Age-related hearing loss in the Korea National Health and Nutrition Examination Survey

The Relationship Between Lower Vitamin D Levels and Hearing Loss in Older Adults

BACKGROUND AND OBJECTIVES

Age-related hearing loss (ARHL) is a sensorineural disease that is associated with a number of factors. In addition to age, sex, environment, lifestyle, and comorbidities are all known to be related to ARHL as well. The prevalence of ARHL can be reduced by controlling the adjustable factors that cause it. Vitamin D levels are strongly related to calcium metabolism, which can affect ARHL. This study aimed to investigate the association between vitamin D and ARHL.

SUBJECTS AND METHODS

A total of 1,104 subjects aged >65 years were enrolled from the fifth Korean National Health and Nutrition Examination Survey, which was conducted from 2010-2012. Every participant received both an audiological assessment and a nutritional survey. The association between ARHL and serum vitamin D concentration was analyzed using logistic regression analyses with complex sampling adjusted for confounding factors such as alcohol consumption, smoking status, mobility, and bone mineral density.

RESULTS

Our multivariable analysis revealed that males in the group with lower serum levels of vitamin D (< 20 ng/mL) had a higher prevalence of ARHL (odds ratio, 1.638, 95% confidence interval, 1.058-2.538, p=0.027).

CONCLUSIONS

This finding suggests that lower serum levels of vitamin D are associated with ARHL in the older male population.

Prevalence and risk factors of hearing loss in the Chinese population aged 45 years and older: Findings from the CHARLS baseline survey

OBJECTIVE

This study aimed to determine the prevalence of hearing loss and identify associated risk factors in a Chinese population aged 45 years and older.

STUDY DESIGN

This study employed a cross-sectional research design. Data from the 4th wave survey of the China Health and Retirement Longitudinal Study (CHARLS) conducted in 2018 were utilized. Participants were assessed using self-reported questionnaires, and various demographic and comorbidity factors were analyzed to elucidate the risk factors associated with hearing loss.

METHODS

A total of 17,695 individuals from 10,257 households in 450 villages and urban settlements were included in the study. Hearing loss was assessed through self-reported questionnaires. Risk factors, including demographic characteristics and comorbidities, were analyzed to identify associations with hearing loss.

RESULTS

The study population had a hearing loss prevalence rate of 17.9% (n = 3,179). Regional variations were observed, with highest rates in Chongqing (28.67%), Yunnan (25.12%), and Qinghai (24.36%), and lowest rates in Zhejiang (17.71%), Tianjin (10.56%), and Shanghai (9.26%). Age ≥70 was associated with higher risk (OR = 3, p<0.05), while being female was associated with reduced risk (OR = 0.81, p<0.05). Higher education level showed lower risk (OR<1, p<0.05). Non-agricultural workers had lower risk (OR = 0.67, p<0.05). Fewer social activities were correlated with decreased risk (OR = 0.89, p = 0.024). Ethnic minorities had slightly higher risk (OR = 1.23, p<0.05).

CONCLUSION

This study provides valuable insights into the prevalence and risk factors associated with hearing loss in the Chinese population aged 45 years and older. The findings emphasize the importance of early detection and intervention, particularly among older individuals and those residing in specific regions, for effective hearing loss management.

Polygenic Risk Score-Based Association Analysis Identifies Genetic Comorbidities Associated with Age-Related Hearing Difficulty in Two Independent Samples

PURPOSE

Age-related hearing loss is the most common form of permanent hearing loss that is associated with various health traits, including Alzheimer's disease, cognitive decline, and depression. The present study aims to identify genetic comorbidities of age-related hearing loss. Past genome-wide association studies identified multiple genomic loci involved in common adult-onset health traits. Polygenic risk scores (PRS) could summarize the polygenic inheritance and quantify the genetic susceptibility of complex traits independent of trait expression. The present study conducted a PRS-based association analysis of age-related hearing difficulty in the UK Biobank sample (N = 425,240), followed by a replication analysis using hearing thresholds (HTs) and distortion-product otoacoustic emissions (DPOAEs) in 242 young adults with self-reported normal hearing. We hypothesized that young adults with genetic comorbidities associated with age-related hearing difficulty would exhibit subclinical decline in HTs and DPOAEs in both ears.

METHODS

A total of 111,243 participants reported age-related hearing difficulty in the UK Biobank sample (> 40 years). The PRS models were derived from the polygenic risk score catalog to obtain 2627 PRS predictors across the health spectrum. HTs (0.25-16 kHz) and DPOAEs (1-16 kHz, L1/L2 = 65/55 dB SPL, F2/F1 = 1.22) were measured on 242 young adults. Saliva-derived DNA samples were subjected to low-pass whole genome sequencing, followed by genome-wide imputation and PRS calculation. The logistic regression analyses were performed to identify PRS predictors of age-related hearing difficulty in the UK Biobank cohort. The linear mixed model analyses were performed to identify PRS predictors of HTs and DPOAEs.

