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

Sex differences in hearing impairment due to diet-induced obesity in CBA/Ca mice

BACKGROUND

Obesity is an independent risk factor for hearing loss. Although attention has focused on major obesity comorbidities such as cardiovascular disease, stroke, and type 2 diabetes, the impact of obesity on sensorineural organs, including the auditory system, is unclear. Using a high-fat diet (HFD)-induced obese mouse model, we investigated the impact of diet-induced obesity on sexual dimorphism in metabolic alterations and hearing sensitivity.

METHODS

Male and female CBA/Ca mice were randomly assigned to three diet groups and fed, from weaning (at 28 days) to 14 weeks of age, a sucrose-matched control diet (10 kcal% fat content diet), or one of two HFDs (45 or 60 kcal% fat content diets). Auditory sensitivity was evaluated based on the auditory brainstem response (ABR), distortion product otoacoustic emission (DPOAE), and ABR wave 1 amplitude at 14 weeks of age, followed by biochemical analyses.

RESULTS

We found significant sexual dimorphism in HFD-induced metabolic alterations and obesity-related hearing loss. Male mice exhibited greater weight gain, hyperglycemia, increased ABR thresholds at low frequencies, elevated DPOAE, and lower ABR wave 1 amplitude compared to female mice. The hair cell (HC) ribbon synapse (CtBP2) puncta showed significant sex differences. The serum concentration of adiponectin, an otoprotective adipokine, was significantly higher in female than in male mice; cochlear adiponectin levels were elevated by HFD in female but not male mice. Adiponectin receptor 1 (AdipoR1) was widely expressed in the inner ear, and cochlear AdipoR1 protein levels were increased by HFD, in female but not male mice. Stress granules (G3BP1) were significantly induced by the HFD in both sexes; conversely, inflammatory (IL-1β) responses were observed only in the male liver and cochlea, consistent with phenotype HFD-induced obesity.

CONCLUSIONS

Female mice are more resistant to the negative effects of an HFD on body weight, metabolism, and hearing. Females showed increased peripheral and intra-cochlear adiponectin and AdipoR1 levels, and HC ribbon synapses. These changes may mediate resistance to HFD-induced hearing loss seen in female mice.

Association of Chronic Kidney Disease with Prior Tinnitus: A Case-Control Study

This population-based, case−control study aims to explore the relationship between prior tinnitus and the occurrence of chronic kidney disease (CKD) using a nationwide, population-based cohort study. We used data from the Taiwan National Health Insurance Research Database to explore the association of CKD with tinnitus. We identified 15,314 patients aged ≥40 years old with a first-time diagnosis of CKD as the cases. We used propensity-scored matching to select 45,942 controls (1:3 ratio). We performed multivariate logistic regression to estimate the odds ratio (OR) of a prior tinnitus diagnosis among the CKD group vs. the control group. Analysis showed that 770 (1.26%) out of the 61,256 sampled patients had previously diagnosed tinnitus. Chi-square testing revealed a significant difference in the rate of previously diagnosed tinnitus between cases and controls (3.86% vs. 0.93%, p < 0.001). Univariate logistic regression analysis showed an OR of prior tinnitus for cases of 10.249 (95% confidence interval (CI): (8.662~12.126)) relative to controls. In adjusted analysis, cases were more likely than controls to have a prior diagnosis of tinnitus (OR = 10.970, 95% CI = 9.255~13.004, p < 0.001) after adjusting for age, sex, monthly income, geographic location, urbanization level, hypertension, diabetes, coronary heart disease, hyperlipidemia, obesity, and autoimmune disease. Our study shows that CKD patients have a higher likelihood of having suffered from tinnitus before CKD was diagnosed, but we have no data suggesting that tinnitus is a predictor of subsequent CKD. Patients diagnosed with tinnitus may benefit from proactive measures to prevent CKD and detect it early through lifestyle modifications and regular renal function examinations, regardless of CKD-related symptoms.

