Serum Uric Acid Relation for Hearing Threshold Shift

The potential relationship between uric acid and the recovery in sudden sensorineural hearing loss

OBJECTIVE

Serum uric acid is proven to be associated with chronic hearing loss, but its effect on Sudden Sensorineural Hearing Loss (SSNHL) is unclear. This study aims to evaluate the prognostic values of serum uric acid levels in SSNHL patients.

METHODS

The clinical records of SSNHL patients were retrospectively reviewed. Patients were divided into different groups based on hearing recovery and audiogram type, and uric acid levels were compared. Based on uric acid levels, patients were categorized into normouricemia and hyperuricemia groups, and clinical features and hearing recovery were evaluated. Univariate and multivariate analyses were performed to identify prognostic factors.

RESULTS

In total, 520 SSNHL patients were included in this study, including 226 females and 294 males. In female patients, 186 patients were included in the normouricemia group, and 40 patients were enrolled in the hyperuricemia group. Significant differences were observed in uric acid levels, Total Cholesterol (TC), rate of complete recovery, and slight recovery between the two groups. In male patients, 237 subjects were categorized into the normouricemia group, and 57 patients were included in the hyperuricemia group. The rate of complete recovery and slight recovery was lower in the hyperuricemia group compared to the normouricemia group. All patients were further divided into good recovery and poor recovery groups based on hearing outcomes. The uric acid levels, initial hearing threshold, rate of hyperuricemia, and TC were lower in the good recovery group than the poor recovery group both in female and male patients. Binary logistic regression results showed that uric acid levels, initial hearing threshold, and hyperuricemia were associated with hearing recovery.

CONCLUSION

Hyperuricemia might be an independent risk factor for hearing recovery in SSNHL patients. Serum uric acid and initial hearing threshold possibly affected the hearing outcome in males and females with SSNHL.

LEVEL OF EVIDENCE

Level 4.

Association between Hyperuricemia and Hearing Impairment: Results from the Korean National Health and Nutrition Examination Survey

Background and Objectives: Hyperuricemia is associated with a variety of comorbidities. The objective of this study was to investigate the association between hyperuricemia and hearing impairment in Korean adults. Materials and Methods: Audiometric and laboratory test data from the 2019 to 2020 Korean National Health and Nutrition Examination Survey (KNHANES) were used for analysis. Hearing impairment was defined as a pure-tone average (0.5, 1, 2, 4 kHz) threshold level ≥ 41 decibels. The definition of hyperuricemia was different for males and females: >7 mg/dL for males vs. >6 mg/dL for females. Results: A total of 4857 (weight n = 17,990,725) subjects were analyzed. The mean age was 56.8 years old. The weighted prevalence was 12.1% for hyperuricemia and 2.5% for gout. The prevalence of hearing impairment was 13.4%. In the univariable analysis, hyperuricemia was significantly associated with hearing impairment. However, the diagnosis of gout was not associated with hearing impairment. In the multivariable analysis, hyperuricemia (odds ratios (OR): 1.41, 95% confidence interval [CI]: 1.03-1.92, p = 0.030) was associated with hearing impairment along with age (OR: 1.12, 95% CI: 1.10-1.14, p < 0.001), female sex (OR: 0.43, 95% CI: 0.34-0.64, p < 0.001), education (OR: 0.43, 95% CI: 0.30-0.63, p = 0.001), and occupational noise exposure (OR: 1.67, 95% CI: 1.25-2.22, p = 0.001). In the subgroup analysis, hyperuricemia was associated with hearing impairment in females (OR: 1.59, 95% CI: 1.02-2.48, p = 0.041) and the elderly aged 60 years or more (OR: 1.45, 95% CI: 1.05-1.99, p = 0.023). Conclusions: Hyperuricemia was independently associated with hearing impairment, especially in females and the elderly aged 60 years or more.

