Subclinical atherosclerosis and increased risk of hearing impairment

Objective: The study's purpose was to test if subclinical atherosclerosis was associated with the risk of developing HI in a large cohort of middle-aged participants. Methods: Study subjects were members of the Beaver Dam Offspring Study (BOSS), a longitudinal study of adult children of participants in the population-based Epidemiology of Hearing Loss Study (1993-present). BOSS examinations took place in 2005-2008 (baseline) and 2010-2013 (5-year follow-up). The 5-year incidence of hearing impairment was defined as a pure-tone average (PTA) of thresholds at 0.5, 1, 2 and 4kHz>25dB Hearing Level (dB HL) in either ear at follow-up among participants at risk (baseline PTA in both ears<= 25dB HL; n=2436, mean age=47.7 years). Atherosclerosis was measured as the mean carotid intima-media thickness and the presence of carotid artery plaque. Results: Among the 1984 participants at-risk with a follow-up audiometric examination, the 5-year incidence of hearing impairment was 8.3% (95% Confidence Interval (C.I.) 7.1, 9.5). With multivariable adjustment, carotid intima-media thickness was positively associated with hearing impairment incidence (Relative Risk (RR)=1.14 per 0.1mm, 95% C.I. 1.04, 1.24). The number of sites (0-6) with plaque was also positively associated with the incidence of impairment (RR=1.16 per site, 95% C.I. 1.01, 1.32). Conclusion: Atherosclerosis was associated with the 5-year incidence of hearing impairment in this predominantly middle-aged cohort. Interventions targeting atherosclerosis prevention may help to prevent or delay the onset of hearing impairment.