Association of Metabolic Syndrome with Sensorineural Hearing Loss

The prevalence of sensorineural hearing loss has increased along with increases in life expectancy and exposure to noisy environments. Metabolic syndrome (MetS) is a cluster of co-occurring conditions that increase the risk of heart disease, stroke and type 2 diabetes, along with other conditions that affect the blood vessels. Components of MetS include insulin resistance, body weight, lipid concentration, blood pressure, and blood glucose concentration, as well as other features of insulin resistance such as microalbuminuria. MetS has become a major public health problem affecting 20–30% of the global population. This study utilized health examination to investigate whether metabolic syndrome was related to hearing loss. Methods: A total of 94,223 people who underwent health check-ups, including hearing tests, from January 2010 to December 2020 were evaluated. Subjects were divided into two groups, with and without metabolic syndrome. In addition, Scopus, Embase, PubMed, and Cochrane libraries were systematically searched, using keywords such as “hearing loss” and “metabolic syndrome”, for studies that evaluated the relationship between the two. Results: Of the 94,223 subjects, 11,414 (12.1%) had metabolic syndrome and 82,809 did not. The mean ages of subjects in the two groups were 46.1 and 43.9 years, respectively. A comparison of hearing thresholds by age in subjects with and without metabolic syndrome showed that the average pure tone hearing thresholds were significantly higher in subjects with metabolic syndrome than in subjects without it in all age groups. (p < 0.001) Rates of hearing loss in subjects with 0, 1, 2, 3, 4, and 5 of the components of metabolic syndrome were 7.9%, 12.1%, 13.8%, 13.8%, 15.5% and 16.3%, respectively, indicating a significant association between the number of components of metabolic syndrome and the rate of hearing loss (p < 0.0001). The odds ratio of hearing loss was significantly higher in subjects with four components of metabolic syndrome: waist circumference, blood pressure, and triglyceride and fasting blood sugar concentrations (p < 0.0001). Conclusions: The number of components of the metabolic syndrome is positively correlated with the rate of sensorineural hearing loss.

Red cell distribution width is associated with hearing impairment in chronic kidney disease population: a retrospective cross-sectional study

PURPOSE

Previous studies have shown that inflammatory markers are associated with hearing impairment in participants with inflammatory diseases. Therefore, screening for inflammatory status may have value in predicting the risk of hearing loss (HL) in participants with underlying inflammation. Therefore, red cell distribution width (RDW), an indirect indicator of inflammatory status, was used. The aim of the present study was to evaluate the clinical association between RDW and hearing impairment in a Korean population with chronic kidney disease (CKD).

METHODS

In this cross sectional study, a total of 461 participants with estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² were included. Participants were divided into three tertiles based on their RDW values. The threshold values at 0.5, 1, and 2 kHz were averaged to obtain the Low/Mid-Freq, and the values at 3, 4, and 6 kHz were averaged to obtain the High-Freq. The average hearing threshold (AHT) was calculated as the pure-tone average of the thresholds at 0.5, 1, 2, and 3 kHz. HL was defined as an AHT of > 40 dB.

RESULTS

The numbers of participants in the Low, Middle, and High tertiles were 172, 154, and 135, respectively. The AUROCs of RDW and hs-CRP for HL were 0.644 and 0.522, respectively. In the multivariate analysis, the Low/Mid-Freq, High-Freq, and AHT values were lowest in the participants in the Low tertile compared with those in the Middle or High tertiles Multivariate logistic regression analyses showed that participants in the High tertile exhibited 2.32- and 1.78-fold higher odds for HL compared to those of the Low and Middle tertiles, respectively. There were positive associations between RDW and AHT values.

CONCLUSION

High RDW was associated with increased odds of hearing impairment in the Korean population with CKD.

Association of metabolic syndrome with the incidence of hearing loss: A national population-based study

Background & aims

Sensorineural hearing loss (HL) is one of the most common public health problems, and its prevalence increases with increasing life expectancy. An association between HL and metabolic syndrome (MetS) is suspected. Although previous epidemiological studies have investigated the association between the two variables, there have been conflicting conclusions. Therefore, we aimed to evaluate the association between the presence of MetS—and individual components of MetS—and HL, using a longitudinal design and a large-scale population.

Methods

A total of 17,513,555 individuals who underwent national health screening between January 2009 and December 2010 were identified. Subject data from the Korean Health Insurance Review and Assessment Service were reviewed. A total of 11,457,931 subjects were ultimately included in the analysis. Baseline comorbidities were defined according to the ICD-10 code from the Korean Health Insurance Review and Assessment Service data. If the participants had an ICD-10 code for HL during the follow-up, they were defined as having incident HL. Criteria for MetS adhered to the revised National Cholesterol Education Program Adult Treatment Panel III.

