Abstract
BACKGROUND: Sleep characteristics might be associated with hearing loss through disturbed energy metabolism and disrupted cochlear blood flow, but prior evidence is limited. This study aims to investigate cross-sectional associations of sleep duration and signs/symptoms of sleep-disordered breathing with hearing in a nationally representative cohort of US older adults aged 70 and older. METHODS: We studied 632 older adults aged 70 and older from the 2005-2006 cycle of the National Health and Nutrition Examination Survey. Hearing thresholds were measured using pure-tone audiometry and were averaged to create speech-frequency (0.5-4 kHz), low-frequency (0.5-2 kHz), and high-frequency (4-8 kHz) pure-tone averages (PTAs) in better-hearing ear, with higher values indicate worse hearing. Sleep duration and signs/symptoms of sleep-disordered breathing (snoring, snorting/stopping breathing, excessive sleepiness) were collected through questionnaires. Multivariable-adjusted spline models with knots at 6 and 8 hours were fitted for associations between sleep duration and PTAs. Multivariable-adjusted linear regression was used for associations between sleep-disordered breathing and PTAs. Primary models adjusted for demographic and lifestyle factors, secondary models additionally adjusted for cardiovascular factors. RESULTS: When sleep duration exceeded 8 hours, every additional hour of sleep duration was marginally associated with higher(poorer) high-frequency PTA (primary: 2.45 dB in hearing level, 95% CI: -0.34 to 5.24; secondary: 2.89 dB in hearing level, 95% CI: 0.02-5.76). No associations were observed between sleep-disordered breathing and hearing. CONCLUSIONS: Longer sleep duration is marginally associated with poorer high-frequency hearing among older adults sleeping more than 8 hours. However, we cannot infer temporality given the cross-sectional design. Future longitudinal studies are needed to establish temporality and clarify mechanisms.