Limited Link of Common Blood Parameters with Tinnitus

Background: Tinnitus severity is generally assessed by psychometric and audiological instruments. However, no objective measure exists to evaluate the subjective discomfort and suffering caused by this hearing phenomenon. The objective of this work was to determine the possible blood parameters for diagnostics and therapy. Methods: We measured tinnitus distress by using the Tinnitus Questionnaire (TQ) and collected tinnitus-related audiological measures, namely the hearing threshold (HT), tinnitus loudness (TL), and sensation level (SL, i.e., the tinnitus loudness/hearing threshold at a tinnitus frequency). Blood samples were taken from 200 outpatients of the Tinnitus Centre of the Charité, and 46 routine blood count parameters were examined. The possible interactions were determined by (robust) linear models. Results: Tinnitus distress and audiological measurements were largely uncorrelated but could partly be predicted by selected blood parameters. First, the erythrocyte counts predicted tinnitus distress to a small extent. Second, the levels of vitamin D3 explained about 6% of tinnitus loudness and, age-dependently, the hearing threshold variability. Last, the levels of uric acid explained about 5% of the sensation level variability. Conclusions: Tinnitus is a multidimensional phenomenon. The marginal influences of blood markers suggest the possible roles of inflammation and oxidative stress produced by psychological or somatic burdens. Clinically, a vitamin D substitution (in older patients) might have a hearing-protective effect.

Genome-wide DNA methylation analysis of middle-aged and elderly monozygotic twins with age-related hearing loss in Qingdao, China

OBJECTIVE

To explore the differences in DNA methylation associated with age-related hearing loss in a study of 57 twin pairs from China.

DESIGN

Monozygotic twins were identified through the Qingdao Twin Registration system. The median age of participants was >50 years. Their hearing thresholds were measured using a multilevel pure-tone audiometry assessment. The pure-tone audiometry was calculated at low frequencies (0.5, 1.0, and 2.0 kHz), speech frequencies (0.5, 1.0, 2.0, and 4.0kHz), and high frequencies (4.0 and 8 kHz). The CpG sites were tested using a linear mixed-effects model, and the function of the cis-regulatory regions and ontological enrichments were predicted using the online Genomic Regions Enrichment of Annotations Tool. The differentially methylated regions were identified using a comb-p python library approach.

RESULTS

In each of the PTA categories (low-, speech-, high-frequency), age-related hearing loss was detected in 25.9%, 19.3%, and 52.8% of participants. In the low-, speech- and high-frequency categories we identified 18, 42, and 12 individual CpG sites and 6, 11, and 6 differentially methylated regions. The CpG site located near DUSP4 had the strongest association with low- and speech-frequency, while the strongest association with high-frequency was near C21orf58. We identified associations of ALG10 with high-frequency hearing, C3 and LCK with low- and speech-frequency hearing, and GBX2 with low-frequency hearing. Top pathways that may be related to hearing, such as the Notch signaling pathway, were also identified.

CONCLUSION

Our study is the first of its kind to identify these genes and their associated with DNA methylation may play essential roles in the hearing process. The results of our epigenome-wide association study on twins clarify the complex mechanisms underlying age-related hearing loss.

Evidence for gene-smoking interactions for hearing loss and deafness in Japanese American families

BACKGROUND

This study investigated the relationship between smoking and hearing loss and deafness (HLD) and whether the relationship is modified by genetic variation. Data for these analyses was from the subset of Japanese American families collected as part of the American Diabetes Association Genetics of Non-insulin Dependent Diabetes Mellitus study. Logistic regression with generalized estimating equations assessed the relationship between HLD and smoking. Nonparametric linkage analysis identified genetic regions harboring HLD susceptibility genes and ordered subset analysis was used to identify regions showing evidence for gene-smoking interactions. Genetic variants within these candidate regions were then each tested for interaction with smoking using logistic regression models.

RESULTS

After adjusting for age, sex, diabetes status and smoking duration, for each pack of cigarettes smoked per day, risk of HLD increased 4.58 times (odds ratio (OR) = 4.58; 95% Confidence Interval (CI): (1.40,15.03)), and ever smokers were over 5 times more likely than nonsmokers to report HLD (OR = 5.22; 95% CI: (1.24, 22.03)). Suggestive evidence for linkage for HLD was observed in multiple genomic regions (Chromosomes 5p15, 8p23 and 17q21), and additional suggestive regions were identified when considering interactions with smoking status (Chromosomes 7p21, 11q23, 12q32, 15q26, and 20q13) and packs-per-day (Chromosome 8q21).

CONCLUSIONS

To our knowledge this was the first report of possible gene-by-smoking interactions in HLD using family data. Additional work, including independent replication, is needed to understand the basis of these findings. HLD are important public health issues and understanding the contributions of genetic and environmental factors may inform public health messages and policies.

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.