RESULTS

The PRS-based association analysis identified 977 PRS predictors across the health spectrum associated with age-related hearing difficulty. Hearing difficulty and hearing aid use PRS predictors revealed the strongest association with the age-related hearing difficulty phenotype. Youth with a higher genetic predisposition to hearing difficulty revealed a subclinical elevation in HTs and a decline in DPOAEs in both ears. PRS predictors associated with age-related hearing difficulty were enriched for mental health, lifestyle, metabolic, sleep, reproductive, digestive, respiratory, hematopoietic, and immune traits. Fifty PRS predictors belonging to various trait categories were replicated for HTs and DPOAEs in both ears.

CONCLUSION

The study identified genetic comorbidities associated with age-related hearing loss across the health spectrum. Youth with a high genetic predisposition to age-related hearing difficulty and other related complex traits could exhibit sub-clinical decline in HTs and DPOAEs decades before clinically meaningful age-related hearing loss is observed. We posit that effective communication of genetic risk, promoting a healthy lifestyle, and reducing exposure to environmental risk factors at younger ages could help prevent or delay the onset of age-related hearing difficulty at older ages.

Impact of cholesterol homeostasis within cochlear cells on auditory development and hearing loss

Cholesterol is the most abundant sterol molecule in mammalian cells, which not only constitutes the cell membrane but also plays essential roles in the synthesis of important hormones, synapse formation, and cell signal transduction. The effect of hypercholesterolemia on hearing has been studied extensively, and multiple studies have demonstrated that hypercholesterolemia is a risk factor for hearing loss. However, the impact of cholesterol homeostasis within auditory cells on peripheral auditory development and maintenance has not been evaluated in detail. Mutations in certain cholesterol metabolism-related genes, such as NPC1, SERAC1, DHCR7, and OSBPL2, as well as derivatives of cholesterol metabolism-related ototoxic drugs, such as β-cyclodextrin, can lead to disruptions of cholesterol homeostasis within auditory cells, resulting in hearing loss. This article aims to review the impact of cholesterol homeostasis within auditory cells on the peripheral auditory function from the following two perspectives: (1) changes in cholesterol homeostasis regulatory genes in various hearing loss models; (2) mechanisms underlying the effects of some drugs that have a therapeutic effect on hearing loss via regulating cholesterol homeostasis. This article aims to summarize and analyze the impact of disruption of cellular cholesterol homeostasis within auditory cells on hearing, in order to provide evidence regarding the underlying mechanisms.

Audiological and psychological assessment of tinnitus patients with normal hearing

Introduction

This study was performed to assess identifiable abnormalities in tinnitus patients with normal hearing.

Methods

The medical records of subjective non-pulsatile tinnitus patients with normal hearing confirmed by conventional pure-tone audiometry who visited our tinnitus clinic between March 2020 and May 2022 were reviewed. The loudness discomfort level (LDL), extended high-frequency hearing loss (EHFHL), summating potential (SP)/action potential (AP) ratio, distortion product otoacoustic emission (DPOAE), thresholds of auditory brainstem response (ABR) wave V, somatic modulation, and psychiatric symptoms, such as anxiety, depression, and stress were evaluated by questionnaires.

Results

Decreased LDL (n = 48, 59.8%) was the most frequent finding, followed by EHFHL (n = 29, 35.4%), increased SP/AP ratio (n = 27, 32.9%), psychiatric symptoms (n = 24, 29.3%), decreased DPOAE (n = 17, 20.7%), somatic modulation (n = 8, 9.8%), and increased ABR threshold (n = 3, 3.7%); 75.6% of patients had one or more of these findings. The presence of psychiatric symptoms was independently associated with the Tinnitus Handicap Inventory (THI) score.

Conclusion

Tinnitus in patients with normal hearing may be accompanied by a combination of various subclinical abnormal audiological findings. However, the presence of psychiatric symptoms alone was independently associated with tinnitus distress.

The impact of self-reported sensory impairment on cognitive function using the Korean longitudinal study of aging survey data

Recent studies suggest that sensory impairment is related to cognitive function at older ages. Therefore, we aimed to investigate the impact of sensory impairment on cognitive function in the Korean population. We used the Korean Longitudinal Study of Aging data from 2006 to 2018. Cognitive function was measured by the Korean version of the Mini-Mental State Examination scale. A score < 24 at the time of assessment was defined as cognitive impairment. Sensory impairment was assessed according to the self-reported levels of hearing or vision, and the development of sensory impairment was investigated using records of prior survey. We used the generalized estimating equation model to determine association between cognitive function and sensory impairment. A total of 4844 participants (age range: 47-95 years; mean age: 58) were included in the study. Compared to people without sensory impairment, people with a single sensory impairment of hearing or vision had a higher risk of cognitive impairment (odds ratio (OR) = 1.65 [95% confidence interval (CI), 1.49-1.82]). People with dual sensory impairment had the greatest risk of cognitive impairment (OR = 3.23 [95% CI, 2.52-4.12]). The findings suggested the need for timely assessment of sensory function in older persons, which may be useful in identifying individuals at risk for cognitive impairment.