Results

There were 7,574,432 subjects without MetS and 3,883,499 with MetS. The incidence of HL in subjects without MetS and with MetS was 1.3% and 1.8% at 1 year, 4.1% and 5.2% at 3 years, and 6.8% and 8.6% at 5 years, respectively (P < 0.001). However, multivariate analyses revealed a negative association. Analyses according to the components of MetS demonstrated a positive association for those associated with dyslipidemia; however, the others exhibited an inverse association with HL. We also performed analyses using 4 groups according to the presence of MetS and the components of dyslipidemia. Univariate analysis revealed a positive association between the presence of MetS and HL; however, multivariate analysis revealed a positive association between the presence of dyslipidemia components and HL, regardless of the presence of MetS.

Conclusion

Among the components of MetS, the association between low HDL or high TG levels and HL was most apparent. It is useful to evaluate each MetS component in isolation, such as the presence of low HDL or high TG levels, rather than the presence of MetS as a cluster of components.

Association of Nutritional Factors with Hearing Loss

Hearing loss (HL) is a major public health problem. Nutritional factors can affect a variety of diseases, such as HL, in humans. Thus far, several studies have evaluated the association between nutrition and hearing. These studies found that the incidence of HL was increased with the lack of single micro-nutrients such as vitamins A, B, C, D and E, and zinc, magnesium, selenium, iron and iodine. Higher carbohydrate, fat, and cholesterol intake, or lower protein intake, by individuals corresponded to poorer hearing status. However, higher consumption of polyunsaturated fatty acids corresponded to better hearing status of studied subjects. In addition to malnutrition, obesity was reported as a risk factor for HL. In studies of the relationship between middle ear infection and nutrition in children, it was reported that lack of vitamins A, C and E, and zinc and iron, resulted in poorer healing status due to vulnerability to infection. These studies indicate that various nutritional factors can affect hearing. Therefore, considering that multifactorial nutritional causes are responsible, in part, for HL, provision of proper guidelines for maintaining a proper nutritional status is expected to prevent some of the causes and burden of HL.

Pure Tone Audiometry Threshold Changes for 10 Years in the Same Individuals of General Population: A Retrospective Cohort Study

Objectives:

The objectives of this study were to measure the changes in hearing thresholds in the same individuals during a period of 10 years and suggest a clinical reference for the threshold changes by aging.

Methods:

In this retrospective cohort study, we used regular health checkup data including 2 pure tone audiometry results with a 10-year interval in the same individuals from 1288 subjects. The subjects’ data including demographics, smoking habits, and the diagnosis of chronic diseases were used.

Results:

Age, male gender, smoking, and osteoporosis were identified as factors affecting age-related hearing loss (ARHL). The sole effect of aging on ARHL for 10 years according to age groups and genders was as follows: a loss of 1.4 dB in 20s, 4.0 dB in 30s, 5.0 dB in 40s, 8.2 dB in 50s, and 11.2 dB in 60s of males compared to a loss of 2.3 dB in 20s, 2.9 dB in 30s, 5.1 dB in 40s, 6.5 dB in 50s, and 9.4 dB in 60s of females.

Conclusions:

We could demonstrate the actual effect of aging on ARHL, and it can be used as a clinical reference. Hearing ability decreases more in males than females but seems to decrease exponentially with age in both males and females.

The association between obesity, diet quality and hearing loss in older adults

BACKGROUND

With the aging population, the prevalence of age-related hearing loss will increase substantially. Prevention requires more knowledge on modifiable risk factors. Obesity and diet quality have been suggested to play a role in the etiology of age-related hearing loss. We aimed to investigate independent associations of body composition and diet quality with age-related hearing loss.

METHODS

We performed cross-sectional and longitudinal analyses (follow-up: 4.4 years) in the population-based Rotterdam Study. At baseline (2006-2014), 2,906 participants underwent assessment of body composition, diet, and hearing. Of these 2,906 participants, 636 had hearing assessment at follow-up (2014-2016). Association of body composition and of diet quality with hearing loss were examined using multivariable linear regression models.

RESULTS

Cross-sectionally, higher body mass index and fat mass index were associated with increased hearing thresholds. These associations did not remain statistically significant at follow-up. We found no associations between overall diet quality and hearing thresholds.

