM) cohort was defined as the cohort including participants diagnosed with OP and participants without OP. Three statistical models were developed where model 1 was unadjusted, model 2 included age, and model 3 included age, body mass index, alcohol intake, smoking habit, diabetes mellitus, hypertension, high density lipoprotein cholesterol, triglyceride level, vitamin D, and alkaline phosphatase.

RESULTS

There were 776 and 233 participants in the groups diagnosed without and with OP, respectively. For propensity score matching, 233 pairs were selected from the 776 participants without OP. In the total cohort, using statistical models 2 and 3, no significant difference in the four hearing thresholds was identified between the 2 groups. Logistic regression indicated that, in model 3, participants with OP had a 1.128 (P=0.323) increased risk HL. A significant HL risk was not observed in participants with OP. Using statistical model 3, there were no significant associations among lumbar spine or femoral neck T-scores and changes in the hearing thresholds. In the PSM cohort, statistical models also showed similar results.

CONCLUSION

The current study did not demonstrate and association between bone mineral density and hearing impairment in the study population of postmenopausal Korean women.

Is Body Mass Index Associated With the Development of Age-Related Hearing Impairment in Koreans? The Korean National Health and Nutrition Examination Survey 2009-2012

Objectives

The aim of this study was to evaluate whether body mass index (BMI) is associated with age-related hearing loss (ARHL) in the Asian elderly population.

Methods

Data from the Korean National Health and Nutrition Examination Survey 2009–2012 were used for the analyses. The pure tones at 0.5 and 1 kHz of both ears of each subject were averaged to obtain the low-frequency, those at 2 and 3 kHz were averaged to obtain the mid-frequency, and those at 4 and 6 kHz were averaged to obtain the high-frequency. The average hearing threshold (AHT) was calculated as pure tone average at 4 frequencies in the better ear. ARHL was defined as the AHT >25 dB.

Results

Univariate analyses revealed an increase in the BMI tertile in men was associated with a decreased low-frequency threshold, while an increase in the BMI tertile in women was associated with decreased mid- and high-frequency thresholds. Multivariate analyses adjusted for confounders show no significant differences in low-, mid-, or high-frequency. There was no significant difference in the prevalence of ARHL by BMI tertiles. Linear regression analyses show no association between BMI and low-, mid-, and high-frequency or AHTs. The area under the receiver operating characteristic curve values for AHT was 0.515 in men and 0.522 in women. The logistic regression analyses showed no association between BMI and ARHL in either sex.

Conclusion

BMI is not advantageous for the prediction of ARHL. In future epidemiological studies, BMI as a covariate of obesity may be replaced by other active metabolic parameters that have better predictive ability of ARHL than BMI.

Metabolic Syndrome Is not an Independent Risk Factor for Hearing Impairment

OBJECTIVE

We aimed to investigate the association between metabolic syndrome (MS) and hearing impairment (HI) using nationally representative data from Korean adults.

DESIGN, SETTING AND PARTICIPANTS

A total of 16,799 subjects (≥19 years old; 7,170 men and 9,629 women) who underwent pure tone audiometry testing were included in the analysis. Data were obtained from the fifth Korea National Health and Nutrition Examination Survey (2010-2012). Subjects were divided into two groups according to the presence of MS.

RESULTS

Among the subjects with MS, 47% had HI. Logistic regression analysis revealed that MS was not an independent risk factor for HI, although increased fasting plasma glucose (OR 1·4, 95% CI: 1·1-1·8) was independently associated with HI. In addition, older age, male sex, very low body mass index (≤17·5 kg/m2), lower education level, smoking history, and occupational noise exposure were independently associated with HI. For low-frequency HI, independent risk factors included older age, lower educational level, lower economic status, and very low BMI (≤17·5 kg/m2). For high-frequency HI, independent risk factors included older age, male sex, lower educational level, lower economic status, increased blood pressure, lower high-density lipoprotein cholesterol, and smoking history.

CONCLUSIONS

MS itself was not an independent risk factor for HI, and, among the individual metabolic components, only increased fasting plasma glucose was independently associated with HI.

Low-fat and low-protein diets are associated with hearing discomfort among the elderly of Korea

Research on the effect of low-fat intake on hearing is limited. This study aimed to elucidate the relationship between fat, carbohydrate and protein intake and the presence of hearing discomfort among the elderly. The Korean National Health and Nutrition Examination Survey was conducted from 2009 through to 2012. A total of 4615 participants ranging in age from 60 to 80 years underwent a pure-tone audiometric evaluation, a physical examination and a nutritional survey. The associations between the participants' hearing thresholds and their protein/fat/carbohydrate intake/total energy intake were analysed using simple and multiple regression models with complex sampling adjusted for confounding factors, such as BMI, income level, smoking status and a history of hypertension, hyperlipidaemia and diabetes. Low fat and protein intakes were associated with hearing discomfort (OR 0·82, 95 % CI 0·71, 0·96, P=0·011; OR 0·81, 95 % CI 0·67, 0·96, P=0·017, respectively). This study revealed that low fat and protein intakes are associated with hearing discomfort in the elderly Korean population.

Association of hearing impairment with chronic kidney disease: a cross-sectional study of the Korean general population

Background

We aimed to evaluate the association between hearing impairment and the prevalence of chronic kidney disease (CKD) in the largest population-based cross-sectional study to date.

