Asymmetric Hearing Loss as a Predictor of Stroke Risk in Older Adults

Overview

This longitudinal cohort study found that asymmetric hearing loss (AHL) in adults aged 50 and older is associated with an increased risk of incident stroke. The findings suggest that AHL may serve as an early peripheral marker of subclinical vascular pathology, beyond the effects of symmetrical age-related hearing loss.

Background

Stroke is a leading cause of death and disability worldwide, with most cases attributable to modifiable risk factors. Hearing impairment, particularly sensorineural hearing loss, has been linked to higher stroke risk in prior studies. Asymmetric hearing loss, which affects sound localization and speech understanding, may reflect localized cochlear ischemia due to microvascular compromise. Despite its prevalence and potential vascular implications, the relationship between AHL and stroke risk has not been extensively studied in large cohorts.

Data Highlights

The study utilized data from the Health and Retirement Study (HRS), analyzing objective bilateral pure-tone audiometry results from Waves 13 to 15. Participants aged 50 years and older with asymmetric hearing loss were followed longitudinally to assess incident stroke risk. The prevalence of asymmetric hearing loss in the population ranged from 3% to 25% depending on audiometric criteria. Prior meta-analyses cited indicate a 33% to 70% increased hazard or odds of stroke associated with hearing loss severity.

Key Findings

• Asymmetric hearing loss is common in adults, affecting up to one quarter depending on criteria used.
• AHL is associated with higher cardiovascular risk factors such as hypertension and diabetes compared to symmetrical hearing loss.
• Individuals with AHL experience greater difficulties with speech discrimination and communication in noisy environments.
• Hearing asymmetry may reflect localized cochlear ischemia due to the cochlea's terminal arterial supply without collateral circulation.
• Population-based evidence suggests AHL predicts incident stroke risk independently of symmetrical hearing loss and traditional risk factors.
• Psychosocial consequences of AHL, including loneliness and depressive symptoms, may further contribute to increased stroke risk.

Clinical Implications

Clinicians should consider asymmetric hearing loss as a potential early indicator of cerebrovascular disease and stroke risk in older adults. Objective audiometric screening for hearing asymmetry may help identify individuals who warrant further vascular evaluation and risk factor management. Addressing communication difficulties and psychosocial impacts in patients with AHL could also mitigate associated cardiovascular risks.

Conclusion

Asymmetric hearing loss in adults aged 50 and older is associated with an elevated risk of incident stroke, likely reflecting underlying microvascular pathology. Recognizing AHL as a marker of vascular health may improve early identification and prevention strategies for stroke.

References

1. Global Diseases Buren 2021 -- Stroke Epidemiology and Burden
2. Meta-Analysis on Hearing Loss and Stroke Risk [7]
3. Health and Retirement Study (HRS) -- Longitudinal Cohort Data