CONCLUSIONS

This study shows that a higher body mass index, and in particular a higher fat mass index, is related to age-related hearing loss. However, whether maintaining a healthy body composition may actually reduce the effects of age-related hearing loss in the aging population requires further longitudinal population-based research.

Metabolic syndrome is associated with hearing disturbance

BACKGROUND

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

AIMS/OBJECTIVES

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS AND SIGNIFICANCE

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

Longitudinal Pure-Tone Threshold Changes in the Same Subjects: Analysis of Factors Affecting Hearing

OBJECTIVES

To investigate the change of hearing threshold over time and analyze factors that could affect hearing, this longitudinal study of pure-tone threshold changes in the same subjects at a 9-year interval was performed.

STUDY DESIGN

Retrospective longitudinal study in a single center (n = 1,978).

METHODS

A total of 1,978 subjects were included; they received pure-tone audiometry at a 9-year interval. The degree of the threshold changes was examined and compared between age groups. The subjects' data, such as the level of cholesterol, were analyzed to find risk factors on hearing.

RESULTS

The average of the threshold changes was 3.35 dB in the 20s to 30s; 4.38 dB in the 30s to 40s; 5.75 dB in the 40s to 50s; 7.21 dB in the 50s to 60s; and 10.00 dB in the 60s to 70s (all P < 0.05). If the low-density lipoprotein cholesterol (LDL-C) was maintained below 100 mg/dl, the difference in the weighted four-frequency average was 5.45 dB, whereas it was 6.15 dB in the subjects whose LDL-C was over 100 mg/dl (P = 0.032, age-adjusted). In current smokers, the thresholds increased more than in never- or ex-smokers (P = 0.026 in the weighted four-frequency average and P = 0.011 at 8,000 Hz, age-adjusted).

CONCLUSION

The degree of the threshold changes exhibited an exponential increase with age. Cessation of smoking is advisable to prevent increased aggravation of hearing. Strict management of the low-density lipoprotein cholesterol may have a positive effect on hearing.

LEVEL OF EVIDENCE

3 Laryngoscope, 129:470-476, 2019.

The Association Between Age-Related Hearing Impairment and Metabolic Syndrome in Korean Women: 5-Year Follow-Up Observational Study

BACKGROUND

Although several observational studies showed a relationship between various conditions of metabolic syndrome (MetS) and hearing threshold, there are no studies about longitudinal audiometric results related MetS. The aim of this study was to investigate the association between MetS and age-related hearing impairment (ARHI) through a large, average 5-year longitudinal follow-up, clinical comparative analysis.

MATERIALS AND METHODS

We recruited 1381 women older than 50 years who were enrolled in 2007 and reevaluated in 2012. They had normal or symmetrical sensorineural hearing loss. For the evaluation of the independent impact of MetS on hearing, multivariate analysis was used.

RESULTS

The average follow-up period was 5.0 ± 0.2 years. Subjects with MetS had higher hearing thresholds than subjects without MetS. The loss in high-frequency hearing (≥2000 Hz) progressed more rapidly in women with MetS over a 5-year period.

CONCLUSION

Our analysis using longitudinal and large data revealed that MetS is associated with ARHI in women 50 years and older. High-frequency hearing loss tended to be greater in women with MetS than in those without MetS at the 5-year follow-up. Therefore, older women with MetS should be followed up closely for hearing evaluation.

A narrative review of obesity and hearing loss

The comorbidities related to obesity are already extensive, but as the prevalence of obesity increases globally, so do the number of its associated conditions. The relationship between hearing impairment and obesity is a relatively recent research interest, but is significant as both conditions have the ability to substantially reduce an individual's quality of life both physically and psychologically. Obesity has a significant effect on vascular function, and this may have an impact on highly vascular organs such as the auditory system. This review aims to provide an overview of the existing literature surrounding the association between hearing loss and obesity, in order to emphasise these two highly prevalent conditions, and to identify areas of further investigation. Our literature search identified a total of 298 articles with 11 articles of relevance to the review. The existing literature in this area is sparse, with interest ranging from obesity and its links to age-related hearing impairment (ARHI) and sudden sensorineural hearing loss (SSNHL), to animal models and genetic syndromes that incorporate both disorders. A key hypothesis for the underlying mechanism for the relationship between obesity and hearing loss is that of vasoconstriction in the inner ear, whereby strain on the capillary walls due to excess adipose tissue causes damage to the delicate inner ear system. The identified articles in this review have not established a causal relationship between obesity and hearing impairment. Further research is required to examine the emerging association between obesity and hearing impairment, and identify its potential underlying mechanisms.

