Association between age-related hearing loss and stroke in an older population.

BACKGROUND AND PURPOSE Very few studies have investigated the association between hearing loss and stroke. A recent article in Stroke reported an increased incidence of stroke among patients with sudden hearing loss over a 5-year follow-up period. Our study aimed to explore this association among subjects with age-related hearing loss from a representative population. Further, we looked at the association between severity of hearing loss and risk of stroke in older persons, acknowledged as a limitation by the authors of the Stroke report. METHODS The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss conducted during 1997 to 1999 and 2002 to 2004, among participants of the Blue Mountains Eye Study. Pure-tone air conduction hearing thresholds from 0.25 to 8.0 kHz were measured by audiologists. Hearing loss was defined as the pure-tone average of frequencies 0.5, 1.0, 2.0, and 4.0 kHz >25 dB HL in the better ear. RESULTS Persons with moderate to severe hearing loss had a significantly higher likelihood of reporting previous stroke (OR, 2.04; 95% CI, 1.20-3.49) after multivariable adjustment. However, moderate to severe hearing loss did not predict incident stroke after 5-year follow-up (OR, 1.14; 95% CI, 0.59-2.23). CONCLUSIONS We observed a strong cross-sectional association between stroke and moderate to severe hearing loss. However, age-related hearing loss did not increase risk of incident stroke in our cohort. Insufficient study power or differing underlying pathologies of sudden sensorineural hearing loss and typical age-related hearing loss may account for the discrepant findings between these studies.