Age-related hearing loss and speech perception disorder: the broken interface between healthcare professionals and older adults

Burden of non-communicable diseases in China and its provinces, 1990-2021: Results from the Global Burden of Disease Study 2021

BACKGROUND

Non-communicable diseases (NCDs) are the primary causes of disability and death. The aim of this study is to analyze the disease burden of NCDs in China from 1990 to 2021.

METHODS

This study used data on NCDs in China and its provinces from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021. The study analyzed the disease burden of NCDs in 2021 and its changes from 1990 to 2021 using indicators including deaths and disability-adjusted life years (DALYs).

RESULTS

Between 1990 and 2021, the NCD burden in China exhibited an upward trend. In 2021, China had 10.6 (95% uncertainty interval [UI]: 9.0-12.2) million deaths and 349.3 (95% UI: 301.5-401.2) million DALYs due to NCDs, accounting for 91.0% (95% UI: 90.4-91.7%) of all deaths and 86.7% (95% UI: 86.0-87.4%) of all DALYs. NCDs caused a lower disease burden in females than in males. Cardiovascular diseases and neoplasms were the main NCD level 2 causes of deaths and DALYs, resulting in 5.1 (95% UI: 4.3-5.9) and 2.8 (95% UI: 2.3-3.4) million deaths and 100.2 (95% UI: 84.6-116.6) million and 71.2 (95% UI: 59.3-85.2) million DALYs in 2021, respectively. Chronic respiratory diseases were the third leading cause of NCD deaths, while musculoskeletal disorders were the third leading cause of NCD DALYs. Qinghai, Xizang, and Heilongjiang had the highest age-standardized mortality rates and age-standardized DALY rates (per 100,000) for NCDs, while Hong Kong Special Administration Region (SAR), Macao SAR, and Shanghai recorded the lowest age-standardized mortality rates and age-standardized DALY rates.

CONCLUSIONS

NCDs disease burden in China and exhibited heterogeneity across sexes provinces. China needs to focus on addressing key NCDs and implement intervention measures tailored to the disease distribution characteristics to reduce the NCD burden.

RNA-seq analysis highlights DNA replication and DNA repair associated with early-onset hearing loss in the cochlea of DBA/2J mice

AIMS

Age-related hearing loss (ARHL) is a significant health concern, and DBA/2J (D2) and C57BL/6 (B6) mouse strains serve as valuable models for its study. B6 mice, harboring a homozygous ahl allele in Cdh23, manifest high-frequency hearing loss at 3 months. In contrast, D2 mice, carrying the R109H variant of the Fascin-2 gene (Fscn2), experience early-onset hearing loss by 3 weeks. Yet, the underlying molecular mechanisms driving early-onset hearing loss in D2 mice remain elusive. This study aimed to identify novel genes and regulatory pathways as therapeutic targets for early deafness.

MAIN METHODS

This study employs RNA-sequencing (RNA-seq) to analyze cochlear mRNA expression at two different ages in D2 and B6 mice, respectively. The differentially expressed genes (DEGs) are uniquely associated with D2 mice by Venn diagram analysis. A protein-protein interaction (PPI) network is further constructed, followed by module analysis utilizing MCODE. Enrichment analysis of GO and KEGG pathways revealed biological functions and molecular pathways. The PPI network and VarElect analysis are conducted for genes within these pathways, facilitating the identification of pivotal genes based on scoring criteria. Subsequently, five genes are meticulously selected and validated through qRT-PCR.

KEY FINDINGS

Notably, 1181 DEGs are uniquely associated with D2 mice by Venn diagram analysis. GO and KEGG pathway enrichment analyses shed light on distinctive pathways in D2 mice, encompassing DNA replication, mismatch repair, base excision repair, and nucleotide excision repair, which are associated with apoptosis. Five genes involved in these pathways were finally selected and validated by qRT-PCR. Their down-regulation with age is consistent with RNA-seq result.

SIGNIFICANCE

Our study underscores the potential implication of down-regulated genes associated with DNA replication and DNA damage repair in the early-onset hearing loss observed in D2 mice.

Research trends and hotspot analysis of age-related hearing loss from a bibliographic perspective

Background

Up-to-date information about the trends of age-related hearing loss (ARHL) and how this varies between countries is essential to plan for an adequate health-system response. Therefore, this study aimed to assess the research hotpots and trends in ARHL and to provide the basis and direction for future research.