Association between sarcopenia and hearing thresholds in postmenopausal women

Background: Given the association between metabolic disturbance and sarcopenia, sarcopenia may be intrinsically associated with the prevalence of HL. However, few studies describe the association between sarcopenia and HL. The aim of this study was to evaluate the clinical association between sarcopenia and HL in postmenopausal Korean women. Patients and Methods: A total of 4,038 women were ultimately included in this study. All participants were postmenopausal. Participants were divided into two groups based on criteria from the Foundation for the National Institute of Health Sarcopenia Project: a normal group (sarcopenia index ≥ 0.512) and a sarcopenia group (sarcopenia index < 0.512). Low-frequency (Low-Freq), mid-frequency (Mid-Freq), and high-frequency (High-Freq) values were obtained. The average hearing threshold (AHT) was calculated as the pure tone average at the 4 frequencies of 0.5 kHz, 1 kHz, 2 kHz, and 3 kHz. Mild HL was as an AHT of 24 to 40 dB; moderate-to-profound HL was defined as an AHT of 40 dB or greater. Results: Of the 4,038 participants, 272 (6.7%) were allocated to the sarcopenia group, leaving 3,766 (93.3%) in the normal group. The groups differed significantly in terms of having hypertension (775 [20.6%] vs. 108 [39.7%]; P < 0.001) or metabolic syndrome (817 [21.7%] vs. 110 [40.4%]; P < 0.001) in the normal and sarcopenia groups, respectively. Visceral fat area (cm³) in the normal and sarcopenia groups was 99.0 ± 21.9 cm³ and 117.0 ± 21.8 cm³ , respectively (P < 0.001). The hsCRP level was higher in the sarcopenia group than in the normal group. For univariate and multivariate analyses, all 4 hearing thresholds were higher in the sarcopenia group than in the normal group. In addition, linear regression analyses showed Low-Freq, Mid-Freq, and High-Freq to be inversely correlated with the sarcopenia index. The unadjusted OR for mild HL was 2.692 (95% CI, 1.963-3.692; P < 0.001) in the sarcopenia group relative to the normal group, with an adjusted OR of 1.584 (95% CI, 1.131-2.217; P = 0.007). The unadjusted OR for moderate-to-profound HL in the sarcopenia group relative to the normal group was 6.246 (95% CI, 4.530-8.612; P < 0.001); the adjusted OR was 2.667 (95% CI, 1.866-3.812; P < 0.001). Conclusion: Sarcopenia may be associated with HL. It may be beneficial to perform screening audiometry in patients with sarcopenia.

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.

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.

Glomerular Filtration Rate and Urine Albumin to Creatinine Ratio Associated With Hearing Impairment Among Korean Adults With Diabetes: A Nationwide Population-Based Study

The objective of this study was to examine the association of estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (ACR) with hearing impairment among diabetic adults in Korea. The study was based on data from Korea National Health and Nutrition Examination Survey 2011 to 2012. Participants were 1206 diabetic adults, aged over 19 years, who completed audiometric testing supervised by nationally certified clinicians. Hearing impairment was defined in three grades: no hearing impairment (pure-tone average 0-25 dB), slight hearing impairment (26-40 dB), and disabling hearing impairment (>40 dB) in the better ear at frequencies 0.5, 1, 2, 3, 4 and 6 kHz. Using logistic regression, risk of hearing impairment was assessed after having controlled for confounding factors. Higher levels of ACR and lower levels of eGFR correlated with an increase in percentage of disabling hearing impairment both unilaterally and bilaterally (P < 0.001). Controlling for possible confounding covariates, odds ratios for hearing impairment showed tendency to increase in higher ACR groups (P for trend = 0.029). Similar pattern was examined between eGFR and hearing impairment (P for trend = 0.006). Odds ratios were 1.981 (1.146, 3.424) for ACR Q4 and 2.773 (1.286, 5.983) for eGFR < 60 mL/min. Fall in eGFR and rise in ACR correlated with severity of hearing impairment. The association existed independently of age, sex, body mass index (BMI), smoking, drinking, exercise, new onset of diabetes, education, income, mental stress, noise exposure, and metabolic syndrome.

