Objective: Hearing impairment (HI) is common in aging adults. Aldosterone, insulin-like growth factor (IGF1), and brain-derived neurotrophic factor (BDNF) have been identified as potentially protective of hearing. The present study aims to investigate these relationships. Methods: The Epidemiology of Hearing Loss Study is a longitudinal population-based study of aging in Beaver Dam, Wisconsin, that began in 1993. Baseline for the present investigation is the 1998 to 2000 phase. Follow-up exams occurred approximately every 5 years, with the most recent occurring from 2013 to 2016. Hearing was measured by pure-tone audiometry. HI was defined as a pure tone average (PTA) > 25 decibels hearing level in either ear. Change in PTA was the difference between follow-up examinations and baseline. Baseline serum samples were used to measure biomarkers in 2017. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated to assess the effect of biomarker levels in the lowest quintile (Q1) versus the highest (Q5) on incident HI and PTA change. Results: There were 1,088 participants (69.3% women) at risk of HI included in analyses. The mean baseline age was 63.8 years (standard deviation = 7.0). The 16-year incidence of HI was 54.9% and was higher in men (61.1%) than women (52.1%). In age- and sex-adjusted models, aldosterone (HR = 1.06, 95% CI = 0.82–1.37), IGF1 (HR = 0.92, 95% CI = 0.71–1.19), and BDNF (HR = 0.86, 95% CI = 0.66–1.12) levels were not associated with risk of HI. PTA change was similarly not affected by biomarker levels. Conclusion: Aldosterone, IGF1, and BDNF were not associated with decreased risk of age-related hearing loss in this study. Level of Evidence: 2b. Laryngoscope, 129:2178–2183, 2019.
Bibliographical noteFunding Information:
The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute on Aging, the National Eye Institute, or Research to Prevent Blindness. The funding organizations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.
This study was supported by the National Institute on Aging, award number R37AG011099 (K.J.C.); the National Eye Institute, grant U10EY06594 (B.E.K.K., R.K.); and an unrestricted grant from Research to Prevent Blindness. The authors have no other funding, financial relationships, or conflicts of interest to disclose.
- brain-derived neurotrophic factor
- insulin-like growth factor
- risk factors
- sensorineural hearing loss