Associations between dietary indices and hearing status among middle-older aged adults- Results from the Baltimore Longitudinal Study of Aging

Background Hearing loss, a public health issue in older populations, is closely related to functional decline. Objective Investigate the longitudinal associations between four dietary indices and hearing status. Methods Data from the Baltimore Longitudinal Study of Aging were used and included 882 participants ≥ 45 years of age. Dietary intake was assessed by a validated food frequency questionnaire and four diet scores (Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay diet [MIND], Mediterranean style diet [MDS], Alternative Healthy Eating Index [AHEI], and Healthy Eating Index [HEI]) were calculated as averages over time. Hearing status was examined using pure-tone audiometry, and pure-tone average (PTA) of hearing thresholds were calculated at speech level (PTA(500, 1000, 2000, 4000 Hz)), low (PTA(500, 1000 Hz)) and high (PTA(4000, 8000 Hz)) frequencies, with lower thresholds indicating better hearing. Multivariable linear mixed effect models were used to examine associations between dietary indices and hearing thresholds change over time adjusted for confounders. Results At baseline, the mean age of participants was 67 years, with 55% female. Over a median of 8 years of follow-up, MDS≥7 was associated with 3.5 (95% CI: -6.5, -0.4) and 5.0 (95% CI: -9.1, -1.0) dB lower PTA(500, 1000, 2000, 4000 Hz)and PTA(4000, 8000 Hz) as compared to MDS≤3; the highest tertile of the AHEI was associated with 2.3 (95% CI: -4.6, -0.1) and 5.0 (95% CI: -8.0, -2.0) dB lower PTA(500, 1000, 2000, 4000 Hz) and PTA(4000, 8000 Hz); and each standard deviation increment in the HEI was associated with 1.6 dB (95% CI: -2.7, -0.6), 1.1 dB (95% CI: -2.1, -0.1), and 2.1 dB (95% CI: -3.5, -0.6) lower PTA(500, 1000, 2000, 4000 Hz), PTA(500, 1000 Hz), and PTA(4000, 8000 Hz), respectively. Conclusions Adherence to healthy dietary patterns was associated with better hearing status, with stronger associations at high frequencies.