Waist circumference is associated with pitch pattern sequence score in older male adults

The Relationship of Cardiometabolic Risk and Auditory Processing among African Americans: The Jackson Heart Study

Objectives

There is limited research in population-based studies on auditory processing. The purpose of this work is to determine the prevalence of auditory processing impairment in the Jackson Heart Study cohort and to identify potential relationships with cardiometabolic risk factors.

Study Design

Cross-sectional study.

Setting

Jackson Heart Study in Jackson, Mississippi.

Subjects

Participants of an all–African American cardiovascular study cohort (n = 1314).

Methods

The Quick Speech-in-Noise and Dichotic Digits, Double Pairs tests were used to assess auditory processing. Logistic regression and multinomial logistic regression models were used to examine how participants’ cardiometabolic risk factors and audiologic characteristics were associated with speech perception in noise and binaural integration.

Results

Quick Speech-in-Noise and Dichotic Digits, Double Pairs testing showed a prevalence of auditory processing impairment in 69% and 71% of the cohort, respectively, which was significantly related to age, hearing thresholds, sex, and education level. With covariate adjustment in statistical models for age, sex, pure tone average, and education level, waist circumference, systolic blood pressure, and hypertension were statistically predictive of auditory processing impairment ( P < .05).

Conclusion

The results suggest a high prevalence of auditory processing deficits in the Jackson Heart Study cohort. In addition, cardiometabolic and audiologic factors show a statistically significant independent relationship with auditory impairment measures.

Effects of Spirulina on the functions and redox status of auditory system in senescence-accelerated prone-8 mice

To our knowledge, the effects of Spirulina platensis water extract (SP) on hearing function have not yet been reported. This study investigated the effects of SP on the function and redox status of the auditory system. Auditory brainstem responses and redox status were compared between two groups of 3-month-old senescence-accelerated prone-8 (SAMP8) mice: the control group was fed a normal diet, and the experimental group was fed a normal diet with oral supplementation of SP for 6 weeks. Compared with the control group, the experimental group had significantly lower hearing thresholds according to auditory brainstem responses measured using click sounds and 8-kHz tone burst sound stimulation at the end of this study. The experimental group had a shorter I-III interval of auditory brainstem responses with 16-kHz tone burst stimulation than the control group that was of borderline significance. Additionally, the experimental group had significantly higher mRNA expression of the superoxide dismutase and catalase genes in the cochlea and brainstem and significantly higher mRNA expression of the glutathione peroxidase gene in the cochlea. Further, the experimental group had significantly lower malondialdehyde levels in the cochlea and brainstem than the control group. However, tumor necrosis factor-α mRNA expression was not significantly different between the control and experimental groups. SP could decrease hearing degeneration in senescence-accelerated prone-8 mice possibly by increasing superoxide dismutase, catalase, and glutathione peroxidase gene expression and decreasing damage from oxidative stress in the cochlea and brainstem.

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.

Soybean β-Conglycinin Prevents Age-Related Hearing Impairment

Obesity-related complications are associated with the development of age-related hearing impairment. β-Conglycinin (β-CG), one of the main storage proteins in soy, offers multiple health benefits, including anti-obesity and anti-atherosclerotic effects. Here, to elucidate the potential therapeutic application of β-CG, we investigated the effect of β-CG on age-related hearing impairment. Male wild-type mice (age 6 months) were randomly divided into β-CG-fed and control groups. Six months later, the body weight was significantly lower in β-CG-fed mice than in the controls. Consumption of β-CG rescued the hearing impairment observed in control mice. Cochlear blood flow also increased in β-CG-fed mice, as did the expression of eNOS in the stria vascularis (SV), which protects vasculature. β-CG consumption also ameliorated oxidative status as assessed by 4-HNE staining. In the SV, lipofuscin granules of marginal cells and vacuolar degeneration of microvascular pericytes were decreased in β-CG-fed mice, as shown by transmission electron microscopy. β-CG consumption prevented loss of spiral ganglion cells and reduced the frequencies of lipofuscin granules, nuclear invaginations, and myelin vacuolation. Our observations indicate that β-CG ameliorates age-related hearing impairment by preserving cochlear blood flow and suppressing oxidative stress.