Materials and methods

The Web of Science Core Collection database was searched and screened according to the inclusion criteria during 2002–2021. Bibliometric analyses were conducted by CiteSpace (Chaomei Chen, Drexel University, Philadelphia, PA, United States) software and VOSviewer (Center for Science and Technology Studies, Leiden University, Leiden, The Netherlands) software.

Results

The query identified 1,496 publications, which showed a growth trend of this filed. These publications were from 62 countries, the United States of America (United States) showed its tremendous impact on this field in publication outputs, total citations, and international collaborations, China following in second. The Journal of Hearing Research was the most productive journal. Weijia Kong published the most papers, and the most productive institution was Washington University. The keyword “presbycusis” ranked first in research frontiers and appeared earlier, and the keywords “age-related hearing loss,” “risk,” “dementia,” “auditory cortex,” “association,” and “decline” began to appear in recent years.

Conclusion

The annual number of publications has grown rapidly in the past two decades and will continue to grow. Epidemiological investigation and laboratory research are lasting hot spots, besides future research will focus on the association between ARHL and cognitive decline, dementia, and Alzheimer’s disease.

Early Noise-Induced Hearing Loss Accelerates Presbycusis Altering Aging Processes in the Cochlea

Several studies identified hearing loss as a risk factor for aging-related processes, including neurodegenerative diseases, as dementia and age-related hearing loss (ARHL). Although the association between hearing impairment in midlife and ARHL has been widely documented by epidemiological and experimental studies, the molecular mechanisms underlying this association are not fully understood. In this study, we used an established animal model of ARHL (C57BL/6 mice) to evaluate if early noise-induced hearing loss (NIHL) could affect the onset or progression of age-related cochlear dysfunction. We found that hearing loss can exacerbate ARHL, damaging sensory-neural cochlear epithelium and causing synaptopathy. Moreover, we studied common pathological markers shared between hearing loss and ARHL, demonstrating that noise exposure can worsen/accelerate redox status imbalance [increase of reactive oxygen species (ROS) production, lipid peroxidation, and dysregulation of endogenous antioxidant response] and vascular dysfunction [increased expression of hypoxia-inducible factor-1alpha (HIF-1α) and vascular endothelial growth factor C (VEGFC)] in the cochlea. Unveiling the molecular mechanisms underlying the link between hearing loss and aging processes could be valuable to identify effective therapeutic strategies to limit the effect of environmental risk factors on age-related diseases.

Retinal Vascular Density on Optical Coherence Tomography Angiography and Age-related Central and Peripheral Hearing Loss in a Southern Italian Older Population

BACKGROUND

Age-related hearing loss (ARHL) and retinal vessel changes have both been associated to neurodegeneration/dementia, suggesting a possible link between these two conditions in older age. We aimed to determine whether superficial and deep vascular density (SVD and DVD) of the capillary plexi of macular vasculature can be associated with peripheral ARHL and age-related central auditory central processing (CAPD).

METHODS

We analyzed data on 886 older participants (65 years+, age range:65-92 years) in the cross-sectional population-based Salus in Apulia Study. Optical coherence tomography angiography (OCT-A) was used to measure SVD and DVD of the capillary plexi of the macula at the 3-mm circle area centered on the fovea (whole retina), the parafoveal quadrant, and foveal quadrant. Disabling peripheral ARHL was defined as >40 dB HL of pure tone average on the frequencies from 0.5, 1, 2, and 4 KHz in the better ear, and age-related CAPD as <50% at the Synthetic Sentence Identification with Ipsilateral Competitive Message test in at least one ear.

RESULTS

DVD at the whole retina and at the parafoveal quadrant were inversely associated only with age-related CAPD [odds ratio (OR):0.93; 95% confidence interval (CI): 0.88-0.96 and OR:0.94; 95 CI:0.90-0.99, respectively]. No further associations with peripheral ARHL were evident.

CONCLUSIONS

Retinal vasculature is associated with central auditory processing pathology, possibly playing an important role in early detection and intervention. The association of retinal vascular density with age-related CAPD may bring us a further step forward in understanding the biological mechanisms underlying the links between neurodegeneration/dementia and ARHL.