Comparison of Various Anthropometric Indices as Risk Factors for Hearing Impairment in Asian Women

Background

The objective of the present study was to examine the associations between various anthropometric measures and metabolic syndrome and hearing impairment in Asian women.

Methods

We identified 11,755 women who underwent voluntary routine health checkups at Yeungnam University Hospital between June 2008 and April 2014. Among these patients, 2,485 participants were <40 years old, and 1,072 participants lacked information regarding their laboratory findings or hearing and were therefore excluded. In total 8,198 participants were recruited into our study.

Results

The AUROC value for metabolic syndrome was 0.790 for the waist to hip ratio (WHR). The cutoff value was 0.939. The sensitivity and specificity for predicting metabolic syndrome were 72.7% and 71.7%, respectively. The AUROC value for hearing loss was 0.758 for WHR. The cutoff value was 0.932. The sensitivity and specificity for predicting hearing loss were 65.8% and 73.4%, respectively. The WHR had the highest AUC and was the best predictor of metabolic syndrome and hearing loss. Univariate and multivariate linear regression analyses showed that WHR levels were positively associated with four hearing thresholds including averaged hearing threshold and low, middle, and high frequency thresholds. In addition, multivariate logistic analysis revealed that those with a high WHR had a 1.347–fold increased risk of hearing loss compared with the participants with a low WHR.

Conclusion

Our results demonstrated that WHR may be a surrogate marker for predicting the risk of hearing loss resulting from metabolic syndrome.

Per-Arnt-Sim Kinase (PASK): An Emerging Regulator of Mammalian Glucose and Lipid Metabolism

Per-Arnt-Sim Kinase (PASK) is an evolutionarily-conserved nutrient-responsive protein kinase that regulates lipid and glucose metabolism, mitochondrial respiration, phosphorylation, and gene expression. Recent data suggests that mammalian PAS kinase is involved in glucose metabolism and acts on pancreatic islet α/β cells and glycogen synthase (GS), affecting insulin secretion and blood glucose levels. In addition, PASK knockout mice (PASK-/-) are protected from obesity, liver triglyceride accumulation, and insulin resistance when fed a high-fat diet, implying that PASK may be a new target for metabolic syndrome (MetS) treatment as well as the cellular nutrients and energy sensors—adenosine monophosphate (AMP)-activated protein kinase (AMPK) and the targets of rapamycin (m-TOR). In this review, we will briefly summarize the regulation of PASK on mammalian glucose and lipid metabolism and its possible mechanism, and further explore the potential targets for MetS therapy.

Association between low-grade albuminuria and hearing impairment in a non-diabetic Korean population: The Korea National Health and Nutrition Examination Survey (2011-2013)

INTRODUCTION

The objective of the present study was to examine the association between low-grade albuminuria and hearing impairment in the non-diabetic population.

MATERIALS AND METHODS

Data from the Korean National Health and Nutrition Examination Survey 2011-2013 were used in the analyses. Participants were excluded from this study if they were younger than 19 years old, or had urine albumin/creatinine ratio (UACR) ≥ 30 mg/g or diabetes mellitus. There were 10,608 participants included in this study. The participants were divided into three groups according to their UACR tertiles.

RESULTS

There were 1560; 1561; and 1552 male and 1982; 1975; and 1978, female participants in the low, middle, and high tertile groups, respectively. The results indicated the association between low-grade albuminuria and the numbers of metabolic syndrome (MetS) components or Framingham risk score, and the presence of MetS or the proportions of participants at high cardiovascular risk. Univariate and multivariate linear regression analyses demonstrated an association between the UACR and average hearing threshold (AHT) that was observed in both sexes. Multivariate analyses showed that mean AHTs in the low, middle, and high tertile groups were, respectively, 16.127 dB, 17.139 dB, and 18.604 dB for men, and 14.842 dB, 15.100 dB, and 16.353 dB, respectively, for women. Low-frequency, mid-frequency, and high-frequency hearing thresholds according to UACR tertiles showed similar trends. In both sexes, multivariate logistic regression analyses revealed that participants in the low and middle tertile groups had a decreased risk for hearing loss compared to participants in the high tertile group.

CONCLUSION

Low-grade albuminuria was associated with hearing impairment in the non-diabetic participants of this study.