Role of Obesity on the Prognosis of Sudden Sensorineural Hearing Loss in Adults

OBJECTIVE

To investigate the role of obesity/overweight on the prognosis of sudden sensorineural hearing loss (SSHL).

STUDY DESIGN

Retrospective cohort study.

SETTING

Outpatient department of a community hospital.

SUBJECTS AND METHODS

We collected 254 adult patients with SSHL from a community hospital. The odd ratios of body mass index (BMI) or obesity/overweight (BMI ≥25 kg/m(2)) on the recovery of SSHL were evaluated with multivariate logistic regression analysis.

RESULTS

There were 120 (47.2%) patients in the nonobesity group (BMI <25 kg/m(2)) and 134 (52.8%) patients in the obesity/overweight group (BMI ≥25 kg/m(2)). The complete and partial recovery rates were 10.0% and 49.2% in the nonobesity group and 9.7% and 47.0% in the obesity/overweight group, respectively. Univariate logistic regression showed that BMI had no significant association with recovery of SSHL (odds ratio [OR] of complete and partial recovery versus no recovery = 1.04, 95% confidence interval [CI] = 0.965-1.113, P = .327). Multivariate logistic regression analysis also showed that BMI (OR = 1.04, 95% CI = 0.964-1.131, P = .292) was not significantly associated with the recovery of SSHL for all subjects, after adjusting for all considered variables. Also, obesity/overweight (BMI ≥25 kg/m(2)) had no significant association with the recovery of SSHL.

CONCLUSION

Obesity/overweight would appear to have no significant effect on the prognosis of SSHL.

No association between plasma adiponectin levels and central auditory function in adults

Adiponectin might play a protective role in cardiometabolic and peripheral auditory disorders, but its role on central auditory function was still unclear. The aim of this study was to examine whether there is an association between plasma adiponectin levels and central auditory function in adults. We recruited 297 adults, with normal or symmetrical sensorineural hearing loss and normal cognitive functions. Multivariate linear regression was performed to assess the association between plasma adiponectin concentrations and pitch pattern sequence (PPS) score, which was one of central auditory tests. The results showed that there were 224 (75.4%) women and 73 (24.6%) men in this study. The mean age was 58.1 ± 8.4 years, the mean waist circumference (WC) was 81.1 ± 8.3 cm, and the mean body mass index (BMI) was 24.0 ± 3.0 kg/m(2). The mean PPS score was 71.5 ± 14.1%, and plasma adiponectin concentration was 12.7 ± 5.5 g/mL. After adjusting for age, gender, WC, coronary artery disease, hypertension, diabetes mellitus, chronic kidney disease, smoking and drinking, plasma adiponectin concentrations (coefficient ± standard error, β ± SE = -0.09 ± 0.16, p = 0.563) were found to have no significant associations with PPS score. When WC was excluded from these variables in the multivariate linear regression model, plasma adiponectin concentrations (β ± SE = -0.03 ± 0.15, p = 0.855) were still not significantly associated with PPS score. In conclusion, plasma adiponectin levels were not significantly associated with PPS score, which was one of central auditory function tests. More studies should be conducted for the underlying mechanisms of obesity-related central auditory dysfunction.

Adiponectin deficiency exacerbates age-related hearing impairment

Obesity-related disorders are closely associated with the development of age-related hearing impairment (ARHI). Adiponectin (APN) exerts protective effects against obesity-related conditions including endothelial dysfunction and atherosclerosis. Here, we investigated the impact of APN on ARHI. APN-knockout (APN-KO) mice developed exacerbation of hearing impairment, particularly in the high frequency range, compared with wild-type (WT) mice. Supplementation with APN prevented the hearing impairment in APN-KO mice. At 2 months of age, the cochlear blood flow and capillary density of the stria vascularis (SV) were significantly reduced in APN-KO mice as compared with WT mice. APN-KO mice also showed a significant increase in terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells in the organ of Corti in the cochlea at 2 months of age. At the age of 6 months, hair cells were lost at the organ of Corti in APN-KO mice. In cultured auditory HEI-OC1 cells, APN reduced apoptotic activity under hypoxic conditions. Clinically, plasma APN levels were significantly lower in humans with ARHI. Multiple logistic regression analysis identified APN as a significant and independent predictor of ARHI. Our observations indicate that APN has an important role in preventing ARHI.