Methods

This cross-sectional study was based on the Korean National Health and Nutritional Examination Survey (KNHANES). It included 5226 participants ≥19 years of age whose estimated glomerular filtration rate (eGFR) and hearing threshold had been measured. We diagnosed CKD as an eGFR <60 mL/min/1.73 m². The participants were also evaluated for the presence of other contributing factors related to kidney dysfunction. We divided the participants at the 40-dB threshold into hearing-impairment and no-hearing-impairment groups, using the average threshold of all six frequencies (500, 1000, 2000, 3000, 4000, and 6000 Hz) for both ears.

Results

The odds of hearing impairment was 1.25 times higher (95 % confidence interval: 1.12–1.64, p-value < 0.001) in participants with an eGFR <60 mL/min/1.73 m² than in those with an eGFR ≥60 mL/min/1.73 m² after adjustments for age, sex, smoking, alcohol, body mass index, diabetes mellitus, hypertension, dyslipidemia, and microalbuminuria. Among the risk parameters of CKD associated with hearing impairment, linear regression analysis adjusted for age and sex determined that each increase of serum creatinine or blood pressure was positively associated with an increase in hearing threshold (p-value < 0.01).

Conclusion

The odds of hearing impairment were greater with lower eGFR than with normal eGFR. Individuals with CKD were more likely to also have hearing impairment. We recommend screening the hearing of patients with CKD to provide earlier identification of hearing impairment and earlier intervention, thereby preventing progression of hearing impairment and providing appropriate treatment strategies.

Age-related hearing impairment and the triad of acquired hearing loss

Understanding underlying pathological mechanisms is prerequisite for a sensible design of protective therapies against hearing loss. The triad of age-related, noise-generated, and drug-induced hearing loss displays intriguing similarities in some cellular responses of cochlear sensory cells such as a potential involvement of reactive oxygen species (ROS) and apoptotic and necrotic cell death. On the other hand, detailed studies have revealed that molecular pathways are considerably complex and, importantly, it has become clear that pharmacological protection successful against one form of hearing loss will not necessarily protect against another. This review will summarize pathological and pathophysiological features of age-related hearing impairment (ARHI) in human and animal models and address selected aspects of the commonality (or lack thereof) of cellular responses in ARHI to drugs and noise.

Understanding the gastrointestinal tract of the elderly to develop dietary solutions that prevent malnutrition

Although the prevalence of malnutrition in the old age is increasing worldwide a synthetic understanding of the impact of aging on the intake, digestion, and absorption of nutrients is still lacking. This review article aims at filling the gap in knowledge between the functional decline of the aging gastrointestinal tract (GIT) and the consequences of malnutrition on the health status of elderly. Changes in the aging GIT include the mechanical disintegration of food, gastrointestinal motor function, food transit, chemical food digestion, and functionality of the intestinal wall. These alterations progressively decrease the ability of the GIT to provide the aging organism with adequate levels of nutrients, what contributes to the development of malnutrition. Malnutrition, in turn, increases the risks for the development of a range of pathologies associated with most organ systems, in particular the nervous-, muscoskeletal-, cardiovascular-, immune-, and skin systems. In addition to psychological, economics, and societal factors, dietary solutions preventing malnutrition should thus propose dietary guidelines and food products that integrate knowledge on the functionality of the aging GIT and the nutritional status of the elderly. Achieving this goal will request the identification, validation, and correlative analysis of biomarkers of food intake, nutrient bioavailability, and malnutrition.

The association between metabolic syndrome or chronic kidney disease and hearing thresholds in Koreans: the Korean National Health and Nutrition Examination Survey 2009-2012

BACKGROUND

The aim of this study was to determine whether metabolic syndrome (MetS) or chronic kidney disease (CKD) is associated with hearing thresholds in the general Korean population.

PATIENTS AND METHODS

A total of 16,554 participants were included in this study. MetS was defined using the National Cholesterol Education Program Adult Treatment Panel III guidelines, and CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2 or a dipstick proteinuria result of ≥1+. The hearing thresholds were measured at 0.5, 1, 2, 3, 4, and 6 kHz. Low-frequency (Freq) was defined as pure-tone averages at 0.5 and 1 kHz, while Mid-Freq and High-Freq were defined as the average thresholds at mid-frequency (2 and 3 kHz) and high frequency (4 and 6 kHz), respectively.

RESULTS

In men, the hearing thresholds were 15.1 ± 14.5 dB, 22.2 ± 21.3 dB, and 37.3 ± 26.5 dB for Low-, Mid-, and High-Freq, respectively. In women, the hearing thresholds were 14.9 ± 15.3 dB, 16.6 ± 18.0 dB, and 26.1 ± 21.5 dB for Low-, Mid-, and High-Freq, respectively. The hearing thresholds for men were significantly higher than the hearing thresholds for women in all 3 threshold categories. Male and female subjects with MetS or CKD had higher hearing thresholds than the subjects that did not have these disorders. In the multivariate analysis, MetS was associated with increased hearing thresholds in women, and CKD was associated with increased hearing thresholds in men and women.

CONCLUSION

MetS is associated with hearing thresholds in women, and CKD is associated with hearing thresholds in men and women. Therefore, patients with MetS or CKD should be closely monitored for hearing impairment.