Association between diabetes mellitus and hearing impairment in American and Korean populations

Environmental Risk Factors, Protective Factors, and Biomarkers for Hearing Loss: An Umbrella Review

OBJECTIVE

We aimed to investigate the potential environmental risk factors, protective factors, and biomarkers of hearing loss (HL), and establish a hierarchy of evidence.

DATA SOURCES

Embase, PubMed, Cochrane Library, and Web of Science electronic database from inception to June 1, 2023.

REVIEW METHODS

We included meta-analyses of observational studies of associations between HL and environmental risk factors, protective factors, or biomarkers. We calculated summary effect estimates, 95% confidence interval, heterogeneity I2 statistic, 95% prediction interval, small study effects, and excess significance biases.

RESULTS

Of the 9211 articles retrieved, 60 eligible articles were included. The 60 eligible articles identified 47 potential environmental risk and protective factors (N = 4,123,803) and 46 potential biomarkers (N = 173,701). Evidence of association was convincing (class I) for rheumatoid arthritis (RA) and every 1 cm increase in height. Evidence of association was highly suggestive (class II) for human immunodeficiency virus (HIV), diabetes, cumulative noise exposure (CNE), smoking, congenital cytomegalovirus (CMV) infection, combined exposure to organic solvents and noise, non-Gaussian noise exposure, each 1 kg increase in birth weight, noise exposure, and alopecia areata (AA).

CONCLUSION

In this umbrella review, RA, every 1 cm increase in height, HIV, diabetes, CNE, smoking, congenital CMV infection, combined exposure to organic solvents and noise, non-Gaussian noise exposure, each 1 kg increase in birth weight, noise exposure, and AA were strongly associated with HL.

[Endothelial dysfunction as a pathogenetic factor of sensorineural hearing loss]

Chronic sensorineural hearing loss (SNHL) is a common disease that leads to disability of the population. Despite the many reports devoted to SNHL, the question of the pathogenesis of the disease is still open. Many researchers consider the development of SNHL as a manifestation of microangiopathy. The mechanism of development of microangiopathy in SNHL is multifactorial, but most researchers agree that endothelial dysfunction (ED) triggers a complex of pathological changes in the vessels of the inner ear.

OBJECTIVE

Review of the results of scientific research in recent years on the problem of etiopathogenesis of sensorineural hearing loss from the perspective of endothelial dysfunction in the formation of auditory disorders.

Underestimated Subsequent Sensorineural Hearing Loss after Septicemia

Background and Objectives: Hearing loss after septicemia has been found in mice; the long-term risk increased 50-fold in young adults in a previous study. Hearing loss after septicemia has not received much attention. The aim of this study was to assess the relationship between septicemia and subsequent hearing loss. Materials and Methods: Inpatient data were obtained from the Taiwan Insurance Database. We defined patients with sensorineural hearing loss and excluded patients under 18 years of age. Patients without hearing loss were selected as controls at a frequency of 1:5. The date of admission was defined as the date of diagnosis. Comorbidities in the 3 years preceding the date of diagnosis were retrieved retrospectively. Associations with hearing loss were established by multiple logistic regression and forward stepwise selection. Results: The odds ratio (OR) for the association between sepsis and hearing loss was 3.052 (95% CI: 1.583-5.884). Autoimmune disease (OR: 5.828 (95% CI: 1.906-17.816)), brain injury (OR: 2.264 (95% CI: 1.212-4.229)) and ischemic stroke (OR: 1.47 (95% CI: 1.087-1.988)) were associated with hearing loss. Conclusions: Our study shows that hearing loss occurred after septicemia. Apoptosis caused by sepsis and ischemia can lead to hair cell damage, leading to hearing loss. Clinicians should be aware of possible subsequent complications of septicemia and provide appropriate treatment and prevention strategies for complications.

Urinary pyrethroid metabolite and hearing threshold shifts of adults in the United States: A cross-sectional study

Hearing loss (HL) is a global health problem with a high prevalence and profound socioeconomic impact. Pyrethroids are one of the most commonly used insecticides. Although previous studies have reported the relationship between pyrethroids and neurotoxicity, little is known about the effect of pyrethroid exposure on the auditory system among the general population. This study is aimed to investigate the association of pyrethroid exposure with hearing threshold shifts of adults in the United States. A total of 726 adults, aged from 20 to 69 years from the 2011-2012 National Health and Nutrition Examination Survey (NHANES) data were included in the study. Urinary 3-phenoxybenzoic acid (3-PBA), a general pyrethroid metabolite, was used as a biomarker for pyrethroid exposure. HL was defined as a pure-tone average (PTA) at 0.5, 1, 2, 4 kHz ≥ 20 dB in the better ear. Analyses by using multivariate linear regressions were conducted to explore the associations of urinary 3-PBA with PTA hearing threshold shifts. There were no statistically significant correlations between Ln-transformed 3-PBA and either low-frequency or high-frequency hearing thresholds after adjusting for age, gender, race/ethnicity, education level, firearm noise exposure, occupational noise exposure, recreational noise exposure, serum cotinine, BMI, hypertension, and diabetes. However, associations of 3-PBA with both low-frequency and high-frequency hearing thresholds depended on age (P interaction < 0.0396 and 0.0017, respectively). Positive associations between Ln-transformed 3-PBA and both low-frequency and high-frequency hearing thresholds were observed in participants aged 20-39 years after adjusting confounders (β = 1.53, 95% CI: 0.04-3.01, and β = 3.14, 95% CI: 0.99-5.29, respectively) with the highest tertile (≥ 0.884 μg/g creatinine) of 3-PBA compared with the lowest tertile (< 0.407 μg/g creatinine). The possibility of interaction between 3-PBA and age on the hearing threshold shifts indicated that pyrethroid insecticides were prone to be more toxic to auditory system in younger adults than in older ones. Further studies will be required to confirm these findings.

Association of Audiometric Thresholds with HbA1c and Blood Lipid Levels

Aims: The purpose of this study is to determine if the combined associations of HbA1c and blood lipid levels with audiometric thresholds are nonadditive, additive, or synergistic. Methods: A retrospective cross-sectional study was performed using the 2009-2010, 2011-2012, and 2015-2016 National Health and Nutritional Examination Survey. Participants were placed into tertial groups based on HbA1c, triglyceride, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels. Two-way analyses of variance were used to measure the combined effect of HbA1c and each lipid on mid- and high-frequency audiometric thresholds. Groups were matched by age and gender among HbA1c and blood lipid groups in three separate datasets. Results: The difference in mid-frequency audiometric thresholds between the lowest and highest level of HbA1c groups was 2.0 dB (P = 0.019) in one data set and 2.6 dB (P = 0.005) in another dataset. The difference in mid-frequency audiometric thresholds was 2.1 dB (P = 0.012) when comparing the lowest and highest triglyceride groups, and 2.4 dB (P = 0.001) when comparing the lowest and highest LDL-C groups. HDL-C levels, high frequency audiometry, and the interaction components were not significant for any analysis. Conclusions: These results indicate that higher HbA1c and blood lipid levels may have an additive effect on mid-frequency audiometric thresholds.