The influence of metabolic syndrome on age-related hearing loss from the perspective of mitochondrial dysfunction

With the increase in life expectancy in the global population, aging societies have emerged in many countries, including China. As a common sensory defect in the elderly population, the prevalence of age-related hearing loss and its influence on society are increasing yearly. Metabolic syndrome is currently one of the main health problems in the world. Many studies have demonstrated that metabolic syndrome and its components are correlated with a variety of age-related diseases of the peripheral sensory system, including age-related hearing loss. Both age-related hearing loss and metabolic syndrome are high-prevalence chronic diseases, and many people suffer from both at the same time. In recent years, more and more studies have found that mitochondrial dysfunction occurs in both metabolic syndrome and age-related hearing loss. Therefore, to better understand the impact of metabolic syndrome on age-related hearing loss from the perspective of mitochondrial dysfunction, we reviewed the literature related to the relationship between age-related hearing loss and metabolic syndrome and their components to discern the possible role of mitochondria in both conditions.

Foreign Body Complications in Ears due to Mishandled Hearing Aid Fitting and Proposed Clinical Guidelines to Address the Complications

BACKGROUND

South Korea has one of the world's fastest aging populations and is witnessing increased age-related hearing impairment cases as well as an increase in the number of hearing aid users. The aim of this study was to analyze complications caused by hearing aid mold materials. In addition, we hope to raise awareness of the harm and danger that inexperienced hearing aid providers can cause to patients.

METHODS

We retrospectively reviewed the medical records of 11 patients who were diagnosed with hearing aid mold material as a foreign body in the ear at a tertiary center between 2016 and 2020. The following data were analyzed: symptoms, endoscopic findings, audiometry, temporal bone CT images, treatment methods, and complications after removal. The currently available literature was also reviewed to develop clinical guidelines, to identify the systematic weaknesses in the South Korean hearing aid market, and to identify policies that warrant better quality control.

RESULTS

Among the 11 cases, 9 were restricted to the external auditory canal, all of which were successfully removed under endoscopy with minor complications. Two cases with middle ear involvement resulted in infection and thus required surgical removal with mastoidectomy. The average age of these patients was 76.4, and all patients received their molding procedure at private hearing aid shops without an otolaryngologist's examination.

CONCLUSION

Thorough patient history-taking and otologic examination must be performed to identify patients at higher risk of complications. Such patients should be referred to an otolaryngologist. If a patient exhibits alarming symptoms, early referral is critical since prompt surgery can minimize complications. A CT scan is highly recommended to determine an optimal approach for foreign body removal. Systematic and regulatory changes in hearing aid dispensers, such as requiring apprenticeship, raising the required level of education, and legally mandating referrals, can help reduce these complications.

Association between kidney function and hearing impairment among middle-aged and elderly individuals: a cross-sectional population-based study

OBJECTIVE

As age-related diseases, chronic kidney disease and hearing impairment (HI) cause a serious socioeconomic burden. Due to structural similarities, there is a certain connection between kidney function and hearing, but there has been no large-scale epidemiological study in China that further explored this connection. Thus, this study aimed to explore the association between indicator levels of kidney function and hearing impairment among middle-aged and elderly individuals in Tianjin, China.

METHOD

In 2020, 1539 participants aged 45 years or older from Tianjin, China, were recruited into this study. All participants completed questionnaire surveys and underwent physical examinations, laboratory examinations, and hearing tests. The estimated glomerular filtration rate (eGFR) was calculated from serum creatinine (Cre) levels. HI was measured using pure-tone audiometry, and audiologists determined the final diagnoses.

RESULT

The prevalence of HI was 49.97%. With each 1-mL/min/1.73 m² increase in eGFR, the overall odds of HI increased by 1.3%; the risk increased by 2.4% and 1.6% for men and people aged 45-65 years, respectively. In contrast, in women, the odds of HI increased as Cre levels increased. Moreover, with each 1-mL/min/1.73 m² increase in eGFR, the overall odds of a one-degree increase in hearing loss increased by 1.7%; the odds increased by 2.3% and 1.5% for men and people aged 45-65 years, respectively. However, in women and people aged ≥65 years, the odds of a one-grade increase in hearing loss increased by 2.1% and 1.5%, respectively, with each 1-µmol/L increase in Cre. In addition, there were no significant relationships between blood urea nitrogen and hearing loss in multivariate analysis (all P > 0.05).

CONCLUSIONS

These findings suggest that eGFR and serum Cre are effective predictors of hearing loss. Thus, to decrease the burden of HI, hearing should be carefully monitored for people aged ≥45 years with elevated serum Cre and eGFR.

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

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

Surgical Removal of Hearing Aid Earmold Impression Material in the Middle Ear

When fitting hearing aids, patients are required to make an earmold impression material for device fixation. It usually causes no problems, although in rare cases, the earmold passes through the middle ear through tympanic membrane perforations.¹-³ Foreign bodies may cause a delayed inflammatory reaction and deterioration of aeration, especially in the Eustachian tube. Herein, we report a rare case of earmold impression material as a foreign body in the middle ear that required surgical removal.